JP2006215092A - Retardation film and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a retardation film contributing to improvement in the viewing angle characteristics of a liquid crystal display device. <P>SOLUTION: The retardation film has an optical anisotropic layer formed of a liquid crystal composition which contains at least each one kind of: discotic liquid crystal compound; boronic acid compound expressed by general formula (I); and copolymer containing a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit having a prescribed hydrophilic group, or a fluorine-based compound having a prescribed hydrophilic group. Molecules of the discotic liquid crystal compound are substantially vertically aligned in the optical anisotropic layer. In the formula (I), each of R<SP>1</SP>and R<SP>2</SP>independently represents a hydrogen atom or a substituted or unsubstituted aliphatic hydrocarbon group, aryl group, or heteroaryl group, and R<SP>3</SP>represents a substituted or unsubstituted aliphatic hydrocarbon group, aryl group or hetero aryl group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, and more particularly to an in-plane switching (IPS) mode liquid crystal display device that performs display by applying a horizontal electric field to a liquid crystal compound aligned in a horizontal direction. The present invention also relates to a retardation film that contributes to improving the viewing angle characteristics of a liquid crystal display device, particularly an IPS mode liquid crystal display device.

  As a liquid crystal display device, a so-called TN mode, in which a liquid crystal layer in which nematic liquid crystal is twisted and arranged between two orthogonal polarizing plates, and an electric field is applied in a direction perpendicular to the substrate is widely used. In this method, since the liquid crystal rises with respect to the substrate during black display, birefringence due to the liquid crystalline compound occurs when viewed from an oblique direction, and light leakage occurs. To solve this problem, a system for optically compensating the liquid crystal cell and preventing this light leakage by using a film in which liquid crystal molecules are hybrid-aligned has been put into practical use. However, even if liquid crystal molecules are used, it is very difficult to completely optically compensate the liquid crystal cell without any problem, resulting in a problem that gradation reversal in the lower direction of the screen cannot be suppressed.

  In order to solve such a problem, a liquid crystal display device using a so-called in-plane switching (IPS) mode in which a lateral electric field is applied to the liquid crystal, or a liquid crystal having a negative dielectric anisotropy is vertically aligned in the panel. A vertical alignment (VA) mode in which alignment is divided by protrusions and slit electrodes has been proposed and put into practical use. In recent years, these panels have been developed not only for monitor applications but also for TV applications, and screen brightness has been greatly improved accordingly. For this reason, slight light leakage in the diagonally oblique incidence direction during black display, which has not been considered as a problem in these operation modes, has become apparent as a cause of deterioration in display quality.

As one means for improving the color tone and the viewing angle of black display, the arrangement of an optical compensation material having birefringence characteristics between the liquid crystal layer and the polarizing plate is also studied in the IPS mode. For example, a white display or halftone display is viewed directly from an oblique direction by arranging a birefringent medium having optical axes orthogonal to each other between the substrate and the polarizing plate to compensate for increase / decrease in retardation of the liquid crystal layer during tilting. It is disclosed that the coloring in the case can be improved (see Patent Document 1). In addition, as a method using an optical compensation film made of a styrene polymer having a negative intrinsic birefringence or a discotic liquid crystalline compound (see Patent Documents 2, 3, and 4), the optical compensation film has a positive birefringence and an optical axis. A method of combining a film in the plane of a film with a film having a positive birefringence and an optical axis in the normal direction of the film (see Patent Document 5), a biaxial retardation film having a retardation of half wavelength Using a film having a negative retardation as a protective film of a polarizing plate and providing an optical compensation layer having a positive retardation on this surface (see Patent Document 7) Has been.
Patent Document 4 discloses a film in which the disc surface of the discotic liquid crystal molecules is aligned and fixed so that the disc surface is substantially perpendicular to the surface direction of the support. In particular, an alignment film having a special molecular structure is disclosed as a technique for vertically aligning (see Patent Documents 8, 9, and 10).

Japanese Patent Laid-Open No. 9-80424 Japanese Patent Laid-Open No. 10-54982 JP-A-11-202323 Japanese Patent Laid-Open No. 9-292522 JP 11-133408 A JP-A-11-305217 JP-A-10-307291 JP 2000-56310 A JP 2000-104073 A JP 2000-105316 A

  However, many of the proposed methods are methods that improve the viewing angle by canceling the birefringence anisotropy of the liquid crystal in the liquid crystal cell, so the polarization axis crossing angle when the orthogonal polarizing plate is viewed from an oblique direction. There is a problem that the light leakage based on the deviation from orthogonality cannot be solved sufficiently. Even in a system that can compensate for this light leakage, it is very difficult to completely optically compensate the liquid crystal cell without any problem. Furthermore, in the optical compensation sheet for IPS mode liquid crystal cell that performs optical compensation with the stretched birefringent polymer film, it is necessary to use a plurality of films. As a result, the thickness of the optical compensation sheet increases, and the display device becomes thinner. It is disadvantageous. Moreover, since an adhesive layer is used for lamination | stacking of a stretched film, the adhesive layer contracted by the temperature / humidity change, and defects, such as peeling and a curvature between films, may generate | occur | produce. In order to solve these problems, a technique for aligning the discotic liquid crystal molecules substantially vertically as described later in the present invention is required. However, the conventional technique causes an alignment defect or repels at the time of alignment. A problem occurred. In addition, it is necessary to modify the polymer in order to impart vertical alignment or to synthesize the polymer using a special monomer. As a result, the alignment film becomes expensive. A technique for aligning discotic liquid crystal molecules substantially vertically using an inexpensive alignment film has been demanded.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an IPS liquid crystal display device with a simple configuration and not only display quality but also a viewing angle that is remarkably improved. Another object of the present invention is to provide a retardation film that contributes to improving the viewing angle characteristics of a liquid crystal display device, particularly an IPS liquid crystal display device, which can be stably produced by a simple method.

The object of the present invention has been achieved by the following retardation films [1] to [4] and liquid crystal display devices [5] to [11].
[1] A retardation film having an alignment film made of at least one polymer and an optically anisotropic layer containing a liquid crystal composition containing at least one discotic liquid crystal compound and at least one boronic acid compound.
[2] The retardation film according to claim 1, wherein the boronic acid compound is represented by at least one of the following general formula (I).

（一般式（Ｉ）中、Ｒ¹及びＲ²はそれぞれ独立に、水素原子、置換もしくは無置換の、アルキル基、アルケニル基、アルキニル基、アリール基又はヘテロアリール基を表し、Ｒ³は置換もしくは無置換の、アルキル基、アルケニル基、アルキニル基、アリール基又はヘテロアリール基を表す。）
［３］光学異方性層にフルオロ脂肪族基含有モノマーより誘導される繰り返し単位と下記一般式（II）で表される繰り返し単位とを含む共重合体の少なくとも一種又は下記一般式（III）で表される化合物の少なくとも一種をさらに含有する、請求項１に記載の位相差膜。

(In the general formula (I), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aryl group or heteroaryl group, and R ³ represents a substituted or unsubstituted group. Represents an unsubstituted alkyl group, alkenyl group, alkynyl group, aryl group or heteroaryl group.)
[3] At least one copolymer comprising a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit represented by the following general formula (II) in the optically anisotropic layer, or the following general formula (III) The retardation film according to claim 1, further comprising at least one compound represented by the formula:

（式中、Ｒ¹¹、Ｒ¹²およびＲ¹³はそれぞれ独立に、水素原子または置換基を表し；Ｌは下記の連結基群から選ばれる２価の連結基または下記の連結基群から選ばれる２つ以上を組み合わせて形成される２価の連結基を表し、
（連結基群）
単結合、−Ｏ−、−ＣＯ−、−ＮＲ¹⁴−（Ｒ¹⁴は水素原子、アルキル基、アリール基またはアラルキル基を表す）、−Ｓ−、−ＳＯ₂−、−Ｐ（＝Ｏ）（ＯＲ¹⁵）−（Ｒ¹⁵はアルキル基、アリール基またはアラルキル基を表す）、アルキレン基およびアリーレン基；
Ｑはカルボキシル基（−ＣＯＯＨ）もしくはその塩、スルホ基（−ＳＯ₃Ｈ）もしくはその塩、またはホスホノキシ基｛−ＯＰ（＝Ｏ）（ＯＨ）₂｝もしくはその塩を表す。）
一般式（III）
（Ｒ⁰）_m−Ｌ⁰−（Ｗ）_n
（式中、Ｒ⁰はアルキル基、末端にＣＦ₃基を有するアルキル基または末端にＣＦ₂Ｈ基を有するアルキル基を表し、ｍは１以上の整数を表し、複数個のＲ⁰は同一でも異なっていてもよいが、少なくとも一つは末端にＣＦ₃基またはＣＦ₂Ｈ基を有するアルキル基を表す。Ｌ⁰は（ｍ＋ｎ）価の連結基を表し、Ｗはカルボキシル基（−ＣＯＯＨ）もしくはその塩、スルホ基（−ＳＯ₃Ｈ）もしくはその塩、またはホスホノキシ基｛−ＯＰ（＝Ｏ）（ＯＨ）₂｝もしくはその塩を表し、ｎは１以上の整数を表す。）
［４］前記一般式（Ｉ）中、Ｒ¹³が重合性基を有する［１］〜［３］のいずれかに記載の位相差膜。
［５］第１偏光膜、該第１偏光膜に接する第１位相差領域と該第１位相差領域に接する第２位相差領域とからなる位相差膜、第１基板、ネマチック液晶材料を含有する液晶層、第２基板及び第２偏光膜をこの順序で配置し、黒表示時に前記ネマチック液晶材料の液晶性化合物が前記一対の基板の表面に対して平行に配向する液晶表示装置であって、前記第１位相差領域の面内のレターデーションＲｅが２０ｎｍ以下で、且つ、前記第１位相差領域の厚み方向のレターデーションＲｔｈが２０ｎｍ〜１２０ｎｍであり、前記第２位相差領域が［１］〜［４］のいずれかに記載の光学異方性層を含み、該第２位相差領域の遅相軸が第１偏光膜の透過軸と黒表示時の液晶性化合物の遅相軸方向に平行である液晶表示装置。
［６］前記第２位相差領域のＲｅが５０ｎｍ〜２００ｎｍである［５］に記載の液晶表示装置。
［７］前記第１位相差領域が複数の層から構成されており、該複数の層のうち第２位相差領域に接する層が配向膜である［５］または［６］に記載の液晶表示装置。
［８］前記第２偏光膜を挟持する一対の保護膜を有し、該一対の保護膜のうち前記液晶層側に配置される保護膜の厚み方向の位相差Ｒｔｈが２０ｎｍ以下である［５］〜［７］のいずれか１項に記載の液晶表示装置。
［９］前記第２偏光膜を挟持する一対の保護膜を有し、該一対の保護膜のうち前記液晶層側に配置される保護膜がセルロースアセテートフィルム又はノルボルネン系フィルムである［５］〜［８］のいずれか１項に記載の液晶表示装置。
［１０］前記第２偏光膜を挟持する一対の保護膜を有し、該一対の保護膜のうち前記液晶層側に配置される保護膜がセルロースアセテートフィルムと垂直配向した棒状液晶性化合物を含む層とからなる［５］〜［９］のいずれか１項に記載の液晶表示装置。
［１１］前記第１位相差領域が複数の層から構成されており、該複数の層のうち第１偏光膜に接する層が第１偏光膜の保護膜として機能する［５］〜［１０］のいずれか１項に記載の液晶表示装置。

(Wherein R ¹¹ , R ¹² and R ¹³ each independently represents a hydrogen atom or a substituent; L is a divalent linking group selected from the following linking group group or 2 selected from the following linking group group: Represents a divalent linking group formed by combining two or more,
(Linked group group)
Single bond, —O—, —CO—, —NR ¹⁴ — (R ¹⁴ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group), —S—, —SO ₂ —, —P (═O) ( OR ¹⁵ ) — (R ¹⁵ represents an alkyl group, an aryl group or an aralkyl group), an alkylene group and an arylene group;
Q 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. )
General formula (III)
(R ⁰ ) _m −L ⁰ − (W) _n
(Wherein 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, m represents an integer of 1 or more, and a plurality of R ⁰ may be the same) At least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal, L ⁰ represents an (m + n) -valent linking group, and 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, and n represents an integer of 1 or more.
[4] The retardation film according to any one of [1] to [3], wherein R ¹³ has a polymerizable group in the general formula (I).
[5] including a first polarizing film, a retardation film composed of a first retardation region in contact with the first polarizing film and a second retardation region in contact with the first retardation film, a first substrate, and a nematic liquid crystal material A liquid crystal display device in which a liquid crystal layer, a second substrate, and a second polarizing film are arranged in this order, and the liquid crystalline compound of the nematic liquid crystal material is aligned in parallel to the surfaces of the pair of substrates during black display. The in-plane retardation Re of the first retardation region is 20 nm or less, the retardation Rth in the thickness direction of the first retardation region is 20 nm to 120 nm, and the second retardation region is [1]. The slow axis of the second retardation region includes the transmission axis of the first polarizing film and the slow axis direction of the liquid crystalline compound during black display. Liquid crystal display device that is parallel to.
[6] The liquid crystal display device according to [5], wherein Re of the second retardation region is 50 nm to 200 nm.
[7] The liquid crystal display according to [5] or [6], wherein the first retardation region is composed of a plurality of layers, and a layer in contact with the second retardation region among the plurality of layers is an alignment film. apparatus.
[8] A pair of protective films sandwiching the second polarizing film, and a thickness direction retardation Rth of the protective film disposed on the liquid crystal layer side of the pair of protective films is 20 nm or less [5] ] The liquid crystal display device according to any one of [7].
[9] A pair of protective films sandwiching the second polarizing film, and the protective film disposed on the liquid crystal layer side of the pair of protective films is a cellulose acetate film or a norbornene film. The liquid crystal display device according to any one of [8].
[10] It has a pair of protective films sandwiching the second polarizing film, and the protective film disposed on the liquid crystal layer side of the pair of protective films contains a rod-like liquid crystalline compound vertically aligned with the cellulose acetate film The liquid crystal display device according to any one of [5] to [9], comprising a layer.
[11] The first retardation region is composed of a plurality of layers, and a layer in contact with the first polarizing film among the plurality of layers functions as a protective film for the first polarizing film [5] to [10]. The liquid crystal display device according to any one of the above.

  In the present invention, the discotic molecules are stably and substantially vertically aligned by orienting the molecules of the discotic liquid crystalline compound in the presence of a boronic acid compound and a polymer or compound having a specific hydrophilic group. Oriented. As a result, a retardation film that can be stably produced by a simple method can be provided. A retardation film having an optically anisotropic layer containing discotic liquid crystalline molecules fixed in vertical alignment is useful for a liquid crystal display device, particularly an IPS liquid crystal display device. In the present invention, a first polarizing film, a retardation film comprising a first retardation region in contact with the first polarizing film, and a second retardation region in contact with the first retardation region, a first substrate, and a nematic liquid crystal material are provided. In the liquid crystal display device in which the liquid crystal layer, the second substrate, and the second polarizing film are arranged in this order, and the liquid crystalline compound of the nematic liquid crystal material is aligned in parallel with the surfaces of the pair of substrates during black display, An in-plane retardation Re is 20 nm or less, a first retardation region having a thickness direction retardation Rth of 20 nm to 120 nm is disposed, and the substantially vertically aligned Re is a discotic liquid crystal of 50 nm to 200 nm. The optically anisotropic layer is used as the second retardation region composed of the light-sensitive compound, and the slow axis of the second retardation region is the transmission axis of the first polarizing film and the retardation of the liquid crystal compound during black display. By arranging the second retardation region so as to be parallel to the axial direction and closer to the liquid crystal layer side than the first retardation region, the oblique azimuth angle direction is not changed without any change in the characteristics of the front direction. When viewed from above, it is possible to improve the contrast reduction caused by the deviation of the absorption axes of the two polarizing plates from 90 degrees, particularly the contrast reduction from the oblique direction of 45 degrees. Furthermore, the contrast can be further improved by setting the Rth of the protective film of the second polarizing film to 20 nm or less.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, an embodiment of the liquid crystal display device of the present invention and its constituent members will be described in order. 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. FIG. 1 is a schematic diagram showing an example of a pixel region of the liquid crystal display device of the present invention. FIG. 2 is a schematic view of an embodiment of the liquid crystal display device of the present invention.

  In the present specification, “parallel” and “orthogonal” mean that the angle is within a range of strictly less than ± 10 °. In this range, an error from a strict angle is preferably less than ± 5 °, and more preferably less than ± 2 °. Further, “substantially vertical” means within a range of less than ± 20 ° from a strict vertical angle. In this range, an error from a strict angle is preferably less than ± 15 °, and more preferably less than ± 10 °. 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, unless otherwise specified, the term “polarizing plate” is cut into a size to be incorporated into a long polarizing plate and a liquid crystal device (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, but “polarizing plate” means a laminate having a transparent protective film for protecting the polarizing film on at least one surface of the “polarizing film”. It shall be.

  In the present specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH (manufactured by Oji Scientific Instruments). Rth (λ) is the light of wavelength λnm from the direction inclined by + 40 ° with respect to the normal direction of the film, with Re (λ) and the in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotary axis). And a retardation value measured by making light of wavelength λ nm incident from a direction inclined by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). KOBRA 21ADH calculates based on the retardation value measured in a total of three directions, the assumed value of the average refractive index, and the input film thickness value. Here, 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. Those whose average refractive index is not known 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 calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

In an optically anisotropic layer in which a discotic compound or rod-shaped compound is oriented, the tilt angle on one surface of the optically anisotropic layer (the physical target axis of the discotic compound or rod-shaped compound is the interface of the optically anisotropic layer) It is difficult to directly and accurately measure θ1 and 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 calculation, the following two points are assumed and the tilt angle at the two interfaces of the optically anisotropic layer is used.
1. The optically anisotropic layer is assumed to be a multilayer body composed of layers containing a discotic compound or a rod-like compound. Further, it is assumed that the minimum unit layer (assuming that the tilt angle of the discotic compound or rod-shaped 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 optically anisotropic layer.
The specific calculation method is as follows.
(1) In a plane in which the tilt angle of each layer changes monotonically with a linear function along the thickness direction of the optically anisotropic layer, the incident angle of the measurement light to the optically anisotropic layer is changed, and three or more The retardation value is measured at the measurement angle. 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 optically anisotropic layer being 0 °. Such measurement is performed by 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 of each layer and the uniaxial optical axis direction of the layer coincide with each other, the calculation of the angular dependence of the retardation value of the optically anisotropic layer agrees with the measured value. Fitting is performed using the tilt angle θ1 on one surface of the isotropic layer 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 optically anisotropic layer can be measured by an optical interference film thickness meter, a cross-sectional photograph of a scanning electron microscope, or the like.

[Liquid Crystal Display]
In general, the liquid crystal cell includes a first substrate 14 and a second substrate 17 and a liquid crystal layer 16 sandwiched between them. The product Δn · d of the thickness d (μm) of the liquid crystal layer and the refractive index anisotropy Δn is optimal in the range of 0.2 to 0.4 μm for the IPS type having no twisted structure in the transmission mode. 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 14 and 17 that are in contact with the liquid crystal layer 16, and the liquid crystal compound is aligned substantially parallel to the surface of the substrate and applied on the alignment film. The rubbing treatments 4, 15, 18 and the like control the liquid crystal compound alignment directions 5a and 5b in the voltage-less application state or the low application state.
Further, electrodes 2 and 3 capable of applying a voltage to the liquid crystalline compound are formed on the inner surface of the substrate 14 or 17.

  When active driving is performed using a nematic liquid crystal having a positive dielectric anisotropy as a field effect liquid crystal, the alignment direction of the liquid crystalline compound in the state of no voltage application or low voltage application is 5a and 5b in FIG. At this time, a black display is obtained. When applied between the electrodes 2 and 3, the liquid crystal compound changes its orientation direction in the 6a and 6b directions according to the voltage. Usually, bright display is performed in this state. However, this drawing shows a very small area corresponding to one pixel.

  In FIG. 2, the transmission axis 9 of the first polarizing film 8 and the transmission axis 21 of the second polarizing film 20 are arranged orthogonally. The optical compensation film 10 is composed of two regions, a first retardation region 11 and a second retardation region 12. Further, the slow axis of the second retardation region 12 is parallel to the transmission axis 9 of the first polarizing film 8 and the slow axis direction 17 of the liquid crystal compound at the time of black display, and the second retardation region 12 is the first retardation region 12. It must be arranged closer to the liquid crystal layer than the phase difference region 11. The optical characteristics of each layer will be described later.

  Although FIG. 2 shows a configuration in which the first polarizing film 8 is sandwiched between two protective films 7a and 7b, 7b may not be used. Further, when the protective film 7b referred to here is used, the protective film 7b is one of the layers constituting the first retardation region 11 in the present invention. In FIG. 2, the second polarizing film 21 is also sandwiched between two protective films 20a and 20b. The thickness direction retardation Rth of the protective film 20a on the liquid crystal side is preferably 20 nm or less.

  In addition, in FIG. 2, although the aspect of the display device of the transmission mode provided with the upper side polarizing plate and the lower side polarizing plate was shown, this invention may be the aspect of the reflection mode provided with only one polarizing plate, In such a case, since the optical path in the liquid crystal cell is doubled, the optimum value of Δn · d is about the above half value.

  The liquid crystal display device of the present invention is not limited to the configuration shown in FIGS. 1 and 2, and may include other members. For example, a color filter may be disposed between the liquid crystal layer and the polarizing film. Further, an antireflection treatment or a hard coat may be applied to the surface of the protective film of the polarizing film. Moreover, you may use what gave electroconductivity to the structural member. In the case of use as a transmission type, a cold cathode or a hot cathode fluorescent tube, or a backlight using a light emitting diode, a field emission element, or an electroluminescent element as a light source can be disposed on the back surface. In addition, a reflective polarizing plate, a diffusion plate, a prism sheet, or a light guide plate can be disposed between the liquid crystal layer and the backlight. In addition, the liquid crystal display device of the present invention may be of a reflective type. In such a case, only one polarizing plate may be disposed on the observation side, and reflected on the back surface of the liquid crystal cell or the inner surface of the lower substrate of the liquid crystal cell. Place the membrane. Of course, it is also possible to provide a front light using the light source on the liquid crystal cell observation side.

  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 three-terminal or two-terminal semiconductor elements such as TFT and 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.

[First retardation region of retardation film]
Regarding the optical characteristics of the first retardation region, the in-plane retardation Re is 20 nm or less, more preferably 10 nm or less, and most preferably 5 nm or less. Moreover, the retardation Rth in the thickness direction is 20 nm to 120 nm, and more preferably in the range of 40 nm to 100 nm. When the protective film 7b that protects the first polarizing film 8 has optical anisotropy, the protective film 7b is a layer constituting the first retardation region 11, so that Rth of the protective film and others It is required that the total Rth of the layers is 40 nm to 100 nm.

  The retardation film having this optical characteristic includes a retardation film made of a birefringent polymer film, and an optically anisotropic layer formed by applying or transferring a low-molecular or high-molecular liquid crystalline compound on a transparent support. Although there is a phase difference film or the like, any of them can be used in the present invention.

  The birefringent polymer film having the optical characteristics can be easily formed by biaxially stretching a polymer film. In addition, cellulose acetates that exhibit this optical property by simply casting without stretching can be suitably used. As this cellulose acetate, what is described in Unexamined-Japanese-Patent No. 2002-90541 can be used. As a material for the polymer film, a synthetic polymer (eg, polycarbonate, polysulfone, polyethersulfone, polyacrylate, polymethacrylate, norbornene resin, cellulose acetate) is generally used.

  The first retardation region may be an optically anisotropic layer having an optical anisotropy based on the orientation of liquid crystalline molecules, which is formed by applying or transferring a composition containing a liquid crystalline compound. For example, a rod-shaped cholesteric liquid crystalline composition containing a chiral structural unit is aligned with its helical axis approximately perpendicular to the substrate and then fixed, or a discotic liquid crystalline compound with negative intrinsic birefringence is horizontally aligned. (Director is perpendicular to the substrate), and polyimide polymer cast and fixed on the substrate.

[Second retardation region of retardation film]
In the second retardation region, the second retardation region may be composed only of the optically anisotropic layer, and is preferably composed of only the optically anisotropic layer. The Re of the second retardation region is preferably 50 nm to 200 nm, and more preferably 80 nm to 160 nm. This Re adjustment is performed by controlling the thickness of the optically anisotropic layer. Further, the discotic liquid crystalline compound needs to be aligned substantially perpendicular to the film surface (average inclination angle in the range of 70 to 90 degrees). When the average inclination angle is smaller than this, the light leakage distribution becomes asymmetric. Substantially perpendicular means that the average angle (average inclination angle) between the disk surface and the surface of the optically anisotropic layer is in the range of 70 ° to 90 °. These discotic liquid crystalline compounds may be aligned obliquely or may be changed so that the inclination angle gradually changes (hybrid alignment). Even in the case of oblique orientation or hybrid orientation, the average tilt angle is preferably 70 ° to 90 °, more preferably 75 ° to 90 °, and most preferably 80 ° to 90 °.

  The discotic liquid crystalline compounds that can be used in the present invention are various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by The Chemical Society of Japan, quarterly). Chemical Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., Page 1794 (1985); Zhang et al., J. Am.Chem.Soc., Vol.116, page 2655 (1994)). The polymerization of discotic liquid crystalline compounds is described in JP-A-8-27284.

The discotic liquid crystalline compound preferably has a polymerizable group so that it can be fixed by polymerization. For example, a structure in which a polymerizable group is bonded as a substituent to a discotic core of a discotic liquid crystalline compound can be considered. However, when a polymerizable group is directly connected to the discotic core, the alignment state is maintained in the polymerization reaction. It becomes difficult. Therefore, a structure having a linking group between the discotic core and the polymerizable group is preferable. That is, the discotic liquid crystalline compound having a polymerizable group is preferably a compound represented by the following formula.
D (-LP) _n
In the formula, D is a discotic core, L is a divalent linking group, P is a polymerizable group, and n is an integer of 4 to 12. Preferred specific examples of the discotic core (D), the divalent linking group (L) and the polymerizable group (P) in the above formula are (D1) to (D15) described in JP-A No. 2001-4837, respectively. ), (L1) to (L25), and (P1) to (P18), and the contents described in the publication can be preferably used.

  The above discotic (discotic) compounds generally have a structure in which these are used as a mother nucleus at the center of a molecule, and a linear alkyl group, an alkoxy group, a substituted benzoyloxy group, etc. are radially substituted as the linear chain. , Which shows liquid crystallinity and is generally called a discotic liquid crystal. However, the molecule itself is not limited to the above description as long as the molecule itself has negative uniaxiality and can give a certain orientation. In the present invention, the term “formed from a discotic compound” does not necessarily mean that the final product is the above-mentioned compound. For example, the low-molecular discotic liquid crystal has a group that reacts with heat, light, or the like. As a result, it may be polymerized or cross-linked by reaction with heat, light or the like, resulting in high molecular weight and loss of liquid crystallinity.

  Preferred examples of the discotic compound are shown below.

[Method for Forming Second Retardation Region]
The optically anisotropic layer includes a discotic liquid crystalline compound, at least one boronic acid compound represented by the following general formula (I), a repeating unit derived from a fluoroaliphatic group-containing monomer, and the following general formula (II): A liquid crystal composition containing at least one type of a copolymer containing a repeating unit represented by the formula (III) or at least one type of a compound represented by the following general formula (III), and, if desired, the following polymerizable initiator and other additions It can form by apply | coating the coating liquid containing an agent on a support body. It is preferable to form an alignment film on a support and apply it on the alignment film.

[Vertical alignment agent]
In order to uniformly and vertically align the discotic liquid crystal compound, it is necessary to vertically control the liquid crystal compound on the alignment film interface side and the air interface side. For this purpose, the alignment control on the alignment film interface side is unevenly distributed at the alignment film interface during the alignment of the discotic liquid crystal, and the liquid crystalline compound is aligned vertically by its excluded volume effect, electrostatic effect, or surface energy effect. A compound that acts on the liquid crystal is mixed in the liquid crystal coating liquid, and the orientation control on the air interface side is unevenly distributed at the air interface during the orientation of the discotic liquid crystal, and the liquid crystallinity is obtained by its excluded volume effect, electrostatic effect, or surface energy effect. A compound having an effect of vertically aligning the compound is added to the liquid crystal coating solution. The following boronic acid compound is preferably used as an additive for vertically aligning the liquid crystalline compound on the alignment film interface side. Examples of the compound for vertically aligning the liquid crystalline compound on the air interface side include a fluoroaliphatic group for uneven distribution on the air interface side, a carboxyl group (—COOH), and a sulfo group (—SO ₃ H). ), A phosphonoxy group {—OP (═O) (OH) ₂ } and one or more hydrophilic groups selected from the group consisting of salts thereof are preferably used. Also, by blending these compounds, the coatability 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]
The second retardation region contains a boronic acid compound represented by the following general formula (I) as an alignment film interface-side vertical alignment agent. By adding the boronic acid compound, the discotic liquid crystalline compound is substantially vertically regulated in the vicinity of the alignment film.

In the general formula (I), R ¹ and R ² each independently represent a hydrogen atom or a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aryl group or heteroaryl group. R ¹ and R ² may combine to form a ring. R ¹ and R ² are most preferably a hydrogen atom.

In the general formula (I), R ³ represents a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aryl group or heteroaryl group.

  Specific examples of the alkyl group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, hexadecyl, Octadecyl group, eicosyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-methylhexyl group, cyclopentyl group, cyclohexyl group, 1- Examples thereof include linear, branched, or cyclic alkyl groups such as an adamantyl group and 2-norbornyl group. Specific examples of the alkenyl group include linear, branched, such as vinyl group, 1-propenyl group, 1-butenyl group, 1-methyl-1-propenyl group, 1-cyclopentenyl group and 1-cyclohexenyl group. Or a cyclic alkenyl group.

  Specific examples of the alkynyl group include ethynyl group, 1-propynyl group, 1-butynyl group, 1-octynyl group and the like. Specific examples of the aryl group include those in which 1 to 4 benzene rings form a condensed ring, and those in which a benzene ring and an unsaturated five-membered ring form a condensed ring. Specific examples include Examples thereof include a phenyl group, a biphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, an indenyl group, an acenaphthenyl group, a fluorenyl group, and a pyrenyl group, and particularly preferred are a phenyl group, a biphenyl group, and a naphthyl group.

  The heteroaryl group containing one or more heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur atoms is a heteroaromatic group containing one or more heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur atoms. There can be mentioned a heteroaryl group obtained by removing one hydrogen atom on the ring. Specific examples of the heteroaromatic ring containing one or more heteroatoms selected from the group consisting of nitrogen atom, oxygen atom and sulfur atom include pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, isoxazole and oxadiazole. , Thiazole, thiadiazole, indole, carbazole, benzofuran, dibenzofuran, thianaphthene, dibenzothiophene, indazolebenzimidazole, anthranyl, benzisoxazole, benzoxazole, benzothiazole, purine, pyridine, pyridazine, pyrimidine, pyrazine, triazine, quinoline, acridine, Examples thereof include isoquinoline, phthalazine, quinazoline, quinoxaline, naphthyridine, phenanthroline, and pteridine.

One or more groups represented by R ³ may be further substituted with an arbitrary substituent. Examples of the substituent include monovalent non-metallic atomic groups excluding hydrogen, halogen atoms (—F, —Br, —Cl, —I), hydroxyl groups, alkoxy groups, aryloxy groups, mercapto groups, alkylthio groups. , Arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N-arylamino group, N, N-diarylamino group, N-alkyl-N-aryl Amino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N, N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyl Oxy, alkylsulfoxy, arylsulfoxy, acylthio Group, acylamino group, N-alkylacylamino group, N-arylacylamino group, ureido group, N′-alkylureido group, N ′, N′-dialkylureido group, N′-arylureido group, N ′, N '-Diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-arylureido Group, N ′, N′-dialkyl-N-alkylureido group, N ′, N′-dialkyl-N-arylureido group, N′-aryl-N-alkylureido group, N′-aryl-N-arylureido Group, N ′, N′-diaryl-N-alkylureido group, N ′, N′-diaryl-N-arylureido group, N′-alkyl-N′-aryl-N-alkyl Raid group, N′-alkyl-N′-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonyl Amino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group and its conjugate base group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl Group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group, N, N-diarylcarbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, alkyl Sulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N, N-dialkylsulfinamoyl group N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-dialkylsulfamoyl group Group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonylsulfur group Famoiru group _{(-SO 2 NHSO 2 (alkyl)} ) and its conjugated base group N- aryl acylsulfamoyl group _{(-SO 2 NHSO 2 (aryl)} ) and its conjugated base group, N- alkylsulfonylcarbamoyl group (-CONHSO ₂ (alkyl)) and its conjugated base group, N- aryl sulfonyl carbamoyl group (—CONHSO ₂ (aryl)) and its conjugate base group, alkoxysilyl group (—Si (Oalkyl) ₃ ), aryloxysilyl group (—Si (Oaryl) ₃ ), hydroxysilyl group (—Si (OH) ₃ ) And its conjugate base group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (—PO ₃ (alkyl) ₂ ), diarylphosphono group (—PO ₃ (aryl) ₂ ), alkyl Arylphosphono group (—PO ₃ (alkyl) (aryl)), monoalkylphosphono group (—PO ₃ H (alkyl)) and its conjugate base group, monoarylphosphono group (—PO ₃ H (aryl)) and its conjugate base group, phosphonooxy group (—OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonooxy Group (—OPO ₃ (alkyl) ₂ ), diarylphosphonooxy group (—OPO ₃ (aryl) ₂ ), alkylarylphosphonooxy group (—OPO ₃ (alkyl) (aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group, monoarylphosphonooxy group (—OPO ₃ H (aryl)) and its conjugate base group, cyano group, nitro group, aryl group, alkenyl group, alkynyl group Is mentioned. In addition, these substituents may combine with each other or with a substituted hydrocarbon group to form a ring, if possible.

  Of the compounds represented by the general formula (I), the compounds represented by the following general formula (IV) are most preferred.

In General Formula (IV), L ¹ represents a single bond or a divalent linking group, and examples of the linking group include —O—, —CO—, —NH—, an alkylene group, an arylene group, a heteroaryl group, and their A group consisting of a combination is preferred, and L ¹ is particularly preferably a single bond. Moreover, the general formula R ¹ in (IV), R ² and R ³ each have the same meanings as commonly R ¹ in formula (I) in, R ² and R ^3.

  Examples of Z in the general formula (II) include polymerizable groups such as acrylate group, methacrylate group, styryl group, vinyl group, vinyl ketone group, butadiene group, vinyl ether group, oxiranyl group, aziridinyl group, and oxetane group. Is a (meth) acrylate group, a styryl group, an oxiranyl group or an oxetane group, most preferably a (meth) acrylate group or a vinyl group.

  Although the specific example of a compound represented by general formula (I) below is shown, the compound used for this invention is not limited to these.

[Air interface side vertical alignment agent]
The second retardation region is at least one copolymer including a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit represented by the following general formula (II) as an air interface side vertical alignment agent. Or at least one compound represented by the following general formula (III).

A copolymer comprising a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit represented by the following general formula (II) (hereinafter sometimes referred to as “fluorine polymer”);

In the formula, R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent; L is a divalent linking group selected from the following linking group group or two selected from the following linking group group Represents a divalent linking group formed by combining the above,
(Linked group group)
Single bond, —O—, —CO—, —NR ¹⁴ — (R ¹⁴ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group), —S—, —SO ₂ —, —P (═O) ( OR ¹⁵ ) — (R ¹⁵ represents an alkyl group, an aryl group or an aralkyl group), an alkylene group and an arylene group;
Q 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.

Fluorine-containing compound represented by the following general formula (III):
Formula I (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 a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, and n represents an integer of 1 or more.

First, the fluorine polymer 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 It contains 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 monomers that can be used in the production of the fluorine-based polymer that can be used in the present invention are listed below, but the present invention is not limited to the following specific examples.

  One aspect of the fluoropolymer usable 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 general formula (II). It is a polymer.

In general formula (II), examples of the substituent represented by R ¹¹ , R ¹² and R ¹³ include substituents selected from the following substituent group.
(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 ¹¹ , R ¹² and R ¹³ 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, etc.), 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 It is particularly preferable that ^b- , an alkylene group or an arylene group is contained. 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 the same substituents as those described above as the substituents for R ^{11 to} R ¹³ .
Although the specific structure of L is illustrated below, this invention is not limited to these specific examples.

  In the general formula (II), 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, Trimethylbenzylammonium, dimethylphenylammonium, etc.), pyridinium salts, etc.), sulfo groups, salts of sulfo groups (examples of cations forming the salts are the same as those described above for carboxyl groups), phosphonoxy groups, salts of phosphonoxy groups ( Examples of the cation forming the salt are the same as those described 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 general formula (II), or may contain two or more types. Moreover, the said fluorine-type polymer may have 1 type or 2 types or more of other 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-eicosene, 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 polycarboxylic 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 its derivatives 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 .

  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 general formula (II) is preferably 0.5% by mass or more of the total amount of constituent monomers of the fluoropolymer, and is 1 to 20% by mass. Is more preferable, and it is further more preferable that it is 1-10 mass%. Since the above-mentioned mass percentage is likely to vary in a preferable range depending on the molecular weight of the monomer used, the content of the repeating unit represented by the general formula (II) is expressed by the number of moles of the functional group per unit mass of the polymer. Can be accurately defined. When this notation is used, the preferable amount of the hydrophilic group (Q in the formula (II)) 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 even 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 hydroxide, 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) And potassium persulfate) and the like. Such radical thermal polymerization initiators can be used alone 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. These organic solvents can be used alone or in combination of two or more. Furthermore, a water-mixed organic solvent in which water is used in combination with the above organic solvent is also applicable from the viewpoint of the solubility of the monomer and the polymer to be produced.

  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.

  In addition, what has a polymeric group as a substituent in order for the fluorine-type polymer of this invention to fix the orientation state of a discotic liquid crystalline compound is also preferable.

  Specific examples of the fluoroaliphatic group-containing copolymer preferably used in the present invention as the fluorine-based polymer are shown below, but the present invention is not limited to these specific examples. Here, the numerical values (numerical values such as a, b, c, and d) in the formula are mass percentages indicating the composition ratio of each monomer, and Mw is the mass average molecular weight in terms of PEO measured by GPC.

  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 optically anisotropic layer, the composition (a composition excluding the solvent in the case of a coating solution) Among these, 0.005 to 8% by mass is preferable, 0.01 to 5% by mass is more preferable, and 0.05 to 1% by mass is even more preferable. 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.

Next, the fluorine-containing compound represented by the general formula (III) will be described.
In general 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 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. 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 general 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— (where R is the number of carbon atoms). 1 to 5 alkyl groups or hydrogen atoms), —O—, —S—, —SO—, —SO ₂ —, and a linking group obtained by combining at least two groups selected from the group consisting of —SO ₂ — is preferable.

In the general 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. To express. The preferable range of W is the same as Q in the general formula (III).

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

一般式（III）−ａ中、Ｒ⁴およびＲ⁵は各々アルキル基、末端にＣＦ₃基を有するアルキル基、または末端にＣＦ₂Ｈ基を有するアルキル基を表すが、Ｒ⁴およびＲ⁵が同時にアルキル基であることはない。Ｗ¹およびＷ²は各々水素原子、カルボキシル基（−ＣＯＯＨ）もしくはその塩、スルホ基（−ＳＯ₃Ｈ）もしくはその塩、ホスホノキシ｛−ＯＰ（＝Ｏ）（ＯＨ）₂｝もしくはその塩、または置換基としてカルボキシル基、スルホ基、ホスホノキシ基を有するアルキル基、アルコキシ基、またはアルキルアミノ基を表すが、Ｗ¹およびＷ²が同時に水素原子であることはない。

In the general 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, wherein R ⁴ and R ⁵ are At the same time, 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 having a carboxyl group, a sulfo group or a phosphonoxy group, an alkoxy group or an alkylamino 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 general 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, m ₂ represents an integer of 1 or more, and Each R ⁷ 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 a combination 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 general formula (III) -a will be described.
R ⁴ and R ⁵ have the same meaning as R ⁰ in the general 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 general 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 and 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 the general 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 or 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 general formulas. It is synonymous with the carboxyl group, sulfo group and phosphonoxy group represented by W in (III), and the preferred 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 general formula (III) -b will be described.
R ⁶ has the same meaning as R ⁰ in 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) or a salt thereof represented by W ³ , 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 general formula (III) -a 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 having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent, or It is synonymous with an alkylamino 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). For example, phenyl 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 having a carbon number of 1-20, more preferably a carbon number of 1-16, particularly preferably a carbon number of 1-12, such as an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc. An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 2 carbon atoms). 2 alkoxycarbonyl groups, for example, methoxycarbonyl group, ethoxycarbonyl group and the like, and aryloxycarbonyl groups (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, and particularly preferably carbon numbers). 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.

  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 crystalline compound.

  Specific examples of the fluorine-containing compound represented by formula (III) that can be used in the present invention are shown below, but the fluorine-containing compound used in the present invention is not limited thereto. In the following specific examples, III-1 to 42 are examples of the compound represented by the general formula (III) -a, and III-43 to 66 are examples of the compound represented by the general formula (III) -b.

  The preferred range of the content of the fluorine-containing compound in the composition for forming an optically anisotropic layer varies depending on its use, but when used for forming an optically anisotropic layer, the composition (a coating solution) is used. In the case of the composition excluding the solvent), it is preferably 0.005 to 8% by mass, more preferably 0.01 to 5% by mass, and further 0.05 to 1% by mass. preferable.

[Coating solvent]
As a solvent used for preparing the coating liquid for forming the optically anisotropic layer, 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. The coating liquid can be applied by a known method (eg, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).

[Polymerization initiator]
The vertically aligned discotic liquid crystal compound 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) 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 weight, more preferably 0.5 to 5% by weight, 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 ^{20mJ / cm 2 ~50J / cm 2} , further 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 optically anisotropic layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and most preferably 1 to 5 μm.

[Other compositions of optically anisotropic layer]
Along with the above liquid crystalline compound and the above two kinds of vertical alignment agents, a plasticizer, a surfactant, a polymerizable monomer, etc. are used in combination to improve the uniformity of the coating film, the strength of the film, the orientation of the liquid crystalline compound, etc. Can be improved. 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.

[Alignment film]
Since the alignment film has a function of defining the alignment direction of the discotic liquid crystalline compound, it is essential for realizing a preferred embodiment of the present invention. However, if the alignment state is fixed after aligning the liquid crystalline compound, the alignment film plays the role, and thus is not necessarily an essential component of the present invention. That is, it is possible to produce the polarizing plate of the present invention by transferring only the optically anisotropic layer on the alignment film in which the alignment state is fixed onto the polarizer.
The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known.
The alignment film is preferably formed by polymer rubbing treatment.

  Examples of the polymer include methacrylate copolymers, styrene copolymers, polyolefins, polyvinyl alcohol and modified polyvinyl alcohol, poly (N-methylol) described in paragraph No. [0022] of JP-A-8-338913. Acrylamide), polyester, polyimide, vinyl acetate copolymer, carboxymethylcellulose, polycarbonate and the like. 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%, more preferably 80 to 100%. The polymerization degree of polyvinyl alcohol is preferably 100 to 5000.

In the alignment film of the present invention, a side chain having a crosslinkable functional group (eg, double bond) is bonded to the main chain, or a crosslinkable functional group having a function of aligning liquid crystalline molecules is introduced into the side chain. It is preferable to do. As the polymer used for the alignment film, either a polymer that can be crosslinked by itself or a polymer that is crosslinked by a crosslinking agent can be used, and a plurality of combinations thereof can be used.
When a side chain having a crosslinkable functional group is bonded to the main chain of the alignment film polymer, or a crosslinkable functional group is introduced into a side chain having a function of aligning liquid crystalline molecules, the alignment film polymer and the optically anisotropic film The polyfunctional monomer contained in the conductive layer can be copolymerized. As a result, not only between the polyfunctional monomer and the polyfunctional monomer, but also between the alignment film polymer and the alignment film polymer and between the polyfunctional monomer and the alignment film polymer is firmly bonded by a covalent bond. Therefore, the strength of the retardation film can be remarkably improved by introducing a crosslinkable functional group into the alignment film polymer.
The crosslinkable functional group of the alignment film polymer preferably contains a polymerizable group in the same manner as the polyfunctional monomer. Specific examples include those described in paragraphs [0080] to [0100] in JP-A-2000-155216.

  Apart from the crosslinkable functional group, the alignment film polymer can also be crosslinked using a crosslinking agent. Examples of the crosslinking agent include aldehydes, N-methylol compounds, silane coupling agents, dioxane derivatives, compounds that act by activating carboxyl groups, active vinyl compounds, active halogen compounds, isoxazole and dialdehyde starch. Two or more kinds of crosslinking agents may be used in combination. Specific examples include compounds described in paragraphs [0023] to [024] in JP-A-2002-62426. Aldehydes having high reaction activity, particularly glutaraldehyde are preferred.

  0.1-20 mass% is preferable with respect to a polymer, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable. The amount of the unreacted crosslinking agent remaining in the alignment film is preferably 1.0% by mass or less, and more preferably 0.5% by mass or less. By adjusting in this way, even if the alignment film is used for a long time in a liquid crystal display device or left in a high temperature and high humidity atmosphere for a long time, sufficient durability without reticulation can be obtained.

  The alignment film is basically formed by applying a solution containing the polymer, the crosslinking agent, and the additive, which is an alignment film forming material, on a transparent support, followed by drying by heating (crosslinking) and rubbing treatment. be able to. As described above, the crosslinking reaction may be performed at an arbitrary time after coating on the transparent support. When a water-soluble polymer such as polyvinyl alcohol is used as the alignment film forming material, the coating solution is preferably a mixed solvent of an organic solvent (eg, methanol) having a defoaming action and water. The ratio of water: methanol is preferably 0: 100 to 99: 1, and more preferably 0: 100 to 91: 9. Thereby, generation | occurrence | production of a bubble is suppressed and the defect of the layer surface of an orientation film and also an optically anisotropic layer reduces remarkably.

  The alignment film is preferably applied by spin coating, dip coating, curtain coating, extrusion coating, rod coating, or roll coating. A rod coating method is particularly preferable. The film thickness after drying is preferably 0.1 to 10 μm. Heating and drying can be performed at 20 ° C to 110 ° C. In order to form sufficient cross-linking, 60 ° C to 100 ° C is preferable, and 80 ° C to 100 ° C is particularly preferable. The drying time can be 1 minute to 36 hours, preferably 1 minute to 30 minutes. The pH is preferably set to an optimum value for the crosslinking agent to be used. When glutaraldehyde is used, the pH is 4.5 to 5.5, and 5 is particularly preferable.

  The alignment film is preferably provided on the transparent support. The alignment film can be obtained by rubbing the surface after crosslinking the polymer layer as described above.

  For the rubbing treatment, a treatment method widely adopted as a liquid crystal alignment treatment process of LCD can be applied. That is, a method of obtaining the orientation by rubbing the surface of the orientation film in a certain direction using paper, gauze, felt, rubber, nylon, polyester fiber or the like can be used. Generally, it is carried out by rubbing several times using a cloth or the like in which fibers having a uniform length and thickness are planted on average.

  Next, the alignment film is caused to function to align the discotic liquid crystalline compound of the optically anisotropic layer provided on the alignment film. Thereafter, as necessary, the alignment film polymer and the polyfunctional monomer contained in the optically anisotropic layer are reacted, or the alignment film polymer is crosslinked using a crosslinking agent. The thickness of the alignment film is preferably in the range of 0.1 to 10 μm.

[Support]
The optically anisotropic layer may be formed on a transparent support. As the transparent support, it is preferable to use a polymer film having a small wavelength dispersion. The transparent support preferably has a small optical anisotropy. That the support is transparent means that the light transmittance is 80% or more. Specifically, the small chromatic dispersion means that the ratio of Re400 / Re700 is preferably less than 1.2. Specifically, the small optical anisotropy means that in-plane retardation (Re) is preferably 20 nm or less, and more preferably 10 nm or less. Examples of the polymer include cellulose ester, polycarbonate, polysulfone, polyethersulfone, polyacrylate and polymethacrylate. Cellulose esters are preferred, acetyl cellulose is more preferred, and triacetyl cellulose is most preferred. The polymer film is preferably formed by a solvent cast method. The thickness of the transparent support is preferably 20 to 500 μm, and more preferably 50 to 200 μm. In order to improve the adhesion between the transparent support and the layer (adhesive layer, vertical alignment film or total retardation) provided on the transparent support, surface treatment (eg, glow discharge treatment, corona discharge treatment, ultraviolet light (UV) ) Treatment, flame treatment). An adhesive layer (undercoat layer) may be provided on the transparent support.

  The second retardation region may be composed only of the optically anisotropic layer, or may be composed of the optically anisotropic layer and other layers. In the latter case, a laminate with a stretched polystyrene film or a laminate with an optically isotropic film such as a cycloolefin can be suitably used. In addition, when a polymer film having appropriate optical characteristics in the first retardation region is used as the support, the support of the optically anisotropic layer that is the second retardation region may also serve as the first retardation region. This is preferable because it contributes to thinning of the liquid crystal display device.

[Protective film for second polarizing plate]
The protective film for the second polarizing plate is preferably a protective film having no absorption in the visible light region, a light transmittance of 80% or more, and a small retardation based on birefringence. Specifically, the in-plane Re is preferably 20 nm or less, more preferably 10 nm or less, and most preferably 5 nm or less. Further, the retardation Rth in the thickness direction is preferably 20 nm or less, more preferably 10 nm or less, and most preferably 5 nm or less. Any film having this property can be preferably used, but from the viewpoint of durability of the polarizing film, a cellulose acetate or norbornene film is more preferable. As a method for reducing the Rth of the cellulose acetate film, it is effective to mix a liquid crystalline compound into the film.

[Bar-shaped liquid crystalline compound]
Examples of the rod-like liquid crystal compound formed on the protective film of the second polarizing film include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes. Cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. In addition to the above low-molecular liquid crystalline molecules, high-molecular liquid crystalline molecules can also be used.

  In the case of the rod-like liquid crystalline compound used in the present invention, it is preferable to substantially align it vertically. In the case of a rod-like liquid crystalline compound, “substantially perpendicular” means that the angle formed by the film surface and the director of the rod-like liquid crystalline compound is in the range of 70 ° to 90 °. The rod-like liquid crystalline compound may be oriented obliquely or may be changed so that the inclination angle gradually changes (hybrid orientation). Even in the case of oblique orientation or hybrid orientation, the average tilt angle is preferably 70 ° to 90 °, more preferably 75 ° to 90 °, and most preferably 80 ° to 90 °.

[Vertical alignment film]
In order to align the rod-like liquid crystalline compound vertically on the alignment film side, it is important to reduce the surface energy of the alignment film. Specifically, the surface energy of the alignment film is lowered by the functional group of the polymer, thereby bringing the rod-like liquid crystal compound into a standing state. As the functional group for reducing the surface energy of the alignment film, a hydrocarbon group having 10 or more fluorine atoms and carbon atoms is effective. In order for a fluorine atom or a hydrocarbon group to be present on the surface of the alignment film, it is preferable to introduce a fluorine atom or a hydrocarbon group into the side chain rather than the main chain of the polymer. The fluoropolymer preferably contains fluorine atoms in a proportion of 0.05 to 80% by weight, more preferably in a proportion of 0.1 to 70% by weight, and in a proportion of 0.5 to 65% by weight. More preferably, it is most preferably contained in a proportion of 1 to 60% by weight. The hydrocarbon group is an aliphatic group, an aromatic group, or a combination thereof. The aliphatic group may be cyclic, branched or linear. The aliphatic group is preferably an alkyl group (which may be a cycloalkyl group) or an alkenyl group (which may be a cycloalkenyl group). The hydrocarbon group may have a substituent that does not exhibit strong hydrophilicity, such as a halogen atom. The hydrocarbon group has preferably 10 to 100 carbon atoms, more preferably 10 to 60, and most preferably 10 to 40 carbon atoms. The main chain of the polymer preferably has a polyimide structure or a polyvinyl alcohol structure.

  Polyimide is generally synthesized by a condensation reaction of tetracarboxylic acid and diamine. A polyimide corresponding to a copolymer may be synthesized using two or more kinds of tetracarboxylic acids or two or more kinds of diamines. The fluorine atom or hydrocarbon group may be present in the repeating unit derived from tetracarboxylic acid, may be present in the repeating unit derived from diamine, or may be present in both repeating units. When introducing a hydrocarbon group into polyimide, it is particularly preferable to form a steroid structure in the main chain or side chain of the polyimide. The steroid structure present in the side chain corresponds to a hydrocarbon group having 10 or more carbon atoms, and has a function of vertically aligning the liquid crystalline compound. In this specification, the steroid structure is a cyclopentanohydrophenanthrene ring structure or a ring structure in which a part of the bond of the ring is an aliphatic ring (a range in which an aromatic ring is not formed) is a double bond. means.

  Further, as a means for vertically aligning the rod-like liquid crystalline compound, a method of mixing an organic acid with a polymer of polyvinyl alcohol or polyimide is preferably used. As the acid to be mixed, carboxylic acid, sulfonic acid and amino acid are preferably used. You may use what shows the acidity among the below-mentioned air interface aligning agent. The mixing amount is preferably 0.1% by weight to 20% by weight and more preferably 0.5% by weight to 10% by weight with respect to the polymer.

[Air interface side vertical alignment agent]
Ordinary rod-like liquid crystalline compounds have the property of being tilted and oriented on the air interface side, so it is necessary to control the orientation of the rod-like liquid crystal compound vertically on the air interface side in order to obtain a uniformly vertically aligned state. It is. As the air interface side vertical alignment agent of the rod-like liquid crystal compound, the same compound as the air interface side vertical alignment agent of the discotic liquid crystal compound can be used, and the preferred range of the amount used is also the same. In addition, the compounds described in JP 2002-20363 A and JP 2002-129162 A can be used as the air interface side vertical alignment agent. Also, paragraph numbers 0072 to 0075 of Japanese Patent Application No. 2002-212100, paragraph numbers 0038 to 0040 and 0048 to 0049 of Japanese Patent Application No. 2002-243600, and paragraph numbers 0037 to 0039 of Japanese Patent Application No. 2002-262239. The matters described in Paragraph Nos. 0071 to 0078 of Japanese Patent Application No. 2003-91752 can also be appropriately applied to the present invention.

  The present invention also provides at least one discotic liquid crystal compound, at least one boronic acid compound represented by the general formula (I), and a repeating unit derived from a fluoroaliphatic group-containing monomer and the general formula (II And a retardation unit having an optically anisotropic layer formed from a liquid crystal composition containing at least one kind of a copolymer containing a repeating unit represented by formula (III) or at least one kind of a compound represented by formula (III). The present invention also relates to a retardation film in which the molecules of the discotic liquid crystal compound are substantially vertically aligned in the optically anisotropic layer. The retardation film of the present invention is useful for improving the viewing angle characteristics of a liquid crystal display device, particularly an IPS liquid crystal display device. The retardation film of the present invention can be incorporated into a liquid crystal display device as it is as a single member or as a member integrated with a polarizing film. For example, when the optically anisotropic layer is formed on a support, a liquid crystal satisfying the properties as a protective film of the polarizing film is used as the support, and an integrated member is obtained. It is preferable because it is easy to handle when incorporated in a display device and contributes to a thin liquid crystal display device.

  The features of the present invention will be described more specifically with reference to examples and comparative 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 should not be construed as being limited by the specific examples shown below.

[Example 1]
<Preparation of IPS mode liquid crystal cell 1>
The electrodes shown in FIG. 1 were provided on a single glass substrate so that the distance between adjacent electrodes was 20 μm, and a polyimide film was provided as an alignment film thereon, and a rubbing treatment was performed. The rubbing process was performed in the direction shown in FIG. A polyimide film was provided on one surface of a separately prepared glass substrate, and a rubbing treatment was performed to obtain an alignment film. Two glass substrates are laminated and bonded so that the alignment films face each other, the distance between the substrates (gap; d) is 3.9 μm, and the rubbing directions of the two glass substrates are parallel. A nematic liquid crystal composition having a refractive index anisotropy (Δn) of 0.0769 and a dielectric anisotropy (Δε) of 4.5 was enclosed. The value of d · Δn of the liquid crystal layer was 300 nm.

<Preparation of optical compensation film 1>
(Production of first retardation region)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution having the following composition.
Composition of cellulose acetate solution Cellulose acetate having an acetylation degree of 60.9% 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) 300 Part by mass Methanol (second solvent) 54 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, 80 parts by mass of methylene chloride, and 20 parts by mass of methanol were added. Then, the mixture was stirred while heating to prepare a retardation increasing agent solution. A dope was prepared by mixing 7 parts by mass of the retardation increasing agent solution with 487 parts by mass of the cellulose acetate solution and stirring sufficiently.

  The obtained dope was cast using a band casting machine. After the film surface temperature on the band reached 40 ° C., the film was dried with warm air of 60 ° C. for 1 minute, and the film was peeled off from the band. Next, the film was dried with a drying air at 140 ° C. for 10 minutes to produce a cellulose acetate film 1 having a thickness of 80 μm.

  The optical properties of this film were determined by measuring the dependency of Re on the light incident angle using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments). Re = 8 nm, Rth = 82 nm there were.

(Production of second retardation region)
After the surface of the cellulose acetate film 1 was saponified, an alignment film coating solution having the following composition was applied onto the film with a wire bar coater at 20 ml / m ² . Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. Next, the formed film was rubbed in a direction parallel to the slow axis direction of the film.
Composition of alignment film coating solution Modified polyvinyl alcohol 10 parts by weight Water 371 parts by weight Methanol 119 parts by weight Glutaraldehyde 0.5 parts by weight

  Next, 1.8 g of the following discotic liquid crystalline compound, 0.2 g of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), a photopolymerization initiator (IRGA) Cure 907, manufactured by Ciba Geigy Co., Ltd.) 0.06 g, sensitizer (Kaya Cure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02 g, alignment film interface side vertical alignment agent (I-2) 0.009 g, air interface side vertical A solution prepared by dissolving 0.0072 g of an alignment agent (P-15) in 3.9 g of methyl ethyl ketone was applied with a wire bar of # 3.4. This was affixed to a metal frame and heated in a thermostatic bath at 125 ° C. for 3 minutes to align the discotic liquid crystal compound. Next, UV irradiation was performed for 30 seconds using a 120 W / cm high-pressure mercury lamp at 100 ° C. to crosslink the discotic liquid crystal compound. Then, it stood to cool to room temperature. Thus, the optical compensation film 1 was produced.

<Evaluation of adhesion>
After producing the optically anisotropic layer thus prepared, the cellophane tape is applied after scratching the surface with a metal fitting, and the tape is peeled off in parallel with the optically anisotropic layer. The adhesion was evaluated. Such adhesion is necessary in order not to peel off even when stored or used for a long time. The evaluation criteria were three stages: A: not peeled off at all, B: peeled off slightly, and C: easy to peel off.

  Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependence of Re of the optical compensation film 1 is measured, and the pre-measured contribution of the cellulose acetate film is subtracted. Thus, the optical characteristics of only the discotic liquid crystal retardation layer were calculated. Re was 130 nm, Rth was −65 nm, the average tilt angle of the liquid crystal was 89.8 °, and the discotic liquid crystal was perpendicular to the film surface. It was confirmed that they were oriented. The direction of the slow axis was parallel to the rubbing direction of the alignment film.

  A polarizing film was produced by adsorbing iodine to a stretched polyvinyl alcohol film. Using the polyvinyl alcohol-based adhesive, the produced optical compensation film 1 was attached to one side of the polarizing film so that the cellulose acetate film was on the polarizing film side. The transmission axis of the polarizing film and the slow axis of the optical compensation film were arranged in parallel. A commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) was subjected to saponification treatment and attached to the opposite side of the polarizing film using a polyvinyl alcohol adhesive. This is arranged so that the slow axis of the optical compensation film 1 is parallel to the rubbing direction of the liquid crystal cell and the discotic liquid crystal application surface side is on the liquid crystal cell side. Pasted on. Subsequently, a commercially available polarizing plate (HLC2-5618, manufactured by Sanritz Co., Ltd.) was attached to the other side of the IPS mode liquid crystal cell 1 in a crossed Nicol arrangement to produce a liquid crystal display device.

<Measurement of leakage light of the manufactured liquid crystal display device>
The leakage light of the liquid crystal display device thus manufactured was measured. Light leakage when observed from the left oblique direction of 70 ° was 0.11%.

[Example 2]
In the production of the second retardation region of Example 1, I-1, I-17, and I-26 were used instead of I-2 as the alignment film side vertical alignment agent added to the discotic liquid crystal compound, and the air interface As the side vertical alignment agent, P-1, P-2, P-5, and P-11 were used, respectively, and a second retardation region was created in the same manner as in Example 1 to form optical compensation films 1-a and 1- b and 1-c were obtained. A liquid crystal display device was manufactured in the same manner as in Example 1, and leakage light was measured when the liquid crystal display device was observed from the left oblique direction of 70 °. Each optical compensation film was subjected to an adhesion test by the above method. The results are shown in the table.

  In any case, as in Example 1, an optical compensation film in which the discotic liquid crystal compound was vertically aligned was obtained, and a liquid crystal display device with less light leakage was obtained by mounting the optical compensation film on the optical compensation film IPS liquid crystal display device. In addition, when a boronic acid compound having a polymerizable group is used as the vertical alignment agent, an optical compensation film having good adhesion can be obtained, and less light leaks when mounted on the optical compensation film IPS liquid crystal display device. In addition, a liquid crystal display device excellent in durability was obtained.

[Example 3]
<Preparation of optical compensation film 2>
Using a commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd., Re = 3 nm, Rth = 45 nm) as the first retardation region, the surface was saponified and carried out on this film The same alignment film coating solution as in Example 1 was applied at 20 ml / m ² with a wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. Next, the formed film was rubbed in a direction parallel to the slow axis direction of the film.

  Subsequently, 1.8 g of the discotic liquid crystalline compound used in Example 1 and ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) were used on the alignment film prepared in Example 1. 0.2 g, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) 0.06 g, sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02 g, alignment film interface side vertical alignment agent (I- 2) A solution prepared by dissolving 0.009 g and 0.0036 g of the air interface side vertical alignment agent (III-52) in 3.9 g of methyl ethyl ketone was applied with a # 3 wire bar. This was affixed to a metal frame and heated in a thermostatic bath at 125 ° C. for 3 minutes to align the discotic liquid crystal compound. Next, UV irradiation was performed for 30 seconds using a 120 W / cm high-pressure mercury lamp at 100 ° C. to crosslink the discotic liquid crystal compound. Then, it stood to cool to room temperature. Thus, the optical compensation film 2 was produced.

  Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependency of Re of the optical compensation film 2 is measured, and the pre-measured contribution of the cellulose acetate film is subtracted. As a result, only the optical characteristics of the discotic liquid crystal retardation layer were calculated. Re was 117 nm, Rth was −55 nm, the average tilt angle of the liquid crystal was 89.6 °, and the discotic liquid crystal was perpendicular to the film surface. It was confirmed that they were oriented. The slow axis direction was parallel to the rubbing direction of the alignment film.

  One of the IPS mode liquid crystal cells 1 produced as described above has the retardation film 2 produced as described above in such a manner that its slow axis is parallel to the rubbing direction of the liquid crystal cell, and the discotic liquid crystal application surface side faces the liquid crystal cell side. Pasted to be. Subsequently, a commercially available polarizing plate (HLC2-5618, manufactured by Sanritz Co., Ltd.) is attached on the retardation film 2 so that the transmission axis is parallel to the rubbing direction of the liquid crystal cell. The same polarizing plate was attached to the other side in a crossed Nicol arrangement to produce a liquid crystal display device.

(Measurement of leakage light of the manufactured liquid crystal display device)
The leakage light of the liquid crystal display device thus manufactured was measured. The leakage light when observed from the left diagonal direction of 70 ° was 0.13%.

[Example 4]
<Production of Second Polarizing Plate 1>
Using a commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd., Re = 3 nm, Rth = 45 nm), the surface was saponified, and a commercially available vertical alignment film (JALS- 204R, manufactured by Nippon Synthetic Rubber Co., Ltd. was diluted 1: 1 with methyl ethyl ketone, and then 2.4 ml / m ^{2 was} applied with a wire bar coater. Immediately, it was dried with warm air of 120 ° C. for 120 seconds.

(Formation of vertically aligned rod-like liquid crystal compound layer)
On the alignment film, 1.8 g of the following rod-like liquid crystal compound, 0.06 g of photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy), 0.02 g of sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.), A solution prepared by dissolving 0.002 g of the air interface side vertical alignment agent (III-52) in 9.2 g of methyl ethyl ketone was applied with a # 2 wire bar. This was affixed to a metal frame and heated in a constant temperature bath at 100 ° C. for 2 minutes to align the rod-like liquid crystal compound. Next, UV irradiation was performed for 30 seconds using a 120 W / cm high-pressure mercury lamp at 100 ° C. to crosslink the rod-like liquid crystal compound. Then, it stood to cool to room temperature. Thus, the protective film 1 for the second polarizing plate was produced.

  Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependency of Re of the protective film 1 was measured. As a result, Re was 3 nm and Rth was 5 nm.

  Next, iodine is adsorbed to the stretched polyvinyl alcohol film to produce a polarizing film, and using the polyvinyl alcohol-based adhesive, the protective film 1 thus prepared is arranged on one side of the polarizing film so that the cellulose acetate film is on the polarizing film side. Pasted on. Subsequently, a commercially available cellulose acetate film (Fujitac TD80UF, manufactured by Fuji Photo Film Co., Ltd.) is subjected to saponification treatment, and a second polarizing plate is attached to the opposite side of the polarizing film using a polyvinyl alcohol adhesive. Formed. Further, in the same manner as in Example 1, the optical compensation film 1 was attached to one side of the polarizing film so that the cellulose acetate film was on the polarizing film side, and a commercially available cellulose acetate film was attached to the opposite side of the polarizing film. One polarizing plate is placed on one side of the IPS mode liquid crystal cell 1 produced in Example 1, so that the slow axis of the optical compensation film 1 is parallel to the rubbing direction of the liquid crystal cell, and the discotic liquid crystal application surface side is the liquid crystal cell. Affixed to the side. The transmission axis of this polarizing plate and the rubbing direction of the liquid crystal cell are parallel. Further, a second polarizing plate is attached to the other side of the liquid crystal cell so that the transmission axis is perpendicular to the rubbing direction of the liquid crystal cell and the surface of the protective film 1 is on the liquid crystal cell side. Produced.

(Measurement of leakage light of the manufactured liquid crystal display device)
The leakage light of the liquid crystal display device thus manufactured was measured. Leakage when observed from the left oblique direction of 70 ° was 0.02%.

[Example 5]
A liquid crystal display device was prepared and leakage light was measured in the same manner as in Example 4 except that the alignment film side vertical alignment agent was changed to I-1 from the discotic liquid crystal coating composition in Example 4. Leakage when observed from the left diagonal direction of 70 ° was 0.03%.

[Comparative Example 1]
A commercially available polarizing plate (HLC2-5618, manufactured by Sanritz Co., Ltd.) was attached to both sides of the produced IPS mode liquid crystal cell 1 in a crossed Nicol arrangement to produce a liquid crystal display device. An optical compensation film was not used. In the liquid crystal display device, as in Example 1, the polarizing plate was attached so that the transmission axis of the upper polarizing plate was parallel to the rubbing direction of the liquid crystal cell. The leakage light of the liquid crystal display device thus manufactured was measured. The leakage light when observed from the left diagonal direction of 70 ° was 0.52%.

[Comparative Example 2]
Compared to the IPS mode liquid crystal cell 1 manufactured in Example 1, the retardation film 2 manufactured in Example 2 is liquid crystal so that its slow axis is orthogonal to the rubbing direction of the liquid crystal cell and the discotic liquid crystal application surface side is liquid crystal Affixed to the cell side. Subsequently, a commercially available polarizing plate (HLC2-5618, manufactured by Sanritz Co., Ltd.) is attached on the retardation film 2 so that the transmission axis is parallel to the rubbing direction of the liquid crystal cell. The same polarizing plate was attached to the other side in a crossed Nicol arrangement to produce a liquid crystal display device. The leakage light of the liquid crystal display device thus manufactured was measured. The leakage light when observed from the left oblique direction of 70 ° was 1.49% and was extremely large.

[Comparative Example 3]
A liquid crystal display device was produced in the same manner as in Example 1 except that the air interface side vertical alignment agent (P-15) was removed from the discotic liquid crystal coating liquid composition in Example 1, and leakage light was measured. The leakage light when observed from the left diagonal direction of 70 ° was 1.17% and was extremely large.

[Comparative Example 4]
A liquid crystal display device was prepared and leakage light was measured in the same manner as in Example 1 except that the alignment film interface-side vertical alignment agent (I-2) was removed from the discotic liquid crystal coating liquid composition in Example 1. The leakage light when observed from the left oblique direction of 70 ° was as large as 0.63%.

[Comparative Example 5]
A liquid crystal display device was prepared and leakage light was measured in the same manner as in Example 3 except that the air interface side vertical alignment agent (III-52) was removed from the discotic liquid crystal coating liquid composition in Example 3. The leakage light when observed from the left diagonal direction of 70 ° was as large as 0.54%.

It is the schematic which shows the pixel area example of the liquid crystal display device of this invention. It is the schematic which shows the example of the liquid crystal display device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Liquid crystal element pixel area 2 Pixel electrode 3 Display electrode 4 Rubbing direction 5a, 5b Director of liquid crystal compound at the time of black display 6a, 6b Director of liquid crystal compound at the time of white display 7a, 7b First protective film for polarizing film 8 DESCRIPTION OF SYMBOLS 1 Polarizing film 9 Polarization transmission axis 10 of 1st polarizing film Optical compensation film 11 1st phase difference region 12 2nd phase difference region 13 Slow axis 14 of 2nd phase difference region 1st board | substrate 15 1st board | substrate rubbing direction 16 Liquid crystal Layer 17 Slow axis direction 18 of liquid crystalline compound Second substrate 19 Second substrate rubbing directions 20a, 20b Protective film for second polarizing film 21 Second polarizing film 22 Second polarizing film Polarized transmission axis

Claims (11)

A retardation film comprising an alignment film comprising at least one polymer and an optically anisotropic layer comprising a liquid crystal composition containing at least one discotic liquid crystal compound and at least one boronic acid compound. The retardation film according to claim 1, wherein the boronic acid compound is represented by at least one of the following general formula (I).

(In the general formula (I), R ¹ and R ² each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group, alkynyl group, aryl group or heteroaryl group, and R ³ represents a substituted or unsubstituted group. Represents an unsubstituted alkyl group, alkenyl group, alkynyl group, aryl group or heteroaryl group.) The optically anisotropic layer is represented by at least one copolymer comprising a repeating unit derived from a fluoroaliphatic group-containing monomer and a repeating unit represented by the following general formula (II) or represented by the following general formula (III): The retardation film according to claim 1, further comprising at least one kind of compound.

(Wherein R ¹¹ , R ¹² and R ¹³ each independently represents a hydrogen atom or a substituent; L is a divalent linking group selected from the following linking group group or 2 selected from the following linking group group: Represents a divalent linking group formed by combining two or more,
(Linked group group)
Single bond, —O—, —CO—, —NR ¹⁴ — (R ¹⁴ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group), —S—, —SO ₂ —, —P (═O) ( OR ¹⁵ ) — (R ¹⁵ represents an alkyl group, an aryl group or an aralkyl group), an alkylene group and an arylene group;
Q 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. )
General formula (III)
(R ⁰ ) _m −L ⁰ − (W) _n
(Wherein 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, m represents an integer of 1 or more, and a plurality of R ⁰ may be the same) At least one represents an alkyl group having a CF ₃ group or a CF ₂ H group at the terminal, L ⁰ represents an (m + n) -valent linking group, and 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, and n represents an integer of 1 or more. The retardation film according to claim 1, wherein R ¹³ has a polymerizable group in the general formula (I). A first polarizing film, a retardation film comprising a first retardation region in contact with the first polarizing film and a second retardation region in contact with the first retardation region, a first substrate, and a liquid crystal layer containing a nematic liquid crystal material A liquid crystal display device in which the second substrate and the second polarizing film are arranged in this order, and the liquid crystalline compound of the nematic liquid crystal material is aligned parallel to the surfaces of the pair of substrates during black display, The in-plane retardation Re of one retardation region is 20 nm or less, the retardation Rth in the thickness direction of the first retardation region is 20 nm to 120 nm, and the second retardation region is defined in claims 1 to 4. A liquid crystal comprising the optically anisotropic layer according to any one of the above, wherein the slow axis of the second retardation region is parallel to the transmission axis of the first polarizing film and the slow axis direction of the liquid crystal compound during black display Display device. The liquid crystal display device according to claim 5, wherein Re of the second retardation region is 50 nm to 200 nm. The liquid crystal display device according to claim 5, wherein the first retardation region is composed of a plurality of layers, and a layer in contact with the second retardation region among the plurality of layers is an alignment film. A pair of protective films sandwiching the second polarizing film, and a thickness direction retardation Rth of the protective film disposed on the liquid crystal layer side of the pair of protective films is 20 nm or less. The liquid crystal display device according to any one of the above. 9. The method according to claim 5, further comprising a pair of protective films sandwiching the second polarizing film, wherein the protective film disposed on the liquid crystal layer side of the pair of protective films is a cellulose acetate film or a norbornene-based film. 2. A liquid crystal display device according to item 1. A pair of protective films sandwiching the second polarizing film, wherein the protective film disposed on the liquid crystal layer side of the pair of protective films includes a layer containing a rod-like liquid crystalline compound that is vertically aligned with the cellulose acetate film The liquid crystal display device according to claim 5. The said 1st phase difference area | region is comprised from several layers, The layer which contact | connects a 1st polarizing film among these several layers functions as a protective film of a 1st polarizing film. A liquid crystal display device according to 1.

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