Method for producing optical laminate, method for producing polarizing plate, optical laminate, polarizing plate, and organic electroluminescent display device

Abstract

The present invention addresses the problem of providing: a method for producing an optical laminate which is capable of producing an optical laminate that can suppress the occurrence of interference color unevenness when used in an organic EL display device; the optical laminate; a polarizing plate; an antireflection film; a method for producing an optical laminate according to the present invention comprises a step for directly coating a liquid crystal composition on an optically anisotropic layer (A) in which an oriented liquid crystal compound is fixed, said optically anisotropic layer (A) having a phase difference but not having a lambda / 4 function, said optically anisotropic layer (A) having a phase difference but not having a lambda / 4 function, said optically anisotropic layer (A) satisfying the following requirements 1 or 2, and said optically anisotropic layer (A) having a phase difference but not having a lambda / 4 function. And forming a laminate having a [lambda] / 4 function. Condition 1: The optically anisotropic layer (A) has been surface-treated. Condition 2: The optically anisotropic layer (A) is formed from a liquid crystal composition containing a photo-alignment polymer.

Description

Technical Field

[0001] This invention relates to a method for manufacturing an optical laminate, a method for manufacturing a polarizer, an optical laminate, a polarizer, and an organic electroluminescent display device. Background Technology

[0002] In the past, circular polarizers have been used in organic electroluminescent display devices (hereinafter also referred to as "organic EL display devices") to suppress adverse effects caused by external light reflection. From the perspective of the thinning requirements of the applicable organic EL display devices, the retardation layer contained in the circular polarizer also needs to be thin. For example, Patent Document 1 discloses an optical laminate containing an optically anisotropic layer obtained by polymerizing a polymeric liquid crystal composition, which achieves thinning of the retardation layer. Patent documents

[0003] Patent Document 1: International Publication No. 2022 / 045187 Summary of the Invention The technical problem to be solved by the invention

[0004] Based on our research on the polarizer with an optical laminate described in Patent Document 1, we have confirmed that when viewing an organic EL display device using this polarizer from an oblique angle, uneven thickness occurs in the adhesive layer between the optically anisotropic layers, resulting in visually discernible uneven interference colors under a specific light source. In particular, this problem is clearly observed when a thin adhesive layer with a thickness of approximately a few μm is used. Furthermore, this uneven interference color is visually perceived as unevenness in the form of interference fringes with different hues (hue differences) within the plane.

[0005] The objective of this invention is to provide a method for manufacturing an optical laminate that can suppress interference color inhomogeneity in the tilt direction when used in an organic EL display device. Furthermore, the present invention also aims to provide a method for manufacturing a polarizer, an optical laminate, a polarizer, and an organic electroluminescent display device. means for solving technical problems

[0006] The inventors have discovered that the above-mentioned problems can be solved by the following structure.

[0007] [1] A method for manufacturing an optical laminate includes the following steps: directly coating a liquid crystal composition that forms an optical anisotropic layer (B) that does not have a λ / 4 function but has a phase difference onto an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies the following necessary conditions 1 or 2 and does not have a λ / 4 function, so as to form a laminate with a λ / 4 function. Necessary condition 1: The above-mentioned optical anisotropic layer (A) has undergone surface treatment. Necessary condition 2: The above-mentioned optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer. [2] The manufacturing method of the optical laminate according to [1], wherein the optical anisotropic layer (A) is a negative uniaxial optical anisotropic layer. [3] The method for manufacturing an optical laminate according to [1] or [2], wherein the optical anisotropic layer (B) is an optical anisotropic layer formed by fixing a twisted and oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis. [4] A method for manufacturing an optical laminate according to any one of [1] to [3], comprising: a step of forming a C-plate by directly coating a liquid crystal composition for further forming a C-plate onto the laminate, or a step of bonding the C-plate via an adhesive layer. [5] A method for manufacturing a polarizer, wherein a polarizer is obtained by laminating an optical laminate obtained by the method for manufacturing an optical laminate as described in any one of [1] to [4] with a polarizer. [6] An optical laminate, wherein an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies the following necessary conditions 1 or 2 and does not have λ / 4 function but has a phase difference, an optical anisotropic layer (B) which does not have λ / 4 function but has a phase difference, an adhesive layer 2 and a plate C are arranged sequentially adjacent to each other, and the plate has λ / 4 function. Necessary condition 1: The above-mentioned optical anisotropic layer (A) has undergone surface treatment. Necessary condition 2: The above-mentioned optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer. [7] The optical laminate according to [6], wherein the adhesive layer 2 has a refractive index of 1.53 to 1.64. [8] The optical laminate according to [6] or [7], wherein silicon is present at the interface between the optical anisotropic layer (A) and the optical anisotropic layer (B). [9] A polarizer, wherein a polarizer, an adhesive layer 1, an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound and satisfying either of the following necessary conditions 1 or 2 and having a phase difference but not having a λ / 4 function, an optical anisotropic layer (B) having a phase difference but not having a λ / 4 function, an adhesive layer 2, and a C plate are arranged sequentially adjacent to each other, and the laminate of the optical anisotropic layer (A) and the optical anisotropic layer (B) has a λ / 4 function. Necessary condition 1: The above-mentioned optical anisotropic layer (A) has undergone surface treatment. Necessary condition 2: The above-mentioned optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer.

[10] An organic electroluminescent display device having an optical laminate as described in any one of [6] to [8].

[11] An organic electroluminescent display device having the polarizer described in [9]. Invention Effects

[0008] According to the present invention, a method for manufacturing an optical laminate is provided that can suppress interference color inhomogeneity in the tilt direction when used in an organic EL display device. Furthermore, according to the present invention, a method for manufacturing a polarizer, an optical laminate, a polarizer, and an organic electroluminescent display device can be provided. Attached Figure Description

[0009] Figure 1 This is an example of a schematic cross-sectional view of one embodiment of the polarizer of the present invention. Figure 2 This is a diagram showing the relationship between the absorption axis of the polarizer and the in-plane slow axes of the optical anisotropic layer (A) and the optical anisotropic layer (B) in one embodiment of the polarizer of the present invention. Figure 3 It means from Figure 1 A schematic diagram showing the angular relationship between the absorption axis of the polarizer and the in-plane slow axes of the optical anisotropic layers (A) and (B) when viewed in the direction of the white arrow. Detailed Implementation

[0010] The present invention will now be described in detail. The following description of the necessary conditions is based on a representative embodiment of the present invention, but the present invention is not limited to this embodiment. In addition, in this specification, the numerical range indicated by “~” refers to the range contained within the values ​​recorded before and after “~” as the lower and upper limits. Furthermore, in this specification, each component may be described using only one substance corresponding to that component, or two or more substances may be used simultaneously. Where two or more substances are used as components, unless otherwise specified, the content of each component refers to the total content of the substances used simultaneously. Furthermore, in this specification, "(meth)acrylic acid" is a term that means "acrylic acid" or "methacrylic acid", and "(meth)acryloyl" is a term that means "acryloyl" or "methacryloyl". Next, the terminology used in this specification will be explained.

[0011] Unless otherwise specified, the slow axis is defined in this specification based on a wavelength of 550 nm.

[0012] In this specification, Re(λ) and Rth(λ) represent the in-plane delay and the thickness direction delay at wavelength λ, respectively. Unless otherwise specified, wavelength λ is set to 550 nm. In this invention, Re(λ) and Rth(λ) are values ​​obtained by measurement at wavelength λ using an AxoScan (manufactured by Axometrics). The following values ​​are calculated by inputting the average refractive index ((nx+ny+nz) / 3) and film thickness (d(μm)) into the AxoScan: Slow axis direction (°); Re(λ) = R0(λ); and Rth(λ)=((nx+ny) / 2-nz)×d. In addition, R0(λ) is represented by the numerical value calculated by AxoScan, which refers to Re(λ).

[0013] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by ATAGO CO.,LTD.) and a sodium lamp (λ=589nm) as the light source. Furthermore, when measuring wavelength dependence, measurements can be performed using a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO.,LTD.) in combination with an interference filter. Furthermore, values ​​from the Polymer Handbook (JOHN WILEY & SONS, INC) and various optical film catalogs can be used. The following examples illustrate the average refractive index values ​​for major optical films: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0014] In this specification, "light" refers to activated light or radiation, such as the bright-line spectrum of a mercury lamp, far-ultraviolet light represented by an excimer laser, extreme ultraviolet (EUV) light, X-rays, ultraviolet light, and electron beams (EB). Among these, ultraviolet light is preferred.

[0015] In this specification, "visible light" refers to light in the range of 380–780 nm. Furthermore, unless otherwise specified, the measurement wavelength is 550 nm. Furthermore, in this specification, the angular relationships (e.g., "orthogonal", "parallel", etc.) are included within the permissible range of error in the technical field to which this invention pertains. Specifically, this means that the error from the strict angle is preferably within ±10°, and more preferably within ±5° or less, and more preferably within ±3° or less.

[0016] In this specification, the horizontal orientation of a rod-shaped liquid crystal compound refers to the state in which the long axis of the liquid crystal compound is horizontal relative to the layer surface and arranged in the same orientation. The term "horizontal" is not strictly required to be horizontal, but rather refers to the orientation in which the average molecular axis of the liquid crystal compound within the layer forms an angle of inclination of less than 20° with the surface of the layer. Furthermore, the same orientation is not strictly required to be the same orientation. Rather, it means that when the orientation of the slow axis is measured at any 20 locations in the plane, the maximum difference between the orientations of the slow axis at the 20 locations (the difference between the two slow axis orientations with the largest difference among the 20 slow axis orientations) is less than 10°. The vertical orientation of a disk-shaped liquid crystal compound refers to the state in which the disk axis of the liquid crystal compound is perpendicular to the layer surface and arranged in the same orientation. The term "vertical" does not strictly require absolute verticality, but rather refers to the orientation where the disk surface of the liquid crystal compound within the layer forms an inclination angle of 70 to 110° with the surface of the layer. Furthermore, the same orientation is not strictly required to be the same orientation. Rather, it means that when the orientation of the slow axis is measured at any 20 locations in the plane, the maximum difference between the orientations of the slow axis at the 20 locations (the difference between the two slow axis orientations with the largest difference among the 20 slow axis orientations) is less than 10°.

[0017] In this specification, an optically anisotropic layer refers to a layer formed by fixing oriented liquid crystal compounds. Furthermore, the "fixed" state refers to the state in which the orientation of the liquid crystal compound is maintained. More specifically, it is a state in which there is no fluidity in the layer within a temperature range of -30 to 70°C under more severe conditions, and the fixed orientation shape can be stably maintained without being affected by external fields or external forces.

[0018] The subject of this invention, namely interference color inhomogeneity, is as follows: When a polarizer, an optical anisotropic layer (A) without λ / 4 function but with phase difference, and an optical anisotropic layer (B) without λ / 4 function but with phase difference are sequentially arranged, and an adhesive layer exists between the optical anisotropic layer (A) and the optical anisotropic layer (B), light incident from the polarizer side is reflected at the interface between the adhesive layer and the optical anisotropic layer, and passes through the polarizer again, thereby being visually perceived as interference color inhomogeneity. If interference color inhomogeneity occurs, even if λ / 4 function is expressed in two or more optical anisotropic layers and arranged as circular polarizers on an organic EL display device, a color tone change will occur when displaying black under a specific light source. In this invention, a manufacturing method for forming an optical anisotropic layer (B) is used, which involves directly coating an optical anisotropic layer (A) with a liquid crystal composition to form an optical anisotropic layer (B). By suppressing interface reflections generated at the interface between the optical anisotropic layer (A) and the optical anisotropic layer (B), interference color inhomogeneity is reduced.

[0019] [Optical laminate] The optical laminate of the present invention will now be described in detail.

[0020] The optical laminate of the present invention is an optical laminate manufactured by a method for manufacturing an optical laminate, the method comprising the following steps: directly coating a liquid crystal composition forming an optical anisotropic layer (B) that does not have a λ / 4 function but has a phase difference onto an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies either of the following necessary conditions 1 or 2 and does not have a λ / 4 function, thereby forming a laminate with a λ / 4 function. That is, the optical laminate of the present invention is a laminate in which an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies either of the following necessary conditions 1 or 2 and does not have a λ / 4 function but has a phase difference, and an optical anisotropic layer (B) that does not have a λ / 4 function but has a phase difference, are arranged adjacent to each other and have a λ / 4 function. Necessary condition 1: The optical anisotropic layer (A) has been surface treated. Necessary condition 2: The optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer. Hereinafter, the optical anisotropic layer (A) of the present invention will sometimes be referred to as a specific optical anisotropic layer (A), and the optical anisotropic layer (B) of the present invention will sometimes be referred to as a specific optical anisotropic layer (B). Specifically, the λ / 4 function refers to the ability to convert linearly polarized light of a specific wavelength into circularly polarized light (or to convert circularly polarized light into linearly polarized light).

[0021] [Optical anisotropy layer (A)] The optical anisotropic layer (A) of the present invention is an optical anisotropic layer that does not have a λ / 4 function but has a phase difference, formed by fixing an oriented liquid crystal compound and satisfying the following necessary conditions 1 or 2. Necessary condition 1: The optical anisotropic layer (A) has been surface treated. Necessary condition 2: The optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer.

[0022] Here, liquid crystal compounds can be classified into rod-shaped and disc-shaped types according to their shape. Furthermore, they can be categorized into low-molecular-weight and high-molecular-weight types. Generally, a high-molecular-weight compound refers to a compound with a degree of polymerization of 100 or more (Polymer Physics • Phase Transition Dynamics, Masao Doi, p. 2, Iwanami Shoten, 1992). In this invention, any liquid crystal compound can be used, but rod-shaped or disc-shaped liquid crystal compounds (disc-shaped liquid crystal compounds) are preferred. Moreover, liquid crystal compounds with relatively low molecular weight, either monomeric or with a degree of polymerization of less than 100, are preferred. Furthermore, from the viewpoint of fixing the orientation, liquid crystal compounds preferably have polymerizable groups. Examples of such polymerizable groups include acryloyl, methacryloyl, epoxy, and vinyl groups. Hereinafter, liquid crystal compounds having polymerizable groups will be simply referred to as "polymerizable liquid crystal compounds". By polymerizing this polymerizable liquid crystal compound, the orientation of the liquid crystal compound can be fixed. Furthermore, after the liquid crystal compound is fixed through polymerization, it is no longer necessary to exhibit liquid crystal properties.

[0023] As rod-shaped liquid crystal compounds, imine derivatives, azo derivatives, cyanobiphenyl derivatives, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexane derivatives, cyano-substituted phenylpyrimidine derivatives, alkoxy-substituted phenylpyrimidine derivatives, phenyl dioxane derivatives, diphenylacetylene derivatives, and alkenylcyclohexylbenzylnitrile derivatives are preferred. The immobilization of these rod-shaped liquid crystal compounds can be achieved by introducing polymerizable groups (similar to those in the disc-shaped liquid crystals described later) into the end structure of the rod-shaped liquid crystal compound and utilizing the polymerization and curing reaction. As a specific example, Japanese Patent Application Publication No. 2006-209073 discloses an example of ultraviolet curing of a polymerizable nematic rod-shaped liquid crystal compound. Furthermore, not only the aforementioned low-molecular-weight liquid crystal compounds can be used, but also high-molecular-weight liquid crystal compounds. The high-molecular-weight liquid crystal compound is a polymer having side chains equivalent to those of the low-molecular-weight liquid crystal compounds described above. Optical compensation sheets using high-molecular-weight liquid crystal compounds are described in Japanese Patent Application Publication No. 5-53016, etc.

[0024] As disc-shaped liquid crystal compounds, these include benzene derivatives described in the research reports of C. Destrade et al., Mol. Cryst., Vol. 71, p. 111 (1981); Truxene derivatives described in the research reports of C. Destrade et al., Mol. Cryst., Vol. 122, p. 141 (1985); Physicslett. A., Vol. 78, p. 82 (1990); Cyclohexane derivatives described in the research reports of B. Kohne et al., Angew. Chem., Vol. 96, p. 70 (1984); and azacrown or phenylacetylene macrocycles described in the research reports of J. M. Lehn et al., J. Chem. Commun., p. 1794 (1985); J. Zhang et al., J. Am. Chem. Soc., Vol. 116, p. 2655 (1994).

[0025] As molecules of disk-shaped liquid crystal compounds, these compounds also contain a parent nucleus at the molecular center, with straight-chain alkyl, alkoxy, or substituted benzoyloxy side chains radially substituted as the parent nucleus, exhibiting liquid crystal properties. The molecules or aggregates of molecules are preferably compounds possessing rotational symmetry and capable of imparting a predetermined orientation. In an optically anisotropic layer formed from a composition containing a disk-shaped liquid crystal compound, the disk-shaped liquid crystal compound does not need to exhibit liquid crystal properties in its final state contained within the optically anisotropic layer. For example, if low-molecular-weight disk-shaped liquid crystal molecules having groups that react with heat or light are polymerized through heating or light irradiation to increase their molecular weight, although they lose their liquid crystal properties, the optically anisotropic layer containing the polymerized compound can still be used in this invention. Preferred examples of disk-shaped liquid crystal compounds include the compounds described in Japanese Patent Application Publication No. 8-050206. Furthermore, the polymerization of disk-shaped liquid crystal molecules is described in Japanese Patent Application Publication No. 8-027284.

[0026] One method for fixing disc-shaped liquid crystal molecules by polymerization is to polymerize a polymerizable group as a substituent with the disc-shaped core of the disc-shaped liquid crystal molecule. The disc-shaped core and the polymerizable group are preferably compounds bonded via a linker, thereby maintaining their orientation even during the polymerization reaction. Examples of disc-shaped liquid crystal molecules having polymerizable groups include compounds described in paragraphs

[0151] to

[0168] of Japanese Patent Application Publication No. 2000-155216.

[0027] In this invention, from the viewpoint of improving the hue in the tilt direction, the optical anisotropy layer (A) is preferably a negative uniaxial optical anisotropy layer, and more preferably an optical anisotropy layer formed by fixing a vertically oriented disk-shaped liquid crystal compound.

[0028] Furthermore, the in-plane retardation of the optical 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 further suppressing the black coloring when visually recognizing the organic EL display device with the optical laminate of the present invention in the front or tilt direction (hereinafter also simply referred to as "the viewpoint of further suppressing the black coloring").

[0029] Furthermore, from the viewpoint of improving refractive index anisotropy and thin-film fabrication, the refractive index of the optical anisotropy layer (A) is preferably 1.50 or higher and 1.70 or lower, more preferably 1.55 or higher and 1.65 or lower. The above refractive index is the refractive index at a wavelength of 550 nm.

[0030] In this invention, the angle between the in-plane slow axis of the optical anisotropic layer (A) and the absorption axis of the polarizer is preferably 40-85°, more preferably 50-85°, and even more preferably 65-85°.

[0031] When the optical laminate of the present invention is elongated, the angle between the length direction of the optical laminate and the in-plane slow axis of the optical anisotropic layer (A) is preferably 40 to 85°, more preferably 50 to 85°, and even more preferably 65 to 85°.

[0032] The thickness of the optical anisotropic layer (A) is preferably 0.5 μm or more, more preferably 0.8 μm or more, and even more preferably 1.0 μm or more. Furthermore, the thickness of the optical anisotropic layer (A) is preferably 5.0 μm or less, more preferably 4.0 μm or less, and even more preferably 3.0 μm or less. The aforementioned thickness was determined by measuring the thickness of any 5 or more points of the optical anisotropic layer (A) and averaging them.

[0033] [Optical Anisotropy Layer (B)] The optical anisotropic layer (B) of the optical laminate of the present invention is a layer formed using the liquid crystal composition described later, and has an optical anisotropic layer formed by fixing an oriented liquid crystal compound. Regarding liquid crystal compounds, examples can be given that are the same liquid crystal compounds described in the optical anisotropy layer (A) above.

[0034] In this invention, from the viewpoint of improving reflectivity and hue in the tilt direction, the optical anisotropic layer (B) is more preferably composed of an optical anisotropic layer formed by fixing a rod-shaped liquid crystal compound with a twisted orientation along the thickness direction as the helical axis.

[0035] As described above, the optical anisotropic layer (B) is preferably an optical anisotropic layer formed by fixing a twisted, oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis, that is, a layer formed by fixing a chiral filamentary phase having a so-called helical structure. Furthermore, when forming the above layer, it is preferable to use a liquid crystal composition formed by mixing a liquid crystal compound that displays a nematic liquid crystal phase with a chiral reagent described later.

[0036] The product of the refractive index anisotropy Δn of the optical anisotropy layer (B) and the thickness d of the optical anisotropy layer (B), measured at a wavelength of 550 nm, is preferably 140 to 220 nm. From the viewpoint of further suppressing black coloring, it is more preferably 150 to 210 nm, and even more preferably 160 to 200 nm. In addition, refractive index anisotropy Δn refers to the refractive index anisotropy of the optical anisotropic layer. Regarding the above method for measuring Δnd, the AxoScan (polarimeter) device from Axometrics was used, and the device analysis software from Axometrics was used for the measurement.

[0037] The twist angle of the liquid crystal compound (the twist angle of the orientation direction of the liquid crystal compound) is preferably 90±30° (in the range of 60 to 120°), and more preferably 90±20° (in the range of 70 to 110°) from the viewpoint of further suppressing black coloring, and even more preferably 90±10° (in the range of 80 to 100°). In addition, regarding the method for measuring the torsion angle, the AxoScan (polarimeter) device from Axometrics Corporation was used, and the device analysis software from Axometrics Corporation was used for the measurement. Furthermore, the twisted orientation of the liquid crystal compound refers to the twisting of the liquid crystal compound from one main surface of the optically anisotropic layer (B) to another main surface, with the thickness direction of the optically anisotropic layer (B) as the axis. At the same time, the orientation direction (in-plane slow axis direction) of the liquid crystal compound varies depending on its position in the thickness direction of the optically anisotropic layer (B).

[0038] The angle between the in-plane slow axis of the optical anisotropic layer (A) and the in-plane slow axis on the surface of the optical anisotropic layer (B) on the side of the optical anisotropic layer (A) is preferably 0 to 20°, more preferably 0 to 15°.

[0039] The thickness of the optical anisotropic layer (B) is not particularly limited, but is preferably 0.5 μm or more, more preferably 0.8 μm or more, and even more preferably 1.0 μm or more. Furthermore, the thickness of the optical anisotropic layer (B) is preferably 5.0 μm or less, more preferably 3.0 μm or less, and even more preferably 2.5 μm or less. The aforementioned thickness was determined by measuring the thickness of any 5 or more points of the optical anisotropic layer (B) and taking the arithmetic mean of them.

[0040] (Chiral agent) As chiral reagents used in the formation of the twisted orientation of liquid crystal compounds, various known chiral reagents can be utilized. Chiral reagents have the function of inducing the helical structure of liquid crystal compounds. The direction of helix or the helical pitch induced varies depending on the compound; therefore, the chiral compound can be selected according to the desired outcome. As a chiral reagent, known compounds can be used, and compounds having a cinnamon yl group are preferred. Examples of chiral reagents include compounds described in the Liquid Crystal Device Handbook (Chapter 3, Items 4-3, TN and STN using chiral reagents, page 199, edited by Committee 142 of the Japanese Society for the Promotion of Science, 1989), Japanese Patent Application Publication Nos. 2003-287623, 2002-302487, 2002-080478, 2002-080851, 2010-181852, and 2014-034581.

[0041] Chiral reagents typically contain a chiral carbon atom, but axially chiral or planar chiral compounds that do not contain a chiral carbon atom can also be used as chiral reagents. Examples of axially chiral or planar chiral compounds include binaphthyl, helicene, p-xylene dimers, and their derivatives. Chiral reagents can have polymerizable groups. When both the chiral reagent and the liquid crystal compound have polymerizable groups, a polymer having repeating units derived from the polymerizable liquid crystal compound and repeating units derived from the chiral reagent can be formed through the polymerization reaction of the chiral reagent and the polymerizable liquid crystal compound. In this manner, the polymerizable chiral reagent preferably possesses the same polymerizable group as the polymerizable liquid crystal compound. Therefore, the polymerizable group of the chiral reagent is preferably an unsaturated polymerizable group, an epoxy group, or an acridine group, more preferably an unsaturated polymerizable group, and especially preferably an olefinic unsaturated polymerizable group. Furthermore, the chiral reagent can be a liquid crystal compound.

[0042] As chiral reagents, isosorbide derivatives, isomannitol derivatives, and binaphthyl derivatives are preferred. For isosorbide derivatives, commercially available products such as BASF's LC-756 can be used. The content of the chiral reagent in the liquid crystal composition is preferably 0.01 to 200 mol% of the liquid crystal compound, more preferably 1 to 30 mol%.

[0043] [Optical Anisotropy Layer (C)] The optical laminate of the present invention preferably further comprises an optical anisotropic layer (C). The optical anisotropic layer (C) is preferably a C-plate. More preferably, it is a layer formed by fixing vertically oriented rod-shaped liquid crystal compounds and is a positive C-plate. Furthermore, a C-plate refers to a plate that satisfies either equation (C1) or equation (C2) when the refractive index along the slow axis in the plane is set to nx, the refractive index along the direction orthogonal to the slow axis in the plane is set to ny, and the refractive index along the thickness direction is set to nz. A plate satisfying equation (C1) is called a positive C-plate, and a plate satisfying equation (C2) is called a negative C-plate. Additionally, the refractive index (Rth) of a positive C-plate is negative, while that of a negative C-plate is positive. Equation (C1) nz>nx≈ny Equation (C2) nz<nx≈ny Furthermore, the “≈” above refers not only to cases where the two are completely identical, but also to cases where they are substantially identical. “Substantially identical” includes, for example, cases where (nx-ny)×d (where d is the film thickness) is 0–10 nm, preferably 0–5 nm, also included in “nx≈ny”.

[0044] The in-plane retardation of the optical anisotropic layer (C) at a wavelength of 550 nm is preferably 0 to 10 nm. From the viewpoint of further suppressing black coloration, the aforementioned in-plane delay is more preferably 0 to 5 nm. Furthermore, the thickness retardation of the optical anisotropic layer (C) at a wavelength of 550 nm is preferably -120 to -20 nm. From the viewpoint of further suppressing black coloring, the aforementioned retardation in the thickness direction is more preferably -110 to -30 nm, and more preferably -100 to -40 nm.

[0045] The thickness of the optical anisotropic layer (C) is not particularly limited, but is preferably 0.2 μm or more, more preferably 0.3 μm or more, and even more preferably 0.5 μm or more. Furthermore, the thickness of the optical anisotropic layer (B) is preferably 4.0 μm or less, more preferably 3.0 μm or less, and even more preferably 2.0 μm or less. The aforementioned thickness was determined by measuring the thickness of any 5 or more points of the optical anisotropic layer (C) and averaging them.

[0046] When the optical laminate of the present invention has an optical anisotropic layer (C), the stacking order of each layer is not particularly limited, but it is preferable to stack the optical anisotropic layer (A), the optical anisotropic layer (B) and the optical anisotropic layer (C) in sequence.

[0047] The optical laminate of the present invention preferably has an optically anisotropic layer (A) formed by fixing a vertically oriented disk-shaped liquid crystal compound, an optically anisotropic layer (B) formed by fixing a twisted, rod-shaped liquid crystal compound with the thickness direction as the helical axis, and an optically anisotropic layer (C) formed by fixing a vertically oriented rod-shaped liquid crystal compound (hereinafter referred to as "specific mode").

[0048] use Figures 1-3 An example of a polarizer having the aforementioned specific configuration of an optical laminate will be described. Figure 1 This is a schematic cross-sectional view of one embodiment of the polarizer 100. and, Figure 2 It means Figure 1 A diagram showing the relationship between the absorption axis of the polarizer 20 in the polarizer 100 and the in-plane slow axes of the optical anisotropic layers (A) 12 and (B) 14. Additionally, Figure 2 The arrow in polarizer 20 indicates the absorption axis, and the arrows in optical anisotropic layer (A) 12 and optical anisotropic layer (B) 14 indicate the in-plane slow axis in each layer. and, Figure 3 It means from Figure 1 The white arrows show the angular relationship between the absorption axis (dashed line) of polarizer 20 and the in-plane slow axes (solid lines) of optical anisotropic layer (A) 12 and optical anisotropic layer (B) 14 when observed. In addition, from Figure 1 When observed with the white arrow in the diagram, the rotation angle of the slow axis in the plane is represented by the absorption axis of the polarizer 20 (0°), with a positive angle value in the counterclockwise direction and a negative angle value in the clockwise direction. Furthermore, from Figure 1 When observing the hollow arrow, the twisting direction of the liquid crystal compound is determined by the in-plane slow axis on the surface of the near front side (polarizer 20 side) of the optical anisotropy layer (B) 14, and whether it is right twist (clockwise) or left twist (counterclockwise).

[0049] like Figure 1 As shown, the polarizer 100 sequentially comprises a polarizer 20, an optical anisotropic layer (A) 12, an optical anisotropic layer (B) 14, and an optical anisotropic layer (C) 16. Furthermore, in the optical laminate of the present invention, the optical anisotropic layer (A) 12 and the optical anisotropic layer (B) 14 are directly stacked. Layers (e.g., adhesive layers) not shown may be present between the optical anisotropic layer (B) 14 and the optical anisotropic layer (C) 16, and between the polarizer 20 and the optical anisotropic layer (A). like Figures 2-3As shown, the angle between the absorption axis of the polarizer 20 and the in-plane slow axis of the optical anisotropic layer (A) 12 is... a1 is 76°. More specifically, the in-plane slow axis of the optical anisotropy layer (A) 12 is rotated -76° (76° clockwise) relative to the absorption axis of the polarizer 20. Additionally, in Figures 2-3 The diagram shows the in-plane slow axis of the optical anisotropy layer (A) 12 located at -76°, but the invention is not limited to this configuration. Preferably, the angle is in the range of -40 to -85°, more preferably in the range of -50 to -85°, and even more preferably in the range of -65 to -85°. That is, the angle between the absorption axis of the polarizer 20 and the in-plane slow axis of the optical anisotropy layer (A) 12 is preferably in the range of 40 to 85°, more preferably in the range of 50 to 85°, and even more preferably in the range of 65 to 85°. In addition, such as Figure 2 As shown, in the optical anisotropy layer (A) 12, the in-plane slow axis on the surface 121 on the polarizer 20 side of the optical anisotropy layer (A) 12 is parallel to the in-plane slow axis on the surface 122 on the optical anisotropy layer (B) 14 side of the optical anisotropy layer (A) 12.

[0050] like Figures 2-3 As shown, the in-plane slow axis of the optical anisotropic layer (A) 12 is parallel to the in-plane slow axis on the surface 141 of the optical anisotropic layer (B) 14 on the side of the optical anisotropic layer (A) 12. Furthermore, the present invention is not limited to this method, and the angle between the in-plane slow axis of the optical anisotropic layer (A) 12 and the in-plane slow axis on the surface 141 of the optical anisotropic layer (B) 14 on the side of the optical anisotropic layer (A) 12 is preferably in the range of 0 to 20°. As described above, the optical anisotropic layer (B) 14 is an optical anisotropic layer formed by fixing a twisted, oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis. Therefore, as Figures 2-3 As shown, the in-plane slow axis on the surface 141 of the optical anisotropy layer (B) 14 on the side of the optical anisotropy layer (A) 12 forms the aforementioned twist angle with the in-plane slow axis on the surface 142 of the optical anisotropy layer (B) 14 on the side opposite to the optical anisotropy layer (A) 12. (Furthermore,) Figure 2 The angle is 81°. That is, the angle between the in-plane slow axis on the surface 141 of the optical anisotropy layer (B) 14 on the side of the optical anisotropy layer (A) 12 and the in-plane slow axis on the surface 142 of the optical anisotropy layer (B) 14 on the side opposite to the optical anisotropy layer (A) 12. 2 is 81°. More specifically, the rod-shaped liquid crystal compound in the optical anisotropy layer (B) 14 is twisted to the left (counterclockwise) with a twist angle of 81°. In addition, Figures 2-3 The diagram shows a twist angle of 81° for the rod-shaped liquid crystal compound in the optical anisotropy layer (B) 14, but it is not limited to this method. As mentioned above, the twist angle of the rod-shaped liquid crystal compound is preferably in the range of 80 ± 30°. That is, the angle between the in-plane slow axis on the surface 141 of the optical anisotropy layer (B) 14 on the side of the optical anisotropy layer (A) 12 and the in-plane slow axis on the surface 142 of the optical anisotropy layer (B) 14 on the side opposite to the optical anisotropy layer (A) 12 is preferably in the range of 80 ± 30°.

[0051] As mentioned above, in Figures 2-3 In this method, when the polarizer 100 is observed from the polarizer 20 side, with the absorption axis of the polarizer 20 as the reference, the in-plane slow axis of the optical anisotropic layer (A) 12 is rotated 81° clockwise, and the twisting direction of the rod-shaped liquid crystal compound in the optical anisotropic layer (B) 14 is counterclockwise (left twist). exist Figures 2-3 The text describes in detail the method of counterclockwise twisting of the rod-shaped liquid crystal compound, but clockwise twisting is also possible as long as the specified angular relationship is met. More specifically, it can also be done as follows: when observing the antireflective film 100 from the polarizer 20 side, with the absorption axis of the polarizer 20 as the reference, the in-plane slow axis of the optical anisotropy layer (A) 12 is rotated 81° counterclockwise, and the twisting direction of the rod-shaped liquid crystal compound in the optical anisotropy layer (B) 14 is clockwise (right twist).

[0052] That is, in Figure 1 In the polarizer 100 shown, when the antireflective film 100 is viewed from the polarizer 20 side, with the absorption axis of the polarizer 20 as a reference, and the in-plane slow axis of the optical anisotropic layer (A) rotating clockwise in the range of 40 to 85° (preferably 50 to 85°, more preferably 65 to 85°), with the in-plane slow axis on the surface of the optical anisotropic layer (B) on the optical anisotropic layer (A) side as a reference, preferably the twisting direction of the rod-shaped liquid crystal compound in the optical anisotropic layer (B) is counterclockwise. Furthermore, in Figure 1In the polarizer 100 shown, when the polarizer 100 is viewed from the polarizer 20 side, with the absorption axis of the polarizer 20 as a reference, and the in-plane slow axis of the optical anisotropy layer (A) rotating counterclockwise within the range of 40 to 85° (preferably 50 to 85°, more preferably 65 to 85°), with the in-plane slow axis on the surface of the optical anisotropy layer (B) on the side of the optical anisotropy layer (A) as a reference, it is preferable that the twisting direction of the rod-shaped liquid crystal compound in the optical anisotropy layer (B) is clockwise. Furthermore, even when the twisting direction of the rod-shaped liquid crystal compound in the optical anisotropy layer (B) is clockwise, the angle between the in-plane slow axis of the optical anisotropy layer (A) and the in-plane slow axis on the surface of the optical anisotropy layer (B) on the side of the optical anisotropy layer (A) is preferably within the range of 0 to 20°.

[0053] [Adhesive layer] The optical laminate of the present invention may, for example, have an adhesive layer or bonding agent layer between the polarizer and the optical anisotropic layer (A), or between the optical anisotropic layer (B) and the optical anisotropic layer (C). Known adhesive layers and bonding agent layers can be cited as examples of adhesive layers.

[0054] As described in Japanese Patent Application Publication No. 11-149015, generally, from the viewpoint of suppressing reflection by adjusting the refractive index between layers, the refractive index of the adhesive or binder in forming each layer of the laminated waveplate or circular polarizer is preferably adjusted. The refractive index difference with the bonded 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. From the viewpoint of suppressing interference color inhomogeneity in the tilt direction when applied to organic EL display devices, the refractive index of the adhesive layer is preferably 1.50 to 1.70, more preferably 1.53 to 1.64. The above refractive index is the refractive index at a wavelength of 550 nm.

[0055] When configured between layers of an optically anisotropic layer using liquid crystal compounds, a high-refractive-index adhesive or bonding agent can be used. To improve the refractive index, it is preferable to use high-refractive-index monomers or high-refractive-index metal particles. As a high-refractive-index monomer, it is preferred to have a benzene ring skeleton in the molecule. Examples of monofunctional monomers having a benzene ring skeleton in the molecule include ethoxylated o-phenylphenol ester (meth)acrylate, o-phenylphenol glycidyl ether (meth)acrylate, p-cumylphenoxyethylene glycol ester (meth)acrylate, 2-methacryloyloxyethyl phthalate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, 2-acryloyloxypropyl phthalate, phenoxyethyl ester (meth)acrylate, EO-modified phenol ester (meth)acrylate, phenoxydiethylene glycol ester (meth)acrylate, EO-modified nonylphenol ester (meth)acrylate, PO-modified nonylphenol ester (meth)acrylate, phenyl glycidyl ether (meth)acrylate, neopentyl glycol benzoate (meth)acrylate, nonylphenoxy polyethylene glycol ester (meth)acrylate, ECH-modified phenoxy ester (meth)acrylate, benzyl acrylate (meth)acrylate, and vinylcarbazole, etc. Examples of components constituting inorganic particles include metal oxides, metal nitrides, metal oxynitrides, and elemental metals. Examples of metal atoms contained in the aforementioned metal oxides, metal nitrides, metal oxynitrides, and elemental metals include titanium atoms, silicon atoms, aluminum atoms, cobalt atoms, and zirconium atoms. Specific examples of inorganic particles include alumina particles, alumina hydrate particles, silica particles, zirconium oxide particles, and inorganic oxide particles such as clay minerals (e.g., montmorillonite). From the viewpoint of refractive index, zirconium oxide microparticles are preferred. By changing the amount of inorganic particles, a predetermined refractive index can be achieved. When zirconium oxide is used as the main component, the average particle size of the inorganic particles in the layer is preferably 1–120 nm, more preferably 1–60 nm, and more preferably 2–40 nm.

[0056] There is no particular limitation on the thickness of the adhesive layer, but it is preferably 0.5 μm or more, and more preferably 0.8 μm or more. Furthermore, the thickness of the adhesive layer is often 50 μm or less, preferably 20 μm or less, and more preferably 5 μm or less. The thickness was determined by observing the cross-section of the adhesive layer using SEM (Scanning Electron Microscope).

[0057] In the optical laminate of the present invention, it is preferable that the optical anisotropic layer (A), the optical anisotropic layer (B), the adhesive layer 2 and the C plate are arranged adjacent to each other in sequence, or that the optical anisotropic layer (A), the optical anisotropic layer (B) and the C plate are arranged adjacent to each other in sequence, and more preferably that the optical anisotropic layer (A), the optical anisotropic layer (B), the adhesive layer 2 and the C plate are arranged adjacent to each other in sequence. The adhesive layer 2 is used to bond the optical anisotropic layer (B) to the C plate. The specific examples and preferred methods are the same as those of the adhesive layer.

[0058] The optical laminate of the present invention preferably contains silicon at the interface between the optical anisotropic layer (A) and the optical anisotropic layer (B). Specifically, the presence of silicon at the interface means that silicon is present on at least one of the surfaces of the optical anisotropic layer (A) on the side of the optical anisotropic layer (B) and the optical anisotropic layer (B) on the side of the optical anisotropic layer (A), and preferably silicon is present on at least the surface of the optical anisotropic layer (A) on the side of the optical anisotropic layer (B). There are no particular limitations on the form of silicon; for example, some of the components (e.g., surfactants described later) in each optical anisotropic layer and their decomposition products or reactants can be cited. The presence of silicon in the interface can be confirmed, for example, by measuring the exposed interface using X-ray photoelectron spectroscopy. As a method for having silicon present at the aforementioned interface, one example is the method of forming an optical anisotropic layer (A) using a liquid crystal composition containing silicon atoms.

[0059] The thickness of the optical laminate of the present invention is not particularly limited, but is preferably 2.0 μm or more, more preferably 3.0 μm or more, and even more preferably 3.5 μm or more. Furthermore, the thickness of the optical laminate is often 15.0 μm or less, preferably 10.0 μm or less, and more preferably 5.0 μm or less. The thickness was determined by observing the cross-section of the laminate using SEM.

[0060] [Manufacturing method of optical laminates] The method for manufacturing the optical laminate of the present invention will be described in detail. The method for manufacturing the optical laminate of the present invention includes the following steps: directly coating a liquid crystal composition that forms an optical anisotropic layer (B) without λ / 4 function but with phase difference on an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies the following necessary conditions 1 or 2 and does not have λ / 4 function but has phase difference, to form a laminate with λ / 4 function. Necessary condition 1: The optical anisotropic layer (A) has been surface treated. Necessary condition 2: The optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer. The specific steps are explained below. First, an optically anisotropic layer (A) is formed by coating a liquid crystal composition onto a support (preferably a strip support). Here, it is necessary to impart the function of orienting the optically anisotropic layer (B) formed thereon to the optically anisotropic layer (A). Methods for imparting this orientation function to the optically anisotropic layer (A) include a method of surface treatment after forming the optically anisotropic layer (A) (necessary condition 1: the optically anisotropic layer (A) has been surface treated.) and a method of imparting the orientation function to the optically anisotropic layer (A) by containing a photo-orientation polymer in the liquid crystal composition used to form the optically anisotropic layer (A), and then curing it. Next, an optically anisotropic layer (B) can be formed by directly coating a liquid crystal composition that forms an optically anisotropic layer (B) onto the obtained optically anisotropic layer (A) to obtain a laminate. When the optical laminate of the present invention satisfies necessary condition 1, the liquid crystal composition forming the optical anisotropic layer (B) is preferably coated on the surface of the optical anisotropic layer (A) that has undergone surface treatment. When necessary condition 2 is satisfied, it is preferably coated on the surface of the optical anisotropic layer (A) where the photo-alignment polymer is present (preferably on the surface of the side where the photo-alignment polymer is biased). In addition, the optical properties of the optical anisotropic layer (A) and the optical anisotropic layer (B) can be appropriately adjusted so that the optical laminate containing the optical anisotropic layer (A) and the optical anisotropic layer (B) has a λ / 4 function. The method for manufacturing the optical laminate of the present invention may further include a step of bonding an optically anisotropic layer (C) (preferably a C-plate) formed by separately coating a liquid crystal composition (preferably a liquid crystal composition forming a C-plate) onto a substrate via an adhesive layer, or a method of directly coating a liquid crystal composition (preferably a liquid crystal composition forming a C-plate) onto the optically anisotropic layer (B) after imparting an orientation function to the optically anisotropic layer (B) by the same method as described above, thereby forming the optically anisotropic layer (C) (preferably a C-plate).

[0061] Preferably, the specific optical anisotropy layer (A) is a negative uniaxial optical anisotropy layer, and the specific optical anisotropy layer (B) is an optical anisotropy layer formed by fixing a twisted and oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis. Alternatively, the structure can be reversed, where the specific optical anisotropy layer (A) is an optical anisotropy layer formed by fixing a twisted, oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis, and the specific optical anisotropy layer (B) is a negative uniaxial optical anisotropy layer. In the case of such an optical laminate, it is preferable to place the optical anisotropy layer (C) (preferably plate C) on the side of the optical anisotropy layer (A) and place the polarizer on the side of the optical anisotropy layer (B) to manufacture the polarizer described later. The following describes in detail the substrate, the liquid crystal composition, and the method for forming an optical anisotropic layer using the liquid crystal composition.

[0062] <Substrate> As a substrate, a transparent substrate is preferred. Furthermore, a transparent substrate refers to a substrate with a visible light transmittance of 60% or more, preferably 80% or more, and more preferably 90% or more.

[0063] There is no particular limitation on the thickness direction retardation value (Rth(550)) of the substrate at a wavelength of 550nm, but it is preferably -110 to 110nm, and more preferably -80 to 80nm. There is no particular limitation on the in-plane retardation value (Re(550)) of the substrate at a wavelength of 550nm, but it is preferably 0 to 50nm, more preferably 0 to 30nm, and even more preferably 0 to 10nm.

[0064] The preferred material for forming the substrate is a polymer with excellent optical transparency, mechanical strength, thermal stability, moisture shielding and isotropy. Examples of polymer films that can be used as substrates include cellulose acylate films (e.g., cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyolefin films such as polyethylene and polypropylene, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyethersulfone films, polypropylene films such as polymethyl methacrylate, polyurethane films, polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyetherketone films, (meth)acrylonitrile films, and films of polymers having an alicyclic structure (norbornene resins (ARTON: product name, manufactured by JSR Corporation; amorphous polyolefins (ZEONEX: product name, manufactured by Zeon Corporation))). The preferred material for the polymer film is triacetyl cellulose, polyethylene terephthalate, or a polymer with an alicyclic structure, with triacetyl cellulose being more preferred.

[0065] The substrate may contain various additives (e.g., optical anisotropy modifiers, wavelength dispersion modifiers, microparticles, plasticizers, UV protectants, degradation inhibitors, stripping agents, etc.).

[0066] There are no particular limitations on the thickness of the substrate, but it is preferably 10 to 200 μm, more preferably 10 to 100 μm, and even more preferably 20 to 90 μm. Furthermore, the substrate can be formed by stacking multiple sheets. To improve the adhesion between the substrate and the layers disposed on the substrate, surface treatments (e.g., glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment) can be applied to the surface of the substrate. Furthermore, an adhesive layer (base coat) can be applied to the substrate. Furthermore, in order to impart sliding properties to the substrate during the transport process, or to prevent adhesion between the back side and the surface after winding, a polymer layer can be disposed on one side of the substrate. The polymer layer is formed by mixing inorganic particles with an average particle size of about 10 to 100 nm at a solid content mass ratio of 5 to 40%.

[0067] The substrate can also be a so-called pseudo-support. That is, the substrate can be peeled off from the optical anisotropic layer after the optical laminate of the present invention has been manufactured.

[0068] Furthermore, the surface of the substrate can be directly rubbed. That is, a substrate that has already undergone rubbing treatment can be used. There are no particular restrictions on the direction of the rubbing treatment; the optimal direction should be appropriately selected based on the desired orientation of the liquid crystal compound. Friction processing is a widely used method for liquid crystal alignment in LCDs (liquid crystal displays). Specifically, it involves rubbing the surface of a substrate in a specific direction using materials such as paper, gauze, felt, rubber, nylon fibers, or polyester fibers to achieve alignment.

[0069] An alignment film can be disposed on the substrate. Orientation films can be formed by methods such as triboelectric treatment of organic compounds (preferably polymers), tilted evaporation of inorganic compounds, formation of layers with microgrooves, or accumulation of organic compounds (e.g., ω-trisanoic acid, dioctadecylmethylammonium chloride, methyl stearate) based on the Langmuir-Blodgett process (LB film). Furthermore, it is also known that alignment films can generate alignment functions by applying an electric field, a magnetic field, or irradiation with light (preferably polarized light). As an example of an alignment film, photoalignment film can also be cited. The thickness of the alignment film is not particularly limited as long as it can perform the alignment function. It is preferably 0.01 to 5.0 μm, more preferably 0.05 to 3.0 μm, and even more preferably 0.5 to 1.0 μm. The alignment film can be peeled off from the optical anisotropic layer along with the substrate.

[0070] <Liquid Crystal Composition> The liquid crystal compound contained in the liquid crystal composition forming the optical anisotropic layer is as described above. Furthermore, as described above, rod-shaped and disk-shaped liquid crystal compounds are appropriately selected based on the characteristics of the formed optical anisotropic layer. The content of liquid crystal compound in the liquid crystal composition is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, relative to the total solid content of the liquid crystal composition. In addition, solid components refer to components that can form optically anisotropic layers after the solvent is removed, and even if they are in liquid form, they are considered solid components.

[0071] Liquid crystal compositions may contain compounds other than liquid crystal compounds. For example, the liquid crystal composition used to form the optically anisotropic layer (A) may contain a photo-alignment polymer. Additionally, the liquid crystal composition used to form an optically anisotropic layer other than the optically anisotropic layer (A) (e.g., an optically anisotropic layer (B)) may contain a photo-alignment polymer. As a photooriented polymer, it is preferred to be a polymer having photooriented groups and unevenly distributed groups. There are no particular limitations on the backbone of the polymer, and well-known structures can be cited. For example, it is preferably a backbone selected from the group consisting of (meth)acrylic acids, styrene, siloxanes, cycloolefins, methylpentenes, amides and aromatic esters. More preferably, the skeleton is selected from the group consisting of (meth)acrylic acid, siloxane and cycloolefin, and even more preferably (meth)acrylic acid skeleton. In addition, (meth)acrylic acid is a general term for acrylic acid and methacrylic acid. As photo-orientation groups, preferably are groups having a skeleton of at least one derivative selected from the group consisting of cinnamic acid derivatives, coumarin derivatives, chalcone derivatives, maleimide derivatives, and benzophenone derivatives, or groups having a skeleton of at least one compound selected from the group consisting of azobenzene compounds, stilbene compounds, spiropyran compounds, cinnamic acid compounds, and hydrazine-β-keto ester compounds. Among these photo-orientation groups, considering that the liquid crystal orientation formed on the upper optical anisotropy layer is better even with a small amount of exposure, groups selected from the group consisting of cinnamyl, azophenyl, chalcone, and coumarin are preferred, and cinnamyl is more preferred. As a heterogeneous distribution group, it is preferable to have substituents containing fluorine or silicon atoms. By using this photo-oriented polymer, the photo-oriented polymer is easily biased onto the surface of the optical anisotropic layer (A), and the optical anisotropic layer (B) formed on the optical anisotropic layer (A) can be more effectively oriented directly. As such photooriented polymers, there are known repeating units containing photooriented groups, such as in International Publication No. 2018 / 216812; copolymers having repeating units with unevenly distributed groups at the ends and having groups that can be cleaved by action of at least one of the group consisting of light, heat, acid and alkali as linking groups; and photooriented polymers having both photooriented groups and unevenly distributed groups, as described in International Publication No. 2022 / 071410 (especially copolymers containing repeating units containing photooriented groups and copolymers containing repeating units containing unevenly distributed groups).

[0072] In order to form an optically anisotropic layer by fixing a twisted, oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis, the liquid crystal compound preferably contains a chiral reagent to achieve the twisted orientation. Details of the chiral reagent are as described above.

[0073] Liquid crystal compositions may contain polymerization initiators. The polymerization initiator used is selected according to the form of polymerization reaction; for example, thermal polymerization initiators and photopolymerization initiators can be cited. The content of polymerization initiator in the liquid crystal composition is preferably 0.01 to 20% by mass relative to the total solid content of the liquid crystal composition, more preferably 0.5 to 10% by mass.

[0074] Other components that may be included in a liquid crystal composition, in addition to those mentioned above, include multifunctional monomers, orientation control agents (vertical orientation agents, horizontal orientation agents), surfactants, adhesion improvers, plasticizers, photoacid generators, and solvents.

[0075] Regarding the surfactants mentioned above, compounds with a so-called leveling function, which makes the coated film flat, are preferred. For example, compounds containing silicon atoms, polyacrylate compounds, and compounds containing fluorine atoms can be used. Specifically, the compounds and amounts described in Japanese Patent Application Publication No. 2020-098349, Japanese Patent Application Publication No. 2020 / 149357, Japanese Patent Application Publication No. 2023 / 054164, etc., can be used with reference to the compounds and amounts described therein. In particular, from the viewpoint of reducing environmental pollution, the surfactant is preferably a compound containing silicon atoms or a polyacrylate compound, and more preferably a compound having a branched siloxane structure. Among them, copolymers (surfactants) described in Table 1 of International Publication No. 2023 / 054164 are preferred. The content of surfactant relative to the total mass of the solid components of the liquid crystal composition is preferably 0.01% to 10%, more preferably 0.01% to 6.0%, and even more preferably 0.05% to 3.0%. Similarly, from the viewpoint of reducing environmental pollution, it is preferable that the surfactant has a low fluorine atom content, preferably 10% or less by weight in the compound, more preferably 5% or less, and even more preferably 3% or less. Regarding the lower limit, 0% is most preferred, but trace amounts (e.g., 0.01 to 1.0%) may be contained within a range where the impact on environmental pollution is minimal. When a silicon-containing compound is used as a surfactant, silicon is present at the interface between the optically anisotropic layer (A) and the optically anisotropic layer (B).

[0076] <Methods for forming optical anisotropic layers> There are no particular limitations on the steps for forming the optical anisotropic layer. For example, a method can be used where the liquid crystal composition described above is coated onto a substrate and then dried as needed (hereinafter, also referred to as the "coating method"). Furthermore, the optical anisotropic layer can be formed by coating the liquid crystal composition onto other layers formed on the substrate, in addition to the aforementioned substrate. For example, the optical anisotropic layer can be formed by directly coating the liquid crystal composition onto the optical anisotropic layer formed on the substrate.

[0077] There are no particular restrictions on the coating method. Examples include wire rod coating, extrusion coating, direct gravure coating, reverse gravure coating, and die coating. Additionally, if necessary, after applying the composition, a drying process can be performed on the coating film applied to the substrate. By performing the drying process, the solvent can be removed from the coating film.

[0078] There is no particular limitation on the thickness of the coating, but it is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm, and even more preferably 0.5 to 10 μm.

[0079] Next, the formed coating is oriented to orient the liquid crystal compound in the coating. Orientation processing can be performed by drying the coating at room temperature or by heating the coating. In the case of thermotropic liquid crystal compounds, the liquid crystal phase formed by orientation processing can usually be transformed by changes in temperature or pressure. In the case of lyotropic liquid crystal compounds, the transformation can also be achieved by adjusting the composition ratio of solvents, etc. In addition, there are no particular restrictions on the conditions for heating the coating, but the heating temperature is preferably 50 to 250°C, more preferably 50 to 150°C, and the heating time is preferably 10 seconds to 10 minutes. Furthermore, after heating the coating and before the curing process (light irradiation treatment) described later, the coating can be cooled as needed. The preferred cooling temperature is 20–200°C, more preferably 30–150°C.

[0080] Next, the coating with the liquid crystal compound orientation is preferably cured. There are no particular limitations on the method of curing the coating film oriented with liquid crystal compounds; for example, light irradiation and heat treatment can be mentioned. From the viewpoint of manufacturing applicability, light irradiation is preferred, and ultraviolet irradiation is more preferred. There are no particular restrictions on the irradiation conditions for light treatment, but 50–1000 mJ / cm² is preferred. 2 The amount of radiation. There are no particular restrictions on the atmosphere during light irradiation treatment, but a nitrogen atmosphere is preferred.

[0081] Furthermore, when the liquid crystal composition contains a photo-alignment polymer, from the viewpoint of imparting an alignment function, it is preferable to perform a photo-alignment process when forming an optically anisotropic layer. As a photoalignment process, examples include irradiating a coating of a liquid crystal composition (containing a cured film that has undergone a curing process) with polarized light or irradiating it with unpolarized light from an angled direction relative to the surface of the coating. There is no particular limitation on the timing of the photoalignment process, but it is more preferable to perform it after the alignment process of the liquid crystal compound.

[0082] In the optical orientation process, there is no particular limitation on the polarized light irradiated. For example, linearly polarized light, circularly polarized light, and elliptically polarized light can be mentioned, with linearly polarized light being preferred. Furthermore, the "tilt direction" of irradiating unpolarized light is not particularly limited as long as it is tilted at a polar angle θ (0 < θ < 90°) relative to the normal direction of the coating surface, and can be appropriately selected according to the purpose. θ is preferably 20 to 80°.

[0083] The wavelength of polarized or unpolarized light is not particularly limited as long as it is light that is photosensitive by photooriented groups. Examples include ultraviolet light, near-ultraviolet light, and visible light, with near-ultraviolet light of 250 to 450 nm being preferred. Furthermore, examples of light sources for irradiating polarized or unpolarized light include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps. For ultraviolet or visible light obtained from such light sources, the wavelength range of the irradiation can be limited by using interference filters or color filters. Moreover, for light from these light sources, linearly polarized light can be obtained by using polarizing filters or polarizing prisms.

[0084] There is no particular limitation on the cumulative light intensity of polarized or unpolarized light, but it is preferably 1 to 300 mJ / cm. 2 More preferably 5–100 mJ / cm 2 . There is no particular limitation on the illuminance of polarized or unpolarized light, but it is preferably 0.1 to 300 mW / cm². 2 More preferably 1–100 mW / cm 2 .

[0085] Furthermore, when the optical anisotropic layer (e.g., optical anisotropic layer (A)) serving as the substrate is formed from a liquid crystal composition that does not contain a photo-alignment polymer, it is preferable to coat the liquid crystal composition that forms the stacked optical anisotropic layer (e.g., optical anisotropic layer (B)) after performing a surface treatment on the optical anisotropic layer serving as the substrate, and then perform the stacking. By performing the surface treatment, the coatability (coating depressions, etc.) of the liquid crystal composition on the optical anisotropic layer serving as the substrate is improved, and the liquid crystal compound in the coated liquid crystal composition is easily aligned along the orientation state of the surface of the optical anisotropic layer serving as the substrate. Examples of surface treatments include glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, and flame treatment, with corona discharge treatment being preferred.

[0086] Regarding corona discharge treatment, when the amount of corona discharge is small, the orientation of the stacked optical anisotropic layers becomes insufficient; when the amount of discharge is large, it can sometimes contaminate the manufacturing process. The preferred amount of corona discharge is 10–200 W·min / m. 2 More preferably, it is 20–100 W·min / m 2 .

[0087] [Polarizing filter] The polarizer and organic EL display device of the present invention will be described in detail below.

[0088] The polarizer of the present invention includes a polarizer and the optical laminate of the present invention. The polarizer can be used as a circular polarizer. In addition, a circular polarizer refers to an optical element that converts unpolarized light into circularly polarized light.

[0089] [Polarizer] The polarizer of the polarizer of the present invention can be any component that has the function of converting natural light into specific linearly polarized light, such as an absorption type polarizer. There are no particular restrictions on the type of polarizer; commonly used polarizers can be used, such as iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Iodine-based and dye-based polarizers are usually made by adsorbing iodine or dichroic dye onto polyvinyl alcohol and then stretching it. In addition, protective films can be installed on one or both sides of the polarizer.

[0090] Furthermore, as described in International Publication No. 2019 / 131943 and Japanese Patent Application Publication No. 2017-083843, a coating-type polarizer can be used as the polarizer. This coating-type polarizer uses a liquid crystal compound and a dichroic organic pigment (e.g., the dichroic azo pigment used in the light-absorbing anisotropic film described in International Publication No. 2017 / 195833) without using polyvinyl alcohol as a binder, and is manufactured by coating. That is, the polarizer can be a polarizer formed using a composition containing a polymerizable liquid crystal compound. This coating-type polarizer utilizes the orientation of a liquid crystal compound to orient dichroic organic pigments. As described in Japanese Patent Application Publication No. 2012-083734, if the polymerizable liquid crystal compound exhibits smectic properties, it is preferable from the viewpoint of improving the degree of orientation. Alternatively, as described in International Publication No. 2018 / 186503, from the viewpoint of improving the degree of orientation, it is also preferable to crystallize the pigment. International Publication No. 2019 / 131943 describes a structure of a polymeric liquid crystal preferred for improving the degree of orientation.

[0091] A polarizer that orients dichroic organic pigments by utilizing the orientation properties of liquid crystals without stretching has the following characteristics: it can be made into a very thin layer, such as about 0.1 μm to 5 μm thick; as described in Japanese Patent Application Publication No. 2019-194685, it is not prone to cracking or thermal deformation when bent; and as described in Japanese Patent Application Publication No. 6483486, it has excellent durability even when used as a polarizer with a high transmittance of more than 50%. Taking advantage of these features, it can be used for applications requiring high brightness and small, lightweight design, micro-optical systems, curved surfaces, and flexible components. It can also be used after peeling off the support and transferring the polarizer.

[0092] Regarding the transmittance of the polarizer, from the viewpoint of energy saving, the transmittance of the visibility correction unit is preferably 40% or more, more preferably 44% or more, and even more preferably 50% or more. There is no particular upper limit, but it is preferably 60% or less. In this invention, the transmittance of the polarizer's visibility correction element is measured using an automated polarizing film measurement device: VAP-7070 (manufactured by JASCO Corporation). The transmittance of the visibility correction element can be measured as follows: A sample (5cm × 5cm) is prepared by attaching the polarizer to glass via adhesive. At this time, the polarizing protective film is attached to the polarizer with the side opposite to the glass (air interface side). The sample is positioned with one side of the glass facing the light source, and the measurement is performed. There are no particular restrictions on the structure of the polarizer protective film. For example, it can be a support or a coating layer, or a laminate of a support and a coating layer. As the coating layer, known layers can be used, such as layers obtained by polymerizing and curing polymers or polyfunctional monomers. Examples of polymers include (meth)acrylic acid polymers or cycloolefin polymers. Examples of polymerizable monomers include free radical polymerizable compounds or cationic polymerizable compounds. There are no particular restrictions on the bonding surface between the polarizer and the protective film. For example, in order to suppress the diffusion of potassium or iodine ions from the polarizer during humid and hot conditions, the coating surface of the support and coating layer can be bonded to the polarizer.

[0093] [Manufacturing method of polarizer] There are no particular restrictions on the manufacturing method of polarizers; well-known methods can be used. For example, a polarizer and an optical laminate are fabricated separately and then bonded together in a predetermined direction with an adhesive layer in between, thereby producing a polarizer. The adhesive layer described above can be used as an example. As a polarizer manufactured by this method, it is preferable to arrange the polarizer, adhesive layer 1, specific optical anisotropy layer (A), specific optical anisotropy layer (B), adhesive layer 2, and plate C in sequence, adjacent to each other. Adhesive layer 1 is the layer that bonds the polarizer and the optical anisotropy layer (A), and specific examples and preferred embodiments are the same as those of the adhesive layer that the optical anisotropy layer may contain. Here, the adhesive layer 2 and plate C may or may not be present, but from the viewpoint of optical properties, the presence of plate C is preferred. Plate C can also be configured to be adjacent to the specific optical anisotropy layer (B) by means of the above method, that is, a structure in which the adhesive layer 2 is not present and plate C is directly adjacent to the specific optical anisotropy layer (B). Furthermore, a coating-type polarizer can be used, and the polarizer can be directly coated onto the optical laminate to manufacture a polarizer that is directly laminated with the optical laminate. As a polarizer manufactured by this method, it is preferable to arrange the polarizer, the specific optical anisotropy layer (A), the specific optical anisotropy layer (B), the adhesive layer 2, and the C plate in sequence, adjacent to each other. Here, the adhesive layer 2 and the C plate may be omitted, but from the viewpoint of optical properties, the presence of the C plate is preferred. The C plate can also be configured to be adjacent to the specific optical anisotropy layer (B) by the above method, i.e., without the adhesive layer 2, the C plate is directly adjacent to the specific optical anisotropy layer (B).

[0094] [Organic EL Display Device] The organic EL display device of the present invention includes the aforementioned optical laminate or polarizer. Typically, the optical laminate or polarizer is disposed on the organic EL display panel of the organic EL display device. That is, the organic EL display device of the present invention includes an organic EL display panel and the aforementioned optical laminate or polarizer.

[0095] An organic EL display panel is a component in which a light-emitting layer or multiple organic compound films containing a light-emitting layer are formed between a pair of electrodes, namely an anode and a cathode. In addition to the light-emitting layer, it may also have a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, etc., and each of these layers may have other functions. Various materials can be used to form each layer. Example

[0096] The features of the present invention will be further described below with examples and comparative examples. The materials, amounts, proportions, processing contents, and processing steps shown in the following examples can be appropriately modified without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as limited by the specific examples shown below.

[0097] <Example 1> (Fabrication of cellulose acylate membrane (substrate)) The following composition was added to a mixing vessel and stirred, then heated at 90°C for 10 minutes. The resulting composition was then filtered through filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare a doped solution. The solids concentration of the doped solution was 23.5% by mass, the amount of plasticizer added was relative to the cellulose acylate, and the solvent for the doped solution was dichloromethane / methanol / butanol = 81 / 18 / 1 (mass ratio).

[0098] ―――――――――――――――――――――――――――――――― Cellulose acylate doped solution ―――――――――――――――――――――――――――――――― Cellulose acylated compound (acetyl substitution degree 2.86, viscosity-uniform polymerization degree 310) 100 parts by weight Sugar ester compound 1 (chemical formula (S4)) 6.0 parts by mass Sugar ester compound 2 (chemical formula (S5)) 2.0 parts by mass 0.1 parts by weight of silica particle dispersion (AEROSIL R972, manufactured by NIPPON AEROSIL CO.,LTD.) Solvents (dichloromethane / methanol / butanol) ――――――――――――――――――――――――――――――――

[0099] [Chemical Formula 1]

[0100] [Chemical Formula 2]

[0101] The dopant solution prepared above is cast using a roller film casting machine. The dopant solution is cast from the mold by contacting a metal support cooled to 0°C, and then the obtained sheet (film) is peeled off from the roller. The roller is made of SUS steel.

[0102] After the film is peeled off from the rollers, it is dried for 20 minutes at 30–40°C using a tenter unit that holds both ends of the film in clamps. Then, the film is further dried by zone heating while being conveyed by rollers. The resulting film is then knurled and wound up. The obtained cellulose acylated membrane has a thickness of 40 μm, an in-plane retardation Re(550) of 1 nm at a wavelength of 550 nm, and a thickness retardation Rth(550) of 26 nm at a wavelength of 550 nm.

[0103] (Alkali saponification treatment) After passing the cellulose acylated membrane through a dielectric heating roller at 60°C to raise the membrane surface temperature to 40°C, an alkaline solution of the composition shown below is applied using a bar coater at a coating rate of 14 ml / m. 2 The coating was applied to the surface of the membrane and conveyed under a steam-type far-infrared heater manufactured by NORITAKE CO., LIMITED and heated to 110°C for 10 seconds. Then, a bar coater was used in the same manner at a rate of 3 ml / m². 2Pure water was applied. Then, after repeated water washing based on a spray coating machine and dehydration based on an air knife three times, the product was conveyed to a drying zone at 70°C for 10 seconds to dry, thus producing an alkali-saponified cellulose acylate membrane.

[0104] ―――――――――――――――――――――――――――――――― alkaline solution ―――――――――――――――――――――――――――――――― 4.7 parts by weight of potassium hydroxide 15.8 parts by weight of water 63.7 parts by weight of isopropanol Surfactant: C 14 H 29 O(CH2CH2O) 20 H 1.0 parts by weight 14.8 parts by weight of propylene glycol ――――――――――――――――――――――――――――――――

[0105] (Formation of the orientation film) Using a #14 wire rod, the following oriented film coating solution was continuously applied to the alkali-saponified surface of the cellulose acylate membrane. It was dried with warm air at 60°C for 60 seconds, and then further dried with warm air at 100°C for 120 seconds.

[0106] ―――――――――――――――――――――――――――――――― Orientation film coating solution ―――――――――――――――――――――――――――――――― 10 parts by weight of the following polyvinyl alcohol 371 parts by weight of water 119 parts by weight of methanol Glutaraldehyde (crosslinking agent) 0.5 parts by weight Citrate ester (manufactured by SANKYO CHEMICAL Co., Ltd.) 0.175 parts by weight ――――――――――――――――――――――――――――――――

[0107] (Polyvinyl alcohol)

[0108] [Chemical Formula 3]

[0109] (Formation of the optical anisotropic layer (A)) The oriented film produced above was continuously subjected to friction treatment. At this time, the length direction of the elongated film was parallel to the conveying direction, and the angle formed between the length direction of the film (conveying direction) and the rotation axis of the friction roller was set to 76°. Setting the length direction of the film (conveying direction) to 90°, viewed from the film side, if clockwise rotation is represented by a positive value with the film width direction as a reference (0°), then the rotation axis of the friction roller is -14°. In other words, viewed from the film side, the position of the rotation axis of the friction roller is 76° clockwise from the length direction of the film.

[0110] Using a die coater, an optical anisotropic layer forming composition (1a) containing a disk-shaped liquid crystal compound with the following composition was coated onto an alignment film that had undergone the above-described rubbing treatment, forming a composition layer. Then, to dry the solvent and ripen the orientation of the disk-shaped liquid crystal compound, the obtained composition layer was heated with warm air at 110°C for 2 minutes. Next, the obtained composition layer was subjected to UV irradiation at 80°C (100 mJ / cm²). 2 The orientation of the liquid crystal compound was fixed to form an optically anisotropic layer (1a). The thickness of the optical anisotropic layer (1a) is 1.1 μm. Furthermore, the in-plane retardation at a wavelength of 550 nm is 168 nm. The average tilt angle of the disk surface of the disk-shaped liquid crystal compound relative to the film surface is 90°, confirming a perpendicular orientation relative to the film surface. Moreover, the angle of the in-plane slow axis of the optical anisotropic layer (1a) is parallel to the rotation axis of the friction roller. If the width direction of the film is set to 0° (the length direction is 90° counterclockwise and -90° clockwise), then when viewed from the optical anisotropic layer (1a) side, the in-plane slow axis is -14°. In addition, the optical anisotropic layer (1a) is equivalent to the optical anisotropic layer (A) that does not have λ / 4 function but has phase difference.

[0111] ―――――――――――――――――――――――――――――――― Composition for forming optical anisotropic layers (1a) ―――――――――――――――――――――――――――――――― 180 parts by weight of the following disc-shaped liquid crystal compound The following disc-shaped liquid crystal compound 2 20 parts by mass The following surface alignment agent for the alignment film: 1 0.55 parts by weight 0.1 parts by weight of the following fluorinated compound A The following fluorinated compound B, 0.05 parts by weight The following fluorine-containing compound C, 0.21 parts by mass Ethylene oxide modified trimethylolpropane triacrylate (V#360, manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) 10 parts by weight Photopolymerization initiator (IRGACURE 907, manufactured by BASF) 3.0 parts by weight 200 parts by weight of methyl ethyl ketone ――――――――――――――――――――――――――――――――

[0112] Disc-shaped liquid crystal compound 1

[0113] [Chemical Formula 4]

[0114] Disc-shaped liquid crystal compound 2

[0115] [Chemical Formula 5]

[0116] Orientation agent 1 for orientation film surface

[0117] [Chemical Formula 6]

[0118] Fluorine compound A

[0119] [Chemical Formula 7]

[0120] In the above, a and b represent the content (mass%) of each repeating unit relative to all repeating units, where a represents 90% mass and b represents 10% mass.

[0121] Fluorine compound B (the values ​​in each repeating unit represent the content (mass%) relative to all repeating units; the content of the repeating unit on the left is 32.5% by mass, and the content of the repeating unit on the right is 67.5% by mass).

[0122] [Chemical Formula 8]

[0123] Fluorine compound C (the values ​​in each repeating unit represent the content (mass%) relative to all repeating units; the content of the repeating unit on the left is 25% by mass, the content of the repeating unit in the middle is 25% by mass, and the content of the repeating unit on the right is 50% by mass).

[0124] [Chemical Formula 9]

[0125] (Formation of a stack of optically anisotropic layers (A) and (B)) (Formation of the optical anisotropic layer (1b)) At 50 W·min / m 2 Under the conditions described above, the surface of the optical anisotropic layer (1a) of the optical anisotropic layer (A) was subjected to corona treatment. Using a die coater, a composition (1b) for forming an optical anisotropic layer containing a rod-shaped liquid crystal compound with the following composition was coated onto the corona-treated surface, and heated with warm air at 80°C for 60 seconds. Next, the obtained composition layer was subjected to UV irradiation (500 mJ / cm²) at 80°C. 2 The orientation of the liquid crystal compound was fixed to form an optically anisotropic layer (1b). The thickness of the optical anisotropic layer (1b) is 1.2 μm, the Δnd at a wavelength of 550 nm is 164 nm, and the twist angle of the liquid crystal compound is 81°. If the width direction of the film is set to 0° (with the length direction as 90°), then when viewed from the optical anisotropic layer (1b) side, the orientation axis angle of the liquid crystal compound is -85° on the air side and -14° on the side in contact with the optical anisotropic layer (1a). In addition, the orientation axis angle of the liquid crystal compound contained in the optical anisotropic layer is set to 0° with the width direction of the substrate as the reference. When viewing the substrate from the surface side of the optical anisotropic layer, clockwise (right turn) is represented as negative and counterclockwise (left turn) is represented as positive. Furthermore, regarding the twist angle of the liquid crystal compound, when observing the substrate from the surface side of the optical anisotropic layer, with the orientation axis direction of the liquid crystal compound on the surface side (front side) as a reference, the orientation axis direction of the liquid crystal compound on the substrate side (inner side) is represented as negative when it is clockwise (right turn) and positive when it is counterclockwise (left turn). In addition, the optical anisotropic layer (1b) is equivalent to the optical anisotropic layer (B) that does not have λ / 4 function but has phase difference.

[0126] ―――――――――――――――――――――――――――――――― Composition for forming optical anisotropic layers (1b) ―――――――――――――――――――――――――――――――― 100 parts by weight of the following rod-shaped liquid crystal compound L-1 Ethylene oxide modified trimethylolpropane triacrylate (V#360, manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) 4 parts by weight Photopolymerization initiator (Irgacure 819, manufactured by BASF) 3 parts by weight The following left-handed tortuous chiral reagent (L1) 0.60 parts by weight The above-mentioned fluorine-containing compound C, 0.08 parts by mass 156 parts by weight of methyl ethyl ketone ――――――――――――――――――――――――――――――――

[0127] Rod-shaped liquid crystal compound L-1

[0128] [Chemical Formula 10]

[0129] Left-handed tortuous chiral reagent (L1)

[0130] [Chemical Formula 11]

[0131] Through the above steps, a laminate (1a-1b) was fabricated by directly stacking an optically anisotropic layer (1a) and an optically anisotropic layer (1b) on a strip-shaped cellulose acylate membrane. The laminate (1a-1b) is equivalent to a laminate with λ / 4 function.

[0132] (Fabrication of the optical anisotropic layer (C))

[0133] Using a die-coating machine, the optical anisotropic layer forming composition 1c described below was coated onto the support fabricated in Example 1, forming a composition layer. The first dummy support with the composition layer formed was heated at 60°C with warm air for 1 minute, and simultaneously purged with nitrogen to achieve an oxygen concentration of less than 100 ppm by volume, while being irradiated with ultraviolet light (irradiation dose 120 mJ / cm²). 2 Using an ultra-high pressure mercury lamp, the orientation of the rod-shaped liquid crystal compound L-1 was fixed to form an optically anisotropic layer (1c). Furthermore, the thickness of the optical anisotropic layer (1c) is 0.7 μm. The Re (550) of the optical anisotropic layer (1c) is 0 nm, and the Rth (550) is -80 nm. The average tilt angle of the rod-shaped liquid crystal compound L-1 relative to the surface of the optical anisotropic layer is 90°, and it is oriented perpendicularly to the surface of the support.

[0134] ─────────────────────────────── Composition for forming optical anisotropic layers (1c) ─────────────────────────────── 100 parts by mass of the above-mentioned rod-shaped liquid crystal compound L-1 Multifunctional monomer (UA-306I, manufactured by KYOEISHA CHEMICAL CO.,LTD.) 5.0 parts by weight Polymerization initiator (IrgacureOXE01, manufactured by BASF) 4.0 parts by weight The following polymer X-1 1.2 parts by weight 1.14 parts by weight of the following onium salt compound The following fluorinated compound (fluoropolymer) F-1, 0.4 parts by weight 43.3 parts by weight of methyl ethyl ketone 95.0 parts by weight of ethyl propionate 494.9 parts by weight of methyl isobutyl ketone ───────────────────────────────

[0135] Polymer X-1

[0136] [Chemical Formula 12]

[0137] Onium salt compounds

[0138] [Chemical Formula 13]

[0139] Fluoropolymer F-1

[0140] [Chemical Formula 14]

[0141] (Formation of a stack of optical anisotropic layers (A), (B), and (C)) A UV-curable adhesive is used to continuously bond the surface side of the optically anisotropic layer (1c) formed on the elongated cellulose acylate film and the surface side of the optically anisotropic layer (1b) of the laminate (1a-1b) formed on the elongated cellulose acylate film. The UV-curable adhesive has a thickness of 1.0 μm and a refractive index of 1.54. Next, the rub-treated oriented cellulose acylate film on the side of the optical anisotropic layer (1a) was peeled off, exposing the cellulose acylate film side of the optical anisotropic layer (1a). This yielded a retardation film (1c-1b-1a) in which optical anisotropic layers (1c), (1b), and (1a) are sequentially stacked on a strip-shaped cellulose acylate film. The thickness of the retardation film (1c-1b-1a) is 4.0 μm.

[0142] (Fabrication of linear polarizer 1) The surface of the support for a cellulose triacetate membrane TJ25 (manufactured by FUJIFILM Corporation: 25 μm thickness) was subjected to alkaline saponification treatment. Specifically, the support was immersed in a sodium hydroxide aqueous solution of a specified concentration of 1.5 at 55°C for 2 minutes, then cleaned in a water bath at room temperature, and subsequently neutralized with sulfuric acid of a specified concentration of 0.1 at 30°C. After neutralization, the support was cleaned in a water bath at room temperature and then dried with warm air at 100°C to obtain a polarizer protective film. A 60 μm thick roll-shaped polyvinyl alcohol (PVA) film was continuously stretched along its length in an iodine aqueous solution and then dried to obtain a polarizer with a thickness of 13 μm. The transmittance of the polarizer's visibility-corrected monomer was 43%. At this point, the absorption axis of the polarizer was aligned with its length. A linear polarizer 1 was fabricated by attaching the protective film of the polarizer to one surface of the polarizer using the PVA adhesive described below.

[0143] (Preparation of PVA adhesive) The PVA adhesive was prepared as follows: 100 parts by mass of polyvinyl alcohol resin with acetylacetyl groups (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, degree of acetylacetylation: 5 mol%) and 20 parts by mass of hydroxymethyl melamine were dissolved in pure water at a temperature of 30°C, and the concentration of solid components was adjusted to 3.7% by mass of the aqueous solution.

[0144] (Fabrication of a circular polarizer) The surface of the optical anisotropy layer (1a) side of the elongated phase retardation film (1c-1b-1a) and the surface of the polarizer of the elongated linear polarizer 1 (the side opposite to the polarizer protective film) are continuously bonded together using a UV-curable adhesive. Next, the cellulose acylate film on the optical anisotropy layer (1c) side is peeled off to expose the surface of the optical anisotropy layer (1c) in contact with the cellulose acylate film. A circular polarizer (P1) consisting of a phase retardation film (1c-1b-1a) and a linear polarizer was thus fabricated. At this time, a polarizer protective film, a polarizer, an optical anisotropic layer (1a), an optical anisotropic layer (1b), and an optical anisotropic layer (1c) were sequentially stacked. The angle between the absorption axis of the polarizer and the slow axis of the optical anisotropic layer (1a) was 76°. Furthermore, with 0° as a reference in the width direction, the alignment axis angle of the liquid crystal compound on the optical anisotropic layer (1b) side of the optical anisotropic layer (1a) was 14°, and it was aligned with the slow axis direction of the optical anisotropic layer (1a). The thickness of the circular polarizer was 43 μm. In addition, the orientation axis angle of the liquid crystal compound contained in the optical anisotropy layer is set to 0° with the width direction of the linear polarizer as the reference. When viewed from the surface side of the polarizer, clockwise (right turn) is represented as negative and counterclockwise (left turn) is represented as positive.

[0145] <Example 2> Except for the method of forming the laminate of optical anisotropic layer (A) and optical anisotropic layer (B), a circular polarizer was fabricated using the same method as in Example 1.

[0146] (Formation of the optical anisotropic layer (A)) Using a die coater, an optical anisotropic layer forming composition (2a) containing a disk-shaped liquid crystal compound with the following composition was coated onto the friction-treated alignment film prepared in Example 1, forming a composition layer. Then, to dry the solvent and ripen the disk-shaped liquid crystal compound, the obtained composition layer was heated with warm air at 110°C for 2 minutes. Next, the obtained composition layer was subjected to UV irradiation at 80°C (100 mJ / cm²). 2 The orientation of the liquid crystal compound was fixed. Then, it was annealed at 120°C for 1 minute using warm air to form an optically anisotropic layer (2a). The thickness of the optical anisotropic layer (2a) is 1.1 μm. Furthermore, the in-plane retardation at a wavelength of 550 nm is 168 nm. The average tilt angle of the disk surface of the disk-shaped liquid crystal compound relative to the film surface is 90°, confirming a perpendicular orientation relative to the film surface. Moreover, the angle of the in-plane slow axis of the optical anisotropic layer (2a) is parallel to the rotation axis of the friction roller. If the width direction of the film is set to 0° (the length direction is 90° counterclockwise and -90° clockwise), then when viewed from the optical anisotropic layer (2a) side, the in-plane slow axis is -14°. In addition, the optical anisotropic layer (2a) is equivalent to the optical anisotropic layer (A) that does not have λ / 4 function but has phase difference.

[0147] ―――――――――――――――――――――――――――――――― Composition for forming optical anisotropic layers (2a) ―――――――――――――――――――――――――――――――― 80 parts by weight of the disc-shaped liquid crystal compound of Example 1 20 parts by weight of the disc-shaped liquid crystal compound 2 in Example 1 0.55 parts by weight of the surface alignment agent 1 for the alignment film in Example 1 The following photo-oriented polymer A-1, 2.0 parts by weight Ethylene oxide modified trimethylolpropane triacrylate (V#360, manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) 10 parts by weight Photopolymerization initiator (IRGACURE 907, manufactured by BASF) 3.0 parts by weight The following photoacid-generating agent D-1, 3.0 parts by weight 200 parts by weight of methyl ethyl ketone ――――――――――――――――――――――――――――――――

[0148] Photooriented polymer A-1 (The values ​​listed in each repeating unit represent the content (mass%) of each repeating unit relative to all repeating units, with repeating units from the left being 40% mass, 25% mass, and 35% mass. The weight-average molecular weight is 69,300.)

[0149] [Chemical Formula 15]

[0150] Photoacid generator D-1

[0151] [Chemical Formula 16]

[0152] (Formation of a stack of optically anisotropic layers (A) and (B)) (Formation of the optical anisotropic layer (2b)) At room temperature, the obtained optical anisotropic layer (2a) was irradiated with 7.9 mJ / cm². 2UV light (ultra-high pressure mercury lamp; UL750; manufactured by HOYA) passing through a wire grid polarizer (wavelength: 313 nm) oriented the orientation component (cinnamic acid ester portion) of the photo-orientation polymer A-1, forming an optically anisotropic layer (2a) with orientation function on the surface. Next, using a die coater, an optically anisotropic layer forming composition (1b) containing the same rod-shaped liquid crystal compound as in Example 1 was coated onto the UV-irradiated surface, and heated with warm air at 80°C for 60 seconds. Subsequently, the obtained composition layer was UV irradiated at 80°C (500 mJ / cm²). 2 The orientation of the liquid crystal compound was fixed to form an optically anisotropic layer (2b). The thickness of the optical anisotropic layer (2b) is 1.2 μm, the Δnd at a wavelength of 550 nm is 164 nm, and the twist angle of the liquid crystal compound is 81°. If the width direction of the film is set to 0° (with the length direction as 90°), then when viewed from the optical anisotropic layer (1b) side, the orientation axis angle of the liquid crystal compound is -85° on the air side and -14° on the side in contact with the optical anisotropic layer (1a). In addition, the optical anisotropic layer (2b) is equivalent to the optical anisotropic layer (B) that does not have λ / 4 function but has phase difference.

[0153] Through the above steps, a laminate (2a-2b) was fabricated by directly stacking an optically anisotropic layer (2a) and an optically anisotropic layer (2b) on a strip-shaped cellulose acylate membrane. The laminate (2a-2b) is equivalent to a laminate with λ / 4 function.

[0154] <Example 3> The thickness of the UV-curable adhesive was changed to 1.0 μm and the refractive index was changed to 1.51. Otherwise, a circular polarizer was fabricated using the same method as in Example 1.

[0155] <Example 4> Except for the methods of forming the optical anisotropic layer (A), optical anisotropic layer (B), and optical anisotropic layer (C), a circular polarizer was fabricated using the same method as in Example 1.

[0156] (Formation of the optical anisotropic layer (A)) Using a die coater, an optical anisotropic layer forming composition (3a) containing a disk-shaped liquid crystal compound with the following composition was coated onto the rub-treated alignment film prepared in Example 1, forming a composition layer. Then, to dry the solvent and ripen the disk-shaped liquid crystal compound, the obtained composition layer was heated with warm air at 110°C for 2 minutes. Next, the obtained composition layer was subjected to UV irradiation at 80°C (100 mJ / cm²).2 The orientation of the liquid crystal compound was fixed. Then, it was annealed at 120°C for 1 minute using warm air to form an optically anisotropic layer (3a). The thickness of the optical anisotropic layer (3a) is 1.4 μm. Furthermore, the in-plane retardation at a wavelength of 550 nm is 168 nm. The average tilt angle of the disk surface of the disk-shaped liquid crystal compound relative to the film surface is 90°, confirming its perpendicular orientation relative to the film surface. Moreover, the angle of the in-plane slow axis of the optical anisotropic layer (3a) is parallel to the rotation axis of the friction roller. If the width direction of the film is set to 0° (the length direction is 90° counterclockwise and -90° clockwise), then when viewed from the optical anisotropic layer (3a) side, the in-plane slow axis is -14°. In addition, the optical anisotropic layer (3a) is equivalent to the optical anisotropic layer (A) that does not have λ / 4 function but has phase difference.

[0157] ―――――――――――――――――――――――――――――――― Composition for forming optical anisotropic layers (3a) ―――――――――――――――――――――――――――――――― 80 parts by weight of the disc-shaped liquid crystal compound of Example 1 20 parts by weight of the disc-shaped liquid crystal compound 2 in Example 1 1.0 parts by weight of the surface alignment agent for the alignment film in Example 1 The following silicon-containing compound A, 0.2 parts by weight Ethylene oxide modified trimethylolpropane triacrylate (V#360, manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) 5 parts by weight Photopolymerization initiator (IRGACURE 907, manufactured by BASF) 4.0 parts by weight 200 parts by weight of methyl ethyl ketone ――――――――――――――――――――――――――――――――

[0158] Silicon-containing compound A (in the following formulas, a, b, c, and d represent the content (mol%) of each repeating unit relative to all repeating units, where a represents 78 mol%, b represents 10 mol%, c represents 1 mol%, and d represents 11 mol%. The weight-average molecular weight is 13500.)

[0159] [Chemical Formula 17]

[0160] (Formation of a stack of optically anisotropic layers (A) and (B)) (Formation of the optical anisotropic layer (3b)) At 50 W·min / m 2 Under the conditions described above, the surface of the optical anisotropic layer (3a) of the optical anisotropic layer (A) was subjected to corona treatment. Using a die coater, a composition (3b) for forming an optical anisotropic layer containing a rod-shaped liquid crystal compound with the following composition was coated onto the corona-treated surface, and heated with warm air at 80°C for 60 seconds. Subsequently, the obtained composition layer was subjected to UV irradiation (500 mJ / cm²) at 80°C. 2 The orientation of the liquid crystal compound was fixed to form an optically anisotropic layer (3b).

[0161] ―――――――――――――――――――――――――――――――― Composition for forming optical anisotropic layers (3b) ―――――――――――――――――――――――――――――――― 100 parts by weight of rod-shaped liquid crystal compound L-1 from Example 1 Ethylene oxide modified trimethylolpropane triacrylate (V#360, manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.) 4 parts by weight Photopolymerization initiator (Irgacure 819, manufactured by BASF) 3 parts by weight 0.60 parts by weight of the left-handed tortuous chiral reagent (L1) of Example 1 The following silicon-containing compound B, 0.15 parts by weight 156 parts by weight of methyl ethyl ketone ――――――――――――――――――――――――――――――――

[0162] Silicon-containing compound B (in the following formula, a, b, and c represent the content (mass%) of each repeating unit relative to all repeating units, where a represents 56% by mass, b represents 36% by mass, and c represents 8% by mass. The weight-average molecular weight is 17,000.)

[0163] [Chemical Formula 18]

[0164] (Fabrication of the optical anisotropic layer (C)) Using a die-coating machine, the liquid crystal composition (3c) described below was coated onto the support prepared in Example 1, forming a composition layer. The first dummy support with the composition layer formed was heated with warm air at 60°C for 1 minute, and simultaneously purged with nitrogen to achieve an oxygen concentration of less than 100 ppm by volume, while being irradiated with ultraviolet light (irradiation dose 120 mJ / cm²). 2 Using an ultra-high pressure mercury lamp, the orientation of the rod-shaped liquid crystal compound L-1 was fixed to form an optically anisotropic layer (3c). In addition, the thickness of the optical anisotropic layer (3c) is 0.7 μm. The Re (550) of the optical anisotropic layer (1c) is 0 nm, and the Rth (550) is -80 nm. The average tilt angle of the rod-shaped liquid crystal compound L-1 relative to the surface of the optical anisotropic layer is 90°, and it is oriented perpendicularly to the surface of the support.

[0165] ─────────────────────────────── Composition for forming optical anisotropic layers (3c) ─────────────────────────────── 100 parts by mass of the above-mentioned rod-shaped liquid crystal compound L-1 Multifunctional monomer (UA-306I, manufactured by KYOEISHA CHEMICAL CO.,LTD.) 5.0 parts by weight Polymerization initiator (IrgacureOXE01, manufactured by BASF) 4.0 parts by weight Polymer X-1 of Example 1, 1.2 parts by weight 1.14 parts by weight of the onium salt compound in Example 1 The following silicon-containing compound C, 0.04 parts by weight The following silicon-containing compound D, 0.21 parts by weight 43.3 parts by weight of methyl ethyl ketone 95.0 parts by weight of ethyl propionate 494.9 parts by weight of methyl isobutyl ketone ───────────────────────────────

[0166] Silicon-containing compound C (weight-average molecular weight: 20,000, where the numbers in the following formulas represent the content (mass%) of each repeating unit relative to all repeating units in silicon-containing compound C).

[0167] [Chemical Formula 19]

[0168] Silicon-containing compound D (weight-average molecular weight: 30,000, where the numbers in the following formulas represent the content (mass%) of each repeating unit relative to all repeating units in silicon-containing compound D).

[0169] [Chemical Formula 20]

[0170] <Comparative Example 1> An optical anisotropic layer (B) was formed by coating the above-mentioned optical anisotropic layer forming composition (1b) onto an alignment film prepared in Example 1 that was not an optical anisotropic layer (1a). An optical anisotropic layer (1a) and an optical anisotropic layer (1b) were continuously bonded together using an ultraviolet curable adhesive with a refractive index of 1.51 to form a laminate (1a-1b). Otherwise, a laminate (1c-1b-1a) was formed in the same manner as in Example 3, and a circular polarizer was formed.

[0171] [Evaluation of uneven interference colors] A circular polarizer was fabricated and attached to a blackboard using a pressure-sensitive adhesive, with the polarizer protective film positioned on the outside. The hue was observed from all angles under fluorescence (FPL-27EX-N) through a diffuser plate. The azimuth dependence of the hue variation was evaluated against the following criteria. A: Uneven tonal distribution is not visually discernible within the surface, or is visually discernible but minimal. (Permissible) B: Uneven color tone is visually apparent within the surface, but the reflected light is minimal, and there are no issues with its use. (Permitted) C: Uneven color tone is visually discernible within the surface and is unacceptable.

[0172] [Table 1]

[0173] The circular polarizers produced in the various embodiments and comparative examples were adhered to an aluminum plate with the polarizer protective film positioned on the outside using a pressure-sensitive adhesive. The results of the reflected color were confirmed from the front and tilt directions under a white light source. No hue or less was observed in any embodiment, and the display performance was good in both the front and tilt directions.

[0174] Based on the above results, it was confirmed that when a circular polarizer incorporating the optical laminate of the present invention is used in an organic EL display device, interference color inhomogeneity is suppressed, and display performance in both the front and tilt directions is good. On the other hand, the circular polarizer of the comparative example did not achieve the desired effect when used in an organic EL display device. A comparison of Example 3 with other examples confirms that when the refractive index of the adhesive layer 2 is 1.53 to 1.64, interference color inhomogeneity can be further suppressed. Symbol Explanation

[0175] 12-Optical anisotropic layer (A), 14-Optical anisotropic layer (B), 16-Optical anisotropic layer (C), 20-Polarizer, 100-Circular polarizer, 121, 122, 141, 142-Surface.

Claims

1. A method for manufacturing an optical laminate, comprising the following steps: directly coating a liquid crystal composition forming an optical anisotropic layer (B) that does not have a λ / 4 function but has a phase difference onto an optical anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies either of the following necessary conditions 1 or 2 and does not have a λ / 4 function, to form a laminate with a λ / 4 function. Necessary condition 1: The optical anisotropic layer (A) has undergone surface treatment; Necessary condition 2: The optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer.

2. The method for manufacturing an optical laminate according to claim 1, wherein, The optical anisotropy layer (A) is a negative uniaxial optical anisotropy layer.

3. The method for manufacturing an optical laminate according to claim 1, wherein, The optical anisotropic layer (B) is an optical anisotropic layer formed by fixing a twisted and oriented rod-shaped liquid crystal compound with the thickness direction as the helical axis.

4. The method for manufacturing an optical laminate according to claim 1, comprising: The process of forming a C-plate by directly coating a liquid crystal composition for forming a C-plate onto the laminate or by bonding a C-plate via an adhesive layer.

5. A method for manufacturing a polarizer, wherein an optical laminate obtained by the method for manufacturing an optical laminate according to any one of claims 1 to 4 is laminated with a polarizer to obtain a polarizer.

6. An optical laminate comprising, sequentially arranged adjacently, an optically anisotropic layer (A) formed by fixing an oriented liquid crystal compound, which satisfies either of the following necessary conditions 1 or 2 and does not have a λ / 4 function but has a phase difference; an optically anisotropic layer (B) which does not have a λ / 4 function but has a phase difference; an adhesive layer (2); and a plate C, which has a λ / 4 function. Necessary condition 1: The optical anisotropic layer (A) has undergone surface treatment; Necessary condition 2: The optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer.

7. The optical laminate according to claim 6, wherein, The adhesive layer (2) has a refractive index of 1.53 to 1.

64.

8. The optical laminate according to claim 6, wherein, Silicon is present at the interface between the optical anisotropic layer (A) and the optical anisotropic layer (B).

9. A polarizer comprising, in sequence, a polarizer, an adhesive layer (1), an optically anisotropic layer (A) formed by fixing an oriented liquid crystal compound and satisfying either of the following necessary conditions 1 or 2 and having a phase difference but not having a λ / 4 function, an optically anisotropic layer (B) having a phase difference but not having a λ / 4 function, an adhesive layer (2), and a C plate, wherein the laminate of the optically anisotropic layer (A) and the optically anisotropic layer (B) has a λ / 4 function. Necessary condition 1: The optical anisotropic layer (A) has undergone surface treatment; Necessary condition 2: The optical anisotropy layer (A) is formed from a liquid crystal composition containing a photo-orientation polymer.

10. An organic electroluminescent display device having an optical laminate according to any one of claims 6 to 8.

11. An organic electroluminescent display device having the polarizer of claim 9.

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