JP4424979B2 - Compound, retardation plate, and method for forming optically anisotropic layer - Google Patents

Description

The present invention relates to a retardation plate, a method for forming an optically anisotropic layer constituting the retardation plate, and a liquid crystal compound suitable for constituting the optically anisotropic layer.
In particular, the present invention has an optically anisotropic layer containing a biaxial liquid crystal compound, and a retardation plate in which the smallest refractive index direction of the optically anisotropic layer is substantially in the normal direction of the film plane of the retardation plate About.

When producing an optical biaxial film, a method of obtaining a film obtained from a polymer by biaxial stretching is common (see, for example, Patent Document 1). However, recently, a method for obtaining a biaxial film using a biaxial liquid crystal has been proposed. A biaxial film using a biaxial liquid crystal has the merit that the film thickness can be made very thin compared to the biaxially stretched film that has been widely used so far. The use of conductive liquid crystal is a useful means for making the device thinner and lighter. As such an example, for example, a method of obtaining a biaxial film by uniaxially stretching a polymer liquid crystal compound that expresses an _SCA phase, which is one of biaxial liquid crystal phases, has been reported ( For example, see Patent Document 2). However, the film using stretching has a problem that the dimensional stability of the film is poor and the optical performance is easily changed by wet heat or the like.

On the other hand, a production example of a biaxial film using a biaxial liquid crystal compound without using any stretching has been reported (for example, see Patent Document 3). However, in this report, the functional group for fixing the orientation is not positively introduced into the biaxial liquid crystal compound, so the problem is that the film is low in hardness and easily damaged. The problem was that the state was disturbed and the biaxiality was lost. In order to eliminate such a problem of hardness and a problem of disorder of the alignment state, a method of fixing the alignment can be considered, and such a method includes introduction of a polymerizable group. There is also a report on an optical film using a biaxial liquid crystal compound into which such a polymerizable group is introduced (for example, see Patent Document 4). However, when such a polymerizable functional group is introduced into a biaxial liquid crystal compound, as described in this report, hybrid alignment (not biaxiality) is obtained. In addition, since alignment disorder occurs due to an increase in the pretilt angle of the liquid crystal compound molecules at the air interface, it is usually very difficult to obtain a biaxial film with high film strength using biaxial liquid crystals. there were. Further, even when a polymerizable group is introduced into the liquid crystal compound, a film having high film strength is not always obtained.
JP-A-2-264905 Japanese Patent Laid-Open No. 11-60972 Japanese Patent Laid-Open No. 2002-6138 JP 2002-174730 A

Accordingly, an object of the present invention is to use a retardation plate having an optically anisotropic layer formed from a liquid crystal compound, particularly a biaxial liquid crystal compound, which has high film strength and is stable biaxially over time. It is an object of the present invention to provide a retardation plate that exhibits the properties and has the smallest refractive index direction of the optically anisotropic layer approximately in the normal direction of the film plane of the retardation plate.
Another object of the present invention is to provide a method for forming the optically anisotropic layer and a liquid crystal compound suitable for constituting the optically anisotropic layer.

  In conventional biaxial liquid crystal compounds that have been attempted to be used for biaxial films, when a polymerizable group is introduced, the orientation of the liquid crystal compound molecules changes at the alignment film interface and the air interface, resulting in a hybrid alignment. Axis will not be shown. As a result of diligent research, the present inventors have found a liquid crystal compound exhibiting optical biaxiality without hybrid alignment even for a liquid crystal compound having a polymerizable group. However, the present invention was completed by finding an optical biaxiality without hybrid alignment. In particular, a novel liquid crystal compound having a polymerizable group and exhibiting a biaxial liquid crystal phase has been found. It was also found that a specific additive can control the orientation of the liquid crystal compound having a polymerizable group at the air interface and can be preferably used to develop a biaxial liquid crystal phase without hybrid orientation. .

That is, the above object of the present invention is achieved by the following retardation plate, optical anisotropic layer forming method, and liquid crystal compound.
1. The compound represented by the following general formula (B-1).
Formula (B-1)

In general formula (B-1),
A represents phenylene, phenylene-phenylene, or naphthylene. Phenylene may have a substituent. The substituent which phenylene may have is a methyl group or a chloro group.
L ₂₁ and L ₂₂ represent —CH═CH—CO—O— * (* represents a position linked to A).
L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , L ₁₅ and L ₁₆ are each independently * —O—an alkylene group having 2 to 12 carbon atoms or * —O—an alkylene group having 2 to 12 carbon atoms— O-CO- (* represents a position linked to a benzene ring).
Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ , Q ₁₆ each independently represents an ethylenically unsaturated polymerizable group selected from Q1 to Q6 or a hydrogen atom, and Q ₁₁ , Q ₁₂ , Q _{13, Q 14, Q 15,} Q 16
At least one represents an ethylenically unsaturated polymerizable group selected from the following Q1 to Q6 .

  2. A retardation plate having at least one optically anisotropic layer formed from a liquid crystal compound on a transparent support, wherein the liquid crystal compound is the compound described in 1 above.

3. A retardation plate having at least one optically anisotropic layer formed from a liquid crystal compound expressing a biaxial liquid crystal phase on a transparent support,
The liquid crystal compound is a polymer compound that is a compound described in 1 above and / or a polymer compound that includes the compound described in 1 above in a partial structure ,
The direction with the smallest refractive index of the biaxial liquid crystal phase substantially coincides with the normal direction of the transparent support.
A retardation film characterized by that.
4 and 5 are deleted.
6). 4. The retardation plate as described in 2 or 3 above , wherein the optically anisotropic layer contains a compound represented by the following general formula (V).
Formula ^{(V) :( Hb-L 51} -) nB 51
In general formula (V), Hb represents an aliphatic group having 6 to 40 carbon atoms or an aliphatic substituted oligosiloxanoxy group having 6 to 40 carbon atoms. n represents an integer of 2 to 12.
L ⁵¹ represents a single bond or an unsubstituted alkylene group having 1 to 40 carbon atoms, a fluorine-substituted alkylene group having 1 to 40 carbon atoms, —O—, —S—, —CO—, —NR—, —SO ₂ —. And a group selected from the group consisting of combinations thereof. Here, R represents a hydrogen atom or an unsubstituted alkyl group having 1 to 20 carbon atoms.
B ⁵¹ represents an n-valent group represented by the following general formula (Va).
Formula (Va): ( -Cy ⁵¹ -L ^52- ) nCy ⁵²
Cy ⁵¹ is a phenylene group, an indenylene group, a naphthylene group, a fluorenylene group, a phenanthrenylene group, an anthrylene group, a pyrenylene group, or a furan ring, a thiophene ring, a pyrrole ring, a pyrroline ring, a pyrrolidine ring, an oxazole ring, an isoxazole Ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiine ring, pyridine ring, piperidine ring, oxazine Ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring, benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxa Ring, benzothiazole ring, indazole ring, benzimidazole ring, chromene ring, chroman ring, isochroman ring, quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, carbazole ring, xanthene ring , Acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring, indolizine ring, quinolidine ring, quinuclidine ring, naphthyridine ring, purine ring, pteridine ring Represents a cyclic group. These groups have no substituent.
L ⁵² represents a single bond or an unsubstituted alkylene group having 1 to 40 carbon atoms, an unsubstituted alkenylene group having 2 to 40 carbon atoms, an unsubstituted alkynylene group having 2 to 40 carbon atoms, -O-, It represents a group selected from the group consisting of —S—, —CO—, —NR—, —SO ₂ — and combinations thereof. R represents a hydrogen atom or an unsubstituted alkyl group having 1 to 30 carbon atoms.
n represents an integer of 2 to 12.
Cy ⁵² is an n-valent cyclic group, which is a benzene ring, indene ring, naphthalene ring, fluorene ring, phenanthrene ring, anthracene ring, pyrene ring, furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole Ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiine ring, pyridine ring, A cyclic group consisting of a ring selected from a piperidine ring, an oxazine ring, a morpholine ring, a thiazine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperazine ring and a triazine ring. These groups have no substituent.

7). The angle 3 formed by the direction of the smallest refractive index of the biaxial liquid crystal phase and the normal direction of the alignment film surface is in the range of 0 to 10 ° at both the alignment film interface and the air interface. The phase difference plate in any one of -6.
8). The retardation plate as described in any one of 3 to 7 above, wherein the scratch strength of the surface of the optically anisotropic layer is 10 g or more.
9. The phase difference plate according to any one of 3 to 8 above, wherein the surface energy of the surface of the optically anisotropic layer is 45 mN / m or less.
10. 10. The retardation film as described in any one of 3 to 9 above, wherein the biaxial liquid crystal phase is a biaxial nematic liquid crystal phase.

11. On the alignment film, a liquid crystal composition containing a polymerizable compound that expresses a biaxial liquid crystal phase and a photopolymerization initiator is applied, and the polymerizable compound that is the compound described in 1 above is monodomain aligned, A method for forming an optically anisotropic layer, wherein the orientation of a polymerizable compound is fixed by polymerization by irradiation with ultraviolet rays in an atmosphere having an oxygen concentration of 7% or less.

  According to the present invention, a polymerizable biaxial liquid crystal compound or a high molecular biaxial liquid crystal compound whose orientation can be fixed is used, and the direction in which the refractive index of the optically anisotropic layer is the smallest is the normal of the film plane. A retardation film having a high film strength and a biaxial optical characteristic is provided.

一般式（Ｂ−１）中、
Ａは、フェニレン、フェニレン−フェニレン、又はナフチレンを表す。フェニレンは置換基を有していてもよい。フェニレンが有していてもよい置換基は、メチル基又はクロロ基である。
Ｌ_２１、Ｌ_２２は、−ＣＨ＝ＣＨ−ＣＯ−Ｏ−＊（＊はＡに連結する位置を表す。）を
表す。
Ｌ₁₁、Ｌ₁₂、Ｌ₁₃、Ｌ₁₄、Ｌ₁₅、Ｌ₁₆は、それぞれ独立に、＊−Ｏ−炭素数２〜１２の
アルキレン基または＊−Ｏ−炭素原子数２〜１２のアルキレン基−Ｏ−ＣＯ−（＊はベンゼン環に連結する位置を表す。）を表す。
Ｑ₁₁、Ｑ₁₂、Ｑ₁₃、Ｑ₁₄、Ｑ₁₅、Ｑ₁₆は、それぞれ独立に、下記Ｑ１〜Ｑ６から選ばれ
るエチレン性不飽和重合性基又は水素原子を表し、Ｑ₁₁、Ｑ₁₂、Ｑ₁₃、Ｑ₁₄、Ｑ₁₅、Ｑ₁₆
の少なくとも一つは下記Ｑ１〜Ｑ６から選ばれるエチレン性不飽和重合性基を表す。

［二軸性液晶化合物］
本発明の光学異方性層を形成するために用いられる液晶化合物は、光学的に二軸性を示す液晶化合物である。換言すれば、液晶相の３軸方向の屈折率ｎｘ、ｎｙ、ｎｚが異なり、例えばｎｘ＞ｎｙ＞ｎｚの関係を満たす液晶化合物である。 Hereinafter, the present invention will be described in more detail.
In addition, although this invention is related with the compound represented by the following general formula (B-1), it described also about the other matter for reference.
Formula (B-1)

In general formula (B-1),
A represents phenylene, phenylene-phenylene, or naphthylene. Phenylene may have a substituent. The substituent which phenylene may have is a methyl group or a chloro group.
L ₂₁ and L ₂₂ represent —CH═CH—CO—O— * (* represents a position linked to A).
L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , L ₁₅ and L ₁₆ are each independently * —O—an alkylene group having 2 to 12 carbon atoms or * —O—an alkylene group having 2 to 12 carbon atoms— O-CO- (* represents a position linked to a benzene ring).
Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ , Q ₁₆ each independently represents an ethylenically unsaturated polymerizable group selected from Q1 to Q6 or a hydrogen atom, and Q ₁₁ , Q ₁₂ , Q _{13, Q 14, Q 15,} Q 16
At least one represents an ethylenically unsaturated polymerizable group selected from the following Q1 to Q6 .

[Biaxial liquid crystal compound]
The liquid crystal compound used for forming the optically anisotropic layer of the present invention is a liquid crystal compound that optically exhibits biaxiality. In other words, it is a liquid crystal compound in which the refractive indexes nx, ny and nz in the triaxial direction of the liquid crystal phase are different and satisfy the relationship of nx>ny> nz, for example.

  The liquid crystal compound used in the present invention desirably has the above properties and at the same time exhibits a good monodomain property for uniform and defect-free alignment. When the monodomain property is poor, the resulting structure is a polydomain, an orientation defect occurs at the boundary between domains, and light is scattered at the defect portion. This is undesirable because it leads to a decrease in the transmittance of the retardation plate.

  Examples of the biaxial liquid crystal phase exhibited by the liquid crystal compound used in the present invention include a biaxial nematic phase, a biaxial smectic A phase, and a biaxial smectic C phase. Among these liquid crystal phases, a biaxial nematic phase (Nb phase) exhibiting good monodomain properties is preferable. The biaxial nematic phase is a kind of liquid crystal phase that can be taken by the nematic liquid crystal compound. When the space of the liquid crystal phase is defined by the x axis, the y axis, and the z axis, the liquid crystal compound is centered on the y axis. This shows a state in which free rotation of the xz plane and free rotation of the xy plane around the z axis are prohibited.

  The liquid crystal compound used in the present invention is a polymerizable compound and / or a polymer compound. The polymerizable compound may be a low molecular compound or a high molecular compound. In the case of a polymer compound, it is preferably a polymerizable compound in order to fix the orientation, but it is not necessarily polymerizable when the glass transition point is 30 ° C. or higher.

  Specific examples of the biaxial liquid crystal compound and the polymerizable compound include, for example, compounds described in pages 124 to 143 of Organic Synthetic Chemistry, Vol. 49; No. 5 (1991), D.I. W. Research report by Bruce et al. [AN EU-SPONSORED 'OXFORD WORKSHOP ON BIAXIAL NEMATICS' (St Benet's Hall, University of Oxford 20-22 December, 1996), p157-293], S. CHANDRASEKHAR et al. [A Thermotropic Biaxial Nematic Liquid Crystal; Mol. Cryst. Liq. Cryst., 1988, Vol. 165, pp. 123-130) D. Demus, J. Goodby et al. (Handbook of Liquid Crystals Vol. 2B: Low Molecular Weight Liquid Crystals II, pp 933) -943: published by WILEY-VCH] and the like.

  As the low-molecular liquid crystal compound having a polymerizable group, for example, compounds described in JP-A No. 2002-174730 can also be used. However, as a compound described in this publication, as a low-molecular compound, when using a compound that easily undergoes hybrid orientation, or a compound that easily causes orientation disorder due to an increase in the pretilt angle of the molecule at the air interface, It is preferable to add an air interface orientation controller described later.

Preferred examples of the polymerizable low-molecular liquid crystal compound that develops a biaxial liquid crystal phase without becoming hybrid alignment or disturbing alignment include the following general formula (B-1).
Formula (B-1)

In the formula, A is selected from the group consisting of a divalent cyclic group, —O—, —CO—, —NH—, —N═CH—, —S—, an alkylene group, an alkenylene group, an alkynylene group, and combinations thereof. Represents a selected divalent linking group.
The divalent cyclic group, alkylene group, alkenylene group, and alkynylene group may have a substituent (eg, alkyl group, halogen atom, cyano group, alkoxy group, acyloxy group).
A preferably contains at least one divalent cyclic group. The divalent cyclic group is preferably a divalent aromatic hydrocarbon group, a divalent heterocyclic group, or a divalent aliphatic ring group, and most preferably a divalent aromatic hydrocarbon group.

The divalent aromatic hydrocarbon group means an arylene group and a substituted arylene group.
Examples of arylene groups include phenylene, indenylene, naphthylene, fluorenylene, phenanthrenylene, anthrylene and pyrenylene. Phenylene and naphthylene are preferred. In particular, 1,4-phenylene, 1,5-naphthylene, and 2,6-naphthylene are preferable.
Examples of the substituent of the substituted arylene group include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (eg, methoxy, ethoxy, methoxyethoxy), an aryloxy group (eg, phenoxy), Arylazo groups (eg, phenylazo), alkylthio groups (eg, methylthio, ethylthio, propylthio), alkylamino groups (eg, methylamino, propylamino), acyl groups (eg, acetyl, propanoyl, octanoyl, benzoyl), acyloxy groups ( Examples include acetoxy, pivaloyloxy, benzoyloxy), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl group, sulfamoyl group and ureido group.

  The divalent heterocyclic group preferably has a 5-membered, 6-membered or 7-membered heterocyclic ring. A 5-membered ring or a 6-membered ring is more preferable, and a 6-membered ring is most preferable. As the hetero atom constituting the heterocyclic ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocyclic ring is generally an unsaturated heterocyclic ring. An unsaturated heterocyclic ring having the most double bond is more preferable. Examples of heterocyclic rings include furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline Ring, pyrazolidine ring, triazole ring, triazane ring, tetrazole ring, pyran ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring included. In particular, a pyridine ring and a pyrimidine ring are preferable, and pyridine-2,5-diyl and pyrimidine-2,5-diyl are more preferable.

Another heterocyclic ring, an aliphatic ring or an aromatic hydrocarbon ring may be condensed with the heterocyclic ring. Examples of the condensed heterocyclic ring include benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxazole ring, benzothiazole ring, indazole ring, benzimidazole ring, chromene ring, chroman ring, Isochroman ring, quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, carbazole ring, xanthene ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring , An indolizine ring, a quinolidine ring, a quinuclidine ring, a naphthyridine ring, a purine ring and a pteridine ring.
The divalent heterocyclic group may have a substituent. Examples of the substituent are the same as the examples of the substituent of the substituted arylene group, but other examples include an alkylidene group, an oxo group, and an imino group.

  The divalent aliphatic ring group preferably has a 5-membered, 6-membered or 7-membered aliphatic ring. Among these, a 5-membered ring and a 6-membered ring are more preferable, and a 6-membered ring is most preferable.

  Another aliphatic ring, a heterocyclic ring or an aromatic hydrocarbon ring may be condensed with the divalent aliphatic ring group. Examples of the fused heterocyclic ring include a tetrahydronaphthalene ring and a pteridine ring. The divalent aliphatic ring group may have a substituent. Examples of the substituent are the same as the examples of the substituent of the substituted arylene group, but other examples include an alkylidene group, an oxo group, and an imino group.

L ₂₁ and L ₂₂ each independently represent a divalent linking group containing at least —CH═CH—, —N═CH— or —C≡C—. Divalent linking groups other than —CH═CH—, —N═CH— or —C≡C— include —O—, —CO—, —NH—, —S—, an alkylene group, an alkenylene group, and an alkynylene. And a group consisting of a group, an arylene group, and a combination thereof. L ₂₁ and L ₂₂ may be different or the same.
Preferred examples of L ₂₁ and L ₂₂ include —CH═CH—, —N═CH—, —C≡C—, —CH═CH—CO—O—, —C≡C—CO—O—, —CH═. CH-CO-NH-, -C≡C-CO-NH-, -CH = CH-CO-S-, and -C≡C-CO-S-. The —CH═CH—, alkylene group, alkenylene group, alkynylene group and arylene group may have a substituent (eg, alkyl group, halogen atom, cyano group, alkoxy group, acyloxy group). L ₂₁ and L ₂₂ are particularly preferably —CH═CH—CO—O— * (* represents a position linked to A).

X ₁ and X ₂ are each independently a halogen atom (F, Cl, Br, etc.), an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or 2 to 2 carbon atoms. It represents an atom or group selected from the group consisting of 13 acyl groups, alkylamino groups having 2 to 12 carbon atoms, and acyloxy groups having 2 to 13 carbon atoms.
The alkyl group having 1 to 12 carbon atoms preferably has 1 to 8 carbon atoms, and is particularly preferably a methyl group, an ethyl group, an n-propyl group, an n-pentyl group or an n-heptyl group. preferable. The alkoxy group having 1 to 12 carbon atoms is preferably a methyl group, a 2-methoxyethoxy group or a vinyloxy group. The acyl group having 2 to 13 carbon atoms is preferably an acetyl group. The alkylamino group having 2 to 12 carbon atoms is preferably a methylamino group, an ethylamino group or a dimethylamino group, particularly preferably a dimethylamino group. The acyloxy group having 2 to 13 carbon atoms is particularly preferably an acetyloxy group or an acryloyl group.

  l and m each independently represent an integer of 0 to 2. Preferably it is 0.

L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , L ₁₅ , and L ₁₆ are each independently —O—, —CO—, —NH—, —N═CH—, —S—, an alkylene group, and an alkenylene group. , An alkynylene group, an arylene group, and a divalent linking group selected from the group consisting of combinations thereof. L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , L ₁₅ and L ₁₆ are selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group, —CO—, —NH—, —O— and S—. It is preferable that at least two divalent groups selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, an arylene group, —CO— and —O— are used. Particularly preferred is a combination of two groups.
The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The alkynylene group preferably has 2 to 12 carbon atoms. The arylene group preferably has 6 to 10 carbon atoms. The alkylene group, alkenylene group, alkynylene group and arylene group may have a substituent (eg, alkyl group, halogen atom, cyano group, alkoxy group, acyloxy group). L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , L ₁₅ , and L ₁₆ are particularly preferably a combination of —O—, —CO—, and an alkylene group, * —O-alkylene group or * —O-alkylene group— O—CO— is particularly preferable (* represents a position linked to a benzene ring).

Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ , Q ₁₆ represent a polymerizable group or a hydrogen atom, and at least one of Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ , Q ₁₆ is Represents a polymerizable group. Preferably, at least two of Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ , and Q ₁₆ are polymerizable groups. Specific examples of the polymerizable group represented by Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ and Q ₁₆ are shown below.

Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ and Q ₁₆ are preferably an unsaturated polymerizable group (Q1 to Q7), an epoxy group (Q8) or an aziridinyl group (Q9). It is more preferably an ionic group, and most preferably an ethylenically unsaturated polymerizable group (Q1 to Q6).
Q _{11 to} Q ₁₆ may be the same as or different from each other.

  Although the specific example of the low molecular liquid crystal compound represented by general formula (BI) below is shown, this invention is not limited to these.

  Specific examples of the polymer liquid crystal compound include, for example, H.P. F. Leube et al. [Optical investigations on a liquid-crystalline side-chain polymer with biaxial nematic and biaxial smectic A phase. Chem. 1991, Vol. 192, pp. 1317-1328], [New bilaterally linked mesogens in main-chain polymers with exhibation of biaxial fusion in nematic phase, Macro98. 31, pp. 3537-3541] and the like can be used.

  Specific examples of the polymer liquid crystal compound other than those described above are shown below, but the present invention is not limited thereto.

As described above, in the case of a polymer liquid crystalline compound having a glass transition temperature of less than 30 ° C., it is preferable to introduce a polymerizable group. In this case, the polymerizable group is represented by the general formula (BI). specific examples of the polymerizable groups Q ₁₁ ~Q ₁₆ (Q1~Q17) and the like.

[Liquid crystal composition]
In the present invention, the optically anisotropic layer is formed from a liquid crystal composition containing at least one biaxial liquid crystal compound. In this liquid crystal composition, two or more types of biaxial liquid crystal compounds may be used in combination. Further, for example, the polymerizable biaxial liquid crystal compound and the non-polymerizable biaxial liquid crystal compound can be used in combination. It is also possible to use a polymerizable low-molecular liquid crystal compound and a high-molecular liquid crystal compound in combination.

  The liquid crystal temperature range of the liquid crystal composition of the present invention is preferably in the range of 10 to 200 ° C., more preferably in the range of 10 to 150 ° C. from the viewpoint of the production suitability of the retardation plate. . When the temperature is lower than 10 ° C., a cooling step or the like may be required to lower the temperature to a temperature range exhibiting a liquid crystal phase. Further, when the temperature exceeds 200 ° C., a high temperature is required to make the isotropic liquid state higher than the temperature range once exhibiting a liquid crystal phase, which may be disadvantageous from waste of heat energy, deformation of the substrate, and alteration. .

[Optically anisotropic layer]
In the present invention, by using a biaxial liquid crystal compound, the optical anisotropy of the optically anisotropic layer is adjusted so as to be optically biaxial with different main refractive index values in three directions orthogonal to each other. When the principal refractive index values in three directions of the optically anisotropic layer are nx, ny, and nz (nx>ny> nz), each value preferably satisfies the following formula (I). It is more preferable that the above is satisfied.

Formula (I): nx-ny> 0.005 and ny-nz> 0.005
Formula (II): nx-ny> 0.01 and ny-nz> 0.01

In the present invention, the biaxial liquid crystal compound is aligned using the following alignment film to form an optical biaxial optically anisotropic layer. Unlike biaxial compounds, biaxial liquid crystalline compounds have different refractive indexes (nx>ny> nz) in three directions orthogonal to each other, and thus the alignment directions in the three directions need to be controlled.
In the retardation plate of the present invention, the direction of the smallest refractive index of the liquid crystal phase expressed by the biaxial liquid crystal compound and the normal direction of the transparent support are substantially matched. Therefore, the three orientation directions of the liquid crystal compound are the nx refractive index direction (the direction with the highest refractive index) and the ny refractive index direction (the refractive index direction with an intermediate refractive index). It is preferably oriented so that it is substantially perpendicular to the linear direction, and the nz refractive index direction (the direction with the lowest refractive index) is substantially parallel to the normal direction of the film plane of the retardation film. The nx refractive index direction may be parallel or orthogonal to the rubbing direction.

Since the liquid crystal composition of the present invention is applied onto the alignment film, the liquid crystal compound is aligned at the pretilt angle of the alignment film at the interface with the alignment film, and is aligned at the pretilt angle at the air interface at the interface with the air. . In the case of a biaxial liquid crystal compound, there are two types of pretilt angles: a pretilt angle formed by the interface with the nx refractive index direction and a pretilt angle formed by the interface with the ny refractive index direction.
In the present invention, the direction in which the refractive index of the biaxial liquid crystal phase is the smallest is substantially parallel to the normal direction of the transparent support (the normal direction of the film surface of the retardation film). Both the pretilt angle and the two types of pretilt angles on the air interface side are 0 to 15 °, preferably 0 to 10 °, that is, a transparent support with the nz refractive index direction (the direction with the lowest refractive index). Means that the angle formed by the normal direction is 0 to 15 °, preferably 0 to 10 °.
In the present invention, it is preferable that the direction in which the birefringent liquid crystal phase has the smallest refractive index hardly changes in the thickness direction of the optically anisotropic layer. The direction in which the refractive index of the biaxial liquid crystal phase is the smallest is almost unchanged in the thickness direction of the optically anisotropic layer. The nz refractive index direction of the liquid crystal compound also in the region between the alignment film interface and the air interface. It means that the angle formed by (the direction having the lowest refractive index) and the normal direction of the transparent support substantially coincides with the pretilt angles at the alignment film interface and the air interface. That is, in the present invention, the angle formed by the nz refractive index direction (the lowest refractive index direction) and the normal direction of the transparent support is 0 to 15 °, preferably 0 to 10 °.
The alignment (angle formed) of the liquid crystalline compound in each of the above regions can be adjusted by an alignment film, its rubbing direction, and further an alignment control agent.

The optically anisotropic layer of the retardation plate of the present invention is fixed to form a layer without impairing the alignment form in the liquid crystal state of the liquid crystal compound. When a polymer compound is used as the liquid crystal compound, it can be obtained by once heating to the liquid crystal phase formation temperature and then cooling while maintaining the alignment state. Moreover, when using a polymeric compound as a liquid crystal compound, after heating the liquid-crystal composition which added the polymerization initiator to the liquid-crystal phase formation temperature, it can superpose | polymerize and can obtain.
Here, the state of being fixed is a state in which the orientation of the liquid crystal compound in the liquid crystal phase is maintained, which is the most typical and preferred embodiment, but is not limited thereto. In the temperature range of -30 ° C to 70 ° C under severer conditions, the optically anisotropic layer has no fluidity, and is fixed without causing any change in the orientation form due to an external field or external force. This indicates a state in which the orientation form can be kept stable.

  Further, when the biaxial liquid crystal compound maintains biaxiality when the optically anisotropic layer is finally formed, liquid crystallinity may be lost. For example, when a polymerizable compound is used as the liquid crystal compound, as a result, the polymerization or crosslinking reaction proceeds by reaction with heat, light, etc., and the liquid crystallinity may be lost by increasing the molecular weight.

  An optically anisotropic layer made of a liquid crystal composition in which the orientation of the liquid crystal compound is fixed needs to have an appropriate hardness from the viewpoint of the suitability for producing a retardation plate. The hardness of the optically anisotropic layer can be clarified by measuring the scratch strength of the surface. The surface scratch strength is preferably 10 g or more, and more preferably 20 g or more. The scratch strength was scratched by visually scratching the surface of the optical anisotropic layer at a speed of 1 cm / second using a sapphire needle having a cone apex angle of 90 degrees and a tip diameter of 0.25 mm. Means the weight (g) when

  The surface energy of the optically anisotropic layer reduces the pretilt angle of the liquid crystal compound at the air interface, prevents orientation disorder at the air interface of the liquid crystal phase, and loses biaxiality such as hybrid orientation. In order to prevent this, it is preferably 45 mN / m or less, and more preferably 20 to 43 mN / m. The surface energy of the surface of the optically anisotropic layer can be lowered by an alignment controller at the air interface, and the surface energy can be adjusted by appropriately using an alignment controller according to the state of the liquid crystal phase.

The surface energy of the solid can be determined by the contact angle method, the wet heat method, and the adsorption method as described in “Basics and Applications of Wetting” (issued by Realize Inc. 1989.12.10). In the case of the optically anisotropic layer of the present invention, the contact angle method is preferably used.
Specifically, a solution of water and diiodomethane, whose surface energy is known, is dropped onto the optically anisotropic layer, and the tangent line drawn to the droplet and the optical system are intersected at the intersection of the surface of the droplet and the surface of the optically anisotropic layer. The angle formed by the surface of the anisotropic layer is defined as the contact angle, and the surface energy of the optically anisotropic layer can be calculated by calculation.

  The thickness of the optically anisotropic layer of the present invention formed from the liquid crystal composition is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and 1 to 10 μm. Most preferred.

[Air interface alignment control agent]
The biaxial liquid crystal compound is aligned at the air interface at the pretilt angle of the air interface. As described above, there are two types of pretilt angles: a pretilt angle formed by the nx refractive index direction and the air interface and a pretilt angle formed by the ny refractive index direction and the air interface. Since this pretilt angle can be controlled by using an external field such as an electric field or a magnetic field or by using an additive, it is preferable to control the pretilt angle also in the present invention in adjusting the alignment state. In particular, it is preferable to use an additive.
Examples of such an additive include a substituted or unsubstituted aliphatic group having 6 to 40 carbon atoms, or a substituted or unsubstituted aliphatic substituted oligosiloxanoxy group having 6 to 40 carbon atoms in the molecule. A compound having at least two is preferred, and a compound having at least two in the molecule is more preferred.
In particular, the compound represented by the following general formula (V) is preferable. This compound, like the compound described in JP-A-2002-174730, is a liquid crystal compound that is easy to hybrid-align as a low-molecular liquid crystal compound, or alignment disorder due to a high molecular pretilt angle at the air interface. It is an additive that enables the realization of a biaxial liquid crystal phase when used together with a liquid crystal compound that is prone to occur.

  Hereinafter, the general formula (V) will be described in detail.

Formula ^{(V) :( Hb-L 51} -) nB 51

In the above general formula (V), Hb represents an aliphatic group having 6 to 40 carbon atoms or an aliphatic substituted oligosiloxanoxy group having 6 to 40 carbon atoms.
Hb is preferably an aliphatic group having 6 to 40 carbon atoms, and is a fluorine-substituted aliphatic group having 6 to 40 carbon atoms or a branched aliphatic group having 6 to 40 carbon atoms. More preferably, it is most preferably a fluorine-substituted alkyl group having 6 to 40 carbon atoms or a branched alkyl group having 6 to 40 carbon atoms.

The aliphatic group is preferably a chain aliphatic group rather than a cyclic aliphatic group. The chain aliphatic group may have a branch. The number of carbon atoms in the aliphatic group is preferably 7 to 35, more preferably 8 to 30, further preferably 9 to 25, and most preferably 10 to 20.
Aliphatic groups include alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, alkynyl groups, and substituted alkynyl groups. An alkyl group, a substituted alkyl group, an alkenyl group and a substituted alkenyl group are preferred, and an alkyl group and a substituted alkyl group are more preferred.
Examples of the substituent of the aliphatic group include a halogen atom, hydroxyl group, cyano group, nitro group, alkoxy group, substituted alkoxy group (for example, oligoalkoxy group), alkenyloxy group (for example, vinyloxy group), acyl group ( Examples include acryloyl group, methacryloyl group), acyloxy group (eg, acryloyloxy group, benzoyloxy group), sulfamoyl group, aliphatic substituted sulfamoyl group and epoxyalkyl group (eg, epoxyethyl group). Of these, a halogen atom is preferable, and a fluorine atom is more preferable. In the fluorine-substituted aliphatic group, the ratio of the fluorine atom replacing the hydrogen atom of the aliphatic group is preferably 50 to 100%, more preferably 60 to 100%, and 70 to 100%. More preferably, it is more preferably 80 to 100%, and most preferably 85 to 100%.

  The number of carbon atoms of the aliphatic substituted oligosiloxanoxy group is preferably 7 to 35, more preferably 8 to 30, still more preferably 9 to 25, and preferably 10 to 20. Most preferred. The aliphatic substituted oligosiloxanoxy group is represented by the following formula.

R ⁵¹ — (Si (R ⁵² ) ₂ —O) _q −

In the formula, R ⁵¹ represents a hydrogen atom, a hydroxyl group or an aliphatic group; R ⁵² represents a hydrogen atom, an aliphatic group or an alkoxy group; and q represents an integer of 1 to 12.
The aliphatic group represented by each of R ⁵¹ and R ⁵² is preferably a chain aliphatic group rather than a cyclic aliphatic group. The chain aliphatic group may have a branch. The number of carbon atoms of the aliphatic group is preferably 1 to 12, more preferably 1 to 8, still more preferably 1 to 6, and particularly preferably 1 to 4.
The aliphatic groups represented by R ⁵¹ and R ⁵² each include an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group. An alkyl group, a substituted alkyl group, an alkenyl group and a substituted alkenyl group are preferred, and an alkyl group and a substituted alkyl group are more preferred.
The aliphatic group represented by each of R ⁵¹ and R ⁵² may have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, a cyano group, a nitro group, an alkoxy group, and a substituted alkoxy group. Group (eg, oligoalkoxy group), alkenyloxy group (eg, vinyloxy group), acyl group (eg, acryloyl group, methacryloyl group), acyloxy group (eg, acryloyloxy group, benzoyloxy group), sulfamoyl group, aliphatic Substituted sulfamoyl groups and epoxyalkyl groups (eg, epoxyethyl groups) are included.

The alkoxy group represented by R ⁵² may have a cyclic structure or a branch. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 8, still more preferably 1 to 6, and still more preferably 1 to 4.
An example of Hb is shown below.

Hb1: n-C ₁₆ H ₃₃ −
_{Hb2: n-C 20 H 41} -
_{Hb3: n-C 6 H 13} -CH (n-C 4 H 9) -CH 2 -CH 2 -
_{Hb4: n-C 12 H 25} -
_{Hb5: n-C 18 H 37} -
_{Hb6: n-C 14 H 29} -
_{Hb7: n-C 15 H 31} -
_{Hb8: n-C 10 H 21} -
_{Hb9: n-C 10 H 21} -CH (n-C 4 H 9) -CH 2 -CH 2 -
_{Hb10: n-C 8 F 17} -

_{Hb11: n-C 8 H 17} -
_{Hb12: CH (CH 3) 2} - {C 3 H 6 -CH (CH 3)} 3 -C 2 H 4 -
_{Hb13: CH (CH 3) 2} - {C 3 H 6 -CH (CH 3)} 2 -C 3 H 6 -C (CH 3) = CH-CH 2 -
_{Hb14: n-C 8 H 17} -CH (n-C 6 H 13) -CH 2 -CH 2 -
_{Hb15: n-C 6 H 13} -CH (C 2 H 5) -CH 2 -CH 2 -
_{Hb16: n-C 8 F 17} -CH (n-C 4 F 9) -CH 2 -
_{Hb17: n-C 8 F 17} -CF (n-C 6 F 13) -CF 2 -CF 2 -
_{Hb18: n-C 3 F 7} -CF (CF 3) -CF 2 -
_{Hb19: Si (CH 3) 2} - {Si (CH 2) 2 -O} 6 -O-
_{Hb20: Si (OC 3 H 7} ) (C 16 F 33) (C 2 H 4 -SO 2 -NH-C 8 F 17) -O-

In the general formula (V), L ⁵¹ represents a single bond or a divalent linking group.
The divalent linking group may be a group selected from the group consisting of an alkylene group, a fluorine-substituted alkylene group, —O—, —S—, —CO—, —NR—, —SO ₂ —, and combinations thereof. preferable. Here, R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, More preferably, it is 12 alkyl groups.
The alkylene group or the fluorine-substituted alkylene group preferably has 1 to 40 carbon atoms, more preferably 1 to 30, more preferably 1 to 20, and more preferably 1 to 15. Furthermore, it is preferable and it is most preferable that it is 1-12.
An example of L ⁵¹ is shown below. The left side is attached to the Hb, the right side is attached to B ^51.

L ⁵¹ 10: Single bond L ⁵¹ 11: —O—
L ⁵¹ 12: —O—CO—
L ⁵¹ 13: —CO—C ₄ H ₈ —O—
L ⁵¹ 14: —O—C ₂ H ₄ —O—C ₂ H ₄ —O—
L ⁵¹ 15: -S-
L ⁵¹ 16: -N (n-C ₁₂ H ₂₅ )-
L ⁵¹ 17: —SO ₂ —N (n—C ₃ H ₇ ) —CH ₂ CH ₂ —O—
L ⁵¹ 18: —O— {CF (CF ₃ ) —CF ₂ —O} ₃ —CF (CF ₃ ) —

  In general formula (V), n represents the integer in any one of 2-12. n is preferably an integer of 2 to 9, more preferably an integer of 2 to 6, further preferably 2, 3 or 4, and preferably 3 or 4. Most preferred.

In the general formula (V), B ⁵¹ is an n-valent linking group containing at least one cyclic structure. B ⁵¹ is preferably an n-valent group containing at least three cyclic structures, and more preferably an n-valent group represented by the following general formula (Va).

Formula (Va): (-Cy ⁵¹ -L ^52- ) nCy ⁵²

In the general formula (Va), Cy ⁵¹ represents a divalent cyclic group. Cy ⁵¹ preferably represents a divalent aromatic hydrocarbon group or a divalent heterocyclic group, and more preferably represents a divalent aromatic hydrocarbon group.
The divalent aromatic hydrocarbon group means an arylene group and a substituted arylene group.
Examples of the arylene group include a phenylene group, an indenylene group, a naphthylene group, a fluorenylene group, a phenanthrenylene group, an anthrylene group, and a pyrenylene group. A phenylene group and a naphthylene group are preferred.
Examples of the substituent of the substituted arylene group include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (for example, a methoxy group, an ethoxy group, a methoxyethoxy group), an aryloxy group (for example, Phenoxy group), arylazo group (for example, phenylazo group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group), alkylamino group (for example, methylamino group, propylamino group), acyl group (for example, acetyl group) , Propanoyl group, octanoyl group, benzoyl group), acyloxy group (for example, acetoxy group, pivaloyloxy group, benzoyloxy group), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl group, sulfamoyl group and ureido group Is included.
In addition, a group corresponding to Hb—L ⁵¹ — may be included as a substituent.

The divalent heterocyclic group represented by Cy ⁵¹ preferably has a 5-membered, 6-membered or 7-membered heterocyclic ring. Among these, a 5-membered ring or a 6-membered ring is more preferable, and a 6-membered ring is most preferable. As the hetero atom constituting the heterocyclic ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocycle is generally an unsaturated heterocycle. An unsaturated heterocyclic ring having the most double bond is more preferable. Examples of heterocyclic rings include furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline Ring, pyrazolidine ring, triazole ring, triazane ring, tetrazole ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring included.

Another heterocyclic ring, an aliphatic ring or an aromatic hydrocarbon ring may be condensed with the heterocyclic ring. Examples of the condensed heterocyclic ring include benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxazole ring, benzothiazole ring, indazole ring, benzimidazole ring, chromene ring, chroman ring, Isochroman ring, quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, carbazole ring, xanthene ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring , An indolizine ring, a quinolidine ring, a quinuclidine ring, a naphthyridine ring, a purine ring and a pteridine ring.
The divalent heterocyclic group may have a substituent. The example of a substituent is the same as the example of the substituent of the said substituted arylene group.
The divalent heterocyclic group may be a hetero atom (for example, a nitrogen atom of a piperidine ring) and may be bonded to L ⁵² or a cyclic group (Cy ⁵² ) at the center of the molecule (when L ⁵² is a single bond). In addition, the bonded hetero atom may form an onium salt (eg, oxonium salt, sulfonium salt, ammonium salt).

Cy ⁵¹ and the cyclic structure of Cy ⁵² described later may form a planar structure as a whole.
Specific examples of Cy ⁵¹ -L ^52- in the form linked with L ⁵¹ are shown below. In specific examples, when a plurality of groups corresponding to Hb-L ⁵¹ -are bonded to a divalent aromatic hydrocarbon group or a divalent heterocyclic group, any one is defined by the general formula (V). Hb—L ⁵¹ — in which the remainder is a substituent of a divalent aromatic hydrocarbon group or a divalent heterocyclic group.

In the general formula (Va), L ⁵² represents a single bond or an alkylene group, an alkenylene group, an alkynylene group, —O—, —S—, —CO—, —NR—, —SO ₂ — and combinations thereof. A divalent linking group selected from the group consisting of R represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms.
L ⁵² is preferably a divalent linking group selected from the group consisting of —O—, —S—, —CO—, —NR—, —SO ₂ —, and combinations thereof. R is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and a hydrogen atom or the number of carbon atoms being 1 to 12. The alkyl group is most preferably.
The alkylene group preferably has 1 to 40 carbon atoms, more preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 15, and still more preferably 1 to 1. Most preferably, it is ~ 12.
The number of carbon atoms of the alkenylene group or alkynylene group is preferably 2 to 40, more preferably 2 to 30, further preferably 2 to 20, and further preferably 2 to 15. Preferably, it is 2-12.
An example of L ⁵² is shown below. The left side is bonded to Cy ⁵¹ and the right side is bonded to Cy ⁵² .

L20: Single bond L21: -S-
L22: —NH—
L23: —NH—SO ₂ —NH—
L24: -NH-CO-NH-
L25: —SO ₂ —
L26: -O-NH-
L27: -C≡C-
L28: -CH = CH-S-
L29: —CH ₂ —O—
L30: -N (CH ₃₎ -
L31: -CO-O-

  In general formula (Va), n represents the integer in any one of 2-12. n is preferably an integer of 2 to 9, more preferably an integer of 2 to 6, further preferably 2, 3 or 4, and preferably 3 or 4. Most preferred.

In the general formula (Va), Cy ⁵² is an n-valent cyclic group. Cy ⁵² is preferably an n-valent aromatic hydrocarbon group or an n-valent heterocyclic group.
Examples of the aromatic hydrocarbon ring of the aromatic hydrocarbon group represented by Cy ⁵² include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring and a pyrene ring. A benzene ring and a naphthalene ring are preferable, and a benzene ring is particularly preferable.
The aromatic hydrocarbon group represented by Cy ⁵² may have a substituent. Examples of the substituent include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (eg, methoxy group, ethoxy group, methoxyethoxy group), an aryloxy group (eg, phenoxy group), Arylazo group (for example, phenylazo group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group), alkylamino group (for example, methylamino group, propylamino group), arylamino group (for example, phenylamino group), Acyl group (for example, acetyl group, propanoyl group, octanoyl group, benzoyl group), acyloxy group (for example, acetoxy group, pivaloyloxy group, benzoyloxy group), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl Group, sulfamoyl group and urei They include groups.

The heterocyclic group represented by Cy ⁵² preferably has a 5-membered, 6-membered or 7-membered heterocyclic ring. A 5-membered ring or 6-membered ring is more preferable, and a 6-membered ring is most preferable. As the hetero atom constituting the heterocyclic ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocycle is generally an unsaturated heterocycle. An unsaturated heterocyclic ring having the most double bond is more preferable. Examples of the heterocyclic ring include furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, Pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring Is included. A triazine ring is preferred, and a 1,3,5-triazine ring is particularly preferred.
Another heterocyclic ring, an aliphatic ring or an aromatic hydrocarbon ring may be condensed with the heterocyclic ring. However, monocyclic heterocycles are preferred.
Hereinafter, a specific example of Cy ⁵² in a form linked to L ⁵² will be shown.

  Below, the specific example of the additive for orientation control by the side of the air interface represented by the said general formula (V) is shown.

  The addition amount of the alignment control additive on the air interface side is preferably 0.001% by mass to 20% by mass, more preferably 0.01% by mass to 10% by mass with respect to the biaxial liquid crystal compound. The most preferable range is 1% by mass to 5% by mass.

[Additive for optically anisotropic layer]
In the optically anisotropic layer of the present invention, in addition to the biaxial liquid crystal compound, the above-mentioned air interface alignment control agent and any additive can be used in combination. Examples of additives other than the air interface alignment additive include repellency inhibitors, polymerization initiators, polymerizable monomers, and the like. These various additives may be appropriately added to the liquid crystal composition for forming the optically anisotropic layer as necessary.

[Anti-repellent agent]
In general, a polymer can be preferably used as a material (anti-repellent agent) used together with the biaxial liquid crystal compound to prevent repellency during application of the liquid crystal composition.
The polymer to be used is not particularly limited as long as the tilt angle change and orientation of the biaxial liquid crystal compound are not significantly inhibited.
Examples of the polymer are described in JP-A-8-95030, and particularly preferred specific polymer examples include cellulose esters. Examples of cellulose esters include cellulose acetate, cellulose acetate propionate, hydroxypropyl cellulose, and cellulose acetate butyrate. In order not to inhibit the orientation of the discotic liquid crystal compound, the amount of the polymer used for the purpose of preventing repellency is generally in the range of 0.1 to 10% by mass with respect to the biaxial liquid crystal compound. More preferably, it is in the range of ˜8 mass%, and further preferably in the range of 0.1 to 5 mass%.

[Polymerization initiator]
In the present invention, the liquid crystal compound is preferably fixed in a monodomain alignment, that is, in a substantially uniformly aligned state. Therefore, when a polymerizable liquid crystal compound is used, the liquid crystal compound is fixed by a polymerization reaction. It is preferable.
The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator, a photopolymerization reaction using a photopolymerization initiator, and a polymerization reaction by electron beam irradiation. In the case of the present invention, the support is deformed by heat. In order to prevent deterioration, a photopolymerization reaction and a polymerization reaction by electron beam irradiation are preferred.
Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin. Compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970).
The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating liquid (liquid crystal composition).
The light irradiation for the polymerization of the biaxial liquid crystal compound preferably uses ultraviolet rays. The irradiation energy is preferably 10mJ~50J / cm ^2, further preferably 50mJ~800mJ / cm ^2. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. Further, since the oxygen concentration in the atmosphere is related to the degree of polymerization, when the desired degree of polymerization is not reached in the air, it is preferable to reduce the oxygen concentration by a method such as nitrogen substitution. The preferable oxygen concentration is preferably 7% or less, and more preferably 3% or less.

[Polymerizable monomer]
A polymerizable monomer may be added to the liquid crystal composition.
The polymerizable monomer to be used is not particularly limited as long as it is compatible with the liquid crystal compound and does not cause a significant change in the tilt angle or disturb the alignment of the liquid crystal compound. Among these, compounds having a polymerization active ethylenically unsaturated group such as a vinyl group, a vinyloxy group, an acryloyl group, and a methacryloyl group are preferably used. The addition amount of the polymerizable monomer is generally in the range of 0.5 to 50% by mass and preferably in the range of 1 to 30% by mass with respect to the liquid crystal compound. In addition, it is particularly preferable to use a monomer having two or more reactive functional groups because an effect of improving the adhesion between the alignment film and the optically anisotropic layer can be expected.

[Coating solvent]
As the solvent used for preparing the liquid crystal composition, an organic solvent is preferably used. Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, toluene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.

[Application method]
The optically anisotropic layer is formed by preparing a liquid crystal composition coating solution using the above-mentioned solvent, coating it on the alignment film, and aligning the biaxial liquid crystal compound. The coating liquid can be applied by a known method (for example, a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, or a die coating method).

[Alignment film]
The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.
As long as the desired orientation can be imparted to the biaxial liquid crystal compound of the optically anisotropic layer provided on the alignment film, any layer may be used as the alignment film. An alignment film formed by irradiation is preferred. Particularly preferred is an alignment film formed by a rubbing treatment of a polymer. The rubbing treatment can be generally carried out by rubbing the surface of the polymer layer several times in a certain direction with paper or cloth. In the present invention, in particular, by the method described in the liquid crystal manual (Maruzen Co., Ltd.). Preferably it is done. The thickness of the alignment film is preferably 0.01 to 10 μm, and more preferably 0.05 to 3 μm.
The polymer used for the alignment film is described in many documents, and many commercially available products can be obtained. For the alignment film used in the retardation plate of the present invention, polyvinyl alcohol and its derivatives are preferably used. Particularly preferred is a modified polyvinyl alcohol having a hydrophobic group bonded thereto. As the alignment film, an alignment film used for a discotic liquid crystal can be used as an alignment film for a biaxial liquid crystal. As such an alignment film, reference can be made to the description on page 43, line 24 to page 49, line 8 of WO01 / 88574A1.

(Rubbing density of alignment film)
Since there is a relationship between the rubbing density of the alignment film and the pretilt angle of the liquid crystal compound at the interface of the alignment film, the pretilt angle decreases as the rubbing density increases, and the pretilt angle increases as the rubbing density decreases. By changing the rubbing density, the pretilt angle can be adjusted.
As a method for changing the rubbing density of the alignment film, a method described in Liquid Crystal Handbook (Maruzen Co., Ltd.) can be used. The rubbing density (L) is quantified by the formula (A).

  Formula (A): L = Nl (1 + 2πrn / 60v)

In the formula (A), N is the number of rubbing, l is the contact length of the rubbing roller, r is the radius of the roller, n is the number of rotations (rpm) of the roller, and v is the stage moving speed (second speed).
In order to increase the rubbing density, the rubbing frequency should be increased, the contact length of the rubbing roller should be increased, the radius of the roller should be increased, the rotation speed of the roller should be increased, and the stage moving speed should be decreased, while the rubbing density should be decreased. To do this, you can reverse this.

[Transparent support]
The transparent support of the retardation plate of the present invention is not particularly limited as long as it is mainly optically isotropic and has a light transmittance of 80% or more, but a polymer film is preferred.
Specific examples of the polymer include cellulose esters (eg, cellulose diacetate, cellulose triacetate), norbornene polymers, poly (meth) acrylate ester films, etc., and many commercially available polymers are preferably used. Is possible. Of these, cellulose esters are preferable from the viewpoint of optical performance, and lower fatty acid esters of cellulose are more preferable. The lower fatty acid is a fatty acid having 6 or less carbon atoms, and the number of carbon atoms is preferably 2 (cellulose acetate), 3 (cellulose propionate) or 4 (cellulose butyrate). Cellulose triacetate is particularly preferred. Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate may be used. In addition, even a conventionally known polymer such as polycarbonate or polysulfone, which easily develops birefringence, should have a decreased expression by modifying the molecule described in WO00 / 26705. You can also.

Hereinafter, the cellulose ester (especially cellulose acetate) preferably used as the transparent support will be described in detail.
As the cellulose ester, it is preferable to use one having an acetylation degree of 55.0 to 62.5%. In particular, the acetylation degree is preferably 57.0 to 62.0%. The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation follows the measurement and calculation of the degree of acetylation in ASTM D-817-91 (test method for cellulose acetate and the like).
The viscosity average polymerization degree (DP) of the cellulose ester is preferably 250 or more, and more preferably 290 or more. The cellulose ester used in the present invention preferably has a narrow molecular weight distribution of Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. The specific value of Mw / Mn is preferably 1.0 to 1.7, more preferably 1.3 to 1.65, and most preferably 1.4 to 1.6. preferable.
In cellulose ester, the hydroxyl groups at the 2nd, 3rd, and 6th positions of cellulose are not evenly distributed by 1/3 of the total substitution degree, and the substitution degree of the 6th hydroxyl group tends to be small. It is preferable that the substitution degree of the 6-position hydroxyl group of cellulose is larger than the 2-position and 3-position. The hydroxyl group at the 6-position with respect to the total substitution degree is preferably 30% or more and 40% or less and is preferably substituted with an acyl group, more preferably 31% or more, and particularly preferably 32% or more. The substitution degree at the 6-position is preferably 0.88 or more. The 6-position hydroxyl group may be substituted with an acyl group having 3 or more carbon atoms (eg, propionyl, butyryl, valeroyl, benzoyl, acryloyl) in addition to the acetyl group. The degree of substitution at each position can be determined by NMR. Cellulose esters having a high degree of substitution at the 6-position hydroxyl group are described in Synthesis Example 1 described in paragraph Nos. 0043 to 0044 of JP-A No. 11-5851, Synthesis Example 2 described in paragraph Nos. It can be synthesized with reference to the method of Synthesis Example 3 described.

In order to adjust the retardation of a polymer film used as a transparent support, particularly a cellulose acetate film, an aromatic compound having at least two aromatic rings can be used as a retardation increasing agent. When using such a retardation increasing agent, a retardation increasing agent is used in 0.01-20 mass parts with respect to 100 mass parts of cellulose acetate. The retardation increasing agent is preferably used in a range of 0.05 to 15 parts by mass, and more preferably in a range of 0.1 to 10 parts by mass with respect to 100 parts by mass of cellulose acetate. Two or more aromatic compounds may be used in combination.
The aromatic ring of the aromatic compound includes an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring.

The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).
Aromatic heterocycles are generally unsaturated heterocycles. The aromatic heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, and more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocyclic rings include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.
As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, More preferred are a benzene ring and a 1,3,5-triazine ring. It is particularly preferred that the aromatic compound has at least one 1,3,5-triazine ring.

The number of aromatic rings contained in the aromatic compound is preferably 2 to 20, more preferably 2 to 12, further preferably 2 to 8, and most preferably 2 to 6. .
The bonding relationship between two aromatic rings can be classified into (a) when forming a condensed ring, (b) when directly connecting with a single bond, and (c) when connecting via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c). Such retardation increasing agents are described in WO01 / 88574A1, WO00 / 2619A1, Japanese Patent Application Laid-Open Nos. 2000-1111914, 2000-275434, 2002-363343, and the like.

The cellulose acetate film is preferably produced from the prepared cellulose acetate solution (dope) by a solvent cast method. The above-mentioned retardation increasing agent may be added to the dope.
The dope is cast on a drum or band, and the solvent is evaporated to form a film. The concentration of the dope before casting is preferably adjusted so that the solid content is 18 to 35%. The surface of the drum or band is preferably finished in a mirror state. Regarding casting and drying methods in the solvent casting method, U.S. Pat. Nos. 2,336,310, 2,367,603, 2,429,078, 2,429,297, 2,429,978, 2,607,704, 2,37,069, 2,273,070, British Patent 6,407,331 No. 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, No. 60-203430, and No. 62-1115035.
The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less. After casting, it is preferable to dry it by applying air for 2 seconds or more. The obtained film can be peeled off from the drum or band and further dried by high-temperature air whose temperature is successively changed from 100 ° C. to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting.

The prepared cellulose acetate solution (dope) can be used to form a film by casting two or more layers of the dope. The dope is cast on a drum or band, and the solvent is evaporated to form a film. The dope before casting is preferably adjusted in concentration so that the solid content is 10 to 40%. The surface of the drum or band is preferably finished in a mirror state.
When casting a plurality of cellulose acetate solutions, a solution containing cellulose acetate is cast from a plurality of casting openings provided at intervals in the traveling direction of the support, and a film is produced while laminating them. May be. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be used. Alternatively, the cellulose acetate solution may be cast from two casting ports to form a film. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, JP-A-61-104413, JP-A-61-158413, and JP-A-6-134933. The method described in the publication can be used. Further, a cellulose acetate film casting method in which a flow of a high-viscosity cellulose acetate solution described in JP-A-56-162617 is wrapped with a low-viscosity cellulose acetate solution and the high-viscosity and low-viscosity cellulose acetate solutions are simultaneously extruded. A method may be used.

  In the cellulose acetate film, the retardation can be further adjusted by a stretching treatment. The draw ratio is preferably in the range of 0 to 100%. When stretching the cellulose acetate film of the present invention, tenter stretching is preferably used, and in order to control the slow axis with high accuracy, the difference between the left and right tenter clip speeds, the separation timing, etc. can be made as small as possible. preferable.

  A plasticizer can be added to the cellulose ester film in order to improve mechanical properties or increase the drying speed. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and di-2-ethylhexyl phthalate (DEHP). . Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred. The addition amount of the plasticizer is preferably 0.1 to 25% by mass of the amount of cellulose ester, more preferably 1 to 20% by mass, and most preferably 3 to 15% by mass.

Degradation inhibitors (eg, antioxidants, peroxide decomposers, radical inhibitors, metal deactivators, acid scavengers, amines) and UV inhibitors may be added to the cellulose ester film. The deterioration preventing agents are described in JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. The addition amount of the deterioration preventing agent is preferably 0.01 to 1% by mass of the solution (dope) to be prepared, and more preferably 0.01 to 0.2% by mass. When the addition amount is less than 0.01% by mass, the effect of the deterioration preventing agent is hardly recognized. When the added amount exceeds 1% by mass, bleeding-out (bleeding) of the deterioration preventing agent to the film surface may be observed.
As a particularly preferred example of the deterioration preventing agent, butylated hydroxytoluene (BHT) can be mentioned. The ultraviolet ray preventing agent is described in JP-A-7-11056.

The cellulose acetate film is preferably subjected to a surface treatment. Specific examples include corona discharge treatment, glow discharge treatment, flame treatment, acid treatment, alkali treatment, and ultraviolet irradiation treatment. In addition, as described in JP-A-7-333433, it is preferable to provide an undercoat layer.
From the viewpoint of maintaining the flatness of the film, the temperature of the cellulose acetate film in these treatments is preferably Tg (glass transition temperature) or lower, specifically 150 ° C. or lower.

As for the surface treatment of the cellulose acetate film, it is particularly preferable to carry out acid treatment or alkali treatment, that is, saponification treatment on cellulose acetate, from the viewpoint of adhesion to an alignment film or the like.
Hereinafter, the alkali saponification treatment will be specifically described as an example.
The alkali saponification treatment is preferably performed in a cycle in which the film surface is immersed in an alkali solution, neutralized with an acidic solution, washed with water and dried.
Examples of the alkaline solution include potassium hydroxide solution and sodium hydroxide solution. The specified concentration of hydroxide ions is preferably in the range of 0.1 to 3.0 mol / l, and more preferably in the range of 0.5 to 2.0 mol / l. The alkaline solution temperature is preferably in the range of room temperature to 90 ° C, more preferably in the range of 40 to 70 ° C.

The surface energy of the cellulose acetate film is preferably 55 mN / m or more, and more preferably in the range of 60 to 75 mN / m.
The surface energy can be obtained by a method similar to the method for calculating the surface energy of the optically anisotropic layer described above.

  The thickness of the cellulose acetate film is usually preferably in the range of 5 to 500 μm, preferably in the range of 20 to 250 μm, more preferably in the range of 30 to 180 μm, and particularly preferably in the range of 30 to 110 μm.

[Phase difference plate]
The retardation plate of the present invention can be used for an elliptically polarizing plate in combination with a polarizing film. Furthermore, it contributes to the expansion of a viewing angle by applying to a transmissive liquid crystal display device in combination with a polarizing film.
The elliptically polarizing plate and liquid crystal display device using the retardation plate of the present invention will be described below.

[Elliptically polarizing plate]
An elliptically polarizing plate can be produced by laminating the retardation plate of the present invention and a polarizing film. By using the retardation plate of the present invention, an elliptically polarizing plate capable of expanding the viewing angle of a liquid crystal display device can be provided.
Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The polarization axis of the polarizing film corresponds to a direction perpendicular to the film stretching direction.

  The polarizing film is laminated on the optically anisotropic layer side of the retardation plate. It is preferable to form a transparent protective film on the surface opposite to the side on which the optical compensation sheet of the polarizing film is laminated. The transparent protective film preferably has a light transmittance of 80% or more. As the transparent protective film, generally a cellulose ester film, preferably a triacetyl cellulose film is used. The cellulose ester film is preferably formed by a solvent cast method. The thickness of the transparent protective film is preferably 20 to 500 μm, and more preferably 50 to 200 μm.

[Liquid Crystal Display]
By using the retardation plate of the present invention, a liquid crystal display device with an enlarged viewing angle can be provided. TN mode liquid crystal cell retardation plates (optical compensation sheets) are described in JP-A-6-214116, US Pat. Nos. 5,583,679, 5,646,703, and German Patent 3,911,620A1. Further, an optical compensation sheet for liquid crystal cells in IPS mode or FLC mode is described in JP-A-10-54982. Furthermore, OCB mode or HAN mode liquid crystal cell optical compensation sheets are described in US Pat. No. 5,805,253 and International Publication No. WO96 / 37804. Furthermore, an optical compensation sheet for an STN mode liquid crystal cell is described in JP-A-9-26572. A VA mode liquid crystal cell optical compensation sheet is described in Japanese Patent No. 2866372.

In the present invention, liquid crystal cell retardation plates (optical compensation sheets) of various modes can be prepared with reference to the above-mentioned publications. The retardation plate of the present invention includes TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Super Twisted Nematic), VA (Vertically Aligned), and HAN. It can be used for liquid crystal display devices of various display modes such as (Hybrid Aligned Nematic) mode.
The retardation plate of the present invention is particularly effective when used for a VA mode liquid crystal display device because the direction of the smallest refractive index of the liquid crystal phase is substantially parallel to the normal line of the transparent support.
The liquid crystal display device includes a liquid crystal cell, a polarizing element, and a phase difference plate (optical compensation sheet). A polarizing element generally comprises a polarizing film and a protective film. As the polarizing film and the protective film, those described for the elliptically polarizing plate can be used.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these specific examples. In addition, Example 8 shall be read as “reference example”.

[Example 1]
Synthesis of 4,4′-di (2,3,4-tri (4-acryloyloxybutyloxy) cinnamoyloxy) biphenyl (m-40).
It can be synthesized according to the following scheme.

(1) Synthesis intermediate: Synthesis of 2,3,4-tri (4-acetyloxybutyloxy) benzaldehyde.
In a three-necked flask, 2,3,4-trihydroxybenzaldehyde (14.5 g), potassium carbonate (51.3 g), 4-chlorobutyl acetate (46.8) g and dimethylformamide (DMF) 200 mL were placed, and the temperature was 120 ° C. For 5 hours. After cooling, the reaction solution was extracted with ethyl acetate and washed with water. The extract was concentrated and purified by column chromatography to obtain the title compound (43.7 g). Yield 91%.

(2) Synthesis intermediate: Synthesis of 2,3,4-tri (4-hydroxybutyloxy) cinnamic acid.
To a three-necked flask, 2,3,4-tri (4-acetyloxybutyloxy) benzaldehyde (40.0 g), malonic acid (10.6 g), piperidine (1 ml) and pyridine 100 mL were added and stirred at 110 ° C. for 5 hours. did. After cooling, water (500 ml) and potassium hydroxide (26.0 g) were added, and the mixture was stirred at 60 ° C. for 2 hours. After cooling, concentrated hydrochloric acid was added until the reaction solution became acidic, extracted with ethyl acetate, and washed with water. The extract was concentrated and purified by column chromatography to give the title compound (30.1 g). Yield 90%.

(3) Synthesis intermediate: Synthesis of 2,3,4-tri (4-acryloyloxybutyloxy) cinnamic acid.
In a three-necked flask, 2,3,4-tri (4-hydroxybutyloxy) cinnamic acid (30.1 g), acrylic acid chloride (7.6 g), N, N-dimethylaniline (11.1 g) and 500 mL of tetrahydrofuran were added. In addition, the mixture was stirred at 60 ° C. for 5 hours. After cooling, the reaction solution was extracted with ethyl and washed with water. The extract was concentrated and purified by column chromatography to obtain the title compound (39.3 g). Yield 95%.

(4) Synthesis of 4,4′-di (2,3,4-tri (4-acryloyloxybutyloxy) cinnamoyloxy) biphenyl (m-40).
To a three-necked flask, 2,3,4-tri (4-acryloyloxybutyloxy) cinnamic acid (10.0 g), thionyl chloride (6.1 g), dimethylformamide (0.01 g) and 30 mL of toluene were added, and 40 ° C. For 30 minutes. After cooling, toluene and excess thionyl chloride were distilled off, and 100 ml of tetrahydrofuran was added. To this reaction liquid, 4,4′-dihydroxybiphenyl (1.6 g) was added, cooled to 5 ° C., triethylamine (2.8 mL) was added dropwise, and then 4-dimethylaminopyridine (0.1 g) was added. The mixture was heated to 25 ° C. and stirred for 5 hours. Thereafter, the reaction solution was added to water (500 mL), and the precipitated crystals were filtered. The crystals were dissolved in dimethylacetamide (20 mL), triethylamine (2.8 mL) was added, and the mixture was stirred at 60 ° C. for 1 hr. After cooling, the reaction solution was extracted with ethyl and washed with water. The extract was concentrated and purified by column chromatography to obtain the title compound (9.5 g). Yield 85%. The NMR spectrum of the obtained m-40 is as follows.

¹ H-NMR (solvent: CDCl _3, standard: tetramethylsilane) [delta] (ppm):
1.80-2.00 (24H, m),
4.00-4.15 (12H, m),
4.15-4.30 (12H, m),
5.70-5.90 (6H, m),
6.05-6.20 (6H, m),
6.35-6.45 (6H, m),
6.60 (2H, d),
6.71 (2H, d),
7.24 (4H, d),
7.35 (2H, d),
7.60 (4H, d),
8.10 (2H, d).

(5) Confirmation of liquid crystallinity of m-40 About 4,4'-di (2,3,4-tri (4-acryloyloxybutyloxy) cinnamoyloxy) biphenyl (m-40) synthesized above, DSC Changes in the liquid crystal phase were observed with a differential scanning calorimeter and a polarizing microscope. As a result, it was found that a nematic phase was developed in the range of 68 to 74 ° C. It can be seen from the texture that the developed nematic phase is a biaxial nematic phase (Nb phase).

[Example 2]
Synthesis of 2,6-di (2,3,4-tri (4-acryloyloxybutyloxy) naphthalene (m-32).
It can be synthesized according to the following scheme.

  The title compound (m-32) was synthesized from 2,3,4-tri (4-acryloyloxybutyloxy) cinnamic acid of Example 1 and 2,6-dihydroxynaphthalene by the same method as in Example 1. The NMR spectrum of the obtained m-32 is as follows.

¹ H-NMR (solvent: CDCl _3, standard: tetramethylsilane) [delta] (ppm):
1.80-2.00 (24H, m),
4.00-4.15 (12H, m),
4.15-4.30 (12H, m),
5.70-5.90 (6H, m),
6.05-6.20 (6H, m),
6.35-6.45 (6H, m),
6.64 (2H, d),
6.73 (2H, d),
7.33 (2H, dd),
7.36 (2H, d),
7.65 (2H, d),
7.85 (2H, d),
8.13 (2H, d).

Confirmation of liquid crystal property of m-32:
Regarding 2,6-di (2,3,4-tri (4-acryloyloxybutyloxy) naphthalene (m-32) synthesized above, the change of the liquid crystal phase was measured with DSC (differential scanning calorimeter) and polarization microscope. As a result, the crystal changed to an isotropic liquid at 41 ° C. when the temperature was raised, and liquid crystallinity could not be confirmed, but the nematic phase was developed at 25 ° C. or less when the temperature was lowered. From the texture, it can be seen that it is a biaxial nematic phase (Nb phase).

[Example 3]
Synthesis of 2,6-di (2,3,4-tri (4-acryloyloxyethyloxy) naphthalene (m-31).
It can be synthesized according to the following scheme.

  2,3,4-tri (4-acryloyloxyethyloxy) cinnamic acid was synthesized from 2,3,4-trihydroxybenzaldehyde and 2-chloroethyl acetate in the same manner as in Example 1. Thereafter, the title compound (m-31) was synthesized from 2,3,4-tri (4-acryloyloxyethyloxy) cinnamic acid and 2,6-dihydroxynaphthalene in the same manner as in Example 1. The NMR spectrum of the obtained m-31 is as follows.

¹ H-NMR (solvent: CDCl _3, standard: tetramethylsilane) [delta] (ppm):
4.25-4.35 (8H, m),
4.40-4.50 (12H, m),
4.57 (4H, t),
5.65-5.90 (6H, m),
6.15-6.25 (6H, m),
6.45-6.50 (6H, m),
6.68 (2H, d),
6.76 (2H, d),
7.33 (2H, dd),
7.37 (2H, d),
7.65 (2H, d),
7.85 (2H, d),
8.16 (2H, d).

Confirmation of liquid crystal properties of m-31:
About 2,6-di (2,3,4-tri (4-acryloyloxyethyloxy) naphthalene (m-31) synthesized above, the change of the liquid crystal phase was measured with DSC (differential scanning calorimeter) and polarization microscope. As a result, when the temperature was raised, the crystal changed to an isotropic liquid at 130 ° C., and liquid crystallinity could not be confirmed, but when the temperature was lowered, a nematic phase was exhibited at 40 ° C. or less. From the texture, it can be seen that it is a biaxial nematic phase (Nb phase).

[Example 4]
Synthesis of 4,4′-di (2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) cinnamoyloxy) biphenyl (m-43).
It can be synthesized according to the following scheme.

(1) Synthesis intermediate: Synthesis of 2,3-dihexyloxy-4- (4-acetyloxybutyloxy) benzaldehyde.
In a three-neck flask, 2,3,4-trihydroxybenzaldehyde (8.5 g), potassium carbonate (36 g), 4-chlorobutyl acetate (8.2) g and dimethylformamide (DMF) 100 mL were placed, and the mixture was stirred at 120 ° C. for 5 minutes. Stir for hours. Thereafter, 1-hexyl bromide (18.9 g) was added, and the mixture was further stirred at 120 ° C. for 5 hours. After cooling, the reaction solution was extracted with ethyl acetate and washed with water. The extract was concentrated and purified by column chromatography to obtain the title compound (6.3 g). Yield 28%.

(2) Synthesis intermediate: Synthesis of 2,3-dihexyloxy-4- (4-acetyloxybutyloxy) cinnamic acid.
To a three-necked flask, 2,3,4-tri (4-acetyloxybutyloxy) benzaldehyde (6.3 g), malonic acid (2.25 g), piperidine (0.5 ml) and pyridine 20 mL were added, Stir for hours. After cooling, water (200 ml) and potassium hydroxide (4.0 g) were added and stirred at 60 ° C. for 2 hours. After cooling, concentrated hydrochloric acid was added until the reaction solution became acidic, extracted with ethyl acetate, and washed with water. The extract was concentrated and purified by column chromatography to give the title compound (6.2 g). Yield 98%.

(3) Synthesis intermediate: Synthesis of 2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) cinnamic acid.
In a three-necked flask, 2,3,4-tri (4-hydroxybutyloxy) cinnamic acid (6.2 g), acrylic acid chloride (1.3 ml), N, N-dimethylaniline (2.1 g) and 100 mL of tetrahydrofuran were added. In addition, the mixture was stirred at 60 ° C. for 5 hours. After cooling, the reaction solution was extracted with ethyl and washed with water. The extract was concentrated and purified by column chromatography to give the title compound (6.0 g). Yield 86%.

(4) Synthesis of 4,4′-di (2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) cinnamoyloxy) biphenyl (m-43).
To a three-necked flask, 2,3,4-tri (4-acryloyloxybutyloxy) cinnamic acid (2.5 g), thionyl chloride (1.5 g), dimethylformamide (0.01 g) and 30 mL of toluene were added, and 40 ° C. For 30 minutes. After cooling, toluene and excess thionyl chloride were distilled off, and 20 ml of tetrahydrofuran was added. To this reaction solution, 4,4′-dihydroxybiphenyl (0.34 g) was added, cooled to 5 ° C., triethylamine (0.6 mL) was added dropwise, and then 4-dimethylaminopyridine (0.01 g) was added. The mixture was heated to 25 ° C. and stirred for 5 hours. Thereafter, the reaction solution was added to water (200 mL), and the precipitated crystals were filtered. The crystals were dissolved in dimethylacetamide (20 mL), triethylamine (0.6 mL) was added, and the mixture was stirred at 60 ° C. for 1 hr. After cooling, the reaction solution was extracted with ethyl and washed with water. The extract was concentrated and purified by column chromatography to give the title compound (2.0 g). Yield 85%. The NMR spectrum of the obtained m-43 is as follows.

¹ H-NMR (solvent: CDCl _3, standard: tetramethylsilane) [delta] (ppm):
0.80-1.00 (12H, m),
1.20-1.40 (16H, m),
1.50-1.60 (8H, m),
1.75-1.85 (8H, m),
1.85-2.00 (8H, m),
3.98 (4H, t),
4.00-4.15 (8H, m),
4.26 (4H, t),
5.70-5.90 (6H, m),
6.05-6.20 (6H, m),
6.35-6.45 (6H, m),
6.60 (2H, d),
6.70 (2H, d),
7.23 (4H, d),
7.33 (2H, d),
7.59 (4H, d),
8.13 (2H, d).

(5) Confirmation of liquid crystallinity of m-43 About 4,4'-di (2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) cinnamoyloxy) biphenyl (m-43) synthesized above The change of the liquid crystal phase was observed with DSC (differential scanning calorimeter) and a polarizing microscope. As a result, it was found that a nematic phase was developed in the range of 93 to 107 ° C. It can be seen from the texture that the developed nematic phase is a biaxial nematic phase (Nb phase).

[Example 5]
Synthesis of 2,6-di (2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) naphthalene (m-35).
It can be synthesized according to the following scheme.

  The title compound (m-35) was synthesized from 2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) cinnamic acid of Example 4 and 2,6-dihydroxynaphthalene by the same method as in Example 4. . The NMR spectrum of the obtained m-35 is as follows.

¹ H-NMR (solvent: CDCl _3, standard: tetramethylsilane) [delta] (ppm):
0.80-1.00 (12H, m),
1.20-1.40 (16H, m),
1.50-1.60 (8H, m),
1.75-1.85 (8H, m),
1.85-2.00 (8H, m),
3.97 (4H, t),
4.00-4.15 (8H, m),
4.26 (4H, t),
5.70-5.90 (6H, m),
6.05-6.20 (6H, m),
6.35-6.45 (6H, m),
6.63 (2H, d),
6.73 (2H, d),
7.32 (2H, dd),
7.36 (2H, d),
7.64 (2H, d),
7.84 (2H, d),
8.12 (2H, d),

Confirmation of liquid crystal property of m-35:
About 2,6-di (2,3-dihexyloxy-4- (4-acryloyloxybutyloxy) naphthalene (m-35) synthesized above, the liquid crystal phase was measured with a DSC (differential scanning calorimeter) and a polarizing microscope. As a result, the crystal transitioned from an isotropic liquid to 98 ° C. at the time of temperature rise and liquid crystallinity could not be confirmed, but the nematic phase was developed at 73 ° C. or less at the time of temperature fall. It can be seen from the texture that the phase is a biaxial nematic phase (Nb phase).

[Example 6]
-Production of retardation plate-
(Preparation of transparent support)
The following components are put into a mixing tank and heated and stirred to prepare a cellulose acetate solution (dope).

(Cellulose acetate solution composition)
Cellulose acetate having an acetylation degree of 60.9% 100 parts by weight Triphenyl phosphate 6.5 parts by weight Biphenyl diphenyl phosphate 5.2 parts by weight The following retardation increasing agent (1) 0.1 part by weight The following retardation increasing agent (2) 0.2 parts by mass Methylene chloride 310.25 parts by mass Methanol 54.75 parts by mass 1-butanol 10.95 parts by mass

  The dope is cast from a casting port onto a drum cooled to 0 ° C. The film is peeled off in a state where the solvent content is 70% by mass, both ends in the width direction of the film are fixed with a pin tenter, and the stretch rate in the width direction (direction perpendicular to the longitudinal direction) in the region where the solvent content is 3 to 5% by mass. Is dried while maintaining an interval of 3%. Then, it is further dried by transporting between the rolls of the heat treatment apparatus, and the stretch ratio in the longitudinal direction is substantially 0% in a region exceeding 120 ° C. (in consideration of stretching by 4% in the longitudinal direction when stripping) A cellulose acetate film having a thickness of 100 μm is prepared by adjusting the ratio of the stretching ratio in the width direction to the stretching ratio in the longitudinal direction to be 0.75. The retardation of the produced film was measured at a wavelength of 632.8 nm. The retardation in the thickness direction was 40 nm and the in-plane retardation was 4 nm. The produced cellulose acetate film is used as a transparent support.

(Formation of first undercoat layer)
On the transparent support, a coating solution having the following composition is coated at 28 ml / m ² and dried to form a first undercoat layer.

(First undercoat layer coating solution composition)
Gelatin 5.42 parts by mass Formaldehyde 1.36 parts by mass Salicylic acid 1.60 parts by mass Acetone 391 parts by mass Methanol 158 parts by mass Methylene chloride 406 parts by mass Water 12 parts by mass

(Formation of second undercoat layer)
On the first undercoat layer, 7 ml / m ² of a coating solution having the following composition is applied and dried to form a second undercoat layer.

(Second undercoat layer coating solution composition)
The following anionic polymer 0.79 parts by mass Citric acid monoethyl ester 10.1 parts by mass Acetone 200 parts by mass Methanol 877 parts by mass Water 40.5 parts by mass

(Formation of back layer)
On the opposite surface of the transparent support, a coating liquid having the following composition is applied at 25 ml / m ² and dried to form a back layer.

(Back layer coating solution composition)
Cellulose diacetate with an acetylation degree of 55% 6.56 parts by mass Silica matting agent (average particle size: 1 μm) 0.65 parts by mass Acetone 679 parts by mass Methanol 104 parts by mass

(Formation of alignment film)
The following modified polyvinyl alcohol and glutaraldehyde (5% by mass of modified polyvinyl alcohol) are dissolved in a methanol / water mixed solvent (volume ratio = 20/80) to prepare a 5% by mass solution.

  This solution is applied onto the second undercoat layer, dried with hot air at 100 ° C. for 120 seconds, and then rubbed to form an alignment film layer. The film thickness of the obtained alignment film layer is 0.5 μm. The rubbing direction of the alignment film is parallel to the casting direction of the transparent support.

(Formation of optically anisotropic layer)
An optically anisotropic layer coating liquid having the following composition is applied onto the rubbed alignment film using a # 4 wire bar.

(Optically anisotropic layer coating solution)
Air interface alignment controller v- (20) 0.2 parts by mass Biaxial liquid crystalline compound m-40 100 parts by mass The following photopolymerization initiator HJ-1 2.0 parts by mass Lucirin TPO-L (manufactured by BASF )) 2.0 parts by mass Methyl ethyl ketone 300 parts by mass

The film coated with the optically anisotropic layer coating solution is placed in a thermostatic bath at 70 ° C., heated to 60 ° C. over about 20 seconds, held for 30 seconds, and then 50% with an oxygen concentration of 2%. Place in a thermostatic bath at 0 ° C., and after 30 seconds, irradiate with 600 mJ ultraviolet rays to fix the alignment state of the optically anisotropic layer. It cools to room temperature, forms an optical anisotropic layer, and produces a phase difference plate. The thickness of the optically anisotropic layer is 1.82 μm.
Determination of biaxiality and inclination angle in the optically anisotropic layer of the obtained retardation plate is performed with a polarizing microscope equipped with a free base. It can be confirmed that it exhibits biaxiality, and the direction with the smallest refractive index substantially coincides with the normal direction of the transparent support, and the direction hardly changes in the thickness direction of the transparent support.

[Example 7]
A retardation plate is produced in the same manner as in Example 6 except that the air interface alignment controller is changed to V- (18). Biaxiality determination and inclination angle determination are performed in the same manner as in the sixth embodiment. It can be confirmed that it exhibits biaxiality, and the direction with the smallest refractive index substantially coincides with the normal direction of the transparent support, and the direction hardly changes in the thickness direction of the transparent support.

[Example 8]
On the rubbed alignment film produced in Example 6, an optically anisotropic layer coating solution having the following composition is applied using a # 4 wire bar.

(Optically anisotropic layer coating solution)
Air interface alignment controller v- (20) 0.1 part by mass The following biaxial liquid crystalline compound NI-1 100 parts by mass Ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) 5 0.0 part by mass The above photopolymerization initiator HJ-1 2.0 parts by mass Lucirin TPO-L (BASF (manufactured)) 2.0 parts by mass Methyl ethyl ketone 300 parts by mass

  The film coated with the optically anisotropic layer coating solution is placed in a thermostatic bath at 140 ° C., heated to 130 ° C. over about 30 seconds, held for 30 seconds, and then 80% oxygen concentration is 2%. Place in a thermostatic bath at 0 ° C., and after 30 seconds, irradiate with 600 mJ ultraviolet rays to fix the alignment state of the optically anisotropic layer. It cools to room temperature, forms an optical anisotropic layer, and produces a phase difference plate. The formed optically anisotropic layer has a thickness of 1.90 μm. Biaxiality determination and inclination angle determination are performed in the same manner as in the sixth embodiment. It can be confirmed that it exhibits biaxiality, and the direction with the smallest refractive index substantially coincides with the normal direction of the transparent support, and the direction hardly changes in the thickness direction of the transparent support.

[ Example 9]
On the rubbed alignment film produced in Example 6, an optically anisotropic layer coating solution having the following composition is applied using a # 4 wire bar.

(Optically anisotropic layer coating solution)
Biaxial liquid crystalline compound m-43 100 parts by mass The above photopolymerization initiator HJ-1 2.0 parts by mass Lucirin TPO-L (BASF (manufactured)) 2.0 parts by mass Methyl ethyl ketone 300 parts by mass

  The film coated with the optically anisotropic layer coating solution is placed in a thermostatic bath at 95 ° C., heated to 90 ° C. over about 30 seconds, held for 30 seconds, and then 80% with an oxygen concentration of 2%. Place in a thermostatic bath at 0 ° C., and after 30 seconds, irradiate with 600 mJ ultraviolet rays to fix the alignment state of the optically anisotropic layer. It cools to room temperature, forms an optical anisotropic layer, and produces a phase difference plate. The formed optically anisotropic layer has a thickness of 1.90 μm. Biaxiality determination and inclination angle determination are performed in the same manner as in the sixth embodiment. It can be confirmed that it exhibits biaxiality, and the direction with the smallest refractive index substantially coincides with the normal direction of the transparent support, and the direction hardly changes in the thickness direction of the transparent support.

[Example 10]
On the rubbed alignment film produced in Example 6, an optically anisotropic layer coating solution having the following composition is applied using a # 4 wire bar.

(Optically anisotropic layer coating solution)
Biaxial liquid crystalline compound P-3 100 parts by weight Methyl ethyl ketone 300 parts by weight

  The film coated with the optically anisotropic layer coating solution is placed in a thermostatic bath at 60 ° C., heated to 50 ° C. over about 30 seconds, held for 60 seconds, and then brought into contact with a metal roller at 20 ° C. Thus, the glass state is set, the orientation state is fixed, the optically anisotropic layer is formed, and the retardation plate is produced. The formed optically anisotropic layer has a thickness of 1.90 μm. Biaxiality determination and inclination angle determination are performed in the same manner as in the sixth embodiment. It can be confirmed that it exhibits biaxiality, and the direction with the smallest refractive index substantially coincides with the normal direction of the transparent support, and the direction hardly changes in the thickness direction of the transparent support.

[Example 11]
A retardation plate is produced in the same manner as in Example 6 except that V- (20) is not added as the air interface alignment controller. Biaxiality determination and inclination angle determination are performed in the same manner as in the sixth embodiment. It can be confirmed that the direction with the smallest refractive index of the optically anisotropic layer is inclined with respect to the normal direction of the transparent support.

[Example 12]
A retardation plate is produced in the same manner as in Example 6 except that the oxygen concentration at the time of ultraviolet irradiation is changed to 18%. It can be confirmed that the film strength on the surface of the obtained retardation plate is weaker than that in the case of ultraviolet irradiation at an oxygen concentration of 2%.
The film strength is evaluated by judging whether the strength is strong or weak by actually touching the surface of the retardation plate (optically anisotropic layer side) (Examples 6 to 11 and Comparative Example 1 also). The same).

[Comparative Example 1]
A retardation plate is produced in the same manner as in Example 8 except that V- (20) is not added as the air interface alignment controller. Biaxiality determination and inclination angle determination are performed in the same manner as in the sixth embodiment. It can be confirmed that the direction with the smallest refractive index of the optically anisotropic layer is inclined with respect to the normal direction of the transparent support.
Table 1 below summarizes the optically anisotropic layers of the retardation plates of Examples 6 to 12 and Comparative Example 1 described above.

From the results shown in Table 1 above, in any of the optically anisotropic layers of the retardation plates of Examples 6 to 8 containing a low-molecular biaxial liquid crystal compound and an air interface controller, the refraction of the thin film is in any case. It can be seen that the direction with the smallest rate is substantially in the normal direction of the film plane, and the object of the present invention can be achieved.
In Example 9 using the compound of the present invention and Example 10 using the polymer biaxial liquid crystal liquid crystal compound, the direction in which the refractive index of the thin film is the smallest is almost in the normal direction of the film plane. It can be seen that the object of the present invention can be achieved.
On the other hand, in Comparative Example 1, it can be seen that the direction with the smallest refractive index is substantially inclined from the normal direction of the film plane, and this object cannot be achieved.
Furthermore, Examples 6, 7 and 11 having a low oxygen concentration when irradiated with ultraviolet light have higher film strength than Example 12 having a high oxygen concentration in any case, and the object of the present invention can be achieved. I understand.

Claims (5)

The compound represented by the following general formula (B-1).
Formula (B-1)

In general formula (B-1),
A represents phenylene, phenylene-phenylene, or naphthylene. Phenylene may have a substituent. The substituent which phenylene may have is a methyl group or a chloro group.
L ₂₁ and L ₂₂ represent —CH═CH—CO—O— * (* represents a position linked to A).
L ₁₁ , L ₁₂ , L ₁₃ , L ₁₄ , L ₁₅ and L ₁₆ are each independently * —O—an alkylene group having 2 to 12 carbon atoms or * —O—an alkylene group having 2 to 12 carbon atoms— O-CO- (* represents a position linked to a benzene ring).
Q ₁₁ , Q ₁₂ , Q ₁₃ , Q ₁₄ , Q ₁₅ , Q ₁₆ each independently represents an ethylenically unsaturated polymerizable group selected from Q1 to Q6 or a hydrogen atom, and Q ₁₁ , Q ₁₂ , Q _{13, Q 14, Q 15,} Q 16
At least one represents an ethylenically unsaturated polymerizable group selected from the following Q1 to Q6 .

  A retardation plate having at least one optically anisotropic layer formed from a liquid crystal compound on a transparent support, wherein the liquid crystal compound is the compound according to claim 1. A retardation plate having at least one optically anisotropic layer formed from a liquid crystal compound expressing a biaxial liquid crystal phase on a transparent support,
The liquid crystal compound is a polymerizable compound that is the compound according to claim 1 and / or a polymer compound that includes the compound according to claim 1 in a partial structure,
The direction with the smallest refractive index of the biaxial liquid crystal phase substantially coincides with the normal direction of the transparent support.
A retardation film characterized by that. 4. The retardation plate according to claim 2, wherein the optically anisotropic layer contains a compound represented by the following general formula (V).
Formula ^{(V) :( Hb-L 51} -) nB 51
In general formula (V), Hb represents an aliphatic group having 6 to 40 carbon atoms or an aliphatic substituted oligosiloxanoxy group having 6 to 40 carbon atoms. n represents an integer of 2 to 12.
L ⁵¹ represents a single bond or an unsubstituted alkylene group having 1 to 40 carbon atoms, a fluorine-substituted alkylene group having 1 to 40 carbon atoms, —O—, —S—, —CO—, —NR—, —SO ₂ —. And a group selected from the group consisting of combinations thereof. Here, R represents a hydrogen atom or an unsubstituted alkyl group having 1 to 20 carbon atoms.
B ⁵¹ represents an n-valent group represented by the following general formula (Va).
Formula (Va): (-Cy ⁵¹ -L ^52- ) nCy ⁵²
Cy ⁵¹ is a phenylene group, an indenylene group, a naphthylene group, a fluorenylene group, a phenanthrenylene group, an anthrylene group, a pyrenylene group, or a furan ring, a thiophene ring, a pyrrole ring, a pyrroline ring, a pyrrolidine ring, an oxazole ring, an isoxazole Ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiine ring, pyridine ring, piperidine ring, oxazine Ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring, benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxa Ring, benzothiazole ring, indazole ring, benzimidazole ring, chromene ring, chroman ring, isochroman ring, quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, carbazole ring, xanthene ring , Acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring, indolizine ring, quinolidine ring, quinuclidine ring, naphthyridine ring, purine ring, and pteridine ring. Represents a cyclic group. These groups have no substituent.
L ⁵² represents a single bond or an unsubstituted alkylene group having 1 to 40 carbon atoms, an unsubstituted alkenylene group having 2 to 40 carbon atoms, an unsubstituted alkynylene group having 2 to 40 carbon atoms, -O-, It represents a group selected from the group consisting of —S—, —CO—, —NR—, —SO ₂ — and combinations thereof. R represents a hydrogen atom or an unsubstituted alkyl group having 1 to 30 carbon atoms.
n represents an integer of 2 to 12.
Cy ⁵² is an n-valent cyclic group, which is a benzene ring, indene ring, naphthalene ring, fluorene ring, phenanthrene ring, anthracene ring, pyrene ring, furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole Ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiine ring, pyridine ring, A cyclic group consisting of a ring selected from a piperidine ring, an oxazine ring, a morpholine ring, a thiazine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a piperazine ring and a triazine ring. These groups have no substituent.   After apply | coating the liquid crystal composition containing the polymeric compound which expresses a biaxial liquid-crystal phase, and a photoinitiator on an alignment film, the polymeric compound which is a compound of Claim 1 is monodomain-aligned. A method for forming an optically anisotropic layer, characterized in that the orientation of a polymerizable compound is fixed by polymerization by irradiation with ultraviolet rays in an atmosphere having an oxygen concentration of 7% or less.