Composition, optical anisotropy layer, polarizing plate, image display device

Abstract

The present invention provides a composition capable of forming an optically anisotropic layer in which the occurrence of orientation unevenness in liquid crystal compounds and the occurrence of orientation defects are suppressed. The present invention also provides an optically anisotropic layer, a polarizing plate, and an image display device. [Solution] A composition comprising a liquid crystal compound having polymerizable groups, an ionic compound having a melting point of 100°C or less, and an organic solvent, A composition having an electrical conductivity of 3.0 μS / cm or more at 25°C.

Description

Technical Field

[0001] The present invention relates to a composition, an optically anisotropic layer, a polarizing plate, and an image display device.

Background Art

[0002] Optical films such as optical compensation sheets and retardation films are used in various image display devices for eliminating image coloring or expanding the viewing angle. Although stretched birefringence films have been used as optical films, in recent years, it has been proposed to use an optical film having an optically anisotropic layer composed of a liquid crystal compound instead of the stretched birefringence film.

[0003] For example, Patent Document 1 discloses an optically anisotropic layer formed using a composition containing a polymerizable liquid crystal compound and an ionic compound having the following structure.

[0004]

Chemical Formula

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] When the present inventor examined the optically anisotropic layer described in Patent Document 1, it was revealed that there is still room for further improvement in suppressing the uneven alignment of the liquid crystal compound in the optically anisotropic layer. In addition, the optically anisotropic layer is also required to have few alignment defects as a basic performance.

[0007] Therefore, the object of the present invention is to provide a composition that can form an optically anisotropic layer in which the occurrence of orientation unevenness in liquid crystal compounds and the occurrence of orientation defects are suppressed. Furthermore, the present invention also aims to provide an optically anisotropic layer, a polarizing plate, and an image display device. [Means for solving the problem]

[0008] The inventors have found that the above problems can be solved by the following configuration.

[0009] [1] A composition comprising a liquid crystal compound having polymerizable groups, an ionic compound having a melting point of 100°C or less, and an organic solvent, A composition having an electrical conductivity of 3.0 μS / cm or more at 25°C. [2] The composition according to [1], wherein the ionic compound is composed of a cation portion and an anion portion, and the anion portion does not contain a halogen atom. [3] The composition according to [1] or [2], wherein the ionic compound is composed of a cation portion and an anion portion, and the molecular weight of the anion portion is 200 or less. [4] The composition according to any one of [1] to [3], wherein the ionic compound is composed of a cation portion and an anion portion, and the cation portion does not contain silicon atoms. [5] The composition according to any one of [1] to [4], wherein the ionic compound is composed of a cation portion and an anion portion, and the molecular weight of the cation portion is 250 or less. [6] The composition according to any one of [1] to [5], wherein the ionic compound is composed of a cation portion and an anion portion, and the anion portion is composed of an anion selected from the group consisting of thiocyanate anion, acetate anion, and dialkyl phosphate anion. [7] The composition according to any one of [1] to [6], wherein the ionic compound is composed of a cation portion and an anion portion, and the anion portion is composed of an anion selected from the group consisting of thiocyanate anions and acetate anions. [8] The composition according to any one of [1] to [7], wherein the ionic compound is one or more selected from the group consisting of a salt compound composed of a thiocyanate anion and an imidazolium cation, a salt compound composed of an acetate ion and a substituted or unsubstituted quaternary ammonium cation, and a salt compound composed of a dialkyl phosphate anion and a substituted or unsubstituted quaternary phosphonium cation. [9] An optically anisotropic layer formed by curing any of the compositions described in [1] to [8].

[10] The optical anisotropic layer according to [9], wherein the liquid crystal compound is oriented in the horizontal direction.

[11] A polarizing plate comprising an optically anisotropic layer formed by curing any of the compositions described in [1] to [8], and a polarizer.

[12] An image display device comprising an optically anisotropic layer formed by curing any of the compositions described in [1] to [8].

[13] The image display device described in

[12] , which is a liquid crystal display device.

[14] The image display device described in

[12] , which is an organic EL display device. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a composition that can form an optically anisotropic layer in which the occurrence of orientation unevenness in liquid crystal compounds and the occurrence of orientation defects are suppressed. Furthermore, according to the present invention, an optically anisotropic layer, a polarizing plate, and an image display device can also be provided. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below. The following description of the constituent elements may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, respectively. Furthermore, in this specification, each component may be represented by a single substance or by a combination of two or more substances. When two or more substances are used in combination for each component, the content of that component refers to the total content of the combined substances, unless otherwise specified. Furthermore, in this specification, "(meth)acrylate" refers to "acrylate" or "methacrylate," and "(meth)acrylic" refers to "acrylic" or "methacrylic." Furthermore, in this specification, the bonding direction of a divalent group (e.g., -CO-O-) is not particularly limited unless the bonding position is specified. For example, if L in XLY is -COO-, and the position where it is bonded on the X side is *1 and the position where it is bonded on the Y side is *2, then L may be *1-O-CO-*2 or *1-CO-O-*2.

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

[0013] Furthermore, in this specification, unless otherwise specified, the melting point refers to the melting point under normal pressure (1 atmosphere, 760 mmHg). Furthermore, in this specification, "solid content" refers to components that form layers, such as optically anisotropic layers, and does not include solvents. Any component that forms a layer is considered solid content, even if its properties are liquid.

[0014] Furthermore, in this specification, "parallel" does not require that they be strictly parallel, but rather means that the angle between one and the other is less than 10°. Furthermore, in this specification, "orthogonal" does not require that the two elements be strictly orthogonal, but rather means that the angle between them is greater than 80° and less than 100°.

[0015] [Composition] The composition of the present invention, A composition comprising a liquid crystal compound having polymerizable groups, an ionic compound having a melting point of 100°C or lower (hereinafter referred to as "ionic liquid"), and an organic solvent, The conductivity at 25°C is 3.0 μS / cm or higher.

[0016] The mechanism of action of this invention is not entirely clear, but the inventors speculate as follows. Through the present inventors' research, it has been found that when forming an optically anisotropic layer on a substrate using the composition, localized charging of the substrate can cause an electric field to form, which can lead to uneven orientation of the liquid crystal compound in the optically anisotropic layer placed on the substrate. For example, one method for forming an optically anisotropic layer using a composition is to feed out a roll-shaped substrate and apply the composition to the substrate on a metal backup roll to form the optically anisotropic layer. Typically, due to peeling charge during feeding, the coated surface of the substrate tends to become charged, while the back surface of the substrate tends to become charged in the opposite direction. It is thought that applying a conductive composition to such a substrate can neutralize the charge on the coated surface of the substrate. However, if the neutralization is insufficient and charge remains on the coated surface of the substrate, corona discharge may occur between the back surface of the substrate and the surface of the metal backup roll. As a result, localized charging occurs on the coated surface of the substrate, and the electric field formed by this charging can cause the orientation direction of the liquid crystal compound in the optically anisotropic layer placed on the substrate to shift, resulting in misalignment of the orientation. In particular, misalignment caused by charging is often observed as streaks in a direction perpendicular to the transport direction (the width direction of the optically anisotropic layer). In relation to the above findings, the composition of the present invention introduces an ionic liquid and sets the conductivity of the composition (at 25°C) to 3.0 μS / cm or higher, thereby facilitating the neutralization of charges on the coated surface when the composition is applied to a substrate. As a result, the occurrence of uneven orientation of the liquid crystal compound in the formed optically anisotropic layer can be suppressed. Furthermore, ionic liquids have superior solubility in organic solvents compared to other ionic compounds (specifically, ionic compounds with a melting point above 100°C) and are less likely to inhibit the orientation of liquid crystal compounds. In other words, the optically anisotropic layer formed by the composition of the present invention can also suppress orientation defects.

[0017] Furthermore, recent studies by the inventors have revealed that the composition of the present invention also exhibits excellent corrosion resistance (metallic corrosion resistance) to metals (especially stainless steel).

[0018] Hereinafter, the superior orientation of the liquid crystal compound in the optically anisotropic layer formed by the composition, the superior orientation defects in the optically anisotropic layer formed by the composition, and / or the superior metal corrosion resistance of the composition are also referred to as "the effects of the present invention being superior."

[0019] The following describes in detail the various components that may be included in the composition of the present invention.

[0020] [Liquid crystal compound] The composition contains a liquid crystal compound having polymerizable groups (hereinafter also referred to as "polymerizable liquid crystal compound"). Here, the polymerizable group is not particularly limited, but a polymerizable group capable of radical polymerization or cationic polymerization is preferred. Examples of radical polymerizable groups include known radical polymerizable groups, with acryloyloxy groups or methacryloyloxy groups being preferred. Examples of cationic polymerizable groups include known cationic polymerizable groups such as alicyclic ether groups, cyclic acetal groups, cyclic lactone groups, cyclic thioether groups, spiroorthoester groups, and vinyloxy groups. Among these, alicyclic ether groups or vinyloxy groups are preferred, and epoxy groups, oxetanyl groups, or vinyloxy groups are more preferred.

[0021] Generally, liquid crystal compounds can be classified into rod-shaped and disc-shaped types based on their shape. Furthermore, each type can be further divided into low-molecular-weight and high-molecular-weight types. High-molecular-weight compounds generally refer to those with a degree of polymerization of 100 or more (Polymer Physics and Phase Transition Dynamics, by Masao Doi, p. 2, Iwanami Shoten, 1992). The liquid crystal compound is not particularly limited and may be either a rod-shaped or disc-shaped compound. Among these, rod-shaped liquid crystal compounds or disc-shaped liquid crystal compounds (discotic liquid crystal compounds) are preferred in that they exhibit superior effects compared to the present invention, and rod-shaped liquid crystal compounds are more preferred. Furthermore, the liquid crystal compound may be either a thermotropic liquid crystal compound or a lyotropic liquid crystal compound, but a thermotropic liquid crystal compound is preferred.

[0022] As the rod-shaped liquid crystal compound, for example, the rod-shaped liquid crystal compound described in claim 1 of Japanese Patent Publication No. 11-513019 and paragraphs

[0026] to

[0098] of Japanese Patent Application Publication No. 2005-289980 is preferred. As discotic liquid crystal compounds, for example, the discotic liquid crystal compounds described in paragraphs

[0020] to

[0067] of Japanese Patent Application Publication No. 2007-108732 and paragraphs

[0013] to

[0108] of Japanese Patent Application Publication No. 2010-244038 are preferred.

[0023] The content of polymerizable liquid crystal compounds (or the total content if multiple types are included) is preferably 95% by mass or less, more preferably 1 to 93% by mass, even more preferably 1 to 85% by mass, and particularly preferably 1 to 80% by mass, based on the total solid content of the composition. Polymerizable liquid crystal compounds may be used individually or in combination of two or more.

[0024] [Organic solvents] The composition contains an organic solvent. Examples of organic solvents include organic solvents capable of dissolving each component incorporated into the composition, and organic solvents having at least one group selected from the group consisting of ether groups, ester groups, carbonyl groups, and amide groups are preferred. Examples of organic solvents include ether-based solvents such as diethyl ether, dipropyl ether, diisopropyl ether, tetrahydrofuran, 1,2-dimethoxyethane, and 1,4-dioxane; ester-based solvents such as ethyl acetate, propyl acetate, butyl acetate, methyl propionate, and ethyl propionate; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, cyclopentanone, and cyclohexanone; and amide-based solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and hexamethylphosphate triamide.

[0025] The amount of organic solvent in the composition (total amount if multiple types are included) is preferably such that the solid content concentration of the composition is 0.5 to 60% by mass, more preferably 1 to 50% by mass, and even more preferably 1 to 45% by mass. Organic solvents may be used individually or in combination of two or more.

[0026] [Ionic compounds with a melting point of 100°C or lower] The composition contains an ionic compound (a so-called ionic liquid; hereinafter also referred to as "specific ionic compound") with a melting point of 100°C or lower. Specific ionic compounds are typically compounds composed of a cation and an anion. Examples of specific ionic compounds include salts having a nitrogen-containing aromatic ring with a positive charge in the cation portion (e.g., imidazolium salts and pyridinium salts), quaternary ammonium salts with a positive charge in the nitrogen atom, and quaternary phosphonium salts with a positive charge in the phosphorus atom. The specific ionic compound may also be an oligomer or polymer. The specific ionic compound may be a compound having multiple parts composed of an anionic part and a cation part.

[0027] The upper limit of the molecular weight of the specific ionic compound is preferably 1000 or less, more preferably 500 or less, even more preferably 400 or less, and particularly preferably 300 or less, in order to better achieve the effects of the present invention. The lower limit is preferably 30 or more, and more preferably 40 or more.

[0028] <Cation Department> The cation portion of a specific ionic compound is preferably an organic cation portion. Examples of the cation portion of a specific ionic compound include nitrogen-containing aromatic ring cations having at least one cationized nitrogen atom (e.g., imidazolium cations and pyridinium cations), substituted or unsubstituted quaternary ammonium cations, and substituted or unsubstituted quaternary phosphonium cations.

[0029] The upper limit of the molecular weight of the cation portion of the specific ionic compound is preferably 400 or less, more preferably 250 or less, and even more preferably 120 or less. The lower limit is preferably 30 or more, more preferably 40 or more, and even more preferably 50 or more.

[0030] The cationic part of the specific ionic compound preferably does not contain a silicon atom in that the effects of the present invention are more likely to be excellent.

[0031] Examples of the above-described substituted or unsubstituted quaternary ammonium cation and substituted or unsubstituted quaternary phosphonium cation include cations represented by the following formula (CA1).

[0032]

Chemical formula

[0033] In formula (CA1), X 101 represents a nitrogen atom or a phosphorus atom. In formula (CA1), the nitrogen atom or phosphorus atom represented by X 101 is cationized.

[0034] R 101 ~R 104 each independently represents a monovalent organic group. Among R 101 ~R 104 adjacent groups may combine with each other to form an alicyclic ring which may have a substituent. R 101 ~R 104 The monovalent organic group represented by preferably represents an alkyl group which may have a substituent. The alkyl group may be linear, branched or cyclic, but is preferably linear or branched, and more preferably linear. The number of carbon atoms of the alkyl group is preferably 1 to 20, more preferably 1 to 12, and still more preferably 1 to 6. The substituent which the alkyl group may have is not particularly limited, and examples thereof include a hydroxyl group, a halogen atom, and an alkoxy group (for example, a linear alkoxy group having 1 to 10 carbon atoms, a branched alkoxy group having 3 to 10 carbon atoms, a cyclic alkoxy group, etc.).

[0035] R 101 ~R 104Adjacent groups among them may be bonded to each other and have substituents. When an alicyclic ring is formed, the alicyclic ring has ring member atoms as specified in the formula X 101 It may also contain other heteroatoms other than nitrogen atoms or phosphorus atoms represented by (for example, oxygen atoms, nitrogen atoms, and sulfur atoms). Furthermore, the ring member atoms may be substituted with carbonyl carbons (>C=O). In terms of the effects of the present invention being more easily achieved, X constituting the alicyclic ring 101 It is also preferable that all ring member atoms other than the nitrogen or phosphorus atom represented by are carbon atoms. The above-mentioned alicyclic ring may be monocyclic or polycyclic. The number of ring member atoms in the above-mentioned alicyclic ring is preferably 5 to 15, more preferably 5 to 10, and even more preferably 5 or 6. The above alicyclic ring may further have substituents. Examples of substituents include alkyl groups, hydroxyl groups, halogen atoms, and alkoxy groups.

[0036] Examples of nitrogen-containing aromatic ring cations having at least one cationized nitrogen atom include the cation represented by the following formula (CA2).

[0037] [ka]

[0038] In formula (CA2), X 201 represents a nitrogen atom or a phosphorus atom. Note that in formula (CA2), XX 201 The nitrogen atom or phosphorus atom represented by is cationized.

[0039] W 201 X is a ring member atom. 201 This represents an aromatic ring containing a nitrogen atom or a phosphorus atom, which may have substituents. W 201 The aromatic ring represented by may be either monocyclic or polycyclic. W 201The aromatic ring represented by may contain, as ring member atoms, other heteroatoms other than the nitrogen atom or phosphorus atom explicitly shown in the formula (e.g., oxygen atom, nitrogen atom, and sulfur atom). The aromatic ring may also preferably contain, as ring member atoms, one to two (preferably one) nitrogen atoms other than the nitrogen atom or phosphorus atom explicitly shown in the formula. W 201 The number of ring member atoms in the aromatic ring represented by is preferably 5 to 15, more preferably 5 to 10, and even more preferably 5 or 6. W 201 The aromatic ring represented by may have further substituents. Examples of substituents include alkyl groups, alkoxy groups, aryl groups (e.g., phenyl groups), halogen atoms (e.g., chlorine atoms and iodine atoms), and hydroxyl groups. Specific examples of the above aromatic rings include imidazolium cations and pyridinium cations.

[0040] R 201 This represents an alkyl group which may have substituents, or an alkoxy group which may have substituents. R 201 The number of carbon atoms in the alkyl group represented is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. The alkyl group may be linear, branched, or cyclic, but linear or branched is preferred, and linear is more preferred. The substituents that the alkyl group may have are not particularly limited and include, for example, hydroxyl groups, halogen atoms, and alkoxy groups. R 201 The alkyl group in the alkoxy group which may have substituents represented by R 201 This is synonymous with an alkyl group which may have substituents represented by , and the preferred embodiment is the same.

[0041] [ka]

[0042] In formula (CA2a), R 211 , R 213 ~R 215 Each of these independently represents a hydrogen atom or an alkyl group which may have substituents. 212 This represents an alkyl group which may have substituents. R 211 ~R 215 The number of carbon atoms in the alkyl group represented is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. The alkyl group may be linear, branched, or cyclic, but linear or branched is preferred, and linear is more preferred. The substituents that the alkyl group may have are not particularly limited and include, for example, hydroxyl groups, halogen atoms, and alkoxy groups.

[0043] <Anion Club> The anionic portion of the specific ionic compound may be either an inorganic anionic portion or an organic anionic portion. The upper limit of the molecular weight of the anion portion of the specific ionic compound is preferably 400 or less, more preferably 200 or less, even more preferably 180 or less, and particularly preferably 100 or less. The lower limit is preferably 30 or more, and more preferably 40 or more.

[0044] The anionic portion of the specific ionic compound preferably does not contain halogen atoms, as this allows for superior efficacy of the present invention.

[0045] A specific example of the anionic part of a particular ionic compound is the thiocyanate anion [SCN - ), acetate anion [CH3COO - ], dimethyl phosphate [R in the following formula (AN1)] an1 and R an2 [anion where R represents a methyl group], diethyl phosphate [R in the following formula (AN1)] an1 and R an2 [Anions representing the ethyl group], chloride anions [Cl - ], bromide anion [Br - ], Yodid Anion [I- ], tetrachloroaluminate anion [AlCl4 - ], heptachlorodialuminate anion [Al2Cl7 - ], tetrafluoroborate anion [BF4 - ], hexafluorophosphate anion [PF6 - ), perchlorate anion [ClO4 - ), nitrate anion [NO3 - ], acetate anion [CH3COO - ], trifluoroacetate anion [CF3COO - ], fluorosulfonate anion [FSO3 - ], methanesulfonate anion [CH3SO3 - ], trifluoromethanesulfonate anion [CF3SO3 - ], p-toluenesulfonate anion [p-CH3C6H4SO3 - ], bis(fluorosulfonyl)imido anion [(FSO2)2N - ], bis(trifluoromethanesulfonyl)imido anion [(CF3SO2)2N - ], Tris(trifluoromethanesulfonyl)methanide anion [(CF3SO2)3C - ], hexafluoroarsenate anion [AsF6 - ], hexafluoroantimonate anion [SbF6 - ], hexafluoroniobate anion [NbF6 - ], hexafluorotantalate anion [TaF6 - ], dimethyl phosphinate anion [(CH3)2POO - ], (poly)hydrofluorofluoride anion [F(HF) n - ] (for example, n represents an integer from 1 to 3), perfluorobutanesulfonate anion [C4F9SO3 - ], bis(pentafluoroethanesulfonyl)imide anion [(C2F5SO2)2N - ], perfluorobutanoate anion [C3F7COO -], (trifluoromethanesulfonyl)(trifluoromethanecarbonyl)imido anion [(CF3SO2)(CF3CO)N - ], and dicyanamide anion [(CN)2N - Examples include:

[0046] The anionic portion of the specific ionic compound preferably contains an anion selected from the group consisting of thiocyanate anions, acetate anions, and dialkyl phosphate anions (dialkyl phosphates; anions represented by the following formula (AN1)), in order to enhance the effects of the present invention, and more preferably contains an anion selected from the group consisting of thiocyanate anions and acetate anions.

[0047] [ka]

[0048] In formula (AN1), R a1 and R a2 Each of these independently represents an alkyl group which may have substituents. R a1 and R a2 The number of carbon atoms in the alkyl group represented is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. The alkyl group may be linear, branched, or cyclic, but linear or branched is preferred, and linear is more preferred. The substituents that the alkyl group may have are not particularly limited and include, for example, hydroxyl groups, halogen atoms, and alkoxy groups.

[0049] (Preferred embodiment) The specific ionic compound is preferably one or more selected from the group consisting of a salt compound composed of a thiocyanate anion and an imidazolium cation, a salt compound composed of an acetate anion and a substituted or unsubstituted quaternary ammonium cation, and a salt compound composed of a dialkyl phosphate anion and a substituted or unsubstituted phosphonium cation, in which the effects of the present invention are more easily achieved. It is more preferably one or more selected from the group consisting of a salt compound composed of a thiocyanate anion and an imidazolium cation, and a salt compound composed of an acetate anion and a substituted or unsubstituted quaternary ammonium cation, and is particularly preferably a salt compound composed of a thiocyanate anion and an imidazolium cation.

[0050] The lower limit of the content of specific ionic compounds (total content if multiple types are included) is preferably 0.05% by mass or more, more preferably 0.10% by mass or more, even more preferably 0.15% by mass or more, and even more preferably 0.20% by mass or more, based on the total mass of the polymerizable liquid crystal compound. The upper limit of the content of specific ionic compounds (total content if multiple types are included) is preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less, based on the total mass of the polymerizable liquid crystal compound.

[0051] When the specific ionic compound is a salt compound composed of a thiocyanate anion and an imidazolium cation, the upper limit of the content of the salt compound composed of a thiocyanate anion and an imidazolium cation (total content if multiple types are included) is preferably 1.0% by mass or less relative to the liquid crystal compound, in that orientation defects in the optical anisotropy layer can be more effectively suppressed. The lower limit is preferably 0.10% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.20% by mass or more, relative to the liquid crystal compound, in that orientation unevenness of the liquid crystal compound in the optical anisotropy layer can be more effectively suppressed. As a preferred example of the content of the salt compound composed of a thiocyanate anion and an imidazolium cation (total content if multiple types are included), relative to the total mass of the polymerizable liquid crystal compound, is 0.10 to 1.0% by mass, preferably 0.15 to 0.40% by mass, and more preferably 0.20 to 0.40% by mass. Specific ionic compounds may be used individually or in combination of two or more.

[0052] [Polymerization initiator] The composition may contain a polymerization initiator. As a polymerization initiator, a photopolymerization initiator that can initiate the polymerization reaction by ultraviolet irradiation (for example, light with a wavelength of 10 to 400 nm) is preferred. Examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, phenazine compounds, oxadiazole compounds, and compounds having an oxime ester structure.

[0053] If the composition contains a polymerization initiator, the content of the polymerization initiator (or the total content if multiple types are included) is preferably 0.1 to 20% by mass, and more preferably 1.0 to 8.0% by mass, relative to the total mass of the polymerizable liquid crystal compound. Polymerization initiators may be used individually or in combination of two or more.

[0054] [Surfactants] The composition may contain a surfactant. As surfactants, known materials such as polyacrylate-based surfactants, fluorine-based surfactants, and silicon-based surfactants can be used. If the composition contains a surfactant, the surfactant content (or total content if multiple types are included) is preferably 0.001 to 10% by mass, and more preferably 0.05 to 3.0% by mass, relative to the total mass of the polymerizable liquid crystal compound. Surfactants may be used individually or in combination of two or more types.

[0055] [Chiral agents] The composition may also preferably contain a chiral agent. Chiral agents (optically active compounds) have the function of inducing helical structures such as torsion-oriented phases and cholesteric liquid crystal phases that have a helical axis in the film thickness direction. Since the direction of helical twist or helical pitch induced differs depending on the chiral agent, it can be selected according to the purpose. The type of chiral agent is not particularly limited. The chiral agent may be either liquid crystalline or non-liquid crystallinity. Chiral agents generally contain an asymmetric carbon atom, but axially asymmetric compounds or planar asymmetric compounds that do not contain an asymmetric carbon atom can also be used as chiral agents. Examples of axially asymmetric compounds and planar asymmetric compounds include binaphthyl, helicene, paracyclophane, and their derivatives. The chiral agent may have polymerizable groups. Examples of such polymerizable groups include those that may be present in the liquid crystal compounds described above. Furthermore, when forming two or more orientation states within the same layer, as described later, it is preferable to use two or more chiral agents.

[0056] If the composition contains a chiral agent, the chiral agent content (or total content if multiple types are included) is preferably 0.1 to 15% by mass, and more preferably 0.5 to 10% by mass, relative to the total mass of the polymerizable liquid crystal compound. Chiral agents may be used individually or in combination of two or more.

[0057] [Other additives] The composition may also contain other additives besides the components described above. Other additives include, for example, antioxidants, ultraviolet absorbers, sensitizers, stabilizers, plasticizers, chain transfer agents, polymerization inhibitors, defoamers, thickeners, flame retardants, dispersants, and colorants such as dyes and pigments.

[0058] 〔conductivity〕 The conductivity of the composition at 25°C is 3.0 μS / cm or higher, preferably 5.0 μS / cm or higher, more preferably 7.0 μS / cm or higher, and particularly preferably 10.0 μS / cm or higher, in terms of superior effects of the present invention. There is no particular upper limit, but it is often 60.0 μS / cm or lower. Furthermore, the conductivity of the composition can be adjusted by the type and content of the components (especially specific ionic compounds) contained in the composition. Conductivity can be measured using an electrical conductivity meter (for example, the "Benchtop pH / Electrical Conductivity Meter F-74" manufactured by Horiba Corporation). Specifically, an electrical conductivity cell (for example, the "Low Electrical Conductivity Cell for Pure Water: 9371-10D" manufactured by Horiba Corporation) is connected to the electrical conductivity meter, and the electrical conductivity cell is immersed in the composition so that the electrode part is completely submerged in a 25°C environment. The conductivity of the composition is measured three times, and the average value is taken as the conductivity (unit: μS / cm).

[0059] [Optical anisotropy layer] The optically anisotropic layer of the present invention is a layer formed by curing the above-described composition, and is preferably a layer formed by oriented the liquid crystal compound in the coating film formed by applying the composition and fixing that state. In other words, the optically anisotropic layer of the present invention is preferably a layer in which the polymerizable liquid crystal compound is fixed in a predetermined orientation state. Note that once it has become a layer, it is no longer necessary to exhibit liquid crystal properties.

[0060] The lower limit of the thickness of the optical anisotropy layer is preferably 0.3 μm or more, more preferably 0.5 μm or more, even more preferably 0.7 μm or more, and particularly preferably 0.9 μm or more. The upper limit is not particularly limited as long as the thinning of the device can be achieved, but it is preferably 5.0 μm or less, more preferably 3.5 μm or less, and even more preferably 3.0 μm or less.

[0061] The orientation state of the liquid crystal compound fixed in the optical anisotropic layer may be any of the following: horizontal orientation, vertical orientation, tilted orientation, or torsional orientation. It is preferable that it is fixed in a state of horizontal orientation with respect to the main surface of the optical anisotropic layer. In this specification, "horizontal orientation" means that the main surface of the optically anisotropic layer and the long axis of the liquid crystal compound are parallel. However, strict parallelism is not required; in this specification, it means an orientation in which the angle between the long axis of the liquid crystal compound and the main surface of the optically anisotropic layer is less than 10°. In the optically anisotropic layer, the angle between the long axis of the liquid crystal compound and the main surface of the optically anisotropic layer is preferably 0 to 5°, more preferably 0 to 3°, and even more preferably 0 to 2°.

[0062] The optically anisotropic layer is preferably a positive A plate or a positive C plate, and more preferably a positive A plate. Furthermore, the optically anisotropic layer preferably contains regions with two or more orientation states in the thickness direction within the same layer, and more preferably contains regions that are not torsionally oriented (regions of the positive A plate) and regions that are torsionally oriented. A method for forming two or more orientation states within the same layer will be described later.

[0063] Here, a positive A plate and a positive C plate are defined as follows: When the refractive index in the slow axis direction within the film plane (the direction in which the refractive index is maximum within the plane) is nx, the refractive index in the direction perpendicular to the slow axis within the plane is ny, and the refractive index in the thickness direction is nz, a positive A plate satisfies the relationship in equation (A1), and a positive C plate satisfies the relationship in equation (C1). Note that a positive A plate shows a positive value for Rth, and a positive C plate shows a negative value for Rth. Formula (A1) nx>ny≒nz Formula (C1) nz>nx≒ny Furthermore, the above "≒" encompasses not only cases where the two are completely identical, but also cases where they are substantially identical. Regarding this "substantially identical" condition, for positive A plates, for example, cases where (ny-nz)×d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, are included in "ny≒nz", and cases where (nx-nz)×d is -10 to 10 nm, preferably -5 to 5 nm, are also included in "nx≒nz". Furthermore, for positive C plates, for example, cases where (nx-ny)×d (where d is the film thickness) is 0 to 10 nm, preferably 0 to 5 nm, are also included in "nx≒ny".

[0064] When the optically anisotropic layer is a positive A plate, in terms of functioning as a λ / 4 plate, Re(550) is preferably 100-180 nm, more preferably 120-160 nm, even more preferably 130-150 nm, and particularly preferably 130-145 nm. Here, a "λ / 4 plate" refers to a plate that has λ / 4 functionality, specifically a plate that has the function of converting linearly polarized light of a certain wavelength into circularly polarized light (or circularly polarized light into linearly polarized light).

[0065] This section details embodiments in which the optically anisotropic layer includes a region that is not torsionally oriented (the positive A plate region, the second region) and a region that is torsionally oriented (the first region) within the same layer. When the thickness of the first region is d1 and the refractive index anisotropy of the first region measured at a wavelength of 550 nm is Δn1, it is preferable that the first region satisfies 100 nm ≤ Δn1d1 ≤ 240 nm. The absolute value of the torsion angle of the liquid crystal compound in the first region is not particularly limited, but 60 to 120° is preferred, and 70 to 110° is more preferred, in that the optical anisotropy layer can be suitably applied to a circular polarizer. Furthermore, when the thickness of the second region is d2 and the refractive index anisotropy of the second region measured at a wavelength of 550 nm is Δn2, it is preferable that the condition 100 nm ≤ Δn2d2 ≤ 240 nm is satisfied.

[0066] [Method for manufacturing an optically anisotropic layer] The method for manufacturing the optically anisotropic layer is not particularly limited, but it is preferable to manufacture the optically anisotropic layer by including the step of forming an optically anisotropic layer on a substrate using the composition described above. Furthermore, the above-mentioned substrate preferably includes a support and an alignment film disposed on the support. In other words, the method for manufacturing the optically anisotropic layer more preferably includes a step of forming an optically anisotropic layer on the alignment film of a substrate having a support and an alignment film disposed on the support, using the composition. The following describes in detail each step of the manufacturing method for the optically anisotropic layer.

[0067] [Base material] The substrate is a component for supporting the optically anisotropic layer. The substrate preferably comprises a support and an orientation film disposed on the support.

[0068] <Support> The type of support is not particularly limited, and any known support can be used. The support is preferably a transparent support. A transparent support is a support with a transmittance of 60% or more of visible light (for example, wavelengths of 380 to 780 nm), preferably 80% or more, and more preferably 90% or more. Furthermore, the support material is preferably removable.

[0069] Examples of support materials include glass substrates and polymer films. Examples of polymer film materials include cellulose polymers; acrylic polymers having acrylic acid ester polymers such as polymethyl methacrylate and lactone ring-containing polymers; thermoplastic norbornene polymers; polycarbonate polymers; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such as polystyrene and acrylonitrile styrene copolymers; polyolefin polymers such as polyethylene, polypropylene and ethylene-propylene copolymers; vinyl chloride polymers; amide polymers such as nylon and aromatic polyamides; imide polymers; sulfone polymers; polyethersulfone polymers; polyetheretherketone polymers; polyphenylene sulfide polymers; vinylidene chloride polymers; vinyl alcohol polymers; vinyl butyral polymers; arylate polymers; polyoxymethylene polymers; epoxy polymers; and polymers obtained by mixing these polymers.

[0070] The thickness of the support is preferably 5 to 60 μm, more preferably 5 to 45 μm, and even more preferably 5 to 40 μm.

[0071] <Orientation film> The orientation film is preferably placed on the support (on the surface of the support). Furthermore, the support described above may also serve as an alignment film.

[0072] The alignment film is not particularly limited as long as it is a film that has the function of aligning the liquid crystal compounds contained in the composition. Alignment films are generally composed primarily of polymers. Numerous polymer materials for alignment films are described in various publications, and many commercially available products are available. As polymer materials for alignment films, polyvinyl alcohol, polyimide, or derivatives thereof are preferred, with modified or unmodified polyvinyl alcohol being more preferred. Examples of alignment films include the alignment film described on page 43, line 24 to page 49, line 8 of WO2001 / 88574; the alignment film made of modified polyvinyl alcohol described in paragraphs

[0071] to

[0095] of Japanese Patent Publication No. 3907735; and the liquid crystal alignment film formed by the liquid crystal alignment agent described in Japanese Patent Application Publication No. 2012-155308.

[0073] It is also preferable to use a photo-alignment film as the alignment film, as this prevents objects from coming into contact with the surface of the alignment film during its formation, thus preventing deterioration of the surface quality. Examples of photoalignment films include: alignment films formed from polymer materials such as polyamide compounds and polyimide compounds as described in paragraphs

[0024] to

[0043] of WO2005 / 096041; liquid crystal alignment films formed from liquid crystal alignment agents having photoalignable groups as described in Japanese Patent Application Publication No. 2012-155308; and Rolic Technologies' trade name LPP-JP265CP.

[0074] The thickness of the orientation film is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm, and even more preferably 0.01 to 0.5 μm, in order to mitigate any surface irregularities present on the support and form an optically anisotropic layer of uniform thickness.

[0075] One specific procedure for forming an optically anisotropic layer involves applying a composition onto an alignment film contained in a substrate to form a coating film on the alignment film, aligning the liquid crystal compounds in the coating film, and then curing the coating film to form an optically anisotropic layer. Methods for coating a composition onto an alignment film include, for example, wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, and die coating. After applying the composition onto the orientation film, the substrate on which the coating film has been formed may be subjected to a drying treatment to remove the solvent, if necessary.

[0076] The method for aligning the liquid crystal compounds in the coating film (orientation treatment) is not particularly limited and includes, for example, heating the coating film and drying the coating film at room temperature. In the case of thermotropic liquid crystal compounds, the liquid crystal phase formed by the orientation treatment can generally be shifted by changing the temperature. In the case of lyotropic liquid crystal compounds, the shift can also be caused by changing the composition ratio, such as the amount of solvent. While there are no particular restrictions on the conditions for heating the coating film, a heating temperature of 50 to 150°C is preferred, and a heating time of 10 seconds to 5 minutes is preferred.

[0077] Next, a curing treatment is applied to the coating film in which the liquid crystal compound is oriented to form an optically anisotropic layer. The curing method is not particularly limited and includes light irradiation and heat treatment, with light irradiation being more preferred. The type of light used for exposure is not particularly limited, but ultraviolet light is preferred. There are no particular restrictions on the irradiation dose during exposure, but 10 mJ / cm² is generally acceptable. 2 ~50J / cm 2 Preferably, 20 mJ / cm 2 ~5J / cm 2 This is more preferable. Furthermore, the polymerization reaction may be carried out under heating conditions to accelerate it.

[0078] In a method for manufacturing an optically anisotropic layer, it is preferable that the coater is made of metal and is grounded. Using the above coater makes it easier to neutralize the charge on the substrate surface when applying a conductive composition. The grounding method is not particularly limited and can be any known method.

[0079] In the method for manufacturing an optically anisotropic layer, the following first and second embodiments are preferred because they allow for the formation of two or more orientation states within the same optically anisotropic layer. The first embodiment includes the following steps 1 to 5. Step 1: A step of forming a composition layer on a substrate using the above-described composition, which contains a photosensitive chiral agent whose helical induced force changes upon light irradiation as a chiral agent, and a liquid crystal compound having a polymerizable group as a liquid crystal compound. Step 2: A step in which the composition layer is subjected to heat treatment to orient the liquid crystal compounds in the composition layer. Step 3: After Step 2, the composition layer is irradiated with light under conditions of an oxygen concentration of 1 volume% or more. Step 5: A step in which the composition layer is subjected to heat treatment between Step 3 and Step 4, which will be described later. Step 4: A curing treatment is performed on the light-irradiated composition layer to fix the orientation state of the liquid crystal compound and form an optically anisotropic layer having multiple regions with different orientation states of the liquid crystal compound along the thickness direction. Although the first embodiment includes step 5, as will be described later, step 3 may be carried out under heating conditions without performing step 5.

[0080] The second embodiment includes the following steps 1 to 4. However, in the second embodiment, step 3 is carried out under heating conditions. Step 1: A step of forming a composition layer on a substrate using the above-described composition, which contains a photosensitive chiral agent whose helical induced force changes upon light irradiation as a chiral agent, and a liquid crystal compound having a polymerizable group as a liquid crystal compound. Step 2: A step in which the composition layer is subjected to heat treatment to orient the liquid crystal compounds in the composition layer. Step 3: After Step 2, the composition layer is irradiated with light under conditions of an oxygen concentration of 1 volume% or more and under heating conditions. Step 4: A curing treatment is performed on the light-irradiated composition layer to fix the orientation state of the liquid crystal compound and form an optically anisotropic layer having multiple regions with different orientation states of the liquid crystal compound along the thickness direction. The second embodiment differs from the first embodiment in that it performs the same process as the first embodiment, except that it omits step 5 and performs step 3 under heating conditions.

[0081] The conditions and preferred modes of each process in the first and second embodiments can be appropriately selected from the conditions and preferred modes of each process in the method for manufacturing an optically anisotropic layer described above. Furthermore, the conditions and preferred modes of each process in the first and second embodiments of WO2021 / 033631 are preferred.

[0082] [Polarizing plate] The polarizing plate of the present invention is a polarizing plate comprising an optically anisotropic layer and a polarizer. The optically anisotropic layer is a layer formed by curing the above-described composition, and the preferred embodiment is as described above.

[0083] [Polarizer] The polarizer is not particularly limited as long as it is a component that has the function of converting light into a specific linear polarization, and it is preferably either a conventionally known absorbing polarizer or a reflective polarizer. Examples of absorptive polarizers include iodine-based polarizers, dye-based polarizers utilizing dichroic dyes, and polyene-based polarizers. Iodine-based and dye-based polarizers include coated polarizers and stretched polarizers, with polarizers produced by adsorbing iodine or a dichroic dye onto polyvinyl alcohol and then stretching the material being preferred. Furthermore, as a method for obtaining a polarizer by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, examples include those described in Japanese Patent Publication No. 5048120, Japanese Patent Publication No. 5143918, Japanese Patent Publication No. 4691205, Japanese Patent Publication No. 4751481, and Japanese Patent Publication No. 4751486, and these known technologies related to polarizers can also be preferably utilized. Examples of coated polarizers include those described in WO2018 / 124198, WO2018 / 186503, WO2019 / 132020, WO2019 / 132018, WO2019 / 189345, Japanese Patent Publication No. 2019-197168, Japanese Patent Publication No. 2019-194685, and Japanese Patent Publication No. 2019-139222, and known technologies related to these polarizers can also be preferably utilized. Examples of reflective polarizers include polarizers made by stacking thin films with different birefringences, wire grid polarizers, and polarizers that combine a cholesteric liquid crystal with a selective reflection range and a λ / 4 plate.

[0084] The polarizing plate of the present invention may have other optical anisotropic layers, protective films, or other functional layers in addition to the above-mentioned components. Other functional layers include, for example, adhesive layers, stress relaxation layers, planarization layers, anti-reflective layers, refractive index adjustment layers, and ultraviolet absorption layers.

[0085] A polarizing plate can be used as a circular polarizing plate if its optical anisotropy layer is a λ / 4 plate (positive A plate). When using a polarizer as a circular polarizer, the optical anisotropy layer described above is a λ / 4 plate (positive A plate), and the angle between the slow axis of the λ / 4 plate and the absorption axis of the polarizer described later is preferably 30 to 60°, more preferably 40 to 50°, even more preferably 42 to 48°, and particularly preferably 45°. In the case of an optically anisotropic layer of a polarizing plate having a region that is not torsionally oriented (second region) and a region that is torsionally oriented (first region) along the thickness direction, the absolute value of the angle between the in-plane slow axis of the second region and the absorption axis of the polarizer is preferably 5 to 25°, and more preferably 10 to 20°, in terms of suitably applying the optically anisotropic layer to circular polarizing plates and the like. Note that the "slow axis" of a λ / 4 plate refers to the direction in which the refractive index is maximum within the plane of the λ / 4 plate, and the "absorption axis" of a polarizer refers to the direction in which the absorbance is highest.

[0086] [Protective film] Examples of protective film materials include cellulose acylate films (e.g., cellulose triacetate film, cellulose diacetate film, cellulose acetate butyrate film, and cellulose acetate propionate film), polyacrylic resin films such as polymethyl methacrylate, polyolefins such as polyethylene and polypropylene, polyester resin films such as polyethylene terephthalate and polyethylene naphthalate, polyethersulfone films, polyurethane resin films, polyester films, polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyetherketone films, (meth)acrylonitrile films, polyolefins, and polymers having an alicyclic structure (norbornene resin (Arton: trade name, manufactured by JSR Corporation, amorphous polyolefin (Zeonex: trade name, manufactured by Nippon Zeon Co., Ltd.))), with cellulose acylate films being preferred.

[0087] The optical properties of the protective film are not particularly limited, but if the protective film is on the same side as the optically anisotropic layer, it is preferable that the following formula is satisfied. 0nm ≤ Re(550) ≤ 10nm -40nm ≤ Rth(550) ≤ 40nm

[0088] [Adhesive layer] The adhesive layer may be placed between the optically anisotropic layer and the polarizer. Examples of adhesive layers include members formed from a material whose ratio of storage modulus G' to loss modulus G'' (tanδ=G'' / G'), measured by a dynamic viscoelasticity measuring device, is 0.001 to 1.5. Examples of such materials include adhesives and creep-prone materials. Examples of adhesives include polyvinyl alcohol-based adhesives.

[0089] [Adhesive layer] A polarizing plate may have an adhesive layer placed between the optical anisotropy layer and the polarizer. The adhesive layer is preferably formed using a curable adhesive composition that hardens upon irradiation with active energy rays or by heating. Examples of curable adhesive compositions include curable adhesive compositions containing cationic polymerizable compounds and curable adhesive compositions containing radical polymerizable compounds. For example, paragraphs

[0062] to

[0080] of Japanese Patent Publication No. 2016-035579 can be referenced as the adhesive layer, and the contents of these paragraphs are incorporated into the present specification.

[0090] [Easy adhesive layer] The polarizing plate may have an easily bonded layer placed between the optically anisotropic layer and the polarizer. The easy-to-bond layer exhibits excellent adhesion between the optical anisotropic layer and the polarizer, and further suppresses the occurrence of cracks in the polarizer, resulting in a storage modulus of 1.0 × 10⁻¹⁰ at 85°C. 6 Pa~1.0×10 7 Pa is preferable. Examples of materials for the easily adhering layer include polyolefin-based components and polyvinyl alcohol-based components. Examples of easily adhesive layers include paragraphs

[0048] to

[0053] of Japanese Patent Publication No. 2018-036345.

[0091] [Image display device] The image display device of the present invention is an image display device that includes the optical anisotropy layer of the present invention. In other words, the image display device of the present invention includes a display element and the optical anisotropy layer of the present invention. The display elements used in the image display device are not particularly limited, and examples include liquid crystal cells, organic electroluminescent (hereinafter abbreviated as "EL (Electro Luminescence)") display panels, and plasma display panels. Of these, liquid crystal cells or organic EL display panels are preferred. In other words, as the image display device, a liquid crystal display device using a liquid crystal cell as the display element, or an organic EL display device using an organic EL display panel as the display element is preferred. [Examples]

[0092] The present invention will be described in more detail below based on the following examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the following examples.

[0093] [Example 1] [Preparation of cellulose acylate film (support)] The cellulose acylate dope of the following composition was added to a mixing tank, stirred, and then heated at 90°C for 10 minutes. Subsequently, the obtained composition was filtered through filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare the dope. The solid content concentration of the dope is 23.5% by mass, the amount of plasticizer added is a ratio to the cellulose acylate, and the organic solvent of the dope is methylene chloride / methanol / butanol = 81 / 18 / 1 (by mass ratio).

[0094] ------------------------------------------------------------------ Cellulose acylate dope ------------------------------------------------------------------ • Cellulose acylate (acetyl substitution degree 2.86, viscosity-average degree of polymerization 310) 100 parts by mass • Sugar ester compound 1 (shown by chemical formula (S4)) 6.0 parts by mass • Sugar ester compound 2 (shown by chemical formula (S5)) 2.0 parts by mass • Silica particle dispersion (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by mass • Organic solvents (methylene chloride / methanol / butanol) ------------------------------------------------------------------

[0095] [ka] TIFF2026112508000007.tif75114

[0096] The dope prepared above was cast using a drum film-forming machine. Specifically, the dope was cast from the die onto a metal support cooled to 0°C, and then the resulting web (film) was peeled off. The drum was made of stainless steel (SUS). Next, the cast web (film) was peeled from the drum and dried for 20 minutes in a tenter device at 30-40°C during film transport, with clips holding both ends of the web in place. Subsequently, the web was further dried by zone heating while being transported on a roll. Next, the obtained web was knurled and then rolled up to produce a cellulose acylate film with a thickness of 41.0 μm.

[0097] <Alkaline saponification treatment> After winding, the web is passed through a dielectric heating roll at 60°C to raise the film surface temperature to 40°C. Then, an alkaline solution with the composition shown below is applied to the band surface of the film using a bar coater at a rate of 14 mL / m². 2 The material was coated and then transported for 10 seconds under a steam-type far-infrared heater manufactured by Noritake Co., Ltd., heated to 110°C. Subsequently, using the same bar coater, 3 mL / m of pure water was applied. 2 The film was then coated. Next, it was washed with water using a fountain coater and dewatered with an air knife three times, and then transported to a 70°C drying zone for 10 seconds to dry, thereby producing an alkaline saponified cellulose acylate film.

[0098] ------------------------------------------------------------------ Alkaline solution ------------------------------------------------------------------ • Potassium hydroxide 4.7 parts by mass ·Water 15.8 parts by mass Isopropanol 63.7 parts by mass • Surfactant SF-1:C 14 H 29 O(CH2CH2O) 20 H 1.0 parts by mass • Propylene glycol 14.8 parts by mass ------------------------------------------------------------------

[0099] [Formation of orientation film] An orientation film composition 1, with the composition described below, was continuously applied to the alkali-saponified surface of a cellulose acylate film using a #14 wire bar. The film was dried with 60°C hot air for 60 seconds, then with 100°C hot air for 120 seconds, and wound up to obtain a roll of cellulose acylate film with an orientation film. The thickness of the orientation film was 0.3 μm.

[0100] ------------------------------------------------------------------ Orientation film composition 1 ------------------------------------------------------------------ • 100 parts by mass of the following modified polyvinyl alcohol-1 • 7.5 parts by mass of the following photopolymerization initiator • 1.75 parts by mass of the following hardener • 0.75 parts by mass of polymer B1 (see below) ·Water 2620 parts by mass • Methanol 873 parts by mass ------------------------------------------------------------------

[0101] Modified Polyvinyl Alcohol-1 [In the formula below, the numerical values ​​listed for each repeating unit represent the content (mol%) of each repeating unit relative to the total number of repeating units.]

[0102] [ka]

[0103] Photopolymerization initiator

[0104] [ka]

[0105] Curing agent [In the formula below, Et represents an ethyl group.]

[0106] [ka]

[0107] Polymer B1 [In the formula below, each numerical value indicated for the repeating units in the main chain represents the content (mass%) of each repeat relative to the total number of repeating units. Each numerical value indicated for the repeating units in the side chains represents the number of additions. Weight-average molecular weight: 16000]

[0108] [ka]

[0109] [Formation of optically anisotropic layer] The cellulose acylate film with the orientation film prepared above was fed from a roll, and the orientation film was continuously rubbed. At this time, the longitudinal direction of the long film was parallel to the transport direction, and the angle between the longitudinal direction of the film (transport direction) and the rotation axis of the rubbing roller was set to 78°. If the longitudinal direction of the film (transport direction) is set to 90°, and when observed from the film side, with the film width direction as the reference (0°) and clockwise direction being expressed as a positive value, the rotation axis of the rubbing roller is at 12°. In other words, the position of the rotation axis of the rubbing roller is the position obtained by rotating 78° counterclockwise with respect to the longitudinal direction of the film.

[0110] Using the cellulose acylate film with the rubbing treatment described above as a substrate, composition 1 containing a rod-shaped liquid crystal compound of the following composition was applied on a metal backup roll using a grounded metal gisser to form a composition layer. The absolute value of the weighted average helical induced force of the chiral agent in the composition layer was 0.0 μm. -1 That was the case. Next, the resulting composition layer was heated at 95°C for 60 seconds. This heating caused the rod-shaped liquid crystal compounds in the composition layer to be oriented in a predetermined direction. Subsequently, under oxygen-containing air (oxygen concentration: approximately 20 vol%) at 30°C, ultraviolet light was irradiated onto the composition layer using a 365 nm LED lamp (manufactured by Acroedge Co., Ltd.) (irradiation dose: 25 mJ / cm²). 2 ). Next, the resulting composition layer was heated at 95°C for 10 seconds. Subsequently, nitrogen purging was performed to achieve an oxygen concentration of 100 ppm by volume, and ultraviolet light was irradiated onto the composition layer at 80°C using a metal halide lamp (manufactured by iGraphics Co., Ltd.) (irradiation dose: 500 mJ / cm²). 2 ), an optically anisotropic layer was formed with a fixed orientation state of the liquid crystal compound. In this way, a laminate (optical film) (F-1) consisting of a support / alignment film / optically anisotropic layer was fabricated.

[0111] ------------------------------------------------------------------ Composition 1 ------------------------------------------------------------------ • 80 parts by mass of the polymerizable rod-shaped liquid crystal compound (A) below • 17 parts by mass of the polymerizable rod-shaped liquid crystal compound (B) below • 3 parts by mass of the following polymerizable rod-shaped liquid crystal compound (C) • Ethylene oxide-modified trimethylolpropane triacrylate (Viscote #360, manufactured by Osaka Organic Chemical Co., Ltd.) 4 parts by mass • Photopolymerization initiator (Irgacure 819, manufactured by BASF) 3 parts by mass • The following left-handed chiral agent (L2): 0.47 parts by mass • The following right-handed chiral agent (R2): 0.42 parts by mass • 0.08 parts by mass of the following polymer (A) • 1-Ethyl-3-methylimidazolium thiocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) 1.8 parts by mass • Methyl isobutyl ketone 78 parts by mass • Ethyl propionate 78 parts by mass ------------------------------------------------------------------

[0112] Polymerizable rod-shaped liquid crystal compound (A) [a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 84:14:2]

[0113] [ka]

[0114] Polymerizable rod-shaped liquid crystal compound (B)

[0115] [ka]

[0116] Polymerizable rod-shaped liquid crystal compound (C) [In the following formula, Me represents a methyl group.]

[0117] [ka]

[0118] Left-hand torsional chiral agent (L2)

[0119] [ka]

[0120] Right-handed chiral agent (R2)

[0121] [ka]

[0122] Polymer (A) [In the formula below, the repeating units on the left account for 39% by mass of the total repeating units, and the repeating units on the right account for 61% by mass. Weight-average molecular weight: 25000]

[0123] [ka]

[0124] The laminate (F-1) prepared as described above was cut parallel to the rubbing direction, and the optically anisotropic layer was observed from the cross-sectional direction using a polarizing microscope. The thickness of the optically anisotropic layer was 2.7 μm. The region with a thickness (d2) of 1.3 μm on the substrate side of the optically anisotropic layer (second region) showed homogeneous orientation with no twist angle, while the region with a thickness (d1) of 1.4 μm on the air side (opposite the substrate) of the optically anisotropic layer (first region) showed torsional orientation of the liquid crystal compound. Furthermore, the optical properties of the laminate (F-1) were determined using Axometrics' Axoscan and its analysis software (Multi-Layer Analysis). The product of Δn2 and thickness d2 (Δn2d2) at a wavelength of 550 nm in the second region was 177 nm, the torsion angle of the liquid crystal compound was 0°, and the orientation axis angle of the liquid crystal compound with respect to the long longitudinal direction was -11° on the side in contact with the substrate and -11° on the side in contact with the first region. Furthermore, the product of Δn1 and thickness d1 (Δn1d1) at a wavelength of 550 nm in the first region was 180 nm, the twist angle of the liquid crystal compound was 80°, and the orientation axis angle of the liquid crystal compound with respect to the longitudinal direction was -11° on the side in contact with the second region and -91° on the air side.

[0125] [Examples 2-10 and Comparative Examples 1-7] <Preparation of Compositions 2-10 and R1-R7> Compositions 2 to 10 and R1 to R7 were prepared with the same composition as Composition 1, except that 1.8 parts by mass of 1-ethyl-3-methylimidazolium thiocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) in Composition 1 (shown in the upper section) was replaced with the additive types and amounts (parts by mass) shown in Table 1 below. Compound (B) in compositions R5 and R6 is an ionic liquid having the following structure.

[0126] [ka]

[0127] <Fabrication of laminates> A laminate was prepared in the same manner as in Example 1, except that composition 1 was replaced with compositions 2 to 10 and R1 to R7.

[0128] [evaluation] [Evaluation of electrical conductivity] A low-conductivity cell for pure water, model 9371-10D (manufactured by Horiba Corporation), was connected to a benchtop pH / electrical conductivity meter F-74 (manufactured by Horiba Corporation). The electrode portion of the electrical conductivity cell was washed with pure water, then washed with acetone, and the acetone was dried by blowing dry air with an air gun. Under conditions of 25°C, the electrical conductivity cell was immersed in a coating solution so that the electrode portion was completely submerged, and the conductivity of the coating solution (compositions 1-10, R1-R7) was measured. The average of three measurement results was taken as the conductivity of the coating solution.

[0129] [Evaluation of corrosiveness] Volume 20cm³ 3 10 mL of the coating solution was placed in the container. A piece of stainless steel tape (0.5 mm thick, 12.7 mm wide: manufactured by Tokyo Sickness Co., Ltd.) was cut so that it was half submerged in the coating solution, and the stainless steel tape was placed in the container and sealed. After the container was left to stand at 60°C for 5 days, the stainless steel tape was removed from the container, wiped repeatedly with acetone, and then the surface was observed with an optical microscope. If rust was observed on the surface of the stainless steel tape, it was judged to be corroded; if no rust was observed, it was judged to be not corroded. In Table 1, "C" indicates that it is corroded and "N" indicates that it is not corroded.

[0130] [Evaluation of orientation unevenness] Optical films for each example and comparative example were prepared in dimensions of 1.3 m (width direction) x 5 m (transport direction). Toner was sprinkled onto the surface of the optically anisotropic layer, and areas to be colored in a band-like pattern in the width direction were marked. After removing the toner, the marked areas were observed using a light box, and the number of uneven areas indicating orientation irregularities was counted. In practical terms, A to D are preferred, with A being the most preferred. <Evaluation Criteria> "A": Not seen at all "B": 1~5 pieces "C": 6~10 pieces "D": 11~20 pieces "E": 21 or more

[0131] [Evaluation of orientation defects] From the laminates of each example and comparative example, a square film with a side length of 40 mm was cut out. The obtained samples were examined under a polarizing microscope (using a 10x objective lens) under crossed nicols, measuring 70 mm. 2 The area was observed and the number of orientation defects was evaluated. In practical terms, A to D are preferred, with A being the most preferred. <Evaluation Criteria> "A": 0~5 pieces "B": 6~10 pieces "C": 11~20 pieces "D": 21~50 pieces "E": 51 or more

[0132] [Table 1]

[0133] The results shown in the table clearly demonstrate that the optically anisotropic layer formed by the composition of the example suppresses the occurrence of orientation unevenness caused by deviations in the orientation direction of the liquid crystal compound, and also suppresses the occurrence of orientation defects. Furthermore, it can be confirmed that the composition of the example exhibits excellent resistance to metal corrosion. Compositions often contain impurities that may be present in the composition's constituent components and / or introduced by its raw material components, and sodium chloride is one example of such impurities. Sodium chloride is a component often used in operations such as salting out of liquid crystal compounds during the synthesis of liquid crystal compounds. When a composition contains sodium chloride as an impurity, hydrochloric acid may be generated in the composition through a reaction with weak acid components that may be present in the composition, and this hydrochloric acid may migrate outside the system (gas phase) and corrode metals such as stainless steel. It is presumed that because the composition contains a specific ionic compound to the extent that it can exhibit an conductivity of 3.0 μS / cm or higher, the specific ionic compound acts as a base, suppressing the generation of hydrochloric acid, and as a result, metal corrosion can be suppressed.

[0134] From a comparison of the examples, it is clear that when the conductivity of the composition is 5.0 μS / cm or higher (preferably 7.0 μS / cm or higher, more preferably 10.0 μS / cm or higher), the alignment unevenness of the liquid crystal compound in the optical anisotropy layer can be further suppressed (see the comparison of Examples 1 to 10 in particular). From a comparison of the examples, it is clear that when the anionic portion of a specific ionic compound is an anion selected from the group consisting of thiocyanate anions and acetate anions, orientation defects in the optical anisotropy layer can be further suppressed (see comparison of Examples 3, 7, and 8 in particular). From a comparison of the examples, it is clear that when the specific ionic compound is one or more selected from the group consisting of a salt compound composed of a thiocyanate anion and an imidazolium cation, a salt compound composed of an acetate ion and a substituted or unsubstituted quaternary ammonium cation, and a salt compound composed of a dialkyl phosphate anion and a substituted or unsubstituted quaternary phosphonium cation, the orientation defects of the optical anisotropy layer can be further suppressed (see comparison of Examples 3 to 10 in particular). From a comparison of Examples 1 to 6, it is clear that when the composition contains 1-ethyl-3-methylimidazolium thiocyonate as a specific ionic compound, the orientation defects of the optical anisotropy layer can be further suppressed when the content of 1-ethyl-3-methylimidazolium thiocyonate is 1.0% by mass or less relative to the liquid crystal compound (see comparison of Examples 1 to 6 in particular). Furthermore, it is clear that when the content of 1-ethyl-3-methylimidazolium thiocyonate is 0.10% by mass or more (preferably 0.15% by mass or more, more preferably 0.20% by mass or more) relative to the liquid crystal compound, the unevenness of the orientation of the liquid crystal compound in the optical anisotropy layer can be further suppressed (see comparison of Examples 1 to 6 in particular).

Claims

1. A composition comprising a liquid crystal compound having polymerizable groups, an ionic compound having a melting point of 100°C or lower, and an organic solvent, A composition having an electrical conductivity of 3.0 μS / cm or more at 25°C.

2. The composition according to claim 1, wherein the ionic compound is composed of a cation portion and an anion portion, and the anion portion does not contain a halogen atom.

3. The composition according to claim 1, wherein the ionic compound is composed of a cation portion and an anion portion, and the molecular weight of the anion portion is 200 or less.

4. The composition according to claim 1, wherein the ionic compound is composed of a cation portion and an anion portion, and the cation portion does not contain silicon atoms.

5. The composition according to claim 1, wherein the ionic compound is composed of a cation portion and an anion portion, and the molecular weight of the cation portion is 250 or less.

6. The composition according to claim 1, wherein the ionic compound is composed of a cation portion and an anion portion, and the anion portion is composed of an anion selected from the group consisting of thiocyanate anion, acetate anion, and dialkyl phosphate anion.

7. The composition according to claim 1, wherein the ionic compound is composed of a cation portion and an anion portion, and the anion portion is composed of an anion selected from the group consisting of thiocyanate anions and acetate anions.

8. The composition according to claim 1, wherein the ionic compound is one or more selected from the group consisting of a salt compound composed of a thiocyanate anion and an imidazolium cation, a salt compound composed of an acetate ion and a substituted or unsubstituted quaternary ammonium cation, and a salt compound composed of a dialkyl phosphate anion and a substituted or unsubstituted quaternary phosphonium cation.

9. An optically anisotropic layer formed by curing the composition according to any one of claims 1 to 8.

10. The optical anisotropic layer according to claim 9, wherein the liquid crystal compound is oriented in the horizontal direction.

11. A polarizing plate comprising an optically anisotropic layer formed by curing a composition according to any one of claims 1 to 8, and a polarizer.

12. An image display device comprising an optically anisotropic layer formed by curing the composition according to any one of claims 1 to 8.

13. The image display device according to claim 12, wherein it is a liquid crystal display device.

14. The image display device according to claim 12, which is an organic EL display device.

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