Light absorption anisotropic film, optical film, and image display device

Abstract

A first problem addressed by the present invention is to provide a light absorption anisotropic film having excellent light resistance and excellent orientation of a dichroic substance. A second problem addressed by the present invention is to provide an optical film and an image display device.　This light absorption anisotropic film includes a liquid crystal compound, a dichroic substance, and a phenol compound, the angle θ formed by the transmittance center axis of the light absorption anisotropic film and the normal direction of the light absorption anisotropic film surface being 0-45°, and the phenol compound including a compound represented by formula (1).

Description

Optically absorbing anisotropic film, optical film, image display device

[0001] The present invention relates to an optically absorptive anisotropic film, an optical film, and an image display device.

[0002] A technique using an optically absorptive anisotropic film having an absorption axis in the thickness direction is known for preventing viewing of an image display device and controlling the viewing angle. For example, Patent Document 1 discloses an example of such an optically absorptive anisotropic film, which is a cured film of a liquid crystal composition containing a polymerizable liquid crystal compound, a reactive group-containing non-liquid crystal compound, and a dichroic dye, and which is cured in a state in which the polymerizable liquid crystal compound and the dichroic dye are aligned in the direction perpendicular to the plane of the optically absorptive anisotropic film.

[0003] Japanese Patent Application Laid-Open No. 2022-136111

[0004] However, optically absorptive anisotropic films are required to have further improvements in light fastness and dichroic material orientation. The present inventors have studied the optically absorptive anisotropic films specifically disclosed in Patent Document 1 and have found that there are cases in which light fastness and dichroic material orientation are not compatible. In other words, it has become clear that there is room for further study on optically absorptive anisotropic films that are excellent in both light fastness and dichroic material orientation.

[0005] Therefore, an object of the present invention is to provide an optically absorptive anisotropic film that is excellent in light resistance and in the alignment of a dichroic material, and also to provide an optical film and an image display device.

[0006] The present inventors have found that the above problems can be solved by the following configuration.

[0007] [1] An optically absorptive anisotropic film comprising a liquid crystal compound, a dichroic substance, and a phenol compound, wherein the angle θ between the transmittance central axis of the optically absorptive anisotropic film and the normal direction to the surface of the optically absorptive anisotropic film is 0 to 45°, and the phenol compound comprises a compound represented by formula (1) described below. [2] The optically absorptive anisotropic film according to [1], further comprising one or more compounds selected from the group consisting of silane coupling agents, hydrolysates thereof, and hydrolyzed condensates thereof. [3] The optically absorptive anisotropic film according to [1] or [2], further comprising an ionic compound. [4] An optical film comprising a substrate and the optically absorptive anisotropic film according to any one of [1] to [3], disposed on the substrate. [5] The optical film according to [4], further comprising a protective layer on the surface of the optically absorptive anisotropic film opposite to the substrate. [6] The optical film according to [5], wherein the protective layer comprises polyvinyl alcohol or a derivative thereof. [7] An image display device comprising the optical film according to any one of [4] to [6].

[0008] According to the present invention, it is possible to provide a light absorption anisotropic film that is excellent in light resistance and in the alignment of a dichroic material, and also to provide an optical film and an image display device.

[0009] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments and specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0010] In this specification, "absorption axis" refers to the polarization direction in which absorbance is maximized in a plane when linearly polarized light is incident. "Reflection axis" refers to the polarization direction in which reflectance is maximized in a plane when linearly polarized light is incident. "Transmission axis" refers to the direction in a plane that is perpendicular to the absorption axis or reflection axis. "Slow axis" refers to the direction in a plane in which refractive index is maximized.

[0011] In this specification, Re(λ) and Rth(λ) represent the in-plane retardation and the thickness retardation, respectively, at a wavelength λ. Unless otherwise specified, the wavelength λ is 550 nm. In the present invention, Re(λ) and Rth(λ) are values ​​measured at a wavelength λ using an AxoScan (manufactured by Axometrics). By inputting the average refractive index ((nx + ny + nz) / 3) and film thickness (d (μm)) into AxoScan, the following slow axis direction (°) is calculated: Re(λ) = R0(λ) Rth(λ) = ((nx + ny) / 2 - nz) × d. Note that R0(λ) is displayed as a numerical value calculated by AxoScan, but it means Re(λ).

[0012] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by Atago Co., Ltd.) with a sodium lamp (λ=589 nm) as a light source. When measuring wavelength dependency, measurements can be made using a multi-wavelength Abbe refractometer DR-M2 (manufactured by Atago Co., Ltd.) in combination with an interference filter. Values ​​from the Polymer Handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can also be used. Examples of average refractive index values ​​for major optical films are listed below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0013] In this specification, A plates and C plates are defined as follows. There are two types of A plates: positive A plates (positive A plates) and negative A plates (negative A plates). When the refractive index in the in-plane slow axis direction (the direction in which the in-plane refractive index is maximum) of the film is nx, the refractive index in the in-plane direction perpendicular to the in-plane slow axis is ny, and the refractive index in the thickness direction is nz, the positive A plates satisfy the relationship of formula (A1), and the negative A plates satisfy the relationship of formula (A2). Note that the positive A plates have a positive Rth value, and the negative A plates have a negative Rth value. Formula (A1) nx>ny≒nz Formula (A2) ny<nx≒nz Note that the above "≒" encompasses not only the case where the two are completely identical, but also the case where the two are substantially identical. "Substantially the same" means, for example, that "ny ≒ nz" also includes cases where (ny - nz) x d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, and "nx ≒ nz" also includes cases where (nx - nz) x d is -10 to 10 nm, preferably -5 to 5 nm. There are two types of C plates: positive C plates (positive C plates) and negative C plates (negative C plates). Positive C plates satisfy the relationship of formula (C1), while negative C plates satisfy the relationship of formula (C2). Note that positive C plates have a negative Rth value, and negative C plates have a positive Rth value. Formula (C1) nz > nx ≒ ny Formula (C2) nz < nx ≒ ny Note that the above "≒" includes not only cases where the two are completely identical, but also cases where the two are substantially identical. The term "substantially the same" includes, for example, the case where (nx-ny) x d (where d is the thickness of the film) is 0 to 10 nm, preferably 0 to 5 nm, in "nx≈ny".

[0014] In this specification, each component may be a single substance corresponding to the component, or two or more substances may be used in combination. When two or more substances are used in combination for each component, the content of the component refers to the total content of the substances used in combination, unless otherwise specified.

[0015] In this specification, "(meth)acryloyl" is used to mean "either one or both of acryloyl and methacryloyl."

[0016] In this specification, the solid content of the composition refers to the components that form the composition layer, and does not include the solvent. The components that form the composition layer may be components that undergo a reaction (polymerization) and change their chemical structure when forming the composition layer. Furthermore, any component that forms the composition layer is considered to be a solid content even if it is in a liquid state.

[0017] The bonding direction of divalent groups represented in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. In addition, the compound may be "X-CO-O-Z" or "X-O-CO-Z".

[0018] [Lightly absorptive anisotropic film] The lightly absorptive anisotropic film of the present invention is a lightly absorptive anisotropic film containing a liquid crystal compound, a dichroic substance, and a phenol compound, wherein the angle θ between the transmittance central axis of the lightly absorptive anisotropic film and the normal direction to the surface of the lightly absorptive anisotropic film is 0 to 45°, and the phenol compound contains a compound represented by formula (1) (hereinafter also referred to as a "specific phenol compound").

[0019] The optically absorptive anisotropic film having the above-described configuration has excellent light resistance and also has excellent alignment of dichroic materials. Although the mechanism of action is not entirely clear, the present inventors speculate as follows: That is, due to its structure, the specific phenol compound is unevenly distributed on the surface of the optically absorptive anisotropic film, and can function as an alignment agent (vertical alignment agent) that promotes vertical alignment of liquid crystal compounds. As a result, the optically anisotropic film is speculated to have excellent alignment of dichroic materials. Furthermore, the specific phenol compound also functions as an antioxidant that captures radicals and prevents autoxidation, and it is speculated that the optically absorptive anisotropic film has excellent light resistance.

[0020] Hereinafter, the better light resistance of the optically absorptive anisotropic film of the present invention and / or the better orientation of the dichroic material in the optically absorptive anisotropic film of the present invention may be referred to as "the effect of the present invention being better."

[0021] The various components contained in the optically absorptive anisotropic film will be described in detail below.

[0022] [Liquid Crystal Compound] As the liquid crystal compound, either a polymer liquid crystal compound or a low molecular weight liquid crystal compound can be used. It is also possible to use a combination of a polymer liquid crystal compound and a low molecular weight liquid crystal compound. Here, the term "polymer liquid crystal compound" refers to a liquid crystal compound having a repeating unit in its chemical structure. Furthermore, the term "low molecular weight liquid crystal compound" refers to a liquid crystal compound having no repeating unit in its chemical structure.

[0023] The liquid crystal compound may exhibit either thermotropic or lyotropic liquid crystal properties, and the phase order structure of the thermotropic liquid crystal may be either nematic or smectic.

[0024] The liquid crystal compound generally includes a liquid crystal compound exhibiting positive wavelength dispersion and a liquid crystal compound exhibiting reverse wavelength dispersion, and either one may be used alone or both may be used in combination. Among them, a liquid crystal compound exhibiting positive wavelength dispersion is preferable.

[0025] In the optically absorptive anisotropic film, the liquid crystal compound is preferably fixed in an aligned state, and more preferably the alignment is fixed by polymerization. When the alignment of the liquid crystal compound in the optically absorptive anisotropic film is fixed by polymerization, the optically absorptive anisotropic film typically contains a cured product in which the polymerizable liquid crystal compound is cured in an aligned state. The polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable group (preferably a photopolymerizable group). The polymerizable liquid crystal compound is not particularly limited, and for example, any polymerizable liquid crystal compound conventionally known in the field of retardation films can be appropriately used. Examples of the polymerizable group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, a (meth)acryloyloxy group, an oxiranyl group, and an oxetanyl group, and among these, a (meth)acryloyloxy group is preferred.

[0026] Specific examples of the polymerizable liquid crystal compound are given below. Examples of the polymerizable liquid crystal compound include a compound containing a group represented by the following formula (Y) (hereinafter, sometimes referred to as "polymerizable liquid crystal compound (Y)"). The polymerizable liquid crystal compound (Y) generally tends to exhibit positive wavelength dispersion.

[0027] P11-B11-E11-B12-A11-B13- (Y)

[0028] In formula (Y), P11 represents a polymerizable group. A11 represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atoms contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group, and the hydrogen atoms contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom. B11 represents -O-, -S-, -CO-O-, -O-CO-O-, -CO-NR １６ B12 and B13 each independently represent -, -CO-, -CS-, or a single bond. ２ -CH ２ -, -O-, -S-, -CO-, -CO-O-, -O-CO-O-, -CH=N-, -N=N-, -CO-NR １６-, -OCH ２ -, -OCF ２ represents -, -CH=CH-CO-O-, or a single bond. １６ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. E11 represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. In addition, at least one —CH ２ - may be replaced by -O- or -CO-.

[0029] The number of carbon atoms in the aromatic hydrocarbon group and alicyclic hydrocarbon group of A11 is preferably 3 to 18, more preferably 5 to 12, and even more preferably 5 or 6. A11 is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

[0030] E11 is preferably a linear alkanediyl group having 1 to 12 carbon atoms. At least one —CH ２ Specific examples of the linear alkanediyl group having 1 to 12 carbon atoms represented by E11 include linear alkanediyl groups having 1 to 12 carbon atoms such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; ２ -CH ２ -O-CH ２ -CH ２ -;-CH ２ -CH ２ -O-CH ２ -CH ２ -O-CH ２ -CH ２ -;-CH ２ -CH ２ -O-CH ２ -CH ２ -O-CH ２ -CH２ -O-CH ２ -CH ２ -; etc. B11 is preferably -O-, -S-, or -CO-O-, and more preferably -CO-O-. B12 and B13 are each independently preferably -O-, -S-, -CO-, -CO-O-, or -O-CO-O-, and more preferably -O- or -O-CO-O-.

[0031] The polymerizable group represented by P11 is not particularly limited, and examples thereof include the polymerizable groups described above. Among these, a vinyl group, a p-stilbene group, an epoxy group, or an oxetanyl group is more preferred. The group represented by P11-B11- is preferably a (meth)acryloyloxy group.

[0032] Examples of the polymerizable liquid crystal compound (Y) include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V), and formula (VI). P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V) P11-B11-E11-B12-A11-B13-A12-F11 (VI)

[0033] In formulae (I) to (VI), A12 to A14 each independently have the same meaning as A11, B14 to B16 each independently have the same meaning as B12, B17 has the same meaning as B11, E12 has the same meaning as E11, and P12 has the same meaning as P11. F11 is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SO ３H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and -CH constituting the above alkyl group and alkoxy group. ２ - may be replaced by -O-.

[0034] Specific examples of the polymerizable liquid crystal compound (Y) include compounds having a polymerizable group among the compounds described in "3.8.6 Network (fully crosslinked)" and "6.5.1 Liquid Crystal Material b. Polymerizable Nematic Liquid Crystal Material" in Liquid Crystal Handbook (edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. on October 30, 2000), and polymerizable liquid crystals described in JP-A Nos. 2010-031223, 2010-270108, 2011-006360, and 2011-207765.

[0035] Specific examples of the polymerizable liquid crystal compound (Y) include compounds represented by the following formulae (I-1) to (I-4), (II-1) to (II-4), (III-1) to (III-26), (IV-1) to (IV-26), (V-1) to (V-2), and (VI-1) to (VI-6). In the following formulae, k1 and k2 each independently represent an integer of 2 to 12.

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] The polymerizable liquid crystal compound is preferably a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity. Examples of the polymerizable liquid crystal compound exhibiting smectic liquid crystallinity include a compound represented by the following formula (Z) (hereinafter, sometimes referred to as "polymerizable liquid crystal compound (Z)"). １ｚ -V １ｚ -W １ｚ -(X １ｚ -Y １ｚ -) ｎｚ -X ２ｚ -W ２ｚ -V ２ｚ -U ２ｚ (Z)

[0046] In formula (Z), X １ｚ and X ２ｚ each independently represents a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. １ｚ and X ２ｚ At least one of Y is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group. １ｚ is a single bond or a divalent linking group. nz is 1 to 3, and when nz is 2 or more, a plurality of X １ｚ may be the same or different. ２ｚ is multiple X １ｚ In addition, when nz is 2 or more, a plurality of Y １ｚ may be the same or different. From the viewpoint of liquid crystal properties, nz is preferably 2 or more. １ｚ represents a hydrogen atom or a (meth)acryloyloxy group. ２ｚ represents a polymerizable group. １ｚ and W ２ｚare each independently a single bond or a divalent linking group. １ｚ and V ２ｚ each independently represents an alkanediyl group having 1 to 20 carbon atoms which may have a substituent, and —CH ２ - may be replaced by -O-, -CO-, -S- or -NH-.

[0047] In the polymerizable liquid crystal compound (Z), X １ｚ and X ２ｚ each independently represents an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, and X １ｚ and X ２ｚ At least one of the groups is preferably an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group, more preferably a trans-cyclohexane-1,4-diyl group. Examples of optional substituents that the optionally substituted 1,4-phenylene group or the optionally substituted cyclohexane-1,4-diyl group may have include alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, and butyl groups, cyano groups, and halogen atoms such as chlorine and fluorine atoms. Preferably, the group is unsubstituted.

[0048] Y １ｚ is -CH ２ CH ２ -, -CH ２ O-, -CH ２ CH ２ O-, -COO-, -O-CO-O-, single bond, -N=N-, -CR ａｚ =CR ｂｚ -, -C≡C-, -CR ａｚ ═N—, or —CO—NR ａｚ - is preferred. ａｚ and R ｂｚ Each of Y independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ｚ is -CH ２ CH ２ -, -COO-, or a single bond is more preferred, and a plurality of Y １ｚ If there exists X ２ｚ Y bonded to１ｚ is -CH ２ CH ２ - or -CH ２ O- is more preferred. １ｚ and X ２ｚ When all of Y are the same structure, two or more Y １ｚ It is preferable that there are plural Y １ｚ When the compound has an asymmetric structure, the compound tends to exhibit smectic liquid crystallinity.

[0049] U ２ｚ is the polymerizable group described above. １ｚ is a hydrogen atom or a polymerizable group. ２ｚ and U １ｚ The polymerizable group represented by the formula (I) is preferably a (meth)acryloyloxy group.

[0050] V １ｚ and V ２ｚ Examples of the alkanediyl group represented by the formula (V) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a decane-1,10-diyl group, a tetradecane-1,14-diyl group, and an icosane-1,20-diyl group. １ｚ and V ２ｚ is preferably an alkanediyl group having 2 to 12 carbon atoms, and more preferably an alkanediyl group having 6 to 12 carbon atoms.

[0051] Examples of the substituent that the alkanediyl group may optionally have include a cyano group and a halogen atom, but the alkanediyl group is preferably unsubstituted, and more preferably an unsubstituted linear alkanediyl group.

[0052] W １ｚ and W ２ｚ are each independently preferably a single bond, —O—, —S—, —COO—, or —O—CO—O—, and more preferably a single bond or —O—.

[0053] The polymerizable liquid crystal compound (Z) preferably has an asymmetric molecular structure, and more preferably has a partial structure represented by the following formulas (A-a) to (A-i). In terms of easily exhibiting high-order smectic liquid crystal properties, it is more preferable that the compound has a partial structure represented by formula (A-a), formula (A-b), or formula (A-c). In formulas (A-a) to (A-i), * represents a bonding position.

[0054]

[0055] Specific examples of the polymerizable liquid crystal compound (Z) include compounds represented by formulae (A-1) to (A-26). When the polymerizable liquid crystal compound (Z) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans isomer.

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062] The polymerizable liquid crystal compound (Z) can be produced by a known method, for example, as described in Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996) or Japanese Patent No. 4719156.

[0063] The content of the liquid crystal compound in the optically absorptive anisotropic film is preferably 25 to 2,000 parts by mass, more preferably 100 to 1,300 parts by mass, and even more preferably 200 to 900 parts by mass, per 100 parts by mass of the dichroic substance. When the content of the liquid crystal compound is within the above range, the degree of orientation of the dichroic substance is further improved. The liquid crystal compound may be contained alone or in combination of two or more types. When two or more types of liquid crystal compounds are contained, the content of the liquid crystal compounds refers to the total content of the liquid crystal compounds.

[0064] [Dichroic Substance] The optically absorptive anisotropic film contains a dichroic substance. In this specification, a dichroic substance refers to a dye whose absorbance varies depending on the direction. The dichroic substance may or may not exhibit liquid crystallinity. When the dichroic azo dye compound exhibits liquid crystallinity, it may exhibit either nematic or smectic properties. The temperature range in which the liquid crystal phase is exhibited is preferably room temperature (approximately 20 to 28°C) to 300°C, and more preferably 50 to 200°C from the viewpoints of handleability and manufacturability. In the optically absorptive anisotropic film, the dichroic substance may be fixed in an oriented state. For example, when the orientation of the dichroic substance in the optically absorptive anisotropic film is fixed by polymerization, the optically absorptive anisotropic film typically contains a cured product in which the dichroic substance is cured in an oriented state.

[0065] The dichroic substance is not particularly limited, and examples thereof include visible light absorbing substances (dichroic dyes), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet absorbing substances, infrared absorbing substances, nonlinear optical substances, carbon nanotubes, and inorganic substances (e.g., quantum rods), and any conventionally known dichroic substance (dichroic dye) can be used. Preferred dichroic substances include dichroic azo dyes, dichroic acridine dyes, dichroic oxazine dyes, dichroic cyanine dyes, dichroic naphthalene dyes, dichroic azo dyes, and dichroic anthraquinone dyes, and among these, dichroic azo dyes are more preferred.

[0066] As the dichroic azo dye, a dichroic azo dye typically used in a so-called coating-type polarizer can be used. The dichroic azo dye is not particularly limited, and a conventionally known dichroic azo dye can be used. Among them, bisazo dyes and trisazo dyes are preferred as the dichroic azo dye. The dichroic azo dye may have a polymerizable group. When the dichroic azo dye has a polymerizable group, the optically absorptive anisotropic film typically contains the dichroic azo dye in a state in which its orientation is fixed by polymerization.

[0067] An example of a dichroic azo dye is a compound represented by formula (A) (hereinafter also referred to as "compound (A)"). When compound (A) has a polymerizable group, the optically absorptive anisotropic film typically contains a polymer of compound (A).１ (-N=N-K ２ ) ｐ -N=N-K ３ (A)

[0068] In formula (A), K １ and K. ３ each independently represents a phenyl group which may have a substituent, a naphthyl group which may have a substituent, or a monovalent heterocyclic group which may have a substituent. ２ represents a p-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, or a divalent heterocyclic group which may have a substituent. p represents an integer of 1 to 4. When p is an integer of 2 or more, a plurality of K ２ may be the same or different. In addition, the —N═N— bond may be substituted with a —C═C—, —COO—, —NHCO—, or —N═CH— bond as long as absorption in the visible region is exhibited.

[0069] Examples of the monovalent heterocyclic group include groups obtained by removing one hydrogen atom from heterocyclic compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. Examples of the divalent heterocyclic group include groups obtained by removing two hydrogen atoms from the heterocyclic compounds. Note that the heterocyclic compound is preferably an aromatic heterocyclic compound. In other words, the monovalent heterocyclic group is preferably a monovalent aromatic heterocyclic group, and the divalent heterocyclic group is preferably a divalent aromatic heterocyclic group.

[0070] K １ and K. ３ Phenyl groups, naphthyl groups, and monovalent heterocyclic groups in the above formula (I), and K ２ The substituents that the p-phenylene group, naphthalene-1,4-diyl group, and divalent heterocyclic group in the formula (I) may optionally have are not particularly limited, but may include, for example, at least one —CH ２ an alkyl group having 1 to 20 carbon atoms in which - may be substituted with a group selected from -CO- and -O-; ２an alkyl group having 1 to 20 carbon atoms, in which - may be substituted with a group selected from -CO- and -O-; an alkenyl group having 1 to 4 carbon atoms; ２ an alkoxy group having 1 to 20 carbon atoms in which - may be substituted with a group selected from -CO- and -O-; ２ Examples of the polymerizable group include an alkoxy group having 1 to 20 carbon atoms, in which - may be substituted with a group selected from -CO- and -O-; a fluorinated alkyl group having 1 to 4 carbon atoms such as a trifluoromethyl group; a cyano group; a nitro group; a halogen atom; and a substituted or unsubstituted amino group. Examples of the polymerizable group include a (meth)acryloyl group and a (meth)acryloyloxy group. Examples of the substituted amino group include -NH(R ａ ) or -N(R ａ ) ２ R represents any one of the groups ａ represents a substituent. ａ The substituent represented by is not particularly limited, but for example, at least one -CH ２ an alkyl group having 1 to 6 carbon atoms in which - may be substituted with a group selected from -CO- and -O-; ２ an alkyl group having 1 to 6 carbon atoms, in which - may be substituted with a group selected from -CO- and -O-; ａ ) ２ In the group represented by the formula ａ may be bonded to each other (e.g., two R ａ In one embodiment, the unsubstituted amino group is —NH ２ is.

[0071] K １ and K. ３ In terms of the substituents that the phenyl group, naphthyl group, and monovalent heterocyclic group in the formula (I) may optionally have, at least one -CH ２ an alkyl group having 1 to 20 carbon atoms in which - may be substituted with a group selected from -CO- and -O-; ２an alkyl group having 1 to 20 carbon atoms, in which - may be substituted with a group selected from -CO- and -O-; ２ an alkoxy group having 1 to 20 carbon atoms in which - may be substituted with a group selected from -CO- and -O-; ２ an alkoxy group having 1 to 20 carbon atoms, in which - may be substituted with a group selected from -CO- and -O-; ａ ) ２ A substituted amino group represented by the formula (wherein R ａ but at least one -CH ２ - is an alkyl group having 1 to 6 carbon atoms which may be substituted with a group selected from -CO- and -O-, or has a polymerizable group, and at least one -CH ２ represents an alkyl group having 1 to 6 carbon atoms which may be substituted with a group selected from —CO— and —O—;

[0072] K １ and K. ３In terms of the substituents that the phenyl group, naphthyl group, and monovalent heterocyclic group in the formula (I) may optionally have, it is preferable that they have at least one moiety substituted with -COO- (ester bond) (hereinafter also referred to as "-COO-substitution moiety"), in that the effects of the present invention are more excellent. Specific examples of the substituent include an alkyl group having 1 to 20 carbon atoms and having a -COO-substitution moiety (preferably an alkyl group having 2 to 20 carbon atoms and having a -COO-substitution moiety, more preferably an alkyl group having 6 to 20 carbon atoms and having a -COO-substitution moiety); an alkyl group having 1 to 20 carbon atoms and having a polymerizable group and a -COO-substitution moiety (preferably an alkyl group having 2 to 20 carbon atoms and having a polymerizable group and a -COO-substitution moiety, more preferably an alkyl group having 6 to 20 carbon atoms and having a polymerizable group and a -COO-substitution moiety). ), an alkoxy group having 1 to 20 carbon atoms and having a —COO- substitution moiety (preferably an alkoxy group having 3 to 20 carbon atoms and having a —COO- substitution moiety, more preferably an alkoxy group having 6 to 20 carbon atoms and having a —COO- substitution moiety); an alkoxy group having 1 to 20 carbon atoms and having a polymerizable group and having a —COO- substitution moiety (preferably an alkoxy group having 3 to 20 carbon atoms and having a polymerizable group and having a —COO- substitution moiety, more preferably an alkoxy group having 6 to 20 carbon atoms and having a polymerizable group and having a —COO- substitution moiety); —N(R ａ ) (R ｂ ) (wherein R ａ represents an alkyl group having 1 to 6 carbon atoms and having a —COO- substitution site, an alkyl group having 1 to 6 carbon atoms and having a polymerizable group and having a —COO- substitution site, or an alkoxy group having 1 to 6 carbon atoms and having a polymerizable group and having a —COO- substitution site (preferably an alkyl group having 2 to 6 carbon atoms and having a —COO- substitution site, an alkyl group having 2 to 6 carbon atoms and having a polymerizable group and having a —COO- substitution site, or an alkoxy group having 3 to 6 carbon atoms and having a polymerizable group and having a —COO- substitution site). ｂ represents an alkyl group having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms); is more preferred.

[0073] Among the compounds (i), compounds represented by any one of the following formulas (i-1) to (i-8) are preferred.

[0074] In formulas (A-1) to (A-8), B １ ~B ３０ Each of B independently represents a hydrogen atom or a substituent. １ ~B ３０ Specific examples of the substituents represented by the formula: １ and K. ３ Phenyl groups, naphthyl groups, and monovalent heterocyclic groups in the above formula (I), and K ２ n1 to n4 are the same as those listed as examples of the optional substituents of the p-phenylene group, naphthalene-1,4-diyl group, and divalent heterocyclic group in the above formula. n1 to n4 each independently represent an integer of 0 to 3. When n1 is 2 or more, a plurality of B ２ may be the same or different, and when n2 is 2 or more, a plurality of B ６ may be the same or different, and when n3 is 2 or more, a plurality of B ９ may be the same or different, and when n4 is 2 or more, a plurality of B １４ may be the same or different from each other.

[0075] As the dichroic acridine dye, dichroic oxazine dye, dichroic cyanine dye, dichroic naphthalene dye, dichroic azo dye, and dichroic anthraquinone dye, the compounds disclosed in paragraphs

[0083] to

[0088] of JP-A-2022-145604 can also be suitably used. In addition, as the dichroic substance, the compounds disclosed in WO 2018 / 186503, WO 2019 / 189345, and WO 2018 / 124198 can also be suitably used.

[0076] The molecular weight of the dichroic substance (weight average molecular weight when the substance has a molecular weight distribution) is typically 300 to 2,000, and preferably 400 to 1,000.

[0077] The optically absorptive anisotropic film may contain one kind of dichroic substance alone or two or more kinds of dichroic substances, but it is preferable that it contains two or more kinds, and more preferably three or more kinds, in terms of better alignment properties.

[0078] The content of the dichroic substance in the optically absorptive anisotropic film is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on the total mass of the optically absorptive anisotropic film. The upper limit is, for example, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. When two or more dichroic substances are contained, the content of the dichroic substances refers to the total content of the dichroic substances.

[0079] [Phenol Compound] The optically absorptive anisotropic film contains, as a phenol compound, a compound (specific phenol compound) represented by formula (1). The specific phenol compound will be described below.

[0080] <Compound represented by formula (1)>

[0081]

[0082] In formula (1), R １ ~R ８ R each independently represents a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group. １ ~R ８ The alkyl group represented by R is preferably a linear or branched alkyl group. １ ~R ８ The number of carbon atoms in the alkyl group represented by R is preferably 1 to 20, more preferably 1 to 15, even more preferably 1 to 10, particularly preferably 1 to 6, and most preferably 1 to 3. １ ~R ８ The alkoxy group represented by R is preferably linear or branched. １ ~R ８ The alkoxy group represented by the formula (I) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, even more preferably 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms, and most preferably 1 to 3 carbon atoms.

[0083] R １ ~R ８As the alkyl group, a methyl group or a hydrogen atom is preferred, and a hydrogen atom is more preferred, in terms of achieving better effects of the present invention.

[0084] In formula (1), L １ represents a single bond or a divalent linking group that does not contain a ring structure. The divalent linking group that does not contain a ring structure is a divalent linking group that does not contain an aromatic ring structure or an alicyclic structure, and specific examples thereof include chain (straight-chain or branched-chain) divalent linking groups. １ Specific examples of the divalent linking group not containing a ring structure represented by the formula: Ｔ Examples of the divalent linking group include -, -C=N-, -N=N-, a chain alkylene group, and a divalent linking group selected from the group consisting of a chain alkylene group, -C=N-, -N=N-, a chain alkylene group, and a combination thereof. The chain alkylene group may be either linear or branched. The number of carbon atoms in the chain alkylene group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. L １ The number of atoms excluding hydrogen atoms of the divalent linking group represented by the formula (I) is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. Ｔ represents a hydrogen atom or a chain alkyl group having 1 to 7 carbon atoms, and is preferably a hydrogen atom.

[0085] L １ As the alkyl group, a single bond, —COO—, or —O— is preferred, and a single bond or —O— is more preferred, in terms of achieving better effects of the present invention.

[0086] In formula (1), L ２ represents a single bond or a divalent linking group. ２ Specific examples of the divalent linking group represented by the formula: Ｔ Examples of the alkylene group include a divalent linking group selected from the group consisting of -, -C=N-, -N=N-, an alkylene group, and a combination thereof. The alkylene group may be linear, branched, or cyclic, and is preferably linear (linear or branched). The number of carbon atoms in the alkylene group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. L ２The number of atoms excluding hydrogen atoms of the divalent linking group represented by the formula (I) is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. Ｔ represents a hydrogen atom or an alkyl group having 1 to 7 carbon atoms, and among these, a hydrogen atom is preferred. Ｔ The alkyl group having 1 to 7 carbon atoms represented by the formula (I) may be any of linear, branched, and cyclic, and is preferably linear (linear or branched).

[0087] L ２ As the alkyl group, a single bond, —COO—, or —O— is preferred, and a single bond or —O— is more preferred, in terms of achieving better effects of the present invention.

[0088] In formula (1), A １ represents a group represented by formula (2), a hydroxyl group, an alkyl group, or an alkoxy group.

[0089]

[0090] In formula (2), R ９ ~R １３ Each independently represents a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group. * represents a bonding position. R ９ ~R １３ The alkyl group represented by R is preferably a linear or branched alkyl group. ９ ~R １３ The number of carbon atoms in the alkyl group represented by R is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 10. ９ ~R １３ The alkoxy group represented by R is preferably linear or branched. ９ ~R １３ The alkoxy group represented by the formula (I) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 10 carbon atoms.

[0091] R ９ , R １０ , R １２ , and R １３ R is preferably a methyl group or a hydrogen atom, more preferably a hydrogen atom, in terms of achieving better effects of the present invention. １１is preferably an alkyl group or an alkoxy group, as this provides better effects of the present invention.

[0092] A １ The alkyl group represented by the formula (I) may be linear, branched, or cyclic. １ The number of carbon atoms in the alkyl group represented by the formula (I) is preferably 1 to 20, more preferably 1 to 15, and even more preferably 1 to 10. １ The alkoxy group represented by the formula (I) is preferably a linear or branched alkoxy group. １ The alkoxy group represented by the formula (I) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 10 carbon atoms.

[0093] A １ Among these, a group represented by formula (2), an alkyl group, or an alkoxy group is preferred.

[0094] In formula (1), n ​​represents an integer of 0 to 2. n is preferably 0 or 1, and more preferably 0, in that the effects of the present invention are more excellent.

[0095] In addition, in formula (1), when n represents 2, there are multiple R ５ R exists in multiple places ６ R exists in multiple places ７ R exists in multiple places ８ L ２ They may be the same or different from each other.

[0096] The molecular weight of the specific phenol compound is preferably 600 or less, more preferably 500 or less, and even more preferably 450 or less.

[0097] The number of hydroxyl groups in the specific phenol compound is preferably one, in terms of achieving better effects of the present invention.

[0098] Specific examples of the specific phenol compound are listed below, but the invention is not limited thereto.

[0099]

[0100] The content of the specific phenol compound in the optically absorptive anisotropic film is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.5% by mass or more, based on the total mass of the optically absorptive anisotropic film.The upper limit is, for example, preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.The specific phenol compound may be contained alone, or two or more types may be contained.When two or more types of specific phenol compounds are contained, the content of the specific phenol compound refers to the total content of the specific phenol compounds.

[0101] [Other Components] In addition to the components described above, the optically absorptive anisotropic film may contain an alignment promoter (vertical alignment agent), an adhesion improver, a plasticizer, a polymer, and the like.

[0102] <Alignment Promoter (Vertical Alignment Agent)> The optically absorptive anisotropic film preferably contains an alignment promoter (vertical alignment agent) in order to obtain excellent effects of the present invention. Examples of the alignment promoter (vertical alignment agent) include an ionic compound and a silane compound.

[0103] (Ionic Compound) The ionic compound is preferably an ionic compound comprising non-metallic atoms. Examples of the ionic compound include onium salts (specifically, quaternary ammonium salts, tertiary sulfonium salts, and quaternary phosphonium salts). Among these, quaternary phosphonium salts or quaternary ammonium salts are preferred, and quaternary ammonium salts are more preferred, in terms of superior vertical alignment of the liquid crystal compound. The onium salt may also be a compound having two or more salt structure moieties in the molecule. The onium salt may also be an oligomer or a polymer.

[0104] The molecular weight of the ionic compound is not particularly limited, but is preferably from 100 to 10,000, more preferably from 100 to 5000, and even more preferably from 100 to 3000, in order to provide a more excellent vertical alignment property of the liquid crystal compound.

[0105] The cation component of the ionic compound may be either an inorganic cation or an organic cation, but an organic cation is preferred because it is less likely to cause orientation defects. Examples of the organic cation include an imidazolium cation, a pyridinium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation.

[0106] The ionic compound typically has an anion component that is a counterpart of the cation component. The anion component may be either an inorganic anion or an organic anion, but an organic anion is preferred because it is less likely to cause alignment defects.

[0107] Specific examples of the anion component include the following: chloride anion [Cl － ], bromide anion [Br － ], iodide anion [I － ], tetrachloroaluminate anion [AlCl ４ － ], heptachlorodialuminate anion [Al ２ Cl ７ － ], tetrafluoroborate anion [BF ４ － ], hexafluorophosphate anion [PF ６ － ], perchlorate anion [ClO ４ － ], nitrate anion [NO ３ － ], acetate anion [CH ３ COO － ], trifluoroacetate anion [CF ３ COO － ], fluorosulfonate anion [FSO ３ － ], methanesulfonate anion [CH ３ SO ３ － ], trifluoromethanesulfonate anion [CF ３ SO ３ －], p-toluenesulfonate anion [p-CH ３ C ６ H ４ SO ３ － ], bis(fluorosulfonyl)imide anion [(FSO ２ ) ２ N － ], bis(trifluoromethanesulfonyl)imide anion [(CF ３ SO ２ ) ２ N － ], tris(trifluoromethanesulfonyl)methanide anion [(CF ３ SO ２ ) ３ C － ], hexafluoroarsenate anion [AsF ６ － ], hexafluoroantimonate anion [SbF ６ － ], hexafluoroniobate anion [NbF ６ － ], hexafluorotantalate anion [TaF ６ － ], dimethylphosphinate anion [(CH ３ ) ２ P.O.O. － ], (poly)hydrofluorofluoride anion [F(HF) ｎ － ] (for example, n represents an integer of 1 to 3), dicyanamide anion [(CN) ２ N － ], thiocyanate anion [SCN － ], perfluorobutanesulfonate anion [C ４ F ９ SO ３ － ], bis(pentafluoroethanesulfonyl)imide anion [(C ２ F ５ SO ２ ) ２ N － ], perfluorobutanoate anion [C ３ F ７ COO －], and (trifluoromethanesulfonyl)(trifluoromethanecarbonyl)imide anion [(CF ３ SO ２ ) (CF ３ CO)N － 〕.

[0108] Specific examples of the ionic compound can be appropriately selected from the combinations of the cationic component and the anionic component described above. Specific examples of the compound that is a combination of a cationic component and an anionic component include the following:

[0109] N-Hexylpyridinium hexafluorophosphate; N-Octylpyridinium hexafluorophosphate; N-Methyl-4-hexylpyridinium hexafluorophosphate; N-Butyl-4-methylpyridinium hexafluorophosphate; N-Octyl-4-methylpyridinium hexafluorophosphate; N-Hexylpyridinium bis(fluorosulfonyl)imide; N-Octylpyridinium bis(fluorosulfonyl)imide; N-Methyl-4-hexylpyridinium bis(fluorosulfonyl)imide; N-Butyl-4-methylpyridinium bis(fluorosulfonyl)imide; N-Octyl-4-methylpyridinium bis(fluorosulfonyl)imide; N-Hexylpyridinium bis(trifluoromethanesulfonyl)imide; N-Octylpyridinium bis(trifluoromethanesulfonyl)imide; N-Methyl-4-hexylpyridinium Pyridinium salts such as bis(trifluoromethanesulfonyl)imide; N-butyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide; N-octyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide; N-hexylpyridinium p-toluenesulfonate; N-octylpyridinium p-toluenesulfonate; N-methyl-4-hexylpyridinium p-toluenesulfonate; N-butyl-4-methylpyridinium p-toluenesulfonate; and N-octyl-4-methylpyridinium p-toluenesulfonate;

[0110] imidazolium salts such as 1-ethyl-3-methylimidazolium hexafluorophosphate; 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide; 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide; 1-ethyl-3-methylimidazolium p-toluenesulfonate; and 1-butyl-3-methylimidazolium methanesulfonate;

[0111] pyrrolidinium salts such as N-butyl-N-methylpyrrolidinium hexafluorophosphate; N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide; N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide; and N-butyl-N-methylpyrrolidinium p-toluenesulfonate;

[0112] Tetrabutylammonium hexafluorophosphate; Tetrabutylammonium bis(fluorosulfonyl)imide; Tetrahexylammonium bis(fluorosulfonyl)imide; Trioctylmethylammonium bis(fluorosulfonyl)imide; (2-hydroxyethyl)trimethylammonium bis(fluorosulfonyl)imide; Tetrabutylammonium bis(trifluoromethanesulfonyl)imide; Tetrahexylammonium bis(trifluoromethanesulfonyl)imide; Trioctylmethylammonium bis(trifluoromethanesulfonyl)imide; (2-hydroxyethyl)trimethylammonium bis(trifluoromethanesulfonyl)imide; Tetrabutylammonium p-toluenesulfonate; Tetrahexylammonium p-toluenesulfonate; Trioctylmethylammonium p-toluenesulfonate; (2-hydroxyethyl)trimethylammonium p-toluenesulfonate; (2-hydroxyethyl)trimethylammonium dimethylphosphinate; 1-(3-trimethoxysilylpropyl)-1,1,1-tributylammonium Ammonium salts such as bis(trifluoromethanesulfonyl)imide; 1-(3-trimethoxysilylpropyl)-1,1,1-trimethylammonium bis(trifluoromethanesulfonyl)imide; 1-(3-trimethoxysilylbutyl)-1,1,1-tributylammonium bis(trifluoromethanesulfonyl)imide; 1-(3-trimethoxysilylbutyl)-1,1,1-trimethylammonium bis(trifluoromethanesulfonyl)imide; N-{(3-triethoxysilylpropyl)carbamoyloxyethyl)}-N,N,N-trimethylammonium bis(trifluoromethanesulfonyl)imide; and N-[2-{3-(3-trimethoxysilylpropylamino)-1-oxopropoxy}ethyl]-N,N,N-trimethylammonium bis(trifluoromethanesulfonyl)imide,

[0113] Tributyl(2-methoxyethyl)phosphonium bis(trifluoromethanesulfonyl)imide; Tributylmethylphosphonium bis(trifluoromethanesulfonyl)imide; 1,1,1-trimethyl-1-[(trimethoxysilyl)methyl]phosphonium bis(trifluoromethanesulfonyl)imide; 1,1,1-trimethyl-1-[2-(trimethoxysilyl)ethyl]phosphonium bis(trifluoromethanesulfonyl)imide; 1,1,1-trimethyl-1-[3-(trimethoxysilyl)propyl]phosphonium bis(trifluoromethanesulfonyl)imide; 1,1,1-trimethyl-1-[4-(trimethoxysilyl)butyl]phosphonium bis(trifluoromethanesulfonyl)imide; 1,1,1-tributyl-1-[(trimethoxysilyl)methyl]phosphonium bis(trifluoromethanesulfonyl)imide; 1,1,1-tributyl-1-[2-(trimethoxysilyl)ethyl]phosphonium Phosphonium salts such as bis(trifluoromethanesulfonyl)imide; 1,1,1-tributyl-1-[3-(trimethoxysilyl)propyl]phosphonium bis(trifluoromethanesulfonyl)imide; and the like.

[0114] In addition, in terms of further improving the vertical alignment of the liquid crystal compound, it is also preferable that the ionic compound has a structure in which the molecular structure of the cationic moiety contains Si and / or F. When the molecular structure of the cationic moiety contains Si and / or F, the ionic compound is likely to segregate on the surface of the light-absorbing anisotropic film, and the vertical alignment of the liquid crystal compound is likely to be more excellent. Among these, the following ionic compounds (I-i) to (I-iii) are preferred as ionic compounds in which all of the constituent elements are non-metallic elements.

[0115] -Ionic compound (Ii)-

[0116]

[0117] -Ionic compound (I-ii)-

[0118]

[0119] -Ionic compound (I-iii)-

[0120]

[0121] In addition, in terms of further improving the vertical alignment property of the liquid crystal compound, it is also preferable that the ionic compound has a structure having a long-chain alkyl group. Specifically, it is preferable that the ionic compound satisfies the relationship of the following formula (I-1): 5<M<16 (I-1) In formula (I-1), M is represented by the following formula (I-2): M=(number of covalent bonds from a positively charged atom to the molecular chain end of the substituent with the largest number of covalent bonds to the molecular chain end, among substituents directly bonded to a positively charged atom)÷(number of positively charged atoms) (I-2)

[0122] When the ionic compound satisfies the relationship of the above formula (I-1), the vertical alignment property of the liquid crystal compound can be effectively improved.

[0123] When two or more positively charged atoms are present in the molecule of an ionic compound, for a substituent having two or more positively charged atoms, the number of covalent bonds from the positively charged atom considered as the base point to the nearest other positively charged atom is considered to be the "number of covalent bonds from the positively charged atom to the molecular chain end" as defined above in the definition of M. Furthermore, when the ionic compound is an oligomer or polymer having two or more repeating units, the constituent unit is considered to be one molecule and the above M is calculated. When a positively charged atom is incorporated into a ring structure, the "number of covalent bonds from the positively charged atom to the molecular chain end" as defined above in the definition of M is the larger of the number of covalent bonds from the number of covalent bonds via the ring structure to the positively charged atom or the number of covalent bonds to the end of the substituent bonded to the ring structure.

[0124] The content of the ionic compound in the optically absorptive anisotropic film is preferably 0.01 to 5 mass %, more preferably 0.05 to 4 mass %, and even more preferably 0.1 to 3 mass %, relative to the total mass of the optically absorptive anisotropic film. One type of ionic compound may be contained alone, or two or more types may be contained. When two or more types of ionic compounds are contained, the content of the ionic compounds refers to the total content of the ionic compounds.

[0125] (Silane compound) The above-mentioned silane compound is preferably a nonionic silane compound, and is preferably a nonionic compound containing Si element.As the nonionic silane compound, for example, silicon polymer such as polysilane; silicone resin such as silicone oil and silicone resin; silicone oligomer; silane coupling agent such as silsesquioxane and alkoxysilane, its hydrolyzate and its hydrolysis condensate selected from the group; etc. can be mentioned.As the silane compound, in view of the fact that the effect of the present invention is more excellent and the adhesion with adjacent layer is more likely to be excellent, the compound selected from the group consisting of silane coupling agent, its hydrolyzate and its hydrolysis condensate selected from the group.

[0126] Examples of silicone oligomer compositions (hereinafter, copolymer compositions will be shown in the form of monomer-monomer) include mercaptopropyl group-containing copolymers such as 3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, and 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer; and mercaptomethyl group-containing copolymers such as mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, and mercaptomethyltriethoxysilane-tetraethoxysilane copolymer. methacryloyloxypropyl group-containing copolymers such as 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane - acryloyloxypropyl group-containing copolymers such as tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetra vinyl group-containing copolymers such as ethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, and vinylmethyldiethoxysilane-tetraethoxysilane copolymer; amino group-containing copolymers such as 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer;

[0127] Silane coupling agents are compounds containing Si atoms and having at least one functional group selected from the group consisting of vinyl groups, epoxy groups, styryl groups, methacrylic groups, acrylic groups, amino groups, isocyanurate groups, ureido groups, mercapto groups, isocyanate groups, carboxy groups, and hydroxy groups at their terminals, and at least one alkoxysilyl group or silanol group. Among these, silane coupling agents having an alkoxysilyl group and another different reactive group (e.g., the above-mentioned functional group) are preferred. Furthermore, silane coupling agents having an alkoxysilyl group and a polar group are preferred, as they provide better vertical alignment of liquid crystal compounds. Examples of polar groups include epoxy groups, amino groups, isocyanurate groups, mercapto groups, carboxy groups, and hydroxy groups. The polar group may have an appropriate substituent or protective group to control the reactivity of the silane coupling agent.

[0128] Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyltriethoxy ... ethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, and 3-glycidoxypropylethoxydimethylsilane.

[0129] Commercially available silane coupling agents include, for example, KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001, KBM-1003, KBE-1003, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-1403, KBM-502, KBM-503, KBE-502, Examples of the silane coupling agent include silane coupling agents manufactured by Shin-Etsu Chemical Co., Ltd., such as KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE-903, KBE-9103, KBM-573, KBM-575, KBM-9659, KBE-585, KBM-802, KBM-803, KBE-846, KBE-9007, and KBE-9103.

[0130] The content of the silane compound (preferably a nonionic silane compound) in the optically absorptive anisotropic film is preferably 0.01 to 5 mass %, more preferably 0.05 to 4 mass %, and even more preferably 0.1 to 3 mass %, relative to the total mass of the optically absorptive anisotropic film. The ionic compound may be contained alone or in combination of two or more types. When two or more types of ionic compounds are contained, the content of the ionic compounds refers to the total content of the ionic compounds.

[0131] <Adhesion improver> Examples of the adhesion improver include the reactive additives described in paragraphs

[0123] to

[0129] of JP2019-091088A, and the boronic acid monomers and polymers thereof described in paragraphs

[0015] to

[0028] of WO2015 / 053359A.

[0132] [Characteristics of Optically Absorbent Anisotropic Film] In an optically absorptive anisotropic film, it is preferable that the oriented liquid crystal compound is fixed. In particular, it is more preferable that the vertically aligned liquid crystal compound is fixed in an optically absorptive anisotropic film. In an optically absorptive anisotropic film, it is preferable that the dichroic substance is oriented in a specific direction. In particular, it is more preferable that the dichroic substance is oriented in one in-plane direction in an optically absorptive anisotropic film. In particular, it is even more preferable that the dichroic substance is also oriented in a vertically aligned liquid crystal compound. As described below, it is preferable that the optically absorptive anisotropic film is a film formed using a composition for forming an optically absorptive anisotropic film containing a liquid crystal compound, a dichroic substance, and a specific phenol compound.

[0133] In the optically absorptive anisotropic film of the present invention, the angle θ between the central transmittance axis of the optically absorptive anisotropic film and the normal direction to the surface of the optically absorptive anisotropic film (hereinafter also abbreviated as "transmittance central axis angle θ") is 0 to 45°. The transmittance central axis angle θ is more preferably 0 to 35°, and even more preferably 0° or more and less than 35°.

[0134] Here, the term "transmittance central axis" refers to the direction that exhibits the highest transmittance when the transmittance is measured by varying the tilt angle (polar angle) and tilt direction (azimuth angle) relative to the normal direction of the optically absorptive anisotropic film surface. Specifically, an AxoScan OPMF-1 (manufactured by OptoScience) is used to measure the Mueller matrix at a wavelength of 550 nm. More specifically, during measurement, the azimuth angle at which the transmittance central axis is tilted is first found, and then, within a plane containing the normal direction of the optically absorptive anisotropic film along that azimuth angle (a plane containing the transmittance central axis and perpendicular to the film surface), the polar angle, which is the angle relative to the normal direction of the optically absorptive anisotropic film surface, is varied (for example, by varying in 1° increments from -70 to 70°), and the Mueller matrix at a wavelength of 550 nm is measured, and the transmittance of the optically absorptive anisotropic film is derived. As a result, the direction with the highest transmittance is designated as the transmittance central axis. The transmittance central axis means the direction of the absorption axis (the direction of the long axis of the molecule) of the dichroic material contained in the optically absorptive anisotropic film.

[0135] The single plate transmittance of the optically absorptive anisotropic film is preferably 40% or more, more preferably 42% or more. There is no particular upper limit, but it is often 60% or less. The degree of polarization of the optically absorptive anisotropic film is preferably 90% or more, more preferably 95% or more, and even more preferably 99% or more. There is no particular upper limit, but it is often less than 100%. The single plate transmittance and degree of polarization of the optically absorptive anisotropic film are measured using an automatic polarizing film measuring device: VAP-7070 (manufactured by JASCO Corporation).

[0136] [Composition for Forming Optically Absorbent Anisotropic Film] The optically absorptive anisotropic film of the present invention is preferably formed using a composition for forming an optically absorptive anisotropic film containing a liquid crystal compound, a dichroic substance, and a specific phenol compound. The various components that can be contained in the composition for forming an optically absorptive anisotropic film are synonymous with, for example, the various components that can be contained in the optically absorptive anisotropic film described above, and preferred embodiments are also the same. However, the preferred ranges for the contents of the various components in the composition for forming an optically absorptive anisotropic film are the same as the preferred ranges obtained by replacing the above-mentioned "contents (% by mass) of the various components relative to the total mass of the optically absorptive anisotropic film" with "contents (% by mass) of the various components relative to the total solid content of the composition for forming an optically absorptive anisotropic film." Specifically, the phrase "The content of the specific phenol compound is preferably X% by mass or more relative to the total mass of the optically absorptive anisotropic film" should be replaced with "The content of the specific phenol compound is preferably X% by mass or more relative to the total solid content of the composition for forming an optically absorptive anisotropic film." The composition for forming an optically absorptive anisotropic film may contain other components such as a polymerization initiator and a solvent in addition to the various components described above.

[0137] <Polymerization initiator> The optically absorptive anisotropic film-forming composition preferably contains a polymerization initiator. The polymerization initiator is preferably a photopolymerization initiator. As the photopolymerization initiator, various compounds can be used without particular limitation. Examples of photopolymerization initiators include α-carbonyl compounds (U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ethers (U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (U.S. Pat. No. 2,722,512), polynuclear quinone compounds (U.S. Pat. Nos. 3,046,127 and 2,951,758), and combinations of triarylimidazole dimers and p-aminophenyl ketones (U.S. Pat. No. 3,549,367). ), acridine and phenazine compounds (JP 60-105667 A and U.S. Pat. No. 4,239,850 A), oxadiazole compounds (U.S. Pat. No. 4,212,970 A), o-acyloxime compounds (JP 2016-027384 A,

[0065] ), and acylphosphine oxide compounds (JP 63-040799 A, JP 5-029234 B, JP 10-095788 A, and JP 10-029997 A).

[0138] The content of the polymerization initiator in the composition for forming an optically absorptive anisotropic film is preferably 0.01 to 30 parts by mass, and more preferably 0.1 to 15 parts by mass, relative to 100 parts by mass of the total of the dichroic substance and liquid crystal compound in the composition for forming an optically absorptive anisotropic film. The polymerization initiator may be contained alone or in combination of two or more types. When two or more types of polymerization initiators are contained, the content of the polymerization initiators refers to the total content of the polymerization initiators.

[0139] <Solvent> The composition for forming an optically absorptive anisotropic film preferably contains a solvent from the viewpoint of workability, etc. Examples of the solvent include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone), ethers (e.g., dioxane, tetrahydrofuran, tetrahydropyran, dioxolane, tetrahydrofurfuryl alcohol, and cyclopentyl methyl ether), aliphatic hydrocarbons (e.g., hexane), alicyclic hydrocarbons (e.g., cyclohexane), aromatic hydrocarbons (e.g., benzene, toluene, xylene, and trimethylbenzene), halogenated carbons (e.g., dichloromethane, trichloromethane (chloroform), dichloroethane, dichlorobenzene, and chloroform), and the like. Examples of suitable solvents include organic solvents such as toluene, esters (e.g., methyl acetate, ethyl acetate, butyl acetate, and diethyl carbonate), alcohols (e.g., ethanol, isopropanol, butanol, and cyclohexanol), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, and 1,2-dimethoxyethane), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone), and heterocyclic compounds (e.g., pyridine), as well as water. These solvents may be used alone or in combination of two or more. Among these solvents, organic solvents are preferred because they provide better effects of the present invention, and halogenated carbons or ketones are more preferred.

[0140] The content of the solvent in the composition for forming an optically absorptive anisotropic film is preferably 80 to 99 mass %, more preferably 83 to 97 mass %, and even more preferably 85 to 95 mass %, based on the total mass of the composition for forming an optically absorptive anisotropic film.

[0141] [Method for producing an optically absorbing anisotropic film] The method for producing an optically absorbing anisotropic film of the present invention is not particularly limited as long as it can produce an optically absorbing anisotropic film having the above-mentioned properties. One example of the method for producing an optically absorbing anisotropic film of the present invention includes a process of applying an optically absorbing anisotropic film-forming composition to a substrate to form a coating film (hereinafter also referred to as a "coating film forming process"), and a process of orienting the liquid crystalline component and dichroic substance contained in the coating film (hereinafter also referred to as an "orientation process"). Note that the liquid crystalline component is a component that includes not only the above-mentioned liquid crystal compound, but also the dichroic substance having liquid crystallinity if the above-mentioned dichroic substance has liquid crystallinity.

[0142] -Coating Film Forming Process- The coating film forming process is a process of forming a coating film by applying a composition for forming an optically absorptive anisotropic film onto a substrate. The composition for forming an optically absorptive anisotropic film includes the dichroic substance and liquid crystal compound described above. The dichroic substance and liquid crystal compound contained in the composition for forming an optically absorptive anisotropic film may have a polymerizable group. When the dichroic substance and liquid crystal compound have a polymerizable group (preferably a photopolymerizable group), these compounds can be fixed in the optically absorptive anisotropic film in the curing process described below. The substrate used in this process is not particularly limited, and the substrates of the optical films described below can be used. Furthermore, an alignment film may be provided on the substrate as needed. By providing an alignment film, the liquid crystal component can be aligned. Examples of the alignment film include photoalignment films. For example, the alignment films disclosed in paragraphs

[0125] to

[0132] of WO 2022 / 138728 can also be suitably used.

[0143] In this step, the composition for forming an optically absorbing anisotropic film can be easily applied by using a composition for forming an optically absorbing anisotropic film that contains a solvent, or by using a composition for forming an optically absorbing anisotropic film that has been converted into a liquid such as a melt by heating, etc. Examples of methods for applying the composition for forming an optically absorbing anisotropic film include known methods such as roll coating, gravure printing, spin coating, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, die coating, spraying, and inkjet printing.

[0144] Orientation Process—The orientation process is a process for orienting the liquid crystalline component contained in the coating film. This process results in the production of the optically absorptive anisotropic film of the present invention. The orientation process may include a drying process. Components such as the solvent can be removed from the coating film by the drying process. The drying process may be performed by leaving the coating film at room temperature for a predetermined period of time (e.g., natural drying), or by heating and / or blowing air. Here, the liquid crystalline component contained in the composition for forming an optically absorptive anisotropic film may be aligned by the above-described coating film formation process or drying process. For example, in an embodiment in which the composition for forming an optically absorptive anisotropic film is prepared as a coating liquid containing a solvent, the coating film is dried to remove the solvent from the coating film, thereby obtaining a coating film with optical absorptive anisotropy. When the drying process is performed at a temperature equal to or higher than the temperature at which the liquid crystalline component contained in the coating film transitions from a liquid crystal phase to an isotropic phase, the heat treatment described below may not be performed.

[0145] The transition temperature from the liquid crystal phase to the isotropic phase of the liquid crystalline component contained in the coating film is preferably 10 to 250°C, more preferably 25 to 190°C, from the viewpoint of manufacturability, etc. A transition temperature of 10°C or higher is preferred because it eliminates the need for a cooling process or the like to lower the temperature to a temperature range in which the liquid crystal phase is exhibited. Furthermore, a transition temperature of 250°C or lower is preferred because it does not require a high temperature even when heating until the isotropic phase is achieved in order to suppress alignment defects, thereby reducing waste of thermal energy and deformation and deterioration of the substrate.

[0146] The orientation step preferably includes a heat treatment. This allows the liquid crystalline component contained in the coating film to be oriented, and the coating film after the heat treatment can be suitably used as an optically absorptive anisotropic film. From the viewpoint of manufacturability, the heat treatment is preferably performed at a temperature of 10 to 250°C, more preferably 25 to 190°C. The heating time is preferably 1 to 300 seconds, more preferably 1 to 60 seconds.

[0147] The alignment step may include a cooling treatment carried out after the heating treatment. The cooling treatment is a treatment in which the coated film after heating is cooled to about room temperature (20 to 25°C). This makes it possible to fix the alignment of the liquid crystalline component contained in the coated film. The cooling method is not particularly limited and can be carried out by a known method.

[0148] Other Steps The method for forming an optically absorbing anisotropic film of the present invention may include a step of curing the optically absorbing anisotropic film (hereinafter also referred to as a "curing step") after the above-described alignment step. For example, when the compound contained in the optically absorbing anisotropic film has a polymerizable group, the curing step is performed by heating and / or light irradiation (exposure). Among these, from the viewpoint of productivity, the curing step is preferably performed by light irradiation. Various light sources such as infrared light, visible light, and ultraviolet light can be used as the light source for curing, but ultraviolet light is preferred. Furthermore, ultraviolet light may be irradiated while heating during curing, or ultraviolet light may be irradiated through a filter that transmits only specific wavelengths. When exposure is performed while heating, the heating temperature during exposure is preferably 25 to 140°C, although this depends on the transition temperature of the liquid crystal component contained in the liquid crystal film. Furthermore, exposure may be performed under a nitrogen atmosphere. When curing of the liquid crystal film proceeds by radical polymerization, exposure under a nitrogen atmosphere is preferred because inhibition of polymerization by oxygen is reduced.

[0149] The thickness of the optically absorptive anisotropic film is not particularly limited, but is preferably 0.3 to 10 μm, more preferably 0.5 to 9 μm, in terms of achieving better effects of the present invention.

[0150] [Optical Film] The optical film of the present invention is not particularly limited as long as it has a substrate and an optically absorptive anisotropic film disposed on the substrate. The optical film of the present invention may have an alignment film disposed on the surface of the substrate facing the optically absorptive anisotropic film. The optical film of the present invention may further have a protective layer on the surface of the optically absorptive anisotropic film opposite the substrate. Each member constituting the optical film will be described below.

[0151] [Substrate] Known transparent resin films, transparent resin plates, transparent resin sheets, and the like can be used as the substrate. Examples of transparent resin films that can be used include cellulose acylate films (e.g., cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, and cellulose acetate propionate film), polyethylene terephthalate films, polyethersulfone films, polyacrylic resin films, polyurethane resin films, polyester films, polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyether ketone films, and (meth)acrylonitrile films. Among these, cellulose acylate films, which have high transparency, low optical birefringence, and are easily produced, and are commonly used as protective films for polarizing plates, are preferred, and cellulose triacetate films are more preferred. The thickness of the substrate is typically 20 μm to 100 μm. In the present invention, it is particularly preferred that the substrate is a cellulose ester film and that its thickness is 20 to 70 μm.

[0152] The substrate may have an alignment film disposed on the surface facing the optically anisotropic film. As the alignment film, the above-mentioned films can be used.

[0153] [Light-Absorption Anisotropic Film] The optically anisotropic film contained in the optical film corresponds to the light-absorption anisotropic layer of the present invention described above.

[0154] [Protective Layer] The optical film of the present invention preferably further has a protective layer. The material of the protective layer is not particularly limited, but from the viewpoint of more excellent effects of the present invention, for example, polyvinyl alcohol or a derivative thereof (hereinafter also referred to as a "polyvinyl alcohol-based resin") is preferred. The polyvinyl alcohol-based resin is not particularly limited, but examples thereof include partially saponified polyvinyl alcohol; fully saponified polyvinyl alcohol; carboxyl group-modified polyvinyl alcohol; reactive group-modified polyvinyl alcohol such as (meth)acryloyloxy group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino group-modified polyvinyl alcohol, and polymers thereof. The lower limit of the thickness of the protective layer is not particularly limited, but from the viewpoint of more excellent effects of the present invention, it is preferably 0.01 μm or more, more preferably 0.1 μm or more, and even more preferably 0.5 μm or more. The upper limit of the thickness of the protective layer is preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, and particularly preferably 10 μm or less, from the viewpoint of reducing the overall thickness of the optical film and achieving excellent productivity.

[0155] [Uses of Optical Film] The optical film of the present invention is preferably used as a viewing angle control film for controlling the viewing angle by being bonded to a polarizer having an in-plane absorption axis. Hereinafter, the optical film having the above configuration may also be referred to as a viewing angle control film. The polarizer is preferably bonded to the side of the light-absorption anisotropic film opposite to the substrate. The polarizer is not particularly limited as long as it is a member having an in-plane absorption axis and having the function of converting light into specific linearly polarized light, and conventionally known polarizers can be used.

[0156] [Image Display Device] The image display device of the present invention is not particularly limited as long as it includes the optical film of the present invention described above. Typically, it includes the optical film of the present invention and a display element. The optical film of the present invention is preferably incorporated into the image display device as the viewing angle control film described above. The display element used in the display device of the present invention is not particularly limited. Examples include liquid crystal cells, organic electroluminescence (hereinafter abbreviated as "EL") display panels, and plasma display panels, with liquid crystal cells being preferred. That is, the display device of the present invention is preferably a liquid crystal display device using a liquid crystal cell as the display element. Some image display devices are thin and can be formed into a curved surface. The optically absorptive anisotropic film used in the present invention is thin and easily bendable, making it suitable for use in image display devices with curved display surfaces. Furthermore, some image display devices have a pixel density exceeding 250 ppi, enabling high-resolution display. The optically absorptive anisotropic film used in the present invention can be suitably applied to such high-resolution image display devices without generating moiré.

[0157] [Liquid Crystal Display Device] A preferred example of a liquid crystal display device according to the present invention is one having the above-described viewing angle control film and a liquid crystal cell. A specific configuration includes a configuration in which the viewing angle control film is disposed on a front-side polarizing plate or a rear-side polarizing plate. These configurations enable viewing angle control in which light is blocked in the vertical or horizontal directions. Furthermore, viewing angle control films may be disposed on both the front-side polarizing plate and the rear-side polarizing plate. This configuration enables viewing angle control in which light is blocked in all directions and light is transmitted only in the front direction. Furthermore, multiple viewing angle control films may be laminated via retardation layers. Controlling the retardation value and optical axis direction allows for control of transmission and light-blocking performance. For example, arranging a polarizer, a viewing angle control film, a λ / 2 wavelength plate (the axis angle of which is shifted by 45° relative to the orientation direction of the polarizer), and a viewing angle control film enables viewing angle control in which light is blocked in all directions and light is transmitted only in the front direction. As the retardation layer, a positive A plate, a negative A plate, a positive C plate, a negative C plate, a B plate, an O plate, or the like can be used. From the viewpoint of thinning the viewing angle control system, the thickness of the retardation layer is preferably as thin as possible as long as it does not impair optical properties, mechanical properties, and manufacturability, and specifically, is preferably 1 to 150 μm, more preferably 1 to 70 μm, and even more preferably 1 to 30 μm. The liquid crystal cell constituting the liquid crystal display device will be described in detail below.

[0158] <Liquid Crystal Cell> The liquid crystal cell used in the liquid crystal display device is preferably, but not limited to, a VA (Vertical Alignment) mode, an OCB (Opticaly Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode. In a TN mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially horizontally when no voltage is applied, and are further aligned with a twist angle of 60 to 120 degrees. TN mode liquid crystal cells are most commonly used in color TFT liquid crystal display devices, and are described in many literatures. In a VA mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied. VA mode liquid crystal cells include (1) narrowly defined VA mode liquid crystal cells in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when voltage is applied (described in JP-A-2-176625), (2) multi-domain VA mode liquid crystal cells (described in SID97, Digest of Tech. Papers (Proceedings) 28 (1997) 845) in order to widen the viewing angle (MVA mode liquid crystal cells), (3) n-ASM mode liquid crystal cells in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when voltage is applied (described in Proceedings of the Japan Liquid Crystal Symposium 58-59 (1998)), and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). The liquid crystal display may be of any of a PVA (Patterned Vertical Alignment) type, an optical alignment type, and a PSA (Polymer-Sustained Alignment) type. Details of these modes are described in detail in Japanese Patent Laid-Open No. 2006-215326 and Japanese Patent Laid-Open No. 2008-538819.

[0159] In an IPS mode liquid crystal cell, the liquid crystal compound is oriented substantially parallel to the substrate, and when an electric field parallel to the substrate surface is applied, the liquid crystal molecules respond in a planar manner. That is, when no electric field is applied, the liquid crystal compound is oriented in-plane. In an IPS mode, when no electric field is applied, a black display is achieved, and the absorption axes of a pair of upper and lower polarizing plates are perpendicular to each other. Methods of using an optical compensation sheet to reduce light leakage during black display in an oblique direction and improve the viewing angle are disclosed in JP-A Nos. 10-054982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0160] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0161] Example 1 Preparation of Optical Film 1 An optical film having an optically absorptive anisotropic film was prepared according to the following procedure.

[0162] <Formation of Alignment Film> The surface of a commercially available cellulose acylate film (manufactured by Fujifilm Corporation, trade name Fujitac TG60UL) was saponified with an alkaline solution, and the following composition for forming an alignment film 1 was applied thereon using a wire bar. The support on which the coating film was formed was dried with hot air at 60°C for 60 seconds and then with hot air at 100°C for 120 seconds to form an alignment film AL1, thereby obtaining a cellulose acylate film 1 with an alignment film. The thickness of the alignment film AL1 was 1 μm.

[0163] ------------------------------------------------------------------ Composition 1 for forming alignment film -------------------------------------------------- 3.80 parts by mass of modified polyvinyl alcohol PVA-1 shown below 0.20 parts by mass Omnirad 2959 (manufactured by IGM RESINS BV) 70 parts by mass Water 30 parts by mass Methanol ------------------------------------------------------------------

[0164] (Modified Polyvinyl Alcohol PVA-1) The composition ratio of each repeating unit is based on mol %.

[0165] <Formation of Optically Absorbent Anisotropic Film P1> The following composition for forming an optically absorbent anisotropic film P1 was continuously applied to the obtained cellulose acylate film 1 with an alignment film using a wire bar, heated at 120°C for 60 seconds, and then cooled to room temperature (23°C). Next, the composition was heated at 85°C for 60 seconds and cooled to room temperature again. Thereafter, an LED lamp (center wavelength 365 nm) was used to illuminate the film from the normal direction at an illuminance of 200 mW / cm. ２ An optically absorptive anisotropic film P1 was formed on the alignment film AL1 for 2 seconds under the irradiation condition of 1.5 μm, and the optically absorptive anisotropic film P1 was used as an optical film 1. The thickness of the optically absorptive anisotropic film P1 was 1.5 μm.

[0166] ------------------------------------------------ Composition P1 for forming optically absorptive anisotropic film------------------------------------------------ 0.78 parts by mass of dichroic substance D-1 below 0.21 parts by mass of dichroic substance D-2 below 1.39 parts by mass of dichroic substance D-3 below 7.39 parts by mass of liquid crystal compound L-1 below 2.46 parts by mass of liquid crystal compound L-2 below 0.71 parts by mass of Omnirad 369 (manufactured by IGM Resins B.V.) 0.036 parts by mass of phenol compound Ph-1 below 87.02 parts by mass of o-xylene------------------------------------------------

[0167] (Dichroic substance D-1)

[0168] (Dichroic substance D-2)

[0169] (Dichroic substance D-3)

[0170] (Liquid crystal compound L-1)

[0171] (Liquid crystal compound L-2)

[0172] (Phenol compound Ph-1)

[0173] [Example 2] [Preparation of Optical Film 2] Optical film 2 was prepared in the same manner as in Example 1, except that in the optically absorptive anisotropic film-forming composition P1 of Example 1, the following phenol compound Ph-2 was used instead of the phenol compound Ph-1.

[0174] (Phenol compound Ph-2)

[0175] [Example 3] [Preparation of Optical Film 3] Optical film 3 was prepared in the same manner as in Example 1, except that in the optically absorptive anisotropic film-forming composition P1 of Example 1, the following phenol compound Ph-3 was used instead of the phenol compound Ph-1.

[0176] (Phenol compound Ph-3)

[0177] Comparative Example 1 Preparation of Optical Film 4 Optical film 4 was prepared in the same manner as in Example 1, except that the phenol compound Ph-1 was not used in the optically absorptive anisotropic film-forming composition P1 of Example 1.

[0178] Comparative Example 2 Preparation of Optical Film 5 Optical film 5 was prepared in the same manner as in Example 1, except that the phenol compound Ph-1 in the composition for forming an optically absorptive anisotropic film P1 used in Example 1 was replaced with the antioxidant AO-1 shown below.

[0179] (Antioxidant AO-1)

[0180] [Example 4] [Preparation of Optical Film 6] Optical film 6 was prepared in the same manner as in Example 1, except that the optically absorptive anisotropic film-forming composition P6 described below was used instead of the optically absorptive anisotropic film-forming composition P1 used in Example 1.

[0181] ------------------------------------------------ Optically absorptive anisotropic film-forming composition P6 -------------------------------------------------- 0.78 parts by mass of dichroic substance D-4 below 0.21 parts by mass of dichroic substance D-5 below 1.38 parts by mass of dichroic substance D-6 below 7.36 parts by mass of the above liquid crystal compound L-1 2.45 parts by mass of the above liquid crystal compound L-2 0.71 parts by mass of Omnirad 369 (manufactured by IGM Resins B.V.) 0.09 parts by mass of the above phenol compound Ph-1 87.02 parts by mass of o-xylene ------------------------------------------------

[0182] (Dichroic substance D-4)

[0183] (Dichroic substance D-5)

[0184] (Dichroic substance D-6)

[0185] [Example 5] [Preparation of Optical Film 7] In the optical film 1 prepared in Example 1, the above-mentioned composition for forming an alignment film 1 was further coated with a wire bar on the surface of the light absorption anisotropic film P1 opposite to the cellulose acylate film side. The support on which the coating film had been formed was dried with hot air at 60°C for 60 seconds and then with hot air at 80°C for 150 seconds to form a protective layer B1, thereby preparing optical film 7. The thickness of the protective layer B1 was 1 μm.

[0186] [Example 6] [Preparation of Optical Film 8] Optical film 8 was prepared in the same manner as in Example 1, except that the optically absorptive anisotropic film-forming composition P8 described below, which contained a silane coupling agent KBE-9103 (manufactured by Shin-Etsu Chemical Co., Ltd.), was used instead of the optically absorptive anisotropic film-forming composition P1 used in Example 1. ------------------------------------------------ Optically absorptive anisotropic film-forming composition P8 -------------------------------------------------- 0.77 parts by mass of the dichroic material D-1 0.21 parts by mass of the dichroic material D-2 1.37 parts by mass of the dichroic material D-3 7.29 parts by mass of the liquid crystal compound L-1 2.43 parts by mass of the liquid crystal compound L-2 0.70 parts by mass of Omnirad 369 (manufactured by IGM Resins B.V.) 0.09 parts by mass of the phenol compound Ph-1 0.13 parts by mass of KBE-9103 (manufactured by Shin-Etsu Chemical Co., Ltd.) o-xylene 87.02 parts by mass ------------------------------------------------

[0187] Example 7 Preparation of Optical Film 9 Optical film 9 was prepared in the same manner as in Example 1, except that the following composition for forming an optically absorptive anisotropic film P9 containing the ionic compound 1,1,1-tributyl-1-[(trimethoxysilyl)methyl]phosphonium bis(trifluoromethanesulfonyl)imide was used instead of composition for forming an optically absorptive anisotropic film P1 in Example 1. 1,1,1-tributyl-1-[(trimethoxysilyl)methyl]phosphonium bis(trifluoromethanesulfonyl)imide was synthesized with reference to Japanese Patent No. 6,177,430.

[0188] ------------------------------------------------ Optically absorptive anisotropic film-forming composition P9 ------------------------------------------------------------------ 0.77 parts by mass of the dichroic material D-1 0.21 parts by mass of the dichroic material D-2 1.37 parts by mass of the dichroic material D-3 7.29 parts by mass of the liquid crystal compound L-1 2.43 parts by mass of the liquid crystal compound L-2 0.70 parts by mass of Omnirad 369 (manufactured by IGM Resins B.V.) 0.09 parts by mass of the phenol compound Ph-1 0.13 parts by mass of 1,1,1-tributyl-1-[(trimethoxysilyl)methyl]phosphonium bis(trifluoromethanesulfonyl)imide 87.02 parts by mass of o-xylene ----------------------------------------------------------------------------------

[0189] Comparative Example 3 Preparation of Optical Film 10 Optical film 10 was prepared in the same manner as in Example 1, except that the phenol compound Ph-4 below was used instead of the phenol compound Ph-1 in the optically absorptive anisotropic film-forming composition P1 of Example 1.

[0190] (Phenol compound Ph-4)

[0191] [Evaluation] [Transmittance Central Axis Evaluation] The transmittance central axis of the obtained optical film was measured by the following method: First, using an AxoScan OPMF-1 (manufactured by OptoScience), the azimuthal angle direction in which the transmittance central axis was tilted was detected, and then the Mueller matrix at a wavelength of 550 nm was measured in the azimuthal angle direction while varying the polar angle to derive the transmittance, and the direction (polar angle) with the highest transmittance was determined as the direction of the transmittance central axis of the optically absorptive anisotropic film.

[0192] In each of the optical films of the Examples and Comparative Examples, it was confirmed that the angle θ formed between the transmittance central axis of the optically absorptive anisotropic film and the normal direction to the surface of the optically absorptive anisotropic film was 0°.

[0193] [Evaluation of Orientation Degree (Orientation)] The degree of orientation of the obtained optical film at a wavelength of 550 nm was calculated using the following method. Using an AxoScan OPMF-1 (manufactured by Optoscience), the polar angle, which is the angle relative to the normal direction of the optically absorptive anisotropic film, was changed in 1° increments from -70° to 70° during measurement, and the Mueller matrix at a wavelength of 550 nm at each polar angle was measured to derive the minimum transmittance (Tmin). Next, after removing the influence of surface reflection, Tmin at the polar angle at which Tmin is highest was defined as Tm(0), and Tmin in the direction 40° larger than the polar angle at which Tmin is highest was defined as Tm(40). The absorbance (A) was calculated from the obtained Tm(0) and Tm(40) using the following formula, and A(0) and A(40) were calculated. A = -log(Tm), where Tm represents transmittance and A represents absorbance. From the calculated A(0) and A(40), the degree of orientation S at a wavelength of 550 nm defined by the following formula Ｐ was calculated and classified according to the following criteria: Ｐ =(4.6×A(40)-A(0)) / (4.6×A(40)+2×A(0)) A: Degree of orientation S Ｐ is 0.90 or more B: Orientation degree S Ｐ is 0.80 or more and less than 0.90 C: Orientation degree S Ｐ is 0.70 or more and less than 0.80 D: degree of orientation S Ｐ is less than 0.70

[0194] [Lightfastness Evaluation] The obtained optical film was irradiated with xenon lamp light from the front direction for 150 hours using a Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd. The Tm(40) before and after irradiation was measured in the same manner as in the above orientation evaluation, and the lightfastness was evaluated according to the following criteria. The change (%) in Tm(40) was calculated using the following formula: (Change in Tm(40)) = 100 x ((Tm(40) after irradiation) - (Tm(40) before irradiation)) / (Tm(40) before irradiation) A: The change in Tm(40) was less than 2% B: The change in Tm(40) was 2% or more and less than 5% C: The change in Tm(40) was 5% or more and less than 10% D: The change in Tm(40) was 10% or more

[0195] Table 1 is shown below.

[0196]

[0197] The results in Table 1 clearly show that the optically absorptive anisotropic films of the examples have excellent lightfastness and excellent alignment of dichroic materials. On the other hand, it is clear that when the optically absorptive anisotropic film does not contain either a phenolic compound or a non-phenolic antioxidant, it has poor lightfastness (Comparative Example 1). Furthermore, it is clear that when the optically absorptive anisotropic film does not contain a specific phenolic compound, but instead contains a phenolic compound or a non-phenolic antioxidant that does not fall under the specific phenolic compound, it has improved lightfastness but poor alignment (Comparative Examples 2 and 3). These results suggest that the specific phenolic compound functions as a vertical alignment agent, while the phenolic compound or the non-phenolic antioxidant that does not fall under the specific phenolic compound acts as a component that inhibits alignment.

[0198] Furthermore, a comparison between Example 1 and Example 4 confirmed that when the optically absorptive anisotropic film contains a dichroic material of a predetermined structure, the light resistance and the alignment of the dichroic material are even more excellent. A comparison between Example 1 and Example 5 confirmed that when the optical film further includes a protective layer, the light resistance is even more excellent. A comparison between Example 1 and Examples 6 and 7 confirmed that when the optically absorptive anisotropic film further contains a compound selected from the group consisting of a silane coupling agent, a hydrolyzate thereof, and a hydrolysis condensate thereof, and / or an ionic compound, the alignment is even more excellent.

Claims

1. An optically absorptive anisotropic film comprising a liquid crystal compound, a dichroic substance, and a phenol compound, wherein the angle θ between the central axis of transmittance of the optically absorptive anisotropic film and the normal direction of the surface of the optically absorptive anisotropic film is 0 to 45°, and the phenol compound comprises a compound represented by formula (1). In the formula, R １ ~R ８ each independently represents a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group. １ represents a divalent linking group that does not contain a single bond or a ring structure. ２ represents a single bond or a divalent linking group. １ represents a group represented by formula (2), a hydroxyl group, an alkyl group, or an alkoxy group. n represents an integer of 0 to 2. When n is 2, a plurality of R ５ R exists in multiple places ６ R exists in multiple places ７ R exists in multiple places ８ L ２ They may be the same or different from each other. In the formula, R ９ ~R １３ each independently represents a hydrogen atom, a hydroxyl group, an alkyl group, or an alkoxy group. * represents the bonding position.

2. The optically absorptive anisotropic film according to claim 1, further comprising at least one compound selected from the group consisting of a silane coupling agent, a hydrolysate thereof, and a hydrolyzed condensate thereof.

3. The optically absorptive anisotropic film according to claim 1 or 2, further comprising an ionic compound.

4. An optical film comprising a substrate and the optically absorptive anisotropic film according to claim 1 or 2 disposed on the substrate.

5. The optical film according to claim 4, further comprising a protective layer on the surface of said optically absorptive anisotropic film opposite to said substrate.

6. The optical film according to claim 5, wherein the protective layer comprises polyvinyl alcohol or a derivative thereof.

7. An image display device comprising the optical film according to claim 4.

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