JP6987883B2 - Photo-aligned copolymer, photo-aligned film and optical laminate - Google Patents

Description

The present invention relates to photo-aligned copolymers, photo-aligned films and optical laminates.

Optical films such as optical compensation sheets and retardation films are used in various image display devices from the viewpoints of eliminating image coloring and expanding the viewing angle.
A stretched birefringence film has been used as the optical film, but in recent years, it has been proposed to use an optically anisotropic layer using a liquid crystal compound instead of the stretched birefringence film.

It is known that such an optically anisotropic layer is provided with an alignment film on a support forming the optically anisotropic layer in order to orient the liquid crystal compound, and rubbing is used as the alignment film. A photo-alignment film that has been subjected to a photo-alignment treatment instead of the treatment is known.

For example, Patent Document 1 contains a composition for a photoalignment film containing a polymer A having a structural unit a1 containing a cinnamate group and a low molecular weight compound B having a cinnamate group and having a molecular weight smaller than that of the polymer A. The product is described ([claim 1]), and an embodiment in which the polymer A has a structural unit a2 containing a crosslinkable group such as an epoxy group and an oxetanyl group is described ([0024] to! [0028]).

International Publication No. 2017/069252

As the polymer A described in Patent Document 1, the present inventors examined a copolymer having a structural unit a1 containing a synnamate group and a structural unit a2 containing a crosslinkable group. As a result, the present inventors examined the type of the crosslinkable group. It was clarified that the orientation of the liquid crystal compound (hereinafter, also referred to as "liquid crystal orientation") may be inferior when the optically anisotropic layer is formed on the obtained photoalignment film.
Further, depending on the type of the crosslinkable group, the present inventors may have a peelability of the optically anisotropic layer when transferring the optically anisotropic layer formed on the obtained photoalignment film to another substrate. It was clarified that it may be inferior.

Therefore, the present invention uses a photo-alignment copolymer capable of producing a photo-alignment film having good orientation of the liquid crystal compound and excellent peelability of the optically anisotropic layer, and a photo-alignment copolymer using the same. An object of the present invention is to provide a produced optical alignment film and an optical laminate.

As a result of diligent studies to achieve the above problems, the present inventors obtained by using a copolymer having a repeating unit containing a specific photo-oriented group and a repeating unit containing a specific cross-linking group. We have found that when an optically anisotropic layer is formed on the optically anisotropic layer to be formed, the orientation of the liquid crystal compound is good and the formed optically anisotropic layer is also excellent in peelability, and the present invention has been completed. rice field.
That is, the present inventors have found that the above-mentioned problems can be achieved by the following configurations.

式（Ａ）中、Ｒ^１は、水素原子またはメチル基を表し、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立に、水素原子または置換基を表す。Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６のうち、隣接する２つの基が結合して環を形成していてもよい。
式（Ｂ）中、Ｒ^７は、水素原子またはメチル基を表し、Ｒ^８は、水素原子、メチル基またはエチル基を表す。
式（Ａ）のＬ^１および式（Ｂ）中のＬ^２は、それぞれ独立に、置換基Ｘを有していてもよい炭素数１〜１０の直鎖状、分岐状または環状のアルキレン基、置換基Ｙを有していてもよい炭素数６〜１２のアリーレン基、エーテル基、カルボニル基、および、置換基Ｚを有していてもよいイミノ基からなる群から選択される少なくとも２以上の基を組み合わせた２価の連結基を表す。
ただし、置換基Ｘは、ハロゲン原子、アルキル基およびアルコキシ基からなる群から選択される少なくとも１種の置換基であり、置換基Ｙは、ハロゲン原子、アルキル基、アリール基、アルコキシ基、アリールオキシ基、シアノ基、カルボキシ基およびアルコキシカルボニル基からなる群から選択される少なくとも１種の置換基であり、置換基Ｚは、アルキル基およびアリール基からなる群から選択される少なくとも１種の置換基である。[1] A photo-oriented copolymer having a repeating unit A containing a photo-oriented group represented by the following formula (A) and a repeating unit B containing a cross-linking group represented by the following formula (B). ..

In formula (A), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently represent a hydrogen atom or a substituent, respectively. Of R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , two adjacent groups may be bonded to form a ring.
In formula (B), R ⁷ represents a hydrogen atom or a methyl group, and R ⁸ represents a hydrogen atom, a methyl group or an ethyl group.
L ¹ and L ² in the formula (B) of formula (A) are each independently a linear 1-10 carbon atoms which may have a substituent group X, branched or cyclic alkylene group, At least two or more selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group that combines groups.
However, the substituent X is at least one substituent selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group, and the substituent Y is a halogen atom, an alkyl group, an aryl group, an alkoxy group and an aryloxy. It is at least one substituent selected from the group consisting of a group, a cyano group, a carboxy group and an alkoxycarbonyl group, and the substituent Z is at least one substituent selected from the group consisting of an alkyl group and an aryl group. Is.

[2] L ^{1 of the} formula (A) may have at least a linear alkylene group having 1 to 10 carbon atoms which may have a substituent X and a substituent X which may have a substituent X. The photo-orientation according to [1], which is a divalent linking group containing any of a cyclic alkylene group of 10 to 10 and an arylene group having 6 to 12 carbon atoms which may have a substituent Y. Copolymer.
[3] L ^{1 of the} formula (A) may have at least a linear alkylene group having 1 to 10 carbon atoms which may have a substituent X, or a carbon which may have a substituent X. The photooriented copolymer according to [2], which is a divalent linking group containing a cyclic alkylene group having a number of 3 to 10.

式（１）中、＊は、式（Ａ）中のベンゼン環との結合位置を表し、Ｒ^９は、１価の有機基を表す。 ^R 2 of [4] Formula ^(A), R ^3, R 4, of ^{R 5} and ^{R 6,} represents at least ^{R 4} is a substituted group, [1] to photoalignable according to any one of [3] Copolymer.
[5] The photooriented copolymer according to [4], wherein ^{R 2} , R ³ , R ⁵ and R ^{6 of the formula (A) all represent hydrogen atoms.
R 4} [6] Formula (A) is an electron-donating substituent, [4] or photoorientable copolymer according to [5].
^{R 4} [7] Formula (A) is a carbon number of alkoxy groups of 4 to 18, photoorientable copolymer according to [6].
[8] The ^{substituents represented by R 2} , R ³ , R ⁴ , R ⁵ and R ^{6 in the} formula (A) are independently halogen atoms, linear, branched or cyclic with 1 to 20 carbon atoms, respectively. Alkyl group, linear halogenated alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms, aryloxy group having 6 to 20 carbon atoms, cyano group, amino The photo-orientation copolymer according to any one of [1] to [7], which is a group or a group represented by the following formula (1).

In the formula (1), * represents the bond position with the benzene ring in the formula (A), and R ⁹ represents a monovalent organic group.

[9] The photo-orientation according to any one of [1] to [8], wherein the content a of the repeating unit A and the content b of the repeating unit B satisfy the following formula (2) in terms of mass ratio. Polymer.
0.2 ≤ a / (a + b) ≤ 0.8 ... (2)
[10] The photooriented copolymer according to [9], wherein the content a of the repeating unit A and the content b of the repeating unit B satisfy the following formula (3) in terms of mass ratio.
0.2 ≤ a / (a + b) ≤ 0.6 ... (3)

式（Ｃ）中、Ｒ^１０は、水素原子またはメチル基を表し、Ｌ^３は、置換基Ｘを有していてもよい炭素数１〜１０の直鎖状、分岐状または環状のアルキレン基、置換基Ｙを有していてもよい炭素数６〜１２のアリーレン基、エーテル基、カルボニル基、および、置換基Ｚを有していてもよいイミノ基からなる群から選択される少なくとも２以上の基を組み合わせた２価の連結基を表す。
式（Ｄ）中、Ｒ^１１は、水素原子またはメチル基を表し、Ｌ^４は、置換基Ｘを有していてもよい炭素数１〜１０の直鎖状、分岐状もしくは環状のアルキレン基、置換基Ｙを有していてもよい炭素数６〜１２のアリーレン基、エーテル基、カルボニル基、および、置換基Ｚを有していてもよいイミノ基からなる群から選択される１または２以上の基を組み合わせた２価の連結基を表し、Ｑは、−ＯＨ、−ＣＯＯＨ、および、−ＣＯＯｔＢｕのいずれかの基を表す。
式（Ｅ）中、Ｒ^１２は、水素原子またはメチル基を表し、Ｌ^５は、置換基Ｘを有していてもよい炭素数１〜１８の直鎖状、分岐状もしくは環状のアルキレン基、置換基Ｙを有していてもよい炭素数６〜１２のアリーレン基、エーテル基、カルボニル基、および、置換基Ｚを有していてもよいイミノ基からなる群から選択される１または２以上の基を組み合わせた２価の連結基を表し、Ｓは、エチレン性不飽和二重結合を有する官能基を表す。
ただし、置換基Ｘは、ハロゲン原子、アルキル基およびアルコキシ基からなる群から選択される少なくとも１種の置換基であり、置換基Ｙは、ハロゲン原子、アルキル基、アリール基、アルコキシ基、アリールオキシ基、シアノ基、カルボキシ基およびアルコキシカルボニル基からなる群から選択される少なくとも１種の置換基であり、置換基Ｚは、アルキル基およびアリール基からなる群から選択される少なくとも１種の置換基である。[11] Further, the repeating unit C containing a crosslinkable group represented by the following formula (C), the repeating unit D containing a crosslinkable group represented by the following formula (D), and the following formula (E) are shown. The photooriented copolymer according to any one of [1] to [10], which has at least one repeating unit selected from the group consisting of the repeating unit E containing a crosslinkable group.

In formula (C), R ¹⁰ represents a hydrogen atom or a methyl group, and L ³ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X. At least two or more selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group that combines groups.
In formula (D), R ¹¹ represents a hydrogen atom or a methyl group, and L ⁴ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X. One or more selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group in which the groups of are combined, and Q represents any of -OH, -COOH, and -COOtBu.
In formula (E), R ¹² represents a hydrogen atom or a methyl group, and L ⁵ is a linear, branched or cyclic alkylene group having 1 to 18 carbon atoms which may have a substituent X. One or more selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group in which the groups of the above are combined, and S represents a functional group having an ethylenically unsaturated double bond.
However, the substituent X is at least one substituent selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group, and the substituent Y is a halogen atom, an alkyl group, an aryl group, an alkoxy group and an aryloxy. It is at least one substituent selected from the group consisting of a group, a cyano group, a carboxy group and an alkoxycarbonyl group, and the substituent Z is at least one substituent selected from the group consisting of an alkyl group and an aryl group. Is.

[12] The photooriented copolymer according to any one of [1] to [11], which has a weight average molecular weight of 1000 to 500000.
[13] The photo-oriented copolymer according to [12], which has a weight average molecular weight of 30,000 to 200,000.

[14] A photo-alignment film formed by using the composition for a photo-alignment film containing the photo-orientation copolymer according to any one of [1] to [13].
[15] An optical laminate having the photoalignment film according to [14] and an optically anisotropic layer formed by using a liquid crystal composition containing a liquid crystal compound.

According to the present invention, a photo-alignment copolymer capable of producing a photo-alignment film having good orientation of a liquid crystal compound and excellent peelability of an optically anisotropic layer, and a photo-alignment copolymer using the same. The produced photo-alignment film and optical laminate can be provided.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be based on the representative embodiments of the present invention, but the present invention is not limited to such embodiments.
In the specification of the present application, the numerical range represented by using "~" means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.

[Photo-orientation copolymer]
The photo-oriented copolymer of the present invention has a repeating unit A containing a photo-oriented group represented by the following formula (A) and a repeating unit B containing a cross-linking group represented by the following formula (B). It is a photo-oriented copolymer having.
In the present invention, as described above, light having a repeating unit A including a photo-oriented group represented by the following formula (A) and a repeating unit B including a cross-linking group represented by the following formula (B). By using the oriented copolymer, when an optically anisotropic layer is formed on the obtained photoalignment film, the orientation of the liquid crystal compound becomes good, and the formed optically anisotropic layer is peelable. Will also be good.
This is not clear in detail, but the present inventors speculate as follows.
That is, it is considered that when the oxetanyl group is introduced as the crosslinkable group, the curing reaction at the time of forming the photoalignment film proceeds more efficiently and the crosslink density becomes higher than when the epoxy group is introduced. As a result, when the optically anisotropic layer is formed, it becomes difficult for the composition containing the liquid crystal compound or the like to permeate the surface of the photoalignment film, and it becomes difficult to form the interlayer mixed layer that affects the adhesion. It can be inferred that the peelability of the anisotropic layer has improved. Further, it is considered that the higher the crosslink density, the more efficiently the photoisomerized orienting groups are immobilized, and the higher the degree of orientation of the photoalignment film. It can be inferred that the degree of orientation of the photo-alignment film is increased, the surface regulatory force is increased, and the liquid crystal orientation is improved.

In the above formula (A), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁴ , R ⁵ and R ⁶ independently represent a hydrogen atom or a substituent, respectively. Of R ² , R ³ , R ⁴ , R ⁵ and R ⁶ , two adjacent groups may be bonded to form a ring.
In the above formula (B), R ⁷ represents a hydrogen atom or a methyl group, and R ⁸ represents a hydrogen atom, a methyl group or an ethyl group.

^{L 1} in the above formula (A) ^{and L 2} in the above formula (B) are linear, branched or cyclic with 1 to 10 carbon atoms which may independently have a substituent X, respectively. It has an alkylene group, an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group (−O−), a carbonyl group (−C (= O) −), and a substituent Z. Represents a divalent linking group that combines at least two or more groups selected from the group consisting of optional imino groups (-NH-).

Here, the substituent X is at least one substituent selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group, and the substituent Y is a halogen atom, an alkyl group, an aryl group and an alkoxy group. , At least one substituent selected from the group consisting of an aryloxy group, a cyano group, a carboxy group and an alkoxycarbonyl group, and the above-mentioned substituent Z is at least one selected from the group consisting of an alkyl group and an aryl group. It is a substituent of the species.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and among them, a fluorine atom and a chlorine atom are preferable.
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, a methyl group, an ethyl group, a propyl group or an isopropyl group) is preferable. , N-butyl group, isobutyl group, sec-butyl group, t-butyl group, cyclohexyl group, etc.) is more preferable, and an alkyl group having 1 to 4 carbon atoms is further preferable, and a methyl group or an ethyl group is used. Is particularly preferable.
As the alkoxy group, for example, an alkoxy group having 1 to 18 carbon atoms is preferable, an alkoxy group having 1 to 8 carbon atoms (for example, a methoxy group, an ethoxy group, an n-butoxy group, a methoxyethoxy group, etc.) is more preferable, and carbon. It is more preferably an alkoxy group having a number of 1 to 4, and particularly preferably a methoxy group or an ethoxy group.
Examples of the aryl group include an aryl group having 6 to 12 carbon atoms, and specific examples thereof include a phenyl group, an α-methylphenyl group, a naphthyl group and the like, and a phenyl group is preferable.
Examples of the aryloxy group include phenoxy, naphthoxy, imidazoleyloxy, benzoimidazoliyloxy, pyridin-4-yloxy, pyrimidinyloxy, quinazolinyloxy, prynyloxy, thiophene-3-yloxy and the like.
Examples of the alkoxycarbonyl group include methoxycarbonyl and ethoxycarbonyl.

Regarding the linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, the linear alkylene group specifically includes, for example, a methylene group, an ethylene group, a propylene group, a butylene group and a pentylene group. Examples include a hexylene group and a decylene group.
Specific examples of the branched alkylene group include a dimethylmethylene group, a methylethylene group, a 2,2-dimethylpropylene group and a 2-ethyl-2-methylpropylene group.
Specific examples of the cyclic alkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cyclooctylene group, a cyclodecylene group, an adamantane-diyl group, and a norbornane-diyl group. , Exo-tetrahydrodicyclopentadiene-diyl group and the like, and among them, the cyclohexylene group is preferable.

Specific examples of the arylene group having 6 to 12 carbon atoms include a phenylene group, a xylylene group, a biphenylene group, a naphthylene group, a 2,2'-methylenebisphenyl group and the like, and a phenylene group is preferable. ..

In the present invention, for the reason that the liquid crystal orientation becomes better, the linear alkylene group having 1 to 10 carbon atoms, wherein ^{L 1 of the above formula (A) may have the above substituent X,} 2 containing at least one of a cyclic alkylene group having 3 to 10 carbon atoms which may have the substituent X and an arylene group having 6 to 12 carbon atoms which may have the substituent Y. It is preferably a valent linking group, a linear alkylene group having 1 to 10 carbon atoms which may have the substituent X, or 3 carbon atoms which may have the substituent X. More preferably, it is a divalent linking group containing at least 10 cyclic alkylene groups, an unsubstituted linear alkylene group having 2 to 6 carbon atoms, or an unsubstituted trans-1,4-cyclohexyl. It is particularly preferable that it is a divalent linking group containing silene.

Next, the ^{substituents represented by R 2} , R ³ , R ⁴ , R ⁵ and R ^{6 in} the above formula (A) will be described, but R ² , R ³ , R ⁴ , R in the above formula (A) will be described. ^{As mentioned above, 5} and R ⁶ may be hydrogen atoms instead of substituents.

ここで、上記式（１）中、＊は、上記式（Ａ）中のベンゼン環との結合位置を表し、Ｒ^９は、１価の有機基を表す。The substituent represented by R ² , R ³ , R ⁴ , R ⁵ and R ⁶ in the above formula (A) is an oxetanyl group or an oxetanyl group from the viewpoint of distinguishing from the repeating unit B represented by the above formula (B). Substituents other than the containing substituents are preferable, and the photoorienting group easily interacts with the liquid crystal compound, and the liquid crystal orientation becomes better. Therefore, the halogen atom and the number of carbon atoms are 1 to 1 independently. 20 linear, branched or cyclic alkyl groups, linear halogenated alkyl groups with 1 to 20 carbon atoms, alkoxy groups with 1 to 20 carbon atoms, aryl groups with 6 to 20 carbon atoms, 6 carbon atoms. It is preferably an aryloxy group, a cyano group, an amino group of ~ 20, or a group represented by the following formula (1).

Here, in the above formula (1), * represents a bond position with the benzene ring in the above formula (A), and R ⁹ represents a monovalent organic group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and among them, a fluorine atom and a chlorine atom are preferable.

Regarding the linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, the linear alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, and specifically, for example, a methyl group or ethyl. Groups, n-propyl groups and the like can be mentioned.
As the branched alkyl group, an alkyl group having 3 to 6 carbon atoms is preferable, and specific examples thereof include an isopropyl group and a tert-butyl group.
The cyclic alkyl group is preferably an alkyl group having 3 to 6 carbon atoms, and specific examples thereof include a cyclopropyl group, a cyclopentyl group and a cyclohexyl group.

As the linear alkyl halide group having 1 to 20 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms is preferable, and specifically, for example, a trifluoromethyl group, a perfluoroethyl group and a perfluoropropyl group. , Perfluorobutyl group and the like, and among them, a trifluoromethyl group is preferable.

As the alkoxy group having 1 to 20 carbon atoms, an alkoxy group having 1 to 18 carbon atoms is preferable, an alkoxy group having 6 to 18 carbon atoms is more preferable, and an alkoxy group having 6 to 14 carbon atoms is further preferable. Specifically, for example, methoxy group, ethoxy group, n-butoxy group, methoxyethoxy group, n-hexyloxy group, n-octyloxy group, n-decyloxy group, n-dodecyloxy group, n-tetradecyloxy. Groups and the like are preferably mentioned, and among them, n-hexyloxy group, n-octyloxy group, n-decyloxy group, n-dodecyloxy group and n-tetradecyloxy group are more preferable.

As the aryl group having 6 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms is preferable, and specific examples thereof include a phenyl group, an α-methylphenyl group, a naphthyl group and the like, and among them, the phenyl group is used. preferable.

The aryloxy group having 6 to 20 carbon atoms is preferably an aryloxy group having 6 to 12 carbon atoms, and specific examples thereof include a phenyloxy group and a 2-naphthyloxy group. Among them, a phenyloxy group. Is preferable.

Examples of the amino group include a primary amino group (-NH ₂ ); a secondary amino group such as a methylamino group; a dimethylamino group, a diethylamino group, a dibenzylamino group, and a nitrogen-containing heterocyclic compound (for example, pyrrolidine). , Piperidine, piperazine, etc.), such as a tertiary amino group having a nitrogen atom as a bond.

Regarding the group represented by the above formula (1) ^{, examples of the monovalent organic group represented by R 9} in the above formula (1) include a linear or cyclic alkyl group having 1 to 20 carbon atoms. ..
The linear alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, and specific examples thereof include a methyl group, an ethyl group and an n-propyl group, and among them, a methyl group or an ethyl group is used. preferable.
As the cyclic alkyl group, an alkyl group having 3 to 6 carbon atoms is preferable, and specific examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group and the like, and among them, a cyclohexyl group is preferable.
^{The monovalent organic group represented by R 9} in the above formula (1) may be a combination of a plurality of the above-mentioned linear alkyl group and cyclic alkyl group directly or via a single bond. good.

^{In the present invention, R 2} , R ³ , R ⁴ , R 5 and ^{R 5 in} the above formula (A) are used because the photo-oriented group easily interacts with the liquid crystal compound and the liquid crystal orientation becomes better. Of R ⁶ , it is preferable that at least R ⁴ represents the above-mentioned substituent, and further, the linearity of the obtained photo-oriented copolymer is improved, and it becomes easy to interact with the liquid crystal compound, so that the liquid crystal orientation is formed. It is more preferable that R ² , R ³ , R ⁵ and R ⁶ all represent a hydrogen atom for the reason of better properties.

In the present invention, because the reaction upon light irradiation to obtain the optical alignment film efficiency is improved, it is preferable R ⁴ in the formula (A) is an electron donating substituent.
Here, the electron-donating substituent (electron-donating group) means a substituent having a Hammett value (Hammett substituent constant σp) of 0 or less, and for example, among the above-mentioned substituents, an alkyl group, Examples thereof include an alkyl halide group and an alkoxy group.
Of these, an alkoxy group is preferable, an alkoxy group having 4 to 18 carbon atoms is more preferable, and an alkoxy group having 6 to 14 carbon atoms is preferable because the orientation becomes better. Is more preferable.

Specific examples of the repeating unit A containing the photooriented group represented by the above formula (A) include the repeating units A-1 to A-116 shown below. In the following formula, Me represents a methyl group.

On the other hand, as the repeating unit B containing the photooriented group represented by the above formula (B), specifically, for example, the repeating units B-1 to B-14 shown below can be mentioned.

In the photooriented copolymer of the present invention, it is preferable that the content a of the repeating unit A described above and the content b of the repeating unit B described above satisfy the following formula (2) in terms of mass ratio. It is more preferable that the following formula (3) is satisfied, and it is further preferable that the following formula (4) is satisfied.
0.2 ≤ a / (a + b) ≤ 0.8 ... (2)
0.2 ≤ a / (a + b) ≤ 0.6 ... (3)
0.3 ≤ a / (a + b) <0.5 ... (4)

The photo-oriented copolymer of the present invention further has a repeating unit C containing a crosslinkable group represented by the following formula (C) and the following, for the reason of making the curing reaction at the time of producing the photo-aligned film more efficient. It is preferable to have at least one of the repeating unit D, which contains a crosslinkable group represented by the formula (D).

In the above formula (C), R ¹⁰ represents a hydrogen atom or a methyl group, and L ³ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X. , At least 2 selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group in which the groups of are combined.
In the above formula (D), R ¹¹ represents a hydrogen atom or a methyl group, and L ⁴ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X. , 1 or 2 selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. A divalent linking group in which the above groups are combined is represented, and Q represents any of -OH, -COOH, and -COOtBu. In addition, "tBu" is a notation indicating tert-butyl.
Here, for the substituent X, the substituent Y and the substituent Z, and the linear, branched or cyclic alkylene group having 1 to 10 carbon atoms, L ¹ in the above formula (A) and the above formula are used. it is similar to those described in (B) L ² in.

Specific examples of the repeating unit C containing the photooriented group represented by the above formula (C) include the repeating units C-1 to C-16 shown below.

Specific examples of the repeating unit D represented by the above formula (D) include the repeating units D-1 to D-12 shown below.

When the photoorientable copolymer of the present invention has the above-mentioned repeating unit C, the content a of the above-mentioned repeating unit A is increased for the reason of increasing the rate of the curing reaction and increasing the cross-linking density after the curing reaction. The content b of the repeating unit B described above and the content c of the repeating unit C described above preferably satisfy the following formula (5) in terms of mass ratio, and satisfy the following formula (6). Is more preferable.
0.1 ≤ c / (a + b + c) ≤ 0.4 ... (5)
0.2 ≤ c / (a + b + c) ≤ 0.3 ... (6)

When the photoorientable copolymer of the present invention has the above-mentioned repeating unit D, the content a of the above-mentioned repeating unit A is increased for the reason of increasing the rate of the curing reaction and increasing the cross-linking density after the curing reaction. The content b of the repeating unit B described above and the content d of the repeating unit D described above preferably satisfy the following formula (7) in terms of mass ratio, and satisfy the following formula (8). Is more preferable.
0.01 ≤ d / (a + b + d) ≤ 0.3 ... (7)
0.05 ≤ d / (a + b + d) ≤ 0.2 ... (8)

Further, the photoorientation copolymer of the present invention increases the strength of the optical laminate of the present invention described later, and any support is peeled off from the optical laminate of the present invention described later and transferred to another substrate. Further, it is preferable to have the repeating unit E represented by the following formula (E) for the reason that the handleability is good.

In the above formula (E), R ¹² represents a hydrogen atom or a methyl group, and L ⁵ is a linear, branched or cyclic alkylene group having 1 to 18 carbon atoms which may have a substituent X. , 1 or 2 selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. A divalent linking group in which the above groups are combined is represented, and S represents a functional group having an ethylenically unsaturated double bond.

Wherein the substituents X, the substituents Y and substituents Z, and, for such an arylene group having 6 to 12 carbon atoms, described in ^{L 2} in ^{L 1} and the formula in the formula (A) (B) It is the same as the one that was done.
The number 1 to 18 linear carbon atoms, the alkylene group branched or cyclic, specifically, for example, in L ² in L ¹ and the formula in the formula (A) (B) Description Examples thereof include undecylenic acid group, dodecylenic group, tridecylenic group, tetradecylenic group, pentadecylenic group, hexadecylenic group, heptadecylen group and octadecylene group.
Specific examples of the functional group having an ethylenically unsaturated double bond include a vinyl group, an allyl group, a styryl group, an acryloyl group, and a methacryloyl group, which may be an acryloyl group or a methacryloyl group. preferable.

Specific examples of the repeating unit E including the photooriented group represented by the above formula (E) include the repeating units E-1 to E-5 shown below.

The reason why the photo-alignment copolymer of the present invention can further increase the strength of the optically anisotropic layer including the photo-alignment film while maintaining good liquid crystal orientation and peelability when the above-mentioned repeating unit E is provided. Therefore, the content a of the repeating unit A described above, the content b of the repeating unit B described above, and the content e of the repeating unit E described above satisfy the following formula (9) in terms of mass ratio. It is preferable that the following formula (10) is satisfied.
0.005 ≤ f / (a + b + f) ≤ 0.2 ... (9)
0.01 ≤ f / (a + b + f) ≤ 0.1 ... (10)

The photoorientable copolymer of the present invention may be used in addition to the above-mentioned repeating unit A and repeating unit B, and any repeating unit C, repeating unit D and repeating unit E, as long as the effects of the present invention are not impaired. It may have a repeating unit.
Examples of the monomer (radical polymerizable monomer) forming such other repeating units include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic acid anhydrides, and styrene compounds. Examples include vinyl compounds.

The method for synthesizing the photoorientable copolymer of the present invention is not particularly limited, and for example, the above-mentioned monomer forming the repeating unit A, the above-mentioned monomer forming the repeating unit B, the above-mentioned repeating unit C, and any of the above-mentioned repeating units C. It can be synthesized by mixing monomers forming other repeating units and polymerizing them in an organic solvent using a radical polymerization initiator.

The weight average molecular weight (Mw) of the photooriented copolymer of the present invention is preferably 1000 to 500,000, and more preferably 30,000 to 200,000 for the reason that the orientation is improved.
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 conditions shown below.
-Solvent (eluent): THF (tetrahydrofuran)
-Device name: TOSOH HLC-8320GPC
-Column: Use by connecting three TOSOH TSKgel Super HZM-H (4.6 mm x 15 cm)-Column temperature: 40 ° C.
-Sample concentration: 0.1% by mass
-Flow velocity: 1.0 ml / min
-Calibration curve: TSK standard polystyrene made by TOSOH A calibration curve with 7 samples from Mw = 2800000 to 1050 (Mw / Mn = 1.03 to 1.06) is used.

[Photo-alignment film]
The photo-alignment film of the present invention is a composition for a photo-alignment film containing the above-mentioned photo-alignment copolymer of the present invention (hereinafter, formally referred to as "composition for a photo-alignment film of the present invention"). It is a photo-alignment film formed by using.
The film thickness of the photoalignment film is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 10 to 1000 nm, more preferably 10 to 700 nm.

The content of the photo-oriented copolymer of the present invention in the composition for a photo-alignment film of the present invention is not particularly limited, but when the organic solvent described later is contained, 0.1 to 50 parts by mass of the organic solvent is used. It is preferably parts by mass, more preferably 0.5 to 10 parts by mass.

The composition for a photoalignment film of the present invention preferably contains an organic solvent from the viewpoint of workability for producing the photoalignment film.
Specific examples of the organic solvent include ketones (eg, acetone, 2-butanone, methylisobutylketone, cyclohexanone, cyclopentanone, etc.), ethers (eg, dioxane, tetrahydrofuran, etc.), and aliphatic hydrocarbons. Classes (eg, hexane, etc.), alicyclic hydrocarbons (eg, cyclohexane, etc.), aromatic hydrocarbons (eg, toluene, xylene, trimethylbenzene, etc.), carbon halides (eg, dichloromethane, dichloroethane, di, etc.) Chlorobenzene, chlorotoluene, etc.), esters (eg, methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (eg, ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (eg, methylcellosolve, ethyl, etc.) Examples include cellosolves), cellosolve acetates, sulfoxides (eg, dimethylsulfoxide, etc.), amides (eg, dimethylformamide, dimethylacetamide, etc.), etc., and these may be used alone or in combination of two or more. It may be used together.

The composition for a photoalignment film of the present invention may contain components other than the above, and examples thereof include a cross-linking catalyst, an adhesion improver, a leveling agent, a surfactant, and a plasticizer.

[Manufacturing method of photoalignment film]
The photoalignment film of the present invention can be produced by a conventionally known production method other than using the above-mentioned composition for a photoalignment film of the present invention, and for example, the above-mentioned composition for a photoalignment film of the present invention is supported. It can be produced by a manufacturing method including a coating step of applying to the body surface and a light irradiation step of irradiating the coating film of the composition for a photoalignment film with polarized light or unpolarized light from an oblique direction to the surface of the coating film. can.
The support will be described later in the optical laminate of the present invention.

<Applying process>
The coating method in the coating step is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include spin coating, die coating, gravure coating, flexographic printing and inkjet printing.

<Light irradiation process>
In the light irradiation step, the polarized light applied to the coating film of the composition for a photoalignment film is not particularly limited, and examples thereof include linearly polarized light, circularly polarized light, and elliptically polarized light, and among them, linearly polarized light is preferable.
Further, the "diagonal direction" for irradiating non-polarized light is not particularly limited as long as it is tilted by a polar angle θ (0 <θ <90 °) with respect to the normal direction of the coating film surface, depending on the purpose. However, it is preferable that θ is 20 to 80 °.

The wavelength of polarized light or non-polarized light is not particularly limited as long as it can impart the ability to control the orientation of liquid crystal molecules to the coating film of the composition for a photoalignment film, and is, for example, ultraviolet rays, near ultraviolet rays, and visible light. And so on. Of these, near-ultraviolet rays of 250 nm to 450 nm are particularly preferable.
Examples of the light source for irradiating polarized or unpolarized light include a xenon lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, and a metal halide lamp. By using an interference filter, a color filter, or the like for ultraviolet rays and visible rays obtained from such a light source, the wavelength range to be irradiated can be limited. Further, linearly polarized light can be obtained by using a polarizing filter or a polarizing prism for the light from these light sources.

The amount of polarized or unpolarized integrated light is not particularly limited as long as the coating film of the composition for a photoalignment film can be imparted with an orientation control ability for liquid crystal molecules, and is not particularly limited, but is 1 to 300 mJ. / Cm ² is preferable, and 5 to 100 mJ / cm ² is more preferable.
The polarized or unpolarized illuminance is not particularly limited as long as it can impart the ability to control the orientation of liquid crystal molecules to the coating film of the composition for a photoalignment film, but is 0.1 to 300 mW / cm ^2. Preferably, 1 to 100 mW / cm ² is more preferable.

[Optical laminate]
The optical laminate of the present invention is an optical laminate having the above-mentioned optical alignment film of the present invention and an optically anisotropic layer formed by using a liquid crystal composition containing a liquid crystal compound.
Further, the optical laminate of the present invention preferably further has a support, and specifically, it is preferable to have the support, the photoalignment film, and the optically anisotropic layer in this order. ..

[Optically anisotropic layer]
The optically anisotropic layer of the optical laminate of the present invention is not particularly limited as long as it is an optically anisotropic layer containing a liquid crystal compound, and a conventionally known optically anisotropic layer may be appropriately adopted and used. can.
Such an optically anisotropic layer is a layer obtained by curing a composition containing a liquid crystal compound having a polymerizable group (hereinafter, also referred to as "composition for forming an optically anisotropic layer"). It may be a single-layer structure or a structure (laminated body) in which a plurality of layers are laminated.
Hereinafter, the liquid crystal compound and any additive contained in the composition for forming an optically anisotropic layer will be described.

<Liquid crystal compound>
The liquid crystal compound contained in the composition for forming an optically anisotropic layer is a liquid crystal compound having a polymerizable group.
Generally, liquid crystal compounds can be classified into rod-shaped type and disk-shaped type according to their shape. Furthermore, there are small molecule and high molecular types, respectively. A polymer generally refers to a molecule having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, p. 2, Iwanami Shoten, 1992).
In the present invention, any liquid crystal compound can be used, but it is preferable to use a rod-shaped liquid crystal compound or a discotic liquid crystal compound, and it is more preferable to use a rod-shaped liquid crystal compound.

In the present invention, a liquid crystal compound having a polymerizable group is used for immobilization of the above-mentioned liquid crystal compound, but it is more preferable that the liquid crystal compound has two or more polymerizable groups in one molecule. When the liquid crystal compound is a mixture of two or more kinds, it is preferable that at least one kind of liquid crystal compound has two or more polymerizable groups in one molecule. After the liquid crystal compound is fixed by polymerization, it is no longer necessary to exhibit liquid crystal property.

The type of the polymerizable group is not particularly limited, and a functional group capable of an addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring-polymerizable group is preferable. More specifically, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group and the like are preferably mentioned, and a (meth) acryloyl group is more preferable. The (meth) acryloyl group is a notation meaning a meta-acryloyl group or an acryloyl group.

As the rod-shaped liquid crystal compound, for example, those described in claim 1 of JP-A No. 11-513019 and paragraphs [0026] to [0098] of JP-A-2005-289980 can be preferably used, and disco As the tick liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 and paragraphs [0013]-[0108] of JP-A-2010-244033 are preferably used. However, it is not limited to these.

Further, in the present invention, as the liquid crystal compound, a liquid crystal compound having a reverse wavelength dispersibility can be used.
Here, the liquid crystal compound having "reverse wavelength dispersibility" in the present specification measures the in-plane retardation (Re) value at a specific wavelength (visible light range) of a retardation film produced by using the liquid crystal compound. When the measurement wavelength is increased, the Re value becomes equal or higher.
Further, the reverse wavelength dispersible liquid crystal compound is not particularly limited as long as it can form a reverse wavelength dispersible film as described above, and is, for example, the general formula (I) described in JP-A-2008-297210. ) (In particular, the compounds described in paragraph numbers [0034] to [0039]) and the compound represented by the general formula (1) described in JP-A-2010-084032 (particularly, paragraph number [3]. 0067] to [0073], compounds represented by the general formula (II) described in JP-A-2016-053709 (particularly, compounds described in paragraph numbers [0036] to [0043]). Further, a compound represented by the general formula (1) described in JP-A-2016-081035 (particularly, the compound described in paragraph numbers [0043] to [0055]) and the like can be used.

<Additives>
The composition for forming an optically anisotropic layer may contain a component other than the liquid crystal compound described above.
For example, the composition for forming an optically anisotropic layer may contain a polymerization initiator. The polymerization initiator used is selected according to the type of the polymerization reaction, and examples thereof include a thermal polymerization initiator and a photopolymerization initiator. For example, examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, and combinations of triarylimidazole dimers and p-aminophenyl ketones. Be done.
The amount of the polymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the total solid content of the composition.

Further, the composition for forming an optically anisotropic layer may contain a polymerizable monomer from the viewpoint of the uniformity of the coating film and the strength of the film.
Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. It is preferably a polyfunctional radically polymerizable monomer, which is copolymerizable with the above-mentioned liquid crystal compound containing a polymerizable group. For example, those described in paragraphs [0018] to [0020] in JP-A-2002-296423 can be mentioned.
The content of the polymerizable monomer is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, based on the total mass of the liquid crystal compound.

Further, the composition for forming an optically anisotropic layer may contain a surfactant from the viewpoint of the uniformity of the coating film and the strength of the film.
Examples of the surfactant include conventionally known compounds, but a fluorine-based compound is particularly preferable. Specific examples thereof include the compounds described in paragraphs [0028] to [0056] in JP 2001-330725 and the compounds described in paragraphs [0069] to [0126] in JP 2005-062673. Be done.

Further, the composition for forming an optically anisotropic layer may contain an organic solvent. Examples of the organic solvent include the same as those described in the above-mentioned composition for a photoalignment film of the present invention.

Further, the composition for forming an optically anisotropic layer includes a polarizing element interface side vertical alignment agent, a vertical alignment accelerator such as an air interface side vertical alignment agent, a polarizing element interface side horizontal alignment agent, and air. Various alignment agents such as a horizontal alignment accelerator such as an interface-side horizontal alignment agent may be contained.
Further, the composition for forming an optically anisotropic layer may contain an adhesion improver, a plasticizer, a polymer and the like in addition to the above components.

The method for forming the optically anisotropic layer using the composition for forming the optically anisotropic layer having such a component is not particularly limited, and for example, the optically anisotropic layer is formed on the above-mentioned photoaligned film of the present invention. It can be formed by applying a forming composition to form a coating film, and then subjecting the obtained coating film to a curing treatment (ultraviolet irradiation (light irradiation treatment) or heat treatment).
The composition for forming an optically anisotropic layer can be applied by a known method (for example, a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method).

In the present invention, the thickness of the optically anisotropic layer is not particularly limited, but is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.

[Support]
As described above, the optical laminate of the present invention may have a support as a base material for forming the optically anisotropic layer.
Examples of such a support include a polarizing element, a polymer film, and the like, and a combination thereof, for example, a laminate of a decoder and a polymer film, and a laminate of a polymer film, a polarizing element, and a polymer film. It may be a body or the like.
Further, the support may be a temporary support that can be peeled off after forming the optically anisotropic layer (hereinafter, may be simply referred to as “temporary support”). Specifically, a polymer film that functions as a temporary support may be peeled off from the optical laminate to provide an optically anisotropic layer. For example, an optical laminate including an optically anisotropic layer and a temporary support is prepared, and the optically anisotropic layer side of the optical laminate is bonded to a support containing a polarizing element with an adhesive or an adhesive. By peeling off the temporary support contained in the optically anisotropic layer, a laminated body of the support containing the polarizing element and the optically anisotropic layer may be provided.

<Polarizer>
In the present invention, when the optical laminate of the present invention is used in an image display device, it is preferable to use at least a polarizing element as a support.
The polarizing element 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 type polarizing elements and reflection type polarizing elements can be used.
As the absorption type polarizing element, an iodine-based polarizing element, a dye-based polarizing element using a dichroic dye, a polyene-based polarizing element, and the like are used. Iodine-based and dye-based polarizing elements include coated and stretched polarizing elements, both of which can be applied, but polarized light produced by adsorbing iodine or a dichroic dye on polyvinyl alcohol and stretching it. Children are preferred.
Further, as a method for obtaining a polarizing element by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, Japanese Patent No. 5048120, Japanese Patent No. 5143918, Japanese Patent No. 5048120, and Patent No. 5048120 are used. Japanese Patent No. 46910205, Japanese Patent No. 4751481, and Japanese Patent No. 4751486 can be mentioned, and known techniques relating to these substituents can also be preferably used.
As the reflective polarizing element, a polarizing element in which thin films having different birefringences are laminated, a wire grid type polarizing element, a carboxylator in which a cholesteric liquid crystal having a selective reflection region and a 1/4 wave plate are combined, and the like are used.
Among them, from the viewpoint of handleability, a _{polymer containing a polyvinyl alcohol-based resin (-CH 2-} CHOH- as a repeating unit is intended. In particular, at least selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers. It is preferable that the polarizing element contains (preferably one).

In an embodiment in which the optical laminate of the present invention includes a removable support, the polarizing plate can be manufactured, for example, as follows.
The support is peeled off from the above-mentioned optical laminate, and the layer containing the optically anisotropic layer is laminated on the support containing the polarizing element. Alternatively, the above-mentioned optical laminate is laminated on a support containing a polarizing element, and then the peelable support contained in the optical laminate is peeled off. At the time of laminating, both layers may be adhered with an adhesive or the like. The adhesive is not particularly limited, but is a curable adhesive of an epoxy compound that does not contain an aromatic ring in the molecule, as shown in JP-A-2004-245925, 360 to JP-A-2008-174667. An active energy ray-curable adhesive containing a photopolymerization initiator having a molar absorption coefficient of 400 or more at a wavelength of 450 nm and an ultraviolet curable compound as essential components, a (meth) acrylic compound described in JP-A-2008-174667. In 100 parts by mass of the total amount of (a), a (meth) acrylic compound having two or more (meth) acryloyl groups in the molecule, and (b) having a hydroxyl group in the molecule, and having only one polymerizable double bond. Examples thereof include an active energy ray-curable adhesive containing (c) a phenolethylene oxide-modified acrylate or a nonylphenolethylene oxide-modified acrylate.

The thickness of the polarizing element is not particularly limited, but is preferably 1 to 60 μm, more preferably 1 to 30 μm, and even more preferably 2 to 20 μm.

<Polymer film>
The polymer film is not particularly limited, and a commonly used polymer film (for example, a polarizing element protective film) can be used.
Specific examples of the polymer constituting the polymer film include a cellulose-based polymer; an acrylic polymer having an acrylic acid ester polymer such as polymethylmethacrylate and a lactone ring-containing polymer; a thermoplastic norbornene-based polymer; and a polycarbonate-based polymer. Polymers; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such as polystyrene and acrylonitrile / styrene copolymers (AS resin); polyolefin polymers such as polyethylene, polypropylene and ethylene / propylene copolymers; vinyl chloride Polymers; amide polymers such as nylon and aromatic polyamides; imide polymers; sulfone polymers; polyether sulfone polymers; polyether ether ketone polymers; polyphenylene sulfide polymers; vinylidene chloride polymers; vinyl alcohol polymers; Examples thereof include vinyl butyral polymers; allylate polymers; polyoxymethylene polymers; epoxy polymers; or polymers in which these polymers are mixed.

Of these, a cellulosic polymer represented by triacetyl cellulose (hereinafter, also referred to as "cellulose acylate") can be preferably used.
Further, from the viewpoint of processability and optical performance, it is also preferable to use an acrylic polymer.
Examples of the acrylic polymer include polymethylmethacrylate and the lactone ring-containing polymer described in paragraphs [0017] to [0107] of JP-A-2009-98605.

The thickness of the polymer film used for the polarizing element protective film or the like is not particularly limited, but is preferably 40 μm or less because the thickness of the optical laminate can be reduced. The lower limit is not particularly limited, but is usually 5 μm or more.

Further, in the present invention, the thickness of the support is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 50 μm, and even more preferably 5 to 20 μm. The thickness of the support means the total thickness of the polarizing element and the polymer film, if any of them is provided.

In the embodiment in which the polymer film is used as the support that can be peeled off from the optical laminate, a cellulosic polymer or a polyester polymer can be preferably used. The thickness of the polymer film is not particularly limited, but is preferably 5 μm to 100 μm, more preferably 20 μm to 90 μm, for reasons such as handling during production. The interface to be peeled off may be between the support and the photoalignment film, between the photoalignment film and the optically anisotropic layer, or may be another interface.

[Image display device]
Since the optical laminate of the present invention can be made thinner by peeling off the support, it can be suitably used when manufacturing an image display device.
The display element used in the image display device is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter abbreviated as “EL”) display panel, and a plasma display panel.
Of these, a liquid crystal cell and an organic EL display panel are preferable, and a liquid crystal cell is more preferable. That is, as the image display device, a liquid crystal display device using a liquid crystal cell as a display element and an organic EL display device using an organic EL display panel as a display element are preferable, and a liquid crystal display device is more preferable.

[Liquid crystal display device]
The liquid crystal display device, which is an example of the image display device, is a liquid crystal display device having the above-mentioned optical laminate of the present invention and a liquid crystal cell.
In the present invention, among the polarizing plates provided on both sides of the liquid crystal cell, it is preferable to use the optical laminate of the present invention as the polarizing plate on the front side.
The liquid crystal cells constituting the liquid crystal display device will be described in detail below.

<LCD cell>
The liquid crystal cell used in the liquid crystal display device is preferably a VA (Vertical Alignment) mode, an OCB (Optically Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode. Not limited to.
In the liquid crystal cell in the TN mode, the rod-shaped liquid crystal molecules (rod-shaped liquid crystal compounds) are substantially horizontally oriented when no voltage is applied, and are further twisted to 60 to 120 °. The TN mode liquid crystal cell is most often used as a color TFT liquid crystal display device, and has been described in many documents.
In the VA mode liquid crystal cell, the rod-shaped liquid crystal molecules are substantially vertically oriented when no voltage is applied. In the VA mode liquid crystal cell, (1) a VA mode liquid crystal cell in a narrow sense (1) in which rod-shaped liquid crystal molecules are oriented substantially vertically when no voltage is applied and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. 2-). In addition to (described in Japanese Patent Application Laid-Open No. 176625), (2) a liquid crystal cell (SID97, Digist of technique. Papers (Proceedings) in which the VA mode is multi-domainized (MVA (Multi-dominant Vertical Algorithm) mode) for expanding the viewing angle. 28 (1997) 845), (3) A mode (n-ASM mode (Axially symmetric aligned microcell)) in which a rod-shaped liquid crystal molecule is substantially vertically oriented when no voltage is applied and twisted and multi-domain oriented when a voltage is applied. Includes liquid crystal cells (described in the Proceedings 58-59 (1998) of the Japan Liquid Crystal Discussion Group) and (4) liquid crystal cells in SURVIVAL (Super Ranged Viewing by Vertical Organic) mode (announced at LCD (liquid crystal display) International 98). .. Further, it may be any of PVA (Patternized Vertical Alignment) type, optical alignment type (Optical Alignment), and PSA (Polymer-Stained Alignment). Details of these modes are described in Japanese Patent Application Laid-Open No. 2006-215326 and Japanese Patent Application Laid-Open No. 2008-538819.
In the IPS mode liquid crystal cell, the rod-shaped liquid crystal molecules are oriented substantially parallel to the substrate, and the liquid crystal molecules respond in a plane by applying an electric field parallel to the substrate surface. In the IPS mode, black is displayed when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are orthogonal to each other. Methods for reducing leakage light when displaying black in an oblique direction and improving the viewing angle by using an optical compensation sheet are described in JP-A-10-54982, JP-A-11-202323, and JP-A-9-292522. It is disclosed in JP-A-11-133408, JP-A-11-305217, JP-A-10-307291, and the like.

Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the examples shown below.

[Synthesis of monomer mA-1]
As the monomers forming the repeating unit A-1 described above, 2-hydroxyethyl methacrylate (HEMA) (Tokyo Chemical Reagent) and katsura according to the method described in Langmuir, 32 (36), 9245-9253, (2016). The following monomer mA-1 was synthesized using an acid chloride (Tokyo Kasei Reagent).

[Synthesis of monomer mA-2, etc.]
The following monomers mA-2, mA-4, mA-6, mA-8, mA- were used in the same manner as the monomer mA-1, except that the raw material cinnamic acid chloride was changed to the corresponding cinnamic acid chloride derivative. 24, mA-94, mA-95, mA-96, mA-97, mA-98, mA-99, mA-100, mA-114, and mA-115 were synthesized.
The following monomers mA-2 and the like correspond to the monomers forming the above-mentioned repeating unit A-2 and the like, respectively.

[Synthesis of Monomer mA-107]
<Synthesis of mA-107 intermediate>
14.0 g of 4-hydroxymethylcyclohexanol, 24.7 g of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide hydrochloride, triethylamine in a 300 mL three-necked flask equipped with a stirring blade, a thermometer, a dropping funnel and a reflux tube. 5.4 g, N, N-dimethyl-4-aminopyridine 6.57 g, and 140 mL of methylene chloride were added, and the mixture was stirred at room temperature (23 ° C.).
Then, at room temperature, 11.1 g of methacrylic acid was added dropwise over 30 minutes using a dropping funnel, and after completion of the dropping, the mixture was stirred at 50 ° C. for 5 hours.
The reaction solution was cooled to room temperature, washed separately with water, and the obtained organic layer was dried over anhydrous magnesium sulfate and concentrated to obtain a pale yellow liquid.
The obtained pale yellow liquid was purified by a silica gel column (developing solvent hexane / ethyl acetate = 2/1) to obtain 15.3 g of 4-methacryloxymethylcyclohexanol, which is the target mA-107 intermediate, as an amorphous solid. Obtained (yield 71%).

<Synthesis of monomer mA-107>
Monomer mA-1 except that the raw material 2-hydroxyethyl methacrylate (HEMA) was changed to the mA-107 intermediate (4-methacryloxymethylcyclohexanol) and the cinnamic acid chloride was changed to the corresponding cinnamic acid chloride derivative. The following monomer mA-107 was synthesized in the same manner as above. The following monomer mA-107 corresponds to the monomer forming the repeating unit A-107 described above.

[Synthesis of Monomer mA-116]
<Synthesis of mA-116 intermediate>
The mA-116 intermediate was synthesized in the same manner as the mA-107 intermediate except that the raw material 4-hydroxymethylcyclohexanol was changed to 1,4-cyclohexanediol.

<Synthesis of monomer mA-116>
Synthesized in the same manner as the monomer mA-107 except that the raw material 2-hydroxyethyl methacrylate (HEMA) was changed to an mA-116 intermediate and the lauric acid chloride was changed to the corresponding katsura acid chloride derivative, and the silica gel column was used. By purifying with (developing solvent hexane / ethyl acetate = 4/1), the following monomer mA-116 having a linking site (1,4-cyclohexyl group) of 100% trans was synthesized. The following monomer mA-116 corresponds to the monomer forming the trans form of the above-mentioned repeating unit A-116.

[Monomer MB-1]
OXE-10 (manufactured by Osaka Organic Chemical Co., Ltd.) was used as the following monomer mB-1 forming the repeating unit B-1 described above.

[Monomer MB-2]
OXE-30 (manufactured by Osaka Organic Chemical Co., Ltd.) was used as the following monomer mB-2 forming the repeating unit B-2 described above.

[Synthesis of monomer mb-3]
The following monomer mb-3 forming the above-mentioned repeating unit B-3 is an alcohol known from 3-ethyl-3-oxetanemethanol and 2-methacryloyloxyethyl isocyanate [Carens MOI (registered trademark), manufactured by Showa Denko KK). It was synthesized by a urethanization reaction using isocyanate.

[Synthesis of monomer mb-4]
The following monomers mb-4 forming the above-mentioned repeating unit B-4 are 3-ethyl-3-oxetanemethanol and 2- (2-isocyanatoethyloxy) ethyl methacrylate [Carens MOI-EG (registered trademark), Showa Denko. Was synthesized by a urethanization reaction using a known alcohol and isocyanate.

[Monomer mC-3]
Cyclomer M100 (manufactured by Daicel) was used as the following monomer mC-3 forming the repeating unit C-3 described above.

[Monomer hd-1 etc.]
The following monomer md-1 uses commercially available methacrylic acid (Wako Pure Chemical Industries, Ltd.), the following monomer md-3 uses commercially available 2-hydroxyethyl methacrylate (Tokyo Kasei reagent), and the following monomer md-4 uses commercially available 2-methacryloyl. Oxyethyl succinate (Shin-Nakamura Kagaku Kogyo) is used, the following monomer mD-5 uses commercially available -butyl methacrylate (Wako Pure Chemical Industries, Ltd.), and the following monomer mD-7 is commercially available 2-methacryloyloxyethyl phthalic acid (new). Nakamura Chemical Industries, Ltd.) was used, and commercially available 2-hydroxyethylmethacrylamide (Tokyo Kasei) was used as the following monomer mD-12.
The following monomers mD-1 and the like correspond to the monomers forming the above-mentioned repeating unit D-1 and the like, respectively.

[Monomer mE-1]
To a 2000 mL three-necked flask equipped with a stirring blade, a thermometer and a dropping funnel, 100 g of 2-hydroxyethyl methacrylate and 240 mL of DMAc were added and cooled in an ice bath. Then, 126.8 g of 3-chloropropionyl chloride was added dropwise, and the mixture was stirred under ice-cooling for 3 hours.
After cooling the reaction solution to room temperature, 1000 mL of ethyl acetate was separated and washed with standard hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution and water, and the obtained organic layer was dried with anhydrous magnesium sulfate and concentrated to obtain the desired monomer. 85 g of mE-1 was obtained as a pale yellow liquid (yield 88%). The following monomer mE-1 corresponds to a monomer forming a precursor of the above-mentioned repeating unit E-1 (that is, a unit before being changed to an acryloyl group by deprotection).

[Other monomers]
As the following monomer mF-1, those synthesized according to Synthesis Example 3 described in JP-A-2014-12823 were used.
Further, as the following monomer mF-2, a commercially available glycidyl methacrylate (Tokyo Kasei Reagent) was used.

Here, the above-mentioned monomers mF-1 and mF-2 correspond to the monomers forming the repeating units F-1 and F-2 shown below, respectively.

[Example 1]
A flask equipped with a cooling tube, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and nitrogen was refluxed by heating in a water bath while flowing nitrogen in the flask at 5 mL / min. Here, 3 parts by mass of monomer mA-1, 7 parts by mass of monomer mb-3, 1 part by mass of 2,2'-azobis (isobutyronitrile) as a polymerization initiator, and 5 parts by mass of 2-butanone as a solvent. The mixed solution 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 was poured into a large excess of methanol to precipitate the polymer, the recovered precipitate was filtered off, washed with a large amount of methanol, and then air-dried at 50 ° C. for 12 hours. A polymer P-1 having a photo-oriented group was obtained.

[Examples 2-28 and Comparative Examples 1-4]
As the monomers forming the repeating units shown in Table 1 below, each synthesized monomer was used, and the amount of the polymerization initiator added was changed so as to have the weight average molecular weight shown in Table 1 below, and the repeating units shown in Table 1 below were added. The polymer was synthesized by the same method as that of the polymer P-1 synthesized in Example 1 except that the compounding amount of the monomer was changed so as to have the content.
The ratio of the blending amounts (parts by mass) of each of the monomers forming the repeating units A, B and C in Example 25 is 0.5: 0.4: 0.1.

The weight average molecular weight of each of the synthesized polymers was measured by the method described above. The results are shown in Table 1 below.

[Preparation of composition for photoalignment film]
To 100 parts by mass of tetrahydrofuran, 1 part by mass of the polymer P-2 synthesized in Example 2 and 0.05 parts by mass of a thermal acid generator represented by the following structural formula were added to form a photoalignment film. The thing was prepared.
For each of the polymers synthesized in Examples 5, 7 to 9, 11, 14, 16, 20 to 28 and Comparative Examples 1 to 4 in the same manner, 1 part by mass of light was added to 100 parts by mass of tetrahydrofuran. A composition for an alignment film was prepared.

[Manufacturing of optical laminate]
The optical laminates of Examples 2, 5, 7 to 9, 11, 14, 16, 20 to 28 and Comparative Examples 1 to 4 were prepared by the following procedure.
As the cellulose acylate film, the same film as in Comparative Example 1 of JP-A-2014-164169 was used.
The composition for each photoalignment film prepared above was applied to one surface of this film with a bar coater. After coating, it was dried on a hot plate at 80 ° C. for 5 minutes to remove the solvent, and a photoisomerized composition layer having a thickness of 0.2 μm was formed. The obtained photoisomerization composition layer was irradiated with polarized ultraviolet rays (10 mJ / cm ² , using an ultrahigh pressure mercury lamp) to form a photoalignment film.
Next, a nematic liquid crystal compound (ZLI-4792, manufactured by Merck Group) was applied onto the photoalignment film with a bar coater to form a composition layer. The formed composition layer was once heated to 90 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation.
After that, the temperature was kept at 60 ° C., ^{and the orientation was fixed by ultraviolet irradiation (500 mJ / cm 2} , using an ultrahigh pressure mercury lamp) under a nitrogen atmosphere (oxygen concentration 100 ppm) to form an optically anisotropic layer with a thickness of 2.0 μm. , An optical laminate was produced.

[Example 29]
An optical laminate was produced by the same method as in Example 16 except that the coating liquid for an optically anisotropic layer (liquid crystal 101) shown below was used instead of the nematic liquid crystal compound coated on the photoalignment film. did. This optical laminate is referred to as the optical laminate of Example 29.

────────────────────────────────
Coating liquid for optically anisotropic layer (liquid crystal 101)
────────────────────────────────
-The following liquid crystal compound L-1 80.00 parts by mass-The following liquid crystal compound L-2 20.00 parts by mass-Polymerization initiator (IRGACURE 184, manufactured by BASF)
3.00 parts by mass, polymerization initiator (IRGACURE OXE-01, manufactured by BASF)
3.00 parts by mass, leveling agent (compound G-1 below) 0.20 parts by mass, methyl ethyl ketone 424.8 parts by mass ――――――――――――――――――――――― ――――――――――

[Example 30]
An optical laminate was produced by the same method as in Example 16 except that the coating liquid for an optically anisotropic layer (liquid crystal 102) shown below was used instead of the nematic liquid crystal compound coated on the photoalignment film. did. This optical laminate is referred to as the optical laminate of Example 30.

―――――――――――――――――――――――――――――――――
Coating liquid for optically anisotropic layer (liquid crystal 102)
―――――――――――――――――――――――――――――――――
-The following liquid crystal compound L-3 42.00 parts by mass-The following liquid crystal compound L-4 42.00 parts by mass-The following polymerizable compound A-1 16.00 parts by mass-The following polymerization initiator S-1 (oxym type) ) 0.50 parts by mass, leveling agent (Compound G-1 above) 0.20 parts by mass, High Solve MTEM (manufactured by Toho Chemical Industry Co., Ltd.) 2.00 parts by mass, NK ester A-200 (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) 1.00 parts by mass, methyl ethyl ketone 424.8 parts by mass ――――――――――――――――――――――――――――――――――
The group adjacent to the acryloyloxy group of the following liquid crystal compounds L-3 and L-4 represents a propylene group (a group in which a methyl group is replaced with an ethylene group), and the following liquid crystal compounds L-3 and L-4 are represented. Represents a mixture of positional isomers with different positions of methyl groups.

[Liquid crystal orientation]
The prepared optical laminate was observed using a polarizing microscope with a deviation of 2 degrees from the quenching position. As a result, it was evaluated according to the following criteria. The results are shown in Table 2 below.
AAA: The liquid crystal director is uniformly aligned and oriented, and the surface shape and display performance are extremely excellent. AA: The liquid crystal director is uniformly aligned and oriented, and the display performance is excellent. A: The liquid crystal director is not disturbed and the surface shape is stable. B: The liquid crystal director is slightly disturbed and the surface is stable. C: The liquid crystal director is partially disturbed and the surface is stable. D: The liquid crystal director is significantly disturbed and the surface is stable. The shape is not stable and the display performance is very poor. In the present specification, the stable planar shape means unevenness or orientation when an optical laminate is placed between two polarizing plates arranged with cross Nicols and observed. It is intended that there are no defects such as defects.
Further, in the present specification, the liquid crystal director is intended to be a vector in the direction (orientation main axis) in which the long axis of the liquid crystal molecule is oriented.

[Removability]
Only the 50 mm × 25 mm portion was bonded to the glass substrate of the produced 80 mm × 25 mm optical laminate. At this time, an adhesive (SK Dyne 2057, manufactured by Soken Chemical Co., Ltd.) was used to bond the optical laminate to the surface on the optically anisotropic layer side.
Next, the peeling force when the optical laminate was peeled from the fixed glass substrate in the 90 ° direction was measured with a Tensilon universal material tester (manufactured by Orientech) and evaluated according to the following criteria. The results are shown in Table 2 below.
A: Peeling force is 0.01 or more and less than 0.10 N / 25 mm B: Peeling force is 0.11 or more and less than 0.20 N / 25 mm C: Peeling force is 0.21 or more and less than 0.50 N / 25 mm D: Cannot be peeled

From the results shown in Table 2, it was found that the photoalignment film using the polymer containing no crosslinkable group and having no repeating unit was inferior in both liquid crystal orientation and peelability (Comparative Example 1).
Further, even if it has a repeating unit containing a crosslinkable group, a photoalignment film using a copolymer having a repeating unit containing a crosslinkable group that does not correspond to the above formula (B) is inferior in peelability. Was found (Comparative Examples 2 and 3).
Further, a photo-alignment film using a copolymer having a repeating unit containing a photo-oriented group not corresponding to the above formula (A) and a repeating unit B containing a cross-linking group represented by the above-mentioned formula (B) can be used. , It was found that the liquid crystal orientation was inferior (Comparative Example 4).

On the other hand, photo-orientation using a copolymer having a repeating unit A containing a photo-oriented group represented by the above formula (A) and a repeating unit B containing a cross-linking group represented by the above-mentioned formula (B). It was found that all the films had good liquid crystal orientation and peelability (Examples 2, 5, 7 to 9, 11, 14, 16, 20 to 30).
In particular, from comparison of Examples 11, 14, 16 and 26 to 28, ^{R 4} in the formula (A) is, when the carbon number is 6 to 14 alkoxy groups, and the liquid crystal orientation becomes better Do you get it.

[Example 31]
Each of the synthesized monomers was used as the monomer forming the repeating unit shown in Table 3 below, and was synthesized in Example 1 except that the compounding amount of the monomer was changed so as to have the content of the repeating unit shown in Table 3 below. The polymer P-29 was synthesized by the same method as that of the polymer P-1. The weight average molecular weight of the synthesized polymer P-29 was 36000.

[Examples 32 to 36]
Each of the synthesized monomers was used as the monomer forming the repeating unit shown in Table 3 below, and was synthesized in Example 31 except that the compounding amount of the monomer was changed so as to have the content of the repeating unit shown in Table 3 below. Polymers P-30 to P-34 were synthesized in the same manner as the polymer P-29.

[Preparation of composition for photoalignment film]
The compositions for each photoalignment film were prepared in the same manner as in Example 2 except that the polymers P-29 to P-34 were used instead of the polymer P-2.

[Manufacturing of optical laminate]
The optical laminates of Examples 31 to 36 and Example 7 were produced by the following procedure.
As the cellulose acylate film, the same film as in Comparative Example 1 of JP-A-2014-164169 was used.
The composition for each photoalignment film prepared above was applied to one surface of this film with a bar coater. After coating, it was dried on a hot plate at 80 ° C. for 5 minutes to remove the solvent, and a photoisomerized composition layer having a thickness of 0.2 μm was formed. The obtained photoisomerization composition layer was irradiated with polarized ultraviolet rays (10 mJ / cm ² , using an ultrahigh pressure mercury lamp) to form a photoalignment film.
Next, a nematic liquid crystal compound (ZLI-4792, manufactured by Merck Group) was applied onto the photoalignment film with a bar coater to form a composition layer. The formed composition layer was once heated to 90 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation.
After that, the temperature was kept at 60 ° C., ^{and the orientation was fixed by ultraviolet irradiation (5 mJ / cm 2} , using an ultrahigh pressure mercury lamp) under a nitrogen atmosphere (oxygen concentration 100 ppm) to form an optically anisotropic layer with a thickness of 2.0 μm. , An optical laminate was produced.

The prepared optical laminate was observed using a polarizing microscope with a deviation of 2 degrees from the quenching position. As a result, it was evaluated according to the following criteria. The results are shown in Table 3 below.
AAA: The liquid crystal director is uniformly aligned and oriented, and the surface shape and display performance are extremely excellent. AA: The liquid crystal director is uniformly aligned and oriented, and the display performance is excellent. A: The liquid crystal director is not disturbed and the surface shape is stable. B: The liquid crystal director is slightly disturbed and the surface is stable. C: The liquid crystal director is partially disturbed and the surface is stable. D: The liquid crystal director is significantly disturbed and the surface is stable. The condition is not stable and the display performance is very poor.

As shown in Table 3, from the comparison results between Examples 31 to 36 and Example 7, the photoalignment film using the copolymer having the repeating unit D represented by the above formula (D) is irradiated with polarized ultraviolet rays. It was found that the liquid crystal orientation was good even when the amount was reduced.

[Example 37]
In a 100 mL three-necked flask equipped with a cooling tube, a thermometer, and a stirrer, 5 parts by mass of 2-butanone was charged as a solvent, and nitrogen was refluxed by heating in a water bath while flowing nitrogen in the flask at 5 mL / min. Here, 4.17 parts by mass of monomer mA-98, 5.47 parts by mass of monomer mA2, 0.36 parts by mass of monomer mE-1, and 2,2'-azobis (isobutyro) as a polymerization initiator. A solution obtained by mixing 1 part by mass of (nitrile) and 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 polymerization reaction, 10 mg of dibutylhydroxytoluene (BHT) was added to the reaction solution to bring the temperature to 60 ° C., then 0.49 g of triethylamine was added and the mixture was stirred at 60 ° C. for 5 hours. After completion of the dehydrochlorination 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 was poured into a large excess of methanol to precipitate the polymer, the recovered precipitate was filtered off, washed with a large amount of methanol, and then air-dried at 50 ° C. for 12 hours. A polymer P-35 having a photo-oriented group was obtained. ^{1 The} composition ratio (weight ratio) calculated by 1 H-NMR was 42/55/3.

[Example 38]
In a 100 mL three-necked flask equipped with a cooling tube, a thermometer, and a stirrer, 5 parts by mass of 2-butanone was charged as a solvent, and nitrogen was refluxed by heating in a water bath while flowing nitrogen in the flask at 5 mL / min. Here, the monomer mA-98 is 3.81 part by mass, the monomer mb-2 is 5.41 part by mass, the 2-hydroxyethyl methacrylate is 0.48 part by mass, and the polymerization initiator is 2,2'-azobis (isobuchi). A solution prepared by mixing 1 part by mass of (lonitrile) and 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 polymerization reaction, 10 mg of BHT was added to the reaction solution to bring the temperature to 70 ° C., then 0.43 g of 2-isocyanatoethyl methacrylate and 44 mg of Neostan U-830 were added, and the mixture was stirred at 70 ° C. for 6 hours. The reaction of the hydroxyl group derived from 2-hydroxyethyl methacrylate and 2-isocyanatoethyl methacrylate repeatedly formed the unit E-2, and the reaction rate was ^{calculated by 1} H-NMR. After the addition reaction of isocyanate was completed, 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 was poured into a large excess of methanol to precipitate the polymer, the recovered precipitate was filtered off, washed with a large amount of methanol, and then air-dried at 50 ° C. for 12 hours. A polymer P-36 having a photo-oriented group was obtained. ^{1 The} composition ratio (weight ratio) calculated by 1 H-NMR was 40/53/7.

[Evaluation of liquid crystal orientation and peelability]
<Preparation of composition for photoalignment film>
The composition for each photoalignment film was prepared by the same method as in Example 2 except that the polymer P-35 to P-36 was used instead of the polymer P-2.
<Manufacturing of optical laminate>
As the cellulose acylate film, the same film as in Comparative Example 1 of JP-A-2014-164169 was used.
The composition for each photoalignment film prepared above was applied to one surface of this film with a bar coater. After coating, it was dried on a hot plate at 80 ° C. for 5 minutes to remove the solvent, and a photoisomerized composition layer having a thickness of 0.2 μm was formed. The obtained photoisomerization composition layer was irradiated with polarized ultraviolet rays (10 mJ / cm ² , using an ultrahigh pressure mercury lamp) to form a photoalignment film.
Next, the same coating liquid for an optically anisotropic layer (liquid crystal 101) as in Example 29 was applied onto the photoalignment film with a bar coater to form a composition layer. The formed composition layer was once heated to 90 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation.
After that, the temperature was kept at 60 ° C., ^{and the orientation was fixed by ultraviolet irradiation (500 mJ / cm 2} , using an ultrahigh pressure mercury lamp) under a nitrogen atmosphere (oxygen concentration 100 ppm) to form an optically anisotropic layer with a thickness of 2.0 μm. , An optical laminate was produced.
The prepared 80 mm × 25 mm optical laminate was evaluated for liquid crystal orientation and peelability by the same method as in Example 2. The results are shown in Table 4 below.

[Evaluation of strength]
Only the 50 mm × 25 mm portion was bonded to the glass substrate of the produced 80 mm × 25 mm optical laminate. At this time, an adhesive (SK Dyne 2057, manufactured by Soken Chemical Co., Ltd.) was used to bond the optical laminate to the surface on the optically anisotropic layer side.
Next, the bonded optical laminate was pulled in the 90 ° direction with respect to the fixed glass substrate, and the cellulose acylate film in the optical laminate was peeled off.
Next, the surface from which the cellulose acylate film was peeled off was bonded to another cellulose cellulose acylate film (hereinafter, abbreviated as "TAC" in this paragraph) using an adhesive (Soken Chemical Co., Ltd., SK Dyne 2057). did. As the TAC, the same one as in Comparative Example 1 of JP-A-2014-164169 was used.
In this way, an evaluation laminate having a TAC, a pressure-sensitive adhesive, a photoalignment film, an optically anisotropic layer, a pressure-sensitive adhesive, and a glass substrate was produced in this order.
For the prepared laminate for evaluation, a TAC was grasped using a Tensilon universal material tester (manufactured by Orientec), and a force was applied to the fixed glass substrate in the 90 ° direction.
At that time, the presence or absence of liberation of the components of the optically anisotropic layer and the photoalignment film in the pressure-sensitive adhesive (layer) adjacent to TAC was measured with Nicolet 6700 (manufactured by Thermo Fisher Scientific Co., Ltd.), and the following was measured. The strength was evaluated according to the criteria of. The results are shown in Table 4 below. Here, after the peeling test, the state in which the components of the photoalignment film or the optically anisotropic layer are attached to the pressure-sensitive adhesive (layer) adjacent to the TAC is regarded as “free”.
A: The component of the optically anisotropic layer or the photoalignment film is not released even with a force of 5N / 25mm B: The component of the optically anisotropic layer or the photoalignment film is released with a force of 0.5N or more and less than 5N / 25mm C : The components of the optically anisotropic layer or the photoalignment film are released with a force of less than 0.5 N / 25 mm.

As shown in Table 4, from the results of Examples 37 and 38, the photoalignment film using the copolymer having the repeating unit E represented by the above formula (E) has good liquid crystal orientation and peelability. It turned out. Further, from the comparison result with Example 24, it was found that the strength of the optical laminate was also improved.

Claims (11)

Has a repeating unit A containing photoalignable group represented by the following formula (A), a repeating unit B containing a crosslinking group represented by the following formula (B), an optical alignment copolymer ,
A photooriented copolymer in which the content a of the repeating unit A and the content b of the repeating unit B satisfy the following formula (2) in terms of mass ratio.
0.2 ≤ a / (a + b) ≤ 0.8 ... (2)

In the formula (A), R ¹ represents a hydrogen atom or a methyl group, and R ² , R ³ , R ⁵ and R ⁶ independently represent a hydrogen atom or a substituent. R ⁴ has a carbon number of an alkoxy group of 4 to 18. Of R ² , R ³ , R ⁵ and R ⁶ , two adjacent groups may be bonded to form a ring.
In the formula (B), R ⁷ represents a hydrogen atom or a methyl group, and R ⁸ represents a hydrogen atom, a methyl group or an ethyl group.
^{L 1 of the} formula (A) ^{and L 2} of the formula (B) are linear, branched or cyclic alkylenes having 1 to 10 carbon atoms which may independently have a substituent X, respectively. At least 2 selected from the group consisting of a group, an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group that combines the above groups.
However, the substituent X is at least one substituent selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group, and the substituent Y is a halogen atom, an alkyl group, an aryl group, an alkoxy group and the like. It is at least one substituent selected from the group consisting of an aryloxy group, a cyano group, a carboxy group and an alkoxycarbonyl group, and the substituent Z is at least one selected from the group consisting of an alkyl group and an aryl group. It is a substituent of. ^{L 1 of the} formula (A) may have at least a linear alkylene group having 1 to 10 carbon atoms which may have a substituent X and 3 to 10 carbon atoms which may have a substituent X. The photooriented co-weight according to claim 1, which is a divalent linking group containing any of a cyclic alkylene group and an arylene group having 6 to 12 carbon atoms which may have a substituent Y. Combined. ^{L 1 of the} formula (A) may have at least a linear alkylene group having 1 to 10 carbon atoms which may have a substituent X, or 3 carbon atoms which may have a substituent X. The photooriented copolymer according to claim 2, which is a divalent linking group containing 10 to 10 cyclic alkylene groups. The photooriented copolymer according to claim 1 ^{, wherein R 2} , R ³ , R ⁵ and R ^{6 of the} formula (A) all represent hydrogen atoms. ^{The substituents represented by R 2} , R ³ , R ⁵ and R ^{6 of the} above formula (A) are independently halogen atoms, linear, branched or cyclic alkyl groups having 1 to 20 carbon atoms, and carbon atoms. A linear alkyl halide group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a cyano group, an amino group, or the following. The photoalignable copolymer according to any one of claims 1 to 3 , which is a group represented by the formula (1).

In the formula (1), * represents the bond position with the benzene ring in the formula (A), and R ⁹ represents a monovalent organic group. Wherein the content a of the repeating units A, and the content b of the repeating unit B is, satisfies the following formula (3) at a mass ratio, photoorientable copolymer of claim 1.
0.2 ≤ a / (a + b) ≤ 0.6 ... (3) Further, a repeating unit C containing a crosslinkable group represented by the following formula (C), a repeating unit D containing a crosslinkable group represented by the following formula (D), and a crosslink represented by the following formula (E). The photooriented copolymer according to any one of claims 1 to 6 , which has at least one repeating unit selected from the group consisting of the repeating unit E containing a sex group.

In the formula (C), R ¹⁰ represents a hydrogen atom or a methyl group, and L ³ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X. , At least 2 selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. Represents a divalent linking group in which the groups of are combined.
In the formula (D), R ¹¹ represents a hydrogen atom or a methyl group, and L ⁴ is a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X. , 1 or 2 selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. A divalent linking group in which the above groups are combined is represented, and Q represents any of -OH, -COOH, and -COOtBu.
In the formula (E), R ¹² represents a hydrogen atom or a methyl group, and L ⁵ is a linear, branched or cyclic alkylene group having 1 to 18 carbon atoms which may have a substituent X. , 1 or 2 selected from the group consisting of an arylene group having 6 to 12 carbon atoms which may have a substituent Y, an ether group, a carbonyl group, and an imino group which may have a substituent Z. A divalent linking group in which the above groups are combined is represented, and S represents a functional group having an ethylenically unsaturated double bond.
However, the substituent X is at least one substituent selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group, and the substituent Y is a halogen atom, an alkyl group, an aryl group, an alkoxy group and the like. It is at least one substituent selected from the group consisting of an aryloxy group, a cyano group, a carboxy group and an alkoxycarbonyl group, and the substituent Z is at least one selected from the group consisting of an alkyl group and an aryl group. It is a substituent of. The photooriented copolymer according to any one of claims 1 to 7 , wherein the weight average molecular weight is 1000 to 500000. The photooriented copolymer according to claim 8 , which has a weight average molecular weight of 30,000 to 200,000. A photo-alignment film formed by using the composition for a photo-alignment film containing the photo-orientation copolymer according to any one of claims 1 to 9. An optical laminate comprising the photoalignment film according to claim 10 and an optically anisotropic layer formed by using a liquid crystal composition containing a liquid crystal compound.