JP2007131740A - Polymerizable composition, optically anisotropic layer and method for producing the same, optical compensation element, liquid crystal display device and liquid crystal projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optically compensate a liquid crystal layer in a black display state with higher accuracy, to prevent light leakage in a wider angle of visibility, to provide an optically anisotropic layer, to provide a method for producing the layer and to provide a liquid crystal display device and a liquid crystal projector having a high angle of visibility, high contrast and high image quality with a long life by using an optical compensation element composed of the optically anisotropic layer. <P>SOLUTION: The polymerizable composition comprises a polymerizable liquid crystal compound, uses an amide compound as a solvent for the polymerizable liquid crystal compound and contains at least either of an ethereal compound and a cellosolve compound in an amount of 1-50 mass% based on the whole solvent therein. The optically anisotropic layer, optical compensation element and liquid crystal display device comprise the polymerizable composition. The liquid crystal projector is equipped with the liquid crystal display device in which illuminating light from a light source is irradiated and a projecting optical system for imaging light subjected to optical modulation with the liquid crystal display device on a screen and the liquid crystal display device is the liquid crystal display device described above. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a polymerizable composition suitable for an optical compensation element or the like, an optically anisotropic layer and a method for producing the same, an optical compensation element, a liquid crystal display device, and a liquid crystal projector.

In recent years, the use of liquid crystal display devices has been rapidly advanced, and is used in mobile phones, personal computer monitors, televisions, liquid crystal projectors, and the like.
In general, a liquid crystal display device is in a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In-Plane Switching) mode, an OCB (Optically Compensatory Bend) mode, an ECB (Electrically Bending mode), or the like. It is a display device that expresses characters and images by operating a liquid crystal and electrically controlling light passing through the liquid crystal to display a difference between light and dark on a screen.

As such a liquid crystal display device, a TFT (Thin Film Transistor) -LCD is generally known, and a TN mode is the main liquid crystal operation mode of the TFT-LCD. On the other hand, as the application development of liquid crystal display devices progresses in recent years, the demand for higher contrast has increased, and research on VA mode liquid crystal display devices has been actively conducted.
In a TN mode liquid crystal display device, nematic liquid crystal twisted by 90 ° is enclosed between two glass substrates, and a pair of polarizing plates are arranged in crossed Nicols outside the two glasses. When no voltage is applied, the linearly polarized light that has passed through the polarizer on the polarizer side is twisted by 90 ° in the liquid crystal layer and passes through the polarizer on the analyzer side, resulting in white display. In addition, when the voltage is sufficiently applied, the alignment direction of the liquid crystal changes substantially perpendicular to the liquid crystal panel, and the linearly polarized light passing through the polarizer on the polarizer side passes through the liquid crystal layer without changing the polarization state. As a result, the light reaches the polarizing plate on the analyzer side and black is displayed.

On the other hand, in a VA mode liquid crystal display device, nematic liquid crystal is sealed between two glass substrates so as to be vertically aligned or vertically inclined, and a pair of polarizing plates is crossed Nicols on the outside of the two glasses. Is arranged in. When no voltage is applied, the linearly polarized light that has passed through the polarizer on the polarizer side passes through the liquid crystal layer with almost no change in the plane of polarization in the liquid crystal layer, reaches the polarizer on the analyzer side, and displays black. Become. In addition, when the voltage is sufficiently applied, the alignment direction of the liquid crystal changes parallel to the liquid crystal panel and is twisted by 90 °, and the linearly polarized light passing through the polarizer on the polarizer side is polarized by the liquid crystal layer. The surface is twisted by 90 ° and passes through the polarizer on the analyzer side, resulting in a white display.
A liquid crystal display device that operates in these display modes has a field of view that display characteristics deteriorate due to a decrease in contrast or a gradation inversion phenomenon in which the brightness is reversed in gradation display when the display screen is viewed from an oblique direction. There is a problem of angular dependence. Such a problem of viewing angle dependency is caused by light leakage even if an attempt is made to display a liquid crystal display device in black, depending on the viewing angle.

Conventionally, the phase difference value of the light passing through the liquid crystal layer in the black display state and the phase difference value of the optical anisotropic film are combined, and the liquid crystal layer in the black display state is optically compensated three-dimensionally, Various optical compensation films have been proposed that eliminate light leakage from any direction and improve the problem of viewing angle dependency. For example, the applicant of the present application first comprises a support such as a triacetyl cellulose (TAC) film and an optically anisotropic layer provided thereon, and the optically anisotropic layer has a discotic structural unit. The disc surface of the discotic structural unit is obtained by coating, orienting, and fixing the structure of the coating liquid containing the compound having optical anisotropy composed of the compound and having the discotic structural unit on the support. And an optical compensation film having a hybrid orientation that is inclined with respect to the support surface and in which the angle formed by the disc surface of the discotic structural unit and the support surface changes in the thickness direction of the optically anisotropic layer. (See Patent Document 1).
According to this optical compensation film, since the discotic structural unit of the optically anisotropic layer is arranged so as to be mirror-symmetrical with the liquid crystal layer in the black display state, the support and the discotic structural unit As the optical characteristics of the entire laminate, the liquid crystal layer in the black display state is optically compensated, and light leakage can be prevented in a wide viewing angle.

However, in this case, by using the optical compensation film, the problem of the viewing angle dependency of the liquid crystal display device has been improved and the viewing angle has been successfully expanded. The demand for liquid crystal monitors, liquid crystal projectors, and the like is increasing, and further wide viewing angles and high contrast are desired for the large screen liquid crystal monitors, liquid crystal projectors, and the like. In addition, since the liquid crystal projector integrates light incident on the liquid crystal cell at various angles and is projected on the screen in an enlarged manner, higher contrast is required, and the optical compensation film still has room for improvement. .
That is, in the optical compensation film, it is difficult to improve the coating property of the compound having the discotic liquid crystal on the support, and there is a problem that the thickness of the optically anisotropic layer becomes nonuniform. For this reason, it is difficult to obtain the desired optical characteristics of the optical anisotropic layer with high accuracy by making the thickness of the optical anisotropic layer non-uniform, and light leakage cannot be prevented in a wide viewing angle. There is a problem.
Therefore, it is still insufficient to prevent light leakage in a wide viewing angle by optically compensating the liquid crystal layer in the black display state with higher accuracy in response to the recent demand for large screen display such as the liquid crystal projector. However, the present situation is that a quick solution is desired.

JP-A-8-50206

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention optically compensates for a liquid crystal layer in a black display state with higher accuracy, prevents light leakage at a wide viewing angle, and provides an optically anisotropic layer, a method for manufacturing the same, and the optical anisotropy. An object of the present invention is to provide a liquid crystal display device and a liquid crystal projector having a high viewing angle, a high contrast, and a high image quality by using an optical compensation element made of a conductive layer.

Means for solving the problems are as follows. That is,
<1> A polymerizable liquid crystal compound is contained, an amide compound is used as a solvent for the polymerizable liquid crystal compound, and at least one of an ether compound and a cellosolve compound is used as the solvent in an amount of 1 to 50% by mass based on the total solvent. It is a polymerizable composition characterized by being contained.
<2> The polymerizable composition according to <1>, wherein the amide compound is at least one selected from N, N-dimethylformamide and N, N-dimethylacetamide.
<3> The polymerizable composition according to any one of <1> to <2>, wherein the ether compound is an ether compound having a boiling point of 100 ° C. or higher.
<4> The polymerizable compound according to any one of <1> to <3>, wherein the ether compound is at least one selected from diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether. It is a composition.
<5> The polymerizable composition according to any one of <1> to <4>, wherein the cellosolve compound is butyl cellosolve.
<6> The polymerizable composition according to any one of <1> to <5>, wherein the polymerizable liquid crystal compound includes a discotic liquid crystal compound.
<7> The polymerizable composition according to any one of <1> to <5>, wherein the polymerizable liquid crystal compound includes a rod-like liquid crystal compound.
<8> An optically anisotropic layer formed using the polymerizable composition according to any one of <1> to <7>.
<9> The alignment angle of the polymerizable liquid crystal compound in the alignment state formed by the polymerizable liquid crystal compound is inclined with respect to the thickness direction of the optically anisotropic layer, and is fixed in the inclined state <8 > Is an optically anisotropic layer.
<10> The optically anisotropic layer according to any one of <8> to <9>, wherein the orientation angle of the polymerizable liquid crystal compound is fixed in a hybrid orientation that changes in the thickness direction of the optically anisotropic layer. is there.
<11> The method for producing an optically anisotropic layer according to any one of <8> to <10>, wherein the polymerizable composition containing a polymerizable liquid crystal compound is heated to 130 ° C. or higher to remove a solvent. It is a manufacturing method of the optically anisotropic layer characterized by including removing.
<12> having at least one support, and having an optically anisotropic layer on at least one surface of the support, wherein the optically anisotropic layer is any one of <8> to <11> It is an optically anisotropic layer described in the above, an optical compensation element.
<13> An optical anisotropy in which the alignment angle of the polymerizable liquid crystal compound in the alignment state formed by the polymerizable liquid crystal compound is inclined with respect to the thickness direction of the optically anisotropic layer and is fixed in the inclined state. It is an optical compensation element as described in said <12> which is a property layer.
<14> The production including the optically anisotropic layer according to any one of <8> to <10>, wherein the polymerizable composition containing a polymerizable liquid crystal compound is heated to 130 ° C. or more to remove the solvent. The optical compensation element according to any one of <12> to <13> manufactured by a method.
<15> The optical compensation element according to any one of <12> to <14>, wherein the optical compensation element includes two optically anisotropic layers and is arranged so that the orientation directions thereof are different.
<16> The optical compensation element according to any one of <12> to <15>, wherein two layers having different orientation directions are provided on one surface of the support.
<17> The optical compensation element according to any one of <12> to <15>, wherein two layers having different orientation directions are provided on both surfaces of the support via a support.
<18> A liquid crystal element having at least a pair of electrodes and liquid crystal molecules sealed between the electrodes, an optical compensation element disposed on both sides or one side of the liquid crystal element, and the liquid crystal element and the optical compensation element. The liquid crystal display device is characterized in that the optical compensation element is the optical compensation element according to any one of <12> to <17>.
<19> The liquid crystal display device according to <18>, wherein the liquid crystal element is a twisted nematic type.
<20> A light source, a liquid crystal display device irradiated with illumination light from the light source, and a projection optical system that forms an image of light modulated by the liquid crystal display device on a screen, the liquid crystal display device A liquid crystal projector according to any one of <18> to <19>.

The polymerizable composition of the present invention contains a polymerizable liquid crystal compound, uses an amide compound as a solvent for the polymerizable liquid crystal compound, further contains at least one of an ether compound and a cellosolve compound in the solvent, and contains the solvent. The polymerizable composition contains 1 to 50% by mass of the total solvent.
As a result, the thickness of the optically anisotropic layer can be made uniform, the optical characteristics of the optically anisotropic layer can be set to desired characteristics with high accuracy, and light leakage can be prevented in a wide viewing angle. It becomes.

  The optically anisotropic layer of the present invention contains the polymerizable composition of the present invention. As a result, an optically anisotropic layer having a uniform thickness can be manufactured, and the optical characteristics of the optically anisotropic layer can be adjusted to desired characteristics with high accuracy, and light leakage can be prevented in a wide viewing angle. It becomes.

  The liquid crystal display device of the present invention includes at least a pair of electrodes and a liquid crystal element having liquid crystal molecules sealed between the pair of electrodes, an optical compensation element disposed on either one or both sides of the liquid crystal element, A polarizing element disposed opposite to the liquid crystal element and the optical compensation element, and the optical compensation element is the optical compensation element of the present invention. As a result, a liquid crystal display device having a high viewing angle, high contrast, and high image quality can be provided.

  The liquid crystal projector of the present invention includes a light source, a liquid crystal display device irradiated with illumination light from the light source, and a projection optical system that forms an image of light modulated by the liquid crystal display device on a screen, The liquid crystal device is the liquid crystal display device of the present invention. As a result, a liquid crystal projector having a high viewing angle, high contrast, and high image quality can be provided.

  According to the present invention, the above-described conventional problems can be solved, the liquid crystal layer in the black display state is optically compensated with higher accuracy, and light leakage is prevented in a wide viewing angle. By using the method and the optical compensation element comprising the optically anisotropic layer, it is possible to provide a liquid crystal display device and a liquid crystal projector having a high viewing angle, a high contrast, a high image quality and a long life.

(Polymerizable composition)
The polymerizable composition of the present invention contains a polymerizable liquid crystal compound and a solvent having a relatively high boiling point, and contains other components appropriately selected as necessary.

-Polymerizable liquid crystal compound-
The polymerizable liquid crystal compound is not particularly limited as long as it has a functional group capable of being polymerized or cross-linked with respect to a compound that can be aligned to form a liquid crystal state. It is preferable to use a polymerizable liquid crystal compound containing a liquid crystal compound capable of fixing the alignment state, and a polymerization containing a rod-like liquid crystal compound, a discotic liquid crystal compound, a banana-like liquid crystal compound, etc. A liquid crystal compound is more preferable, and a polymerizable liquid crystal compound containing a discotic liquid crystal compound is particularly preferable. Moreover, the polymerizable liquid crystal compound containing the liquid crystal compound can contain other components appropriately selected as necessary.

  The polymerizable liquid crystal compound including the rod-like liquid crystal compound is not particularly limited and can be appropriately selected depending on the purpose. For example, the alignment state of the rod-like liquid crystal compound can be fixed using a polymer binder. Examples thereof include polymerizable liquid crystal compounds and polymerizable liquid crystal compounds having a polymerizable group that can fix the alignment state of the liquid crystal compound by polymerization. Among these, preferred are the polymerizable liquid crystal compounds having a polymerizable group.

  The rod-like liquid crystal compound (rod-like liquid crystal molecule) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoate esters , Cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, alkenylcyclohexylbenzonitriles and the like.

  Examples of the polymerizable liquid crystal compound containing the rod-like liquid crystal compound include a polymer liquid crystal compound obtained by polymerizing a rod-like liquid crystal compound having a low-molecular polymerizable group represented by the following structural formula (1).

However, in the structural formula (1), Q ¹ and Q ² each represent a polymerizable group, and L ¹ , L ² , L ³ and L ⁴ each represent a single bond or a divalent linking group, At least one of L ² and L ³ represents —O—CO—O—. A ¹ and A ² each independently represent a spacer group having 2 to 20 carbon atoms. M represents a mesogenic group.

  The polymerizable liquid crystal compound including the discotic liquid crystalline compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the alignment state of the discotic liquid crystalline compound is fixed using a polymer binder. Polymerizable liquid crystal compounds, and polymerizable liquid crystal compounds having a polymerizable group capable of fixing the alignment state of the discotic liquid crystalline compound by polymerization, and the like. Among these, the polymerizable compounds having a polymerizable group are mentioned. A liquid crystal compound is preferable.

  Examples of the polymerizable liquid crystal compound having a polymerizable group include a structure in which a linking group is introduced between a discotic core and a polymerizable group. Specific examples of the polymerizable liquid crystal compound include compounds represented by the following structural formula (2).

In the structural formula (2), D represents a discotic core, L represents a divalent linking group, and P represents a polymerizable group. Moreover, n is an integer of 4-12. Further, the combination of a plurality of divalent linking groups L and the polymerizable group P may be a combination of different divalent linking groups and a polymerizable group, but the same combination is preferable. As the disk-shaped core D, two or more kinds can be used in combination.

  In the structural formula (2), specific examples of the disk-shaped core D include disk-shaped cores represented by the following structural formulas (D1) to (D15).

  In the structural formula (2), the divalent linking group L is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an alkylene group, an alkenylene group, an arylene group, —CO—, —NH -, -O-, -S-, combinations thereof and the like are preferable, alkylene group, alkenylene group, arylene group, -CO-, -NH-, -O-, -S-, and a divalent group selected from these More preferred is a divalent linking group in which at least two of the above groups are combined, and an alkylene group, alkenylene group, arylene group, -CO-, -O-, or at least two divalent groups selected from these are combined. A divalent linking group is particularly preferred.

  The number of carbon atoms of the alkylene group is preferably 1-12. The number of carbon atoms of the alkenylene group is preferably 2-12. The number of carbon atoms in the arylene group is preferably 6-10. The alkylene group, the alkenylene group, and the arylene group may have a substituent such as an alkyl group, a halogen atom, a cyano, an alkoxy group, or an acyloxy group.

Examples of the divalent linking group L include -AL-CO-O-AL-, -AL-CO-O-AL-O-, -AL-CO-O-AL-O-AL-, and -AL. -CO-O-AL-O-CO-, -CO-AR-O-AL-, -CO-AR-O-AL-O-, -CO-AR-O-AL-O-CO-, -CO -NH-AL-, -NH-AL-O-, -NH-AL-O-CO-, -O-AL-, -O-AL-O-, -O-AL-O-CO-, -O -AL-O-CO-NH-AL-, -O-AL-S-AL-, -O-CO-AL-AR-O-AL-O-CO-, -O-CO-AR-O-AL -CO-, -O-CO-AR-O-AL-O-CO-, -O-CO-AR-O-AL-O-AL-O-CO-, -O-CO-AR-O-AL -O-AL-O-AL-OC -, - S-AL -, - S-AL-O -, - S-AL-O-CO -, - S-AL-S-AL -, - S-AR-AL-, and the like.
However, in the specific example of the divalent linking group L, the left side is bonded to the discotic core D, and the right side is bonded to the polymerizable group P. AL represents an alkylene group or an alkenylene group, and AR represents an arylene group.

  In the structural formula (2), the polymerizable group P is not particularly limited and may be appropriately selected depending on the kind of the polymerization reaction, and is preferably an unsaturated polymerizable group or an epoxy group, and is ethylenically unsaturated. A polymerizable group is more preferable. Specific examples of the polymerizable group P include polymerizable groups represented by the following structural formulas (P1) to (P18).

However, in the polymerizable groups represented by the structural formulas (P1) to (P18), n represents an integer of 4 to 12, and is a value determined by the type of the discotic core D.
As for these polymerizable liquid crystal compounds, for example, JP-A-9-104656, JP-A-11-92220, JP-A 2000-34251, JP-A 2000-44507, JP-A 2000-44517. JP-A 2000-86589 can be exemplified.

-Other ingredients-
The other components contained in the polymerizable liquid crystal compound are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a polymerization initiator that initiates a polymerization reaction of the polymerizable liquid crystal compound. .

The polymerization initiator is not particularly limited and may be appropriately selected depending on the purpose.For example, a thermal polymerization initiator that initiates a thermal polymerization reaction, a photopolymerization initiator that initiates a photopolymerization reaction, and the like. Among these, the said photoinitiator is mentioned suitably.
Specific examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. No. 2,367,661 and US Pat. No. 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α- Hydrocarbon-substituted aromatic acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. No. 3,046,127, US Pat. No. 2,951,758), triarylimidazole dimers and p-aminophenyl ketone (Described in US Pat. No. 3,549,367), acridine and phenazine compounds (JP-A-60-105667, US Pat. No. 4,239,850), oxadiazole compounds (US Pat. No. 4,221,970) Etc.).
There is no restriction | limiting in particular as content in the said polymeric liquid crystal compound of the said photoinitiator, According to the objective, it can select suitably, 0.01-20 of solid content in the coating liquid of the said polymeric liquid crystal compound % By mass is preferable, and 0.5 to 5% by mass is more preferable.
There is no restriction | limiting in particular as a light irradiation means used for the said photopolymerization reaction, According to the objective, it can select suitably, For example, an ultraviolet-ray is mentioned suitably. The irradiation energy of the light irradiation unit is ^{preferably 20mJ / cm 2 ~50J / cm 2} , and more preferably 100 to 800 mJ / cm ^2. In order to promote the photopolymerization reaction, light irradiation may be performed under heating conditions.

-Solvent-
As the solvent, an amide compound is used, and further includes at least one of an ether compound and a cellosolve compound. The content of the solvent with respect to the polymerizable compound is preferably 1 to 50% by mass, The mass% is more preferable, and 10 to 40% is particularly preferable. When the content is less than 1% by mass, the coatability may be deteriorated and the thickness of the optically anisotropic layer may not be uniformed. When the content exceeds 50% by mass, The solubility may deteriorate and the thickness may not be uniform.
By applying the respective components for forming the optically anisotropic layer on the support by the solvent, the viscosity of the polymerizable composition is adjusted to a desired value in order to obtain a uniform layer. As these solvents, it is preferable to use a compound that dissolves the material of the polymerizable composition satisfactorily and that is quickly removed after the preparation of the polymerizable composition.

<Solvent containing amide compound>
Since the solvent containing the amide compound is a solvent for obtaining a suitable evaporation rate when the polymerizable composition solution is applied, the boiling point is preferably high enough not to cause deterioration of other materials. . Specifically, 100 ° C. or higher is particularly preferable.
The solvent containing the amide compound having a boiling point of 100 ° C. or higher is not particularly limited and may be appropriately selected depending on the intended purpose. For example, formamide, N-methylformamide, N, N-dimethylformamide, N, N— Examples include diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N, methylpropionamide and the like. Among these, N, N-dimethylformamide and N, N-dimethylacetamide are more preferable.

<Solvent containing ether compound>
Since the solvent containing the ether compound is a solvent for obtaining a suitable evaporation rate when the polymerizable composition solution is applied, its boiling point should be high enough not to cause deterioration of other materials. preferable. Specifically, 100 ° C. or higher is particularly preferable.
The solvent containing an ether compound having a boiling point of 100 ° C. or higher is not particularly limited and may be appropriately selected depending on the intended purpose. Examples include ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether. Among these, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether are more preferable.

<Solvent containing cellosolve compound>
Since the solvent containing the cellosolve compound is a solvent for obtaining a suitable evaporation rate when the polymerizable composition solution is applied, the boiling point of the solvent should be high enough not to cause deterioration of other materials. preferable. Specifically, 100 ° C. or higher is particularly preferable.
The solvent containing the cellosolve compound having a boiling point of 100 ° C. or higher is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include methyl cellosolve, ethyl cellosolve, and butyl cellosolve, and among these, butyl cellosolve Is more preferable.

When the ether-based and cellosolve-based solvents are used in combination, the ratio of use is preferably 1 to 50% by mass, more preferably 5 to 45% by mass, and particularly preferably 10 to 40% by mass with respect to the total amount of solvent.
When the ratio of the cellosolve to ether is less than 1% by mass, the uniformity may be insufficient, and when it exceeds 50% by mass, the solubility of the polymerizable liquid crystal compound and other additives deteriorates. As a result, the filtration and application processes may be hindered.

(Optically anisotropic layer)
The optically anisotropic layer of the present invention contains at least the polymerizable liquid crystal compound, and is formed from a polymerizable composition containing other components as necessary.
In the polymerizable composition, the polymerizable liquid crystal compound is preferably in an aligned state immediately before the polymerization reaction for forming the layer. The alignment state is not particularly limited and can be appropriately selected depending on the purpose. For example, the polymerizable liquid crystal compound is fixed by polymerization or crosslinking, and does not exhibit a liquid crystal state in the optically anisotropic layer. May be.
Here, in the present invention, the alignment state in the present invention is a natural axis due to the molecular shape of the molecules constituting the liquid crystal state, that is, if it is a rod-like molecule such as a rod, the major axis direction, if it is a plate-like molecule, When the natural axis is set in the normal direction of the plate, the average directions of the natural axes of the molecules constituting the liquid crystal state included in the observed minute region are substantially aligned, that is, the molecules constituting the liquid crystal state. Refers to the orientation state.

  Further, in the present invention, when in this orientation state, the average direction of the natural axis of the liquid crystalline compound in the microscopic area of interest and the stacking direction of the optical compensation element (normal line at the interface between the optically anisotropic layer and the support) The angle formed with the direction) is referred to as the orientation angle, and the component obtained by projecting the average direction of the natural axes onto the interface is referred to as the orientation direction.

As the alignment state, the liquid crystal compound has a state in which the alignment angle is inclined, that is, the alignment angle is not uniformly parallel to or perpendicular to the thickness direction of the optical compensation layer. Preferable examples include those having a hybrid alignment in which the orientation angle continuously changes in the thickness direction between the upper surface and the lower surface of the optically anisotropic layer.
The orientation angle in the hybrid orientation is preferably adjusted so as to continuously change in the range of 20 ° ± 20 ° to 65 ° ± 25 ° from the orientation film side to the air interface side.
As the alignment state determined by the alignment angle and the alignment direction of the polymerizable liquid crystal compound, it is preferable that the alignment angle and the alignment method are adjusted so that the liquid crystal layer in a black display state and a mirror surface target.
Here, in the optically anisotropic layer, the orientation angle of the polymerizable liquid crystal compound in the vicinity of the orientation film side, the orientation angle on the air interface side, and the average orientation angle are ellipsometers (M-150, manufactured by JASCO Corporation). Is a value calculated from the refractive index ellipsoid model assuming a refractive index ellipsoid model from the measured retardation.
In addition, as a method of calculating the orientation angle from the retardation, it is also possible to calculate by an approach described in Design Concepts of Discrete Negative Birefringence Compensation Films SID98 DIGEST. The measurement direction of the retardation in calculating the orientation angle is not particularly limited and may be appropriately selected depending on the purpose. For example, the retardation in the normal direction of the optically anisotropic layer (Re0 ), Retardation in the −40 ° direction with respect to the normal direction (Re-40) and retardation in the + 40 ° direction (Re40).
The measurements of Re0, Re-40, and Re40 are values obtained by changing the observation angle in each of the measurement directions using the ellipsometer.

There is no restriction | limiting in particular as another structure with which the said optically anisotropic layer is equipped, According to the objective, it can select suitably, The alignment film for orientating the said polymeric liquid crystal compound is mentioned suitably. It is preferable that the polymerizable liquid crystal compound is laminated on the alignment film by coating or the like.
The alignment film is not particularly limited and may be appropriately selected depending on the intended purpose. For example, an alignment film made of a rubbed organic compound (polymer), an alignment film having a microgroup, a Langmuir-Blodgett method (LB film) alignment film in which organic compounds such as ω-triconic acid, dioctadecyldimethylammonium chloride, methyl stearylate are accumulated, alignment film in which inorganic compounds are obliquely deposited, alignment by electric field, magnetic field or light irradiation Examples thereof include an alignment film having a function, and an alignment film made of the rubbed organic compound is preferable.
There is no restriction | limiting in particular as said rubbing process, According to the objective, it can select suitably, For example, the process which rubs the surface of the film | membrane which consists of the said organic compound several times in a fixed direction with paper or cloth is mentioned.

The type of the organic compound is not particularly limited, and can be determined according to the alignment state (particularly the alignment angle) of the liquid crystalline compound. For example, in order to align the liquid crystalline compound horizontally, Examples thereof include polymers for alignment films that do not lower the surface energy.
As specific examples of the alignment film polymer, when the liquid crystalline compound is aligned in a direction orthogonal to the rubbing treatment direction, modified polyvinyl alcohol (see JP-A-2002-62427), acrylic acid type Preferable examples include copolymers (see JP-A-2002-98836) polyimide, polyamic acid (see JP-A-2002-268068), and the like.

The alignment film preferably has a reactive group for the purpose of improving adhesion to the polymerizable liquid crystal compound and the support. There is no restriction | limiting in particular as said reactive group, According to the objective, it can select suitably, For example, what introduce | transduced the reactive group into the side chain of the repeating unit of the said polymer for alignment films, The said polymer for alignment films In which a substituent of a cyclic group is introduced.
The alignment film that forms a chemical bond with the polymerizable liquid crystal compound and the support by the reactive group is not particularly limited and may be appropriately selected depending on the intended purpose. For example, JP-A-9-152509 It is also possible to use the alignment film described in the publication.
There is no restriction | limiting in particular as thickness of the said alignment film, According to the objective, it can select suitably, It is preferable that it is 0.01-5 micrometers, and it is more preferable that it is 0.05-2 micrometers.

(Method for producing optically anisotropic layer)
The method for producing an optically anisotropic layer of the present invention includes a step of applying the polymerizable composition of the present invention on at least one surface of a support and heating the polymerizable composition to 130 ° C. or higher. And further includes other steps as necessary.

As the support, those similar to the optical compensation element described later can be used.
There is no restriction | limiting in particular as a coating method on the said support body (or alignment film) of the said coating liquid, According to the objective, it can select suitably, For example, extrusion coating method, direct gravure coating method, reverse gravure coating Publicly known methods such as a method, a die coating method, and a spin coating method.

  As the method for producing the optically anisotropic layer, the polymerizable liquid crystal compound is aligned using the alignment film, and then the liquid crystalline molecules are fixed in the aligned state to form the optically anisotropic layer. Then, only the optically anisotropic layer may be transferred onto a support such as a polymer film. According to such a manufacturing method, it is not necessary to consider the influence of birefringence by the alignment film, and the liquid crystal layer in the black display state can be optically compensated with higher accuracy.

(Optical compensation element)
The optical compensation element of the present invention comprises an optically anisotropic layer on at least one surface of a support, the optically anisotropic layer has the optically anisotropic layer of the present invention, and If necessary, it has other layers.

-Support-
The support is not particularly limited as long as it is transparent enough to transmit 50% or more with respect to the wavelength of light to be used, and can be appropriately selected according to the purpose. For example, alkali-free glass, white plate glass, Examples include blue plate glass, quartz glass, sapphire glass, and organic polymer films.
Among these, the glass which consists of said various inorganic material can be used suitably from a viewpoint of the smoothness of a surface.
The organic polymer film is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polyolefins such as polyarylate-based, polyester-based, polycarbonate-based and norbornene-based polymers, polyether-based, and polysulfin. 1 type or 2 types or more selected from polymer groups such as poly (meth) acrylic acid esters such as poly (meth) acrylates such as cellulose, polysulfone, polyethersulfone, cellulose ester such as cellulose acetate and cellulose diacetate, and polymethyl methacrylate Examples include combinations.

  There is no restriction | limiting in particular as thickness of the said support body, According to the objective, it can select suitably, 0.1 micrometer or more is preferable, and the upper limit of thickness is substantially 0.5-1.5 mm.

-Other layers-
The other layer is not particularly limited and may be appropriately selected depending on the purpose. For example, an additional optically anisotropic layer (hereinafter referred to as “structure complex”) having the optical characteristics of a negative uniaxial refractive index ellipsoid. Sometimes referred to as a “refractive layer”), a protective layer, an antireflection layer, and the like.
The function of the additional optically anisotropic layer (structurally birefringent layer) is added, for example, to eliminate the influence of the incident angle of light and the influence of the liquid crystal at the center of the cell in the TN liquid crystal cell. be able to.

  As the retardation of these additional optically anisotropic layers, the retardation Rth represented by the following formula 1 is preferably 40 to 200 nm, and more preferably 50 to 150 nm.

<Formula 1>
Rth = {(n _x + _ny ) / 2−n _z } × d
However, in Equation 1, _nx , _ny, and _nz are X, Y, and Z axis directions orthogonal to each other in the structural birefringent layer when the normal direction of the support is the Z axis. Refractive index is expressed respectively. D represents the thickness of the optically anisotropic layer.

There is no restriction | limiting in particular as the number of layers in the multilayer film of the said structural birefringent layer, According to the objective, it can select suitably.
The thickness of the structural birefringent layer is preferably one that satisfies the retardation, specifically 20 to 300 μm, more preferably 40 to 200 μm, and 50 to 150 μm. Is particularly preferred.
The support itself may have the function of the additional optically anisotropic layer. When a material such as triacetyl cellulose stretched on the support is used and the function is achieved only by the retardation, the structural birefringent layer may not be provided. On the other hand, when an optically isotropic material such as glass is used for the support, the structural birefringent layer can be suitably used. In this case, the thickness in the case of the optically anisotropic layer other than the structural birefringence may have a function as a protective film or a support, and can be appropriately determined in consideration of these functions.
In addition, a layer in which layers having different refractive indexes as described above are alternately stacked can be given a function as an antireflection layer by appropriately selecting each layer configuration from the viewpoint of optical film thickness. In the case of this antireflection layer, not only an inorganic material but also an organic material or a material obtained by adding an inorganic material to an organic material is used as a material constituting a layer having a different refractive index as long as the optical film thickness design condition is satisfied. be able to.

There is no restriction | limiting in particular as a raw material of the said structural birefringent layer, According to the objective, it can select suitably, For example, various raw materials, such as an organic material and an inorganic material, are mentioned.
As the organic material, for example, a material in which birefringence is generated by stretching a plastic film and orienting molecules is known. In this case, the material used as the support may have a function as a birefringent layer. For example, a film obtained by stretching a film of triacetyl cellulose is well known as a support for an optical compensation film.
Examples of the inorganic material include a plurality of layers in which a plurality of inorganic materials having different refractive indexes are periodically stacked with the normal direction of the support being a stacking direction, and the refractive index in the stacking direction is periodically changed. Preferred examples include a structure having a periodic structure multilayer film in which the period of refractive index change is shorter than the wavelength of light in the visible light region. Among these, it is particularly preferable that the periodic structure multilayer film is composed of two layers of two kinds of inorganic materials.
The structure of the structural birefringent layer is not particularly limited as long as it is formed of an inorganic material and has optical characteristics of a negative uniaxial refractive index ellipsoid, and can be appropriately selected according to the purpose. For example, a periodic structure multilayer film of a plurality of layers in which a plurality of inorganic materials having different refractive indexes are periodically stacked with the normal direction of the support as a stacking direction and the refractive index in the stacking direction periodically changes The structure in which the period of the refractive index change is shorter than the wavelength of light in the visible light region is preferred, and among these, the periodic structure multilayer film is particularly preferably composed of two layers of two kinds of inorganic materials. It is mentioned in.

Such a structural birefringent layer is equivalent to a medium having a uniform refractive index in the stacking direction of the multilayer film, that is, in the normal direction of the support. Due to the occurrence of anisotropy called, it has the optical characteristics of a negative refractive index ellipsoid that is not uniaxially inclined.
The period of the periodic structure multilayer film is not particularly limited as long as it is shorter than the wavelength of light in the visible light region, and can be appropriately selected from the visible light region according to the purpose. The visible light region means a wavelength region of 400 to 700 nm, unless otherwise specified. Therefore, it is preferable that the period of the periodic structure is appropriately selected within a range of 400 to 700 nm.
In addition, as the refractive index in the visible light region of the periodic structure multilayer film, when the multilayer film is composed of a plurality of layers, the difference between the maximum value and the minimum value of the refractive index is preferably 0.5 or more. In the case of consisting of different types of layers, the refractive index difference of each layer is preferably 0.5 or more.
Here, the refractive index is a value measured at a wavelength of 550 nm, unless otherwise specified.
There is no restriction | limiting in particular as the number of layers in the multilayer film of the said structural birefringent layer, According to the objective, it can select suitably.

The material of the periodic structure multilayer film constituting the structural birefringent layer is not particularly limited and can be appropriately selected according to the purpose, and a combination of a plurality of materials appropriately selected from oxide films is preferable. A combination of SiO ₂ layer and TiO ₂ layer is more preferable.
Therefore, the retardation of the structural birefringent layer can be prepared with high accuracy and ease by appropriately selecting the material, film thickness, number of layers, period of refractive index change, and the like of the periodic structure multilayer film. Is possible.

The protective layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include cellulose esters such as cellulose acetate, cellulose acetate butyrate, and cellulose propionate, polycarbonate, polyolefin, polystyrene, polyester, and the like. Is mentioned.
Specific examples of the protective layer include polyolefins such as cellulose triacetate, ZEONEX, ZEONOR (both manufactured by Nippon Zeon Co., Ltd.), and ARTON (manufactured by JSR Co., Ltd.).
Further, non-birefringent optical resin materials described in JP-A-8-110402 and JP-A-11-293116 can also be used.

  The material and structure of the antireflection layer is not particularly limited as long as it reduces the reflectance and increases the transmittance, and can be appropriately selected according to the purpose. A known AR film (Anti Reflection) Coat Film) and a laminate composed of two kinds of inorganic materials having different refractive indexes.

<Structure of optical compensation element>
There is no restriction | limiting in particular as a structure of the said optical compensation element, According to the objective, it can select suitably, For example, the optical compensation element of the 1st-8th structure shown below is mentioned suitably.
In the following structure examples, the first optically anisotropic layer may have a function of the support or may not be necessary from the viewpoint of functional design, and may not necessarily be provided.

(Optical compensation element having the first structure)
FIG. 1 is a cross-sectional view of an optical compensation element according to the first structure.
The optical compensation element according to the first structure includes a first optical anisotropic layer composed of the structural birefringent layer on one surface of the support, and the optical compensation element of the present invention on the other surface. Two second optically anisotropic layers made of an isotropic layer and having different orientation directions are provided. That is, as shown in FIG. 1, the optical compensation element 10 according to the first structure has an alignment film 4A, a second optical anisotropic layer 3A, an alignment film 4B, a first film on one surface of the support 1. The optically anisotropic layer 3B and the antireflection layer 5B are laminated so that the antireflection layer 5B is disposed on the outermost surface, and the first optically anisotropic layer is formed on the other surface of the support 1. 2. The antireflection layer 5A is laminated so that the antireflection layer 5A is disposed on the outermost surface.
The first optically anisotropic layer 2 is a periodic structure laminate of a TiO ₂ layer 2A and a SiO ₂ layer 2B, and each layer has a thickness of about 15 nm. The first optical anisotropic layer 2 can also have an antireflection function by using such a periodic structure laminate.
Moreover, it is preferable that the directions of rubbing treatment of the alignment film 4A and the alignment film 4B differ by 90 °. By providing the alignment film 4A and the alignment film 4B, the alignment directions of the liquid crystalline compounds contained in the polymerizable liquid crystal compounds in the second anisotropic layers 3A and 3B are aligned in directions different by 90 °. Is possible.

(Optical compensation element having the second structure)
FIG. 2 is a cross-sectional view showing an example of an optical compensation element according to the second structure.
The optical compensation element according to the second structure includes the first optical anisotropic layer and the second anisotropic layer in this order on at least one surface of the support.
That is, as shown in FIG. 2, the optical compensation element 20 according to the second structure has the first optical anisotropic layer 22, the alignment film 24, and the second optical difference on one surface of the support 21. The isotropic layer 23 and the antireflection layer 25B are laminated in this order so that the antireflection layer 25B is disposed on the outermost surface, and the antireflection layer 25A is laminated on the other surface of the support 21. is there.
The structure of the first optical anisotropic layer 22 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
In addition, two optical compensation elements 20 according to the second structure can be stacked. In this case, it is preferable that the direction of rubbing treatment of the alignment film in each optical compensation element is different by 90 °.
As shown in the optical compensation element 20 according to the second structure, the mode of disposing each layer on one surface of the support depends on the material constituting each layer and the combination, but generally has good handling, Manufacturing is also easy.

(Optical compensation element of the third structure)
FIG. 3 is a cross-sectional view showing an example of an optical compensation element according to the third structure.
The optical compensation element according to the third structure is formed by providing two second anisotropic layers having different orientation directions on one surface of the support.
That is, as shown in FIG. 3, the optical compensation element 30 according to the third structure has the first optical anisotropic layer 32, the alignment film 34A, and the second optical difference on one surface of the support 31. The isotropic layer 33A, the alignment film 34B, the second optically anisotropic layer 33B, and the antireflection layer 35B are laminated in this order so that the antireflection layer 35B is disposed on the outermost surface. The antireflection layer 35A is laminated on the surface.
The structure of the first optically anisotropic layer 32 can be the same as that of the first optically anisotropic layer 2 in the optical compensation element 10 according to the first structure.
Further, it is preferable that the rubbing treatment directions of the alignment film 34A and the alignment film 34B are different by 90 °. By providing such alignment films 34A and 34B, the alignment direction of the liquid crystal compound contained in the polymerizable liquid crystal compound in the second anisotropic layers 33A and 33B can be aligned in a direction different by 90 °. Become.

(Fourth structure optical compensation element)
FIG. 4 is a cross-sectional view showing an example of an optical compensation element according to the fourth structure.
The optical compensation element according to the fourth structure is provided with two second anisotropic layers having different orientation directions through the support.
That is, as shown in FIG. 4, the optical compensation element 40 according to the fourth structure has the first optical anisotropic layer 42, the alignment film 44A, and the second optical difference on one surface of the support 41. The isotropic layer 43A and the antireflection layer 45B are laminated in this order so that the antireflection layer 45B is disposed on the outermost surface, and the orientation film 44B and the second optical anisotropy are formed on the other surface of the support 41. The layer 43B and the antireflection layer 45A are laminated so as to be arranged in this order.
The structure of the first optical anisotropic layer 42 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
Further, it is preferable that the rubbing treatment directions of the alignment film 44A and the alignment film 44B are different by 90 °. By providing such alignment films 44A and 44B, the alignment direction of the liquid crystalline compound contained in the polymerizable liquid crystal compound in the second anisotropic layers 43A and 43B can be aligned in a direction different by 90 °. It becomes.

(5th structure optical compensation element)
FIG. 5 is a cross-sectional view showing an example of an optical compensation element according to the fifth structure.
The optical compensation element according to the fifth structure includes the first optical anisotropic layer and the second anisotropic layer on at least one surface of the support.
That is, as shown in FIG. 5, the optical compensation element 50 according to the fifth structure has an alignment film 54, a second optical anisotropic layer 53, and a first optical difference on one surface of a support 51. The isotropic layer 52 and the antireflection layer 55B are laminated in this order so that the antireflection layer 55B is disposed on the outermost surface, and the antireflection layer 55A is laminated on the other surface of the support 51. is there.
The structure of the first optical anisotropic layer 52 can be the same as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
It is also possible to use two optical compensation elements 50 according to the fifth structure in a stacked manner. In this case, it is preferable that the direction of rubbing treatment of the alignment film in each optical compensation element is different by 90 °.

(Optical compensation element of sixth structure)
FIG. 6 is a cross-sectional view showing an example of an optical compensation element according to the sixth structure.
The optical compensation element according to the sixth structure includes the two second anisotropic layers having different orientation directions. That is, as shown in FIG. 6, the optical compensation element 60 according to the sixth structure has an alignment film 64A, a second optical anisotropic layer 63A, an alignment film 64B, a first film on one surface of a support 61. The second optically anisotropic layer 63B, the first optically anisotropic layer 62, and the antireflection layer 65B are laminated in this order so that the antireflection layer 65B is disposed on the outermost surface. The antireflection layer 65A is laminated on the surface.
The structure of the first optical anisotropic layer 62 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
In addition, it is preferable that the rubbing treatment directions of the alignment film 64A and the alignment film 64B differ by 90 °. By providing the alignment film 64A and the alignment film 64B, the alignment direction of the liquid crystal compound contained in the polymerizable liquid crystal compound in the second anisotropic layer 63A and the second anisotropic layer 63B is 90. It is possible to align in different directions.

(7th structure optical compensation element)
FIG. 7 is a cross-sectional view showing an example of an optical compensation element according to the seventh structure.
The optical compensation element according to the seventh structure is provided with the two second anisotropic layers having different orientation directions through the support.
That is, as shown in FIG. 7, the optical compensation element 70 according to the seventh structure has an alignment film 74A, a second optical anisotropic layer 73A, and a first optical difference on one surface of a support 71. The isotropic layer 72 and the antireflection layer 75B are laminated in this order so that the antireflection layer 75B is disposed on the outermost surface. The alignment film 74B and the second optical anisotropy are formed on the other surface of the support 71. The layer 73B, the first optical anisotropic layer 72, and the antireflection layer 75A are laminated in this order so that the antireflection layer 75A is disposed on the outermost surface.
The structure of the first optical anisotropic layer 72 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure. Further, it is sufficient that at least one first optical anisotropic layer 72 is provided, and either one of the first optical anisotropic layers 72 can be omitted.
In addition, it is preferable that the rubbing treatment directions of the alignment film 74A and the alignment film 74B differ by 90 °. By providing such alignment films 74A and 74B, it is possible to align the alignment direction of the liquid crystal compound contained in the polymerizable liquid crystal compound in the second anisotropic layers 73A and 73B in directions different by 90 °. It becomes.

(Eighth structure optical compensation element)
FIG. 8 is a cross-sectional view showing an example of an optical compensation element according to the eighth structure.
An optical compensation element according to an eighth structure includes the first optical anisotropic layer on one surface of the support and the second optical anisotropic layer on the other surface. .
That is, as shown in FIG. 8, the optical compensation element 80 according to the eighth structure includes the alignment film 84, the second optical anisotropic layer 83, and the antireflection layer 85B on one surface of the support 81. The antireflection layer 85B is laminated so as to be disposed on the outermost surface in order, and the first optical anisotropic layer 82 and the antireflection layer 85A are arranged on the other surface of the support 81 in this order. 85A is laminated so as to be disposed on the outermost surface.
The structure of the first optical anisotropic layer 82 can be the same structure as that of the first optical anisotropic layer 2 in the optical compensation element 10 according to the first structure.
Further, two optical compensation elements 80 according to the eighth structure can be used in a stacked manner. In this case, it is preferable that the direction of rubbing treatment of the alignment film in each optical compensation element is different by 90 °.

  In the optical compensation element, the optical characteristics of the first optical anisotropic layers 2, 22, 32, 42, 52, 62, 72, and 82 are determined by the periodic structure pitch of the periodic structure laminate made of an inorganic material. Therefore, it is possible to prevent problems of optical non-uniformity such as refractive index variation and haze value decrease in the surface of the polymer film due to residual stress generated when the polymer film is uniaxially stretched to obtain predetermined optical characteristics. It is possible to increase the optical uniformity in the plane of the first optical anisotropic layer. Therefore, the optical compensation element can optically compensate the liquid crystal layer in the black display state with higher accuracy.

In addition, the first optically anisotropic layer 2, 22, 32, 42, 52, 62, 72, 82 can control the in-plane thickness within a range of several tens of nm, and can realize high smoothness. It is possible to increase the optical uniformity in the plane of the first optical anisotropic layer. Therefore, the liquid crystal layer in the black display state can be optically compensated with higher accuracy to reduce light leakage and prevent streaky irregularity from becoming apparent.
Further, the first optically anisotropic layer 2, 22, 32, 42, 52, 62, 72, 82 does not expand or contract even when used for a long time in a high temperature / high humidity environment.
As a whole, the optical compensation element as a whole can minimize the change in optical characteristics over a long period of time, and the durability is remarkably improved.

  In particular, in the optical compensation elements having the first to third structures, the first optical anisotropy capable of in-plane thickness control in the range of several tens of nanometers on the supports 1, 21, and 31. Layers 2, 22, and 32 are provided. For this reason, the first optically anisotropic layers 2, 22, and 32 can prevent in-plane thickness unevenness with high accuracy, and the first optically anisotropic layer having a highly smooth surface can be used. Can be obtained. Since the second optical anisotropic layer 3, 23, 33 is laminated on the first optical anisotropic layer 2, 22, 32 having such a smooth surface, the second optical anisotropic layer is laminated. It becomes possible to prevent orientation defects in the plane of the isotropic layers 3, 23, 33. For this reason, it is possible to realize an optical compensation element that optically compensates the liquid crystal layer in the black display state with higher accuracy and prevents light leakage at a wide viewing angle. By using the optical compensation element in a projector or the like, a liquid crystal display device and a liquid crystal projector with high image quality and high contrast can be realized.

(Liquid crystal display device)
The liquid crystal display device of the present invention includes at least a pair of electrodes and a liquid crystal element having liquid crystal molecules sealed between the pair of electrodes, an optical compensation element disposed on either one or both sides of the liquid crystal element, A polarizing element disposed opposite to the liquid crystal element and the optical compensation element, and further includes other configurations as necessary, and the optical compensation element of the present invention is used as the optical compensation element.
The display mode of the liquid crystal element is not particularly limited and may be appropriately selected according to the purpose. For example, a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In-Plane Switching) mode, An OCB (Optically Compensatory Bend) mode, an ECB (Electrically Controlled Birefringence) mode, and the like can be given. Among these, the TN mode is preferable because of its high optical compensation effect.

<Method of manufacturing optical compensation element>
There is no restriction | limiting in particular as a manufacturing method of the said optical compensation element, According to the objective, it can select suitably, For example, the 1st optical anisotropic layer formation process, the alignment film formation process, 2nd optical Examples include a manufacturing method including an anisotropic layer forming step, a heat treatment step, a second optically anisotropic layer polymerization and curing step, an antireflection layer forming step, and other layer forming steps.

Hereinafter, each forming process will be described.
-First optical anisotropic layer forming step-
The first optically anisotropic layer forming step is not particularly limited as long as it satisfies the optical characteristics, and can be appropriately selected according to the purpose. For example, the first optically anisotropic layer forming step may be performed on the support. A step of stacking a plurality of layers having different refractive indexes in a regular order with a normal direction as a stacking direction, and forming a periodic structure stacked body having a repeating structure (repeating repeating units); Preferably mentioned.
The material of the periodic structure laminate is not particularly limited as long as it is an inorganic material, and can be appropriately selected according to the purpose. It is preferable to use a combination of a material having a high refractive index or a material having a low refractive index.
The high refractive index material is preferably TiO ₂ , ZrO ₂ or the like, and the low refractive index material is preferably SiO ₂ or MgF ₂ . These may be used alone or in combination of two or more.
Specifically, it is preferably selected from a combination of materials in which the difference in refractive index between the maximum value and the minimum value of the refractive index in the visible light region is 0.5 or more, and a plurality of materials appropriately selected from oxides more preferably a combination of, SiO ₂ combinations (refractive index n = from 1.4870 to 1.5442) and TiO ₂ (refractive index n = from 2.583 to 2.741) is particularly preferred.
The number of layers constituting the repetitive structure is not particularly limited as long as it is a plurality of layers having different refractive indexes, but is preferably formed of two or more layers of two kinds of inorganic materials. More preferably, SiO ₂ and TiO ₂ are alternately deposited on the support using a sputtering apparatus under reduced pressure to form a periodic structure laminate composed of several tens of layers.
The optical thickness of the repeating unit, that is, the thickness in the stacking direction of the repeating structure in the periodic structure laminate is preferably formed to be thinner than the wavelength of light in the visible light region, for example, light in the visible light region. Λ / 100 to λ / 5 is preferable, λ / 50 to λ / 5 is more preferable, and λ / 30 to λ / 10 is particularly preferable. Each layer is preferably thin, but the number of laminations increases to obtain the required total thickness. Therefore, when determining the number of laminations of each layer, desired optical characteristics and layers of the first optical anisotropic layer In consideration of coloring problems due to mutual interference, it is preferable that the thickness of each layer be optimized from the material, refractive index, thickness ratio, total thickness, etc. of each layer. For example, it is preferable to select and form within a range of 400 to 700 nm.
There is no restriction | limiting in particular as thickness of the said 1st optically anisotropic layer, According to the objective, it can select suitably, For example, it is preferable to form so that it may become 100-1500 micrometers.

-Alignment film formation process-
The first alignment film forming step is a step of forming a film having a function of determining an alignment direction of the liquid crystalline compound in the second optical anisotropic layer on the first optical anisotropic layer. .
The material for the alignment film is not particularly limited and may be appropriately selected depending on the intended purpose. Alignment film in which organic compounds such as ω-triconic acid, dioctadecyldimethylammonium chloride, methyl stearylate are accumulated by jet method (LB film), alignment film in which inorganic compounds are obliquely deposited, electric field, magnetic field, light irradiation, etc. An alignment film that generates an alignment function by the above-described method is preferable, and an alignment film made of the rubbed organic compound is preferable.
There is no restriction | limiting in particular as said rubbing process, According to the objective, it can select suitably, For example, the process which rubs the surface of the film | membrane which consists of the said organic compound several times in a fixed direction with paper or cloth is mentioned.

The type of the organic compound is not particularly limited, and can be determined according to the alignment state (particularly the alignment angle) of the liquid crystalline compound. For example, in order to align the liquid crystalline compound horizontally, Examples thereof include polymers for alignment films that have an effect of not reducing the surface energy.
Specific examples of the alignment film polymer include modified polyvinyl alcohol, acrylic acid copolymer, polyimide, and polyamic acid when the liquid crystalline compound is aligned in a direction orthogonal to the rubbing treatment direction. A polyimide having excellent orientation is more preferable.
There is no restriction | limiting in particular as thickness of the said alignment film, According to the objective, it can select suitably, 0.01-5 micrometers is preferable and 0.02-2 micrometers is more preferable.

-Second optical anisotropic layer forming step-
The second optically anisotropic layer forming step is a step of forming an optically anisotropic layer using at least a polymerizable composition on the alignment film.
The viscosity of the polymerizable composition is preferably 2 to 30 cP, more preferably 3 to 25 cP at 20 ° C. from the viewpoint of handling such as coating. The preferred range varies slightly depending on how the polymerizable composition is handled. In the case where a large shear force is applied as in the spin coating method, it is preferable to set it slightly higher because it can be hardly affected by the shear force.
Examples of the apparatus for applying the solution include a blade coater, a rod coater, a knife coater, a roll doctor coater, a reverse roll coater, a transfer roll coater, a gravure coater, a kiss roll coater, a curtain coater, and an extrusion coater. Among these, a spin coater, a slit coater, and a blade coater are preferable, and a spin coater is particularly preferable. Since the coating liquid using the solvent of the present invention is relatively stable against shearing force, it can be preferably used for such a coating method.
The polymerizable liquid crystal compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is preferable to use a polymerizable liquid crystal compound containing a liquid crystal compound in which the alignment state can be fixed. A polymerizable liquid crystal compound containing a liquid crystal compound such as a liquid crystal compound, a discotic liquid crystal compound, or a banana liquid crystal compound is more preferred, and a polymerizable liquid crystal compound containing a discotic liquid crystal compound is particularly preferred.
Further, the polymerizable liquid crystal compound can contain other components appropriately selected as necessary.
Examples of other components include a polymerization initiator for initiating a polymerization reaction of the polymerizable liquid crystal compound, a solvent for preparing a coating liquid for the polymerizable liquid crystal compound, and the like.

-Heat treatment process-
The heat treatment step is a step of heating the second optically anisotropic layer to make the orientation uniform, aging, and maintaining it.
The coating layer is heated at 60 to 120 ° C. to volatilize and dry the solvent. After drying the solvent, the curing temperature is sufficiently controlled by controlling the heating temperature in the range of 85 to 180 ° C. or until the liquid crystal shows the ND layer in order to mature the alignment of the polymerizable liquid crystal compound including the liquid crystal compound. The polymerizable liquid crystal compound is polymerized by irradiating an energy amount of ultraviolet rays to fix the orientation of the polymerizable liquid crystal compound containing the liquid crystal compound, thereby obtaining an optically anisotropic layer.

-Second optical anisotropic layer polymerization curing step-
The second optical anisotropic layer polymerization curing step is a step of polymerizing and curing the second optical anisotropic layer while maintaining the transition temperature.
The polymerization and curing step of the second optically anisotropic layer with matured orientation is not particularly limited as long as the orientation of the liquid crystal layer can be fixed, and can be appropriately selected according to the purpose. For example, what performs a hardening reaction by irradiating the active ray for photopolymerization is mentioned. As an actinic ray for photopolymerization, an electron beam, an ultraviolet ray, a visible ray, an infrared ray (heat ray) or the like can be appropriately selected and used as necessary, and an ultraviolet ray is generally preferable. Examples of ultraviolet light sources include low-pressure mercury lamps (sterilization lamps, fluorescent chemical lamps, black lights), high-pressure discharge lamps (high-pressure mercury lamps, metal halide lamps), and short arc discharge lamps (extra-high pressure mercury lamps, xenon lamps, mercury xenon). Lamp).
Examples of radical polymerization initiators for the polymerization reaction of ethylenically unsaturated groups include azobis compounds, peroxides, hydroperoxides, redox catalysts, such as potassium persulfate, ammonium persulfate, tert-butyl peroctoate, and benzoyl. Peroxide, isopropyl percarbonate, 2,4-dichlorobenzoyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, dicumyl peroxide, azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) Hydrochloride or benzophenones, acetophenones, benzoins, thioxanthones and the like can be mentioned. Details thereof are described in “Ultraviolet Curing System” General Technical Center, pages 63 to 147, 1989, and the like.

For the polymerization of a compound having an epoxy group, for example, an allyldiazonium salt (hexafluorophosphate, tetrafluoroborate, etc.), a diallyl iodonium salt, a group VIa allylonium salt (PF ₆ , AsF) can be used as an ultraviolet-activated cation catalyst. _6, allyl sulfonium salts having an anion such as SbF _6, etc.) are generally used.
In addition, when performing a curing reaction using a radical reaction, in order to avoid a delay in the polymerization reaction due to the presence of oxygen in the air, irradiation with the active ray in a nitrogen atmosphere shortens the reaction time and reduces the amount of light. It is preferable at the point which can be hardened by.

-Antireflection layer formation process-
The antireflection layer forming step is a step of forming an antireflection layer on the cured second optically anisotropic layer. For example, in the case of forming with an inorganic material, a method of forming on the second optically anisotropic layer by a vapor deposition method or in the case of an organic material by a coating method can be mentioned.
The vapor deposition method is not particularly limited and may be appropriately selected depending on the purpose. For example, the CVD or evaporation in which a sample is placed in a gas raw material atmosphere and a layer is formed on the sample surface by a chemical reaction. And PVD formed by attaching a raw material in the form of particles to a sample by sputtering.
Among these, PVD physically produced by sputtering using a sputtering target and a sputtering target formed of a metal that is a material of the antireflection layer is more preferable.
The coating method is not particularly limited and can be appropriately selected depending on the purpose. For example, the coating method can be formed by a coating method such as a wire bar coating method, a gravure coating method, a micro gravure method, or a die coating method. . The micro gravure method and the gravure method are preferable from the viewpoint of eliminating drying unevenness by minimizing the wet coating amount, and the forward gravure from the viewpoint of the uniformity of the thickness in the width direction and the uniformity of the thickness in the longitudinal direction over the time of application. The method is more preferred.

-Other layer formation process-
The other layer forming steps include the first optical anisotropic layer forming step, the alignment film forming step, the second optical anisotropic layer forming step, the heat treatment step, and the second optical anisotropic layer polymerization curing. Each process up to the process is repeated at least once in this order to form a second optical anisotropy that forms a second optical anisotropic layer having a different orientation direction from the previously formed second optical anisotropic layer. A layer formation process is mentioned.
Before or after the antireflection layer forming step, other layers can be appropriately selected, and examples thereof include a forming step of a protective layer, an antiglare layer, an antifouling layer, an antistatic layer, and the like.

--Protective layer formation process--
The protective layer forming step is a step of forming a protective layer, and is not particularly limited and can be appropriately selected depending on the purpose. For example, the second optically anisotropic layer polymerization and curing step allows the second After the optically anisotropic layer is polymerized and cured and the orientation of the liquid crystal layer is fixed, a step of laminating on the second optically anisotropic layer is preferable. The protective layer is a layer that improves the durability by blocking the second optical anisotropic layer made of an organic material from an oxidation reaction, and is preferably laminated on the second optical anisotropic layer. is there.

The method for laminating the protective layer is not particularly limited and may be appropriately selected according to the purpose. In the case of an organic material, a protective layer forming solution is prepared and the second optically anisotropic layer is formed The method of laminating by applying to is preferred.
The application method is not particularly limited, and examples thereof include an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a die coating method, and a spin coating method.
In the case of an inorganic material, the vapor deposition method which laminate | stacks by vapor-depositing material is mentioned suitably.
The vapor deposition method is not particularly limited and may be appropriately selected depending on the purpose. For example, a chemical vapor deposition method in which a sample is placed in an atmosphere of a gas source and a thin film is formed on the sample surface by a chemical reaction. (CVD: Chemical Vapor Deposition) or physical vapor deposition (PVD: Physical Vapor Deposition), in which a raw material in the form of particles is attached to a sample by evaporation or sputtering.
Among these, PVD that is physically manufactured by sputtering using a sputtering target formed of a metal that is a material of the protective layer under reduced pressure is more preferable.

(Liquid crystal display device)
The liquid crystal display device of the present invention includes at least a pair of electrodes and a liquid crystal element having liquid crystal molecules sealed between the electrodes, an optically anisotropic layer disposed on both sides or one side of the liquid crystal element, the liquid crystal element, A polarizing element disposed opposite to the optically anisotropic layer, and further provided with other components as necessary, and using the optically anisotropic layer of the present invention as the optically anisotropic layer. .

  The display mode of the liquid crystal element is not particularly limited and may be appropriately selected according to the purpose. For example, a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, an IPS (In-Plane Switching) mode, An OCB (Optically Compensatory Bend) mode, an ECB (Electrically Controlled Birefringence) mode, and the like can be given. Among these, the TN mode is preferable because of its high optical compensation effect.

9 to 12 are schematic configuration diagrams of the liquid crystal display device of the present invention.
In order to facilitate understanding in these drawings, the schematic configuration of the liquid crystal display device shown in each drawing shows a mode in which light from a light source is incident from the lower side of the drawings and is emitted toward the upper side of the drawings. As for those including two components of the second optically anisotropic layer, the upper direction of the drawing is expressed as “upper side” and the lower direction of the drawing is expressed as “lower side”. .
As shown in FIG. 9, the liquid crystal display device 100 includes a pair of an upper polarizing element 101 (analyzer) and a lower polarizing element 116 (polarizer) in which absorption axes 102 and 115 are substantially orthogonal and opposed to each other in crossed Nicols , An optical compensation element 108 disposed between the upper and lower polarizing elements 101 and 116, and a liquid crystal element 114 (liquid crystal cell).
In place of the upper and lower polarizing elements 101 and 116, a polarizing beam splitter such as a Glan-Thompson prism may be used as a polarizing element so as to be opposed to the liquid crystal element 114.

  In the liquid crystal element 114, an upper substrate 109 made of a glass substrate and a lower substrate 113 are arranged to face each other, and for example, a nematic liquid crystal 111 is sealed between the upper substrate 109 and the lower substrate 113. On the opposing surfaces of the upper substrate 109 and the lower substrate 113, pixel electrodes (not shown), circuit elements (thin film transistors), and the like are formed. Upper and lower alignment films (not shown) are formed on opposing surfaces of the upper substrate 109 and the lower substrate 113 that are in contact with the nematic liquid crystal 111. A rubbing process is performed on the surface of the alignment film in contact with the nematic liquid crystal 111 in order to align the alignment direction of the liquid crystal molecules. For example, in the case of a TN mode liquid crystal display device, the rubbing directions 110 and 112 in the upper and lower alignment films are substantially orthogonal to each other as the direction of the groove (rubbing direction) carved by the rubbing treatment.

  FIG. 10 shows an alignment state of liquid crystal molecules in a normal state where no voltage is applied to the liquid crystal element 114. The nematic liquid crystals 111 on the upper substrate 109 and the lower substrate 113 are arranged in substantially the same direction as the rubbing directions 110 and 112 by the action of the rubbing treatment applied to the alignment film (not shown). Since the rubbing directions 110 and 112 are orthogonal to each other, the molecules of the nematic liquid crystal 111 are in a state where the major axis of the liquid crystal molecules is twisted by 90 ° as it goes from the upper substrate 109 to the lower substrate 113. Arranged.

The polarizing element preferably has a light transmittance of 0.001% or less when the polarizing element is arranged in a crossed Nicol state, where the light transmittance when the polarizing element is arranged in parallel Nicols is 100%. .
The upper polarizing element 101 (analyzer) and the lower polarizing element 116 (polarizer) have at least a polarizing film, and further have other configurations as necessary.

The polarizing film is not particularly limited and may be appropriately selected depending on the purpose. For example, the polarizing film may be selected from hydrophilic polymers such as polyvinyl alcohol, partially formalized polyvinyl alcohol, and partially saponified ethylene / vinyl acetate copolymer. And a film obtained by adsorbing a dichroic substance such as iodine, azo series, anthraquinone series, tetrazine series dichroic dyes, and the like on the resulting film.
The stretching orientation treatment is not particularly limited and may be appropriately selected depending on the purpose. Preferably mentioned. Such a width direction uniaxial stretching type tenter stretching machine has an advantage that foreign matter hardly enters during bonding.
As the stretching orientation treatment, a stretching method described in JP-A No. 2002-131548 can be used.

There is no restriction | limiting in particular as said other structure, According to the objective, it can select suitably, The protective layer, antireflection layer, glare-proofing layer, etc. which are provided in the single side | surface or both surfaces of the said polarizing film are mentioned.
The upper and lower polarizing elements 101 and 116 are structured such that a polarizing plate having the protective layer on at least one surface of the polarizing film and a liquid crystal element 114 as a support are integrated with one surface of the optical compensation element. Suitable examples include those having the polarizing film.
The protective layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include cellulose esters such as cellulose acetate, cellulose acetate butyrate, and cellulose propionate, polycarbonate, polyolefin, polystyrene, polyester, and the like. Is mentioned. Specific examples include polyolefins such as cellulose triacetate, ZEONEX, ZEONOR (both manufactured by Nippon Zeon Co., Ltd.), and ARTON (manufactured by JSR Co., Ltd.). Further, non-birefringent optical resin materials described in JP-A-8-110402 and JP-A-11-293116 can also be used.

The method for producing the polarizing plate is not particularly limited and may be appropriately selected according to the purpose. The polarizing plate is continuously formed so that the longitudinal direction thereof coincides with the long polarizing film supplied in a roll form. It is preferable that they are bonded together.
Moreover, it is preferable that the polarizing film and the polarizing plate are fixed to the optical compensation element from the viewpoints of preventing optical axis misalignment and preventing foreign matters such as dust from entering.
There is no restriction | limiting in particular as said antireflection layer, According to the objective, it can select suitably, For example, optical interference layers, such as a coating layer of a fluorine-type polymer, a multilayer metal vapor deposition layer, etc. are mentioned.
Is the optical properties and durability (short-term, long-term storage stability) of the upper and lower polarizing elements 101, 116 equivalent to a commercially available super high contrast product (for example, HLC2-5618 manufactured by Sanlitz Co., Ltd.)? It is preferable to have more performance.

The optical compensation element 108 uses the optical compensation element of the present invention.
As the optical compensation element, when the white display transmittance of the liquid crystal display device 100 in a state incorporated in the liquid crystal display device 100 is Vw and the black display transmittance is Vb, the white display on the front surface of the liquid crystal display device 100 is performed. The ratio between the transmittance Vw and the black display transmittance Vb, that is, the contrast ratio Vw: Vb is preferably 100: 1 or more, more preferably 200: 1 or more, and further preferably 300: 1 or more.
Further, in all azimuth directions inclined by 60 ° from the normal direction on the display surface of the liquid crystal display device 100, the maximum value of the black display transmittance is preferably 10% or less, more preferably 5% or less with respect to Vw. By using such an optical compensation element, it is possible to realize a liquid crystal display device having a wide viewing angle with high contrast and no gradation inversion.
Further, in order to accurately compensate a liquid crystal element having a large residual twist component, the optical compensation element is disposed between a pair of polarizing elements disposed in crossed Nicols, and the normal direction of the optical compensation element is used as a rotation axis. There is no direction in which the liquid crystal display device is extinguished when the optical compensation element is rotated, and the light transmittance is preferably 0.01% or more in all directions.

The optical compensation element 108 is disposed between the upper polarizing element 101 and the liquid crystal element 114, and includes a first optical anisotropic layer 107, an upper second optical anisotropic layer 103, and a lower second optical anisotropic layer. 105.
Each of the optically anisotropic layers constituting the optical compensation element 108 includes a rubbing direction 104 of the alignment film in the upper second optically anisotropic layer 103 and a rubbing direction 110 of the upper alignment film in the upper substrate 109 of the liquid crystal element 114. The rubbing direction 106 of the alignment film in the lower second optical anisotropic layer 105 and the rubbing direction 112 of the lower alignment film in the lower substrate 113 of the liquid crystal element 114 are arranged so that the angle formed by The angle formed by is arranged to be 180 °.
The relationship between the second optically anisotropic layer and the rubbing direction of the alignment film in the substrate of the liquid crystal element may be replaced, and the rubbing direction 106 of the alignment film in the lower second optically anisotropic layer 105; The liquid crystal element 114 is arranged so that the angle formed with the rubbing direction 110 of the upper alignment film on the upper substrate 109 of the liquid crystal element 114 is 180 °, the rubbing direction 104 of the alignment film in the upper second optical anisotropic layer 103, and the liquid crystal element 114. The angle formed by the rubbing direction 112 of the lower alignment film on the lower substrate 113 may be 180 °.
The first optical anisotropic layer 107 is preferably provided so as to be on the liquid crystal element 114 side.

  FIG. 11 shows an arrangement state of liquid crystal molecules in a black display state, that is, in a state where a voltage is applied to the liquid crystal element 114, in the TN mode liquid crystal display device. When a voltage is applied to the liquid crystal element 114, the alignment state of the liquid crystal molecules changes so that the liquid crystal molecules rise, that is, the major axis of the liquid crystal molecules is perpendicular to the light incident surface. Ideally, it is desirable that all the liquid crystal molecules in the liquid crystal element 114 when a voltage is applied are parallel to the light incident surface, but actually, as shown in FIG. The liquid crystal molecules in the liquid crystal element 114 are gradually in a state where the major axis of the liquid crystal molecules rises from the upper substrate 109 and the lower substrate 113 toward the central region of the liquid crystal element 114. Accordingly, the liquid crystal molecules in the vicinity of the interface between the upper substrate 109 and the lower substrate 113 are in a tilted arrangement state in which the major axis of the liquid crystal molecules is not parallel to the light incident surface even when a voltage is applied. Thus, the presence of liquid crystal molecules tilted with respect to the light incident surface may cause light leakage depending on the viewing angle without causing a black display state.

Further, nematic liquid crystal used in a TN mode liquid crystal display device is generally a rod-like liquid crystal and exhibits optically positive uniaxiality. For this reason, even when the liquid crystal molecules exist in the central region of the liquid crystal element 114 and are completely upright, when the liquid crystal display device 100 is viewed from an oblique direction, birefringence is manifested. This may cause light leakage without being displayed.
Therefore, with respect to the alignment state of the liquid crystal in the liquid crystal element 114 near the interface between the upper substrate 109 and the lower substrate 113 in the black display state, the alignment of the liquid crystal molecules included in the second optical anisotropic layers 103 and 105 The state is mirror-symmetrical and optically compensates for the occurrence of birefringence in the interface region on the upper substrate 109 and lower substrate 113 side. The liquid crystal display element 114 in a black display state as a whole is three-dimensionally arranged by being optically compensated by the first optical anisotropic layer 107 having an optical characteristic of a negative refractive index ellipsoid that is not inclined. Thus, it is possible to prevent optical leakage over a wide viewing angle by optically compensating.

Further, the optical compensation element 108 can be provided on the lower surface of the liquid crystal element 114 as shown in FIG. 11, and further, can be provided as 108a and 108b on the upper and lower surfaces of the liquid crystal element 114 as shown in FIG. . Note that in the case of disposing the liquid crystal element on the upper and lower surfaces, either the first optical anisotropic layer 107a or 107b can be omitted, and in the case where the first optical anisotropic layer is provided for each, 107a. , 107b, the total retardation value.
As the optical compensation element 108, the support (not shown) provided in the optical compensation element 108 can be the upper substrate 109 and the lower substrate 113 of the liquid crystal element 114. In this case, the first optical anisotropic layer 107 a or 107 b shown in FIG. 12 is directly formed on the upper substrate 109 and the lower substrate 113.

(LCD projector)
The liquid crystal projector of the present invention is a liquid crystal projector that displays an image by irradiating a liquid crystal display device with illumination light from a light source and forming an image on the screen by a projection optical system using light modulated by the liquid crystal display device. The liquid crystal display device uses the liquid crystal display device of the present invention.
The liquid crystal projector is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a screen projection type front projector and a rear projection television. The liquid crystal display device used for the liquid crystal projector is not particularly limited and may be appropriately selected depending on the intended purpose. Suitable examples include a transmissive liquid crystal display device and a reflective liquid crystal display device.

FIG. 13 is an external view showing an example of a rear type liquid crystal projector.
As shown in FIG. 13, the liquid crystal projector 200 is provided with a diffusion transmission type screen 203 on the front surface of the housing 202, and an image projected on the back surface is observed from the front surface side of the screen 203. A projection unit 300 is incorporated in the housing 202, and a projection image projected by the projection unit 300 is reflected by the mirrors 206 and 207 and formed on the back surface of the screen 203. In the liquid crystal projector 200, a tuner circuit (not shown), a well-known circuit unit for reproducing a video signal and an audio signal, and the like are disposed inside the housing 202.
The projection unit 300 incorporates a liquid crystal display device (not shown) as image display means. The liquid crystal display device displays the reproduced image of the video signal, so that the image can be displayed on the screen 203.

FIG. 14 is a configuration diagram illustrating an example of the projection unit 300.
As shown in FIG. 14, the projection unit 300 includes three transmissive liquid crystal elements 311R, 311G, and 311B, and can perform full-color image projection.
Light emitted from the light source 312 passes through a filter 313 that cuts ultraviolet rays and infrared rays to become white light including red light, green light, and blue light, and illumination light from the light source 312 to the liquid crystal elements 311R, G, and B. It enters the glass rod 314 along the axis. The light incident surface of the glass rod 314 is located near the focal position of the parabolic mirror used for the light source 312, and the light from the light source 312 efficiently enters the glass rod 314.

A relay lens 315 is disposed on the exit surface of the glass rod 314, and the white light emitted from the glass rod 314 becomes parallel light by the relay lens 315 and the subsequent collimator lens 316 and enters the mirror 317.
The white light reflected by the mirror 317 is divided into two light beams by a dichroic mirror 318R that transmits only red light, and the transmitted red light is reflected by the mirror 319 to illuminate the liquid crystal element 311R from the back.
Further, the green light and the blue light reflected by the dichroic mirror 318R are further divided into two light beams by the dichroic mirror 318G that reflects only the green light. The green light reflected by the dichroic mirror 318G illuminates the liquid crystal element 311G from the back side. The blue light transmitted through the dichroic mirror 318G is reflected by the mirrors 318B and 320, and illuminates the liquid crystal element 311B from the back.

  Each of the liquid crystal elements 311R, 311G, 311B is composed of a TN mode liquid crystal element, and each liquid crystal element displays a density pattern image of a red image, a green image, and a blue image constituting a full color image. The A synthesis prism 324 is arranged so that the center is optically equidistant from these liquid crystal elements 311R, 311G, and 311B, and a projection lens 325 is provided to face the emission surface of the synthesis prism 324. Yes. The combining prism 324 includes two dichroic surfaces 324a and 324b inside, and combines the red light transmitted through the liquid crystal element 311R, the green light transmitted through the liquid crystal element 311G, and the blue light transmitted through the liquid crystal element 311B. To enter the projection lens 325.

  A projection lens 325 is provided on the projection optical axis from the center of the exit surface of each of the liquid crystal elements 311R, 311G, 311B, through the center of the combining prism 324 and the projection lens 325 to the center of the screen 3. The projection lens 325 is disposed such that the object-side focal plane coincides with the exit surfaces of the liquid crystal elements 311R, 311G, and 311B, and the image-plane focal plane coincides with the screen 3. Therefore, the full color image synthesized by the synthesis prism 324 is formed on the screen 303.

Polarizing plates 326R, 326G, and 326B are provided on the illumination light incident surfaces of the liquid crystal elements 311R, 311G, and 311B, respectively. Further, optical compensation elements 327R, 327G, and 327B and polarizing plates 328R, 328G, and 328B are provided on the emission surface side of each liquid crystal element. The polarizing plates 326R, 326G, and 326B on the incident surface side and the polarizing plates 328R, 328G, and 328B on the outgoing surface side are arranged in a crossed Nicols state. Acts as an analyzer.
The liquid crystal display device of the present invention includes liquid crystal elements 311R, 311G, 311B, polarizing plates 326R, 326G, 326B, 328R, 328G, 328B, and optical compensation elements 327R, 327G, 327B.
In addition, although the liquid crystal element provided for each color channel, the action of the polarizing plate and the optical compensation element respectively provided on both sides thereof are different based on each color light, the basic action is substantially common. Therefore, the operation will be described below using the red channel.

  The red illumination light reflected by the mirror 319 becomes linearly polarized light by the polarizing plate 326R on the incident surface side and enters the liquid crystal element 311R. In the normally white mode, a signal voltage is applied to the pixel of the TN mode liquid crystal used for the liquid crystal element 311R in order to display black of a red image. At this time, the liquid crystal molecules contained in the liquid crystal layer take various orientations, and even if the red illumination light becomes a parallel light flux and enters the liquid crystal element 311R, the liquid crystal layer exhibits optical rotation and birefringence. The light emitted from the emission surface of the liquid crystal element 311R does not become completely linearly polarized light, and generally elliptically polarized image light is emitted, causing light leakage from the analyzer-side polarizing plate 328R, which is sufficient. I can't get black. Even in the normally black mode, the black level does not become sufficiently black due to a slight inclination of the liquid crystal molecules.

In addition, in the state where black display is desired, if the light that passes through the liquid crystal molecules in the liquid crystal element obliquely is included, the image light modulated by the liquid crystal layer has a slightly optical phase different from the linearly polarized light. Becomes different elliptical polarized light, light leaks from the analyzer-side polarizing plate 328R, and sufficient black cannot be obtained.
The liquid crystal projector of the present invention uses the liquid crystal display device of the present invention provided with the optical compensation element of the present invention. Then, the optical compensation element 327R can optically compensate the liquid crystal layer in the black display state with higher accuracy to prevent light leakage in a wide viewing angle.
Therefore, the liquid crystal projector of the present invention can obtain a high viewing angle, high contrast, and high image quality.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
-Fabrication of optical compensation element-
As the optical compensation element, an optical compensation element 60 shown in FIG. 6 was produced. As shown in FIG. 6, the optical compensation element 60 includes a first alignment film 64A, a second optical anisotropic layer 63A, a second alignment film 64B, a first alignment film 64B on the surface side of a glass substrate 61 as a support. An optical compensation element in which an optically anisotropic layer 63B, a first optically anisotropic layer 62, and an antireflection layer 65B are formed in this order, and an antireflection layer 65A is formed on the back side of the glass substrate 61. It is.

<Adjustment of liquid crystal alignment film composition coating solution>
RN1175 (Nissan Chemical Co., Ltd.) powder, N, N-dimethylformamide (DMF) and butyl cellosolve are mixed in a ratio of 4:76:20, and the RN1175 powder is dispersed and dissolved to form a composition solution. (1) is prepared, N, N-dimethylformamide (DMF) and butyl cellosolve are mixed at a ratio of 80:20 to prepare a mixed solution (2), and further mixed with the composition solution (1). The solution (2) was mixed at a ratio of 1: 1 to prepare a liquid crystal alignment film composition coating solution.

<Preparation of polymerizable liquid crystal compound coating solution>
A coating liquid of a polymerizable liquid crystal compound composed of the following composition was prepared.
------------------------------------
-Discotic liquid crystal compound of the following structural formula (3) ... 4.27g
・ Ethylene oxide modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) ・ ・ ・ ・ ・ ・ ・ ・ ・ 0.42g
・ Cellulose acetate butyrate (CAB551-0.2, manufactured by Eastman Chemical Co., Ltd.) ... 0.09g
・ Cellulose acetate butyrate (CAB531-1, Eastman Chemical Co., Ltd.) ... 0.02g
・ Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) ・ ・ ・ ・ 0.14g
・ Sensitizer (Kaya Cure DETX-S, manufactured by Nippon Kayaku Co., Ltd.) 0.05g
・ Solvent Dimethylacetamide ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 9.22 g (95%)
Dipropylene glycol dimethyl ether: 0.49 g (5%)
------------------------------------

-Formation of alignment film-
The liquid crystal alignment film forming coating solution is spin-coated on the glass substrate at 2,000 rpm for 20 seconds. Then, it dried at 220 degreeC for 10 minute (s), and produced the 50-nm-thick orientation film. Next, a rubbing process was performed on the formed alignment film to produce a first alignment film 64A that is aligned in a predetermined alignment direction.

-Formation of second optically anisotropic layer-
On the obtained alignment film 64A, the polymerizable liquid crystal compound coating solution is spin-coated at 2,000 rpm for 20 seconds. Then, it heated at 130 degreeC for 3 minute (s), and the said polymeric liquid crystal compound was orientated. Then, UV irradiation was performed with an irradiation energy of 300 mJ / cm ² using a high-pressure mercury lamp, the polymerizable liquid crystal compound was polymerized, and the alignment state was fixed. Then, after annealing at 220 ° C. for 10 minutes in a clean oven, the product was allowed to cool to room temperature, and the second optically anisotropic layer 63A was produced.
In the formed second optically anisotropic layer 63A, the discotic liquid crystal compound has an angle (orientation angle) between a vertical axis normal to the disc surface and a normal to the glass substrate 61 of 10 °. It increased from the glass substrate 61 side toward the air interface side at 62 °, and the discotic liquid crystal compound was hybrid aligned.
The orientation angle of the discotic liquid crystal compound is measured using an ellipsometer (M-150, manufactured by JASCO Corporation) to measure the retardation while changing the observation angle, and the refractive index ellipsoid model is obtained from the obtained measured values. Was calculated by the method described in “Design Concepts of the Discrete Negative Birefringence Compensation Films SID98 DIGEST”.

A second alignment film 64B was further formed on the surface of the second optically anisotropic layer 63A so that the alignment direction was substantially orthogonal to the first alignment film 64A. At this time, the surface of the second optically anisotropic layer 63A was not attacked by the solvent, coating defects such as cissing did not occur, and coating could be performed satisfactorily. Then, the second optical anisotropic layer 63B is spin-coated on the second alignment film 64B at a spin coating rotational speed of 1,250 rpm for 20 seconds, and further the second optical anisotropy. The layer 63B was annealed in a clean oven at 220 ° C. for 10 minutes to produce an optical compensation element having the same structure as that shown in FIG.
In the obtained second optically anisotropic layer 63B, the discotic liquid crystal compound has an angle (orientation angle) between the vertical axis of the disc surface and the normal line of the glass substrate 61 of 12 ° to 65 °. It increased from the glass substrate 61 side toward the air interface side, and the discotic liquid crystal compound was hybrid aligned. The obtained second optically anisotropic layer 63B was a uniform layer having no defects such as schlieren.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 130 μm and 105 μm, respectively.

-First optical anisotropic layer-
On the surface of the obtained second optically anisotropic layer 63B, SiO ₂ and TiO ₂ were alternately deposited using a sputtering apparatus under reduced pressure, and each layer was 26 layers, totaling 52 layers in total. A first optically anisotropic layer 62 made of a laminate was produced. The total thickness of the formed first optically anisotropic layer 62 was 760 nm and Rth = 200 nm.

―Antireflection layer―
An antireflection layer 65B is formed on the obtained first optically anisotropic layer 62, and the antireflection layer 65A is formed on the glass substrate 61 opposite to the antireflection layer 65B by using a sputtering apparatus under reduced pressure. Then, SiO ₂ and TiO ₂ were alternately deposited. The thicknesses of the formed antireflection layers 65A and 65B were both 0.24 μm.

<Evaluation of uniformity of optically anisotropic layer>
The uniformity of layer formation was determined as a single layer, and the confirmation was made with a laminate provided up to the second optically anisotropic layer by the above-described manufacturing method. However, the rotation speed of the spin coat was adjusted so that the thickness of the optically anisotropic layer was 0.5 to 1 μm and 1.2 to 1.5 μm. The optically anisotropic layer of the obtained laminate was irradiated with a fluorescent lamp from a position 10 cm away from the surface, and the uniformity of the film was evaluated by observing the interference pattern of the anisotropic layer. The results are shown in Table 1. ○ indicates that a uniform interference color is observed radially from the rotation center of the spin coat, and a highly uniform optical anisotropic layer is obtained. × indicates that the interference color is not uniform with respect to the rotation center. This shows that an optically anisotropic layer with uneven film thickness was obtained.

Example 1A
<Production of liquid crystal display device>
The optical compensation element 60 produced in Example 1 was superimposed on a normally white mode TN mode liquid crystal element with white display of 1.5 V and black display of 3 V to produce a liquid crystal display device of Example 1A.

-Evaluation of contrast of liquid crystal display devices-
About the produced liquid crystal display device, the contrast in the place of an elevation angle of 60 degrees and an azimuth angle of 30 degrees from the front of the display surface was measured using a conoscope (manufactured by Atlantic-Melcher). Here, the contrast was measured as white display illuminance, black display illuminance, and contrast (white display illuminance / black display illuminance) calculated from the ratio thereof. The measurement results are shown in Table 1.

(Example 1B)
<Production of liquid crystal projector>
A liquid crystal projector of Example 1B was manufactured by mounting three liquid crystal display devices (Example 1A) for each of RGB colors on a commercially available TN liquid crystal projector.

-Evaluation of contrast of LCD projector-
About the obtained liquid crystal projector (Example 1B), the contrast (white display illuminance / black display illuminance) calculated from the white display illuminance, the black display illuminance on the screen set at a distance of 3 m from the projection lens, and the ratio thereof. ) Was measured.

(Example 2)
In Example 1, the polymerizable composition contained 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether, 8.74 g (90%) of dimethylacetamide, and 0 of dipropylene glycol dimethyl ether. Except for the change to .97 g (10%), the optical compensation element of Example 2, the liquid crystal display device of Example 2A, and the liquid crystal projector of Example 2B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 1.0 μm and 1.5 μm, respectively.

(Example 3)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 7.77 g (80%) of dimethylacetamide, 1 dipropylene glycol dimethyl ether 1 Except for replacing with .94 g (20%), the optical compensation element of Example 3, the liquid crystal display device of Example 3A, and the liquid crystal projector of Example 3B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.5 μm, respectively.

Example 4
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 6.80 g (70%) of dimethylacetamide, dipropylene glycol dimethyl ether 2 Except for replacing with .91 g (30%), the optical compensation element of Example 4, the liquid crystal display device of Example 4A, and the liquid crystal projector of Example 4B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.4 μm, respectively.

(Example 5)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 5.82 g (60%) of dimethylacetamide, dipropylene glycol dimethyl ether 3 Except for replacing with .89 g (40%), the optical compensation element of Example 5, the liquid crystal display device of Example 5A, and the liquid crystal projector of Example 5B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.4 μm, respectively.

(Example 6)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 4.86 g (50%) of dimethylacetamide, 4 of dipropylene glycol dimethyl ether 4 Except that it was replaced with .85 g (50%), the optical compensation element of Example 6, the liquid crystal display device of Example 6A, and the liquid crystal projector of Example 6B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.8 μm and 1.4 μm, respectively.

(Example 7)
In Example 1, 9.22 g (95%) of dimethylacetamide and 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition were converted to 9.22 g (95%) of dimethylformamide and dipropylene glycol dimethyl ether. An optical compensation element of Example 7, a liquid crystal display device of Example 7A, and a liquid crystal projector of Example 7B were produced in the same manner as in Examples 1, 1A, and 1B except that the amount was changed to 0.49 g (5%). ,evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 1.0 μm and 1.5 μm, respectively.

(Example 8)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 8.74 g (90%) of dimethylformamide, 0 of dipropylene glycol dimethyl ether Except that it was replaced with .97 g (10%), the optical compensation element of Example 8, the liquid crystal display device of Example 8A, and the liquid crystal projector of Example 8B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 1.0 μm and 1.5 μm, respectively.

Example 9
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 7.77 g (80%) of dimethylformamide, 1 of dipropylene glycol dimethyl ether 1 Except for replacing with .94 g (20%), the optical compensation element of Example 9, the liquid crystal display device of Example 9A, and the liquid crystal projector of Example 9B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.5 μm, respectively.

(Example 10)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 6.80 g (70%) of dimethylformamide, 2 of dipropylene glycol dimethyl ether 2 Except for replacing with .91 g (30%), the optical compensation element of Example 10, the liquid crystal display device of Example 10A, and the liquid crystal projector of Example 10B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.4 μm, respectively.

(Example 11)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 5.82 g (60%) of dimethylformamide, 3 of dipropylene glycol dimethyl ether 3 The optical compensation element of Example 11, the liquid crystal display device of Example 11A, and the liquid crystal projector of Example 11B were obtained in the same manner as in Examples 1, 1A, and 1B, except that the mixture was changed to .89 g (40%). Prepared and evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.4 μm, respectively.

(Example 12)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 4.86 g (50%) of dimethylformamide, 4 of dipropylene glycol dimethyl ether 4 The optical compensation element of Example 12, the liquid crystal display device of Example 12A, and the liquid crystal projector of Example 12B were obtained in the same manner as in Examples 1, 1A, and 1B except that the liquid mixture was changed to .85 g (50%). Prepared and evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.8 μm and 1.4 μm, respectively.

(Example 13)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 9.22 g (95%) of dimethylacetamide, and 0.49 g of butyl cellosolve ( 5%) except that the mixed solution was used, and the optical compensation element of Example 13, the liquid crystal display device of Example 13A, and the liquid crystal projector of Example 13B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 1.0 μm and 1.5 μm, respectively.

(Example 14)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 8.74 g (90%) of dimethylacetamide, and 0.97 g of butyl cellosolve ( 10%) except that the mixed solution was used, and the optical compensation element of Example 14, the liquid crystal display device of Example 14A, and the liquid crystal projector of Example 14B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 1.0 μm and 1.5 μm, respectively.

(Example 15)
In Example 1, 9.22 g (95%) of dimethylacetamide contained in the polymerizable composition, 0.49 g (5%) of dipropylene glycol dimethyl ether, 7.77 g (80%) of dimethylacetamide, 1.94 g of butyl cellosolve ( 20%) except that the mixed solution was used, and the optical compensation element of Example 15, the liquid crystal display device of Example 15A, and the liquid crystal projector of Example 15B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated. This polymerizable composition had a viscosity at 20 ° C. of 6 cP.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.5 μm, respectively.

(Example 16)
In Example 1, 9.22 g (95%) of dimethylacetamide contained in the polymerizable composition, 0.49 g (5%) of dipropylene glycol dimethyl ether, 6.80 g (70%) of dimethylacetamide, and 2.91 g of butyl cellosolve ( 30%) except that the mixed solution was used, and the optical compensation element of Example 16, the liquid crystal display device of Example 16A, and the liquid crystal projector of Example 16B were produced in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.4 μm, respectively.

(Example 17)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 5.82 g (60%) of dimethylacetamide, and 3.89 g of butyl cellosolve ( 40%) except that the liquid mixture was changed to the optical compensation element of Example 17, the liquid crystal display device of Example 17A, and the liquid crystal projector of Example 17B in the same manner as in Examples 1, 1A, and 1B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.4 μm, respectively.

(Example 18)
In Example 1, 9.22 g (95%) of dimethylacetamide, 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition, 4.86 g (50%) of dimethylacetamide, and 4.85 g of butyl cellosolve ( 50%), except that the liquid mixture was changed to the optical compensation element of Example 18, the liquid crystal display device of Example 18A, and the liquid crystal projector of Example 18B. evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.8 μm and 1.4 μm, respectively.

(Comparative Example 1)
In Example 1, 9.22 g (95%) of dimethylacetamide and 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition were replaced with 15.00 g of 2- (1-methoxypropyl) acetate, Except for spin coating the polymerizable composition solution at 1,600 rpm and 1,100 rpm for 15 seconds, in the same manner as in Examples 1, 1A and 1B, the optical compensation element of Comparative Example 1, the liquid crystal display device of Comparative Example 1A, A liquid crystal projector of Comparative Example 1B was produced and evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 0.8 μm and 1.2 μm, respectively.

(Comparative Example 2)
In Example 1, 9.22 g (95%) of dimethylacetamide and 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition were replaced with 15.00 g of ethyl lactate, and the polymerizable composition solution was changed to 1 The optical compensation element of Comparative Example 2, the liquid crystal display device of Comparative Example 2A, and the liquid crystal projector of Comparative Example 2B were prepared in the same manner as in Examples 1, 1A, and 1B, except that spin coating was performed at 650 rpm and 1,100 rpm for 15 seconds. Prepared and evaluated.
The thicknesses of the obtained optically anisotropic layers 63A and 63B were measured and found to be 1.0 μm and 1.4 μm, respectively.

(Comparative Example 3)
In Example 1, 9.22 g (95%) of dimethylacetamide and 0.49 g (5%) of dipropylene glycol dimethyl ether contained in the polymerizable composition were replaced with 15.00 g of ethyl 3-ethoxypropionate. The optical compensation element of Comparative Example 3, the liquid crystal display device of Comparative Example 3A, and Comparative Example 3 were the same as in Examples 1, 1A, and 1B except that the physical solution was spin-coated at 1,600 rpm and 1,100 rpm for 15 seconds. A liquid crystal projector was manufactured and evaluated.
When the thicknesses of the obtained optically anisotropic layers 63A and 63B were measured, they were 0.9 μm and 1.3 μm, respectively.

From the results shown in Table 1, optically anisotropic layers having high uniformity up to 1.5 μm were obtained in Examples 1 to 18, whereas in Comparative Examples 1 to 3, the thickness was 1.2 μm or more. In some cases, the optically anisotropic layer becomes non-uniform. Moreover, it turns out that all of the liquid crystal display devices of Examples 1A to 18A are excellent in viewing angle dependency and have a high viewing angle. It can also be seen that the liquid crystal projectors of Examples 1B to 18B all have high contrast. In addition, as in Examples 1 to 18, the thickness of the optically anisotropic layer can be adjusted to 1.5 μm while maintaining uniformity, according to the specifications of the liquid crystal cell, and is highly versatile. I understand.

  The polymerizable composition of the present invention, an optically anisotropic layer using the polymerizable composition, an optical compensation element having the optically anisotropic layer, and a liquid crystal display device comprising the optical compensation element are a mobile phone, It can be suitably used for personal computer monitors, televisions, liquid crystal projectors, and the like.

FIG. 1 is a cross-sectional view showing an example of the optical compensation element having the first structure. FIG. 2 is a cross-sectional view showing an example of the optical compensation element having the second structure. FIG. 3 is a cross-sectional view showing an example of the optical compensation element having the third structure. FIG. 4 is a cross-sectional view showing an example of an optical compensation element having a fourth structure. FIG. 5 is a cross-sectional view showing an example of the optical compensation element having the fifth structure. FIG. 6 is a cross-sectional view showing an example of an optical compensation element having a sixth structure. FIG. 7 is a cross-sectional view showing an example of an optical compensation element having a seventh structure. FIG. 8 is a sectional view showing an example of an optical compensation element having an eighth structure. FIG. 9 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 10 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 11 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 12 is a schematic view showing an example of the liquid crystal display device of the present invention. FIG. 13 is an external view showing an example of a rear type liquid crystal projector. FIG. 14 is a configuration diagram illustrating an example of a projection unit.

Explanation of symbols

1, 2, 31, 41, 51, 61, 71, 81... Support 2, 22, 32, 42, 52, 62, 72, 82... First optical anisotropic layer 3, 23, 33, 43, 53, 63, 73, 83 ... Second optical anisotropic layer 4, 24, 34, 44, 54, 64, 74, 84 ... Alignment film 5, 25, 35, 45, 55, 65, 75, 85... Antireflection layer 10, 20, 30, 40, 50, 60, 70, 80... Optical compensation element 100.・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal display device 101 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Upper polarizing plate 102 ・ ・ ・ ・ ・ ・... upper polarizing plate absorption axis 103 ... upper second optically anisotropic layer 104 ... ... Upper second light The rubbing direction during the production of the anisotropic layer 105 ......... The lower second optically anisotropic layer 106 ... ..Rubbing direction at the time of preparation of the lower second optically anisotropic layer 107... The first optically anisotropic layer 108.・ ・ ・ ・ ・ ・ Optical compensation element 109 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal cell upper substrate 110 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Upper substrate liquid crystal alignment Rubbing direction 111 ... nematic liquid crystal (liquid crystal layer)
112 ································································································································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal element 115 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Absorption axis of lower polarizing plate 116・ ・ Lower polarizing plate 200 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Liquid crystal projector 300 ・ ・ ・ ・ ・ ・ Projection unit

Claims (20)

  A polymerizable liquid crystal compound is contained, an amide compound is used as a solvent for the polymerizable liquid crystal compound, and at least one of an ether compound and a cellosolve compound is contained in the solvent in an amount of 1 to 50% by mass with respect to the total solvent. A polymerizable composition characterized by the above.   The polymerizable composition according to claim 1, wherein the amide compound is at least one selected from N, N-dimethylformamide and N, N-dimethylacetamide.   The polymerizable composition according to claim 1, wherein the ether compound is an ether compound having a boiling point of 100 ° C. or higher.   The polymerizable composition according to any one of claims 1 to 3, wherein the ether compound is at least one selected from diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether.   The polymerizable composition according to claim 1, wherein the cellosolve compound is butyl cellosolve.   The polymerizable composition according to any one of claims 1 to 5, wherein the polymerizable liquid crystal compound comprises a discotic liquid crystal compound.   The polymerizable composition according to any one of claims 1 to 5, wherein the polymerizable liquid crystal compound contains a rod-like liquid crystal compound.   An optically anisotropic layer formed using the polymerizable composition according to claim 1.   The alignment angle of the polymerizable liquid crystal compound in the alignment state formed by the polymerizable liquid crystal compound is inclined with respect to the thickness direction of the optically anisotropic layer, and is fixed in the inclined state. Optically anisotropic layer.   The optically anisotropic layer according to any one of claims 8 to 9, wherein the orientation angle of the polymerizable liquid crystal compound is fixed in a hybrid orientation that changes in the thickness direction of the optically anisotropic layer.   It is a manufacturing method of the optically anisotropic layer in any one of Claims 8-10, Comprising: Heating this polymeric composition containing a polymeric liquid crystal compound to 130 degreeC or more and removing a solvent is included. A method for producing an optically anisotropic layer characterized by the following.   The optical anisotropy according to any one of claims 8 to 11, comprising at least one support, and having an optically anisotropic layer on at least one surface of the support. An optical compensation element which is a layer.   The alignment angle of the polymerizable liquid crystal compound in the alignment state formed by the polymerizable liquid crystal compound is inclined with respect to the thickness direction of the optically anisotropic layer, and the optically anisotropic layer is fixed in the inclined state. The optical compensation element according to claim 12.   The optically anisotropic layer according to any one of claims 8 to 10, wherein the optically anisotropic layer is produced by a production method comprising removing a solvent by heating a polymerizable composition containing a polymerizable liquid crystal compound to 130 ° C or higher. Item 14. The optical compensation element according to any one of Items 12 to 13.   The optical compensation element according to claim 12, wherein the optical compensation element has two optically anisotropic layers and is arranged so that the orientation directions thereof are different.   The optical compensation element according to claim 12, wherein two layers having different orientation directions are provided on one surface of the support.   The optical compensation element according to claim 12, wherein two layers having different orientation directions are provided on both surfaces of the support via a support.   A liquid crystal element having at least a pair of electrodes and liquid crystal molecules sealed between the electrodes, an optical compensation element disposed on both sides or one side of the liquid crystal element, and a polarizing element disposed opposite to the liquid crystal element and the optical compensation element A liquid crystal display device, wherein the optical compensation element is the optical compensation element according to claim 12.   The liquid crystal display device according to claim 18, wherein the liquid crystal element is a twisted nematic type. The liquid crystal display device includes: a light source; a liquid crystal display device irradiated with illumination light from the light source; and a projection optical system that forms an image of light modulated by the liquid crystal display device on a screen. 20. A liquid crystal projector according to any one of items 1 to 19.