JP2007225912A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device causing less light leakage in black display, and thereby, showing high contrast, little change in colors by angles and excellent productivity. <P>SOLUTION: The device includes: a first polarizing layer; a liquid crystal cell comprising a pair of substrates and a liquid crystal layer held between the substrates and having liquid crystal molecules to be aligned substantially parallel to the substrates during black display; a first optical anisotropic layer 34 disposed between the first polarizing layer and the liquid crystal layer and showing an in-plane retardation of 0 to 10 nm and a retardation of -400 to -30 nm in the thickness direction; and a second optical anisotropic layer showing an in-plane retardation of 20 to 150 nm; wherein at least the first optical anisotropic layer 34 is formed on the substrate (first substrate 30) nearer to the first polarizing layer of the pair of substrates, and the second optical anisotropic layer is disposed between the first optical anisotropic layer 34 and the first polarizing layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of liquid crystal display devices, and particularly relates to liquid crystal display devices in IPS mode and FFS mode. The present invention also relates to an optical compensation method that contributes to improvement of display characteristics of a liquid crystal display device such as an IPS mode, and particularly to an increase in viewing angle.

  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. In order to solve this problem, a system in which a liquid crystal cell is optically compensated and a light leakage is prevented by using a film in which liquid crystal compounds are hybrid-aligned has been put into practical use. However, even if a liquid crystal compound is used, it is very difficult to completely optically compensate the liquid crystal cell without any problem, and there is a problem that gradation inversion 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 IPS mode or FFS mode in which a lateral electric field is applied to the liquid crystal, a protrusion formed in the panel by vertically aligning a liquid crystal having a negative dielectric anisotropy, A vertical alignment (VA) mode in which alignment is divided by a slit electrode 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, disposing an optical compensation material having birefringence characteristics between the liquid crystal layer and the polarizing plate is also studied in the IPS and FFS modes. For example, by arranging a birefringent medium having an optical axis orthogonal to each other to compensate for the increase / decrease in retardation of the liquid crystal layer during tilting, a white display or a halftone display is diagonally arranged between the substrate and the polarizing plate. It is disclosed that coloring can be improved when viewing directly from (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 positive birefringence and an optical axis in the normal direction of the film (see Patent Document 5), biaxial optical compensation 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 8 proposes an IPS liquid crystal device in which a compensation film in which a rod-like liquid crystal is applied and oriented on a biaxial cellulose acylate film produced by stretching is mounted. In this method, the display quality and viewing angle are remarkably improved with a simple configuration.

The method disclosed in the above-mentioned document, particularly the method described in Patent Document 8, is effective in that an inexpensive and thin display device can be obtained. However, it has been found that these methods still have a problem that light is slightly leaked in an oblique direction and the color changes depending on the angle.
These retardation films are generally obtained by stretching a polymer film in a certain direction, or applying a polymerizable liquid crystal molecule on a base film and aligning it in a certain direction, and then curing, or combining them. The retardation value is kept constant in the plane.
For this reason, when the display device is colored (for example, when the display device has pixels composed of display areas of three colors of red, green, and blue), it is caused by the wavelength of light of each color that passes through the display area of each color of the pixel. As a result of the study by the present inventors, it is clear that the optical polarization becomes incomplete due to variations in the polarization state of light, and leakage light of two colors of red, green and blue is generated. It became.

In Patent Document 9, in a liquid crystal display device having pixels composed of display areas of three colors of red, green and blue, the amount of retardation corresponding to the wavelength range of light passing through each fine area is set for each color display area. A method of forming optical compensation fine regions having different film thicknesses on a liquid crystal cell substrate is disclosed.
However, in the above method, in an optical compensation method that requires two or more optically anisotropic layers, in order to optimize the film thickness for each color, two types of optically anisotropic layers are patterned for each color. However, it is necessary to form it, and productivity is reduced remarkably.

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 2005-265889 A JP 2004-191832 A

  In view of the above, an object of the present invention is to provide a liquid crystal display device, particularly an IPS mode liquid crystal display, which has less light leakage at the time of black display, and therefore has high contrast, little color change due to angle, and excellent productivity. Device.

Means for solving the above-mentioned problems are as follows.
[1] A liquid crystal cell having a first polarizing layer, a pair of substrates, and a liquid crystal layer in which liquid crystal molecules sandwiched between the pair of substrates are aligned substantially parallel to the substrate during black display, A first optically anisotropic layer disposed between the first polarizing layer and the liquid crystal layer, having an in-plane retardation of 0 to 10 nm and a thickness direction retardation of −400 to −30 nm. And a second optically anisotropic layer having an in-plane retardation of 20 to 150 nm, wherein at least the first optically anisotropic layer is the first of the pair of substrates. A layer formed on a substrate (first substrate) disposed closer to the first polarizing layer, and the second optically anisotropic layer includes the first optically anisotropic layer and A liquid crystal display device disposed between the first polarizing layer and the first polarizing layer.
[2] The first optically anisotropic layer is composed of a composition containing a rod-like liquid crystalline compound, and the molecules of the rod-like liquid crystalline compound in the first optically anisotropic layer are relative to the layer plane. The liquid crystal display device according to [1], which is fixed in a substantially vertically aligned state.
[3] The liquid crystal display device according to [1] or [2], wherein the first substrate further includes a plurality of colored layers having different patterned hues.
[4] The first optically anisotropic layer is patterned corresponding to the arrangement of the colored layer, and has a retardation value in the thickness direction that varies depending on the hue of the colored layer located below or above the colored layer. [3] The liquid crystal display device.
[5] The first optically anisotropic layer is patterned corresponding to the arrangement of the colored layer, and exhibits different retardation values in the thickness direction depending on the hue of the colored layer located below or above the colored layer. The liquid crystal display device according to [3] or [4] having different film thicknesses.
[6] In the second optically anisotropic layer, the A1 value defined by the following formula (1) is in the range of 0.10 to 0.95, and the A2 value defined by the following formula (2) The liquid crystal display device according to any one of [1] to [5], wherein is in the range of 1.01 to 1.50:
(1): A1 value = Re (450) / Re (550)
(2): A2 value = Re (650) / Re (550)
In the formula, Re (λ) is an in-plane retardation value for light having a wavelength of λ nm.
[7] In the second optically anisotropic layer, the B1 value defined by the following formula (3) is in the range of 0.40 to 0.95, and the B2 value defined by the following formula (4) The liquid crystal display device according to any one of [1] to [6], wherein is in the range of 1.05 to 1.93:
(3): B1 value = {Re (450) / Rth (450)} / {Re (550) / Rth (550)}
(4): B2 value = {Re (650) / Rth (650)} / {Re (550) / Rth (550)}
In the formula, Re (λ) is an in-plane retardation value for light having a wavelength of λnm, and Rth (λ) is a retardation value in the thickness direction for light having a wavelength of λnm.
[8] The liquid crystal display device according to any one of [1] to [7], wherein the second optically anisotropic layer is a transparent protective film of the first polarizing layer.
[9] The liquid crystal display device according to any one of [1] to [8], wherein the second optically anisotropic layer is a biaxial transparent plastic film.
[10] The liquid crystal display device according to any one of [1] to [9], wherein the second optically anisotropic layer is a biaxial cellulose acylate film.
[11] Only a substantially isotropic adhesive layer and / or a substantially isotropic transparent protective film is provided between the second optically anisotropic layer and the first polarizing layer. The liquid crystal display device according to any one of [1] to [10].
[12] The liquid crystal display device according to [11], wherein the transparent protective film is a film containing cellulose acylate or cyclic polyolefin, the in-plane retardation is 0 to 10 nm, and the retardation in the thickness direction is -20 to 20 nm. .
[13] Any one of [1] to [12], wherein the second optically anisotropic layer is disposed so that a slow axis thereof is substantially perpendicular to an absorption axis of the first polarizing layer. Liquid crystal display device.
[14] The liquid crystal display according to [13], wherein the second optically anisotropic layer is disposed so that a slow axis thereof is substantially parallel to a major axis direction of liquid crystal molecules in the liquid crystal layer during black display. apparatus.
[15] The apparatus further includes a second polarizing layer disposed so as to sandwich the liquid crystal cell together with the first polarizing layer, and absorption axes of the first and second polarizing layers are orthogonal to each other. ] The liquid crystal display device according to any one of [14].
[16] A substantially isotropic adhesive layer between the second polarizing layer and a substrate (second substrate) positioned closer to the pair of substrates, and / or substantially. The liquid crystal display device according to any one of [1] to [15], wherein only the isotropic transparent protective film is included.
[17] The liquid crystal display device according to [16], wherein the transparent protective film is a film containing cellulose acylate or cyclic polyolefin, the in-plane retardation is 0 to 10 nm, and the retardation in the thickness direction is -20 to 20 nm. .

  According to the present invention, there is provided a liquid crystal display device, in particular, an IPS mode liquid crystal display device that has less light leakage during black display, and therefore has high contrast, little color change due to angle, and excellent productivity. Can do.

BEST MODE FOR CARRYING OUT THE INVENTION

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

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

In the 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 10 ° from −50 ° to + 50 ° with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH) and the tilt axis (rotating axis). In step, light of wavelength λ nm is incident from each inclined direction and measured at 11 points, and KOBRA 21ADH calculates based on the measured retardation value, the assumed 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 the 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.

  An example of the liquid crystal display device of the present invention includes a first polarizing layer, a liquid crystal cell, a first optical anisotropic layer exhibiting predetermined optical characteristics, and a second optical anisotropy exhibiting predetermined optical characteristics. And having a layer. The liquid crystal cell includes a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates, and the liquid crystal molecules are aligned substantially parallel to the pair of substrates during black display. In the present invention, the first optically anisotropic layer is a layer formed on one surface of a pair of substrates of the liquid crystal cell. The first optically anisotropic layer may be formed on the inner surface (surface on the liquid crystal layer side) of the substrate or on the outer surface (surface on the first polarizing layer side) of the substrate. It may be. On the other hand, the second optical anisotropic layer is disposed between the first optical anisotropic layer and the first polarizing layer. When the second optically anisotropic layer is made of a polymer film or the like, it may be incorporated in the liquid crystal display device as a single member, or as a protective film for the first polarizing layer, that is, polarized light. It may be incorporated as a member of the plate. Furthermore, it may be a layer formed on the surface of the liquid crystal cell substrate together with the first optically anisotropic layer.

  The mode of the liquid crystal cell included in the liquid crystal display device of the present invention is not limited as long as the above requirements are satisfied, but is preferably an IPS mode or an FFS mode.

[Substrate for liquid crystal cell]
In the present invention, as at least one of the pair of liquid crystal cell substrates, a substrate on which a first optical anisotropic layer having predetermined optical characteristics is formed is used. When the first optically anisotropic layer is made of a liquid crystalline composition, an alignment film for controlling the alignment of the liquid crystalline composition is interposed between the substrate and the first optically anisotropic layer. It may be arranged. A transparent electrode layer for driving the liquid crystal cell and an alignment layer for controlling the alignment of the liquid crystal molecules in the liquid crystal cell may be formed on the first optically anisotropic layer. .

The substrate may have a color filter on its surface. The color filter is generally composed of a plurality of colored layers (for example, a red (R) layer, a green (G) layer, and a blue (B) layer) patterned in a fine region and having different hues. When the first optical anisotropic layer is formed on or below the color filter, the retardation value Rth in the thickness direction of the first optical anisotropic layer is located above or below it. It is different depending on the hue of each colored layer of the color filter, and more specifically, it is preferably optimized according to the hue.
The color filter may be formed on the counter substrate of the substrate on which the first optical anisotropic layer is formed. In such a case, the Rth of the first optical anisotropic layer is opposite to the color filter. Depending on the hue of the colored layer arranged at the corresponding position of the color filter formed on the substrate, it is preferable that the color layer is different, more specifically optimized.

  For example, in the case where the first optical anisotropic layer is formed above or below a color filter composed of red, green, and blue colored layers, an R (red) layer, a G (green) layer, and a B (blue) ) Where Rth (R), Rth (G), and Rth (B) are Rth (B) <Rth (Rth (R), Rth (G), and Rth (B)), respectively. R) is preferably satisfied, and more preferably Rth (B) <Rth (G) <Rth (R).

  The first optical anisotropic layer may be formed directly on the substrate by coating or the like, or after the first optical anisotropic layer is provided on a temporary support, the first optical anisotropic layer is transferred onto the substrate. May be. It is also a preferred aspect of the present invention that patterning is performed on a fine region in accordance with the patterning of the colored layer of the color filter. Examples of the patterning method for the first optically anisotropic layer include a method using a photolithography method and a method using an inkjet. A method of patterning a micro color filter by using a transfer type color filter is also widely used (for example, “Color filter film forming technology and chemical” CMC p69 to p79: Morimasa Sato: 1998). By using this method, a color filter in which the first optical anisotropy is laminated can be produced, and the first optical anisotropic layer and the color filter can be simultaneously patterned according to the pattern of the color filter.

  JP-A-2004-191832 forms a retardation film with an ultraviolet curable composition containing polymerizable liquid crystal molecules, changes the irradiation amount of ultraviolet rays in units of fine regions of each color, controls the cured liquid crystal molecular weight, A method of changing the amount of retardation for each pixel area of each color by washing and removing uncured liquid crystal molecules with an organic solvent, and further drying by ultraviolet irradiation after drying, is disclosed in the present invention. The first optically anisotropic layer can be formed using a simple method.

In forming a color filter, an alignment film, particularly a vertical alignment film, can be simultaneously formed for use in forming the first optical anisotropic layer. For example, when a color filter is formed using a transfer material, a transfer type color filter in which vertical alignment films are stacked can be manufactured, and the vertical alignment film can be transferred onto the substrate simultaneously with the color filter.
In the case of forming a color filter by a method combining photolithography and coating, the color filter can be provided with a function of a vertical alignment film by containing a fluorosurfactant in a coating solution for forming a color filter. Alternatively, the first optically anisotropic layer can have a function as a color filter, and only one layer of the first optically anisotropic layer can satisfy the functions of both.

  FIG. 1 shows a schematic cross-sectional view of an example of a liquid crystal cell substrate that can be used in the liquid crystal display device of the present invention. A liquid crystal cell substrate 30 shown in FIG. 1 has an R (red) layer 50R, a G (green) layer 50G separated by a light shielding layer 35 and a light shielding layer 35 on the surface of a substrate 40 made of glass or the like. And a color filter 50 including a B (blue) layer 50 </ b> B (hereinafter, each colored layer may be referred to as a “micro color filter”), a first optical anisotropic layer 34, and an alignment layer 60. The alignment layer 60 has a function of controlling the alignment of the liquid crystal molecules in the liquid crystal layer when the substrate 30 is disposed with another liquid crystal layer sandwiching the liquid crystal layer.

  In the substrate 30 of FIG. 1, the formed colored layers, the R layer 50R, the G layer 50G, and the B layer 50B have different film thicknesses. Therefore, the first optical anisotropy formed on each colored layer is different. The thickness of the layer 34 is also different from each other. As a result, the film thickness of the first optical anisotropic layer can be changed according to the hue of the colored layer, and the retardation value of the first optical anisotropic layer can be optimized for each color. it can. When the thicknesses of the first optical anisotropic layers arranged at the positions corresponding to the colored layers of the respective colors (red, green, blue) are d (R), d (G), and d (B), respectively. , D (B) <d (R) is preferably satisfied, and d (B) <d (G) <d (R) is more preferable.

  In the liquid crystal cell substrate 30 shown in FIG. 1, for example, a color filter 50 composed of a plurality of colored layers having different thicknesses according to the hue is formed on the surface of a substrate 40 having a uniform surface. After the vertical alignment film is formed thereon, the first optical anisotropic layer 34 can be formed thereon so that the surface is uniform. In the configuration in which the substrate, the color filter, and the first optical anisotropic layer are formed in this order, the thickness of the color filter is changed for each color (red, green, blue), and the first optical anisotropic layer A method of optimizing optical properties is preferred.

  The thicknesses of the colored layers of each color (red, green, blue), R (red) layer 50R, G (green) layer 50G, and B (blue) layer 50B are respectively d (CFR), d (CFG), d ( When CFB), d (CFR) <d (CFB) is preferably satisfied, and d (CFR) <d (CFG) <d (CFB) is more preferable.

  When forming a vertical alignment film used for forming the first optically anisotropic layer on the color filter 50, in order not to lose the thickness difference between the colored layers of the respective colors, the vertical alignment film is It is preferably formed by a method such as vapor deposition.

If necessary, the surface of the color filter 50 (50R, 50G, 50B) may be subjected to fluorination treatment in advance before forming the first optically anisotropic layer. In this fluorination treatment, for example, the substrate 40 on which the color filter 50 is formed is accommodated in a chamber, and the atmosphere in the chamber is a mixed atmosphere of helium (He) gas and tetrafluoroethylene (CF ₄ ) gas. It can be performed by activating CF ₄ gas by performing discharge while adding. In this case, for example, the flow rate of He gas can be 10 liters / minute, the flow rate of CF ₄ gas can be 100 cc / minute, the frequency of the high frequency electric field can be 13.56 MHz, and the discharge power can be 300 W. By performing a fluorination treatment on the surface of the color filter 50 in advance, it is possible to impart a function of a vertical alignment film to the color filter 50.

  The substrate 40 can have a single-layer structure or a multi-layer structure depending on a desired function or the like. When the substrate 40 has a single layer structure, the substrate 40 can be formed of an inorganic material such as glass or an organic material such as resin. When the substrate 40 has a multi-layer structure, the structure can be appropriately selected according to the desired function of the liquid crystal cell substrate, and even in this case, it is the base of the first optical anisotropic layer 34. The layer is preferably formed of an inorganic material such as glass or an organic material such as a resin. The substrate 40 is preferably optically isotropic, but a light shielding region or the like can be locally provided as necessary. The light transmittance of the substrate 40 can be appropriately selected according to the desired function of the liquid crystal cell substrate.

  The first optically anisotropic layer 34 formed on the substrate 40 may be a stretched polymer film or a layer composed of a liquid crystalline composition. In the case of forming from a liquid crystalline composition, for example, a liquid crystalline composition containing at least one rod-shaped liquid crystalline compound is used, and rod-shaped liquid crystalline molecules are homeotropically aligned and fixed in that state. Can do. Details of the first optically anisotropic layer will be described later.

  The color filter 50 is a primary color system in which a red micro color filter 50R, a green micro color filter 50G, and a blue micro color filter 50B are arranged in a predetermined pattern. The arrangement of the micro color filters 50R, 50G, and 50B for each color is not particularly limited, and may be any of various arrangements called a stripe type, a mosaic type, and a triangle type. It is also possible to use a complementary color filter instead of the primary color filter.

  The color filter 50 is formed by, for example, patterning a color resin coating film as a material for each color micro color filter 50R, 50G, 50B into a predetermined shape by, for example, a photolithography method, or by microcolor filters of each color. Each filter 50R, 50G, 50B can be formed by applying a color filter ink as a material in a predetermined shape.

  The light shielding layer 35 is for preventing light leakage (leakage light) from between pixels in the display liquid crystal panel and light deterioration of the active elements in the active matrix driving type display liquid crystal panel. Individual pixels are defined on the panel in plan view. The colored layers 50R, 50G, and 50B of the respective colors are arranged so as to cover predetermined pixels defined by the light shielding layer 35 in plan view.

  The light shielding layer 35 can be formed by patterning a metal thin film having a light shielding property or a light absorbing property such as a metal chromium thin film or a tungsten thin film into a predetermined shape. It is also possible to form the light shielding layer 35 by printing an organic material such as a black resin in a predetermined shape. In addition, it is also possible to use a monochromatic color filter as the color filter 50. In this case, the light shielding layer 35 can be omitted.

  FIG. 2 is a schematic cross-sectional view of another example of a liquid crystal cell substrate that can be used in the liquid crystal display device of the present invention. The same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. A liquid crystal cell substrate 30 ′ shown in FIG. 2 is formed on a substrate 40 made of a glass plate or the like, on a first optical anisotropic layer 34 ′ made of regions 34R ′, 34G ′, and 34B ′ having different thicknesses. A color filter 50 ′ composed of a light shielding layer 35 and an R (red) layer 50R ′, a G (green) layer 50G ′, and a B (blue) layer 50B ′ separated by the light shielding layer 35, and an orientation A film 60 is provided.

  When the first optically anisotropic layer 34 ′ contains a rod-like liquid crystal compound fixed in a vertically aligned state, a vertical alignment film is generally used when vertically aligning rod-like liquid crystal molecules. However, in the liquid crystal cell substrate 30 ′, a substrate having vertical alignment with respect to the rod-like liquid crystalline molecules is used as the substrate 40, so that the first optical element of this embodiment can be used without forming a vertical alignment film. An anisotropic layer 34 'can be formed, which is very preferable from the viewpoint of productivity.

  In the liquid crystal cell substrate 30 ′ of FIG. 2, an optically anisotropic layer 34 ′ composed of regions 34 </ b> R, 34 </ b> G, and 34 </ b> B having different thicknesses is formed on the substrate 40. The thicknesses of the first optical anisotropic layers 34R ′, 34G ′, and 34B ′ arranged at positions corresponding to the colored layers of the respective colors (red, green, and blue) are respectively d (R) and d (G). And d (B), it is preferable to satisfy d (B) <d (R), and it is more preferable to satisfy d (B) <d (G) <d (R).

  FIG. 3 is a schematic cross-sectional view of another example of a liquid crystal cell substrate that can be used in the liquid crystal display device of the present invention. The same members as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted. A liquid crystal cell substrate 30 ″ shown in FIG. 3 is formed with a color filter layer 50 ″ (consisting of an R (red) layer 50R ″, a G (green) layer 50G ″, and a B (blue) layer 50B ″) of the substrate 40. A first optically anisotropic layer 34 ″ comprising regions 34R ″, 34G ″, and 34B ″ having different thicknesses is disposed on the surface opposite to the surface on which the liquid crystal cell is formed. The liquid crystal cell shown in FIG. Similarly to the substrate 30 ′, the material of the substrate 40 is selected, which is advantageous in terms of productivity because it is not necessary to use the vertical alignment film.

  The liquid crystal cell substrates 30, 30 ′ and 30 ″ shown in FIGS. 1 to 3 are respectively arranged to face the counter substrate with the alignment layer 60 inside, and a liquid crystal material is injected between the substrates to constitute the liquid crystal cell. A transparent electrode layer for driving the liquid crystal cell may be formed on or below the alignment layer 60.

[First optically anisotropic layer]
In the present invention, the first optically anisotropic layer formed on the first liquid crystal cell substrate has an in-plane retardation of 0 to 10 nm and a thickness direction retardation of −400 to −30 nm. is there. The in-plane retardation of the first optically anisotropic layer is preferably 0 to 5 nm, and most preferably 0 to 3 nm. Further, the retardation in the thickness direction of the optically anisotropic layer is preferably −360 to −50 nm, more preferably −320 to −60 nm, and particularly preferably −300 to −70 nm. .

  The first optically anisotropic layer is preferably formed from a composition containing at least one liquid crystalline compound. The liquid crystal compound is preferably a rod-like liquid crystal compound. When a rod-like liquid crystalline compound is used, it is preferable that rod-like molecules are vertically aligned in the first optically anisotropic layer.

  The type of liquid crystal compound is not particularly limited. The first optically anisotropic layer may be prepared, for example, by forming a low molecular liquid crystalline compound in a nematic orientation in a liquid crystal state and then immobilizing it by photocrosslinking or thermal crosslinking. Alternatively, the polymer liquid crystalline compound may be formed in a nematic alignment in a liquid crystal state and then cooled to cool the alignment. In the present invention, a liquid crystalline compound is used for the production of the optically anisotropic layer, but the liquid crystalline compound is often contained in the optically anisotropic layer in a state of being fixed by polymerization or the like in the production process. Finally, it is not necessary to show liquid crystallinity. The polymerizable liquid crystal compound may be a polyfunctional polymerizable liquid crystal or a monofunctional polymerizable liquid crystal compound.

  In the first optically anisotropic layer, the molecules of the liquid crystalline compound are preferably fixed in a predetermined alignment state, preferably in a vertical alignment state. The term “substantially perpendicular to the rod-like liquid crystalline compound” means that the angle formed between the surface of the liquid crystal cell substrate and the director of the rod-like liquid crystalline compound is in the range of 70 ° to 90 °. 80 ° to 90 ° are more preferable, and 85 ° to 90 ° are more preferable.

Hereinafter, materials used for manufacturing the first optically anisotropic layer, manufacturing methods, and the like will be described in detail.
The first optically anisotropic layer can be formed from a composition containing a liquid crystal compound such as a rod-like liquid crystal compound and, if desired, the following polymerization initiator, alignment control agent, and other additives.
(Bar-shaped liquid crystalline compound)
In the present invention, it is preferable to form the first optically anisotropic layer using a rod-like liquid crystalline compound. Examples of rod-like liquid crystalline compounds 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. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used. It is more preferable to fix the alignment of the rod-like liquid crystal compound by polymerization. As the liquid crystalline compound, those having a partial structure capable of causing polymerization or crosslinking reaction by actinic rays, electron beams, heat, or the like are suitably used. The number of the partial structures is preferably 1 to 6, more preferably 1 to 3. As the polymerizable rod-like liquid crystalline compound, Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. No. 4,683,327, US Pat. No. 5,622,648, US Pat. No. 5,770,107, International Publication WO95 / 22586. No. 95/24455, No. 97/00600, No. 98/23580, No. 98/52905, JP-A-1-272551, No. 6-16616, and No. 7-110469. 11-80081, JP 2001-328773, JP 2004-240188, JP 2005-99236, JP 2005-99237, JP 2005-121827, JP It is possible to use the compounds described in 2002-30042 That.

(Vertical alignment accelerator)
In order to uniformly align the liquid crystalline compound vertically, it is necessary to vertically control the alignment of the liquid crystalline compound on the alignment film interface side and the air interface side. For this purpose, a composition obtained by adding a compound having an effect of vertically aligning the liquid crystalline compound by an excluded volume effect, an electrostatic effect, or a surface energy effect to the alignment film may be employed. In addition, with regard to alignment control on the air interface side, a compound that is unevenly distributed at the air interface during alignment of the liquid crystalline compound and acts to align the liquid crystalline compound vertically by its excluded volume effect, electrostatic effect, or surface energy effect is blended The liquid crystal composition may be used. As such a compound (alignment film interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the alignment film interface side, a pyridinium derivative is preferably used. As a compound (air interface side vertical alignment agent) that promotes the vertical alignment of the molecules of the liquid crystal compound on the air interface side, a fluoro aliphatic group that promotes the uneven distribution of the compound on the air interface side, One or more hydrophilic groups selected from the group consisting of a carboxyl group (—COOH), a sulfo group (—SO ₃ H), a phosphonoxy group {—OP (═O) (OH) ₂ }, and salts thereof. A compound is preferably used. Further, by blending these compounds, for example, when a liquid crystalline composition is prepared as a coating solution, the coating property of the coating solution is improved, and the occurrence of unevenness and repellency is suppressed. The vertical alignment agent will be described in detail below.

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

  Formula (I)

In the formula (I), L ⁰ represents a divalent linking group, an alkylene group and —O—, —S—, —CO—, —SO ₂ —, —NR ^a — (where R ^a is the number of carbon atoms. Is an alkyl group or a hydrogen atom having 1 to 5), an alkenylene group, an alkynylene group or an arylene group, and preferably a divalent linking group having 1 to 20 carbon atoms. The alkylene group may be linear or branched.

In the formula (I), R ⁰ is a hydrogen atom, an unsubstituted amino group, or a substituted amino group substituted with a substituent having 1 to 20 carbon atoms. When R ⁰ is a substituted amino group, it is preferably substituted with an aliphatic group. Examples of the aliphatic group include an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group. When R ⁰ is a disubstituted amino group, two aliphatic groups may be bonded to each other to form a nitrogen-containing heterocyclic ring. The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring. R ⁰ is preferably a hydrogen atom, an unsubstituted amino group or a substituted amino group having 1 to 20 carbon atoms, and is a hydrogen atom, an unsubstituted amino group or a substituted amino group having 2 to 12 carbon atoms. More preferably, it is more preferably a hydrogen atom, an unsubstituted amino group, or a substituted amino group having 2 to 8 carbon atoms. When R ⁰ is an amino group, it is preferably substituted at the 4-position of the pyridinium ring.

In the formula (I), X ⁰ is an anion. Examples of anions include halogen anions (eg, fluorine ions, chlorine ions, bromine ions, iodine ions, etc.), sulfonate ions (eg, methanesulfonate ions, trifluoromethanesulfonate ions, methyl sulfate ions, p-toluene). Sulfonate ion, p-chlorobenzenesulfonate ion, 1,3-benzenedisulfonate ion, 1,5-naphthalenedisulfonate ion, 2,6-naphthalenedisulfonate ion, sulfate ion, carbonate ion, nitrate ion, thiocyanate Acid ions, perchlorate ions, tetrafluoroborate ions, picrate ions, acetate ions, formate ions, trifluoroacetate ions, phosphate ions (for example, hexafluorophosphate ions), hydroxide ions, and the like. X ⁰ is preferably a halogen anion, a sulfonate ion, or a hydroxide ion.

In the formula (I), Y ¹ is a divalent linking group having 1 to 30 carbon atoms having a 5-membered or 6-membered ring as a partial structure. The cyclic partial structure contained in Y ¹ is more preferably a cyclohexyl ring, an aromatic ring or a heterocyclic ring. Examples of the aromatic ring include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, a biphenyl ring, and a pyrene ring. More preferred are a benzene ring, a biphenyl ring, and a naphthalene ring. The hetero atom constituting the hetero ring is preferably a nitrogen atom, an oxygen atom or a sulfur atom. For example, a furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole Ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, dioxane ring, dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine ring Morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring. The heterocycle is preferably a 6-membered ring. The divalent linking group having a 5-membered or 6-membered ring represented by Y ¹ as a partial structure may have a substituent.

In the formula (I), Z represents a halogen-substituted phenyl group, a nitro-substituted phenyl group, a cyano-substituted phenyl group, a phenyl group substituted with an alkyl group having 1 to 10 carbon atoms, or an alkoxy having 2 to 10 carbon atoms. A phenyl group substituted with a group, an alkyl group having 1 to 12 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxy having 2 to 13 carbon atoms A carbonyl group, an aryloxycarbonyl group having 7 to 26 carbon atoms, an arylcarbonyloxy group having 7 to 26 carbon atoms, a cyano-substituted phenyl group, a halogen-substituted phenyl group, and an alkyl having 1 to 10 carbon atoms. Phenyl group substituted with a group, phenyl group substituted with an alkoxy group having 2 to 10 carbon atoms, aryloxycarboe having 7 to 26 carbon atoms Group or carbon atoms is preferably an aryl carbonyl group having 7 to 26.
Z may further have a substituent, and examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), a cyano group, a nitro group, and a carbon atom number of 1 to 16. An alkyl group having 1 to 16 carbon atoms, an alkynyl group having 1 to 16 carbon atoms, a halogen-substituted alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, An acyl group having 2 to 16 carbon atoms, an alkylthio group having 1 to 16 carbon atoms, an acyloxy group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, a carbon atom An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included.

  The pyridinium compound used in the present invention is preferably a pyridinium compound represented by the following formula (Ia).

Formula (Ia)

In the formula (Ia), L ⁰³ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═. CH—, —N═N—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, —CO—. O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or O-CO-AL-CO -O-. AL is an alkylene group having 1 to 10 carbon atoms. L ⁰³ is a single bond, —O—, —O—AL—O—, —O—AL—O—CO—, —O—AL—CO—O—, —CO—O—AL—O—, — CO-O-AL-O-CO-, -CO-O-AL-CO-O-, -O-CO-AL-O-, -O-CO-AL-O-CO- or O-CO-AL It is preferably —CO—O—, more preferably a single bond or O—.

In the formula (Ia), L ⁰⁴ represents a single bond, —O—, —O—CO—, —CO—O—, —C≡C—, —CH═CH—, —CH═N—, —N═. CH- or N = N-.

In the formula (Ia), R ⁰³ is a hydrogen atom, an unsubstituted amino group, or an alkyl-substituted amino group having 2 to 20 carbon atoms. When R ⁰³ is a dialkyl-substituted amino group, two alkyl groups may be bonded to each other to form a nitrogen-containing heterocycle. The nitrogen-containing heterocycle formed at this time is preferably a 5-membered ring or a 6-membered ring. R ⁰³ is more preferably a hydrogen atom, an unsubstituted amino group, or a dialkyl-substituted amino group having 2 to 12 carbon atoms, and most preferably a hydrogen atom, an unsubstituted amino group, or a dialkyl-substituted amino group having 2 to 8 carbon atoms. . When R ⁰³ is an unsubstituted amino group, the 4-position of the pyridinium ring is preferably amino-substituted.

In the formula (Ia), Y ² and Y ³ are each independently a divalent group consisting of a 6-membered ring optionally having a substituent. Examples of the 6-membered ring include an aliphatic ring, an aromatic ring (benzene ring), and a heterocyclic ring. Examples of the 6-membered aliphatic ring include a cyclohexane ring, a cyclohexene ring, and a cyclohexadiene ring. Examples of 6-membered heterocycles include pyran ring, dioxane ring, dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring. Can be mentioned. Another 6-membered ring or 5-membered ring may be condensed to the 6-membered ring.
Examples of the substituent include a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms. The alkyl group and the alkoxy group may be substituted with an acyl group having 2 to 12 carbon atoms or an acyloxy group having 2 to 12 carbon atoms. The definition of an acyl group and an acyloxy group will be described later.

In the formula (Ia), X ⁰¹ is an anion. X ⁰¹ is preferably a monovalent anion. Examples of anions include halogen anions (eg, fluorine ions, chlorine ions, bromine ions, iodine ions) and sulfonate ions (eg, methanesulfonate ions, p-toluenesulfonate ions, benzenesulfonate ions). It is.

In Formula (Ia), Z ¹ is a hydrogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and the alkyl group and the alkoxy group are each a carbon atom. It may be substituted with an acyl group having 2 to 12 atoms or an acyloxy group having 2 to 12 carbon atoms.

In the formula (Ia), m is 1 or 2, and when m is 2, two L ⁰⁴ and two Y ³ may be different.
When m is 2, Z ¹ is preferably a cyano group, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.
When m is 1, Z ¹ is an alkyl group having 7 to 12 carbon atoms, an alkoxy group having 7 to 12 carbon atoms, an acyl-substituted alkyl group having 7 to 12 carbon atoms, and 7 carbon atoms. It is preferably an acyl-substituted alkoxy group having -12, an acyloxy-substituted alkyl group having 7-12 carbon atoms, or an acyloxy-substituted alkoxy group having 7-12 carbon atoms.

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

In formula (Ia), p is an integer of 1-10. C _p H _2p means a chain alkylene group which may have a branched structure. C _p H _2p is preferably a linear alkylene group. Further, p is more preferably 1 or 2.

  Specific examples of the compound represented by formula (I) and / or (Ia) are shown below. Here, Me represents a methyl group.

  A pyridinium derivative is generally obtained by alkylating a pyridine ring (Menstokin reaction).

  The preferable range of the content of the pyridinium derivative in the liquid crystal composition varies depending on the use, but 0.005 in the liquid crystal composition (liquid crystal composition excluding the solvent when prepared as a coating liquid). It is preferably -8% by mass, more preferably 0.01-5% by mass.

(Air interface side vertical alignment agent)
As the air interface side vertical alignment agent usable in the present invention, a fluoro aliphatic group, a carboxyl group (—COOH), 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 the salts thereof, a fluoroaliphatic group-containing polymer (hereinafter referred to as “fluorine polymer”), or a compound represented by the general formula (III) Fluorine compounds are preferably used.

First, the fluorine polymer will be described.
Fluoropolymers that can be used in the present invention include fluoroaliphatic groups, carboxyl groups (—COOH), sulfo groups (—SO ₃ H), phosphonoxy groups {—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” (written by Takayuki Otsu, published by Kagaku Dojin Co., 1968) on pages 1 to 4, for example, polyolefins, polyesters, polyamides, polyimides. , Polyurethanes, polycarbonates, polysulfones, polycarbonates, polyethers, polyacetals, polyketones, polyphenylene oxides, polyphenylene sulfides, polyarylates, polytetrafluoroethylene (PTFE), polyvinylidene fluorides And cellulose derivatives. 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 needed, and used for the production of a fluoropolymer.

  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 embodiment of a fluorine-based polymer that can be used in the present invention is represented by a repeating unit derived from a fluoroaliphatic group-containing monomer (hereinafter sometimes referred to as “fluorine-based monomer”) and the following formula (II): It is a copolymer having a repeating unit containing a hydrophilic group.

  Formula (II)

In the above formula (II), R ⁶¹ , R ⁶² and R ⁶³ each independently represents a hydrogen atom or a substituent. Q represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof. L represents an arbitrary group selected from the following linking group group, or a divalent linking group formed by combining two or more thereof.
(Linked group group)
Single bond, —O—, —CO—, —NR ^b — (R ^b represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), —S—, —SO ₂ —, —P (═O) (OR ^f ) — (R ^f represents an alkyl group, an aryl group, or an aralkyl group), an alkylene group, and an arylene group.

In formula (II), R ⁶¹ , R ⁶² and R ⁶³ each independently represent a hydrogen atom or a substituent selected from the substituent group exemplified below.
(Substituent group)
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, still more 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, More preferably, it is a C2-C8 alkenyl group, for example, a vinyl group, an aryl group, 2-butenyl group, 3-pentenyl group etc., an alkynyl group (preferably C2-C20, more preferably). Is an alkynyl group having 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, such as a propargyl group or a 3-pentynyl group. An aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms, such as a phenyl group, a p-methylphenyl group, A naphthyl group), an aralkyl group (preferably an aralkyl group having 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, still more preferably 7 to 12 carbon atoms, such as a benzyl group, a phenethyl group, A 3-phenylpropyl group), a substituted or unsubstituted amino group (preferably an amino group having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, still more preferably 0 to 6 carbon atoms, For example, an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, an anilino group, etc.)

An alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more 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, still more 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, still more 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, still more preferably 2 carbon atoms 10 acylamino groups such as acetylamino group and benzoylamino group), alkoxycarbonylamino groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 2 carbon atoms). 12 alkoxycarbonylamino groups, for example, a methoxycarbonylamino group and the like, and aryloxycarbonylamino groups (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, still more preferably 7 carbon atoms). To 12 aryloxycarbonylamino groups, such as phenyloxycarbonylamino group, and sulfonylamino groups (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably carbon atoms). 1 to 12 sulfonylamino groups, for example, Sulfonylamino groups, benzenesulfonylamino groups, etc.), sulfamoyl groups (preferably 0-20 carbon atoms, more preferably 0-16 carbon atoms, still more preferably 0-12 carbon atoms sulfamoyl groups, , Sulfamoyl 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, still more preferably A carbamoyl group having 1 to 12 carbon atoms, and examples thereof include an unsubstituted carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, and a phenylcarbamoyl group).

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is a C6-C20, More preferably, it is a C6-C16, More preferably, it is a 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, still more preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group), a sulfinyl group (preferably having a carbon number of 1 to 20, and more. A sulfinyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, is preferable. A ureido group (preferably a benzenesulfinyl group), a ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms. 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, and further preferably having 1 to 12 carbon atoms) Group such as diethyl phosphoramide group and phenylphosphoric acid amide group), hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group Group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably A heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, such as a heterocyclic group having a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as an imidazolyl group, a pyridyl group, or a quinolyl group; Group, 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, More preferably, it is 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 ⁶¹ , R ⁶² and R ⁶³ are each independently a hydrogen atom, an alkyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), or a group represented by -LQ described later. It is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a chlorine atom, or a group represented by -LQ, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Particularly preferred are a hydrogen atom and an alkyl group having 1 to 2 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, n-butyl group, sec-butyl group and the like. The alkyl group may have a suitable substituent. Examples of the substituent include a halogen atom, aryl group, heterocyclic group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, hydroxyl group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl Group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamido group, sulfolyl group, carboxyl group and the like. The carbon number of the alkyl group does not include the carbon atom of the substituent. The same applies to the carbon number of other groups.

L represents a divalent linking group selected from the above linking group group, or a divalent linking group formed by combining two or more thereof. In the linking group group, R ^{b in} —NR ^b — represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and preferably a hydrogen atom or an alkyl group. R ^f in —PO (OR ^f ) — represents an alkyl group, an aryl group or an aralkyl group, and preferably an alkyl group. When R ^b and R ^f represent an alkyl group, an aryl group, or an aralkyl group, the carbon number is the same as that described in the “substituent group”. L preferably contains a single bond, —O—, —CO—, —NR ^b —, —S—, —SO ₂ —, an alkylene group or an arylene group, and —CO—, —O—, —NR ^b- , an alkylene group or an arylene group is particularly preferred. When L contains an alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 6 carbon atoms. Specific examples of particularly preferable alkylene groups include a methylene group, an ethylene group, a trimethylene group, a tetrabutylene group, and a hexamethylene group. When L contains an arylene group, the carbon number of the arylene group is preferably 6 to 24, more preferably 6 to 18, and still more preferably 6 to 12. Specific examples of particularly preferred arylene groups include phenylene groups 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 still more 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 ⁶¹ , R ⁶² and R ⁶³ .
The specific structure of L is illustrated below.

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

Monomer group (1) Alkenes ethylene, propylene, 1-butene, isobutene, 1-hexene, 1-dodecene, 1-octadecene, 1-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, etc.

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

  The fluoropolymer used in the present invention has a mass average molecular weight of preferably 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. For example, a polymerization method such as cation polymerization, radical polymerization, or anion polymerization using a vinyl group can be employed. Polymerization is particularly preferred in that it can be used for general purposes. As the polymerization initiator for radical polymerization, known compounds such as radical thermal polymerization initiators and radical photopolymerization initiators can be used, and it is particularly preferable to use radical thermal polymerization initiators. Here, the radical thermal polymerization initiator is a compound that generates radicals by heating to a decomposition temperature or higher. Examples of such radical thermal polymerization initiators include diacyl peroxide (acetyl peroxide, benzoyl peroxide, etc.), ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), hydroperoxide (hydrogen peroxide, tert. -Butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, etc.), peroxyesters (tert-butyl peroxyacetate, tert -Butyl peroxypivalate, etc.), azo compounds (azobisisobutyronitrile, azobisisovaleronitrile, etc.), persulfates (ammonium persulfate, sodium persulfate) Beam, such as potassium sulphate). Such radical thermal polymerization initiators can be used 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 are: alcohols such as isopropanol and butanol; ethers such as dibutyl ether, ethylene glycol dimethyl ether, tetrahydrofuran and dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate and acetic acid And esters such as butyl, amyl acetate, and γ-butyrolactone; and aromatic hydrocarbons such as benzene, toluene, and xylene. In addition, these organic solvents can be used individually by 1 type or in combination of 2 or more types. Furthermore, a water-mixed organic solvent in which water is used in combination with the 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, 1,1,1-trichloroethane, 1,1,1-tribromooctane, etc.) and low-activity monomers (α-methylstyrene, α-methylstyrene dimer, etc.) can be used, but preferably It is a mercaptan having 4 to 16 carbon atoms. The amount of these chain transfer agents to be 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%, more preferably 0.05 mol% to 30 mol%, still more 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 is preferable for a fluoropolymer to fix the orientation state of a discotic liquid crystalline compound.

  Specific examples that can be preferably used in the present invention as fluorine-based polymers 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-mentioned fluorine-based monomer, a monomer having a hydrogen bonding group, and the like, and polymerizing it. 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 liquid crystalline composition (liquid crystalline composition excluding the solvent when prepared as a coating liquid) varies depending on the application, but the liquid crystalline composition (coating liquid) In the composition excluding the solvent), it is preferably 0.005 to 8% by mass, more preferably 0.01 to 5% by mass, and 0.05 to 1% by mass. Is 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 formula (III) that can be similarly used as the air interface side vertical alignment agent will be described.
Formula (III)
(R ¹⁰⁰ ) _mo −L ¹⁰⁰ − (W) _no
In the formula, R ¹⁰⁰ 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 mo represents an integer of 1 or more. A plurality of R ¹⁰⁰ 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 ¹⁰⁰ represents a (mo + no) -valent linking group, W is a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or phosphonoxy {—OP (═O) (OH) ₂ } Or a salt thereof, and no represents an integer of 1 or more.

In the formula (III), R ¹⁰⁰ functions as a hydrophobic group of the fluorine-containing compound. The alkyl group represented by R ¹⁰⁰ 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 ¹⁰⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and even more preferably 4 to 8. The alkyl group having a CF ₃ group at the terminal is an alkyl group in which part or all of the hydrogen atoms contained in the alkyl group are substituted with fluorine atoms. 50% or more of hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and particularly preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with the substituents exemplified as the substituent group D described later. The alkyl group having a CF ₂ H group at the terminal represented by R ¹⁰⁰ preferably has 1 to 20 carbon atoms, more preferably 4 to 16 and even more 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 the hydrogen atoms in the alkyl group are preferably substituted with fluorine atoms, more preferably 60% or more are substituted, and even more preferably 70% or more are substituted. The remaining hydrogen atoms may be further substituted with a substituent exemplified as the substituent group D described later. Examples of an alkyl group having a CF ₃ group at the terminal represented by R ¹⁰⁰ or an alkyl group having a CF ₂ H group at the terminal are shown below.

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

In the formula (III), the represented by L ¹⁰⁰ (mo + no) -valent linking group is an alkylene group, an alkenylene group, an aromatic group, a heterocyclic ^{group, -CO -, - NR d -} (R d are carbon atoms Is preferably a linking group in which at least two groups selected from the group consisting of —O—, —S—, —SO—, and —SO ₂ — are combined.

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

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

  Formula (III) -a

In formula (III) -a, R ¹⁰⁴ and R ¹⁰⁵ each represents an alkyl group, an alkyl group having a CF ₃ group at the terminal, or an alkyl group having a CF ₂ H group at the terminal, and R ¹⁰⁴ and R ¹⁰⁵ are simultaneously It is not an alkyl group. W ¹ and W ² are each a hydrogen atom, a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or An alkyl group, an alkoxy group or an alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent is represented, but W ¹ and W ² are not simultaneously hydrogen atoms.

Formula (III) -b
_{^{(R 106 -L 102 -) m2}} (Ar 101) -W 3
Wherein (III) -b, R ¹⁰⁶ represents an alkyl group having an alkyl group, or terminal to CF ₂ H group having a CF ₃ group alkyl group, the terminus, m2 represents an integer of 1 or more, a plurality of R ¹⁰⁶ 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. ^L102 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-, It represents a divalent linking group selected from the group consisting of —SO ₂ — and combinations thereof, and a plurality of L ¹⁰² may be the same or different. Ar ¹⁰¹ represents an aromatic hydrocarbon ring or an aromatic heterocycle, W ³ represents a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group or an alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent.

First, the formula (III) -a will be described.
R ¹⁰⁴ and R ¹⁰⁵ are synonymous with R ¹⁰⁰ in the formula (III), and their preferred ranges are also the same. The carboxyl group (—COOH) or a salt thereof represented by W ¹ and W ² , a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof is It is synonymous with W in Formula (III), and its preferable range is also the same. The alkyl group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ^{1 or} W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. It is an alkyl group, More preferably, it is a 1-8 alkyl group, Most preferably, it is a 1-3 alkyl group. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, sulfo group, or phosphonoxy group. It is synonymous with the carboxyl group, sulfo group and phosphonoxy group represented by W in formula (III), and the preferred range is also the same. The alkyl group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent may be substituted with any other substituent, and the substituent is any of the substituents exemplified as the substituent group D described later. Can be applied. The alkoxy group having a carboxyl group, a sulfo group or a phosphonoxy group as a substituent represented by W ¹ and W ² may be linear or branched, and preferably has 1 to 20 carbon atoms. An alkoxy group, more preferably an alkoxy group of 1 to 8, and particularly preferably an alkoxy group of 1 to 4. The alkoxy group having a carboxyl group, a sulfo group, or a phosphonoxy group as the substituent only needs to have at least one carboxyl group, a sulfo group, or a phosphonoxy group. It is synonymous with the 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 the 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 still more preferably 1 to 4 alkylamino groups. The alkylamino group having a carboxyl group, a sulfo group, or a phosphonoxy group may have at least one carboxyl group, a sulfo group, or a phosphonoxy group. Examples of the carboxyl group, the sulfo group, and the phosphonoxy group include the above-described formula ( It is synonymous with the carboxyl group, 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 the cation represented by M, for example, protonium ion, alkali metal ion (lithium ion, sodium ion, potassium ion, etc.), alkaline earth metal ion (barium ion, calcium ion, etc.), ammonium ion, etc. are preferably applied. . Of these, proton ions, lithium ions, sodium ions, potassium ions, and ammonium ions are particularly preferable.

Next, the formula (III) -b will be described.
R ¹⁰⁶ has the same meaning as R ¹⁰⁰ in formula (III) -b, and its preferred range is also the same. L ¹⁰² 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, more 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 ¹⁰¹ preferably represents an aromatic hydrocarbon ring having 6 to 12 carbon atoms, more preferably a benzene ring or a naphthalene ring. As a carboxyl group (—COOH) represented by W ³ or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, a phosphonoxy group {—OP (═O) (OH) ₂ } or a salt thereof, or a substituent The alkyl group, alkoxy group, or alkylamino group having a carboxyl group, a sulfo group or a phosphonoxy group is a carboxyl group (—COOH) represented by W ¹ and W ² in the above formula (III) -a or a salt thereof, sulfo Group (—SO ₃ H) or a salt thereof, phosphonoxy {—OP (═O) (OH) ₂ } or a salt thereof, or an alkyl group, an alkoxy group, or an alkyl having a carboxyl group, a sulfo group, or a phosphonoxy group as a substituent. It is synonymous with an amino group and its preferable range is also the same.

W ³ is preferably a carboxyl group (—COOH) or a salt thereof, a sulfo group (—SO ₃ H) or a salt thereof, or a carboxyl group (—COOH) or a salt thereof or a sulfo group (—SO ₃ H) as a substituent. Alternatively, it is an alkylamino group having a salt thereof, and 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 the cation represented by M, for example, protonium ion, alkali metal ion (lithium ion, sodium ion, potassium ion, etc.), alkaline earth metal ion (barium ion, calcium ion, etc.), ammonium ion, etc. 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, more 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, still more preferably 2 to 8 carbon atoms, Argyl group, 3-pentynyl group and the like), an aryl group (preferably an aryl group having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and further preferably 6 to 12 carbon atoms). Group, p-methylphenyl group, naphthyl group and the like), substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and further 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, still more 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, still more preferably 6 to 12 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably A C2-C12 alkoxycarbonyl group, for example, a methoxycarbonyl group, an ethoxycarbonyl group, and the like; an aryloxycarbonyl group (preferably having a carbon number of 7-20, more preferably having a carbon number of 7-16, even more preferably Is an aryloxycarbonyl group having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and still more preferably carbon atoms). An acyloxy group having a number of 2 to 10, and examples thereof include 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, still more 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, still more 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, still more preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group) A sulfonylamino group (preferably having 1 to 20 carbon atoms) Preferably it is a C1-C16, More preferably, it is a C1-C12 sulfonylamino group, for example, a methanesulfonylamino group, a benzenesulfonylamino group, etc.), a sulfamoyl group (preferably C0-20). More preferably, it is a sulfamoyl group having 0 to 16 carbon atoms, more 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 still more preferably 1 to 12 carbon atoms, such as an unsubstituted carbamoyl group, a methylcarbamoyl group, or a diethylcarbamoyl group. Group, phenylcarbamoyl group, etc.),

An alkylthio group (preferably an alkylthio group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as a methylthio group and an ethylthio group), an arylthio group ( Preferably it is a C6-C20, More preferably, it is a C6-C16, More preferably, it is a 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, still more preferably 1 to 12 carbon atoms, and examples thereof include a mesyl group and a tosyl group), a sulfinyl group (preferably having a carbon number of 1 to 20, and more. A sulfinyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, is preferable. A ureido group (preferably a benzenesulfinyl group), a ureido group (preferably a ureido group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms. 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, and further preferably having 1 to 12 carbon atoms) Group such as diethyl phosphoramide group and phenylphosphoric acid amide group), hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group Group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably A heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, such as a heterocyclic group having a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as an imidazolyl group, a pyridyl group, or a quinolyl group; Group, 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, More preferably, it is 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 preferably has a polymerizable group as a substituent in order to fix the orientation state of the discotic liquid crystalline compound.

  Specific examples of the fluorine-containing compound represented by the 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.

  The preferable range of the content of the fluorine-containing compound in the liquid crystal composition varies depending on the use, but 0.005 to 0.005 in the liquid crystal composition (a composition excluding the solvent in the case of a coating liquid). The content is preferably 8% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 1% by mass.

(Polymerization initiator)
It is preferable to fix the molecules of the liquid crystal compound aligned in a desired alignment state (for example, vertical alignment in the case of a rod-like liquid crystal compound) 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 aromatics. Group acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US patents) No. 3549367), acridine and phenazine compounds (JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compounds (US Pat. No. 4,221,970).
It is preferable that the usage-amount of a photoinitiator is 0.01-20 mass% of solid content of a coating liquid, and it is more preferable that it is 0.5-5 mass%.

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

  Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Preferably, it is a polyfunctional radically polymerizable monomer and is preferably copolymerizable with the polymerizable group-containing liquid crystalline 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 compounds described in paragraphs [0069] to [0126] in Japanese Patent Application No. 2003-295212. 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 first optically anisotropic layer is, for example, a coating liquid prepared by dissolving and / or dispersing a liquid crystalline compound and additives such as a polymerization initiator and an alignment controller added as required in a solvent. It can be formed by coating on a support. It is preferable to form an alignment film on a support and apply the coating solution on the surface of the alignment film. As a solvent used for preparing the coating solution, an organic solvent is preferably used. Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.

(Application method)
The coating liquid can be applied by a known method (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method). Especially, when forming the said 1st optically anisotropic layer, it is preferable to apply | coat using a wire bar coating method, and it is preferable that the rotation speed of a wire bar satisfy | fills a following formula.
0.6 <(W × (R + 2r) × π) / V <1.4
[W: Number of revolutions of wire bar (rpm), R: Diameter of bar core (m), r: Diameter of wire (m), V: Conveying speed of support (m / min)]
The range of (W × (R + 2r) × π) / V is more preferably 0.7 to 1.3, and still more preferably 0.8 to 1.2.

[Second optically anisotropic layer]
The second anisotropic layer included in the liquid crystal display device of the present invention has Re of 20 nm to 150 nm. In order to effectively reduce oblique light leakage, Re of the second anisotropic layer is more preferably 30 nm to 130 nm, and further preferably 40 nm to 110 nm.

  As long as the second anisotropic layer has the optical characteristics, the material and form thereof are basically not particularly limited. For example, it is formed by coating or transferring a retardation film made of a birefringent polymer film, a film obtained by heating and stretching a polymer compound on a support, and a low-molecular or polymer liquid crystalline compound on the support. Any of retardation films having a retardation layer can be used. Moreover, each can also be laminated | stacked and used.

  The birefringent polymer film is preferably a film having excellent controllability of birefringence characteristics, transparency and heat resistance. In this case, the polymer material to be used is not particularly limited as long as it is a polymer capable of achieving uniform biaxial orientation, but is preferably a conventionally known material that can be formed by a solution casting method or an extrusion method, and is preferably a norbornene-based material. Polymers, polycarbonate polymers, polyarylate polymers, polyester polymers, aromatic polymers such as polysulfone, cellulose acylate, or polymers in which two or more of these polymers are mixed It is done.

The biaxial orientation of the film is a film made of the thermoplastic resin produced by an appropriate method such as an extrusion molding method or a casting film forming method, for example, a longitudinal stretching method using a roll, a transverse stretching method using a tenter, or a biaxial stretching method. For example, it can be achieved by performing a stretching treatment. In the longitudinal stretching method using the roll, a heating method such as a method using a heating roll, a method of heating an atmosphere, or a method using them in combination can be employed. In addition, the biaxial stretching method using a tenter can employ methods such as a simultaneous biaxial stretching method using an all tenter method and a sequential biaxial stretching method using a roll tenter method.
Moreover, a thing with little orientation nonuniformity and phase difference nonuniformity is preferable. Although the thickness can be determined by a phase difference or the like, it is generally preferably 1 to 300 μm, more preferably 10 to 200 μm, and further preferably 20 to 150 μm from the viewpoint of thinning.

  As the norbornene-based polymer, norbornene and its derivatives, tetracyclododecene and its derivatives, dicyclopentadiene and its derivatives, methanotetrahydrofluorene and its monomers as a main component of a monomer polymer, Ring-opening polymer of norbornene monomer, ring-opening copolymer of norbornene monomer and other monomer capable of ring-opening copolymerization, addition polymer of norbornene monomer, copolymerizable with norbornene monomer Examples include addition copolymers with other monomers and hydrogenated products thereof. Among these, from the viewpoints of heat resistance, mechanical strength, and the like, a ring-opening polymer hydride of a norbornene monomer is most preferable. The molecular weight of the norbornene-based polymer, the polymer of the monocyclic olefin or the polymer of the cyclic conjugated diene is appropriately selected according to the purpose of use, but the cyclohexane solution (toluene solution if the polymer resin does not dissolve) Polyisoprene or polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography, preferably 5,000 to 500,000, more preferably 8,000 to 200,000, still more preferably 10,000 to 100 In the range of 1,000, the mechanical strength of the film (A) and the moldability are highly balanced, which is preferable. Typical polymers include those described in JP2003-327800A and JP2004233604A.

In the present invention, the A1 value defined by the following formula (1) of the second optically anisotropic layer is preferably 0.10 to 0.95, and preferably 0.3 to 0.8. More preferred is 0.5 to 0.75. Moreover, it is preferable that A2 value defined by following formula (2) is 1.01-1.50, 1.10-1.45 are more preferable, 1.20-1.40 are especially preferable.
(1): A1 value = Re (450) / Re (550)
(2): A2 value = Re (650) / Re (550)
In the formula, Re (450) is the in-plane retardation value of the second optical anisotropic layer for light having a wavelength of 450 nm, and Re (550) is the surface of the second optical anisotropic layer for light having a wavelength of 550 nm. Re (650) is the in-plane retardation value of the second optically anisotropic layer with respect to light having a wavelength of 650 nm.

  By suppressing the A1 value and A2 value of the second optically anisotropic layer within the above ranges, the red, green, and blue polarization states can be more accurately compensated. As a method of suppressing the A1 value and A2 value indicating Re wavelength dispersion of the second optically anisotropic layer within the above range, for example, when the second optically anisotropic layer is made of a birefringent polymer film Includes a method of stretching the film under predetermined conditions and a method of adding an additive into the film. When the A1 value and the A2 value are within the above ranges by these methods, the wavelength dispersion of the Rth of the film may change, and may exhibit a larger Rth at a short wavelength. Deviation due to the wavelength of Rth can be corrected by changing the retardation value of the first optically anisotropic layer in each of red, green, and blue colors. Such a combination is one of the preferred embodiments of the present invention.

As a method for controlling Re of the optical film of the present invention, a transparent polymer film is stretched at a high temperature at a temperature of 25 ° C. to 100 ° C. above the glass transition point of the polymer, that is, the transparent polymer film is subjected to glass transition of the polymer. When the point is Tg, a method of stretching at a temperature of Tg + 25 ° C. to Tg + 100 ° C. is preferably used.
On the other hand, the transmittance of the optical film is preferably 85% or more, and more preferably 90% or more. Even if the same material is used by applying the stretching method of the present invention, an optical film having a higher transmittance can be obtained. According to the present inventor, it is estimated that by stretching at a very high temperature, impurities and the like in the polymer material are volatilized and the scattering factor in the film is reduced.

The mechanism by which Re at each wavelength becomes a desired value by stretching at high temperature will be described by taking cellulose acylate as the most preferred embodiment as an example.
Cellulose acylate is formed of a main chain composed of a glucopyranose ring and a side chain composed of an acyl group. When a film made of cellulose acylate is stretched, the main chain is oriented in the stretching direction and expresses Re. As a result of extensive research, the present inventor reduced Re at 450 nm and increased Re at 650 nm by stretching at a very high temperature of 165 ° C. to 240 ° C. (Tg of the cellulose acylate used was 140 ° C.). I found out.
In addition, in the cellulose acylate film after stretching at the same high temperature, an X-ray diffraction peak thought to be derived from crystallization appears, and the crystallization changes the orientation state of the main chain and side chain, and the wavelength dependence of Re. Estimated that sex has changed.
That is, in order to realize the optical film of the present invention, crystallization is an important factor, and the orientation degree P of the main chain defined by the following formula (5) calculated from the X-ray diffraction measurement of the film after stretching is 0.04 to 0.30 is preferable, and 0.06 to 0.25 is more preferable.
(5) P = <3 cos ² β-1> / 2
However, <cos ² β> = ∫ (0, π) cos ² βI (β) sinβdβ / ∫ (0, π) I (β) sinβdβ.
In the formula, β is an angle formed by an incident surface of incident X-rays and one direction in the film plane; I is a diffraction intensity at 2θ = 8 ° in an X-ray diffraction chart measured at an angle β.
The orientation degree (orientation order parameter) P of the film surface was detected by rotating the X-ray detector and the sample at an angle of 2θχ and Φ using a book film X-ray In-Plain method measurement. It can be calculated from the peak intensity of 11 ° by the above formula (5).

On the other hand, in order to improve the color shift of the liquid crystal display device, it is preferable to control Rth of the second optical anisotropic layer.
The second optically anisotropic layer has a B1 value defined by the following formula (3) of 0.40 to 0.95 and a B2 value defined by the following formula (4) of 1.05 to 1. .93 and Rth (550) is preferably 70 to 400 nm.
(3) B1 value = {Re (450) / Rth (450)} / {Re (550) / Rth (550)}
(4) B2 value = {Re (650) / Rth (650)} / {Re (550) / Rth (550)}
In the formula, Re (λ) is a retardation value of the film with respect to light having a wavelength λnm; Rth (λ) is a retardation value in the thickness direction of the film with respect to light having a wavelength of λnm.

That is, the ratio Re / Rth (450 nm) of Re and Rth at a wavelength of 450 nm in the visible light region of the second optically anisotropic layer is 0.40 to 0.95 of Re / Rth (550 nm) at a wavelength of 550 nm. Is preferably 0.4 to 0.8 times, more preferably 0.5 to 0.7 times, and Re / Rth (650 nm) at a wavelength of 650 nm is Re / Rth. It is preferably 1.05 to 1.93 times (550 nm), more preferably 1.1 to 1.7 times, and still more preferably 1.3 to 1.6 times. Further, Rth at a wavelength of 550 nm is preferably 70 to 400 nm. Note that Re / Rth at wavelengths of 450 nm, 550 nm, and 650 nm, respectively, is preferably in the range of 0.1 to 0.8.
As a method for controlling Rth, a liquid crystal composition described later is applied to separately form an optically anisotropic layer, and an additive is added to the second optically anisotropic layer (for example, a birefringent film). A method of adding and controlling Rth is preferably used.

(Cellulose acylate film)
A cellulose acylate film is mentioned as an example of the 2nd optically anisotropic layer which shows the said preferable optical characteristic. Hereinafter, a method for producing a cellulose acylate film preferable as the second optically anisotropic layer will be described in detail below.
(Cellulose acylate)
A known raw material can be used for the raw material cotton of the cellulose acylate used when producing the cellulose acylate film used as the second optically anisotropic layer (see, for example, the Japanese Society of Invention and Innovation Technique 2001-1745). Cellulose acylate can also be synthesized by a known method (for example, see Mita et al., Wood Chemistry pages 180-190 (Kyoritsu Shuppan, 1968)). The viscosity average polymerization degree of cellulose acylate is preferably 200 to 700, more preferably 250 to 500, and most preferably 250 to 350. The cellulose ester used in the present invention preferably has a narrow molecular weight distribution of Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. The specific value of Mw / Mn is preferably 1.5 to 5.0, more preferably 2.0 to 4.5, and most preferably 3.0 to 4.0. preferable.

The acyl group of the cellulose acylate film is not particularly limited, but an acetyl group or a propionyl group is preferably used, and an acetyl group is particularly preferable. The degree of substitution of all acyl groups is preferably 2.7 to 3.0, more preferably 2.8 to 2.95. In this specification, the substitution degree of an acyl group is a value calculated according to ASTM D817. The acyl group is most preferably an acetyl group, and when cellulose acetate having an acyl group as the acetyl group is used, the degree of acetylation is preferably 57.0 to 62.5%, and 58.0 to 62.0. % Is more preferable. When the acetylation degree is within this range, Re does not become larger than a desired value due to the conveyance tension during casting, there is little in-plane variation, and there is little change in the retardation value due to temperature and humidity.
In particular, it is obtained by substituting the hydroxyl group of the glucose unit constituting the cellulose of the cellulose acylate film with an acyl group having 2 or more carbon atoms, and the substitution degree of the 2-position hydroxyl group of the glucose unit with the acyl group is DS2, 3-position. When the substitution degree of the hydroxyl group of the hydroxyl group with DS3 is DS3 and the substitution degree of the hydroxyl group at the 6-position with DS6 is DS6, if the following formulas (I) and (II) are satisfied, the Re value fluctuates more with temperature and humidity. It is small and preferable.
(I): 2.0 ≦ DS2 + DS3 + DS6 ≦ 3.0
(II): DS6 / (DS2 + DS3 + DS6) ≧ 0.315

(Stretching)
The cellulose acylate film may be subjected to a stretching treatment, and may exhibit the preferable optical characteristics by the stretching treatment.
The cellulose acylate film is preferably stretched in the width direction. For example, they are described in JP-A-62-115035, JP-A-4-152125, JP-A-4-284221, JP-A-4-298310, JP-A-11-48271, and the like. As described above, the stretching of the film is preferably performed under a temperature condition of 25 ° C. to 100 ° C. above the glass transition point Tg. The film may be stretched uniaxially or biaxially. The film can be stretched by a treatment during drying, and is particularly effective when the solvent remains. For example, the film is stretched by adjusting the speed of the film transport roller so that the film winding speed is higher than the film peeling speed. The film can also be stretched by conveying the film while holding it with a tenter and gradually widening the width of the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine). The stretch ratio of the film (the ratio of the increase due to stretching relative to the original length) is preferably 0.5 to 300%, more preferably 1 to 200%, particularly 1 to 100%. Is preferred. The cellulose acylate film of the present invention is preferably manufactured by sequentially or continuously performing a film forming step by a solvent cast method and a step of stretching the formed film, and the draw ratio is 1.2 times or more. It is preferably 8 times or less. In addition, stretching may be performed in a single stage or in multiple stages. When performing in multiple stages, the product of each draw ratio may be within this range.

  The stretching speed is preferably 5% / min to 1000% / min, and more preferably 10% / min to 500% / min. The stretching temperature is preferably 30 ° C to 160 ° C, more preferably 70 ° C to 150 ° C. 85-150 degreeC is especially preferable. The stretching is preferably performed by a heat roll or / and a radiant heat source (such as an IR heater) or warm air. Moreover, you may provide a thermostat in order to improve the uniformity of temperature. When performing uniaxial stretching by roll stretching, it is preferable that L / W which is ratio of the distance (L) between rolls and the film width (W) of this phase difference plate is 2.0-5.0.

  It is preferable to provide a preheating step before stretching. You may heat-process after extending | stretching. The heat treatment temperature is preferably 20 ° C. to 10 ° C. higher than the glass transition temperature of the cellulose acetate film, and the heat treatment time is preferably 1 second to 3 minutes. The heating method may be zone heating or partial heating using an infrared heater. You may slit the both ends of a film in the middle or the end of a process. These slit scraps are preferably recovered and reused as raw materials. Further, regarding the tenter, in JP-A-11-0777718, when the web is dried while maintaining the width with the tenter, the drying gas blowing method, the blowing angle, the wind speed distribution, the wind speed, the air volume, the temperature difference, the air volume difference, and the upper and lower blowing air volume. By appropriately controlling the ratio and the use of a high specific heat drying gas, it is possible to ensure quality prevention such as flatness when increasing the speed by the solution casting method or widening the web width.

  Japanese Patent Laid-Open No. 11-077782 describes an invention in which a stretched thermoplastic resin film is heat treated by providing a temperature gradient in the width direction of the film in the thermal relaxation step after the stretching step in order to prevent unevenness. Yes.

  Furthermore, in order to prevent the occurrence of unevenness, Japanese Patent Application Laid-Open No. 4-204503 discloses an invention in which the film is stretched with the solvent content of 2 to 10% based on the solid content.

  Further, in order to suppress curling due to the regulation of the clip biting width, Japanese Patent Application Laid-Open No. 2002-248680 discloses stretching with a tenter clip biting width D ≦ (33 / (log stretch rate × log volatile content)). Describes an invention that suppresses curling and facilitates film conveyance after the stretching step.

  Furthermore, in order to achieve both high-speed soft film conveyance and stretching, Japanese Patent Application Laid-Open No. 2002-337224 describes an invention that switches tenter conveyance to a first half pin and a second half clip.

  Japanese Patent Application Laid-Open No. 2002-187960 discloses that a cellulose ester dope solution is cast on a casting support for the purpose of easily improving the viewing angle characteristics and improving the viewing angle. The web (film) peeled from the support for stretching is stretched 1.0 to 4.0 times in at least one direction while the amount of residual solvent in the web is 100% by mass or less, particularly 10 to 100% by mass. An optically biaxial invention obtained by doing so is described. As a more preferred embodiment, it is described that the film is stretched 1.0 to 4.0 times in at least one direction while the amount of residual solvent in the web is in the range of 100% by mass or less, particularly 10 to 100% by mass. . In addition, as another stretching method, a circumferential speed difference is applied to a plurality of rolls, and a longitudinal stretching is performed using the difference between the circumferential speeds of the rolls, and both ends of the web are fixed with clips or pins. Examples include a method of extending the interval in the traveling direction and stretching in the vertical direction, a method of expanding in the horizontal direction and extending in the horizontal direction, a method of expanding the vertical and horizontal directions simultaneously and stretching in both the vertical and horizontal directions, a method using a combination of these, and the like. It has been. Further, in the case of the so-called tenter method, it is shown that it is preferable to drive the clip portion by the linear drive method because smooth stretching can be performed and the risk of breakage or the like can be reduced.

  Furthermore, in order to produce a retardation film with little additive bleed-out, no delamination phenomenon between layers, good slipperiness and excellent transparency, it is described in JP-A-2003-014933. In addition, a dope A containing a resin, an additive and an organic solvent, and a dope B containing no additive or a resin having a lower additive content than the dope A, an additive and an organic solvent are prepared. The co-cast on the support so that the dope A becomes the core layer and the dope B becomes the surface layer, and after evaporating the organic solvent until it can be peeled off, the web is peeled off from the support and further stretched. The invention describes that the residual solvent in the resin film is stretched 1.1 to 1.3 times in at least one axial direction in the range of 3 to 50% by mass. Furthermore, as a preferred embodiment, the web is peeled from the support and further stretched 1.1 to 3.0 times in the uniaxial direction at a stretching temperature in the range of 140 ° C. to 200 ° C., and a resin and an organic solvent are included. A dope B containing a dope A, a resin, fine particles, and an organic solvent is prepared, and the dope A is co-cast on the support so that the dope A becomes a core layer and the dope B becomes a surface layer, and is organic until it becomes peelable. After the solvent is evaporated, the web is peeled from the support, and the residual solvent amount in the resin film at the time of stretching is 1.1 to 3.0 times in at least one axial direction in the range of 3 to 50% by mass. Stretching, further stretching at least uniaxially in the range of 140 ° C to 200 ° C in a uniaxial direction, 1.1 to 3.0 times, dope A containing resin, organic solvent and additives, and additives Resin with less additive content than dope A A dope B containing an additive and an organic solvent, and a dope C containing a resin, fine particles, and an organic solvent are prepared. The dope A is a core layer, the dope B is a surface layer, and the dope C is a surface opposite to the dope B. After co-casting on the support so as to form a layer and evaporating the organic solvent until it can be peeled, the web is peeled from the support, and the amount of residual solvent in the resin film during stretching is 3 mass Stretching 1.1 to 3.0 times in at least uniaxial direction in the range of 50% by mass to 50% by mass, 1.1 to 3.0 times stretching in at least uniaxial direction in the range of 140 ° C to 200 ° C. The additive amount in the dope A is 1 to 30% by mass with respect to the resin, the additive amount in the dope B is 0 to 5% by mass with respect to the resin, and the additive is a plasticizer or UV absorber. Agent or retardation control agent, in dope A and dope It is preferred that the organic solvent in to use in that it contains more than 50 wt% methylene chloride or methyl acetate with respect to the total organic solvents.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-014933, as a method of stretching, a transverse stretching machine called a tenter that stretches in the lateral direction by fixing both ends of the web with clips and pins and widening the interval between the clips and pins in the lateral direction. It is described that can be preferably used. It is also disclosed that stretching or shrinking in the longitudinal direction can be performed by widening or shrinking the interval in the transport direction of the clip or pin in the transport direction (vertical direction) using a simultaneous biaxial stretching machine. . In addition, driving the clip portion by the linear drive method is preferable because it can be smoothly stretched and the risk of breakage can be reduced, and as a method of stretching in the longitudinal direction, a difference in peripheral speed is applied to a plurality of rolls. In the meantime, it is suggested that a method of stretching in the longitudinal direction by utilizing the difference in the circumferential speed of the roll can be used. In addition, these extending | stretching methods can also be used combining, and extending | stretching processes may be divided into 2 steps or more like (longitudinal stretching, lateral stretching, longitudinal stretching) or (longitudinal stretching, longitudinal stretching). It is described that it is good.

  Further, in order to prevent foaming of the tenter-dried web, improve detachability, and prevent dust generation, Japanese Patent Application Laid-Open No. 2003-004374 discloses that in the drying apparatus, hot air from the dryer is applied to both edges of the web. The invention is described in which the width of the dryer is formed shorter than the width of the web so as not to hit.

  Further, in order to prevent foaming of the tenter-dried web, improve releasability, and prevent dust generation, Japanese Patent Application Laid-Open No. 2003-019775 discloses that both ends of the web are prevented from hitting the holding portion of the tenter. An invention is described in which a wind shield is provided on the inside of the part.

  Furthermore, in order to stably carry and dry, Japanese Patent Application Laid-Open No. 2003-053749 discloses that the thickness after drying of both ends of the film carried by the pin tenter is X μm, the average after drying of the product part of the film When the thickness is T μm, the relationship between X and T is 40 ≦ X ≦ 200 when Equation (1) T ≦ 60, and 40+ (T−60) × 0 when Equation (2) 60 <T ≦ 120. The invention that satisfies the relationship of 52+ (T−120) × 0.2 ≦ X ≦ 400 when .2 ≦ X ≦ 300 or Formula (3) 120 <T is described.

  In order to prevent wrinkles from occurring in the multistage tenter, JP-A-2-182654 discloses a tenter device in which a heating chamber and a cooling chamber are provided in a dryer of the multistage tenter, and left and right clip chains are provided. A separate cooling invention is described.

  Furthermore, in order to prevent web breakage, wrinkles, and conveyance failure, Japanese Patent Application Laid-Open No. 9-077315 describes an invention in which the inner pin density is increased and the outer pin density is decreased in the pin tenter pins. Yes.

  In addition, in order to prevent foaming of the web itself and adhesion of the web to the holding means in the tenter, Japanese Patent Application Laid-Open No. 9-085846 discloses that both side edge holding pins of the web are blown-type cooled in the tenter drying apparatus. An invention is described in which a pin is cooled to below the foaming temperature of the web and the pin immediately before the web is entrapped is cooled to a gelling temperature of the dope + 15 ° C. or lower in the duct type cooler.

  Further, in order to prevent pin tenter losing and improve foreign matter, Japanese Patent Application Laid-Open No. 2003-103542 discloses a web surface that cools the insertion structure and contacts the insertion structure in the pin tenter. An invention relating to a solution casting method in which the temperature does not exceed the gelling temperature of the web is described.

  In order to prevent deterioration in quality such as flatness when the speed is increased by the solution casting method or the width of the web is widened by a tenter, JP-A-11-0777718 discloses a web in the tenter. Is dried at a wind speed of 0.5 to 20 (40) m / s, a transverse temperature distribution of 10% or less, a web up / down air volume ratio of 0.2-1, and a dry gas ratio of 30-250 J /. The invention of Kmol is described. Furthermore, preferable drying conditions are disclosed depending on the amount of residual solvent in drying in the tenter. Specifically, after the web is peeled off from the support, the angle at which the air blows from the blowout port is 30 ° to 150 ° with respect to the film plane until the amount of residual solvent in the web reaches 4% by mass. And the difference between the upper limit value and the lower limit value is within 20% of the upper limit value when the wind speed distribution on the film surface located in the direction in which the drying gas blows out is based on the upper limit value of the wind speed, the drying gas When the amount of residual solvent in the web is 130% by mass or less and 70% by mass or more, the wind speed of the dry gas blown from the blow type dryer on the web surface is 0.5 m / sec. When the residual solvent amount is less than 70% by mass and less than 4% by mass and the residual solvent amount is less than 70% by mass and less than 4% by mass, the dry gas wind blown out at a wind speed of 0.5m / sec to 40m / sec. When the temperature distribution of the drying gas in the width direction of the web is based on the upper limit value of the gas temperature, the difference between the upper limit value and the lower limit value should be within 10% of the upper limit value, the residual solvent in the web It is described that when the amount is 4% by mass or more and 200% by mass or less, the air flow ratio q of the dry gas blown out from the blow-out port of the blow-type dryer located above and below the conveyed web is 0.2 ≦ q ≦ 1. Has been. Furthermore, as a preferred embodiment, at least one kind of gas is used for the drying gas, the average specific heat is 31.0 J / K · mol or more and 250 J / K · mol or less, and the room temperature contained in the drying gas during drying. And the concentration of the liquid organic compound is dried with a drying gas having a saturated vapor pressure of 50% or less.

  In order to prevent the flatness and coating from deteriorating due to the generation of contaminants, Japanese Patent Application Laid-Open No. 11-0777719 describes an invention in which a tenter clip incorporates a heating portion in a TAC manufacturing apparatus. Has been. As a further preferable aspect, a device for removing foreign matter generated at the contact portion between the clip and the web between the time when the tenter clip releases the web and the time when the web is carried again is provided. Remove foreign matter using a brush, the residual amount when the clip or pin contacts the web is 12% by mass or more and 50% by mass or less, and the surface temperature of the contact part between the clip or pin and the web is 60 ° or more. It is disclosed that it is 200 ° or less (more preferably 80 ° or more and 120 ° or less).

  In order to improve flatness, improve quality deterioration due to tearing in the tenter, and increase productivity, Japanese Patent Application Laid-Open No. 11-090943 discloses an arbitrary transport length Lt (m) of the tenter. The ratio Lr = Ltt / Lt of the total length Ltt (m) in the conveying direction of the portion where the clip of the tenter having the same length as Lt holds the web is 1.0 ≦ Lr ≦ 1.99 The invention is described. Furthermore, as a preferable aspect, it is disclosed that the portion holding the web is arranged without a gap when viewed from the web width direction.

  In addition, when introducing a web into a tenter, in order to improve flatness deterioration and instability due to web sagging, Japanese Patent Application Laid-Open No. 11-090944 discloses a plastic film manufacturing apparatus in front of a tenter entrance. Describes an invention having a sag suppressing device in the web width direction. Further, as a more preferable aspect, the sag suppressing device is a rotating roller that rotates in the direction range of 2 to 60 ° in the width direction, has an air intake device on the top of the web, and can blow air from under the web. It has also disclosed having a simple blower.

  In order to prevent deterioration of quality and sagging that hinders productivity, Japanese Patent Application Laid-Open No. 11-090945 discloses that a web peeled from a support has an angle with respect to the horizontal in the TAC manufacturing method. The invention to be introduced into the tenter is described.

  In order to make a film having stable physical properties, Japanese Patent Application Laid-Open No. 2000-289903 discloses a transport device that transports while applying tension in the width direction of the web when the solvent content is 50 to 12% by mass. A web width detecting means, a web holding means, and an invention that has two or more variable bending points, calculates the web width from a detection signal in web width detection, and changes the position of the bending point. Has been.

  Furthermore, in order to improve the clipping property, prevent web breakage for a long period of time, and obtain a film with excellent quality, Japanese Patent Application Laid-Open No. 2003-033933 discloses the right and left sides of the web on both the left and right sides of the tenter entrance portion. A web side edge curl prevention guide plate is disposed at least below the upper and lower side edges, and the web facing surface of the guide plate is arranged in the web conveying direction and the web. It is described that it comprises a contact metal part. As a further preferred embodiment, the web contact resin portion of the web facing surface of the guide plate is disposed on the upstream side in the web conveyance direction, the web contact metal portion is disposed on the downstream side, the web contact resin portion of the guide plate, and The level difference (including the inclination) between the web contact metal parts is within 500 μm, and the width of the guide plate web contact resin part and the web contact metal part contacting the web is 2 to 2, respectively. It is 150 mm, the distance of the web contact direction of the web contact resin part of the guide plate and the web contact metal part in the web conveyance direction is 5 to 120 mm, respectively, and the web contact resin part of the guide plate is made of metal. Provided by surface resin processing or resin coating on the guide substrate, the web contact resin part of the guide plate is made of a single resin, the left and right side edges of the web The distance between the web facing surfaces of the guide plates arranged above and below is 3 to 30 mm, and the distance between the web facing surfaces of the upper and lower guide plates at the left and right side edges of the web. In the width direction of the web and inward, it is enlarged at a rate of 2 mm or more per 100 mm width, and the upper and lower guide plates have a length of 10 to 300 mm at the left and right side edges of the web, respectively. And the upper and lower guide plates are arranged so as to be displaced back and forth along the web conveying direction, and the distance of the deviation between the upper and lower guide plates is −200 to +200 mm, the upper guide The web facing surface of the plate is made of resin or metal only, the web contact resin portion of the guide plate is made of Teflon (registered trademark), and the web contact metal portion is made of stainless steel. It is disclosed that it is made of stainless steel, the surface roughness of the web facing surface of the guide plate or the web contact resin portion and / or the web contact metal portion provided on the guide plate is 3 μm or less, etc. Yes. Further, it is also described that the installation position of the upper and lower guide plates for preventing web side edge curl generation is preferably between the peeling side end portion of the support and the tenter introduction portion, and more preferably installed near the tenter entrance. Has been.

  Furthermore, in order to prevent the cutting and unevenness of the web that occurs during drying in the tenter, Japanese Patent Application Laid-Open No. 11-048271 discloses a width stretching apparatus at the time when the solvent content of the web is 50 to 12% by mass after peeling. In the invention, the film is stretched and dried at a time when the web has a solvent content of 10% by mass or less, and a pressure device applies a pressure of 0.2 to 10 KPa from both sides of the web. As a more preferred embodiment, when applying pressure using a nip roll as a method of finishing applying the tension when the solvent content is 4% by mass or more and applying pressure from both sides of the web (film), the nip roll pair is 1 It is also disclosed that about 8 sets are preferable, and the temperature when pressurizing is preferably 100 to 200 ° C.

In addition, in JP-A-2002-036266, which is an invention for obtaining a high-quality thin cellulose acylate film having a thickness of 20 to 85 μm, as a preferred embodiment, along the direction of conveyance of the web before and after the tenter. The difference in acting tension is 8 N / mm ² or less, a preheating step for preheating the web after the peeling step, a stretching step for stretching the web using a tenter after the preheating step, and the stretching step And a relaxation step for relaxing the web by an amount smaller than the stretch amount in the stretching step, and the temperature T1 in the preheating step and the stretching step is set to (glass transition temperature Tg-60 of film) or higher. And the temperature T2 in a relaxation process shall be (T1-10) degrees C or less, and the web width | variety just before entering this extending process is set to the extending | stretching rate of the web in an extending process. It is disclosed that the stretch ratio of the web in the relaxation process is -10 to 10% in a ratio of 0 to 30%.

  Further, JP 2002-225054 A, which aims to have a dry film thickness of 10 to 60 μm and a low durability with light weight and moisture permeability, has a residual solvent amount of 10 mass after peeling. %, Gripping both ends of the web with clips, suppressing drying shrinkage by holding the width, and / or stretching in the width direction, the formula S = {(Nx + Ny) / 2} -Nz A film having a degree of plane orientation (S) of 0.0008 to 0.0020 (where Nx is the refractive index in the direction of the largest refractive index in the plane of the film, and Ny is relative to Nx) The refractive index in the direction perpendicular to the surface, Nz is the refractive index in the film thickness direction), the time from casting to peeling is set to 30 to 90 seconds, and the web after peeling in the width direction and / or For example, stretching in the longitudinal direction is disclosed.

  Japanese Patent Application Laid-Open No. 2002-341144 discloses a solution film-forming method having a stretching process in which the mass concentration of a retardation increasing agent has a higher optical distribution as it approaches the center in the film width direction in order to suppress optical unevenness. Are listed.

  Furthermore, in Japanese Patent Application Laid-Open No. 2003-071863, which is an invention for obtaining a film that does not cause fogging, the draw ratio in the width direction is preferably 0 to 100%, and when used as a polarizing plate protective film, It is described that 5 to 20% is more preferable, and 8 to 15% is most preferable. On the other hand, when used as a retardation film, 10 to 40% is more preferable, 20 to 30% is most preferable, Re can be controlled by the stretching ratio, and the higher the stretching ratio, the finished film. It is disclosed that it is preferable because of its excellent flatness. Further, when the tenter is used, the residual solvent amount of the film is preferably 20 to 100% by mass at the start of the tenter, and drying is performed while the tenter is applied until the residual solvent amount of the film becomes 10% by mass or less. It is preferable that the content is 5% by mass or less. Further, the drying temperature in the case of performing the tenter is preferably 30 to 150 ° C, more preferably 50 to 120 ° C, most preferably 70 to 100 ° C, and the lower the drying temperature, the less the transpiration such as the ultraviolet absorber and the plasticizer. It is also disclosed that process contamination can be reduced, but that the higher the drying temperature, the better the flatness of the film.

  Japanese Patent Laid-Open No. 2002-248639, which is an invention that reduces vertical and horizontal dimensional fluctuations during storage under high temperature and high humidity conditions, continuously casts a cellulose ester solution on a support. In the method for producing a film that is peeled and dried, the invention is such that the drying shrinkage satisfies the formula: 0 ≦ dry shrinkage (%) ≦ 0.1 × residual solvent amount (%) when peeling Are listed. Furthermore, as a preferred embodiment, when the residual solvent amount of the cellulose ester film after peeling is in the range of 40 to 100% by mass, at least the residual solvent amount is 30% by mass while holding both ends of the cellulose ester film by tenter conveyance. The amount of residual solvent at the tenter transport entrance of the cellulose ester film after peeling is 40 to 100% by mass, the amount of residual solvent at the exit is 4 to 20% by mass, and the cellulose ester film is transported by tenter transport. It is disclosed that the tension to be conveyed increases from the entrance to the exit of the tenter conveyance, the tension to convey the cellulose ester film by the tenter conveyance and the tension in the width direction of the cellulose ester film are substantially equal. Yes.

  In order to obtain a film having a thin film thickness and excellent optical isotropy and flatness, Japanese Patent Application Laid-Open No. 2000-239403 discloses a residual solvent ratio X at the time of peeling and a residual solvent at the time of introduction into a tenter. It is disclosed that film formation is performed with the relationship of the rate Y being in the range of 0.3X ≦ Y ≦ 0.9X.

  Japanese Patent Application Laid-Open No. 2002-286933 includes a method of stretching a film to be formed by casting, a method of stretching under heating conditions and a method of stretching under solvent-containing conditions, and stretching under heating conditions. In some cases, it is preferable to stretch at a temperature below the glass transition point of the resin. On the other hand, when the cast film is stretched under solvent-impregnated conditions, the once dried film is contacted with the solvent again. It is disclosed that it can be impregnated with a solvent and stretched.

(Re control method: retardation increasing agent whose maximum absorption wavelength (λmax) is shorter than 250 nm)
The cellulose acylate film used as the second optically anisotropic layer has a maximum in the ultraviolet absorption spectrum of the solution in order to control the absolute value of Re to the range required for the second optically anisotropic layer. A compound having an absorption wavelength (λmax) shorter than 250 nm is preferably contained as a retardation increasing agent. By using such a compound, the absolute value can be controlled without substantially changing the wavelength dependency of Re in the visible region. “Retardation increasing agent” means that the Re retardation value measured at a wavelength of 550 nm of a cellulose acylate film containing a certain additive is exactly the same except that the additive is not included. The “additive” means a value that is 20 nm or more higher than the Re retardation value measured in. The increase in retardation value is preferably 30 nm or more, more preferably 40 nm or more, and most preferably 60 nm or more.
From the viewpoint of the function of the retardation increasing agent, rod-like compounds are preferable, preferably having at least one aromatic ring, and more preferably having at least two aromatic rings.

  The rod-shaped compound used as the retardation increasing agent preferably has a linear molecular structure. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation can be performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to obtain a molecular structure that minimizes the heat of formation of a compound. The molecular structure being linear means that the angle of the molecular structure is 140 degrees or more in the thermodynamically most stable structure obtained by calculation as described above.

The rod-shaped compound used as the retardation increasing agent preferably exhibits liquid crystallinity. More preferably, the rod-like compound exhibits liquid crystallinity upon heating (has thermotropic liquid crystallinity). The liquid crystal phase is preferably a nematic phase or a smectic phase.
Preferred compounds are described in JP-A-2004-4550, but are not limited thereto. Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.

  The rod-shaped compound used as the retardation increasing agent can be synthesized with reference to methods described in the literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989), J. Am. Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 (1975), Tetrahedron, 48, 16, 1637 (1992).

  The addition amount of the retardation increasing agent is preferably from 0.1 to 30% by mass, more preferably from 0.5 to 20% by mass, based on the amount of the polymer.

(Rth control method: retardation increasing agent having a maximum absorption wavelength (λmax) longer than 250 nm)
The cellulose acylate film used as the second optically anisotropic layer preferably contains a retardation increasing agent in order to exhibit Rth required for the second optically anisotropic layer. Here, the “retardation increasing agent” is a cellulose acylate film produced in exactly the same manner except that the Rth retardation value measured at a wavelength of 550 nm of a cellulose acylate film containing an additive does not contain the additive. Means an “additive” that is 20 nm or more higher than the Rth retardation value measured at a wavelength of 550 nm. The increase in retardation value is preferably 30 nm or more, more preferably 40 nm or more, and most preferably 60 nm or more.

  The retardation increasing agent is preferably a compound having at least two aromatic rings. The retardation increasing agent is preferably used in the range of 0.01 to 20 parts by mass, more preferably in the range of 0.1 to 10 parts by mass, with respect to 100 parts by mass of the polymer. It is more preferable to use in the range of ˜5 parts by mass, and most preferable to use in the range of 0.5 to 2 parts by mass. Two or more types of retardation increasing agents may be used in combination. The retardation increasing agent preferably has a maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region. The retardation increasing agent for controlling Rth preferably does not affect Re expressed by stretching, and a discotic compound is preferably used.

The discotic compound used as the Rth retardation increasing agent includes an aromatic heterocyclic ring in addition to the aromatic hydrocarbon ring. In particular, the aromatic hydrocarbon ring is a 6-membered ring (that is, a benzene ring). It is particularly preferred that
The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.
As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.
An aromatic compound is used in 0.01-20 mass parts with respect to 100 mass parts of cellulose acylates. The aromatic compound is preferably used in a range of 0.05 to 15 parts by mass, and more preferably in a range of 0.1 to 10 parts by mass with respect to 100 parts by mass of cellulose acylate. Two or more kinds of compounds may be used in combination.

(Rth control method: method using optically anisotropic layer)
When a cellulose acylate film is used as the second optically anisotropic layer, the second optical anisotropy is used to obtain a desired Re by stretching the cellulose acylate film and to control Rth without affecting the Re. A method in which the functional layer is constituted not only by the cellulose acylate film but also by an optically anisotropic layer made of a liquid crystalline composition is preferably used. For example, a liquid crystalline composition containing at least one discotic liquid crystalline compound is disposed on the surface by coating or the like, and the discotic liquid crystalline compound molecules are aligned in a state where the disc surface is oriented within 5 degrees with respect to the layer surface. An optically anisotropic layer formed in a fixed state (for example, see JP-A-10-32166), a liquid crystalline composition containing a rod-like liquid crystalline compound is disposed on the surface by coating or the like, and rod-like liquid crystalline An optically anisotropic layer (see, for example, Japanese Patent Application Laid-Open No. 2000-304932) formed by fixing a compound molecule in a state where its major axis is oriented within an angle of 5 degrees with respect to the layer surface. It is preferable to form on a cellulose acylate film.

(Arrangement in the liquid crystal display)
When the second optically anisotropic layer is made of a polymer film such as a cellulose acylate film, it can be incorporated into a liquid crystal display device as an optical compensation film that is a single member. Further, it may be disposed between the observer-side polarizing plate and the liquid crystal cell, or may be disposed between the rear-side polarizing plate and the liquid crystal cell. In addition, as a protective film for protecting the polarizing film, a cellulose acylate film or the like that satisfies the optical characteristics required for the second optically anisotropic layer is used, and is incorporated into the liquid crystal display device as a member of a polarizing plate. You can also. Furthermore, it may be formed on a liquid crystal cell substrate in the same manner as the first optically anisotropic layer. Of course, the second optically anisotropic layer may be composed of two or more layers.

(adhesive)
As an adhesive used when adhering a cellulose acylate film or the like used as the second optically anisotropic layer to an optically anisotropic layer comprising a polarizing layer, a substrate or a liquid crystalline composition, And has sufficient adhesive strength and does not impair the optical properties of the liquid crystal material layer, for example, acrylic resin, methacrylic resin, epoxy resin, ethylene-vinyl acetate copolymer system , Rubber-based, urethane-based, polyvinyl ether-based and mixtures thereof, and various reactive types such as thermosetting type and / or photo-curing type and electron beam curable type. These adhesives include those having the function of a transparent protective layer for protecting the liquid crystal substance layer. A pressure-sensitive adhesive can be used as the adhesive.

[Polarizer]
Of the pair of polarizing plates used in the liquid crystal display device of the present invention, at least one preferably includes a polarizing layer and a second optically anisotropic layer.
For the polarizing layer, an iodine polarizing film, a dye polarizing film using a dichroic dye, or a polyene polarizing film can be used. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The absorption axis of the polarizing film corresponds to the stretching direction of the film. Accordingly, the polarizing film stretched in the longitudinal direction (transport direction) has an absorption axis parallel to the longitudinal direction, and the polarizing film stretched in the lateral direction (perpendicular to the transport direction) is perpendicular to the longitudinal direction. Has an absorption axis.

  The preferable manufacturing method of the polarizing plate of this invention includes the process of laminating | stacking a polarizing film and a 2nd optically anisotropic layer continuously in a respectively elongate state. The long polarizing plate is cut according to the screen size of the liquid crystal display device used.

  The polarizing layer generally has a protective film on both surfaces. In the present invention, the second optically anisotropic layer can function as a protective film for the polarizing layer. In such a case, it is not necessary to separately attach a protective film to the surface of the polarizing layer on the second optically anisotropic layer side. In the polarizing plate of the present invention, only an isotropic adhesive layer and / or a substantially isotropic transparent protective film is included between the polarizing layer and the second optically anisotropic layer. It is preferable. Specifically, the substantially isotropic transparent protective film is a film having an in-plane retardation of 0 to 10 nm and a retardation in the thickness direction of -20 to 20 nm. A film containing cellulose acylate or cyclic polyolefin is preferred.

When the second optically anisotropic layer is bonded to the polarizing layer, the slow axis direction of the second optically anisotropic layer and the absorption axis direction of the polarizing layer are substantially orthogonal to each other. It is preferable to do this. The direction of the slow axis of the second optically anisotropic layer made of a specific cellulose acylate film can be adjusted by the stretching direction or the like when producing the cellulose acylate film.
Even when the second optically anisotropic layer is incorporated into the liquid crystal display device as a single member, for example, an optical compensation film, the absorption axis of the polarizing plate disposed at a closer position and the slow axis thereof Are preferably arranged so as to be substantially orthogonal.

[Liquid Crystal Display]
The liquid crystal display device shown in FIG. 5 has a polarizing layer 8 and 22, a second optically anisotropic layer 10, a substrate 12 on which a first optically anisotropic layer 13 is formed, and a substrate 12. And a liquid crystal layer 16 sandwiched between the substrates 12 and 20. The polarizing layers 8 and 22 are sandwiched between the protective film 7 and the second optically anisotropic layers 10 and 21a and 21b, respectively.

  In the liquid crystal display device of FIG. 5, the liquid crystal cell includes substrates 12 and 20 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. Alignment films 14 and 18 are formed on the surfaces of the substrates 12 and 20 that are in contact with the liquid crystal layer 16, and the rubbing process is performed on the alignment films while aligning liquid crystal molecules substantially parallel to the surface of the substrate. The liquid crystal molecule alignment direction in the voltage non-application state or the low application state is controlled by the direction (15 and 19 in FIG. 5) and the like. Further, an electrode (not shown in FIG. 5) capable of applying a voltage to the liquid crystal molecules is formed on the inner surface of the substrate 1220.

  FIG. 4 schematically shows the orientation of liquid crystal molecules in one pixel region of the liquid crystal layer 15. FIG. 4 shows the alignment of the liquid crystal molecules in a very small area corresponding to one pixel of the liquid crystal layer 15 in the rubbing direction 4 of the alignment film formed on the inner surfaces of the substrates 13 and 17 and the substrates 13 and 17. It is the schematic diagram shown with the electrodes 2 and 3 which can apply a voltage to the liquid crystal molecule formed in the inner surface. When active driving is performed using a nematic liquid crystal having positive dielectric anisotropy as a field effect liquid crystal, the liquid crystal molecule alignment directions in a no voltage application state or a low application state are 5a and 5b. A display is obtained. When applied between the electrodes 2 and 3, the liquid crystal molecules change their alignment direction in the directions of 6 a and 6 b in accordance with the voltage. Usually, bright display is performed in this state.

  In FIG. 5 again, the polarizing layers 8 and 22 are arranged with their absorption axes 9 and 23 orthogonal to each other. The slow axis 11 of the second optical anisotropic layer 10 is perpendicular to the absorption axis 9 of the polarizing layer 8 and parallel to the slow axis direction 17 of the liquid crystal molecules in the liquid crystal layer 16 during black display. .

  The first optically anisotropic layer 13 has a Re of 0 to 10 nm and a Rth of −400 to −30 nm, and a composition containing a rod-like liquid crystal compound is applied to the inner surface of the substrate 12 by coating or the like. It is a layer formed by arranging, vertically aligning the molecules of the rod-like liquid crystalline compound and fixing in the aligned state. A vertical alignment film may be disposed between the first optically anisotropic layer 13 and the inner surface of the substrate 12. FIG. 5 shows an in-cell type structure in which the first optically anisotropic layer 13 is disposed in the liquid crystal cell (for example, the liquid crystal cell substrate 30 or 30 ′ shown in FIG. 1 or 2 is used as the substrate 12). However, an embodiment in which the first optically anisotropic layer 13 is provided outside the liquid crystal cell is also included in the present invention. Such an embodiment includes, for example, a liquid crystal display device having the liquid crystal cell substrate 30 ″ shown in FIG.

The second optically anisotropic layer 10 has an in-plane retardation of 20 to 150 nm and is made of a stretched polymer film such as a cellulose acylate film. The second optical anisotropic layer 10 may be incorporated in the liquid crystal display device as an optical compensation film, or the polarizing layer 8, the protective film 7, and the second optical anisotropic layer 10 are laminated. The polarizing plate may be incorporated in a liquid crystal display device. 5 shows a configuration in which the polarizing layer 8 is sandwiched between the protective film 7 and the second optical anisotropic layer 10 that also functions as a protective film. A protective film may be used separately between the isotropic layer 10 and the polarizing layer 8.
The first optical anisotropic layer 13 and the second optical anisotropic layer 10 may be disposed between the liquid crystal cell and the viewing-side polarizing film with reference to the position of the liquid crystal cell. And it may be arrange | positioned between the liquid crystal cell and the polarizing film of the back side.

  In addition, in FIG. 5, 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. 4 and 5 and may include other members. For example, a color filter may be disposed between the liquid crystal layer and the polarizing layer. 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 having a light emitting diode, a field emission element, or an electroluminescent element as a light source can be disposed on the back surface. In this case, the backlight may be arranged on the upper side or the lower side in FIG. 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, as described above, 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 the back side of the liquid crystal cell or the lower side of the liquid crystal cell. A reflective film is disposed on the inner surface of the substrate. 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 a three-terminal or two-terminal semiconductor element such as TFT or MIM. Of course, a mode applied to a passive matrix liquid crystal display device called time-division driving is also effective.

  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.

<Production of IPS mode liquid crystal cell>
(Production of first liquid crystal cell substrate (LCS-2))
A liquid crystal cell substrate 30 having the same configuration as that of FIG. 1 was produced. Specifically, first, a non-alkali glass substrate (NH35 manufactured by NH Techno Glass) 40 having a thickness of 0.7 mm had a shape corresponding to the pattern shown in FIG. 4 using the resin composition for black matrix. A stripe-shaped black matrix and a frame-shaped light shielding portion 35 were formed. Thereafter, a color filter 50 composed of colored films 50R, 50G, and 50B of R (red), G (green), and B (blue) was formed. The thickness of each colored film was 1.90 μm, 2.05 μm, and 2.20 μm, respectively, 50R, 50G, and 50B.

The glass substrate with the color filter prepared above is housed in a vacuum chamber, and a high-frequency electric field of 13.56 MHz is discharged as a mixed atmosphere of helium (He) gas 10 liter / min and tetrafluoroethylene (CF ₄ ) gas 100 cc / min. The color filter surface was fluorinated by setting the power to 300 W to form a vertical alignment film (not shown in the figure).

  25 parts by mass of the rod-shaped liquid crystal compound (I), 1 part by mass of a photopolymerization initiator, and 2 parts by mass of a surfactant are dissolved in 72 parts by mass of chlorobenzene to obtain a coating composition for forming a first birefringence layer. Prepared. At this time, the above-mentioned octadecyldimethyl (3-trimethoxypropyl) ammonium chloride was used as a photopolymerization initiator. Octadodecyldimethyl (3-trimethoxysilylpropyl) ammonium chloride is a vertical alignment agent capable of homeotropic alignment of a polymerizable liquid crystal having a rod-like molecular shape.

  The coating composition for forming the first optical anisotropic layer was spin-coated on the vertical alignment film of the glass substrate to form a coating film, and the coating film was heated at 120 ° C. for 3 minutes. The coating film changed from a cloudy state to a transparent state as it was heated. From this, it was confirmed that the polymerizable liquid crystal in the coating film had undergone a phase transition from the liquid crystal layer to the liquid crystal layer by heating.

While the coating film in which the polymerizable liquid crystal had undergone phase transition was heated to 120 ° C., this coating film was irradiated with ultraviolet rays in a nitrogen gas atmosphere to cross-link the polymerizable liquid crystal in the coating film three-dimensionally. At this time, ultraviolet irradiation was performed using an ultraviolet irradiation apparatus having an ultrahigh pressure mercury lamp under the conditions of irradiation intensity of 30 mW / cm ² and irradiation time of 1 minute.

  By performing the above-described crosslinking step, the polymerizable liquid crystal represented by the formula (I) has a three-dimensionally crosslinked structure and contains the above-described surfactant as a surfactant. A conductive layer 34 was formed. When the film thickness of the first optical anisotropic layer was measured with a laser film thickness meter, the first optical anisotropy formed on each of the R layer 50R, the G layer 50G, and the B layer 50B was measured. The layer thickness d was R: d = 0.85 μm, G: d = 0.70 μm, and B: d = 0.55 μm.

  Further, a polyimide film 60 was provided as an alignment film on the first optical anisotropic layer, and a rubbing treatment was performed to produce a first liquid crystal cell substrate.

(Production of first liquid crystal cell substrate (LCS-1))
In the manufacturing method of the first liquid crystal cell substrate (LCS-2), the thicknesses of the R, G and B layers are all set to 1.9 μm, and the absorbance of each color filter is equal to (LCS-2). Thus, (LCS-1) was prepared. The film thickness of the first optically anisotropic layer was 0.7 μm with respect to all of R, G, and B.

(Production of first liquid crystal cell substrate (LCS-3))
In the manufacturing method of the first liquid crystal cell substrate (LCS-2), the thicknesses of the R, G and B layers are all formed to be 1.9 μm, and the absorbance of each color filter is equivalent to (LCS-2). Thus, (LCS-3) was prepared. It was 2.4 μm with respect to all the film thicknesses R, G, and B of the first optical anisotropic layer.

(Production of first liquid crystal cell substrate (LCS-4))
In the method for manufacturing the first liquid crystal cell substrate (LCS-2), the thicknesses of the R, G, and B layers are 1.9 μm, 2.1 μm, and 2.3 μm, respectively, and the absorbance of each color filter is (LCS- (LCS-4) was prepared by adjusting to be equivalent to 2). The film thickness of the first optically anisotropic layer was 2.6 μm, 2.4 μm, and 2.2 μm for R, G, and B, respectively.

(Production of first liquid crystal cell substrate (LCS-0))
A first liquid crystal cell substrate (LCS-0) was produced in the same manner except that the alignment film and the first optically anisotropic layer were not provided for the first liquid crystal cell substrate (LCS-1).

(Production of liquid crystal cell (LCC-2))
As shown in FIG. 4, electrodes 2 and 3 are arranged on a glass substrate so that the distance between adjacent electrodes is 20 μm, and a polyimide film is provided as an alignment film thereon, and a rubbing treatment is performed. Then, a second liquid crystal cell substrate was produced.
The first liquid crystal cell substrate LCS-2 produced as described above was rubbed in the direction 4 shown in FIG. Two glass substrates are laminated and bonded so that the alignment films are opposed to each other, the distance between the substrates (gap; d) is 3.9 μm, and the rubbing directions of the two substrates are parallel to each other, and then refraction is performed. A nematic liquid crystal compound having a dielectric anisotropy (Δn) of 0.0769 and a dielectric anisotropy (Δε) of 4.5 was sealed to prepare a liquid crystal cell LCC-2. The value of d · Δn of the liquid crystal layer was 300 nm.

(Production of Liquid Crystal Cell (LCC-0) (LCC-1) (LCC-3) (LCS-4))
In the production of the liquid crystal cell (LCC-2), the cell substrate LCS-2 used as the first liquid crystal cell substrate is changed to the cell substrates LCS-0, LCS-1, LCS-3, and LCS-4. Liquid crystal cells LCC-0, LCC-1, LCC-3, and LCC-4 were produced in the same manner except for the changes.

<Preparation of polarizing plate>
(Production of cellulose acylate film PK-3 (second optically anisotropic layer))
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose triacetate solution.

───────────────────────────────────────
Material / solvent composition ────────────────────────────────────
Cellulose acetate (substitution degree 2.77, acetylation degree 59.7%) 100 parts by mass triphenyl phosphate (plasticizer) 6.5 parts by mass biphenyl diphenyl phosphate (plasticizer) 5.2 parts by mass methylene chloride (first solvent) 500 parts by weight Methanol (second solvent) 80 parts by weight The above retardation increasing agent 3.5 parts by weight ─────────────────────────── ─────────

The obtained dope was cast using a casting machine having a band having a width of 2 m and a length of 65 m. After the film surface temperature on the band reached 40 ° C., the film was dried for 1 minute, peeled off, and further dried with 135 ° C. drying air for 20 minutes. Thereafter, the film was uniaxially stretched under a temperature condition of 185 ° C. so that the length after stretching was 135%. In addition, Tg of the used cellulose acylate is 140 degreeC.
The thickness of the produced cellulose acylate film (PK-3) was 88 μm. Using an ellipsometer (M-150, manufactured by JASCO Corporation), the retardation value (Re) at a wavelength of 550 nm after being conditioned for 2 hours in an environment of 25 ° C. and 55% RH is 70 nm. there were. Further, the retardation value (Rth) at a wavelength of 550 nm was measured and found to be 64 nm.
Similarly, the retardation values (Re) at wavelengths of 450 nm and 650 nm were measured and found to be 49 nm and 92 nm, respectively. Moreover, when the retardation value (Rth) in wavelength 450nm and 650nm was measured, they were 45nm and 75nm, respectively.
That is, the produced cellulose acylate film (PK-3) had an A1 value of 0.70 and an A2 value of 1.31. The B1 value was 1.00, and the B2 value was 1.12.

A 1.0 N potassium hydroxide solution (solvent: water / isopropyl alcohol / propylene glycol = 69.2 mass parts / 15 mass parts / 15.8 masses) is formed on the band surface side of the produced cellulose acylate film (PK-3). Part) was applied at 10 cc / m ² and kept at a temperature of about 40 ° C. for 30 seconds, then the alkaline solution was scraped off, washed with pure water, and water droplets were removed with an air knife. Then, it dried at 100 degreeC for 15 second. It was 42 degrees when the contact angle with respect to the pure water of this film (PK-3) was calculated | required.

(Preparation of polarizing plate (P1))
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm continuously dyed in an aqueous iodine solution was stretched 5 times in the transport direction and dried to obtain a long polarizing film. The cellulose acetate film (PK-3) saponified on one side of this polarizing film, and a commercially available cellulose acylate film (Fujitac TD80UL, Fuji Film Co., Ltd.) saponified on the other side were made of polyvinyl alcohol. A polarizing plate (P1) was produced by continuously bonding using an adhesive.

(Preparation of cellulose acetate film (T0))
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acetate solution A.
Composition of cellulose acetate solution A ――――――――――――――――――――――――――――――――――――
Cellulose acetate with an acetyl substitution degree of 2.94 100.0 parts by mass Methylene chloride (first solvent) 402.0 parts by mass Methanol (second solvent) 60.0 parts by mass ――――――――――――― ――――――――――――――――――――――

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

The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.
Additive solution composition ――――――――――――――――――――――――――――――
The following optical anisotropy reducing agent 49.3 parts by mass The following wavelength dispersion adjusting agent 4.9 parts by mass Methylene chloride (first solvent) 58.4 parts by mass Methanol (second solvent) 8.7 parts by mass Cellulose acetate Solution A 12.8 parts by mass ――――――――――――――――――――――――――――――

  94.6 parts by mass of the cellulose acetate solution A, 1.3 parts by mass of the matting agent solution, and 4.1 parts by mass of the additive solution were mixed after filtration, and cast using a band casting machine. The mass ratio of the compound that reduces optical anisotropy and the wavelength dispersion adjusting agent to cellulose acetate in the above composition was 12% and 1.2%, respectively. The film was peeled from the band with a residual solvent amount of 30%, and dried at 140 ° C. for 40 minutes to produce a long cellulose acetate film T0 having a thickness of 80 μm. The in-plane retardation (Re) of the obtained film was 1 nm (the slow axis was perpendicular to the film longitudinal direction), and the thickness direction retardation (Rth) was −1 nm.

<Production of Polarizing Plate (P0)>
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm continuously dyed in an aqueous iodine solution was stretched 5 times in the transport direction and dried to obtain a long polarizing film. A polyvinyl alcohol-based adhesive was prepared by using the cellulose acetate film T0 saponified on one side of the polarizing film and a commercially available cellulose acetate film (Fujitac TD80UL, manufactured by Fuji Photo Film Co., Ltd.) on the other side. Was continuously bonded together to produce a polarizing plate P0.

(Preparation of cellulose acylate film T1 (second optically anisotropic layer))
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.

──────────────────────────────────
Cellulose acetate solution composition ──────────────────────────────────
Cellulose acetate having an acetylation degree of 60.9% (degree of polymerization: 300, Mn / Mw = 1.5) 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 parts by weight Methanol (second solvent) 54 parts by weight 1-butanol (third solvent) 11 parts by weight ──────────────────── ──────────────

  In another mixing tank, 16 parts by mass of the above-mentioned retardation increasing agent A, 8 parts by mass of the following retardation increasing agent B, 0.28 parts by mass of silicon dioxide fine particles (average particle size: 0.1 μm), methylene chloride 80 parts by mass and 20 parts by mass of methanol were added and stirred while heating to prepare a retardation increasing agent solution (and a fine particle dispersion). The dope was prepared by mixing 45 parts by mass of the retardation increasing agent solution with 474 parts by mass of the cellulose acetate solution and stirring sufficiently.

Retardation increasing agent (A)

Retardation raising agent B

  The obtained dope was cast using a casting machine having a band having a width of 2 m and a length of 65 m. A film having a residual solvent amount of 15% by mass was stretched transversely at a stretch ratio of 20% using a tenter under the conditions of 130 ° C., held at 50 ° C. for 30 seconds with the stretched width, and then clipped to remove cellulose. An acetate film was prepared. The residual solvent amount at the end of stretching was 5% by mass, and further dried to prepare a cellulose acetate film (T1) with the residual solvent amount being less than 0.1% by mass. In addition, Tg of the used cellulose acylate is 140 degreeC.

The resulting cellulose acetate film (T1) had a width of 1340 mm and a thickness of 88 μm. When the in-plane retardation (Re) at a wavelength of 550 nm was measured, it was 60 nm. The retardation (Rth) in the thickness direction was 190 nm.
Similarly, the in-plane retardation (Re) values at wavelengths of 450 nm and 650 nm were 63 nm and 58 nm, respectively. The retardation (Rth) values in the thickness direction at wavelengths of 450 nm and 650 nm were 194 nm and 188 nm, respectively.

  That is, A1 value = 1.05 and A2 value = 0.97. B1 value = 1.03 and B2 value = 0.98.

(Preparation of polarizing plate (P2))
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm continuously dyed in an aqueous iodine solution was stretched 5 times in the transport direction and dried to obtain a long polarizing film. The cellulose acetate film (T1) saponified on one side of the polarizing film and a commercially available cellulose acetate film (Fujitac TD80UL, manufactured by Fuji Photo Film Co., Ltd.) saponified on the other side were made of polyvinyl alcohol. A polarizing plate (P2) was produced by continuously bonding using an adhesive.

<Mounting evaluation with liquid crystal display devices>
A polarizing plate (P1) and a polarizing plate (P0) were bonded to the upper and lower glass substrates of the horizontal alignment cell (LCC-1) using an adhesive. At this time, the cellulose acylate film contained in the polarizing plate (P0) so that the second optical anisotropic layer (PK-3) contained in the polarizing plate (P1) is in contact with the viewer-side glass substrate. Bonding was performed such that (T0) was in contact with the glass substrate on the backlight side. In addition, the absorption axis of the polarizing plate (P1) and the rubbing direction of the liquid crystal cell were made parallel, and the absorption axes of the polarizing plate (P1) and the polarizing plate (P0) were orthogonal to each other.
A rectangular wave voltage of 55 Hz was applied to the liquid crystal cell. A normally black mode with 5 V white display and 0 V black display was set. The leakage light in the front direction in black display and in the oblique direction (azimuth angle 45 °, polar angle ± 60 °) was evaluated visually according to the following criteria.

(Light leakage evaluation)
A: Almost no light leakage can be seen.
○: There is light leakage when viewed closely.
Δ: Slight light leakage can be seen.
X: Light leakage is clearly visible.

  For the liquid crystal display device (L1), the liquid crystal cell and the polarizing plate on the viewer side are changed as shown in Table 1, and liquid crystal display devices (L0) and (L2) to (L4) are produced and the same as described above. Evaluation was performed. These results are shown in Table 1.

From the above results, the following is clear.
The liquid crystal display device of the present invention equipped with the first optical anisotropic layer showing the predetermined optical characteristics and the second optical anisotropic layer showing the predetermined optical characteristics had less light leakage in the oblique direction. . In particular, by optimizing the film thickness of the first optically anisotropic layer formed on the surface of the liquid crystal cell substrate for each color, it was possible to reduce the leakage light and coloring in the oblique direction. In addition, by controlling the wavelength dispersion of the second optically anisotropic layer, it is possible to further reduce oblique light leakage and coloring.

It is a schematic sectional drawing of an example of the board | substrate for liquid crystal cells which can be used for the liquid crystal display device of this invention. It is a schematic sectional drawing of an example of the board | substrate for liquid crystal cells which can be used for the liquid crystal display device of this invention. It is a schematic sectional drawing of an example of the board | substrate for liquid crystal cells which can be used for the liquid crystal display device of this invention. It is the schematic which shows the pixel area example of the IPS mode liquid crystal display device of this invention. It is a schematic diagram of an 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 7 First protective film for polarizing layer 8 First Polarizing layer 9 Polarization absorption axis 10 of the first polarizing layer Second optical anisotropic layer (also protective film for the first polarizing layer)
11 Slow axis 12 of second optical anisotropic layer 1st substrate 13 1st optical anisotropic layer 14 1st alignment film 15 rubbing direction 16 of 1st alignment film liquid crystal layer 17 in liquid crystal layer Slow axis direction 18 of liquid crystal molecules Second alignment film 19 Rubbing direction 20 of second alignment film Second substrate 21a, 21b Second protective layer 22 for polarizing layer Second polarizing layer 23 Second polarized light Layer absorption axis 30, 30 ', 30 "liquid crystal cell substrate 34, 34', 34" first optical anisotropic layer 35 light shielding layer 40 substrate 50, 50 ', 50 "color filter 60 alignment film

Claims (17)

A liquid crystal cell having a first polarizing layer, a pair of substrates, and a liquid crystal layer sandwiched between the pair of substrates and having liquid crystal molecules aligned substantially parallel to the substrate during black display; A first optically anisotropic layer disposed between the polarizing layer and the liquid crystal layer, having an in-plane retardation of 0 to 10 nm and a thickness direction retardation of −400 to −30 nm; A second optically anisotropic layer having an inner retardation of 20 to 150 nm, wherein at least the first optically anisotropic layer is the first of the pair of substrates. A layer formed on a substrate (first substrate) disposed closer to the polarizing layer, and the second optically anisotropic layer includes the first optically anisotropic layer and the first optically anisotropic layer. The liquid crystal display device arrange | positioned between the polarizing layers. The first optically anisotropic layer is made of a composition containing a rod-like liquid crystalline compound, and in the first optically anisotropic layer, the molecules of the rod-like liquid crystalline compound are substantially in a layer plane. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is fixed in a vertically aligned state. 3. The liquid crystal display device according to claim 1, wherein the first substrate further includes a pixel including a plurality of colored layers having different hues. 4. The first optically anisotropic layer is patterned into a plurality of regions corresponding to the arrangement of the colored layers, and each region has a thickness direction different depending on the hue of the colored layer located below or above the regions. The liquid crystal display device according to claim 3, which exhibits a retardation value. The first optically anisotropic layer is patterned into a plurality of regions corresponding to the arrangement of the colored layers, and each region has a thickness direction different depending on the hue of the colored layer located below or above the regions. The liquid crystal display device according to claim 3, wherein the liquid crystal display devices have different film thicknesses so as to exhibit a retardation value. In the second optically anisotropic layer, the A1 value defined by the following formula (1) is in the range of 0.10 to 0.95, and the A2 value defined by the following formula (2) is 1. It is the range of 01-1.50, The liquid crystal display device of any one of Claims 1-5:
(1): A1 value = Re (450) / Re (550)
(2): A2 value = Re (650) / Re (550)
In the formula, Re (λ) is an in-plane retardation value for light having a wavelength of λ nm. In the second optically anisotropic layer, the B1 value defined by the following formula (3) is in the range of 0.40 to 0.95, and the B2 value defined by the following formula (4) is 1. It is the range of 05-1.93, The liquid crystal display device of any one of Claims 1-6:
(3): B1 value = {Re (450) / Rth (450)} / {Re (550) / Rth (550)}
(4): B2 value = {Re (650) / Rth (650)} / {Re (550) / Rth (550)}
In the formula, Re (λ) is an in-plane retardation value for light having a wavelength of λnm, and Rth (λ) is a retardation value in the thickness direction for light having a wavelength of λnm. The liquid crystal display device according to claim 1, wherein the second optically anisotropic layer is a transparent protective film of the first polarizing layer. The liquid crystal display device according to claim 1, wherein the second optically anisotropic layer is a biaxial transparent plastic film. The liquid crystal display device according to claim 1, wherein the second optically anisotropic layer is a biaxial cellulose acylate film. Only a substantially isotropic adhesive layer and / or a substantially isotropic transparent protective film is included between the second optically anisotropic layer and the first polarizing layer. The liquid crystal display device according to claim 1. The liquid crystal display device according to claim 11, wherein the transparent protective film is a film containing cellulose acylate or cyclic polyolefin, and has an in-plane retardation of 0 to 10 nm and a retardation in a thickness direction of -20 to 20 nm. The liquid crystal according to any one of claims 1 to 12, wherein the second optically anisotropic layer is disposed so that a slow axis thereof is substantially orthogonal to an absorption axis of the first polarizing layer. Display device. 14. The liquid crystal display device according to claim 13, wherein the second optically anisotropic layer is arranged so that a slow axis thereof is substantially parallel to a major axis direction of liquid crystal molecules in the liquid crystal layer during black display. . The first polarizing layer further includes a second polarizing layer disposed so as to sandwich the liquid crystal cell, and the absorption axes of the first and second polarizing layers are orthogonal to each other. The liquid crystal display device according to any one of the above. A substantially isotropic adhesive layer and / or a substantially isotropic layer between the second polarizing layer and a substrate (second substrate) located closer to the pair of substrates. The liquid crystal display device according to any one of claims 1 to 15, wherein only a transparent protective film is included. The liquid crystal display device according to claim 16, wherein the transparent protective film is a film containing cellulose acylate or cyclic polyolefin, and has an in-plane retardation of 0 to 10 nm and a thickness direction retardation of -20 to 20 nm.

Images