JP7295259B2 - Photo-alignable polymer, photo-alignment film and optical laminate - Google Patents

Description

The present invention relates to a photo-alignable polymer, a photo-alignment film and an optical laminate.

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

For such an optically anisotropic layer, it is known to provide an alignment film on the support forming the optically anisotropic layer in order to orient the liquid crystalline compound. A photo-alignment film is known which is subjected to a photo-alignment treatment instead of the treatment.

For example, in Patent Documents 1 and 2, a repeating unit A containing a predetermined photo-alignment group and a repeating unit B containing a predetermined cross-linkable group are used for a photo-alignment film containing a photo-alignment copolymer. A photo-alignment film formed using the composition is described.

WO2018/173727 WO2019/117082

The present inventors examined the photo-alignment films described in Patent Documents 1 and 2, and found that the alignment of the liquid crystalline compound (hereinafter also abbreviated as "liquid crystal alignment") is excellent. It has been clarified that there is room for improvement in the adhesion to the optically anisotropic layer (hereinafter also simply referred to as "adhesion").

Therefore, the present invention provides a photo-alignment polymer capable of producing a photo-alignment film excellent in both liquid crystal alignment and adhesion, and a photo-alignment film and an optical laminate produced using the same. The challenge is to

As a result of intensive studies to achieve the above object, the present inventors have found that a photo-alignment film obtained by using a photo-alignment polymer having 3 to 20 polymer chains having a repeating unit containing a photo-alignment group. The inventors have found that both liquid crystal orientation and adhesion are good, and completed the present invention.
That is, the inventors have found that the above object can be achieved by the following configuration.

ここで、上記式（１）中、
ｍは、３～２０の整数を表す。
Ｘは、ｍ価の連結基を表す。
Ｐは、光配向性基を含む繰り返し単位を有するポリマー鎖を表し、ｍ個のＰは、同一であっても、異なっていてもよい。[1] A photo-alignable polymer represented by the following formula (1).

Here, in the above formula (1),
m represents an integer from 3 to 20;
X represents an m-valent linking group.
P represents a polymer chain having a repeating unit containing a photo-orientation group, and m P's may be the same or different.

ここで、上記式（２）中、
ｍは、３～２０の整数を表す。
Ｚは、置換基を有していてもよい炭素数１～６の直鎖状、炭素数３～６の分岐状もしくは環状のｍ価の脂肪族炭化水素基、置換基を有していてもよい炭素数６～１４のｍ価の芳香族炭化水素基、置換基を有していてもよい炭素数３～１４のｍ価の芳香族複素環基、これらの組み合わせ、および、これらが炭素原子、酸素原子もしくは窒素原子を介して２個以上連結したｍ価の基、からなる群から選択されるｍ価の有機基を表す。ただし、脂肪族炭化水素基が環状である場合、環を構成する－ＣＨ_２－の１個以上が、－Ｏ－、－ＣＯ－、もしくは、－ＮＲ^１０－で置換されていてもよく、Ｒ^１０は、水素原子または炭素数１～６のアルキル基を表す。
Ｙは、単結合、あるいは、置換基を有していてもよい炭素数１～２０の直鎖状もしくは炭素数３～２０の分岐状のアルキレン基、－Ｏ－、－ＣＯ－、－ＮＲ^１０－、または、これらの２つ以上の組み合わせからなる２価の連結基を表し、Ｒ^１０は、水素原子または炭素数１～６のアルキル基を表す。ｍ個のＹは、同一であっても、異なっていてもよい。
Ｓは、硫黄原子を表す。
Ｐは、光配向性基を含む繰り返し単位を有するポリマー鎖を表し、ｍ個のＰは、同一であっても、異なっていてもよい。[2] The photo-alignable polymer according to [1], represented by the following formula (2).

Here, in the above formula (2),
m represents an integer from 3 to 20;
Z is a linear, branched or cyclic m-valent aliphatic hydrocarbon group having 1 to 6 carbon atoms and having 3 to 6 carbon atoms, which may have a substituent; an m-valent aromatic hydrocarbon group having 6 to 14 carbon atoms, an optionally substituted m-valent aromatic heterocyclic group having 3 to 14 carbon atoms, a combination thereof, and a carbon atom represents an m-valent organic group selected from the group consisting of two or more m-valent groups linked via an oxygen atom or a nitrogen atom. However, when the aliphatic hydrocarbon group is cyclic, one or more —CH ₂ — constituting the ring may be substituted with —O—, —CO—, or —NR ¹⁰ —; ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y is a single bond, or an optionally substituted linear or branched alkylene group having 1 to 20 carbon atoms or 3 to 20 carbon atoms, —O—, —CO—, —NR ¹⁰ -, or a divalent linking group consisting of a combination of two or more thereof, and R ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The m Y's may be the same or different.
S represents a sulfur atom.
P represents a polymer chain having a repeating unit containing a photo-orientation group, and m P's may be the same or different.

ここで、上記式（Ｚ－１）～（Ｚ－１５）中、
＊は、上記式（２）中のＹとの結合位置を表す。
Ｒは、水素原子または置換基を表す。
Ｌは、置換基を有していてもよい炭素数１～６のアルキレン基を表す。
Ｄは、－Ｏ－、－ＣＯ－、－ＮＲ^１０－、または、これらの２つ以上の組み合わせからなる２価の連結基を表し、Ｒ^１０は、水素原子または炭素数１～６のアルキル基を表す。[3] The photo-alignable polymer according to [2], wherein Z in formula (2) above represents an organic group represented by any one of formulas (Z-1) to (Z-15) below.

Here, in the above formulas (Z-1) to (Z-15),
* represents the bonding position with Y in the above formula (2).
R represents a hydrogen atom or a substituent.
L represents an optionally substituted alkylene group having 1 to 6 carbon atoms.
D represents —O—, —CO—, —NR ¹⁰ —, or a divalent linking group consisting of a combination of two or more thereof, and R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms represents

[4] Z in the above formula (2) is an optionally substituted linear, branched or cyclic m-valent aliphatic hydrocarbon having 1 to 6 carbon atoms and having 3 to 6 carbon atoms. represents the group,
Y in the above formula (2) is an optionally substituted alkylene group having 1 to 8 carbon atoms, -O-, -CO-, or a divalent divalent consisting of a combination of two or more thereof The photo-alignable polymer according to [2] or [3], which represents a linking group.
[5] The photo-alignable polymer according to [1] or [2], wherein m in formula (1) or (2) represents an integer of 3 to 10.
[6] The photo-alignable polymer according to any one of [1] to [5], wherein the polymer chain further has a repeating unit containing a crosslinkable group.
[7] A photo-alignment film formed using a composition for photo-alignment film containing the photo-alignment polymer according to any one of [1] to [6].
[8] An optical laminate comprising the photo-alignment film of [7] and an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystalline compound.

According to the present invention, the present invention provides a photo-alignment polymer capable of producing a photo-alignment film excellent in both liquid crystal alignment and adhesion, and a photo-alignment film and an optical laminate produced using the same body can be provided.

The present invention will be described in detail below.
The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.
In the specification of the present application, a numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits.
In addition, in the present specification, each component may be a substance corresponding to each component either singly or in combination of two or more. Here, when two or more substances are used in combination for each component, the content of the component refers to the total content of the substances used in combination unless otherwise specified.

[Photo-alignable polymer]
The photo-alignable polymer of the present invention is a photo-alignable polymer represented by the following formula (1).

In the above formula (1), m represents an integer of 3-20.
In the above formula (1), X represents an m-valent linking group.
Moreover, in the above formula (1), P represents a polymer chain having a repeating unit containing a photo-orientation group, and m P's may be the same or different.

In the present invention, by using the photo-alignment polymer represented by the above formula (1), the resulting photo-alignment film has good liquid crystal alignment and adhesion.
Although this is not clear in detail, the present inventor presumes as follows.
That is, the photo-alignable polymer represented by the above formula (1) has 3 to 20 polymer chains having a repeating unit containing a photo-alignable group, which is described in Patent Documents 1 and 2. It is considered that the number of photo-alignable groups per unit mass of the polymer is increased compared with the photo-alignable polymer obtained in the above, and the liquid crystal alignment is improved.
In addition, by having 3 to 20 polymer chains, the number of polymer chain ends with high mobility increases compared to the photo-alignable copolymers described in Patent Documents 1 and 2. It is thought that the adhesion was improved because the interfacial mixing between the liquid crystal layer and the photo-alignment film layer was promoted.

The photo-alignable polymer of the present invention is a photo-alignable polymer represented by the following formula (2), i.e., X in the above formula (1) is the following formula A photoalignable polymer represented by ZYS in (2) is preferable.

In the above formula (2), m represents an integer of 3-20.
Further, in the above formula (2), Z is a linear, branched or cyclic m-valent aliphatic hydrocarbon group having 1 to 6 carbon atoms and having 3 to 6 carbon atoms, which may have a substituent. , an optionally substituted m-valent aromatic hydrocarbon group having 6 to 14 carbon atoms, an optionally substituted m-valent aromatic heterocyclic group having 3 to 14 carbon atoms, these and m-valent organic groups in which two or more of these are linked via a carbon atom, an oxygen atom or a nitrogen atom. However, when the aliphatic hydrocarbon group is cyclic, one or more —CH ₂ — constituting the ring may be substituted with —O—, —CO—, or —NR ¹⁰ —; ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Further, in the above formula (2), Y is a single bond, or an optionally substituted linear or branched alkylene group having 1 to 20 carbon atoms or 3 to 20 carbon atoms, —O -, -CO-, -NR ¹⁰ -, or a divalent linking group consisting of a combination of two or more thereof, where R ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The m Y's may be the same or different.
Moreover, in said formula (2), S represents a sulfur atom.
In formula (2) above, P represents a polymer chain having a repeating unit containing a photo-orientation group, and m P's may be the same or different.

Next, m in the above formula (2) will be explained.

m in the above formulas (1) and (2) represents an integer of 3 to 20, but is preferably an integer of 3 to 10 because the resulting photo-alignment film has better adhesion. , more preferably an integer of 3 to 8, more preferably an integer of 3 to 6, and particularly preferably 3 or 4.

Next, Z in the above formula (2) will be explained.

Regarding Z in the above formula (2), the substituent (hereinafter also abbreviated as "substituent T") which may have an aliphatic hydrocarbon group or the like includes, for example, a halogen atom, an alkyl group, an alkoxy group , an aryl group, an aryloxy group, a cyano group, a carboxy group, an alkoxycarbonyl group and a hydroxyl group.
The halogen atom includes, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Among them, a fluorine atom and a chlorine atom are preferable.
The alkyl group is preferably, for example, a linear alkyl group having 1 to 18 carbon atoms, a branched or cyclic alkyl group having 3 to 18 carbon atoms, a linear alkyl group having 1 to 8 carbon atoms, or a branched alkyl group having 3 to 8 carbon atoms. More preferably, a linear or cyclic alkyl group (e.g., methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, and cyclohexyl group), and the number of carbon atoms A 1 to 4 linear alkyl group is more preferred, and a methyl group or an ethyl group is particularly preferred.
As the alkoxy group, for example, an alkoxy group having 1 to 18 carbon atoms is preferable, and an alkoxy group having 1 to 8 carbon atoms (eg, methoxy group, ethoxy group, n-butoxy group, methoxyethoxy group, etc.) is more preferable. An alkoxy group of number 1 to 4 is more preferred, and a methoxy group or an ethoxy group is particularly preferred.
The aryl group includes, for example, an aryl group having 6 to 12 carbon atoms, and specific examples thereof include a phenyl group, an α-methylphenyl group, a naphthyl group, etc. Among them, a phenyl group is preferred.
Aryloxy groups include, for example, phenoxy, naphthoxy, imidazoyloxy, benzimidazolyloxy, pyridin-4-yloxy, pyrimidinyloxy, quinazolinyloxy, purinyloxy, thiophen-3-yloxy and the like.
Alkoxycarbonyl groups include, for example, methoxycarbonyl, ethoxycarbonyl and the like.

In addition, the linear aliphatic hydrocarbon group having 1 to 6 carbon atoms, the branched or cyclic aliphatic hydrocarbon group having 3 to 6 carbon atoms, which is represented by one aspect of Z in the above formula (2), includes, for example, 1 carbon atom Examples include a group obtained by removing m arbitrary hydrogen atoms bonded to a carbon atom from a linear, branched or cyclic alkane having 3 to 6 carbon atoms and having 1 to 6 carbon atoms.
Specific examples of linear alkanes include methane, ethane, propane, and butane.
Specific examples of branched alkanes include 2-methylpropane, 2,2-dimethylpropane, and 2,2-dimethylbutane.
Specific examples of cyclic alkanes include cyclopropane, cyclobutane, and cyclohexane.

Further, the aromatic hydrocarbon group having 6 to 14 carbon atoms represented by one aspect of Z in the above formula (2) includes, for example, any is removed from m hydrogen atoms.
Specific examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, and phenanthroline rings.

In addition, the m-valent aromatic heterocyclic group having 3 to 14 carbon atoms represented by one aspect of Z in the above formula (2) may be, for example, an aromatic heterocyclic ring having 3 to 14 carbon atoms that is bound to a carbon atom. and a group in which m arbitrary hydrogen atoms are removed.
Specific examples of aromatic heterocyclic rings include furan rings, pyrrole rings, thiophene rings, pyridine rings, thiazole rings, and benzothiazole rings.

In the present invention, Z in the above formula (2) is an organic group represented by any one of the following formulas (Z-1) to (Z-15) for reasons of raw material availability and easy production. Preferably.

In the above formulas (Z-1) to (Z-15), * represents the bonding position with Y in the above formula (2).
Moreover, R represents a hydrogen atom or a substituent. In addition, the thing similar to the substituent T mentioned above is mentioned as a substituent.
L represents an optionally substituted alkylene group having 1 to 6 carbon atoms. In addition, the thing similar to the substituent T mentioned above is mentioned as a substituent. Further, specific examples of the alkylene group having 1 to 6 carbon atoms include methylene group, ethylene group, propylene group, butylene group, etc. Among them, methylene group or ethylene group is preferable.
D represents —O—, —CO—, —NR ¹⁰ —, or a divalent linking group consisting of a combination of two or more thereof, and R ¹⁰ is a hydrogen atom or a C 1-6 represents an alkyl group. Specific examples of the alkyl group having 1 to 6 carbon atoms represented by one embodiment of R ¹⁰ include, for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, and the like.

In the present invention, since the adhesion of the resulting photo-alignment film is better, Z in the above formula (2) is a linear chain having 1 to 6 carbon atoms which may have a substituent, It preferably represents a branched or cyclic m-valent aliphatic hydrocarbon group having 3 to 6 carbon atoms.
Here, the linear, branched or cyclic m-valent aliphatic hydrocarbon group having 1 to 6 carbon atoms, branched or cyclic aliphatic hydrocarbon group having 3 to 6 carbon atoms includes, for example, linear, branched or cyclic alkane to carbon atom A group in which m arbitrary hydrogen atoms bonded to are removed.
Specific examples of linear alkanes include methane, ethane, propane, and butane.
Specific examples of branched alkanes include 2-methylpropane, 2,2-dimethylpropane, and 2,2-dimethylbutane.
Specific examples of cyclic alkanes include cyclopropane, cyclobutane, and cyclohexane.
Moreover, as a substituent, the thing similar to the substituent T mentioned above is mentioned.

Next, Y in the above formula (2) will be explained.

Regarding the optionally substituted linear or branched C 1-20 alkylene group having 3-20 carbon atoms represented by one embodiment of Y in the above formula (2), linear Specific examples of the alkylene group include methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, and hexadecylene group. , a heptadecylene group, an octadecylene group, and the like.
Specific examples of the branched alkylene group include dimethylmethylene group, methylethylene group, 2,2-dimethylpropylene group and 2-ethyl-2-methylpropylene group.
Moreover, as a substituent, the thing similar to the substituent T mentioned above is mentioned.

In addition, with respect to —NR ¹⁰ — represented by one embodiment of Y in the above formula (2), R ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and the alkyl group having 1 to 6 carbon atoms is Specific examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group and the like.

In the present invention, since the adhesion of the resulting photo-alignment film is better, Y in the above formula (2) is an alkylene group having 1 to 8 carbon atoms which may have a substituent, - O-, -CO-, or preferably represents a divalent linking group consisting of a combination of two or more thereof, optionally substituted alkylene group having 1 to 8 carbon atoms, -O- and -CO- more preferably represents a divalent linking group in which both are combined, *1-O-CO-L-*2, or *1-CO-OL-*2. More preferred. Note that *1 represents the bonding position with Z in the above formula (2), L represents an alkylene group having 1 to 6 carbon atoms which may have a substituent, *2 represents the above formula It represents the bonding position with S (sulfur atom) in (2).
Examples of the alkylene group having 1 to 8 carbon atoms include methylene group, ethylene group, propylene group, butylene group, pentylene group and hexylene group.
Moreover, as a substituent, the thing similar to the substituent T mentioned above is mentioned.

Next, P in the above formula (2) will be explained.

P in the above formula (2) represents a polymer chain having a repeating unit containing a photo-orientation group.
Here, as the photo-alignment group, at least one of dimerization and isomerization occurs due to the action of light because the thermal stability and chemical stability of the monomer having the photo-alignment group are improved. It is preferably a group.
Specific examples of groups that dimerize by the action of light include, for example, cinnamic acid derivatives (M. Schadt et al., J. Appl. Phys., vol. 31, No. 7, page 2155 (1992)). , coumarin derivatives (M. Schadt et al., Nature., vol. 381, page 212 (1996)), chalcone derivatives (Toshihiro Ogawa et al., Liquid Crystal Conference Lecture Proceedings, 2AB03 (1997)), maleimide derivatives, and Preferable examples include groups having a skeleton of at least one derivative selected from the group consisting of benzophenone derivatives (YK Jang et al., SID Int. Symposium Digest, P-53 (1997)).
On the other hand, specific examples of groups that are isomerized by the action of light include azobenzene compounds (K. Ichimura et al., Mol. Cryst. Liq. Cryst., 298, 221 (1997)), stilbene compounds (JG Victor and JM Torkelson, Macromolecules, 20, 2241 (1987)), spiropyran compounds (K. Ichimura et al., Chemistry Letters, page 1063 (1992); K. Ichimura et al., Thin Solid Films, vol. 235, page 101 (1993) )), cinnamic acid compounds (K. Ichimura et al., Macromolecules, 30, 903 (1997)), and hydrazono-β-ketoester compounds (S. Yamamura et al., Liquid Crystals, vol. 13, No. 2, page 189 (1993)), preferably a group having a skeleton of at least one compound selected from the group consisting of:

Among such photoalignable groups, at least one derivative or compound skeleton selected from the group consisting of cinnamic acid derivatives, coumarin derivatives, chalcone derivatives, maleimide derivatives, azobenzene compounds, stilbene compounds and spiropyran compounds. Among them, the group having a cinnamic acid derivative or an azobenzene compound skeleton is more preferable for the reason that the resulting photo-alignment film has better liquid crystal alignment, and has a cinnamic acid derivative skeleton. A group (hereinafter also abbreviated as "cinnamoyl group") is more preferred.

As a repeating unit containing a photoalignable group, which the polymer chain represented by P in the above formula (2) has, for example, a repeating unit represented by the following formula (A) (hereinafter also abbreviated as "repeating unit A"). ).

In formula (A) above, R ¹ represents a hydrogen atom or a substituent, L ¹ represents a divalent linking group, and A represents a photo-orientation group represented by formula (a1) described later. .

Next, the hydrogen atom or substituent represented by R ¹ in the above formula (A) will be described.
In the above formula (A), examples of substituents represented by one embodiment of R ¹ include a halogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, and 1 to 20 linear halogenated alkyl group, 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 or amino group preferable.

The halogen atom includes, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Among them, a fluorine atom and a chlorine atom are preferable.

Regarding linear alkyl groups having 1 to 20 carbon atoms, branched or cyclic alkyl groups having 3 to 20 carbon atoms, the linear alkyl group is preferably an alkyl group having 1 to 6 carbon atoms. Examples include methyl group, ethyl group, n-propyl group and the like.
The branched alkyl group is preferably an alkyl group having 3 to 6 carbon atoms, and specific examples thereof include isopropyl group and tert-butyl group.
The cyclic alkyl group is preferably an alkyl group having 3 to 6 carbon atoms, and specific examples thereof include cyclopropyl, cyclopentyl and cyclohexyl groups.

The linear halogenated alkyl group having 1 to 20 carbon atoms is preferably a fluoroalkyl group having 1 to 4 carbon atoms, and specific examples thereof include trifluoromethyl group, perfluoroethyl group and perfluoropropyl group. , a perfluorobutyl group, etc. Among them, a trifluoromethyl group is preferable.

The alkoxy group having 1 to 20 carbon atoms is preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 6 to 18 carbon atoms, and still more preferably an alkoxy group having 6 to 14 carbon atoms. 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 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.

The aryl group having 6 to 20 carbon atoms is preferably 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. 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, a 2-naphthyloxy group, etc. Among them, a phenyloxy group. is preferred.

The amino group includes, for example, primary amino group (—NH ₂ ); secondary amino group such as methylamino group; dimethylamino group, diethylamino group, dibenzylamino group, nitrogen-containing heterocyclic compound (e.g., pyrrolidine , piperidine, piperazine, etc.);

Next, the divalent linking group represented by L ¹ in the above formula (A) will be described.
As the divalent linking group, the number of carbon atoms that may have a substituent is increased for the reason that the photo-alignment group easily interacts with the liquid crystalline compound and the liquid crystal alignment of the adjacent liquid crystal layer becomes more favorable. 1 to 18 linear, branched or cyclic C3 to C18 alkylene groups, optionally substituted C6 to C12 arylene groups, ether groups (—O—), carbonyl groups (-C(=O)-) and an imino group optionally having a substituent (-NH-) is a divalent linking group combining at least two groups selected from the group consisting of is preferred.

Here, examples of the substituent that the alkylene group, the arylene group and the imino group may have include those similar to the substituent T described above.

Regarding the linear alkylene group having 1 to 18 carbon atoms, branched or cyclic alkylene group having 3 to 18 carbon atoms, specific examples of the linear alkylene group include methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and the like.
Specific examples of the branched alkylene group include dimethylmethylene group, methylethylene group, 2,2-dimethylpropylene group and 2-ethyl-2-methylpropylene group.
Specific examples of the cyclic alkylene group include, for example, 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, etc. Among them, cyclohexylene group is preferred.

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, etc. Among them, a phenylene group is preferred. .

In the present invention, L ¹ in the above formula (A) may represent a divalent linking group containing a nitrogen atom and a cycloalkane ring for the reason that the resulting photo-alignment film has good solvent resistance. preferable.
In this preferred embodiment, some of the carbon atoms constituting the cycloalkane ring may be substituted with heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur. In addition, when some of the carbon atoms constituting the cycloalkane ring are substituted with nitrogen atoms, the cycloalkane ring does not have to have a nitrogen atom.
Here, the cycloalkane ring is preferably a cycloalkane ring having 6 or more carbon atoms, and specific examples thereof include cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclododecane ring, cyclodocosane ring and the like.

上記式（３）～（１２）中、＊１は、上記式（Ａ）中のＲ^１と結合している炭素原子との結合位置を表し、＊２は、上記式（Ａ）中のＡとの結合位置を表す。Further, in the present invention, L ¹ in the above formula (A) is represented by any one of the following formulas (3) to (12) for the reason that the resulting photo-alignment film has better liquid crystal orientation. is preferably a divalent linking group.

In the above formulas (3) to (12), *1 represents the bonding position with the carbon atom bonded to R ¹ in the above formula (A), *2 is A in the above formula (A) represents the binding position with

Among the divalent linking groups represented by any of the above formulas (3) to (12), the solubility in the solvent used for forming the photo-alignment film and the solvent resistance of the resulting photo-alignment film A divalent linking group represented by any one of the above formulas (4), (5), (9) and (10) is preferred for the reason of good balance.

Next, the photo-orientation group represented by the following formula (a1) represented by A in the above formula (A) will be described.

In the above formula (a1), one of the two * represents a bonding position with L ¹ , the other represents R ⁶ , and R ² to R ⁵ and R ⁶ are each independently a hydrogen atom or a substituted represents a group, and two adjacent groups may combine to form a ring.

In the present invention, the photo-alignment group represented by the above formula (a1) is preferably a photo-alignment group represented by the following formula (a2).

In the above formula (a2), * represents the bonding position with L ¹ , R ² to R ⁶ each independently represent a hydrogen atom or a substituent, and two adjacent groups combine to form a ring. You may have

ここで、上記式（ａ３）中、＊は、上記式（ａ２）中のベンゼン環との結合位置を表し、Ｒ^７は、１価の有機基を表す。Here, the substituents represented by one aspect of R ² to R ⁶ are each independent because the photo-alignment group is likely to interact with the liquid crystalline compound and the liquid crystal alignment of the adjacent liquid crystal layer is improved. , a halogen atom, a straight chain having 1 to 20 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, a straight halogenated alkyl group having 1 to 20 carbon atoms, a An alkoxy group, 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 a group represented by the following formula (a3) is preferable.
Specific examples of substituents other than the group represented by the following formula (a3) include the same substituents as described for the one aspect of R ¹ in the above formula (A).

Here, in the above formula (a3), * represents the bonding position with the benzene ring in the above formula (a2), and ^R7 represents a monovalent organic group.

Examples of the monovalent organic group represented by R ⁷ in the above formula (a3) include linear or cyclic alkyl groups having 1 to 20 carbon atoms.
As the straight-chain alkyl group, an alkyl group having 1 to 6 carbon atoms is preferable, and specific examples thereof include methyl group, ethyl group, n-propyl group, etc. Among them, methyl group or ethyl group is preferred. preferable.
As the cyclic alkyl group, an alkyl group having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopropyl, cyclopentyl, cyclohexyl, etc. Among them, cyclohexyl is preferable.
The monovalent organic group represented by R ⁷ in the above formula (a3) may be a combination of a plurality of the linear alkyl groups and cyclic alkyl groups described above directly or via a single bond. good.

In the present invention, ^the photo-alignment group is likely to interact with the liquid crystalline compound, and the liquid crystal alignment ^of the adjacent liquid crystal layer is more favorable. , At least one of R ² to R ⁶ in the above formula (a2) (especially R ⁶ ) is preferably the substituent described above, and the linearity of the resulting photo-alignable polymer is improved, An electron-donating substituent is more preferable because it improves the reaction efficiency when irradiated with polarized light.
Here, the electron-donating substituent (electron-donating group) refers to a substituent having a Hammett value (Hammett substituent constant σp) of 0 or less. Examples include halogenated alkyl groups and alkoxy groups.
Among these, an alkoxy group is preferable, and an alkoxy group having 6 to 16 carbon atoms is more preferable because the liquid crystal orientation of the adjacent liquid crystal layer is further improved, and an alkoxy group having 7 to 10 carbon atoms is more preferable. An alkoxy group is more preferred.

Specific examples of the repeating unit A represented by the above formula (A) include repeating units A-1 to A-160 shown below. In addition, Me represents a methyl group in the following formula.

In the present invention, the polymer chain represented by P in the above formula (2) further has a repeating unit containing a crosslinkable group for the reason that the adhesion of the resulting photo-alignment film is further improved. is preferred.

Examples of repeating units having a crosslinkable group include repeating units represented by the following formula (B) (hereinafter also abbreviated as “repeating unit B”).

In formula (B) above, R ⁸ represents a hydrogen atom or a substituent. Examples of the substituent represented by one aspect of R ⁸ include the same substituents as those described for the one aspect of R ¹ in the formula (A).
Moreover, ^L2 represents a divalent linking group. The divalent linking group represented by L ² includes the same divalent linking groups as described for the divalent linking group represented by L ¹ in the formula (mA).
Further, B represents any crosslinkable group represented by the following formulas (PG-1) to (PG-9).

In the above formulas (PG-1) to (PG-9), * represents the bonding position with ^L2 .
^R9 represents a hydrogen atom, a halogen atom, a methyl group, an ethyl group, or a trifluoromethyl group. However, a plurality of R ⁹ in the above formulas (PG-2), (PG-5), (PG-6) and (PG-9) may be the same or different.

Specific examples of the repeating unit represented by formula (B) include repeating units B-1 to B-52 shown below.

In the photo-alignable polymer of the present invention, the content a of the repeating unit A described above and the content b of the repeating unit B described above preferably satisfy the following formula (13) in mass ratio. More preferably, it satisfies formula (14).
0.03≦a/(a+b)≦0.5 (13)
0.05≦a/(a+b)≦0.4 (14)

The photo-alignable polymer of the present invention may have other repeating units in addition to the above repeating unit A and repeating unit B as long as the effect of the present invention is not impaired.
Examples of monomers (radical polymerizable monomers) that form such other repeating units include acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, A vinyl compound etc. are mentioned.

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

The weight-average molecular weight (Mw) of the photo-alignable polymer of the present invention is preferably 10,000 to 500,000, more preferably 30,000 to 300,000, because the resulting photo-alignment film has improved liquid crystal alignment.
Here, the weight average molecular weight and number average molecular weight in the present invention are values measured by a gel permeation chromatography (GPC) method under the conditions shown below.
- Solvent (eluent): THF (tetrahydrofuran)
・Device name: TOSOH HLC-8320GPC
・ Column: TOSOH TSKgel Super HZM-H (4.6 mm × 15 cm
) are used by connecting three columns ・Column temperature: 40°C
・Sample concentration: 0.1% by mass
・Flow rate: 1.0 ml/min
・ Calibration curve: TOSOH TSK standard polystyrene Mw = 2800000 to 1050 (Mw / Mn = 1.03 to 1.06) using a calibration curve from 7 samples

[Photo-alignment film]
The photo-alignment film of the present invention uses a composition for a photo-alignment film containing the above-described photo-alignment polymer of the present invention (hereinafter also referred to formally as the “composition for a photo-alignment film of the present invention”). It is a photo-alignment film formed by a method and has the ability to control the alignment of liquid crystalline molecules.
The film thickness of the photo-alignment film is not particularly limited and can be appropriately selected depending on the intended purpose.

The content of the photo-alignable polymer of the present invention in the composition for photo-alignment film of the present invention is not particularly limited. parts, more preferably 0.5 to 10 parts by mass.

The composition for a photo-alignment film of the present invention preferably contains a solvent from the viewpoint of workability for producing a photo-alignment film.
Specific examples of solvents include ketones (eg, acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, etc.), ethers (eg, dioxane, tetrahydrofuran, etc.), and aliphatic hydrocarbons. (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., toluene, xylene, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, dichloroethane, dichlorobenzene) , chlorotoluene, etc.), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve etc.), cellosolve acetates, sulfoxides (e.g., dimethylsulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, etc.), etc., and these may be used singly or in combination of two or more. You may

The composition for photo-alignment film of the present invention may contain components other than those mentioned above, such as crosslinking catalysts, adhesion improvers, leveling agents, surfactants and plasticizers.

[Method for producing photo-alignment film]
The photo-alignment film of the present invention can be produced by a conventionally known production method except for using the composition for photo-alignment film of the present invention described above. It can be produced by a manufacturing method having a coating step of applying to the body surface and a light irradiation step of irradiating the coating film of the composition for photo-alignment film with polarized light or non-polarized light from an oblique direction to the coating film surface. can.
The support will be described later in the optical layered body of the present invention.

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

<Light irradiation process>
In the light irradiation step, the polarized light with which the coating film of the composition for photo-alignment film is irradiated is not particularly limited, and examples thereof include linearly polarized light, circularly polarized light, and elliptically polarized light.
In addition, the "oblique direction" in which non-polarized light is irradiated is not particularly limited as long as it is a direction inclined at a polar angle θ (0<θ<90°) with respect to the normal direction of the coating film surface, depending on the purpose. θ is preferably 20 to 80°.

The wavelength of polarized light or non-polarized light is not particularly limited as long as the coating film of the composition for photo-alignment film can be provided with the ability to control the alignment of liquid crystalline molecules. etc. Among them, near ultraviolet rays of 250 nm to 450 nm are particularly preferable.
Examples of light sources for polarized or non-polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultrahigh-pressure mercury lamps, and metal halide lamps. By using an interference filter, a color filter, or the like, it is possible to limit the wavelength range of the ultraviolet light or visible light obtained from such a light source. Also, by using a polarizing filter or a polarizing prism for the light from these light sources, linearly polarized light can be obtained.

The integrated amount of polarized or unpolarized light is not particularly limited as long as the coating film of the composition for photo-alignment film can be provided with the ability to control the alignment of liquid crystalline molecules, and is not particularly limited, but is 1 to 300 mJ. /cm ² is preferred, and 5 to 100 mJ/cm ² is more preferred.
The illuminance of polarized or non-polarized light is ^not particularly limited as long as the coating film of the composition for photo-alignment film can be provided with the ability to control the alignment of liquid crystalline molecules. Preferably, 1 to 100 mW/cm ² is more preferable.

[Optical laminate]
The optical layered body of the present invention is an optical layered body having the above-described photo-alignment film of the present invention and an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystalline compound.
Further, the optical layered body of the present invention preferably further comprises a support. Specifically, it preferably comprises a support, a photo-alignment film and an 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 contains a liquid crystalline compound, and conventionally known optically anisotropic layers can be used as appropriate. can.
Such an optically anisotropic layer is a layer obtained by curing a composition containing a liquid crystalline compound having a polymerizable group (hereinafter also referred to as "composition for forming an optically anisotropic layer"). is preferable, and it may have a single-layer structure or a structure in which a plurality of layers are laminated (laminate).
The liquid crystalline compound and optional additives contained in the composition for forming an optically anisotropic layer are described below.

<Liquid crystal compound>
The liquid crystalline compound contained in the composition for forming an optically anisotropic layer is a liquid crystalline compound having a polymerizable group.
In general, liquid crystalline compounds can be classified into a rod-like type and a disk-like type according to their shape. Furthermore, there are low-molecular-weight and high-molecular-weight types, respectively. Polymers generally refer to those having a degree of polymerization of 100 or more (Polymer Physics: Phase Transition Dynamics, Masao Doi, p. 2, Iwanami Shoten, 1992).
Although any liquid crystalline compound can be used in the present invention, a rod-like liquid crystalline compound or a discotic liquid crystalline compound is preferably used, and a rod-like liquid crystalline compound is more preferably used.

In the present invention, a liquid crystalline compound having a polymerizable group is used for immobilizing the liquid crystalline compound described above, and it is more preferable that the liquid crystalline compound has two or more polymerizable groups in one molecule. In the case of a mixture of two or more liquid crystal compounds, at least one liquid crystal compound preferably has two or more polymerizable groups in one molecule. After the liquid crystalline compound is fixed by polymerization, it is no longer necessary to exhibit liquid crystallinity.

Moreover, the type of the polymerizable group is not particularly limited, and a functional group capable of 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 preferred, and a (meth)acryloyl group is more preferred. The (meth)acryloyl group is a notation meaning a methacryloyl group or an acryloyl group.

As the rod-shaped liquid crystalline compound, for example, those described in claim 1 of JP-A-11-513019 and paragraphs [0026] to [0098] of JP-A-2005-289980 can be preferably used. As the tick liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 and paragraphs [0013] to [0108] of JP-A-2010-244038 are preferably used. can be, but are not limited to:

Further, in the present invention, a reverse wavelength dispersion liquid crystalline compound can be used as the liquid crystalline compound.
Here, in the present specification, the liquid crystalline compound of "reverse wavelength dispersion" means the in-plane retardation (Re) value at a specific wavelength (visible light range) of the retardation film produced using this. When measured, the Re value becomes equal or higher as the measurement wavelength increases.
Further, the reverse wavelength dispersion liquid crystal compound is not particularly limited as long as it can form a reverse wavelength dispersion film as described above, for example, the general formula (1 ) Compounds represented by (especially the compounds described in paragraphs [0067] to [0073]), compounds represented by the general formula (II) described in JP-A-2016-053709 (especially paragraphs [ 0036] to [0043]), and compounds represented by the general formula (1) described in JP-A-2016-081035 (in particular, compounds described in paragraphs [0043] to [0055]) etc.

In particular, as the reverse wavelength dispersion liquid crystalline compound, for example, compounds represented by the following formulas (15) to (36) are preferably exemplified. Examples of K (side chain structure) of are compounds having side chain structures shown in Tables 1 to 3 below.
In Tables 1 to 3 below, "*" shown in the side chain structure of K represents the bonding position with the aromatic ring.
In the side chain structures represented by 2-2 in Table 2 below and 3-2 in Table 3 below, the groups adjacent to the acryloyloxy group and the methacryloyl group, respectively, are propylene groups (a methyl group is an ethylene group substituted group), and represents a mixture of regioisomers in which the position of the methyl group differs.

<Additive>
The composition for forming an optically anisotropic layer may contain components other than the liquid crystalline compound described above.
For example, the composition for forming an optically anisotropic layer may contain a polymerization initiator. The polymerization initiator to be used is selected according to the type of polymerization reaction, and examples thereof include thermal polymerization initiators and photopolymerization initiators. For example, examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, combinations of triarylimidazole dimers and p-aminophenyl ketones, and the like. be done.
The amount of 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.

Moreover, 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.
Polymerizable monomers include radically polymerizable or cationically polymerizable compounds. Preferably, it is a polyfunctional radically polymerizable monomer and is preferably copolymerizable with the polymerizable group-containing liquid crystalline compound. Examples thereof include those described in paragraphs [0018] to [0020] of JP-A-2002-296423.
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 crystalline 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.
Surfactants include conventionally known compounds, and fluorine compounds are particularly preferred. Specific examples include compounds described in paragraphs [0028] to [0056] of JP-A-2001-330725 and compounds described in paragraphs [0069] to [0126] of JP-A-2005-062673. be done.

The composition for forming an optically anisotropic layer may also contain a dichroic substance from the viewpoint of making the optically anisotropic layer function as a polarizer.
The dichroic substance is not particularly limited, and includes visible light absorbing substances (dichroic dyes), luminescent substances (fluorescent substances, phosphorescent substances), ultraviolet ray absorbing substances, infrared absorbing substances, nonlinear optical substances, carbon nanotubes, inorganic Substances (for example, quantum rods) and the like can be mentioned, and conventionally known dichroic substances (dichroic dyes) can be used.
Specifically, for example, [ 0008] to [0015] paragraphs, [0045] to [0058] paragraphs of JP-A-2013-14883, [0012]-[0029] paragraphs of JP-A-2013-109090, JP-A-2013-101328 [0009] to [0017] paragraphs, [0051] to [0065] paragraphs of JP-A-2013-37353, [0049] to [0073] paragraphs of JP-A-2012-63387, JP-A-11-305036 [0016] to [0018] paragraphs, [0009] to [0011] paragraphs of JP-A-2001-133630, [0030]-[0169] of JP-A-2011-215337, JP-A-2010-106242 [0021] ~ [0075] paragraph, JP 2010-215846 [0011] ~ [0025] paragraph, JP 2011-048311 [0017] ~ [0069] paragraph, JP 2011-213610 [0013] to [0133] paragraphs of the publication, [0074] to [0246] paragraphs of JP-A-2011-237513, [0005]-[0051] paragraphs of JP-A-2016-006502, International Publication No. 2016/ [0005] to [0041] paragraphs of No. 060173, [0008] to [0062] paragraphs of WO 2016/136561, [0014] to [0033] paragraphs of WO 2017/154835, WO 2017 /154695 [0014] to [0033] paragraphs, International Publication No. 2017/195833 [0013] to [0037] paragraphs, and the like.
In the present invention, two or more dichroic substances may be used in combination. For example, from the viewpoint of making the light absorption anisotropic layer closer to black, at least one substance having a maximum absorption wavelength in the wavelength range of 370 to 550 nm. and at least one dichroic substance having a maximum absorption wavelength in the wavelength range of 500 to 700 nm.

Further, the composition for forming an optically anisotropic layer may contain an organic solvent. Examples of the organic solvent include those similar to those described in the composition for photo-alignment film of the present invention.

The composition for forming an optically anisotropic layer includes a vertical alignment agent on the polarizer interface side, a vertical alignment promoter such as a vertical alignment agent on the air interface side, a horizontal alignment agent on the polarizer interface side, and an air Various alignment agents such as a horizontal alignment accelerator such as an interfacial horizontal alignment agent may be included.
Furthermore, the composition for forming an optically anisotropic layer may contain an adhesion improver, a plasticizer, a polymer, etc., in addition to the above components.

The method for forming an optically anisotropic layer using the composition for forming an optically anisotropic layer containing such components is not particularly limited. It can be formed by applying the forming composition to form a coating film, and subjecting the obtained coating film to curing treatment (ultraviolet irradiation (light irradiation treatment) or heat treatment).
Application of the optically anisotropic layer-forming composition can be carried out by known methods (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, 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 layered body of the present invention may have a support as a substrate for forming the optically anisotropic layer.
Such a support includes, for example, a polarizer, a polymer film, and the like, and a combination of these, for example, a laminate of a polarizer and a polymer film, a laminate of a polymer film, a polarizer, and a polymer film. It may be a body or the like.
The support may also be a temporary support that can be peeled off after the optically anisotropic layer is formed (hereinafter sometimes simply referred to as "temporary support"). Specifically, the optically anisotropic layer may be provided by peeling the polymer film functioning as a temporary support from the optical laminate. For example, an optical laminate containing an optically anisotropic layer and a temporary support is prepared, and the optically anisotropic layer side of the optical laminate is attached to a support containing a polarizer with a pressure-sensitive adhesive or an adhesive. A laminate of a support containing a polarizer and an optically anisotropic layer may be provided by peeling off the temporary support contained in the optically anisotropic layer.

<Polarizer>
In the present invention, when the optical layered body of the present invention is used in an image display device, it is preferable to use at least a polarizer as a support.
The polarizer is not particularly limited as long as it is a member having a function of converting light into specific linearly polarized light, and conventionally known absorptive polarizers and reflective polarizers can be used.
As the absorbing polarizer, an iodine-based polarizer, a dye-based polarizer using a dichroic dye, a polyene-based polarizer, or the like is used. Iodine-based polarizers and dye-based polarizers include coating-type polarizers and stretching-type polarizers, and both can be applied. child is preferred.
In addition, as a method of obtaining a polarizer by stretching and dyeing a laminated film in which a polyvinyl alcohol layer is formed on a substrate, there are disclosed in Japanese Patent Nos. 5048120, 5143918, 4691205, and No. 4,751,481 and Japanese Patent No. 4,751,486 can be cited, and known techniques relating to these polarizers can also be preferably used.
As a reflective polarizer, a polarizer in which thin films having different birefringences are laminated, a wire grid polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection region and a quarter wavelength plate are combined, and the like are used.
Among them, polyvinyl alcohol resins (polymers containing —CH ₂ —CHOH— as repeating units are intended from the point of view of handling. In particular, at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymers. one is preferred).

In an aspect in which the optical layered body of the present invention includes a peelable support, the polarizing plate can be produced, for example, as follows.
The support is peeled off from the optical layered body described above, and the layer containing the optically anisotropic layer is laminated on the support containing the polarizer. Alternatively, the optical layered body described above is laminated to a support containing a polarizer, and then the peelable support contained in the optical layered body is peeled off. At the time of lamination, both layers may be adhered with an adhesive or the like. The adhesive is not particularly limited, but curable adhesives of epoxy compounds containing no aromatic ring in the molecule, such as those shown in JP-A-2004-245925, 360 to 360 described in JP-A-2008-174667. An active energy ray-curable adhesive comprising, as essential components, a photopolymerization initiator having a molar extinction coefficient of 400 or more at a wavelength of 450 nm and an ultraviolet-curable compound, and 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) a hydroxyl group in the molecule and only one polymerizable double bond and (c) an active energy ray-curable adhesive containing a (meth)acrylic compound and (c) a phenol ethylene oxide-modified acrylate or a nonylphenol ethylene oxide-modified acrylate.

Although the thickness of the polarizer is not particularly limited, it is preferably 1 to 60 μm, more preferably 1 to 30 μm, 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 polarizer protective film, etc.) can be used.
Specific examples of the polymer constituting the polymer film include, for example, cellulose-based polymers; acrylic polymers having acrylic acid ester polymers such as polymethyl methacrylate and lactone ring-containing polymers; thermoplastic norbornene-based polymers; Polymers; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such as polystyrene and acrylonitrile-styrene copolymers (AS resins); polyolefin polymers such as polyethylene, polypropylene and ethylene-propylene copolymers; vinyl chloride amide-based polymer such as nylon and aromatic polyamide; imide-based polymer; sulfone-based polymer; polyethersulfone-based polymer; polyetheretherketone-based polymer; polyphenylene sulfide-based polymer; vinylidene chloride-based polymer; vinyl butyral-based polymer; arylate-based polymer; polyoxymethylene-based polymer; epoxy-based polymer;

Among these, cellulose-based polymers (hereinafter also referred to as “cellulose acylate”) typified by triacetyl cellulose can be preferably used.
From the viewpoint of workability and optical performance, it is also preferable to use an acrylic polymer.
Examples of acrylic polymers include polymethyl methacrylate and lactone ring-containing polymers described in paragraphs [0017] to [0107] of JP-A-2009-98605.

Although the thickness of the polymer film used for the polarizer protective film and the like is not particularly limited, it is preferably 40 μm or less because the thickness of the optical laminate can be reduced. Although the lower limit is not particularly limited, it is usually 5 μm or more.

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, even more preferably 5 to 20 μm. The thickness of the support means the total thickness of the polarizer and the polymer film when the support has both.

Cellulose-based polymers or polyester-based polymers can be preferably used in embodiments in which a polymer film is used as a support that can be peeled off from the optical laminate. Although the thickness of the polymer film is not particularly limited, it is preferably 5 μm to 100 μm, more preferably 20 μm to 90 μm, for reasons such as handling during production. The peeling interface may be between the support and the photo-alignment film, between the photo-alignment film and the optically anisotropic layer, or any other interface.

[Image display device]
Since the optical layered body of the present invention can be thinned by peeling off the support, it can be suitably used when producing an image display device.
The display element used in the image display device is not particularly limited, and examples thereof include liquid crystal cells, organic electroluminescence (hereinafter abbreviated as "EL") display panels, and plasma display panels.
Among these, liquid crystal cells and organic EL display panels are preferable, and liquid crystal cells are more preferable. That is, the image display device is preferably a liquid crystal display device using a liquid crystal cell as a display element, an organic EL display device using an organic EL display panel as a display element, and more preferably a liquid crystal display device.

[Liquid crystal display device]
A liquid crystal display device, which is an example of an image display device, is a liquid crystal display device having the above-described optical layered body 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 layered body of the present invention as the front-side polarizing plate.
The liquid crystal cell constituting the liquid crystal display device will be described in detail below.

<Liquid crystal cell>
Liquid crystal cells used in liquid crystal display devices are VA (Vertical Alignment
) mode, OCB (Optically Compensated Bend) mode, IPS (In-Plane-Switching) mode, or TN (Twisted Nematic) mode, but not limited thereto.
In the TN mode liquid crystal cell, rod-like liquid crystal molecules (rod-like liquid crystal compounds) are substantially horizontally aligned when no voltage is applied, and are twisted at an angle of 60° to 120°. TN mode liquid crystal cells are most commonly used as color TFT liquid crystal display devices, and are described in many documents.
In the VA mode liquid crystal cell, the rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied. VA mode liquid crystal cells include (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied and substantially horizontally aligned when voltage is applied (Japanese Unexamined Patent Application Publication No. 2-2002). 176625), (2) VA mode multi-domain (MVA (Multi-domain Vertical Alignment) mode) liquid crystal cell (SID97, Digest of tech. Papers (preliminary collection) ) 28 (1997) 845), (3) a mode (n-ASM mode (axially symmetrically aligned microcell)) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multidomain alignment is performed when voltage is applied. Liquid crystal cell (described in Proceedings of Japan Liquid Crystal Forum 58-59 (1998)) and (4) Survival (Super Ranged Viewing by Vertical Alignment) mode liquid crystal cell (presented at LCD (liquid crystal display) International 98) . Moreover, any of PVA (Patterned Vertical Alignment) type, optical alignment type, and PSA (Polymer-Sustained Alignment) type may be used. Details of these modes are described in Japanese Unexamined Patent Application Publication No. 2006-215326 and Japanese National Publication of International Patent Application No. 2008-538819.
In the IPS mode liquid crystal cell, the rod-like liquid crystal molecules are oriented substantially parallel to the substrate, and the liquid crystal molecules respond planarly by applying an electric field parallel to the substrate surface. In the IPS mode, a black display is obtained when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are perpendicular to each other. A method of using an optical compensatory sheet to reduce leakage light during black display in an oblique direction and improve the viewing angle is disclosed in Japanese Patent Application Laid-Open Nos. 10-54982, 11-202323 and 9-292522. JP-A-11-133408, JP-A-11-305217 and JP-A-10-307291.

The present invention will be described in more detail based on examples below. The materials, amounts used, proportions, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the examples shown below.

[Synthesis of monomer having photo-orientation group]
[Synthesis of Monomer mA-98]
800 g of N,N-dimethylacetamide, 90.4 g of 2-hydroxyethyl methacrylate, 192 g of 4-octyloxycinnamic acid, 1-(3-dimethyl 146 g of aminopropyl)-3-ethylcarbodiimide hydrochloride and 42.4 g of N,N-dimethylaminopyridine were added and reacted at room temperature for 4 hours.
While stirring the reaction solution at room temperature, 800 mL of methanol and a mixed solvent of methanol/water (320 mL/480 mL) were successively added dropwise to precipitate a white solid. The precipitated white solid was separated by suction filtration, washed, and dried overnight at 50° C. to obtain 188 g of monomer mA-98 shown below as a white solid (yield 70%).
The monomer mA-98 shown below corresponds to the monomer forming the repeating unit A-98 described above.

[Synthesis of Monomer mA-125]
270 g of N-methylpyrrolidone, 90 g of p-hydroxybenzaldehyde, 132 g of potassium carbonate, and 1.2 g of potassium iodide were weighed into a 2 L three-necked flask equipped with a stirring blade, thermometer, dropping funnel and reflux tube, and stirred at 60°C. .
Then, 157 g of 1-bromooctane was added dropwise using a dropping funnel over 1 hour, and after the dropwise addition was completed, the mixture was stirred at 70° C. for 3 hours.
After cooling the reaction solution to room temperature (23° C.), it was transferred to a separating funnel, and 320 mL of ethyl acetate and 640 mL of pure water were added for liquid separation washing, and the resulting organic layer was further separated with 340 mL of brine. washed.
The obtained organic layer was transferred to a 2 L three-necked flask equipped with a stirring blade, a thermometer, a dropping funnel and a reflux tube. and reacted at 60° C. for 1 hour and 80° C. for 4 hours.
After cooling the reaction solution to 45° C. while stirring, 120 mL of methanol, 100 mL of dilute hydrochloric acid, and methanol/water mixed solvent (120 mL/120 mL) were sequentially added to precipitate a white solid.
The precipitated white solid was separated by suction filtration, washed, and then air-dried at 70° C. overnight to obtain 198 g of 4-octyloxycinnamic acid (yield 97%).

80.0 g of 4-aminocyclohexanol, 77.3 g of triethylamine, and 704 g of N,N-dimethylacetamide were weighed into a 2 L three-necked flask equipped with a stirring blade, thermometer, dropping funnel and reflux tube, and cooled with ice. Stirred.
Then, 76.2 g of methacrylic acid chloride was added dropwise using a dropping funnel over 1 hour, and after completion of dropping, the mixture was stirred at 40°C for 1 hour.
After cooling the reaction solution to room temperature, the precipitated salt was removed by suction filtration. The obtained organic layer was transferred to a 5 L three-necked flask equipped with a stirring blade, a thermometer, a dropping funnel and a reflux tube, and stirred under water cooling.
Then, 192 g of 4-octyloxycinnamic acid, 146 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 42.4 g of N,N-dimethylaminopyridine were added and allowed to react at room temperature for 4 hours. rice field.
While stirring the reaction solution at room temperature, 800 mL of methanol and a mixed solvent of methanol/water (320 mL/480 mL) were successively added dropwise to precipitate a white solid.
The precipitated white solid was separated by suction filtration, washed, and dried overnight at 50° C. to obtain 240 g of monomer mA-125 shown below as a white solid (yield 79%).
The monomer mA-125 shown below corresponds to the monomer forming the repeating unit A-125 described above.

[Synthesis of Monomer mA-30]
After adding 500 mL of methylene chloride, 50.0 g of hydroquinone, 34.5 g of triethylamine, and 5 mg of dibutylhydroxytoluene to a 1 L three-necked flask equipped with a stirring blade, a thermometer, a dropping funnel and a reflux tube, chloride was added while stirring at 0°C. 29.57 g of methacrylic acid chloride dissolved in 40 mL of methylene was added dropwise and reacted at room temperature for 3 hours.
The reaction solution was separated and washed successively with 600 mL of water, 1N hydrochloric acid and saturated brine, and 5 mg of dibutylhydroxytoluene was added to the obtained organic layer, followed by drying over sodium sulfate. After removing sodium sulfate by filtration and concentrating the organic layer, 17.2 g of compound mA-30 precursor was obtained by purifying with a silica gel column (hexane/ethyl acetate=3/1).

A 300 mL three-necked flask equipped with a stirring blade, thermometer, dropping funnel and reflux tube was charged with 8.5 g of compound mA-30 precursor, 2.91 g of dimethylaminopyridine, 9.65 g of triethylamine, and 50 mL of dimethylacetamide. 10.32 g of 4-methoxycinnamic acid chloride was added dropwise while stirring at 0° C., and the reaction was allowed to proceed at room temperature for 5 hours.
200 mL of ethyl acetate was added to the reaction solution, the organic layer was separated and washed with 200 mL of saturated aqueous sodium bicarbonate solution, 2 mg of dibutylhydroxytoluene was added to the obtained organic layer, and the organic layer was dried over sodium sulfate. Sodium sulfate was removed by filtration, and the organic layer was concentrated and then recrystallized with ethyl acetate to obtain 6.6 g of monomer mA-30 shown below as a white solid.
The following monomer mA-30 corresponds to the monomer forming the repeating unit A-30 described above.

[Synthesis of compound mB-1C]
After adding 100.0 g of hydroxyethyl methacrylate and 600 mL of dimethylacetamide to a 3 L three-necked flask equipped with a stirring blade, a thermometer, a dropping funnel and a reflux tube, 126.6 g of 3-chloropropionyl chloride was added while stirring at 0°C. was added dropwise and reacted at room temperature for 3 hours.
1 L of ethyl acetate was added to the reaction solution, and the organic layer obtained was washed with 1N hydrochloric acid, saturated aqueous sodium bicarbonate, ion-exchanged water and saturated brine successively, and the resulting organic layer was dried over magnesium sulfate. Magnesium sulfate was filtered off, the organic layer was concentrated, and then purified with a silica gel column (hexane/ethyl acetate=3/1) to obtain 148.8 g of compound mB-1C shown below.
The compound mB-1C corresponds to a monomer that forms the above repeating unit B-1 through a polymer reaction according to the following scheme.

[Monomer mB-32]
Cychromer M-100 (manufactured by Daicel Corporation) was used as the following monomer mB-32 that forms the repeating unit B-32 described above.

[Monomer mB-41]
Commercially available glycidyl methacrylate (Tokyo Kasei Reagent Co., Ltd.) was used as the following monomer mB-41 that forms the repeating unit B-41 described above.

[Monomer mB-42]
OXE-30 (manufactured by Osaka Organic Industry Co., Ltd.) was used as the following monomer mB-42 that forms the repeating unit B-42 described above.

[Other monomers]
The repeating unit CB-1 represented by the following formula is formed by polymerizing a monomer mB-32 represented by the following formula in the following scheme according to the method described in Example 2 of JP-A-2015-31823. rice field.

[Synthesis Example 1]
A flask equipped with a condenser, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and refluxed by heating in a water bath while flowing nitrogen into the flask at 5 mL/min.
Here, 10 parts by weight of monomer mA-98, 1 part by weight of 2,2′-azobis(isobutyrate)dimethyl as a polymerization initiator, 0.5 parts by weight of sucrose octa (3-mercaptopropionate), and A solution prepared by mixing 5 parts by mass of 2-butanone as a solvent was added dropwise over 3 hours, and the mixture was further stirred for 3 hours while maintaining the reflux state.
After completion of the reaction, the mixture was allowed to cool to 40° C. and diluted with 30 parts by mass of 2-butanone to obtain a polymer solution of about 20% by mass.
The resulting polymer solution was poured into a large amount of methanol to precipitate the polymer, and the collected precipitate was separated by filtration, repeatedly washed with methanol, and dried with air at 50°C for 12 hours. 4 and a photo-alignable polymer P-1 having a polymer chain having a repeating unit containing a photo-alignable group.

[Synthesis Examples 2 to 17 and Comparative Synthesis Examples 1 to 3]
Same as polymer P-1 synthesized in Synthesis Example 1, except that each monomer described above was used as a monomer forming the repeating unit shown in Table 4 below, and a mercapto compound corresponding to the core structure shown in Table 4 below was used. Photo-alignable polymers P-2 to P-17 and H-1 to H-3 were synthesized by the method of . In Comparative Synthesis Examples 1 to 3, since no mercapto compound was used, the photo-alignable polymer did not have a core structure.

Next, the photo-alignable polymers synthesized in Synthesis Examples 1 to 17 and Comparative Synthesis Examples 1 to 3 were evaluated as follows.

[Example 1]
[Preparation of composition for photo-alignment film]
To 80 parts by mass of butyl acetate, 22 parts by mass of the polymer P-1 synthesized in Synthesis Example 1 and 0.07 parts by mass of a thermal acid generator represented by the following structural formula were added to form a photo-alignment film. A composition was prepared.

[Production of optical laminate]
As the cellulose acylate film, the same one as in Comparative Example 1 of JP-A-2014-164169 was used.
One side of this film was coated with the previously prepared composition for photo-alignment film using a bar coater. After coating, the coating was dried on a hot plate at 80° C. for 5 minutes to remove the solvent and form a photoisomerizable composition layer with a thickness of 0.2 μm. A photo-alignment film was formed by irradiating the obtained photoisomerizable composition layer with polarized ultraviolet rays (10 mJ/cm ² , using an ultra-high pressure mercury lamp).
Next, a commercially available rod-like liquid crystalline compound (ZLI-4792, manufactured by Merck) was applied onto the photo-alignment 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.
Thereafter, the temperature was maintained at 60° C., and the orientation was fixed by ultraviolet irradiation (500 mJ/cm ² , using an ultra-high pressure mercury lamp) in a nitrogen atmosphere (oxygen concentration: 100 ppm) to form an optically anisotropic layer having a thickness of 2.0 μm. , an optical laminate was produced.

[Examples 2 to 4]
Optical laminates were produced in the same manner as in Example 1, except that the photo-alignable polymers P-2 to P-4 were used instead of the photo-alignable polymer P-1.

[Examples 5 to 13 and Comparative Examples 1 to 3]
A photo-alignment film was prepared in the same manner as in Example 1, except that the photo-alignment polymers P-5 to P-13 and H-1 to H-3 were used instead of the photo-alignment polymer P-1. formed.
Next, an optical laminate was prepared in the same manner as in Example 1, except that the optically anisotropic layer coating liquid (liquid crystal 101) shown below was used instead of the nematic liquid crystalline compound coated on the photo-alignment film. was made.

──────────────────────────────────
Coating liquid for optically anisotropic layer (liquid crystal 101)
──────────────────────────────────
・ 80.00 parts by mass of the following liquid crystalline compound L-1 ・ 20.00 parts by mass of the following liquid crystalline compound L-2 ・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―――――――――――――――――――――――― ――――――――――

Liquid crystalline compound L-1

Liquid crystalline compound L-2

Compound G-1

[Example 14]
A photo-alignment film was formed in the same manner as in Example 1, except that the photo-alignment polymer P-14 was used instead of the photo-alignment polymer P-1.
Next, an optical laminate was prepared in the same manner as in Example 1, except that the optically anisotropic layer coating liquid (liquid crystal 102) shown below was used instead of the nematic liquid crystalline compound coated on the photo-alignment film. was made.

―――――――――――――――――――――――――――――――――
Coating liquid for optically anisotropic layer (liquid crystal 102)
―――――――――――――――――――――――――――――――――
42.00 parts by mass of the following liquid crystalline compound L-3 42.00 parts by mass of the following liquid crystalline compound L-4 16.00 parts by mass of the following polymerizable compound A-1 The following polymerization initiator S-1 (oxime type ) 0.50 parts by mass Leveling agent (the above compound G-1) 0.20 parts by mass Hisolve 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 in the liquid crystal compounds L-3 and L-4 below represents a propylene group (a group in which a methyl group is substituted with an ethylene group), and the liquid crystal compounds L-3 and L-4 below. represents a mixture of positional isomers that differ in the position of the methyl group.

Liquid crystalline compound L-3

Liquid crystalline compound L-4

Polymerizable compound A-1

Polymerization initiator S-1

[Example 15]
A photo-alignment film was formed in the same manner as in Example 1, except that the photo-alignment polymer P-15 was used instead of the photo-alignment polymer P-1.
Next, an optical laminate was prepared in the same manner as in Example 1, except that the optically anisotropic layer coating liquid (liquid crystal 103) shown below was used instead of the nematic liquid crystalline compound coated on the photo-alignment film. was made.

―――――――――――――――――――――――――――――――――
Coating liquid for optically anisotropic layer (liquid crystal 103)
―――――――――――――――――――――――――――――――――
・The following liquid crystalline compound L-5 42.00 parts by mass ・The following liquid crystalline compound L-6 42.00 parts by mass ・The above polymerizable compound A-1 16.00 parts by mass ・The above polymerization initiator S-1 (oxime type ) 0.50 parts by mass Leveling agent (the above compound G-1) 0.20 parts by mass Hisolve 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 ――――――――――――――――――――――――――――――――――

Liquid crystalline compound L-5

Liquid crystalline compound L-6

[Example 16]
A photo-alignment film was formed in the same manner as in Example 1, except that the photo-alignment polymer P-16 was used instead of the photo-alignment polymer P-1.
Next, an optical laminate was prepared in the same manner as in Example 1, except that the optically anisotropic layer coating liquid (liquid crystal 104) shown below was used instead of the nematic liquid crystalline compound coated on the photo-alignment film. was made.

―――――――――――――――――――――――――――――――――
Coating liquid for optically anisotropic layer (liquid crystal 104)
―――――――――――――――――――――――――――――――――
・ 4.032 parts by mass of the following polymer liquid crystalline compound L-7 ・ 0.039 parts by mass of the following interface improver F1 ・ Polymerization initiator IRGACURE819 (manufactured by BASF) 0.043 parts by mass ・ Cyclopentanone 66.500 parts by mass・ Tetrahydrofuran 28.500 parts by mass ――――――――――――――――――――――――――――――――

Polymer liquid crystalline compound L-7

Interface improver F1

[Example 17]
A photo-alignment film was formed in the same manner as in Example 1 except that the photo-alignment polymer P-17 was used instead of the photo-alignment polymer P-1.
Next, an optical laminate was prepared in the same manner as in Example 1, except that the optically anisotropic layer coating liquid (liquid crystal 105) shown below was used instead of the nematic liquid crystalline compound coated on the photo-alignment film. was made.

──────────────────────────────────
Coating liquid for optically anisotropic layer (liquid crystal 105)
──────────────────────────────────
・The following liquid crystalline compound L-8 83.00 parts by mass ・The following liquid crystalline compound L-9 15.00 parts by mass ・The following liquid crystalline compound L-10 2.00 parts by mass ・Polymerization initiator (IRGACURE 184, manufactured by BASF Corporation )
3.00 parts by mass Polymerization initiator (IRGACURE OXE-01, manufactured by BASF)
3.00 parts by mass Leveling agent (Compound G-1 above) 0.20 parts by mass Methyl ethyl ketone 424.8 parts by mass―――――――――――――――――――――――― ――――――――――

Liquid crystalline compound L-8

Liquid crystalline compound L-9

Liquid crystalline compound L-10

[Liquid crystal orientation]
The produced optical layered body was observed using a polarizing microscope in a state shifted by 2 degrees from the extinction position. As a result, evaluation was made according to the following criteria. The results are shown in Table 4 below.
A: The liquid crystal directors are evenly aligned and the display performance is excellent. B: Disturbance of the liquid crystal directors is minimal and the surface condition is stable. Stable D: The liquid crystal director is greatly disturbed and the surface condition is not stable, and the display performance is very poor. It means a state in which there are no defects such as unevenness or poor orientation when the optical layered body is installed and observed.
In the specification of the present application, the term "liquid crystal director" means a vector in the direction in which the long axes of liquid crystalline molecules are aligned (orientation principal axis).

[Adhesion]
Adhesion of the produced optical layered body was evaluated by a cross-cut test (cross-cut method) conforming to JIS K 5400 according to the following criteria. The results are shown in Table 4 below.
A: In the cross-cut (100 squares) test, the remaining number is 95 or more and 100 or less B: In the cross-cut (100 squares) test, the remaining number is 80 or more and less than 95 C: In the cross-cut (100 squares) test , the remaining number is 70 or more and less than 80 D: the remaining number is 50 or more and less than 70 in the cross-cut (100 mass) test E: the remaining number is less than 50 in the cross-cut (100 mass) test

In Table 4 above, the core structure (X) is as shown in the following formula. In the formula below, * represents the bonding position with the polymer chain having a repeating unit containing a photo-orientation group.

From the results shown in Table 4 above, it was found that the adhesion of the photo-alignment film was poor when the photo-alignment polymer did not have 3 or more polymer chains having a repeating unit containing a photo-alignment group. (Comparative Examples 1 to 3).
On the other hand, by using a photo-alignment polymer having 3 to 20 polymer chains having a repeating unit containing a photo-alignment group, the resulting photo-alignment film has both good liquid crystal alignment and adhesion. It was found that (Examples 1 to 17).
In particular, from the comparison between Example 1 and Examples 2 to 4, it was found that the adhesion of the resulting photo-alignment film is better when the polymer chain further has a repeating unit containing a crosslinkable group. .
Further, from the comparison between Example 5 and Example 6, and the comparison between Example 7 and Example 9, Z in the above formula (2) has 1 to 1 carbon atoms which may have a substituent. It has been found that the linear, branched or cyclic m-valent aliphatic hydrocarbon group having 3 to 6 carbon atoms gives the obtained photo-alignment film better liquid crystal orientation.
Further, from the comparison of Examples 6, 8 and 9, it was found that when m in the above formula (1) or (2) is 3 or 4, the resulting photo-alignment film has better adhesion. .

Claims (6)

A photo-alignable polymer represented by the following formula ( 2 ).

Here, in the above formula (2),
m represents an integer of 3 to 8;
Z is a linear, branched or cyclic m-valent aliphatic hydrocarbon group having 1 to 6 carbon atoms and having 3 to 6 carbon atoms, which may have a substituent; an m-valent aromatic hydrocarbon group having 6 to 14 carbon atoms, an optionally substituted m-valent aromatic heterocyclic group having 3 to 14 carbon atoms, a combination thereof, and a carbon atom represents an m-valent organic group selected from the group consisting of two or more m-valent groups linked via an oxygen atom or a nitrogen atom. However, when the aliphatic hydrocarbon group is cyclic, one or more —CH ₂ — constituting the ring may be substituted with —O—, —CO—, or —NR ¹⁰ —, R ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y is a single bond, or an optionally substituted linear or branched alkylene group having 1 to 20 carbon atoms or 3 to 20 carbon atoms, —O—, —CO—, —NR ¹⁰ -, or a divalent linking group consisting of a combination of two or more thereof, and R ¹⁰ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. m Y's may be the same or different.
S represents a sulfur atom.
P represents a polymer chain having a repeating unit containing a photo-alignment group, the photo-alignment group is a group in which at least one of dimerization and isomerization occurs by the action of light, m P is the same or may be different. 2. The photo-alignable polymer according to claim 1 , wherein Z in the formula (2) represents an organic group represented by any one of the following formulas (Z-1) to (Z-15).

Here, in the above formulas (Z-1) to (Z-15),
* represents the bonding position with Y in the formula (2).
R represents a hydrogen atom or a substituent.
L represents an optionally substituted alkylene group having 1 to 6 carbon atoms.
D represents —O—, —CO—, —NR ¹⁰ —, or a divalent linking group consisting of a combination of two or more thereof, and R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms represents Z in the formula (2) represents an optionally substituted linear, branched or cyclic m-valent aliphatic hydrocarbon group having 1 to 6 carbon atoms and having 3 to 6 carbon atoms. ,
Y in the formula (2) is an optionally substituted alkylene group having 1 to 8 carbon atoms, —O—, —CO—, or a divalent group consisting of a combination of two or more thereof 3. The photo-alignable polymer according to claim 1 , which represents a linking group. The photo-orientable polymer according to any one of claims 1 to 3 , wherein the polymer chain further has a repeating unit containing a crosslinkable group. A photo-alignment film formed using a composition for photo-alignment film containing the photo-alignment polymer according to any one of claims 1 to 4 . An optical laminate comprising the photo-alignment film according to claim 5 and an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystalline compound.