WO2019159960A1 - Optical film, polarizing plate, image display device - Google Patents

Abstract

The present invention addresses the problem of providing an optical film that includes an optically anisotropic film that has excellent reverse wavelength dispersion, excellent wet-heat resistance, and reduced alignment defects. The present invention also addresses the problem of providing: a polarizing plate that uses the optical film; and an image display device that uses the optical film or the polarizing plate. This optical film includes, in order: an optically anisotropic film that is formed from a polymerizable liquid crystal composition; a photoalignment film; and a polymer support body. The polymerizable liquid crystal composition includes polymerizable liquid crystal compounds that have a prescribed structure. The weight average of the CLogP values of the liquid crystal compounds included in the polymerizable liquid crystal composition is 10.0–20.0. The photoalignment film is formed from a thermally crosslinkable photoalignment film formation composition. The photoalignment film formation composition includes a photoalignable copolymer that includes a photoalignable repeating monomer that has a prescribed structure and a thermally crosslinkable repeating monomer that has a prescribed structure. The thermally crosslinkable group equivalent of the photoalignable copolymer is 340–500.

Description

Optical film, polarizing plate, image display device

The present invention relates to an optical film, a polarizing plate, and an image display device.

The polymerizable compound exhibiting reverse wavelength dispersion has features such as being able to convert the light wavelength accurately in a wide wavelength range and being capable of thinning the retardation film because it has a high refractive index. Therefore, it has been actively studied (see, for example, Patent Documents 1 to 4).
In addition, for the purpose of improving film productivity and suppressing foreign matter defects, a conventional retardation film using a rubbing alignment film is being replaced with a retardation film using a photo-alignment film (for example, Patent Documents). (See 5-7).

JP 2008-273925 A JP 2010-031223 A International Publication No. 2014/010325 JP 2016-081035 A Japanese Patent Laid-Open No. 8-15681 JP 2010-52273 A JP 2010-096892 A

In recent years, as various display devices have been developed for various applications, retardation films (optically anisotropic films) are used in more severe wet heat environments, or in foldable sheet-like ultra-thin display devices. Applications such as use, which have not been conventionally envisaged, are now being demanded.
The present inventors examined the polymerizable liquid crystal compounds having reverse wavelength dispersion described in Patent Documents 1 to 3, and found that a polymerizable liquid crystal compound group (hereinafter referred to as “hydrophobic polymerizable liquid crystal compound” using ClogP value as an index). It has been found that the wet heat durability of the optically anisotropic film to be formed can be improved by selecting "." However, when the support is replaced with a polymer support to enable production in a roll-to-roll process, an optically anisotropic film is provided on a photo-alignment film disposed on a glass plate as a test. It was found that the alignment defects of the optically anisotropic film increased compared with the case of the above.

Then, this invention makes it a subject to provide the optical film containing the optically anisotropic film which was excellent in reverse wavelength dispersion and wet heat durability, and the orientation defect was suppressed.
Another object of the present invention is to provide a polarizing plate using the optical film, and an image display device using the optical film or the polarizing plate.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have formed an optically anisotropic film using a polymerizable liquid crystal composition containing a hydrophobic polymerizable liquid crystal compound on a polymer support. However, by using a specific photo-alignment copolymer in the composition for forming a photo-alignment film, the orientation of the optical anisotropic film can be controlled uniformly and precisely (an optical anisotropic film in which orientation defects are suppressed). The present invention was completed.
That is, it has been found that the above problem can be solved by the following configuration.

[1]
An optical film including an optically anisotropic film formed from a polymerizable liquid crystal composition, a photo-alignment film, and a polymer support in this order,
The polymerizable liquid crystal composition includes a polymerizable liquid crystal compound represented by the following formula (1) described below,
The load average of the CLogP values of the liquid crystal compounds contained in the polymerizable liquid crystal composition is 10.0 to 20.0,
The photo-alignment film is formed from a thermally crosslinkable photo-alignment film forming composition,
The composition for forming a photo-alignment film is a photo-alignment copolymer containing a photo-alignment repeating unit represented by the formula (A) described later and a thermally crosslinkable repeating unit represented by the formula (B) described later. And the photo-alignment copolymer has a thermally crosslinkable group equivalent in the range of 340 to 500.
[2]
M in the above formula (1) is 1, A ¹ and G ¹ are both optionally substituted cyclohexylene groups, E ¹ is a single bond, and
In the above formula (1), n is 1, A ² and G ² are both optionally substituted cyclohexylene groups, and E ² is a single bond, according to [1] Optical film.

[3]
The optical film according to [1] or [2], wherein Ar ¹ in the formula (1) represents a group represented by the formula (Ar-1) or (Ar-2).
[4]
The thermally crosslinkable group contained in the photo-alignment copolymer is chain polymerizable,
The composition for forming a photo-alignment film includes any one of [1] to [3], including the photo-alignment copolymer and a thermal polymerization initiator that initiates chain polymerization of the thermally crosslinkable group. Optical film.

[5]
[1] to [4] The optically anisotropic film is provided so as to be peelable from the photoalignment film, or the photoalignment film is provided so as to be peelable from the polymer support. ] The optical film in any one of.
[6]
A polarizing plate comprising the optical film according to any one of [1] to [5] and a polarizer.
[7]
An image display device comprising the optical film according to any one of [1] to [5] or the polarizing plate according to [6].

ADVANTAGE OF THE INVENTION According to this invention, the optical film containing the optical anisotropic film which was excellent in reverse wavelength dispersion and wet heat durability, and the orientation defect was suppressed can be provided.
Moreover, according to this invention, the polarizing plate using the said optical film and the image display apparatus using the said optical film or the said polarizing plate can be provided.

It is a cross-sectional schematic diagram which shows an example of the optical film of this invention. It is a cross-sectional schematic diagram which shows an example of the circularly-polarizing plate containing the optically anisotropic film | membrane transferred from the optical film of this invention. It is a schematic diagram which shows an example of the manufacturing process of the optical film of this invention.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

In addition, in this specification, the description “(meth) acryl” intends “one or both of acrylic and methacrylic”. Further, the description “(meth) acryloyl” intends “one or both of acryloyl and methacryloyl”.

In this specification, the bonding direction of a divalent group represented (for example, —CO—O—) is not particularly limited, and for example, D ¹ in formula (1) described later is —CO—O—. In this case, assuming that the position bonded to the G ¹ side is * 1, and the position bonded to the Ar ¹ side is * 2, D ¹ may be * 1-CO—O— * 2. * 1-O-CO- * 2.

[Optical film]
The optical film of the present invention includes an optically anisotropic film formed from a polymerizable liquid crystal composition, a photoalignment film, and a polymer support in this order.
FIG. 1 is a schematic cross-sectional view showing an example of the optical film of the present invention. FIG. 1 is a schematic diagram, and the relationship between the thicknesses of each layer, the positional relationship, and the like do not necessarily match those of an actual one.
The optical film 10 shown in FIG. 1 includes a polymer support 16, a photo-alignment film 14, and an optical anisotropic film 12 in this order.

Among the polymer supports described below, industrially usable films may contain various low molecular weight functional additives in the film in order to control film properties. In general, these additive components are hydrophobic in order to provide stable performance even under wet heat conditions. In addition, the components constituting the polymer itself constituting the polymer support or the surface modification layer (for example, an easy-adhesion layer) provided for the purpose of modifying the surface physical properties of the polymer support are mixed during raw material production. Or a low molecular weight oligomer component and / or a hydrophobic low molecular weight impurity due to a processing environment during processing into a film (for example, processing into a polymer film and processing into a surface modified layer). There is.
In the present specification, these low-molecular functional additives and low-molecular weight oligomer components and low-hydrophobic components that are brought into the polymer support due to contamination during raw material production or processing environment during processing into a film. Molecular weight impurities are collectively referred to as hydrophobic low molecular weight components derived from the polymer support.
The molecular weight of the hydrophobic low molecular weight component is typically 3000 or less, preferably 300 to 3000, and more preferably 700 to 2000.

When forming an optically anisotropic film using the polymerizable liquid crystal composition containing the above-described reverse-wavelength-dispersible polymerizable liquid crystal compound excellent in wet heat durability, the inventors have used a glass plate and various polymers as a support. Examination of the film revealed that the polymerizable liquid crystal compound has many alignment defects on various polymer films even though a well-known photo-alignment film disposed on the glass plate can realize a good alignment state. I found out. As a result of investigating the cause of the alignment defect, the present inventors have found that the hydrophobic low molecular weight component derived from the polymer support has shifted to the optically anisotropic film and disturbs the alignment of the polymerizable liquid crystal compound. I got a hypothesis.

As a result of intensive studies based on the above hypothesis, the inventors include an optically anisotropic film that exhibits a good alignment state even when various polymer films are used when a specific photo-alignment film is used. It has been found that an optical film can be obtained. That is, it was found that an optical film including an optically anisotropic film excellent in reverse wavelength dispersion and wet heat durability and having orientation defects suppressed can be obtained.
Hereinafter, various members used in the optical film of the present invention will be described in detail.

(Optically anisotropic film)
The optically anisotropic film constituting the present invention is an optically anisotropic film formed from a polymerizable liquid crystal composition described later. Examples of the method for forming the optically anisotropic film include a method in which a polymerizable liquid crystal composition described later is used to obtain a desired alignment state and then fixed by polymerization.
The optically anisotropic film exhibits reverse wavelength dispersion.

The thickness of the optically anisotropic film is not particularly limited, but is preferably 0.1 to 10 μm and more preferably 0.5 to 5 μm from the viewpoint that a thin film is desired for mounting on a display device.

(Polymerizable liquid crystal composition)
The polymerizable liquid crystal composition used for forming the optically anisotropic film is a polymerizable liquid crystal composition containing a specific polymerizable liquid crystal compound described later, and each ClogP of the liquid crystal compound contained in the polymerizable liquid crystal composition. The load average of the values is 10.0 to 20.0. Here, the target liquid crystal compound is not limited to the specific polymerizable liquid crystal compound, but includes all liquid crystal compounds included in the polymerizable liquid crystal composition.
The ClogP value of the compound is a value obtained by calculating the common logarithm logP of the distribution coefficient P between 1-octanol and water. Known methods and software can be used for calculating the ClogP value. However, unless otherwise specified, the present invention uses the ClogP program incorporated in ChemBioDraw Ultra 13.0 of Cambridge software. In the present invention, the ClogP value is a value obtained by discarding two decimal places.
The load average is the sum of products of the ClogP value of each compound and the ratio (mass ratio) of each compound to the solid content of the entire liquid crystal compound. When there is only one type of liquid crystal compound, the ClogP value of that compound is treated as a load average value.

High ClogP means that the affinity for hydrophobic molecules (1-octanol as an index) is higher than water molecules. Accordingly, although details are not clear, the liquid crystal molecular structure in the optically anisotropic film contains water molecules and other polar components that cause deterioration in wet heat durability by setting the load average of the ClogP value of the liquid crystal compound within the above range. It is speculated that the wet heat durability is improved as a result.

<< Specific polymerizable liquid crystal compound >>
The polymerizable liquid crystal composition contains a polymerizable liquid crystal compound represented by the following formula (1) (hereinafter also referred to as “specific polymerizable liquid crystal compound”). When the optically anisotropic film is formed by curing the specific polymerizable liquid crystal compound, the optically anisotropic film exhibits reverse wavelength dispersion.

Formula (1):
L ¹ -SP ^1- (E ³ -A ¹ ) _m -E ¹ -G ¹ -D ¹ -Ar ¹ -D ² -G ² -E ^2- (A ² -E ⁴ ) _n -SP ² -L ²

In the above formula (1), D ¹ , D ² , E ¹ , E ² , E ³ , and E ⁴ are each independently a single bond, —CO—O—, —C (═S) O—, — CR ¹ R ² —, —CR ¹ R ² —CR ³ R ⁴ —, —O—CR ¹ R ² —, —CR ¹ R ² —O—CR ³ R ⁴ —, —CO—O—CR ¹ R ² —, —O—CO—CR ¹ R ² —, —CR ¹ R ² —O—CO—CR ³ R ⁴ —, —CR ¹ R ² —CO—O—CR ³ R ⁴ —, —NR ¹ —CR ² R ³ — or —CO—NR ¹ — is represented. R ¹ , R ² , R ³ , and R ⁴ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 4 carbon atoms.
In the above formula (1), G ¹ and G ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms which may have a substituent. One or more of —CH ₂ — constituting the formula hydrocarbon group may be substituted with —O—, —S—, or —NH—.
In the above formula (1), A ¹ and A ² each independently have a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent or a substituent. Represents a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and at least one of —CH ₂ — constituting the alicyclic hydrocarbon group is —O—, —S—, Alternatively, it may be substituted with -NH-.
In the above formula (1), SP ¹ and SP ² are each independently a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a linear chain having 1 to 12 carbon atoms. Or a divalent linkage in which one or more of —CH ₂ — constituting the branched alkylene group is substituted with —O—, —S—, —NH—, —N (Q) —, or —CO—. Represents a group, Q represents a substituent.
In the formula (1), L ¹ and L ² each independently represent a monovalent organic group, and at least one of L ¹ and L ² represents a polymerizable group. However, when Ar ¹ is an aromatic ring represented by the following formula (Ar-3), at least one of L ¹ and L ² and L ³ and L ^{4 in} the following formula (Ar-3) is polymerizable. Represents a group.
In the above formula (1), m represents an integer of 0 to 2, and when m is 2, the plurality of E ³ may be the same or different, and the plurality of A ¹ are May be the same or different.
In the above formula (1), n represents an integer of 0 to 2, and when n is 2, the plurality of E ⁴ may be the same or different, and the plurality of A ² are May be the same or different.
In the above formula (1), Ar ¹ represents any aromatic ring selected from the group consisting of groups represented by formulas (Ar-1) to (Ar-5) described later.

The alkyl group having 1 to 4 carbon atoms represented by R ¹ , R ² , R ³ , and R ⁴ may be linear, branched, or cyclic. Specifically, methyl Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like.

In the above formula (1), the divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms represented by G ¹ and G ² is preferably a 5-membered ring or a 6-membered ring. The alicyclic hydrocarbon group may be saturated or unsaturated, but is preferably a saturated alicyclic hydrocarbon group. As the divalent alicyclic hydrocarbon group represented by G ¹ and G ² , for example, the description in paragraph [0078] of JP2012-21068A can be referred to, and the contents thereof are incorporated in the present specification. .
Of these, a cyclohexylene group (a divalent group derived from a cyclohexane ring) is preferable, a 1,4-cyclohexylene group is more preferable, and a trans-1,4-cyclohexylene group is still more preferable.
In the above formula (1), the substituent that the divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms represented by G ¹ and G ² may have is represented by the following formula (Ar-1 And the same substituents as those which may be possessed by the aromatic hydrocarbon group having 6 to 12 carbon atoms and the aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ^{1 in the} formula ( ¹ ).

In the above formula (1), the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms represented by A ¹ and A ² includes 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene Group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group and the like. Among them, 1,4-phenylene group is preferable, and trans-1,4-phenylene group is more preferable. preferable.
Examples of the divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms represented by A ¹ and A ² include the same groups as those described for G ¹ and G ² in the above formula (1). A cyclohexylene group (a divalent group derived from a cyclohexane ring) is preferred, a 1,4-cyclohexylene group is more preferred, and a trans-1,4-cyclohexylene group is still more preferred.
In addition, in the above formula (1), the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms and the divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms represented by A ¹ and A ² have. The substituent may be an aromatic hydrocarbon group having 6 to 12 carbon atoms and an aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ in the formula (Ar-1) described later. The thing similar to a good substituent is mentioned.

In the above formula (1), examples of the linear or branched alkylene group having 1 to 12 carbon atoms represented by SP ¹ and SP ² include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, A hexylene group, a methylhexylene group, a heptylene group, or the like is preferable. SP ¹ and SP ² are as described above, wherein one or more of —CH ₂ — constituting a linear or branched alkylene group having 1 to 12 carbon atoms is —O—, —S—, — It may be a divalent linking group substituted by NH—, —N (Q) —, or —CO—, and examples of the substituent represented by Q include Y in formula (Ar-1) described later. ¹ is an aromatic heterocyclic group of aromatic hydrocarbon group and having 3 to 12 carbon atoms of 6 to 12 carbon atoms include the same substituent which may have indicated.

In the above formula (1), examples of the monovalent organic group represented by L ¹ and L ² include an alkyl group, an aryl group, a heteroaryl group, and a cyano group.
The alkyl group may be linear, branched or cyclic, but is preferably linear. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and still more preferably 1 to 10 carbon atoms.
The aryl group may be monocyclic or polycyclic but is preferably monocyclic. The aryl group preferably has 6 to 25 carbon atoms, more preferably 6 to 10 carbon atoms.
The heteroaryl group may be monocyclic or polycyclic. The number of heteroatoms constituting the heteroaryl group is preferably 1 to 3. The hetero atom constituting the heteroaryl group is preferably a nitrogen atom, a sulfur atom, or an oxygen atom. The carbon number of the heteroaryl group is preferably 6-18, more preferably 6-12. Further, the alkyl group, aryl group, and heteroaryl group may be unsubstituted or may have a substituent. Examples of the substituent include a substituent that may be possessed by an aromatic hydrocarbon group having 6 to 12 carbon atoms and an aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ in formula (Ar-1) described later. The same thing is mentioned.

In the above formula (1), the polymerizable group represented by at least one of L ¹ and L ² is not particularly limited, but a polymerizable group capable of radical polymerization (radical polymerizable group) or a polymerizable group capable of cationic polymerization. (Cationically polymerizable group) is preferred.
As the radical polymerizable group, a generally known radical polymerizable group can be used, and an acryloyl group or a methacryloyl group is preferable. Comparing the acryloyl group and the methacryloyl group, it is generally known that the polymerization rate of the acryloyl group is faster, and the acryloyl group is preferable from the viewpoint of productivity improvement, but the methacryloyl group is also used as the polymerizable group. it can.
As the cationic polymerizable group, generally known cationic polymerizable can be used. Specifically, an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester group, and A vinyloxy group etc. are mentioned. Among these, an alicyclic ether group or a vinyloxy group is preferable, and an epoxy group, an oxetanyl group, or a vinyloxy group is more preferable.
As the polymerizable group, those exemplified below are preferable.

In the above formula (1), it is preferable that L ¹ and L ² in the above formula (1) are both polymerizable groups, and are an acryloyl group or a methacryloyl group, for better wet heat durability. It is more preferable.

On the other hand, in the above formula (1), Ar ¹ represents any aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-5). In the following formulas (Ar-1) to (Ar-5), * represents a bonding position with D ¹ or D ² in the above formula (I).
Hereinafter, formulas (Ar-1) to (Ar-5) will be described.

Here, in the formula (Ar-1), Q ¹ represents N or CH.
Q ² represents —S—, —O—, or —N (R ⁵ ) —, and R ⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ¹ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent or an aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent.

Specific examples of the alkyl group having 1 to 6 carbon atoms represented by R ⁵ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, Examples thereof include an n-pentyl group and an n-hexyl group.
Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms represented by Y ¹ include aryl groups such as a phenyl group, a 2,6-diethylphenyl group, and a naphthyl group.
Examples of the aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ include heteroaryl groups such as thienyl group, thiazolyl group, furyl group, and pyridyl group.
Examples of the substituent that the aromatic hydrocarbon group having 6 to 12 carbon atoms and the aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ may have include an alkyl group, an alkoxy group, and a halogen atom. An atom etc. are mentioned.
As the alkyl group, for example, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms is preferable, and an alkyl group having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group, isopropyl group) Group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, cyclohexyl group, etc.), more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group or an ethyl group.
As the alkoxy group, for example, an alkoxy group having 1 to 18 carbon atoms is preferable, and an alkoxy group having 1 to 8 carbon atoms (for example, a methoxy group, an ethoxy group, an n-butoxy group, and a methoxyethoxy group) is more preferable. An alkoxy group having 1 to 4 carbon atoms is more preferable, and a methoxy group or an ethoxy group is particularly preferable.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example, Among these, a fluorine atom or a chlorine atom is preferable.

In the formulas (Ar-1) to (Ar-5), Z ¹ , Z ² , and Z ³ are each independently a hydrogen atom, a monovalent straight chain having 1 to 20 carbon atoms, or Branched aliphatic hydrocarbon group, monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, halogen atom, cyano group, nitro group, —OR ⁶ , —NR ⁷ R ⁸ , —SR ⁹ , —COOR ^X , or —OCOR ^Y is represented, and R ⁶ to R ⁹ , R ^X , and R ^Y each independently represent a hydrogen atom or a carbon number of 1 to 6 represents an alkyl group, and Z ¹ and Z ² may combine with each other to form an aromatic ring.
As the monovalent linear or branched aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alkyl group having 1 to 15 carbon atoms is preferable, and an alkyl group having 1 to 8 carbon atoms is more preferable. Specifically, methyl group (Me), ethyl group, isopropyl group, tert-pentyl group (1,1-dimethylpropyl group), tert-butyl group (tBu), or 1,1-dimethyl-3,3-dimethyl group A -butyl group is more preferable, and a methyl group, an ethyl group, or a tert-butyl group is particularly preferable.
Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, methylcyclohexyl group, and ethyl. Monocyclic saturated hydrocarbon groups such as cyclohexyl group; cyclobutenyl group, cyclopentenyl group, cyclohexenyl group, cycloheptenyl group, cyclooctenyl group, cyclodecenyl group, cyclopentadienyl group, cyclohexadienyl group, cyclooctadienyl group, and Monocyclic unsaturated hydrocarbon groups such as cyclodecadiene; bicyclo [2.2.1] heptyl group, bicyclo [2.2.2] octyl group, 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 ] dodecyl group, polycyclic saturated hydrocarbon group such as adamantyl group, and the like.
Specific examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group, a 2,6-diethylphenyl group, a naphthyl group, and a biphenyl group. Twelve aryl groups (especially phenyl groups) are preferred.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, for example, Among these, a fluorine atom, a chlorine atom, or a bromine atom is preferable.
On the other hand, specific examples of the alkyl group having 1 to 6 carbon atoms represented by R ⁶ to R ⁹ , R ^X , and R ^Y include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. Group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group and the like.

In the formula (Ar-2) and the formula (Ar-3), A ³ and A ⁴ are each independently —O—, —N (R ¹⁰ ) —, —S—, and —CO—. Represents a group selected from the group consisting of: R ¹⁰ represents a hydrogen atom or a substituent. Examples of the substituent include a substituent that may be possessed by the aromatic hydrocarbon group having 6 to 12 carbon atoms and the aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ in the formula (Ar-1). The same thing is mentioned.

Further, in the above formula (Ar-2), X represents a hydrogen atom or a non-metal atom of Groups 14 to 16 to which a substituent may be bonded.
In addition, examples of the non-metal atoms of Group 14 to 16 represented by X include an oxygen atom, a sulfur atom, a nitrogen atom having a substituent, and a carbon atom having a substituent. Specific examples of the substituent include Include an alkyl group, an alkoxy group, an alkyl-substituted alkoxy group, a cyclic alkyl group, an aryl group (eg, phenyl group, naphthyl group, etc.), cyano group, amino group, nitro group, alkylcarbonyl group, sulfo group, hydroxyl group, etc. Is mentioned.

In the above formula (Ar-3), D ³ and D ⁴ each independently represent a single bond, —CO—O—, —C (═S) O—, —CR ¹ R ² —, —CR ¹ R ² —CR ³ R ⁴ —, —O—CR ¹ R ² —, —CR ¹ R ² —O—CR ³ R ⁴ —, —CO—O—CR ¹ R ² —, —O—CO—CR ¹ R ² —, —CR ¹ R ² —O—CO—CR ³ R ⁴ —, —CR ¹ R ² —CO—O—CR ³ R ⁴ —, —NR ¹ —CR ² R ³ —, or —CO— NR ¹ -is represented. R ¹ , R ² , R ³ , and R ⁴ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 4 carbon atoms.
The alkyl group having 1 to 4 carbon atoms represented by R ¹ , R ² , R ³ , and R ⁴ may be linear, branched, or cyclic. Specifically, methyl Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group and the like.

In the above formula (Ar-3), each of SP ³ and SP ⁴ independently represents a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a straight chain having 1 to 12 carbon atoms. A divalent group in which one or more of —CH ₂ — constituting a chain or branched alkylene group is substituted with —O—, —S—, —NH—, —N (Q) —, or —CO—. Q represents a substituent.
Examples of the linear or branched alkylene group having 1 to 12 carbon atoms represented by SP ³ and SP ⁴ include the same as those described for SP ¹ and SP ² in the above formula (1). .
The substituent represented by Q may have an aromatic hydrocarbon group having 6 to 12 carbon atoms and an aromatic heterocyclic group having 3 to 12 carbon atoms represented by Y ¹ in the formula (Ar-1). The same thing as a substituent is mentioned.

In the formula (Ar-3), L ³ and L ⁴ each independently represent a monovalent organic group, and L ³ and L ⁴ and at least one of L ¹ and L ^{2 in} the formula (1) Represents a polymerizable group.
Examples of the monovalent organic group represented by L ³ and L ⁴ include the same groups as those described for L ¹ and L ² in the above formula (1).
Further, the polymerizable group include the same as those described in L ¹ and L ² in the formula (1).

In the formula (Ar-4) and the formula (Ar-5), Ax has at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring, and has 2 to 30 organic groups are represented.
In the above formulas (Ar-4) and (Ar-5), Ay represents a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, or an aromatic hydrocarbon ring. And an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of aromatic heterocycles.
Here, the aromatic ring in Ax and Ay may have a substituent, and Ax and Ay may combine to form a ring.
In the above formulas (Ar-4) and (Ar-5), Q ³ represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms.

Examples of Ax and Ay include those described in paragraphs [0039] to [0095] of Patent Document 2 (International Publication No. 2014/010325).
Specific examples of the alkyl group having 1 to 6 carbon atoms represented by Q ³ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl. Group, n-pentyl group, n-hexyl group and the like. In addition, examples of the substituent that the alkyl group having 1 to 6 carbon atoms represented by Q ³ may have include an aromatic hydrocarbon group having 6 to 12 carbon atoms represented by Y ¹ in the above formula (Ar-1). And the same substituents that the aromatic heterocyclic group having 3 to 12 carbon atoms may have.

As the specific polymerizable liquid crystal compound, in the above formula (1), m is 1, and A ¹ and A ¹ because the ClogP value is high and the wet-heat durability of the formed optically anisotropic film becomes better G ¹ is an optionally substituted cyclohexylene group, E ¹ is a single bond, n is 1, and A ² and G ² both have a substituent. A compound which is a good cyclohexylene group and E ² is a single bond is preferable.
In the above formula (1), Ar ¹ is the formula (Ar-1) or the above formula (Ar) because the ClogP value is high and the wet-heat durability of the formed optically anisotropic film is better. -2) is preferred.

Further, for reasons of better light resistance, the pKa of the diphenol compound represented by HO—Ar ¹ —OH derived from the structure of Ar ^{1 in} the above formula (1) is preferably 11 or less. .
Here, pKa is a value of an acid dissociation constant in a mixed solvent having a volume ratio of tetrahydrofuran (THF) / water = 6/4 at 25 ° C.
As the method for measuring the acid dissociation constant in the present invention, the alkali titration method described on pages 215 to 217 of Experimental Chemistry Course Second Edition published by Maruzen Co., Ltd. can be used.

As the specific polymerizable liquid crystal compound, for example, compounds represented by the following formulas (1-1) to (1-14) are preferable, and specifically, the following formulas (1-1) to (1-14) ) (Side chain structure) in () includes compounds having side chain structures shown in Table 1 and Table 2 below.
In Tables 1 and 2 below, “*” shown in the side chain structure of K represents the bonding position with the aromatic ring.
In the side chain structures represented by 1-2 in the following Table 1 and 2-2 in the following Table 2, the groups adjacent to the acryloyloxy group and the methacryloyl group are each a propylene group (a methyl group is an ethylene group). Represents a substituted group), and represents a mixture of positional isomers having different methyl group positions.

<< Other polymerizable compounds >>
The polymerizable liquid crystal composition may contain other polymerizable compound having one or more polymerizable groups in addition to the specific polymerizable liquid crystal compound described above.
Here, the polymerizable group that the other polymerizable compound has is not particularly limited, and examples thereof include a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among these, a (meth) acryloyl group is preferable as the polymerizable group.

The other polymerizable compound is preferably another polymerizable compound having 1 to 4 polymerizable groups because the durability of the formed optically anisotropic film is further improved. More preferred are other polymerizable compounds having 2-4.

Such other polymerizable compounds are represented by the formula (M1), formula (M2), and formula (M3) described in paragraphs [0030] to [0033] of JP2014-077068A. Compounds, and more specifically, specific examples described in paragraphs [0046] to [0055] of the publication.

Also, a known polymerizable liquid crystal compound may be added for the purpose of adjusting the size of wavelength dispersion and refractive index anisotropy and adjusting the liquid crystal phase transition temperature of the coating film. Examples of such polymerizable liquid crystal compounds include various polymerizable liquid crystal compounds described in “Liquid Crystal Handbook” (edited by Liquid Crystal Handbook Editorial Committee, Maruzen).

<Polymerization initiator>
The polymerizable liquid crystal composition preferably contains a polymerization initiator.
The polymerization initiator is preferably a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation.
Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substitution, and the like. Aromatic acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone ( U.S. Pat.No. 3,549,367), acridine and phenazine compounds (JP-A-60-105667, and U.S. Pat. No. 4,239,850), oxadiazole compounds (described in U.S. Pat. No. 4,221,970), And acylphosphine oxide compounds (Japanese Patent Publication No. 63-40799, Japanese Patent Publication No. 5-29234, Japanese Patent Application Laid-Open No. 10-95788, and Japanese Patent Application Laid-Open No. 10-29997) and the like.

In the present invention, it is preferable that the polymerization initiator is an oxime type polymerization initiator because the wet heat durability becomes better. Specifically, the polymerization initiator is represented by the following formula (I). More preferably.

In the above formula (I), X ² represents a hydrogen atom or a halogen atom.
In the above formula (I), Ar ³ represents a divalent aromatic group, and D ⁵ represents a divalent organic group having 1 to 12 carbon atoms.
In the above formula (I), R ¹¹ represents an alkyl group having 1 to 12 carbon atoms, and Y ² represents a monovalent organic group.

In the above formula (I), examples of the halogen atom represented by X ² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, a chlorine atom is preferable.
In the formula (I), examples of the aromatic ring constituting the divalent aromatic group represented by Ar ³ include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthroline ring. An aromatic heterocycle such as a furan ring, a pyrrole ring, a thiophene ring, a pyridine ring, a thiazole ring, and a benzothiazole ring;
In the above formula (I), examples of the divalent organic group having 1 to 12 carbon atoms represented by D ⁵ include a linear or branched alkylene group having 1 to 12 carbon atoms. Specifically, a methylene group, an ethylene group, or a propylene group is preferable.
In the above formula (I), the alkyl group having 1 to 12 carbon atoms represented by R ¹¹ is specifically preferably, for example, a methyl group, an ethyl group, or a propyl group.
In the above formula (I), examples of the monovalent organic group represented by Y ² include a functional group containing a benzophenone skeleton ((C ₆ H ₅ ) ₂ CO). Specifically, a functional group containing a benzophenone skeleton in which the terminal benzene ring is unsubstituted or mono-substituted, such as groups represented by the following formula (Ia) and the following formula (Ib), is preferable. In the following formula (Ia) and the following formula (Ib), * represents a bonding position, that is, a bonding position with the carbon atom of the carbonyl group in the above formula (I).

Examples of the oxime type polymerization initiator represented by the above formula (I) include a compound represented by the following formula (S-1) and a compound represented by the following formula (S-2). .

A polymerization initiator may be used individually by 1 type, and may use 2 or more types together.
In the polymerizable composition, the content of the polymerization initiator (the total content when plural types are included) is not particularly limited, but may be 0.01 to 20% by mass of the solid content of the polymerizable liquid crystal composition. Preferably, the content is 0.5 to 5% by mass.

"solvent"
The polymerizable liquid crystal composition preferably contains a solvent from the viewpoint of workability and the like for forming the optically anisotropic film.
Specific examples of the solvent include ketones (eg, acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone), ethers (eg, dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons. (For example, hexane), alicyclic hydrocarbons (for example, cyclohexane), aromatic hydrocarbons (for example, toluene, xylene, trimethylbenzene, etc.), halogenated carbons (for example, dichloromethane, dichloroethane, di) Chlorobenzene and chlorotoluene), esters (for example, methyl acetate, ethyl acetate, and butyl acetate), water, alcohols (for example, ethanol, isopropanol, butanol, and cyclohexanol), cellosolves (for example, methyl) Cellosolve and ethyl Cellosolve, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), and amides (e.g., dimethylformamide, and dimethylacetamide, etc.) and the like.
An organic solvent may be used individually by 1 type, and may use 2 or more types together.

《Leveling agent》
The polymerizable liquid crystal composition preferably contains a leveling agent from the viewpoint of keeping the surface of the optical anisotropic film smooth and facilitating alignment control.
Such a leveling agent is preferably a fluorine-based leveling agent or a silicon-based leveling agent because of its high leveling effect with respect to the amount added, and from the viewpoint of preventing crying (bloom, bleed), a fluorine-based leveling agent. It is more preferable that
Specific examples of the leveling agent include compounds described in paragraphs [0079] to [0102] of JP2007-069471, and general formula (I) described in JP2013-047204A. (Especially compounds described in paragraphs [0020] to [0032]), compounds represented by general formula (I) described in JP 2012-211306 (particularly [0022] to [0032] [0029] and the liquid crystal alignment accelerators represented by the general formula (I) described in JP-A No. 2002-129162 (particularly [0076] to [0078] and [0082] to [0084]. And the compounds represented by general formulas (I), (II) and (III) described in JP-A-2005-099248 (particularly [00 2], and - [0096] the compound described in paragraph), or the like. In addition, you may have the function as an orientation control agent mentioned later.

<Orientation control agent>
The polymerizable liquid crystal composition may contain an alignment control agent as necessary.
Various orientation states such as tilted orientation, hybrid orientation, and cholesteric orientation as well as homogeneous orientation can be formed by the orientation control agent, and a specific orientation state is controlled more uniformly and precisely. be able to.

As the alignment control agent that promotes homogeneous alignment, for example, a low molecular alignment control agent and a high molecular alignment control agent can be used.
Examples of the low molecular orientation control agent include paragraphs [0009] to [0083] in JP-A No. 2002-20363, paragraphs [0111] to [0120] in JP-A No. 2006-106662, and JP-A 2012-2012. The description in paragraphs [0021] to [0029] of the 211306 gazette can be referred to, the contents of which are incorporated herein.
As the polymer orientation control agent, for example, refer to paragraphs [0021] to [0057] of JP-A No. 2004-198511 and paragraphs [0121] to [0167] of JP-A No. 2006-106662. The contents of which are incorporated herein by reference.

When the polymerizable liquid crystal composition includes an alignment control agent, the content of the alignment control agent (the total content when there are a plurality of alignment control agents) is 0.01 to based on the total solid mass in the polymerizable liquid crystal composition. The content is preferably 10% by mass, and more preferably 0.05 to 5% by mass. When the content of the alignment control agent is within this range, it is possible to obtain a uniform and highly transparent optically anisotropic film without realizing precipitation, phase separation, alignment defects and the like while realizing a desired alignment state.
These alignment control agents may further have a polymerizable functional group, in particular, a polymerizable functional group that can be polymerized with the specific polymerizable liquid crystal compound constituting the polymerizable liquid crystal composition used in the present invention.

《Other ingredients》
The polymerizable liquid crystal composition may contain other components other than the components described above. Examples of other components include liquid crystal compounds other than the polymerizable liquid crystal compounds described above, surfactants, tilt angle control agents, alignment aids, plasticizers, and crosslinking agents. As the alignment aid, Hisolv MTEM (manufactured by Toho Chemical Co., Ltd.), NK ester A-200 (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like are preferable.

(Photo-alignment film)
The photo-alignment film constituting the optical film of the present invention is a photo-alignment film formed using a thermally crosslinkable photo-alignment film-forming composition containing a photo-alignment copolymer described later.

The film thickness of the photo-alignment film is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 to 1000 nm, and more preferably 10 to 700 nm. Within this range, the alignment regulating force can be sufficiently imparted, and the surface of the alignment film can be flattened even if there are irregularities and other foreign matters on the surface of the polymer support. Uniform orientation can be realized.

(Photo-alignment copolymer)
The photo-alignment copolymer contained in the photo-alignment film constituting the present invention comprises a photo-alignment repeating unit represented by the following formula (A) and a thermally crosslinkable repeating unit represented by the following formula (B). And the thermally crosslinkable group equivalent is in the range of 340-500. The photoalignable repeating unit represented by the following formula (A) is a repeating unit containing a photoalignable group, and the thermally crosslinkable repeating unit represented by the following formula (B) is a thermally crosslinkable group. Including repeating unit.
Here, the heat-crosslinkable group equivalent represents the mass of the solid content containing 1 mol of a heat-crosslinkable group described later. For example, when an epoxy group is employed as the thermally crosslinkable group, it is equal to the epoxy equivalent described in JIS K 7236. When a hydroxyl group and a free acid group are used as the thermally crosslinkable group, a hydroxyl group equivalent or a free acid equivalent (mol) per gram of solid content is obtained using a titration method described in JIS K 0700, and the reciprocal number is taken. The heat crosslinkable group equivalent can be determined by The polymer solid content refers to a component having a molecular weight exceeding 3000 in the total solid content contained in the composition for forming a photo-alignment film.

In formula (A) and formula (B), B ¹ and B ² each independently represent —O—, —CO—O—, —O—CO—O—, or a phenylene group.
R ¹ and R ² each independently represents a hydrogen atom or a methyl group.
Sp ¹ and Sp ² are each independently a single bond or a linear or branched alkylene group which may have a substituent, an alicyclic alkylene group which may have a substituent, and It represents a divalent linking group composed of one or more selected from the group consisting of an aromatic group which may have a substituent. The alkylene group which may have the above-mentioned substituent and the alicyclic alkylene group which may have the above-mentioned substituent have an arbitrary carbon atom, an ether bond, an ester bond, an amide bond, a urethane bond, And may be substituted with a carbonate bond, but it does not become an —O—O— bond at the connection portion with B ¹ and B ² .
P ² represents a thermally crosslinkable group.
Cin ¹ represents a photo-alignment group represented by the following formula (3-1) or (3-2).

In formula (3-1) or formula (3-2), * represents a bonding position with Sp ¹ .
However, when Cin ¹ represents a photo-alignment group represented by the formula (3-2), the connection portion between the formula (3-2) and Sp ² does not become an —O—O— bond.
R ³ represents a substituent.

In the divalent linking group represented by Sp ¹ and Sp ² in the formula (A), the linear or branched alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. 1-6 are more preferable. The carbon number of the alicyclic alkylene group is preferably 1-12. Examples of the aromatic ring constituting the aromatic group include aromatic hydrocarbon rings such as benzene ring, naphthalene ring, anthracene ring, and phenanthroline ring; furan ring, pyrrole ring, thiophene ring, pyridine ring, Aromatic heterocyclic rings such as thiazole ring and benzothiazole ring; and the like.
Examples of the substituent that the linear or branched alkylene group, the alicyclic alkylene group, and the aromatic group may have include, for example, Y in the above-described formula (Ar-1). ¹ is an aromatic heterocyclic group of aromatic hydrocarbon group and having 3 to 12 carbon atoms of 6 to 12 carbon atoms include the same substituent which may have indicated.
The divalent linking group represented by Sp ¹ and Sp ² is preferably a linear or branched alkylene group.

In the formula (A), the definition of the thermally crosslinkable group represented by P ² is as described later.

In the formula (3-1) or the formula (3-2), examples of the substituent represented by R ³ include an aromatic group having 6 to 12 carbon atoms represented by Y ¹ in the formula (Ar-1) described above. Examples thereof include the same substituents that the hydrocarbon group and the aromatic heterocyclic group having 3 to 12 carbon atoms may have.

Since the photo-alignment film in the optical film of the present invention is formed of a composition for forming a photo-alignment film containing such a photo-alignment copolymer, even if it is disposed on a polymer support with a thin film thickness, The alignment regulating power for the liquid crystal compound can be sufficiently exhibited. Moreover, the optically anisotropic film formed on the photo-alignment film using the polymerizable liquid crystal composition exhibits a uniform alignment state in which disorder of alignment is suppressed. The reason for this is not clear in detail, but the present inventors speculate as follows.
In producing the optical film of the present invention, a photo-alignment film is provided on a polymer support, and then a polymerizable liquid crystal composition is applied onto the photo-alignment film. At this time, the solvent contained in the coating film of the polymerizable liquid crystal composition permeates the photo-alignment film and extracts the hydrophobic low molecular weight component derived from the polymer support to the coating film side. In particular, in the present invention, the liquid crystal compound constituting the polymerizable liquid crystal composition has a high load average CLOGP value, and therefore has a high affinity with the hydrophobic component. A relatively large amount can be extracted. When a hydrophobic low molecular weight component derived from a polymer support is extracted into the coating film, the optically anisotropic film obtained by curing the coating film is visible because the interaction between liquid crystal molecules is disturbed. It is presumed that the liquid crystal molecules are affected by the fact that the reverse wavelength dispersibility is lowered by generating random alignment defects and / or partially randomizing the refractive index anisotropy of the liquid crystal molecules. On the other hand, it can be inferred that the above-described photo-alignment film inhibited the extraction of the hydrophobic low molecular weight component derived from the polymer support into the coating film, so that a good alignment state was obtained.

When the heat-crosslinkable group equivalent of the photo-alignable copolymer is 500 or less (that is, when the content of the heat-crosslinkable group contained per 1 g of the composition is large), the content of the heat-crosslinkable group is sufficient. Yes, the above-described extraction inhibition effect can be sufficiently exerted. When the photocrosslinkable copolymer has a heat crosslinkable group equivalent of 340 or more (that is, when the content of the heat crosslinkable group contained per 1 g of the composition is small), the photoalignable group is a photoalignment film. A large proportion of the surface occupies the surface, and the photo-alignment film can exert a high alignment regulating force by being imparted with an appropriate degree of mobility. Furthermore, when the thermally crosslinkable group equivalent is in the range of 340 to 500, it is estimated that these two effects can be achieved.
Although details are unknown, it is presumed that the structure of the photo-alignment copolymer contributes to the extraction inhibition effect.

In the present specification, the thermally crosslinkable group includes, for example, an oxirane group, oxetanyl group, 3,4-epoxycyclohexyl group, amide group, N-alkoxymethyl group, N-hydroxymethyl group, phenolic hydroxyl group, carboxyl group, And a hydroxyl group. Among these, the oxirane group, the oxetanyl group, and the 3,4-epoxycyclohexyl group can be chain-polymerized under cationic polymerization conditions, and are referred to as chain-polymerizable in this specification.

The photo-alignment copolymer has other repeating units in addition to the repeating unit represented by the above formula (A) and the repeating unit represented by the above formula (B) unless the effects of the present invention are inhibited. May be included.
Examples of such a monomer that forms another repeating unit include a radical polymerizable monomer. Examples of the radical polymerizable monomer include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, and vinyl compounds.
In the case where the photo-alignment copolymer contains a repeating unit other than the repeating unit represented by the above-described formula (A) and the repeating unit represented by the above-described formula (B), the above-described formula (A) The total content of the repeating unit represented by formula (B) and the repeating unit represented by the above-described formula (B) is preferably 70 mol% or more, more than 80 mol%, based on all repeating units of the photoalignable copolymer. Is more preferable, 90 mol% or more is further preferable, and 95 mol% or more is particularly preferable. The upper limit is not particularly limited, but may be less than 100 mol%.

The method for synthesizing the photo-alignment copolymer is not particularly limited, and examples thereof include a monomer that forms the repeating unit represented by the above-described formula (A), and a monomer that forms the repeating unit represented by the above-described formula (B). , And any other monomer that forms a repeating unit, and can be synthesized by polymerization using a radical polymerization initiator in an organic solvent.

The weight average molecular weight (Mw) of the photo-alignment copolymer is preferably 10,000 to 500,000, more preferably 25,000 to 200,000, and more preferably 25,000 or more, 50, More preferably, it is less than 000.
Here, the weight average molecular weight and the number average molecular weight in the present invention are values measured by a gel permeation chromatograph (GPC) method under the following conditions.
・ Solvent (eluent): THF (tetrahydrofuran)
・ Device name: TOSOH HLC-8320GPC
・ Column: 3 TOSOH TSKgel Super HZM-H (4.6 mm × 15 cm) connected to each other ・ Column temperature: 40 ° C.
Sample concentration: 0.1% by mass
・ Flow rate: 1.0 ml / min
・ Calibration curve: TOSOH TSK standard polystyrene Mw = 2800000 to 1050 (Mw / Mn = 1.03 to 1.06) calibration curve using 7 samples

In the composition for forming a photo-alignment film, the content of the photo-alignment copolymer is not particularly limited. However, when the composition for forming a photo-alignment film contains an organic solvent described later, the content of the photo-alignment film is 0. The amount is preferably 1 to 50 parts by mass, and more preferably 0.5 to 10 parts by mass.

(solvent)
The composition for forming a photo-alignment film used in the present invention preferably contains an organic solvent from the viewpoint of workability for producing the photo-alignment film.
Specific examples of the organic solvent include ketones (for example, methyl ethyl ketone, acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone), ethers (for example, dioxane, tetrahydrofuran, and the like), Aliphatic hydrocarbons (for example, hexane, etc.), alicyclic hydrocarbons (for example, cyclohexane, etc.), aromatic hydrocarbons (for example, toluene, xylene, trimethylbenzene, etc.), halogenated carbons (for example, Dichloromethane, dichloroethane, dichlorobenzene, and chlorotoluene), esters (eg, methyl acetate, ethyl acetate, and butyl acetate), water, alcohols (eg, ethanol, isopropanol, butanol, and cyclohexanol), cellosolve Class (for example , Methyl cellosolve, and ethyl cellosolve), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), and amides (e.g., dimethylformamide, and dimethylacetamide, etc.) and the like.
As an organic solvent, these may be used individually by 1 type and may use 2 or more types together.

(Other ingredients)
The composition for forming a photo-alignment film may contain components other than those described above, for example, a polymer compound, a crosslinking agent or a crosslinking reaction initiator, a polymer crosslinking catalyst, an adhesion improver, a leveling agent, and a sensitization. Agents and the like. These compounds may further have a functional group capable of reacting with the above-described photoalignable copolymer.
From the viewpoint of realizing a sufficient crosslinking reaction in a short time by the roll-to-roll process, only the chain-polymerizable thermally crosslinkable group selected from the group consisting of oxirane group, oxetanyl group, and 3,4-epoxycyclohexyl group is heated. In the case of using a photoalignable copolymer containing a crosslinkable group, the composition for forming a photoalignment film preferably further contains a thermal polymerization initiator (preferably a thermal cationic polymerization initiator) as a thermal crosslinking reaction initiator. . When using a photoalignment copolymer containing a thermal crosslinkable group selected from the group consisting of an amide group, an N-alkoxymethyl group, an N-hydroxymethyl group, a phenolic hydroxyl group, a carboxyl group, and a hydroxyl group, The film-forming composition preferably further contains a crosslinking agent and a crosslinking catalyst.

(Polymer support)
The optical film of the present invention includes a polymer support. The polymer support is preferably elongate for application to a roll-to-roll process. Such a support is preferably transparent, and specifically has a light transmittance of 80% or more. Note that the upper limit value of the light transmittance is, for example, 100% or less.
Further, the configuration of the polymer support is not particularly limited, but may be a configuration composed of a single polymer film, for example, or a polymer film and a surface modified layer (for example, easy adhesion) disposed on the polymer film. Layer).

Materials for such a polymer film include: cellulose polymers; acrylic polymers such as polymethyl methacrylate and acrylic polymers having an acrylate polymer such as a lactone ring-containing polymer; thermoplastic norbornene polymers; polycarbonate Polymers: Polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; Styrene polymers such as polystyrene and acrylonitrile / styrene copolymers (AS resin); Polyolefins such as polyethylene, polypropylene, and ethylene / propylene copolymers Polymers; vinyl chloride polymers; amide polymers such as nylon and aromatic polyamide; imide polymers; sulfone polymers; polyethersulfone polymers; -Ether ether ketone polymer; polyphenylene sulfide polymer; vinylidene chloride polymer; vinyl alcohol polymer; vinyl butyral polymer; arylate polymer; polyoxymethylene polymer; epoxy polymer; and polymers obtained by mixing these polymers Etc.
Moreover, the mode which the polarizer mentioned later serves also as such a support body may be sufficient.

In particular, in an embodiment in which the polymer support is used as a part of an optical film, the polymer support is capable of controlling transparency, adhesion to other members, and birefringence from zero to any direction / size. As the polymer constituting the cellulose, a cellulose polymer, an acrylic polymer, or a thermoplastic norbornene polymer is preferable. That is, the polymer support is preferably a film made of a cellulose polymer, a film made of an acrylic polymer, or a film made of a thermoplastic norbornene polymer. Among them, a cellulose acylate film is more preferable as the polymer support.
Further, in an embodiment in which only the optically anisotropic film is transferred to a polarizing plate or an image display device with the polymer support being easily peelable, a film made of a cellulose-based polymer, because it is excellent in film strength and easily available, Or a polyethylene terephthalate film is preferable.

The thickness of the polymer support is not particularly limited, but is preferably 5 to 60 μm, and more preferably 5 to 30 μm.

(Cellulose acylate film)
As a preferred embodiment of the polymer support, a cellulose acylate film can be used. Cellulose acylate is obtained by acylating a hydroxyl group of cellulose, and the substituent can be any acetyl group having 2 carbon atoms in the acyl group to those having 22 carbon atoms.

The acyl group having 2 to 22 carbon atoms substituted for the hydroxyl group of cellulose is not particularly limited, and may be an aliphatic group or an aromatic group, and may be a single group or a mixture of two or more types. Examples of cellulose acylate substituted with these groups include cellulose alkylcarbonyl ester, cellulose alkenylcarbonyl ester, cellulose aromatic carbonyl ester, cellulose aromatic alkylcarbonyl ester, and the like. It may have a group.
Examples of the acyl group include acetyl group, propionyl group, butanoyl group, benzoyl group, naphthylcarbonyl group, and cinnamoyl group. Among these, an acetyl group, a propionyl group, a butanoyl group, a benzoyl group, a naphthylcarbonyl group, or a cinnamoyl group is preferable, and an acetyl group, a propionyl group, or a butanoyl group is more preferable. In particular, an acetyl group or a propionyl group is more preferable, and an acetyl group is particularly preferable from the viewpoints of ease of synthesis, cost, and ease of control of substituent distribution. Moreover, when 2 or more types of acyl groups substitute, the combination of an acetyl group and a propionyl group is preferable.

In the cellulose acylate, the acyl substitution degree to the hydroxyl group of cellulose is not particularly limited, but when used for applications such as a polarizing plate protective film and an optical film, the higher the acyl substitution degree, the better the various additives It is preferable because it dissolves. Therefore, the acyl substitution degree (total substitution degree) of the hydroxyl group of cellulose is preferably 2.50 to 3.00, more preferably 2.70 to 2.96, and 2.80 to 2 More preferred is .95. Further, when only the acetyl group is substituted in cellulose acylate, the degree of substitution of the acetyl group is preferably 2.70 to 2.96, and more preferably 2.80 to 2.95. When only the propionyl group is substituted in cellulose acylate, the degree of substitution of the propionyl group is preferably 0.20 to 2.60.
In cellulose acylate, the method for measuring the degree of substitution (acyl substitution degree) of acetic acid and / or a fatty acid having 3 to 22 carbon atoms substituted on the hydroxyl group of cellulose is a method according to ASTM D-817-91, and An example is NMR (nuclear magnetic resonance).

In the cellulose acylate film, cellulose acylate can be used by mixing two or more kinds of cellulose acylates, which are single or different, from the viewpoint of substituent, substitution degree, polymerization degree, molecular weight distribution, and the like.

The cellulose acylate film may further contain an additive. Examples of the additive include a plasticizer, a hydrophobizing agent, an ultraviolet absorber, and a retardation adjusting agent. Specific examples of the additive include polyester oligomers, sugar ester compounds, and phosphate ester compounds. As will be described later, when the cellulose acylate film also functions as a polarizer protective film, a polyester oligomer or a sugar ester compound is preferable from the viewpoint of excellent wet heat durability.

The polyester oligomer has a repeating unit composed of a dicarboxylic acid and a diol, and can be synthesized by a known method such as a dehydration condensation reaction of a dicarboxylic acid and a diol, or an addition of a dicarboxylic anhydride to a diol and a dehydration condensation reaction. .

As the dicarboxylic acid, aliphatic dicarboxylic acid and aromatic dicarboxylic acid can be used. Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, and 1,4-cyclohexanedicarboxylic acid. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and 1,4-naphthalenedicarboxylic acid.

Examples of the diol (glycol) include aliphatic or alicyclic diols having 2 to 12 carbon atoms, alkyl ether diols having 4 to 20 carbon atoms, and aromatic ring-containing diols having 6 to 20 carbon atoms. Two or more selected may be used in combination. The aromatic diol preferably has 6 to 12 carbon atoms.

It is preferable that at least one end of both ends of the polyester oligomer is sealed. In particular, the terminal is an aliphatic group having 1 to 22 carbon atoms, an aromatic ring-containing group having 6 to 20 carbon atoms, an aliphatic carbonyl group having 1 to 22 carbon atoms, and an aromatic carbonyl group having 6 to 20 carbon atoms. It is preferably at least one selected from

When both ends are sealed, the polyester oligomer is less likely to be in a solid form at room temperature, and handling is good. As a result, a polymer film excellent in humidity stability and polarizing plate durability can be obtained.

In the cellulose acylate film, the content of the polyester oligomer as an additive (when there are a plurality of polyester oligomers) is preferably 1 to 30% by mass with respect to the cellulose acylate, and preferably 5 to 20% by mass. More preferred is 5 to 15% by mass.

The sugar ester compound is a compound in which at least one substitutable group (for example, a hydroxyl group and a carboxyl group) in the sugar skeleton structure constituting the compound and at least one substituent are ester-bonded. Say that. That is, the sugar ester compound referred to here includes a wide range of sugar derivatives, for example, a compound containing a sugar residue such as gluconic acid as a structure. That is, the sugar ester compound includes an ester of glucose and carboxylic acid and an ester of gluconic acid and alcohol.

The sugar ester compound is a sugar ester compound obtained by alkylating all or part of the OH groups of the compound (M) having one furanose structure or one pyranose structure, or at least one of a furanose structure or a pyranose structure. A sugar ester compound in which all or a part of the OH group of the compound (D) in which two species are bonded is alkylesterified is preferable. More preferably, it is a sugar ester compound that is a monocycle of a furanose structure or a pyranose structure, and in which all or part of the hydroxyl groups of the structure are alkyl esterified, and a sugar in which all or part of the hydroxyl groups of the glucose structure are alkyl esterified More preferably, it is an ester compound.

Examples of the compound (M) include glucose, galactose, mannose, fructose, xylose, and arabinose. Glucose or fructose is preferable, and glucose is more preferable.
Examples of the compound (D) include lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose, and kestose. Moreover, gentiobiose, gentiotriose, gentiotetraose, xylotriose, galactosyl sucrose, etc. are also mentioned.
Among these compounds (D), compounds having both a furanose structure and a pyranose structure are particularly preferable, sucrose, kestose, nystose, 1F-fructosyl nystose, or stachyose is more preferable, and sucrose is more preferable.

In order to alkylate all or part of the OH groups in the compound (M) and the compound (D), it is preferable to use an aliphatic monocarboxylic acid.
Examples of the aliphatic monocarboxylic acid include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid , Saturated fatty acids such as tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid Unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid, and octenoic acid; among them, acetic acid, propionic acid, or isobutyric acid is preferable. That is, the substituent in the sugar ester compound is preferably an acetyl group, a propionyl group, or an isobutyryl group.

The aliphatic monocarboxylic acid used to alkylate all or part of the OH group may be two or more aliphatic monocarboxylic acids, at least one of which is branched. Of these, an aliphatic monocarboxylic acid is more preferable. Among them, isobutyric acid is more preferable as the branched aliphatic monocarboxylic acid.
The above embodiment will be described more specifically. Specifically, it is preferable to esterify all or part of the OH group with acetic acid and isobutyric acid. In other words, the substituent in the sugar ester compound is preferably an acetyl group and an isobutyryl group. When the substituent consists only of an acetyl group and an isobutyryl group, the ratio is preferably acetyl group / isobutyryl group = 1/7 to 4/4, more preferably 1/7 to 3/5. More preferably, it is / 6.

A method for producing an aliphatic sugar ester compound substituted with an aliphatic monocarboxylic acid is described, for example, in JP-A-8-245678.

In the cellulose acylate film, the content of the above additives (the total content when a plurality of additives are included) is preferably 5 to 20% by mass with respect to the cellulose acylate.

Moreover, when bonding the optical film of this invention by a polarizer and a polymer support side, the compound of following General formula (4) may be added to the cellulose acylate film to be used from a viewpoint of suppressing the wet heat deterioration of a polarizer. it can.

General formula (4)

In the general formula (4), each of R ¹¹ , R ¹³ and R ¹⁵ is independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an alkyl group having 2 to 20 carbon atoms. An alkenyl group, an aralkyl group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms is represented.

Regarding these compounds and the synthesis method thereof, the content of JP 2013-174861 A (compounds described in paragraph numbers 0090 to 0122 of the same publication can be used) can be referred to.
When the cellulose acylate film contains the compound represented by the general formula (4), the content of the compound represented by the general formula (4) is 1 to 20% by mass with respect to the cellulose acylate polymer. It is preferable.

The cellulose acylate film preferably contains fine particles as a matting agent. As fine particles, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, etc. can be used. .

The fine particles preferably have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more. These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm and form irregularities of 0.1 to 3.0 μm on the film surface. Thereby, when making the optical film of the present invention a long roll in the roll-to-roll process, quality deterioration due to rubbing of the films and / or a phenomenon in which the films adhere to each other (also referred to as blocking) in advance. Can be prevented.

The fine particles may be added so that both surfaces of the cellulose acylate film are provided with irregularities. However, in order to control the orientation of the optically anisotropic film, the cellulose acylate film is required to make the surface of the photo-alignment film flat. It is preferable to add so that unevenness is provided only on the surface opposite to the side where the photo-alignment film is provided.

(Polyethylene terephthalate film)
In this specification, the polyethylene terephthalate film refers to a film containing polyethylene terephthalate as a main component. Polyethylene terephthalate is a polyester having a repeating unit derived from terephthalic acid as a dicarboxylic acid component and a repeating unit derived from ethylene glycol as a diol component, and 80 mol% or more of all repeating units are converted to ethylene terephthalate. It is a repeating unit derived from it, and may further contain a repeating unit derived from another copolymerization component, if necessary.

As a method for producing polyethylene terephthalate, in addition to a direct polymerization method in which terephthalic acid, ethylene glycol and, if necessary, other dicarboxylic acid and / or other diol are directly reacted, dimethyl ester of terephthalic acid, ethylene glycol, and If necessary, any production method such as a so-called transesterification reaction in which a dimethyl ester of another dicarboxylic acid and / or another diol is transesterified can be applied.

The polyethylene terephthalate film may have a surface modification layer on the surface for the purpose of effectively forming various functional layers. As such a surface modification layer, those coated with various binder resins can be used. Examples of the binder resin include a polyester resin, an acrylic resin, a urethane resin, a polyalkylene glycol, a polyalkyleneimine, methylcellulose, and hydroxycellulose. Among them, a polyester resin, an acrylic resin, or a urethane resin is preferable. Furthermore, crosslinking agents such as melamine compounds, epoxy compounds, oxazoline compounds, isocyanate compounds, and carbodiimide compounds can be used in combination as necessary.

The surface modification layer can be provided by various known methods. For example, in the case of providing by in-line coating, a coating solution prepared by adjusting the above-described components such as the binder resin and the crosslinking agent as an aqueous solution or an aqueous dispersion with a solid content concentration of about 0.1 to 50% by mass as a guide is applied to the polyethylene terephthalate film. By applying, a film provided with a surface modification layer can be obtained.

The thickness of the surface modification layer is usually 0.002 to 1.0 μm, preferably 0.03 to 0.5 μm, and more preferably 0.04 to 0.2 μm. Within the above range, it is possible to suppress occurrence of blocking and increase in haze while exhibiting a sufficient surface modification function.

[Other layers]
The optical film of the present invention may further contain other functional layers in addition to the above-described optically anisotropic film, photoalignment film, and polymer support. Examples of the functional layer include an adhesive layer, a hard coat layer, an optically anisotropic film other than those described above, and a colored layer. Examples of the method for providing the functional layer include a method in which the functional layer is separately prepared and transferred via an adhesive layer, and a method in which the functional layer is separately provided on a support and bonded together with the support. In addition, as another method of providing the functional layer, the surface of the optical anisotropic film constituting the optical film of the present invention opposite to the photo-alignment film, or the polymer support constituting the optical film of the present invention is used. There is a method in which a coating liquid for forming the functional layer is directly applied on the surface opposite to the photo-alignment film.

In the optical film of the present invention, the optical anisotropic film may be provided so as to be peelable. When the optically anisotropic film is detachably provided, it may be peeled off at the interface between the photoalignment film and the optically anisotropic film (in other words, the optically anisotropic film is It may be provided so as to be peelable) or may be peeled off at the interface between the photo-alignment film and the polymer support (in other words, the photo-alignment film is peelable from the polymer support). May be provided). Especially, it is preferable to peel at the interface between the photo-alignment film and the optical anisotropic film.

[Manufacturing process of optical film]
In the optical film of the present invention, after a photo-alignment film is provided on a polymer support, a polymerizable liquid crystal composition is further applied on the photo-alignment film and an alignment treatment is applied, and then the alignment state by a polymerization reaction is fixed. Formed. A schematic diagram of these steps is shown in FIG. From the viewpoint of productivity, it is preferable to use a roll-to-roll process as shown in FIG.

(Formation of photo-alignment film)
The photo-alignment film can be produced by a conventionally known production method except that the above-described composition for forming a photo-alignment film is used.
As an example of the manufacturing method of a photo-alignment film, for example, the above-mentioned composition for forming a photo-alignment film is applied to the surface of a polymer support to form a coating film, and the coating film is thermally crosslinked by heating. Examples include a heating step and a light irradiation step of irradiating polarized light to the heated coating film or irradiating non-polarized light from the oblique direction to the surface of the heated coating film. . In addition, the said manufacturing method may include the heating process further after the light irradiation process as needed.

Hereinafter, the manufacturing method will be described with reference to FIG.

≪Application process≫
The application method in the application step is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include spin coating, die coating, gravure coating, flexographic printing, and inkjet printing.
In FIG. 3, application | coating is performed using the die | dye 32 on the polymer support body 1 unwound from the winding body (roll) of the polymer support body.

≪Heating process≫
The heating method in the heating step is not particularly limited, and the coated polymer support obtained through the coating step may be heated by a known method.
As a heating method, for example, a method of heating a polymer support with a coating by exposing it to a heating atmosphere, or a method of heating a polymer support with a coating by bringing it into contact with a transport roll or the like through which a heat medium is passed And the method of heating the polymer support body with a coating film by irradiating with a heat ray is mentioned. The heating temperature is preferably 30 to 200 ° C.
By properly controlling the solvent removal in the coating film and the thermal crosslinking reaction of the photo-alignment film during the heating process, the adhesion between the polymer support and the photo-alignment film is strengthened, and it is derived from the polymer support. Control of the extraction of the hydrophobic low molecular weight component to be performed can improve the orientation control of the optically anisotropic film.
In FIG. 3, the polymer support with a coating film is heated by the heating device 33.

≪Light irradiation process≫
In the light irradiation step, the polarized light applied to the coating film after heating is not particularly limited, and examples thereof include linearly polarized light, circularly polarized light, and elliptically polarized light. Among these, linearly polarized light is preferable.
Further, the “oblique direction” for irradiating non-polarized light is not particularly limited as long as it is a direction inclined by a polar angle θ (0 <θ <90 °) with respect to the normal direction of the coating film surface. However, θ is preferably 20 to 80 °.

The wavelength in polarized light or non-polarized light is not particularly limited as long as it is a wavelength capable of controlling the orientation of the liquid crystalline molecules contained in the coating film after heating. Can be mentioned. Of these, near ultraviolet rays having a wavelength of 250 nm to 450 nm are preferable.
Examples of the light source for irradiating polarized light or non-polarized light include a xenon lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, and a metal halide lamp. By applying an interference filter, a color filter, or the like to ultraviolet rays and visible rays from such a light source, the wavelength range to be irradiated can be adjusted as appropriate. Moreover, linearly polarized light can be obtained by applying a polarizing filter and a polarizing prism to the light from these light sources.

The accumulated light quantity of polarized light or non-polarized light is not particularly limited as long as it is a wavelength capable of controlling the orientation of liquid crystalline molecules contained in the coating film after heating, but is preferably 1 to 300 mJ / cm ² , and preferably 5 to 100 mJ / cm ² is more preferable.
The illuminance of polarized light or non-polarized light is not particularly limited as long as it is a wavelength capable of controlling the orientation of liquid crystalline molecules contained in the coating film after heating, but is preferably 0.1 to 300 mW / cm ^2. More preferably, it is ˜100 mW / cm ² .
In addition, as shown in FIG. 3, when performing light irradiation with respect to the said coating film after a heating, the polymer support body 1 is a point which does not produce the nonuniformity and variation in the orientation of the liquid crystal molecule contained in a coating film. It is preferable to provide a backup roll 38 for preventing the camera from swinging with respect to the light source.

(Formation of optically anisotropic film)
Examples of the method for forming the optically anisotropic film include a method in which the above-described polymerizable liquid crystal composition is used to obtain a desired alignment state and then fixed by polymerization. Typically, a coating step of coating a polymerizable liquid crystal composition on a photo-alignment film to form a coating film, and a liquid crystal molecule such as a specific polymerizable liquid crystal compound contained in the coating film with a desired alignment state The alignment aging step and the alignment fixing step for fixing the alignment state by polymerization are performed in this order, and various known methods can be applied as the coating method and the alignment aging method.
In the orientation fixing step, the polymerization conditions are not particularly limited, but in polymerization by light irradiation, it is preferable to use ultraviolet rays. The irradiation amount is preferably 10 mJ / cm ² to 50 J / cm ² , more preferably 20 mJ / cm ² to 5 J / cm ² , and still more preferably 30 mJ / cm ² to 3 J / cm ^2. 50 to 1000 mJ / cm ² is particularly preferable. Moreover, in order to accelerate | stimulate a polymerization reaction, you may implement on heating conditions. As the exposure method, various known methods can be used.
In addition, it is preferable to perform the formation process of an optical anisotropic film | membrane continuously with the formation process of a photo-alignment film, as shown in FIG. In FIG. 3, the coating process of the polymerizable liquid crystal composition is performed by the die 35, the alignment aging process is performed by the heating device 36, and the alignment fixing process is performed by the exposure process using the light source 37. In the roll-to-roll process, the produced optical film can be wound as a wound body (roll) 39.

[Optical characteristics of optical film]
The optical film of the present invention can impart various optical properties depending on the purpose.
As a preferred embodiment, the optically anisotropic film can be a positive A plate. Here, the A plate is defined as follows.
The refractive index in the slow axis direction (direction in which the in-plane refractive index is maximum) in the optically anisotropic film is nx, the refractive index in the direction orthogonal to the in-plane slow axis is ny, and the thickness. When the refractive index in the direction is nz, the positive A plate satisfies the relationship of the formula (A1).
Formula (A1) nx> ny≈nz
The above “≈” includes not only the case where both are completely the same, but also the case where both are substantially the same. “Substantially the same” means, for example, that (ny−nz) × d (where d is the film thickness) is −10 to 10 nm, preferably −5 to 5 nm, “ny≈nz”. And (nx−nz) × d is also included in “nx≈nz” when −10 to 10 nm, preferably −5 to 5 nm.

The positive A plate can be typically obtained by horizontal alignment (homogeneous alignment) of rod-like liquid crystal compounds. In the present invention, since the specific polymerizable liquid crystal compound described above is a rod-like liquid crystal compound, a positive A plate can be obtained by horizontal alignment on the photo-alignment film.

The optically anisotropic film constituting the optical film of the present invention can satisfy the following formula (3) or formula (4) by using the above-mentioned specific polymerizable liquid crystal compound. Furthermore, it is preferable that the following formula (5) is satisfied.
Re (450) / Re (550) <1 (3)
Rth (450) / Rth (550) <1 (4)
0.50 <Re (450) / Re (550) <1.00 (5)

In the above formulas (3) and (5), Re (450) represents the in-plane retardation of the optically anisotropic film at a wavelength of 450 nm, and Re (550) represents the in-plane of the optically anisotropic film at a wavelength of 550 nm. Represents retardation. In addition, in this specification, when the measurement wavelength of retardation is not specified, the measurement wavelength is 550 nm.
In the above formula (4), Rth (450) represents retardation in the thickness direction at a wavelength of 450 nm of the optically anisotropic film, and Rth (550) represents thickness direction of the optically anisotropic film in the thickness of 550 nm. Represents retardation.

In the present invention, the values of in-plane retardation and retardation in the thickness direction are values measured using AxoScan OPMF-1 (manufactured by Optoscience) and using light having a measurement wavelength.
Specifically, by inputting an average refractive index ((Nx + Ny + Nz) / 3) and a film thickness (d (μm)) in AxoScan OPMF-1.
Slow axis direction (°)
Re (λ) = R0 (λ)
Rth (λ) = ((nx + ny) / 2−nz) × d
Is calculated.
Note that R0 (λ) is displayed as a numerical value calculated by AxoScan OPMF-1, and means Re (λ).

When the optically anisotropic film is a positive A plate, from the viewpoint of functioning as a quarter wavelength plate, Re (550) is preferably 100 to 180 nm, more preferably 120 to 160 nm, and 130 to It is more preferably 150 nm, and particularly preferably 130 to 140 nm. Within this range, in correlation with satisfying the above-mentioned formula (3) or formula (5), it is possible to obtain an optically anisotropic film that provides polarization conversion for a quarter wavelength over a wide band in the visible light region. it can.

The polymer support can be of any optical property.
For example, as a preferable aspect, nx≈ny≈nz. Here, nx, ny, and nz are to read the definition of optical anisotropy described above as a polymer support. That is, Re (550) can be −10 to 10 nm, preferably −5 to 5 nm, and Rth (550) can be −10 to 10 nm, preferably −5 to 5 nm. With such optical characteristics, when polarized light enters from the optically anisotropic film side, the polarization state of the light emitted from the optically anisotropic film through the polymer support is only polarization conversion by the optically anisotropic film. There is an advantage that the optical design becomes easy.

In another aspect, the polymer support can be a positive A plate, a negative A plate, a negative biaxial plate, a positive biaxial plate, a positive C plate, or a negative C plate. Moreover, the optical anisotropy of nx>nz> ny can be shown.
here,
Positive A plate: nx> ny≈nz
Negative A plate: nz≈nx> ny
Negative biaxial plate: nx>ny> nz
Positive biaxial plate: nz>nx> ny
Positive C plate: nx≈ny <nz
Negative C plate: nx≈ny> nz

The optical anisotropy film and the optical anisotropy of the polymer support can be appropriately designed according to the use of the optical film of the present invention as described later.

[Polarizer]
A polarizing plate can be formed by bonding the optical film of the present invention and a polarizer.
In addition, when the optical anisotropic film in the optical film of the present invention is peelable from the photo-alignment film, a polarizing plate is also formed by bonding the optical anisotropic film transferred from the optical film and a polarizer. can do. An example of using such a polarizing plate is a circularly polarizing plate with a positive C plate 18 schematically shown in FIG. 2 (note that the pressure-sensitive adhesive layer is omitted in FIG. 2).

[Polarizer]
The polarizer is not particularly limited as long as it is a member having a function of converting light into specific linearly polarized light, and conventionally known absorption polarizers and reflection polarizers can be used.
Examples of the absorption polarizer include iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Iodine polarizer and dye polarizer include coating polarizers and stretchable polarizers, both of which can be applied. Polarized light produced by adsorbing iodine or dichroic dye to polyvinyl alcohol and stretching. A child is preferred.
In addition, as a method of obtaining a polarizer by stretching and dyeing in the state of a laminated film in which a polyvinyl alcohol layer is formed on a substrate, Patent No. 5048120, Patent No. 5143918, Patent No. 4691205, Patent No. 4751481 and Japanese Patent No. 4751486 can be cited, and known techniques relating to these polarizers can also be preferably used.
As the reflective polarizer, a polarizer in which thin films having different birefringence are laminated, a wire grid polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region and a quarter wavelength plate are combined, or the like is used. .
Among these, at least one selected from the group consisting of polyvinyl alcohol resins (polymers containing —CH ₂ —CHOH— as a repeating unit, in particular, polyvinyl alcohol and ethylene-vinyl alcohol copolymers, in terms of better adhesion. Are preferably included.

The thickness of the polarizer is not particularly limited, but is preferably 3 μm to 60 μm, more preferably 5 μm to 30 μm, and even more preferably 5 μm to 15 μm.

(Adhesive layer)
In these polarizing plates, an adhesive layer may be disposed between the optically anisotropic film transferred from the optical film of the present invention and the polarizer.
As the pressure-sensitive adhesive layer used for laminating the optically anisotropic film and the polarizer, for example, the ratio of the storage elastic modulus G ′ and the loss elastic modulus G ″ measured with a dynamic viscoelasticity measuring apparatus (tan δ = G ″ / G ′) represents a material having a value of 0.001 to 1.5, and includes a so-called pressure-sensitive adhesive and a material that easily creeps. Examples of the adhesive that can be used in the present invention include, but are not limited to, a polyvinyl alcohol-based adhesive.

[Image display device]
The optical film of the present invention can be incorporated into an image display device by incorporating it as an optical film as it is, or by peeling off an optical anisotropic film and incorporating it.
The display elements used in these image display devices are not particularly limited. For example, a liquid crystal cell, an organic electroluminescence (hereinafter abbreviated as “EL”) display panel, a plasma display panel, and a micro LED (light emitting diode) display. A panel etc. are mentioned.
As an example, when applied to a liquid crystal cell, it can be used as an optical compensation film or a viewing angle compensation film. In addition, when applied to self-luminous display elements such as EL display panels, plasma display panels, and micro LED display panels, the optically anisotropic film has a retardation of λ / 4 wavelength, and its slow axis is a linear polarizer. A circularly polarizing plate is formed by combining at 45 ° with the absorption axis, and arranged in the order of polarizer / (polymer support / photo-alignment film) / optical anisotropic film / display element (description of the adhesive layer, etc. is omitted). By doing so, it is possible to provide a function of preventing light reflected from outside the panel from reaching the observer.

Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

Hereinafter, SK-2057 (manufactured by Soken Chemical Co., Ltd.) was used as the adhesive unless otherwise specified.

<Example 1>
(Synthesis of polymer PA-1 having thermally crosslinkable group and photo-alignable group)
In accordance with the method described in Langmuir, 32 (36), 9245-9253, (2016), the following monomer m -1 was synthesized.

Cinnamic acid chloride derivatives

Monomer m-1

A flask equipped with a condenser, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and refluxed by heating in a water bath while flowing 5 mL / min of nitrogen into the flask. Here, 5 parts by mass of monomer m-1, 5 parts by mass of cyclomer M100 (3,4-epoxycyclohexylmethyl methacrylate, manufactured by Daicel), 2,2′-azobis (isobutyronitrile) as a polymerization initiator A solution prepared by mixing 1 part by mass with 5 parts by mass of 2-butanone as a solvent was added dropwise over 3 hours, and the mixture was further stirred for 3 hours while maintaining the reflux state. After completion of the reaction, the mixture was allowed to cool to room temperature and diluted by adding 30 parts by mass of 2-butanone to obtain a polymer solution of about 20% by mass. The obtained polymer solution is poured into a large excess of methanol to precipitate the polymer, and the collected precipitate is filtered off, washed with a large amount of methanol, and then blown and dried at 50 ° C. for 12 hours, A polymer PA-1 having a thermally crosslinkable group and a photoalignable group was obtained. The obtained polymer PA-1 had an epoxy equivalent of 396 and a weight average molecular weight of 28,000.

(Preparation of photo-alignment film P-1)
The following photo-alignment is performed on an additive-containing polymer support (specifically, an additive-containing cellulose acylate film) produced by the method described in paragraphs [0120] to [0122] of JP-A-2018-124528. The film-forming composition PC-1 was continuously applied with a # 2.4 wire bar. Next, the support on which the coating film was formed was dried with warm air of 140 ° C. for 120 seconds, followed by irradiation with polarized ultraviolet rays (10 mJ / cm ² , using an ultrahigh pressure mercury lamp), whereby the photo-alignment film P-1 Formed.

In the polymer support, polyester compound B (specifically, 1,2-cyclohexanedicarboxylic acid and ethylene glycol described in Examples of JP-A-2015-227955 is used as an additive. A polyester oligomer having a repeating unit (molar ratio of 50 mol% each) (number average molecular weight: 850) having both ends sealed with cyclohexanoyl groups) and the following compound F: It is.
Moreover, content of the said polyester compound B is 12 mass% with respect to a cellulose acylate polymer, and content of the said compound F is 2 mass% with respect to a cellulose acylate polymer.

Compound F

────────────────────────────────
Photoalignment film forming composition PC-1
────────────────────────────────
Polymer PA-1 100.00 parts by mass Photopolymerization initiator (Sun-Aid SI-B3A, manufactured by Sanshin Chemical) 5.00 parts by mass Isopropyl alcohol 16.50 parts by mass Butyl acetate 1072.00 parts by mass Methyl ethyl ketone 268.00 parts by mass ────────────────────────────────

(Formation of optical film 1)
The following polymerizable liquid crystal composition A-1 was coated on the photo-alignment film P-1 using a bar coater. The coating film formed on the photo-alignment film P-1 was heated to 180 ° C. with warm air, then cooled to 120 ° C., and ultraviolet rays of 100 mJ / cm ² at a wavelength of 365 nm using a high-pressure mercury lamp in a nitrogen atmosphere. Was applied to the coating film to fix the orientation of the liquid crystal compound, and an optical film 1 was produced in the order of polymer support / photo-alignment film P-1 / optical anisotropic film A-1. Re (550) of the optically anisotropic film A-1 was 144 nm, and it was a positive A plate showing optical anisotropy of nx> ny≈nz.
Table 3 shows the load average of the CLogP values of the liquid crystal compounds contained in the polymerizable liquid crystal composition A-1 shown below.
In the polymerizable liquid crystal composition A-1, the polymerizable liquid crystal compound L-1, the polymerizable liquid crystal compound L-2, and the mesogenic compound A-1 correspond to the liquid crystal compounds.

―――――――――――――――――――――――――――――――――
Polymerizable liquid crystal composition A-1
―――――――――――――――――――――――――――――――――
-42.50 parts by mass of the following polymerizable liquid crystal compound L-1-42.50 parts by mass of the following polymerizable liquid crystal compound L-2-15.00 parts by mass of the following mesogenic compound A-1-The following polymerization initiator S-1 (oxime) Type) 3.00 parts by mass Leveling agent (Compound T-1 below) 0.20 parts by mass Cyclopentanone 219.30 parts by mass ――――――――――――――――――― ――――――――――――――

(Formation of positive C plate C-1)
The positive C plate C-1 prepared by the same method as the positive C plate described in paragraph [0124] of JP-A-2015-200601 (however, the positive C plate is adjusted so that Rth (550) is −69 nm). A film C1 having a controlled thickness) on a temporary support for formation was prepared.

(Formation of circularly polarizing plate 1)
The surface of TD80UL (manufactured by FUJIFILM Corporation) as a support was subjected to alkali saponification treatment. Specifically, the support was immersed in an aqueous 1.5 N sodium hydroxide solution at 55 ° C. for 2 minutes, and the taken-out support was washed in a water bath at room temperature and 0.1 N sulfuric acid at 30 ° C. Was neutralized. Thereafter, the obtained support was washed again in a room temperature water tub and further dried with hot air at 100 ° C.
Subsequently, a rolled polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an iodine aqueous solution, and the stretched film was dried to obtain a polarizer having a thickness of 20 μm.
The obtained polarizer and a support (TD80UL) subjected to alkali saponification treatment were bonded together to obtain a polarizing plate with the polarizer exposed on one side.
Next, the surface of the polarizing plate where the polarizer is exposed and the optically anisotropic film A-1 so that the absorption axis of the polarizer and the slow axis of the optically anisotropic film A-1 are 45 °. Then, the positive alignment plate A-1 alone was transferred to the polarizing plate by peeling off the photo-alignment film and the polymer support of the optical film 1 from the polarizing plate. Subsequently, the surface of the positive C plate C-1 in the film C-1 is bonded to the surface of the transferred positive A plate A-1 using an adhesive, and the temporary support for forming the film C1 is peeled off. Thus, only the positive C plate C-1 was transferred onto the optically anisotropic film A-1, and the circularly polarizing plate 1 was produced.

<Example 2>
The optically anisotropic film A-2 was formed by changing the polymerizable liquid crystal composition A-1 to the following polymerizable liquid crystal composition A-2 and adjusting the thickness so that Re (550) was 144 nm. The optical film 2 was produced by the same method as in Example 1, and then the circularly polarizing plate 2 was produced. The refractive index anisotropy of the optically anisotropic film A-2 was a positive A plate with nx> ny≈nz.
Table 3 shows the load average of the CLogP values of the liquid crystal compounds contained in the polymerizable liquid crystal composition A-2 below.
In the polymerizable liquid crystal composition A-2, the polymerizable liquid crystal compound L-1, the polymerizable liquid crystal compound L-2, and the mesogenic compound A-1 correspond to the liquid crystal compounds.

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Polymerizable liquid crystal composition A-2
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-62.00 parts by mass of the polymerizable liquid crystal compound L-1-20.00 parts by mass of the polymerizable liquid crystal compound L-2-18.00 parts by mass of the mesogenic compound A-1-The polymerization initiator S-1 (oxime) Type) 3.00 parts by mass Leveling agent (Compound T-1) 0.20 parts by mass Cyclopentanone 219.30 parts by mass ――――――――――――――――――― ――――――――――――――

<Example 3>
The optically anisotropic film A-3 was formed by changing the polymerizable liquid crystal composition A-1 to the following polymerizable liquid crystal composition A-3 and adjusting the thickness so that Re (550) was 144 nm. The optical film 3 was produced by the same method as in Example 1, and then the circularly polarizing plate 3 was produced. The refractive index anisotropy of the optically anisotropic film A-3 was a positive A plate with nx> ny≈nz.
Table 3 shows the load average of the CLogP values of the liquid crystal compounds contained in the polymerizable liquid crystal composition A-3 shown below.
In the polymerizable liquid crystal composition A-3, the polymerizable liquid crystal compound L-1 and the mesogenic compound A-1 correspond to the liquid crystal compounds.

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Polymerizable liquid crystal composition A-3
―――――――――――――――――――――――――――――――――
・ The polymerizable liquid crystal compound L-1 84.00 parts by mass. The mesogenic compound A-1 16.00 parts by mass. The polymerization initiator S-1 (oxime type) 3.00 parts by mass. The leveling agent (the compound T -1) 0.20 parts by mass / cyclopentanone 219.30 parts by mass --------------

<Example 4>
The optically anisotropic film A-4 was formed by changing the polymerizable liquid crystal composition A-1 to the following polymerizable liquid crystal composition A-4 and adjusting the thickness so that Re (550) was 144 nm. The optical film 4 was produced by the same method as in Example 1, and then the circularly polarizing plate 4 was produced. The refractive index anisotropy of the optically anisotropic film A-4 was a positive A plate with nx> ny≈nz.
Table 3 shows the load average of the CLogP values of the liquid crystal compounds contained in the polymerizable liquid crystal composition A-4 below.
In the polymerizable liquid crystal composition A-4, the polymerizable liquid crystal compound L-2 and the mesogenic compound A-1 correspond to the liquid crystal compounds.

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Polymerizable liquid crystal composition A-4
―――――――――――――――――――――――――――――――――
-73.00 parts by mass of the polymerizable liquid crystal compound L-2-27.00 parts by mass of the mesogenic compound A-1-3.00 parts by mass of the polymerization initiator S-1 (oxime type)-leveling agent (the compound T -1) 0.20 parts by mass / cyclopentanone 219.30 parts by mass --------------

<Example 5>
A positive A plate A-5 was prepared in the same manner as in Example 1 except that the polymerizable liquid crystal composition A-1 was changed to the following polymerizable composition A-5 and the thickness was adjusted, and circularly polarized light was prepared. A plate 5 was produced.
Table 3 shows the load average of the CLogP values of the liquid crystal compounds contained in the polymerizable liquid crystal composition A-5 shown below.
In the polymerizable liquid crystal composition A-5, the polymerizable liquid crystal compound L-3 corresponds to the liquid crystal compound.

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Polymerizable liquid crystal composition A-5
―――――――――――――――――――――――――――――――――
The following polymerizable liquid crystal compound L-3 100.00 parts by mass The polymerization initiator S-1 (oxime type) 3.00 parts by mass The leveling agent (the compound T-1) 0.20 parts by mass Cyclopentanone 219.30 parts by mass ―――――――――――――――――――――――――――――――――

<Comparative Example 1>
A positive A plate A-11 was produced in the same manner as in Example 1 except that the polymerizable liquid crystal composition A-1 was changed to the following polymerizable liquid crystal composition A-11 and the thickness was adjusted, and a circular A plate A-11 was prepared. A polarizing plate 11 was produced.
Table 3 shows the load average of the CLogP values of the liquid crystal compounds included in the polymerizable liquid crystal composition A-11 shown below.
In the polymerizable liquid crystal composition A-11, the polymerizable liquid crystal compound L-4, the polymerizable liquid crystal compound L-5, and the mesogenic compound A-2 correspond to the liquid crystal compounds.

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Polymerizable liquid crystal composition A-11
―――――――――――――――――――――――――――――――――
-43.75 parts by mass of the following polymerizable liquid crystal compound L-4-43.75 parts by mass of the following polymerizable liquid crystal compound L-5-12.50 parts by mass of the following mesogenic compound A-2-The above polymerization initiator S-1 (oxime) Type) 3.00 parts by mass Leveling agent (Compound T-1) 0.20 parts by mass Cyclopentanone 219.30 parts by mass ――――――――――――――――――― ――――――――――――――

<Comparative example 2>
In place of the polymer PA-1 having a thermally crosslinkable group and a photoalignable group in Example 1, a composition PC-2 for forming a photoalignment film using a polymer PA-2 synthesized by the following method was used. Except for the above, the optical film 12 and the circularly polarizing plate 12 were produced in the same manner as in Example 1.

(Synthesis of polymer PA-2 having thermally crosslinkable group and photo-alignable group)
A flask equipped with a condenser, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and refluxed by heating in a water bath while flowing 5 mL / min of nitrogen into the flask. Here, 6.5 parts by mass of monomer m-1, 3.5 parts by mass of cyclomer M100 (manufactured by Daicel), 1 part by mass of 2,2′-azobis (isobutyronitrile) as a polymerization initiator, A solution prepared by mixing 5 parts by mass of 2-butanone as a solvent was added dropwise over 3 hours, and the mixture was further stirred for 3 hours while maintaining the reflux state. After completion of the reaction, the mixture was allowed to cool to room temperature and diluted by adding 30 parts by mass of 2-butanone to obtain a polymer solution of about 20% by mass. The obtained polymer solution is poured into a large excess of methanol to precipitate the polymer, and the collected precipitate is filtered off, washed with a large amount of methanol, and then blown and dried at 50 ° C. for 12 hours, A polymer PA-2 having a thermally crosslinkable group and a photoalignable group was obtained. The obtained polymer PA-2 had an epoxy equivalent of 566 and a weight average molecular weight of 28,000.

<Comparative Example 3>
In place of the polymer PA-1 having a thermally crosslinkable group and a photoalignment group in Example 1, a composition PC-3 for forming a photoalignment film using a polymer PA-3 synthesized by the following method was used. Except for the above, an optical film 13 and a circularly polarizing plate 13 were produced in the same manner as in Example 1.

(Synthesis of polymer PA-3 having thermally crosslinkable group and photo-alignable group)
A flask equipped with a condenser, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and refluxed by heating in a water bath while flowing 5 mL / min of nitrogen into the flask. Here, 4 parts by mass of monomer m-1, 6 parts by mass of cyclomer M100 (manufactured by Daicel), 1 part by mass of 2,2′-azobis (isobutyronitrile) as a polymerization initiator, and 2- A solution mixed with 5 parts by weight of butanone was added dropwise over 3 hours, and the mixture was further stirred for 3 hours while maintaining the reflux state. After completion of the reaction, the mixture was allowed to cool to room temperature and diluted by adding 30 parts by mass of 2-butanone to obtain a polymer solution of about 20% by mass. The obtained polymer solution is poured into a large excess of methanol to precipitate the polymer, and the collected precipitate is filtered off, washed with a large amount of methanol, and then blown and dried at 50 ° C. for 12 hours, A polymer PA-3 having a thermally crosslinkable group and a photoalignable group was obtained. The obtained polymer PA-3 had an epoxy equivalent of 330 and a weight average molecular weight of 28,000.

<Reference Example 1>
A photo-alignment film GP-1 was formed on the glass substrate in the same manner as in Example 1 except that a glass substrate was used instead of the polymer support and the thickness of the optically anisotropic film was adjusted so that Re (550) was 144 nm. A laminated body G1 in which the optically anisotropic film GA-1 was formed in this order was produced. Next, a circularly polarizing plate was produced in the same manner as in Example 1. The refractive index anisotropy of the optically anisotropic film GA-1 was a positive A plate with nx> ny≈nz.

<Reference Example 2>
In the same manner as in Reference Example 1, except that the photo-alignment film forming composition PC-2 was used instead of the photo-alignment film-forming composition PC-1, the photo-alignment film GP-2 and the optically different film on the glass substrate were used. A laminate G2 in which the isotropic film GA-2 was formed in this order was produced. Next, a circularly polarizing plate was produced in the same manner as in Example 1. The refractive index anisotropy of the optically anisotropic film GA-2 was a positive A plate with nx> ny≈nz.

<Example 6>
(Synthesis of polymer PA-4 having thermally crosslinkable group and photo-alignment group)
In the synthesis of polymer PA-1 of Example 1, instead of 5 parts by mass of monomer m-1 and 5 parts by mass of cyclomer M100, 6 parts by mass of monomer m-1 and 4 parts by mass of OXE-10 ( (3-Ethyloxetane-3-yl) methyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used to obtain a polymer PA-4.

(Preparation of photoalignment film-forming composition PC-4)
In the production of the photoalignment film-forming composition PC-1 of Example 1, the photoalignment film-forming composition PC- was prepared in the same manner except that the polymer PA-4 was used instead of the polymer PA-1. 4 was prepared.

(Preparation of optical film 6)
In the production of the optical film of Example 1, an optical film 6 was produced in the same manner except that the photo-alignment film-forming composition PC-4 was used instead of the photo-alignment film-forming composition PC-1. Next, a circularly polarizing plate 6 was produced.

<Example 7>
(Synthesis of polymer PA-5 having thermally crosslinkable group and photo-alignable group)
In the synthesis of the polymer PA-1 of Example 1, instead of 5 parts by mass of monomer m-1 and 5 parts by mass of cyclomer M100, 6 parts by mass of monomer m-1 and 4 parts by mass of glycidyl methacrylate (Tokyo) Polymer PA-5 was obtained using Kasei Kogyo Co., Ltd.

(Preparation of photoalignment film-forming composition PC-5)
In the preparation of the photoalignment film-forming composition PC-1 of Example 1, the photoalignment film-forming composition PC- was prepared in the same manner except that the polymer PA-5 was used instead of the polymer PA-1. 5 was prepared.

(Preparation of optical film 7)
In the production of the optical film of Example 1, an optical film 7 was produced by the same method except that the above-described photoalignment film-forming composition PC-5 was used instead of the photoalignment film-forming composition PC-1. Next, a circularly polarizing plate 7 was produced.

<Liquid crystal alignment evaluation>
The prepared optical film was placed on a polarizing microscope and the polarizing plate was made cross Nicol, and then the angle of the optical film was adjusted and set to the extinction position. Microscopic observation was performed in this state, and 10 fields of a 500 μm × 500 μm region were observed while changing the location, and the average value of the number of bright spots observed therein was evaluated as an index of liquid crystal alignment. The evaluation criteria were as follows.
A: The number of bright spots observed in an area of 500 μm × 500 μm is less than 3 on average D: The number of bright spots observed in an area of 500 μm × 500 μm is 3 or more on average

<Durability evaluation>
A positive A plate with a pressure-sensitive adhesive was prepared by pasting a pressure-sensitive adhesive on the prepared positive A plate, and the ReA (550) after maintaining this in an environment of 85 ° C. and 85% for 500 hours was evaluated according to the following criteria. did.
A: When the ratio of ReA (550) after holding is 98% or more with respect to ReA (550) before holding at 85 ° C. and 85% B: With respect to ReA (550) before holding at 85 ° C. and 85%, When the ratio of ReA (550) after holding is 95% or more and less than 98% C: The ratio of ReA (550) after holding is 90% or more with respect to ReA (550) before holding at 85 ° C. and 85%. D: When the ratio of ReA (550) after holding is less than 90% with respect to ReA (550) before holding at 85 ° C. and 85%

(Mounting on organic EL display devices)
Disassemble the GALAXY S IV manufactured by SAMSUNG equipped with an organic EL display panel, peel off the circularly polarizing plate, and paste each circularly polarizing plate produced in Examples, Comparative Examples, and Reference Examples on the organic EL display panel. Thus, an organic EL display device was produced. The circularly polarizing plates 1 to 7, G1, and G2 prepared in Examples and Reference Examples, and the circularly polarizing plate 11 prepared in Comparative Example 1 have a front reflection color close to neutral black and a 45 ° direction when displaying black. Although the squint reflection color was shown, the polarizing plates 12 and 13 produced in Comparative Examples 2 and 3 have a bright spot even during black display, and in the front reflection and the 45 ° direction squint reflection, the color is different from that of neutral black. It was something you could feel.

The optically anisotropic film in the optical films of the examples exhibited reverse wavelength dispersion and excellent wet heat durability. In addition, even when the optically anisotropic film is disposed on a polymer support containing a hydrophobic low molecular weight component, extraction of the hydrophobic low molecular weight component does not occur in Reference Example 1 (example using a glass support). Applicable)). That is, it is clear that the optical film of the present invention is suitable for a roll-to-roll process, and the optically anisotropic film exhibits excellent optical properties and wet heat durability.

DESCRIPTION OF SYMBOLS 10 Optical film 3, 12 Optical anisotropic film 2, 14 Photo-alignment film 1, 16 Polymer support body 18 Positive C plate 20 Polarizing plate 22 Circular polarizing plate 30 Optical film manufacturing process 31, 39 Roll 32, 35 Die 33, 36 Heating device 34, 37 Light source 38 Backup roll

Claims (7)

An optical film including an optically anisotropic film formed from a polymerizable liquid crystal composition, a photo-alignment film, and a polymer support in this order,
The polymerizable liquid crystal composition includes a polymerizable liquid crystal compound represented by the following formula (1),
The load average of the CLogP value of each liquid crystal compound contained in the polymerizable liquid crystal composition is 10.0 to 20.0,
The photo-alignment film is formed from a thermally crosslinkable photo-alignment film forming composition,
The composition for forming a photo-alignment film includes a photo-alignment copolymer containing a photo-alignment repeating unit represented by the following formula (A) and a thermally crosslinkable repeating unit represented by the following formula (B). An optical film in which the photo-alignable copolymer has a thermally crosslinkable group equivalent of 340 to 500.
Formula (1):
L ¹ -SP ^1- (E ³ -A ¹ ) _m -E ¹ -G ¹ -D ¹ -Ar ¹ -D ² -G ² -E ^2- (A ² -E ⁴ ) _n -SP ² -L ²
In formula (1), D ¹ , D ² , E ¹ , E ² , E ³ , and E ⁴ are each independently a single bond, —CO—O—, —C (═S) O—, —CR ¹ R ² —, —CR ¹ R ² —CR ³ R ⁴ —, —O—CR ¹ R ² —, —CR ¹ R ² —O—CR ³ R ⁴ —, —CO—O—CR ¹ R ² — , —O—CO—CR ¹ R ² —, —CR ¹ R ² —O—CO—CR ³ R ⁴ —, —CR ¹ R ² —CO—O—CR ³ R ⁴ —, —NR ¹ —CR ² R ³ — or —CO—NR ¹ — is represented. R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms.
G ¹ and G ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms which may have a substituent, and —CH constituting the alicyclic hydrocarbon group One or more of ₂ — may be substituted with —O—, —S—, or —NH—.
A ¹ and A ² are each independently a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, or 5 to 8 carbon atoms which may have a substituent. Wherein at least one of —CH ₂ — constituting the alicyclic hydrocarbon group is substituted with —O—, —S—, or —NH—. Good.
SP ¹ and SP ² each independently constitute a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a linear or branched alkylene group having 1 to 12 carbon atoms. Represents a divalent linking group in which one or more of —CH ₂ — is substituted with —O—, —S—, —NH—, —N (Q) —, or —CO—, where Q is a substituent Represents.
L ¹ and L ² each independently represent a monovalent organic group, and at least one of L ¹ and L ² represents a polymerizable group. However, when Ar ¹ is an aromatic ring represented by the following formula (Ar-3), at least one of L ¹ and L ² and L ³ and L ^{4 in} the following formula (Ar-3) is polymerizable. Represents a group.
m represents an integer of 0 to 2, and when m is 2, the plurality of E ³ may be the same or different, and the plurality of A ¹ are the same or different. May be.
n represents an integer of 0 to 2, and when n is 2, the plurality of E ⁴ may be the same or different, and the plurality of A ² may be the same or different. May be.
Ar ¹ represents any aromatic ring selected from the group consisting of groups represented by the following formulas (Ar-1) to (Ar-5).

In formula (Ar-1) to formula (Ar-5), * represents a bonding position with D ¹ or D ² .
Q ¹ represents N or CH.
Q ² represents —S—, —O—, or —N (R ⁵ ) —, and R ⁵ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ¹ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 3 to 12 carbon atoms which may have a substituent.
Z ¹ , Z ² and Z ³ are each independently a hydrogen atom, a monovalent linear or branched aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent group having 3 to 20 carbon atoms. An alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, —OR ⁶ , —NR ⁷ R ⁸ , —SR ⁹ , —COOR ^X , Or -OCOR ^Y , R ⁶ to R ⁹ , R ^X , and R ^Y each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z ¹ and Z ² are bonded to each other. An aromatic ring may be formed.
A ³ and A ⁴ each independently represents a group selected from the group consisting of —O—, —N (R ¹⁰ ) —, —S—, and —CO—, and R ¹⁰ represents a hydrogen atom or a substituent. Represents a group.
X represents a hydrogen atom or a nonmetallic atom of Groups 14 to 16 to which a substituent may be bonded.
D ³ and D ⁴ are each independently a single bond, —CO—O—, —C (═S) O—, —CR ¹ R ² —, —CR ¹ R ² —CR ³ R ⁴ —, —O ^{-CR 1 R 2 -, - CR} 1 R 2 -O-CR 3 R 4 -, - CO-O-CR 1 R 2 -, - O-CO-CR 1 R 2 -, - CR 1 R 2 -O It represents —CO—CR ³ R ⁴ —, —CR ¹ R ² —CO—O—CR ³ R ⁴ —, —NR ¹ —CR ² R ³ —, or —CO—NR ¹ —. R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms.
SP ³ and SP ⁴ each independently constitute a single bond, a linear or branched alkylene group having 1 to 12 carbon atoms, or a linear or branched alkylene group having 1 to 12 carbon atoms. Represents a divalent linking group in which one or more of —CH ₂ — is substituted with —O—, —S—, —NH—, —N (Q) —, or —CO—, where Q is a substituent Represents.
L ³ and L ⁴ each independently represent a monovalent organic group, and at least one of L ³ and L ⁴ and L ¹ and L ^{2 in} the formula (1) represents a polymerizable group.
Ax represents an organic group having 2 to 30 carbon atoms having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring.
Ay has a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, or at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring. Represents an organic group having 2 to 30 carbon atoms.
The aromatic ring in Ax and Ay may have a substituent, and Ax and Ay may be bonded to form a ring.
Q ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent.

In formula (A) and formula (B), B ¹ and B ² each independently represent —O—, —CO—O—, —O—CO—O—, or a phenylene group.
R ¹ and R ² each independently represents a hydrogen atom or a methyl group.
Sp ¹ and Sp ² are each independently a single bond or a linear or branched alkylene group which may have a substituent, an alicyclic alkylene group which may have a substituent, and It represents a divalent linking group composed of one or more selected from the group consisting of an aromatic group which may have a substituent. In the alkylene group which may have the substituent and the alicyclic alkylene group which may have the substituent, any carbon atom may be an ether bond, an ester bond, an amide bond, a urethane bond, And may be substituted with a carbonate bond, but it does not become an —O—O— bond at the bond portion with B ¹ and B ² .
P ² represents a thermally crosslinkable group.
Cin ¹ represents a photo-alignment group represented by the following formula (3-1) or (3-2).

In Formula (3-1) or Formula (3-2), * represents a bonding position with Sp ¹ .
However, when Cin ¹ represents a photoalignable group represented by the formula (3-2), the bond between the photoalignable group represented by the formula (3-2) and Sp ¹ is —O—O—. There is no connection.
R ³ represents a substituent. M in the formula (1) is 1, A ¹ and G ¹ are both optionally substituted cyclohexylene groups, E ¹ is a single bond, and
And n is 1 in the formula (1), both A ² and G ² are good cyclohexylene group which may have a substituent, E ² is a single bond, according to claim 1 Optical film. The optical film according to claim 1 or 2, wherein Ar ¹ in the formula (1) represents a group represented by the formula (Ar-1) or the formula (Ar-2). The thermally crosslinkable group contained in the photo-alignment copolymer is chain polymerizable,
The composition for forming a photo-alignment film includes the photo-alignment copolymer and a thermal polymerization initiator that initiates chain polymerization of the thermally crosslinkable group. Optical film. The optically anisotropic film is provided so as to be peelable from the photoalignment film, or the photoalignment film is provided so as to be peelable from the polymer support. The optical film according to any one of the above. A polarizing plate comprising the optical film according to any one of claims 1 to 5 and a polarizer. An image display device comprising the optical film according to any one of claims 1 to 5 or the polarizing plate according to claim 6.

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