Method for manufacturing optically anisotropic films

Abstract

To provide an optical anisotropic film manufacturing method with which it is possible to efficiently manufacture an optical anisotropic film in which the occurrence of uneven tilt of a liquid crystal compound is suppressed.SOLUTION: Provided is an optical anisotropic film manufacturing method for manufacturing an optical anisotropic film by a roll-to-roll system. The optical anisotropic film manufacturing method includes: a step 1 for orienting a liquid crystal compound in a liquid crystal composition layer while conveying a liquid crystal compound having maximum absorption in a 300-400 nm wavelength range and having a polymerizable group and a liquid crystal composition layer that includes a chain transfer agent; and a step 2 for conveying the liquid crystal composition layer with the liquid crystal compound having been oriented, to an environment where an oxygen concentration is 2000 ppm by volume or less and irradiating the liquid crystal composition layer under the environment with an ultraviolet ray to cure it. In the step 2, the application of the ultraviolet ray is carried out within 0.10 second after the liquid crystal composition layer being conveyed enters the environment.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a method for producing optically anisotropic films. [Background technology]

[0002] Optically anisotropic films formed using liquid crystal compounds generally exhibit birefringence and are used in various display devices to improve viewing angle, contrast, and color shift. Materials used for optically anisotropic films may exhibit anomalous dispersion (inverse wavelength dispersion), where the birefringence decreases as the wavelength decreases.

[0003] Furthermore, when using liquid crystal compounds in optically anisotropic films, it is common practice to irradiate the film with active light, such as ultraviolet light, to react the polymerizable groups of the compounds contained in the optically anisotropic film, thereby fixing the orientation direction of the liquid crystal compounds. Patent Document 1 discloses that a coating film of a composition containing a liquid crystal compound having inverse wavelength dispersion was subjected to orientation treatment, and then the orientation direction was fixed by irradiation with ultraviolet light. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2019 / 160016 [Overview of the project] [Problems that the invention aims to solve]

[0005] In optically anisotropic films, the orientation direction of the liquid crystal compound is often fixed in a specific direction. Furthermore, in order to ensure the display performance of the display device used, the orientation direction of the liquid crystal compound in the optically anisotropic film must be uniform. In other words, an optically anisotropic film with minimal unevenness (tilt variation) in the orientation direction of the liquid crystal compound is required. Furthermore, from an economic standpoint, it is preferable that optically anisotropic films can be manufactured efficiently, i.e., have high productivity. When the present inventors investigated the production of optically anisotropic films using liquid crystal compounds, they found that the method described in Patent Document 1 has room for improvement in at least one aspect: the occurrence of tilt lumens and productivity.

[0006] Therefore, the object of the present invention is to provide a method for efficiently producing an optically anisotropic film in which the occurrence of tilt lumens in liquid crystal compounds is suppressed. [Means for solving the problem]

[0007] The inventors of this invention have diligently studied and developed the present invention to solve the above problems. Specifically, they have found that the above problems can be solved by the following configuration.

[0008] [1] A method for manufacturing an optically anisotropic film using a roll-to-roll method, Step 1 involves oriented the liquid crystal compound in the liquid crystal composition layer while transporting a liquid crystal composition layer containing a liquid crystal compound having maximum absorption in the wavelength range of 300 to 400 nm and polymerizable groups, and a chain transfer agent. The process includes step 2, which involves transporting the liquid crystal composition layer in which the above liquid crystal compound is oriented to an environment with an oxygen concentration of 2000 ppm by volume or less, and curing the liquid crystal composition layer by irradiating it with ultraviolet light in the above environment. A method for manufacturing an optically anisotropic film, wherein in step 2 above, the ultraviolet light is irradiated within 0.10 seconds after the liquid crystal composition layer being transported comes into the environment described above. [2] The method for producing an optically anisotropic film according to [1], wherein the content of the chain transfer agent is 0.75 to 2.5% by mass with respect to the total mass of the solid content of the liquid crystal composition layer. [3] The method for manufacturing an optically anisotropic film according to [1] or [2], wherein the ultraviolet light source is a light-emitting diode. [4] A method for producing an optically anisotropic film according to any one of [1] to [3], further comprising step 3, after step 2, transporting the result obtained in step 2 and further irradiating it with ultraviolet light. [5] A method for manufacturing an optically anisotropic film, wherein the optically anisotropic film manufactured by the method described in any one of [1] to [4] satisfies the relationship between formulas (OP1) and (OP2) described later. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a method for efficiently producing optically anisotropic films in which the occurrence of tilt lumens in liquid crystal compounds is suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram illustrating the time until UV irradiation in step 2. [Figure 2] This is a schematic diagram illustrating the time until UV irradiation in step 2. [Figure 3] This is a schematic diagram illustrating the time until UV irradiation in step 2. [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.

[0012] The following definitions are used within this specification. 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. In this specification, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as their intended purpose is achieved. In this specification, "ppm" is an abbreviation for "parts per million," and 10 -6 It means...

[0013] In this specification, "(meth)acrylic" is a concept that encompasses both acrylic and methacrylic, and "(meth)acryloxy group" is a concept that encompasses both acryloxy group and methacryloxy group. 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. In this specification, the "solid content" of a liquid crystal composition layer refers to components that, excluding the solvent, can form an optically anisotropic film by treatment such as irradiation with active light. Components that are liquid before treatment such as irradiation with active light but can form an optically anisotropic film after treatment are considered to be solid content.

[0014] [Method for manufacturing optically anisotropic films] The present invention relates to a method for manufacturing an optically anisotropic film, which involves manufacturing the optically anisotropic film using a roll-to-roll method. Step 1 involves aligning the liquid crystal compound in the liquid crystal composition layer while transporting a liquid crystal composition layer containing a liquid crystal compound having a maximum absorption in the wavelength range of 300 to 400 nm and polymerizable groups, and a chain transfer agent. The process includes step 2, which involves transporting a liquid crystal composition layer in which liquid crystal compounds are oriented to an environment with an oxygen concentration of 2000 ppm by volume or less, and curing the liquid crystal composition layer by irradiating it with ultraviolet light in the above environment. In step 2, ultraviolet light is irradiated within 0.10 seconds after the transported liquid crystal composition layer reaches the above environment.

[0015] The time from when the liquid crystal composition layer being transported reaches the above environment until it is irradiated with ultraviolet light will be explained with reference to the figure. Figures 1, 2, and 3 are schematic cross-sectional views illustrating some embodiments of the present invention. The method for manufacturing an optically anisotropic film of the present invention is carried out by conveying from roll to roll (roll-to-roll method), which is not shown in Figures 1, 2, and 3. In Figures 1, 2, and 3, the process is carried out while conveying a film 12 containing a liquid crystal composition layer in the conveying direction TD, and in step 2, the film 12 containing the liquid crystal composition layer is irradiated with ultraviolet light by an ultraviolet lamp 16 placed in a chamber 14. The ultraviolet light emitted from the ultraviolet lamp 16 irradiates an irradiation area 18 on the surface of the conveyed film 12. The inside of the chamber 14 is an environment with an oxygen concentration of 2000 ppm by volume or less, and the ultraviolet lamp 16 is positioned so that ultraviolet light is irradiated perpendicularly to the film surface of the film 12 containing the liquid crystal composition layer. Figure 1 shows point A, which represents a point on the film 12 containing the liquid crystal composition layer, located outside the chamber 14. The film 12 containing the liquid crystal composition layer is transported along the transport direction TD, and point A reaches the chamber 14 as shown in Figure 2, where the oxygen concentration reaches an environment of 2000 ppm by volume or less. Time 1 is defined as the moment point A reaches this environment. Subsequently, point A is transported to the irradiation area 18 and irradiated with ultraviolet light. Time 2 is defined as the moment when point A reaches the center of the irradiation area 18 (center in the transport direction). In step 2 above, "irradiating with ultraviolet light within 0.10 seconds after the transported liquid crystal composition layer reaches the above environment" means that the time from time 1 to time 2 is 0.10 seconds or less. Hereafter, the time from time 1 to time 2 will also be referred to as "elapsed time until irradiation".

[0016] The mechanism by which the optical anisotropy film manufacturing method of the present invention can efficiently produce optical anisotropy films with suppressed tilt lumens is not entirely clear, but the inventors speculate as follows. Liquid crystal compounds exhibiting inverse wavelength dispersion often have maximum absorption in the wavelength range of 300-400 nm. When a liquid crystal composition layer containing such a liquid crystal compound is irradiated with ultraviolet light, the absorption of ultraviolet light by the liquid crystal compound makes it difficult for the polymerizable group reaction to proceed on the side of the liquid crystal composition layer opposite to the irradiation surface of the ultraviolet light source. As a result, the orientation direction of the liquid crystal compound is not sufficiently fixed, and tilt unevenness is likely to occur. Here, in order to ensure that the reaction of the polymerizable groups described above proceeds sufficiently, methods include extending the ultraviolet irradiation time and thoroughly removing oxygen gas from the liquid crystal composition layer, which is thought to inhibit the polymerization reaction. However, in the above method, when manufacturing an optically anisotropic film while conveying the liquid crystal composition layer using a roll-to-roll method, it is necessary to either reduce the conveying speed and extend the irradiation time, or extend the time from when the environment becomes low-oxygen to when ultraviolet irradiation is performed, which is undesirable in terms of productivity. On the other hand, in the method for producing an optically anisotropic film of the present invention, since the liquid crystal composition layer contains a chain transfer agent, the polymerization reaction can proceed sufficiently and the orientation direction of the liquid crystal compound can be fixed even without reducing the transport speed, that is, even if ultraviolet light is irradiated within 0.10 seconds after reaching the above environment. As a result, the production method of the present invention makes it possible to efficiently produce an optically anisotropic film in which the occurrence of tilt turbulence is suppressed.

[0017] The following describes the steps that may be included in the method for manufacturing an optically anisotropic film of the present invention. Note that the method for manufacturing an optically anisotropic film of the present invention is not limited to the embodiments shown in Figures 1, 2, and 3, but may also be the embodiments described below. Furthermore, the ability to manufacture optically anisotropic films with suppressed tilt turbulence will also be referred to as "suppression of tilt turbulence," and the ability to manufacture optically anisotropic films efficiently will also be referred to as "excellent productivity."

[0018] <Process for forming the liquid crystal composition layer> The method for manufacturing an optically anisotropic film of the present invention preferably includes a step of forming a liquid crystal composition layer on a support film (a step of forming a liquid crystal composition layer), which will be described in detail later. By forming a liquid crystal composition layer on a support film, a form suitable for conveying by a roll-to-roll system can be obtained.

[0019] The support film is not particularly limited, but it is preferably transparent, and more specifically, it is preferably light transmittance of 80% or more.

[0020] Examples of such support films include polymer films, and 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 copolymer (AS resin); polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymer; 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; or polymers which are mixtures of these polymers. Furthermore, the support film may have the function of a polarizer, as described later.

[0021] The thickness of the support film is not particularly limited, but is preferably 5 to 100 μm, and more preferably 5 to 40 μm.

[0022] The liquid crystal composition layer will be described below.

[0023] (Liquid crystal composition layer) The liquid crystal composition layer used in the present invention comprises a liquid crystal compound having a maximum absorption in the wavelength range of 300 to 400 nm and polymerizable groups, and a chain transfer agent. The liquid crystal composition layer may also contain components other than those mentioned above. The following describes the components that the liquid crystal composition layer may contain.

[0024] -Liquid crystal compounds- The liquid crystal compound contained in the liquid crystal composition layer has maximum absorption in the wavelength range of 300 to 400 nm and has polymerizable groups. The liquid crystal compound is not particularly limited as long as the above requirements are met, and known liquid crystal compounds can be used. The liquid crystal composition layer may contain multiple types of liquid crystal compounds, and it is sufficient if one or more of these liquid crystal compounds satisfy the above requirements.

[0025] Liquid crystal compounds can generally be classified into rod-shaped and disc-shaped types based on their shape. Furthermore, each of these types can be 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). In the present invention, any liquid crystal compound can be used, but it is preferable to use a rod-shaped liquid crystal compound or a disc-shaped liquid crystal compound, and more preferably to use a rod-shaped liquid crystal compound.

[0026] Furthermore, having a maximum absorption in the wavelength range of 300-400 nm means that, in the ultraviolet-visible light absorption spectrum measured by a spectrophotometer using a solution in which the liquid crystal compound is dissolved, there is a maximum value in the wavelength range of 300-400 nm. Furthermore, it is preferable that the liquid crystal compound contained in the liquid crystal composition layer exhibits inverse wavelength dispersion. In this specification, a liquid crystal compound having "inverse wavelength dispersion" refers to a liquid crystal compound in which, when the in-plane retardation (Re) value of a phase difference film made using only that liquid crystal compound is measured at a specific wavelength (visible light range), the Re value becomes equivalent or higher as the measured wavelength increases. When liquid crystal compounds exhibit inverse wavelength dispersion, they often have a maximum absorption in the wavelength range of 300-400 nm.

[0027] The liquid crystal compound contained in the liquid crystal composition layer has polymerizable groups. As the polymerizable group, a polymerizable group capable of radical polymerization or cationic polymerization is preferred. As the radical polymerizable group, generally known radical polymerizable groups can be used, and preferred examples include the acryloyloxy group or the methacryloyloxy group. In this case, the polymerization rate is generally known to be faster with the acryloyloxy group, and the acryloyloxy group is preferred in terms of improving productivity, but the methacryloyloxy group can also be used as a polymerizable group in a similar manner. As cationic polymerizable groups, generally known cationic polymerizable groups can be used, specifically, 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 particularly preferred.

[0028] As for liquid crystal compounds, those having an aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-7) are preferred in that they exhibit inverse wavelength dispersion.

[0029] [ka]

[0030] In the above formulas (Ar-1) to (Ar-7), * represents the bonding position, that is, the bonding position with a part of the liquid crystal compound other than the aromatic ring.

[0031] In the above equation (Ar-1), Q 1 represents N or CH, and Q 2 -S-, -O-, or -N(R 6 )- represents R 6represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Y 1 represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, an aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent, or an alicyclic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, and one or more of -CH2- constituting the alicyclic hydrocarbon group may be substituted with -O-, -S- or -NH-.

[0032] Also, Y 1 Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms represented by include aryl groups such as a phenyl group, a 2,6 - diethylphenyl group, and a naphthyl group. Y 1 Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms represented by include heteroaryl groups such as a thienyl group, a thiazolyl group, a furyl group, and a pyridyl group. Y 1 Examples of the alicyclic hydrocarbon group having 6 to 20 carbon atoms represented by include a cyclohexylene group, a cyclopentylene group, a norbornylene group, and an adamantylene group. Y 1 Examples of the substituent that Y may have include the following substituent X.

[0033] The substituent X includes, for example, an alkyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, an alkylamino group, a dialkylamino group, an alkylamide group, an alkenyl group, an alkynyl group, a halogen atom, a cyano group, a nitro group, an alkylthiol group, and an N - alkylcarbamate group. Among them, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, or a halogen atom is preferable. As the alkyl group, linear, branched, or cyclic alkyl groups having 1 to 18 carbon atoms are preferred, alkyl groups having 1 to 8 carbon atoms (e.g., methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, and cyclohexyl group, etc.) are more preferred, alkyl groups having 1 to 4 carbon atoms are even more preferred, and methyl or ethyl groups are particularly preferred. As the alkoxy group, a C1 to C18 alkoxy group is preferred, a C1 to C8 alkoxy group (e.g., methoxy group, ethoxy group, n-butoxy group, and methoxyethoxy group) is more preferred, a C1 to C4 alkoxy group is even more preferred, and a methoxy group or ethoxy group is particularly preferred. Examples of alkoxycarbonyl groups include groups in which an oxycarbonyl group (-O-CO- group) is bonded to an alkyl group as exemplified above. Among these, methoxycarbonyl groups, ethoxycarbonyl groups, n-propoxycarbonyl groups, or isopropoxycarbonyl groups are preferred, with methoxycarbonyl groups being more preferred. Examples of alkylcarbonyloxy groups include groups in which a carbonyloxy group (-CO-O- group) is bonded to an alkyl group as exemplified above. Among these, methylcarbonyloxy groups, ethylcarbonyloxy groups, n-propylcarbonyloxy groups, or isopropylcarbonyloxy groups are preferred, with methylcarbonyloxy groups being more preferred.

[0034] In the above equations (Ar-1) to (Ar-7), Z 1 , Z 2 and Z 3 These are, independently, a hydrogen atom, a monovalent aliphatic hydrocarbon group with 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group with 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group with 6 to 20 carbon atoms, a monovalent aromatic heterocyclic group with 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, and -OR. 7 , -NR 8 R 9 , -SR 10 ,-COOR 11 , or -COR 12 Represents R 7 ~R 12Each of these independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Z 1 and Z 2 These may combine with each other to form an aromatic ring.

[0035] Here, as the monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, alkyl groups having 1 to 15 carbon atoms are preferred, and alkyl groups having 1 to 8 carbon atoms are more preferred. Specifically, methyl groups, ethyl groups, isopropyl groups, tert-pentyl groups (1,1-dimethylpropyl groups), tert-butyl groups, or 1,1-dimethyl-3,3-dimethyl-butyl groups are even more preferred, and methyl groups, ethyl groups, or tert-butyl groups are particularly preferred. Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monocyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, methylcyclohexyl, and ethylcyclohexyl; monocyclic unsaturated hydrocarbon groups such as cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclodecenyl, cyclopentadienyl, cyclohexadienyl, cyclooctadienyl, and cyclodecadien; bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl, and tricyclo[5.2.1.0] 2,6 ]decyl group, tricyclo[3.3.1.1 3,7 ] Decyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 Examples include polycyclic saturated hydrocarbon groups such as dodecyl groups and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include phenyl groups, 2,6-diethylphenyl groups, naphthyl groups, and biphenyl groups, with aryl groups having 6 to 12 carbon atoms (particularly phenyl groups) being preferred. Examples of monovalent aromatic heterocyclic groups having 6 to 20 carbon atoms include 4-pyridyl, 2-furyl, 2-thienyl, 2-pyrimidinyl, and 2-benzothiazolyl groups. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms, chlorine atoms, and bromine atoms being preferred. On the other hand, R 7 ~R 10 Examples of C1-C6 alkyl groups represented by include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl groups.

[0036] Furthermore, in the above formulas (Ar-2) and (Ar-3), A 3 and A 4 These are -O- and -N(R) independently of each other. 13 R represents a group selected from the group consisting of -, -S-, and -CO-. 13 represents a hydrogen atom or substituent. R 13 Examples of substituents represented by include those similar to substituent X described above.

[0037] In the above formula (Ar-2), X represents a nonmetal atom of Groups 14 to 16, which may have a hydrogen atom or a substituent attached to it. Furthermore, nonmetal atoms of groups 14-16 represented by X include, for example, oxygen atoms, sulfur atoms, hydrogen atoms, or nitrogen atoms to which substituents are attached [=NR]. N1 ,R N1 represents a hydrogen atom or substituent. ], and a carbon atom to which a hydrogen atom or substituent is bonded [=C-(R C1 )2,R C1 represents a hydrogen atom or substituent. Examples include: Examples of substituents include alkyl groups, alkoxy groups, alkyl-substituted alkoxy groups, cyclic alkyl groups, aryl groups (e.g., phenyl group, naphthyl group, etc.), cyano groups, amino groups, nitro groups, alkylcarbonyl groups, sulfo groups, and hydroxyl groups.

[0038] Also, in the above formula (Ar-3), D 7 and D 8These are, independently, single bonds, or -CO-, -O-, -S-, -C(=S)-, -CR 1 R 2 -, -CR 3 =CR 4 -, -NR 5 -, or represents a divalent linking group consisting of two or more combinations thereof, R 1 ~R 5 Each of these independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms.

[0039] Here, D 7 and D 8 Examples of divalent linking groups shown in one aspect include -CO-, -O-, -CO-O-, -C(=S)O-, and -CR 1 R 2 -, -CR 1 R 2 -CR 1 R 2 -, -O-CR 1 R 2 -, -CR 1 R 2 -O-CR 1 R 2 -,-CO-O-CR 1 R 2 -, -O-CO-CR 1 R 2 -, -CR 1 R 2 -O-CO-CR 1 R 2 -, -CR 1 R 2 -CO-O-CR 1 R 2 -, -NR 5 -CR 1 R 2 -, and -CO-NR 5 - are some examples. 1 , R 2 and R 5 Each of these independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. Of these, -CO-, -O-, and -CO-O- are preferred.

[0040] In the above formula (Ar-3), SP 3 and SP 4 Each of these independently represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a divalent linking group in which one or more of the -CH2- groups constituting a linear or branched alkylene group having 1 to 12 carbon atoms are substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, where Q represents a substituent. Examples of substituents include those similar to substituent X described above.

[0041] Here, SP 3 and SP 4 Examples of linear or branched alkylene groups having 1 to 12 carbon atoms as shown in one embodiment include, for example, methylene, ethylene, propylene, butylene, pentylene, hexylene, methylhexylene, and heptylene groups. 1 and SP 2 As described above, the substituent may be a divalent linking group in which one or more of the -CH2- groups constituting a linear or branched alkylene group having 1 to 12 carbon atoms are substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, and examples of substituents represented by Q are the same as those of substituent X described above.

[0042] In the above formula (Ar-3), L 3 and L 4 Each of these independently represents a monovalent organic group. Examples of monovalent organic groups include alkyl groups, aryl groups, and heteroaryl groups. The alkyl group may be linear, branched, or cyclic, but linear is preferred. The number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10. Furthermore, the aryl group may be monocyclic or polycyclic, but monocyclic is preferred. The number of carbon atoms in the aryl group is preferably 6 to 25, and more preferably 6 to 10. In addition, the heteroaryl group may be monocyclic or polycyclic. The number of heteroatoms constituting the heteroaryl group is preferably 1 to 3. The heteroatoms constituting the heteroaryl group are preferably nitrogen atoms, sulfur atoms, and oxygen atoms. The number of carbon atoms in the heteroaryl group is preferably 6 to 18, more preferably 6 to 12. In addition, the alkyl group, aryl group, and heteroaryl group may be unsubstituted or may have a substituent. Examples of the substituent include the same ones as the above-described substituent X.

[0043] In the above formulas (Ar-4) to (Ar-7), Ax represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. In addition, in the above formulas (Ar-4) to (Ar-7), Ay represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, or an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Here, the aromatic rings in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring. In addition, Q 3 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. Examples of Ax and Ay include those described in paragraphs

[0039] to

[0095] of WO 2014 / 010325. In addition, examples of the alkyl group having 1 to 20 carbon atoms represented by Q 3 include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, etc. Examples of the substituent include the same ones as the above-described substituent X.

[0044] The liquid crystal compound used in the present invention preferably is a compound represented by the following formula (I) because it has a high refractive index anisotropy and thus can form a thin optical anisotropic film. In the following formula (I), Ar represents any aromatic ring selected from the group consisting of the groups represented by the above formulas (Ar-1) to (Ar-7). However, when q1 in the following formula (I) is 2, the plurality of Ars may be the same or different from each other. L 1 -SP 1 -D 5 -(A 1 ) a1 [[ID=1K]]-D 3 -(G 1 ) g1 -D 1 -〔Ar-D 2 〕 q1 -(G 2 ) g2 -D 4 -(A 2 ) a2 -D 6 -SP 2 -L 2 ···(I)

[0045] In the above formula (I), a1, a2, g1 and g2 each independently represent 0 or 1. However, at least one of a1 and g1 represents 1, and at least one of a2 and g2 represents 1. Also, in the above formula (I), q1 represents 1 or 2. Also, in the above formula (I), D 1 、D 2 、D 3 、D 4 、D 5 およびD 6 each independently represents a single bond or a divalent linking group consisting of -CO-, -O-, -S-, -C(=S)-, -CR 1 R 2 -, -CR 3 =CR 4 -, -NR 5 -, or a combination of two or more of these, and R 1 ~R 5Each of these independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 12 carbon atoms. However, if q1 is 2, multiple D 2 These may be the same or different. Also, in the above formula (I), G 1 and G 2 Each of these independently represents an aromatic ring having 6 to 20 carbon atoms, which may have substituents, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms, which may have substituents, and one or more of the -CH2- groups constituting the alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NH-. Also, in the above formula (I), A 1 and A 2 Each of these independently represents an aromatic ring having 6 to 20 carbon atoms, which may have substituents, or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms, which may have substituents, and one or more of the -CH2- groups constituting the alicyclic hydrocarbon group may be substituted with -O-, -S-, or -NH-. Furthermore, in equation (I) above, SP 1 and SP 2 Each of these independently represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a divalent linking group in which one or more of the -CH2- groups constituting a linear or branched alkylene group having 1 to 12 carbon atoms are substituted with -O-, -S-, -NH-, -N(Q)-, or -CO-, where Q represents a substituent. Also, in the above formula (I), L 1 and L 2 Each of these independently represents a monovalent organic group, L 1 and L 2 At least one of them represents a polymerizable group. However, if Ar is an aromatic ring represented by the formula (Ar-3) above, then L 1 and L 2 Furthermore, L in the above-mentioned equation (Ar-3) 3 and L 4 At least one of them represents a polymerizable group.

[0046] In the above formula (I), a1, a2, g1, and g2 are all preferably 1. Furthermore, in the above formula (I), q1 is preferably 1.

[0047] In the above formula (I), D 1 , D 2 , D 3 , D 4 , D 5 and D 6 One aspect of the divalent linking group shown is D in formula (M-3) above. 7 and D 8 The same examples as those explained in [previous section] can be cited. Of these, -CO-, -O-, and -CO-O- are preferred.

[0048] In the above formula (I), G 1 and G 2 Examples of aromatic rings having 6 to 20 carbon atoms as shown in one embodiment include aromatic hydrocarbon rings such as benzene rings, naphthalene rings, anthracene rings, and phenanthroline rings; and aromatic heterocycles such as furan rings, pyrrole rings, thiophene rings, pyridine rings, thiazole rings, and benzothiazole rings; among these, benzene rings (e.g., 1,4-phenyl group) are preferred.

[0049] In the above formula (I), G 1 and G 2 In one embodiment, the divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms is preferably a 5-membered or 6-membered ring. Furthermore, the alicyclic hydrocarbon group may be saturated or unsaturated, but a saturated alicyclic hydrocarbon group is preferred. 1 and G 2 As a divalent alicyclic hydrocarbon group represented by , for example, one can refer to the description in paragraph

[0078] of Japanese Patent Application Publication No. 2012-21068, which is incorporated herein by reference.

[0050] In the above equation (I), G 1 and G 2 A cycloalkane ring is preferred. Examples of cycloalkane rings include cyclohexane rings, cyclopeptane rings, cyclooctane rings, cyclododecane rings, and cyclodocosane rings. Of these, a cyclohexane ring is preferred, a 1,4-cyclohexylene group is more preferred, and a trans-1,4-cyclohexylene group is even more preferred.

[0051] Also, in the above formula (I), G 1 and G 2 Regarding this, the substituents that may be present on an aromatic ring having 6 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms include Y in the above formula (Ar-1). 1 Examples of substituents that may be present include those similar to those that the molecule may have.

[0052] In the above formula (I), A 1 and A 2 As an aromatic ring with 6 to 20 or more carbon atoms shown in one aspect, G in formula (I) above. 1 and G 2 The same examples as those explained in [previous section] can be cited. Also, in the above formula (I), A 1 and A 2 One embodiment of the divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms is G in formula (I) above. 1 and G 2 The same examples as those explained in [previous section] can be cited. Note A 1 and A 2 Regarding this, examples of substituents that may be present on an aromatic ring having 6 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 5 to 20 carbon atoms include those similar to substituent X described above.

[0053] In the above formula (I), SP 1 and SP 2 One embodiment of the linear or branched alkylene group having 1 to 12 carbon atoms is SP in formula (M-3) above. 3 and SP 4 The same examples as those explained in [previous section] can be cited.

[0054] In the above formula (I), L 1 and L 2 The monovalent organic group shown is L in formula (M-3) above. 3 and L4 The same examples as those explained in [previous section] can be cited.

[0055] In the above formula (I), L 1 and L 2 Examples of polymerizable groups represented by at least one of these include the polymerizable groups that can be radically polymerized or cationically polymerized as described above.

[0056] In the above formula (I), L in the above formula (I) is used because it results in good durability. 1 and L 2 However, it is preferable that all of them be polymerizable groups, and more preferably that they be acryloyloxy groups or methacryloyloxy groups.

[0057] Examples of compounds represented by the above formula (I) include compounds represented by general formula (1) described in Japanese Patent Publication No. 2010-084032 (particularly the compounds described in paragraphs

[0067] to

[0073] ), compounds represented by general formula (II) described in Japanese Patent Publication No. 2016-053709 (particularly the compounds described in paragraphs

[0036] to

[0043] ), and compounds represented by general formula (1) described in Japanese Patent Publication No. 2016-081035 (particularly the compounds described in paragraphs

[0043] to

[0055] ).

[0058] Furthermore, as compounds represented by formula (I) above, compounds represented by the following formulas (1) to (22) are preferred, and specifically, as K (side chain structure) in formulas (1) to (22), compounds having the side chain structures represented by K-1-1 to K-8-9 below are examples. However, the two Ks shown in formulas (1) to (22) below are selected such that at least one of them has a polymerizable group. The asterisk (*) in the side chain structures shown below (K-1-1 to K-8-9) indicates the bond position to the aromatic ring. Furthermore, in the side chain structures represented by K-1-12, etc., the groups adjacent to the acryloyloxy group and the methacryloyl group, respectively, represent propylene groups (groups in which a methyl group is replaced by an ethylene group), and represent a mixture of positional isomers with different methyl group positions.

[0059]

change

[0060]

change

[0061]

change

[0062]

change

[0063]

change

[0064]

change

[0065]

change

[0066]

change

[0067]

change

[0068] The liquid crystal compound content is preferably 30.0 to 99.9% by mass, more preferably 50.0 to 99.5% by mass, and even more preferably 70.0 to 99.0% by mass, based on the total mass of solids in the liquid crystal composition layer.

[0069] Furthermore, the liquid crystal composition layer may also preferably contain a liquid crystal compound exhibiting inverse wavelength dispersion and a liquid crystal compound that does not exhibit inverse wavelength dispersion. For example, it is preferable to include a liquid crystal compound having maximum absorption in the wavelength range of 300 to 400 nm and a liquid crystal compound that does not have maximum absorption in the wavelength range of 300 to 400 nm. The ratio of the content of compounds that do not exhibit inverse wavelength dispersion to the content of liquid crystal compounds that exhibit inverse wavelength dispersion (compounds that do not exhibit inverse wavelength dispersion / liquid crystal compounds that exhibit inverse wavelength dispersion) is preferably 0.1 to 4.0, more preferably 0.2 to 2.0, and even more preferably 0.25 to 1.0. When the above ratio is within the preferred range, the ultraviolet transmittance of the liquid crystal composition layer becomes appropriate, and tilt turbulence can be further suppressed.

[0070] Examples of liquid crystal compounds that do not exhibit inverse wavelength dispersion include compounds in which Ar in formula (I) above is replaced with the following formula (Ar-n).

[0071] [ka]

[0072] In the above formula (Ar-n), * represents the bond position. In equation (Ar-n), Z 4 ~Z 7 represents a hydrogen atom or a substituent, and examples of substituents include the substituent X mentioned above. Furthermore, the group that can bond to the above formula (Ar-n) is the K (side chain structure) in formulas (1) to (22), specifically the side chain structures represented by K-1-1 to K-8-9. Furthermore, examples of liquid crystal compounds that do not exhibit inverse wavelength dispersion include compounds in which Ar in formula (I) is replaced with formula (Ar-n), and in formula (Ar-n), one of the asterisks is bonded to a hydrogen atom and the other asterisk is bonded to the side chain structure described above.

[0073] -Chain Transfer Agent- The liquid crystal composition layer contains a chain transfer agent. Examples of chain transfer agents include compounds that have the function of transferring radicals, and conventionally known compounds can be used. Examples of chain transfer agents include octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, n-tetradecyl mercaptan, mercaptoethanol, 1-thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, methoxybutyl-3-mercaptopropionate, stearyl-3-mercaptopropionate, trim Tyrolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), thiomalic acid, octyl thioglycolate, octyl 3-mercaptopropionate, 2-mercaptoethanesulfonic acid, and butyl thioglycolate, etc. Lucapto compounds; disulfide compounds such as dimethyl xanthogen disulfide, diethyl xanthogen disulfide, diisopropyl xanthogen disulfide, tetramethyl thiuram disulfide, tetraethyl thiuram disulfide, and tetrabutyl thiuram disulfide; halogenated hydrocarbons such as carbon tetrachloride, methylene chloride, bromoform, bromotrichloroethane, carbon tetrabromide, and ethylene bromide; secondary alcohols such as isopropanol and glycerin, phosphorous acid, hypophosphorous acid, and their salts. Examples include lower inorganic oxides and their salts such as sodium hypophosphite, potassium hypophosphite, sulfurous acid, bisulfite, dithionite, metabisulfite, and their salts (sodium bisulfite, potassium bisulfite, sodium dithionite, potassium dithionite, sodium metabisulfite, potassium metabisulfite, etc.); as well as allyl alcohol, 2-ethylhexyl thioglycolate, α-methylstyrene dimer, terpinolene, α-terpinene, γ-terpinene, dipentene, and anisole.

[0074] Among the above-mentioned chain transfer agents, mercapto compounds are preferred, and polyfunctional mercapto compounds having two or more mercapto groups are preferred.

[0075] Commercially available chain transfer agents may be used. Examples of commercially available chain transfer agents include Karens MT(registered trademark) PE1, BD1, NR1, and TPMB, manufactured by Showa Denko Corporation.

[0076] The content of the chain transfer agent is preferably 0.25 to 10% by mass, more preferably 0.4 to 5.0% by mass, even more preferably 0.75 to 2.5% by mass, and particularly preferably 0.9 to 2.0% by mass, based on the total mass of the solid content of the liquid crystal composition layer.

[0077] -Other polymerizable compounds- The liquid crystal composition layer may contain other polymerizable compounds having one or more polymerizable groups. Here, the polymerizable groups of other polymerizable compounds are not particularly limited, and examples include acryloyl groups, methacryloyl groups, vinyl groups, styryl groups, and allyl groups. Among these, it is preferable to have an acryloyl group or a methacryloyl group.

[0078] Other polymerizable compounds include non-liquid crystal polymerizable compounds. Specifically, these include esters of polyhydric alcohols and (meth)acrylic acid (e.g., ethylene glycol di(meth)acrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate, and polyester polyacrylate, etc.), vinylbenzene and its derivatives, vinyl sulfone, acrylamide, and methacrylamide, etc.

[0079] When other polymerizable compounds are included, their content is preferably less than 50% by mass, more preferably 40% by mass or less, and even more preferably 2 to 30% by mass, relative to the mass of the liquid crystal compounds (or the total mass of the liquid crystal compounds if there are multiple liquid crystal compounds).

[0080] -Polymerization initiator- The liquid crystal composition layer may contain a polymerization initiator. The polymerization initiator used is preferably a photopolymerization initiator that can initiate the polymerization reaction by ultraviolet irradiation. Examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, combinations of triarylimidazole dimers and p-aminophenyl ketones, acridine compounds, phenazine compounds, oxadiazole compounds, and acylphosphine oxide compounds. It is also preferable that the polymerization initiator is an oxime-type polymerization initiator, and specific examples include the initiators described in paragraphs

[0049] to

[0052] of International Publication No. 2017 / 170443.

[0081] - Leveling agent - The liquid crystal composition layer may contain a leveling agent. The inclusion of a leveling agent helps to keep the surface of the liquid crystal composition layer smooth, facilitating orientation control. As such leveling agents, fluorine-based leveling agents or silicon-based leveling agents are preferred because they have a high leveling effect relative to the amount added. Examples of leveling agents include the compounds described in paragraphs

[0079] to

[0102] of JP 2007-069471, the compounds represented by general formula (I) described in JP 2013-047204 (particularly the compounds described in paragraphs

[0020] to

[0032] ), the compounds represented by general formula (I) described in JP 2012-211306 (particularly the compounds described in paragraphs

[0022] to

[0029] ), and the liquid crystal alignment promoters represented by general formula (I) described in JP 2002-129162 (particularly

[0076] to

[0078] and

[0082] Examples include compounds described in paragraph

[0084] , compounds represented by general formulas (I), (II), and (III) as described in Japanese Patent Application Publication No. 2005-099248 (particularly the compounds described in paragraphs

[0092] to

[0096] ). These compounds may also have the function of an orientation control agent, as described later.

[0082] -Orientation control agent- The liquid crystal composition layer may contain an alignment control agent. Orientation control agents can control the orientation of liquid crystal compounds contained in the liquid crystal composition layer, enabling more uniform and precise control of specific orientation states. The type of orientation is not particularly limited, and various orientation states can be cited, including homogeneous orientation, homeotropic orientation (vertical orientation), tilted orientation, hybrid orientation, and cholesteric orientation.

[0083] As orientation control agents that promote homogeneous orientation, for example, low-molecular-weight orientation control agents or high-molecular-weight orientation control agents can be used. For low molecular weight orientation control agents, for example, reference can be given to paragraphs

[0009] to

[0083] of Japanese Patent Publication No. 2002-020363, paragraphs

[0111] to

[0120] of Japanese Patent Publication No. 2006-106662, and paragraphs

[0021] to

[0029] of Japanese Patent Publication No. 2012-211306, the contents of which are incorporated herein by reference. Furthermore, as polymer orientation control agents, for example, paragraphs

[0021] to

[0057] of Japanese Patent Publication No. 2004-198511 and paragraphs

[0121] to

[0167] of Japanese Patent Publication No. 2006-106662 can be referenced, and this content is incorporated herein.

[0084] Furthermore, examples of orientation control agents that form or promote homeotropic orientation include boronic acid compounds and onium salt compounds. Specifically, reference can be given to the compounds described in paragraphs

[0023] to

[0032] of Japanese Patent Publication No. 2008-225281, paragraphs

[0052] to

[0058] of Japanese Patent Publication No. 2012-208397, paragraphs

[0024] to

[0055] of Japanese Patent Publication No. 2008-026730, and paragraphs

[0043] to

[0055] of Japanese Patent Publication No. 2016-193869, and this information is incorporated herein by reference.

[0085] On the other hand, cholesteric orientation can be achieved by adding a chiral agent to the liquid crystal composition layer, and the direction of rotation of the cholesteric orientation can be controlled by the direction of its chirality. Furthermore, the pitch of the cholesteric orientation can be controlled according to the orientation-regulating force of the chiral agent.

[0086] When the liquid crystal composition layer contains an alignment control agent, the content of the alignment control agent is preferably 0.01 to 10% by mass, and more preferably 0.05 to 5% by mass, relative to the total solid content mass of the liquid crystal composition layer. When the content is within this range, a uniform and highly transparent optical anisotropic film can be obtained without precipitation, phase separation, or alignment defects, while achieving the desired orientation state. These orientation control agents can further impart polymerizable groups (preferably polymerizable groups that can polymerize with liquid crystal compounds containing polymerizable groups, which are included in the liquid crystal composition layer).

[0087] -Other ingredients- The liquid crystal composition layer may contain components other than those described above, such as surfactants, tilt angle control agents, orientation aids, plasticizers, and crosslinking agents.

[0088] (Formation of orientation film) In the method for manufacturing an optically anisotropic film of the present invention, an alignment film may be formed on the support film before forming the liquid crystal composition layer on the support film. That is, the method for manufacturing an optically anisotropic film of the present invention may include a step of forming an alignment film on the support film. In that case, the liquid crystal composition layer is formed on the alignment film. Furthermore, the support film described above may also function as an orientation film.

[0089] Examples of alignment films include rubbing-treated films containing polyvinyl alcohol, obliquely vapor-deposited films of inorganic compounds, films with microgrooves formed on them, and photo-alignment films.

[0090] In the present invention, it is preferable to use a photo-alignment film because it is possible to prevent deterioration of the surface. The photo-alignment film is not particularly limited, but an alignment film formed from a photo-aligning polymer is preferred. Examples of photo-aligning polymers include polymers having photo-aligning groups. Examples of photo-aligning groups include azo groups, stilbene groups, chalcone groups, and cinnamoyl groups.

[0091] Furthermore, in the present invention, the thickness of the orientation film is not particularly limited, but in order to form an optically anisotropic film with a uniform thickness, it is preferably 0.01 to 10 μm, more preferably 0.01 to 1 μm, and even more preferably 0.01 to 0.5 μm.

[0092] The method for forming the orientation film described above is not particularly limited, and known methods can be used. For example, one method for forming a photo-alignment film is to apply an alignment film-forming composition containing the components to be included in the alignment film and a solvent to the support film, dry it to form a coated film, and then irradiate the coated film with ultraviolet light or the like to form the alignment film. The solvent contained in the above alignment film forming composition may include the solvent that the above liquid crystal composition layer may contain. Furthermore, the alignment film forming composition may also contain other components such as a thermal acid generator. The above coating method is not particularly limited, and any known method may be used. Examples of coating methods include the air knife coating method, the curtain coating method, the roller coating method, the wire bar coating method, the gravure coating method, and the die coating method. The formation of the orientation film is preferably carried out while conveying it using a roll-to-roll method.

[0093] (Formation of liquid crystal layer) The method for forming the liquid crystal composition layer is not particularly limited, and it can be formed by applying a liquid crystal composition layer forming composition containing the components of the liquid crystal composition layer onto the support film or alignment film. The above-mentioned liquid crystal layer-forming composition may contain a solvent. Examples of solvents include ketone solvents (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, etc.), ether solvents (e.g., dioxane, tetrahydrofuran, etc.), cyclic amide solvents (e.g., N-methylpyrrolidone, N-ethylpyrrolidone, N,N'-dimethylimidazolidinone, etc.), aliphatic hydrocarbon solvents (e.g., hexane, etc.), alicyclic hydrocarbon solvents (e.g., cyclohexane, etc.), aromatic hydrocarbon solvents (e.g., toluene, xylene, trimethylbenzene, etc.), and halogenated carbon solvents (e.g., dichloromethylbenzene, etc.). Examples of solvents include tan, dichloroethane, dichlorobenzene, chlorotoluene, etc., ester solvents (e.g., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohol solvents (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolve solvents (e.g., methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetate solvents, sulfoxide solvents (e.g., dimethyl sulfoxide, etc.), and chain amide solvents (e.g., dimethylformamide, dimethylacetamide, etc.). These may be used individually or in combination of two or more.

[0094] In particular, the solvent is preferably at least one selected from the group consisting of ketone solvents, ether solvents, and cyclic amide solvents, as it can suppress the increase in filtration pressure during production.

[0095] The coating method is not particularly limited; for example, the coating method described above for the orientation film can be used. After coating, the solvent contained in the liquid crystal layer-forming composition may be removed. The removal method is not particularly limited and includes natural drying, reduced pressure treatment, and heating. The heating temperature can be set appropriately depending on the type of solvent, and is typically between 40 and 200°C. The formation of the liquid crystal composition layer is preferably carried out while conveying it using a roll-to-roll method.

[0096] The thickness of the formed liquid crystal composition layer is preferably 0.5 to 10 μm.

[0097] <Process 1 (Liquid Crystal Alignment Process)> The present invention provides a method for manufacturing an optically anisotropic film, comprising a step 1 (liquid crystal alignment step) in which liquid crystal compounds in a liquid crystal composition layer are aligned. The liquid crystal alignment step is performed while conveying the liquid crystals using a roll-to-roll method. The type of orientation of the liquid crystal compound is not particularly limited, and various orientation states such as homogeneous orientation, homeotropic orientation (vertical orientation), tilted orientation, hybrid orientation, and cholesteric orientation can be cited. The method for orienting the liquid crystal compound is not particularly limited, and known methods can be used. Methods for aligning the liquid crystal compound include applying an electric field to the liquid crystal composition layer and heating to induce a phase transition to the liquid crystal phase, with the heating method being preferred. The heating temperature can be selected according to the liquid crystal compound contained in the liquid crystal composition layer, and is typically between 40 and 200°C, with 100 to 150°C being preferred. The liquid crystal alignment process may be performed simultaneously with the heating carried out when removing any solvents that may be contained in the liquid crystal composition layer. Furthermore, if heating is performed, it is also preferable to carry out a step (temperature control step) after heating in which the liquid crystal composition layer is heated to a temperature lower than that of the liquid crystal alignment step in order to stabilize the orientation direction of the liquid crystal compound. The above temperature is preferably 40 to 100°C, and more preferably 40 to 80°C.

[0098] <Process 2 (UV irradiation process)> The present invention provides a method for manufacturing an optically anisotropic film, comprising step 2 (ultraviolet irradiation step) of transporting a liquid crystal composition layer in which liquid crystal compounds are oriented to an environment with an oxygen concentration of 2000 ppm by volume or less, and curing the liquid crystal composition layer by irradiating it with ultraviolet light in the above environment. In the ultraviolet irradiation step, the ultraviolet irradiation is performed within 0.10 seconds after the transported liquid crystal composition layer reaches the above environment. That is, the elapsed time until irradiation, as explained with reference to Figures 1 to 3, is within 0.10 seconds. When irradiated with ultraviolet light, the polymerizable groups of the liquid crystal compounds contained in the liquid crystal composition layer react, fixing the orientation of the liquid crystal compounds and forming an optically anisotropic film.

[0099] In the above process, the elapsed time until irradiation is preferably less than 0.10 seconds, more preferably 0.08 seconds or less, and even more preferably 0.06 seconds or less. The lower limit of the elapsed time until irradiation is often 0.01 seconds or more.

[0100] The oxygen concentration in the above process is 2000 ppm by volume or less, preferably 1000 ppm by volume or less, more preferably 100 ppm by volume or less, and even more preferably 50 ppm by volume or less. An environment with an oxygen concentration of 2000 ppm by volume or less can be created by replacing the inside of the device that performs ultraviolet irradiation or the space in which the device is located with an inert gas. Nitrogen gas or argon gas is preferred as the inert gas. It is believed that a certain amount of oxygen gas dissolved in the liquid crystal composition layer can be removed by transporting it under the above environment.

[0101] In this specification, "ultraviolet light" refers to electromagnetic waves that mainly include electromagnetic waves with wavelengths of 200 to 400 nm, and preferably mainly include electromagnetic waves with wavelengths of 300 to 400 nm. The ultraviolet light source is not particularly limited, and known light sources can be used, and ultraviolet light including any wavelength range may be irradiated using filters or the like. Examples of ultraviolet light sources include high-pressure mercury lamps, metal halide lamps, and light-emitting diodes (LEDs), with light-emitting diodes being preferred.

[0102] The amount of ultraviolet radiation can be set as appropriate, but a range of 10 to 1000 mJ / cm² is recommended. 2 Preferably, 20-300 mJ / cm² 2 More preferably, 50-200 mJ / cm² 2 That is even more preferable.

[0103] In the embodiments described using Figures 1 to 3, the ultraviolet lamp 16 is positioned so that ultraviolet light is irradiated perpendicularly to the film surface of the film 12 containing the liquid crystal composition layer. However, ultraviolet light may be irradiated from a direction inclined from the direction perpendicular to the film surface.

[0104] <Process 3 (UV irradiation process A)> The present invention's method for manufacturing an optically anisotropic film may also involve transporting the result obtained in step 2 (the object irradiated with ultraviolet light in step 2) and further irradiating it with ultraviolet light in step 3 (ultraviolet irradiation step A). ​​Note that there is a step between step 2 and step 3 in which ultraviolet light is not irradiated. When ultraviolet irradiation step A is performed, the liquid crystal compound obtained in step 2 may still contain polymerizable groups. The environment in which step 3 is carried out is preferably one with a low oxygen concentration, and is similar to the environment in step 2 described above.

[0105] Furthermore, it is preferable to perform a step (temperature control step A) to control the temperature of the result obtained in step 2 before carrying out step 3. The temperature of the liquid crystal composition layer in temperature control step A is preferably 40 to 150°C, and more preferably 80 to 120°C. It is also preferable that the temperature is higher than that of the temperature control step.

[0106] Examples of ultraviolet light sources include those listed in the ultraviolet irradiation process described above, with high-pressure mercury lamps being preferred.

[0107] The amount of ultraviolet radiation can be set as appropriate, but a range of 10 to 1000 mJ / cm² is recommended. 2 Preferably, 50-500 mJ / cm² 2 More preferably, 100-300 mJ / cm² 2 That is even more preferable.

[0108] The conveying speed in the roll-to-roll method in each of the above processes is set as appropriate, but for superior productivity, it is preferably 5 m / min or more, more preferably 10 m / min or more, and even more preferably 15 m / min or more. The upper limit of the conveying speed is often 40 m / min or less.

[0109] In the method for manufacturing an optically anisotropic film of the present invention, steps 1 and 2 may be repeated. By repeatedly performing steps 1 and 2, a laminated film having multiple optically anisotropic films can be obtained. The optically anisotropic films in the laminated film may be identical or different.

[0110] [Properties of optically anisotropic films] The optically anisotropic film produced by the manufacturing method of the present invention preferably satisfies the following formulas (OP1) and (OP2). (OP1) 100nm ≤ Re(550) ≤ 180nm (OP2) Re(450) / Re(550)<1.0 In equations (OP1) and (OP2), Re(λ) represents the in-plane retardation measured at a wavelength of λnm. The in-plane retardation value refers to the value measured using an AxoScan OPMF-1 (manufactured by OptoScience Co., Ltd.) with light at the measurement wavelength. Specifically, by inputting the average refractive index ((Nx+Ny+Nz) / 3) and film thickness (d(μm)) into the AxoScan OPMF-1, 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 the AxoScan OPMF-1, and it means Re(λ).

[0111] The optically anisotropic film is preferably a positive A plate or a positive C plate, and more preferably a positive A plate.

[0112] Here, positive A plates and positive C plates 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. "Substantially identical" means that, for positive A plates, for example, when (ny-nz)×d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, it is included in "ny≒nz", and when (nx-nz)×d is -10 to 10 nm, preferably -5 to 5 nm, it is included in "nx≒nz". Also, for positive C plates, for example, when (nx-ny)×d (where d is the film thickness) is 0 to 10 nm, preferably 0 to 5 nm, it is included in "nx≒ny".

[0113] When the optically anisotropic film is a positive A plate, it is preferable that it satisfies the above formula (OP1) in order to function as a λ / 4 plate, and in formula (OP1), Re(550) is more preferably 120-160 nm, even more preferably 130-150 nm, and particularly preferably 130-140 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).

[0114] [Applications of optically anisotropic films] The optically anisotropic film produced by the manufacturing method of the present invention may be used as an optical film in combination with other components. Other components mentioned above include a support film and a hard coat layer.

[0115] Furthermore, the optically anisotropic film or optical film produced by the manufacturing method of the present invention may be used as a polarizing plate in combination with a polarizer. Any known polarizer can be used, and both absorptive and reflective polarizers can be utilized. The thickness of the polarizer is not particularly limited, but is preferably 3 to 60 μm, more preferably 5 to 30 μm, and even more preferably 5 to 15 μm. Furthermore, an adhesive layer may be placed between the optically anisotropic film and the polarizer.

[0116] The above-mentioned optical film or polarizing plate can be suitably used in an image display device. The display elements used in image display devices are not particularly limited and include, for example, liquid crystal cells, organic electroluminescent (hereinafter abbreviated as "EL") display panels, plasma display panels, and the like. Of these, liquid crystal cells or organic EL display panels are preferred, and liquid crystal cells are more preferred. In other words, as an image display device, a liquid crystal display device using a liquid crystal cell as a display element, or an organic EL display device using an organic EL display panel as a display element is preferred, and a liquid crystal display device is more preferred. [Examples]

[0117] The present invention will be described in more detail below based on examples. The materials, quantities, proportions, processing details, 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.

[0118] [Example 1] <Preparation of Orientation Film Forming Composition 1> A composition 1 for forming an orientation film with the following composition was prepared. • Copolymer A (8.4 parts by mass) • The following thermal acid generator B (0.3 parts by mass) Butyl acetate (80.0 parts by mass) • Methyl ethyl ketone (20.0 parts by mass)

[0119] ·Copolymer A The numbers attached to each repeating unit indicate the mass ratio of that unit to the total number of repeating units.

[0120] [ka]

[0121] • Heat acid generator B

[0122] [ka]

[0123] <Preparation of Composition 1 for Forming a Liquid Crystal Layer> A liquid crystal layer-forming composition 1 with the following composition was prepared. • The following rod-shaped liquid crystal compound C (21.2 parts by mass) • The following rod-shaped liquid crystal compound D (16.1 parts by mass) • The following rod-shaped liquid crystal compound E (39.0 parts by mass) • The following rod-shaped liquid crystal compound F (15.3 parts by mass) • The following rod-shaped liquid crystal compound G (8.5 parts by mass) • Chain transfer agent 1: Karenz MT-NR1 (2.0 parts by mass, manufactured by Showa Denko Corporation) • The following photopolymerization initiator H (0.5 parts by mass) • Copolymer I (0.1 parts by mass) • Cyclopentanone (175.0 parts by mass) • Methyl ethyl ketone (50.0 parts by mass) • Triacetin (10.0 parts by mass)

[0124] ·Rod-shaped liquid crystal compound C

[0125] [ka]

[0126] ·Rod-shaped liquid crystal compound D

[0127] [ka]

[0128] ·Rod-shaped liquid crystal compound E

[0129] [ka]

[0130] ·Rod-shaped liquid crystal compound F

[0131] [ka]

[0132] ·Rod-shaped liquid crystal compound G

[0133] [ka]

[0134] • Polymerization initiator H

[0135] [ka]

[0136] ·Copolymer I The numbers attached to each repeating unit indicate the mass ratio of that unit to the total number of repeating units.

[0137] [ka]

[0138] The rod-shaped liquid crystal compounds C, D, and E correspond to liquid crystal compounds having a maximum absorption in the wavelength range of 300 to 400 nm and having a polymerizable group.

[0139] <Manufacture of Film with Optical Anisotropy Film> Composition 1 for forming an alignment film was continuously applied onto the surface of a support film (TG40, a cellulose-based polymer film, manufactured by Fuji Film Co., Ltd.) using a bar coater. After application, it was dried for 1 minute in a heating zone at 120 °C to remove the solvent, thereby forming a coating film with a thickness of 0.3 μm. Subsequently, while winding it around a mirror-finished back roll, polarized ultraviolet rays were irradiated (10 mJ / cm 2 , light source: ultra-high pressure mercury lamp) to form an alignment film P-1. Next, Composition 1 for forming a liquid crystal composition layer was applied onto the alignment film P-1 formed on the support film using a die coater to form a liquid crystal composition layer. The formed liquid crystal composition layer was dried at 120 °C for 1 minute to stabilize the alignment. Thereafter, the temperature of the liquid crystal composition layer was stabilized at 60 °C and it was conveyed into a casing filled with a nitrogen atmosphere (oxygen concentration 30 ppm), and ultraviolet rays were irradiated (100 mJ / cm 2 , light source: LED lamp (main wavelength λ = 365 nm)). The elapsed time until ultraviolet irradiation in the casing of the liquid crystal composition layer was 0.05 seconds. Next, the liquid crystal composition layer that had been irradiated with ultraviolet rays was conveyed out of the above casing, heated to 100 °C and stabilized at that temperature, and then conveyed into a casing filled with a nitrogen atmosphere (oxygen concentration 30 ppm) and further irradiated with ultraviolet rays (200 mJ / cm 2 , light source: ultra-high pressure mercury lamp). [[ID=IS=19]] By the above procedure, an optical anisotropy film with a thickness of 2.7 μm was formed on the alignment film P-1 to obtain Film 1 with an optical anisotropy film. The manufacture of the above optical anisotropy film was carried out by a roll-to-roll method, and the conveyance speed was 20 m / min.

[0140] [Example 2] An optically anisotropic film 2 was obtained by forming an optically anisotropic film in the same manner as in Example 1, except that the chain transfer agent 1 in the composition 1 for forming a liquid crystal composition layer used in Example 1 was changed to chain transfer agent 2: Kuraray MT-PE1 (manufactured by Showa Denko K.K.).

[0141] [Example 3] An optically anisotropic film 3 was obtained by forming an optically anisotropic film in the same manner as in Example 1, except that the chain transfer agent 1 in the composition 1 for forming a liquid crystal composition layer used in Example 1 was changed to chain transfer agent 3: Kuraray MT-BD1 (manufactured by Showa Denko K.K.).

[0142] [Example 4] An optically anisotropic film 4 was obtained by forming an optically anisotropic film in the same manner as in Example 1, except that the addition amount of the chain transfer agent 1 in the composition 1 for forming a liquid crystal composition layer used in Example 1 was changed to 0.5 parts by mass.

[0143] [Example 5] An optically anisotropic film 5 was obtained by forming an optically anisotropic film in the same manner as in Example 1, except that the addition amount of the chain transfer agent 1 in the composition 1 for forming a liquid crystal composition layer used in Example 1 was changed to 1.0 parts by mass.

[0144] [Example 6] An optically anisotropic film 6 was obtained by forming an optically anisotropic film in the same manner as in Example 1, except that the addition amount of the chain transfer agent 1 in the composition 1 for forming a liquid crystal composition layer used in Example 1 was changed to 3.0 parts by mass.

[0145] [Example 7] An optically anisotropic film 7 was obtained by forming an optically anisotropic film in the same manner as in Example 1, except that the alignment film P-1 formed in Example 1 was changed to the alignment film P-2 formed by the method shown below.

[0146] [Formation of Alignment Film P-2] (Preparation of Composition 2 for Alignment Film Formation) Composition 2 for alignment film formation with the following composition was prepared. · The following rod-like liquid crystal compound J (83.0 parts by mass) · The following rod-like liquid crystal compound K (15.0 parts by mass) · The following rod-like liquid crystal compound L (2.0 parts by mass) · Acrylate monomer: A-400 (4.2 parts by mass, manufactured by Shin-Nakamura Chemical Co., Ltd.) · The following polymer M (2.0 parts by mass) · The following vertical alignment agent N (1.9 parts by mass) · The above photoinitiator H (5.1 parts by mass) · The following photoacid generator O (3.0 parts by mass) · The following photoalignment polymer P (0.8 parts by mass) · Methyl isobutyl ketone (567.0 parts by mass)

[0147] [[ID=2​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0155] • Vertical alignment agent N

[0156] [ka]

[0157] • Photoacid generator O

[0158] [ka]

[0159] Photo-oriented polymer P (In the formula below, a to c represent the mass ratio of each repeating unit to the total repeating units in the polymer, where a:b:c = 17:64:19. Weight-average molecular weight: 80000)

[0160] [ka]

[0161] The prepared alignment film-forming composition 2 was continuously applied to the support film using a bar coater. After application, the solvent was dried to form a coated film, which was then heated at 70°C for 2 minutes. The coated film was transported to an environment with an oxygen concentration of less than 100 ppm and irradiated with ultraviolet light (150 mJ / cm²). 2 (Light source: ultra-high pressure mercury lamp). Then, annealing is performed at 120°C for 1 minute, and ultraviolet light is irradiated through a wire grid polarizer (7.9 mJ / cm²). 2 Using a high-pressure mercury lamp as the light source, an orientation film P-2 with a thickness of 0.5 μm was formed.

[0162] [Example 8] An optically anisotropic film was formed in the same manner as in Example 1, except that the alignment film P-1 formed in Example 1 was replaced with an alignment film P-3 formed by the method described below, thereby obtaining an optically anisotropic film-coated film 8. Specifically, a positive C plate was first formed on a support film, and the alignment film-forming composition 1 was applied to the positive C plate to form the alignment film P-3. After forming the alignment film P-3, the liquid crystal composition layer-forming composition 1 was applied in the same manner as in Example 1, and ultraviolet light irradiation was performed to obtain an optically anisotropic film-coated film 8. The procedure up to the formation of the alignment film P-3 will be described below.

[0163] <Formation of a positive C plate> A composition 1 for positive C plates with the following composition was prepared. • The above-mentioned rod-shaped liquid crystal compound J (83.0 parts by mass) • The above-mentioned rod-shaped liquid crystal compound K (15.0 parts by mass) • The above-mentioned rod-shaped liquid crystal compound L (2.0 parts by mass) • Acrylate monomer: UA-601I (5.0 parts by mass, manufactured by Kyoeisha Chemical Co., Ltd.) • The above polymer M (1.14 parts by mass) • The above-mentioned vertical orientation agent N (1.2 parts by mass) • IRGACURE OXE-01 (4.0 parts by mass, manufactured by BASF Japan Ltd.) • Polymer Q (0.4 parts by mass) • Methyl isobutyl ketone (494.9 parts by mass) • Ethyl propionate (95.0 parts by mass) • 2-Butanone (43.3 parts by mass)

[0164] • Polymer Q (In the formula below, a to d represent the mass ratio of each repeating unit to the total repeating units in the polymer, where a:b:c:d = 29:12:56:3. Weight-average molecular weight: 9600) [ka]

[0165] The prepared positive C plate composition 1 was continuously applied to the support film using a bar coater. After application, the solvent was dried to form a coating film, and the film was heated at 60°C for 2 minutes. The coating film was transported to an environment with an oxygen concentration of less than 100 ppm and irradiated with ultraviolet light (150 mJ / cm²). 2 A positive C plate C-1 with a thickness of 0.7 μm was formed on a support film (light source: ultra-high pressure mercury lamp). Next, while feeding out positive C plate C-1, corona treatment was performed on the surface of positive C plate C-1. After corona treatment, the orientation film forming composition 1 was applied using a Gieser coating machine, and after application, the solvent was removed by drying in a 120°C heating zone for 1 minute to form a coated film with a thickness of 0.3 μm. Subsequently, while being wrapped around a mirror-finish backup roll, polarized ultraviolet light was irradiated (10 mJ / cm²). 2 (Light source: ultra-high pressure mercury lamp), and an alignment film P-3 was formed. In the formation of the positive C plate C-1 and the orientation film P-3 described above, the conveying was carried out using a roll-to-roll method, and the conveying speed was 20 m / min.

[0166] [Comparative Example 1] An optically anisotropic film was formed in the same manner as in Example 1, except that a liquid crystal layer-forming composition 7 was used in which the chain transfer agent 1 in the liquid crystal layer-forming composition 1 used in Example 1 was not added, and an optically anisotropic film-coated film 9 was obtained.

[0167] [evaluation] <Tiltmudra Evaluation Method> The tilt of the obtained optically anisotropic coated film was evaluated by the following method. The resulting optically anisotropic film was placed between two polarizers arranged in a crossed nicol configuration, and observed by detecting light leakage on a light box. The phase-advancing axis of the optically anisotropic film was positioned parallel to the absorption axis of one of the polarizers, and observations were made from an angle of 45° (polar angle 45°) relative to the normal of the film, coinciding with the azimuth angle of the phase-advancing axis of the optically anisotropic film. The tilt motor was evaluated based on the following criteria. In practical terms, a rating of 1 or 2 is preferred. 1: There are no visible inconsistencies when viewed on a light box. 2: There are faintly visible inconsistencies when viewed on a light box. 3: There are inconsistencies that are clearly visible on a light box.

[0168] <Lettering> The in-plane retardation of the obtained optically anisotropic coated film was measured according to the method described above. The table shown later shows the values ​​for Re(550) and Re(450) / Re(550). Note that Re(λ) represents the in-plane retardation measured at a wavelength of λnm.

[0169] [result] Table 1 shows the composition of the optically anisotropic films produced in each example and comparative example, and the evaluation results. In the table, the "Chain Transfer Agent Content" column represents the mass ratio (mass%) of the chain transfer agent content to the solid content in the liquid crystal layer-forming composition. In the table, "ultraviolet-absorbing liquid crystal compound" refers to a liquid crystal compound that has maximum absorption in the wavelength range of 300 to 400 nm and also has polymerizable groups.

[0170] [Table 1]

[0171] The results in Table 1 confirm that the examples containing the chain transfer agent were able to produce optically anisotropic films with suppressed tilt turbulence compared to the comparative examples without the chain transfer agent, demonstrating superior productivity. Comparing Examples 4 and 6 with Examples 1 and 5, it was confirmed that when the chain transfer agent content is 0.75 to 2.5% by mass relative to the total solid content of the liquid crystal composition layer, an optically anisotropic film with suppressed tilt turbulence can be produced. [Explanation of Symbols]

[0172] 12 Film containing a liquid crystal composition layer 14 chambers 16 UV lamps 18 Irradiation area

Claims

1. A method for manufacturing an optically anisotropic film using a roll-to-roll method, Step 1 involves oriented the liquid crystal compound in the liquid crystal composition layer while transporting a liquid crystal composition layer containing a liquid crystal compound having a maximum absorption in the wavelength range of 300 to 400 nm and having polymerizable groups, and a chain transfer agent. The process includes: 1) transporting the liquid crystal composition layer on which the liquid crystal compound is oriented to an environment with an oxygen concentration of 2000 ppm by volume or less, and 2) curing the liquid crystal composition layer by irradiating it with ultraviolet light in the environment. A method for manufacturing an optically anisotropic film, wherein in step 2, the ultraviolet light is irradiated within 0.10 seconds after the liquid crystal composition layer being transported comes into the environment.

2. The method for producing an optically anisotropic film according to claim 1, wherein the content of the chain transfer agent is 0.75 to 2.5% by mass with respect to the total mass of the solid content of the liquid crystal composition layer.

3. The method for manufacturing an optically anisotropic film according to claim 1 or 2, wherein the ultraviolet light source is a light-emitting diode.

4. A method for producing an optically anisotropic film according to claim 1 or 2, further comprising a step 3 in which the result obtained in step 2 is transported and then irradiated with ultraviolet light.

5. A method for manufacturing an optically anisotropic film according to claim 1 or 2, wherein the optically anisotropic film produced by the method satisfies the following relationship between formulas (OP1) and (OP2). (OP1) 100nm≦Re(550)≦180nm (OP2) Re(450) / Re(550)<1.0 In equations (OP1) and (OP2), Re(λ) represents the in-plane retardation measured at a wavelength of λnm.

Images