JP2001051119A - Optical anistropic element and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve remarkably display characteristics, such as a contrast, a visual characteristic, and aim great improvement of mechanical characteristics, by using a liquid crystalline polymer showing an optically positive uniaxial property, to which a specific compound is added. SOLUTION: This optical anistropic element comprises a combination between a liquid crystal film obtained by immobilizing the orientation state formed in the liquid crystal state by a liquid crystalline composition including a liquid crystalline polymer showing an optically positive uniaxial property and a polycyclic compound shown by a formula: R1-B1-A1-...-Bn-An-Bn+1-R2 and having a molecular weight of 1,000 or less, and a light, diffusion pressure sensitive adhesive layer. In the formula, R1 and R2 show a hydrocarbon group having a carbon number of 1-20 individually, and A1-An show a carbocyclic structure or a heterocyclic structure individually. B1-Bn+1 show a linkage chain having the number of principal chain atoms of 0-4 individually, and (n) shows an integer of 2 or more and simultaneously 8 or less. But, individual carbocyclic structure or heterocyclic structure is not bonded to the linkage chains B1-Bn+1 with the same carbon atom in the same ring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optically anisotropic element in which display characteristics such as contrast and viewing angle characteristics are remarkably improved and mechanical characteristics are significantly improved, and a liquid crystal display device in which the optically anisotropic element is arranged.

[0002]

2. Description of the Related Art An active drive twisted nematic liquid crystal display device (hereinafter abbreviated as TN-LCD) using a TFT element or an MIM element is thin, lightweight, and thin.
In addition to the low power consumption inherent in LCDs, it has an image quality comparable to a CRT when viewed from the front. For this reason, it is widely used as a display device for notebook computers, portable televisions, portable information terminals, and the like. However, in the conventional TN-LCD, the problem of the viewing angle that the display color changes or the display contrast decreases when viewed obliquely due to the refractive index anisotropy of the liquid crystal molecules is essentially unavoidable. There is a strong demand for improvement, and various attempts have been made for improvement. In recent years, various optical compensation films have been proposed for the purpose of solving the viewing angle problem, and the development of TN-LCDs having a wide viewing angle has been remarkably progressed. For example, in Japanese Patent Application Laid-Open No. 10-104611,
There is disclosed a liquid crystal display device in which optical compensation means is provided on both sides of a driving liquid crystal cell, and a light diffusion layer is provided on a light emitting surface side of a liquid crystal cell portion. In this publication, a light diffusing layer is provided on the light exit side surface of the polarizing plate, so that the outgoing light transmitted through the polarizing plate is diffused in all directions by the light diffusing layer, thereby realizing a high viewing angle. Also, Japanese Patent Application Laid-Open No. 10-142591 proposes a liquid crystal display device provided with an optically anisotropic film exhibiting negative uniaxiality and a light diffusion film. However, providing a light-diffusing layer on the light-emitting side as in JP-A-10-104611 means that the light-diffusing layer is located at the outermost layer of the LCD. It is necessary to perform anti-reflection treatment, impart a hard coat property to the surface, impart light resistance, and the like, which is disadvantageous in that the manufacturing cost is increased. Also, JP-A-10-14
In the case where an optically anisotropic film and a light diffusing film are laminated and used as in No. 2591, the thickness of the optical member is increased, so that one of the features of the LCD, namely, the thinness is not only deteriorated. In addition, when an optical element including a polarizing plate is bonded to a liquid crystal cell, the thickness of the optical element becomes large, and there is a problem that it cannot be processed by an existing bonding machine.
When the optical element as described above is provided between the polarizing plate and the liquid crystal cell, when left under high temperature or high temperature and high humidity, between the light diffusing film and the polarizing plate, or between the light diffusing film. Peeling may occur between the film and the optically anisotropic film, and there is a problem in mechanical properties.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to form an alignment and fix an alignment using an optically positive uniaxial liquid crystalline polymer to which a specific compound is added. A high-quality liquid crystal film with high reliability, excellent strength, and few defects and unevenness.
We propose a new optical anisotropic element combining with a light diffusion adhesive layer. The present invention also proposes a TN-LCD having improved viewing angle characteristics using the optically anisotropic element. The TN-LCD can be used without changing a conventional TN-LCD manufacturing process. It is possible to manufacture.

[0004]

The optically anisotropic element of the present invention comprises: a liquid crystalline polymer (a) having optically positive uniaxiality;
A liquid crystal composition (A) obtained by fixing a liquid crystal composition containing a polycyclic compound (b) having a molecular weight of 1,000 or less represented by the following general formula (1) in a liquid crystal state, It consists of a combination with the light diffusion adhesive layer (B). . R ¹ -B ¹ -A ¹ -... -B ⁿ -A ⁿ -B ^{n + 1} -R ² (1) (wherein, R ¹ and R ² each independently have 1 to 20 carbon atoms) A ^{1 to An} each independently represent a carbocyclic or heterocyclic structure; B ^{1 to} B ^{n + 1} each independently represent a connecting chain having 0 to 4 main chain atoms; Represents an integer of 2 to 8. However, each carbocyclic or heterocyclic structure is not bonded to the connecting chains B ^{1 to} B ^{n + 1} at the same carbon atom in the same ring.) One of the liquid crystal films (A) in the optically anisotropic element of the present invention is in a state where the nematic hybrid alignment is fixed, the other is in a state where the twisted nematic hybrid alignment is fixed, and another one is Is in a state where the twisted nematic orientation is fixed. The liquid crystal display element of the present invention comprises an optically anisotropic element comprising a liquid crystal film (A) in which any one of the above-mentioned alignment states is fixed and a light-diffusing adhesive layer (B), It is characterized by being provided between the liquid crystal cell.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The optically anisotropic element of the present invention can be used for various optical element applications, for example, depending on the alignment state of the liquid crystal film (A) and the light diffusion characteristics of the light diffusion adhesive layer (B). It can be used as a viewing angle improving element, as a color compensating element, or as a polarizing element. The liquid crystal film (A) of the present invention has a desired composition such as nematic hybrid orientation, twisted nematic hybrid orientation, twisted nematic orientation, etc., depending on the composition ratio of the liquid crystalline composition as a film material, film formation method, alignment method, and the like. An alignment state can be formed and fixed. Among these alignment states, the liquid crystal film (A) in which the nematic hybrid alignment is fixed can be suitably used as a viewing angle improving film for a TN-LCD, and greatly increases the viewing angle dependence of the TN-LCD. Can be eliminated. By the way, the nematic hybrid alignment of the liquid crystal film (A) means that the liquid crystal polymer is nematically aligned, and the angle formed by the director of the liquid crystal polymer and the film plane is different between the upper surface and the lower surface of the film. Say. For this reason, in the liquid crystal film (A) having the nematic hybrid orientation, the angle formed between the director of the liquid crystalline polymer and the film plane continuously changes in the thickness direction of the film. In other words, the inclination angle of the director of the liquid crystalline polymer with respect to one surface of the film is different at all places in the film thickness direction. Therefore, such a film does not have an optical axis when viewed macroscopically.

The liquid crystal film (A) of the present invention can be obtained from a liquid crystalline composition containing a liquid crystalline polymer (a) having optically positive uniaxiality and a polycyclic compound (b) described later. it can. As the liquid crystal polymer (a), a condensation type liquid crystal polymer obtained by condensing a compound having a carboxylic acid group, an alcohol group, a phenol group, an amino group, a thiol group, or the like;
Liquid crystalline vinyl polymer obtained from liquid crystalline compounds having double bonds such as acryloyl group, methacryloyl group, vinyl group, allyl group, etc., liquid crystalline polysiloxane synthesized from liquid crystal compound having alkoxysilane group, epoxy group, etc. And a mixture of the above liquid crystalline polymer and a liquid crystalline epoxy resin synthesized from a liquid crystalline compound having the following. Among these various liquid crystalline polymers, condensed liquid crystalline polymers are most preferred in view of the optical characteristics of the resulting film. The condensed liquid crystalline polymer can be usually obtained by condensing a bifunctional monomer by an appropriate method. As the bifunctional monomer, a bifunctional monomer having an aromatic or cyclohexane ring is desirable, specifically, diamines such as phenylenediamine,
Hydroquinone, 2-methylhydroquinone, resorcinol, catechol, 4-methylcatechol, 4-te
diols such as rt-butylcatechol and 2,3-dihydroxynaphthalene, 1,4-phenylenedithiol,
Dithiols such as 1,2-phenylenedithiol, salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 3-hydroxy-2-naphthoic acid, 6-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid Hydroxycarboxylic acids such as acids, 2-aminobenzoic acid, 3
-Amino acids such as aminobenzoic acid and 4-aminobenzoic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-
Dicarboxylic acids such as naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-bifinyldicarboxylic acid, 4,4'-stilbenedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid Examples thereof include acids. Among them, a condensed liquid crystalline polymer containing a catechol unit as an essential structural unit as a component having a hydroxy group is most preferable. The raw material monomer when preparing the condensation type liquid crystalline polymer, to the extent that the liquid crystallinity is not destroyed, for example, oxalic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, Aliphatic dicarboxylic acids such as sebacic acid, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol,
Aliphatic diols such as heptanediol, octanediol, nonanediol, and decanediol; aliphatic diamines such as diaminoethane, diaminopropane, diaminobutane, diaminopentane, diaminohexane, diaminoheptane, diaminooctane, diaminononane, and diaminodecane; Aliphatic hydroxycarboxylic acids such as hydroxyacetic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxyhexanoic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, hydroxynonanoic acid and hydroxydecanoic acid can be added. Further, in order to modify the main chain terminal of the liquid crystalline polymer, a monofunctional monomer, a trifunctional monomer, or the like can be added to the raw material monomer as needed. Examples of the monofunctional monomer include a carboxylic acid group, an amine group, an alcohol group, a phenol group, a thiol group and the like having one in one molecule, such as aromatic carboxylic acids, aliphatic carboxylic acids, aromatic amines, and aliphatic amines. Phenols and aliphatic phenols. Also, as a trifunctional monomer,
For example, trimellitic acid, dihydroxybenzoic acid, hydroxybenzenecarboxylic acid, benzenetricarboxylic acid, pyromellitic acid and the like can be mentioned. The method for condensing these monomers to obtain a condensed liquid crystalline polymer, specifically, a liquid crystalline polyester is not particularly limited, and any method known in the art can be appropriately employed.
For example, a method in which a carboxylic acid is activated by making the carboxylic acid an acid halide or in the presence of dicyclohexylcarbodiimide or the like, followed by a reaction with an alcohol or an amine, or a method of reacting a phenol with carboxylic acid and then reacting with the carboxylic acid to remove the phenol. A method of synthesizing by an acetic acid reaction, a method of converting an carboxylic acid into an esterified product such as a methyl ester, and then reacting with an alcohol in the presence of an appropriate catalyst, if necessary, and synthesizing by a dealcoholization reaction can be arbitrarily adopted. As the liquid crystalline polymer (a) of the present invention, the above-mentioned condensed liquid crystalline polymer can be used alone, or a mixture of two or more kinds of condensed liquid crystalline polymers is used. You can also. Further, an optically active liquid crystalline polymer within a range that does not impair the effects of the present invention,
Various liquid crystal polymers such as a liquid crystal vinyl polymer, a liquid crystal polysiloxane, and a liquid crystal epoxy resin, and a non-liquid crystal polymer can be appropriately mixed and used.

In order to obtain a film having a nematic hybrid alignment as the liquid crystal film (A),
It is desirable that the liquid crystalline polymer (a) has a tilt alignment property or a homeotropic alignment property in a liquid crystal state. Here, the tilt orientation means that when a layer of a liquid crystalline polymer placed on an appropriate substrate is heat-treated in the air or in a vacuum, the die of the liquid crystalline polymer near the substrate-side film interface (a). The angle between the liquid crystal polymer director and the interface (b) near the air-side or vacuum-side film interface (b), rather than the angle on the acute side formed by the collector and the interface (b). Means that the angle can be increased. On the other hand, homeotropic alignment refers to a property in which a director of a liquid crystalline polymer can be in an alignment state substantially perpendicular to a substrate plane in a similar case. The determination as to whether the liquid crystalline polymer has a tilt alignment property or a homeotropic alignment property can be made by forming a liquid crystalline polymer layer on a substrate and observing the alignment state. As a substrate that can be used for this determination, for example, a glass substrate (specifically, an optical glass such as soda glass, potash glass, borosilicate glass or crown glass, or flint glass), or a liquid crystalline polymer exhibits a liquid crystal state. Plastic substrates with heat resistance in the temperature range, for example, polyethylene terephthalate, polyethylene naphthalate, polyphenylene oxide, polyimide, polyamideimide, polyetherimide, polyamide, polyetherketone, polyetheretherketone, polyketonesulfide, polyethersulfone, etc. Typical examples are plastic films and sheets. These substrates are acid,
Used after cleaning the surface with alcohols, detergents, etc. The substrate used for the determination of the orientation is preferably not subjected to a surface treatment such as a silicon treatment, a rubbing treatment, and a uniaxial stretching treatment. Can be used. Actually, the orientation determination is performed by forming a liquid crystal polymer layer having a thickness of 0.1 to 1000 μm on some of the above-described substrates and performing a heat treatment in a temperature region where the liquid crystal polymer exhibits a liquid crystal state. Alternatively, the presence or absence of homeotropic orientation is determined. A liquid crystalline polymer showing tilt alignment or homeotropic alignment on any one substrate is
It is suitable as a liquid crystalline polymer (a). However, some liquid crystalline polymers exhibit specific homeotropic alignment at a temperature near the liquid crystal-isotropic phase transition point. Therefore, it is usually desirable to perform the above heat treatment at a temperature of 15 ° C. or less, preferably 20 ° C. or less from the liquid crystal-isotropic phase transition point. If the liquid crystal polymer shows tilt orientation in this judgment, the state where the extinction axes of the adjacent domains are the same and the disclination line is inserted (the tilt directions are opposite) State). In addition, as long as it shows homeotropic orientation, the orientation can be confirmed by a conoscope or the like. The molecular weight of the liquid crystalline polymer (a) can be determined in various solvents, for example, phenol / tetrachloroethane (60/40 (weight ratio) mixed solvent), 30
The logarithmic viscosity measured at ° C is usually in the range of 0.01 to 1.0, preferably 0.03 to 0.3. Logarithmic viscosity is 0.0
If it is smaller than 1, the mechanical strength of the liquid crystal film (A) may be weak, or the reliability at high temperature and high humidity may be impaired. If it is larger than 1.0, the alignment may be hindered, or the viscosity at the time of forming the liquid crystal alignment may become too high, and the time required for the alignment may become long.

The polycyclic compound (b) constituting the liquid crystalline composition of the present invention together with the above liquid crystalline polymer (a) has a structure in which a plurality of carbon ring structures and / or heterocyclic structures have 0 to 0 atoms.
And a compound having 1 carbon atom at both ends of the compound.
It is a compound having a molecular weight of 1000 or less in which 〜20 hydrocarbon groups are bonded via a connecting chain having 0 to 4 main chain atoms, and can be represented by the following general formula (1). R ¹ -B ¹ -A ¹ -... -B ⁿ -A ⁿ -B ^{n + 1} -R ² (1) (wherein, R ¹ and R ² each independently have 1 to 20 carbon atoms) A ^{1 to An} each independently represent a carbocyclic or heterocyclic structure; B ^{1 to} B ^{n + 1} each independently represent a connecting chain having 0 to 4 main chain atoms; Represents an integer of 2 or more and 8 or less, provided that the individual carbocyclic or heterocyclic structures are not bonded to the connecting chains B ^{1 to} B ^{n + 1} at the same carbon atom in the same ring.) ¹ at least one of the carbon ring or heterocyclic ring represented by to a ⁿ is preferably a 6-membered ring structure. The carbocyclic structure includes an aromatic ring structure and an alicyclic ring structure, and the aromatic ring structure includes a condensed ring structure. When specific examples of the aromatic ring structure are exemplified by a compound name, benzene, indene, naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene and the like can be mentioned. In addition, when specific examples of the alicyclic ring structure are exemplified by compound names, cyclohexane, cyclohexene, tetrahydronaphthalene, decahydronaphthalene, acenaphthene, and the like can be given. Similarly, when a specific example of the heterocyclic structure is exemplified by a compound name, pyridine, pyrimidine, pyrazine, pyridazine, triazole, isoquinoline, quinoline, fluorene, acenaphthylene, dibenzofuran, carbazole, xanthene, phenoxazine, phenazine, dibenzodioxin, etc. Can be mentioned. These carbocyclic or heterocyclic structures can have one or more substituents, such as hydrocarbon groups having 1 to 10 carbon atoms, alkoxy groups, phenoxy groups, tri Examples include a fluoromethyl group, a hydroxy group, an amino group, a nitro group, and a halogen atom. When it has a plurality of substituents, the substituents may be the same or different.

In the general formula (1), B ^{1 to} B ^{n + 1} each independently represent a connecting chain having 0 to 4 main chain atoms. , Indicates that the connecting chain is a single bond. To illustrate a specific example of the connecting chain,
^{-O -, - NR '-,} - CO -, - O-CO -, - NR'
-CO-, -CR ^' = CR ^' -,-C≡C-,-CHR ^{"
-CR '= CR' -CHR ''} -, - CHR '' -C≡C-C
HR ^″ —, —O—CO—C≡C—, —S ＝ O—, —NR
^{'-CO-CR' = CR '} -, - O-CR' = CR '-O
-, -O-CO-C = C-,-(CHR ^" ) _n- (n = 1 to 4), -O- (CHR ^" ) _n- O- (n = 1 to 2),-( _{^{CHR '') n -O-CH}} 2 - (n = 1~2), -O- (CHR '') n - (n = 1~3), -O-CO- (CHR '') n - ( ^{n = 1~2), -NR 3 -} (CHR '') n - (n = 1~3), -N = CH- (CHR '') n - (n = 0~2), - (CHR '^' ) _N- O-CO- (n = 1 to 2). Here, R ^′ and R ^″ in the formula represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. Among these connecting chains, a group (listed below)
This group is conveniently referred to as Group A), which is suitable as connecting chains B ^{1 to} B ^{n + 1} . -O-, -CO-, -O-CO-,-
^{NR '-CO -, - CR'} = CR '-, - NR' -CO-C
^{R '= CR' -, -} O-CO-C = C-, - (CHR '') n - (n = 1~4), -O- (CHR '') n -O- (n = 1~ ^{2), - (CHR ''} ) n -O-CH 2 - (n = 1~2), -O- (CHR '') n - (n = 1~3), -O-CO- (CHR '^' ) _N- (n = 1 to 2),-(CHR ^" ) _n- O-CO- (n = 1 to 2)

R ¹ and R ² in the general formula (1) each independently represent a hydrocarbon group having 1 to 20 carbon atoms, and specific examples of the hydrocarbon group include a methyl group, an ethyl group and a propyl group. Group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group,
Linear saturated hydrocarbon groups such as dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, methylethyl group, 1-methylpropyl group, 2-methylpropyl group , 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-methylpentyl, 2
-Methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1-methylhexyl group, 2-methylhexyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 1-methyl Heptyl group, 2
-Methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 6-methylheptyl group, 1-methyloctyl group, 1-methylnonyl group,
2-ethylhexyl group, 3,7-dimethyloctyl group,
Branched such as 3,5,5-trimethylhexyl group, dimethylethyl group, unsaturated secondary or tertiary hydrocarbon group, unsaturated hydrocarbon group such as allyl group, butenyl group, pentenyl group, hexenyl group, cyclopentyl group , Cyclohexyl group, cyclohexenyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylpropyl group, phenyl group, benzyl group, phenethyl group, naphthyl group, naphthylmethyl group, menthyl group, norbornyl group, bornyl group, isomenthyl group, etc. Examples thereof include a hydrocarbon group having a structure.

The general formula (1) representing the polycyclic compound (b) of the present invention is represented by the following more specific structural formula.

Embedded image In the structural formula 1, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁰ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ represents a single bond or one connecting chain selected from the above group A, and X ₂ and X ₃ represent a single bond or a connecting chain selected from —O—, —O—CO—. However, the connecting chains represented by X ₁ , X ₂ and X ₃ include connecting chains in which the arrangement of the constituent atoms is left-right reversed.

Embedded image In the structural formula 2, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁴ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ is a single bond or one connecting chain selected from the above group A, and X ₃ and X ₄ are a single bond or —O—, —O—CO)
-Represents a connecting chain selected from-. However, the connecting chain of X ₁ , X ₂ , X ₃ and X ₄ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 3, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁸ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ represents a single bond or one connecting chain selected from group A, and X ₃ and X ₄ represent a single bond or —O—, —O— (C =
O)-represents a connecting chain selected from-. Where X ₁ , X ₂ , X
The connecting chain of ₃ and X ₄ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 4, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁴ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ represents a single bond or one connecting chain selected from the above group A, and X ₃ and X ₄ represent a single bond or —O—, —O—CO—
Represents a connecting chain selected from However, the connecting chain of X ₁ , X ₂ , X ₃ and X ₄ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 5, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁴ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ represents a single bond or one connecting chain selected from group A, and X ₃ and X _{4 each} represent a single bond or a connecting chain selected from —O—, —O—CO—. However, the connecting chain of X ₁ , X ₂ , X ₃ and X ₄ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 6, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁸ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ represents a single bond or one connecting chain selected from the above group A, and X ₃ and X ₄ represent a single bond or —O—, —O—CO—
Represents a connecting chain selected from However, a structural formula in which the bonding hands in the organic groups of X ₁ , X ₂ , X ₃ and X ₄ are reversed is also included.

Embedded image In the structural formula 7, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁸ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ and X ₃ are a single bond or one connecting chain selected from the above group A, and X ₄ and X ₅ are a single bond or —O—, —O—C
Shows a connecting chain selected from O-. However, X ₁ , X ₂ ,
The connecting chain of X ₃ , X ₄ and X ₅ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 8, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ²² represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ , X ₃ and X ₄ represent a single bond or one connecting chain selected from the above group A, and X ₅ and X ₆ represent a single bond or —O—,
Shows a connecting chain selected from O-CO-. Where X ₁ ,
The connecting chain of X ₂ , X ₃ , X ₄ , X ₅ and X ₆ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 9, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ⁶ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ , X ₂
Represents a single bond or a connecting chain selected from -O- and -O-CO-. However, the connecting chain of X ₁ and X ₂ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In the structural formula 10, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ⁶ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. , X ₁ ,
X ₂ represents a single bond or a connecting chain selected from —O— and —O—CO—. However, the connecting chain of X ₁ and X ₂ includes a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

Embedded image In Structural Formula 11, R ¹ and R ² represent a hydrocarbon group having 1 to 20 carbon atoms, and R ^{3 to} R ¹⁰ represent a hydrogen atom, F, Cl, Br, a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group. ,
X ₁ and X ₂ represent a single bond or one connecting chain selected from the above group A, and X ₃ and X ₄ represent a single bond or —O—, —O—C
Shows a connecting chain selected from O-. However, X ₁ , X ₂ , X ₃
And the connecting chain of X ₄ include a connecting chain in which the arrangement of its constituent atoms is left-right reversed.

The method for synthesizing the polycyclic compound (b) used in the present invention is not limited, and a method known in the art can be employed. In addition, the compound does not need to be a pure compound, and may be a by-product during the synthesis unless it inhibits the alignment, causes coloration, or adversely affects the production or use of the liquid crystal film (A) of the present invention. Impurities may be contained. Furthermore, a plurality of types of polycyclic compounds (b) can be mixed to orient the liquid crystalline composition of the present invention. In preparing the liquid crystalline composition of the present invention, the polycyclic compound (b) represented by the general formula (1) is reacted with the liquid crystalline polymer (a) described above.
Usually, it is added in the range of 0.1 to 20% by weight, preferably 0.3 to 10% by weight. When the addition amount is less than 0.1% by weight, a uniform alignment form may not be obtained. On the other hand, if it is more than 20% by weight, adverse effects may appear in reliability tests such as heat resistance.

The liquid crystal film (A) of the present invention is prepared from a liquid crystal composition containing a liquid crystal polymer (a) and a polycyclic compound (b). As long as the effects of the present invention are not impaired, a crosslinking agent such as a bisazide compound or glycidyl methacrylate may be added. By adding these cross-linking agents, cross-linking (immobilization) can be performed in a state where a nematic hybrid orientation is developed. Various additives such as a dichroic dye, a dye, a pigment, an antioxidant, an ultraviolet absorber, and a hard coat agent can be appropriately added to the liquid crystal composition as long as the effects of the present invention are not impaired. The liquid crystal film (A) of the present invention is obtained by developing the above-mentioned liquid crystalline composition on an alignment substrate and providing a uniform desired liquid crystal alignment on the substrate, specifically, a nematic hybrid alignment, a twisted nematic hybrid alignment or After the twisted nematic orientation is developed by heat treatment or the like, the orientation can be obtained by fixing the orientation form to glass or fixing it by a heat / photocrosslinking reaction. The thickness of the liquid crystal film (A) is
Usually 0.1 μm to 5 μm, preferably 0.2 μm to 4 μm
m, more preferably from 0.3 μm to 3 μm, most preferably from 0.4 μm to 1 μm. If the thickness is less than 0.1 μm, a sufficient viewing angle improving effect may not be obtained. If the thickness is more than 5 μm, unnecessary coloring or the like may occur. When the liquid crystal film (A) forms a nematic hybrid orientation, an angle formed between one surface of the film and a director of liquid crystal molecules near the surface is usually 0 to 50 °, preferably 2 to 45 °.
゜, more preferably 3 to 40 ゜. The angle formed between the other film surface and the director of liquid crystal molecules near the surface is usually 60 to 90 °, preferably 65 °.
゜ 87 °, more preferably 70-85 °. If the angle between the director of the liquid crystal molecules and the film plane in the vicinity of both surfaces of the film is out of the above range,
There is a possibility that LCD display characteristic effects such as a viewing angle improvement effect and a color compensation effect cannot be sufficiently exhibited. When the liquid crystal film (A) has a twisted nematic hybrid orientation or a twisted nematic orientation, the twist angle is usually 10 to 360 °, preferably 20 to 270 °, more preferably 30 to 180 °. . If the twist angle is out of the above range, there is a possibility that LCD display characteristics such as a viewing angle improving effect and a color compensating effect cannot be sufficiently exhibited.
The liquid crystal film (A) is in a form as it is formed on the alignment substrate (alignment substrate / (alignment film) / liquid crystal film), or in a form in which the liquid crystal film is transferred to a transparent substrate film different from the alignment substrate (transparent substrate film) When the liquid crystal film itself has a self-supporting property, the liquid crystal film may be in a single-layer form (liquid crystal film). Examples of the above transparent substrate film include triacetyl cellulose films such as Fujitac (manufactured by Fuji Photo Film Co., Ltd.) and Konikatac (manufactured by Konica), TPX film (manufactured by Mitsui Chemicals, Inc.), Arton film (manufactured by Nippon Synthetic Rubber Co., Ltd.) And ZEONEX film (manufactured by Nippon Zeon Co., Ltd.) and acrylene film (manufactured by Mitsubishi Rayon Co., Ltd.). Further, as a transfer method, an adhesive is applied to the liquid crystal film layer, the adhesive is cured after laminating another substrate film different from the oriented substrate, and the oriented substrate is peeled from the film laminate to remove the liquid crystal film. Can only be transcribed. It is recommended to use this method when a non-optically isotropic film such as a rubbing polyimide film or a rubbing polyethylene terephthalate film or an opaque film in a visible light wavelength region is used as the alignment substrate.

The light-diffusing pressure-sensitive adhesive layer (B) used in combination with the liquid crystal film (A) is a layer having the property of diffusing incident light isotropically or anisotropically and having adhesiveness. This means that the material is not particularly limited as long as it has this property. As the light diffusion pressure-sensitive adhesive layer, for example, a non-self-supporting sheet-like material or film-like material in which particles having a refractive index different from that of the matrix are dispersed in an adhesive matrix can be used. Specifically, an acrylic adhesive, a rubber adhesive, a silicone adhesive, an ethylene-vinyl acetate copolymer adhesive, a urethane adhesive,
A matrix composed of a vinyl ether-based adhesive, a polyvinyl alcohol-based adhesive, a polyacrylamide-based adhesive, and a mixed adhesive thereof, for example, polystyrene-based fine particles having an average particle size of 0.5 to 5 μm, polymethacrylic acid-based fine particles, and the like. Organic fine particles of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, etc., inorganic fine particles, hollow fine particles containing gas, and microcapsules containing liquid are dispersed as appropriate. This layer can be used as the light diffusion pressure-sensitive adhesive layer (B). As the matrix, an acrylic pressure-sensitive adhesive is preferable because of its excellent transparency, weather resistance, heat resistance, and the like. When obtaining a superposed layer of the light diffusion pressure-sensitive adhesive layer (B), the same or different light diffusion pressure-sensitive adhesive layers are used in appropriate combination. As the acrylic pressure-sensitive adhesive, any of known materials can be used. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group,
t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2-
Ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group, undecyl group, lauryl group, tridecyl group, tetradecyl group, stearyl group,
One or two types of acrylic acid alkyl esters comprising esters of acrylic acid or methacrylic acid having a linear or branched alkyl group having 1 to 18 carbon atoms such as an octadecyl group.
An adhesive based on an acrylic polymer using at least one of the above-mentioned types may be used. The light-diffusing adhesive includes, for example, a petroleum resin, a rosin resin, a terpene resin, a synthetic petroleum resin, a phenol resin, a xylene resin, and an alicyclic petroleum as long as the effects of the present invention are not impaired. Tackifiers such as resin, coumarone indene resin, styrene resin, dicyclopentadiene resin, etc., softeners such as phthalic acid ester, phosphate ester, chloride paraffin, polybutene, polyisobutylene or other various fillers, aging prevention An appropriate additive such as an agent or a crosslinking agent can be blended.

The optically anisotropic element of the present invention has a structure in which the light diffusion pressure-sensitive adhesive layer (B) is laminated on the surface of a liquid crystal film (A). As a method for producing the optically anisotropic element, an appropriate method can be adopted. For example, a solid content of a solution or a dispersion or an emulsion with an appropriate organic solvent such as toluene or ethyl acetate in water is usually 10 to 40% by weight.
A light-diffusing adhesive solution is prepared by adjusting a light-diffusing pressure-sensitive adhesive solution to a suitable degree, such as a casting method or a coating method, or directly attaching the liquid-crystal film (A) to the liquid crystal film (A). A liquid diffusing adhesive layer (B) formed on a separator according to the method of applying the agent to the liquid crystal film (A) and irradiating the liquid crystal film (A), and bonding the light diffusing adhesive layer (B) on the liquid crystal film (A). System. Therefore, the superposed layer of the light diffusion pressure-sensitive adhesive layer can also be formed by an appropriate method such as a recoating method or a laminating method. When the superposed light diffusion pressure-sensitive adhesive layers (B) are provided on both sides of the liquid crystal film (A), the light diffusion pressure-sensitive adhesive layers (B) of different compositions or types can be formed on the front and back of the liquid crystal film (A). . Further, the light diffusion pressure-sensitive adhesive layer (B) can be provided at any one or each of a liquid crystal film surface, an alignment substrate surface, and a support film surface different from the alignment substrate. The pressure-sensitive adhesive layer (B) may be a single layer or a plurality of layers. The thickness of the light diffusion pressure-sensitive adhesive layer (B) is not particularly limited, but is usually 1 μm to 100 μm, preferably 5 μm to 50 μm, and more preferably 10 μm to 30 μm. The total light transmittance of the light diffusion pressure-sensitive adhesive layer (B) is usually 50% or more, preferably 60% or more, and more preferably 70% or more. Further, the haze value defined by the ratio of diffuse transmittance / total light transmittance is desirably 20 to 70%, preferably 25 to 65%, and more preferably 30 to 60%. Haze value of 3
If it is less than 0%, the viewing angle expanding effect is poor, and if it is more than 60%, unnecessary bleeding of the display screen and reduction in contrast are caused.

The optically anisotropic element of the present invention is suitably used as a viewing angle improving member for a twisted nematic liquid crystal display element or the like. In this case, the optically anisotropic element of the present invention is laminated on a polarizing plate of the display element. be able to. In laminating the polarizing plate and the optically anisotropic element, the adhesiveness of the light diffusion adhesive layer (B) of the optically anisotropic element can be utilized. Alternatively, an appropriate adhesive layer or The liquid crystal film (A) or the light diffusion pressure-sensitive adhesive layer (B) of the optically anisotropic element and the polarizing plate can be laminated via an adhesive layer. Considering simplification of the manufacturing process and cost reduction, the former method, that is, a method in which the light diffusion pressure-sensitive adhesive layer is used for lamination with the polarizing plate is more preferable. The adhesive used in the latter method is not particularly limited as long as it is of an optical grade, but for example, acrylic, epoxy, ethylene-vinyl acetate copolymer, urethane and a mixture thereof. Can be used. In addition, these adhesives can be used without any problem whether they are of a thermosetting type, a photocuring type, or an electron beam curing type. Further, a light diffusion pressure-sensitive adhesive layer (B) is formed on the polarizing plate according to the method described above.
Is provided, and a liquid crystal film (A) is laminated on the light diffusion pressure-sensitive adhesive layer to produce a laminate having substantially the same form as the laminate of the optically anisotropic element and the polarizing plate of the present invention. Can also. As the polarizing plate, an appropriate polarizing plate having a polarizing function can be used, but generally, a polarizing plate is used. The polarizing film is not particularly limited, and for example, iodine and / or iodine may be added to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, and a cellulose-based film. Or a film stretched by adsorbing a dichroic dye, a polyene oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride, and the like. The thickness of the polarizing film is usually 5 μm to 80 μm
However, the present invention is not limited to this. The polarizing plate may be a polarizing film itself or a polarizing film provided with a transparent protective layer on one side or both sides. Transparent protective layer, for example, transparency, mechanical strength,
It is not particularly limited as long as it is excellent in heat stability, moisture shielding property, etc., for example, polyester resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin,
An appropriate resin such as an acrylic resin, an acetate resin, a cellulose resin, or a thermosetting or ultraviolet curable resin such as an acrylic, urethane, acrylic urethane, epoxy, or silicone resin can be used.

The optically anisotropic element of the present invention can be incorporated in a liquid crystal display element according to a known technique. That is, in general, a liquid crystal display element includes a drive circuit by appropriately assembling necessary components such as a twisted nematic type driving liquid crystal cell including a pair of transparent substrates having electrodes and a nematic liquid crystal, a polarizing plate, and an illumination system. The optical anisotropic element of the present invention may be formed between the liquid crystal cell and one of the upper and lower polarizing plates,
Or placed between both. The optically anisotropic element of the present invention comprising a liquid crystalline film (A) having a fixed nematic hybrid alignment and a light diffusion pressure-sensitive adhesive layer (B) is particularly preferably TN-
It is suitable as a viewing angle improving member for LCD. When the TN-LCD to be compensated is classified according to the driving method, it can be classified into a simple matrix method and a TFT using active elements as electrodes (Thi-LCD).
n FilmTransistor) electrode, MIM (Met
al Insulator Metal or TF
D; Thin Film Diode) can be subdivided as in an active matrix system using electrodes. The optically anisotropic element of the present invention is effective for any driving method. The halftone gray scale method (pixel division method) and the domain division method, which are well-known techniques, are LC
This was conceived in an attempt to expand the viewing angle of D from the driving liquid crystal cell side. The optically anisotropic element of the present invention suitably acts on such an LCD in which the viewing angle is improved to some extent, and can further exhibit a viewing angle expanding effect. The optical anisotropic element of the present invention is TN-LC
When used as a viewing angle improving member for D, the liquid crystal film (A) constituting the optically anisotropic element is in a nematic hybrid alignment state, so that the upper and lower sides of the film are not optically equivalent, and The upper and lower portions of the optically anisotropic element are not optically equivalent. Therefore, the viewing angle improving effect of the liquid crystal display element differs depending on which side of the light diffusion pressure-sensitive adhesive layer (B) or the liquid crystal film (A) is arranged on the cell side. The present invention does not limit which surface of the optically anisotropic element is brought closer to the driving liquid crystal cell,
It is desirable to install the optically anisotropic element of the present invention in the liquid crystal display element in consideration of the cell parameters of the liquid crystal display element, required optical performance, and the like.

[0018]

EXAMPLES Examples will be described below, but the present invention is not limited to these examples. In addition, each analysis method used in the Example is as follows. (1) Determination of composition of liquid crystalline polymer and determination of structure of compound Dissolved in deuterated chloroform or deuterated trifluoroacetic acid, and determined using 400 MHz ¹ H-NMR (JNM-GX400 manufactured by JEOL Ltd.). . (2) Film thickness measurement SURFACE TEXTURE ANA manufactured by SLOAN
LYSIS SY-STEM Dektak 3030
ST was used. In addition, interference wave measurement (manufactured by JASCO Corporation)
An ultraviolet / visible / near-infrared spectrophotometer V-570) and a method of determining the film thickness from the data of the refractive index were also used. Reference Example 1 40 mmol of terephthalic acid, 40 mmol of 2,6-naphthalenedicarboxylic acid, 85 mm of catechol diacetate
ol, acetoxybenzoic acid (80 mmol), polymerization was performed at 260 ° C. for 4 hours under nitrogen atmosphere, at 290 ° C. for 2 hours, and then at 290 ° C. for 4 hours under a nitrogen flow of 100 ml / min. I got This liquid crystalline polyester has a logarithmic viscosity of 0.16, a nematic phase as a liquid crystal phase, and an isotropic phase-liquid crystal phase transition temperature of 300 ° C.
As described above, the glass transition point was 120 ° C. Using the obtained liquid crystalline polyester, a 10% by weight phenol / tetrachloroethane mixed solvent (6/4 weight ratio) solution was prepared. This solution was applied on a soda glass plate by a bar coating method, dried, and heat-treated at 190 ° C. for 30 minutes, and then cooled and fixed at room temperature to obtain a liquid crystal film having a thickness of 1 μm. By observing the film under a polarizing microscope, a portion where the extinction axis of the adjacent domain was the same and a disclination line was found was found, and it was confirmed that the film had tilt orientation.

Embedded image Reference Example 2 4-octyloxybenzoic acid 10 mmol, terephthalic acid 50 mmol, naphthalenedicarboxylic acid 45 mmol,
Using catechol diacetate 50 mmol, 3-methylcatechol diacetate 50 mmol, and 4-acetoxybenzoic acid 50 mmol under nitrogen atmosphere at 270 ° C.
After that, deacetic acid polymerization was carried out at the same temperature for 2 hours under a nitrogen stream at 30 ml / min. Next, the obtained reaction product was dissolved in tetrachloroethane, followed by reprecipitation with methanol to purify the product, thereby obtaining a liquid crystalline polyester (see Formula 2). The logarithmic viscosity of this liquid crystalline polyester was 0.10, the liquid crystal phase had a nematic phase, the isotropic phase-liquid crystal phase transition temperature was 240 ° C., and the glass transition point was 75 ° C. Using the obtained liquid crystalline polyester, a 10% by weight phenol / tetrachloroethane mixed solvent (6/4 weight ratio) solution was prepared. This solution was applied on a soda glass plate by spin coating, dried, and heat-treated at 220 ° C. for 30 minutes, then cooled and fixed at room temperature to obtain a liquid crystal film having a uniform thickness of 10 μm. . When the resulting liquid crystalline film was observed with a conoscope, it was confirmed that the film had homeotropic alignment.

Embedded image Reference Example 3 tert-butyl hydroquinone diacetate 10 mm
ol, 6-pentyloxy-2-naphthoic acid 20 mmol
In a nitrogen atmosphere at 250 ° C. for 4 hours, at 270 ° C. for 2 hours,
Subsequently, the reaction was carried out at 270 ° C. for 2 hours under a nitrogen stream of 30 ml / min. Subsequently, the compound was treated with methanol / ethyl acetate = 1.
The compound of formula (3) was obtained by recrystallization from a mixed solvent of / 1.

Embedded image Example 1 Liquid crystalline polyester (see formula 1) 75 obtained in Reference Example
Parts, 20 parts of a liquid crystalline polyester (see formula 2) and 5 parts of a compound (see formula 3) were blended to prepare a liquid crystalline composition. Next, an 8 wt% tetrachloroethane solution of the composition was prepared. The solution is applied on a glass substrate having a rubbing polyimide film by a spin coating method, and dried,
Heat treatment was performed at 220 ° C. for 20 minutes. After the heat treatment, the resultant was air-cooled to obtain a liquid crystal film 1 in which a nematic hybrid alignment was formed. The liquid crystal film 1 on the substrate was transparent and uniform with no alignment defects. The film thickness was 0.63 μm, and the average tilt angle in the film thickness direction was 34 degrees. Next, a light diffusion pressure-sensitive adhesive layer (total light transmittance 90.1%, diffusion transmittance 47.1%) in which polystyrene fine particles are dispersed in an acrylic pressure-sensitive adhesive is provided on one surface of the liquid crystal film 1, and an optically anisotropic element is formed. Produced. Using this optically anisotropic element, a liquid crystal display element was manufactured in the arrangement shown in FIG. The used TN-type driving liquid crystal cell uses ZLI-4792 as a liquid crystal material, and cell parameters are a cell gap of 4.8 μm, a twist angle of 90 ° (left twist), and a pretilt angle of 3 °. A voltage of 0 V to 6 V was applied to the liquid crystal cell, and a color luminance meter B manufactured by Topcon Corporation was applied.
Using M-5, the transmittance in the vertical direction at each gradation was measured, and the results are shown in FIG. In this case, when the liquid crystal cell was viewed at −60 degrees, that is, the angle formed by the line of sight and the line of sight of the liquid crystal cell from below was 60 degrees, gradation inversion occurred. Comparative Example 1 Using the same TN-type driving liquid crystal cell as in Example 1, the transmittance in the vertical direction at each gradation was measured under the same conditions except that the liquid crystalline film 1 and the light diffusion adhesive layer were not attached. The results are shown in FIG. In this case, the angle between the liquid crystal cell and the normal line of the liquid crystal cell from the lower side to the line of sight is 2 degrees.
When viewed at 0 degrees, gradation inversion occurred. Comparative Example 2 Using the same TN-type driving liquid crystal cell as in Example 1, the transmittance in the vertical direction at each gradation was measured under the same conditions except that the light diffusion adhesive layer was not attached. The results are shown in FIG. In this case, when the liquid crystal cell was viewed at −30 degrees, that is, the angle formed by the line of sight and the line of sight of the liquid crystal cell from below was 30 degrees, gradation inversion occurred. Comparative Example 3 An 8 wt% tetrachloroethane solution was prepared using the same liquid crystal composition except that 5 parts of the compound (Formula 3) was removed from Example 1. The solution was applied on a glass substrate having a rubbing polyimide film by a spin coating method and dried. Then, it was heat-treated at 210 ° C. for 10 minutes and cooled to obtain a liquid crystal film 2. The film 2 on the substrate was transparent, but had many alignment defects. Table 1 summarizes the above examples and comparative examples.

[0019]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a layout view of each optical element in a liquid crystal display device described in Example 1.

FIG. 2 is a graph showing the transmittance in the vertical direction at each gradation of the liquid crystal display device described in Example 1.

FIG. 3 is a graph showing the transmittance in the vertical direction at each gradation of the liquid crystal display device described in Comparative Example 1.

FIG. 4 is a graph showing the transmittance in the vertical direction at each gradation of the liquid crystal display device described in Comparative Example 2.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H049 BA02 BA06 BA42 BB03 BB51 BB63 BC03 BC04 BC22 2H091 FA11X FA11Z FB02 FC30 GA06 GA17 JA01 LA02 LA17 LA19 4H027 BA01 BA12 BB01 BD20 BD21 DK01

Claims (5)

[Claims] 1. A liquid crystalline polymer (a) having optically positive uniaxiality and a molecular weight of 10 represented by the following general formula (1):
Combination of a liquid crystal film (A) obtained by fixing an alignment state formed in a liquid crystal state with a liquid crystalline composition containing a polycyclic compound (b) of 00 or less, and a light diffusion adhesive layer (B) An optically anisotropic element consisting of R ¹ -B ¹ -A ¹ -... -B ⁿ -A ⁿ -B ^{n + 1} -R ² (1) (wherein, R ¹ and R ² each independently have 1 to 20 carbon atoms) A ^{1 to An} each independently represent a carbocyclic or heterocyclic structure; B ^{1 to} B ^{n + 1} each independently represent a connecting chain having 0 to 4 main chain atoms; Represents an integer of 2 to 8. However, each carbocyclic or heterocyclic structure is not bonded to the connecting chains B ^{1 to} B ^{n + 1} at the same carbon atom in the same ring.) 2. The liquid crystal film (A) is in a nematic hybrid alignment state.
An optically anisotropic element as described in the above. 3. The optically anisotropic element according to claim 1, wherein the alignment state of the liquid crystal film (A) is a twisted nematic hybrid alignment. 4. The optically anisotropic element according to claim 1, wherein the alignment state of the liquid crystal film (A) is a twisted nematic alignment. 5. A liquid crystal display device comprising the optical anisotropic element according to claim 1, provided between a driving liquid crystal cell and a polarizing plate.