JP5291323B2 - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device with which an image with a high contrast ratio is displayed in a viewing angle of a wide range, and a color shift (variation of a color tone when seen from oblique directions) is reduced. <P>SOLUTION: The liquid crystal display device has first and second polarizers 11, 12 disposed so as to make their transmission axes vertical to each other, a liquid crystal layer 13 disposed between the first and second polarizers, and a first optically anisotropic layer 14 between the first or second polarizer and the liquid crystal layer, wherein in-plane retardation Re of the first optically anisotropic layer 14 is positive at a wavelength &lambda;1 of the visible ray region and is negative at a wavelength &lambda;2 of the visible ray region (where &lambda;1&ne;&lambda;2), and ¾Rth(550)¾ is 50 nm or more. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a liquid crystal display device having excellent viewing angle characteristics.

Liquid crystal display devices are widely used in monitors for personal computers and portable devices, and for television applications because of their various advantages, such as low voltage and low power consumption, enabling miniaturization and thinning. Various modes have been proposed for such a liquid crystal display device depending on the alignment state of the liquid crystal molecules in the liquid crystal cell. Conventionally, the liquid crystal display device is in an alignment state twisted by about 90 ° from the lower substrate to the upper substrate of the liquid crystal cell. The TN mode was mainstream.
In general, a liquid crystal display device includes a liquid crystal cell, an optical compensation sheet, and a polarizer. The optical compensation sheet is used for eliminating image coloring or expanding the viewing angle, and a stretched birefringent film or a film obtained by applying a liquid crystal to a transparent film is used. For example, Patent Document 1 discloses a technique for applying an optical compensation sheet in which a discotic liquid crystal is applied on a triacetyl cellulose film, aligned, and fixed to a TN mode liquid crystal cell to widen the viewing angle. However, a television-use liquid crystal display device that is expected to be viewed from various angles on a large screen has a strict requirement for viewing angle dependency, and even with the above-described method, the requirement cannot be satisfied. Therefore, liquid crystal display devices different from the TN mode, such as an IPS (In-Plane Switching) mode, an OCB (Optically Compensatory Bend) mode, and a VA (Vertically Aligned) mode, have been studied. In particular, the VA mode is attracting attention as a liquid crystal display device for TV because of its high contrast and relatively high manufacturing yield.

However, in the VA mode, although almost complete black display is possible in the normal direction of the panel, there is a problem that when the panel is observed from an oblique direction, light leakage occurs and the viewing angle becomes narrow. In order to solve this problem, it has been proposed to improve the viewing angle characteristics of the VA mode by using an optically biaxial retardation plate having different refractive indexes in the three-dimensional direction of the film (for example, Patent Document 1).
JP2003-344856

However, the above method only reduces light leakage for a certain wavelength range (for example, green light near 550 nm), and light for other wavelength ranges (for example, blue light near 450 nm, red light near 650 nm). Leakage is not considered. For this reason, for example, when black is displayed and observed from an oblique direction, the so-called color shift problem of coloring blue or red has not been solved.
The present invention has been made in view of such circumstances, and can display an image with a high contrast ratio in a wide range of viewing angles, and a liquid crystal display with reduced color shift (color change when viewed from an oblique direction). The purpose is to provide a device.

Means for solving the above-mentioned problems are as follows.
[1] First and second polarizers arranged with transmission axes orthogonal to each other;
A liquid crystal layer disposed between the first and second polarizers;
A liquid crystal display device having a first optically anisotropic layer between the first or second polarizer and a liquid crystal layer,
The in-plane retardation (Re) of the first optically anisotropic layer becomes positive at a wavelength λ1 in the visible light region, becomes negative at a wavelength λ2 in the visible light region (where λ1 ≠ λ2), and | Rth (550 ) | Is 50 nm or more.
[2] The liquid crystal display device according to [1], wherein the first optically anisotropic layer satisfies the following formulas (1) and (2):
Re (450) × Re (650) <0 Formula (1)
| Rth (550) / Re (550) |> 10 Formula (2)
In the formula, Re (λ) is an in-plane retardation (unit: nm) measured by making light having a wavelength λ nm incident, and Re of the first optical anisotropic layer is positive or negative with respect to the liquid crystal cell. With reference to the absorption axis of the polarizer arranged on the same side, the direction parallel to the absorption axis is positive.
[3] A second optically anisotropic layer is provided between the first or second polarizer and the liquid crystal layer, and the second optically anisotropic layer has the following formulas (3) and (4): The liquid crystal display device according to [1] or [2], wherein:
30 nm <Re (550) <400 nm Formula (3)
−100 nm <Rth (550) <300 nm Formula (4)
In the formula, Re (λ) is an in-plane retardation (unit: nm) measured by making light of wavelength λnm incident; Rth (λ) is measured in the thickness direction measured by making light of wavelength λnm incident Retardation value (unit: nm).
[4] The first optical anisotropic layer is between the liquid crystal layer and the first polarizer, and the second optical anisotropic layer is the liquid crystal layer and the second polarization. The liquid crystal display device according to [3], wherein the liquid crystal display device is disposed between the liquid crystal display device and the child.

[5] The liquid crystal display device according to any one of [1] to [4], which is in a VA mode.
[6] The first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | ≧ 1.0
[5] The liquid crystal display device according to [5], wherein
[7] The first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | <1.0
[5] The liquid crystal display device according to [5], wherein
[8] The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | <1.0
[5] The liquid crystal display device according to [5], wherein
[9] The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550)> 0 and | Rth (450) | / | Rth (650) | ≧ 1.0
[5] The liquid crystal display device according to [5], wherein

[10] The liquid crystal display device according to any one of [1] to [4], which is in a horizontal alignment mode.
[11] The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | ≧ 1.0
[10] The liquid crystal display device according to [10], wherein
[12] The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | <1.0
[10] The liquid crystal display device according to [10], wherein
[13] The first optically anisotropic layer has the following formula: Re (450)> 0,
Re (650) <0,
Rth (550) <0 and | Rth (450) | / | Rth (650) | <1.0
[10] The liquid crystal display device according to [10], wherein
[14] The first optically anisotropic layer has the following formula: Re (450)> 0,
Re (650) <0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | ≧ 1.0
[10] The liquid crystal display device according to [10], wherein

[15] The liquid crystal display device according to any one of [1] to [14], wherein the first optically anisotropic layer is made of a cellulose acylate film.
[16] The liquid crystal display device according to any one of [1] to [15], wherein the first optically anisotropic layer contains at least one Rth enhancer.

  According to the present invention, it is possible to provide a liquid crystal display device capable of displaying an image with a high contrast ratio in a wide range of viewing angles and with reduced color shift (color change when viewed from an oblique direction).

The present invention will be described below. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. Further, substantially orthogonal or parallel means a range of a strict angle ± 10 °.
In the present specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).

When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light is incident at a wavelength of λ nm from the inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction of the rotation axis of KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), Rth can also be calculated from the following formula (21) and formula (22) based on the value, the assumed value of the average refractive index, and the input film thickness value.

Ｒｔｈ＝｛（ｎｘ＋ｎｙ）／２−ｎｚ｝×ｄ −−−式（２２）
式中、上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値をあらわす。
また式中、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘ及びｎｙに直交する方向の屈折率を表し、ｄは膜厚を表す。

Rth = {(nx + ny) / 2−nz} × d −−−- type (22)
In the formula, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In the formula, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction orthogonal to nx in the plane, nz represents the refractive index in the direction orthogonal to nx and ny, d represents a film thickness.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotating axis). In each of the 10 degree steps, light of wavelength λ nm is incident from the inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated.
In the above measurement, the assumed value of the average refractive index may be a value in a polymer handbook (John Wiley & Sons, Inc.) or a catalog of various optical films. Those whose average refractive index is not known can be measured with an Abbe refractometer. Examples of the average refractive index values of main optical films are given below:
Cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59). The KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

In this specification, the values of Re (450), Re (550), Re (650), Rth (450), Rth (550), and Rth (650) were obtained as follows. It is assumed that measurement is performed using three or more different wavelengths (for example, λ = 479.2546.3, 632.8, and 745.3 nm) by a measurement apparatus, and Re and Rth are calculated from the respective wavelengths. These values are approximated by Cauchy's equation (up to the third term, Re = A + B / λ ² + C / λ ⁴ ) to obtain values A, B, and C. From the above, Re and Rth at the wavelength λ are re-plotted, and the Re and Rth values at the wavelengths of 450, 550, and 650 nm are Re (450), Re (550), Re (650), Rth (450), and Rth. (550), Rth (650) can be obtained.

The liquid crystal display device of the present invention includes an in-plane retardation (Re) between a liquid crystal cell, first and second polarizers disposed on both sides of the liquid crystal cell, and the first and second polarizers, respectively. ) Becomes positive at a wavelength λ1 in the visible light region, becomes negative at a wavelength λ2 in the visible light region (where λ1 ≠ λ2), and | Rth (550) | is 50 nm or more. It is characterized by having. An example of the first optically anisotropic layer is an optically anisotropic layer that satisfies the following formulas (1) and (2).
Re (450) × Re (650) <0 Formula (1)
Rth (550) / Re (550)> 10 Formula (2)
In the formula, Re (λ) is an in-plane retardation (unit: nm) measured by making light having a wavelength λ nm incident, and Re of the first optical anisotropic layer is positive or negative with respect to the liquid crystal cell. With reference to the absorption axis of the polarizer arranged on the same side, the direction parallel to the absorption axis is positive.
In the formula, Re (λ) is an in-plane retardation (unit: nm) measured by making light having a wavelength λ nm incident, and Re of the first optical anisotropic layer is positive or negative with respect to the liquid crystal cell. With reference to the absorption axis of the polarizer arranged on the same side, the direction parallel to the absorption axis is positive.
The first optically anisotropic layer alone or in combination with other optically anisotropic layers contributes to improvement of display characteristics of various modes of liquid crystal display devices. The first optically anisotropic layer may be combined with an optically anisotropic layer having at least one optical axis.

The operation of the present invention will be described below with reference to the drawings.
One mode of the liquid crystal display device of the present invention is shown in FIG. The present invention does not depend on the driving method of the liquid crystal display device, and may be effective in any liquid crystal mode. However, as an example, FIG. 1 shows a configuration of a VA mode liquid crystal display device. The liquid crystal display device of FIG. 1 includes a liquid crystal cell 13 and a pair of polarizers 11 and 12 arranged with the liquid crystal cell 13 interposed therebetween. Between the polarizer 11 and the liquid crystal cell 13, the first optical anisotropic layer 14 that satisfies the above formulas (1) and (2), and between the polarizer 12 and the liquid crystal cell 13, A second optically anisotropic layer 15 having at least one optical axis is included. The polarizers 11 and 12 are arranged with their transmission axes orthogonal to each other. The second optically anisotropic layer 15 is preferably arranged with its in-plane slow axis orthogonal to the absorption axis of the polarizer 12.

  The polarizers 11 and 12 may be on the backlight side or on the display surface side. Moreover, the 1st optically anisotropic layer 14 and the 2nd optically anisotropic layer 15 may be arrange | positioned in contact with each surface as a protective film of the polarizers 11 and 12, respectively. Further, a protective film may be separately disposed between the polarizer 11 and the first optical anisotropic layer 14 and between the polarizer 12 and the second optical anisotropic layer 15. However, the protective film is preferably an isotropic film having a phase difference close to zero.

  Next, the operation of the present invention will be described with reference to the drawings. For comparison, FIG. 7 shows a schematic diagram illustrating a configuration of a general VA mode liquid crystal display device. In general, a VA mode liquid crystal display device sandwiches a liquid crystal cell 53 having a liquid crystal layer in which liquid crystal is vertically aligned with respect to the substrate surface when no voltage is applied, that is, when black is displayed, In addition, the polarizing plate 51 and the polarizing plate 52 are disposed so that their transmission axis directions (shown by stripes in FIG. 7) are orthogonal to each other. In FIG. 7, light enters from the polarizing plate 52 side. When light traveling in the normal direction, that is, in the z-axis direction is incident when no voltage is applied, the light that has passed through the polarizing plate 52 passes through the liquid crystal cell 53 while maintaining the linearly polarized state. Completely shaded. As a result, an image with high contrast can be displayed.

  However, as shown in FIG. 8, the situation is different in the case of oblique light incidence. When light is incident from an oblique direction other than the z-axis direction, that is, from an oblique direction with respect to the polarization direction of the polarizing plates 51 and 52 (so-called OFF AXIS), the incident light passes through the vertically aligned liquid crystal layer of the liquid crystal cell 53. When passing, the polarization state changes due to the influence of the oblique retardation. Furthermore, the apparent transmission axes of the polarizing plate 51 and the polarizing plate 52 deviate from the orthogonal arrangement. Due to these two factors, incident light from an oblique direction in OFF AXIS is not completely shielded by the polarizing plate 51, and light leakage occurs during black display, resulting in a decrease in contrast.

  Here, polar angle and azimuth angle are defined. The polar angle is the normal direction of the film surface, that is, the inclination angle from the z-axis in FIGS. 7 and 8. For example, the normal direction of the film surface is the direction of polar angle = 0 degrees. The azimuth angle represents an azimuth rotated counterclockwise with respect to the positive direction of the x-axis. For example, the positive direction of the x-axis is the direction of the azimuth angle = 0 degrees, and the positive direction of the y-axis is Azimuth angle = 90 degrees. The diagonal direction in OFF AXIS described above mainly refers to the case where the polar angle is not 0 degree and the azimuth angle is 45 degrees, 135 degrees, 225 degrees, and 315 degrees.

  Conventionally, it has been proposed to eliminate the decrease in contrast in the oblique direction of a VA mode liquid crystal display device by using a biaxial plate and a C plate (for example, Patent Document 1). By the way, various stretched polymer films are conventionally used for the optical compensation film. Generally, the stretched polymer film has an in-plane retardation Re of Re (450) ≧ Re (550) ≧ Re (650). Rth in the thickness direction satisfies the relationship of Rth (450) ≧ Rth (550) ≧ Rth (650), that is, Re and Rth each have a larger value as the shorter wavelength in the visible light region (hereinafter referred to as “Rth”) In some cases, this property is referred to as “forward dispersion”, and the opposite property, that is, the property that Re and Rth each have a larger value for longer wavelengths in the visible light region is sometimes referred to as “reverse dispersion”). .

  FIG. 9 shows a schematic diagram of an example of a conventional VA mode liquid crystal display device using a biaxial plate and a C plate. The liquid crystal display device of FIG. 9 has a liquid crystal cell 53 and a pair of polarizing plates 51 and 52, and an optical compensation film 55 for the A plate between the polarizing plate 52 and the liquid crystal cell 53, the polarizing plate 51 and the liquid crystal cell 53. In between, a C-plate optical compensation film 54 is provided. FIG. 10 is a diagram illustrating the compensation mechanism in the configuration of FIG. 9 using a Poincare sphere. The Poincare sphere is a three-dimensional map that describes the polarization state, and the equator of the sphere represents linearly polarized light. Here, the propagation direction of light in the liquid crystal display device is azimuth = 45 degrees and polar angle = 34 degrees. In FIG. 10, the S2 axis is an axis that penetrates vertically from the bottom to the top of the page, and FIG. 10 is a view of the Poincare sphere viewed from the positive direction of the S2 axis. Here, the S1, S2, and S3 coordinates represent Stokes parameter values in a certain polarization state. Also, since FIG. 10 is shown in a plan view, the displacement of the point before and after the change of the polarization state is indicated by the straight arrows in the figure, but actually it passes through the liquid crystal layer and the optical compensation film. The change in the polarization state due to this is expressed by rotating a specific angle around a specific axis determined according to each optical characteristic on the Poincare sphere.

  The polarization state of incident light that has passed through the polarizing plate 52 in FIG. 9 corresponds to the point (i) in FIG. 10, and the polarization state shielded by the absorption axis of the polarizing plate 51 in FIG. Corresponds to (ii). Conventionally, in a VA mode liquid crystal display device, OFF AXIS light omission in an oblique direction is caused by a deviation of the polarization state of emitted light from the point (ii). The optical compensation film is generally used for correctly changing the polarization state of incident light from the point (i) to the point (ii) including the change of the polarization state in the liquid crystal layer.

  The change in the polarization state of the incident light by passing through the optical compensation film 55 which is the A plate follows a locus indicated by an arrow marked with “A” in FIG. 10 on the Poincare sphere. The rotation angle on the Poincare sphere is proportional to the value Δn′d ′ / λ obtained by dividing the effective retardation Δn′d ′ from the oblique direction for observing the liquid crystal display device by the light wavelength λ. As described above, when a general stretched polymer film is used as the optical compensation film 55, Re becomes larger as the wavelength is shorter, the effective retardation Re is different for R, G, and B, and the reciprocal of the wavelength λ is also shorter. Since the wavelength increases as the wavelength increases, the rotation angle is in the order of B> G> R at each of R, G, and B having different wavelengths. That is, the polarization states of R, G, and B after rotation, that is, (S1, S2, S3) coordinates are as shown in FIG.

  Since the liquid crystal layer of the liquid crystal cell 53 exhibits positive refractive index anisotropy and is vertically aligned, the change in the polarization state of incident light caused by passing through the liquid crystal layer is “LC” in FIG. 10 on the Poincare sphere. Followed by a trajectory indicated by an arrow from the top to the bottom marked with “,” and expressed as a rotation around the S1 axis.

Next, the conversion of the polarization state of B light, G light, and R light when passing through the optical compensation film 54 that is the C plate is indicated by an arrow with “C” in FIG. 10 on the Poincare sphere. As shown, it is represented by the movement of the S1-S2 plane in the normal direction. As shown in FIG. 10, it is impossible to convert all of R light, G light, and B light in different polarization states into the polarization state of point (ii) due to this movement, because the S1 coordinates do not match. is there. Since the light having the shifted wavelength is not blocked by the polarizing plate, light leakage occurs. Since the color of light consists of R, G, and B, when only light of a specific wavelength leaks, the ratio of the sum of R, G, and B light shifts, and the color changes. It happens. This is observed as a “color change” when the liquid crystal display device is viewed from an oblique direction.
Here, in this specification, as wavelengths of R, G, and B, R has a wavelength of 650 nm, G has a wavelength of 550 nm, and B has a wavelength of 450 nm. The wavelengths of R, G, and B are not necessarily represented by these wavelengths, but are considered to be suitable wavelengths for defining the optical characteristics that exhibit the effects of the present invention.

In the present invention, by using the first optically anisotropic layer that satisfies the following formulas (1) and (2), the polarization state of each of the R light, G light, and B light is changed to the point (ii). It is possible to convert to the position.
Re (450) × Re (650) <0 Formula (1)
Rth (550) / Re (550)> 10 Formula (2)
An example of a compensation mechanism of the liquid crystal display device of the present invention having the configuration shown in FIG. 1 will be described using the Poincare sphere shown in FIG. The light incident in the oblique direction passes through the polarizer 12 and becomes linearly polarized light in the polarization state at the point (i) shown in FIG. Next, when passing through the second optical anisotropic layer 15, the polarization state is converted by the optical characteristics of the second optical anisotropic layer. Such conversion of the polarization state is performed on the Poincare sphere with a predetermined axis determined by the optical characteristics of the second optical anisotropic layer 15 as a rotation axis, as indicated by an arrow with “15” in FIG. The rotation is expressed by an angle of a magnitude proportional to the value Δn′d ′ / λ obtained by dividing the effective retardation Δn′d ′ from the oblique direction by the wavelength λ of the light. As described above, since the effective retardation usually changes depending on the wavelength, and the reciprocal of the wavelength λ also changes depending on the size of the wavelength, as shown in FIG. , G and B polarization states, that is, (S1, S2, S3) coordinates are different from each other.

  Since the liquid crystal layer of the liquid crystal cell 13 exhibits positive refractive index anisotropy and is vertically aligned, the change in the polarization state of incident light due to passing through the liquid crystal layer is “LC” in FIG. 2 on the Poincare sphere. Followed by a trajectory indicated by an arrow from the top to the bottom marked with “,” and expressed as rotation about the S1 axis.

  Next, the incident light passes through the first optical anisotropic layer 14. Since the first optically anisotropic layer 14 satisfies the above formula (2), the change in the polarization state of the incident light follows a locus similar to the rotation around the S1 axis as shown in FIG. Furthermore, since the first optical anisotropic layer 14 also satisfies the above formula (1), light of each wavelength of R, G, and B passes through the first optical anisotropic layer 14, Optical compensation is performed with a different slow axis and retardation for each wavelength. More specifically, the wavelength R (650 nm) is at the lower right of the point (ii), and in order to move from here to the point (ii), it is necessary to move to the upper left, so that such movement is possible. In this case, it is sufficient that Re (650) of the first optical anisotropic layer 14 is negative and Rth (650) is positive. Similarly, the wavelength G (550 nm) is below the point (ii). To move from here to the point (ii), Re (550) of the first optical anisotropic layer 14 is zero, and Rth (550) may be positive. Further, the wavelength B (450 nm) is at the lower left of the point (ii), and in order to move from here to the point (ii), it is necessary to move to the upper right. It is sufficient that Re (450) of one optical anisotropic layer 14 is positive and Rth (450) is also a positive value. That is, by using the first optical anisotropic layer 14 having the optical characteristics schematically shown in the graph of FIG. 3, all of the R light, G light, and B light are polarized at the point (ii). The color change when observed from an oblique direction can be reduced (the above configuration corresponds to the classification A among the classifications described later).

The optical compensation mechanism shown in FIG. 2 is an example, and in the present invention, the first optical anisotropic layer may satisfy the above formulas (1) and (2). The wavelength dependency of Re and Rth is not particularly limited. The wavelength dependency of Re and Rth of the first optical anisotropic layer may be any of forward dispersion, reverse dispersion, and constant, and the Re and / or Rth of the second optical anisotropic layer may be constant. It can be determined according to the wavelength dependency.
FIG. 4 shows preferable combinations of the wavelength dependency of Re and Rth of the second optical anisotropic layer and the wavelength dependency of Re and Rth of the first optical anisotropic layer as classifications A to H. It was. The graph in FIG. 4 is schematically described for easy understanding, and is not a graph created by measuring actual optical characteristics. The same applies to the graph in FIG. 6 to be described later.

In classification A, the first optically anisotropic layer has the following formula: Re (450)> 0,
Re (650) <0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | ≧ 1.0
It is an embodiment that satisfies all of the above. Preferably, both Re and Rth are combined with a second optically anisotropic layer exhibiting forward dispersion. In this embodiment, it is preferable that the first optical anisotropic layer further satisfies Re (450)> 5 nm and Re (650) <− 5 nm. The second optically anisotropic layer more preferably satisfies 0.70 <Rth (450) / Rth (550) <1.15, and 0.90 <Rth (450) / Rth (550). It is more preferable to satisfy <1.10.

In classification B, the first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | <1.0
It is an embodiment that satisfies all of the above. It is preferable to combine with a second optically anisotropic layer in which Re exhibits reverse dispersion and Rth exhibits forward dispersion. In this embodiment, it is preferable that the first optical anisotropic layer further satisfies Re (450)> 5 nm and Re (650) <− 5 nm. The second optically anisotropic layer preferably satisfies Rth (450) / Rth (550) ≧ 1.15 and Rth (550) / Rth (650) ≧ 1.15, and Rth (450) / More preferably, Rth (550) ≧ 1.10.

In classification C, the first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | <1.0
It is an embodiment that satisfies all of the above. Preferably, both Re and Rth are combined with a second optically anisotropic layer exhibiting reverse dispersion. In this embodiment, it is preferable that the first optical anisotropic layer further satisfies Re (450) <− 5 nm and Re (650)> 5 nm. The second optically anisotropic layer more preferably satisfies Re (450) / Re (550) <0.70.

In classification D, the first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550)> 0 and | Rth (450) | / | Rth (650) | ≧ 1.0
It is an embodiment that satisfies all of the above. As the second optically anisotropic layer, an optically anisotropic layer in which both Re and Rth exhibit reverse dispersibility, and Re is substantially 0 at any wavelength in the visible light range, and Rth exhibits forward dispersibility. It is preferable to use a laminate with an optically anisotropic layer. In this embodiment, it is preferable that the first optical anisotropic layer further satisfies Re (450) <− 5 nm and Re (650)> 5 nm. The second optical anisotropic layer includes an optical anisotropic layer satisfying Re (450) / Re (550) <0.80 and an optical satisfying Rth (450) / Rth (550)> 1.25. It is more preferable to use a laminate with an anisotropic layer; an optically anisotropic layer satisfying Re (450) / Re (550) <0.75, and Rth (450) / Rth (550)> 1.30. It is more preferable to use a laminate with an optically anisotropic layer that satisfies the above.

In classification E, the first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | ≧ 1.0
It is an embodiment that satisfies all of the above. Preferably, both Re and Rth are combined with a second optically anisotropic layer exhibiting forward dispersion. In this embodiment, it is more preferable that the first optical anisotropic layer satisfies Re (450) <− 5 nm and Re (650)> 5 nm. The second optically anisotropic layer more preferably satisfies 0.70 <Rth (450) / Rth (550) <1.15, and 0.90 <Rth (450) / Rth (550) < It is more preferable to satisfy 1.10.

In classification F, the first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | <1.0
It is an embodiment that satisfies all of the above. In this embodiment, it is preferable to combine with the second optical anisotropic layer in which Re exhibits reverse dispersion and Rth exhibits forward dispersion. The first optically anisotropic layer more preferably satisfies Re (450) <− 5 nm and Re (650)> 5 nm. The second optically anisotropic layer preferably satisfies Rth (450) / Rth (550) ≧ 1.15 and Rth (550) / Rth (650) ≧ 1.15, and Rth (450) More preferably, /Rth(550)≧1.10.

In classification G, the first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550) <0 and | Rth (450) | / | Rth (650) | <1.0
It is an embodiment that satisfies all of the above. Preferably, both Re and Rth are combined with a second optically anisotropic layer exhibiting reverse dispersion. In this embodiment, it is preferable that the first optical anisotropic layer further satisfies Re (450) <− 5 nm and Re (650)> 5 nm. The second optically anisotropic layer more preferably satisfies Re (450) / Re (550) <0.70.

In classification H, the first optically anisotropic layer is represented by the following formula: Re (450)> 0,
Re (650) <0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | ≧ 1.0
It is an embodiment that satisfies all of the above. As the second optically anisotropic layer, an optically anisotropic layer in which both Re and Rth exhibit reverse dispersibility, and Re is substantially 0 at any wavelength in the visible light range, and Rth exhibits forward dispersibility. It is preferable to use a laminate with an optically anisotropic layer. In this embodiment, it is preferable that the first optical anisotropic layer further satisfies Re (450) <− 5 nm and Re (650)> 5 nm. The second optical anisotropic layer includes an optical anisotropic layer satisfying Re (450) / Re (550) <0.80 and an optical satisfying Rth (450) / Rth (550)> 1.25. It is more preferable to use a laminate with an anisotropic layer; an optically anisotropic layer satisfying Re (450) / Re (550) <0.75, and Rth (450) / Rth (550)> 1.30. It is more preferable to use a laminate with an optically anisotropic layer that satisfies the above.

FIG. 1 shows an embodiment in which the first and second optically anisotropic layers are arranged with the liquid crystal cell sandwiched therebetween, but both the first and second optically anisotropic layers are separated from the liquid crystal cell. You may arrange | position between a display surface side polarizer or between a liquid crystal cell and a backlight side polarizer.
Moreover, although the aspect of the liquid crystal display device of the vertical alignment mode was demonstrated above, this invention is not limited to this aspect, Horizontal alignment modes, such as IPS mode, may be sufficient.

FIG. 5 is a schematic cross-sectional view of an example in which the present invention is applied to an IPS mode liquid crystal display device. The liquid crystal display device of FIG. 5 includes a pair of polarizers 21 and 22, an IPS mode liquid crystal cell 23 disposed between the pair of polarizers, and the above formula between the polarizer 21 and the liquid crystal cell 23. It has the 1st optically anisotropic layer 24 which satisfies (1) and (2), and the 2nd optically anisotropic layer 25 which has an at least 1 optical axis. The polarizers 21 and 22 are arranged with their absorption axes (arrows in 21 and 22 in FIG. 5) orthogonal to each other. The second optically anisotropic layer 25 is arranged with its in-plane slow axis parallel to the absorption axis of the polarizer 21.
In FIG. 5, no layer is disposed between the polarizer 22 and the liquid crystal cell 23, but a protective film for the polarizer 22 is generally disposed. In the embodiment shown in FIG. 5, the protective film of the polarizer 22 disposed between the liquid crystal cell 23 is preferably a film having a retardation of almost 0. For example, cellulose acylate described in JP-A-2005-138375 A film is preferred.

  The liquid crystal cell 23 is an IPS-mode liquid crystal cell, and performs black display in a voltage non-application state (or low application state) and white display in a voltage application state. An alignment film is formed on the surface of the liquid crystal cell that contacts the liquid crystal on the upper and lower substrates, and the liquid crystal molecules are aligned substantially parallel to the surface of the substrate, and depending on the rubbing treatment direction applied on the alignment film. During black display, the long axis is controlled to be parallel to the absorption axis of the backlight-side polarizer (polarizer 22 in FIG. 5). That is, the liquid crystal cell 23 has an A-plate-like action having a slow axis in a direction parallel to the absorption axis of the polarizer 22 with respect to incident light.

FIG. 6 is a diagram illustrating the compensation mechanism of the liquid crystal display device having the configuration shown in FIG. 5 during black display using a Poincare sphere. Classification E to classification H in FIG. 6 are classifications of preferable combinations of the Re and Rth wavelength dependencies of the first and second optically anisotropic layers, and are the same as classifications E to H in FIG. .
In FIG. 5, the polarization state incident on the polarizer 22 is located at (i). When passing through the liquid crystal cell 23, the polarization state changes depending on the birefringence of the liquid crystal cell 23. As described above, the liquid crystal cell 23 is delayed in the direction parallel to the absorption axis of the polarizer 22 with respect to the incident light. Since it acts like an A-plate with an axis, the change is expressed as a rotation around (i). For this reason, the polarization state of the light that has passed through the liquid crystal cell 23 remains unchanged (i). Thereafter, when passing through the second optically anisotropic layer 25, the polarization state is converted by the birefringence, and, as shown in FIG. 6, depending on the Re · Rth wavelength dependence, R, G, A different polarization state is obtained at each wavelength of B. According to the classification shown in FIG. 6, by selecting the first optical anisotropic layer exhibiting a predetermined Re · Rth wavelength dependency, separation has occurred by passing through the second optical anisotropic layer 25 Different polarization states of R, G, and B can be converted into the extinction point (ii) of the polarizer 21.

  By appropriately combining the retardation values of the first and second optically anisotropic layers in relation to the optical characteristics of the liquid crystal cell and the like, the viewing angle contrast is good and the hue change is small in any mode. A liquid crystal display device can be realized. In an embodiment having a vertical alignment mode, for example, a VA mode liquid crystal cell, the sum of Rth (550) of the first optical anisotropic layer and Rth (550) of the second optical anisotropic layer is 100 nm. It is preferably ˜400 nm, more preferably 200 nm to 300 nm. Further, in an embodiment having a liquid crystal cell of a horizontal alignment mode, for example, an IPS mode, the sum of Rth (550) of the first optical anisotropic layer and Rth (550) of the second optical anisotropic layer is , −150 nm to 100 nm is preferable, and −100 nm to 50 nm is more preferable.

  Next, the optical properties, materials, manufacturing methods, and the like of the first optical anisotropic layer and the second optical anisotropic layer that can be used in the present invention will be described in detail.

[First optically anisotropic layer]
In the present invention, an optically anisotropic layer satisfying the following formulas (1) and (2) is used as the first optically anisotropic layer.
Re (450) × Re (650) <0 Formula (1)
Rth (550) / Re (550)> 10 Formula (2)
The present invention includes an embodiment in which Re of the first optical anisotropic layer satisfies Re (550) = 0. It is preferable that Rth (550) / Re (550)> 15 is satisfied. The first optically anisotropic layer can contribute to a reduction in tint regardless of the value of Rth (550), but the larger the value of | Rth (550) |, the greater the effect of tint compensation. , | Rth (550) | ≧ 50 nm. In general, | Rth (550) | is preferably 200 nm or less, more preferably 140 nm or less, and even more preferably 80 nm or less. On the other hand, | Re (550) | is preferably small, and | Re (550) | <20 nm.

The optically anisotropic layer satisfying the formula (1) can be produced by various methods. For example, the wavelength dispersion characteristic of a polymer film is affected by the polarizability of a polymer main chain (usually along the longitudinal direction of the film) and the side chain that exists in a direction perpendicular to the main chain. . It is also affected by the position of the absorption peak in the UV wavelength region of the polymer film. Therefore, a polymer film satisfying the formula (1) can be obtained by adjusting the factors affecting these wavelength dispersion characteristics.
For example, in cellulose acylate, a hydrogen atom of a hydroxyl group in a cellulose unit is substituted with an acyl group, and the presence of the acyl group causes polarizability anisotropy in a direction perpendicular to the main chain. Therefore, a polymer film satisfying the characteristics required for the first optical anisotropy can be produced using cellulose acylate. In addition to cellulose acylate, various polymers with substituents having polarizability anisotropy in the side chain are selected to produce polymer films that satisfy the characteristics required for the first optical anisotropy. can do.
As an example of the production method, the degree of crystallization of the polymer side chain is adjusted by holding the polymer film with a clip or the like, or adjusting the temperature at the time of stretching in at least one direction and / or the treatment time thereof. Thereby obtaining the desired Re wavelength dispersion characteristics.

[Second optically anisotropic layer]
The liquid crystal display device of the present invention may have a second optical anisotropic layer having at least one optical axis. As long as the second optically anisotropic layer has at least one optical axis, the optical properties are not particularly limited. For example, a retardation plate generally referred to as an A plate can be used. In general, the second optically anisotropic layer preferably satisfies the following formulas (3) and (4).
30 nm <Re (550) <400 nm Formula (3)
−100 nm <Rth (550) <300 nm Formula (4)
Furthermore, it is preferable to satisfy the following formula (3) ′, or it is preferable to satisfy the following formula (4) ′.
40 nm <Re (550) <300 nm Formula (3) ′
−50 nm <Rth (550) <250 nm Formula (4) ′

  The materials for the first optical anisotropic layer and the second optical anisotropic layer are not particularly limited. When the first and second optically anisotropic layers are polymer films, they can be bonded to a polarizer. The polymer film material is preferably a polymer excellent in optical performance, transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, etc., but any material is acceptable as long as it satisfies the above conditions. May be used. Examples include polycarbonate polymers, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, acrylic polymers such as polymethyl methacrylate, and styrene polymers such as polystyrene and acrylonitrile / styrene copolymer (AS resin). Polyolefins such as polyethylene and polypropylene, polyolefin polymers such as ethylene / propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers, polyethersulfone polymers , Polyether ether ketone polymers, polyphenylene sulfide polymers, vinylidene chloride polymers, vinyl alcohol polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, or polymers mixed with the above polymers Take as an example.

  As a material for forming the polymer film, a thermoplastic norbornene resin can be preferably used. Examples of the thermoplastic norbornene-based resin include ZEONEX, ZEONOR manufactured by Nippon Zeon Co., Ltd., and ARTON manufactured by JSR Corporation.

  In addition, as a material for forming the polymer film, a cellulose polymer (hereinafter referred to as cellulose acylate) that has been conventionally used as a transparent protective film of a polarizing plate can be particularly preferably used. A representative example of cellulose acylate is triacetyl cellulose. Examples of cellulose as a cellulose acylate raw material include cotton linter and wood pulp (hardwood pulp, softwood pulp). Cellulose acylate obtained from any raw material cellulose can be used, and in some cases, a mixture may be used. Detailed descriptions of these raw material celluloses can be found, for example, by Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, published by Nikkan Kogyo Shimbun (published in 1970), and the Japan Institute of Invention and Technology Publication No. 2001 The cellulose described in No. -1745 (pages 7 to 8) can be used, and the cellulose acylate film is not particularly limited.

  The cellulose acylate film for the first optically anisotropic layer is preferably composed of a composition containing cellulose acylate having two or more kinds of substituents. Preferred examples of such cellulose acylates include mixed fatty acid esters having an acylation degree of 2 to 2.9 and having a plurality of acyl groups (for example, an acetyl group and an acyl group having 3 to 4 carbon atoms). . The acylation degree of the mixed fatty acid ester is more preferably 2.2 to 2.85, still more preferably 2.4 to 2.8. The degree of acetylation is preferably less than 2.5, more preferably less than 1.9. In the fatty acid ester residue, the aliphatic acyl group preferably has 2 to 20 carbon atoms. Specific examples include acetyl, propionyl, butyryl, isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, lauroyl, stearoyl and the like, preferably acetyl, propionyl and butyryl.

The cellulose acylate may be a mixed acid ester having a fatty acid acyl group and a substituted or unsubstituted aromatic acyl group.
In the case of a cellulose fatty acid monoester, the substitution degree of the aromatic acyl group is preferably 2.0 or less, more preferably 0.1 to 2.0 with respect to the remaining hydroxyl group. In the case of cellulose fatty acid diester (cellulose diacetate), it is preferably 1.0 or less, more preferably 0.1 to 1.0, based on the remaining hydroxyl group.

  The cellulose acylate preferably has a mass average degree of polymerization of 350 to 800, and more preferably has a mass average degree of polymerization of 370 to 600. The cellulose acylate used in the present invention preferably has a number average molecular weight of 70000 to 230,000, more preferably 75000 to 230,000, and more preferably 78000 to 120,000. Further preferred.

  The cellulose acylate can be synthesized using an acid anhydride or acid chloride as an acylating agent. In the industrially most general synthesis method, cellulose obtained from cotton linter, wood pulp, etc. is converted into organic acids (acetic acid, propionic acid, butyric acid) corresponding to acetyl groups and other acyl groups, or their acid anhydrides (anhydrous anhydride). A cellulose ester is synthesized by esterification with a mixed organic acid component containing acetic acid, propionic anhydride, and butyric anhydride).

  The cellulose acylate film is preferably produced by a solvent cast method. About the manufacture example of the cellulose acylate film using a solvent cast method, U.S. Pat. Nos. 2,336,310, 2,367,603, 2,492,078, 2,492,977, 2,492,978, 2,607,704, 2,739,069 and 2,739,070, British Patent Nos. 640731 and 736892, Reference can also be made to the descriptions of JP-B-45-4554, JP-A-49-5614, JP-A-60-176834, JP-A-60-203430 and JP-A-62-115035. The cellulose acylate film may be subjected to a stretching treatment. For the stretching method and conditions, see, for example, the examples described in JP-A-62-115035, JP-A-4-152125, JP-A-2842211, JP-A-298310, JP-A-11-48271, etc. Can be. In the case of producing a cellulose acylate film satisfying the optical characteristics required for the first optically anisotropic layer, a transverse stretching process (a stretching process in the width direction of the film, which is performed in the machine direction) (Orthogonal direction) or, instead of the stretching process, it is preferable to carry it while being held by a tenter clip, and the temperature and / or processing time during these processes affects the wavelength dispersion characteristics of Re. As described above.

  In order to produce a cellulose acylate film that satisfies the conditions for the first optically anisotropic layer, an Rth enhancer may be added to the cellulose acylate film. Here, the “Rth enhancer” is a compound having the property of developing or increasing birefringence in the thickness direction of the film.

  As the Rth enhancer, a compound having a large polarizability anisotropy having an absorption maximum in a wavelength range of 250 nm to 380 nm is preferable. As the Rth enhancer, a compound represented by the following general formula (I) can be particularly preferably used.

In the formula, X ¹ is a single bond, —NR ⁴ —, —O— or S—; X ² is a single bond, —NR ⁵ —, —O— or S—; X ³ is a single bond A bond, —NR ⁶ —, —O— or S—. R ¹ , R ² , and R ³ are each independently an alkyl group, an alkenyl group, an aromatic ring group, or a heterocyclic group; R ⁴ , R ^5, and R ⁶ are each independently a hydrogen atom , An alkyl group, an alkenyl group, an aryl group or a heterocyclic group.

  Preferred examples (I- (1) to IV- (10)) of the compounds represented by the general formula (I) are shown below, but the present invention is not limited to these specific examples.

  As the Rth enhancer, a compound represented by the following general formula (III) is also preferable. Hereinafter, the compound of the general formula (III) will be described in detail.

In the general formula (III), R ² , R ⁴ and R ⁵ each independently represent a hydrogen atom or a substituent, R ¹¹ and R ¹³ each independently represent a hydrogen atom or an alkyl group, and L ¹ and L ² are Each independently represents a single bond or a divalent linking group. Ar ¹ represents an arylene group or an aromatic heterocyclic ring, Ar ² represents an aryl group or an aromatic heterocyclic ring, n represents an integer of 3 or more, and n ² types of L ² and Ar ¹ are the same. It may or may not be. However, R ¹¹ and R ¹³ are different from each other, and the alkyl group represented by R ¹³ does not contain a hetero atom.

In general formula (III), R ² , R ⁴ and R ⁵ each independently represents a hydrogen atom or a substituent. Substituent T described later can be applied as the substituent.

R ² in the general formula (III) is preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group or a hydroxyl group, more preferably a hydrogen atom, an alkyl group or an alkoxy group, still more preferably a hydrogen atom or an alkyl group. Group (preferably 1 to 4 carbon atoms, more preferably a methyl group), an alkoxy group (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, particularly Preferably it is C1-C4. Particularly preferred are a hydrogen atom, a methyl group and a methoxy group, and most preferred is a hydrogen atom.

R ⁴ in the general formula (III) is preferably a hydrogen atom or an electron donating group, more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, or a hydroxyl group, and still more preferably a hydrogen atom or a carbon number. An alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 12 carbon atoms (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 4 carbon atoms). And particularly preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and most preferably a hydrogen atom or a methoxy group.

R ⁵ in the general formula (III) is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an amino group or a hydroxyl group, more preferably a hydrogen atom, an alkyl group or an alkoxy group, still more preferably a hydrogen atom. An atom, an alkyl group (preferably having 1 to 4 carbon atoms, more preferably a methyl group), an alkoxy group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and further preferably 1 to 6 carbon atoms). Particularly preferably, it has 1 to 4 carbon atoms. Particularly preferred are a hydrogen atom, a methyl group and a methoxy group. Most preferably, it is a hydrogen atom.

R ¹¹ and R ¹³ in the general formula (III) each independently represent a hydrogen atom or an alkyl group, R ¹¹ and R ¹³ are different from each other, and the alkyl group represented by R ¹³ does not contain a hetero atom. Here, the hetero atom means an atom other than a hydrogen atom or a carbon atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, phosphorus, silicon, a halogen atom (F, Cl, Br, I), and boron.
The alkyl group represented by R ¹¹ and R ¹³ is linear, branched or cyclic and represents a substituted or unsubstituted alkyl group, preferably a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms. A substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms (that is, a monovalent structure in which one hydrogen atom is removed from a bicycloalkane having 5 to 30 carbon atoms) And a tricyclo structure having more ring structures.

Preferable examples of the alkyl group represented by R ¹¹ and R ¹³ include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl group, iso-pentyl group, n -Hexyl group, n-heptyl group, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1,3-trimethylhexyl group, n-decyl group, 2-hexyldecyl group, Examples thereof include a cyclohexyl group, a cycloheptyl group, a 2-hexenyl group, an oleyl group, a linoleyl group, and a linolenyl group. Examples of the cycloalkyl group include cyclohexyl, cyclopentyl, 4-n-dodecylcyclohexyl, and examples of the bicycloalkyl group include bicyclo [1,2,2] heptan-2-yl and bicyclo [2,2,2] octane-3. -Yl and the like.

R ¹¹ is more preferably a hydrogen atom, methyl group, ethyl group, n-propyl group, or isopropyl group, particularly preferably a hydrogen atom or methyl group, and most preferably a methyl group.
R ¹³ is particularly preferably an alkyl group containing 2 or more carbon atoms, more preferably an alkyl group containing 3 or more carbon atoms. Those having a branched or cyclic structure are particularly preferably used.

Hereinafter, specific examples (O-1 to O-20) of the alkyl group represented by R ¹³ will be described. However, the present invention is not limited to the following specific examples. In the specific examples below, “#” means the oxygen atom side.

Ar ¹ in the general formula (III) represents an arylene group or an aromatic heterocyclic ring, and all Ar ¹ in the repeating unit may be the same or different. Ar ² represents an aryl group or an aromatic heterocyclic ring.
In the general formula (III), the arylene group represented by Ar ¹ is preferably an arylene group having 6 to 30 carbon atoms, which may be a single ring or may form a condensed ring with another ring. Good. Further, if possible, it may have a substituent, and the substituent T described later can be applied as the substituent. More preferably, the arylene group represented by Ar ¹ has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenylene group, a p-methylphenylene group, and a naphthylene group.
In general formula (III), the aryl group represented by Ar ² is preferably an aryl group having 6 to 30 carbon atoms, which may be monocyclic or may form a condensed ring with another ring. Good. Further, if possible, it may have a substituent, and the substituent T described later can be applied as the substituent. The aryl group represented by Ar ² has more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyl group, a p-methylphenyl group, and a naphthyl group.

In the general formula (III), the aromatic heterocycle represented by Ar ¹ or Ar ² may be an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom, preferably 5 It is an aromatic heterocycle containing at least one of a 6-membered oxygen atom, nitrogen atom or sulfur atom. Moreover, you may have a substituent further if possible. Substituent T described later can be applied as the substituent.

In the general formula (III), specific examples of the aromatic heterocycle represented by Ar ¹ and Ar ² include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, Indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole , Benzotriazole, tetrazaindene, pyrrolotriazole, pyrazolotriazole and the like. Preferred as the aromatic heterocycle are benzimidazole, benzoxazole, benzthiazole, and benzotriazole.

In general formula (III), L ¹ and L ² each independently represents a single bond or a divalent linking group. L ¹ and L ² may be the same or different. Further, all L ² in the repeating unit may be the same or different.
Preferred as the divalent linking group are —O—, —NR— (R represents a hydrogen atom or an alkyl group or an aryl group which may have a substituent), —CO—, —SO ₂ —, -S-, an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, and a group obtained by combining two or more of these divalent groups, more preferably -O-,- NR -, - CO -, - SO 2 NR -, - NRSO 2 -, - CONR -, - NRCO -, - COO-, and OCO-, an alkynylene group. R preferably represents a hydrogen atom.

In the compound represented by the general formula (III) in the present invention, Ar ¹ is bonded to L ¹ and L ^{2. When} Ar ¹ is a phenylene group, L ^1- Ar ¹ -L ² and L ^2- Ar ¹ -L ² is particularly preferably in a para-position (1,4-position) to each other.

  In general formula (III), n represents an integer greater than or equal to 3, Preferably it is 3-7, More preferably, it is 3-6, More preferably, it is 3-5.

  As the compound represented by the general formula (III), compounds represented by the following general formulas (IV) and (V) can be particularly preferably used.

In general formula (IV), R ² and R ⁵ each independently represent a hydrogen atom or a substituent, R ¹¹ and R ¹³ each independently represent a hydrogen atom or an alkyl group, and L ¹ and L ² Each independently represents a single bond or a divalent linking group. Ar ¹ represents an arylene group or an aromatic heterocyclic ring, Ar ² represents an aryl group or an aromatic heterocyclic ring, n represents an integer of 3 or more, and n ² types of L ² and Ar ¹ are the same. It may or may not be. However, R ¹¹ and R ¹³ are different from each other, and the alkyl group represented by R ¹³ does not contain a hetero atom.

In general formula (IV), R ² , R ⁵ , R ¹¹ , and R ¹³ have the same meanings as those in general formula (III), and preferred ranges are also the same. L ¹ , L ² , Ar ¹ and Ar ² are also synonymous with those in the general formula (III), and preferred ranges are also the same.

In general formula (V), R ² and R ⁵ each independently represent a hydrogen atom or a substituent, R ¹¹ , R ¹³ and R ¹⁴ each independently represent a hydrogen atom or an alkyl group, and L ¹ and L ² are Each independently represents a single bond or a divalent linking group. Ar ¹ represents an arylene group or an aromatic heterocyclic ring, Ar ² represents an aryl group or an aromatic heterocyclic ring, n represents an integer of 3 or more, and n ² types of L ² and Ar ¹ are the same. It may or may not be. However, R ¹¹ and R ¹³ are different from each other, and the alkyl group represented by R ¹³ does not contain a hetero atom.

In the general formula (V), R ² , R ⁵ , R ¹¹ and R ¹³ have the same meanings as those in the general formula (III), and preferred ranges are also the same. L ¹ , L ² , Ar ¹ and Ar ² have the same meanings as those in formula (III), and preferred ranges are also the same.
In the general formula (V), R ¹⁴ represents a hydrogen atom or an alkyl group, and as the alkyl group, alkyl groups shown as preferred examples of R ¹¹ and R ¹³ are preferably used. R ¹⁴ is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group. R ¹¹ and R ¹⁴ may be the same or different, but both are particularly preferably methyl groups.

  Moreover, as a compound represented by the said general formula (V), the compound represented by general formula (VA) or general formula (VB) is also preferable.

In general formula (VA), R ² and R ⁵ each independently represent a hydrogen atom or a substituent, R ¹¹ and R ¹³ each independently represent a hydrogen atom or an alkyl group, L ¹ , L ² each independently represents a single bond or a divalent linking group. Ar ¹ represents an arylene group or an aromatic heterocyclic ring, n represents an integer of 3 or more, and n ² types of L ² and Ar ² may be the same or different. However, R ¹¹ and R ¹³ are different from each other, and the alkyl group represented by R ¹³ does not contain a hetero atom.

In general formula (VA), R ² , R ⁵ , R ¹¹ , R ¹³ , L ¹ , L ² , Ar ¹ , and n have the same meanings as those in general formula (III), and preferred ranges are also the same. is there.

In general formula (V-B), R ² and R ⁵ each independently represent a hydrogen atom or a substituent, and R ¹¹ , R ¹³ and R ¹⁴ each independently represent a hydrogen atom or an alkyl group, L ¹ and L ² each independently represents a single bond or a divalent linking group. Ar ¹ represents an arylene group or an aromatic heterocyclic ring, n represents an integer of 3 or more, and n types of L ¹ and Ar ² may be the same or different. However, R ¹¹ and R ¹³ are different from each other, and the alkyl group represented by R ¹³ does not contain a hetero atom.

In general formula (V-B), R ² , R ⁵ , R ¹¹ , R ¹³ , R ¹⁴ , L ¹ , L ² , Ar ¹ , n are as defined in general formulas (III) and (V). The preferred range is also the same.

The aforementioned substituent T will be described below.
The substituent T is preferably a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, Isopropyl group, t-butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, such as cyclohexyl group, cyclopentyl group, 4 -N-dodecylcyclohexyl group), a bicycloalkyl group (preferably a mono- or di-substituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom is removed from a bicycloalkane having 5 to 30 carbon atoms. For example, bicyclo [1,2,2] heptan-2-yl, bicyclo [2,2,2] octane-3 Yl), an alkenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group or an allyl group), a cycloalkenyl group (preferably a substituted or unsubstituted cyclohexane having 3 to 30 carbon atoms). An alkenyl group, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms, such as 2-cyclopenten-1-yl and 2-cyclohexen-1-yl), a bicycloalkenyl group ( A substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. For example, bicyclo [2,2,1] hept-2-en-1-yl, bicyclo [2,2,2] oct-2-en-4-yl), al An aryl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl group, propargyl group), an aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms such as phenyl Group, p-tolyl group, naphthyl group), heterocyclic group (preferably a monovalent group obtained by removing one hydrogen atom from a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic compound And more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms (for example, 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group),

A cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group (preferably a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, such as a methoxy group, an ethoxy group, an isopropoxy group, a t-butoxy group, n -Octyloxy group, 2-methoxyethoxy group), aryloxy group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, for example, phenoxy group, 2-methylphenoxy group, 4-tert-butyl) Phenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group), silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, for example, trimethylsilyloxy group, tert-butyldimethylsilyloxy group), hetero A ring oxy group (preferably a substituted or unsubstituted hete Ring oxy group, 1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy group), acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, carbon number 6-30 substituted or unsubstituted arylcarbonyloxy groups such as formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group), carbamoyloxy group (preferably A substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms, such as N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octyl Aminocarbonyloxy group, Nn-oct Rucarbamoyloxy group), alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n-octylcarbonyl group) Oxy group), aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, for example, phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexa Decyloxyphenoxycarbonyloxy group),

An amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group, a methylamino group, a dimethylamino group; , Anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted 6 to 30 carbon atoms, or Unsubstituted arylcarbonylamino group, for example, formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), aminocarbonylamino group (preferably substituted or unsubstituted amino having 1 to 30 carbon atoms) Carbonylamino group, for example, carbamoylamino group, N, N-dimethylaminocarbonyl Mino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group), alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, such as methoxycarbonylamino group, ethoxycarbonylamino Group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably substituted or unsubstituted aryloxycarbonyl having 7 to 30 carbon atoms) An amino group such as a phenoxycarbonylamino group, a p-chlorophenoxycarbonylamino group, an mn-octyloxyphenoxycarbonylamino group, a sulfamoylamino group (preferably having 0 to 30 carbon atoms); Substituted or unsubstituted sulfamoylamino groups, such as sulfamoylamino groups, N, N-dimethylaminosulfonylamino groups, Nn-octylaminosulfonylamino groups, alkyl and arylsulfonylamino groups (preferably carbon A substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, a substituted or unsubstituted arylsulfonylamino group having 6 to 30 carbon atoms, such as a methylsulfonylamino group, a butylsulfonylamino group, a phenylsulfonylamino group, 2, 3 , 5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group), mercapto group, alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms such as methylthio group, ethylthio group, n- Hexadecylthio group), arylthio group (Preferably a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, for example, phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), heterocyclic thio group (preferably substituted having 2 to 30 carbon atoms) Or an unsubstituted heterocyclic thio group, for example, 2-benzothiazolylthio group, 1-phenyltetrazol-5-ylthio group),

Sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms such as N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group , N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably substituted or non-substituted having 1 to 30 carbon atoms) Substituted alkylsulfinyl groups, 6-30 substituted or unsubstituted arylsulfinyl groups such as methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl and arylsulfonyl groups (preferably C1-C30 substituted or unsubstituted An alkylsulfonyl group, a 6-30 substituted or unsubstituted arylsulfonyl group such as a methylsulfonyl group, an ethylsulfonyl group, a phenylsulfonyl group, a p-methylphenylsulfonyl group), an acyl group (preferably a formyl group, 2 carbon atoms) -30 substituted or unsubstituted alkylcarbonyl group, C7-30 substituted or unsubstituted arylcarbonyl group such as acetyl group and pivaloylbenzoyl group), aryloxycarbonyl group (preferably 7 carbon atoms) To 30 substituted or unsubstituted aryloxycarbonyl groups such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxycarbonyl group), alkoxycarbonyl group (preferably, C2-C30 substitution or Unsubstituted alkoxycarbonyl group, for example, methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group), carbamoyl group (preferably a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms, For example, carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (methylsulfonyl) carbamoyl group), aryl and heterocyclic azo groups (preferably C6-C30 substituted or unsubstituted arylazo group, C3-C30 substituted or unsubstituted heterocyclic azo group, for example, phenylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4 -Thiadiazol-2-ylazo group), imide group (preferably N-sul Succinimide group, N-phthalimido group), phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, such as dimethylphosphino group, diphenylphosphino group, methylphenoxyphosphino group), phosphinyl group (Preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, for example, phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group), phosphinyloxy group (preferably having 2 carbon atoms) -30 substituted or unsubstituted phosphinyloxy group, for example, diphenoxyphosphinyloxy group, dioctyloxyphosphinyloxy group, phosphinylamino group (preferably substituted or substituted with 2 to 30 carbon atoms) Unsubstituted phosphinylamino group such as dimethoxyphosphinylamino group, dimethylamino Phosphinyl amino group), a silyl group (preferably, represents a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, e.g., trimethylsilyl group, tert- butyldimethylsilyl group, a phenyldimethylsilyl group).

  Among the above substituents, those having a hydrogen atom may be substituted with the above groups after removing this. Examples of such a functional group include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Specific examples include a methylsulfonylaminocarbonyl group, p- Examples include methylphenylsulfonylaminocarbonyl group, acetylaminosulfonyl group, and benzoylaminosulfonyl group.

  Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

Preferred compounds represented by formula (VA) are those in which R ¹¹ is a methyl group, R ² and R ⁵ are both hydrogen atoms, and R ¹³ has 3 or more carbon atoms. An alkyl group, and L ¹ is a single bond, —O—, —CO—, —NR—, —SO ₂ NR—, —NRSO ₂ —, —CONR—, —NRCO—, —COO—, and OCO—. , An alkynylene group (R represents a hydrogen atom, an optionally substituted alkyl group or an aryl group, preferably a hydrogen atom), and L ² represents —O— or NR— (R represents a hydrogen atom). Represents an alkyl group or an aryl group which may have a substituent, preferably a hydrogen atom.), Ar ¹ is an arylene group, and n is 3-6.

  Specific examples of the compounds represented by formulas (VA) and (VB) will be described below in detail, but the present invention is not limited to the following specific examples.

The compound represented by the general formula (III) can be synthesized by first synthesizing a substituted benzoic acid, followed by a general ester reaction or amidation reaction between the substituted benzoic acid and a phenol derivative or aniline derivative. Any reaction may be used as long as it is a formation reaction. For example, a method of converting a substituted benzoic acid to an acid halide and then condensing it with a phenol derivative or aniline derivative, a method of dehydrating condensation of a substituted benzoic acid and a phenol derivative or aniline derivative using a condensing agent or catalyst, etc. It is done.
As a method for producing the compound represented by the general formula (III), a method in which a substituted benzoic acid is functionally converted to an acid halide and then condensed with a phenol derivative or an aniline derivative is preferable in consideration of the production process and the like.

  In the method for producing the compound represented by the general formula (III), examples of the reaction solvent include hydrocarbon solvents (preferably toluene and xylene), ether solvents (preferably dimethyl ether, tetrahydrofuran, dioxane and the like). ), Ketone solvents, ester solvents, acetonitrile, dimethylformamide, dimethylacetamide, and the like. These solvents may be used alone or in admixture of several kinds, and the solvent is preferably toluene, acetonitrile, dimethylformamide, or dimethylacetamide.

The reaction temperature is preferably 0 to 150 ° C, more preferably 0 to 100 ° C, still more preferably 0 to 90 ° C, and particularly preferably 20 ° C to 90 ° C.
Moreover, it is preferable not to use a base for this reaction. When a base is used, it may be either an organic base or an inorganic base, preferably an organic base, such as pyridine or tertiary alkylamine (preferably triethylamine, ethyldiisopropylamine, etc.).

  The compounds represented by the general formulas (VA) and (VB) can be synthesized by a known method. For example, in the case of a compound where n = 4, a raw material compound having the following structure A and a hydroxyl group The following intermediate B 2 molecule obtained by reaction with a derivative having a reactive site such as an amino group can be obtained by linking with 1 molecule of the following compound C. However, the synthesis method of the compounds represented by the general formulas (VA) and (VB) is not limited to this example.

In the formula, A represents a reactive group such as a hydroxyl group or a halogen atom, R ¹¹ , R ² , R ¹³ , and R ⁵ are as described above, and R ⁴ is a hydrogen atom or OR ¹⁴ described above. Is a substituent.

In the formula, A ′ represents a reactive group such as a carboxyl group, and R ¹¹ , R ² , R ¹³ , R ⁴ , R ⁵ , Ar ¹ , and L ¹ are as described above.

In the formula, B and B ′ represent a reactive group such as a hydroxyl group and an amino group, and Ar ² and L ² have the same meanings as Ar ¹ and L ¹ described above.

The content of the Rth enhancer represented by the general formulas (I) and (III) to (V) in the present invention with respect to 100 parts by mass of cellulose acylate is preferably 0.1 to 30% by mass, and 1 to 25% by mass. Is more preferable, and 3 to 15% by mass is even more preferable.
When the cellulose acylate film is produced by a solvent cast method, the Rth enhancer may be added to the dope. The timing of adding the Rth enhancer is not particularly limited, and the Rth enhancer is dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, etc., and then added to the cellulose acylate solution (dope) or directly in the dope composition. It may be added inside.

  As the Rth enhancer, one type of the compounds represented by the general formulas (I) and (III) to (V) may be used alone, or two or more types may be mixed and used. Moreover, in this invention, combined use of the Rth expression agent represented by general formula (I), (III)-(V) is also preferable.

  The cellulose acylate film, particularly the cellulose acylate film used as the first optically anisotropic layer, may contain an ultraviolet absorber. The ultraviolet absorber can also function as an Rth developing agent and / or a Re wavelength dispersion adjusting agent. Examples of the ultraviolet absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. System compounds are preferred. Further, ultraviolet absorbers described in JP-A-10-182621 and JP-A-8-337574 and polymer ultraviolet absorbers described in JP-A-6-148430 are also preferably used. In the cellulose acylate film, as an ultraviolet absorber, from the viewpoint of preventing deterioration of a polarizer and a liquid crystal, it has an excellent ability to absorb ultraviolet rays having a wavelength of 370 nm or less, and from the viewpoint of display properties, a wavelength of 400 nm or more. A thing with little absorption of visible light is preferable.

  Specific examples of the benzotriazole ultraviolet absorber useful in the present invention include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert). -Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl Phenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl) benzotriazole, 2,2 -Methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2 ' Hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy Examples include, but are not limited to, a mixture of -5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate. As commercially available products, TINUVIN 109, TINUVIN 171 and TINUVIN 326 (all manufactured by Ciba Specialty Chemicals Co., Ltd.) can be preferably used.

  Further, in order to produce a cellulose acylate film that satisfies the conditions as the first optically anisotropic layer, a plasticizer such as triphenyl phosphate or biphenyl phosphate may be added to the cellulose acylate film.

  The liquid crystal display device of the present invention may be in a vertical alignment mode such as VA mode, in a horizontal alignment mode such as ISP mode, or in OCB mode or TN mode.

The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.
[Preparation of first retardation film for optically anisotropic layer]
(Preparation of cellulose acylate solution CA-1)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution CA-1.
─────────────────────────────────────
(Cellulose acylate solution CA-1 composition)
─────────────────────────────────────
Cellulose acetate 100.0 parts by mass (Ac substitution degree 2.92)
Rth reducing agent 119 12.0 parts by mass Methylene chloride (first solvent) 402.0 parts by mass Methanol (second solvent) 60.0 parts by mass ───────────────── ────────────────────

(Preparation of matting agent solution MT-1)
20 parts by mass of silica particles having an average particle diameter of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) and 80 parts by mass of methanol were mixed well for 30 minutes to obtain a silica particle dispersion. This dispersion was put into a disperser together with the following composition, and further stirred for 30 minutes or more to dissolve each component to prepare a matting agent solution MT-1.
─────────────────────────────────────
(Matting agent solution MT-1 composition)
─────────────────────────────────────
Silica particle dispersion liquid having an average particle diameter of 16 nm 10.0 parts by mass Methylene chloride (first solvent) 76.3 parts by mass Methanol (second solvent) 3.4 parts by mass Cellulose acylate solution CA-1 10.3 parts by mass ────────────────────────────────────

(Preparation of additive solution)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an additive solution AD-1.
─────────────────────────────────────
(Additive solution AD-1 composition)
─────────────────────────────────────
The following wavelength dispersion regulator UV-265 18.1 parts by weight Methylene chloride (first solvent) 58.4 parts by weight Methanol (second solvent) 8.7 parts by weight Cellulose acylate solution CA-1 12.8 parts by weight ───────────────────────────────────

(Preparation of retardation film sample 101)
94.0 parts by mass of the cellulose acylate solution CA-1, 1.5 parts by mass of the matting agent solution MT-1, and 4.5 parts by mass of the additive solution AD-1 were mixed after filtration, and then a band casting machine. Was used for casting. In the above composition, the mass ratios of the Rth reducing agent and the wavelength dispersion adjusting agent to cellulose acylate were 12.0% and 5.0%, respectively. The film was peeled from the band with a residual solvent amount of 30% and dried at 135 ° C. for 20 minutes to produce a cellulose acylate film. The cast film was transversely stretched at a stretch ratio of 5% using a tenter under the condition of 160 ° C. to obtain a retardation film 101 having a thickness of 80 μm.

  The film was conditioned at 25 ° C. and 60% RH for 2 hours or more, and then using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments) for 2 hours in an environment of 25 ° C. and 60% RH. The humidity was adjusted as described above, and three-dimensional birefringence measurement was performed at wavelengths of 450 nm, 550 nm, and 650 nm, and the in-plane retardation Re and the retardation Rth in the film thickness direction obtained by measuring Re by changing the tilt angle were obtained. However, the optical performance shown in Table 1 was found.

(Preparation of retardation film sample 102)
In preparation of the retardation film sample 101, 7.0 parts by mass of triphenyl phosphate and 5.0 parts by mass of biphenyl phosphate are added in place of the Rth reducing agent 119 in the cellulose acylate solution CA-1, and the additive The amount of the wavelength dispersion adjusting agent UV-265 in the solution AD-1 was changed to 10.5 parts by mass (the mass ratio of the wavelength dispersion adjusting agent UV-265 to the cellulose acylate in the cellulose solution was changed to 3.0%. In the same manner as the sample 101, a retardation film 102 having a film thickness of 80 μm and optical characteristics shown in Table 1 was obtained.

(Preparation of retardation film sample 103)
In the production of the retardation film sample 101, the amount of the wavelength dispersion adjusting agent UV-265 in the additive solution AD-1 was changed to 21.5 parts by mass (the cellulose reed in the cellulose solution of the wavelength dispersion adjusting agent UV-265). A film was produced by casting in the same manner as Sample 101 except that the mass ratio to the rate was changed to 6.0%. Instead of the transverse stretching, the film was set at a film temperature of 180 ° C. and held and conveyed by a tenter clip for 3 minutes to obtain a retardation film 103 having a film thickness of 87 μm and optical characteristics shown in Table 1. .

(Preparation of retardation film sample 104)
In the production of the retardation film sample 104, the cellulose acylate used in the cellulose acylate solution CA-1 was replaced with a cellulose acylate having a substitution degree of 2.86, and instead of the Rth reducing agent 119, triphenyl phosphate 7. 0 parts by mass, 5.0 parts by mass of biphenyl phosphate were added, and the amount of the wavelength dispersion adjusting agent UV-265 in the additive solution AD-1 was changed to 1.8 parts by mass (the wavelength dispersion adjusting agent UV-265. The film was cast in the same manner as in the sample 101 except that the mass ratio of the cellulose solution to cellulose acylate in the cellulose solution was changed to 0.5%. Instead of the transverse stretching, the film was set at a film temperature of 180 ° C., held and transported by a tenter clip for 3 minutes, and obtained a retardation film 104 having a film thickness of 87 μm and optical characteristics shown in Table 1. It was.

(Preparation of retardation film sample 105)
In the production of the retardation film sample 101, the amount of the wavelength dispersion adjusting agent UV-265 in the additive solution AD-1 was changed to 21.5 parts by mass (the cellulose reed in the cellulose solution of the wavelength dispersion adjusting agent UV-265). The retardation film 105 was cast in the same manner as the sample 101 except that the mass ratio to the rate was changed to 6.0%, and the film thickness was 85 μm and the optical properties shown in Table 1 were obtained. Stretching is not performed.

(Preparation of polarizing plate)
The surface of the retardation film 101 produced above was subjected to alkali saponification treatment. It was immersed in a 1.5 N aqueous sodium hydroxide solution at 55 ° C. for 2 minutes, washed in a water bath at room temperature, and neutralized with 0.1 N sulfuric acid at 30 ° C. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. Subsequently, a roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in an iodine aqueous solution and dried to obtain a polarizing film having a thickness of 20 μm. Using the aqueous solution of polyvinyl alcohol (Kuraray PVA-117H) 3% as an adhesive, the alkali saponified retardation film sample 101 and the same alkali saponified Fujitac TD80UL (Fuji Photo Film Co., Ltd.) were prepared. The polarizing film 101 was bonded so that the saponified surface was on the polarizing film side with the polarizing film sandwiched therebetween, and the retardation film 101 and TD80UL were the protective film for the polarizing film. At this time, the retardation film sample 101 was attached so that the MD direction of the retardation film sample 101 and the slow axis of TD80UL were parallel to the absorption axis of the polarizing film.
Similarly, a polarizing plate was produced using the retardation film samples 102 to 104 produced above and the retardation film sample 105 of the comparative example. Hereinafter, these polarizing plates are referred to as polarizing plates 102 to 104 and 105. All of these polarizing plates showed sufficient polarization performance.

[Production of Second Optically Anisotropic Layer Retardation Film]
(Preparation of retardation film sample 201)
(Preparation of cellulose acylate solution CA-2)
─────────────────────────────────────
(Cellulose acylate solution CA-2 composition)
─────────────────────────────────────
Cellulose acetate having an Ac substitution degree of 2.81 100.0 parts by mass TPP (triphenyl phosphate) 7.8 parts by mass BDP (biphenyldiphenyl phosphate) 3.9 parts by mass methylene chloride (first solvent) 402.0 parts by mass methanol (Second solvent) 60.0 parts by mass ──────────────────────────────────────

(Preparation of matting agent solution MT-2)
20 parts by mass of silica particles having an average particle diameter of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) and 80 parts by mass of methanol were mixed well for 30 minutes to obtain a silica particle dispersion. This dispersion was put into a disperser together with the following composition, and further stirred for 30 minutes or more to dissolve each component to prepare a matting agent solution MT-2.
─────────────────────────────────────
(Matting agent solution MT-2 composition)
─────────────────────────────────────
Silica particle dispersion liquid having an average particle size of 16 nm 10.0 parts by mass Methylene chloride (first solvent) 76.3 parts by mass Methanol (second solvent) 3.4 parts by mass Cellulose acylate solution CA-2 10.3 parts by mass ────────────────────────────────────

(Preparation of additive solution)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an additive solution AD-2.
─────────────────────────────────────
(Additive solution AD-2 composition)
─────────────────────────────────────
Retardation expression agent X 21.7 parts by mass Methylene chloride (first solvent) 58.4 parts by mass Methanol (second solvent) 8.7 parts by mass Cellulose acylate solution CA-2 12.8 parts by mass ──────────────────────────────────

Retardation expression agent X

(Preparation of Cellulose Acylate Film Sample 01)
94.0 parts by mass of the cellulose acylate solution CA-2, 1.5 parts by mass of the matting agent solution MT-2, and 4.5 parts by mass of the additive solution AD-2 were mixed after filtration, and the band was cast. It was cast using a machine. In the above composition, the mass ratio of the retardation enhancer to cellulose acylate was 6.0%. The film was peeled from the band with a residual solvent amount of 30%, and dried at 140 ° C. for 40 minutes to produce a cellulose acylate film sample 01. The produced cellulose acylate film sample 01 had a residual solvent amount of 0.2% and a film thickness of 120 μm.

(Preparation of retardation film sample 201)
The cellulose acylate film sample 01 obtained above has a step of stretching a continuous long film in the width direction using a tenter having a structure that becomes narrow while the longitudinal interval of the tenter clip is gripped and conveyed. The film was set to 160 ° C. and stretched 1.25 times in the film width direction to obtain a retardation film sample 201 having a film thickness of 104 μm after stretching. The optical characteristics of the retardation film sample 201 are shown in Table 2 below.

(Preparation of retardation film sample 202)
Using the cellulose acylate film sample 01 obtained above, the film temperature was set to 180 ° C., and after 30 seconds, the film was stretched after passing through the heating zone, stretched 1.35 times in the film width direction, The longitudinal direction of the film shrunk by 0.65 times, and a retardation film sample 202 having a film thickness of 140 μm after stretching was obtained. The optical characteristics of the retardation film sample 202 are shown in Table 2 below.

(Preparation of retardation film sample 203)
In the method for producing the cellulose acylate film sample 01, the additive solution AD-2 was prepared by replacing the cellulose acetate having an Ac substitution degree of 2.81 with a cellulose acetate having an Ac substitution degree of 2.92 in the composition of the cellulose acylate solution CA-2. A cellulose acylate film sample 03 was obtained in the same manner as in the composition except that the retardation developer X was changed to 10.0 parts by mass. Using this, the film temperature was set to 180 ° C., and after 30 seconds passed through the heating zone, stretching was started, and the film width direction contracted 1.25 times, and the film longitudinal direction contracted 0.75 times. A phase difference film sample 203 having a film thickness of 135 μm after stretching was obtained. The optical characteristics of the retardation film sample 203 are shown in Table 2 below.

(Preparation of retardation film sample 204 ′)
In the method for producing the cellulose acylate film sample 01, the additive solution AD-2 was substituted for cellulose acetate having an Ac substitution degree of 2.81 and cellulose acetate having an Ac substitution degree of 2.86 in the cellulose acylate solution CA-2 composition. A cellulose acylate film sample 04 was obtained in the same manner as in the composition except that the retardation developer X was not added. Using this, the film temperature was reduced to 200 ° C., 1.3 times in the film longitudinal direction and 0.7 times in the film width direction to obtain a retardation film sample 204 ′ having a film thickness of 125 μm after stretching. The optical properties of the retardation film sample 204 ′ are shown in Table 2 below.

(Preparation of retardation film sample 204 ″)
In the method for preparing the cellulose acylate film sample 01, the additive solution AD-2 was replaced with cellulose acetate having an Ac substitution degree of 2.81 and cellulose acetate having an Ac substitution degree of 2.92 in the composition of the cellulose acylate solution CA-2. A cellulose acylate film sample 05 was obtained in the same manner as in the composition except that 21.7 parts by mass of the retardation developing agent X was replaced with 25.0 parts by mass of the wavelength dispersion adjusting agent UV-265. Using this, the film temperature was set to 160 ° C., and axial stretching was started. The film was stretched 1.1 times in the width direction of the film and 1.1 times in the longitudinal direction of the film, and the film thickness after stretching was about 100 μm. A retardation film sample 204 ″ was obtained. The optical properties of the retardation film sample 204 ″ are shown in Table 2 below.

(Preparation of retardation film sample 204)
The retardation film samples 204 ′ and 204 ″ were laminated to prepare a retardation film sample 204.

(Preparation of polarizing plate)
A polarizing film was produced in the same manner as described above. A retardation film sample 201 having a surface saponified on one surface of this polarizing film, and a cellulose triacetate film (Fujitack TD80UL, manufactured by Fuji Photo Film Co., Ltd.) having a surface saponified on the other surface, polyvinyl alcohol. The polarizing plate 201 was produced by bonding using a system adhesive.
A polarizing plate was produced in the same manner using the retardation film samples 202 to 204 produced above. Hereinafter, these polarizing plates are referred to as polarizing plates 202 to 204. All of these polarizing plates showed sufficient polarization performance.

[Example 1]
(Production of liquid crystal display device)
Depending on the type of optical characteristics of the optical compensation film used in the liquid crystal display device, mounting evaluation on the VA panel was performed in the following four systems A to D.
(Liquid crystal display devices 001 and 005)
The front and back polarizing plates and the retardation plate of a VA mode liquid crystal TV (LC37-GE2, manufactured by Sharp Corporation) were peeled off and used as a mounting solution liquid crystal cell. In the configuration of FIG. 1, the polarizing plate 101 is used as the polarizer 11 and the first optical anisotropic layer 14, the VA liquid crystal cell is used as the liquid crystal cell 13, and the polarized light is used as the polarizer 12 and the second optical anisotropic layer 15. Each of the plates 201 was bonded using an adhesive. At this time, bonding was performed so that the retardation film sample 201 of the polarizing plate 201 was on the liquid crystal cell 13 side, and the retardation film sample 101 of the polarizing plate 101 was on the liquid crystal cell 13 side. Further, the retardation film sample 201 was bonded so that the slow axis of the retardation film sample 201 was orthogonal to the absorption axis of the polarizing plate 201. A liquid crystal display device 001 was produced. The liquid crystal display device 001 belongs to the category A.
Further, in the method for manufacturing the liquid crystal display device 001, a liquid crystal display device 005 was manufactured in the same manner except that the polarizing plate 105 was used instead of the polarizing plate 101.

(Liquid crystal display devices 002 and 006)
In the same configuration as the liquid crystal display device 001 (Category A), the polarizing plates 102 and 105 are used instead of the polarizing plate 101, and the polarizing plate 202 is used instead of the polarizing plate 201. 006 was produced respectively. Among these, the liquid crystal display device 002 belongs to the classification B.

(Liquid crystal display devices 003 and 007)
In the same configuration as the liquid crystal display device 001 (class A), the polarizing plates 103 and 105 are used instead of the polarizing plate 101, and the polarizing plate 203 is used instead of the polarizing plate 201. 007 was produced respectively. Among these, the liquid crystal display device 003 belongs to the category C.

(Liquid crystal display devices 004 and 008)
In the same configuration as the liquid crystal display device 001 (Category A), the polarizing plates 104 and 105 are used instead of the polarizing plate 101, and the polarizing plate 204 is used instead of the polarizing plate 201. 008 was produced respectively. Among these, the liquid crystal display device 004 belongs to the category D.

(Panel color viewing angle evaluation)
About the produced VA mode liquid crystal display devices 001 to 008, a backlight is installed on the polarizer 2 side in FIG. 1 (that is, the polarizing plate 201 to 204 side), and a measuring instrument (EZ-Contrast XL88, ELDIM) is provided for each. The luminance and chromaticity of black display and white display were measured in a dark room, and the color shift and contrast ratio in black display were calculated.

(Black color shift in polar direction)
In black display, changes in chromaticity Δxθ and Δyθ when the viewing angle is tilted from the normal direction of the liquid crystal cell to the direction of the center line of the transmission axis of the pair of polarizing plates (azimuth angle 45 degrees) are polar angles 0 to 80 degrees. It is preferable that the following formulas (II) and (III) are always satisfied.
Formula (II): 0 ≦ Δxθ ≦ 0.1
Formula (III): 0 ≦ Δyθ ≦ 0.1
[Where Δxθ = xθ−xθ ₀ , Δyθ = yθ−yθ ₀ , (xθ ₀ , yθ ₀ ) is the chromaticity measured in the normal direction of the liquid crystal cell in black display, and (xθ, yθ) is black display Chromaticity measured in the direction of tilting the viewing angle from the normal direction of the liquid crystal cell to the center line of the transmission axis of the pair of polarizing plates up to a polar angle of θ degrees]

(Black color shift in azimuth direction)
Further, the color when the viewing angle is tilted from the normal direction of the liquid crystal cell to 60 degrees in the absorption axis direction of the polarizing plate on the viewing side, and the chromaticity is measured by rotating 360 degrees around the normal with the direction as the base point. It is preferable that the degree change Δxφ always satisfies the following formulas (IV) and (V) between azimuth angles 0 to 360 degrees.
Formula (IV): −0.02 ≦ Δxφ ≦ 0.1
Formula (V): −0.02 ≦ Δyφ ≦ 0.1
[In the formula, Δxφ = xφ−xφ ₀ , Δyφ = yφ−yφ ₀ , and (xφ ₀ , yφ ₀ ) is 60 degrees from the normal direction of the liquid crystal cell in the black display to the absorption axis direction of the viewing side polarizing plate. The chromaticity measured by tilting the viewing angle, (xφ, yφ), tilts the viewing angle from the normal direction of the liquid crystal cell in black display to the absorption axis direction of the viewing side polarizing plate to 60 degrees, and the azimuth angle with the normal direction as the center Chromaticity measured from φ direction]

(Viewing angle)
A larger contrast ratio (CR @ φ = 45 / Θ = 60) at an azimuth angle of 45 degrees and a polar angle of 60 degrees means a wider viewing angle.
The results are shown in Table 3 below.

It is a schematic diagram of an example of the liquid crystal display device of this invention. It is the figure used in order to demonstrate an example on the Poincare sphere of the optical compensation mechanism of the liquid crystal display device of this invention. The optical characteristic of an example of the 1st optically anisotropic layer which can be used for the liquid crystal display device of this invention is typically shown on the graph. It is the figure which classified and showed the various aspects of the liquid crystal display device of this invention to classification | category AH. It is a schematic diagram of an example of the liquid crystal display device of this invention. It is the figure which classified and showed the various aspects of the liquid crystal display device of this invention of the structure of FIG. It is a schematic diagram of an example of a general VA mode liquid crystal display device. It is a schematic diagram of an example of a general VA mode liquid crystal display device. It is a schematic diagram of an example of a conventional VA mode liquid crystal display device. It is the figure used in order to demonstrate an example of the optical compensation mechanism of the liquid crystal display device of the conventional VA mode on a Poincare sphere.

Explanation of symbols

11, 21, 51 Polarizer 12, 22, 52 Polarizer 13, 23, 53 Liquid crystal cell 14, 24 First optical anisotropic layer 15, 25 Second optical anisotropic layer 54 Optical compensation film (C plate )
55 Optical compensation film (A plate)

Claims (15)

First and second polarizers arranged with their transmission axes orthogonal to each other;
A liquid crystal layer disposed between the first and second polarizers;
A liquid crystal display device having a first optically anisotropic layer between the first or second polarizer and a liquid crystal layer,
The in-plane retardation (Re) of the first optically anisotropic layer becomes positive at a wavelength λ1 in the visible light region, becomes negative at a wavelength λ2 in the visible light region (where λ1 ≠ λ2), and | Rth (550 ) | Is 50 nm or more, and the first optically anisotropic layer satisfies the following formulas (1) and (2), and Re (λ) and A liquid crystal display device in which the wavelength dependency of Rth (λ) is selected :
Re (450) × Re (650) <0 Formula (1)
| Rth (550) / Re (550) |> 10 Formula (2)
In the formula, Re (λ) is an in-plane retardation (unit: nm) measured by incidence of light having a wavelength of λ nm, and Re of the first optical anisotropic layer is positive or negative with respect to the liquid crystal cell. With reference to the absorption axis of the polarizer disposed on the same side, the parallel direction of the absorption axis and the slow axis of the first optically anisotropic layer is positive. Rth (λ) is a thickness direction retardation (unit: nm) measured by making light having a wavelength λ nm incident. A second optical anisotropic layer is provided between the first or second polarizer and the liquid crystal layer, and the second optical anisotropic layer satisfies the following formulas (3) and (4): The liquid crystal display device according to claim 1, wherein:
30 nm <Re (550) <400 nm Formula (3)
−100 nm <Rth (550) <300 nm Formula (4)
In the formula, Re (λ) is an in-plane retardation (unit: nm) measured by making light of wavelength λnm incident; Rth (λ) is measured in the thickness direction measured by making light of wavelength λnm incident Retardation value (unit: nm). The first optically anisotropic layer is between the liquid crystal layer and the first polarizer, and the second optically anisotropic layer is between the liquid crystal layer and the second polarizer. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is disposed between them. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is in a VA mode. The first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | ≧ 1.0
The liquid crystal display device according to claim 4, wherein all of the above are satisfied. The first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | <1.0
The liquid crystal display device according to claim 4, wherein all of the above are satisfied. The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550)> 0, and | Rth (450) | / | Rth (650) | <1.0
The liquid crystal display device according to claim 4, wherein all of the above are satisfied. The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550)> 0 and | Rth (450) | / | Rth (650) | ≧ 1.0
The liquid crystal display device according to claim 4, wherein all of the above are satisfied. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is in a horizontal alignment mode. The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | ≧ 1.0
The liquid crystal display device according to claim 9, wherein all of the above are satisfied. The first optically anisotropic layer has the following formula Re (450) <0,
Re (650)> 0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | <1.0
The liquid crystal display device according to claim 9, wherein all of the above are satisfied. The first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550) <0 and | Rth (450) | / | Rth (650) | <1.0
The liquid crystal display device according to claim 9, wherein all of the above are satisfied. The first optically anisotropic layer has the following formula Re (450)> 0,
Re (650) <0,
Rth (550) <0, and | Rth (450) | / | Rth (650) | ≧ 1.0
The liquid crystal display device according to claim 9, wherein all of the above are satisfied. The liquid crystal display device according to claim 1, wherein the first optically anisotropic layer is made of a cellulose acylate film. The liquid crystal display device according to claim 1, wherein the first optically anisotropic layer contains at least one kind of Rth enhancer.

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