Circularly polarizing plate, organic electroluminescence display device, display device

Abstract

The present application provides a circular polarizer, an organic electroluminescence display device, and an optical device, which can suppress color unevenness in a tilt direction and is less likely to cause the color unevenness in the tilt direction over time when applied to an organic EL display device, particularly, to a curved display and a high-aspect-ratio display for a vehicle. The circular polarizer of the present application includes a polarizer and a phase difference film laminated on one surface side of the polarizer, wherein the water content of the phase difference film is 1.8% or less, and the absolute value of colorimetric a * and the absolute value of colorimetric b * are each 10 or less when the circular polarizer and an aluminum sheet are adhered to each other in a manner that the phase difference film in the circular polarizer and the aluminum sheet are opposed to each other, and colorimetric a * and colorimetric b * are measured at all azimuth angles at a polar angle of 40° from the normal direction of the circular polarizer of the obtained laminate, and the reflectance is 3.0% or less at any azimuth angle when the reflectance is measured at all azimuth angles at a polar angle of 40° from the normal direction of the circular polarizer of the laminate.

Description

TECHNICAL FIELD

[0001] The present application relates to a circular polarizing plate, an organic electroluminescence display device, and a display device. BACKGROUND

[0002] In recent years, development of a polarizing plate (so-called wideband polarizing plate) which can impart the same effect in correspondence with light of all wavelengths to a synthetic wave, i.e., white light, which is a mixture of light rays in the visible light region, is being conducted, and in particular, thinning of a phase difference layer included in the polarizing plate is also required in consideration of the demand for thinning of a device to which the polarizing plate is applied.

[0003] In response to such a demand, for example, in Example 9 of Patent Literature 1, a phase difference sheet is disclosed in which a polymerizable liquid crystal compound having reverse wavelength dispersion is used as a polymerizable compound for forming an optically anisotropic layer, and a phase difference sheet in which different kinds of optically anisotropic layers showing prescribed optical characteristics are stacked.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2018 / 216812 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] As a result of the present inventors' and others' studies on a polarizing plate having an optically anisotropic layer obtained by polymerizing a polymerizable liquid crystal composition containing a compound (polymerizable liquid crystal compound) described in Patent Literature 1, it was confirmed that when a device to which the polarizing plate is applied is observed from a tilted direction, color tone variation occurs depending on the azimuth angle, in other words, color tone unevenness occurs when the azimuth angle is changed (hereinafter, the case where color tone unevenness occurs when observed from a tilted direction and the azimuth angle is changed will also be simply described as "color tone unevenness in a tilted direction occurs"). In particular, when applied to a curved display or a high-aspect-ratio in-vehicle display, and the like, the above problem is conspicuous.

[0009] Furthermore, if the long-term use of various devices is considered, color tone unevenness when observed from a tilted direction is also required not to occur with the passage of time.

[0010] The present application is to provide a circular polarizing plate which, when applied to an organic EL display device (in particular, a curved display and a high-aspect-ratio in-vehicle display), can suppress color tone unevenness in a tilted direction, and the color tone unevenness in the above tilted direction is also less likely to occur with the passage of time.

[0011] Furthermore, the present application is also to provide an organic electroluminescence display device and a display device.

[0012] Means for solving technical problems

[0013] The present inventors have found that the above problems can be solved by the following structure.

[0014] (1) A circular polarizer comprising a polarizer and a phase difference film laminated on one surface side of the polarizer, wherein

[0015] the water content of the phase difference film is 1.8% or less,

[0016] when the circular polarizer and an aluminum sheet are attached to each other in such a manner that the phase difference film in the circular polarizer and the aluminum sheet are opposed to each other, and the chromaticity a * and the chromaticity b * are measured at all azimuth angles at which the polar angle from the normal direction of the circular polarizer of the obtained laminate is 40°, the absolute value of the chromaticity a * and the absolute value of the chromaticity b * at any azimuth angle are each 10 or less,

[0017] when the reflectance is measured at all azimuth angles at which the polar angle from the normal direction of the circular polarizer of the laminate is 40°, the reflectance at any azimuth angle is 3.0% or less.

[0018] (2) The circular polarizer according to (1), wherein the phase difference film comprises an optically anisotropic layer (B) in which a rod-like liquid crystal compound that is twisted in the thickness direction is fixed.

[0019] (3) The circular polarizer according to (1) or (2), wherein the phase difference film comprises an optically anisotropic layer (A) that is uniaxial and negative.

[0020] (4) The circular polarizer according to any one of (1) to (3), wherein the thickness of the phase difference film is 30 μm or less.

[0021] (5) The circular polarizer according to any one of (1) to (4), wherein the phase difference film is formed by laminating three optically anisotropic layers.

[0022] (6) The circular polarizer according to any one of (1) to (5), wherein the phase difference film is formed by laminating three optically anisotropic layers in which oriented liquid crystal compounds are fixed.

[0023] (7) The circular polarizer according to any one of (1) to (6), wherein the polarizer is formed using a composition containing a polymerizable liquid crystal compound,

[0024] the thickness of the polarizer is 8 μm or less.

[0025] (8) An organic electroluminescent display device having the circularly polarizing plate described in any one of (1) to (7).

[0026] (9) A display device having the circularly polarizing plate described in any one of (1) to (7), wherein

[0027] The circularly polarizing plate is disposed in a manner following a curved surface possessed by the display device.

[0028] Effects of the Invention

[0029] According to the present application, it is possible to provide a circularly polarizing plate which, when applied to an organic EL display device (for example, a curved display and a high-aspect-ratio display for a vehicle), can suppress color unevenness in a tilt direction and is less likely to cause color unevenness in the tilt direction over time.

[0030] Further, according to the present application, it is possible to provide an organic electroluminescent display device and a display device. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic cross-sectional view showing an example of an embodiment of the circularly polarizing plate of the present application.

[0032] Figure 2 is a schematic cross-sectional view showing an example of an embodiment of the circularly polarizing plate of the present application.

[0033] Figure 3 is a view for explaining the definition of polar angle and azimuth angle. DETAILED DESCRIPTION

[0034] Hereinafter, the present application will be described in detail. In the present specification, a numerical range represented by "to" indicates a range including the numerical values recited before and after "to" as lower limit value and upper limit value. First, the terms used in the present specification will be described.

[0035] Unless otherwise specifically stated, the in-plane slow axis is defined at 550 nm.

[0036] In the present application, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness direction retardation at a wavelength λ, respectively. Unless otherwise specifically recited, the wavelength λ is set to 550 nm.

[0037] In the present application, Re(λ) and Rth(λ) are values obtained by measurement at a wavelength λ using AxoScan (manufactured by Axometrics, Inc.). By inputting the average refractive index ((nx+ny+nz) / 3) and the film thickness (d (μm)) in AxoScan, the in-plane retardation Re(λ) and the thickness direction retardation Rth(λ) are calculated.

[0038] Slow axis direction (°)

[0039] Re(λ) = RO(λ)

[0040] Rth(λ) = ((nx+ny) / 2-nz) x d.

[0041] In addition, RO(λ) is shown as a value calculated using AxoScan, but indicates Re(λ).

[0042] In the present specification, with respect to the refractive indexes nx, ny, and nz, an Abbe refractometer (NAR-4T, manufactured by ATA GO CO., LTD.) was used, and a sodium lamp (λ = 589 nm) was used as a light source for measurement. Also, in the case of measuring wavelength dependency, a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO., LTD.) can be used in combination with an interference filter to perform measurement.

[0043] Also, values of the average refractive indexes of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0044] In the present specification, “light” means an active light ray or a radiation ray, and for example, means a bright line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, extreme ultraviolet (EUV light), X-rays, ultraviolet rays, and electron beams (EB), and the like.

[0045] Among them, ultraviolet rays are preferable.

[0046] In the present specification, “visible light” means light of 380 to 780 nm. Also, in the present specification, in the case where a measurement wavelength is not particularly described, the measurement wavelength is 550 nm.

[0047] Also, in the present specification, the relationship of angles (for example, “orthogonal”, “parallel”, and the like) includes a range of errors allowed in the technical field to which the present application pertains. Specifically, it is meant that the error from a strict angle is preferably within ±5°, more preferably within ±3°, in a range of less than ±10° from the strict angle.

[0048] In the present specification, the vertical alignment of a rod-shaped liquid crystal compound means a state in which the long axis of the rod-shaped liquid crystal compound is aligned in the same orientation while being perpendicular to the surface of the layer.

[0049] The vertical is not strictly required to be vertical, but indicates an orientation in which an inclined angle formed by the average molecular axis of the rod-shaped liquid crystal compound in the layer and the layer surface is 70° or more.

[0050] The same orientation is not strictly required to be the same orientation, but indicates that when the orientations of the slow axes are measured at arbitrary 20 positions, the maximum difference in the orientations of the slow axes (the difference between the two slow axis orientations having the largest difference among the 20 slow axis orientations) is less than 10°.

[0051] In the present specification, the vertical alignment of the discotic liquid crystal compound refers to a state in which the discotic axis of the discotic liquid crystal compound is vertically aligned with respect to the layer surface and is aligned in the same orientation.

[0052] The vertical is not strictly required to be vertical, but indicates an orientation in which an inclined angle formed by the discotic face of the discotic liquid crystal compound in the layer and the layer surface is 70 to 90°.

[0053] The same orientation is not strictly required to be the same orientation, but indicates that when the orientations of the in-plane slow axes are measured at arbitrary 20 positions in the plane, the maximum difference in the orientations of the in-plane slow axes (the difference between the two in-plane slow axis orientations having the largest difference among the 20 in-plane slow axis orientations) is less than 10°.

[0054] In the present specification, the optically anisotropic layer can be any layer that exhibits a predetermined optical property, and is preferably a layer in which the alignment state of the aligned liquid crystal compound is fixed.

[0055] In addition, the "fixed" state is a state in which the alignment of the liquid crystal compound is maintained. Specifically, it is more preferable that the layer has no fluidity in a temperature range of usually 0 to 50°C, more rigorously -30 to 70°C, and is capable of stably maintaining the fixed alignment state without changing the alignment state due to an external field or external force.

[0056] Circularly polarizing plate

[0057] As a feature of the circularly polarizing plate of the present application, it can be cited that when a laminate obtained by adhering the circularly polarizing plate to an aluminum sheet is observed from a prescribed direction, the chromaticity a * , the chromaticity b * , and the reflectance are within prescribed ranges.

[0058] The polymerizable liquid crystal compound used in Patent Document 1, which exhibits reverse wavelength dispersion, has excellent front surface reflectance, but has a problem in that the reflectance becomes high at a certain specific azimuth angle in the oblique direction, resulting in color unevenness in the oblique direction. In contrast, in the circularly polarizing plate of the present application, the above problem is solved by using a phase difference film satisfying prescribed characteristics.

[0059] (An embodiment of a circular polarizer)

[0060] like Figure 1 As shown, the circular polarizer 10, as an embodiment of the present invention, includes a polarizer 3 and a retardation film 1. The retardation film 1 sequentially has an optical anisotropy layer (A) 1a, an optical anisotropy layer (B) 1b, and an optical anisotropy layer (C) 1c. The polarizer 3 is disposed on the side of the retardation film 1 opposite to the side of the optical anisotropy layer (C) 1c.

[0061] The optical anisotropy layer (A)1a is an optical anisotropy layer exhibiting negative uniaxiality, which will be described in detail later.

[0062] The optical anisotropic layer (B)1b is a layer formed by fixing a rod-shaped liquid crystal compound with a twisted orientation along the thickness direction as the helical axis. Details will be described later.

[0063] The optical anisotropic layer (C)1c is a layer formed by fixing vertically oriented rod-shaped liquid crystal compounds or horizontally oriented disk-shaped liquid crystal compounds, which will be described in detail later.

[0064] (A different implementation of a circular polarizer)

[0065] like Figure 2 As shown, the circular polarizer 20, as a different embodiment of the present invention, includes a polarizer 3 and a retardation film 2. The retardation film 2 sequentially has an optical anisotropy layer (A) 2a, an optical anisotropy layer (C) 2c, and an optical anisotropy layer (B) 2b. The polarizer 3 is disposed on the side of the retardation film 2 opposite to the side of the optical anisotropy layer (B) 2b.

[0066] The optical anisotropy layer (A)2a is an optical anisotropy layer exhibiting negative uniaxiality, which will be described in detail later.

[0067] The optical anisotropic layer (B)2b is a layer formed by fixing a rod-shaped liquid crystal compound with a twisted orientation along the thickness direction as the helical axis. Details will be described later.

[0068] The optical anisotropic layer (C)2c is a layer formed by fixing vertically oriented rod-shaped liquid crystal compounds or horizontally oriented disk-shaped liquid crystal compounds, which will be described in detail later.

[0069] The thickness of the circular polarizer is not particularly limited, but it is preferably 80 μm or less, more preferably 60 μm or less, and even more preferably 40 μm or less. Furthermore, the lower limit of the thickness of the circular polarizer is not particularly limited, but it is preferably 1 μm or more.

[0070] The circularly polarizing plate and the aluminum sheet were laminated so that the retardation film in the circularly polarizing plate was opposed to the aluminum sheet, and when the chromaticity a * and the chromaticity b * at all azimuth angles at an angle of 40° from the normal direction of the circularly polarizing plate of the obtained laminate (hereinafter, also simply referred to as "specific laminate") were measured, the absolute value of the chromaticity a * and the absolute value of the chromaticity b * at any azimuth angle were each 10 or less. The above features were explained using the drawings.

[0071] A specific laminate 40 in which a circularly polarizing plate 10 and an aluminum sheet 30 are laminated is shown in Figure 3 . As shown in Figure 3 , the circularly polarizing plate 10 is composed of a polarizer 3 and a retardation film 1, and the retardation film 1 is disposed so as to be opposed to the aluminum sheet 30.

[0072] Next, first, the polar angle and the azimuth angle are explained according to Figure 3 . The polar angle and the azimuth angle are explained according to

[0073] In Figure 3 , the plane (main surface. The plane perpendicular to the thickness direction) of the circularly polarizing plate 10 is set as the xy plane, and the y axis direction is set as the absorption axis of the polarizer 3. Therefore, in Figure 3 , the y axis direction becomes the reference of the azimuth angle of 0°. As shown in Figure 3 , each θ formed by the vector v1 and the z axis is defined as the polar angle (the angle formed with the normal direction of the circularly polarizing plate 10), and the angle φ formed by the projection of the vector v1 on the xy plane and the y axis (the absorption axis of the polarizer 3) is defined as the azimuth angle. That is, the polar angle indicates the angle formed with the normal direction of the circularly polarizing plate 10. Also, the azimuth angle indicates the angle formed with the absorption axis of the polarizer 3.

[0074] Therefore, the polar angle of 40° indicates the angle of θ of 40° in Figure 3 . Also, for example, the azimuth angle of 45° indicates the angle of φ of 45° in Figure 3 .

[0075] Also, in the present application, when the azimuth angle is indicated, it is observed from the circularly polarizing plate side of the specific laminate, and indicated by a positive value counterclockwise from the absorption axis direction of the polarizer 3 as the reference. Therefore, in Figure 3 , in the case of the azimuth angle of 45°, the azimuth in which the y axis as the reference is rotated counterclockwise by 45° is indicated.

[0076] When the chromaticity a * at all azimuth angles (0 to 360°) at an angle of 40° from the normal direction of the circularly polarizing plate in the above specific laminate was measured, the absolute value of the chromaticity a *are 10 or less. That is, it is expressed as follows: when the chromaticity a * at each azimuth angle is measured from the normal direction of the circularly polarizing plate in the specific laminate at a polar angle of 40° and the azimuth angle is changed in the range of 0 to 360°, the absolute values of the chromaticity a * at each azimuth angle are 10 or less.

[0077] From the viewpoint of more excellent effects of the present application, the absolute value of the chromaticity a * is preferably 9 or less, more preferably 8 or less. There is no particular limitation on the lower limit, but 0 can be mentioned.

[0078] Also, when the chromaticity b * at each azimuth angle is measured from the normal direction of the circularly polarizing plate in the specific laminate at a polar angle of 40° and the azimuth angle is changed in the range of 0 to 360°, the absolute values of the chromaticity b * at each azimuth angle are 10 or less. That is, it is expressed as follows: when the chromaticity b * at each azimuth angle is measured from the normal direction of the circularly polarizing plate in the specific laminate at a polar angle of 40° and the azimuth angle is changed in the range of 0 to 360°, the absolute values of the chromaticity b * at each azimuth angle are 10 or less.

[0079] From the viewpoint of more excellent effects of the present application, the absolute value of the chromaticity b * is preferably 9 or less, more preferably 8 or less. There is no particular limitation on the lower limit, but 0 can be mentioned.

[0080] In the L * a * b * colorimetric system standardized by the International Commission on illumination (CIE), the chromaticity a * and the chromaticity b * represent the chromaticity representing the hue and the chroma.

[0081] As the measurement method of the chromaticity a * and the chromaticity b * , a method in which a spectrocolorimeter (manufactured by Konica Minolta, Inc.) is disposed at a prescribed position (prescribed polar angle, prescribed azimuth angle) on the circularly polarizing plate side of the specific laminate, and the chromaticity a * and the chromaticity b * are measured under a fluorescent lamp can be mentioned.

[0082] Further, when the reflectance at all azimuth angles (0 to 360°) at a polar angle of 40° from the normal direction of the circularly polarizing plate in the specific laminate was measured, the reflectance at any azimuth angle was 3.0% or less. That is, when the reflectance at each azimuth angle was measured while changing the azimuth angle in the range of 0 to 360° at a polar angle of 40° from the normal direction of the circularly polarizing plate in the specific laminate was observed from the side of the circularly polarizing plate in the specific laminate, the reflectance obtained was 3.0% or less.

[0083] From the viewpoint of more excellent effects of the present application, the reflectance is preferably 2.5% or less, more preferably 2.0% or less. The lower limit is not particularly limited, but 0% can be given.

[0084] As the method of measuring the reflectance, a detector was disposed at a position at a polar angle of 40° from the normal direction of the circularly polarizing plate in the specific laminate, a light source was disposed at a position at a polar angle of 40° from the normal direction of the circularly polarizing plate in the specific laminate, and the reflectance was measured with the detector. The above steps were performed in the range of azimuth angles of 0 to 360°, and the reflectance at each azimuth angle was measured.

[0085] Further, the reflectance indicates the visibility-corrected reflectance in the wavelength region of wavelengths of 400 to 750 nm. More specifically, it refers to the reflectance that has been subjected to visibility correction according to JIS Z 8701.

[0086] Further, in the above measurement, a standard plate (white calibration plate CS-A5 manufactured by Konica Minolta, Inc.) was used instead of the specific laminate, and the reflectance was calculated based on the reflected light measured by the above steps.

[0087] The aluminum sheet used for forming the above specific laminate is a sheet having an aluminum foil in the outermost layer, and can be composed of an aluminum foil alone or can be a laminate including a support and an aluminum foil disposed on the support.

[0088] In the case where the aluminum sheet is a laminate including a support and an aluminum foil disposed on the support, the type of the support is not particularly limited, and a resin substrate can be given.

[0089] The reflectance of the aluminum sheet alone is preferably 80 to 90%.

[0090] < Polarizer >

[0091] The polarizer is a component having a function of converting natural light into a specific linearly polarized light, and an absorption-type polarizer can be given, for example.

[0092] The type of polarizer is not particularly limited, and a generally used polarizer can be used, and examples thereof include an iodine-based polarizer, a dye-based polarizer using a dichroic dye, and a polyene-based polarizer. The iodine-based polarizer and the dye-based polarizer are generally produced by adsorbing iodine or a dichroic dye on a polyvinyl alcohol and stretching.

[0093] In addition, a protective film can be provided on one or both sides of the polarizer.

[0094] Further, as described in WO 2019 / 131943 and Japanese Patent Application Publication No. 2017-083843, as the polarizer, a coating-type polarizer can be used, which is produced by coating using a liquid crystal compound and a dichroic organic dye (for example, a dichroic azo dye used in the light-absorbing anisotropic film described in WO 2017 / 195833) without using a polyvinyl alcohol as a binder.

[0095] The coating-type polarizer is a technology that uses the orientation of a liquid crystal compound to orient a dichroic organic dye. As described in Japanese Patent Application Publication No. 2012-083734, if a polymerizable liquid crystal compound exhibits a smectic phase, it is preferable from the viewpoint of improving the degree of orientation. Alternatively, as described in WO 2018 / 186503, it is also preferable to crystallize the dye from the viewpoint of improving the degree of orientation. In WO 2019 / 131943, the structure of a high-molecular liquid crystal that is preferable for improving the degree of orientation is described.

[0096] A polarizer that uses the orientation of a liquid crystal to orient a dichroic organic dye without stretching has many advantages, such as being able to be very thin, such as having a thickness of about 0.1 to 8 μm, being less likely to crack when bent as described in Japanese Patent Application Publication No. 2019-194685, having small thermal deformation, being excellent in durability even as a polarizing plate having high transmittance, such as more than 50%, as described in Japanese Patent No. 6483486, and the like.

[0097] By using these advantages, it can be applied to uses that require high brightness or are small and light, uses for fine optical systems, molding uses on sites having curved surfaces, and uses on flexible sites. Of course, when a polarizer is produced on a support, the polarizer can be transferred to a prescribed transfer recipient, and the support can be peeled off to use only the polarizer.

[0098] Due to the above-mentioned features, the circularly polarizing plate of the present application preferably uses a polarizer formed using a composition containing a polymerizable liquid crystal compound and having a thickness of 8 μm or less. More specifically, the above-mentioned composition preferably contains a polymerizable liquid crystal compound and a dichroic organic dye. The type of the polymerizable liquid crystal compound is not particularly limited, and examples thereof include a polymerizable liquid crystal compound (e.g., a rod-like liquid crystal compound having a polymerizable group) used in the production of the phase difference film described later.

[0099] From the viewpoint of power saving, the transmittance (visibility correction single transmittance) of the polarizer is preferably 40% or more, more preferably 44% or more, and further preferably 50% or more.

[0100] <Phase difference film>

[0101] The water content of the phase difference film in the circularly polarizing plate of the present application is 1.8% or less. As long as the water content of the phase difference film is within the above-mentioned range, the desired effects can be obtained. Among them, from the viewpoint of more excellent effects of the present application, 1.5% or less, and more preferably 1.0% or less is preferred. The lower limit is not particularly limited, but 0% or more is more common.

[0102] The water content of the phase difference film is a value measured after conditioning in an environment at a temperature of 25°C and a relative humidity of 60% for 24 hours or more, and the measurement of the water content is performed by the Karl Fischer method.

[0103] As long as the chromaticity a * , the chromaticity b * , and the reflectance satisfy the prescribed ranges, the structure of the phase difference film in the circularly polarizing plate of the present application is not particularly limited.

[0104] Among them, from the viewpoint of more excellent effects of the present application, the phase difference film preferably includes an optically anisotropic layer (corresponding to the optically anisotropic layer (B) shown in Figure 1 and Figure 2 ) formed by fixing a rod-like liquid crystal compound in a twisted orientation with the thickness direction as the helical axis.

[0105] Further, from the viewpoint of more excellent effects of the present application, the phase difference film preferably includes an optically anisotropic layer (corresponding to the optically anisotropic layer (A) shown in Figure 1 and Figure 2 ) exhibiting a negative uniaxiality.

[0106] Further, from the viewpoint of more excellent effects of the present application, the phase difference film is preferably a phase difference film formed by laminating three layers of optically anisotropic layers, and more preferably a phase difference film formed by laminating three layers of optically anisotropic layers formed by fixing oriented liquid crystal compounds.

[0107] In particular, as described aboveFigure 1 and Figure 2 As shown in FIG. 1, the phase difference film preferably includes three optically anisotropic layers of an optically anisotropic layer (A), an optically anisotropic layer (B), and an optically anisotropic layer (C).

[0108] Hereinafter, specific examples of the structures of the optically anisotropic layers (A) to (C) will be described.

[0109] In the phase difference film, it is preferable that at least any one of the optically anisotropic layer (A) and the optically anisotropic layer (B) and the optically anisotropic layer (C) are directly laminated, and the optically anisotropic layer (C) contains a photo-orientable polymer having a photo-orientable group, and the photo-orientable polymer having a photo-orientable group is present on the surface of the optically anisotropic layer (C) on the side in contact with the optically anisotropic layer (A) or the optically anisotropic layer (B).

[0110] Here, the surface of the optically anisotropic layer (C) on the side in contact with the optically anisotropic layer (A) or the optically anisotropic layer (B) means a surface layer region from the interface of the optically anisotropic layer (C) and the optically anisotropic layer (A) or the optically anisotropic layer (B) to 20 nm in the thickness direction of the optically anisotropic layer (C), which will be also simply referred to as "surface layer C" hereinafter.

[0111] Further, the presence of the above-described photo-orientable polymer on the surface layer C of the optically anisotropic layer (C) can be confirmed, for example, by time-of-flight secondary ion mass spectrometry (TOF-SIMS). In addition, as to the TOF-SIMS method, the method described in "Surface Analysis Technology Selection Book Secondary Ion Mass Spectrometry" edited by The Japan Society of Vacuum and Surface Science, MARUZEN GROUP (published in 1999) can be employed.

[0112] Specifically, in the case where the photo-orientable polymer having a photo-orientable group is present on the surface of the optically anisotropic layer (C) on the side in contact with the optically anisotropic layer (A) or the optically anisotropic layer (B), a fragment derived from the photo-orientable group is detected in the vicinity of the interface of the optically anisotropic layer (C) and the optically anisotropic layer (A) or the optically anisotropic layer (B).

[0113] Further, regarding the composition distribution in the thickness direction of the optically anisotropic layer (C) and the optically anisotropic layer (A) or the optically anisotropic layer (B), analysis is performed by repeatedly performing ion beam irradiation and measurement according to TOF-SIMS from the air interface side of either of the optically anisotropic layers. In addition, regarding the ion beam irradiation and measurement according to TOF-SIMS, the following series of operations are repeatedly performed: after performing composition analysis of a region up to 1 to 2 nm in the thickness direction from the surface, further digging 1 to several hundred nm in the thickness direction and performing composition analysis of the next surface region.

[0114] Further, regarding the distribution of the photo-orienting polymer in the thickness direction of the optically anisotropic layer (C), analysis is performed by measuring the intensity of secondary ions derived from the unit having a photo-orienting group.

[0115] As the kind of the ion beam, for example, an ion beam based on an argon gas cluster ion gun (Ar-GCIB gun) can be given.

[0116] (Optically anisotropic layer (A))

[0117] The optically anisotropic layer (A) is an optically anisotropic layer that exhibits negative uniaxiality.

[0118] The in-plane retardation of the optically anisotropic layer (A) at a wavelength of 550 nm is preferably 140 to 220 nm, and more preferably 150 to 200 nm from the viewpoint of more excellent effects of the present application.

[0119] The angle formed by the in-plane slow axis of the optically anisotropic layer (A) and the absorption axis of the polarizer is not particularly limited, but as a preferred mode, it is preferably 40 to 100°, more preferably 50 to 85°, and further preferably 65 to 85° from the viewpoint of more excellent effects of the present application. Also, as another preferred mode, it is preferably 5 to 60°, more preferably 5 to 50°, and further preferably 5 to 25°.

[0120] As an embodiment when the optically anisotropic layer (A) is formed in a long strip shape, the angle θ1 formed by the length direction and the in-plane slow axis of the optically anisotropic layer (A) is not particularly limited, but is preferably 40 to 85°, more preferably 50 to 85°, and further preferably 65 to 85°.

[0121] Further, from the viewpoint of being able to reduce the thickness of the optically anisotropic layer (A), the optically anisotropic layer (A) is preferably a layer formed using a liquid crystal compound, and more preferably an optically anisotropic layer in which an oriented liquid crystal compound is fixed.

[0122] More specifically, the optically anisotropic layer (A) is preferably a layer formed using a discotic liquid crystal compound, and more preferably a layer in which a discotic liquid crystal compound that is vertically aligned is fixed.

[0123] There is no particular limitation on the kind of liquid crystal compound. In general, liquid crystal compounds can be classified into a rod-like type (rod-like liquid crystal compound) and a disc-like type (discotic liquid crystal compound) according to their shape. Also, liquid crystal compounds can be classified into a low-molecular type and a high-molecular type. High-molecular generally refers to a compound having a polymerization degree of 100 or more (High-molecular Physics / Phase Transition Dynamics, Shigeo Doi, 2nd edition, Gakushu-no-Tomo, 1992). In the present application, any liquid crystal compound can be used, but a rod-like liquid crystal compound is preferably used. Two or more kinds of rod-like liquid crystal compounds or a mixture of a rod-like liquid crystal compound and a discotic liquid crystal compound can be used.

[0124] In addition, as the rod-like liquid crystal compound, for example, a rod-like liquid crystal compound described in Claim 1 of Japanese Patent Application Laid-Open No. 11-513019 or paragraphs 0026 to 0098 of Japanese Patent Application Laid-Open No. 2005-289980 can be preferably used.

[0125] As the discotic liquid crystal compound, for example, a discotic liquid crystal compound described in paragraphs 0020 to 0067 of Japanese Patent Application Laid-Open No. 2007-108732 or paragraphs 0013 to 0108 of Japanese Patent Application Laid-Open No. 2010-244038 can be preferably used.

[0126] The liquid crystal compound preferably has a polymerizable group.

[0127] There is no particular limitation on the kind of polymerizable group possessed by the liquid crystal compound, and a functional group that can undergo an addition polymerization reaction is preferable, and a polymerizable ethylenic unsaturated group or a ring polymerizable group is more preferable, and a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group is further preferable.

[0128] The liquid crystal compound can be a positive wavelength dispersion liquid crystal compound or a reverse wavelength dispersion liquid crystal compound, but in the case where the liquid crystal compound is a positive wavelength dispersion liquid crystal compound, it is preferable from the viewpoint of reduction in manufacturing cost of the film and improvement in durability.

[0129] In the present specification, a positive wavelength dispersion liquid crystal compound refers to a compound in which, when a retardation (Re) value in the plane in the visible light range of an optically anisotropic layer produced using the liquid crystal compound is measured, the Re value becomes smaller as the measurement wavelength becomes larger. On the other hand, a reverse wavelength dispersion liquid crystal compound refers to a compound in which, when the Re value is measured similarly, the Re value becomes larger as the measurement wavelength becomes larger.

[0130] The optically anisotropic layer (A) can be a polymer film containing a resin having a negative intrinsic birefringence.

[0131] The resin having a negative intrinsic birefringence is a resin in which the slow axis is in the direction of extension and the direction perpendicular thereto. In other words, the resin having a negative intrinsic birefringence is a resin in which the refractive index in the direction of extension is smaller than the refractive index in the direction orthogonal to the direction of extension.

[0132] Further, as the resin having a negative intrinsic birefringence, a polystyrene-based polymer containing a homopolymer of styrene or a styrene derivative (e.g., polystyrene, fluorinated polystyrene) and a copolymer of styrene or a styrene derivative and an arbitrary monomer; a polyacrylonitrile polymer; a (meth)acrylic acid-based polymer such as polymethyl methacrylate; a polyester-based resin; or a multi-component copolymer thereof; and a cellulose compound such as cellulose ester can be given. More specifically, polymethyl methacrylate, polystyrene, fluorinated polystyrene, polyvinyl naphthalene, and a fumaric acid ester-based resin, etc. can be given.

[0133] The thickness of the optically anisotropic layer (A) is not particularly limited, but in the case where the optically anisotropic layer (A) is a layer formed using a discotic liquid crystal compound, from the viewpoint of the balance between thinness and usability, it is preferably 0.5 to 5 μm, more preferably 0.5 to 2 μm.

[0134] (Optically anisotropic layer (B))

[0135] The optically anisotropic layer (B) is a layer in which a rod-shaped liquid crystal compound in a twisted orientation with the thickness direction as the helical axis is fixed. It is preferably a layer in which a chiral nematic phase having a so-called helical structure is fixed. Further, in forming the above phase, it is preferable to use a mixture of a liquid crystal compound that exhibits a nematic liquid crystal phase and a chiral reagent described later.

[0136] Further, the meaning of the "fixed" state is as described above.

[0137] The value of the product Δnd of the refractive index anisotropy Δn of the optically anisotropic layer (B) and the thickness d of the optically anisotropic layer (B) measured at a wavelength of 550 nm is not particularly limited, but is preferably 140 to 220 nm, more preferably 150 to 210 nm, and further preferably 160 to 200 nm, from the viewpoint of further suppressing color unevenness.

[0138] Further, the refractive index anisotropy Δn represents the refractive index anisotropy of the optically anisotropic layer.

[0139] As a method for measuring the above-described Δnd, an AxoScan (polarimeter) device manufactured by Axometrics was used, and measurement was performed using a device analysis software manufactured by Axometrics.

[0140] The twist angle of the liquid crystal compound (twist angle of the orientation direction of the liquid crystal compound) is preferably in the range of 90 ± 30° (in the range of 60 to 120°), more preferably in the range of 90 ± 20° (in the range of 70 to 110°), further preferably in the range of 90 ± 10° (in the range of 80 to 100°) from the viewpoint of further suppressing color unevenness.

[0141] In addition, as a method for measuring the twist angle, an AxoScan (polarimeter) device manufactured by Axometrics was used, and measurement was performed using a device analysis software manufactured by Axometrics.

[0142] Further, the twist orientation of the liquid crystal compound means that the liquid crystal compound twists from one main surface to the other main surface of the optically anisotropic layer (B) with the thickness direction of the optically anisotropic layer (B) as an axis. At the same time, the orientation direction (in-plane slow axis direction) of the liquid crystal compound differs depending on the position in the thickness direction of the optically anisotropic layer (B).

[0143] The thickness of the optically anisotropic layer (B) is not particularly limited, but is preferably in the range of 0.5 to 5 μm, more preferably in the range of 0.5 to 2 μm from the viewpoint of the balance between thinness and usability.

[0144] The in-plane slow axis of the optically anisotropic layer (A) is preferably parallel to the in-plane slow axis on the surface of the optically anisotropic layer (B) on the side of the optically anisotropic layer (A). Therefore, in the case where the optically anisotropic layer (A) and the optically anisotropic layer (B) are in a long strip shape, the angle formed by the in-plane slow axis on the surface of the optically anisotropic layer (B) on the side of the optically anisotropic layer (A) and the length direction is preferably in correspondence with the above-described θ1.

[0145] Further, the in-plane slow axis on the surface of the optically anisotropic layer (B) on the side of the optically anisotropic layer (A) and the in-plane slow axis on the surface of the optically anisotropic layer (B) on the side opposite to the side of the optically anisotropic layer (A) preferably form the above-described twist angle (in the range of 90 ± 30°). Among them, the in-plane slow axis on the surface of the optically anisotropic layer (B) on the side opposite to the side of the optically anisotropic layer (A) is preferably rotated clockwise by a predetermined angle (in the range of 90 ± 30°) with the in-plane slow axis on the surface of the optically anisotropic layer (B) on the side of the optically anisotropic layer (A) as a reference.

[0146] The kind of liquid crystal compound used to form the optically anisotropic layer (B) is not particularly limited, and examples of the liquid crystal compound used to form the optically anisotropic layer (A) can be given.

[0147] As the chiral agent used in the twisted alignment of the liquid crystal compound, various known chiral agents can be used. The chiral agent has a function of inducing a helical structure of the liquid crystal compound. Since the handedness or the pitch of the helix twisted by the compound is different, the chiral compound can be selected as desired.

[0148] As the chiral agent, known compounds can be used, but a cinnamyl group is preferred. As examples of the chiral agent, compounds described in "Liquid Crystal Device Manual" (Chapter 3, Item 4-3, Chiral Agents for TN, STN, p. 199, Japan Society for the Promotion of Science, Committee 142, 1989) and Japanese Patent Application Publication No. 2003-287623, Japanese Patent Application Publication No. 2002-302487, Japanese Patent Application Publication No. 2002-080478, Japanese Patent Application Publication No. 2002-080851, Japanese Patent Application Publication No. 2010-181852, and Japanese Patent Application Publication No. 2014-034581, and the like can be given.

[0149] The chiral agent generally contains an asymmetric carbon atom, but an axial asymmetric compound or a surface asymmetric compound not containing an asymmetric carbon atom can also be used as the chiral agent. In the case of the axial asymmetric compound or the surface asymmetric compound, binaphthalene, spirobenzopyran, p-xylylene dimer, and derivatives thereof can be given. The chiral agent can have a polymerizable group.

[0150] In the case where both the chiral agent and the liquid crystal compound have a polymerizable group, a polymer having a repeating unit derived from the polymerizable liquid crystal compound and a repeating unit derived from the chiral agent can be formed by the polymerization reaction of the polymerizable chiral agent and the polymerizable liquid crystal compound. In this mode, the polymerizable group possessed by the polymerizable chiral agent is preferably the same group as the polymerizable group possessed by the polymerizable liquid crystal compound. Therefore, the polymerizable group of the chiral agent is also preferably an unsaturated polymerizable group, an epoxy group, or an aziridine group, more preferably an unsaturated polymerizable group, and particularly preferably an ethylenically unsaturated polymerizable group.

[0151] Also, the chiral agent can be a liquid crystal compound.

[0152] As the chiral agent, isosorbide derivatives, isomannide derivatives, binaphthalene derivatives, and the like are preferred. As the isosorbide derivative, commercially available products such as LC-756 manufactured by BASF Corporation can be used.

[0153] The content of the chiral agent in the optically anisotropic layer (B) is preferably 0.01 to 200 mol%, more preferably 1 to 30 mol%, relative to the total molar amount of the liquid crystalline compound.

[0154] The optically anisotropic layer (B) can contain other materials in addition to the above-described materials.

[0155] As the other materials, for example, a surfactant, an alignment control agent, a polymer, and the like used in the manufacturing method of the optically anisotropic layer (B) described later can be mentioned.

[0156] (Optically anisotropic layer (C))

[0157] The optically anisotropic layer (C) is a layer in which a rod-shaped liquid crystalline compound oriented vertically or a discotic liquid crystalline compound oriented horizontally is fixed.

[0158] From the viewpoint of usefulness as a compensation layer of a circularly polarizing plate or a display device, the layer in which the rod-shaped liquid crystalline compound oriented vertically is fixed is preferably a positive C-plate, and the layer in which the discotic liquid crystalline compound oriented horizontally is fixed is preferably a negative C-plate.

[0159] Here, the positive C-plate (positive C-plate) and the negative C-plate (negative C-plate) are defined as follows.

[0160] In the case where the refractive index in the slow axis direction in the film plane (the direction of the maximum refractive index in the plane) is set to nx, the refractive index in the direction orthogonal to the slow axis in the plane is set to ny, and the refractive index in the thickness direction is set to nz, the positive C-plate satisfies the relationship of formula (C1), and the negative C-plate satisfies the relationship of formula (C2). In addition, Rth of the positive C-plate represents a negative value, and Rth of the negative C-plate represents a positive value.

[0161] Formula (C1) nz > nx ≈ ny

[0162] Formula (C2) nz < nx ≈ ny

[0163] In addition, the above-described "≈" includes not only the case where both are completely the same, but also the case where both are actually the same.

[0164] "Actually the same" means, for example, the case where the absolute value of (nx-ny) x d (where d is the thickness of the film) is 0 to 10 nm, preferably 0 to 5 nm, is also included in "nx ≈ ny".

[0165] The in-plane retardation at a wavelength of 550 nm of the optically anisotropic layer (C) is not particularly limited, but is preferably 0 to 10 nm, and more preferably 0 to 5 nm, from the viewpoint of further suppressing color unevenness.

[0166] In the case where the optically anisotropic layer (C) is a layer in which a rod-shaped liquid crystal compound oriented vertically is fixed, the retardation in the thickness direction at a wavelength of 550 nm of the optically anisotropic layer (C) is preferably -140 to -20 nm, more preferably -130 to -30 nm, and further preferably -120 to -40 nm.

[0167] In the case where the optically anisotropic layer (C) is a layer in which a discotic liquid crystal compound oriented horizontally is fixed, the retardation in the thickness direction at a wavelength of 550 nm of the optically anisotropic layer (C) is preferably 20 to 140 nm, more preferably 30 to 130 nm, and further preferably 40 to 120 nm.

[0168] As the upper limit of the thickness of the phase difference film, it is preferably 30 μm or less, more preferably 20 μm or less, and further preferably 10 μm or less, and particularly preferably 5 μm or less. As the lower limit of the thickness of the phase difference film, it is preferably 1 μm or more. Note that the thickness of the phase difference film refers to the thickness including the adhesive or the like when the optically anisotropic layer is attached with the adhesive or the like.

[0169] <Other Components>

[0170] The circularly polarizing plate can further include other components.

[0171] The circularly polarizing plate can include a substrate.

[0172] As the substrate, a transparent substrate is preferable. Note that the transparent substrate refers to a substrate having a transmittance of visible light of 60% or more, and the transmittance is preferably 80% or more, and more preferably 90% or more.

[0173] The retardation value in the thickness direction at a wavelength of 550 nm (Rth(550)) of the substrate is not particularly limited, but is preferably -110 to 110 nm, and more preferably -80 to 80 nm.

[0174] The retardation value in the plane at a wavelength of 550 nm (Re(550)) of the substrate is not particularly limited, but is preferably 0 to 50 nm, more preferably 0 to 30 nm, and further preferably 0 to 10 nm.

[0175] As the material forming the substrate, a polymer having excellent optical properties, transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy is preferable.

[0176] As the polymer film which can be used as the substrate, for example, cellulose acylate film (e.g., triacetyl cellulose film (refractive index 1.48), diacetyl cellulose film, cellulose acetate butyrate film, and cellulose acetate propionate film), polyolefin film such as polyethylene and polypropylene, polyester film such as polyethylene terephthalate and polyethylene naphthalate, polyether sulfone film, polymethyl methacrylate film, polyurethane film, polycarbonate film, polysulfone film, polyether film, polymethyl pentene film, polyether ketone film, (meth)acrylonitrile film, and film of a polymer having alicyclic structure (norbornene-based resin (ARTON: product name, manufactured by JSR Corporation., amorphous polyolefin (ZEONEX: product name, manufactured by Zeon Corporation)) can be mentioned.

[0177] As the material of the polymer film, triacetyl cellulose, polyethylene terephthalate, or a polymer having alicyclic structure is preferable, and triacetyl cellulose is more preferable.

[0178] The substrate can contain various additives (e.g., optical anisotropy adjusting agent, wavelength dispersion adjusting agent, fine particles, plasticizer, ultraviolet inhibitor, deterioration inhibitor, and peeling agent).

[0179] The thickness of the substrate is not particularly limited, but is preferably 10 to 200 μm, more preferably 10 to 100 μm, and further preferably 20 to 90 μm. Also, the substrate can be formed by laminating a plurality of pieces. In order to improve the adhesion of the substrate to a layer provided on the substrate, surface treatment (e.g., glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment) can be performed on the surface of the substrate.

[0180] Also, an adhesive layer (primer layer) can be provided on the substrate.

[0181] Also, in order to impart slidability in the conveying process to the substrate, or to prevent the sticking of the back surface to the surface after winding, a polymer layer in which inorganic particles having an average particle diameter of about 10 to 100 nm are mixed at a solid content mass ratio of 5 to 40 mass% can be provided on one side of the substrate.

[0182] The substrate can also be a so-called dummy support. That is, after the manufacturing method of the present application is performed, the substrate can be peeled from the optically anisotropic layer.

[0183] Also, the surface of the substrate can be directly subjected to rubbing treatment. That is, a substrate which has been subjected to rubbing treatment can be used. The direction of the rubbing treatment is not particularly limited, and the optimum direction is appropriately selected depending on the direction in which the liquid crystalline compound is to be oriented.

[0184] The rubbing treatment is a widely used treatment method that can be applied as a liquid crystal alignment treatment process for LCDs (liquid crystal displays). That is, a method of obtaining alignment by rubbing the surface of a substrate in a certain direction using paper, gauze, felt, rubber, nylon fibers, polyester fibers, or the like can be used.

[0185] An alignment film can be provided on the substrate.

[0186] The alignment film can be formed using rubbing treatment of an organic compound (preferably a polymer), oblique evaporation of an inorganic compound, formation of a layer having microgrooves, or a method of accumulation of an organic compound (e.g., omega-tricosanoic acid, dioctadecylmethylammonium chloride, methyl stearate) based on the Langmuir-Blodgett method (LB film).

[0187] Furthermore, an alignment film that generates an alignment function by imparting an electric field, imparting a magnetic field, or light irradiation (preferably polarized light) is also known.

[0188] Also, a close contact layer can be provided between the layers of the circularly polarizing plate. As the close contact layer, a known adhesive layer and a bonding agent layer can be given.

[0189] As described in Japanese Patent Application Laid-Open No. 11-149015, generally, from the viewpoint of suppressing reflection by adjusting the refractive index between the layers, the refractive index of the bonding agent or adhesive of each layer of the stacked wave plate or circularly polarizing plate is preferably adjusted. The difference in refractive index from the bonding object is preferably 0.1 or less, more preferably 0.08 or less, further preferably 0.06 or less, and most preferably 0.03 or less.

[0190] In the case where an optically anisotropic layer using a polymerizable liquid crystal is provided between the layers, a high-refractive bonding agent or adhesive can be used.

[0191] In order to increase the refractive index, a high-refractive monomer or high-refractive metal fine particles are also preferably used.

[0192] As the high-refractive monomer, it is preferable to have a benzene ring skeleton in the molecule. As the monofunctional monomer having a benzene ring skeleton in the molecule, for example, ethoxylated o-phenylphenol (meth) acrylate, o-phenylphenol glycidyl ether (meth) acrylate, p-cumylphenoxy ethylene glycol (meth) acrylate, 2-methacryloyloxyethyl phthalate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, 2-acryloyloxypropyl phthalate, phenoxyethyl (meth) acrylate, EO-modified phenol (meth) acrylate, phenoxy diethylene glycol (meth) acrylate, EO-modified nonyl phenol (meth) acrylate, PO-modified nonyl phenol (meth) acrylate, phenyl glycidyl ether (meth) acrylate, neopentyl glycol benzoic acid (meth) acrylate, nonyl phenoxy polyethylene glycol (meth) acrylate, ECH-modified phenoxy (meth) acrylate, benzyl (meth) acrylate, vinyl carbazole, and the like can be given.

[0193] As the component constituting the inorganic particles, metal oxides, metal nitrides, metal oxynitrides, and metal monomers can be given. As the metal atoms contained in the above-mentioned metal oxides, metal nitrides, metal oxynitrides, and metal monomers, titanium atoms, silicon atoms, aluminum atoms, cobalt atoms, and zirconium atoms can be given. As specific examples of the inorganic particles, inorganic oxide particles such as alumina particles, alumina hydrate particles, silica particles, zirconia particles, and clay minerals (e.g., montmorillonite) can be given. From the viewpoint of the refractive index, fine particles of zirconia are preferable. The refractive index can be adjusted to a prescribed value by changing the amount of the inorganic fine particles. In the case where zirconia is used as the main component, the average particle diameter of the inorganic fine particles in the layer is preferably from 1 to 120 nm, further preferably from 1 to 60 nm, and further preferably from 2 to 40 nm.

[0194] <Method for manufacturing a circularly polarizing plate and method for manufacturing a phase difference film>

[0195] The above-mentioned method for manufacturing a circularly polarizing plate is not particularly limited, and a publicly known method can be employed. For example, a method for laminating a polarizer and a phase difference film can be given. At the time of lamination, an adhesion layer can be used as necessary.

[0196] Further, the above-mentioned method for manufacturing a phase difference film is not particularly limited, and a publicly known method can be employed. In particular, the above-mentioned method for manufacturing a phase difference film can be continuously performed in a roll-to-roll manner.

[0197] For example, an optical anisotropic layer (A) to an optical anisotropic layer (C) each exhibiting a prescribed optical property are prepared, and these optical anisotropic layers and a substrate (e.g., a long substrate) are laminated in a prescribed order via an adhesion layer (e.g., an adhesive layer or a bonding layer), whereby a phase difference film can be manufactured.

[0198] Further, the optical anisotropic layers (A) to (C) included in the retardation film can be formed by sequentially applying the polymerizable liquid crystal composition described later to a substrate. For example, the optical anisotropic layer (C) can be formed by applying the polymerizable liquid crystal composition to a substrate, and the optical anisotropic layer (B) can be formed by applying the polymerizable liquid crystal composition to the optical anisotropic layer (C). Further, the optical anisotropic layer (A) can be formed by applying the polymerizable liquid crystal composition to the optical anisotropic layer (B).

[0199] Further, the method of bonding the above-described optical anisotropic layers can be combined with the method of forming the optical anisotropic layers using the polymerizable liquid crystal composition. More specifically, the following method can be mentioned, for example: the optical anisotropic layer (C) can be formed by applying the polymerizable liquid crystal composition to a substrate, and the optical anisotropic layer (B) can be formed by applying the polymerizable liquid crystal composition to the optical anisotropic layer (C) to obtain a laminate, and further, the optical anisotropic layer (A) can be manufactured by bonding the optical anisotropic layer (A) and the laminate which are separately manufactured.

[0200] Hereinafter, the method of manufacturing each layer will be described in detail.

[0201] Hereinafter, each component will be described in detail.

[0202] The optical anisotropic layers (A) to (C) included in the retardation film are preferably layers in which the oriented liquid crystal compound is fixed.

[0203] Further, the optical anisotropic layer manufactured in the present application is preferably a layer in which the liquid crystal compound having a polymerizable group (rod-like liquid crystal compound or discotic liquid crystal compound having a polymerizable group) is fixed by polymerization or the like.

[0204] The above-described optical anisotropic layers (A) to (C) are preferably formed by using the polymerizable liquid crystal composition, respectively. More specifically, it is preferable to form a composition layer by applying the polymerizable liquid crystal composition, to orient the liquid crystal compound in the composition layer, and then to perform a curing treatment, thereby forming a predetermined optical anisotropic layer.

[0205] The polymerizable liquid crystal composition is a composition containing a liquid crystal compound having a polymerizable group. The various components included in the polymerizable liquid crystal composition will be described in detail later.

[0206] Hereinafter, the above-described steps will be described in detail.

[0207] The step of forming the above-described composition layer is not particularly limited, and for example, a method in which the polymerizable liquid crystal composition is applied to a substrate and a drying treatment is performed as necessary can be mentioned.

[0208] The coating method is not particularly limited, and examples thereof include a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method.

[0209] The film thickness of the composition layer is not particularly limited, but is preferably from 0.1 to 20 μm, more preferably from 0.2 to 15 μm, and further preferably from 0.5 to 10 μm.

[0210] Next, the formed composition layer is subjected to an orientation treatment to orient the polymerizable liquid crystal compound in the composition layer.

[0211] The orientation treatment can be performed by drying the coating film at room temperature or heating the coating film. In the case of a thermotropic liquid crystal compound, the liquid crystal phase formed by the orientation treatment can generally be changed by a change in temperature or pressure. In the case of a lyotropic liquid crystal compound, it can also be changed by the composition ratio of the solvent amount or the like.

[0212] In addition, the conditions for heating the composition layer are not particularly limited, but the heating temperature is preferably from 50 to 250°C, and more preferably from 50 to 150°C, and the heating time is preferably from 10 seconds to 10 minutes.

[0213] Further, after heating the composition layer, and before the curing treatment (light irradiation treatment) described later, the coating film can be cooled as necessary. The cooling temperature is preferably from 20 to 200°C, and more preferably from 30 to 150°C.

[0214] Next, the composition layer in which the polymerizable liquid crystal compound is oriented is subjected to a curing treatment.

[0215] The method for subjecting the composition layer in which the polymerizable liquid crystal compound is oriented to the curing treatment is not particularly limited, and examples thereof include a light irradiation treatment and a heating treatment. Among them, from the viewpoint of manufacturing suitability, the light irradiation treatment is preferred, and the ultraviolet irradiation treatment is more preferred.

[0216] The irradiation conditions for the light irradiation treatment are not particularly limited, but the irradiation amount is preferably from 50 to 1000 mJ / cm 2 .

[0217] The environment during the light irradiation treatment is not particularly limited, but a nitrogen atmosphere is preferred.

[0218] In addition, the above-described method for forming the composition layer by coating the polymerizable liquid crystal composition is described, but the composition layer can also be formed separately and transferred to a prescribed substrate.

[0219] The polymerizable liquid crystal composition used in the above contains the above liquid crystal compound having a polymerizable group and, in addition to this, other components (for example, a chiral agent, a polymerization initiator, a polymerizable monomer, a surfactant, a polymer, a photo-alignment polymer, and a solvent, etc.) used as necessary.

[0220] The content of the liquid crystal compound in the polymerizable liquid crystal composition is not particularly limited, but from the viewpoint of easily controlling the alignment state of the liquid crystal compound, it is preferably 60% by mass or more, more preferably 70% by mass or more, relative to the total solid content in the polymerizable liquid crystal composition. The upper limit is not particularly limited, but it is preferably 99% by mass or less, more preferably 97% by mass or less.

[0221] In addition, the solid content means a component capable of forming an optically anisotropic layer from which a solvent is removed, and even if the properties are in a liquid state, it is regarded as a solid content.

[0222] As described above, the polymerizable liquid crystal composition can contain other components in addition to the liquid crystal compound.

[0223] For example, the polymerizable liquid crystal composition can contain a polymerization initiator. In the case where the polymerizable liquid crystal composition contains a polymerization initiator, the polymerization of the liquid crystal compound having a polymerizable group is more effectively performed.

[0224] As the polymerization initiator, a known polymerization initiator can be given, and a photopolymerization initiator and a thermal polymerization initiator can be given, and a photopolymerization initiator is preferable.

[0225] The content of the polymerization initiator in the polymerizable liquid crystal composition is not particularly limited, but it is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, relative to the total solid content in the polymerizable liquid crystal composition.

[0226] The polymerizable liquid crystal composition can contain a chiral agent.

[0227] The kind of the chiral agent is not particularly limited, and a known chiral agent can be given.

[0228] The content of the chiral agent in the polymerizable liquid crystal composition is not particularly limited, but it is preferably 0.01 to 20% by mass, more preferably 0.3 to 10% by mass, relative to the total solid content in the polymerizable liquid crystal composition.

[0229] The polymerizable liquid crystal composition can contain a polymerizable monomer different from the liquid crystal compound having a polymerizable group. As the polymerizable monomer, a radical polymerizable compound and a cationic polymerizable compound can be given, and a multifunctional radical polymerizable monomer is preferable. As the polymerizable monomer, for example, the polymerizable monomers described in paragraphs 0018 to 0020 of Japanese Patent Application Publication No. 2002-296423 can be given.

[0230] The content of the polymerizable monomer in the polymerizable liquid crystal composition is not particularly limited, but is preferably 1 to 50% by mass, more preferably 5 to 30% by mass, relative to the total mass of the liquid crystal compound.

[0231] The polymerizable liquid crystal composition can contain a surfactant. As the surfactant, there can be mentioned an alkyl ether compound, a silicone compound, or a fluorine compound, which are conventionally known, and a fluorine compound is preferred. Specifically, there can be mentioned, for example, the compounds described in paragraphs 0028 to 0056 of Japanese Patent Application Publication No. 2001-330725 and the compounds described in paragraphs 0069 to 0126 of Japanese Patent Application Publication No. 2003-295212.

[0232] The polymerizable liquid crystal composition can contain a polymer. As the polymer, there can be mentioned a cellulose ester. As the cellulose ester, there can be mentioned the cellulose ester described in paragraph 0178 of Japanese Patent Application Publication No. 2000-155216.

[0233] The content of the polymer in the polymerizable liquid crystal composition is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.1 to 8% by mass, relative to the total mass of the liquid crystal compound.

[0234] In addition to the above, the polymerizable liquid crystal composition can contain an additive (an alignment control agent) that promotes horizontal alignment or vertical alignment to bring the liquid crystal compound into a horizontal alignment state or a vertical alignment state.

[0235] The polymerizable liquid crystal composition can contain a photoalignment polymer. The photoalignment polymer is a polymer having a photoalignment group. In the case where the photoalignment polymer has a repeating unit having a fluorine atom or a silicon atom represented by formula (1) or formula (2) described later or in the case where the photoalignment polymer is a cleavage-type photoalignment polymer, the photoalignment polymer is easily distributed unevenly on the surface of a composition layer when the composition layer is formed using the polymerizable liquid crystal composition. In an optically anisotropic layer formed using such a composition layer, the photoalignment polymer is unevenly distributed in the vicinity of the surface, and thus, if a photoalignment treatment is performed, a surface shape having a prescribed alignment limiting force is formed. As a result, it is possible to further coat the polymerizable liquid crystal composition on the optically anisotropic layer without additionally providing an alignment film to manufacture a desired optically anisotropic layer.

[0236] The photo-orientation group possessed by the photo-orientation polymer is a group having a photo-orientation function of inducing reorganization or anisotropy by irradiation with light (e.g., plane polarized light or the like) having anisotropy, and from the viewpoint of excellent uniformity of orientation and good thermal stability and chemical stability, it is preferable that the photo-orientation group be a photo-orientation group that at least one of dimerization and isomerization is generated by the action of light.

[0237] As the group that dimerizes by the action of light, specifically, for example, a group having a skeleton selected from at least one derivative of a group including a cinnamic acid derivative, a coumarin derivative, a chalcone derivative, a maleimide derivative, and a benzophenone derivative, or the like can be preferably selected.

[0238] On the other hand, as the group that isomerizes by the action of light, specifically, for example, a group having a skeleton selected from at least one compound of a group including an azobenzene compound, a stilbene compound, a spiropyran compound, a cinnamic acid compound, and a hydrazono-β-keto ester compound can be preferably selected.

[0239] Among these photo-orientation groups, from the viewpoint that the liquid crystal orientation of the optically anisotropic layer formed on the upper layer of the optically anisotropic layer containing the photo-orientation polymer becomes more excellent even with a smaller exposure amount, it is preferable that the group be selected from a group including a cinnamoyl group, an azobenzene group, a chalcone group, and a coumarin group.

[0240] The photo-orientation polymer is preferably a photo-orientation polymer containing a repeating unit having a photo-orientation group and a repeating unit having a fluorine atom or a silicon atom.

[0241] Further, from the viewpoint that the liquid crystal orientation of the optically anisotropic layer formed on the upper layer of the optically anisotropic layer containing the photo-orientation polymer becomes more excellent, the photo-orientation polymer is preferably a photo-orientation polymer having a repeating unit A containing a cleavage group that generates a polar group by decomposition by at least one action selected from a group including light, heat, an acid, and a base, the repeating unit A having the cleavage group in a side chain and having a fluorine atom or a silicon atom in the side chain more distal than the cleavage group (hereinafter, also referred to simply as a "cleavage-type photo-orientation polymer").

[0242] Among these, the "polar group" contained in the repeating unit A is a group having at least one or more heteroatoms, and specifically, for example, a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a nitro group, an ammonium group, a cyano group, or the like can be mentioned. Among these, a hydroxyl group, a carbonyl group, or a carboxyl group is preferable.

[0243] Further, the "cleavage group that generates a polar group" is a group that generates the above-described polar group by cleavage, but in the present application, a group that generates a polar group by reacting with an oxygen molecule after radical cleavage is also included.

[0244] As such a cleavage-type photo-alignment polymer, for example, the photo-alignment polymers described in paragraphs 0014 to 0049 of Patent Literature 1 (International Publication No. 2018 / 216812) can be cited, the contents of which are incorporated into the present specification.

[0245] For example, by including a photo-alignment polymer in the optically anisotropic layer (C), it is possible to coat the polymerizable liquid crystal composition that forms the optically anisotropic layer (B) on the optically anisotropic layer (C) without additionally coating an alignment film to form the optically anisotropic layer (B) that aligns the liquid crystal compound. That is, it is possible to directly laminate the optically anisotropic layer (C) and the optically anisotropic layer (A) or (B).

[0246] As another example of a photo-alignment polymer including a repeating unit having a fluorine atom or a silicon atom, a copolymer having a repeating unit represented by formula (1) or formula (2) below having a fluorine atom or a silicon atom and a repeating unit having a photo-alignment group (hereinafter, also simply referred to as "specific copolymer") can be preferably cited.

[0247] In addition, the repeating unit represented by formula (1) or formula (2) below having a fluorine atom or a silicon atom is a repeating unit including a cleavage group that generates a polar group by decomposition by at least one action selected from the group consisting of light, heat, acid, and base.

[0248] [Chemical Formula 1]

[0249]

[0250] In the above formula (1) and (2), r and s each independently represent an integer of 1 or more.

[0251] and R B1 and R B2 each independently represent a hydrogen atom or a substituent.

[0252] and Y 1 and Y 2 each independently represent -O- or -NR Z . In the formula, R Z represents a hydrogen atom or a substituent.

[0253] and L B1 represents a linking group of r+1 valence.

[0254] and L B2 represents a linking group of s+1 valence.

[0255] and B1 represents a group represented by the following formula (B1). In the formula (B1) below, * represents a bond to LB1 For the bonding positions, when r is an integer greater than 2, multiple B1s can be the same or different.

[0256] Furthermore, B2 represents the group represented by the following formula (B2). In the following formula (B2), * indicates a group related to L. B2 In the case that s is an integer greater than 2, multiple B2s can be the same or different.

[0257] [Chemical Formula 2]

[0258]

[0259] In equations (B1) and (B2) above, * indicates the bonding position.

[0260] Furthermore, n represents an integer greater than or equal to 1. Multiple n values ​​can be the same or different.

[0261] Furthermore, m represents an integer greater than 2.

[0262] Furthermore, R b1 It represents a hydrogen atom or a substituent.

[0263] Furthermore, R b2 R b3 and R b4 Each can independently represent a hydrogen atom or a substituent. Among them, the two R's... b3 They can bond together to form a ring, multiple R b2 They can be the same or different; multiple R's b3 They can be the same or different; multiple R's b4 They can be the same or different.

[0264] Furthermore, L b1 This represents a linking group with an n+1 valence. Multiple L... b1 They can be the same or different.

[0265] Furthermore, L b2 This indicates a linking group with a valence of m+1.

[0266] Furthermore, Z represents an aliphatic hydrocarbon group or an organosiloxane group containing a fluorine atom. The aforementioned aliphatic hydrocarbon group may contain an oxygen atom, and multiple Z groups may be identical or different.

[0267] In the above equation (1), R is... B1 The substituents represented can be well-known examples. Preferably, they are alkyl groups having 1 to 12 carbon atoms, and more preferably, they are methyl groups.

[0268] In the above formula (1), Y1 respectively independently represent -O- or -NR Z -, R Z represents a hydrogen atom or a substituent. As the substituent of R Z , a known substituent can be mentioned, and a methyl group is preferred. Y 1 preferably represents -O- or -NH-, and more preferably -O-.

[0269] In the above formula (1), L B1 represents an r+1-valent linking group. As the r+1-valent linking group, an r+1-valent hydrocarbon group having 1 to 24 carbon atoms which can have a substituent and in which a part of the carbon atoms constituting the hydrocarbon group can be substituted with a hetero atom is preferred, and a 1 to 10 carbon aliphatic hydrocarbon group which can contain an oxygen atom or a nitrogen atom is more preferred. As the r+1-valent linking group, a 2 to 3 valent linking group is preferred, and a 2 valent linking group is more preferred.

[0270] In the above formula (1), r represents an integer of 1 or more. Among them, from the viewpoint of synthesis applicability, an integer of 1 to 3 is preferred, an integer of 1 to 2 is more preferred, and 1 is further preferred.

[0271] In the above formula (2), as the substituent represented by R B2 , a known substituent can be mentioned. Among them, an alkyl group having 1 to 12 carbon atoms is preferred, and a methyl group is more preferred.

[0272] In the above formula (2), Y 2 represents -O- or -NR Z -. Among them, R Z represents a hydrogen atom or a substituent. As the substituent of R Z , a known substituent can be mentioned, and a methyl group is preferred. Y 2 preferably represents -O- or -NH-, and more preferably -O-.

[0273] In the above formula (2), L B2 represents an s+1-valent linking group. As the s+1-valent linking group, an s+1-valent hydrocarbon group having 1 to 24 carbon atoms which can have a substituent and in which a part of the carbon atoms constituting the hydrocarbon group can be substituted with a hetero atom is preferred, and a 1 to 10 carbon aliphatic hydrocarbon group which can contain an oxygen atom or a nitrogen atom is more preferred.

[0274] As the s+1-valent linking group, a 2 valent linking group is preferred.

[0275] In the above formula (2), s represents an integer of 1 or more. Among them, from the viewpoint of synthesis applicability, an integer of 1 to 2 is preferred, and 1 is more preferred.

[0276] In the substituent represented by the above formula (B1), as R b1 In the substituent represented by the above formula (B1), as R b1 In the substituent represented by the above formula (B1), as R

[0277] In the substituent represented by the above formula (B1), as R b2 In the substituent represented by the above formula (B1), as R b1 In the substituent represented by the above formula (B1), as R b2 Preferably represents a hydrogen atom.

[0278] In the substituent represented by the above formula (B1), L b1 In the substituent represented by the above formula (B1), L

[0279] In the substituent represented by the above formula (B1), L

[0280] In the substituent represented by the above formula (B1), n represents an integer of 1 or more. Among them, from the viewpoint of synthesis applicability, an integer of 1 to 5 is preferable, an integer of 1 to 3 is more preferable, and 1 is further preferable.

[0281] In the above formula (B1) and the above formula (B2), Z represents an aliphatic hydrocarbon group having a fluorine atom or a silicone alkoxyl group. Among them, the above aliphatic hydrocarbon group can have an oxygen atom, and a plurality of Z can be the same or different.

[0282] As the aliphatic hydrocarbon group having a fluorine atom, for example, a fluorine atom-containing alkyl group, a group in which one or more -CH2- constituting the fluorine atom-containing alkyl group is substituted with -O-, and a fluorine atom-containing alkenyl group, and the like can be given. The number of carbon atoms of the aliphatic hydrocarbon group having a fluorine atom is not particularly limited, and is preferably 1 to 30, more preferably 3 to 20, and further preferably 3 to 10.

[0283] The number of fluorine atoms contained in the aliphatic hydrocarbon group having a fluorine atom is not particularly limited, and is preferably 1 to 30, more preferably 5 to 25, and further preferably 7 to 20.

[0284] In the substituent represented by the above formula (B2), as R b3 In the substituent represented by the above formula (B2), as R b4 In the substituent represented by the above formula (B2), as R b1groups exemplified in the substituent represented. Also, R b3 preferably 2 Rb 3 more preferably 2 Rb 3 more preferably 2 Rb b4 preferably represents a hydrogen atom.

[0285] In the above formula (B2), L b2 represents an m+1-valent linking group.

[0286] As the m+1-valent linking group, it is preferable that it be an m+1-valent hydrocarbon group having 1 to 24 carbon atoms which can have a substituent and a part of the carbon atoms constituting the hydrocarbon group can be substituted with a hetero atom, and it is more preferable that it be an aliphatic hydrocarbon group having 1 to 10 carbon atoms which can contain an oxygen atom or a nitrogen atom. As the m+1-valent linking group, it is preferable that it be a 3- to 4-valent linking group, and it is more preferable that it be a 4-valent linking group.

[0287] In the above formula (B2), m represents an integer of 2 or more. Among them, from the viewpoint of synthesis applicability, it is preferable that it be an integer of 2 to 4, and it is more preferable that it be an integer of 2 to 3.

[0288] As a specific example of the repeating unit containing the group represented by the above formula (B1), the repeating units represented by the following formulas B-1 to B-22 can be given, and as a specific example of the repeating unit containing the group represented by the above formula (B2), the repeating units represented by the following formulas B-23 to B-24 can be given.

[0289] [Chemical Formula 3]

[0290]

[0291]

[0292] The content of the repeating unit having a fluorine atom or a silicon atom represented by formula (1) or formula (2) in the photoalignment polymer is not particularly limited, and from the viewpoint of improving the wind mark suppression effect, it is preferable that it be 15 to 75 mass% with respect to all the repeating units of the photoalignment polymer, it is more preferable that it be 20 to 50 mass%, and it is further preferable that it be 25 to 45 mass%.

[0293] The structure of the main chain of the repeating unit having a photoalignment group is not particularly limited, and known structures can be given, and it is preferable that it be a skeleton selected from the group consisting of (meth)acrylic acid series, styrene series, siloxane series, cycloolefin series, methylpentene series, amide series, and aromatic ester series.

[0294] Among them, it is more preferable that it be a skeleton selected from the group consisting of (meth)acrylic acid series, siloxane series, and cycloolefin series, and it is further preferable that it be a (meth)acrylic acid series skeleton.

[0295] As a specific example of the repeating unit having a photo-orienting group, the following can be given.

[0296] [Chemical Formula 4]

[0297]

[0298] [Chemical Formula 5]

[0299]

[0300] [Chemical Formula 6]

[0301]

[0302] [Chemical Formula 7]

[0303]

[0304] [Chemical Formula 8]

[0305]

[0306] [Chemical Formula 9]

[0307]

[0308] The content of the repeating unit having a photo-orienting group in the photo-orienting polymer is not particularly limited, and from the viewpoint of the liquid crystal alignment of the optically anisotropic layer formed on the upper layer becoming more excellent, it is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and further preferably 15 to 40% by mass, relative to all the repeating units of the photo-orienting polymer.

[0309] The specific copolymer can have, in addition to the repeating unit having a fluorine atom or a silicon atom represented by Formula (1) or Formula (2) and the repeating unit having a photo-orienting group, a repeating unit having a crosslinking group.

[0310] The kind of the crosslinking group is not particularly limited, and a publicly known crosslinking group can be given. Among them, an epoxy group, an epoxy cyclohexyl group, an oxetanyl group, an acryloyl group, a methacryloyl group, a vinyl group, a styryl group, and an allyl group can be given.

[0311] The structure of the main chain of the repeating unit having a crosslinking group is not particularly limited, and a publicly known structure can be given, and for example, a skeleton selected from the group consisting of a (meth)acrylic acid series, a styrene series, a siloxane series, a cyclic olefin series, a methyl pentene series, an amide series, and an aromatic ester series is preferable.

[0312] Among these, more preferable is a skeleton selected from the group consisting of (meth)acrylic, siloxane, and cyclic olefin, and further preferable is a (meth)acrylic skeleton.

[0313] Specific examples of the repeating unit having a crosslinkable group include the following.

[0314] [Chemical Formula 10]

[0315]

[0316] The content of the repeating unit having a crosslinkable group in the specific copolymer is not particularly limited, and from the viewpoint of making the liquid crystal alignment properties of the optically anisotropic layer formed on the upper layer more excellent, it is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, relative to all the repeating units of the photoalignment polymer.

[0317] As the monomer (radical polymerizable monomer) forming other repeating units than the above, for example, an acrylate compound, a methacrylate compound, a maleimide compound, an acrylamide compound, acrylonitrile, maleic anhydride, a styrene compound, and a vinyl compound can be given.

[0318] The synthesis method of the photoalignment polymer is not particularly limited, and for example, it can be synthesized by mixing a monomer forming the above-mentioned repeating unit having a fluorine atom or a silicon atom represented by formula (1) or formula (2), a monomer forming the above-mentioned repeating unit having a photoreactive group, and a monomer forming an arbitrary other repeating unit, and polymerizing in an organic solvent using a radical polymerization initiator.

[0319] The weight average molecular weight (Mw) of the photoalignment polymer is not particularly limited, but from the viewpoint of making the liquid crystal alignment properties of the optically anisotropic layer formed on the upper layer more excellent, it is preferably 25,000 or more, more preferably 25,000 to 500,000, further preferably 25,000 to 300,000, and particularly preferably 30,000 to 150,000.

[0320] Here, the weight average molecular weight in the photoalignment polymer and the surfactant is a value measured by gel permeation chromatography (GPC) under the conditions shown below.

[0321] • Solvent (eluent): THF (tetrahydrofuran)

[0322] • Apparatus name: TOSOH HLC-8320 GPC

[0323] • Column: Used by connecting 3 TOSOH TSKgel Super HZM-H (4.6 mm x 15 cm)

[0324] • Column temperature: 40°C

[0325] • Sample concentration: 0.1 mass%

[0326] • Flow rate: 1.0 ml / min

[0327] • Calibration curve: A calibration curve based on 7 samples of TOSOH standard polystyrene Mw = 2800000 ~ 1050 (Mw / Mn = 1.03 ~ 1.06) was used

[0328] Organic EL display device

[0329] The organic EL display device of the present application has the above-mentioned circular polarizing plate. Generally, the circular polarizing plate is provided on an organic EL display panel of the organic EL display device. That is, the organic EL display device of the present application has an organic EL display panel and the above-mentioned circular polarizing plate.

[0330] As an example of the organic EL display device, an organic EL display panel, a phase difference film, and a polarizer are sequentially provided.

[0331] The organic EL display panel is a member in which a light-emitting layer or a plurality of thin films of organic compounds including a light-emitting layer are formed between a pair of electrodes of an anode and a cathode, and can have, in addition to the light-emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, and the like, and each of these layers can have other functions. As to the formation of each layer, various materials can be used, respectively.

[0332] Display device

[0333] The above-mentioned circular polarizing plate can also be used in various display devices having a curved surface. For example, it can be used in a lens of a roll-up display having a curved surface, a lens of a head-up display, a lens of a goggle for an image display device, and the like.

[0334] The circular polarizing plate of the present application can be attached to a curved surface or integrally molded with a resin, and thus contributes to the improvement of designability. The organic EL display device using the circular polarizing plate of the present application can suppress color unevenness in the oblique direction, and thus is preferably used in a curved surface display or a display for a vehicle.

[0335] It is also preferably used in an optical system of a head-up display for a vehicle or the like, an optical system of AR glasses and VR glasses or the like, and an optical sensor of LiDAR, a face recognition system, and polarization imaging or the like. Furthermore, in a display device having a curved surface, the circular polarizing plate of the present application is also preferably used while being arranged along the curved surface.

[0336] Example

[0337] The following examples and comparative examples further specifically illustrate the features of the present application. The materials, amounts, ratios, processing details, and processing steps shown in the following examples can be suitably changed as long as the gist of the present application is not deviated. Therefore, the scope of the present application should not be construed restrictively from the specific examples shown below.

[0338] <Example 1>

[0339] (Production of Cellulose Acylate Film (Substrate))

[0340] The following composition was put into a mixing tank and stirred, and further heated at 90°C for 10 minutes. Thereafter, the obtained composition was filtered using a filter paper having an average pore diameter of 34 μm and a sintered metal filter having an average pore diameter of 10 μm, thereby preparing a dope. The solid content concentration of the dope was 23.5 mass%, and the additive amount of the plasticizer was 1 part by mass to 10 parts by mass of the cellulose acylate. The solvent of the dope was dichloromethane / methanol / butanol = 81 / 18 / 1 (mass ratio).

[0341]

[0342] [Chemical Formula 11]

[0343]

[0344] [Chemical Formula 12]

[0345]

[0346] The dope produced in the above manner was cast using a drum film casting machine. The dope was cast from a die so as to be brought into contact with a metal support body cooled to 0°C, and the obtained web (film) was peeled from the drum. In addition, the drum was made of SUS.

[0347] When the web (film) obtained by casting was peeled from the drum and the film was transported, a tenter device that grips both ends of the web with clips and transports the web was used at 30 to 40°C, and the web was dried in the tenter device for 20 minutes. Subsequently, the web was post-dried by area heating while being rolled. After the obtained web was knurled, the web was wound.

[0348] The cellulose acylate film obtained had a film thickness of 40 μm, an in-plane retardation Re(550) of 1 nm at a wavelength of 550 nm, and a thickness direction retardation Rth(550) of 26 nm at a wavelength of 550 nm.

[0349] (Alkali Saponification Treatment)

[0350] After passing the cellulose acylate film through a dielectric heating roller at a temperature of 60°C to raise the film surface temperature to 40°C, an alkali solution of the composition shown below was applied at an application amount of 14 ml / m 2 applied to the film surface, and conveyed for 10 seconds under a steam-type far infrared heater manufactured by NORITAKE CO., LIMITED, which was heated to 110°C. Next, pure water was applied at 3 ml / m using a bar coater in the same manner. 2 Next, after repeating water washing based on a spray coater and dehydration based on an air knife three times, drying was performed by conveying for 10 seconds to a drying area at 70°C, thereby producing a cellulose acylate film subjected to alkali saponification treatment.

[0351]

[0352]

[0353] (Formation of alignment film)

[0354] An alignment film coating solution of the following composition was continuously applied to the alkali saponification-treated surface of the cellulose acylate film using a wire bar #14. Drying was performed using a warm air at 60°C for 60 seconds, and further using a warm air at 100°C for 120 seconds.

[0355]

[0356] (Polyvinyl alcohol)

[0357] [Chemical Formula 13]

[0358]

[0359] (Formation of optically anisotropic layer (A))

[0360] A rubbing treatment was continuously performed on the above-produced alignment film. At this time, the length direction of the long strip-shaped film was parallel to the conveying direction, and the angle formed by the length direction of the film (conveying direction) and the rotation axis of the rubbing roller was set to 76°. The length direction of the film (conveying direction) was set to 90°, and, as viewed from the film side, if the positive value is indicated in the clockwise direction with the film width direction as the reference (0°), the rotation axis of the rubbing roller was -14°. In other words, as viewed from the film side, the position of the rotation axis of the rubbing roller was a position rotated 76° in the clockwise direction with the length direction of the film as the reference.

[0361] An optical anisotropic layer (1a) corresponding to the optical anisotropic layer (A) was formed by coating a discotic liquid crystalline compound optical anisotropic layer-forming composition (1a) containing the following components on the alignment film subjected to the rubbing treatment using a die coater, and then heating the obtained composition layer at 110°C for 2 minutes using a warm air to dry the solvent and cure the alignment of the discotic liquid crystalline compound. Subsequently, UV irradiation (500 mJ / cm2) was performed on the obtained composition layer at 80°C to fix the alignment of the liquid crystalline compound, thereby forming the optical anisotropic layer (1a). 2 ) to fix the alignment of the liquid crystalline compound, thereby forming the optical anisotropic layer (1a) corresponding to the optical anisotropic layer (A).

[0362] The thickness of the optical anisotropic layer (1a) was 1.1 μm. Further, the in-plane retardation at a wavelength of 550 nm was 168 nm. The average tilt angle of the discotic plane of the discotic liquid crystalline compound with respect to the film surface was 90°, and a homeotropic alignment with respect to the film surface was confirmed. Further, the angle of the in-plane slow axis of the optical anisotropic layer (1a) was parallel to the rotation axis of the rubbing roller, and if the width direction of the film was set to 0° (the length direction was 90° counterclockwise, -90° clockwise), the in-plane slow axis was -14° when viewed from the optical anisotropic layer (1a) side.

[0363]

[0364] Discotic liquid crystalline compound 1

[0365] [Chemical Formula 14]

[0366]

[0367] Discotic liquid crystalline compound 2

[0368] [Chemical Formula 15]

[0369]

[0370] Alignment film surface alignment agent 1

[0371] [Chemical Formula 16]

[0372]

[0373] Fluorine-containing compound A

[0374] [Chemical Formula 17]

[0375]

[0376] The above a and b represent the content (mass %) of each repeating unit with respect to all repeating units, a represents 90 mass %, and b represents 10 mass %.

[0377] Fluorine-containing compound B (The numerical value in each repeating unit indicates the content (mass%) with respect to all repeating units, the content of the left-side repeating unit is 32.5 mass%, and the content of the right-side repeating unit is 67.5 mass%.)

[0378] [Chemical Formula 18]

[0379]

[0380] Fluorine-containing compound C (The numerical value in each repeating unit indicates the content (mass%) with respect to all repeating units, the content of the left-side repeating unit is 25 mass%, the content of the middle repeating unit is 25 mass%, and the content of the right-side repeating unit is 50 mass%.)

[0381] [Chemical Formula 19]

[0382]

[0383] (Formation of a laminate of the optically anisotropic layer (C) and the optically anisotropic layer (B))

[0384] (Formation of the optically anisotropic layer (1c))

[0385] An optically anisotropic layer-forming composition (1c) containing a rod-like liquid crystal compound having the following composition was applied to the above-prepared cellulose acylate film using a die coater, thereby forming a composition layer. Then, while holding both ends of the film, a cooling plate (9°C) was disposed on the side of the film on which the composition layer was formed so as to be 5 mm away from the film, and a heater (75°C) was disposed on the side of the film opposite to the side on which the composition layer was formed so as to be 5 mm away from the film, and the film was dried for 2 minutes.

[0386] Next, the film was heated at 60°C for 1 minute using a warm air, and while performing nitrogen purge so that the oxygen concentration became 100 ppm or less, the film was irradiated with 365 nm UV-LED at an irradiation amount of 100 mJ / cm 2 After that, the film was annealed at 120°C for 1 minute using a warm air, thereby forming the optically anisotropic layer (1c).

[0387] At room temperature, the obtained optically anisotropic layer (1c) was irradiated with UV light (ultra-high pressure mercury lamp; UL750; HOYA Corporation) passed through a wire grid polarizer at an irradiation amount of 7.9 mJ / cm 2 (wavelength: 313 nm), thereby forming the optically anisotropic layer (1c) having an alignment controlling ability on the surface.

[0388] Furthermore, the thickness of the formed optical anisotropic layer (1c) is 0.5 μm. The in-plane retardation Re at 550 nm is 0 nm, and the thickness retardation Rth at 550 nm is -68 nm. The average tilt angle of the long axis of the rod-shaped liquid crystal compound relative to the film surface is 90°, confirming its perpendicular orientation relative to the film surface.

[0389] An optical anisotropic layer (1c) corresponding to the optical anisotropic layer (C) is formed in the manner described above.

[0390]

[0391]

[0392] Rod-shaped liquid crystal compound (A) (hereinafter, a mixture of compounds)

[0393] [Chemical Formula 20]

[0394]

[0395] Polymerization initiator S-1

[0396] [Chemical Formula 21]

[0397]

[0398] Photoacid generator D-1

[0399] [Chemical Formula 22]

[0400]

[0401] Polymer M-1

[0402] [Chemical Formula 23]

[0403]

[0404] Vertical Orientation Agent S01

[0405] [Chemical Formula 24]

[0406]

[0407] Photooriented polymer A-1 (the values ​​recorded in each repeating unit represent the content (mass%) of each repeating unit relative to all repeating units, starting from the repeating units on the left: 43 mass%, 27 mass%, 30 mass%). Furthermore, the weight-average molecular weight is 69,800.

[0408] [Chemical Formula 25]

[0409]

[0410] Surfactant B-1 (weight average molecular weight: 2200.)

[0411] [Chemical Formula 26]

[0412]

[0413] (Formation of optically anisotropic layer (1b))

[0414] Next, the optically anisotropic layer-forming composition (1b) containing a rod-like liquid crystal compound having the following composition was applied to the optically anisotropic layer (1c) produced above using a die coater, and heated using a warm air of 80°C for 60 seconds. Next, the obtained composition layer was subjected to UV irradiation (500 mJ / cm2) at 80°C to fix the orientation of the liquid crystal compound, thereby forming an optically anisotropic layer (1b) corresponding to the optically anisotropic layer (B). 2 ) to fix the orientation of the liquid crystal compound, thereby forming an optically anisotropic layer (1b) corresponding to the optically anisotropic layer (B).

[0415] The thickness of the optically anisotropic layer (1b) was 1.2 μm, Δnd at a wavelength of 550 nm was 164 nm, and the twist angle of the liquid crystal compound was 81°. If the width direction of the film is set to 0° (the length direction is set to 90°), the orientation axis angle of the liquid crystal compound is 14° on the air side and 95° on the side in contact with the optically anisotropic layer (1c) when viewed from the side of the optically anisotropic layer (1b).

[0416] In addition, the orientation axis angle of the liquid crystal compound contained in the optically anisotropic layer is set to 0° based on the width direction of the substrate, the substrate is viewed from the surface side of the optically anisotropic layer, and is expressed as negative when clockwise (right turn) and as positive when counterclockwise (left turn).

[0417] Also, regarding the twist angle of the liquid crystal compound, the substrate side (inside) is expressed as negative when clockwise (right turn) and as positive when counterclockwise (left turn) based on the orientation axis direction of the liquid crystal compound on the surface side (front side) when the substrate is viewed from the surface side of the optically anisotropic layer.

[0418]

[0419] Left-handed chiral reagent (L1)

[0420] [Chemical Formula 27]

[0421]

[0422] By the above procedure, a laminate (1c-1b) in which the optically anisotropic layer (1c) and the optically anisotropic layer (1b) were directly laminated on the long cellulose acylate film was produced. Further, as a result of confirming the surface of the side of the optically anisotropic layer (1c) which contacted the optically anisotropic layer (1b) by the above procedure, it was confirmed that the optically alignable polymer was present.

[0423] (Formation of laminate of optically anisotropic layer (A), optically anisotropic layer (B), and optically anisotropic layer (C))

[0424] The surface side of the optically anisotropic layer (1a) formed on the above produced long cellulose acylate film and the surface side of the optically anisotropic layer (1b) of the laminate (1c-1b) formed on the above produced long cellulose acylate film were continuously adhered using an ultraviolet-curable adhesive.

[0425] Next, the cellulose acylate film on the side of the optically anisotropic layer (1a) was peeled to expose the surface of the optically anisotropic layer (1a) which contacted the cellulose acylate film. In this manner, a phase difference film (1c-1b-1a) in which the optically anisotropic layer (1c), the optically anisotropic layer (1b), and the optically anisotropic layer (1a) were sequentially laminated on the long cellulose acylate film was obtained. The thickness of the phase difference film (1c-1b-1a) was 4.0 μm. The water content of the obtained phase difference film (1c-1b-1a) was 0.8%. The in-plane slow axis of the surface of the side of the optically anisotropic layer (1b) which contacted the optically anisotropic layer (1a) was parallel to the in-plane slow axis of the optically anisotropic layer (1a).

[0426] (Production of linear polarizing plate 1)

[0427] An alkali saponification treatment was performed on the support surface of a triacetyl cellulose film TJ25 (manufactured by Fujifilm Corporation; thickness: 25 μm). Specifically, the support was immersed in a 1.5% by weight aqueous sodium hydroxide solution at 55°C for 2 minutes, and then washed in a water bath at room temperature, and further neutralized using a 0.1% by weight sulfuric acid solution at 30°C. After the neutralization, the support was washed in a water bath at room temperature, and then dried using a warm air at 100°C, thereby obtaining a polarizer protective film.

[0428] A roll-shaped polyvinyl alcohol (PVA) film having a thickness of 60 μm was continuously extended in the length direction in an aqueous iodine solution and dried, thereby obtaining a polarizer having a thickness of 13 μm. The visible light corrected monochromatic transmittance of the polarizer was 43%. At this time, the absorption axis direction of the polarizer coincided with the length direction.

[0429] The polarizer protective film was attached to one surface of the polarizer using the PVA adhesive described below, thereby producing a linear polarizing plate 1.

[0430] (Preparation of PVA adhesive)

[0431] A PVA adhesive was prepared by dissolving 100 parts by mass of a polyvinyl alcohol-based resin having an acetoacetyl group (average degree of polymerization: 1200, saponification degree: 98.5 mol%, acetoacetyl degree: 5 mol%) and 20 parts by mass of methylol melamine in pure water so that the solid content concentration was adjusted to 3.7% by mass at a temperature of 30°C.

[0432] (Production of circular polarizing plate)

[0433] The surface of the optically anisotropic layer (1a) of the long strip-shaped phase difference film (1c-1b—1a) produced above and the surface of the polarizer of the long strip-shaped linear polarizing plate 1 produced above (the surface on the opposite side of the polarizer protective film) were continuously attached using an ultraviolet-curable adhesive. Next, the cellulose acylate film on the optically anisotropic layer (1c) side was peeled to expose the surface of the optically anisotropic layer (1c) that was in contact with the cellulose acylate film.

[0434] A circular polarizing plate (P1) composed of a phase difference film (1c-1b—1a) and a linear polarizing plate was produced in the above-described manner. At this time, the polarizer protective film, the polarizer, the optically anisotropic layer (1a), the optically anisotropic layer (1b), and the optically anisotropic layer (1c) were sequentially stacked, and the angle formed by the absorption axis of the polarizer and the slow axis of the optically anisotropic layer (1a) was 76°. Further, the angle of the orientation axis of the liquid crystal compound on the optically anisotropic layer (1a) side of the optically anisotropic layer (1b) was 14° with respect to 0° as a reference in the width direction of the linear polarizing plate, and coincided with the slow axis direction of the optically anisotropic layer (1a). The thickness of the circular polarizing plate was 43 μm.

[0435] Further, the angle of the orientation axis of the liquid crystal compound included in the optically anisotropic layer was set to 0° with respect to the width direction of the linear polarizing plate as a reference, and was expressed as negative when clockwise (right turn) and positive when counterclockwise (left turn) when viewed from the surface side of the polarizing plate.

[0436] <Example 2>

[0437] (Formation of alignment film)

[0438] The optical orientation film forming material described in Example 1 of WO2016 / 002722 was coated on the above-mentioned cellulose acylate film in a long strip shape. Thereafter, the coated film was heated to 125°C using a warm air to form a hard film. Subsequently, polarized light ultraviolet rays of 313 nm were irradiated to the obtained coated film, whereby an optical orientation film was produced.

[0439] (Formation of the optically anisotropic layer (B))

[0440] The optically anisotropic layer forming composition (1b) containing the rod-like liquid crystal compound of the above-mentioned composition was coated on the above-mentioned optical orientation film using a die coater, and heated for 60 seconds using a warm air of 80°C. Subsequently, UV irradiation (500 mJ / cm2) was performed on the obtained composition layer at 80°C to fix the orientation of the liquid crystal compound, whereby an optically anisotropic layer (2b) corresponding to the optically anisotropic layer (B) was formed. 2 ) to fix the orientation of the liquid crystal compound, whereby an optically anisotropic layer (2b) corresponding to the optically anisotropic layer (B) was formed.

[0441] The thickness of the optically anisotropic layer (2b) was 1.2 μm, Δnd at a wavelength of 550 nm was 164 nm, and the twist angle of the liquid crystal compound was 81°. If the width direction of the film is set to 0° (the length direction is set to 90°), the orientation axis angle of the liquid crystal compound is -76° on the air side and 5° on the side in contact with the cellulose acylate film when viewed from the side of the optically anisotropic layer (2b).

[0442] In addition, the orientation axis angle of the liquid crystal compound included in the optically anisotropic layer is set to 0° with the width direction of the substrate as a reference, the substrate is viewed from the surface side of the optically anisotropic layer, and is expressed as negative when clockwise (right turn) and as positive when counterclockwise (left turn).

[0443] Further, regarding the twist angle of the liquid crystal compound, the substrate is viewed from the surface side of the optically anisotropic layer, and is expressed as negative when clockwise (right turn) and as positive when counterclockwise (left turn) with the orientation axis direction of the liquid crystal compound on the surface side (front side) as a reference.

[0444] (Formation of the optically anisotropic layer (C) and the laminate of the optically anisotropic layer (A))

[0445] (Formation of the optically anisotropic layer (2c))

[0446] In the formation of the optically anisotropic layer (1c) of Example 1, the thickness of the composition layer was changed, and otherwise, the optically anisotropic layer (2c) having an orientation control ability on the surface was formed in the same manner.

[0447] Further, the optical anisotropic layer (2c) thus formed had a film thickness of 0.7 μm. The in-plane retardation Re at a wavelength of 550 nm was 0 nm, and the thickness direction retardation Rth at a wavelength of 550 nm was -96 nm. The average tilt angle of the long axis direction of the rod-shaped liquid crystal compound with respect to the film surface was 90°, and it was confirmed that the alignment was perpendicular with respect to the film surface.

[0448] The optical anisotropic layer (2c) corresponding to the optical anisotropic layer (C) was formed in the above-described manner.

[0449] (Formation of the optical anisotropic layer (2a))

[0450] Next, the optical anisotropic layer-forming composition (2a) containing a rod-shaped liquid crystal compound having the following composition was applied to the optical anisotropic layer (2c) thus produced using a die coater, and heated using a warm air of 80°C for 60 seconds. Next, the obtained composition layer was subjected to UV irradiation (500 mJ / cm2) at 80°C to fix the alignment of the liquid crystal compound, and thus the optical anisotropic layer (2a) corresponding to the optical anisotropic layer (A) was formed. 2 ) to fix the alignment of the liquid crystal compound, and thus the optical anisotropic layer (2a) corresponding to the optical anisotropic layer (A) was formed.

[0451] The thickness of the optical anisotropic layer (2a) was 1.2 μm. Further, the retardation at a wavelength of 550 nm was 168 nm. The average tilt angle of the long axis direction of the rod-shaped liquid crystal compound with respect to the film surface was 0°, and it was confirmed that the alignment was horizontal with respect to the film surface. Further, if the width direction of the film was set to 0° (the length direction was set to 90°), the slow axis was -76° when viewed from the optical anisotropic layer (2a) side.

[0452]

[0453]

[0454] By the above-described steps, the laminate (2c-2a) in which the optical anisotropic layer (2c) and the optical anisotropic layer (2a) were directly laminated on the long cellulose acylate film was produced. Further, as a result of confirming the surface of the side of the optical anisotropic layer (2c) which contacted with the optical anisotropic layer (2a) by the above-described method, it was confirmed that the photoalignment polymer was present.

[0455] (Formation of the laminate of the optical anisotropic layer (A), the optical anisotropic layer (C), and the optical anisotropic layer (B), and production of the circularly polarizing plate)

[0456] The surface of the optical anisotropic layer (2a) of the laminate (2c-2a) formed on the long cellulose acylate film produced above was continuously bonded to the surface of the polarizer of the long linear polarizing plate 1 produced above using an ultraviolet-curable adhesive. Next, the cellulose acylate film on the optical anisotropic layer (2c) side was peeled to expose the surface of the optical anisotropic layer (2c) in contact with the cellulose acylate film.

[0457] The surface of the optical anisotropic layer (2c) exposed was continuously bonded to the surface side of the optical anisotropic layer (2b) formed on the long cellulose acylate film produced above using an ultraviolet-curable adhesive. Next, the cellulose acylate film on the optical anisotropic layer (2b) side was peeled to expose the surface of the optical anisotropic layer (2b) in contact with the cellulose acylate film.

[0458] A circular polarizing plate (P2) composed of the optical phase difference film (2b-2c-2a) and the linear polarizing plate 1 was produced in the above manner. The thickness of the phase difference film (2b-2c-2a) was 4.0 μm. The water content of the obtained phase difference film (2b-2c-2a) was 0.8%. At this time, the polarizer protective film, the polarizer, the optical anisotropic layer (2a), the optical anisotropic layer (2c), and the optical anisotropic layer (2b) were sequentially laminated, and the angle formed by the absorption axis of the polarizer and the slow axis of the optical anisotropic layer (2a) was 14°. Further, the angle of the orientation axis of the liquid crystal compound on the optical anisotropic layer (2c) side of the optical anisotropic layer (2b) was 76° with respect to 0° as the width direction, and coincided with the slow axis direction of the optical anisotropic layer (2a). The thickness of the circular polarizing plate was 43 μm.

[0459] Further, the angle of the orientation axis of the liquid crystal compound included in the optical anisotropic layer was set to 0° with respect to the width direction of the linear polarizing plate, and was expressed as negative when clockwise (right turn) and positive when counterclockwise (left turn) when observed from the surface side of the polarizing plate.

[0460] <Comparative Example 1>

[0461] The optical anisotropic layer (1c) was formed on the long cellulose acylate film in the same manner as in Example 1.

[0462] Next, the optical anisotropic layer (1h) containing the reverse wavelength dispersion liquid crystal compound was formed on the thus produced optical anisotropic layer (1c) using the composition A-1 described in Example 9 of Patent Document 1. The retardation at a wavelength of 550 nm was 138 nm. The average tilt angle of the long axis direction of the reverse wavelength dispersion liquid crystal compound with respect to the film surface was 0°, and the horizontal alignment with respect to the film surface was confirmed. Further, if the width direction of the film was set to 0° (the length direction was set to 90°), the slow axis was 45° when viewed from the optical anisotropic layer (1h) side.

[0463] The thus produced optical anisotropic layer (1c) containing the vertically aligned rod-shaped liquid crystal compound and the optical anisotropic layer (1h) containing the horizontally aligned reverse wavelength dispersion liquid crystal compound were directly laminated to obtain a laminate.

[0464] The linear polarizing plate 1 produced by the same method as in Example 1 and the laminate including the optical anisotropic layer (1c) and the optical anisotropic layer (1h) produced in the above manner were continuously laminated using the ultraviolet-curable adhesive in such a manner that the surface of the optical anisotropic layer (1h) was opposed to the surface of the polarizer of the linear polarizing plate 1 (the surface on the opposite side of the polarizer protective film). Next, the cellulose acylate film on the optical anisotropic layer (1c) side was peeled to expose the surface of the optical anisotropic layer (1c) in contact with the cellulose acylate film.

[0465] The circular polarizing plate composed of the linear polarizing plate was produced in the above manner. At this time, the polarizer protective film, the polarizer, the optical anisotropic layer (1h), and the optical anisotropic layer (1c) were sequentially laminated, and the angle formed by the absorption axis of the polarizer and the slow axis of the optical anisotropic layer (1h) was 45°.

[0466] <Comparative Example 2>

[0467] The optical anisotropic layer (1c) was formed on the long cellulose acylate film in the same manner as in Example 1.

[0468] Next, the optical anisotropic layer (2h) was formed on the thus produced optical anisotropic layer (1c) using the above optical anisotropic layer-forming composition (2a). The retardation at a wavelength of 550 nm was 138 nm. The average tilt angle of the long axis direction of the rod-shaped liquid crystal compound with respect to the film surface was 0°, and the horizontal alignment with respect to the film surface was confirmed. Further, if the width direction of the film was set to 0° (the length direction was set to 90°), the slow axis was 45° when viewed from the optical anisotropic layer (2h) side.

[0469] A laminate obtained by directly laminating the optical anisotropic layer (1c) containing the rod-shaped liquid crystal compound aligned vertically and the optical anisotropic layer (2h) containing the rod-shaped liquid crystal compound aligned horizontally was produced in the above manner.

[0470] A linear polarizing plate 1 produced by the same method as in Example 1 and a laminate including the optical anisotropic layer (1c) and the optical anisotropic layer (2h) produced in the above manner were continuously laminated using an ultraviolet-curable adhesive in such a manner that the surface of the optical anisotropic layer (2h) opposes the surface of the polarizer of the linear polarizing plate 1 (the side opposite to the polarizer protective film). Subsequently, the cellulose acylate film on the optical anisotropic layer (1c) side was peeled to expose the surface of the optical anisotropic layer (1c) that had been in contact with the cellulose acylate film.

[0471] A circular polarizing plate composed of a linear polarizing plate was produced in the above manner. At this time, the polarizer protective film, the polarizer, the optical anisotropic layer (2h), and the optical anisotropic layer (1c) were sequentially laminated, and the angle formed by the absorption axis of the polarizer and the slow axis of the optical anisotropic layer (2h) was 45°.

[0472] <Comparative Example 3>

[0473] (Formation of the optical anisotropic layer (3h))

[0474] A rubbing treatment was continuously performed on the alignment film provided on the cellulose acylate film used in the production of the optical anisotropic layer A of Example 1. At this time, the length direction of the long strip-shaped film was parallel to the transport direction, and the angle formed by the length direction (transport direction) of the film and the rotation axis of the rubbing roller was set to 75°. The length direction (transport direction) of the film was set to 90°, and, as viewed from the film side, if the positive value is indicated in the clockwise direction with the film width direction as the reference (0°), then the rotation axis of the rubbing roller was 165°.

[0475] The same optical anisotropic layer coating liquid (1a) as in Example 1 was applied to the alignment film subjected to the rubbing treatment described above using a die coater, thereby forming an optical anisotropic layer (3h) corresponding to the optical anisotropic layer (A).

[0476] The thickness of the optical anisotropic layer (3h) was 2.0 μm. Also, the retardation at a wavelength of 550 nm was 250 nm. The average tilt angle of the disc plane of the discotic liquid crystal compound with respect to the film surface was 90°, and perpendicular alignment with respect to the film surface was confirmed. Also, the angle of the slow axis of the optical anisotropic layer (3h) was parallel to the rotation axis of the rubbing roller, and, if the width direction of the film was set to 0° (the length direction was counterclockwise 90°, clockwise -90°), then the slow axis was 165° as viewed from the optical anisotropic layer (3h) side.

[0477] (Formation of the optically anisotropic layer (4h))

[0478] The rubbing treatment was continuously performed on the oriented film disposed on the cellulose acylate film used when the optically anisotropic layer A of Production Example 1 was produced. At this time, the length direction of the long film was parallel to the transport direction, and the angle formed by the length direction (transport direction) of the film and the rotation axis of the rubbing roll was set to 75°.

[0479] The length direction (transport direction) of the film was set to 90°, and the rotation axis of the rubbing roll was 165° when viewed from the film side, with the film width direction as the reference (0°) and positive values indicated in the clockwise direction.

[0480] The same optically anisotropic layer-forming composition (1a) as in Example 1 was applied to the oriented film subjected to the rubbing treatment described above using a die coater, thereby forming an optically anisotropic layer (4h) corresponding to the optically anisotropic layer (A).

[0481] The thickness of the optically anisotropic layer (4h) was 0.8 μm. Also, the retardation at a wavelength of 550 nm was 120 nm. The average tilt angle of the long axes of the rod-shaped liquid crystalline compounds with respect to the film surface was 0°, and horizontal alignment with respect to the film surface was confirmed. Also, the angle of the slow axis of the optically anisotropic layer (4h) was parallel to the rotation axis of the rubbing roll, and the slow axis was 105° when viewed from the optically anisotropic layer (4h) side, with the width direction of the film set to 0° (the length direction was counterclockwise 90°, and clockwise -90°).

[0482] A linear polarizing plate 1 produced by the same method as in Example 1 and a cellulose acylate film on which the optically anisotropic layer (3h) was disposed were continuously laminated so that the surface of the optically anisotropic layer (3h) and the surface of the polarizer of the linear polarizing plate 1 (the surface of the polarizer protective film on the opposite side) faced each other using an ultraviolet-curable adhesive. Next, the cellulose acylate film on the optically anisotropic layer (3h) side was peeled to expose the surface of the optically anisotropic layer (3h) that had been in contact with the cellulose acylate film. The surface of the exposed optically anisotropic layer (3h) and the surface side of the optically anisotropic layer (4h) formed on the long cellulose acylate film produced above were continuously laminated using an ultraviolet-curable adhesive. Next, the cellulose acylate film on the optically anisotropic layer (4h) side was peeled to expose the surface of the optically anisotropic layer (4h) that had been in contact with the cellulose acylate film.

[0483] A circular polarizing plate composed of a linear polarizing plate was produced in the above-described manner. At this time, the polarizer protective film, the polarizer, the optically anisotropic layer (3h), and the optically anisotropic layer (4h) were sequentially laminated, and the angle formed by the absorption axis of the polarizer and the slow axis of the optically anisotropic layer (3h) was 75°.

[0484] <Comparative Example 4>

[0485] A cellulose acylate film (3c) was produced in the same manner as in Example 1, except that the optical anisotropic layer (1c) of Example 15 of Japanese Patent Application Laid-Open No. 2006-265309 was not extended. Re and Rth were the same as those of the optical anisotropic layer (1c).

[0486] After the cellulose acylate film (3c) was subjected to alkali saponification treatment to form an oriented film, an optical anisotropic layer (3b) was formed. The optical anisotropic layer (3b) was produced in the same manner as the optical anisotropic layer (1b) of Example 1, except that the optical anisotropic layer (1c) of Example 1 was changed to the above-mentioned cellulose acylate film (3c).

[0487] The surface side of the optical anisotropic layer (1a) produced in Example 1 and the surface side of the above-mentioned optical anisotropic layer (3b) were continuously attached using an ultraviolet-curable adhesive. Thereafter, the cellulose acylate film on the side of the optical anisotropic layer (1a) was peeled, thereby obtaining a phase difference film (3c-3b-1a). The water content of the obtained phase difference film was 2.1%, and the thickness was 303 μm.

[0488] The surface of the optical anisotropic layer (1a) of the above-mentioned long strip-shaped phase difference film (3c-3b-1a) and the surface of the polarizer of the above-mentioned long strip-shaped linear polarizing plate 1 (the side opposite to the polarizer protective film) were continuously attached using an ultraviolet-curable adhesive.

[0489] A circular polarizing plate composed of the phase difference film (3c-3b-1a) and the linear polarizing plate was produced in the above-mentioned manner. At this time, the polarizer protective film, the polarizer, the optical anisotropic layer (1a), the optical anisotropic layer (3b), and the optical anisotropic layer (3c) were sequentially stacked, and the angle formed by the absorption axis of the polarizer and the slow axis of the optical anisotropic layer (1a) was 76°. Further, the angle of the orientation axis of the liquid crystalline compound on the side of the optical anisotropic layer (1a) of the optical anisotropic layer (3b) was 14° with respect to the width direction, and coincided with the direction of the slow axis of the optical anisotropic layer (1a). The thickness of the circular polarizing plate was 342 μm.

[0490] <Measurement of Chromaticity and Reflectance>

[0491] A reflective substrate was produced by adhering an aluminum foil to a 100 μm-thick PET film using an adhesive sheet.

[0492] The circularly polarizing plate produced in the Examples and Comparative Examples was disposed on the aluminum foil side of the obtained reflective substrate, whereby a laminate (corresponding to a specific laminate) was obtained. In addition, the reflective substrate and the circularly polarizing plate were laminated in such a manner that the phase difference film of the circularly polarizing plate faced the aluminum foil. Using a spectrocolorimeter (manufactured by Konica Minolta, Inc.), the chroma a * and the chroma b * at an azimuth angle (0 to 360°) at an angle of 40° from the normal direction of the circularly polarizing plate of the obtained laminate were measured from the circularly polarizing plate side of the laminate.

[0493] In addition, the angle of the azimuth angle indicates an angle formed with the absorption axis of the polarizer with the absorption axis of the polarizer as a reference. Furthermore, in the case of indicating the azimuth angle, the value is indicated in a counterclockwise direction from the absorption axis direction of the polarizer from the circularly polarizing plate side of the obtained laminate.

[0494] <Manufacture of Organic EL Display Device>

[0495] (Mounting on Display Device)

[0496] A Royole FlexPai equipped with an organic EL display panel (organic EL display element) was disassembled, and the circularly polarizing plate was peeled off from the organic EL display device. Next, the circularly polarizing plate produced in the above-described manner was attached to the panel side of the disassembled organic EL display panel in such a manner that the protective film was disposed on the outer side using a pressure-sensitive adhesive, whereby an organic EL display device was produced.

[0497] (Evaluation of Display Performance)

[0498] (Front Direction)

[0499] Black was displayed on the produced organic EL display device, and the color unevenness was evaluated from the front direction in bright light in a state in which the display was unfolded, based on the following criteria. The results are shown in Table 1.

[0500] A: Color unevenness was completely invisible (allowed)

[0501] B: Color unevenness was slightly visible, but there was no problem in use (allowed)

[0502] C: Color unevenness was visible, and there was a problem in use.

[0503] (Oblique Direction)

[0504] The color unevenness was evaluated based on the following criteria, with the black color displayed on the produced organic EL display device, in a state where the display was bent, under bright light, from a slanting direction, and in all azimuth angles. The results are shown in Table 1.

[0505] A: Color unevenness completely invisible (acceptable)

[0506] B: Color unevenness slightly visible, but no problem in use (acceptable)

[0507] C: Color unevenness visible, and a problem in use.

[0508] (Evaluation over time)

[0509] The color unevenness was evaluated based on the following criteria, with the black color displayed on the produced organic EL display device, in a state where the display was bent, under bright light, after the organic EL display device was left to stand in an environment of 25°C and 10% relative humidity for 72 hours. The results are shown in Table 1.

[0510] A: No change over time

[0511] B: Change over time

[0512] In Table 1, in the column of "Type of liquid crystal compound", "discotic" indicates that the optically anisotropic layer is a layer formed using a discotic liquid crystal compound, "rod-like" indicates that the optically anisotropic layer is a layer formed using a rod-like liquid crystal compound, and "reverse dispersion liquid crystal" indicates that the optically anisotropic layer is a layer formed using a liquid crystal compound having reverse wavelength dispersion.

[0513] In the column of "State of alignment", "horizontal" indicates that the liquid crystal compound is horizontally aligned. "Twisted" indicates that the liquid crystal compound is twistedly aligned. "Vertical" indicates that the liquid crystal compound is vertically aligned.

[0514] In Table 1, the column of "Reflectance" indicates the reflectance in all azimuth angles measured in the above-mentioned <Measurement of color and reflectance>, "<X%" indicates that the reflectance in any one of the azimuth angles is less than X%, and ">Y%" indicates that the reflectance in any one of the azimuth angles exceeds Y%.

[0515] In Table 1, the column of "a * " indicates the absolute value of the color a * in all azimuth angles measured in the above-mentioned <Measurement of color and reflectance>, "<X" indicates that the absolute value of the color a * in any one of the azimuth angles is less than X, and ">Y" indicates that the absolute value of the color a * in any one of the azimuth angles exceeds Y.

[0516] In Table 1, the column of "b *" indicates that the absolute value of the chromaticity b at any azimuth angle is less than X, and " > Y" indicates that the absolute value of the chromaticity b at any azimuth angle exceeds Y. * * *

[0517]

[0518] From the results shown in Table 1, it was confirmed that the circularly polarizing plate of the present application, when used in an organic EL display device, can suppress color hue unevenness in the normal direction and in the oblique direction. Further, color hue unevenness due to the passage of time was also suppressed. On the other hand, the circularly polarizing plate of the comparative example, when used in an organic EL display device, did not achieve the desired effect.

[0519] <Example 3>

[0520] A phase difference film (1c-1b-1a) in which the optically anisotropic layer (1c), the optically anisotropic layer (1b), and the optically anisotropic layer (1a) were sequentially layered on a long cellulose acylate film was obtained in the same manner as in Example 1.

[0521] Next, as the linear polarizing plate 3, a polarizer using a dichroic organic dye and a polymerizable liquid crystal was prepared. A coating liquid PA1 for forming an alignment layer described later was continuously coated on a cellulose triacetate film TJ40 (manufactured by Fujifilm Corporation; thickness: 40 μm) using a wire bar. By drying the support on which the coating film was formed using a warm air at 140°C for 120 seconds, and then performing polarized ultraviolet irradiation (using a 10 mJ / cm 2 of an ultrahigh pressure mercury lamp) on the coating film, a photo-alignment layer PA1 was formed, and a TAC film with the photo-alignment layer PA1 was obtained.

[0522] The film thickness of the photo-alignment layer PA1 was 0.3 μm.

[0523]

[0524] Polymer PA-1

[0525] [Chemical Formula 28]

[0526]

[0527] Acid generator PAG-1

[0528] [Chemical Formula 29]

[0529]

[0530] ​​​Acid generator CPI-110F

[0531] [Chem. 30]

[0532]

[0533] The following light-absorbing anisotropic layer-forming composition P2 was continuously coated on the obtained photo-alignment layer PA1 using a wire bar, thereby forming a coating film P2.

[0534] Next, after the coating film P2 was heated at 140°C for 30 seconds, the coating film P2 was cooled to room temperature (23°C).

[0535] Next, the obtained coating film P2 was heated at 90°C for 60 seconds and cooled to room temperature again.

[0536] After that, the photo-alignment layer PA1 was irradiated with an LED (light emitting diode) lamp (center wavelength 365 nm) under irradiation conditions of illuminance 200 mW / cm2for 2 seconds, thereby producing a light-absorbing anisotropic layer P2 on the photo-alignment layer PA1. The molar content of the radical polymerizable group was 1.17 mmol / g. 2

[0537] The film thickness of the light-absorbing anisotropic layer P2 was 1.3 μm.

[0538]

[0539]

[0540] Dichroic dye D-4

[0541] [Chem. 31]

[0542]

[0543] Dichroic dye D-5

[0544] [Chem. 32]

[0545]

[0546] Dichroic dye D-6

[0547] [Chem. 33]

[0548]

[0549] Polymer liquid crystal compound P-1

[0550] [Chem. 34]

[0551] ​

[0552] Low-molecular liquid crystalline compound M-1

[0553] [Chemical Formula 35]

[0554]

[0555] Surfactant F-1

[0556] [Chemical Formula 36]

[0557]

[0558] A coating film was formed by continuously coating the following solidification layer-forming composition K1 on the obtained light-absorbing anisotropic layer P2 using a wire bar.

[0559] Next, after drying the coating film at room temperature, the coating film was irradiated for 15 seconds using a high-pressure mercury lamp under irradiation conditions of an illuminance of 28 mW / cm2, thereby producing a solidification layer K1 on the light-absorbing anisotropic layer P2. 2

[0560] The film thickness of the solidification layer K1 was 0.05 μm.

[0561]

[0562] Mixture L1 of rod-like liquid crystalline compounds (the numerical values in the following formula represent mass%, and R represents a group bonded by an oxygen atom.)

[0563] [Chemical Formula 37]

[0564]

[0565] Modified trimethylolpropane triacrylate

[0566] [Chemical Formula 38]

[0567]

[0568] Photopolymerization initiator I-1

[0569] [Chemical Formula 39]

[0570]

[0571] Surfactant F-3

[0572] [Chemical Formula 40]

[0573]

[0574] ​The following oxygen barrier layer-forming composition B2 was continuously coated on the cured layer K1 using a wire bar. Thereafter, an oxygen barrier layer B2 having a thickness of 1.0 μm was formed on the cured layer K1 by drying for 2 minutes using a warm air of 100°C, thereby producing a polarizing film including the light-absorbing anisotropic layer P2.

[0575] The visibility-corrected monomer transmittance of the polarizing film was 43%.

[0576]

[0577] Modified polyvinyl alcohol

[0578] [Chemical Formula 41]

[0579]

[0580] The oxygen barrier layer B2 side of the polarizing film and the polarizing film protective film were attached using an adhesive sheet. Thereafter, only the TJ40 of the polarizing film was peeled off, and the surface of the optically anisotropic layer (1a) of the long strip-shaped phase difference film (1c-1b-1a) was continuously attached using an ultraviolet-curable adhesive. Next, the cellulose acylate film of the optically anisotropic layer (1c) was peeled off to expose the surface of the optically anisotropic layer (1c) that had been in contact with the cellulose acylate film. In this manner, a circularly polarizing plate was produced. The thickness of the circularly polarizing plate was 38 μm.

[0581] [Example 4]

[0582] A circularly polarizing plate was produced in the same manner as in Example 3, except that the film thickness of the light-absorbing anisotropic layer P2 of Example 3 was set to 0.8 μm. The visibility-corrected monomer transmittance of the polarizing film was 45%. The thickness of the circularly polarizing plate was 37 μm.

[0583] (Evaluation of display performance)

[0584] By installing the circularly polarizing plate of Example 3 or Example 4 on an organic EL display device in the same manner as in Example 1, the same display performance as in Example 1 was confirmed. Moreover, the thickness of the entire circularly polarizing plate can be reduced, and the yield during the processing of irregular shapes such as curved displays can be improved.

[0585] [Example 5]

[0586] (Production of circularly polarizing plate using high-refractive adhesive)

[0587] The surface side of the optically anisotropic layer (1a) formed on the long cellulose acylate film produced in the same manner as in Example 1 and the surface side of the optically anisotropic layer (1b) of the laminate (1c-1b) formed on the above-mentioned produced long cellulose acylate film were continuously attached using an ultraviolet-curable adhesive. As the ultraviolet-curable adhesive, an adhesive in which a high-refractive monomer was added to an acrylic compound and the refractive index after curing was controlled to 1.53 was used. The difference between the refractive index averaged in the axial direction of the adjacent optically anisotropic layers and the refractive index of the adhesive was within 0.08. The refractive index was controlled, and otherwise, the circularly polarizing plate was produced in the same manner as in Example 1.

[0588] <Example 6>

[0589] A circularly polarizing plate was produced in the same manner as in Example 1 using an ultraviolet-curable adhesive in which the refractive index after curing was controlled to 1.58 by the same method as in Example 5. The difference between the refractive index averaged in the axial direction of the adjacent optically anisotropic layers and the refractive index of the adhesive was within 0.05.

[0590] <Example 7>

[0591] An ultraviolet-curable adhesive in which the refractive index was controlled to 1.53 was prepared by the same method as in Example 5. The surface of the optically anisotropic layer (1a) of the long phase difference film (1c-1b-1a) produced in Example 5 and the surface of the polarizer of the above-mentioned produced long linear polarizing plate 1 (the side opposite to the side of the polarizer protective film) were continuously attached using an ultraviolet-curable adhesive in which the refractive index after curing was controlled to 1.53. Otherwise, the circularly polarizing plate was produced in the same manner as in Example 5. The difference between the average refractive index of the polarizer and the refractive index of the adhesive was within 0.05.

[0592] (Evaluation of display performance)

[0593] As a result of mounting the polarizing plates of Example 5, Example 6, and Example 7 on an organic EL display device by the same method as in Example 1, the same display performance as in Example 1 was confirmed.

[0594] Explanation of symbols

[0595] 1, 2 - phase difference film, 10, 20 - circularly polarizing plate, 1a, 2a - optically anisotropic layer (A), 1b, 2b - optically anisotropic layer (B), 1c, 2c - optically anisotropic layer (C), 3 - polarizer, 30 - aluminum sheet, 40 - specific laminate.

Claims

1. A circular polarizer comprising a polarizer and a retardation film laminated on one surface side of the polarizer, wherein the water content of the retardation film is 1.8% or less, The circular polarizer and the aluminum sheet are bonded together such that the phase difference film in the circular polarizer is opposite to the aluminum sheet. The chromaticity 'a' is measured at all azimuth angles with a polar angle of 40° from the normal direction of the circular polarizer of the obtained laminate. * and chromaticity b * At any azimuth angle, chromaticity a * absolute value and chromaticity b * The absolute values ​​of all of them are below 10. the reflectance at any azimuth angle is 3.0% or less when the reflectance is measured at all azimuth angles at a polar angle of 40° from the normal direction of the circular polarizer of the laminate, the retardation film comprises an optically anisotropic layer (A), an optically anisotropic layer (B), and an optically anisotropic layer (C), the optically anisotropic layer (A) is an optically anisotropic layer showing negative uniaxiality, the optically anisotropic layer (B) is an optically anisotropic layer in which a rod-like liquid crystal compound in a twisted orientation with a thickness direction as a helical axis is fixed, the optically anisotropic layer (C) is a layer in which a rod-like liquid crystal compound in a vertical orientation or a discotic liquid crystal compound in a horizontal orientation is fixed, the polar angle indicates an angle formed with the normal direction of the circular polarizer, and the azimuth angle indicates an angle formed with an absorption axis of the polarizer, the chromaticity a * and the chromaticity b * denotes the L * a * b * chromaticity in the CIE color system, the reflectance indicates a visibility correction reflectance in a wavelength region of wavelengths of 400 to 750 nm, the reflectance of the aluminum sheet alone is 80 to 90%, the water content of the retardation film is a value measured after conditioning in an environment at a temperature of 25°C and a relative humidity of 60% for 24 hours or more, and the water content is measured by the Karl Fischer method.

2. The circular polarizer of claim 1, wherein, the thickness of the retardation film is 30 μm or less.

3. The circular polarizer of claim 1, wherein, the retardation film is formed by laminating three optically anisotropic layers.

4. The circular polarizer of claim 1, wherein, the retardation film is formed by laminating three optically anisotropic layers, and the optically anisotropic layers are layers in which oriented liquid crystal compounds are fixed.

5. The circular polarizer of claim 1, wherein, the polarizer is formed using a composition comprising a polymerizable liquid crystal compound, the thickness of the polarizer is 8 μm or less.

6. An organic electroluminescent display device having the circular polarizer according to any one of claims 1 to 5.

7. A display device having the circular polarizer according to any one of claims 1 to 5, wherein the circular polarizer is disposed in a manner along a curved surface possessed by the display device.

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