WO2019117082A1

WO2019117082A1 - Photo-aligning copolymer, photo-aligned film, and optical layered product

Info

Publication number: WO2019117082A1
Application number: PCT/JP2018/045302
Authority: WO
Inventors: 考浩加藤; 隆史飯泉; 寛野副; 美帆朝日
Original assignee: 富士フイルム株式会社
Priority date: 2017-12-15
Filing date: 2018-12-10
Publication date: 2019-06-20
Also published as: JP6987883B2; JPWO2019117082A1

Abstract

The present invention addresses the problem of providing: a photo-aligning copolymer capable of forming a photo-aligned film which has the property of satisfactorily aligning liquid-crystalline compounds and highly prevents the optically anisotropic layer from peeling off; and a photo-aligned film and an optical layered product each produced using the photo-aligning copolymer. The photo-aligning copolymer of the present invention comprises a repeating unit A represented by formula (A) and including a photo-aligning group and a repeating unit B represented by formula (B) and including a crosslinkable group.

Description

Photoalignment copolymer, photoalignment film and optical laminate

The present invention relates to a photoalignable copolymer, a photoalignment film and an optical laminate.

Optical films, such as an optical compensation sheet and a retardation film, are used in various image display devices from the viewpoint of image coloration cancellation, viewing angle widening, and the like.
A stretched birefringence 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 in place of the stretched birefringence film.

Such an optically anisotropic layer is known to be provided with an alignment film on a support forming the optically anisotropic layer in order to align the liquid crystal compound, and rubbing is performed as the alignment film. A photo alignment film which has been subjected to a photo alignment process instead of the process is known.

For example, Patent Document 1 discloses 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. Products are described ([Claim 1]), and the 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] [0028]).

International Publication No. 2017/069252

When the present inventors examined a copolymer having a structural unit a2 containing a crosslinkable group together with a structural unit a1 containing a cinnamate group as the polymer A described in Patent Document 1, the kind of the crosslinkable group is It became clear that the orientation (hereinafter also referred to as “liquid crystal orientation”) of the liquid crystal compound may be inferior when forming the optically anisotropic layer on the obtained photoalignment film depending on the case.
In addition, depending on the type of crosslinkable group, the present inventors found that the releasability of the optically anisotropic layer is at the time of transferring the optically anisotropic layer formed on the resulting photo alignment film to another substrate. It became clear that it might be inferior.

Therefore, in the present invention, a photoalignment copolymer which can form a photoalignment film which is excellent in the alignment property of the liquid crystal compound and is also excellent in the removability of the optically anisotropic layer, and using the same It is an object of the present invention to provide a produced photoalignment film and an optical laminate.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors obtained by using a copolymer having a repeating unit containing a specific photoalignable group and a repeating unit containing a specific crosslinkable group. When forming an optically anisotropic layer on the resulting photo alignment film, it is found that the alignment of the liquid crystal compound is good and the releasability of the formed optical anisotropic layer is also excellent, and the present invention is completed. The
That is, the present inventors found that the above-mentioned subject can be achieved by the following composition.

[1] A photoalignable copolymer having a repeating unit A containing a photoalignable group represented by the following formula (A) and a repeat unit B containing a crosslinkable 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 each independently represent a hydrogen atom or a substituent. ^Two adjacent groups among R ² , R ³ , R ⁴ , R ⁵ and R ⁶ may be combined 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 in} Formula (A) and L ² in Formula (B) each independently represent a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X, At least two or more members 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 It represents a divalent linking group in which groups are combined.
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, an aryloxy And at least one substituent selected from the group consisting of an alkyl group and an aryl group, at least one substituent selected from the group consisting of a group, a cyano group, a carboxy group and an alkoxycarbonyl group It is.

[2] L ^{1 in the} formula (A) has at least a linear alkylene group of 1 to 10 carbon atoms which may have a substituent X, and 3 carbons which may have a substituent X The photoalignment property according to [1], which is a divalent linking group containing any of a cyclic alkylene group of to 10 and an arylene group having 6 to 12 carbon atoms which may have a substituent Y. Copolymer.
[3] L ^{1 in the} formula (A) is at least a linear alkylene group of 1 to 10 carbon atoms which may have a substituent X, or carbon which may have a substituent X The photoalignable copolymer according to [2], which is a divalent linking group containing several 3 to 10 cyclic alkylene groups.

[4] The photoorientation according to any one of [1] to [3], wherein at least R ⁴ in R ² , R ³ , R ⁴ , R ⁵ and R ⁶ in formula (A) represents a substituent. Copolymer.
[5] The photoalignable copolymer according to [4], wherein each of R ² , R ³ , R ⁵ and R ^{6 in} Formula (A) represents a hydrogen atom.
[6] The photoalignable copolymer according to [4] or [5], wherein R ^{4 in the} formula (A) is an electron donating substituent.
[7] The photoalignable copolymer according to [6], wherein R ^{4 in the} formula (A) is an alkoxy group having 4 to 18 carbon atoms.
[8] The substituents represented by R ² , R ³ , R ⁴ , R ⁵ and R ^{6 in the} formula (A) are each independently a halogen atom or a linear, branched or cyclic C ¹ to C 20 carbon atom. 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 photoalignable copolymer according to any one of [1] to [7], which is a group or a group represented by the following formula (1).

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

[9] The photoalignable co-alignment as described in 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) by mass ratio Polymer.
0.2 ≦ a / (a + b) ≦ 0.8 (2)
[10] The photoalignable 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) by mass ratio.
0.2 ≦ a / (a + b) ≦ 0.6 (3)

[11] 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 table represented by the following formula (E) The photoalignable copolymer according to any one of [1] to [10], having at least one repeating unit selected from the group consisting of repeating units E containing a crosslinkable group.

In formula (C), R ¹⁰ represents a hydrogen atom or a methyl group, L ³ represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X, At least two or more members 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 It represents a divalent linking group in which groups are combined.
In formula (D), R ¹¹ represents a hydrogen atom or a methyl group, L ⁴ represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X, 1 or 2 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 And Q represents any one of —OH, —COOH, and —COOtBu.
In formula (E), R ¹² represents a hydrogen atom or a methyl group, L ⁵ represents a linear, branched or cyclic alkylene group having 1 to 18 carbon atoms which may have a substituent X, 1 or 2 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 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, an aryloxy And at least one substituent selected from the group consisting of an alkyl group and an aryl group, at least one substituent selected from the group consisting of a group, a cyano group, a carboxy group and an alkoxycarbonyl group It is.

[12] The photoalignable copolymer according to any one of [1] to [11], which has a weight average molecular weight of 10000 to 500000.
[13] The photoalignable copolymer according to [12], which has a weight average molecular weight of 30,000 to 200,000.

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

According to the present invention, a photoalignable copolymer which is capable of producing a photoalignment film excellent in the alignment property of the liquid crystal compound and excellent also in the removability of the optically anisotropic layer, and using the same The produced photo alignment film and optical laminated body can be provided.

Hereinafter, the present invention will be described in detail.
Although the description of the configuration requirements described below may be made based on the representative embodiments of the present invention, the present invention is not limited to such embodiments.
In the specification of the present application, a numerical range represented using “to” means a range including numerical values described before and after “to” as the lower limit value and the upper limit value.

[Photo-alignable copolymer]
The photoalignable copolymer of the present invention comprises a repeating unit A containing a photoalignable group represented by the following formula (A) and a repeating unit B containing a crosslinkable group represented by the following formula (B) It is a photoalignable copolymer.
In the present invention, as described above, light having a repeating unit A containing a photoalignable group represented by the following formula (A) and a repeating unit B containing a crosslinkable group represented by the following formula (B) When an optically anisotropic layer is formed on the resulting photo-alignment film by using an oriented copolymer, the orientation of the liquid crystal compound becomes good, and the releasability of the formed optically anisotropic layer Will also be good.
Although this is not clear in detail, the present inventors speculate as follows.
That is, when the oxetanyl group is introduced as the crosslinkable group, it is considered that the curing reaction at the time of forming the photoalignment film proceeds efficiently and the crosslinking density becomes high, as compared with the case where the epoxy group is introduced. As a result, when forming an optically anisotropic layer, a composition containing a liquid crystal compound or the like hardly penetrates to the surface of the photo alignment film, and an interlayer mixed layer affecting adhesion is hardly formed. It can be inferred that the removability of the porous layer has become good. In addition, it is considered that, as the crosslink density becomes high, the photoisomerized orientation group is efficiently fixed, and the degree of orientation of the photoalignment film becomes high. Then, it can be inferred that the surface control force is enhanced and the liquid crystal alignment is improved by the increase in the degree of alignment of the photo alignment film.

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 each independently represent a hydrogen atom or a substituent. ^Two adjacent groups among R ² , R ³ , R ⁴ , R ⁵ and R ⁶ may be combined 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 each independently a linear, branched or cyclic C ^{1 to} C 10 optionally having substituent X 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 This represents a divalent linking group in which at least two or more groups selected from the group consisting of optionally substituted imino groups (-NH-) are combined.

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, an alkoxy group And 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 species.
As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example, Especially, it is preferable that it is a fluorine atom and a chlorine atom.
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 (eg, methyl group, ethyl group, propyl group, isopropyl group) N-butyl group, isobutyl group, sec-butyl group, t-butyl group, cyclohexyl group and the like are more preferable, an alkyl group having 1 to 4 carbon atoms is still more preferable, and a methyl group or an ethyl group is more preferable Is particularly preferred.
The alkoxy group is, for example, preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 1 to 8 carbon atoms (eg, methoxy group, ethoxy group, n-butoxy group, methoxyethoxy group, etc.) More preferably, it is an alkoxy group of the number 1 to 4, and particularly preferably a methoxy group or an ethoxy group.
The aryl group includes, for example, an aryl group having a carbon number of 6 to 12, and specific examples thereof include a phenyl group, an α-methylphenyl group and a naphthyl group. Among these, a phenyl group is preferable.
Examples of the aryloxy group include phenoxy, naphthoxy, imidazoyloxy, benzimidazoyloxy, pyridin-4-yloxy, pyrimidinyloxy, quinazolinyloxy, purinyloxy, thiophen-3-yloxy and the like.
As the alkoxycarbonyl group, for example, methoxycarbonyl, ethoxycarbonyl and the like can be mentioned.

Specific examples of the linear, branched or cyclic alkylene group having 1 to 10 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and the like. Hexylene group, decylene group and the like can be mentioned.
Specific examples of branched alkylene groups include dimethylmethylene, methylethylene, 2,2-dimethylpropylene and 2-ethyl-2-methylpropylene.
Moreover, as the cyclic alkylene group, specifically, for example, cyclopropylene group, cyclobutylene group, cyclopentylene group, cyclohexylene group, cyclooctylene group, cyclodecylene group, adamantane-diyl group, norbornane-diyl group And exo-tetrahydrodicyclopentadiene-diyl group etc., among which cyclohexylene group is preferable.

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

In the present invention, L ^{1 in the} above formula (A) is a linear alkylene group having 1 to 10 carbon atoms which may have the above-mentioned substituent X for the reason that the liquid crystal alignment property is better. 2 containing at least one of a cyclic alkylene group of 3 to 10 carbon atoms which may have the above-mentioned substituent X, and an arylene group of 6 to 12 carbon atoms which may have the above-mentioned substituent Y And is preferably a monovalent linking group, and may be a linear alkylene group of 1 to 10 carbon atoms which may have the above-mentioned substituent X, or 3 carbon atoms which may have the above-mentioned substituent X It is more preferable that it is a divalent linking group containing at least a cyclic alkylene group of 10 to 10, and it is preferably an unsubstituted linear C 2 to C 6 alkylene group or an unsubstituted trans-1,4-cyclohexene group. Particularly preferred is a divalent linking group containing silene. Yes.

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 and R in the above formula (A) will be described. As described above, ⁵ and R ⁶ may be a hydrogen atom instead of a substituent.

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) It is preferable that the substituent be a substituent other than the substituent contained, and the photoalignable group easily interacts with the liquid crystal compound, and the liquid crystal alignment property is further improved. 20 linear, branched or cyclic alkyl groups, linear C 1-20 alkyl halides, C 1-20 alkoxy groups, C 6-20 aryl groups, C 6 carbons It is preferable that it is a -20 aryloxy group, a cyano group, an amino group, or a group represented by the following formula (1).

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

As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example, Especially, it is preferable that it is a fluorine atom and a chlorine atom.

As 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, ethyl And n-propyl group.
The branched alkyl group is preferably an alkyl group having a carbon number of 3 to 6, and specific examples thereof include an isopropyl group and a tert-butyl group.
The cyclic alkyl group is preferably an alkyl group having a carbon number of 3 to 6, and specific examples thereof include a cyclopropyl group, a cyclopentyl group and a cyclohexyl group.

The linear halogenated alkyl group having 1 to 20 carbon atoms is preferably a fluoroalkyl group having 1 to 4 carbon atoms, and specifically, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group And perfluorobutyl group etc., among which 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 Preferred examples of the group include n-hexyloxy group, n-octyloxy group, n-decyloxy group, n-dodecyloxy group and n-tetradecyloxy group.

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, and a naphthyl group. Among them, a phenyl group is preferable. 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. Is preferred.

Examples of the amino group include: primary amino group (—NH ₂ ); secondary amino group such as methylamino group; dimethylamino group, diethylamino group, dibenzylamino group, nitrogen-containing heterocyclic compound (eg, pyrrolidine) , And a tertiary amino group such as a group having a nitrogen atom of piperidine, piperazine and the like as a bond;

As the monovalent organic group represented by R ⁹ in the above formula (1) for the group represented by the above formula (1), for example, a linear or cyclic alkyl group having 1 to 20 carbon atoms can be mentioned .
The linear alkyl group is preferably an alkyl group having a carbon number of 1 to 6, and specific examples thereof include a methyl group, an ethyl group and an n-propyl group. Among them, a methyl group or an ethyl group is preferable. preferable.
The cyclic alkyl group is preferably an alkyl group having a carbon number of 3 to 6, and specific examples thereof include a cyclopropyl group, a cyclopentyl group and a cyclohexyl group. Among these, a cyclohexyl group is preferable.
The monovalent organic group represented by R ⁹ in the above formula (1) may be a combination of the linear alkyl group and the cyclic alkyl group described above directly or via a single bond. Good.

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

In the present invention, it is preferable that R ^{4 in the} above formula (A) is an electron donating substituent, because the reaction efficiency is improved when the resulting photo alignment film is irradiated with 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, and, for example, among the above-mentioned substituents, an alkyl group, A halogenated alkyl group, an alkoxy group, etc. are mentioned.
Among them, 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 orientation becomes better. Is more preferred.

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

Specific examples of the repeating unit B containing a photoalignable group represented by the above formula (B) include repeating units B-1 to B-14 shown below.

In the photoalignable copolymer 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 (2) by mass ratio, It is more preferable to satisfy the following formula (3), and it is further preferable to satisfy the following formula (4).
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 photoalignable copolymer of the present invention further has a repeating unit C containing a crosslinkable group represented by the following formula (C), and the following because the curing reaction at the time of producing the photoalignment film is made more efficient. It is preferable to have at least one of the repeating units D containing a crosslinkable group represented by Formula (D).

In the above formula (C), R ¹⁰ represents a hydrogen atom or a methyl group, and L ³ represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X And 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 And a divalent linking group obtained by combining the groups of
In the above formula (D), R ¹¹ represents a hydrogen atom or a methyl group, and L ⁴ represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X Or 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 It represents a divalent linking group in which the above groups are combined, and Q represents any one of -OH, -COOH and -COOtBu. "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 It is the same as that described for L ² in (B).

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

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

When the photoalignable copolymer of the present invention has the repeating unit C described above, the content a of the repeating unit A mentioned above and the content a of the repeating unit A mentioned above are for the purpose of increasing the speed of curing reaction and increasing the crosslinking density after the curing reaction It is preferable that the content b of the repeating unit B described above and the content c of the repeating unit C described above satisfy the following formula (5) by mass ratio, and satisfy the following formula (6) Is more preferred.
0.1 ≦ c / (a + b + c) ≦ 0.4 (5)
0.2 ≦ c / (a + b + c) ≦ 0.3 (6)

When the photoalignable copolymer of the present invention has the repeating unit D described above, the content a of the repeating unit A described above and the content a of the repeating unit A described above increase the speed of the curing reaction and increase the crosslinking density after the curing reaction. It is preferable that the content b of the repeating unit B described above and the content d of the repeating unit D described above satisfy the following formula (7) by mass ratio, and satisfy the following formula (8) Is more preferred.
0.01 ≦ d / (a + b + d) ≦ 0.3 (7)
0.05 ≦ d / (a + b + d) ≦ 0.2 (8)

In addition, the photoalignable copolymer of the present invention increases the strength of the optical laminate of the present invention described later, peels any support from the optical laminate of the present invention described later, and transfers it to another substrate. It is preferable to further have a repeating unit E represented by the following formula (E) for the reason that the handling property at the time of carrying out becomes good.

In the above formula (E), R ¹² represents a hydrogen atom or a methyl group, and L ⁵ represents a linear, branched or cyclic alkylene group having 1 to 18 carbon atoms which may have a substituent X Or 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 It represents a divalent linking group in which the above groups are combined, and S represents a functional group having an ethylenically unsaturated double bond.

Here, for the substituent X, the substituent Y and the substituent Z, and the arylene group having a carbon number of 6 to 12, etc., explanations are given for L ¹ in the above-mentioned formula (A) and L ² in the above-mentioned formula (B) It is the same as
Further, specific examples of the linear, branched or cyclic alkylene group having 1 to 18 carbon atoms include the groups represented by L ¹ in the above formula (A) and L ² in the above formula (B). In addition to those mentioned above, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and the like can be mentioned.
Specific examples of the functional group having an ethylenically unsaturated double bond include, for example, a vinyl group, an allyl group, a styryl group, an acryloyl group and a methacryloyl group, and an acryloyl group or a methacryloyl group preferable.

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

When the photoalignable copolymer of the present invention has the repeating unit E described above, the strength of the optically anisotropic layer including the photoalignment film can be further enhanced while maintaining good liquid crystal alignment and releasability. From the above, 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 mass ratio Preferably, it is more preferable to satisfy the following formula (10).
0.005 ≦ f / (a + b + f) ≦ 0.2 (9)
0.01 ≦ f / (a + b + f) ≦ 0.1 (10)

The photoalignable copolymer of the present invention is not limited 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.
As a monomer (radically polymerizable monomer) which forms such other repeating units, for example, acrylic acid ester compounds, methacrylic acid ester compounds, maleimide compounds, acrylamide compounds, acrylonitrile, maleic anhydride, styrene compounds, Vinyl compounds and the like can be mentioned.

The synthesis method of the photoalignable copolymer of the present invention is not particularly limited. For example, a monomer forming the above-mentioned repeating unit A, a monomer forming the above-mentioned repeating unit B, the above-mentioned repeating unit C, and any It can synthesize | combine by mixing the monomer which forms another repeating unit, and superposing | polymerizing in an organic solvent using a radical polymerization initiator.

The weight average molecular weight (Mw) of the photoalignable copolymer of the present invention is preferably 10,000 to 500,000, and more preferably 30,000 to 200,000 because the orientation is improved.
Here, the weight average molecular weight and the number average molecular weight in the present invention are values measured by gel permeation chromatography (GPC) under the conditions shown below.
Solvent (eluent): THF (tetrahydrofuran)
・ Device name: TOSOH HLC-8320GPC
・ Column: Three TOSOH TSKgel Super HZM-H (4.6 mm × 15 cm) connected and used ・ Column temperature: 40 ° C
Sample concentration: 0.1% by mass
・ Flow rate: 1.0 ml / min
Calibration curve: A calibration curve with seven samples up to TSO standard polystyrene Mw = 2800000 to 1050 (Mw / Mn = 1.03 to 1.06) manufactured by TOSOH

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

The content of the photoalignable copolymer of the present invention in the composition for photoalignment film of the present invention is not particularly limited, but in the case of containing the organic solvent described later, 0.1 to 50 with respect to 100 parts by mass of the organic solvent It is preferable that the amount is in the range of 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 a photoalignment film.
As the organic solvent, specifically, for example, ketones (eg, acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (eg, dioxane, tetrahydrofuran etc.), aliphatic hydrocarbons (Eg, hexane), alicyclic hydrocarbons (eg, cyclohexane), aromatic hydrocarbons (eg, toluene, xylene, trimethylbenzene etc.), halogenated carbons (eg, dichloromethane, dichloroethane, di) Chlorobenzene, chlorotoluene etc., esters (eg methyl acetate, ethyl acetate, butyl acetate etc), water, alcohols (eg ethanol, isopropanol, butanol, cyclohexanol etc), cellosolves (eg methyl cellosolve, ethyl Rosolve, etc.), cellosolve acetates, sulfoxides (eg, dimethyl sulfoxide, etc.), amides (eg, dimethylformamide, dimethylacetamide, etc.), etc. may be used alone or two or more of them may be used You may use together.

The composition for photo alignment film of the present invention may contain other components other than the above, and examples thereof include a crosslinking catalyst, an adhesion improver, a leveling agent, a surfactant, a plasticizer and the like.

[Method of producing photo alignment film]
The photoalignment film of the present invention can be produced by a conventionally known production method except that the composition for photoalignment film of the present invention described above is used. For example, the composition for photoalignment film of the present invention described above is supported Producing by a manufacturing method including a coating step of coating on a body surface, and a light irradiation step of irradiating non-polarized light in a direction oblique to the polarized light or the coated film surface with respect to the coated film of the composition for photo alignment film it can.
The support will be described in the optical laminate of the present invention described later.

<Coating process>
The coating method in the coating step is not particularly limited and may be appropriately selected depending on the 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 irradiated to the coating film of the composition for photo alignment film is not particularly limited, and examples thereof include linearly polarized light, circularly polarized light, elliptically polarized light and the like, among which linearly polarized light is preferable.
In addition, the “oblique direction” for irradiating non-polarized light 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. Can be selected as appropriate, but preferably θ is 20 to 80 °.

The wavelength in 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, for example, ultraviolet light, near ultraviolet light, visible light Etc. Among them, near ultraviolet light of 250 nm to 450 nm is particularly preferable.
Moreover, as a light source for irradiating polarized light or non-polarized light, for example, a xenon lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp and the like can be mentioned. The wavelength range to be irradiated can be limited by using an interference filter, a color filter, or the like for ultraviolet light or visible light obtained from such a light source. In addition, linearly polarized light can be obtained by using a polarizing filter or a polarizing prism for the light from these light sources.

The integrated light quantity of polarized light or non-polarized light is not particularly limited as long as the coating of the composition for photo alignment film can be given the ability to control the alignment of liquid crystalline molecules, and is not particularly limited. / Cm ² is preferable, and 5 to 100 mJ / cm ² is more preferable.
The illumination intensity of polarized light or non-polarized light is not particularly limited as long as the coating of the composition for photo alignment film can be provided with the ability to control the alignment of liquid crystalline molecules, but 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-described photoalignment film of the present invention and an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystalline compound.
In addition, the optical laminate of the present invention preferably further comprises a support, and specifically preferably comprises a support, an optical alignment film and an optically anisotropic layer in this order. .

[Optically anisotropic layer]
The optically anisotropic layer included in the optical laminate of the present invention is not particularly limited as long as it is an optically anisotropic layer containing a liquid crystalline compound, and conventionally known optically anisotropic layers may be appropriately employed and used it 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 a “composition for forming an optically anisotropic layer”). And may be a single layer structure or a structure (laminated body) in which a plurality of layers are laminated.
The liquid crystal compound and optional additives contained in the composition for forming an optically anisotropic layer are described below.

<Liquid crystalline 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 crystal compounds can be classified into rod-like types and discotic types according to their shapes. Furthermore, there are low molecular weight and high molecular type respectively. In general, a polymer refers to one having a degree of polymerization of 100 or more (Polymer physics / phase transition dynamics, Masao Doi, page 2, Iwanami Shoten, 1992).
In the present invention, any liquid crystal compound can be used, but it is preferable to use a rod-like liquid crystal compound or a discotic liquid crystal compound, and it is more preferable to use a rod-like liquid crystal compound.

In the present invention, although a liquid crystal compound having a polymerizable group is used to fix the above-mentioned liquid crystal compound, it is more preferable that the liquid crystal compound has two or more polymerizable groups in one molecule. In the case where the liquid crystal compound is a mixture of two or more types, it is preferable that at least one type of liquid crystal compound has two or more polymerizable groups in one molecule. In addition, after the liquid crystal compound is fixed by polymerization, it is no longer necessary to exhibit liquid crystallinity.

Further, 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, (meth) acryloyl group, vinyl group, styryl group, allyl group and the like are preferably mentioned, and (meth) acryloyl group is more preferable. In addition, a (meth) acryloyl group is a description which means a methacryloyl group or an acryloyl group.

As the rod-like 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, and As the tick liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP2007-108732A and paragraphs [0013] to [0108] of JP2010-244038A are preferably used. But not limited thereto.

In the present invention, a liquid crystal compound having reverse wavelength dispersion can be used as the liquid crystal compound.
Here, in the present specification, the “reverse wavelength dispersive” liquid crystal compound refers to the in-plane retardation (Re) value at a specific wavelength (visible light range) of a retardation film produced using this In this case, the Re value becomes equal or higher as the measurement wavelength increases.
The liquid crystal compound having reverse wavelength dispersion is not particularly limited as long as it can form a film having reverse wavelength dispersion as described above, and, for example, the general formula (I) described in JP-A-2008-297210 Compounds represented by the general formula (1) described in JP 2010-084032 A (especially, compounds described in paragraph Nos. [0034] to [0039]); Compounds described in JP-A-2016-053709 (especially, compounds described in paragraphs [0036] to [0043]); In addition, a compound represented by the general formula (1) described in JP-A-2016-081035 (in particular, compounds described in Paragraph Nos. [0043] to [0055]) can be used.

<Additives>
The composition for forming an optically anisotropic layer may contain components 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 to be used is selected according to the type of polymerization reaction, and examples thereof include a thermal polymerization initiator and a photopolymerization initiator. For example, examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon substituted aromatic acyloin compounds, polynuclear quinone compounds, combinations of triarylimidazole dimers and p-aminophenyl ketones, etc. Be
The amount of the polymerization initiator used is preferably 0.01 to 20% by mass, and more preferably 0.5 to 5% by mass, with respect to the total solid content of the composition.

In addition, 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. Preferred are polyfunctional radically polymerizable monomers, and those copolymerizable with the above-mentioned polymerizable group-containing liquid crystal compound. 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, and more preferably 2 to 30% by mass, with respect to the total mass of the liquid crystal compound.

In addition, a surfactant may be contained in the composition for forming an optically anisotropic layer from the viewpoint of the uniformity of the coating film and the strength of the film.
As surfactant, although a conventionally well-known compound is mentioned, especially a fluorine-type compound is preferable. Specifically, for example, compounds described in paragraphs [0028] to [0056] in JP-A-2001-330725, and compounds described in paragraphs [0069]-[0126] of JP-A-2005-062673 are listed. Be

In addition, an organic solvent may be contained in the composition for forming an optically anisotropic layer. As an organic solvent, the thing similar to what was demonstrated in the composition for photoalignment films of this invention mentioned above can be mentioned.

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

The formation method of the optically anisotropic layer using the composition for optically anisotropic layer formation which has such a component is not specifically limited, For example, on the photo-alignment film of this invention mentioned above, an optically anisotropic layer The composition for formation can be applied to form a coating film, and the resulting coating film can be formed by curing treatment (irradiation with ultraviolet light (light irradiation treatment) or heat treatment).
The application of the composition for forming an optically anisotropic layer can be carried out 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, and more preferably 0.5 to 5 μm.

[Support]
The optical layered product of the present invention may have a support as a substrate for forming an optically anisotropic layer as described above.
Examples of such a support include a polarizer, a polymer film and the like, and combinations thereof, such as 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.
In addition, the support may be a temporary support which may be peeled off (hereinafter, it may simply be referred to simply as a “temporary support”) after the formation of the optically anisotropic layer. Specifically, the optically anisotropic layer may be provided by peeling the polymer film functioning as a temporary support from the optical laminate. For example, after preparing an optical laminate including an optically anisotropic layer and a temporary support, and bonding the optically anisotropic layer side of the optical laminate to a support including a polarizer with an adhesive or an adhesive, By peeling off the temporary support contained in the optically anisotropic layer, a laminate of a support including a polarizer and an optically anisotropic layer may be provided.

<Polarizer>
In the present invention, when the optical laminate of the present invention is used for 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 linear polarization, and conventionally known absorption polarizers and reflection polarizers can be used.
As the absorption type polarizer, an iodine based polarizer, a dye based polarizer using a dichroic dye, a polyene based polarizer and the like are used. As iodine type polarizers and dye type polarizers, there are coating type polarizers and stretching type polarizers, either of which can be applied, but polarized light produced by adsorbing iodine or a dichroic dye to polyvinyl alcohol and stretching it Preferably a child.
Moreover, as a method of obtaining a polarizer by giving extending | stretching and dyeing in the state of the laminated | multilayer film which formed the polyvinyl alcohol layer on the base material, patent 5048120, patent 5143918, patent 5048120, patent No. 4,691,205, Japanese Patent No. 4,751,481, Japanese Patent No. 4,751,486 can be mentioned, and known techniques relating to these polarizers can also be preferably used.
As a reflection type polarizer, a polarizer in which thin films different in birefringence are laminated, a wire grid type polarizer, a polarizer in which a cholesteric liquid crystal having a selective reflection area and a quarter wavelength plate are combined, etc. are used.
Among them, from the viewpoint of handleability, a polymer containing polyvinyl alcohol resin (-CH ₂ -CHOH- as a repeating unit) is intended, in particular, at least one selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymer It is preferable that it is a polarizer containing one is preferable.

In the aspect in which the optical laminate 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 above-mentioned optical laminate, and the layer containing the optically anisotropic layer is laminated on the support containing a polarizer. Alternatively, the above-mentioned optical laminate is laminated on a support including a polarizer, and then the peelable support contained in the optical laminate is peeled off. At the time of lamination, both layers may be adhered by an adhesive or the like. The adhesive is not particularly limited, but as described in JP-A-2004-245925, a curable adhesive of an epoxy compound having no aromatic ring in the molecule, as described in JP-A-2008-174667, 360 to An active energy ray-curable adhesive comprising 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, (meth) acrylic compound described in JP-A-2008-174667 (A) a (meth) acrylic compound having two or more (meth) acryloyl groups in the molecule, and (b) a hydroxyl group in the molecule in a total amount of 100 parts by mass, and only one polymerizable double bond And (c) phenol ethylene oxide modified acrylate or nonyl phenol ethylene oxide modified acrylic Such as an active energy ray-curable adhesive containing a chromatography bets and the like.

The thickness of the polarizer is not particularly limited, but is preferably 1 to 60 μm, more preferably 1 to 30 μm, and still 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 or the like) can be used.
Specifically as a polymer which comprises a polymer film, For example, A cellulose polymer; An acrylic polymer which has acrylic acid ester polymers, such as a polymethyl methacrylate and a lactone ring containing polymer; A thermoplastic norbornene-type polymer; A polycarbonate system Polymers; Polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; Styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); Polyolefin-based polymers such as polyethylene, polypropylene and ethylene-propylene copolymer; Vinyl chloride Based polymers; amide based polymers such as nylon and aromatic polyamides; imide based polymers; sulfone based polymers; polyether sulfone based polymers; polyether ether ketone Polymers; polyphenylene sulfide polymers; vinylidene chloride polymer; vinyl alcohol-based polymer, vinyl butyral-based polymers; arylate polymers; polyoxymethylene polymers, epoxy-based polymers; or polymers obtained by mixing these polymers.

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

Although the thickness of the polymer film used for a polarizer protective film etc. is not specifically limited, 40 micrometers or less are preferable from the reasons that thickness of an optical laminated body can be made thin. The lower limit is not particularly limited, but 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, and still more preferably 5 to 20 μm. In addition, the thickness of the said support body means the thickness of the sum total of these thickness, when it has both a polarizer and a polymer film.

In the aspect using a polymer film as a support which can be peeled off from the optical laminate, a cellulose 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 and more preferably 20 μm to 90 μm from the viewpoint of handling at the time of production and the like. The interface to be peeled off may be between the support and the photoalignment film, may be between the photoalignment film and the optically anisotropic layer, or may be another interface.

[Image display device]
The optical layered body of the present invention can be used preferably in the production of an image display device because the thickness of the support can be peeled off.
The display element used for an image display apparatus is not specifically limited, For example, a liquid crystal cell, organic electroluminescence (it abbreviates to "EL" hereafter) display panel, a plasma display panel etc. are mentioned.
Among these, a liquid crystal cell and an organic EL display panel are preferable, and a liquid crystal cell is more preferable. That is, the image display device is preferably 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, and more preferably a liquid crystal display device.

[Liquid crystal display device]
The liquid crystal display device which is an example of an image display device is a liquid crystal display device which has the optical laminated body of this invention mentioned above, 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 a polarizing plate on the front side.
Hereinafter, the liquid crystal cell constituting the liquid crystal display device will be described in detail.

<Liquid crystal cell>
The liquid crystal cell used for 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. It is not limited to
In the TN mode liquid crystal cell, rod-like liquid crystalline molecules (rod-like liquid crystalline compounds) are substantially horizontally aligned when no voltage is applied, and are further twisted at 60 to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.
In the VA mode liquid crystal cell, rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied. In a VA mode liquid crystal cell, (1) a narrow definition VA mode liquid crystal cell in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and substantially horizontally aligned when a voltage is applied (2) A liquid crystal cell (in multi-domain vertical alignment (MVA) mode) liquid crystal cell (SID 97, Digest of tech. Papers (preliminary paper)) in which the VA mode is multi-domained in order to widen the viewing angle. 28) (1997) 845), (3) in a mode (n-ASM mode (Axially symmetric aligned microcell)) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied, and twisted multidomain aligned when voltage is applied Liquid Crystal Cell Liquid crystal cells (described in LCD (International Liquid Crystal Display) International 98) are included, as described in US Pat. No. 59 (1998) and (4) SUR VIVAL (Super Ranged Viewing by Vertical Alignment) mode. Moreover, any of PVA (Pattered Vertical Alignment) type, optical alignment type (Optical Alignment), and PSA (Polymer-Sustained Alignment) may be used. The details of these modes are described in detail in JP-A-2006-215326 and JP-A-2008-538819.
In the liquid crystal cell of the IPS mode, rod-like liquid crystalline molecules are aligned substantially parallel to the substrate, and the liquid crystalline molecules respond in a planar manner by the application of 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. Japanese Patent Application Laid-Open Nos. 10-54982, 11-202323 and 9-292522 are methods for reducing the leaked light during black display in an oblique direction using an optical compensation sheet to improve the viewing angle. No. 11-133408, 11-305217, 10-307291 and the like.

Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, proportions, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Accordingly, the scope of the present invention should not be construed as limited by the following examples.

[Synthesis of Monomer mA-1]
According to the method described in Langmuir, 32 (36), 9245-9253 (2016), 2-hydroxyethyl methacrylate (HEMA) (Tokyo Kasei's reagent) and cinnamon are used as monomers to form the above-mentioned repeating unit A-1 Monomer mA-1 shown below was synthesized using acid chloride (Tokyo Kasei Reagent).

[Synthesis of Monomer mA-2 etc.]
Monomers mA-2, mA-4, mA-6, mA-8, mA- shown below in the same manner as 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 monomers forming the above-mentioned repeating unit A-2 and the like.

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

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

[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>
A silica gel column was synthesized in the same manner as monomer mA-107, except that the raw material 2-hydroxyethyl methacrylate (HEMA) was changed to the mA-116 intermediate and cinnamic acid chloride was changed to the corresponding cinnamic acid chloride derivative. By purification with (developing solvent hexane / ethyl acetate = 4/1), a monomer mA-116 shown below in which the coupling site (1,4-cyclohexyl group) becomes 100% of the trans isomer was synthesized. The following monomer mA-116 corresponds to the monomer forming the trans form of the repeating unit A-116 described above.

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

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

[Synthesis of Monomer mB-3]
The following monomers mB-3 forming the repeating unit B-3 described above are known alcohols from 3-ethyl-3-oxetanemethanol and 2-methacryloyloxyethyl isocyanate (KAREZ MOI (registered trademark), Showa Denko KK). It synthesize | combined by the urethanization reaction which used and.

[Synthesis of Monomer mB-4]
The following monomers mB-4 which form the above-mentioned repeating unit B-4 are 3-ethyl-3-oxetanemethanol and 2- (2-isocyanatoethyloxy) ethyl methacrylate [Karenz MOI-EG (registered trademark), Showa Denko Manufactured by Kobayashi Chemical Industries, Ltd. from urethanization reaction using a known alcohol and isocyanate.

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

[Monomer mD-1 etc.]
The following monomer mD-1 uses commercially available methacrylic acid (Wako Pure Chemical Industries, Ltd.), and 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 ester. The following monomer mD-5 uses commercially available -butyl methacrylate (Wako Pure Chemical Industries, Ltd.) using oxyethyl succinate (Shin-Nakamura Chemical Co., Ltd.), and the following monomer mD-7 uses commercially available 2-methacryloyloxyethyl phthalic acid (New The following monomer mD-12 used commercially available 2-hydroxyethyl methacrylamide (Tokyo Kasei Kogyo Co., Ltd.).
The following monomers mD-1 and the like correspond to the monomers forming the above-described repeating unit D-1 and the like.

[Monomer mE-1]
In 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. Next, 126.8 g of 3-chloropropionyl chloride was added dropwise and stirred for 3 hours under ice cooling.
The reaction solution is cooled to room temperature, and then 1000 mL of ethyl acetate is separated and washed with 1 N hydrochloric acid, a saturated aqueous solution of sodium hydrogen carbonate and water, and the obtained organic layer is dried over 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 the monomer forming the precursor of the above-mentioned repeating unit E-1 (ie, the unit before changing to an acryloyl group by deprotection).

[Other monomer]
The following monomer mF-1 was used which was synthesized according to Synthesis Example 3 described in JP-A-2014-12823.
Moreover, the following monomer mF-2 used commercially available glycidyl methacrylate (Tokyo Kasei Reagent).

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

Example 1
In a flask equipped with a condenser, a thermometer and a stirrer, 5 parts by mass of 2-butanone as a solvent was charged, and the flask was heated to reflux with a nitrogen bath flowing 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 of 2-butanone as a solvent The solution which mixed parts was dripped over 3 hours, and it stirred, maintaining reflux condition for another 3 hours. After completion of the reaction, the reaction solution was allowed to cool to room temperature, and 30 parts by mass of 2-butanone was added and diluted to obtain a polymer solution of about 20% by mass. The resulting polymer solution is poured into a large excess of methanol to precipitate the polymer, and the collected precipitate is separated by filtration, washed with a large amount of methanol and then air-dried at 50 ° C. for 12 hours, A polymer P-1 having a photoalignable group was obtained.

[Examples 2 to 28 and Comparative Examples 1 to 4]
As the monomers forming the repeating units shown in Table 1 below, using the synthesized monomers, the addition amount of the polymerization initiator is changed so as to obtain the weight average molecular weight shown in Table 1 below, A polymer was synthesized in the same manner as the polymer P-1 synthesized in Example 1 except that the blending amount of the monomers was changed so as to be the content.
The ratio of the blending amounts (parts by mass) of the respective 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 photo alignment film]
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 with respect to 100 parts by mass of tetrahydrofuran, and a composition for photo alignment film Prepared.
With respect to each polymer 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 added to 100 parts by mass of tetrahydrofuran A composition for alignment film was prepared.

[Production of Optical Laminate]
Optical laminates of Examples 2, 5, 7 to 9, 11, 14, 16, 20 to 28 and Comparative Examples 1 to 4 were produced by the following procedure.
As a cellulose acylate film, the same one as Comparative Example 1 of JP-A-2014-164169 was used.
The composition for each light alignment film prepared above was applied to one side of this film by a bar coater. After application, the solvent was removed by drying for 5 minutes on a hot plate at 80 ° C. to form a 0.2 μm thick photoisomerization composition layer. The obtained photoisomerization composition layer was irradiated with polarized ultraviolet light (10 mJ / cm ² , using an ultra-high pressure mercury lamp) to form a photo alignment film.
Next, a nematic liquid crystal compound (ZLI-4792, manufactured by Merck) was coated on the photoalignment film with a bar coater to form a composition layer. The composition layer thus formed was heated to 90 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation.
Thereafter, the temperature is maintained at 60 ° C., and the orientation is fixed by ultraviolet irradiation (500 mJ / cm ² , using an ultra-high pressure mercury lamp) under nitrogen atmosphere (oxygen concentration 100 ppm) to form a 2.0 μm thick optically anisotropic layer , And an optical laminate was produced.

[Example 29]
An optical laminate was produced in the same manner as in Example 16, except that the coating liquid for an optically anisotropic layer (liquid crystal 101) shown below was used in place 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 solution for optically anisotropic layer (liquid crystal 101)
── ─ ──
Liquid crystal compound L-1: 80.00 parts by mass Liquid crystal compound L-2: 20.00 parts by mass Polymerization initiator (IRGACURE 184, manufactured by BASF AG)
3.00 parts by mass of a polymerization initiator (IRGACURE OXE-01, manufactured by BASF)
3.00 parts by mass-leveling agent (the following compound G-1) 0.20 parts by mass-methyl ethyl ketone 424.8 parts by mass----------------- ――――――――――――

[Example 30]
An optical laminate was produced in the same manner as in Example 16, except that the coating liquid for an optically anisotropic layer (liquid crystal 102) shown below was used in place 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 solution for optically anisotropic layer (liquid crystal 102)
――――――――――――――――――――――――――――――――――――
Liquid crystal compound L-3 42.00 parts by mass Liquid crystal compound L-4 42.00 parts by mass Polymerizable compound A-1 16.00 parts by mass Polymerization initiator S-1 (oxime type) 0.50 parts by mass, leveling agent (the above compound G-1) 0.20 parts by mass, Hysorb MTEM (manufactured by Toho Chemical Industry Co., Ltd.) 2.00 parts by mass, NK ester A-200 (manufactured by Shin-Nakamura Chemical Co., Ltd.) 1.00 parts by mass and 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 substituted with an ethylene group), and the following liquid crystal compounds L-3 and L-4 Represents a mixture of regioisomers different in the position of the methyl group.

[Liquid crystal orientation]
About the produced optical laminated body, it observed in the state which shifted 2 degrees from the extinction position using the polarization microscope. As a result, it evaluated by the following criteria. The results are shown in Table 2 below.
AAA: The liquid crystal director is uniformly aligned and aligned, and the surface condition and display performance are extremely excellent. AA: the liquid crystal director is uniformly aligned and aligned, and the display performance is excellent. A: the liquid crystal director is not disturbed and the surface condition is stabilized. B: The disturbance of the liquid crystal director is minimal and the surface is stable C: The disturbance of the liquid crystal director is partial and the surface is stable D: the liquid crystal director is largely disturbed and the surface In the present specification, the term “stable planar shape” refers to unevenness or orientation when observed by placing an optical laminate between two polarizing plates arranged in crossed nicols. It is intended that there is no defect such as a defect.
Further, in the specification of the present application, a liquid crystal director intends a vector in a direction (alignment main axis) in which the major axis of liquid crystalline molecules is aligned.

[Peelability]
About the produced 80 mm x 25 mm optical laminated body, only the 50 mm x 25 mm part was bonded to the glass substrate. Under the present circumstances, it bonded together on the surface at the side of the optically anisotropic layer of an optical laminated body using the adhesive (The Soken Chemical make, SK dyne 2057).
Subsequently, the peeling force when the optical laminated body was peeled in the direction of 90 ° with respect to the fixed glass substrate was measured with a Tentiron universal material tester (manufactured by ORIENTEC Co., Ltd.), and evaluated based on the following criteria. The results are shown in Table 2 below.
A: Peeling force 0.01 to 0.10 N / 25 mm B: Peeling force 0.11 to 0.20 N / 25 mm C: Peeling force 0.21 to 0.50 N / 25 mm D: Peeling impossible

From the results shown in Table 2, it was found that the photoalignment film using the polymer having no repeating unit containing a crosslinkable group was inferior in both the liquid crystal alignment and the releasability (Comparative Example 1).
Moreover, even when it is a case where it has a repeating unit containing a crosslinkable group, the photo-alignment film using a copolymer having a repeating unit containing a crosslinkable group which does not fall under the above formula (B) is inferior in releasability. Were found (Comparative Examples 2 and 3).
In addition, a photoalignment film using a copolymer having a repeating unit containing a photoalignable group that does not fall under the above formula (A) and a repeating unit B containing a crosslinkable group represented by the above formula (B) The liquid crystal alignment was found to be inferior (Comparative Example 4).

On the other hand, photoalignment using a copolymer having a repeating unit A containing a photoalignable group represented by the above formula (A) and a repeating unit B containing a crosslinkable group represented by the above formula (B) All the films were found to have good liquid crystal alignment and releasability (Examples 2, 5, 7 to 9, 11, 14, 16, 20 to 30).
In particular, when R ^{4 in the} above-mentioned formula (A) is an alkoxy group having 6 to 14 carbon atoms, the liquid crystal alignment can be further improved in comparison with Examples 11, 14, 16 and 26 to 28. I understood.

[Example 31]
As a monomer which forms a repeating unit shown in the following Table 3, it synthesize | combined in Example 1 except having changed the compounding quantity of the monomer so that it might become content of the repeating unit shown in following Table 3 using each monomer synthesize | combined. Polymer P-29 was synthesized in the same manner as for polymer P-1. The weight average molecular weight of the synthesized polymer P-29 was 36000.

[Examples 32 to 36]
As a monomer which forms a repeating unit shown in the following Table 3, it synthesize | combined in Example 31 except having changed the compounding quantity of the monomer so that it might become content of the repeating unit shown in following Table 3 using each monomer synthesize | combined. Polymers P-30 to P-34 were synthesized in the same manner as the polymer P-29.

[Preparation of composition for photo alignment film]
Each composition for photo alignment layers was prepared in the same manner as in Example 2 except that Polymers P-29 to P-34 were used instead of Polymer P-2.

[Production of Optical Laminate]
The optical laminates of Examples 31 to 36 and Example 7 were produced by the following procedure.
As a cellulose acylate film, the same one as Comparative Example 1 of JP-A-2014-164169 was used.
The composition for each light alignment film prepared above was applied to one side of this film by a bar coater. After application, the solvent was removed by drying for 5 minutes on a hot plate at 80 ° C. to form a 0.2 μm thick photoisomerization composition layer. The obtained photoisomerization composition layer was irradiated with polarized ultraviolet light (10 mJ / cm ² , using an ultra-high pressure mercury lamp) to form a photo alignment film.
Next, a nematic liquid crystal compound (ZLI-4792, manufactured by Merck) was coated on the photoalignment film with a bar coater to form a composition layer. The composition layer thus formed was heated to 90 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation.
Thereafter, the temperature is maintained at 60 ° C., and the orientation is fixed by ultraviolet irradiation (5 mJ / cm ² , using ultra-high pressure mercury lamp) under nitrogen atmosphere (oxygen concentration 100 ppm) to form a 2.0 μm thick optically anisotropic layer , And an optical laminate was produced.

About the produced optical laminated body, it observed in the state which shifted 2 degrees from the extinction position using the polarization microscope. As a result, it evaluated by the following criteria. The results are shown in Table 3 below.
AAA: The liquid crystal director is uniformly aligned and aligned, and the surface condition and display performance are extremely excellent. AA: the liquid crystal director is uniformly aligned and aligned, and the display performance is excellent. A: the liquid crystal director is not disturbed and the surface condition is stabilized. B: The disturbance of the liquid crystal director is minimal and the surface is stable C: The disturbance of the liquid crystal director is partial and the surface is stable D: the liquid crystal director is largely disturbed and the surface Is unstable and display performance is very poor

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

[Example 37]
A 100 mL three-necked flask equipped with a condenser, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and the bath was heated to reflux while flowing nitrogen at 5 mL / min. Here, 4.17 parts by mass of monomer mA-98, 5.47 parts by mass of monomer mB-2, 0.36 parts by mass of monomer mE-1, and 2,2'-azobis (isobutyro) as a polymerization initiator. A solution prepared 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 make the temperature 60 ° C., 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 reaction solution was allowed to cool to room temperature, and 30 parts by mass of 2-butanone was added for dilution to obtain an about 20% by mass polymer solution. The resulting polymer solution is poured into a large excess of methanol to precipitate the polymer, and the collected precipitate is separated by filtration, washed with a large amount of methanol and then air-dried at 50 ° C. for 12 hours, A polymer P-35 having a photoalignable group was obtained. ^The compositional ratio (weight ratio) calculated by ¹ H-NMR was 42/55/3.

[Example 38]
A 100 mL three-necked flask equipped with a condenser, a thermometer, and a stirrer was charged with 5 parts by mass of 2-butanone as a solvent, and the bath was heated to reflux while flowing nitrogen at 5 mL / min. Here, 3.81 parts by mass of monomer mA-98, 5.41 parts by mass of monomer mB-2, 0.48 parts by mass of 2-hydroxyethyl methacrylate, and 2,2′-azobis (isobutyric acid) as a polymerization initiator A solution prepared by mixing 1 part by mass of ronitrile) 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 liquid, and the temperature was adjusted to 70 ° C. 0.43 g of 2-isocyanatoethyl methacrylate and 44 mg of neostanne U-830 were added and stirred at 70 ° C. for 6 hours. The repeating unit E-2 was formed by the reaction of the hydroxyl group derived from 2-hydroxyethyl methacrylate and 2-isocyanatoethyl methacrylate, and the reaction rate was calculated by ¹ H-NMR. After completion of the addition reaction of isocyanate, the reaction solution was allowed to cool to room temperature, and 30 parts by mass of 2-butanone was added for dilution to obtain a polymer solution of about 20% by mass. The resulting polymer solution is poured into a large excess of methanol to precipitate the polymer, and the collected precipitate is separated by filtration, washed with a large amount of methanol and then air-dried at 50 ° C. for 12 hours, A polymer P-36 having a photoalignable group was obtained. ^The compositional ratio (weight ratio) calculated by ¹ H-NMR was 40/53/7.

[Evaluation of liquid crystal alignment and releasability]
<Preparation of composition for photo alignment film>
Each composition for photo alignment film was prepared in the same manner as in Example 2 except that Polymers P-35 to P-36 were used instead of Polymer P-2.
<Preparation of Optical Laminate>
As a cellulose acylate film, the same one as Comparative Example 1 of JP-A-2014-164169 was used.
The composition for each light alignment film prepared above was applied to one side of this film by a bar coater. After application, the solvent was removed by drying for 5 minutes on a hot plate at 80 ° C. to form a 0.2 μm thick photoisomerization composition layer. The obtained photoisomerization composition layer was irradiated with polarized ultraviolet light (10 mJ / cm ² , using an ultra-high pressure mercury lamp) to form a photo alignment film.
Next, the coating solution for the optically anisotropic layer (liquid crystal 101) similar to that of Example 29 was coated on the photoalignment film with a bar coater to form a composition layer. The composition layer thus formed was heated to 90 ° C. on a hot plate and then cooled to 60 ° C. to stabilize the orientation.
Thereafter, the temperature is maintained at 60 ° C., and the orientation is fixed by ultraviolet irradiation (500 mJ / cm ² , using an ultra-high pressure mercury lamp) under nitrogen atmosphere (oxygen concentration 100 ppm) to form a 2.0 μm thick optically anisotropic layer , And an optical laminate was produced.
The prepared 80 mm × 25 mm optical laminate was evaluated for liquid crystal alignment and releasability in the same manner as in Example 2 and the like. The results are shown in Table 4 below.

[Evaluation of strength]
About the produced 80 mm x 25 mm optical laminated body, only the 50 mm x 25 mm part was bonded to the glass substrate. Under the present circumstances, it bonded together on the surface at the side of the optically anisotropic layer of an optical laminated body using the adhesive (The Soken Chemical make, SK dyne 2057).
Then, the bonded optical laminate was pulled in the direction of 90 ° with respect to the fixed glass substrate to peel off the cellulose acylate film in the optical laminate.
Next, the surface from which the cellulose acylate film has been peeled is bonded with another cellulose cellulose acylate film (hereinafter abbreviated as "TAC" in this paragraph) using an adhesive (SK Dyne 2057, manufactured by Soken Chemical Co., Ltd.) did. As the TAC, the same one as in Comparative Example 1 of JP-A-2014-164169 was used.
Thus, a laminate for evaluation having a TAC, a pressure-sensitive adhesive, a photoalignment film, an optically anisotropic layer, a pressure-sensitive adhesive and a glass substrate in this order was produced.
With respect to the produced evaluation laminate, using a TENSILON universal material tester (manufactured by ORIENTEC Co., Ltd.), TAC was held, and a force was applied to the fixed glass substrate in a 90 ° direction.
At that time, the presence or absence of liberation of the components of the optically anisotropic layer and the photo alignment film was measured using Nicolet 6700 (manufactured by Thermo Fisher Scientific Co., Ltd.) with an adhesive (layer) adjacent to TAC. The strength was evaluated on the basis of The results are shown in Table 4 below. Here, after the peeling test, the state in which the component of the photo alignment film or the optically anisotropic layer was attached to the adhesive (layer) adjacent to the TAC was regarded as “free”.
A: The component of the optically anisotropic layer or the photoalignment film is not released even with a force of 5 N / 25 mm. B: The component of the optically anisotropic layer or the photo alignment film is released by the force of 0.5 N or more and 5 N / 25 mm. : A component of the optically anisotropic layer or photo alignment film is 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 photo alignment film using the copolymer having the repeating unit E represented by the above formula (E) has good liquid crystal alignment and releasability. I found that. Also, from the comparison results with Example 24, it was found that the strength of the optical laminate was also improved.

Claims

A photoalignable copolymer having a repeating unit A containing a photoalignable group represented by the following formula (A) and a repeat unit B containing a crosslinkable 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 each independently represent a hydrogen atom or a substituent. Two adjacent groups among R 2 , R 3 , R 4 , R 5 and R 6 may be combined 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 in the formula (A) and L 2 in the formula (B) are each independently a linear, branched or cyclic alkylene having 1 to 10 carbon atoms which may have a substituent X Group, at least two 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 It represents a divalent linking group in which the above groups are combined.
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, 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 Is a substituent of
L 1 in the formula (A) is at least a linear alkylene group having 1 to 10 carbon atoms which may have a substituent X, and 3 to 10 carbons which may have a substituent X The photoalignable co-weight according to claim 1, which is a divalent linking group containing any one of a cyclic alkylene group of the following and an arylene group having 6 to 12 carbon atoms which may have a substituent Y. United.
L 1 in the formula (A) is at least a linear alkylene group of 1 to 10 carbon atoms which may have a substituent X, or 3 carbons which may have a substituent X The photoalignable copolymer according to claim 2, which is a divalent linking group containing a cyclic alkylene group of -10.
The photoalignable coweight according to any one of claims 1 to 3, wherein at least R 4 represents a substituent among R 2 , R 3 , R 4 , R 5 and R 6 in the formula (A) United.
The photoalignable copolymer according to claim 4, wherein each of R 2 , R 3 , R 5 and R 6 in the formula (A) represents a hydrogen atom.
The photoalignable copolymer according to claim 4 or 5, wherein R 4 in the formula (A) is an electron donating substituent.
The photoalignable copolymer according to claim 6, wherein R 4 in the formula (A) is an alkoxy group having 4 to 18 carbon atoms.
The substituents represented by R 2 , R 3 , R 4 , R 5 and R 6 in the above formula (A) are each independently a halogen atom or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms A linear halogenated alkyl 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, The photoalignable copolymer according to any one of claims 1 to 7, which is a group represented by the following formula (1).

In the formula (1), * represents a bonding position to a benzene ring in the formula (A), and R 9 represents a monovalent organic group.
The photoalignable coweight according to any one of claims 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 mass ratio: United.
0.2 ≦ a / (a + b) ≦ 0.8 (2)
The photoalignable copolymer according to claim 9, wherein the content a of the repeating unit A and the content b of the repeating unit B satisfy the following formula (3) by mass ratio.
0.2 ≦ a / (a + b) ≦ 0.6 (3)
Furthermore, repeating unit C containing a crosslinkable group represented by the following formula (C), repeating unit D containing a crosslinkable group represented by the following formula (D), and crosslinking represented by the following formula (E) The photoalignable copolymer according to any one of claims 1 to 10, which has at least one kind of repeating unit selected from the group consisting of repeating units E containing a property group.

In formula (C), R 10 represents a hydrogen atom or a methyl group, and L 3 represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X And 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 And a divalent linking group obtained by combining the groups of
In formula (D), R 11 represents a hydrogen atom or a methyl group, and L 4 represents a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent X Or 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 It represents a divalent linking group in which the above groups are combined, and Q represents any one of -OH, -COOH and -COOtBu.
In the formula (E), R 12 represents a hydrogen atom or a methyl group, L 5 is linear and having 1 carbon atoms which may 18 have a substituent X, branched or cyclic alkylene group Or 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 It represents a divalent linking group in which the above groups 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, 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 Is a substituent of
The photoalignable copolymer according to any one of claims 1 to 11, which has a weight average molecular weight of 10000 to 500000.
The photoalignable copolymer according to claim 12, having a weight average molecular weight of 30,000 to 200,000.
A photoalignment film formed using a composition for photoalignment film containing the photoalignment copolymer according to any one of claims 1 to 13.
An optical laminate comprising the photoalignment film according to claim 14 and an optically anisotropic layer formed using a liquid crystal composition containing a liquid crystalline compound.