JP5688336B2 - IPS or FFS type liquid crystal display device - Google Patents

Description

  The present invention relates to an IPS or FFS type liquid crystal display device with improved viewing angle characteristics.

  In recent years, applications of IPS type and FFS type liquid crystal display devices such as television display devices have been expanded. Conventionally, it is known that a retardation layer containing a vertically aligned discotic liquid crystal compound contributes to an improvement in viewing angle characteristics of an IPS liquid crystal display device (Patent Documents 1 and 2). By using the retardation layer, the viewing angle contrast can be remarkably improved with a simple configuration.

Japanese Patent No. 4253259 JP 2005-309382 A

However, television display devices and the like are required to have better viewing angle characteristics. As for the IPS liquid crystal display device, there is a case where a color shift occurs in an oblique direction, and improvement is demanded. In addition, gradation inversion (particularly inversion between black gradation and one higher brightness gradation) may occur in an oblique direction, and improvement is required.
An object of the present invention is to provide an IPS or FFS type liquid crystal display device in which not only the viewing angle contrast is improved but also the color shift and gradation inversion in the oblique direction are reduced.

  As a result of intensive studies by the present inventors, the color shift observed in the IPS liquid crystal display device having the above configuration is affected by the wavelength dispersion of retardation of the retardation layer containing the discotic liquid crystal compound, Furthermore, it has been found that the liquid crystal molecules in the liquid crystal layer are slightly tilted and oriented to the gradation inversion, and further studies are made based on this knowledge, and the present invention has been completed. . The effect of the present invention can be obtained not only in the IPS type but also in the FFS type liquid crystal display device similarly classified into the horizontal alignment mode.

Means for solving the above-mentioned problems are as follows.
[1] a first polarizing film;
An optical compensation film comprising a first retardation region and a second retardation region in contact with the first retardation region;
A first substrate;
A liquid crystal layer made of a nematic liquid crystal material;
A second substrate;
In this order, and the liquid crystal display device in which the liquid crystal molecules of the nematic liquid crystal material are aligned in parallel to the surfaces of the pair of substrates during black display,
The first retardation region and the slow axis of the second retardation region are parallel to each other;
In-plane retardation Re (550) of wavelength 550 nm of the second retardation region is 20 nm or less, retardation Rth (550) in the thickness direction of wavelength 550 nm of the second retardation region is 20 nm to 120 nm,
The first retardation region includes a retardation layer containing a discotic liquid crystal compound tilted and oriented at an average tilt angle θ (θ> 0), and has Re, Re (450), Re (wavelengths of 450 nm, 550 nm, and 650 nm). 550) and Re (650) satisfying Re (450) / Re (550) of 1 or more and 1.13 or less and Re (650) / Re (550) satisfying 0.94 or more and 1 or less. Liquid crystal display device: However, in-plane retardation Re and thickness direction retardation are obtained by using in-plane refractive index nx and ny (nx ≧ ny), thickness direction refractive index nz, and film thickness d, respectively. , Re = (nx−ny) × d and Rth = {(nx + ny) / 2−nz} × d.
[2] The IPS or FFS liquid crystal display device according to [1], wherein the average tilt angle θ is 0 to 10 °.
[3] In the first retardation region, the discotic liquid crystal compound is tilted and oriented in a direction in which the angle between the molecular director and the director of the liquid crystal layer in the black state decreases [1] or [2] IPS or FFS liquid crystal display device.
[4] The IPS or FFS liquid crystal display device according to any one of [1] to [3], which is disposed in the order of the first polarizing film, the first retardation region, and the second retardation region.
[5] The IPS or FFS liquid crystal display device according to any one of [1] to [3], which is disposed in the order of the first polarizing film, the second retardation region, and the first retardation region.
[6] The IPS or FFS type liquid crystal display device according to any one of [1] to [5], wherein Re (550) of the first retardation region is 50 nm to 200 nm.
[7] The IPS or FFS liquid crystal display device according to any one of [1] to [6], wherein an absolute value | Rth (550) | of Rth (550) of the entire optical compensation film is 40 nm or less.
[8] The second retardation region includes a plurality of layers, a layer in contact with the first retardation region among the plurality of layers is an alignment film, and the first retardation region includes a discotic liquid crystal compound and The IPS according to any one of [1] to [7], comprising an composition containing at least an alignment control agent, wherein the alignment control agent has an action of reducing the tilt angle of the director of the discotic liquid crystal compound on the air interface side. Or an FFS type liquid crystal display device.
[9] The IPS or FFS of any one of [4] to [8], wherein the first retardation region has a polymer film together with the retardation layer, and the polymer film is in contact with the first polarizing film. Type liquid crystal display device.
[10] The IPS or FFS type liquid crystal display device according to any one of [1] to [9], further including a second polarizing film on the outer side of the second substrate.
[11] The IPS or FFS type liquid crystal display device according to [10], wherein a polymer film is provided between the second polarizing film and the second substrate.
[12] The polymer film has an in-plane retardation Re (550) absolute value | Re (550) | of a wavelength of 550 nm of 10 nm or less, and an absolute value of retardation Rth (550) in the thickness direction of the same wavelength. IPS or FFS liquid crystal display device according to [9] or [11], wherein | Rth (550) | is 30 nm or less.
[13] The polymer film has a | Re (400) -Re (700) | of 10 nm or less and a | Rth (400) -Rth (700) | of 35 nm or less [9], [11] or [12] The IPS or FFS type liquid crystal display device.
[14] The IPS or FFS type liquid crystal display device according to any one of [9] and [11] to [13], wherein the polymer film has a thickness of 10 to 90 μm.
[15] The IPS or FFS type liquid crystal display device according to any one of [9] and [11] to [14], wherein the polymer film includes a cellulose acylate film, a cyclic olefin polymer film, or an acrylic polymer film. .
[16] The acrylic polymer film is an acrylic polymer film containing an acrylic polymer containing at least one unit selected from a lactone ring unit, a maleic anhydride unit, and a glutaric anhydride unit. [15] Liquid crystal display device.

  According to the present invention, it is possible to provide an IPS or FFS type liquid crystal display device in which not only the viewing angle contrast is improved but also the oblique color shift and gradation inversion are reduced.

It is a cross-sectional schematic diagram of an example of the IPS or FFS type liquid crystal display device of this invention. It is a cross-sectional schematic diagram of the other example of the IPS or FFS type liquid crystal display device of this invention. It is a cross-sectional schematic diagram of the other example of the IPS or FFS type liquid crystal display device of this invention. It is a cross-sectional schematic diagram of the other example of the IPS or FFS type liquid crystal display device of this invention. It is the schematic which shows the pixel area example which can be used for this invention. A schematic diagram (A) showing the tilted alignment state of the discotic liquid crystal compound (D-LCD) in the first retardation region together with the alignment state of the nematic liquid crystal compound (N-LC) in the liquid crystal layer is shown in FIG. It is the figure shown by contrast with the schematic diagram (B) of the vertical alignment state of (D-LC). It is the figure which showed typically an example of the locus | trajectory of the polarization state which injected into the liquid crystal display device of this invention on the Poincare sphere.

  Hereinafter, an embodiment of the liquid crystal display device of the present invention and its constituent members will be described in sequence. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  In this specification, the relationship between the optical axes includes errors allowed in the technical field to which the present invention belongs. Specifically, “parallel” and “orthogonal” mean that the angle is within a strict angle of less than ± 10 °, preferably less than ± 5 °, and less than ± 3 °. More preferred. Further, the “slow axis” means a direction in which the refractive index is maximized. Further, the measurement wavelength of the refractive index is a value at λ = 550 nm in the visible light region unless otherwise specified.

  In this specification, “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal device unless otherwise specified (in this specification, “cutting” includes “punching” and “cutting out”. It is used in the meaning including both of the polarizing plates. In this specification, “polarizing film” and “polarizing plate” are distinguished from each other. “Polarizing plate” means a laminate having a transparent protective film for protecting the polarizing film on at least one side of the “polarizing film”. It shall be.

  In the description of the present embodiment, the term “director” refers to the director when the molecule has a rotational symmetry axis. However, in a strict sense, it does not require that the molecule is rotationally symmetric. Absent. In general, in a discotic liquid crystal compound, the director coincides with an axis perpendicular to the disc surface passing through the center of the disc surface. Sometimes called the molecular symmetry axis.

In this 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 with KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength of λ nm incident in the normal direction of the film. In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like. When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method. This measuring method is also partially used for measuring the average tilt angle on the alignment film side of the discotic liquid crystal molecules in the retardation layer, which will be described later, and the average tilt angle on the opposite side.
Rth (λ) is the film surface when Re (λ) is used and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) (if there is no slow axis) Measurement is performed at a total of 6 points by injecting light of wavelength λ nm from each inclined direction in steps of 10 degrees from the normal direction to 50 ° on one side with respect to the film normal direction (with any rotation direction as the rotation axis). Then, 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. The retardation value is measured from two inclined directions with the slow axis as the tilt axis (rotation axis) (if there is no slow axis, the arbitrary direction in the film plane is the rotation axis). Rth can also be calculated from the following formula (A) and formula (III) based on the value, the assumed value of the average refractive index, and the input film thickness value.

なお、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（Ａ）における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す。
Ｒｔｈ＝（（ｎｘ＋ｎｙ）／２−ｎｚ）×ｄ・・・・・・・・・・・式（ＩＩＩ）

Note that Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. In the formula (A), 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, and nz is the direction orthogonal to nx and ny. Represents the refractive index.
Rth = ((nx + ny) / 2−nz) × d (formula (III))

  When the film to be measured is a film that cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film without a so-called optical axis, Rth (λ) is calculated by the following method. Rth (λ) is from −50 ° to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotary axis). Measured at 11 points by making light of wavelength λ nm incident in 10 ° steps up to + 50 °, and based on the measured retardation value, average refractive index assumption value and input film thickness value. KOBRA 21ADH or WR is calculated. In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. If the average refractive index is not known, it can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), 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.

  Unless otherwise specified, the measurement wavelengths of Re and Rth are values at λ = 550 nm in the visible light region.

(Measurement of tilt angle)
In the retardation layer in which the discotic liquid crystal compound is aligned, the tilt angle on one surface of the retardation layer (the angle formed by the physical target axis in the discotic liquid crystal compound and the interface of the retardation layer is the tilt angle) θ1 In addition, it is difficult to directly and accurately measure the tilt angle θ2 of the other surface. Therefore, in this specification, θ1 and θ2 are calculated by the following method. Although this method does not accurately represent the actual orientation state of the present invention, it is effective as a means for expressing the relative relationship of some optical properties of the optical film.
In this method, in order to facilitate the calculation, the following two points are assumed and the tilt angle at the two interfaces of the retardation layer (also referred to as an optically anisotropic layer) is used.
1. The retardation layer is assumed to be a multilayer body composed of layers containing a discotic liquid crystal compound. Further, it is assumed that the minimum unit layer (assuming that the tilt angle of the discotic liquid crystal compound is uniform in the layer) is optically uniaxial.
2. It is assumed that the tilt angle of each layer changes monotonically with a linear function along the thickness direction of the retardation layer.
The specific calculation method is as follows.
(1) Within the plane in which the tilt angle of each layer changes monotonically with a linear function along the thickness direction of the retardation layer, the incident angle of the measurement light to the retardation layer is changed, and the letter is measured at three or more measurement angles. Measure the foundation value. In order to simplify measurement and calculation, it is preferable to measure the retardation value at three measurement angles of −40 °, 0 °, and + 40 °, with the normal direction to the retardation layer being 0 °. Such measurements include KOBRA-21ADH and KOBRA-WR (manufactured by Oji Scientific Instruments), transmission type ellipsometer AEP-100 (manufactured by Shimadzu Corporation), M150 and M520 (manufactured by JASCO Corporation). ), ABR10A (manufactured by UNIOPT Co., Ltd.).
(2) In the above model, the refractive index of ordinary light in each layer is no, the refractive index of extraordinary light is ne (ne is the same value in all layers, and no is the same), and the thickness of the entire multilayer body is d. And Further, based on the assumption that the tilt direction in each layer and the uniaxial optical axis direction of the layer coincide with each other, the calculation of the angle dependence of the retardation value of the retardation layer matches the measured value so that the retardation value of the retardation layer coincides with the measured value. Fitting is performed using the tilt angle θ1 on one surface and the tilt angle θ2 on the other surface as variables, and θ1 and θ2 are calculated.
Here, known values such as literature values and catalog values can be used for no and ne. If the value is unknown, it can also be measured using an Abbe refractometer. The thickness of the retardation layer can be measured by an optical interference film thickness meter, a cross-sectional photograph of a scanning electron microscope, or the like.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an embodiment of the IPS or FFS type liquid crystal display device of the present invention.
The liquid crystal display device shown in FIG. 1 includes a pair of first polarizing film 16 and second polarizing film 18, a first phase difference region 20 in contact with the first polarizing film 16, and a second phase difference in contact with the first phase difference region. The optical compensation film F including the region 22 and at least an IPS or FFS type liquid crystal cell LC are provided. A backlight 26 is disposed further outside the second polarizing film 18.

  In the liquid crystal display device of FIG. 1, the liquid crystal cell LC includes a first substrate 12, a liquid crystal layer 10 made of a nematic liquid crystal material, and a second substrate 14. The liquid crystal layer 10 is an IPS or FFS type liquid crystal cell in which liquid crystal molecules of the nematic liquid crystal material are aligned parallel to the surfaces of the pair of substrates 12 and 14 during black display. The product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn is, in the transmission mode, in the range of 0.2 to 0.4 μm for the IPS type having no twisted structure, and 0 for the FFS type. The range of 3 to 0.5 μm is the optimum value. In this range, the white display luminance is high and the black display luminance is small, so that a bright and high-contrast display device can be obtained. An alignment film (not shown) is formed on the surfaces of the substrates 12 and 14 that are in contact with the liquid crystal layer 10, and the liquid crystal molecules are aligned substantially parallel to the surface of the substrate and are rubbed on the alignment film. The liquid crystal molecule alignment direction in a voltage non-application state or a low application state is controlled by the processing direction or the like. Further, an electrode (not shown in FIG. 1) capable of applying a voltage to the liquid crystal molecules is formed on the inner surface of the substrate 12 or 14.

  When no voltage is applied, the liquid crystal layer 10 is controlled by the rubbing direction of the alignment film formed on the inner surfaces of the substrates 12 and 14, for example, without twisting the liquid crystal molecules and aligned in a certain horizontal direction. Yes. When a voltage is applied, the liquid crystal molecules are horizontally rotated by a predetermined angle by an electric field formed in the in-plane direction, and are aligned in a predetermined direction. Various shapes and arrangements of electrodes have been proposed, and any of them can be used. FIG. 5 schematically shows an example of the alignment of liquid crystal molecules in one pixel region of the liquid crystal layer 10. FIG. 5 shows the alignment of the liquid crystal molecules in a very small area corresponding to one pixel of the liquid crystal layer 10 in the rubbing direction 4 of the alignment film formed on the inner surfaces of the substrates 12 and 14 and the substrates 12 and 14. It is an example of the schematic diagram shown with the electrodes 2 and 3 which can apply a voltage to the liquid crystal molecule formed in the inner surface. When active driving is performed using a nematic liquid crystal having positive dielectric anisotropy as a field effect liquid crystal, the liquid crystal molecule alignment directions in a no voltage application state or a low application state are 5a and 5b. A display is obtained. When applied between the electrodes 2 and 3, the liquid crystal molecules change their alignment direction in the directions of 6 a and 6 b in accordance with the voltage. Normally, white display is performed in this state.

  In FIG. 1 again, the absorption axis 16a of the first polarizing film 16 and the absorption axis 18a of the second polarizing film 18 are arranged orthogonally. When no voltage is applied, the liquid crystal molecules of the liquid crystal layer 10 are horizontally aligned so that the slow axis 10 a of the liquid crystal layer 10 is parallel to the absorption axis 18 a of the second polarizing film 18. Therefore, the light incident from the backlight 26 is added with the liquid crystal layer 10 while maintaining the polarization state substantially, and is blocked by the absorption axis 16a of the first polarizing film 16 to display black. However, light incident from an oblique direction among the light incident from the backlight 26 causes light leakage because the absorption axes 16a and 18a of the polarizing films 16 and 18 are shifted from the orthogonal relationship, that is, The viewing angle contrast is reduced. The optical compensation film F has an effect of reducing the light leakage and improving the viewing angle contrast.

  The optical compensation film F includes, for example, a second retardation region 22 including a polymer film that can be a support, and a first retardation region 20 including a retardation layer containing a tilted and aligned discotic liquid crystal compound. Conventionally, when a retardation layer containing a vertically aligned discotic liquid crystal compound is used for viewing angle compensation of a liquid crystal display device such as an IPS mode, the viewing angle contrast is remarkably improved. In some cases, it is difficult to simultaneously improve the viewing angle contrast and reduce the color shift.

  One cause of the color shift in the oblique direction is that the retardation of the retardation layer used for optical compensation is not suitable for wavelength dispersion. In general, the Re wavelength dispersion of a retardation layer formed using a discotic liquid crystal compound is determined by the properties of the discotic liquid crystal compound used. In order to reduce the color shift, Re of the retardation layer is ideally reverse wavelength dispersive in the visible light region, but on the other hand, it is generally formed using a discotic liquid crystal compound. The Re of the retardation layer has forward wavelength dispersion. As a result of intensive studies by the inventor, the wavelength dispersion of Re in the first retardation region 20 is such that Re (450) / Re (550) is 1 or more and 1.13 or less, and Re (650) / Re (550). ) Satisfies 0.94 or more and 1 or less, it has been found that the color shift can be reduced to the extent that there is no sense of incongruity even when observed with the human eye. Examples of discotic liquid crystal compounds that satisfy this characteristic will be described later.

In the IPS and FFS modes, the liquid crystal molecules in the liquid crystal layer are ideally horizontally aligned with respect to the substrate in both the white state and the black state. It was found that most of them were tilted and this tilted orientation was the cause of gradation inversion (particularly inversion between black gradation and one higher brightness). . As a result of intensive studies by the inventor, this gradation inversion is achieved by using a retardation layer containing a discotic liquid crystal compound that is tilt-aligned at a low tilt angle (the tilt angle is sometimes referred to as “tilt angle”). It turned out that it can suppress. The average inclination angle θ is θ> 0, preferably 0 ° <θ <10 °, more preferably 0 ° <θ <5 ° , and further preferably 0 ° <θ <3 ° . . If the average inclination angle becomes too large (for example, more than 10 °), problems such as deterioration of the viewing angle contrast occur. Here, the average inclination angle θ refers to an angle formed by the molecular director of the discotic liquid crystal compound and the layer surface (the layer surface is generally parallel to the cell substrate). For example, since the molecular director of the discotic liquid crystal compound that is vertically aligned (that is, aligned with the disk surface perpendicular to the layer surface) is in the normal direction of the disk surface, it is parallel to the layer surface. The average tilt angle of the molecular director is 0 °.

  Such a tilted orientation state with a low tilt angle can be formed by once vertically aligning the discotic liquid crystal compound and then applying hot air at a horizontal to 10 ° with respect to the coated surface, as will be described later. .

In addition, the tilt direction of the discotic liquid crystal compound affects the effect of suppressing gradation inversion. It is preferable that the discotic liquid crystal compound is tilted in the direction in which the angle between the molecular director and the director of the liquid crystal layer in the black state is reduced, because the effect of suppressing gradation inversion is excellent. FIG. 6A schematically shows a preferred tilted alignment state, and FIG. 6B is a schematic diagram of a conventional vertical alignment state. As schematically shown in FIG. 6B, when the nematic liquid crystal N-LC in the liquid crystal layer is in an ideal horizontal alignment state, the director d2 of the liquid crystal molecules in the liquid crystal layer is parallel to the layer surface. And the molecular director d1 of the ideal vertically aligned discotic liquid crystal compound D-LC is parallel to the layer surface because it is in the normal direction of the disk surface, that is, both are parallel and do not intersect. . In the present invention, as schematically shown in FIG. 6A, the molecular director d1 of the discotic liquid crystal compound D-LC is tilted with an average tilt angle θ, and the tilt direction is as shown in FIG. ), The angle between the molecular director d1 and the director d2 of the liquid crystal layer in the black state is preferably reduced.
FIG. 6A shows an example in which the director of nematic liquid crystal molecules in the liquid crystal layer is tilted. Of course, the present invention shows that the director of nematic liquid crystal molecules in the liquid crystal layer is relative to the layer surface. Spray orientation may be used, and even with spray orientation, gradation inversion can be suppressed by tilting the director of the discotic liquid crystal compound at an appropriate angle.

  As long as the first retardation region 20 satisfies the above optical characteristics, Re and Rth are not particularly limited, but as the entire optical compensation film F including the first retardation region 20 and the second retardation region 22 When the absolute value of Rth (550) is 40 nm or less, it is preferable from the viewpoint of viewing angle contrast and color shift improvement. The reason for this is that, when the black display is viewed using the configuration of FIG. 1 as an example, light incident in an oblique direction from the backlight 26 is converted into the second polarizing film 18, the liquid crystal layer 10, the optical compensation film F, and the first polarized light. When the transition of the polarization state due to the addition of the film 16 is shown on the Poincare sphere, the polarized light (incident polarized light) that has passed through the second polarizing film passes through the trajectory as shown in FIG. It changes to polarized light (emitted polarized light) before passing through one polarizing film. Since the emitted polarized light at this time is in a crossed Nicols relationship with the first polarizing film, the luminance of black display can be suppressed. As a result of intensive studies by the present inventors, it has been found that when the absolute value of Rth (550) of the optical compensation film is 40 nm or less, the relationship between the outgoing polarized light and the crossed Nicols of the first polarizing film is improved.

  The second retardation region 22 satisfies Re (550) of 20 nm or less and Rth (550) of 20 to 120 nm. As long as the second retardation region 22 satisfies this optical characteristic, the material thereof is not particularly limited, and may be a single layer structure or a laminated structure including two or more layers. It is preferable to include a self-supporting polymer film because it can be used as a support for the first retardation region 20 formed by coating or the like. An example is an example in which the second retardation region 22 is a laminate including a polymer film and an alignment film, and the alignment film is in contact with the first retardation region 20. The surface of the alignment film may be subjected to rubbing treatment, and the rubbing treatment direction is parallel to the slow axis direction of the polymer film (generally in many cases coincides with the longitudinal direction of the polymer film). It is preferable because it is excellent in production suitability. Examples of the polymer film and the alignment film that can be used in the second retardation region will be described later.

  In the liquid crystal display device of FIG. 1, a protective film 24 for the second polarizing film 18 is disposed between the second polarizing film 18 and the liquid crystal cell LC. From the viewpoint of improving the viewing angle contrast, the protective film 24 preferably has a low phase difference. Specifically, the absolute value | Re (550) | of Re (550) is 10 nm or less (more preferably 5 nm or less). And the absolute value | Rth (550) | of Rth (550) is preferably 30 nm or less (more preferably 15 nm or less). In addition, the protective film 24 preferably has low wavelength dispersion from the viewpoint of reducing the color shift that occurs in an oblique direction. Specifically, | Re (400) −Re (700) | is 10 nm or less ( More preferably, it is 5 nm or less), and | Rth (400) −Rth (700) | is 35 nm or less (more preferably 15 nm or less). The protective film 24 preferably has a certain thickness from the viewpoint of durability, and specifically, the thickness is preferably 10 to 90 μm (more preferably 40 to 80 μm). Examples of polymer films that can be used as the protective film 24 will be described later.

  The protective film 24 is disposed for improving the durability of the second polarizing film 18 and the adhesiveness between the second polarizing film 18 and the substrate 14. If the adhesiveness with the substrate 14 is sufficient, it is not necessary.

  It is preferable that a protective film is disposed on the outer surfaces of the first polarizing film 16 and the second polarizing film 18, and the first polarizing film 16 has an optical compensation film F on one surface thereof, and the other surface. The polarizing plate PL1 having a protective film and the second polarizing film 18 may be incorporated in a liquid crystal display device as a polarizing film PL2 having a protective film 24 on one surface and a protective film on the other surface. Good.

  Note that the surface of the optical compensation film F that adheres to the first polarizing film 16 is a first retardation region 20 including a retardation layer containing a tilted and aligned discotic liquid crystal, and the first retardation region 20 is a disco layer. When it consists only of the retardation layer formed by hardening | curing the curable composition containing a tick liquid crystal compound, the adhesiveness with the 1st polarizing film 16 may be weak. A polymer film may be laminated on the surface of the retardation layer to improve adhesiveness with the first polarizing film 16. From the viewpoint of improving the viewing angle contrast, the polymer film is preferably a film having low Re and low Rth and small wavelength dispersion of Re and Rth, that is, exhibiting the same optical characteristics as the protective film 24. preferable.

  Further, the first phase difference region 20 and the second phase difference region 22 may be arranged interchangeably, that is, the configuration shown in FIG. In any configuration, the same effect of reducing color shift can be obtained. In the configuration of FIG. 2, the adhesion between the optical compensation film F and the first polarizing film 16 can be improved, which is preferable from the viewpoint of durability, but on the other hand, the first retardation region 20 and the second retardation region 22 are delayed. Suitable for roll-to-roll systems where the phase axis needs to be rotated 90 degrees, and a protective film with an adhesive laid on one side and a different type of roll-shaped optical compensation film on the other are adhered to each other while being conveyed. 1 is preferable because the productivity deteriorates.

The configuration of the backlight 26 is not particularly limited. Any of a light guide plate method and a direct type method may be used. The light guide plate type backlight unit includes a light source and a light guide plate, and the direct type backlight unit includes a light source and a diffusion plate. The light source used is not particularly limited, and any of light bulbs, light emitting diodes (LEDs), electroluminescence panels (ELP), one or more cold cathode fluorescent lamps (CCFL), hot cathode fluorescent lamps (HCFL), etc. should be used. Can do.
The backlight 26 can be made of a member such as a reflector or a brightness enhancement film in order to increase the light use efficiency. Furthermore, when forming the liquid crystal display device, in addition to the above-described members, for example, components such as a diffusion plate, a protective plate, a prism array, a lens array sheet, and a light diffusion plate can be appropriately arranged in one layer or two or more layers.

  1 and 2 show the configuration in which the backlight 26 is disposed outside the second polarizing film 18, the backlight 26 may be disposed outside the first polarizing film 16, that is, FIG. And the structure of FIG. 4 may be sufficient. The same effects as in FIGS. 1 and 2 can be obtained.

  The liquid crystal display device of the present invention includes an image direct view type, an image projection type, and a light modulation type. The present invention is particularly effective when applied to an active matrix liquid crystal display device using a three-terminal or two-terminal semiconductor element such as TFT or MIM. Of course, a mode applied to a passive matrix liquid crystal display device called time-division driving is also effective.

  Hereinafter, preferred optical characteristics of various members usable in the liquid crystal display device of the present invention, materials used for the members, manufacturing methods thereof, and the like will be described in detail.

1. Optical Compensation Film The liquid crystal display device of the present invention is in contact with the first retardation region including a retardation layer containing a discotic liquid crystal compound that is tilted and aligned, and satisfies the predetermined optical characteristics. One feature is that the optical compensation film has a second retardation region, and the wavelength dispersion of Re in the first retardation region is within a predetermined range. In the optical compensation film, the slow axis of the first retardation region and the slow axis of the second retardation region are parallel. Each of the first and second retardation regions may have a single layer structure or a laminated structure including two or more layers. By using the compensation film, the present invention not only improves the viewing angle contrast but also reduces the color shift that occurs in the oblique direction.

  The wavelength dispersion in the visible light region of the retardation of the first retardation region affects the color shift that occurs in the oblique direction. From the viewpoint of reducing the color shift, it is ideal that the wavelength dispersion of Re in the first retardation region is reverse wavelength dispersion, but in general, it is formed by fixing the orientation of the discotic liquid crystal compound. The Re wavelength dispersion of the retardation layer tends to be forward wavelength dispersion. As a result of intensive studies by the present inventors, even if Re in the first retardation region is not reverse wavelength dispersive, Re (450) / Re (550) is 1 or more and 1.13 or less (more preferably 1-1. 10), if Re (650) / Re (550) is 0.94 or more and 1 or less (more preferably 0.96 to 1.0), the occurrence of oblique color shift can be reduced, and this is a practical problem. I knew it was n’t there. Examples of the discotic liquid crystal compound capable of achieving the wavelength dispersion include a discotic liquid crystal compound represented by the formula (I) described later.

  Re (550) of the second retardation region is 20 nm or less, and Rth (550) is 20 nm to 120 nm. Re (550) is preferably 15 nm or less, and more preferably 10 nm or less. Rth (550) is preferably 30 to 110 nm, and more preferably 40 to 100 nm.

  On the other hand, Re and Rth in the first retardation region are not particularly limited, but Re (550) is preferably 50 to 200 nm from the viewpoint of improving the viewing angle contrast of the entire optical compensation film, and Rth (550) ) Is preferably 40 nm or less. In particular, if | Rth (550) | as the entire optical compensation film exceeds 40 nm, the viewing angle contrast may deteriorate. Considering the optical characteristics of the second retardation region and the optical compensation film as a whole, Re (55) of the first retardation region is preferably 50 to 200 nm, more preferably 80 to 170 nm, 100 More preferably, it is ˜150 nm; Rth (550) is preferably 25 to 100 nm, more preferably 40 to 85 nm, and even more preferably 50 to 75 nm.

  An example of the optical compensation film is formed from a composition containing a discotic liquid crystal compound disposed in contact with the second retardation region composed of a polymer film and an alignment film formed thereon, and the alignment film. An optical compensation film comprising a first retardation region including a retardation layer. When the optical compensation film having the structure is continuously produced in a long shape, from the viewpoint of production suitability, the longitudinal direction of the polymer film serving as a support (usually coincides with the slow axis of the polymer film) and orientation In general, the alignment control direction of the film (for example, the rubbing treatment direction in the case of a rubbing alignment film) is matched. In general, the disk-like liquid crystal molecules are tilted (hereinafter sometimes referred to as “parallel tilt alignment”) by inserting the disk surface along the grooves on the alignment film surface formed by rubbing. The slow axis of the retardation layer formed by fixing the orientation state is parallel to the slow axis of the polymer film.

Hereinafter, materials and methods used for manufacturing the optical compensation film having the above-described configuration will be described in detail.
(1) Second retardation region An example of the second retardation region used in the optical compensation film having the above-described configuration is a laminated film having at least a polymer film serving as a support and an alignment film thereon.
Polymer film:
As long as the optical characteristics are exhibited, there is no particular limitation on the material of the polymer film used in the second retardation region. Examples of polymers include cellulose acylate films (for example, cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone. Film, polyacrylic resin film, polyurethane resin film, polyester film, polycarbonate film, polysulfone film, polyether film, polymethylpentene film, polyetherketone film, (meth) acrylonitrile film polyolefin, alicyclic structure Polymer (Norbornene resin (Arton: trade name, manufactured by JSR, amorphous polyolefin (ZEONEX: trade name, This Zeon Co., Ltd.)), and polypropylene. Among these, triacetyl cellulose, polyethylene terephthalate, is preferably a polymer having an alicyclic structure, particularly triacetyl cellulose preferred.

  The cellulose acylate film is preferably formed 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, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, JP-A-60-203430, and JP-A-62-115035 can be referred to. The cellulose acylate film may be subjected to a stretching treatment. With respect to the stretching method and conditions, for example, refer to JP-A-62-115035, JP-A-4-152125, 4-284221, 4-298310, and 11-48271. can do.

Examples of methods for stretching in the width direction (TD stretching) include, for example, JP-A-62-115035, JP-A-4-152125, JP-A-4-284221, JP-A-4-298310, and JP-A-11-48271. It is described in. In the case of stretching in the width direction, the film can also be stretched by conveying the film while holding it with a tenter and gradually widening the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine). In the case of longitudinal stretching (MD stretching), for example, two pairs of nip rolls are installed, and the peripheral speed of the nip roll on the outlet side is made faster than the peripheral speed of the nip roll on the inlet side while heating between them. Under the present circumstances, the expression of the retardation of the thickness direction can be changed by changing the space | interval (L) between nip rolls, and the film width (W) before extending | stretching. When L / W exceeds 2 and is 50 or less (long span stretching), Rth can be decreased, and when L / W is 0.01 to 0.3 (short span stretching), Rth can be increased. In the present invention, any of a long span stretching, a short span stretching, and a region between them (intermediate stretching = L / W is more than 0.3 and 2 or less) may be used. Short span stretching is preferred. Further, when aiming at high Rth, it is more preferable to use short span stretching, and when aiming at low Rth, it is distinguished from long span stretching.
The preferred stretching temperature for these longitudinal stretching is (Tg-10 ° C) to (Tg + 50) ° C, more preferably (Tg-5 ° C) to (Tg + 40) ° C, and even more preferably (Tg + 5) to (Tg + 30). ° C. The film is stretched by adjusting the speed of the film conveying roller so that the film winding speed is higher than the film peeling speed.
In the above description, the optical compensation film having a laminate structure in which a retardation layer is provided on a support has been described. However, the present invention is not limited to this embodiment, and the retardation layer is, of course, a stretched polymer. Even if it consists only of a film, it may consist only of the liquid crystal film formed from the composition containing a liquid crystalline compound. Preferred examples of the stretched polymer film are the same as the preferred examples of the support that the optical film has. Moreover, the preferable example of a liquid crystal film is the same as the preferable example of the phase difference layer which the said optical compensation film has.

  In addition, the 2nd phase difference area | region may consist only of a stretched polymer film, or may consist only of the liquid crystal film formed from the composition containing a liquid crystalline compound.

  It is preferable that the second retardation region is continuously manufactured in a long state. When the second retardation region is formed of a liquid crystal compound, the angle of the slow axis of the second retardation region can be adjusted by the rubbing angle. When the second retardation region is formed from a stretched polymer film, the angle of the slow axis can be adjusted depending on the stretching direction. By making the slow axis of the second retardation region parallel or orthogonal to the longitudinal direction of the long film, it becomes possible to bond the long polarizing film to the roll film by roll-to-roll. This makes it possible to produce a polarizing plate with high accuracy of the shaft angle and high productivity.

  It is preferable that the optical compensation film is continuously manufactured in a long state. When the retardation layer is formed from a liquid crystalline compound, the angle of the slow axis of the retardation layer can be adjusted by the rubbing angle. When the retardation layer is formed from a stretched polymer film, the angle of the slow axis can be adjusted depending on the stretching direction. By making the slow axis of the retardation layer at a parallel or orthogonal angle with respect to the longitudinal direction of the long film, it becomes possible to bond the long polarizing film to the roll film by roll to roll. It is possible to manufacture a polarizing plate with high angle accuracy and high productivity.

  The surface of the polymer film is subjected to surface treatment (eg, glow discharge treatment, corona discharge treatment, ultraviolet (UV) treatment, flame treatment, alkali saponification) treatment for the purpose of improving adhesion to the alignment film. May be. An adhesive layer (undercoat layer) may be provided. In this embodiment, the back surface of the polymer film (the surface on which the alignment film and the second retardation region are not formed) is adhered to the polarizing film, so that the back surface is also subjected to surface treatment such as alkali saponification treatment. Is preferred.

Alignment film:
An example of the alignment film that can be used in this embodiment is not particularly limited, but among them, a rubbing alignment film formed by rubbing the surface of a film made of a composition containing a polymer as a main component is preferable. Examples of polymers that can be used for forming the alignment film include methacrylate copolymers, styrene copolymers, polyolefins, polyvinyl alcohols, and modified compounds described in paragraph No. [0022] of JP-A-8-338913. Polyvinyl alcohol, poly (N-methylol acrylamide), polyester, polyimide, vinyl acetate copolymer, carboxymethyl cellulose, polycarbonate and the like are included. Silane coupling agents can be used as the polymer. Water-soluble polymers (eg, poly (N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferred, and polyvinyl alcohol and modified polyvinyl alcohol are most preferred. . The saponification degree of polyvinyl alcohol is preferably 70 to 100%, and more preferably 80 to 100%. The polymerization degree of polyvinyl alcohol is preferably 100 to 5000.

In order to form the alignment film, a crosslinking reaction may be allowed to proceed. In order to advance the crosslinking reaction, a polymer having a crosslinkable functional group in the side chain may be used as the main component polymer, or a crosslinking agent may be used or used in combination.
The alignment film can be formed by applying a coating liquid containing the main component polymer on the surface of the polymer film, drying, and allowing a crosslinking reaction to proceed as desired. Examples of available coating methods include spin coating, dip coating, curtain coating, extrusion coating, rod coating or roll coating.
preferable. A rod coating method is particularly preferable. The film thickness after drying is preferably 0.1 to 10 μm.

  After film formation, the film surface is rubbed. From the viewpoint of production suitability, the rubbing treatment is preferably performed along the transport direction of the polymer film, that is, along the longitudinal direction of the continuously produced long film. The rubbing treatment can be carried out by rubbing the surface of the membrane in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like.

  In addition, a photo-alignment film can also be used as the alignment film.

  In this way, the polymer film having predetermined optical characteristics and an alignment film are provided, and the slow axis direction of the polymer film (generally coincides with the longitudinal direction of the polymer film in many cases) and the alignment A second retardation region made of a laminated film in which the orientation control direction of the film (rubbing treatment direction in the case of a rubbing alignment film) coincides can be produced.

(2) First retardation region One example of the first retardation region has a retardation layer formed by curing a curable composition containing a discotic liquid crystal compound, or the retardation layer and a polymer film thereon. It is a laminate. The said polymer film is used for the improvement of adhesiveness with a 1st polarizing film, and it is preferable to arrange | position as an outermost layer adhere | attached with a 1st polarizing film.
Examples of discotic liquid crystal compounds that can be used to form the first retardation region include various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981)). Edited by Chemical Society of Japan, Quarterly Chemical Review, No. 22, Chemistry of Liquid Crystal, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. page 1794 (1985); J. Zhang et al., J. Am. Chem. Soc., vol. 116, page 2655 (1994)).

  Among them, the compound represented by the following general formula (I) is suitable for forming the above-described wavelength-dispersed retardation layer.

In the formula, Y ¹¹ , Y ¹² and Y ¹³ each independently represent a methine group or a nitrogen atom which may be substituted.

When Y ¹¹ , Y ¹² and Y ¹³ are methine, the hydrogen atom of methine may be replaced with a substituent. Examples of the substituent that methine may have include an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an alkylthio group, an arylthio group, a halogen atom, and A cyano group can be mentioned as a preferred example. Among these substituents, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, a halogen atom and a cyano group are more preferable, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and a carbon number. A 2-12 alkoxycarbonyl group, a C2-C12 acyloxy group, a halogen atom, and a cyano group are more preferable.
Y ¹¹ , Y ¹² and Y ¹³ are all preferably methine, and more preferably unsubstituted, from the viewpoint of ease of synthesis of the compound and cost.

L ¹ , L ² and L ³ each independently represents a single bond or a divalent linking group.
When L ¹ , L ² and L ³ are divalent linking groups, each independently represents —O—, —S—, —C (═O) —, —NR ⁷ —, —CH═CH—, —C. It is preferably a bivalent linking group selected from the group consisting of ≡C—, a divalent cyclic group, and combinations thereof. R ⁷ is an alkyl group having 1 to ⁷ carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group or a hydrogen atom. Preferably, it is a hydrogen atom.

The divalent cyclic group in L ¹ , L ² and L ³ is a divalent linking group having at least one cyclic structure (hereinafter sometimes referred to as a cyclic group). The cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. Further, the ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferred examples of the aromatic ring include a benzene ring and a naphthalene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. The cyclic group is more preferably an aromatic ring or a heterocyclic ring. In addition, the divalent cyclic group in the present invention is more preferably a divalent linking group consisting of only a cyclic structure (including a substituent) (hereinafter the same).

Of the divalent cyclic groups represented by L ¹ , L ² and L ³ , the cyclic group having a benzene ring is preferably a 1,4-phenylene group. As the cyclic group having a naphthalene ring, a naphthalene-1,5-diyl group and a naphthalene-2,6-diyl group are preferable. The cyclic group having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic group having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic group having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group.

The divalent cyclic group represented by L ¹ , L ² and L ³ may have a substituent. Examples of the substituent include a halogen atom (preferably a fluorine atom and a chlorine atom), a cyano group, a nitro group, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, and 2 to 2 carbon atoms. 16 alkynyl group, halogen-substituted alkyl group having 1 to 16 carbon atoms, alkoxy group having 1 to 16 carbon atoms, acyl group having 2 to 16 carbon atoms, alkylthio group having 1 to 16 carbon atoms, 2 carbon atoms ˜16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, carbamoyl group substituted with C2-C16 alkyl group and C2-C16 acylamino group are included.

L ¹ , L ² and L ³ include a single bond, * —O—CO—, * —CO—O—, * —CH═CH—, * —C≡C—, * —divalent cyclic group— * -O-CO-divalent cyclic group-, * -CO-O-divalent cyclic group-, * -CH = CH-divalent cyclic group-, * -C≡C-divalent cyclic group Group-, * -divalent cyclic group-O-CO-, * -divalent cyclic group-CO-O-, * -divalent cyclic group-CH = CH- and * -divalent cyclic group- C≡C— is preferred. In particular, a single bond, * —CH═CH—, * —C≡C—, * —CH═CH—divalent cyclic group— and * —C≡C—divalent cyclic group— are preferable, and a single bond is Most preferred. Here, * represents the position bonded to the 6-membered ring side including Y ¹¹ , Y ¹² and Y ¹³ in the general formula (I).

In the general formula ^{(I), H 1, H} 2 and H ³ represent each group independently formula (I-A) or (I-B).

In general formula (IA), YA ¹ and YA ² each independently represents a methine or nitrogen atom;
XA represents an oxygen atom, a sulfur atom, methylene or imino;
* Represents the position of bonding to the L ^{1 to} L ³ side in the above general formula (I);
** represents a position bonded to the R ^{1 to} R ³ side in the general formula (I).

In the general formula (IB), YB ¹ and YB ² each independently represent a methine or a nitrogen atom;
XB represents an oxygen atom, a sulfur atom, methylene or imino;
* Represents the position of bonding to the L ^{1 to} L ³ side in the above general formula (I);
** represents a position bonded to the R ^{1 to} R ³ side in the general formula (I).

In general formula (I), R < ¹ >, R < ² > and R < ³ > represent the following general formula (IR) each independently.

General formula (IR)
*-(-L ²¹ -Q ² ) _n1 -L ²² -L ²³ -Q ¹
In general formula (I-R), * represents a position bonded to the H ^{1 to} H ³ side in general formula (I).
L ²¹ represents a single bond or a divalent linking group. When L ²¹ is a divalent linking group, the group consisting of —O—, —S—, —C (═O) —, —NR ⁷ —, —CH═CH—, —C≡C—, and combinations thereof It is preferably a divalent linking group selected more. R ⁷ is an alkyl group having 1 to ⁷ carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group or a hydrogen atom. Preferably, it is a hydrogen atom.

L ²¹ is a single bond, ***-O-CO-, ***-CO-O-, ***-CH = CH- and ***-C≡C- (where *** is general Any one of the formulas (DI-R) is preferred, and a single bond is more preferred.

Q ² represents a divalent group (cyclic group) having at least one kind of cyclic structure. Such a cyclic group is preferably a cyclic group having a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a cyclic group having a 5-membered ring or a 6-membered ring, and a cyclic group having a 6-membered ring. Further preferred. The cyclic structure contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. Further, the ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferable examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

Of Q ^2, the cyclic group having a benzene ring is preferably a 1,4-phenylene group. As a cyclic group having a naphthalene ring, naphthalene-1,4-diyl group, naphthalene-1,5-diyl group, naphthalene-1,6-diyl group, naphthalene-2,5-diyl group, naphthalene-2,6 -A diylnaphthalene-2,7-diyl group is preferred. The cyclic group having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic group having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic group having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group. Among these, a 1,4-phenylene group, a naphthalene-2,6-diyl group, and a 1,4-cyclohexylene group are particularly preferable.

Q ² may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, nitro group, alkyl group having 1 to 16 carbon atoms, alkenyl group having 2 to 16 carbon atoms, carbon An alkynyl group having 2 to 16 atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, and 1 to 16 carbon atoms An alkylthio group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms. included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.

  n1 represents the integer of 0-4. n1 is preferably an integer of 1 to 3, and more preferably 1 or 2.

L ²² is **-O-, **-O-CO-, **-CO-O-, **-O-CO-O-, **-S-, **-NH-, ** —SO ₂ —, ** — CH ₂ —, ** — CH═CH—, or ** — C≡C— is represented, and ** represents a position bonded to the Q ² side.
L ²² is preferably ** — O—, ** — O—CO—, ** — CO—O—, ** — O—CO—O—, ** — CH ₂ —, ** — CH. ═CH—, ** — C≡C—, more preferably ** — O—, ** — O—CO—, ** — O—CO—O—, ** — CH ₂ —. . When L ²² is a group containing a hydrogen atom, the hydrogen atom may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 to 2 carbon atoms Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ²³ represents —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, —C≡C— and combinations thereof. Represents a divalent linking group selected from the group consisting of Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 to 2 carbon atoms Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred. By being substituted by these substituents, when preparing a liquid crystalline composition from the liquid crystalline compound of the present invention, the solubility in a solvent to be used can be improved.

L ²³ is preferably selected from the group consisting of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. L ²³ preferably contains 1 to 20 carbon atoms, more preferably 2 to 14 carbon atoms. Furthermore, L ²³ preferably contains 1 to 16 —CH ₂ —, and more preferably ₂ to 12 —CH ₂ —.

Q ¹ represents a polymerizable group or a hydrogen atom. When the liquid crystalline compound of the present invention is used for an optical film or the like that preferably has a phase difference that does not change due to heat, such as an optical compensation film, Q ¹ is preferably a polymerizable group. The polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. That is, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

  Furthermore, the polymerizable group is particularly preferably a functional group capable of addition polymerization reaction. Such a polymerizable group is preferably a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group.

  Examples of the polymerizable ethylenically unsaturated group include the following formulas (M-1) to (M-6).

In formulas (M-3) and (M-4), R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.
Among the formulas (M-1) to (M-6), (M-1) or (M-2) is preferable, and (M-1) is more preferable.

  The ring-opening polymerizable group is preferably a cyclic ether group, and more preferably an epoxy group or an oxetanyl group.

  Among the compounds of the formula (I), compounds represented by the following general formula (I ′) are more preferable.

In the general formula (DI), Y ¹¹ , Y ¹² and Y ¹³ each independently represent methine or a nitrogen atom, methine is preferred, and methine is preferably unsubstituted.

R ¹¹ , R ¹² and R ¹³ each independently represent the following general formula (I′-A), the following general formula (I′-B) or the following general formula (I′-C). In order to reduce the wavelength dispersion of intrinsic birefringence, general formula (I′-A) or general formula (I′-C) is preferable, and general formula (I′-A) is more preferable. R ¹¹ , R ¹² and R ¹³ are preferably R ¹¹ = R ¹² = R ¹³ .

In general formula (I′-A), A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ each independently represents a methine or nitrogen atom.
At least one of A ¹¹ and A ¹² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
Of A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ , at least three of them are preferably methine, more preferably all methine. Furthermore, the methine is preferably unsubstituted.
Examples of substituents when A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ or A ¹⁶ is methine include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, nitro groups An alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, and 1 carbon atom -16 alkoxy group, C2-C16 acyl group, C1-C16 alkylthio group, C2-C16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ¹ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

In general formula (I′-B), A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ and A ²⁶ each independently represents a methine or nitrogen atom. At least one of A ²¹ and A ²² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
Of A ²³ , A ²⁴ , A ²⁵ and A ²⁶ , at least three of them are preferably methine, more preferably all methine.
Examples of substituents when A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ or A ²⁶ is methine include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, nitro groups An alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, and 1 carbon atom -16 alkoxy group, C2-C16 acyl group, C1-C16 alkylthio group, C2-C16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ² represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

In general formula (I′-C), A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ and A ³⁶ each independently represents a methine or nitrogen atom.
At least one of A ³¹ and A ³² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
At least three of A ³³ , A ³⁴ , A ³⁵ and A ³⁶ are preferably methine, more preferably methine.
When A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ or A ³⁶ is methine, the methine may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, nitro group, alkyl group having 1 to 16 carbon atoms, alkenyl group having 2 to 16 carbon atoms, carbon An alkynyl group having 2 to 16 atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, and 1 to 16 carbon atoms An alkylthio group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms. included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ³ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

L ^{11 in} the general formula (I′-A), L ^{21 in} the general formula (I′-B), and L ³¹ in the general formula (I′-C) are each independently —O—, —C (═O) —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C— is represented. Preferably, —O—, —C (═O) —, —O—CO—, —CO—O—, —O—CO—O—, —CH ₂ —, —CH═CH—, —C≡C are preferable. —, More preferably —O—, —O—CO—, —CO—O—, —O—CO—O—, —C≡C—. In particular, L ¹¹ in the general formula (DI-A) that can be expected to have small intrinsic birefringence wavelength dispersibility is particularly preferably —O—, —CO—O—, —C≡C—, and among them, —CO— -O- is preferable because it can exhibit a discotic nematic phase at a higher temperature. When the above group is a group containing a hydrogen atom, the hydrogen atom may be replaced with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 to 2 carbon atoms Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ^{12 in} the general formula (I′-A), L ^{22 in} the general formula (I′-B), and L ³² in the general formula (I′-C) are each independently —O—, —S. A divalent linking group selected from the group consisting of —, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. Represents. Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and 1 carbon atom. -6 alkoxy group, C2-C6 acyl group, C1-C6 alkylthio group, C2-C6 acyloxy group, C2-C6 alkoxycarbonyl group, carbamoyl group, Preferred examples include a carbamoyl group substituted with an alkyl having 2 to 6 carbon atoms and an acylamino group having 2 to 6 carbon atoms, and a halogen atom, a hydroxyl group, and an alkyl group having 1 to 6 carbon atoms are more preferable. A halogen atom, a methyl group, and an ethyl group are preferable.

L ¹² , L ²² , and L ³² are each independently selected from the group consisting of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. It is preferable to be selected.

L ¹² , L ²² and L ³² each independently preferably have 1 to 20 carbon atoms, and more preferably 2 to 14 carbon atoms. The number of carbon atoms is preferably 2 to 14, more preferably 1 to 16 —CH ₂ —, and still more preferably ₂ to 12 —CH ₂ —.

The number of carbon atoms constituting L ¹² , L ²² , and L ³² affects the phase transition temperature of the liquid crystal and the solubility of the compound in the solvent. Generally the more increased the number of carbon atoms, transition temperature of the discotic nematic phase from (N _D phase) to the isotropic liquid tends to decrease. Further, the solubility in a solvent generally tends to improve as the number of carbon atoms increases.

Q ^{11 in} the general formula (I′-A), Q ^{21 in} the general formula (I′-B), and Q ³¹ in the general formula (I′-C) each independently represent a polymerizable group or a hydrogen atom. Represent. Q ¹¹ , Q ²¹ and Q ³¹ are preferably a polymerizable group. The polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. That is, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Hereinafter, examples of the polymerizable group are the same as described above, and preferable examples are also the same as described above.

  Specific examples of the compound represented by the general formula (I) include the compounds described in JP-A-2009-97002 [0038] to [0069], and the following compounds. It is not limited to.

  Examples of the discotic liquid crystal compound having a small wavelength dispersion, which is a triphenylene compound, include the compounds described in paragraphs [0062] to [0067] of JP-A-2007-108732, but the present invention is not limited thereto. Absent.

[Vertical alignment accelerator]
In forming the retardation layer, the molecules of the liquid crystal compound are tilted and aligned, but in the present invention, the tilt alignment is preferably performed at a low tilt angle, and in this embodiment, the molecules of the liquid crystal compound are vertically aligned, Alternatively, after the vertical alignment, it is preferable to perform a process for the tilt alignment. In order to once vertically align the liquid crystal molecules, it is preferable to use an alignment control agent capable of vertically controlling the liquid crystalline compound on the alignment film interface side and the air interface side. The action of vertically aligning the discotic liquid crystal compound corresponds to the action of reducing the tilt angle of the director, that is, the angle formed between the director and the liquid crystal air side surface. In particular, it is preferable to use an air interface vertical alignment accelerator having an action of reducing the tilt angle of the director of the discotic liquid crystal compound on the air interface side.
Examples of the vertical alignment accelerator include a compound that acts to vertically align the liquid crystalline compound by an excluded volume effect, electrostatic effect or surface energy effect on the alignment film, and an air interface at the time of alignment of the liquid crystalline compound. A compound that is unevenly distributed and acts to vertically align the liquid crystalline compound by its excluded volume effect, electrostatic effect, or surface energy effect is included.

  As the compound (alignment film interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the alignment film interface side, a pyridinium derivative is preferably used. As a compound (air interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the air interface side, a fluoro aliphatic group that promotes the uneven distribution of the compound on the air interface side, A compound containing at least one hydrophilic group selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO 3 H), a phosphonoxy group {—OP (═O) (OH) 2}, and salts thereof. Preferably used. Further, by blending these compounds, for example, when a liquid crystalline composition is prepared as a coating solution, the coating property of the coating solution is improved, and the occurrence of unevenness and repellency is suppressed. The vertical alignment agent will be described in detail below.

[Alignment film interface side vertical alignment agent]
As the alignment film interface side vertical alignment agent usable in the present invention, a pyridinium derivative (pyridinium salt) represented by the following formula (II) is preferably used. By adding at least one of the pyridinium derivatives to the liquid crystalline composition, the molecules of the discotic liquid crystal compound can be aligned substantially vertically in the vicinity of the alignment film.

In the formula, L ²³ and L ²⁴ each represent a divalent linking group.
L ²³ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═CH—, —N═. N-, -O-AL-O-, -O-AL-O-CO-, -O-AL-CO-O-, -CO-O-AL-O-, -CO-O-AL-O- CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or -O-CO-AL-CO-O-. And AL is an alkylene group having 1 to 10 carbon atoms. L ²³ represents a single bond, —O—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, — CO-O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or -O-CO- AL-CO-O- is preferable, a single bond or -O- is more preferable, and -O- is most preferable.

L ²⁴ is L ⁴ is a single bond, -O -, - O-CO -, - CO-O -, - C≡C -, - CH = CH -, - CH = N -, - N = CH- Or -N = N- is preferable, and -O-CO- or -CO-O- is more preferable. When m is 2 or more, it is more preferable that the plurality of L ²⁴ are alternately —O—CO— and —CO—O—.

R ²² is a hydrogen atom, an unsubstituted amino group, or a substituted amino group having 1 to 25 carbon atoms.
When R ²² is a dialkyl-substituted amino group, two alkyl groups may be bonded to each other to form a nitrogen-containing heterocycle. The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring. R ²³ is more preferably a hydrogen atom, an unsubstituted amino group, or a dialkyl-substituted amino group having 2 to 12 carbon atoms, and a hydrogen atom, an unsubstituted amino group, or a dialkyl-substituted group having 2 to 8 carbon atoms. Even more preferred is an amino group. When R ²³ is an unsubstituted amino group or a substituted amino group, the 4-position of the pyridinium ring is preferably substituted.

X is an anion.
X is preferably a monovalent anion. Examples of anions include anions of halogens (eg, fluorine ions, chlorine ions, bromine ions, iodine ions, etc.), sulfonate ions (eg, methanesulfonate ions, trifluoromethanesulfonate ions, methyl sulfate) Ion, p-toluenesulfonic acid ion, p-chlorobenzenesulfonic acid ion, 1,3-benzenedisulfonic acid ion, 1,5-naphthalenedisulfonic acid ion, 2,6-naphthalenedisulfonic acid ion), sulfate ion, carbonate ion , Nitrate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, formate ion, trifluoroacetate ion, phosphate ion (for example, hexafluorophosphate ion), hydroxide ion, etc. Is mentioned. X is preferably a halogen anion, a sulfonate ion, or a hydroxide ion.

Y ²² and Y ²³ are each a divalent linking group having a 5- or 6-membered ring as a partial structure.
The 5- or 6-membered ring may have a substituent. Preferably, at least one of Y ²² and Y ²³ is a divalent linking group having a 5- or 6-membered ring having a substituent as a partial structure. Y ²² and Y ²³ are preferably each independently a divalent linking group having a 6-membered ring which may have a substituent as a partial structure. The 6-membered ring includes an aliphatic ring, an aromatic ring (benzene ring) and a heterocyclic ring. Examples of the 6-membered aliphatic ring include a cyclohexane ring, a cyclohexene ring, and a cyclohexadiene ring. Examples of 6-membered heterocyclic rings include pyran ring, dioxane ring, dithiane ring, thiin ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring. Including. Another 6-membered ring or 5-membered ring may be condensed to the 6-membered ring.
Examples of the substituent include a halogen atom, cyano, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. The alkyl group and the alkoxy group may be substituted with an acyl group having 2 to 12 carbon atoms or an acyloxy group having 2 to 12 carbon atoms. The substituent is preferably an alkyl group having 1 to 12 (more preferably 1 to 6, more preferably 1 to 3) carbon atoms. The number of substituents may be 2 or more. For example, when Y ²² and Y ²³ are a phenylene group, the number of carbon atoms of 1 to 4 is 1 to 12 (more preferably 1 to 6, more preferably 1 to The alkyl group of 3) may be substituted.

Here, m is 1 or 2, and is preferably 2. When m is 2, the plurality of Y ²³ and L ²⁴ may be the same as or different from each other.

Z ²¹ is halogen-substituted phenyl, nitro-substituted phenyl, cyano-substituted phenyl, phenyl substituted with an alkyl group having 1 to 25 carbon atoms, phenyl substituted with an alkoxy group having 1 to 25 carbon atoms, carbon atoms An alkyl group having 1 to 25 carbon atoms, an alkynyl group having 2 to 25 carbon atoms, an alkoxy group having 1 to 25 carbon atoms, an alkoxycarbonyl group having 1 to 25 carbon atoms, and 7 to 26 carbon atoms And a monovalent group selected from the group consisting of an arylcarbonyloxy group having 7 to 26 carbon atoms.
When m is 2, Z ²¹ is preferably cyano, an alkyl group having 1 to 25 carbon atoms, or an alkoxy group having 1 to 25 carbon atoms, and is an alkoxy group having 4 to 20 carbon atoms. Is more preferable.
When m is 1, Z ²¹ is an alkyl group having 7 to 25 carbon atoms, an alkoxy group having 7 to 25 carbon atoms, an acyl-substituted alkyl group having 7 to 25 carbon atoms, or 7 carbon atoms. An acyl-substituted alkoxy group having ˜25, an acyloxy-substituted alkyl group having 7 to 12 carbon atoms, or an acyloxy-substituted alkoxy group having 7 to 25 carbon atoms is preferable.

  The acyl group is represented by —CO—R, the acyloxy group is represented by —O—CO—R, and R is an aliphatic group (alkyl group, substituted alkyl group, alkenyl group, substituted alkenyl group, alkynyl group, substituted alkynyl group) or aromatic. Group (aryl group, substituted aryl group). R is preferably an aliphatic group, and more preferably an alkyl group or an alkenyl group.

p is an integer of 1-10. It is particularly preferable that p is 1 or 2. C _p H _2p means a chain alkylene group which may have a branched structure. C _p H _2p is preferably a linear alkylene group (— (CH ₂ ) _p —).

  Among the compounds represented by the formula (II), a compound represented by the following formula (II ′) is preferable.

In the formula (II ′), the same symbols as those in the formula (II) have the same meaning, and the preferred ranges are also the same. L ²⁵ has the same meaning as L ²⁴ , and the preferred range is also the same. L ²⁴ and L ²⁵ are preferably —O—CO— or —CO—O—, L ²⁴ is preferably —O—CO—, and L ²⁵ is preferably —CO—O—.

R ²³ , R ²⁴ and R ²⁵ are each an alkyl group having 1 to 12 carbon atoms (more preferably 1 to 6, more preferably 1 to 3). n ₂₃ is 0-4, n ₂₄ is 1 to 4, and n ₂₅ represents 0 to 4. In n ₂₃ and n ₂₅ is 0, n ₂₄ is preferably a 1-4 (more preferably 1-3).

  Specific examples of the compound represented by the general formula (II) include compounds described in [0058] to [0061] in JP-A-2006-113500.

Other specific examples of the compound represented by the general formula (II) include the following compounds. However, the anion (X ⁻ ) was omitted in the following formula.

Specific examples of the compound represented by the general formula (II ′) are shown below. However, the anion (X ⁻ ) was omitted in the following formula.

  The pyridinium derivative of the formula (II) is generally obtained by alkylating the pyridine ring (Menstokin reaction).

  The preferred range of the content of the pyridinium derivative in the composition for forming the retardation layer varies depending on its use, but in the composition (liquid crystalline composition excluding the solvent when prepared as a coating liquid), It is preferable that it is 0.005-8 mass%, and it is more preferable that it is 0.01-5 mass%.

[Air interface side vertical alignment agent]
The air interface side vertical alignment agent is preferably a compound having a fluorine atom and a hydrophilic group in the molecule. The air interface side vertical alignment agent usable in the present invention includes a fluorine-based polymer having a fluoroaliphatic group and a hydrophilic group, and a fluorine-containing compound represented by the general formula (III).

Fluoropolymer:
First, a fluorine-based polymer that can be used as an air interface side vertical alignment agent will be described.
The fluoropolymer usable in the present invention includes a fluoroaliphatic group, a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and their And one or more hydrophilic groups selected from the group consisting of salts. The types of polymers are described in “Revised Chemistry of Polymer Synthesis” (Takayuki Otsu, published by Kagaku Dojin Co., 1968), pages 1-4, for example, polyolefins, polyesters, polyamides, polyimides. , Polyurethanes, polycarbonates, polysulfones, polycarbonates, polyethers, polyacetals, polyketones, polyphenylene oxides, polyphenylene sulfides, polyarylates, PTFEs, polyvinylidene fluorides, cellulose derivatives, etc. It is done. The fluoropolymer is preferably a polyolefin.

  The fluorine-based polymer is a polymer having a fluoroaliphatic group in the side chain. The fluoroaliphatic group preferably has 1 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. The aliphatic group may be linear or cyclic, and when it is linear, it may be linear or branched. Of these, a linear fluoroaliphatic group having 6 to 10 carbon atoms is preferable. The degree of substitution with fluorine atoms is not particularly limited, but 50% or more of hydrogen atoms in the aliphatic group are preferably substituted with fluorine atoms, and more preferably 60% or more are substituted. The fluoroaliphatic group is contained in a side chain bonded to the polymer main chain via an ester bond, an amide bond, an imide bond, a urethane bond, a urea bond, an ether bond, a thioether bond, an aromatic ring, or the like. One of the fluoroaliphatic groups is derived from a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method). Regarding the production method of these fluoroaliphatic compounds, for example, “Synthesis and Function of Fluorine Compounds” (Supervision: Nobuo Ishikawa, Issue: CMC Co., 1987), “Chemistry of Organic Fluorines Compounds”. II "(Monograph 187, Ed by Milos Hudricky and Attila E. Pavlath, American Chemical Society 1995). The telomerization method is a method of synthesizing a telomer by radical polymerization of a fluorine-containing vinyl compound such as tetrafluoroethylene using an alkyl halide having a large chain transfer constant such as iodide as a telogen (example in Scheme-1). showed that).

  The obtained terminal iodinated telomer is usually subjected to appropriate terminal chemical modification such as [Scheme 2], and led to a fluoroaliphatic compound. These compounds are further converted into a desired monomer structure as necessary, and used for the production of a fluoroaliphatic group-containing polymer.

  Specific examples of the monomer that can be used in the production of the fluoropolymer that can be used in the present invention include compounds described in paragraphs [0075] to [0081] of JP-A-2006-113500. It is not limited at all by these specific examples.

  One aspect of a fluoropolymer that can be used in the present invention is a copolymer having a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit containing a hydrophilic group represented by the following formula (IV): It is a coalescence.

In the above formula (IV), R ¹ , R ² and R ³ each independently represents a hydrogen atom or a substituent. Q represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. L represents an arbitrary group selected from the following linking group group, or a divalent linking group formed by combining two or more thereof.
(Linked group group)
Single bond, —O—, —CO—, —NR ^b — (R ^b represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), —S—, —SO ₂ —, —P (═O) (OR ^c ) — (R ^c represents an alkyl group, an aryl group, or an aralkyl group), an alkylene group, and an arylene group.

In formula (IV), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent selected from the substituent group exemplified below.
(Substituent group)
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, Particularly preferred are alkenyl groups having 2 to 8 carbon atoms, such as vinyl group, aryl group, 2-butenyl group and 3-pentenyl group), alkynyl groups (preferably having 2 to 20 carbon atoms, more preferred). Is an alkynyl group having 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as propargyl group and 3-pentynyl group. An aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenyl group, a p-methylphenyl group, and a naphthyl group. Aralkyl groups (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as benzyl group, phenethyl group, 3- Phenylpropyl group and the like), a substituted or unsubstituted amino group (preferably an amino group having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, Unsubstituted amino group, methylamino group, dimethylamino group, diethylamino group, anilino group, etc.),

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 10 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as a methoxycarbonyl group and an ethoxycarbonyl group), acyloxy A group (preferably an acyloxy group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as an acetoxy group and a benzoyloxy group), an acylamino group (preferably 2-20 carbon atoms, more preferably 2-16 carbon atoms, particularly preferably 2-10 carbon atoms. A silamino group, for example, an acetylamino group, a benzoylamino group, and the like, an alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms). An alkoxycarbonylamino group, for example, a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably 7 to 12 carbon atoms). Aryloxycarbonylamino group, for example, phenyloxycarbonylamino group and the like, sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 1 carbon atoms). 12 sulfonylamino groups such as methanesulfonyl And sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, such as sulfamoyl group). Group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group and the like), carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably carbon number). 1 to 12 carbamoyl groups, for example, unsubstituted carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group and the like),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12 arylthio group, for example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, particularly preferably a sulfonyl group having 1 to 12 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 20, more A sulfinyl group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms is preferable. Zensulfinyl group and the like), ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having a carbon number of 1 to 0, more preferably a heterocyclic group of 1 to 12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group , Piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group and the like), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably A silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group). These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

R ¹ , R ² and R ³ are each independently a hydrogen atom, an alkyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), or a group represented by -LQ described later. It is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a chlorine atom, or a group represented by -LQ, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Particularly preferred are a hydrogen atom and an alkyl group having 1 to 2 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, sec-butyl group and the like. The alkyl group may have a suitable substituent. Examples of the substituent include a halogen atom, aryl group, heterocyclic group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, hydroxyl group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl Group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamido group, sulfolyl group, carboxyl group and the like. The carbon number of the alkyl group does not include the carbon atom of the substituent. The same applies to the carbon number of other groups.

L represents a divalent linking group selected from the above linking group group, or a divalent linking group formed by combining two or more thereof. In the linking group group, R ^{b in} —NR ^b — represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and preferably a hydrogen atom or an alkyl group. R ^c in —PO (OR ^c ) — represents an alkyl group, an aryl group or an aralkyl group, and preferably an alkyl group. When R ^b and R ^c represent an alkyl group, an aryl group, or an aralkyl group, the number of carbon atoms is the same as that described in the “substituent group”. L preferably contains a single bond, —O—, —CO—, —NR ^b —, —S—, —SO ₂ —, an alkylene group or an arylene group, and —CO—, —O—, —NR ^b- , an alkylene group or an arylene group is particularly preferred. When L contains an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Specific examples of particularly preferred alkylene groups include methylene, ethylene, trimethylene, tetrabutylene, hexamethylene groups and the like. When L contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and particularly preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene and naphthalene groups. When L contains a divalent linking group (that is, an aralkylene group) obtained by combining an alkylene group and an arylene group, the carbon number of the aralkylene group is preferably 7 to 34, more preferably 7 to 26, and particularly preferably. 7-16. Specific examples of particularly preferred aralkylene groups include a phenylenemethylene group, a phenyleneethylene group, and a methylenephenylene group. The group listed as L may have a suitable substituent. Examples of such a substituent include those similar to the substituents exemplified above as the substituents for R ^{1 to} R ³ . Specific examples of L include structures described in paragraphs [0090] to [0091] of JP-A-2006-113500, but the present invention is not limited to these specific examples.

  In the formula (IV), Q is a carboxyl group, a salt of a carboxyl group (for example, lithium salt, sodium salt, potassium salt, ammonium salt (for example, ammonium, tetramethylammonium, trimethyl-2-hydroxyethylammonium, tetrabutylammonium, trimethyl). Benzylammonium, dimethylphenylammonium, etc.), pyridinium salts, etc.), sulfo groups, salts of sulfo groups (examples of cations forming salts are the same as those described above for carboxyl groups), phosphonoxy groups, salts of phosphonoxy groups (salts) Examples of the cation that forms are the same as those described above for the carboxyl group). A carboxyl group, a sulfo group, and a phospho group are more preferable, and a carboxyl group or a sulfo group is particularly preferable.

  The fluoropolymer may contain one type of repeating unit represented by the formula (IV) or two or more types. Moreover, the said fluorine-type polymer may have 1 type (s) or 2 or more types of repeating units other than said each repeating unit. The other repeating units are not particularly limited, and preferred examples thereof include repeating units derived from ordinary radical polymerizable monomers. Hereinafter, specific examples of monomers for deriving other repeating units will be given. The fluoropolymer may contain a repeating unit derived from one or more monomers selected from the following monomer group.

Monomer group (1) Alkenes Ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, 1-eicocene, hexafluoropropene, vinylidene fluoride, chlorotrifluoroethylene, 3, 3, 3-trifluoropropylene, tetrafluoroethylene, vinyl chloride, vinylidene chloride, etc .;
(2) Dienes 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-n-propyl-1,3-butadiene, 2,3-dimethyl-1,3 -Butadiene, 2-methyl-1,3-pentadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, 2-chloro -1,3-butadiene, 1-bromo-1,3-butadiene, 1-chlorobutadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro-1,3-butadiene, 1,1,2- Trichloro-1,3-butadiene and 2-cyano-1,3-butadiene, 1,4-divinylcyclohexane and the like;

(3) Derivatives of α, β-unsaturated carboxylic acid (3a) Alkyl acrylates Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, tert-butyl acrylate Amyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, tert-octyl acrylate, dodecyl acrylate, phenyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, 2-bromoethyl acrylate, 4-chlorobutyl acrylate, 2-cyanoethyl acrylate, 2-acetoxyethyl acrylate, methoxybenzyl Chryrate, 2-chlorocyclohexyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, 2-methoxyethyl acrylate, ω-methoxypolyethylene glycol acrylate (number of added polyoxyethylene: n = 2 to 100), 3-methoxy Butyl acrylate, 2-ethoxyethyl acrylate, 2-butoxyethyl acrylate, 2- (2-butoxyethoxy) ethyl acrylate, 1-bromo-2-methoxyethyl acrylate, 1,1-dichloro-2-ethoxyethyl acrylate, glycidyl acrylate Such);

(3b) Alkyl methacrylates Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, amyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2 -Ethylhexyl methacrylate, n-octyl methacrylate, stearyl methacrylate, benzyl methacrylate, phenyl methacrylate, allyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, cresyl methacrylate, naphthyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, ω Methoxypolyethylene glycol methacrylate (number of added polyoxyethylene: n = 2 to 100), 2-acetoxyethyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, 2- (2-butoxyethoxy) ethyl methacrylate Glycidyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc .;

(3c) Diesters of unsaturated polyvalent carboxylic acids Dimethyl maleate, dibutyl maleate, dimethyl itaconate, dibutyl taconate, dibutyl crotonate, dihexyl crotonate, diethyl fumarate, dimethyl fumarate, etc .;

(3d) Amides of α, β-unsaturated carboxylic acids N, N-dimethylacrylamide, N, N-diethylacrylamide, Nn-propylacrylamide, N-tertbutylacrylamide, N-tertoctylmethacrylamide, N- Cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-benzylacrylamide, N-acryloylmorpholine, diacetone acrylamide, N-methylmaleimide and the like;

(4) Unsaturated nitriles Acrylonitrile, methacrylonitrile, etc .;
(5) Styrene and derivatives thereof Styrene, vinyl toluene, ethyl styrene, p-tert butyl styrene, methyl p-vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-methoxy styrene, p-hydroxy Methyl styrene, p-acetoxy styrene, etc .;
(6) Vinyl esters Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, vinyl methoxyacetate, vinyl vinyl acetate, etc .;

(7) Vinyl ethers Methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, n-pentyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, n-dodecyl Vinyl ether, n-eicosyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, fluorobutyl vinyl ether, fluorobutoxyethyl vinyl ether, etc .; and (8) other polymerizable monomers N-vinyl pyrrolidone, methyl vinyl ketone, phenyl vinyl ketone, Methoxyethyl vinyl ketone, 2-vinyl oxazoline, 2-isopropenyl oxazoline, etc.

  In the fluoropolymer, the amount of the fluoroaliphatic group-containing monomer is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 30% by mass or more of the total amount of constituent monomers of the polymer. Is more preferable. In the fluoropolymer, the amount of the repeating unit represented by the formula (IV) is preferably 0.5% by mass or more, and preferably 1 to 20% by mass of the total amount of the constituent monomers of the fluoropolymer. More preferably, it is 1 to 10% by mass. Since the above-mentioned mass percentage easily varies in a preferable range depending on the molecular weight of the monomer used, the content of the repeating unit represented by the formula (IV) is expressed by the number of moles of the functional group per unit mass of the polymer. Can be defined accurately. When this notation is used, the preferable amount of the hydrophilic group (Q in the formula (IV)) contained in the fluoropolymer is 0.1 mmol / g to 10 mmol / g, and the more preferable amount is 0. .2 mmol / g to 8 mmol / g.

  The fluorine-based polymer used in the present invention preferably has a mass average molecular weight of 1,000,000 or less, more preferably 500,000 or less, and still more preferably 100,000 or less. The mass average molecular weight can be measured as a value in terms of polystyrene (PS) using gel permeation chromatography (GPC).

  The polymerization method of the fluorine-based polymer is not particularly limited, and for example, a polymerization method using a vinyl group such as cationic polymerization, radical polymerization, or anionic polymerization can be employed. Polymerization is particularly preferred in that it can be used for general purposes. As the polymerization initiator for radical polymerization, known compounds such as radical thermal polymerization initiators and radical photopolymerization initiators can be used, and it is particularly preferable to use radical thermal polymerization initiators. Here, the radical thermal polymerization initiator is a compound that generates radicals by heating to a decomposition temperature or higher. Examples of such radical thermal polymerization initiators include diacyl peroxide (acetyl peroxide, benzoyl peroxide, etc.), ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), hydroperoxide (hydrogen peroxide, tert. -Butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyesters (tert-butyl peroxyacetate, tert -Butyl peroxypivalate, etc.), azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.), persulfates (ammonium persulfate, sodium persulfate) Beam, such as potassium sulphate). Such radical thermal polymerization initiators can be used singly or in combination of two or more.

  The radical polymerization method is not particularly limited, and an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, a solution polymerization method, and the like can be adopted. The solution polymerization, which is a typical radical polymerization method, will be described more specifically. The outlines of other polymerization methods are the same, and details thereof are described, for example, in “Polymer Science Experimental Method” edited by Polymer Society (Tokyo Kagaku Dojin, 1981).

  An organic solvent is used for solution polymerization. These organic solvents can be arbitrarily selected as long as the objects and effects of the present invention are not impaired. These organic solvents are usually organic compounds having boiling points under atmospheric pressure in the range of 50 to 200 ° C., and organic compounds that uniformly dissolve each component are preferred. Examples of preferred organic solvents include alcohols such as isopropanol and butanol; ethers such as dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate and acetic acid And esters such as butyl, amyl acetate, and γ-butyrolactone; and aromatic hydrocarbons such as benzene, toluene, and xylene. In addition, these organic solvents can be used individually by 1 type or in combination of 2 or more types. Furthermore, a water-mixed organic solvent in which water is used in combination with the organic solvent is also applicable from the viewpoint of the solubility of the monomer and the polymer to be formed.

  Also, the solution polymerization conditions are not particularly limited, but for example, it is preferable to heat within a temperature range of 50 to 200 ° C. for 10 minutes to 30 hours. Furthermore, in order not to deactivate the generated radicals, it is preferable to perform an inert gas purge not only during solution polymerization but also before the start of solution polymerization. Usually, nitrogen gas is suitably used as the inert gas.

  In order to obtain the fluoropolymer in a preferable molecular weight range, a radical polymerization method using a chain transfer agent is particularly effective. As chain transfer agents, mercaptans (for example, octyl mercaptan, decyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, octadecyl mercaptan, thiophenol, p-nonylthiophenol, etc.), polyhalogenated alkyls (for example, carbon tetrachloride, chloroform, etc.) , 1,1,1-trichloroethane, 1,1,1-tribromooctane, etc.) and low-activity monomers (α-methylstyrene, α-methylstyrene dimer, etc.) can be used, preferably carbon These are mercaptans of 4-16. The amount of these chain transfer agents used is remarkably influenced by the activity of the chain transfer agent, the combination of the monomers, the polymerization conditions and the like, and must be precisely controlled. It is about 01 mol% to 50 mol%, preferably 0.05 mol% to 30 mol%, particularly preferably 0.08 mol% to 25 mol%. These chain transfer agents may be present in the system simultaneously with the target monomer whose degree of polymerization is to be controlled in the polymerization process, and the addition method is not particularly limited. It may be added after being dissolved in the monomer, or may be added separately from the monomer.

  The fluoropolymer of the present invention preferably has a polymerizable group as a substituent in order to fix the alignment state of the discotic liquid crystal compound.

  Specific examples of the fluoroaliphatic group-containing copolymer preferably used in the present invention as a fluorine-based polymer include the compounds described in paragraphs [0110] to [0114] of JP-A-2006-113500. Is not limited by these specific examples.

  The fluoropolymer used in the present invention can be produced by a publicly known and commonly used method. For example, it can be produced by adding a general-purpose radical polymerization initiator to an organic solvent containing the above-described monomer having a fluoroaliphatic group, a monomer having a hydrogen bonding group, and the like, and polymerizing the mixture. Further, in some cases, other addition-polymerizable unsaturated compounds can be further added and produced by the same method as described above. Depending on the polymerizability of each monomer, a dropping polymerization method in which a monomer and an initiator are added dropwise to a reaction vessel is also effective for obtaining a polymer having a uniform composition.

  The preferred range of the content of the fluoropolymer in the composition varies depending on the application, but when used for forming the retardation layer, in the composition (a composition excluding the solvent in the case of a coating solution), The amount is preferably 0.005 to 8% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 3% by mass. If the addition amount of the fluorine-based polymer is less than 0.005% by mass, the effect is insufficient, and if it exceeds 8% by mass, the coating film cannot be sufficiently dried, or the performance as an optical film (for example, letter Adversely affects the uniformity of the foundation.

Fluorine-containing compound represented by the following formula (III):
Next, a fluorine-containing compound represented by the following formula (III) that can be used as an air interface side vertical alignment agent will be described.
(III) (R ⁰ ) _m -L ^0- (W) _n
In the formula, R ⁰ represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, and m represents an integer of 1 or more. A plurality of R ⁰ may be the same or different, but at least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal. L ⁰ represents a (m + n) -valent linking group, W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or phosphonoxy {—OP (═O) (OH) ₂ } Or a salt thereof, and n represents an integer of 1 or more.

In the formula (III), R ⁰ functions as a hydrophobic group of the fluorine-containing compound. The alkyl group represented by R ⁰ is a substituted or unsubstituted alkyl group, which may be linear or branched, preferably an alkyl group having 1 to 20 carbon atoms, more preferably Is an alkyl group of 4 to 16, particularly preferably an alkyl group of 6 to 16. As the substituent, any of the substituents exemplified as the substituent group D described later can be applied. The alkyl group having a CF ₃ group at the terminal represented by R ⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and particularly preferably 4 to 8. The alkyl group having a CF ₃ group at the terminal is an alkyl group in which part or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and particularly preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with the substituents exemplified as the substituent group D described later. The alkyl group having a CF ₂ H group at the terminal represented by R ⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and particularly preferably 4 to 8. The alkyl group having a CF ₂ H group at the terminal is an alkyl group in which some or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and particularly preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with the substituents exemplified as the substituent group D described later. Examples of an alkyl group having a CF ₃ group at the terminal represented by R ⁰ or an alkyl group having a CF ₂ H group at the terminal are shown below.

R1: n-C ₈ F _{17-
R2: n-C 6 F 13} -
_{R3: n-C 4 F 9} -
_{R4: n-C 8 F 17} - (CH 2) 2 -
_{R5: n-C 6 F 13} - (CH 2) 2 -
_{R6: n-C 4 F 9} - (CH 2) 2 -
_{R7: H- (CF 2) 8} -
_{R8: H- (CF 2) 6} -
_{R9: H- (CF 2) 4} -
_{R10: H- (CF 2) 8} - (CH 2) -
R11: H— (CF ₂ ) ₆ — (CH ₂ ) —
_{R12: H- (CF 2) 4} - (CH 2) -

In the formula (III), the (m + n) -valent linking group represented by L ⁰ is an alkylene group, an alkenylene group, an aromatic group, a heterocyclic group, —CO—, —NR— (R has 1 carbon atom) A linking group in which at least two groups selected from the group consisting of —O—, —S—, —SO—, and —SO ₂ — are combined.

In formula (III), W represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. . The preferred range of W is the same as Q in formula (IV).

  Among the fluorine-containing compounds represented by the formula (III), compounds represented by the following formula (III) -a or formula (III) -b are preferable.

In formula (III) -a, R ⁴ and R ⁵ each represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, and R ⁴ and R ⁵ are simultaneously It is not an alkyl group. W ¹ and W ² are each a hydrogen atom, a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or An alkyl group, an alkoxy group or an alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent is represented, but W ¹ and W ² are not simultaneously hydrogen atoms.

Formula (III) -b
_{^{(R 6 -L 2 -) m2}} (Ar 1) -W 3
In formula (III) -b, R ⁶ represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, m2 represents an integer of 1 or more, R ⁶ may be the same or different, but at least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal. L ² represents an alkylene group, an aromatic group, —CO—, —NR— (R is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom), —O—, —S—, —SO—, —SO. _2- represents a divalent linking group selected from the group consisting of combinations thereof, and a plurality of L ² may be the same or different. Ar ¹ represents an aromatic hydrocarbon ring or an aromatic heterocycle, W ³ represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent.

First, the formula (III) -a will be described.
R ⁴ and R ⁵ are synonymous with R ⁰ in the formula (III), and their preferred ranges are also the same. The carboxyl group (—COOH) represented by W ¹ and W ² or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof is It is synonymous with W in Formula (III), and its preferable range is also the same. The alkyl group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ^{1 or} W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. It is an alkyl group, More preferably, it is a 1-8 alkyl group, Most preferably, it is a 1-3 alkyl group. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, sulfo group, or phosphonoxy group. It is synonymous with the carboxyl group, sulfo group and phosphonoxy group represented by W in formula (III), and the preferred range is also the same. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent may be substituted with any other substituent, and the substituent is any of the substituents exemplified as the substituent group D described later. Can be applied. The alkoxy group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ¹ and W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. An alkoxy group, more preferably an alkoxy group of 1 to 8, and particularly preferably an alkoxy group of 1 to 4. The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, a sulfo group, or a phosphonoxy group. It is synonymous with the parent carboxyl group, sulfo group and phosphonoxy group represented by W in formula (III), and the preferred range is also the same. The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as Substituent Group D described later can be applied as the substituent. . The alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ^{1 or} W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. More preferably 1 to 8 alkylamino groups, and particularly preferably 1 to 4 alkylamino groups. The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may have at least one carboxyl group, a sulfo group, or a phosphonoxy group. Examples of the carboxyl group, the sulfo group, and the phosphonoxy group include the above-described formula ( It is synonymous with the carboxyl group represented by W in III), a sulfo group, and a phosphonoxy group, and its preferable range is also the same. The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may be substituted with other substituents, and any of the substituents exemplified as Substituent Group D described later is applied as the substituent. it can.

W ¹ and W ² are particularly preferably each a hydrogen atom or (CH ₂ ) _n SO ₃ M (n represents 0 or 1). M represents a cation, but M may not be present when the charge is 0 in the molecule. As cations represented by M, for example, protonium ions, alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions and the like are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

Next, the formula (III) -b will be described.
R ⁶ has the same meaning as R ⁰ in the formula (III), and its preferred range is also the same. L ² is preferably an alkylene group having 1 to 12 carbon atoms, an aromatic group having 6 to 12 carbon atoms, —CO—, —NR—, —O—, —S—, —SO—, —SO ₂ — and Represents a linking group having a total carbon number of 0 to 40 consisting of a combination thereof, particularly preferably an alkylene group having 1 to 8 carbon atoms, a phenyl group, —CO—, —NR—, —O—, —S—, —SO. ₂ represents a linking group having 0 to 20 carbon atoms and a combination thereof. Ar ¹ preferably represents an aromatic hydrocarbon ring having 6 to 12 carbon atoms, particularly preferably a benzene ring or a naphthalene ring. As a carboxyl group (—COOH) represented by W ³ or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or a substituent A carboxyl group, a sulfo group, an alkyl group having a phosphonoxy group, an alkoxy group, or an alkylamino group is a carboxyl group (—COOH) represented by W ¹ and W ² in the above formula (III) -a or a salt thereof, sulfo Group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkyl having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent. It is synonymous with an amino group and its preferable range is also the same.

W ³ is preferably a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a carboxyl group (—COOH) or a salt thereof or a sulfo group (—SO ₃ H) as a substituent. Or an alkylamino group having a salt thereof, particularly preferably SO ₃ M or CO ₂ M. M represents a cation, but M may not be present when the charge is 0 in the molecule. As cations represented by M, for example, protonium ions, alkali metal ions (lithium ions, sodium ions, potassium ions, etc.), alkaline earth metal ions (barium ions, calcium ions, etc.), ammonium ions and the like are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

  In the present specification, the substituent group D includes an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as a methyl group. , Ethyl group, isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably having 2 carbon atoms) -20, more preferably an alkenyl group having 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 2-butenyl group, and a 3-pentenyl group), alkynyl A group (preferably an alkynyl group having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, And aryl groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms). Group, p-methylphenyl group, naphthyl group and the like), substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and particularly preferably 0 to 6 carbon atoms). An amino group, for example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group and the like),

  An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). An aryloxy group (preferably an aryloxy group having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. ), An acyl group (preferably an acyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an acetyl group, a benzoyl group, a formyl group, a pivaloyl group. An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 carbon atoms). 12 is an alkoxycarbonyl group, and examples thereof include a methoxycarbonyl group and an ethoxycarbonyl group), an aryloxycarbonyl group (preferably having a carbon number of 7 to 20, more preferably a carbon number of 7 to 16, and particularly preferably a carbon number). An aryloxycarbonyl group having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, an acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms). 10 acyloxy groups such as an acetoxy group and a benzoyloxy group)

  An acylamino group (preferably an acylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as an acetylamino group and a benzoylamino group), alkoxycarbonyl An amino group (preferably an alkoxycarbonylamino group having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), aryloxy Carbonylamino group (preferably an aryloxycarbonylamino group having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group) Sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferred Or a sulfonylamino group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include a methanesulfonylamino group and a benzenesulfonylamino group, and a sulfamoyl group (preferably having a carbon number of 0 to 20). More preferably, it is a sulfamoyl group having 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, and examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, and a phenylsulfamoyl group. ), A carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, an unsubstituted carbamoyl group, a methylcarbamoyl group, diethylcarbamoyl group Group, phenylcarbamoyl group, etc.),

  An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is C6-C20, More preferably, it is C6-C16, Most preferably, it is C6-C12 arylthio group, for example, a phenylthio group etc. are mentioned, A sulfonyl group (preferably C1-C1). 20, more preferably a sulfonyl group having 1 to 16 carbon atoms, particularly preferably a sulfonyl group having 1 to 12 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 20, more A sulfinyl group having 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms is preferable. Zensulfinyl group and the like), ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, an unsubstituted ureido group , Methylureido group, phenylureido group, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms). Yes, for example, diethyl phosphoric acid amide group, phenyl phosphoric acid amide group, etc.), hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, Carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having a carbon number of 1 to 0, more preferably a heterocyclic group of 1 to 12, for example, a heterocyclic group having a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group , Piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group and the like), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably A silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group). These substituents may be further substituted with these substituents. Further, when two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

  In addition, the fluorine-containing compound of the present invention preferably has a polymerizable group as a substituent in order to fix the alignment state of the discotic liquid crystal compound.

  Specific examples of the fluorine-containing compound represented by the formula (III) that can be used in the present invention include compounds described in paragraphs [0136] to [0140] of JP-A-2006-113500, and the like. It is not limited.

  The content of the fluorine-containing compound in the composition is preferably 0.005 to 8% by mass in the composition (a composition excluding the solvent in the case of a coating solution), and 0.01 to 5% by mass. % Is more preferable, and 0.05 to 3% by mass is even more preferable.

[Polymerization initiator]
The liquid crystal compound subjected to the tilt alignment is fixed while maintaining the alignment state. The immobilization is preferably performed by a polymerization reaction of the polymerizable group (P) introduced into the liquid crystal compound. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin. Compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Description), acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970).

  The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating solution. Light irradiation for polymerization of discotic liquid crystalline molecules is preferably performed using ultraviolet rays. The irradiation energy is preferably 20 mJ / cm 2 to 50 J / cm 2, and more preferably 100 to 800 mJ / cm 2. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. The thickness of the retardation layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and most preferably 1 to 5 μm.

[Other additives for retardation layer]
Along with the liquid crystal compound, a plasticizer, a surfactant, a polymerizable monomer, and the like can be used in combination to improve the uniformity of the coating film, the strength of the film, the orientation of the liquid crystal compound, and the like. These materials are preferably compatible with the liquid crystal compound and do not inhibit the alignment.

  Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Preferably, it is a polyfunctional radically polymerizable monomer and is preferably copolymerizable with the above-described polymerizable group-containing liquid crystal compound. Examples thereof include those described in paragraph numbers [0018] to [0020] in JP-A No. 2002-296423. The amount of the compound added is generally in the range of 1 to 50% by mass and preferably in the range of 5 to 30% by mass with respect to the discotic liquid crystalline molecules.

  Examples of the surfactant include conventionally known compounds, and fluorine compounds are particularly preferable. Specifically, for example, compounds described in paragraphs [0028] to [0056] in JP-A No. 2001-330725, and paragraphs [0069] to [0126] in Japanese Patent Application No. 2003-295212 are described. The compound of this is mentioned.

The polymer used together with the liquid crystal compound is preferably capable of thickening the coating solution. A cellulose ester can be mentioned as an example of a polymer. Preferable examples of the cellulose ester include those described in paragraph [0178] of JP-A No. 2000-155216. The addition amount of the polymer is preferably in the range of 0.1 to 10% by mass, and in the range of 0.1 to 8% by mass with respect to the liquid crystal molecules so as not to inhibit the alignment of the liquid crystal compound. It is more preferable.
The discotic nematic liquid crystal phase-solid phase transition temperature of the liquid crystal compound is preferably 70 to 300 ° C, more preferably 70 to 170 ° C.

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

[Coating method]
The coating liquid can be applied by a known method (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method). Especially, when forming the said phase difference layer, it is preferable to apply | coat using a wire bar coating method, and it is preferable that the rotation speed of a wire bar satisfy | fills a following formula.
0.6 <(W × (R + 2r) × π) / V <1.4
[W: Number of rotations of wire bar (rpm), R: Diameter of core of bar (m), r: Diameter of wire (m), V: Conveying speed of support (m / min)]
The range of (W × (R + 2r) × π) / V is more preferably 0.7 to 1.3, and still more preferably 0.8 to 1.2.

  A die coating method is preferably used for forming the retardation layer, and a coating method using a slide coater or a slot die coater is particularly preferable.

[Method of forming retardation layer with fixed tilt orientation]
A retardation layer having a fixed tilt orientation with an average tilt angle of less than 10 ° (for example, 1 to 3 °) can be stably formed by, for example, the following method.
First, a coating liquid containing a discotic liquid crystal compound and optionally the above-mentioned additive is prepared, and the coating liquid is applied to the surface of the support or the alignment film formed thereon to obtain a coating layer. Next, if necessary, the solvent is removed from the coating layer, the discotic liquid crystal is vertically aligned, and warm air is applied from the horizontal to 10 ° direction with respect to the coating surface to tilt the liquid crystal molecules. While maintaining the state (for example, while performing the above-described treatment), a curing reaction such as a polymerization reaction is advanced by light donation such as ultraviolet rays and / or heat donation, and the tilted orientation is fixed to obtain a retardation layer. .
In addition, depending on the addition amount and kind of the additive, the tilted alignment state may be stably formed without going through the vertical alignment state once, so the method is not limited to the above method.

2. 1st and 2nd polarizing film There is no restriction | limiting in particular about the polarizing film utilized for this invention. As the polarizing film, any of an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film may be used. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The absorption axis of the polarizing film corresponds to the stretching direction of the film. Accordingly, the polarizing film stretched in the longitudinal direction (transport direction) has an absorption axis parallel to the longitudinal direction, and the polarizing film stretched in the lateral direction (perpendicular to the transport direction) is perpendicular to the longitudinal direction. Has an absorption axis.

  The polarizing film generally has a protective film. In the present invention, the optical compensation film can function as a protective film for the first polarizing film, and is preferably disposed with the first retardation region side set to the first polarizing film side. It is preferable to dispose a protective film on the other surface of the first polarizing film to which the optical compensation film is adhered. There is no particular limitation on the protective film disposed outside the polarizing film, and cellulose acylate film, cyclic olefin polymer film, polyvinyl alcohol film, polypropylene film, polycarbonate film, norbornene film, acrylic film, PET film, etc. Can be used. Among these, it is preferable to use a cellulose acylate film.

  The polarizing film generally has a protective film. In the present invention, the optical compensation film can function as a protective film for the first polarizing film, and the first retardation region is disposed in contact with the first polarizing film. It is preferable to arrange a protective film on the other surface of the first polarizing film to which the optical compensation film is adhered. There is no restriction | limiting in particular about a protective film, A cellulose acylate film, a cyclic olefin polymer film, a polyvinyl alcohol film, a polypropylene film, a polycarbonate film, a norbornene film, an acrylic film, a PET film, etc. can be used. Among them, it is preferable to use a cellulose acylate film having high optical isotropy.

  It is preferable to laminate a protective film on both surfaces of the second polarizing film. In particular, a protective film disposed on the liquid crystal cell side is required to have low Re and low Rth from the viewpoint of improving viewing angle contrast. Specifically, the absolute value | Re (550) | of Re (550) is 10 nm or less, and the absolute value | Rth (550) | of Rth (550) is 30 nm or less. Ideally, both | Re (550) | and | Rth (550) | are 0 nm. Further, from the viewpoint of reducing the color shift that occurs in the oblique direction, Re of the protective film preferably has a small wavelength dispersion, and specifically, | Re (400) −Re (700) | is 10 nm or less. , And | Rth (400) -Rth (700) | are 35 nm or less, and ideally, | Re (400) -Re (700) | and | Rth (400) -Rth (700) | is there.

  In order to achieve low Re and low Rth, it is preferable to reduce the thickness of the film. On the other hand, if the thickness is too thin, the function as a protective film becomes insufficient and the durability of the polarizing film decreases. As a result, the durability of the liquid crystal display device decreases. From these viewpoints, the thickness of the protective film for the second polarizing film and disposed on the liquid crystal cell side is preferably 10 to 90 μm, and more preferably 30 to 80 μm.

  Examples of the film having the above-mentioned thickness and capable of achieving the above-described optical characteristics and suitably used as a protective film for the second polarizing film include a cellulose acylate film, a cyclic olefin polymer film, and an acrylic film. Polymer film is included. Among acrylic polymer films, an acrylic polymer film containing an acrylic polymer containing at least one unit selected from a lactone ring unit, a maleic anhydride unit, and a glutaric anhydride unit is optically isotropic. This is preferable because of its high properties. The details of the acrylic polymer film are described in JP-A-2008-9378 and can be referred to. Each example is the same as the examples of the cellulose acylate film, the cyclic olefin polymer film, and the acrylic polymer film that can be used as the first transparent film described in JP2010-33041A.

  The preferable manufacturing method of a polarizing plate includes the process of laminating | stacking continuously two sheets of protective films and a polarizing film in a respectively long state. The long polarizing plate is cut in accordance with the screen size of the image display device used. In addition, about the 1st polarizing film, the said optical compensation film is bonded on one surface. The polarizing plate thus produced is arranged with the optical compensation film on the liquid crystal cell side. Any of the first and second retardation regions constituting the optical compensation film may be arranged on the polarizing film side. However, in terms of adhesion to the polarizing film, a polymer film is arranged. In a mode in which the first retardation region is bonded to the polarizing film, a polymer film is disposed on the retardation layer formed using a discotic liquid crystal compound, and the polymer film is bonded to the polarizing film. It is preferable to do this. The polymer film preferably has low Re and low Rth, and examples of usable polymer films include examples of polymer films suitably used as a protective film for the second polarizing film (easy-layer cell-side protective film). It is the same.

3. Liquid Crystal Cell The liquid crystal display device of the present invention has IPS and FFS type liquid crystal cells. These modes are described in various documents, and any configuration can be adopted in the present invention. It can be obtained in any of the display devices. IPS type liquid crystal display devices are disclosed in, for example, JP2003-15160, JP2003-75850, JP2003-295171, JP200412730, JP200412731, JP2005-106967, JP-A-2005-134914, JP-A-2005-241923, JP-A-2005-284304, JP-A-2006-189758, JP-A-2006-194918, JP-A-2006-220680, JP-A-2007-140353, JP 2007-178904, JP 2007-293290, JP 2007-328350, JP 2008-3251, JP 2008-39806, JP 2008-40291, JP 2008-65196, JP 2008-76849, JP 2008-96815 It can be used those described in JP.

  An FFS type (hereinafter also referred to as FFS mode) liquid crystal cell has a counter electrode and a pixel electrode. These electrodes are made of a transparent material such as ITO, and are narrower than the distance between the upper and lower substrates, etc., and are wide enough to drive all the liquid crystal molecules placed on the electrodes. Has been. With this configuration, in the FFS mode, it is possible to obtain an aperture ratio that is improved compared to the IPS mode. Further, since the electrode portion is light transmissive, it is possible to obtain a transmittance that is improved compared to the IPS mode. Regarding the FFS mode liquid crystal cell, for example, refer to the descriptions in Japanese Patent Laid-Open Nos. 2001-100193, 2002-14374, 2002-182230, 2003-131248, and 2003-233083. it can.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

1. Preparation of Polymer Film (1) Preparation of Polymer Film 1 A commercially available triacetyl cellulose film “Fujitac TD80UL” (manufactured by Fuji Film Co., Ltd.) was prepared and used as the polymer film 1.

(2) Preparation of polymer film 4 The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.
(Cellulose acetate solution composition)
Cellulose acetate having an acetylation degree of 60.7 to 61.1% 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Methylene chloride (first solvent) 336 parts by weight Methanol (second solvent) 29 parts by mass 1-butanol (third solvent) 11 parts by mass

  In another mixing tank, 16 parts by mass of the following retardation increasing agent (A), 92 parts by mass of methylene chloride and 8 parts by mass of methanol were added and stirred while heating to prepare a retardation increasing agent solution. A dope was prepared by mixing 474 parts by mass of the cellulose acetate solution with 25 parts by mass of the retardation increasing agent solution and stirring sufficiently. The addition amount of the retardation increasing agent was 6.0 parts by mass with respect to 100 parts by mass of cellulose acetate.

  The obtained dope was cast using a band stretching machine. After the film surface temperature on the band reaches 40 ° C., the film is dried with warm air of 70 ° C. for 1 minute, and the film from the band is dried with 140 ° C. drying air for 10 minutes, and the residual solvent amount is 0.3% by mass. A cellulose acetate film was prepared. The obtained long cellulose acetate film had a width of 1490 mm and a thickness of 60 μm. This was used as polymer film 4.

(3) Preparation of Polymer Film 6 A commercially available triacetyl cellulose film “Z-TAC” (manufactured by Fuji Film Co., Ltd.) was prepared and used as the polymer film 6.

  The characteristics of the polymer films 1, 4 and 6 are shown in the following table.

2. Production of Optical Compensation Film (1) Preparation of Support Polymer Film 1 or 4 was used as a support, respectively.
(Alkaline saponification treatment)
After passing the polymer film through a dielectric heating roll having a temperature of 60 ° C. and raising the film surface temperature to 40 ° C., an alkali solution having the composition shown below is applied to one side of the film using a bar coater. It was transported for 10 seconds under a steam far infrared heater manufactured by Noritake Co., Ltd., which was applied at m2 and heated to 110 ° C. Subsequently, 3 ml / m 2 of pure water was applied using the same bar coater. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then transported to a drying zone at 70 ° C. for 10 seconds and dried to prepare an alkali saponified cellulose acylate film.

(Alkaline saponification treatment)
After passing the polymer film through a dielectric heating roll having a temperature of 60 ° C. and raising the film surface temperature to 40 ° C., an alkali solution having the composition shown below is applied to one side of the film using a bar coater. It was transported for 10 seconds under a steam far infrared heater manufactured by Noritake Co., Ltd., which was applied at m2 and heated to 110 ° C. Subsequently, 3 ml / m 2 of pure water was applied using the same bar coater. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then transported to a drying zone at 70 ° C. for 10 seconds and dried to prepare an alkali saponified cellulose acylate film.
Alkaline solution composition:
Potassium hydroxide 4.7 parts by weight Water 15.8 parts by weight Isopropanol 63.7 parts by weight Surfactant SF-1: C ₁₄ H ₂₉ O (CH ₂ CH ₂ O) ₂₀ H 1.0 part by weight Propylene glycol 14. 8 parts by mass

(Formation of alignment film)
On the long cellulose acetate film saponified as described above, an alignment film coating solution having the following composition was continuously applied with a # 14 wire bar. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds.
Composition of alignment film coating solution:
The following modified polyvinyl alcohol 10 parts by mass Water 371 parts by mass Methanol 119 parts by mass Glutaraldehyde 0.5 parts by mass Photopolymerization initiator (Irgacure 2959, manufactured by Ciba Japan) 0.3 parts by mass

(Formation of retardation layer containing discotic liquid crystalline compound)
The alignment film thus prepared was continuously rubbed. At this time, the longitudinal direction of the long film and the transport direction were parallel, and the rotation axis of the rubbing roller was orthogonal to the film longitudinal direction.

A coating liquid A containing a discotic liquid crystal compound having the following composition was continuously applied on the prepared alignment film with a # 2.7 wire bar. The conveyance speed (V) of the film was 36 m / min. In order to dry the solvent of the coating liquid and to mature the orientation of the discotic liquid crystal compound, the coating liquid was heated for 90 seconds with warm air at 115 ° C., and warm air was applied from a direction of 10 ° to 10 ° with respect to the coated surface. Subsequently, UV irradiation was performed at 80 ° C., the orientation of the liquid crystal compound was fixed, the retardation layer 1 was formed, and an optical compensation film was obtained.
Composition of retardation layer 1 coating liquid The following discotic liquid crystal compound 100 parts by mass photopolymerization initiator (Irgacure 907, manufactured by Ciba Japan) 3 parts by mass sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass The following pyridinium salt 1 part by mass The following fluoropolymer (FP1) 0.4 part by mass Methyl ethyl ketone 252 parts by mass

  The direction of the slow axis was orthogonal to the rotation axis of the rubbing roller. That is, the slow axis was parallel to the longitudinal direction of the support. Separately, instead of using a cellulose acetate film as a support, a layer containing a discotic liquid crystal compound is formed using glass as a substrate, and Re (0 °), Re (40 °), and Re (−40 °) are obtained. When measured using KOBRA21 ADH, they were 140.3 nm, 126.9 nm, and 126.7 nm, respectively. (Re (°) indicates the incident angle with the normal direction of the sample surface being 0 °.) From these results, the average tilt angle of the disc surface of the discotic liquid crystalline molecules with respect to the film surface is 88 °, In the phase difference layer, it was confirmed that the discotic liquid crystal was fixed in a tilted orientation with an average tilt angle of 2 °. The wavelength dispersion of the formed retardation layer was Re (450) / Re (550) of 1.10 and Re (650) / Re (550) of 0.96.

  In the formation of the retardation layer 1, a retardation layer for a reference example was formed in the same manner except that no warm air was applied from a direction of 10 ° to 10 ° with respect to the coating surface. In this retardation layer, the average tilt angle of the disc surface of the discotic liquid crystalline molecules with respect to the film surface was 90 °, and it was confirmed that the discotic liquid crystal was fixed in the vertically aligned state in the retardation layer.

(Formation of retardation layer 2 containing a discotic liquid crystalline compound (a retardation layer for a comparative example))
An alignment film similar to the retardation layer 1 was formed on the polymer film.
A coating solution containing a discotic liquid crystal compound having the following composition was continuously applied to the prepared alignment film with a # 4.0 wire bar. The conveyance speed (V) of the film was 20 m / min. In order to dry the solvent of the coating solution and to mature the orientation of the discotic liquid crystal compound, it was heated with 115 ° C. warm air for 90 seconds, and then the orientation of the liquid crystal compound was fixed by UV irradiation to form the retardation layer 2. A compensation film was obtained.
Composition of retardation layer 2 coating solution:
The following discotic liquid crystalline compound 91 parts by mass Ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) 9 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 3 parts by mass Sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1 part by mass The following pyridinium salt 0.5 part by mass The above fluoropolymer (FP2) 0.4 part by mass Methyl ethyl ketone 195 parts by mass

  The direction of the slow axis was orthogonal to the rotation axis of the rubbing roller. That is, the slow axis was parallel to the longitudinal direction of the support. In the same manner as in Example 1, Re (0 °), Re (40 °), and Re (−40 °) were measured using KOBRA21 ADH, and were measured at 139.7 nm, 125.3 nm, and 125.4 nm, respectively. there were. From these results, it was confirmed that the average tilt angle of the disc surface of the discotic liquid crystal molecules with respect to the film surface was 90 °, and that the discotic liquid crystal was fixed in the vertically aligned state in the retardation layer. The wavelength dispersion of the formed retardation layer was 1.16 (Re (450) / Re (550)) and 0.93 (Re (650) / Re (550)).

  Thus, the optical compensation films of Examples, Reference Examples, and Comparative Examples were produced by combining the polymer film 1 or 4 and the retardation layer 1 or 2 respectively.

3. Preparation of Polarizing Plate The surface of a support of TD80UL (manufactured by Fuji Film) 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.
One of the optical compensation films prepared above or one of the polymer films is bonded to the other surface, and the polarizing film is sandwiched between them. TD80UL and the optical compensation film or polymer film serve as a protective film for the polarizing film. A polarizing plate was prepared. . For pasting, an aqueous polyvinyl alcohol adhesive solution was used. Moreover, when bonding a cellulose acylate film, it bonded, after implementing the saponification process by an alkaline solution. The lamination was performed by laminating the slow axis of the optical compensation film or polymer film to be laminated and the absorption axis of the polarizing film in parallel or orthogonal. In addition, it produced similarly about the polarizing plate which bonded TD80UL only to the surface of the polarizing film, and did not bond any film on the other surface.

4). Production and evaluation of liquid crystal display device (1) Production of IPS type liquid crystal display device The polarizing plates on both sides were peeled off from a liquid crystal TV manufactured by Toshiba (37Z3500) and used as an IPS type liquid crystal cell. Δn · d = 311 nm and the pretilt was 2.0 degrees.

An IPS mode liquid crystal display device of an example, a reference example, and a comparative example having the same configuration as in FIG. 1 was produced. Specifically, as the polarizing plates PL1 and PL2 in FIG. 1, any of the polarizing plates prepared above was disposed. In addition, although the polarizing plate of an Example has an optical compensation film which has a phase difference layer formed by fixing inclination orientation, when laminating with a liquid crystal cell, this phase difference layer is used as a molecular director of a discotic liquid crystal compound. In the direction in which the angle with the director of the liquid crystal layer in the black state decreases, the bonding was performed. The same applies to the following FFS type liquid crystal display devices. The characteristics and the like of each member used in each of Examples and Comparative Examples are summarized in the following table.

(2) Production of FFS type liquid crystal display device The polarizing plates on both sides were peeled off from the portable terminal of GALAXY TAB manufactured by Samsunung, and used as an FFS type liquid crystal cell. Δn · d = 327 nm and the pretilt was 1.8 °. FFS type liquid crystal display devices of Examples, Reference Examples, and Comparative Examples having the same configuration as in FIG. 3 were produced in the same manner as described above except that an FFS type liquid crystal cell was used instead of the IPS type liquid crystal cell.

(3) Evaluation of liquid crystal display device and evaluation of color shift Each produced liquid crystal display device is displayed in black, and a color luminance meter (Topcon Co., Ltd.) is colored in the direction of a polar angle of 60 ° from the normal direction of the display surface. BM-5) was used, and the blackness change amount ΔE was calculated. The blackness change amount ΔE is a color difference in the Luv color system, and is calculated when the azimuth direction is changed in increments of 0 to 360 ° and 15 ° in the polar angle 60 ° direction from the normal direction. Defined as the average value of color difference. In practice, ΔE is required to be 0.3 or less.

・ Evaluation of viewing angle contrast Each of the produced liquid crystal display devices is displayed in black, and the luminance ratio (contrast) at the time of white display and black display at a polar angle of 60 ° from the normal direction of the display surface is measured with a color luminance meter ( BM-5 manufactured by Topcon Co., Ltd., respectively, and the average value obtained by changing the azimuth direction in the polar angle of 60 degrees direction in increments of 0 to 360 degrees and 15 degrees was calculated, and the viewing angle contrast was calculated. . The results are shown in the table below.

・ Evaluation of gradation inversion Each half-tone display (15 gradations) and black display (0 gradations) when each liquid crystal display device is divided into 255 with black display as 0 gradation and white display as 255 gradations. The brightness was measured using Ezcontrast (manufactured by ELDIM). At this time, an angle in the polar angle direction in which the luminance of black display is higher than the luminance of halftone display was defined as an inversion angle and calculated.

In the table below,
Regarding the absorption axis and the slow axis, “⇔” means parallel to the horizontal direction of the display surface, “◎” means parallel to the vertical direction of the display surface, and “⇔” and “◎” are orthogonal to each other. Means that
Re450 / 550 means Re (450) / Re (550), Re650 / 550 means Re (650) / Re (550);
| Rth | represents the absolute value of Rth of the optical compensation film in which the first retardation region and the second retardation region are combined;
The DLC retardation layer means a retardation layer containing a discotic liquid crystal compound.

From the results shown in the above table, a second retardation region including a polymer film satisfying a predetermined optical characteristic, and a retardation layer in which a discotic liquid crystal is fixed in an inclined alignment state and Re has a predetermined wavelength dispersion In the IPS or FFS type liquid crystal display device of the example using the optical compensation film in which the first retardation regions including the first retardation region and the slow axes are laminated in parallel, the wavelength dispersion of the retardation layer is the present invention. It can be understood that the color shift in the oblique direction is reduced as compared with the IPS or FFS type liquid crystal display device of the comparative example which is out of the range.
In addition, the embodiment using the first retardation region including the retardation layer in which the tilted alignment state of the discotic liquid crystal compound is fixed is the first position including the retardation layer in which the vertical alignment state of the discotic liquid crystal compound is fixed. It can be understood that the gradation inversion is remarkably suppressed as compared with the reference example using the phase difference region.

DESCRIPTION OF SYMBOLS 10 Liquid crystal layer 12, 14 Substrate 16 1st polarizing film 18 2nd polarizing film 20 1st phase difference area | region 22 2nd phase difference area | region 24 Protective film 26 Backlight

Claims (16)

A first polarizing film;
An optical compensation film comprising a first retardation region and a second retardation region in contact with the first retardation region;
A first substrate;
A liquid crystal layer made of a nematic liquid crystal material;
A second substrate;
In this order, and the liquid crystal display device in which the liquid crystal molecules of the nematic liquid crystal material are aligned in parallel to the surfaces of the pair of substrates during black display,
The first retardation region and the slow axis of the second retardation region are parallel to each other;
In-plane retardation Re (550) of wavelength 550 nm of the second retardation region is 20 nm or less, retardation Rth (550) in the thickness direction of wavelength 550 nm of the second retardation region is 20 nm to 120 nm,
The first retardation region includes a retardation layer containing a discotic liquid crystal compound tilted and oriented at an average tilt angle θ (θ> 0), and has Re, Re (450), Re (wavelengths of 450 nm, 550 nm, and 650 nm). 550) and Re (650) satisfying Re (450) / Re (550) of 1 or more and 1.13 or less and Re (650) / Re (550) satisfying 0.94 or more and 1 or less. Liquid crystal display device: However, in-plane retardation Re and thickness direction retardation are obtained by using in-plane refractive index nx and ny (nx ≧ ny), thickness direction refractive index nz, and film thickness d, respectively. , Re = (nx−ny) × d and Rth = {(nx + ny) / 2−nz} × d. The IPS or FFS liquid crystal display device according to claim 1, wherein the average inclination angle θ is 0 <θ <10 ° . 3. The discotic liquid crystal compound in the first retardation region is tilted and oriented in a direction in which an angle between a molecular director of the liquid crystal compound and a director of the liquid crystal layer in a black state decreases. IPS or FFS liquid crystal display device. 4. The IPS or FFS type liquid crystal display device according to claim 1, wherein the IPS or FFS type liquid crystal display device is disposed in the order of a first polarizing film, a first retardation region, and a second retardation region. The IPS or FFS type liquid crystal display device according to any one of claims 1 to 3, wherein the IPS or FFS type liquid crystal display device is disposed in the order of a first polarizing film, a second retardation region, and a first retardation region. The IPS or FFS type liquid crystal display device according to any one of claims 1 to 5, wherein Re (550) of the first retardation region is 50 nm to 200 nm. The IPS or FFS type liquid crystal display device according to claim 1, wherein an absolute value | Rth (550) | of Rth (550) of the entire optical compensation film is 40 nm or less. The second retardation region includes a plurality of layers, a layer in contact with the first retardation region among the plurality of layers is an alignment film, and the first retardation region is a discotic liquid crystal compound and an alignment control agent. The IPS or the IPS according to any one of claims 1 to 7, wherein the alignment control agent has an action of reducing a tilt angle of a director of a discotic liquid crystal compound on the air interface side. FFS type liquid crystal display device. The IPS or FFS type according to any one of claims 4 to 8, wherein the first retardation region has a polymer film together with the retardation layer, and the polymer film is in contact with the first polarizing film. Liquid crystal display device. The IPS or FFS type liquid crystal display device according to claim 1, further comprising a second polarizing film on an outer side of the second substrate. The IPS or FFS type liquid crystal display device according to claim 10, further comprising a polymer film between the second polarizing film and the second substrate. The polymer film has an in-plane retardation Re (550) having an absolute value | Re (550) | of 10 nm or less, and an absolute value of the retardation Rth (550) in the thickness direction of the same wavelength | Rth ( 550) | is 30 nm or less, The IPS or FFS type liquid crystal display device according to claim 9 or 11. The IPS according to claim 9, 11 or 12, wherein the polymer film has | Re (400) -Re (700) | of 10 nm or less and | Rth (400) -Rth (700) | of 35 nm or less. Or an FFS type liquid crystal display device. 14. The IPS or FFS type liquid crystal display device according to claim 9, wherein the polymer film has a thickness of 10 to 90 μm. The IPS or FFS type liquid crystal display device according to any one of claims 9 and 11 to 14, wherein the polymer film includes a cellulose acylate film, a cyclic olefin polymer film, or an acrylic polymer film. The acrylic polymer film according to claim 15, wherein the acrylic polymer film is an acrylic polymer film containing an acrylic polymer containing at least one unit selected from a lactone ring unit, a maleic anhydride unit, and a glutaric anhydride unit. Liquid crystal display device.

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