JP2002174730A - Optical compensation film and liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical compensation film which can increase the viewing angle of a liquid crystal display and which generates little coloring when the display is viewed in an oblique direction and to provide a liquid crystal display device in which the compensation film is assembled. SOLUTION: The optical compensation film contains a liquid crystal compound having two optical axes in the liquid crystal state among liquid crystal compounds having nematic phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optical compensation film capable of compensating a viewing angle of a liquid crystal display, and a wide viewing angle liquid crystal display device incorporating the optical compensation film.

[0002]

2. Description of the Related Art A CRT type display has conventionally been used as a display device representing OA equipment such as a desktop personal computer and a word processor. However, since CRT displays are large and heavy and consume large amounts of power, recently, attention has been paid to liquid crystal display elements (liquid crystal display devices) that are small and consume little power, and various research and It is being developed and commercialized. A liquid crystal display element (hereinafter, also referred to as LCD) generally used at present is
Twisted nematic liquid crystal is used, and the mainstream display method is roughly divided into STN
A birefringent mode using (super twisted nematic) liquid crystal and a TFT-LCD or M using active elements using TN (twisted nematic) liquid crystal.
It can be divided into a rotation mode called an IM-LCD or the like.

A liquid crystal display device based on a birefringence mode uses an STN liquid crystal in which the twist angle of liquid crystalline molecules is 90 degrees or more, and has an abrupt electric characteristic. Therefore, an active device such as a thin film transistor or a diode is used. There is an advantage that a large-capacity display can be realized by time-sharing driving even with a simple matrix-shaped electrode structure without the necessity. However, the liquid crystal display element based on the birefringence mode has drawbacks such as a low response speed (approximately several hundred milliseconds) and difficulty in displaying multiple gradations.

On the other hand, liquid crystal display devices based on the optical rotation mode such as TFT-LCD and MIM-LCD use TN liquid crystal in which the alignment state of liquid crystal molecules is twisted by 90 degrees. In this display system, the response speed is high (approximately). Tens of milliseconds),
It is said that it is the most effective method as compared with other types of liquid crystal display devices because of its advantages such as easy black-and-white display and high display contrast. However, since the twisted nematic liquid crystal is used, the viewing angle is narrow due to the principle of the display method, and there are unfavorable viewing angle characteristics such that the display color and display contrast change depending on the viewing direction.

That is, the liquid crystal molecules have different refractive indices in the major axis direction and the minor axis direction. When polarized light is incident, the polarization state of the incident light changes depending on the angle of incidence on the liquid crystal layer. The arrangement of liquid crystal molecules in a liquid crystal cell using twisted nematic liquid crystal molecules has a structure in which the liquid crystal molecules are twisted in the thickness direction of the liquid crystal cell. The light propagates through the liquid crystal layer while changing the polarization state depending on the direction of the liquid crystal molecules, and reaches the opposite side. Therefore,
The polarization state of light propagating through the liquid crystal cell is different between the case where light is vertically incident on the liquid crystal cell and the case where light is obliquely incident on the liquid crystal cell. As a result, the image formed on the liquid crystal layer is viewed in the viewing direction. Depending on the angle and the angle, it may be difficult to see or even completely invisible, which is not practically preferable as a display device.

As a method for improving the above-mentioned undesirable viewing angle characteristics, for example, Japanese Patent Application Laid-Open No. 4-229828
And a method using a retardation compensation film (optical compensation film) disclosed in JP-A No. 4-258923 and the like. That is, a typical liquid crystal display element is configured by a liquid crystal cell in which a TN type liquid crystal layer is sandwiched between two electrode substrates having alignment surfaces, and two polarizing elements arranged on both sides of the liquid crystal cell. This is a method of arranging a film for compensating a phase difference (a retardation compensation film, that is, an optical compensation film) between the liquid crystal cell and the polarizing element on at least one side. The retardation compensation films proposed in these publications have a phase difference in a direction perpendicular to the surface of the liquid crystal cell of almost zero, and light incident directly in front of the liquid crystal cell has no optical characteristics. On the other hand, a phase difference is developed when inclined light is incident without exerting an effect to compensate for the phase difference generated in the liquid crystal cell. However, the compensation of the phase difference by such a method alone does not sufficiently improve the viewing angle of a liquid crystal display device (LCD). In particular, when the liquid crystal display element is mounted on a vehicle such as an automobile, or when it is used as an alternative display device of a CRT display device, a high degree of viewing angle needs to be improved. I can't say that.

[0007] Japanese Patent Application Laid-Open No. 4-366808 and
In the invention described in JP-A-366809, the viewing angle is improved by providing a chiral nematic liquid crystal layer having an inclined optical axis as a retardation compensation layer in a liquid crystal display element, but in this system, a two-layer liquid crystal system is used. Therefore, there are drawbacks such as an increase in bulk and a significant increase in the mass of the entire display device.

The phase difference compensating films aimed at solving the above problems are disclosed in JP-A-7-181324 and JP-A-7-18132.
Nos. 5, 7-198942 and 7-198943
No. That is, use of an inclined phase difference (compensation) plate having an optical axis in a direction intersecting with the plate surface, or a phase difference plate in which two phase difference plates are stacked so as to be orthogonal to each other is disclosed. As a result, while being lightweight,
In particular, it is described that a decrease in display contrast at oblique incidence can be effectively prevented. However, even when this retardation compensation film is used, the viewing angle characteristics of the liquid crystal display element are still significantly different from the visual characteristics of a CRT display device, and further improvement is desired.

In recent optical compensation films, a rod-shaped polymer liquid crystal having a positive optical anisotropy and having only one optical axis is used. It has been proposed to mix a discotic liquid crystal compound having only one axis into a polymer, or to introduce a polymerizable group into the discotic liquid crystal compound to stably fix the alignment state by a polymerization reaction. 9 shows a remarkable effect on the expansion of the viewing angle of the liquid crystal display. However, the rod-shaped polymer liquid crystal has a liquid crystal temperature range that is too high, so it is necessary to take unnecessary manufacturing steps.The optical compensation form using the discotic liquid crystal compound has a wide viewing angle when viewed obliquely. It has the drawback of yellowing. Further, improvement of these compounds is desired also in view of production cost, and development of new materials capable of achieving a wider viewing angle of a liquid crystal display is desired.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an optical compensation film which enlarges the viewing angle of a liquid crystal display and has less coloring when viewed from an oblique direction. Another object of the present invention is to provide a liquid crystal display device incorporating the compensation film.

[0011]

The above object of the present invention is achieved by the following constitution.

1. An optical compensation film comprising a liquid crystal compound having two optical axes in a liquid crystal state among liquid crystal compounds having a nematic phase.

2. When the liquid crystal compound is Nb (biaxial)
(2) The optical compensation film according to (1), which has a nematic phase.

3. When the refractive indices of the liquid crystal phase in the triaxial directions of the liquid crystal compound are nx, ny, and nz in ascending order, 0.2
3. The optical compensation film as described in 1 or 2, wherein a relationship of <| ny-nz | / | ny-nx | ≦ 2.0 is satisfied.

4. A liquid crystal compound having a polymerizable group,
4. The optical compensation film as described in 1, 2, or 3, which is a low-molecular liquid crystal compound or an oligomer liquid crystal compound.

5. The liquid crystal compound has a liquid crystal temperature range of 10 to 10.
The optical compensation film according to 4, wherein the optical compensation film exists within a range of 150 ° C.

6. 5. The liquid crystal display device according to 5, wherein the liquid crystal compound has at least one layer containing a liquid crystal compound on a transparent film, and the molecular axis of the liquid crystal compound is inclined within a range from the plane of the film to the normal direction of the film. The optical compensation film according to the above.

7. A liquid crystal display device comprising at least one optical compensation film described in 1, 2, 3, 4, 5, or 6.

Hereinafter, the present invention will be described in detail. The optical compensation film of the present invention will be described.

The liquid crystal compound used in the optical compensation film of the present invention is a liquid crystal compound having two optical axes in a liquid crystal state among liquid crystal compounds having a nematic phase. In other words, when the refractive indices of the liquid crystal phase in the three axial directions are nx, ny, and nz in ascending order, nx <ny <n
It is a liquid crystalline compound satisfying the relationship of z.
The liquid crystal compound satisfies the relationship of 2 <| ny-nz | / | ny-nx | ≦ 2.0. More preferably 0.4 <|
ny−nz | / | ny-nx | ≦ 1.8. | Ny
-Nz | / | ny-nx | is 0.2 or less;
If it exceeds 0, a sufficient compensation effect in all directions may not be obtained.

As described above, the liquid crystalline compound used in the optical compensation film of the present invention refers to a material in which the refractive index in one direction is different from the refractive index in another direction, and the material may be a compound alone or at least one kind. In the present invention, the orientation order of these molecules is not particularly limited, but those having an Nb phase as a liquid crystal phase are preferred. The Nb phase is a kind of liquid crystal phase that a nematic liquid crystal compound can take.
When the liquid crystal compound is defined by an axis, a y-axis, and a z-axis, the free rotation of the liquid crystal compound on the xz plane about the y-axis is
This shows a state in which free rotation in the y plane is also prohibited.

The optical compensation film of the present invention is obtained by heating to a liquid crystal phase formation temperature once and then cooling while maintaining the alignment state in order to fix the alignment state in the liquid crystal state without impairing the alignment state. be able to.
Alternatively, the optical compensation film of the present invention can be obtained by heating a composition obtained by adding a polymerization initiator to a liquid crystal compound having a polymerizable group to a liquid crystal phase forming temperature, and then polymerizing and cooling.

The liquid crystal temperature range of the liquid crystal compound of the present invention is as follows.
10 to 200 ° C from the viewpoint of the suitability for production of the optical compensation film
, And more preferably in the range of 10 to 150 ° C. If the temperature is lower than 10 ° C., a cooling step or the like may be required to lower the temperature to a temperature range in which a liquid crystal phase is exhibited. On the other hand, if the temperature exceeds 200 ° C., a high temperature is required in order to make the liquid state once higher than the temperature range in which the liquid crystal phase is exhibited, which is disadvantageous from waste of heat energy, deformation and deterioration of the substrate.

Further, the state of immobilization in the present invention is the most typical and preferable mode in which the orientation is maintained, but is not limited thereto. , Specifically, usually 0 ° C
To 50 ° C, -30 ° C to 70 ° C under more severe conditions
In this temperature range, the film does not have fluidity, and does not cause a change in the orientation mode due to an external field or an external force, and can stably maintain the fixed orientation mode.

The liquid crystalline compound used in the present invention preferably has the above-mentioned properties and, at the same time, exhibits good domain integration for uniform defect-free alignment. When domain integration is poor, the resulting structure is a polydomain, and alignment defects occur at boundaries between domains, causing light to be scattered. In addition, the transmittance of the film is undesirably reduced.

The liquid crystal compound is composed of a mother nucleus generally called a mesogen, a substituent around the core and a side chain. As the side chain, a monofunctional one is preferably used, but a compound obtained by partially linking the compounds by using a bifunctional one and oligomerizing them can also be preferably used as the material of the present invention.

The liquid crystal compound of the present invention may contain a polymerization initiator, and may further contain other compounds other than the polymerization initiator. The polymerization initiator may be a thermal polymerization initiator, but is more preferably a photopolymerization initiator. By adding other compounds, the birefringence (Δn) of the optically anisotropic layer and the inclination angle β of the optical axis of the uniformly aligned liquid crystal molecules can be changed in some cases.

Other compounds to be mixed with the liquid crystal compound include:
Polymethyl methacrylate, acrylic acid-methacrylic acid copolymer, styrene-maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide,
Styrene-vinyl toluene copolymer, chlorosulfonated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, Silylate-based polymers and the like can be mentioned. Various low molecular compounds may be used in addition to the above high molecular compounds. The low molecular weight compound is preferably ethylene glycol-1,4-diacrylate, ethylene glycol-1,4-diglycidyl ether, or a commercially available ultraviolet curable resin monomer. In addition, cationic, anionic, and nonionic surfactants are also preferably used.

Hereinafter, specific examples of the liquid crystalline compound which can be used in the present invention will be shown, but the present invention is not limited to these.

[0030]

Embedded image

[0031]

Embedded image

[0032]

Embedded image

However, R in the above compound represents a substituent or a side chain, and may be the same or different.
When R is a substituent, examples of the substituent include an alkyl group (eg, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, a t-butyl group, etc.), a cycloalkyl group Groups (eg, cyclopentyl group, cyclohexyl group, etc.), aralkyl groups (eg, benzyl group, 2-phenethyl group, etc.), aryl groups (eg, phenyl group, naphthyl group, p-tolyl group,
p-chlorophenyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, isopropoxy group, butoxy group, etc.), aryloxy group (eg, phenoxy group, etc.), cyano group, acylamino group (eg, acetylamino group, propionylamino group) ), An alkylthio group (eg, methylthio group, ethylthio group, butylthio group, etc.), an arylthio group (eg, phenylthio group, etc.), a sulfonylamino group (eg, methanesulfonylamino group, benzenesulfonylamino group, etc.), a ureido group (eg, 3- A methylureido group, a 3,3-dimethylureido group, a 1,3-dimethylureido group, a sulfamoylamino group (eg, a dimethylsulfamoylamino group), a carbamoyl group (eg, a methylcarbamoyl group, an ethylcarbamoyl group), Dimethylcarbamoy Group), sulfamoyl group (eg, ethylsulfamoyl group, dimethylsulfamoyl group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenoxycarbonyl group, etc.), sulfonyl Groups (eg, methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group, etc.), acyl groups (eg, acetyl group, propanoyl group, butyroyl group, etc.), amino groups (eg, methylamino group, ethylamino group, dimethylamino group, etc.), Examples include a hydroxyl group, a nitro group, and an imide group (for example, a phthalimide group). In the above compounds, m represents an integer of 2 or more and 20 or less, and more preferably an integer of 3 or more and 16 or less. In the case where R represents a side chain, for example, the following R _{1 is used} for fixing without impairing the alignment form in the liquid crystal state.
Preferably it has a polymerizable group represented by to R ₃₉ or the like as R (when the side chain). Here, C _n H _2n represents a linear or branched alkylene chain. n represents an integer of 2 or more and 16 or less, and more preferably an integer of 3 or more and 12 or less.

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

Other oligomer liquid crystal compounds preferably used in the present invention include side chain oligomer liquid crystal compounds, main chain oligomer liquid crystal compounds, and (side chain-main chain) composite oligomer liquid crystal compounds. Is more preferably a side chain oligomer liquid crystalline compound, (side chain-
(Main chain) is a complex type oligomer liquid crystalline compound. The side chain type oligomer liquid crystal compound generally has a mesogen group bonded to the oligomer main chain via a spacer,
The skeleton chain includes polyester, polyamide, polysiloxane and the like, and a linear or cyclic skeleton can be used. From the viewpoint of the chemical stability of the oligomer liquid crystal compound, a cyclic structure is preferable. On the other hand, the main chain type oligomer liquid crystal compound is a compound in which a mesogen group is directly introduced into the oligomer main chain, and the (side chain-main chain) composite type oligomer liquid crystal compound is a compound in which the mesogen group has an oligomer main chain. It is bonded to the oligomer main chain via the middle and spacers.

Hereinafter, specific examples of the oligomer liquid crystal compound that can be used in the present invention will be shown, but the present invention is not limited to these.

[0039]

Embedded image

[0040]

Embedded image

However, R 'in the above compounds represents a substituent or a side chain and may be the same or different. When R ′ represents a substituent, examples of the substituent include an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, a t-butyl group, and the like), Alkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), aralkyl group (eg, benzyl group, 2-phenethyl group, etc.), aryl group (eg, phenyl group, naphthyl group, p
-Tolyl group, p-chlorophenyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, isopropoxy group,
A butoxy group, an aryloxy group (eg, a phenoxy group), a cyano group, an acylamino group (eg, an acetylamino group, a propionylamino group, etc.), an alkylthio group (eg, a methylthio group, an ethylthio group, a butylthio group, etc.), an arylthio group ( A phenylthio group, etc.), a sulfonylamino group (eg, a methanesulfonylamino group,
Benzenesulfonylamino group, etc.), ureido group (for example, 3-methylureido group, 3,3-dimethylureido group,
1,3-dimethylureido group, etc.), sulfamoylamino group (eg, dimethylsulfamoylamino group), carbamoyl group (eg, methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), sulfamoyl group (eg, ethylsulfoyl group) Famoyl group, dimethylsulfamoyl group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenoxycarbonyl group, etc.), sulfonyl group (eg, methanesulfonyl group,
Butanesulfonyl group, phenylsulfonyl group, etc.), acyl group (eg, acetyl group, propanoyl group, butyroyl group, etc.), amino group (eg, methylamino group, ethylamino group, dimethylamino group, etc.), hydroxyl group, nitro group, imide Groups (for example, a phthalimido group). In the above compounds, C _x H _{2 x} represents a linear or branched alkylene chain. x represents an integer of 1 or more and 16 or less, and more preferably an integer of 2 or more and 12 or less. Further, when R ′ represents a side chain, for example, the above R
It is preferred that R ′ (when representing a side chain) has a polymerizable group represented by _{1 to} R ₃₉ or the like.

The oligomer liquid crystalline compound is used for drying and alignment treatment at the time of lamination with the substrate, so that the transition temperature from the liquid crystal phase to the isotropic phase is 200 ° C. or less, preferably 170 ° C.
° C or lower, more preferably 150 ° C or lower, particularly preferably 10 to 150 ° C, the length of Sp (hereinafter referred to as a spacer) or Mes (hereinafter referred to as a mesogen group). The type, p (hereinafter referred to as the number of repeating units).

The mesogenic group in the present invention means a rod-shaped or plate-shaped group having a function of exhibiting liquid crystallinity in a molten state. The mesogenic group is relatively rigid and rich in anisotropy, and is often a para-substituted type in which an aromatic ring or a heteroaromatic ring is bonded by a conjugated atomic group. Typical examples include those in which two hydrogen atoms have been eliminated from benzylideneaniline, azobenzene, stilbene, phenylbenzoate, biphenyl, or the like to form a divalent group. By containing a mesogen group, the anisotropy of the whole molecule is increased, and a property that the liquid crystal is easily aligned is provided.

The oligomer liquid crystalline compound used in the present invention needs to be oriented in order to have anisotropy of the refractive index. The number of the repeating units is important as a factor for determining the easiness of the operation. is there. If the number of repeating units is large, the viscosity is high and the liquid crystal transition temperature is high, so that a high temperature or a long time is required for the alignment. If the number of repeating units is small, the alignment is relaxed at room temperature, which is not preferable. The number p of the repeating units is preferably an integer from 1 to 40, and more preferably 4 to 21.

In the side chain type and (side chain-main chain) composite type oligomer liquid crystal compound, the liquid crystal transition temperature and the orientation are also affected by the spacer connecting the main chain and the mesogen group. As a short spacer, the orientation of the mesogen group is not good, and a long spacer tends to relax after the orientation of the mesogen group. Therefore, the spacer is preferably an alkylene group or an alkyleneoxy group having 2 to 10 carbon atoms. In particular, from the viewpoint of high orientation, an alkylene group or an alkyleneoxy group having 2 to 6 carbon atoms is preferable, and
An alkyleneoxy group is more preferred from the viewpoint of ease of synthesis.

Incidentally, all of these compounds can be easily synthesized by a synthesis method known to those skilled in the art. less than,
An example of synthesis will be described.

Synthesis Example (Synthesis of Compound (E)-(R ': -OMe))

[0048]

Embedded image

5.8 g of 4-hydroxy-4'-methoxybiphenyl and diethyl 6-bromohexylmalonate
2 g was dissolved in 45 ml of acetone, 3.4 g of potassium carbonate was added thereto, and the mixture was heated under reflux for 72 hours. Once filtration was performed, the solvent was concentrated under reduced pressure, and recrystallized from ethanol to obtain diethyl 6- (4'-methoxybiphenylroxy) hexylmalonate (I) -1.

Next, 4,4'-dihydroxyazobenzene and 6-bromo-1-hexanol were dissolved in acetone in the same manner as above, and potassium carbonate was added thereto.
The mixture was heated under reflux for 2 hours. Once filtered, the solvent is concentrated under reduced pressure and recrystallized from ethanol to give 4,4 '.
-Bis (6-hydroxyhexyloxy) azobenzene (I) -2 was obtained.

6- (4'-methoxybiphenylroxy)
Diethyl hexylmalonate (I) -1 and 4,4'-bis (6-hydroxyhexyloxy) azobenzene (I) -2 are reacted at a mixing ratio of 1: 1 to obtain the desired oligomeric liquid crystal compound (E) -(R ': -OMe) was obtained.

This oligomer liquid crystalline compound was analyzed by elemental analysis.
The structure was confirmed from the infrared absorption spectrum and the H-NMR spectrum.

When this oligomeric liquid crystalline compound was observed orthoscopically with a polarizing microscope, it showed a nematic liquid crystal phase at 122 ° C. The low molecular weight liquid crystalline compound was homeotropically aligned and subjected to conoscopic observation with a polarizing microscope. Having two optical axes, | ny-nz | / |
It was found that ny−nx | = 0.8.

The optical compensation film of the present invention may be composed of only an optically anisotropic layer composed of only a liquid crystal compound. However, at least one optically anisotropic layer containing a liquid crystal compound is provided on a transparent support. Preferably, it is coated. Depending on the application, a protective film or a support may be present above and below the liquid crystal layer or between the liquid crystal layers.

It is desirable that the material of the support has good transmittance and close to optical isotropy. Therefore, glass, ZEONEX (manufactured by ZEON CORPORATION), ARTON (ART
ON, manufactured by Nippon Synthetic Rubber Co., Ltd.). Further, triacetyl cellulose, polycarbonate, polyacrylate, polystyrene, and polyether sulfone are also preferably used.

Materials for the protective film include polymethyl methacrylate, acrylic acid-methacrylic acid copolymer, styrene-maleic anhydride copolymer, polyvinyl alcohol, N-methylolacrylamide, styrene-vinyltoluene copolymer, and chloroform. Sulfonated polyethylene,
Examples include nitrocellulose, polyvinyl chloride, polyolefin chloride, polyester, polyimide, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate, and other high-molecular substances, and silane coupling agents. be able to. Cumulative films formed by Langmuir-Blodgett (LB method) such as ω-tricosanoic acid, dioctadecyldimethylammonium chloride and methyl stearate can also be used.

The optically anisotropic layer is formed by vapor deposition, spin coating,
It can be formed on a support by a coating method such as dip coating or extrusion coating. The liquid crystal compound is fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction of a polymerizable group. The polymerization reaction includes a thermal polymerization reaction and a photopolymerization reaction, and a photopolymerization reaction is preferred. It is preferable to use a photopolymerization initiator for the photopolymerization reaction. Examples of photopolymerization initiators include α-carbonyl compounds, acyloin ethers, aromatic acyloin compounds substituted with α-hydrocarbons, polynuclear quinone compounds, combinations of triarylimidazole dimers / p-aminophenyl ketone, acridine compounds and phenazines And oxadiazole compounds.
Regarding the concentration of the photopolymerization initiator, the solid content of the coating solution was 0.1%.
It is preferably from 01 to 20% by mass, more preferably from 0.5 to 5% by mass.

Light rays for polymerization include electron beam, ultraviolet ray,
Visible light and infrared rays (heat rays) are preferred, and ultraviolet rays are more preferred. Radical polymerization and cationic polymerization using a photopolymerization initiator by ultraviolet rays generally have a very high polymerization rate and are preferred in terms of productivity in the production process. As the radical light source, a low-pressure mercury lamp, a high-pressure discharge lamp and a short arc discharge lamp are preferably used, and a high-pressure discharge lamp is more preferably used. The irradiation energy is preferably ²⁰ to 50 mJ / cm ² ,
More preferably, it is from 00 to 800 mJ / cm ² .
Light irradiation may be performed under heating conditions to promote the photopolymerization reaction.

The optical compensation film of the present invention is a film for compensating a viewing angle of a liquid crystal display element, and preferably, the director is different between the upper surface and the lower surface of the film.
More preferably, a hybrid orientation that is gradually changed in the film thickness direction is formed, and no optical axis exists.

In the present invention, as a condition for greatly improving the viewing angle characteristics of the TN type liquid crystal cell, the optical axis is preferably inclined at 5 to 50 degrees from the normal direction of the film surface, preferably at 10 to 40 degrees. The degree is more preferable.

To obtain a compensation film in which the hybrid alignment is fixed uniformly using the liquid crystal compound as described above,
It is preferable in the present invention that the substrate and each step described below are taken.

In order to obtain the hybrid alignment of the present invention, the upper and lower portions of the liquid crystalline material may be sandwiched between different interfaces, or an electric field,
It is desirable to use a magnetic field or the like. As a specific mode, a single substrate and an air interface are used, and the lower interface of the liquid crystal layer is in contact with the substrate and the upper interface is in contact with air. Although the substrate having different upper and lower interfaces can be used, it is preferable that the coating be performed on the support in a state where one interface is in contact with the gas phase in the production process.

The substrate that can be used in the present invention is desirably an anisotropic alignment substrate so that the tilt direction of the liquid crystal (projection of the director onto the alignment substrate) can be defined. The alignment substrate has a function of defining the alignment direction of the compound of the optically anisotropic layer. The alignment substrate is formed by rubbing an organic compound (preferably a polymer), obliquely depositing an inorganic compound, forming a layer having microgrooves, or an organic compound (eg, ω-tricosanoic acid) by the Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Further, an alignment substrate having an alignment function by application of an electric field, a magnetic field, or light irradiation can also be used.

In the present invention, the alignment substrate may be subjected to a surface treatment such as a hydrophilic treatment or a hydrophobic treatment.

The optical compensation film of the present invention can be obtained by applying the above-mentioned liquid crystalline compound on these alignment substrates, then performing a uniform alignment process and a fixing process. Coating on the substrate,
A solution in which the material is dissolved in various solvents, or a solution in which the material is melted can be used. However, in the process, solution coating in which a solution in which a liquid crystal compound is dissolved in a solvent is preferably used. .

The concentration of the solution depends on the solubility of the material and ultimately the thickness of the target optical compensation film, and cannot be unconditionally determined. However, it is usually used in the range of 1 to 60% by mass. Ranges from 3 to 40% by weight. These solutions are then applied on the alignment substrate described above. After application,
The solvent is removed, and a layer having a uniform thickness is first formed on the substrate. The solvent removal conditions are not particularly limited, as long as the solvent can be substantially removed and the layer of the material does not flow or even fall off. Usually, the solvent is removed by air drying at room temperature, drying on a hot plate, drying in a drying furnace, or blowing hot or hot air.

The purpose of this coating-drying step is to first form a liquid crystal compound layer on the substrate, and the material layer has not yet been oriented. In the present invention, it is preferable to perform a heat treatment for the orientation, and the heat treatment is performed at a temperature equal to or higher than the liquid crystal transition point of the liquid crystal compound. That is, the alignment is performed in the liquid crystal state of the material, or the material is once brought into an isotropic liquid state higher than the temperature range in which the material exhibits a liquid crystal phase, and then the temperature is lowered to the temperature range in which the material exhibits a liquid crystal phase. Usually, the temperature of the heat treatment is from 10 ° C to 200 ° C.
C., and particularly preferably in the range of 10 to 150.degree.

The liquid crystal temperature range of the liquid crystal compound of the present invention is as follows.
10 to 200 ° C from the viewpoint of the suitability for production of the optical compensation film
, And more preferably in the range of 10 to 150 ° C. If the temperature is lower than 10 ° C., a cooling step or the like may be required to lower the temperature to a temperature range in which a liquid crystal phase is exhibited. On the other hand, if the temperature exceeds 200 ° C., a high temperature is required in order to make the liquid state once higher than the temperature range in which the liquid crystal phase is exhibited, which is disadvantageous from waste of heat energy, deformation and deterioration of the substrate.

In the present invention, in the heat treatment step, a magnetic field or an electric field may be used to align the liquid crystal compound. The alignment state thus obtained is then cooled or polymerized by light, heat, etc., and fixed without impairing the alignment state to obtain the optical compensation film of the present invention.

The thus obtained optical compensation film of the present invention is incorporated in a liquid crystal display device in an arrangement as described below, thereby exhibiting an optical compensation effect, ie, viewing angle compensation, on the liquid crystal display. it can. The optical compensatory film is usually used as one or more sheets, but preferably one or two sheets, especially two sheets, can exhibit a suitable optical compensation effect.

For compensating the viewing angle, it is more preferable that the absolute value of the product of the birefringence of the liquid crystal and the film thickness is substantially equal between the liquid crystal cell and the optically anisotropic material. The birefringence here is the anisotropy of the refractive index inherent in the liquid crystal, and the refraction in the optical axis direction obtained when the director of the liquid crystal is uniaxially oriented so as to face one direction. It is the difference between the index and the refractive index in the direction perpendicular to it. The product of such birefringence and film thickness is usually 50 nm or more and 2000 nm or less, preferably 100 nm or less, for the liquid crystal cell and the optical compensation film.
nm or more and 1000 nm or less. When a plurality of optical compensation films are used, the value obtained by summing the absolute values of the products of the birefringence and the film thickness of each optical compensation film is preferably within the above range. However, the value obtained by multiplying the birefringence and the film thickness does not necessarily need to be completely the same between the liquid crystal cell and the optical compensation film. As compared with the case where no film is incorporated, a remarkable viewing angle compensation effect can be obtained.

Next, the configuration of the liquid crystal display device of the present invention will be described. A typical configuration example of the liquid crystal display element of the present invention is, for example, a liquid crystal cell including two substrates having transparent electrodes and orthogonally oriented surfaces and a twisted nematic liquid crystal sealed between the substrates. A pair of polarizing plates provided on both sides of the liquid crystal cell, an optical compensation film and a backlight disposed between the liquid crystal cell and the polarizing plate are combined to form a liquid crystal display element. The optical compensation film may be arranged on only one side or on both sides.

Typical examples of the structure of the color liquid crystal display device of the present invention include, for example, a glass substrate provided with an opposing transparent electrode and a color filter, a glass substrate provided with a pixel electrode and a TFT, and sealed between these two substrates. A liquid crystal cell composed of a twisted-aligned nematic liquid crystal, a pair of polarizing plates provided on both sides of the liquid crystal cell, and a pair of optical compensation films disposed between the liquid crystal cell and the polarizing plate are combined to form a color liquid crystal. It constitutes a display element. The optical compensation film may be arranged on only one side or on both sides.

As the color filter used in the color liquid crystal display device of the present invention, any color filter having high color purity, dimensional accuracy, and heat resistance can be used. Preferred examples include a dyeing filter, a printing filter, an electrodeposition filter, and a pigment dispersion filter. These are described in "Color LCD Display" edited by Shunsuke Kobayashi (Sangyo Tosho, 172-173).
Pp. 237-251 (1990) or Nikkei Microdevices, "Flat Panel Display 19".
94 "(Nikkei BP, page 216).
For example, the staining filter is gelatin, casein, PV
After adding a dichromate to a substrate such as A to impart photosensitivity and patterning by photolithography,
It can be obtained by dyeing.

Examples of the liquid crystal used in the (color) liquid crystal display device of the present invention include, for example, “Liquid Crystal Device Handbook” edited by the 142nd Committee of the Japan Society for the Promotion of Science (Nikkan Kogyo Shimbun,
Nematic liquid crystals described on pages 107 to 213) are preferred. Since the major axis of the liquid crystal molecules is twisted by approximately 90 degrees between the upper and lower substrates of the liquid crystal cell, the incident linearly polarized light has a 90-degree polarization direction due to the optical rotation of the liquid crystal cell when there is no applied electric field. Instead, the light is emitted from the liquid crystal cell. When a sufficiently high electric field higher than the threshold value is applied, the long axis of the liquid crystal molecules changes in the direction of the electric field and is arranged perpendicular to the electrode surface, so that the optical rotation almost disappears. Therefore,
In order to sufficiently exhibit the effect of the optical rotation, the twist angle is preferably from 70 to 100 degrees, and more preferably from 80 to 90 degrees.

In order to reduce defects (disclination) in alignment of liquid crystal molecules due to the electric field, it is preferable to give a pretilt angle to the liquid crystal molecules in advance. The pretilt angle is preferably 5 degrees or less, more preferably 2 to 4 degrees. The twist angle and the pretilt angle are described in “Liquid Crystal Application” edited by Koji Okano and Shunsuke Kobayashi (Baifukan, pp. 16-28).

The value of the product (Δn · d) of the refractive index anisotropy Δn of the liquid crystal cell and the thickness d of the liquid crystal layer in the liquid crystal cell is described in, for example, “Liquid Crystal Device Handbook” edited by the 142nd Committee of the Japan Society for the Promotion of Science. (The Nikkan Kogyo Shimbun, pp. 329-33
As described in (p. 7), as d increases, the contrast is improved, but the response speed is slow and the viewing angle is also small. Therefore, the range of 0.3 to 1.0 μm is preferable. The range of 3 to 0.6 μm is more preferable.

The signals applied to the color liquid crystal display device of the present invention are described in, for example, “Liquid Crystal Device Handbook” edited by the 142nd Committee of the Japan Society for the Promotion of Science (Nikkan Kogyo Shimbun, p.
465 pages) or Koji Okano and Shunsuke Kobayashi, "Liquid Crystals"
As described in “Applied Edition” (Baifukan, pp. 85-105), etc., the alternating current of 5-100 Hz and the voltage of 20
V or less, preferably 8 V or less. For example, in the normally white mode, the applied voltage is 0 to 1.5 V
For bright display, 1.5V to 3.0V for halftone display, 3.0V
The dark display is generally performed as described above.

[0079]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 << Liquid crystal display device (1) using optical compensation film (1) containing low molecular liquid crystal compound (I) -R ₂₅ (n = 12) >>
In addition, this low molecular liquid crystal compound (I) -R ₂₅ (n = 12)
Is a heart observed by an orthoscope with a polarizing microscope, 90
° C, the low-molecular liquid crystalline compound was homeotropically aligned, and was observed conoscopically with a polarizing microscope. The compound had two optical axes, had an Nb phase, and | ny-nz | / | Ny-nx | = 0.6.

(Preparation of Optical Compensation Film (1)) A gelatin layer (0.1 μm) was provided on one side of a triacetyl cellulose (TAC) film, and a modified Povar was applied thereon as an alignment film. The film was rubbed with a rubbing machine. The liquid crystal compound (I) -R ₂₅ (n
= 12) in a 10% by mass methyl ethyl ketone solution, a coating solution in which a photopolymerization initiator (Irgacure 907 manufactured by Ciba Geigy) and a sensitizer (Kayacure DETX manufactured by Nippon Kayaku Co., Ltd.) were dissolved in extremely small amounts was applied by a spin coater at 1000 rpm, and the liquid crystal was applied. A coating layer of a hydrophilic compound was formed. Surface temperature 95 ° C
After contacting with a heated metal roller from the support side for 40 seconds to orient the liquid crystal, the liquid crystal was kept at 95 ° C. at 120 W / cm.
UV light was applied to the coated surface for 2 seconds at an illuminance of 600 mW / cm ² using a high-pressure mercury lamp described above, and then returned to room temperature to obtain a triacetyl cellulose film (optical compensation film (1)) provided with a liquid crystal compound-containing layer. Produced.

The in-plane retardation (Δnd) of this film was measured using ellipsometry (AEP-100, manufactured by Shimadzu Corporation), and the optical axis inclination angle β was determined from the angle dependence. Here, the retardation (Δnd) is represented by the product of the birefringence (Δn) and the film thickness (d) of the optically anisotropic layer. Δn was determined by dividing the measured retardation (Δnd) by the film thickness (d). However, since Δnd did not become 0 even at the minimum point (there was no optical axis), the angle of the minimum point was regarded as the apparent inclination angle β. As a result of the measurement, the apparent inclination angle β was 31 °,
Δn was 0.080. Further, no phase change was observed even when reheating to 200 ° C.

(Production of Liquid Crystal Display Element (1)) A TN type liquid crystal cell having a product of the difference between the refractive indexes of the extraordinary light and ordinary light of the liquid crystal and the gap size of the liquid crystal cell of 470 nm and having a twist angle of 90 degrees was formed. Two optical compensation films (1) are mounted so as to sandwich the liquid crystal display element, thereby producing the liquid crystal display element (1). As the visual characteristics, the angle dependence of the contrast with respect to the liquid crystal cell at a rectangular wave of 0 to 5 V of 30 Hz ( The contrast range of 10 or more) was measured by LCD-5000 (manufactured by Otsuka Electronics Co., Ltd.). An angle range of 10 or more in contrast is 163 ° or more in left and right, and 112 ° in up and down
Obtained above.

Example 2 << Liquid crystal display device (2) using optical compensation film (2) containing low molecular liquid crystal compound (II) -R ₁ (n = 4) >>
Incidentally, this low-molecular liquid crystal compound (II) -R ₁ (n = 4)
Are orthoscopic observations with a polarizing microscope.
It shows a nematic liquid crystal phase at 04 ° C., and this low molecular weight liquid crystalline compound is homeotropically aligned, and conoscopically observed with a polarizing microscope.
ny-nz | / | ny-nx | = 1.2.

(Preparation of Optical Compensation Film (2)) A gelatin layer (0.1 μm) was coated on one side of a triacetyl cellulose (TAC) film, and NMP (N-
A 1% solution of poly [1- (2-oxo-2H-1-benzopyran-7-yl) -ethylene] dissolved in methylpyrrolidone) was spin-coated at 4000 rpm. After preliminary drying at 80 ° C. for 2 hours on a heat bench, drying was performed at 100 ° C. for 4 hours under reduced pressure. The coated triacetylcellulose (TAC) film was irradiated with a linearly polarized light beam at 25 ° C. for 5 minutes at an angle inclined by 40 ° from the normal line of the film using a 400 W ultra-high pressure mercury lamp to form a photo-alignment film.

Further, the above-mentioned liquid crystalline compound (II) -R
_{1 A} photopolymerization initiator (Irgacure 907 manufactured by Ciba-Geigy) was added to a 10% by mass (n = 4) solution of methyl ethyl ketone,
A coating solution in which a minimal amount of a sensitizer (Kayacure DETX manufactured by Nippon Kayaku) was dissolved was applied at 1,000 rpm by a spin coater to form a coating layer of a liquid crystal compound. The coated material was placed in a temperature atmosphere of 110 ° C., heated for 3 minutes to align the liquid crystal, and then kept at 110 ° C. using a high-pressure mercury lamp of 120 W / cm at an illuminance of 600 mW / cm ² for 1 second on the coated surface. After the UV irradiation, the temperature was returned to room temperature to prepare a triacetylcellulose film (optical compensation film (2)) coated with a liquid crystal compound-containing layer.

The in-plane retardation (Δnd) of this film was measured using ellipsometry (AEP-100, manufactured by Shimadzu Corporation), and the optical axis inclination angle β was determined from the angle dependence. Here, the retardation (Δnd) is represented by the product of the birefringence (Δn) and the film thickness (d) of the optically anisotropic layer. Δn was determined by dividing the measured retardation (Δnd) by the film thickness (d). However, since Δnd did not become 0 even at the minimum point (there was no optical axis), the angle of the minimum point was regarded as the apparent inclination angle β. As a result of the measurement, the apparent inclination angle β was 20 °,
Δn was 0.075. Further, no phase change was observed even when reheating to 200 ° C.

(Preparation of Liquid Crystal Display Element (2)) The product of the difference between the refractive index of the extraordinary light and the ordinary light of the liquid crystal and the gap size of the liquid crystal cell was 470 nm, and the twist angle was 90 degrees. Two optical compensation films (2) are mounted so as to sandwich the liquid crystal display element, thereby producing the liquid crystal display element (2). As the visual characteristics, the angle dependence of the contrast with respect to the liquid crystal cell in a 30 Hz rectangular wave of 0 to 5 V ( The contrast range of 10 or more) was measured by LCD-5000 (manufactured by Otsuka Electronics Co., Ltd.). An angle range of 10 or more in contrast is 155 ° or more in left and right, and 107 ° in up and down
Obtained above.

Example 3 << Liquid crystal display device (3) using optical compensation film (3) containing oligomer liquid crystal compound (E)-(R ': OMe) >> This oligomer liquid crystal compound (E)-(R ´:
OMe) shows a nematic liquid crystal phase at 122 ° C. when observed orthoscopically with a polarizing microscope, and when this low-molecular liquid crystalline compound is homeotropically aligned and is observed with a conical microscope with a polarizing microscope, it has two optical axes. | Ny-nz | / | ny-nx | = 0.8.

(Preparation of Optical Compensation Film (3)) Thickness 8
A gelatin layer (0.1 μm) was coated on a 0 μm triacetyl cellulose (TAC) film, and a modified Poval was applied thereon as an alignment film, and the film was rubbed with a rubbing machine. A 5% by mass solution of the above-mentioned oligomer liquid crystal compound (E)-(R ': OMe) in methylene chloride was applied thereon at 1000 rpm by a spin coater to form a coating layer of the liquid crystal compound. Surface temperature 13
After contacting the metal roller heated to 0 ° C. from the support side for 40 seconds to align the liquid crystal, the metal roller heated to a surface temperature of 20 ° C. was contacted from the support side for 20 seconds to coat the liquid crystal compound-containing layer. A triacetyl cellulose film (optical compensation film (3)) was produced.

The in-plane retardation (Δnd) of this film was measured using ellipsometry (AEP-100, manufactured by Shimadzu Corporation), and the optical axis inclination angle β was determined from the angle dependence. Here, the retardation (Δnd) is represented by the product of the birefringence (Δn) and the film thickness (d) of the optically anisotropic layer. Δn was determined by dividing the measured retardation (Δnd) by the film thickness (d). However, since Δnd did not become 0 even at the minimum point (the optical axis did not exist), the angle of the minimum point was regarded as the apparent inclination angle β. As a result of the measurement, the apparent inclination angle β was 26 °,
Δn was 0.084.

(Preparation of Liquid Crystal Display Element (3)) The product of the difference between the refractive index of the extraordinary light and the ordinary light of the liquid crystal and the gap size of the liquid crystal cell was 470 nm, and the twist angle was 90 degrees. Two optical compensation films (3) were mounted so as to sandwich the liquid crystal display element to produce a liquid crystal display element. As visual characteristics, the angle dependence of the contrast with respect to the liquid crystal cell in a 30 Hz rectangular wave of 0 to 5 V (contrast 1)
The angle range of 0 or more) was measured by LCD-5000 (manufactured by Otsuka Electronics Co., Ltd.). An angle range of 10 or more in contrast was obtained at 159 ° or more at the left and right, and 131 ° or more at up and down.

Comparative Example 1 << Liquid crystal display device (4) using uniaxially stretched film (4) as optical compensation film (4) >> (Preparation of uniaxially stretched film (4)) Polyolefin resin ZEONEX 280 manufactured by Zeon Corporation of Japan was converted to toluene. / Methylene chloride (75% / 25%)
A 5% solution was obtained. Cast this on a steel band,
A 100 μm thick ZEONEX film was obtained. The Re value of this film was almost zero as measured by ellipsometry (AEP-100, manufactured by Shimadzu Corporation). The film was stretched 10% by transverse uniaxial stretching using a tenter under a stretching condition of 170 ° to prepare a uniaxially stretched film (4) having birefringence.

The in-plane retardation (Δnd) of this film was measured using ellipsometry (AEP-100, manufactured by Shimadzu Corporation), and the optical axis inclination angle β was determined from the angle dependence. Here, the retardation (Δnd) is represented by the product of the birefringence (Δn) and the film thickness (d) of the optically anisotropic layer. Δn was determined by dividing the measured retardation (Δnd) by the film thickness (d). As a result of the measurement, the inclination angle β was 0 ° and Δn was 0.0006. A birefringent film having a Re value of 53 nm (uniaxially stretched film (4)) was obtained.

(Production of Liquid Crystal Display Element) The product of the difference between the refractive indexes of the extraordinary light and ordinary light of the liquid crystal and the gap size of the liquid crystal cell is 47.
Two uniaxially stretched films (4) were mounted on a TN-type liquid crystal cell having a twist angle of 90 degrees at 0 nm so as to sandwich the liquid crystal display element, and a liquid crystal display element (4) was produced. Angle dependence of contrast for a liquid crystal cell in a 30 Hz square wave of ５5 V (contrast 10
LCD-5000 (Otsuka Electronics Co., Ltd.)
Manufactured). An angle range of 10 or more in contrast was obtained at 81 ° or more on the left and right, and 73 ° or more on the up and down.

Comparative Examples 2 and 3 (Evaluation of Performance for Enlarging Viewing Angle of TN-Type Liquid Crystal Display Element)
The angle dependence of the contrast in the Hz square wave was measured by Otsuka Electronics LCD-5000. The position of the contrast 10 was defined as the viewing angle, and the up, down, left, and right viewing angles were determined.

Here, the measured values of a liquid crystal display element (5) (Comparative Example 2) which is a TN type liquid crystal cell equipped with a commercially available WV (manufactured by Fuji Photo Film Co., Ltd.) instead of the above film, and the film The measurement value of the liquid crystal display element (6) (Comparative Example 3), which is only the TN type liquid crystal cell without mounting, was obtained.

The results are shown in Table 1 below.

[0099]

[Table 1]

[0100]

Embedded image

Incidentally, when the comparative compound (1) was orthoscopically observed with a polarizing microscope, it showed a discotic nematic liquid crystal phase at 116 ° C. The low molecular liquid crystal compound was homeotropically aligned, and was observed with a polarizing microscope. When the scope was observed, it had only one optical axis,
| Ny-nz | / | ny-nx | = 0. The comparative compound (1) is substantially the same type of discotic liquid crystal compound used in commercially available WV.

From Table 1, it can be seen that the liquid crystal display device (1) using the optical compensation films (1), (2) and (3) of the present invention,
(2) and (3) are excellent in the viewing angle compensation effect for the liquid crystal cell, and are a liquid crystal display element (4) using a uniaxially stretched film (4) (Comparative Example 1) and a liquid crystal display element (5 using a commercially available WV). ) (Comparative Example 2) and the liquid crystal display element (6) (Comparative Example 3) in which no optical compensation film was used, it can be seen that a superior viewing angle compensation effect was exhibited particularly in the horizontal direction (left and right).

The liquid crystal display element (5) using a commercially available WV (Comparative Example 2) had a wide viewing angle when viewed from the right and left, but was colored yellow. In the liquid crystal display devices (1), (2), and (3) using (1), (2), and (3), unnecessary coloring did not occur even when viewed from right, left, up, and down.

[0104]

According to the present invention, it is possible to provide an optical compensatory film which enlarges the viewing angle of a liquid crystal display and has less coloring when viewed obliquely. Further, a liquid crystal display device incorporating the compensation film can be provided.

Claims (7)

[Claims] 1. An optical compensation film comprising a liquid crystal compound having two optical axes in a liquid crystal state among liquid crystal compounds having a nematic phase. 2. The method according to claim 1, wherein the liquid crystal compound is Nb (biaxial).
2. A composition according to claim 1, wherein said composition has a (nematic) phase.
The optical compensation film according to the above. 3. When the refractive indices of the liquid crystal phase of the liquid crystal compound in the three axial directions are nx, ny, and nz in ascending order, 0.2 <0.2
3. The optical compensation film according to claim 1, wherein a relationship of | ny-nz | / | ny-nx | ≦ 2.0 is satisfied. 4. The optical compensation film according to claim 1, wherein the liquid crystal compound is a low molecular weight liquid crystal compound or an oligomer liquid crystal compound having a polymerizable group. 5. A liquid crystal compound having a liquid crystal temperature range of 10 to 1
The optical compensation film according to claim 4, wherein the temperature is within a range of 50 ° C. 6. It is preferable that at least one layer containing a liquid crystal compound is provided on the transparent film, and that the molecular axis of the liquid crystal compound is inclined within a range from the plane of the film to the normal direction of the film. The optical compensation film according to claim 5, wherein: 7. A liquid crystal display device comprising at least one optical compensation film according to claim 1, 2, 3, 4, 5, or 6.