Alignment film forming composition, alignment film, method for manufacturing alignment substrate, method for manufacturing layered body, and method for manufacturing optically anisotropic layer

Abstract

The present invention addresses the problem of providing: an alignment-film-forming composition that can form an alignment film that is such that when an operation of forming an optically anisotropic layer on the alignment film and peeling the optically anisotropic layer from the alignment film is repeated, the optical characteristics of the optically anisotropic layer are not prone to change; an alignment film; a method for manufacturing an alignment substrate; a method for manufacturing a layered body; and a method for manufacturing an optically anisotropic layer. This alignment-film-forming composition includes a dichroic azo dye compound, a compound A having a reactive group that reacts with the dichroic azo dye compound, and a metal catalyst.

Description

Composition for forming alignment film, alignment film, method for manufacturing alignment substrate, method for manufacturing laminate, method for manufacturing optically anisotropic layer

[0001] The present invention relates to a composition for forming an alignment film, an alignment film, a method for producing an alignment substrate, a method for producing a laminate, and a method for producing an optically anisotropic layer.

[0002] Optical films such as optical compensation sheets and retardation films are used in various display devices to eliminate image coloration and control the viewing angle. In recent years, films having an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystal compound have been used as such optical films. It is known that such an optically anisotropic layer is provided on an alignment film in order to align the liquid crystal compound.

[0003] For example, Patent Document 1 discloses an alignment film used in an optically absorptive anisotropic film obtained using a composition containing a liquid crystal compound, a dichroic substance having an azo group, and an oxidizing agent.

[0004] Japanese Patent Application Laid-Open No. 2007-140465

[0005] It has been found that when an optically anisotropic layer is formed on an alignment film such as that described in Patent Document 1 and the operation of peeling the optically anisotropic layer from the alignment film (formation and peeling operation) is repeated, the optical properties (e.g., retardation, etc.) of the resulting optically anisotropic layer are likely to change.

[0006] An object of the present invention is to provide a composition for forming an alignment film, which can form an alignment film in which the optical properties of the resulting optically anisotropic layer are unlikely to change even when the process of forming an optically anisotropic layer on the alignment film and peeling the optically anisotropic layer from the alignment film is repeated. Another object of the present invention is to provide a method for producing an alignment film, an alignment substrate, a laminate, and an optically anisotropic layer, which are related to the composition for forming an alignment film.

[0007] As a result of extensive research into the problems of the prior art, the present inventors have found that the above-mentioned problems can be solved by the following configuration.

[0008] [1] A composition for forming an alignment film, comprising a dichroic azo dye compound, a compound A having a reactive group reactive with the dichroic azo dye compound, and a metal catalyst. [2] The composition for forming an alignment film according to [1], wherein the reactive group is an epoxy group. [3] The composition for forming an alignment film according to [1] or [2], wherein the metal catalyst contains an aluminum atom. [4] The composition for forming an alignment film according to any one of [1] to [3], wherein, when the compound A has three or more reactive groups, the content of the metal catalyst is 3% by mass or more relative to the content of the compound A, or, when the compound A has one or two reactive groups, the content of the metal catalyst is 5% by mass or more relative to the content of the compound A. [5] The composition for forming an alignment film according to any one of [1] to [4], wherein the compound A has three or more reactive groups. [6] An alignment film obtained by curing the composition for forming an alignment film according to any one of [1] to [5]. [7] A method for producing an alignment substrate, comprising the steps of: applying the composition for forming an alignment film according to any one of [1] to [5] onto a support to form a coating film; irradiating the coating film with light to align the dichroic azo dye compound; and heat-treating the light-irradiated coating film to form an alignment film. [8] A method for producing a laminate according to [7], further comprising the step of forming an optically anisotropic layer on a surface of the alignment film on the alignment substrate opposite to the support, using a liquid crystal composition containing a liquid crystal compound. [9] A method for producing an optically anisotropic layer according to [8], further comprising the step of peeling off the optically anisotropic layer in the laminate.

[10] A method for producing an optically anisotropic layer, comprising: Step 1, forming an optically anisotropic layer A using a liquid crystal composition containing a liquid crystal compound on a surface of the alignment film in the alignment substrate described in [7] opposite to the support, to obtain a laminate; Step 2, peeling off the optically anisotropic layer A in the laminate obtained in Step 1, to obtain the optically anisotropic layer A separated from the alignment substrate; Step 3, forming an optically anisotropic layer B using a liquid crystal composition containing a liquid crystal compound on a surface of the alignment film in the alignment substrate from which the optically anisotropic layer A has been separated, opposite to the support, to obtain a laminate; and Step 4, peeling off the optically anisotropic layer B in the laminate obtained in Step 3, to obtain the optically anisotropic layer B separated from the alignment substrate, wherein Steps 3 and 4 are repeated at least once.

[0009] According to the present invention, there is provided a composition for forming an alignment film, which can form an alignment film in which the optical properties of the resulting optically anisotropic layer are unlikely to change even when the process of forming an optically anisotropic layer on the alignment film and peeling the optically anisotropic layer from the alignment film is repeated. Furthermore, there are also provided methods for producing an alignment film, an alignment substrate, a laminate, and an optically anisotropic layer, which are related to the composition for forming an alignment film.

[0010] Fig. 2 is a diagram conceptually showing an example of an alignment substrate of the present invention. Fig. 3 is a plan view of an alignment film in the alignment substrate shown in Fig. 1. Fig. 4 is a plan view conceptually showing another example of an alignment film. Fig. 5 is a diagram conceptually showing an example of an exposure apparatus for producing an alignment film. Fig. 6 is a diagram conceptually showing an example of a laminate of the present invention. Fig. 7 is a diagram for explaining that an optically anisotropic layer can be obtained from the laminate of the present invention.

[0011] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] 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.

[0013] In this specification, the various components may be used singly or in combination of two or more substances corresponding to the various components. Here, when two or more substances are used in combination for each component, the content of the component means the total content of the substances used in combination, unless otherwise specified.

[0014] The term "solid content" refers to all components in various compositions other than the solvent. Even if a component is liquid, it is considered to be a solid content as long as it is a component other than the solvent.

[0015] In this specification, the bonding direction of a divalent group (e.g., -CO-O-, etc.) is not limited unless otherwise specified. For example, when Y is -CO-O- in a compound represented by the formula "X-Y-Z," the compound may be either "X-O-CO-Z" or "X-CO-O-Z."

[0016] [Composition for forming an alignment film] The composition for forming an alignment film (hereinafter also referred to simply as "composition") contains a dichroic azo dye compound, a compound A having a reactive group (hereinafter also referred to as "reactive group X") that reacts with the dichroic azo dye compound, and a metal catalyst.

[0017] A characteristic feature of the composition of the present invention is that it contains a dichroic azo dye compound, Compound A, and a metal catalyst. As described above, when an alignment film obtained using the composition of the present invention is repeatedly subjected to the steps of forming an optically anisotropic layer on the alignment film and peeling the optically anisotropic layer from the alignment film, the optical properties (e.g., retardation) of the resulting optically anisotropic layer are unlikely to change. Hereinafter, the fact that the optical properties of the resulting optically anisotropic layer are unlikely to change when the above steps are repeatedly performed is also referred to as "excellent durability of repeated optical properties." The inventors speculate as follows about the mechanism by which the desired effect is exhibited. When an optically anisotropic layer is formed on the alignment film and then repeatedly peeled off, the alignment film is exposed to exposure treatment and heat treatment multiple times. The inventors have found that this may cause the alignment of the alignment film to gradually deviate from the predetermined orientation, which may result in the optically anisotropic layer formed on the alignment film not achieving the desired optical properties. On the other hand, the metal catalyst contained in the composition of the present invention can further promote the reaction (curing reaction) between the dichroic azo dye compound and compound A, and the alignment film is unlikely to deviate from the predetermined alignment even when exposed to exposure treatment or the like multiple times, and therefore it is presumed that the composition has excellent durability of optical properties against repeated exposure.

[0018] [Dichroic Azo Dye Compound] The composition contains a dichroic azo dye compound. The dichroic azo dye compound refers to a dye compound having an azobenzene structure and having a light absorption spectrum in which the absorbance varies depending on the direction of the plane of polarization of linearly polarized light.

[0019] The dichroic azo dye compound preferably has a reactive group (hereinafter also referred to as "reactive group Y") that reacts with compound A described later. The reactive group Y is preferably a group having active hydrogen, and more preferably a phenolic hydroxyl group. The number of reactive groups Y that the dichroic azo dye compound has is preferably 1 or more, more preferably 2 to 10, and even more preferably 2 to 5. The reactive group Y may be a polymerizable group that the dichroic azo dye compound described later can have, and it is also preferable that the reactive group Y is other than the above-mentioned polymerizable groups.

[0020] The dichroic azo dye compound may have a polymerizable group, such as an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, a methacrylamide group, a vinyl group, a vinyloxy group, a maleimide group, an azide group, a chloromethyl group, or an epoxy group.

[0021] The dichroic azo dye compound may be either liquid crystalline or non-liquid crystalline. The liquid crystalline dichroic azo dye compound may be either nematic or smectic. The temperature range at which the compound exhibits liquid crystallinity is preferably room temperature (20 to 28°C) to 300°C, and more preferably 50 to 200°C from the viewpoints of handling and production suitability.

[0022] Examples of dichroic azo dye compounds include Direct Yellow, Direct Yellow 12, Direct Yellow 26, Direct Yellow 28, Disperse Yellow 7, Disperse Yellow 9, Acid Yellow 9, Acid Yellow 36, Acid Orange 8, Mordant Yellow 1, Mordant Yellow 10, and Mordant Yellow 12.

[0023] The dichroic azo dye compound is preferably a compound represented by formula (1).

[0024]

[0025] In formula (1), R １ and R ２ R each independently represents a polymerizable group selected from the group consisting of an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, a methacrylamide group, a vinyl group, a vinyloxy group, and a maleimide group, or a hydroxyl group. ３ and R ４ each independently represents a hydrogen atom, a halogen atom, a carboxy group or a salt thereof, an alkyl group having a hydroxyl group, a carbamoyl group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a hydroxyl group, or —OR Ｔ Represents R Ｔ represents an alkyl group having 2 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms substituted with an alkoxy group having 1 to 6 carbon atoms.５ and R ６ R each independently represents a carboxy group or a salt thereof, a sulfo group or a salt thereof, an amino group or a salt thereof, a nitro group, a carbamoyl group, an alkoxycarbonyl group, a sulfamoyl group, or a hydroxyl group. １ is a hydroxyl group, X １ represents a single bond, R １ is a polymerizable group, X １ Ha-(A １ -B １ ) ｍ represents a group represented by -. ２ is a hydroxyl group, X ２ represents a single bond, R ２ is a polymerizable group, X ２ Ha-(A ２ -B ２ ) ｎ represents a group represented by -. １ and A ２ each independently represents a single bond or a divalent hydrocarbon group. １ and B ２ each independently represents a single bond, —O—, —COO—, —CONH—, or —NHCOO—, and m and n each independently represent an integer of 1 to 4.

[0026] In formula (1), R １ and R ２ R each independently represents a polymerizable group selected from the group consisting of an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, a methacrylamide group, a vinyl group, a vinyloxy group, and a maleimide group, or a hydroxyl group. The polymerizable group is preferably an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, or a maleimide group. １ and R ２ As the group, a hydroxyl group is preferred.

[0027] In formula (1), R ３ and R ４each independently represents a hydrogen atom, a halogen atom, a carboxy group or a salt thereof, an alkyl group having a hydroxyl group, a carbamoyl group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a hydroxyl group, or —OR Ｔ represents. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the salt of the carboxy group include alkali metal salts such as sodium salt (-COONa) and potassium salt (-COOK). The number of carbon atoms in the alkyl group constituting the alkyl group having a hydroxyl group is preferably 1 to 5, more preferably 1 to 3. The number of hydroxyl groups in the alkyl group is preferably 1 to 5, more preferably 1 or 2. Examples of the halogenated methoxy group include a chloromethoxy group and a trifluoromethoxy group. R Ｔ represents an alkyl group having 2 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms substituted with an alkoxy group having 1 to 6 carbon atoms. The alkyl group having 2 to 6 carbon atoms may be linear, branched, or cyclic. Examples of the alkyl group having 2 to 6 carbon atoms include linear alkyl groups such as an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a 1-methylethyl group; and cycloalkyl groups having 3 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms substituted with an alkoxy group having 1 to 6 carbon atoms include a methoxymethyl group, a 1-ethoxyethyl group, and a tetrahydropyranyl group. R ３ and R ４ As the alkyl group, a carboxyl group or a salt thereof, an alkyl group having a hydroxyl group, a carbamoyl group, or a halogenated methyl group is preferred.

[0028] In formula (1), R ５ and R ６ R each independently represents a carboxy group or a salt thereof, a sulfo group or a salt thereof, an amino group or a salt thereof, a nitro group, a carbamoyl group, an alkoxycarbonyl group, a sulfamoyl group, or a hydroxyl group. Examples of the salts of the carboxy group and the sulfo group include alkali metal salts such as sodium salts and potassium salts. Examples of the salts of the amino group include hydrochlorides. ５ and R６ As the group, a carboxy group or a salt thereof, a sulfo group or a salt thereof, a carbamoyl group, an alkoxycarbonyl group or a sulfamoyl group is preferred, and a sulfo group or a salt thereof is more preferred.

[0029] In formula (1), R １ is a hydroxyl group, X １ represents a single bond, R １ is a polymerizable group, X １ Ha-(A １ -B １ ) ｍ represents a group represented by -. ２ is a hydroxyl group, X ２ represents a single bond, R ２ is a polymerizable group, X ２ Ha-(A ２ -B ２ ) ｎ represents a group represented by -. １ and X ２ is preferably a single bond.

[0030] A １ and A ２ each independently represents a single bond or a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include linear alkylene groups having 1 to 18 carbon atoms, such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, and dodecamethylene; 1-methylethylene, 1-methyltriethylene, 2-methyltriethylene, 1-methyltetraethylene, 2-methyltetraethylene; branched alkylene groups having 1 to 18 carbon atoms, such as a phenylene group, a 1-methylpentamethylene group, a 2-methylpentamethylene group, and a 3-methylpentamethylene group; and arylene groups, such as a p-phenylene group, a 2-methoxy-1,4-phenylene group, a 3-methoxy-1,4-phenylene group, a 2-ethoxy-1,4-phenylene group, a 3-ethoxy-1,4-phenylene group, a 2,3,5-trimethoxy-1,4-phenylene group, and a 2,6-naphthalenediyl group. １ If there are multiple １They may be the same or different. ２ If there are multiple ２ They may be the same or different.

[0031] B １ and B ２ each independently represents a single bond, —O—, —COO—, —CONH—, or —NHCOO—. １ If there are multiple B １ They may be the same or different. ２ If there are multiple B ２ They may be the same or different.

[0032] m and n each independently represent an integer of 1 to 4. Preferably, m and n are integers of 1 to 3.

[0033] Examples of the dichroic azo dye compound include the following compounds.

[0034]

[0035] The dichroic azo dye compound may be either a high molecular weight compound or a low molecular weight compound, with a low molecular weight compound being preferred. The weight-average molecular weight of the high molecular weight dichroic azo dye compound is preferably 3,000 or more, more preferably 6,000 or more. The upper limit is preferably 1,000,000 or less. The number of azo groups (-N=N-) contained in the high molecular weight dichroic azo dye compound is preferably 11 or more, more preferably 20 or more. The upper limit is preferably 10,000 or less. The molecular weight of the low molecular weight dichroic azo dye compound is preferably 300 to 1,000, more preferably 500 to 800. The number of azo groups (-N=N-) contained in the low molecular weight dichroic azo dye compound is preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. The lower limit is preferably 1 or more, more preferably 2 or more.

[0036] The dichroic azo dye compound may be used alone or in combination of two or more. The content of the dichroic azo dye compound is preferably from 50 to 99% by mass, more preferably from 60 to 98% by mass, and even more preferably from 80 to 98% by mass, based on the total solid content of the composition.

[0037] [Compound A] The composition contains compound A. Compound A is a compound having a reactive group (reactive group X) that reacts with a dichroic azo dye compound. In other words, compound A is a compound that reacts with a dichroic azo dye compound and has at least one reactive group X.

[0038] Examples of reactive groups X include cationically polymerizable groups such as an epoxy group and an oxetanyl group (a group formed by removing one hydrogen atom from an oxetane ring), with a glycidyl ether group being preferred. The number of reactive groups X in compound A is preferably 1 or more, more preferably 3 or more, and even more preferably 4 or more. The upper limit is preferably 10 or less, more preferably 5 or less. Compound A may further have other groups as long as it has a reactive group X. Examples of other groups include a hydroxyl group, an aromatic ring group, and -O-.

[0039] Compound A is preferably a compound represented by formula (EP).

[0040]

[0041] In formula (EP), Z represents a ne-valent linking group. ne represents an integer of 2 to 10. As the ne-valent linking group, a ne-valent aliphatic hydrocarbon group which may have a substituent and which may have -O-, or a ne-valent aromatic hydrocarbon group is preferred. The ne-valent aliphatic hydrocarbon group may be linear, branched, or cyclic. The ne-valent aliphatic hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms. A hydroxyl group is preferred as a substituent which the ne-valent aliphatic hydrocarbon group may have. The ne-valent aromatic hydrocarbon group may be either monocyclic or polycyclic. A benzene ring group is preferred as the ne-valent aromatic hydrocarbon group.

[0042] Examples of compound A include epoxy compounds (compounds having an epoxy group) and oxetane compounds (compounds having an oxetanyl group). Examples of the epoxy compound include diglycidyl ether compounds of aliphatic polyols such as ethylene glycol, hexanediol, neopentyl glycol, trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, sorbitol, and hydrogenated bisphenol A; polyglycidyl ether compounds of aromatic polyols such as bisphenol A, bisphenol F, bisphenol S, dihydroxyphenyl ether, dihydroxybenzophenone, cresol formaldehyde resin, phenol formaldehyde, naphthol phenyl aldehyde resin, methylene bisaniline, dihydroxynaphthalene, naphthol dimer, tetramethylbiphenol, resorcinol, hydroquinone, and catechol; polyethylene glycol, polypropylene polyglycidyl ether compounds of polyether polyols such as ethylene glycol and polytetraethylene glycol; polyglycidyl ether compounds of tris(2-hydroxyethyl)isocyanurate, and polyglycidyl ether compounds of aliphatic or aromatic polycarboxylic acids such as adipic acid, butanetetracarboxylic acid, propanetricarboxylic acid, phthalic acid, terephthalic acid, and trimellitic acid; bisepoxide compounds of hydrocarbon dienes such as butadiene, hexadiene, octadiene, dodecadiene, cyclooctadiene, α-pinene, and vinylcyclohexene; and alicyclic polyepoxy compounds such as bis(3,4-epoxycyclohexylmethyl)adipate and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate.

[0043] Examples of the oxetane compound include 1,4-bis[{(3-ethyloxetan-3-yl)methoxy}methyl]benzene and bis(3-ethyl-3-oxetanylmethyl)ether.

[0044] The compound A may be used alone or in combination of two or more. The content of the compound A is preferably 0.01 to 30 mass%, more preferably 0.1 to 10 mass%, and even more preferably 1 to 5 mass%, based on the total solid content of the composition. The content of the compound A is preferably 1 to 100 mass%, more preferably 1 to 30 mass%, even more preferably 1 to 10 mass%, and particularly preferably 1 to 5 mass%, based on the content of the dichroic azo dye compound.

[0045] [Metal Catalyst] The composition contains a metal catalyst. Examples of the metal catalyst include an octylate metal catalyst and an acetylacetone metal catalyst. Examples of metal atoms constituting the metal catalyst include an aluminum atom, a cobalt atom, a copper atom, a zinc atom, an iron atom, a nickel atom, a manganese atom, and a tin atom, with an aluminum atom being preferred. In other words, the metal catalyst preferably contains an aluminum atom. A preferred metal catalyst is an acetylacetone aluminum catalyst. When the composition contains an acetylacetone aluminum catalyst, the curing reaction of the coating film formed using the composition is further accelerated. As a result, even when the alignment film is used repeatedly, the retardation of the resulting optically anisotropic layer is less likely to change, i.e., the alignment film has excellent durability against repeated use. Examples of the metal catalyst include tris(pentanedionato)aluminum, tetrakis(pentanedionato)titanium, quinolinolatoaluminum, and bis(pentanedionato)magnesium, with tris(pentanedionato)aluminum being preferred.

[0046] The metal catalyst may be used alone or in combination of two or more. The content of the metal catalyst is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and even more preferably 0.1 to 3% by mass, based on the total solids content of the composition. The content of the metal catalyst is preferably 0.1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, based on the content of compound A. The upper limit is preferably 10% by mass or less. Furthermore, when compound A has three or more reactive groups X, it is also preferable that the content of the metal catalyst is 3% by mass or more based on the content of compound A, or when compound A has one or two reactive groups X, it is also preferable that the content of the metal catalyst is 5% by mass or more based on the content of compound A.

[0047] [Solvent] The composition may contain a solvent. Examples of the solvent include water and organic solvents. Examples of the organic 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, chloroform, dichloroethane, dichlorobenzene, and chloroform), and the like. Examples of suitable solvents include: toluene, esters (e.g., methyl acetate, ethyl acetate, butyl acetate, diethyl carbonate, etc.), alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, 1,2-dimethoxyethane, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, etc.), and heterocyclic compounds (e.g., pyridine, etc.). The solvent is preferably water, an alcohol, or a mixture thereof.

[0048] The solvent may be used alone or in combination of two or more. When the composition contains a solvent, the content of the solvent is preferably 80 to 99.9 mass %, more preferably 83 to 99 mass %, and still more preferably 85 to 98 mass %, based on the total mass of the composition.

[0049] [Other Components] The composition may contain other components in addition to the various components described above, such as a dichroic substance other than a dichroic azo dye compound, a polymerizable compound other than Compound A, a curing accelerator other than a metal catalyst, a photoacid generator, and a surfactant.

[0050] [Alignment Film and Alignment Substrate] An alignment film can be produced using the above composition. An embodiment of an alignment substrate including an alignment film formed using the above composition will be described in detail below. FIG. 1 is a side view conceptually illustrating an example of an alignment substrate of the present invention. FIG. 2 is a plan view of the alignment substrate shown in FIG. 1. FIG. 1 is a cross-sectional view taken along line A-A in FIG. 2. Note that the alignment film included in the alignment substrate shown in FIGS. 1 and 2 has a predetermined alignment pattern in which the optical axis derived from the dichroic azo dye compound rotates in one direction in the plane. However, the alignment substrate and alignment film of the present invention are not limited to this alignment pattern and may have other alignment patterns. For example, the optical axis derived from the dichroic azo dye compound may be oriented along one direction. Aligning a liquid crystal compound on an alignment film having such an alignment pattern can achieve homogeneous alignment of the liquid crystal compound. The plan view is a view of the alignment substrate 10 in FIG. 1 viewed from above. That is, FIG. 1 is a view of the alignment substrate 10 viewed from the thickness direction (i.e., the stacking direction of each layer (film)). In other words, FIG. 1 is a view of the alignment film 14 viewed from a direction perpendicular to the main surface. In FIG. 2, in order to clearly illustrate the configuration of the alignment substrate 10 of the present invention, only the dichroic azo dye compound 30 on the side of the alignment film 14 opposite the support 12 side is shown. The alignment substrate 10 shown in FIG. 1 includes a support 12 and an alignment film 14. The alignment film 14 is a film formed using the above-described composition. The dichroic azo dye compound 30 has a predetermined alignment pattern in which the optical axis direction of the dichroic azo dye compound 30 rotates in one direction in the plane. In the alignment film 14, the dichroic azo dye compound 30 reacts with a reactive group X (e.g., an epoxy group) possessed by compound A, thereby fixing the alignment. While the alignment substrate 10 shown in the figure includes a support 12 and an alignment film 14, the alignment substrate of the present invention is not limited to this configuration. Below, each component constituting the alignment substrate 10 is described in detail.

[0051] [Support] The alignment substrate has a support. The support 12 is a member that supports the alignment film 14. The support 12 in the alignment substrate is a member that supports the alignment film 14, and the support 12 in the laminate is a member that supports the alignment film 14 and the optically anisotropic layer 16. The support 12 may be any material that can support the alignment film 14 and the optically anisotropic layer 16, and examples thereof include various sheet-like materials (for example, films and plate-like materials). The transmittance of the support 12 is not particularly limited. The transmittance of the support 12 for light with a wavelength of 550 nm is preferably 50% or more, more preferably 70% or more, and even more preferably 85% or more. The upper limit is preferably 100% or less.

[0052] The thickness of the support 12 is not particularly limited and may be appropriately set depending on the application of the alignment substrate 10 and the material forming the support 12. The thickness of the support 12 is preferably 1 to 1000 μm, more preferably 3 to 250 μm, and even more preferably 5 to 150 μm.

[0053] The support 12 may be either a single layer or a multilayer. Examples of single layer supports 12 include glass, triacetyl cellulose, polyethylene terephthalate, polycarbonate, polyvinyl chloride, poly(meth)acrylate, and polyolefin. Examples of multilayer supports 12 include those that include any of the above single layer supports as a substrate and have other layers provided on the surface of this substrate.

[0054] [Alignment Film] The alignment substrate 10 has an alignment film 14. The alignment film 14 is a film formed by curing the above-described composition. The alignment film 14 is a film for aligning the liquid crystal compound contained in the liquid crystal composition from which the optically anisotropic layer is derived into a predetermined liquid crystal alignment pattern. The alignment film 14 may contain various components other than the solvent that may be contained in the above-described composition, their condensates, decomposition products, and / or cured products. The alignment film 14 preferably has an alignment pattern in which the direction of the optical axis derived from the dichroic azo dye compound is continuously rotated along at least one direction in the plane. An alignment film having the above-described continuously rotated alignment pattern can be produced by a method for forming an alignment film alignment pattern using a laser, as described below.

[0055] Hereinafter, a detailed description will be given of an embodiment in which an alignment film has an alignment pattern in which the direction of the optical axis derived from the dichroic azo dye compound continuously rotates along at least one direction in the plane. As shown in FIG. 2, the alignment film 14 has an alignment pattern in which the direction of the optical axis 30A derived from the dichroic azo dye compound 30 changes while continuously rotating counterclockwise in one direction indicated by arrow X within the plane of the alignment film 14. Note that in FIG. 2, the direction of the optical axis 30A derived from the dichroic azo dye compound 30 rotates counterclockwise, but the present invention is not limited to this embodiment and may also rotate clockwise. Note that the optical axis 30A derived from the dichroic azo dye compound 30 is the axis along which the refractive index of the dichroic azo dye compound 30 is highest. In the following description, the "one direction indicated by arrow X" will also be simply referred to as the "arrow X direction." In the following description, the optical axis 30A derived from the dichroic azo dye compound 30 is also referred to as the "optical axis 30A of the dichroic azo dye compound 30" or the "optical axis 30A." In the alignment film 14, the dichroic azo dye compounds 30 are two-dimensionally oriented in a plane parallel to the direction of arrow X and the direction of Y perpendicular to the direction of arrow X. In FIG. 1, the direction of Y is perpendicular to the paper surface.

[0056] FIG. 2 conceptually shows a plan view of the alignment film 14. The alignment film 14 has an alignment pattern in which the orientation of the optical axis 30A derived from the dichroic azo dye compound 30 changes while continuously rotating along the direction of the arrow X within the plane of the alignment film 14. The phrase "the orientation of the optical axis 30A of the dichroic azo dye compound 30 changes while continuously rotating in the direction of the arrow X (a predetermined direction)" specifically means that the angle between the optical axis 30A of the dichroic azo dye compound 30 aligned along the direction of the arrow X and the direction of the arrow X varies depending on the position in the direction of the arrow X, and the angle between the optical axis 30A and the direction of the arrow X sequentially changes from θ to θ+180° or θ-180° along the direction of the arrow X. The difference in angle between the optical axes 30A of the liquid crystal compounds 30 adjacent to each other in the direction of the arrow X is preferably 45° or less, more preferably 15° or less, and even more preferably 5° or less.

[0057] On the other hand, the dichroic azo dye compounds 30 forming the alignment film 14 are arranged at equal intervals in the Y direction perpendicular to the direction of the arrow X, i.e., in the Y direction perpendicular to the direction in which the optical axes 30A continuously rotate. In other words, among the dichroic azo dye compounds 30 forming the alignment film 14, the angles between the directions of the optical axes 30A and the direction of the arrow X are equal among the dichroic azo dye compounds 30 arranged in the Y direction.

[0058] In the alignment substrate 10, in the alignment pattern of the dichroic azo dye compound 30, the length (distance) over which the optical axis 30A of the dichroic azo dye compound 30 rotates 180° in the direction of arrow X, in which the orientation of the optical axis 30A continuously changes in plane, is defined as the length Λ of one period in the alignment pattern. In other words, the length of one period in the alignment pattern is defined as the distance over which the angle between the optical axis 30A of the dichroic azo dye compound 30 and the direction of arrow X is from θ to θ + 180°. That is, the length Λ of one period is defined as the distance between the centers in the direction of arrow X of two dichroic azo dye compounds 30 that have the same angle with the direction of arrow X. Specifically, as shown in FIG. 2 , the length Λ of one period is defined as the distance between the centers in the direction of arrow X of two dichroic azo dye compounds 30 whose optical axes 30A coincide with the direction of arrow X. In the following description, this length Λ of one period is also referred to as "one period Λ." In the alignment substrate 10 of the present invention, the alignment pattern of the alignment film 14 may repeat this one period Λ in the direction of arrow X, that is, in one direction in which the direction of the optical axis 30A changes by continuously rotating.

[0059] The 180° rotation period in the alignment film 14 does not need to be uniform over the entire surface. That is, there may be regions in the plane where the length of the 180° rotation period (length of one period Λ) is different. The minimum value of the length of one period, which is the length of the in-plane rotation of the optical axis direction derived from the dichroic azo dye compound by 180°, is preferably 20 μm or less, more preferably 5 μm or less, and even more preferably 2 μm or less. The lower limit is preferably 0.5 μm or more.

[0060] The thickness of the alignment film 14 is preferably 0.01 to 0.5 μm, and more preferably 0.03 to 0.2 μm.

[0061] 1 and 2, the orientation of the optical axis 30A of the dichroic azo dye compound 30 in the orientation pattern of the orientation film 14 continuously rotates only along the direction of the arrow X. As described above, the orientation film 14 is not limited to this, and other orientation patterns may also be used.

[0062] As an example, an alignment film 34 is exemplified, in which the alignment pattern is a concentric pattern having one direction in which the orientation of the optical axis of the dichroic azo dye compound 30 changes while continuously rotating, concentrically from the inside to the outside, as conceptually shown in the plan view of Fig. 3. In other words, the alignment pattern of the alignment film 34 shown in Fig. 4 is an alignment pattern in which one direction in which the orientation of the optical axis of the dichroic azo dye compound 30 changes while continuously rotating is provided radially from the center of the alignment film 34. More specifically, the orientation of the optical axis of the dichroic azo dye compound 30 is provided in a number of directions from the center of the alignment film 34 toward the outside, for example, in the directions indicated by arrow A. １ The direction indicated by arrow A ２ The direction indicated by arrow A ３ It changes while rotating continuously along the direction indicated by...

[0063] [Method for producing alignment substrate] The method for producing the alignment substrate is not particularly limited. The method for producing the alignment substrate is preferably a method for producing an alignment substrate including a step of applying a composition to a support to form a coating film, a step of irradiating the coating film with light to align the dichroic azo dye compound, and a step of heat-treating the irradiated coating film to form an alignment film.

[0064] Examples of methods for applying the composition include known methods for applying a liquid, such as bar coating, gravure coating, spray coating, etc. After the composition is applied to the support, a drying treatment may be carried out as necessary.

[0065] Next, the coating film formed by coating is irradiated with light to align the dichroic azo dye compound. By performing the alignment treatment, the dichroic azo dye compound in the coating film is oriented in a predetermined orientation state.

[0066] The light irradiated onto the coating film may be either linearly polarized or unpolarized. The irradiated light preferably has a peak wavelength in the wavelength range of 200 to 700 nm, more preferably in the wavelength range of 200 to 400 nm. Examples of light sources used for light irradiation include lamps such as tungsten lamps, halogen lamps, xenon lamps, xenon flash lamps, mercury lamps, mercury xenon lamps, and carbon arc lamps; semiconductor lasers, helium-neon lasers, argon ion lasers, helium-cadmium lasers, and YAG (yttrium aluminum garnet) lasers; light-emitting diodes; and cathode ray tubes.

[0067] Examples of methods for irradiating linearly polarized light include a method using a polarizing plate (e.g., an iodine polarizing plate, a dichroic material polarizing plate, and a wire grid polarizing plate), a method using a prism-based element (e.g., a Glan-Thompson prism) or a reflective polarizer utilizing the Brewster angle, and a method using light emitted from a polarized laser light source. When the irradiated light is linearly polarized, a method in which the light is irradiated from the top or back surface of the alignment film, perpendicularly or obliquely to the alignment film surface, is preferred. The incident angle of the light is preferably 0 to 90°. When the irradiated light is unpolarized, a method in which the light is irradiated obliquely to the alignment film is preferred. The incident angle is preferably 10 to 80°. The amount of light to be irradiated is not particularly limited as long as it is an amount that results in the desired alignment state of the dichroic azo dye compound, but is preferably 600 to 3000 mJ / cm. ２ is preferred, and 1000 to 2000 mJ / cm ２ is more preferred.

[0068] The light to be irradiated may be laser light. When the light to be irradiated is laser light, it is preferable to irradiate the laser using the following exposure device.

[0069] Fig. 4 conceptually shows an example of an exposure device for forming an alignment pattern on an alignment film using a laser. The exposure device 60 shown in Fig. 4 includes a light source 64 equipped with a laser 62, a λ / 2 plate 65 for changing the polarization direction of laser light M emitted by the laser 62, a beam splitter 68 for splitting the laser light M emitted by the laser 62 into two beams MA and MB, mirrors 70A and 70B arranged on the optical paths of the two split beams MA and MB, and λ / 4 plates 72A and 72B. Although not shown, the light source 64 emits linearly polarized light P ０ The λ / 4 plate 72A emits linearly polarized light P ０ (ray MA) is right circularly polarized P Ｒ The λ / 4 plate 72B is a linearly polarized light P ０ (Light ray MB) is polarized by left-handed circular polarization P Ｌ are converted to , respectively.

[0070] A support 12 having a coating film 18 (a coating film formed by applying a composition) before the formation of an orientation pattern is placed in an exposure section, and two light beams MA and MB are caused to intersect and interfere on the coating film 18, and the coating film 18 is exposed to the interference light. This interference causes the polarization state of the light irradiating the coating film 18 to periodically change in the form of interference fringes. This results in an orientation film having an orientation pattern in which the orientation state periodically changes. In the exposure device 60, the period of the orientation pattern can be adjusted by changing the crossing angle α of the two light beams MA and MB. That is, in the exposure device 60, by adjusting the crossing angle α, the length of one period (one period Λ) in which the orientation of the optical axis 30A derived from the dichroic azo dye compound 30 rotates 180° in one direction in an orientation pattern in which the orientation of the optical axis 30A continuously rotates along one direction can be adjusted. By forming an optically anisotropic layer on an alignment film having such an alignment pattern in which the alignment state changes periodically, it is possible to form an optically anisotropic layer having a liquid crystal alignment pattern in which the direction of the optical axis derived from the liquid crystal compound continuously rotates in one direction, as will be described later. Furthermore, by rotating the optical axes of the λ / 4 plates 72A and 72B by 90° each, the rotation direction of the optical axis 30A can be reversed.

[0071] Next, the irradiated coating film is subjected to a heat treatment to form an alignment film. By subjecting the coating film to a heat treatment (curing treatment), the dichroic azo dye compound in the coating film is fixed in an aligned state. Specifically, the orientation of the dichroic azo dye compound is fixed by reacting a reactive group (e.g., an epoxy group) in compound A with a reactive group Y (e.g., a phenolic hydroxyl group) in the dichroic azo dye compound. In addition, a metal catalyst can further promote the reaction. The heating temperature is preferably 100 to 180°C, and the heating time is preferably 1 to 20 minutes.

[0072] [Method for Producing Laminate] A laminate including an alignment substrate and an optically anisotropic layer can be produced using the alignment substrate. The method for producing the laminate is not particularly limited. A preferred method for producing a laminate is one that includes a step of forming an optically anisotropic layer using a liquid crystal composition containing a liquid crystal compound on the surface of the alignment film on the alignment substrate opposite the support. Of these, a more preferred method for producing a laminate is one that includes a step of applying a liquid crystal composition containing a liquid crystal compound to the surface of the alignment film opposite the support to align the liquid crystal compound, and then curing the coating. By the above method, a laminate 20 is produced that includes a support 12, an alignment film 14, and an optically anisotropic layer 16, as shown in FIG. 5 .

[0073] Examples of methods for applying the liquid crystal composition include known methods for applying a liquid, such as bar coating, gravure coating, and spray coating. Next, the coating film formed by coating is subjected to an alignment treatment to align the liquid crystal compound. By performing the alignment treatment, the liquid crystal compound in the coating film is oriented in a predetermined alignment state according to the alignment pattern of the alignment film. As the alignment treatment, a heat treatment is preferred. The heating conditions are not particularly limited, and the heating temperature is preferably 50 to 180°C. The heating time is preferably 1 to 5 minutes.

[0074] Next, the resulting coating film is subjected to a curing treatment. Examples of the curing treatment include a light irradiation treatment and a heat treatment, and a light irradiation treatment is preferred. The irradiation energy in the light irradiation treatment is 20 mJ / cm. ２ ~50 J / cm ２ is preferred, and 50 to 1500 mJ / cm ２is more preferable. In order to promote the photopolymerization reaction, light irradiation may be carried out under heating conditions or in a nitrogen atmosphere. The wavelength of the irradiated light is preferably any wavelength between 250 and 430 nm. By subjecting the coating film to a curing treatment, the liquid crystal compound in the coating film is fixed in a state (liquid crystal orientation pattern) in which it is aligned along the orientation pattern of the optically anisotropic layer in the orientation substrate. Note that the liquid crystal compound does not need to exhibit liquid crystallinity when the optically anisotropic layer is completed. In other words, the liquid crystal compound may be polymerized by the curing reaction and lose its liquid crystallinity.

[0075] Various components that the liquid crystal composition may contain will be described in detail below.

[0076] [Liquid Crystal Composition] The liquid crystal composition contains a liquid crystal compound.

[0077] <Liquid Crystal Compound> The liquid crystal compound preferably has a radical polymerizable group. Examples of the radical polymerizable group include an acryloyl group, a methacryloyl group, a vinyl group, a styryl group, and an allyl group, and an acryloyl group or a methacryloyl group is preferred.

[0078] The number of radical polymerizable groups contained in the liquid crystal compound is preferably 1 to 6, and more preferably 1 to 3. In addition, in terms of fixing the alignment of the liquid crystal compound, the liquid crystal compound preferably has two or more polymerizable groups. When the liquid crystal compound is a mixture of two or more types, it is preferable that at least one type of liquid crystal compound has two or more polymerizable groups in one molecule.

[0079] Examples of liquid crystal compounds include rod-shaped (rod-shaped liquid crystal compounds) and discotic (discotic liquid crystal compounds). Each of these compounds may be divided into low molecular weight and high molecular weight compounds. Polymer generally refers to a compound with a degree of polymerization of 100 or more (see "Polymer Physics: Phase Transition Dynamics," by Masao Doi, p. 2, Iwanami Shoten, 1992). The liquid crystal compound is preferably a rod-shaped liquid crystal compound or a discotic liquid crystal compound (discotic liquid crystal compound). Alternatively, the liquid crystal compound may be a mixture of two or more rod-shaped liquid crystal compounds, two or more discotic liquid crystal compounds, or a mixture of a rod-shaped liquid crystal compound and a discotic liquid crystal compound.

[0080] As the rod-shaped liquid crystal compound, the compounds described in claim 1 of JP-A-11-513019 or paragraphs

[0026] to

[0098] of JP-A-2005-289980 are preferred. As the discotic liquid crystal compound, the compounds described in paragraphs

[0020] to

[0067] of JP-A-2007-108732 or paragraphs

[0013] to

[0108] of JP-A-2010-244038 are preferred. As the liquid crystal compound, rod-shaped liquid crystal compounds are preferred, and azomethines, azoxy compounds, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, or alkenylcyclohexylbenzonitriles are more preferred.

[0081] The content of the liquid crystal compound is preferably 75 to 99.9% by mass, more preferably 80 to 99% by mass, based on the total solid content of the liquid crystal composition.

[0082] <Other Components> The liquid crystal composition may contain other components in addition to the liquid crystal compound. Examples of the other components include surfactants, chiral agents, polymerization initiators, solvents, polymerization inhibitors, antioxidants, UV absorbers, light stabilizers, colorants, and metal oxide fine particles. The other components may be used alone or in combination of two or more.

[0083] (Surfactant) Examples of the surfactant include the compounds described in paragraphs

[0082] to

[0090] of JP-A No. 2014-119605, the compounds described in paragraphs

[0031] to

[0034] of JP-A No. 2012-203237, the compounds described in paragraphs

[0092] to

[0093] of JP-A No. 2005-099248, the compounds described in paragraphs

[0076] to

[0078] and

[0082] to

[0085] of JP-A No. 2002-129162, and the fluorine acrylate polymers and fluorine methacrylate polymers described in paragraphs

[0018] to

[0043] of JP-A No. 2007-272185, etc. As the fluorine-based surfactant, the compounds described in paragraphs

[0082] to

[0090] of JP-A-2014-119605 are preferred.

[0084] The content of the surfactant in the liquid crystal composition is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, based on the total mass of the liquid crystal compound.

[0085] (Chiral Agent) A chiral agent has the function of inducing a helical structure in a cholesteric liquid crystal phase. Since the twist direction or helical pitch of the helix induced by a chiral agent varies depending on the compound, a chiral agent may be selected according to the purpose. Examples of the chiral agent include known compounds (for example, those described in Liquid Crystal Device Handbook, Chapter 3, Section 4-3, "Chiral Agents for TN (Twisted Nematic)" and STN (Super Twisted Nematic) on page 199, edited by the 142nd Committee of the Japan Society for the Promotion of Science, 1989), isosorbide, and isomannide derivatives.

[0086] The content (molar amount) of the chiral dopant in the liquid crystal composition is preferably 0.01 to 200 mol %, more preferably 1 to 30 mol %, based on the molar amount of the liquid crystal compound.

[0087] (Polymerization Initiator) The polymerization initiator is preferably a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation. The content of the polymerization initiator in the liquid crystal composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 12% by mass, based on the content of the liquid crystal compound.

[0088] (Solvent) The solvent can be appropriately selected depending on the purpose, and is preferably an organic solvent. Examples of the organic solvent include ketones such as methyl ethyl ketone, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, and ethers.

[0089] [Method for Producing Optically Anisotropic Layer] The method for producing an optically anisotropic layer is not particularly limited. Examples of methods for producing an optically anisotropic layer include a method for producing an optically anisotropic layer comprising a step of peeling off the optically anisotropic layer from the laminate described above. The method for producing an optically anisotropic layer preferably comprises step 1 of forming an optically anisotropic layer A using a liquid crystal composition containing a liquid crystal compound on the surface of the alignment film of the alignment substrate opposite the support to obtain a laminate, and step 2 of peeling off the optically anisotropic layer A from the laminate obtained in step 1 to obtain the optically anisotropic layer A separated from the alignment substrate. By the above procedure, the optically anisotropic layer 16 is separated from the laminate 20 of FIG. 5, as shown in FIG. 6.

[0090] The procedure of step 1 is the same as the procedure in the above-mentioned method for producing a laminate.

[0091] In step 2, the method for peeling off the optically anisotropic layer A (optically anisotropic layer 16 in FIG. 5 ) is not particularly limited, and any known method may be used. For example, a known transfer film or the like may be attached to the optically anisotropic layer A, and the optically anisotropic layer A may be peeled off together with the transfer film from the alignment substrate.

[0092] The alignment film of the present invention may be repeatedly used to repeatedly produce the optically anisotropic layer A. That is, the method for producing an optically anisotropic layer of the present invention preferably includes the following steps: Step 1: forming an optically anisotropic layer A using a liquid crystal composition containing a liquid crystal compound on the surface of the alignment film of the alignment substrate opposite to the support, thereby obtaining a laminate; Step 2: peeling the optically anisotropic layer A from the laminate obtained in Step 1, thereby obtaining the optically anisotropic layer A separated from the alignment substrate; Step 3: forming an optically anisotropic layer B using a liquid crystal composition containing a liquid crystal compound on the surface of the alignment film of the alignment substrate from which the optically anisotropic layer A has been separated, opposite to the support, thereby obtaining a laminate; and Step 4: peeling the optically anisotropic layer B from the laminate obtained in Step 3, thereby obtaining the optically anisotropic layer B separated from the alignment substrate, wherein Steps 3 and 4 are repeated at least once.

[0093] In the method for producing an optically anisotropic layer comprising steps 1 to 4, optically anisotropic layers can be repeatedly produced. When forming an alignment pattern by laser interference exposure as described above, an exposure time of about 5 minutes is required for an area of ​​about 5 cm square, resulting in very low productivity. However, by using a predetermined alignment film and forming an optically anisotropic layer on the alignment film as in the present invention, exposure to produce an alignment film having a predetermined alignment pattern is not required every time an optically anisotropic layer is produced, thereby increasing productivity.

[0094] The number of times that steps 3 and 4 are repeated is not particularly limited, and steps 3 and 4 may be repeated multiple times.

[0095] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment details, 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.

[0096] Example 1 Preparation of Alignment Substrate Dichroic azo dye compound Z1 (1 part by mass), compound A1 (0.05 parts by mass), and metal catalyst B1 (0.0015 parts by mass) were mixed, and a mixture of water and butoxyethanol (1:1 mass ratio, 25.236 parts by mass) was added and stirred at room temperature to obtain a composition. The resulting composition was spin-coated at 500 rpm for 5 seconds and then at 2500 rpm for 20 seconds onto a quartz glass substrate cut to a size of 2 cm x 3 cm to form a coating film. The coating film was then dried by heating at 60°C for 1 minute. The dried coating film was irradiated with polarized light from the front of the exposed coating film side through a 365 nm wire grid, aligning the dichroic azo dye compound in a direction perpendicular to the transmission axis of the wire grid. The irradiance of the 365 nm light was 1.2 J / cm. ２ Thereafter, the substrate was heated at 140° C. for 20 minutes to obtain the alignment substrate of Example 1. The thickness of the alignment film was 0.04 μm.

[0097] [Preparation of Laminate] The following liquid crystal composition was applied to the alignment film of the obtained alignment substrate using a spin coater to form a coating film. The coating film was dried at 80°C for 1 minute, and then irradiated with unpolarized light having a wavelength of 365 nm at 300 mJ / cm under a nitrogen atmosphere. ２ Irradiation gave a laminate having the support, the alignment film, and the optically anisotropic layer in this order, with the thickness of the optically anisotropic layer being 0.6 μm.

[0098] Liquid crystal composition ------------------------------------------------ Compound 1 (liquid crystal compound) 1 part by mass Compound 2 (surfactant) 0.003 part by mass Irgacure 907 (Ciba Specialty Chemicals) 0.03 part by mass Methyl ethyl ketone 9 parts by mass ----------------------------------------------------------------

[0099]

[0100] [Examples and Comparative Examples Other Than Example 1] Except for changing the type of composition to the formulation shown in the table below, laminates of Examples and Comparative Examples other than Example 1 were prepared in the same manner as Example 1. The thicknesses of the alignment film and the optically anisotropic layer in the laminates of Examples and Comparative Examples other than Example 1 were all the same as those in Example 1.

[0101] [Various ingredients] [Dichroic azo dye compound]

[0102]

[0103] [Compound A]

[0104]

[0105] Compound A1: Polyglycerol polyglycidyl ether (Denacol Ex-512, manufactured by Nagase ChemteX Corporation) Compound A2: Trimethylolpropane polyglycidyl ether (Denacol Ex-321, manufactured by Nagase ChemteX Corporation) Compound A3: Sorbitol polyglycidyl ether (Denacol Ex-614, manufactured by Nagase ChemteX Corporation) Compound A4: Resorcinol diglycidyl ether (Denacol Ex-201, manufactured by Nagase ChemteX Corporation)

[0106] Metallic or other catalysts

[0107]

[0108] [Evaluation] [Repeated Durability of Optical Properties] A release sheet was attached to the exposed surface of the optically anisotropic layer of each laminate, and then the laminate was separated into the optically anisotropic layer and the alignment substrate. The in-plane retardation Re(550) of the separated optically anisotropic layer at a wavelength of 550 nm was measured using an AxoScan (manufactured by Axometrics) and recorded as Re(550) after the first peeling. Next, an optically anisotropic layer was again formed on the alignment film of the separated alignment substrate using the liquid crystal composition in the same manner as described above to obtain a laminate. The obtained laminate was further separated into the optically anisotropic layer and the alignment substrate to obtain an optically anisotropic layer after the second peeling. The above procedure was repeated, and the Re(550) of the optically anisotropic layer after the tenth peeling was measured. The variation rate of Re(550) after the tenth peeling relative to Re(550) after the first peeling was calculated using the following formula to evaluate the repeated durability of the optical properties. Fluctuation rate of Re(550)={|Re(550) after 1st peeling−Re(550) after 10th peeling| / Re(550) after 1st peeling}×100

[0109] A: Fluctuation rate is 5.0% or less. B: Fluctuation rate is more than 5.0% and 10.0% or less. C: Fluctuation rate is more than 10.0%.

[0110] The evaluation results are shown in the table. In the table, the column "Content (mass % relative to azo dye)" for "Compound A" indicates the content (mass %) of Compound A relative to the content of the dichroic azo dye compound. The column "Content (mass % relative to Compound A)" ​​for "Metal catalyst or other catalyst" indicates the content (mass %) of the metal catalyst or other catalyst relative to the content of Compound A. As described above, the column "Re(550) variation rate (%)" indicates the value calculated by {|Re(550) after 1st peeling - Re(550) after 10th peeling| / Re(550) after 1st peeling} × 100.

[0111]

[0112] As shown in the table, it was confirmed that the alignment film formed using the composition of the present invention has excellent durability of optical properties against repeated use. It was confirmed that when compound A has three or more reactive groups X, the durability of optical properties against repeated use is even more excellent (Examples 1 to 4, etc.). When compound A has three or more reactive groups X, the content of the metal catalyst is 3% by mass or more relative to the content of compound A, or when compound A has one or two reactive groups X, the content of the metal catalyst is 5% by mass or more relative to the content of compound A, it was confirmed that the durability of optical properties against repeated use is even more excellent (Examples 4 and 5, etc.).

[0113] REFERENCE SIGNS LIST 10 Alignment substrate 12 Support 14, 34 Alignment film 16 Optically anisotropic layer 18 Coating film 20 Laminate 30 Dichroic azo dye compound 30A Optical axis 60 Exposure device 62 Laser 64 Light source 65 λ / 2 plate 68 Beam splitter 70A, 70B Mirror 72A, 72B λ / 4 plate

Claims

1. A composition for forming an alignment film, comprising: a dichroic azo dye compound; a compound A having a reactive group that reacts with the dichroic azo dye compound; and a metal catalyst.

2. The composition for forming an alignment film according to claim 1 , wherein the reactive group is an epoxy group.

3. The composition for forming an alignment film according to claim 1 , wherein the compound A has three or more of the reactive groups.

4. The composition for forming an alignment film according to claim 1 , wherein the metal catalyst contains an aluminum atom.

5. When the compound A has three or more of the reactive groups, the content of the metal catalyst is 3 mass% or more relative to the content of the compound A, or 2. The composition for forming an alignment film according to claim 1, wherein when the compound A has one or two of the reactive groups, the content of the metal catalyst is 5 mass % or more with respect to the content of the compound A.

6. The composition for regulating an alignment film described in claim 1, wherein the dichroic azo dye compound includes a compound represented by formula (1). 【Chemistry 1】 In formula (1), R 1 and R 2 each independently represent a polymerizable group selected from the group consisting of an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acrylamide group, a methacrylamide group, a vinyl group, a vinyloxy group, and a maleimide group, or a hydroxyl group. R 3 and R 4 each independently represent a hydrogen atom, a halogen atom, a carboxy group or a salt thereof, an alkyl group having a hydroxyl group, a carbamoyl group, a halogenated methyl group, a halogenated methoxy group, a cyano group, a hydroxyl group, or -OR T , where R T represents an alkyl group having 2 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms substituted with an alkoxy group having 1 to 6 carbon atoms. R 5 and R 6 each independently represent a carboxy group or a salt thereof, a sulfo group or a salt thereof, an amino group or a salt thereof, a nitro group, a carbamoyl group, an alkoxycarbonyl group, a sulfamoyl group, or a hydroxyl group. When R 1 is a hydroxyl group, X 1 represents a single bond, and when R 1 is the polymerizable group, X 1 represents a group represented by -(A 1 -B 1 ) m -. When R 2 is a hydroxyl group, X 2 represents a single bond, and when R 2 is the polymerizable group, X 2 represents a group represented by -(A 2 -B 2 ) n -. A 1 and A 2 each independently represent a single bond or a divalent hydrocarbon group. B 1 and B 2 each independently represent a single bond, -O-, -COO-, -CONH- or -NHCOO-. m and n each independently represent an integer of 1 to 4.

7. An alignment film obtained by curing the composition for forming an alignment film according to any one of claims 1 to 6.

8. A step of applying the composition for forming an alignment film according to any one of claims 1 to 6 onto a support to form a coating film; a step of irradiating the coating film with light to orient the dichroic azo dye compound; and a step of subjecting the coating film irradiated with light to a heat treatment to form an alignment film.

9. The method for producing a laminate according to claim 8 , further comprising a step of forming an optically anisotropic layer on a surface of the alignment film of the alignment substrate opposite to the support, using a liquid crystal composition containing a liquid crystal compound.

10. The method for producing an optically anisotropic layer according to claim 9 , further comprising a step of peeling off the optically anisotropic layer in the laminate.

11. A step 1 of forming an optically anisotropic layer A using a liquid crystal composition containing a liquid crystal compound on a surface of the alignment film of the alignment substrate according to claim 8 opposite to the support to obtain a laminate; a step 2 of peeling off the optically anisotropic layer A in the laminate obtained in the step 1 to obtain the optically anisotropic layer A separated from the alignment substrate; a step 3 of forming an optically anisotropic layer B on a surface of the alignment substrate from which the optically anisotropic layer A has been separated, the surface being opposite to the support of the alignment film, using a liquid crystal composition containing a liquid crystal composition, to obtain a laminate; and a step 4 of peeling off the optically anisotropic layer B in the laminate obtained in the step 3 to obtain the optically anisotropic layer B separated from the alignment substrate, The method for producing an optically anisotropic layer, comprising repeating the steps 3 and 4 at least once.

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