阅读说明：本技术 光取向性聚合物、粘合剂组合物、粘合剂层、光学层叠体、光学层叠体的制造方法及图像显示装置 (Photo-alignment polymer, adhesive composition, adhesive layer, optical laminate, method for producing optical laminate, and image display device ) 是由 田村显夫 犬岛玲子 饭泉隆史 野副宽 西川秀幸 中川一茂 渥美匡广 于 2018-05-25 设计创作，主要内容包括：本发明的课题在于提供一种涂布性优异、能够抑制膜厚不均匀、形成为层之后上层涂布性优异、液晶取向性也良好的光取向性聚合物、粘合剂组合物、粘合剂层、光学层叠体、光学层叠体的制造方法及图像显示装置。本发明的光取向性聚合物为具有重复单元A的光取向性聚合物,所述重复单元A包含通过选自由光、热、酸及碱组成的组中的至少一种的作用进行分解而产生极性基团的裂解基团,重复单元A在侧链上具有裂解基团,并且,在侧链的比裂解基团更靠末端侧具有氟原子或硅原子,所述光取向性聚合物满足以下所示的条件1或条件2。条件1：除了重复单元A以外,还具有包含光取向性基团的重复单元B。条件2：重复单元A在侧链的比裂解基团更靠主链侧包含光取向性基团。(The invention provides a photo-alignment polymer, an adhesive composition, an adhesive layer, an optical laminate, a method for manufacturing the optical laminate, and an image display device, which have excellent coating performance, can inhibit uneven film thickness, have excellent coating performance of an upper layer after being formed into a layer, and have good liquid crystal alignment performance. The photo-alignment polymer of the present invention is a photo-alignment polymer having a repeating unit a including a cleavage group that is decomposed by an action of at least one selected from the group consisting of light, heat, acid, and base to generate a polar group, the repeating unit a having the cleavage group in a side chain, and a fluorine atom or a silicon atom in the side chain on a terminal side of the side chain with respect to the cleavage group, and the photo-alignment polymer satisfying the following condition 1 or condition 2. Condition 1: the photo-alignment layer contains a repeating unit B containing a photo-alignment group in addition to the repeating unit A. Condition 2: the repeating unit a includes a photo-alignment group on the side chain closer to the main chain than the cleavage group.)

1. A photo-alignment polymer having a repeating unit A including a cleavage group which is decomposed by the action of at least one selected from the group consisting of light, heat, an acid and a base to generate a polar group,

the repeating unit A has the cleavage group in a side chain, and has a fluorine atom or a silicon atom on a terminal side of the side chain than the cleavage group,

the photo-alignment polymer satisfies the following condition 1 or condition 2,

condition 1: a repeating unit B containing a photo-alignment group in addition to the repeating unit A,

condition 2: the repeating unit A includes a photo-alignment group on the main chain side of the side chain than the cleavage group.

2. The photo-alignment polymer according to claim 1,

the photo-alignment polymer satisfies the condition 1,

the repeating unit A is a repeating unit represented by the following formula (1) or a repeating unit represented by the following formula (2-1) or (2-2),

the repeating unit B is a repeating unit represented by the following formula (3) or a repeating unit represented by the following formula (4-1) or (4-2),

here, in the formulae (1), (2-1), (3) and (4-1), R¹Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a plurality of R in the formulae (1) and (3)¹May be the same or different from each other,

and, in the above-mentioned formulae (1), (2-1) and (2-2), X¹And X²Each independently represents a single bond or a 2-valent linking group, RK represents the cleavage group, RL represents a 1-valent organic group containing a fluorine atom or a silicon atom,

and, in the above-mentioned formulae (3), (4-1) and (4-2), X¹Represents a single bond or a 2-valent linking group, and RO represents the photo-alignment group.

3. The photo-alignment polymer according to claim 1,

the photo-alignment polymer satisfies the condition 2,

the repeating unit A is a repeating unit represented by the following formula (5) or a repeating unit represented by the following formula (6-1) or (6-2),

here, in the formulae (5) and (6-1), R¹Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a plurality of R in the formula (5)¹May be the same or different from each other,

and, in the above-mentioned formulae (5), (6-1) and (6-2), X¹、X²And X³Each independently represents a single bond or a 2-valent linking group, RK represents the cleavage group, RL represents a 1-valent organic group containing a fluorine atom or a silicon atom, and RO represents the photo-alignment group.

4. The photo-alignment polymer according to claim 2,

RK in the formulae (1), (2-1) and (2-2) is a cleavage group represented by any one of the following formulae (RK-1) to (RK-13),

in the formulae (rk-1) to (rk-13), 1 represents X in the formulae (1), (2-1) and (2-2)¹And X²2 represents a bonding position with X in the above formulae (1), (2-1) and (2-2)¹And X²Wherein R represents independently a hydrogen atom or a 1-valent organic group, respectively.

5. The photo-alignment polymer according to claim 3, wherein,

RK in the formulas (5), (6-1) and (6-2) is a cleavage group represented by any one of the following formulas (RK-1) to (RK-13),

in the formulae (rk-1) to (rk-13), 1 represents X in the formulae (5), (6-1) and (6-2)³And X²2 represents a bond site with X in the above formulae (5), (6-1) and (6-2)³And X²Wherein R represents independently a hydrogen atom or a 1-valent organic group, respectively.

6. The photo-alignment polymer according to claim 2 or 4, wherein,

the photo-alignment polymer satisfies the condition 1,

the repeating unit A is a repeating unit represented by the following formula (7),

the repeating unit B is a repeating unit represented by the following formula (8),

in the above formulae (7) and (8), R¹Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R represents a hydrogen atom or a 1-valent organic group, and each of R may be the same or different,

in the formula (7), X represents a hydrogen atom or a fluorine atom, ma and na each independently represent an integer of 1 to 20,

in the formula (8), L represents a linking group having a valence of 2, and Y represents a hydrogen atom or an organic group having a valence of 1.

7. An adhesive composition comprising an adhesive and the photo-alignment polymer according to any one of claims 1 to 6.

8. An adhesive layer formed using the adhesive composition of claim 7.

9. An optical laminate comprising the adhesive layer according to claim 8 and an optically anisotropic layer provided on the adhesive layer,

the optically anisotropic layer is formed using a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound,

the adhesive layer and the optically anisotropic layer are laminated adjacent to each other.

10. A method for producing an optical laminate according to claim 9, comprising the steps of:

a first coating step of applying the adhesive composition according to claim 7 to a support;

a pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer after the 1 st coating step;

an action step of causing at least one selected from the group consisting of light, heat, acid, and alkali to act;

a light irradiation step of irradiating polarized light or unpolarized light;

a second coating step of directly coating the polymerizable liquid crystal composition for forming the optically anisotropic layer on the adhesive layer; and

an optically anisotropic layer forming step of forming an optically anisotropic layer after the 2 nd coating step,

the working step is performed between the pressure-sensitive adhesive layer forming step and the 2 nd coating step or simultaneously with the pressure-sensitive adhesive layer forming step or the 2 nd coating step,

the light irradiation step is performed between the pressure-sensitive adhesive layer formation step and the 2 nd coating step, or simultaneously with the pressure-sensitive adhesive layer formation step or the 2 nd coating step.

11. An image display device having the adhesive layer according to claim 8 or the optical laminate according to claim 9.

Technical Field

The present invention relates to a photo-alignment polymer, an adhesive composition, an adhesive layer, an optical laminate, a method for producing an optical laminate, and an image display device.

Background

Optical films such as optical compensation sheets and retardation films are used in various image display devices from the viewpoint of eliminating image coloration and widening a viewing angle.

A stretched birefringent film is used as the optical film, but in recent years, it has been proposed to use an optically anisotropic layer using a liquid crystal compound instead of the stretched birefringent film.

As such an optically anisotropic layer, it is known that an alignment film is provided on a support on which the optically anisotropic layer is formed in order to align a liquid crystal compound, and as the alignment film, a photo-alignment film subjected to photo-alignment treatment in place of rubbing treatment is known.

For example, patent document 1 discloses a liquid crystal alignment layer formed from a thermosetting film-forming composition containing an acrylic copolymer having a photo-dimerization site such as cinnamoyl group and a crosslinking agent ([ claim 1] [ claim 3] [ claim 11] [0028 ]).

Prior art documents

Patent document

Patent document 1: international publication No. 2010/150748

Disclosure of Invention

Technical problem to be solved by the invention

The present inventors have conducted studies to more rapidly produce an optical laminate having a liquid crystal alignment layer described in patent document 1 and the like and an optically anisotropic layer formed on the liquid crystal alignment layer and using a polymerizable liquid crystal composition, it is found that when a liquid crystal alignment layer is formed using a known fluorine-based surfactant, the coating property is good, further, it is also possible to suppress film thickness unevenness (hereinafter, also referred to as "wind unevenness") caused by drying wind during drying, but it is clear that depending on the type of fluorine-based surfactant used, there are cases where the coating property of a composition for an optically anisotropic layer provided on an upper layer of a liquid crystal alignment layer formed is poor (hereinafter, also referred to as "upper layer coating property"), and cases where the alignment property of the optically anisotropic layer formed is poor (hereinafter, also referred to as "liquid crystal alignment property").

Accordingly, an object of the present invention is to provide a photo-alignment polymer, an adhesive composition, an adhesive layer, an optical laminate, a method for producing an optical laminate, and an image display device, which have excellent coatability, can suppress unevenness in film thickness, have excellent coatability of an upper layer after formation of a layer, and have good liquid crystal alignment properties.

Means for solving the technical problem

As a result of intensive studies to achieve the above object, the present inventors have found that when a photo-alignment polymer having a repeating unit containing a cleavage group that is decomposed by the action of light or the like to generate a polar group in a side chain, a fluorine atom or a silicon atom on the side chain end side of the cleavage group, and a photo-alignment group so as to satisfy a predetermined condition is prepared, the photo-alignment polymer is excellent in coatability, can suppress unevenness in film thickness, is excellent in overcoatability after formation of a layer, and is also excellent in liquid crystal alignment, and have completed the present invention.

That is, it is found that the above-mentioned problems can be achieved by the following configuration.

[1] A photo-alignment polymer having a repeating unit A including a cleavage group that is decomposed by an action of at least one selected from the group consisting of light, heat, an acid, and a base to generate a polar group, wherein,

the repeating unit A has a cleavage group on a side chain, and has a fluorine atom or a silicon atom on a side chain terminal to the cleavage group,

the photo-alignment polymer satisfies the following condition 1 or condition 2.

Condition 1: the photo-alignment layer contains a repeating unit B containing a photo-alignment group in addition to the repeating unit A.

Condition 2: the repeating unit a includes a photo-alignment group on the side chain closer to the main chain than the cleavage group.

[2] The photo-alignment polymer according to [1], which satisfies condition 1, wherein the repeating unit A is a repeating unit represented by formula (1) or a repeating unit represented by formula (2-1) or (2-2), and the repeating unit B is a repeating unit represented by formula (3) or a repeating unit represented by formula (4-1) or (4-2).

[3] The photo-alignment polymer according to [1], which satisfies condition 2, wherein the repeating unit A is a repeating unit represented by formula (5) or a repeating unit represented by formula (6-1) or (6-2).

[4] The photo-alignment polymer according to [2], wherein RK in the formulae (1), (2-1) and (2-2) is a cleavage group represented by any one of formulae (RK-1) to (RK-13) described below.

[5] The photo-alignment polymer according to [3], wherein RK in the formulae (5), (6-1) and (6-2) is a cleavage group represented by any one of formulae (RK-1) to (RK-13) described below.

[6] The photo-alignment polymer according to [2] or [4], which satisfies condition 1, wherein the repeating unit A is a repeating unit represented by formula (7) described below, and the repeating unit B is a repeating unit represented by formula (8) described below.

[7] An adhesive composition comprising an adhesive and the photo-alignment polymer according to any one of [1] to [6 ].

[8] An adhesive layer formed using the adhesive composition of [7 ].

[9] An optical laminate comprising the adhesive layer according to [8] and an optically anisotropic layer provided on the adhesive layer, wherein in the optical laminate,

the optically anisotropic layer is formed by using a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound,

the adhesive layer and the optically anisotropic layer are laminated adjacent to each other.

[10] A method for producing an optical laminate according to [9], the method comprising:

a first coating step of coating the adhesive composition according to [7] on a support;

an adhesive layer forming step of forming an adhesive layer after the 1 st coating step;

an action step of causing at least one selected from the group consisting of light, heat, acid, and alkali to act;

a light irradiation step of irradiating polarized light or unpolarized light;

a second coating step of directly coating the polymerizable liquid crystal composition for forming the optically anisotropic layer on the adhesive layer; and

an optically anisotropic layer forming step of forming an optically anisotropic layer after the 2 nd coating step,

the working step is a step performed between the pressure-sensitive adhesive layer forming step and the 2 nd coating step or simultaneously with the pressure-sensitive adhesive layer forming step or the 2 nd coating step,

the light irradiation step is a step performed between the pressure-sensitive adhesive layer formation step and the 2 nd application step or simultaneously with the pressure-sensitive adhesive layer formation step or the 2 nd application step.

[11] An image display device comprising the adhesive layer according to [8] or the optical laminate according to [9 ].

Effects of the invention

According to the present invention, it is possible to provide a photo-alignment polymer, a pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer, an optical laminate, a method for producing an optical laminate, and an image display device, which have excellent coatability, can suppress unevenness in film thickness, have excellent coatability of an upper layer after formation of a layer, and have good liquid crystal alignment properties.

Detailed Description

The present invention will be described in detail below.

The following description of the constituent elements may be based on a representative embodiment of the present invention, but the present invention is not limited to such an embodiment.

In the present specification, the numerical range expressed by the term "to" means a range including the numerical values described before and after the term "to" as the lower limit value and the upper limit value.

[ photo-alignment Polymer ]

The photo-alignment polymer of the present invention is a photo-alignment polymer having a repeating unit a including a cleavage group that is decomposed by an action of at least one selected from the group consisting of light, heat, acid, and base to generate a polar group.

In the photo-alignment polymer of the present invention, the repeating unit a has a cleavage group in a side chain, and further has a fluorine atom or a silicon atom in the side chain on the terminal side of the cleavage group.

The photo-alignment polymer of the present invention has a photo-alignment group so as to satisfy the following condition 1 or condition 2.

Condition 1: the photo-alignment layer contains a repeating unit B containing a photo-alignment group in addition to the repeating unit A.

Condition 2: the repeating unit a includes a photo-alignment group on the side chain closer to the main chain than the cleavage group.

The "polar group" contained in the repeating unit a means a group having at least 1 atom or more of a hetero atom or a halogen atom, and specific examples thereof include a hydroxyl group, a carbonyl group, a carboxyl group, an amino group, a nitro group, an ammonium group, a cyano group and the like. Among them, hydroxyl group and carboxyl group are preferable.

Also, "polar group-generating cleavage group" means a group that generates the above-mentioned polar group by cleavage, but in the present invention, a group that reacts with an oxygen molecule after radical cleavage and generates a polar group is also included.

In the present invention, as described above, when a photo-alignment polymer having a repeating unit containing a cleavage group that is decomposed by the action of light or the like to generate a polar group in a side chain, a fluorine atom or a silicon atom on the side chain end side of the cleavage group, and a photo-alignment group so as to satisfy a predetermined condition is prepared, the coating property is excellent, the film thickness unevenness can be suppressed, the coating property on the upper layer after the formation of the layer is excellent, and the liquid crystal alignment property is also excellent.

The present inventors speculate as follows, although the detailed reason is not clear.

That is, it is considered that when a composition containing the photo-alignment polymer of the present invention is coated, the photo-alignment polymer itself of the present invention having a fluorine atom or a silicon atom in a side chain functions as a surfactant or a leveling agent, whereby the coating property becomes good and the film thickness unevenness can be suppressed.

After the layer is formed as a pressure-sensitive adhesive layer or the like, at least one selected from the group consisting of light, heat, acid, and alkali is allowed to act on the photo-alignment polymer of the present invention locally present on the air interface side, whereby the cleavage group contained in the side chain is decomposed to generate a polar group, and a substituent containing a fluorine atom or a silicon atom present on the terminal side of the side chain with respect to the cleavage group is removed, whereby the coating property of the upper layer becomes good.

After the formation of the adhesive layer, the optically anisotropic layer, or the like, the photo-alignment polymer of the present invention, which is locally biased toward the air interface side, is irradiated with light, whereby the photo-alignment groups are aligned, and the liquid crystal alignment property of the optically anisotropic layer formed on the upper layer is improved.

When the photo-alignment polymer of the present invention satisfies condition 1, it is preferable that the repeating unit a is a repeating unit represented by the following formula (1) or a repeating unit represented by the following formula (2-1) or (2-2), and the repeating unit B is a repeating unit represented by the following formula (3) or a repeating unit represented by the following formula (4-1) or (4-2), from the viewpoint of further suppressing the film thickness unevenness (wind unevenness).

Among these, the repeating unit a is more preferably a repeating unit represented by the following formula (1), and the repeating unit B is preferably a repeating unit represented by the following formula (3).

[ chemical formula 1]

In the above formulae (1), (2-1), (3) and (4-1), R¹Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R's in the formulae (1) and (3)¹The same or different.

As R¹Preferably a hydrogen atom or a methyl group.

And, in the above formulae (1), (2-1) and (2-2), X¹And X²Each independently represents a single bond or a 2-valent linking group, RK represents a cleavage group, and RL represents a 1-valent organic group containing a fluorine atom or a silicon atom.

X in the above formulae (1), (2-1) and (2-2)¹And X²Examples of the 2-valent linking group include at least one group selected from the group consisting of a linear, branched or cyclic alkylene group having 1 to 10 carbon atoms which may have a substituent, an arylene group having 6 to 12 carbon atoms which may have a substituent, an ether group (-O-), a carbonyl group (-C (-O-) and an imino (-NH-) which may have a substituent.

Examples of the substituent which the alkylene group, arylene group and imino group may have include an alkyl group, an alkoxy group, a halogen atom and a hydroxyl group.

The alkyl group is preferably a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclohexyl, etc.), further preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a methyl group or an ethyl group.

The alkoxy group is preferably an alkoxy group having 1 to 18 carbon atoms, more preferably an alkoxy group having 1 to 8 carbon atoms (e.g., methoxy group, ethoxy group, n-butoxy group, methoxyethoxy group, etc.), further preferably an alkoxy group having 1 to 4 carbon atoms, and particularly preferably a methoxy group or an ethoxy group.

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

The linear alkylene group having 1 to 10 carbon atoms may be, for example, a methylene group, a vinyl group, a propylene group, a butylene group, a pentylene group, a hexylene group, or a decenyl group.

Specific examples of the branched alkylene group include dimethylmethylene, methylethylene, 2-dimethylpropylene, and 2-ethyl-2-methylpropylene.

Specific examples of the cyclic alkylene group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a cyclodecenyl group, an adamantyl group, a norbornanediyl group and an exo-tetrahydrodicyclopentadiene-diyl group, and among them, a cyclohexyl group is preferable.

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

Examples of the cleavage group represented by RK in the above formulae (1), (2-1) and (2-2) include cleavage groups (bonds) represented by any of the following formulae (RK-1) to (RK-13).

[ chemical formula 2]

In the above formulae (rk-1) to (rk-13), 1 represents X in the formulae (1), (2-1) and (2-2)¹And X²2 represents a position bonded to X in the formulae (1), (2-1) and (2-2)¹And X²Wherein R represents independently a hydrogen atom or a 1-valent organic group, respectively.

Examples of the 1-valent organic group represented by R include a chain or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms which may have a substituent, and the like.

The anion moiety in the above formulae (rk-10) and (rk-11) is not particularly limited since it does not affect cleavage, and an inorganic anion or an organic anion can be used.

Specific examples of the inorganic anion include halide ions such as chloride ion and bromide ion; a sulfonate anion; and the like.

Specific examples of the organic anion include carboxylate anions such as acetate anion; organic sulfonate anions such as methane sulfonate anion and p-toluene sulfonate anion; and the like.

In the present invention, among these cleavage groups, a cleavage group represented by the above formula (rk-1) is preferable from the viewpoint of quantum efficiency when cleavage is performed using light, and a cleavage group represented by the above formula (rk-9) is preferable from the viewpoint of cleavage rate when cleavage is performed using an acid.

Examples of the 1-valent organic group containing a fluorine atom or a silicon atom, which is represented by RL in the above formulae (1), (2-1) and (2-2), include an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, in which at least one carbon atom has a fluorine atom as a substituent.

And, in the above formulae (3), (4-1) and (4-2), X¹Represents a single bond or a 2-valent linking group, and RO represents a photo-alignment group.

As in the above formulae (3), (4-1) and (4-2)X of (2)¹Examples of the linking group having a valence of 2 which is represented by the formula (1), (2-1) and (2-2) above include¹The same groups.

The photo-alignment group represented by RO in the above formulas (3), (4-1) and (4-2) means a group having a photo-alignment function of inducing rearrangement and anisotropic chemical reaction by irradiation with anisotropic light (for example, plane polarized light), and is preferably a photo-alignment group that generates at least one of dimerization and isomerization by the action of light, because it is excellent in uniformity of alignment and excellent in thermal stability and chemical stability.

Specific examples of the photo-alignment group that dimerizes by the action of light include a group having a skeleton of at least one derivative selected from the group consisting of cinnamic acid derivatives (m.schadt et al, j.appl.phys., vol.31, No.7, page 2155(1992)), coumarin derivatives (m.schadt et al, nature, vol.381, page 212(1996)), chalcone derivatives (junbo et al, proceedings of the liquid crystal symposium, 2AB03(1997)), maleimide derivatives, and benzophenone derivatives (y.k.jang et al, int sid.symposium Digest, P-53 (1997)).

On the other hand, as the photo-alignment group which is isomerized by the action of light, specifically, there may be suitably mentioned, for example, a group having at least one skeleton selected from the group consisting of azobenzene compounds (k.ichimura et al, mol.cryst.liq.cryst.,298,221(1997)), stilbene compounds (j.g.victor and j.m.torkels on, Macromolecules,20,2241(1987)), spiropyran compounds (k.ichimura et al, Chemistry Letters, page 1063(1992), k.ichimura et al, Thin solids, vol.235, page 101(1993)), cinnamic acid compounds (k.ichimura et al, M acromolecules,30, 903(s) (13, 13) and hydrazino- β -ketoester compounds (s.yamura et al, light solids, taqj.13, vol.1993).

Among these, the photo-alignment group is preferably a group having a skeleton of at least one derivative selected from the group consisting of a cinnamic acid derivative, a coumarin derivative, a chalcone derivative, a maleimide derivative, an azobenzene compound, a stilbene compound, and a spiropyran compound, and more preferably a group having a cinnamic acid derivative or a coumarin derivative skeleton.

When the photo-alignment polymer of the present invention satisfies condition 1, it is preferable that the repeating unit a is a repeating unit represented by formula (7) below and the repeating unit B is a repeating unit represented by formula (8) below from the viewpoint of the cleavage rate and the ease of synthesis when cleavage is performed using an acid.

[ chemical formula 3]

In the above formulae (7) and (8), R¹Represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R represents a hydrogen atom or a 1-valent organic group, and each of R may be the same or different.

In the formula (7), X represents a hydrogen atom or a fluorine atom, and ma and na each independently represent an integer of 1 to 20.

In the formula (8), L represents a linking group having a valence of 2, and Y represents a hydrogen atom or an organic group having a valence of 1.

Examples of the 1-valent organic group represented by R and Y include a chain or cyclic alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms which may have a substituent, and the like.

As R in the above formula (7)¹Preferably a hydrogen atom or a methyl group.

R in the formula (7) is preferably a hydrogen atom.

Further, ma in the above formula (7) is preferably 1 or 2, and na is preferably 3 to 7.

In the formula (7), X is preferably a fluorine atom.

Examples of the repeating unit a represented by the above formula (7) include repeating units obtained by polymerizing a monomer represented by any one of the following formulae (7-1) to (7-6).

[ chemical formula 4]

(7-1)

(7-2)

(7-3)

(7-4)

(7-5)

(7-6)

As R in the above formula (8)¹Preferably a hydrogen atom or a methyl group.

R in the formula (8) is preferably a hydrogen atom.

The 2-valent linking group represented by L in formula (8) includes, for example, a 2-valent linking group composed of at least one selected from the group consisting of a substituted or unsubstituted aliphatic chain group, a substituted or unsubstituted aliphatic cyclic group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, and among these, an aliphatic chain group, an aliphatic cyclic group, and a combination thereof are preferable, and an aliphatic chain group or an aliphatic cyclic group having 2 to 8 carbon atoms is more preferable.

Y in the formula (8) is preferably a hydrogen atom, a methoxy group, or a cyclohexyl group.

Examples of the repeating unit B represented by the above formula (8) include repeating units obtained by polymerizing a monomer represented by any one of the following formulae (8-1) to (8-6).

[ chemical formula 5]

(8-1)

(8-2)

(8-3)

(8-4)

(8-5)

(8-6)

When the photo-alignment polymer of the present invention satisfies the condition 1, it may have other repeating units in addition to the repeating unit a and the repeating unit B.

Examples of the monomer (radical polymerizable monomer) forming such another repeating unit include an acrylate compound, a methacrylate compound, a maleimide compound, an acrylamide compound, acrylonitrile, maleic anhydride, a styrene compound, and a vinyl compound.

Specifically, the photo-alignment polymer of the present invention satisfying condition 1 includes, for example, a copolymer using any one of the monomers represented by the above formulae (7-1) to (7-6), any one of the monomers represented by the above formulae (8-1) to (8-6), and any other repeating unit, and among them, copolymers represented by the following formulae C-1 to C-5 can be appropriately exemplified.

[ chemical formula 6]

C-1

C-2

C-3

C-4

C-5

On the other hand, when the photo-alignment polymer of the present invention satisfies condition 2, it is preferable that the repeating unit a is a repeating unit represented by formula (5) below or a repeating unit represented by formula (6-1) or (6-2) below from the viewpoint of liquid crystal alignment of the optically anisotropic layer formed on the upper layer.

Among these, the repeating unit a is more preferably a repeating unit represented by the following formula (5).

[ chemical formula 7]

In the above formulae (5) and (6-1), R¹A hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a plurality of R in the formula (5)¹The same or different.

As R¹Preferably a hydrogen atom or a methyl group.

And, in the above formulae (5), (6-1) and (6-2), X¹、X²And X³Each independently represents a single bond or a 2-valent linking group.

Here, X in the above formulae (5), (6-1) and (6-2) is defined as¹、X²And X³Examples of the linking group having a valence of 2 which is represented by the formula (1), (2-1) and (2-2) above include¹The same groups.

In the above formulae (5), (6-1) and (6-2), RK represents a cleavage group.

Examples of the cleavage group represented by RK in the formulae (5), (6-1) and (6-2) include cleavage groups (bonds) represented by any of the formulae (RK-1) to (RK-13) as in RK in the formulae (1), (2-1) and (2-2). In the above formulae (rk-1) to (rk-13), 1 represents X in the formulae (5), (6-1) and (6-2)³And X²2 represents a bonding position with X in the above formulae (5), (6-1) and (6-2)³And X²Wherein R represents independently a hydrogen atom or a 1-valent organic group, respectively.

In the formulae (5), (6-1) and (6-2), RO represents a photo-alignment group.

Examples of the photo-alignment group include the same photo-alignment groups represented by RO in the above formulas (3), (4-1) and (4-2).

Specific examples of the photo-alignment polymer of the present invention satisfying condition 2 include polymers represented by the following formulas H-1 to H-3.

[ chemical formula 8]

H-1

H-2

H-3

The weight average molecular weight (Mw) of the photo-alignment polymer of the present invention is preferably 1000 to 500000, more preferably 1500 to 400000, and particularly preferably 2000 to 300000.

The number average molecular weight (Mn) of the photo-alignment polymer of the present invention is preferably 500 to 250000, more preferably 1000 to 200000, and particularly preferably 1500 to 150000.

The degree of dispersion (Mw/Mn) of the photo-alignment polymer of the present invention is preferably 1.00 to 20.00, more preferably 1.00 to 18.00, and particularly preferably 1.00 to 16.00.

The weight average molecular weight and the number average molecular weight are values measured by Gel Permeation Chromatography (GPC) under the following conditions.

[ eluent ] Tetrahydrofuran (THF)

[ device name ] Ecosec HLC-8220GPC (manufactured by Tosoh Corporation)

[ column ] TSKgel SuperHZM-H, TSKgel SuperHZ4000, TSKgel SuperHZM200 (manufactured by Tosoh Corporation)

[ column temperature ]40 deg.C

[ flow Rate ]50 ml/min

[ adhesive composition ]

The adhesive composition of the present invention is a composition containing an adhesive and the photo-alignment polymer of the present invention.

The content of the photo-alignment polymer contained in the adhesive composition of the present invention is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of an adhesive described later.

[ adhesive ]

The binder contained in the binder composition of the present invention is not particularly limited, and may be a resin which is merely dried and cured (hereinafter, also referred to as "resin binder") and may be a polymerizable compound, such as a resin itself composed of only a resin having no polymerization reactivity.

< resin adhesive >

Specific examples of the resin binder include epoxy resins, diallyl phthalate resins, silicone resins, phenol resins, unsaturated polyester resins, polyimide resins, polyurethane resins, melamine resins, urea resins, ionomer resins, ethylene ethyl acrylate resins, acrylonitrile-acrylate-styrene copolymer resins, acrylonitrile-styrene resins, acrylonitrile-polyvinyl chloride-styrene copolymer resins, ethylene-vinyl acetate resins, ethylene-vinyl alcohol copolymer resins, acrylonitrile-butadiene-styrene copolymer resins, vinyl chloride resins, chlorinated polyethylene resins, polyvinylidene 1, 1-dichloroethylene resins, cellulose acetate resins, fluorine resins, polyoxymethylene resins, polyamide resins, polyarylate resins, and aromatic polycarbonate resins, Thermoplastic polyurethane elastomers, polyether ester ketone resins, polyether sulfone resins, polyethylene, polypropylene, polycarbonate resins, polystyrene-maleic acid copolymer resins, polystyrene-acrylic acid copolymer resins, polyphenylene ether resins, polyphenylene sulfide resins, polybutadiene resins, polybutylene terephthalate resins, acrylic resins, methacrylic resins, methylpentene resins, polylactic acid, polybutylene succinate resins, butyral resins, formaldehyde resins, polyvinyl alcohol, polyvinyl pyrrolidone, ethyl cellulose, carboxymethyl cellulose, gelatin, and copolymer resins thereof.

< polymerizable Compound >

Examples of the polymerizable compound include epoxy monomers, acrylic monomers, and oxetanyl monomers, and among them, epoxy monomers and acrylic monomers are preferable.

In the present invention, a polymerizable liquid crystal compound can be used as the polymerizable compound.

(epoxy monomer)

Examples of the epoxy group-containing monomer of the epoxy-based monomer include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, brominated bisphenol A-type epoxy resins, bisphenol S-type epoxy resins, diphenyl ether-type epoxy resins, hydroquinone-type epoxy resins, naphthalene epoxy resins, biphenyl epoxy resins, fluorene epoxy resins, phenol novolac epoxy resins, o-cresol novolac epoxy resins, trihydroxyphenyl methane type epoxy resin, trifunctional type epoxy resin, tetrahydroxyphenyl ethane type epoxy resin, dicyclopentadiene phenol type epoxy resin, hydrogenated bisphenol a type epoxy resin, bisphenol a type core-containing polyhydric alcohol type epoxy resin, polypropylene glycol type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, glyoxal type epoxy resin, alicyclic type epoxy resin, heterocyclic type epoxy resin, and the like.

(acrylic monomer)

Examples of the acrylic acid ester monomer and the methacrylic acid ester monomer of the acrylic acid monomer include trimethylolpropane triacrylate, trimethylolpropane PO (propylene oxide) -modified triacrylate, trimethylolpropane EO (ethylene oxide) -modified triacrylate, trimethylolpropane trimethacrylate, and pentaerythritol triacrylate, which are 3-functional monomers. Examples of the 4-or more functional monomer and oligomer include pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, and the like.

(polymerizable liquid Crystal Compound)

The polymerizable liquid crystal compound is not particularly limited, and for example, a compound capable of performing any one of vertical alignment, uniform alignment, hybrid alignment, and cholesteric alignment can be used.

Here, generally, liquid crystal compounds can be classified into rod-like types and disk-like types according to their shapes. Furthermore, there are low molecular and high molecular types, respectively. The polymer is a substance having a polymerization degree of usually 100 or more (polymer physical/phase transition kinetics, edited by Otto-Douglas, 2 pp., Shibo bookshop, 1992). In the present invention, any liquid crystal compound can be used, preferably a rod-like liquid crystal compound (hereinafter, also simply referred to as "CLC") or a discotic liquid crystal compound (hereinafter, also simply referred to as "DLC") is used, and preferably a monomer or a relatively low molecular weight liquid crystal compound having a polymerization degree of less than 100 is used.

Specific examples of the polymerizable group of the polymerizable liquid crystal compound include an acryloyl group, a methacryloyl group, an epoxy group, and a vinyl group.

By polymerizing such a polymerizable liquid crystal compound, the alignment of the liquid crystal compound can be fixed. In addition, after the liquid crystal compound is fixed by polymerization, it is no longer necessary to exhibit liquid crystallinity.

As the rod-like liquid crystal compound, for example, the compounds described in claim 1 of Japanese patent application laid-open No. 11-513019 or paragraphs [0026] to [0098] of Japanese patent application laid-open No. 2005-289980 can be preferably used, and as the disk-like liquid crystal compound, for example, the compounds described in paragraphs [0020] to [0067] of Japanese patent application laid-open No. 2007-laid-open No. 108732 or paragraphs [0013] to [0108] of Japanese patent application laid-open No. 2010-laid-open No. 244038 can be preferably used, but not limited thereto.

In the present invention, as the polymerizable liquid crystal compound, a liquid crystal compound having reverse wavelength dispersibility can be used.

Here, in the present specification, the liquid crystal compound of "reverse wavelength dispersibility" means that when the retardation (Re) value in the plane at a specific wavelength (visible light range) of a retardation film produced using the same is measured, the Re value becomes equal or higher as the measurement wavelength increases.

The liquid crystal compound having reverse wavelength dispersibility is not particularly limited as long as it is a compound capable of forming a film having reverse wavelength dispersibility as described above, and examples thereof include a compound represented by the general formula (I) described in japanese patent application laid-open No. 2008-297210 (particularly, compounds described in paragraphs [0034] to [0039 ]), a compound represented by the general formula (1) described in japanese patent application laid-open No. 2010-084032 (particularly, compounds described in paragraphs [0067] to [0073 ]), and a compound represented by the general formula (1) described in japanese patent application laid-open No. 2016-081035 (particularly, compounds described in paragraphs [0043] to [0055 ]).

Further, compounds described in paragraphs [0027] to [0100] of Japanese patent application laid-open No. 2011-006360, paragraphs [0028] to [0125] of Japanese patent application laid-open No. 2011-006361, paragraphs [0034] to [0298] of Japanese patent application laid-open No. 2012-207765, paragraphs [0016] to [0345] of Japanese patent application laid-open No. 2012-077055, paragraphs [0017] to [0072] of WO12/141245, paragraphs [0021] to [0088] of WO12/147904, and paragraphs [0028] to [0115] of WO14/147904 can be used.

[ polymerization initiator ]

When the adhesive composition of the present invention uses a polymerizable compound as an adhesive, it preferably contains a polymerization initiator.

Such a polymerization initiator is not particularly limited, and a thermal polymerization initiator and a photopolymerization initiator may be mentioned depending on the form of the polymerization reaction.

In the present invention, a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation is preferable.

Examples of the photopolymerization initiator include an α -carbonyl compound (described in U.S. Pat. Nos. 2367661 and 2367670), a ketol ether (described in U.S. Pat. No. 2448828), an α -hydrocarbon-substituted aromatic acyloin compound (described in U.S. Pat. No. 2722512), a polyquinone compound (described in U.S. Pat. Nos. 3046127 and 2951758), a combination of a triarylimidazole dimer and p-aminophenyl ketone (described in U.S. Pat. No. 3549367), an acridine and phenazine compound (described in Japanese patent application laid-open No. Sho 60-105667 and U.S. Pat. No. 4239850), an oxadiazole compound (described in U.S. Pat. No. 4212970), an acylphosphine oxide compound (described in Japanese patent application laid-open No. Sho 63-040799, Japanese patent application laid-open No. Hei 5-029234, an acylphosphine oxide compound, Japanese patent laid-open Nos. H10-095788 and H10-029997).

[ photoacid generators ]

When the photo-alignment polymer is a polymer having a specific group having a valence of 1 including a cleavage group which is decomposed by the action of an acid to generate a polar group, the binder composition of the present invention preferably contains a photoacid generator.

The photoacid generator is preferably a compound that is sensitive to active light having a wavelength of 300nm or more (preferably, 300 to 450nm) and generates an acid, but the chemical structure thereof is not limited. Further, the photoacid generator which is not directly sensitive to active light having a wavelength of 300nm or more can be preferably used in combination with a sensitizer as long as it is a compound which is sensitive to active light having a wavelength of 300nm or more and generates an acid by being used together with the sensitizer. The photoacid generator used in the present invention is preferably a photoacid generator that generates an acid having a pKa of 4 or less, more preferably a photoacid generator that generates an acid having a pKa of 3 or less, and most preferably a photoacid generator that generates an acid having a pKa of 2 or less. In the present invention, the pKa substantially refers to the pKa of water at 25 ℃. The pKa that cannot be measured in water means the pKa that is changed to a solvent suitable for the measurement and measured. Specifically, the pKa described in the chemical review and the like can be referred to. The acid having a pKa of 3 or less is preferably a sulfonic acid or a phosphonic acid, and more preferably a sulfonic acid.

Examples of the photoacid generator include onium salt compounds, trichloromethyl s-triazines, sulfonium salts, iodonium salts, quaternary ammonium salts, diazomethane compounds, imide sulfonate compounds, and oxime sulfonate compounds. Among these, onium salt compounds, imide sulfonate compounds and oxime sulfonate compounds are preferable, and onium salt compounds and oxime sulfonate compounds are particularly preferable. The photoacid generator can be used alone in1 kind or in combination of 2 or more kinds.

[ solvent ]

The pressure-sensitive adhesive composition of the present invention preferably contains a solvent from the viewpoint of workability of forming the pressure-sensitive adhesive layer and the like.

Specific examples of the solvent include ketones (e.g., acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone), ethers (e.g., dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (e.g., hexane, etc.), alicyclic hydrocarbons (e.g., cyclohexane, etc.), aromatic hydrocarbons (e.g., toluene, xylene, trimethylbenzene, etc.), halogenated carbons (e.g., dichloromethane, dichloroethane, dichlorobenzene, chlorotoluene, etc.), esters (e.g., methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (e.g., ethanol, isopropanol, butanol, cyclohexanol, etc.), cellosolves (e.g., methyl cellosolve, ethyl cellosolve, etc.), cellosolve acetates, sulfoxides (e.g., dimethyl sulfoxide, etc.), amides (e.g., dimethylformamide, dimethylacetamide, etc.), and 1 can be used alone, more than 2 kinds may be used simultaneously.

[ adhesive layer ]

The pressure-sensitive adhesive layer of the present invention is a layer formed using the pressure-sensitive adhesive composition of the present invention.

The method for forming the pressure-sensitive adhesive layer is not particularly limited, and when a polymerizable compound is used as the pressure-sensitive adhesive, it can be formed by a conventionally known method such as photo cation polymerization or radical polymerization.

[ optical layered body ]

The optical laminate of the present invention is an optical laminate having the adhesive layer of the present invention and an optically anisotropic layer provided on the adhesive layer.

In the optical laminate of the present invention, the optically anisotropic layer provided on the pressure-sensitive adhesive layer is formed using a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound, and the pressure-sensitive adhesive layer and the optically anisotropic layer are laminated adjacent to each other.

The optical laminate of the present invention preferably has a support for supporting the pressure-sensitive adhesive layer.

Preferred embodiments of the optical laminate of the present invention will be described in detail below.

[ support body ]

Examples of the support include a glass substrate and a polymer film.

Examples of the material of the polymer film include cellulose-based polymers; acrylic polymers having an acrylate polymer such as polymethyl methacrylate and polymers containing a lactone ring; a thermoplastic norbornene-based polymer; a polycarbonate-series polymer; polyester polymers such as polyethylene terephthalate and polyethylene naphthalate; styrene polymers such AS polystyrene and acrylonitrile-styrene copolymer (AS resin); polyolefin polymers such as polyethylene, polypropylene, and ethylene-propylene copolymers; a vinyl chloride polymer; amide polymers such as nylon and aromatic polyamide; an imide polymer; a sulfone-based polymer; a polyether sulfone-based polymer; a polyether ether ketone polymer; polyphenylene sulfide-based polymer; a vinylidene chloride polymer; a vinyl alcohol polymer; a vinyl butyral polymer; an aryl ester polymer; a polyoxymethylene polymer; an epoxy polymer; or a polymer obtained by mixing these polymers.

The thickness of the support is not particularly limited, but is preferably 5 to 200. mu.m, more preferably 10 to 100. mu.m, and still more preferably 20 to 90 μm.

[ adhesive layer ]

The adhesive layer is the adhesive layer of the present invention described above.

In the present invention, the thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

[ optically anisotropic layer ]

The optically anisotropic layer is formed using the polymerizable liquid crystal composition containing the polymerizable liquid crystal compound as described above.

Examples of the polymerizable liquid crystal composition for forming the optically anisotropic layer include a composition obtained by blending the polymerizable liquid crystal compound described as an optional component in the adhesive composition of the present invention, a polymerization initiator, a solvent, and the like.

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.

[ method for producing optical laminate ]

A method for producing an optical laminate according to the present invention is a method for producing the optical laminate according to the above preferred embodiment of the present invention, and includes: a first coating step of coating the adhesive composition of the present invention on the support; an adhesive layer forming step of forming an adhesive layer after the 1 st coating step; an action step of causing at least one selected from the group consisting of light, heat, acid, and alkali to act; a light irradiation step of irradiating polarized light or unpolarized light; a second coating step of directly coating the polymerizable liquid crystal composition for forming the optically anisotropic layer on the adhesive layer; and an optically anisotropic layer forming step of forming an optically anisotropic layer after the 2 nd coating step.

In the method for producing an optical laminate according to the present invention, the working step is performed between the pressure-sensitive adhesive layer-forming step and the 2 nd coating step or simultaneously with the pressure-sensitive adhesive layer-forming step or the 2 nd coating step.

In the method for producing an optical laminate according to the present invention, the light irradiation step is performed between the pressure-sensitive adhesive layer formation step and the 2 nd coating step or simultaneously with the pressure-sensitive adhesive layer formation step or the 2 nd coating step.

[1 st coating Process ]

The 1 st coating step is a step of coating the adhesive composition of the present invention on the support.

The method for applying the adhesive composition of the present invention is not particularly limited, and specific examples of the application method include spin coating, air knife coating, curtain coating, roll coating, wire bar coating, gravure coating, and die coating.

[ adhesive layer Forming Process ]

The pressure-sensitive adhesive layer forming step is a step of forming a pressure-sensitive adhesive layer after the 1 st coating step, and can be formed by subjecting the coating film obtained in the 1 st coating step to a curing treatment (irradiation of ultraviolet rays (light irradiation treatment) or heating treatment).

The conditions of the curing treatment are not particularly limited, and in polymerization by light irradiation, ultraviolet rays are preferably used. The irradiation dose is preferably 10mJ/cm²～50J/cm²More preferably 20mJ/cm²～5J/cm²More preferably 30mJ/cm²～3J/cm²Particularly preferably 50 to 1000mJ/cm². Further, the polymerization reaction may be carried out under heating to promote the polymerization reaction.

[ working procedure ]

The action step is a step of causing at least one selected from the group consisting of light, heat, acid, and alkali to act.

In addition, the working step is a step performed between the pressure-sensitive adhesive layer forming step and the 2 nd coating step or simultaneously with the pressure-sensitive adhesive layer forming step or the 2 nd coating step, from the viewpoint of ensuring coatability when forming the optically anisotropic layer as the upper layer.

Here, "between the pressure-sensitive adhesive layer forming step and the 2 nd coating step" means that the working step (for example, a step of causing light to act) is performed before the 2 nd coating step is performed on the pressure-sensitive adhesive layer formed in the pressure-sensitive adhesive layer forming step (for example, thermal polymerization).

The term "simultaneously with the pressure-sensitive adhesive layer-forming step" means a step of forming a pressure-sensitive adhesive layer, for example, a step of forming a pressure-sensitive adhesive layer by polymerization of an olefin monomer by radical photo-polymerization and polymerization of an epoxy monomer by photoacid-polymerization, and an action step (for example, a step of causing light to act) performed simultaneously. That is, it means that light for polymerization of the adhesive layer and light for cleavage simultaneously cause 2 actions.

The phrase "simultaneously with the 2 nd coating step" means that the applying step (for example, the step of applying heat) is performed simultaneously with the 2 nd coating step performed on the pressure-sensitive adhesive layer formed in the pressure-sensitive adhesive layer forming step (for example, photopolymerization).

Among them, from the viewpoint of process simplification, a step of simultaneously performing the pressure-sensitive adhesive layer forming step while allowing light to act is preferable.

Examples of the method of causing light to act include a method of irradiating the pressure-sensitive adhesive layer with ultraviolet light. As the light source, a lamp that emits ultraviolet rays such as a high-pressure mercury lamp or a metal halide lamp can be used. Further, the irradiation dose is preferably 10mJ/cm²～50J/cm²More preferably 20mJ/cm²～5J/cm²More preferably 30mJ/cm²～3J/cm²Particularly preferably 50 to 1000mJ/cm²。

Examples of the method of applying heat include a method of heating the pressure-sensitive adhesive layer. The heating temperature is preferably 50 to 200 ℃, more preferably 60 to 150 ℃, and particularly preferably 70 to 130 ℃.

Examples of the method of causing the acid to act include a method of adding an acid to the adhesive layer in advance, a method of adding a photoacid generator to the adhesive layer and generating an acid using light as a trigger, a method of adding a thermal acid generator to the adhesive layer and generating an acid using heat as a trigger, and the like. Among these, a method using a photoacid generator and a thermal acid generator is preferable.

Examples of the method of allowing the base to act include a method of adding a base to the pressure-sensitive adhesive layer in advance, a method of adding a photobase generator to the pressure-sensitive adhesive layer and generating a base using light as a trigger, and a method of adding a thermobase generator to the pressure-sensitive adhesive layer and generating a base using heat as a trigger. Among these, a method using a photobase generator and a thermobase generator is preferable.

[ irradiation procedure ]

The irradiation step is a step of irradiating polarized light or unpolarized light, that is, a step of imparting an alignment function.

In order to secure coatability when forming the optically anisotropic layer as the upper layer, the irradiation step is performed between the pressure-sensitive adhesive layer forming step and the 2 nd coating step or simultaneously with the pressure-sensitive adhesive layer forming step or the 2 nd coating step.

Here, "between the pressure-sensitive adhesive layer forming step and the 2 nd coating step" means that the irradiation step (for example, a step of irradiating polarized light) is performed before the 2 nd coating step is performed on the pressure-sensitive adhesive layer formed in the pressure-sensitive adhesive layer forming step (for example, thermal polymerization).

The phrase "simultaneously with the pressure-sensitive adhesive layer forming step" means that a step of forming a pressure-sensitive adhesive layer, for example, a step of forming a pressure-sensitive adhesive layer by polymerization of an olefin monomer by radical light generation and polymerization of an epoxy monomer by photoacid generation, and an irradiation step (for example, a step of irradiating polarized light) are performed simultaneously. That is, it means that light for polymerization of the adhesive layer and light for alignment cause 2 kinds of actions simultaneously.

The phrase "simultaneously with the 2 nd coating step" means that the irradiation step (for example, a step of irradiating polarized light) is simultaneously performed when the 2 nd coating step is performed on the pressure-sensitive adhesive layer formed in the pressure-sensitive adhesive layer forming step (for example, photopolymerization).

Among these, the step performed between the pressure-sensitive adhesive layer forming step and the 2 nd coating step is preferable.

As a method of irradiation, for example, a method of polarized irradiation of ultraviolet rays is preferable, and specifically, a method using a polarizing plate (for example, an iodine polarizing plate, a dichroic dye polarizing plate, a wire grid polarizing plate, or the like); a method using a prism-like element (e.g., a glan-thomson prism, etc.) and a reflective polarizer at the brewster angle; a method of using light emitted from a laser light source having polarized light; and the like.

Here, the light source for ultraviolet irradiation is not particularly limited as long as it is a light source that generates ultraviolet rays, and for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

[2 nd coating Process ]

The second coating step 2 is a step of directly coating the polymerizable liquid crystal composition for forming the optically anisotropic layer on the pressure-sensitive adhesive layer.

The method of applying the polymerizable liquid crystal composition for forming an optically anisotropic layer is not particularly limited, and the same method as in the first application step 1 can be used.

[ procedure for Forming optically Anisotropic layer ]

The optically anisotropic layer forming step is a step of forming an optically anisotropic layer after the 2 nd coating step, and can be formed by subjecting the coating film obtained in the 2 nd coating step to a curing treatment (irradiation of ultraviolet rays (light irradiation treatment) or heating treatment).

The conditions of the curing treatment are not particularly limited, and in polymerization by light irradiation, ultraviolet rays are preferably used. The irradiation dose is preferably 10mJ/cm²～50J/cm²More preferably 20mJ/cm²～5J/cm²More preferably 30mJ/cm²～3J/cm²Particularly preferably 50 to 1000mJ/cm². Further, the polymerization reaction may be carried out under heating to promote the polymerization reaction.

[ image display apparatus ]

The image display device of the present invention is an image display device having the optically anisotropic layer of the present invention or the optical laminate of the present invention.

The display element used in the image display device of the present invention is not particularly limited, and examples thereof include a liquid crystal cell, an organic electroluminescence (hereinafter, abbreviated as "EL") display panel, and a plasma display panel.

Among these, a liquid crystal cell and an organic EL display panel are preferable, and a liquid crystal cell is more preferable. That is, as the image display device of the present invention, a liquid crystal display device using a liquid crystal cell as a display element and an organic EL display device using an organic EL display panel as a display element are preferable.

[ liquid Crystal display device ]

A liquid crystal display device which is an example of an image display device of the present invention is a liquid crystal display device having the optically anisotropic layer of the present invention or the optical laminate of the present invention and a liquid crystal cell.

Hereinafter, a liquid crystal cell constituting the liquid crystal display device will be described in detail.

< liquid crystal cell >

The liquid crystal cell used In the liquid crystal display device is preferably a VA (Vertical Alignment) mode, an OCB (Optically Compensated Bend) mode, an IPS (In-Plane-Switching) mode, or a TN (Twisted Nematic) mode, but is not limited thereto.

In a TN mode liquid crystal cell, when no voltage is applied, rod-like liquid crystalline molecules (rod-like liquid crystalline compounds) are aligned substantially horizontally and are twisted by 60 to 120 degrees to be aligned. TN mode liquid crystal cells are most widely used as color TFT liquid crystal display devices and are described in many documents.

In the VA mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes (1) a narrow VA mode liquid crystal cell (described in japanese patent application laid-open No. h 2-176625) in which rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied and aligned substantially horizontally when a voltage is applied, and further includes (2) a liquid crystal cell (SID97, described in Digest of technology. papers 28 (1997)) 845) in which the VA mode is Multi-domain (Multi-domain Vertical Alignment) in order to enlarge the Viewing angle, and (3) a liquid crystal cell (LCD) in which rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied and aligned Multi-domain (axialm-symmetric microcells) in which rod-like liquid crystal molecules are twisted when a voltage is applied) (described in japanese discussion talk book 58-1998) and (4) Vertical Alignment (super-cell) in which the VA mode is vertically aligned (super-nematic) in which the VA mode is Multi-domain (Vertical Alignment) in which the voltage is applied) display: liquid crystal display) published in international 98). Further, any of a PVA (Patterned vertical Alignment) type, a photo-Alignment type (Optical Alignment) and a PSA (Polymer-Sustained Alignment) type may be used. The details of these modes are described in detail in Japanese patent laid-open No. 2006-215326 and Japanese Table 2008-538819.

In the IPS mode liquid crystal cell, rod-like liquid crystalline molecules are aligned substantially parallel to a substrate, and the liquid crystalline molecules respond in-plane by applying a parallel electric field to the substrate surface. The IPS mode displays black when no electric field is applied, and the absorption axes of the upper and lower polarizing plates are orthogonal to each other. Methods for improving the viewing angle by reducing light leakage during black display in an oblique direction using an optical compensation sheet are disclosed in japanese patent application laid-open nos. 10-054982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[ organic EL display device ]

As an example of the image display device of the present invention, an organic EL display device may be appropriately exemplified which includes, in order from the viewing side, a polarizer, the optically anisotropic layer of the present invention, the optical laminate of the present invention, and an organic EL display panel.

< polarizer >

The polarizer is not particularly limited as long as it has a function of converting light into specific linearly polarized light, and conventionally known absorption polarizers and reflection polarizers can be used.

As the absorption type polarizer, an iodine type polarizer, a dye type polarizer using a dichroic dye, a polyene type polarizer, and the like can be used. The iodine-based polarizer and the dye-based polarizer may be applied to any of a coated polarizer and an extended polarizer.

Further, as a method for obtaining a polarizer by stretching and dyeing in a state where a laminated film of a polyvinyl alcohol layer is formed on a substrate, there can be mentioned japanese patent No. 5048120, japanese patent No. 5143918, japanese patent No. 4691205, japanese patent No. 4751481, and japanese patent No. 4751486, and known techniques relating to these polarizers can also be preferably used.

As the reflective polarizer, a polarizer in which films having different birefringence are laminated, a wire grid polarizer, a polarizer in which cholesteric liquid crystal having a selective reflection region and an 1/4 wavelength plate are combined, or the like can be used.

Of these, from the viewpoint of more excellent adhesion, the polyvinyl alcohol-based resin (containing-CH) is preferably contained₂-CHOH-as a polymer of repeating units. In particular, at least 1) of polarizers selected from the group consisting of polyvinyl alcohol and ethylene-vinyl alcohol copolymer.

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

< organic EL display Panel >

The organic EL display panel is a member in which a light-emitting layer or a plurality of organic compound films including a light-emitting layer are formed between a pair of electrodes, i.e., an anode and a cathode, and may include a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, and the like in addition to the light-emitting layer, and these layers may be layers each having another function. Each layer can be formed using various materials.