TW201447429A - Laminated polarizing plate and horizontal alignment liquid crystal display device - Google Patents

Abstract

Provided are a laminated polarizing plate having superior field of view characteristics and a horizontal alignment liquid crystal display device. The laminated polarizing plate results from laminating, in the given order, at least a first polarizing plate, a first optically anisotropic layer, and a second optically anisotropic layer. The first optically anisotropic layer satisfies [1]-[7], the second optically anisotropic layer satisfies [8] and [9], and the first optically anisotropic layer and second optically anisotropic layer satisfy [10]. [1]: 50 nm ≤ Re1 (550) ≤ 200 nm. [2]: 30 nm ≤ Rth1 (550) ≤ 330 nm. [3]: 0.5 ≤ Rth1 (550)/Re1 (550) ≤ 1.5. [4]: 0.7 ≤ Re1 (450)/Re1 (550) < 1.1. [5]: 0.7 ≤ Rth1 (450)/Rth1 (550) < 1.1. [6]: 0.95 ≤ Re1 (650)/Re1 (550) < 1.2. [7]: 0.95 ≤ Rth1 (650)/Rth1 (550) < 1.2. [8]: -10 nm ≤ Re2 (550) ≤ 10 nm. [9]: -200 nm ≤ Rth2 (550) ≤ -50 nm. [10]: -60 nm ≤ Rth1 (550) + Rth2 (550) ≤ 60 nm. (Here, Re and Re 2 are the in-plane retardation values for the first and second optically anisotropic layers, and Rth1 and Rth2 are the thickness-direction retardation values of the first and second optically anisotropic layers.)

Description

Multilayer polarizing plate and horizontal alignment type liquid crystal display device

The present invention relates to a laminated polarizing plate and a horizontal alignment type liquid crystal display device which are excellent in viewing angle characteristics.

In one of the display modes of the liquid crystal display device, in the initial state, the liquid crystal molecules in the liquid crystal cell are arranged in a horizontal alignment pattern in parallel with the substrate surface (Patent Document 1). When no voltage is applied, the liquid crystal molecules are arranged in parallel to the surface of the substrate, and if the linear polarizing plates are arranged orthogonally on both sides of the liquid crystal cell, a black display can be obtained.

When a voltage is applied, the liquid crystal molecules are rotated from the direction parallel to the surface of the substrate to the direction of the electric field, and as a result, a bright display can be obtained.

The black display of the horizontal alignment type liquid crystal display device can obtain a good black display in the front field of view, but light leakage occurs in the oblique field of view, resulting in a problem of a decrease in contrast.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] US Patent No. 3,807,831

An object of the present invention is to provide a laminated polarizing plate for a horizontal alignment type liquid crystal display device and a horizontal alignment type liquid crystal display device which are excellent in viewing angle characteristics.

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be attained by the laminated polarizing plate for a horizontal alignment type liquid crystal display device and a horizontal alignment type liquid crystal display device using the same. this invention.

That is, the present invention is as follows.

[1] A laminated polarizing plate in which at least a first polarizing plate, a first optical anisotropic layer, and a second optical anisotropic layer are laminated, wherein the first optical device is characterized in that: The anisotropic layer satisfies the following [1] to [7], and the second optical anisotropic layer satisfies the following [8] to [9], the first optical anisotropic layer and the above 2 The optical anisotropic layer satisfies the following [10].

[1] 50nm ≦ Re1 (550) ≦ 200nm

[2] 30nm≦Rth1(550)≦300nm

[3]0.5≦Rth1(550)/Re1(550)≦1.5

[4]0.7≦Re1(450)/Re1(550)<1.1

[5]0.7≦Rth1(450)/Rth1(550)<1.1

[6]0.95≦Re1(650)/Re1(550)<1.2

[7]0.95≦Rth1(650)/Rth1(550)<1.2

(wherein Re1 (450), Re1 (550), and Re1 (650) refer to delay values in the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively; Rth1 (450), Rth1 (550) and Rth1 (650) refer to thickness direction retardation values of the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. Re1 (450), Re1 (550) and Re1 (650), and Rth1 (450), Rth1 (550), and Rth1 (650) are respectively Re1 (450) = (nx1 (450) - ny1 (450)) × d1 [nm], Re1 (550) = (nx1 (550) - ny1 (550)) × d1 [nm], Re1 (650) = (nx1 (650) - ny1 (650)) × d1 [nm], Rth1 ( 450)={(nx1(450)+ny1(450))/2-nz1(450)}×d1[nm], Rth1(550)={(nx1(550)+ny1(550))/2-nz1 (550)}×d1[nm], Rth1(650)={(nx1(650)+ny1(650))/2-nz1(650)}×d1[nm]. Further, d1 is the thickness of the first optical anisotropic layer; nx1 (450), nx1 (550), and nx1 (650) are respectively in the first optical anisotropic layer of light having wavelengths of 450, 550, and 650 nm. The maximum principal refractive index; ny1 (450), ny1 (550), and ny1 (650) are principal refractive indices orthogonal to the orientations of nx1 (450), nx1 (550), and nx1 (650), respectively; nz1 (450), Nz1 (550) and nz1 (650) are principal refractive indices in the thickness direction of light of wavelengths of 450, 550, and 650 nm, respectively; nx1 (550) > ny1 (550) > nz1 (550). )

[8]-10nm≦Re2(550)≦10nm

[9]-200nm≦Rth2(550)≦-50nm

(Re2 (550) is the retardation value in the second optical anisotropic layer of light having a wavelength of 550 nm; and Rth2 (550) is the retardation in the thickness direction of the second optical anisotropic layer of light having a wavelength of 550 nm. Values: Re2(550) and Rth2(550) are Re2(550)={nx2(550)-ny2(550)}×d2[nm], Rth2(550)=[{nx2(550)+ny2(550, respectively) }/2-nz2(550)]×d2[nm]. Further, d2 is the thickness of the second optical anisotropic layer; nx2(550) is in the second optical anisotropic layer of light having a wavelength of 550 nm. The maximum principal refractive index; ny2 (550) is the principal refractive index of the orientation orthogonal to nx2 (550); nz2 (550) is the thickness of the main refractive index of the wavelength of 550 nm; nz2 (550) > Nx2(550)=ny2. )

[10]-60nm≦Rth1(550)+Rth2(550)≦60nm

[2] The laminated polarizing plate according to the above [1], wherein the second optical anisotropic layer is formed by vertically aligning the liquid crystal composition having a positive uniaxiality in a liquid crystal state. The vertical alignment liquid crystal film is formed.

[3] The laminated polarizing plate according to the above [2], wherein the liquid crystal composition having a positive uniaxiality contains a side chain type liquid crystalline polymer having an oxetane group.

[4] The laminated polarizing plate according to any one of the above [1], wherein the first optical anisotropic layer contains polycarbonate or a cyclic polyolefin.

[5] The laminated polarizing plate according to any one of the above [1], wherein an angle between an absorption axis of the first polarizing plate and a slow axis of the first optical anisotropic layer is set to be When r, it is laminated in such a manner as to satisfy 85°≦r≦95°.

[6] A horizontal alignment type liquid crystal display device in which at least a first polarizing plate, a first optical anisotropic layer, a second optical anisotropic layer, a horizontal alignment type liquid crystal cell, and a second polarized light are disposed in order In the horizontal alignment type liquid crystal display device of the present invention, the first optical anisotropic layer satisfies the following [1] to [7]; and the second optical anisotropic layer satisfies the following [8]. ~[9]; The first optical anisotropic layer and the second optical anisotropy layer satisfy the following [10].

[1] 50nm ≦ Re1 (550) ≦ 200nm

[2] 30nm≦Rth1(550)≦300nm

[3]0.5≦Rth1(550)/Re1(550)≦1.5

[4]0.7≦Re1(450)/Re1(550)<1.1

[5]0.7≦Rth1(450)/Rth1(550)<1.1

[6]0.95≦Re1(650)/Re1(550)<1.2

[7]0.95≦Rth1(650)/Rth1(550)<1.2

(wherein Re1 (450), Re1 (550), and Re1 (650) refer to delay values in the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively; Rth1 (450), Rth1 ( 550) and Rth1 (650) are thickness direction retardation values of the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively, Re1 (450), Re1 (550), and Re1 (650), and Rth1 (450), Rth1 (550), and Rth1 (650) are respectively Re1 (450) = (nx1 (450) - ny1 (450)) × d1 [nm], Re1 (550) = (nx1 (550) - ny1 (550)) × d1 [nm], Re1 (650) = (nx1 (650) - ny1 (650)) × d1 [nm], Rth1 (450) = {(nx1 (450) + ny1 (450)) / 2-nz1(450)}×d1[nm], Rth1(550)={(nx1(550)+ny1(550))/2-nz1(550)}×d1[nm], Rth1(650)={ (nx1(650)+ny1(650))/2-nz1(650)}×d1[nm]. Further, d1 is the thickness of the first optical anisotropic layer; nx1 (450), nx1 (550), Nx1 (650), ny1 (450), ny1 (550), and ny1 (650) are principal refractive indices in the first optical anisotropy plane of wavelengths of 450, 550, and 650 nm, respectively; nz1 (450), nz1 (550) and nz1 (650) are principal refractive indices in the thickness direction of light of wavelengths of 450, 550, and 650 nm, respectively; nx1 (550) > ny1 (550) > nz1 (550).

[8]-10nm≦Re2(550)≦10nm

[9]-200nm≦Rth2(550)≦-50nm

(wherein Re2 (550) means a retardation value in a second optical anisotropic layer at a wavelength of 550 nm; Rth2 (550) means a thickness direction of a second optical anisotropic layer of light having a wavelength of 550 nm. Delay value. Re2 (550) and Rth2 (550) are Re2 (550) = {nx2 (550) - ny2 (550)} × d2 [nm], Rth2 (550) = [{nx2 (550) + ny2 ( 550)}/2-nz2(550)]×d2[nm]. Further, d2 is the thickness of the second optical anisotropic layer; nx2(550) is the second optical anisotropic layer of light with a wavelength of 550 nm. The maximum principal refractive index; ny2(550) is the principal refractive index of the orientation orthogonal to nx2(550); nz2(550) is the thickness-direction principal refractive index of the wavelength of 550nm light; nz2(550)>nx2(550 )=ny2.)

[10]-60nm≦Rth1(550)+Rth2(550)≦60nm

[7] A horizontal alignment type liquid crystal display device in which at least a first polarizing plate, a first optical anisotropic layer, a second optical anisotropic layer, a horizontal alignment type liquid crystal cell, and a third optical are disposed in order The horizontal alignment type liquid crystal display device of the non-isotropic layer and the second polarizing plate, wherein the first optical anisotropic layer satisfies the following [1] to [7]; and the second optical anisotropic layer The following [8] to [9] are satisfied; the first optical anisotropic layer and the second optical anisotropy layer satisfy the following [10]; the third optical anisotropic layer satisfies The following [11]~[12].

[1] 50nm ≦ Re1 (550) ≦ 200nm

[2] 30nm≦Rth1(550)≦300nm

[3]0.5≦Rth1(550)/Re1(550)≦1.5

[4]0.7≦Re1(450)/Re1(550)<1.1

[5]0.7≦Rth1(450)/Rth1(550)<1.1

[6]0.95≦Re1(650)/Re1(550)<1.2

[7]0.95≦Rth1(650)/Rth1(550)<1.2

(wherein Re1 (450), Re1 (550), and Re1 (650) refer to delay values in the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively; Rth1 (450), Rth1 ( 550) and Rth1 (650) are thickness direction retardation values of the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively, Re1 (450), Re1 (550), and Re1 (650), and Rth1 (450), Rth1 (550), and Rth1 (650) are respectively Re1 (450) = (nx1 (450) - ny1 (450)) × d1 [nm], Re1 (550) = (nx1 (550) - ny1 (550)) × d1 [nm], Re1 (650) = (nx1 (650) - ny1 (650)) × d1 [nm], Rth1 (450) = {(nx1 (450) + ny1 (450)) / 2-nz1(450)}×d1[nm], Rth1(550)={(nx1(550)+ny1(550))/2-nz1(550)}×d1[nm], Rth1(650)={ (nx1(650)+ny1(650))/2-nz1(650)}×d1[nm]. Further, d1 is the thickness of the first optical anisotropic layer; nx1 (450), nx1 (550), Nx1 (650) is the maximum principal refractive index in the first optical anisotropic layer of light of wavelengths 450, 550, and 650 nm, respectively; ny1 (450), ny1 (550), and ny1 (650) are orthogonal to nx1, respectively. The main refractive indices of the orientations of (450), nx1 (550), and nx1 (650); nz1 (450), nz1 (550), and nz1 (650) are the main directions of the thickness direction of the wavelengths of 450, 550, and 650 nm, respectively. Rate; nx1 (550)> ny1 (550)> nz1 (550)).

[8]-10nm≦Re2(550)≦10nm

[9]-200nm≦Rth2(550)≦-50nm

(wherein Re2 (550) means a retardation value in a second optical anisotropic layer at a wavelength of 550 nm; Rth2 (550) means a thickness direction of a second optical anisotropic layer of light having a wavelength of 550 nm. Delay value. Re2 (550) and Rth2 (550) are Re2 (550) = {nx2 (550) - ny2 (550)} × d2 [nm], Rth2 (550) = [{nx2 (550) + ny2 ( 550)}/2-nz2(550)]×d2[nm]. Also, d2 is the second The thickness of the optical anisotropic layer; nx2 (550) is the maximum principal refractive index in the second optical anisotropic layer of light having a wavelength of 550 nm; ny2 (550) is orthogonal to the orientation of nx2 (550). Refractive index; nz2 (550) is a thickness direction main refractive index for light having a wavelength of 550 nm; nz2 (550) > nx2 (550) = ny2. )

[10]-60nm≦Rth1(550)+Rth2(550)≦60nm

[11]-10nm≦Re3(550)≦10nm

[12]-10nm≦Rth3(550)≦10nm

(wherein Re3 (550) refers to the retardation value in the third optical anisotropic layer at a wavelength of 550 nm; Rth3 (550) refers to the thickness of the third optical anisotropic layer at a wavelength of 550 nm. Direction delay value. Re3 (550) and Rth3 (550) are respectively Re3 (550) = (nx3 (550) - ny3 (550)) × d3 [nm], Rth3 (550) = {(nx3 (550) + ny3 (550))/2-nz3(550)}×d3[nm]. Further, d3 is the thickness of the third optical anisotropic layer; nx3 (550) and ny3 (550) are the third for the wavelength of 550 nm. The main refractive index in the optical anisotropic layer; nz3 (550) is the thickness direction main refractive index of light with a wavelength of 550 nm; nx3 (550) ≧ ny 3 (550) ≧ nz 3 (550).

[8] The horizontal alignment type liquid crystal display device according to the above [6], wherein the second optical anisotropic layer is formed by a liquid crystal composition having a positive uniaxiality in a liquid crystal state. After the vertical alignment, the alignment is performed on the fixed vertical alignment liquid crystal film.

[9] The horizontal alignment type liquid crystal display device according to the above [8], wherein the liquid crystal composition having a positive uniaxiality contains a side chain type liquid crystalline polymer having an oxetane group.

The horizontal alignment type liquid crystal display device according to any one of the above aspects, wherein the first optical anisotropic layer contains polycarbonate or a cyclic polyolefin.

The horizontal alignment type liquid crystal display device according to any one of the above-mentioned [6], wherein the absorption axis of the first polarizing plate and the slow axis of the first optical anisotropic layer are When the angle is set to r, the layer is laminated in such a manner as to satisfy 85°≦r≦95°.

[12] The horizontal alignment type liquid crystal display device according to the above [11], wherein the angle between the absorption axis of the first polarizing plate and the absorption axis of the second polarizing plate is s, and satisfies 85°≦s≦ When the angle between the absorption axis of the second polarizing plate and the liquid crystal axis of the horizontal alignment type liquid crystal cell is set to t, the layer is laminated so as to satisfy -5°≦t≦5°.

The horizontal alignment type liquid crystal display device of the present invention displays bright and omnidirectional high contrast display.

1‧‧‧1st polarizer

2‧‧‧Protective film

3‧‧‧1st optical anisotropic layer

4‧‧‧2nd optical anisotropic layer

5‧‧‧Laminated polarizing plate

6, 8‧‧‧ substrate

7‧‧‧Transparent electrode

9‧‧‧Liquid layer (horizontal alignment)

10‧‧‧Horizontal alignment liquid crystal cell

11‧‧‧2nd polarizer

12‧‧‧3rd optical anisotropic layer

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view showing a laminated polarizing plate of the present invention.

2 is a schematic cross-sectional view showing a horizontal alignment type liquid crystal display device used in Embodiment 2.

Fig. 3 is a plan view showing the angular relationship of each constituent member of the horizontal alignment type liquid crystal display device used in the second embodiment.

Fig. 4 is a view showing the contrast of the horizontal alignment type liquid crystal display device of the second embodiment when viewed from all directions.

5 is a pair of the horizontal alignment type liquid crystal display device of Embodiment 3 when viewed from all directions. Ratio chart.

Fig. 6 is a view showing the contrast of the horizontal alignment type liquid crystal display device of the fourth embodiment when viewed from all directions.

Fig. 7 is a schematic cross-sectional view showing a horizontal alignment type liquid crystal display device used in the fifth embodiment.

Fig. 8 is a plan view showing the angular relationship of each constituent member of the horizontal alignment type liquid crystal display device used in the fifth embodiment.

Fig. 9 is a view showing the contrast of the horizontal alignment type liquid crystal display device of the fifth embodiment when viewed from all directions.

Fig. 10 is a view showing a contrast ratio when the horizontal alignment type liquid crystal display device of Comparative Example 1 is viewed from all directions.

Fig. 11 is a view showing the contrast of the horizontal alignment type liquid crystal display device of Comparative Example 2 when viewed from all directions.

Fig. 12 is a view showing the contrast of the horizontal alignment type liquid crystal display device of Comparative Example 3 when viewed from all directions.

Fig. 13 is a view showing the contrast when the horizontal alignment type liquid crystal display device of Comparative Example 4 is viewed from all directions.

Hereinafter, the present invention will be described in detail.

As shown in FIG. 1, the laminated polarizing plate of the present invention has a laminated polarizing plate of a first polarizing plate, a first optical anisotropic layer, and a second optical anisotropic layer, at least in sequence.

Hereinafter, the constituent members used in the present invention will be described in order.

First, the horizontal alignment type liquid crystal cell used in the present invention will be described. liquid crystal The unit is not particularly limited and may be, for example, a liquid crystal cell such as a penetrating type, a reflective type, or a semi-transmissive type. The driving method of the liquid crystal cell is not particularly limited, and may be a passive matrix method used for an STN-LCD or the like, a TFT (Thin Film Transistor) electrode, a TFD (Thin Film Diode) electrode, or the like. Any driving method such as active matrix mode and plasma addressing mode of the active electrode.

The transparent substrate constituting the liquid crystal cell is not particularly limited as long as the liquid crystal material constituting the liquid crystal layer is aligned in a specific alignment direction. Specifically, the substrate itself may have a transparent substrate having a liquid crystal alignment property, and the substrate itself may be provided with a transparent substrate having an alignment film or the like having a liquid crystal alignment property, although it lacks an alignment ability. Further, a known material such as ITO can be used as the electrode of the liquid crystal cell. The electrode may be disposed on the transparent substrate surface that the liquid crystal layer contacts, and may be disposed between the substrate and the alignment film when the substrate having the alignment film is used.

The material which forms a liquid crystal layer having a liquid crystal property is based on a material having a positive dielectric constant anisotropy, and the rest thereof is not particularly limited, and for example, various ordinary low molecular liquid crystal materials and polymer liquid crystals which can constitute various liquid crystal cells can be used. Substances and mixtures of these. Further, a coloring matter, a non-liquid crystalline substance, or the like may be added in such a range as not to impair the liquid crystallinity.

In the horizontal alignment type liquid crystal display device of the present invention, in addition to the above-described constituent members, other constituent members may be attached. For example, by providing a color filter attached to the liquid crystal display device of the present invention, it is possible to produce a color liquid crystal display device capable of performing color or full color display with high color purity.

Next, the optical anisotropic layer used in the present invention will be described in order.

First, the first optical anisotropic layer will be described.

The first optical anisotropic layer can be, for example, to be composed of, for example, polycarbonate a cyclic polyolefin such as an olefinic resin; a film formed of a suitable polymer such as polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene, or other polyolefin, polyarylate, or polyamide; Or a biaxial stretching treatment method, or a birefringent film produced by a method of thermally shrinking a width direction of a long film and increasing a phase difference in a thickness direction by using a heat shrinkable film disclosed in Japanese Laid-Open Patent Publication No. Hei 5-157911; An alignment film made of a liquid crystal material such as a liquid crystal polymer; or an alignment layer in which a liquid crystal material is supported by a film.

When the direction in which the in-plane principal refractive index is the largest in the in-plane direction is the x direction, the orthogonal direction in the x direction is the y direction, and the thickness direction is the z direction, the positive uniaxial optical anisotropy The refractive index of the layer has a relationship of nx>ny=nz. Further, the refractive index of the positive biaxial optical anisotropic layer has a relationship of nx>nz>ny. The refractive index of the negative uniaxial optical anisotropic layer has a relationship of nx=ny>nz. The refractive index of the negative biaxial optical anisotropic layer has a relationship of nx>ny>nz.

The first optical anisotropic layer contributes to the viewing angle compensation of the first polarizing plate, and it is necessary to satisfy the following [1] to [7]:

[1] 50nm ≦ Re1 (550) ≦ 200nm

[2] 30nm≦Rth1(550)≦300nm

[3]0.5≦Rth1(550)/Re1(550)≦1.5

[4]0.7≦Re1(450)/Re1(550)<1.1

[5]0.7≦Rth1(450)/Rth1(550)<1.1

[6]0.95≦Re1(650)/Re1(550)<1.2

[7]0.95≦Rth1(650)/Rth1(550)<1.2

In the above [1] to [7], Re1 (450), Re1 (550), and Re1 (650) refer to retardation values in the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively; Rth1 (450), Rth1 (550), and Rth1 (650) refer to thickness direction retardation values of the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. Re1 (450), Re1 (550) and Re1 (650), and Rth1 (450), Rth1 (550), and Rth1 (650) are respectively Re1 (450) = (nx1 (450) - ny1 (450)) × d1 [nm], Re1 (550) = (nx1 (550) - ny1 (550)) × d1 [nm], Re1 (650) = (nx1 (650) - ny1 (650)) × d1 [nm], Rth1 ( 450)={(nx1(450)+ny1(450))/2-nz1(450)}×d1[nm], Rth1(550)={(nx1(550)+ny1(550))/2-nz1 (550)}×d1[nm], Rth1(650)={(nx1(650)+ny1(650))/2-nz1(650)}×d1[nm]. Further, the thickness of the d1-type first optical anisotropic layer, nx1 (450), nx1 (550), and nx1 (650) are respectively in the first optical anisotropic layer of light having wavelengths of 450, 550, and 650 nm. The maximum principal refractive index; ny1 (450), ny1 (550), and ny1 (650) are principal refractive indices orthogonal to the orientations of nx1 (450), nx1 (550), and nx1 (650), respectively; nz1 (450), Nz1 (550) and nz1 (650) are principal refractive indices in the thickness direction of light of wavelengths of 450, 550, and 650 nm, respectively; nx1 (550) > ny1 (550) > nz1 (550).

That is, the retardation value Re1 (550) in the first optical anisotropy layer is required to be 50 nm to 200 nm, preferably 70 mm to 180 nm, and more preferably 90 nm to 160 nm. When the Re1 (550) value is within the above range, a sufficient viewing angle improvement effect can be obtained, and unnecessary coloring when viewed from an oblique direction can be prevented.

Further, the retardation value Rth1 (550) in the thickness direction of the first optical anisotropic layer is required to be in the range of 30 nm to 300 nm, preferably 40 nm to 200 nm, more preferably 50 nm to 150 nm. When over When the above range is exceeded, there is a possibility that a sufficient viewing angle improvement effect cannot be obtained or unnecessary coloring occurs when viewed from an oblique direction.

Furthermore, Rth1(550)/Re1(550) must be in the range of 0.5 to 1.5, preferably 0.5 to 1.2. When the above range is exceeded, there is a possibility that a sufficient viewing angle improvement effect cannot be obtained or unnecessary coloring occurs when viewed from an oblique direction.

Furthermore, Re1 (450), Re1 (550), and Re1 (650) must satisfy the following [4] and [6] relationships, and Rth1 (450), Rth1 (550), and Rth1 (650) must satisfy the following [5]. ] and [7] relationship. When the range is exceeded, there is a possibility that a sufficient viewing angle improvement effect cannot be obtained, or unnecessary coloring occurs when viewed from an oblique direction.

[4]0.7≦Re1(450)/Re1(550)<1.1

[5]0.7≦Rth1(450)/Rth1(550)<1.1

[6]0.95≦Re1(650)/Re1(550)<1.2

[7]0.95≦Rth1(650)/Rth1(550)<1.2

Furthermore, the first optical anisotropic layer and the second optical anisotropic layer must satisfy the following [10]:

[10]-60nm≦Rth1(550)+Rth2(550)≦60nm

The above range is more preferably -55 nm ≦ Rth1 (550) + Rth 2 (550) ≦ 55 nm. When Rth1(550)+Rth2(550) is in the above range, excellent viewing angle characteristics are exhibited.

Further, when the angle between the absorption axis of the first polarizing plate and the slow axis of the first optical anisotropic layer is r, r is preferably in the range of 85° to 95°, more preferably in the range of 88 to 92°. Very good Slightly 90° (orthogonal). The roller of the first polarizing plate is slightly orthogonal to the long roller of the first optical anisotropic layer (referring that the angle of intersection is within 90°±5°, preferably within ±2°), and the roller is By laminating and integrating the rollers, it is possible to manufacture a high-efficiency and thin laminated polarizing plate, which can be integrated with a slight fit, and the slow axis of the first optical anisotropic layer must be disposed in the direction of the roll strip. Orthogonal directions. Therefore, the first optical anisotropic layer is preferably produced by lateral uniaxial stretching or biaxial stretching. It is generally known that when manufactured by transverse uniaxial stretching or biaxial stretching, the refractive index relationship of the retardation film becomes a negative biaxiality of nx>ny>nz.

Next, the second optical anisotropic layer will be described.

It is preferable that the second optical anisotropic layer is formed by vertically aligning the liquid crystal material having a positive uniaxiality in a liquid crystal state, and then aligning the fixed vertical alignment liquid crystal film.

In the present invention, when a liquid crystal film in which the vertical alignment of the liquid crystal material is fixed is obtained, the selection of the liquid crystal material and the alignment substrate is extremely important.

The liquid crystal material used in the present invention contains at least a side chain type liquid crystalline polymer such as poly(meth)acrylate or polyoxyalkylene as a main constituent. Further, the side chain type liquid crystal polymer used in the present invention preferably has a polymerizable oxetane group at its terminal. More specifically, for example, the (meth)acryl-based moiety of the (meth)acrylic acid compound having an oxetanyl group represented by the formula (1) is polymerized alone or with another (meth)acrylic compound. A side chain type liquid crystalline polymer material obtained by copolymerization.

In the above formula (1), R ₁ represents hydrogen or a methyl group; R ₂ represents hydrogen, a methyl group or an ethyl group; and L ₁ and L ₂ each independently represent a single bond, -O-, -O-CO-, or -CO-O-; M system represents formula (2), formula (3) or formula (4); n and m each represent an integer from 0 to 10.

-P1-L3-P2-L4-P3- (2)

-P1-L3-P3- (3)

-P3- (4)

In the formulae (2) to (4), P1 and P2 each represent a group selected from the formula (5); P3 represents a group selected from the formula (6); and L3 and L4 respectively represent a single bond, -CH =CH-, -C≡C-, -O-, -O-CO- or -CO-O-.

The synthesis method of the (meth)acrylic acid compound having an oxetane group is not particularly limited, and it can be synthesized by a method generally used in an organic chemical synthesis method. For example, by using an ether synthesis by Williamson or an ester synthesis using a condensing agent, a site having an oxetane group and a site having a (meth)acryl group can be bonded to each other to form a component. A (meth)acrylic compound of an oxetanyl group having two reactive functional groups such as an oxetanyl group and a (meth)acryl group.

The (meth)acryl-based moiety of the (meth)acrylic acid compound having an oxetanyl group represented by the formula (1) is polymerized alone or copolymerized with another (meth)acrylic compound to obtain a content. A side chain type liquid crystalline polymer material of the unit represented by the following formula (7). The polymerization conditions are not particularly limited, and the conditions of ordinary radical polymerization and anionic polymerization can be employed.

The radical polymerization example can be, for example, dissolving a (meth)acrylic compound in a solvent such as dimethylformamide (DMF), and using 2,2'-azobisisobutyronitrile (AIBN), benzoyl peroxide. A method in which a formazan (BPO) or the like is used as a starter and is reacted at 60 to 120 ° C for several hours. Further, in order to make the liquid crystal phase appear calmly, copper (I)/2,2'-bipyridine and copper 2,2,6,6-tetramethylpiperidine oxide are used. ‧ The free radical (TEMPO) system is the initiator and is subjected to living radical polymerization, and the method of controlling the molecular weight distribution is also effective. These free radical polymerizations are preferably carried out under deoxygenation conditions.

The anion polymerization example can be, for example, a method in which a (meth)acrylic compound is dissolved in a solvent such as tetrahydrofuran (THF), and a strong base such as an organolithium compound, an organic sodium compound or a Grignard reagent is used as a starting agent. Further, the molecular weight distribution can also be controlled by optimizing the starting agent and the reaction temperature and performing living anionic polymerization. These anionic polymerizations must be carried out under strict dehydration and deoxygenation conditions.

In addition, the (meth)acrylic compound to be copolymerized at this time is not particularly limited, and the polymer material to be synthesized may be liquid crystal, and it is preferable to have liquid crystal for improving the liquid crystal property of the polymer material to be synthesized. A primary (meth)acrylic compound. For example, a (meth)acrylic compound represented by the following formula can be exemplified as a preferred compound.

Here, R represents hydrogen, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or a cyano group.

The side chain type liquid crystalline polymer material preferably contains 5 to 100 mol% of the unit represented by the formula (7), and more preferably 10 to 100 mol%. Further, the weight average molecular weight of the side chain type liquid crystalline polymer material is preferably 2,000 to 100,000, more preferably 5,000 to 50,000.

The liquid crystal material used in the present invention may contain, in addition to the above-mentioned side chain type liquid crystalline polymer material, various compounds which are compatible in the range of liquid crystal properties. The compound which can be contained is, for example, a compound having a cationically polymerizable functional group such as an oxetane group, an epoxy group or a vinyl ether group; various polymer materials having a film forming ability; and various low molecular liquid crystals having liquid crystallinity. Compound, polymer liquid crystal compound, and the like. When the side chain type liquid crystalline polymer material is used as a composition, the ratio of the side chain type liquid crystalline polymer substance to the entire composition is 10% by mass or more, preferably 30% by mass or more, and more preferably 50% by mass. %the above. When the content of the side chain type liquid crystalline polymer material is less than 10% by mass, the concentration of the polymerizable group in the composition is lowered, and the mechanical strength after the polymerization is insufficient, which is not preferable.

Further, after the liquid crystal material is subjected to the alignment treatment, the oxetane group is crosslinked by cationic polymerization, and the liquid crystal state is immobilized. Therefore, it is preferable that the liquid crystal material contains a photocation generator and/or a thermal cation generator which generate cations by external stimuli such as light or heat. Further, various sensitizers may be used in combination as needed.

The "photo cation generating agent" is a compound which generates a cation by irradiation with light of a suitable wavelength, and examples thereof include an organic phosphonium salt system, an iodonium salt system, and a phosphonium salt system. The counter ion of these compounds is preferably a phosphonium salt, a phosphate salt, a borate or the like. Specific examples of the compound include Ar ₃ S ⁺ SbF ₆ ^- , Ar ₃ P ⁺ BF ₄ ^- , Ar ₂ I ⁺ PF ₆ ^- (wherein Ar is a phenyl group or a substituted phenyl group). In addition, it is also possible to use, for example, sulfonate esters, three Classes, diazomethanes, β-ketooximes, imidosulfonates, benzoin sulfonates, and the like.

The "thermal cation generating agent" refers to a compound which generates a cation by heating to a suitable temperature, and examples thereof include a benzyl sulfonium salt, a benzyl ammonium salt, a benzyl pyridinium salt, and a benzyl sulfonium salt. Strontium salts, carboxylic acid esters, sulfonates, amine quinones, antimony pentachloride-ethidium chloride complex, diaryliodonium salt-dibenzyloxy copper, boron halide- Tertiary amine adducts, etc.

The amount of the cation generating agent to be added to the liquid crystal material depends on the structure of the liquid crystal original portion and the spacer portion of the side chain type liquid crystalline polymer material to be used, and the oxetane group equivalent, liquid crystal alignment condition, and the like. The factors vary, but it is not possible to say the same, but the side chain type liquid crystalline polymer material is usually set at 100 ppm by mass to 20% by mass, preferably 1,000 ppm by mass to 10% by mass, more preferably 0.2% by mass. The range of ~7 mass%, especially the range of 0.5 mass% to 5 mass%. When the amount is less than 100 ppm by mass, the amount of the generated cation will be insufficient, and the polymerization may not be carried out. On the other hand, if it is more than 20% by mass, the decomposition residue of the cation generator remaining in the liquid crystal film may be decomposed. It will increase, and it will cause deterioration of light resistance and the like, so it is not good.

Next, the alignment substrate will be described.

The alignment substrate preferably has a smooth flat surface, such as a film or sheet formed of an organic polymer material, or a glass plate, a metal plate or the like. From the viewpoint of cost and continuous productivity, it is preferable to use a material formed of an organic polymer. Examples of the organic polymer material may be exemplified by, for example, polyvinyl alcohol, polyimide, polyphenylene oxide, polyether ketone, polyetheretherketone, polyethylene terephthalate, polyethylene naphthalate A polyester-based polymer such as a diester; a cellulose-based polymer such as diethyl phthalocyanine or triethylene fluorene; a transparent polymer such as a polycarbonate polymer or an acrylic polymer such as polymethyl methacrylate; The formed film. Further, examples thereof include styrene polymers such as polystyrene, acrylonitrile ‧ styrene copolymers; olefin polymers such as polyethylene, polypropylene, ethylene ‧ propylene copolymers; A film formed of a transparent polymer such as a cyclic polyolefin such as a polyolefin structure, a vinyl chloride polymer, or a polyamide or aromatic polyamide. Further, for example, it may be: a quinone imine polymer, a fluorene polymer, a polyether fluorene polymer, a polyether ether ketone polymer, a polyphenylene sulfide polymer, a vinyl alcohol polymer, or a second A film formed of a transparent polymer such as a vinyl chloride polymer, an ethylene butyral polymer, an aryl ester polymer, a polyacetal polymer, an epoxy polymer, or a blend of the above polymers. Among these, it is preferable to use triacetyl cellulose, polycarbonate, and lower as an optical film. A plastic film such as a polyolefin. In particular, ZEONOR (trade name, Japan ZEON Co., Ltd.), ZEONEX (trade name, Japan ZEON Co., Ltd.), Arton (trade name, JSR (share) system), etc. A plastic film formed of a polymer material having an olefin structure is preferred because it has excellent optical properties. Further, the metal thin film is a thin film which can be formed, for example, of aluminum or the like.

In order to stably obtain the vertical alignment using the liquid crystal material, the material constituting the substrates preferably has a long chain (usually having a carbon number of 4 or more, preferably 8 or more) alkyl groups, or a long-chain alkyl group is provided on the surface of the substrate. a layer of the compound. In particular, it is preferred to form a layer formed of a polyvinyl alcohol having a long-chain alkyl group, and the formation method is also relatively easy. In addition, these organic high scores The sub-materials may be used alone as a substrate, or may be formed on other substrates. In the liquid crystal field, a polishing process for wiping a substrate by a cloth or the like is generally employed. However, since the vertical alignment liquid crystal layer used in the present invention is an alignment structure that does not substantially cause in-plane anisotropy, it is not necessarily Be sure to perform the grinding process. However, in order to suppress the occurrence of plucking when the liquid crystal material is applied, it is preferable to carry out a light rubbing treatment. The important set value for specifying the grinding conditions is the weekly speed ratio. This ratio is a ratio of the cloth moving speed to the substrate moving speed when the substrate is wiped while the polishing cloth is wound around the roll and rotated. In the present invention, the "light polishing treatment" generally means a peripheral speed ratio of 50 or less, preferably 25 or less, more preferably 10 or less. If the peripheral speed ratio is greater than 50, the grinding effect will be too strong, resulting in the liquid crystal material not being completely vertically aligned, which may become the alignment of the vertical direction from the vertical direction.

Next, a method of manufacturing a vertical alignment liquid crystal film will be described.

The method for producing a liquid crystal film is not limited to these. For example, the liquid crystal material may be developed on the alignment substrate, and after the liquid crystal material is aligned, the alignment state may be fixed by performing light irradiation and/or heat treatment. Can be made.

A method of forming a liquid crystal material layer on a alignment substrate by forming a liquid crystal material, for example, a method of directly applying a liquid crystal material to a alignment substrate in a molten state, or applying a solution of a liquid crystal material to an alignment substrate, and then A method in which the coating film is dried and the solvent is distilled off.

The solvent used in the preparation of the relevant solution is prepared before the solvent which can dissolve the liquid crystal material of the present invention and can be distilled off under appropriate conditions, and the rest is not particularly limited, and it is generally preferred to use, for example, acetone, methyl ethyl ketone, and isophor. Ketones such as ketone and cyclohexanone; ether alcohols such as butoxyethanol, hexyloxyethanol and methoxy-2-propanol; ethylene glycol dimethyl ether and diethylene glycol dimethyl ether Ethylene glycol ethers; esters such as ethyl acetate and ethyl lactate; phenols such as phenol and chlorophenol; N,N-dimethylformamide, N,N-dimethylacetamide, N-A A guanamine such as a pyrrolidone; a halogen such as chloroform, tetrachloroethane or dichlorobenzene; or a mixed system thereof. Further, in order to form a uniform coating film on the alignment substrate, a surfactant, an antifoaming agent, a leveling agent, or the like may be added to the solution.

Regarding the method of directly coating the liquid crystal material or the method of applying the solution, the related coating method is a method for ensuring the uniformity of the coating film, and the rest is not particularly limited, and a known method can be employed. For example, a spin coating method, a die coating method, a curtain coating method, a dip coating method, a roll coating method, and the like. The method of coating the solution of the liquid crystal material is preferably carried out by a drying step of removing the solvent after coating. This drying step is carried out before the method for maintaining the uniformity of the coating film, and the rest is not particularly limited, and a known method can be employed. For example: heater (furnace), hot air blowing, etc.

The film thickness of the liquid crystal layer depends on the liquid crystal display device and various optical parameters, and therefore cannot be generally set to 0.2 μm to 10 μm, preferably 0.3 μm to 5 μm, and more preferably 0.5 μm to 2 μm. If the film thickness is thinner than 0.2 μm, there is a fear that a sufficient viewing angle improvement or a luminance enhancement effect cannot be obtained. Moreover, if it exceeds 10 μm, there is a fear that the liquid crystal display device may be unnecessarily colored.

Next, the liquid crystal material layer formed on the alignment substrate is formed into a liquid crystal alignment by a heat treatment or the like, and then cured by light irradiation and/or heat treatment to be immobilized. The initial heat treatment is performed by heating to the temperature range of the liquid crystal phase of the liquid crystal material used, so that the liquid crystal material can be aligned by the self-alignment ability originally possessed by the liquid crystal material. The conditions of the heat treatment are different depending on the liquid crystal phase behavior temperature (transfer temperature) of the liquid crystal material used. The optimum conditions and limit values, therefore, cannot be generally set at 10 to 250 ° C, preferably in the range of 30 ° C to 160 ° C, preferably depending on the temperature above the glass transition point (Tg) of the liquid crystal material. More preferably, the heat treatment is performed at a temperature higher than Tg by more than 10 °C. If the temperature is too low, there is a fear that the liquid crystal alignment cannot be sufficiently performed. On the other hand, if the temperature is high, there is a fear that the cationically polymerizable reactive group or the alignment substrate in the liquid crystal material is adversely affected. Further, the relevant heat treatment time is usually set in the range of 3 seconds to 30 minutes, preferably in the range of 10 seconds to 10 minutes. If the heat treatment time is shorter than 3 seconds, there is a fear that the liquid crystal alignment is not sufficiently completed; on the other hand, if the heat treatment time exceeds 30 minutes, the productivity is deteriorated, and it is preferable to avoid it in any case.

After the liquid crystal alignment is formed by performing heat treatment or the like on the liquid crystal material layer, the liquid crystal material is cured by polymerization reaction with the oxetane group in the composition while maintaining the liquid crystal alignment state. The purpose of the hardening step is to use a hardening (crosslinking) reaction for the completed liquid crystal alignment to fix the liquid crystal alignment state and to modify it into a more robust film.

Since the liquid crystal material of the present invention has a polymerizable oxetane group, a cationic polymerization initiator (cation generator) is preferably used in the polymerization (crosslinking) of the reactive group as described above. Further, as the polymerization initiator, a photocation generator is preferably used as compared with the thermal cation generator.

When a photocationic cation generating agent is used, if the photocationic cation generating agent is added, the steps up to the heat treatment for performing liquid crystal alignment are carried out under dark conditions (light blocking conditions in which the photocation generating agent does not dissociate). Then, the liquid crystal material does not harden until the alignment stage, and has sufficient fluidity and liquid crystal alignment. Then, the liquid crystal material layer is cured by irradiating light from a light source that emits light of a suitable wavelength to cause cation formation.

The method of light irradiation is to irradiate light from a light source having a spectrum in an absorption wavelength region of a photocation generator used, such as a metal halide lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, an arc lamp, a laser, etc., to cause photocation generation. Dissociation of the agent. The irradiation amount per square centimeter is usually set to 1 to 2000 mJ, preferably 10 to 1000 mJ, based on the integral irradiation amount. However, the case where the absorption region of the photo cation generator is significantly different from the spectrum of the light source, or the case where the liquid crystal material itself has the wavelength absorption ability of the light source is not limited thereto. In these cases, a method of mixing, for example, a suitable photosensitizer or two or more photocation generators having different absorption wavelengths may be employed.

The temperature at the time of light irradiation must be set to a temperature range in which the liquid crystal material becomes a liquid crystal alignment. Further, in order to sufficiently enhance the hardening effect, it is preferred to perform light irradiation at a temperature higher than Tg of the liquid crystal material.

The liquid crystal material layer obtained by the above steps becomes a sufficiently strong film. Specifically, the liquid crystal source is three-dimensionally bonded by a hardening reaction, and the heat resistance (the upper limit temperature of the liquid crystal alignment retention) is improved not only before the curing, but also related to scratch resistance, abrasion resistance, and turtle resistance. Mechanical strength such as cracking can also be greatly improved.

In addition, the alignment substrate is not optically isotropic, or the obtained liquid crystal film is opaque in the final target use wavelength region, or when the alignment substrate film thickness is too thick, which may cause hindrance in practical use, etc. From the form formed on the alignment substrate, a form in which a stretched film having a phase difference function is transferred is used. The transfer method can employ a known method. For example, as described in Japanese Laid-Open Patent Publication No. Hei-4-57017, No. 5-333313, the liquid crystal film layer is laminated with an adhesive or an adhesive, and a substrate different from the alignment substrate is laminated, and then an adhesive or an adhesive is used as needed. The method of applying a hardening treatment to the surface, and then peeling off the alignment substrate from the laminate, thereby transferring only the liquid crystal layer.

The adhesive or the adhesive used in the transfer may be an optical grade, and the rest is not particularly limited, and a general-purpose substance such as an acrylic type, an epoxy type, or an urethane type can be used.

According to the vertical alignment liquid crystal layer obtained as described above, the optical phase difference of the liquid crystal layer can be quantified by performing measurement at an obliquely perpendicular incidence angle. In the case of a vertically aligned liquid crystal layer, the phase difference is symmetrical with respect to normal incidence. There are several methods for measuring the optical phase difference, and for example, an automatic birefringence measuring device (manufactured by Oji Scientific Instruments Co., Ltd.) and a polarizing microscope can be used. The vertical alignment liquid crystal layer will see black between the orthogonal polarizing elements. According to this, the evaluation of vertical alignment is performed.

The second optical anisotropic layer must satisfy the following [8]~[9]:

[8]-10nm≦Re2(550)≦10nm

[9]-200nm≦Rth2(550)≦-50nm

Wherein Re2 (550) refers to a retardation value in a second optical anisotropic layer at a wavelength of 550 nm; and Rth 2 (550) refers to a retardation in a thickness direction of a second optical anisotropic layer of light having a wavelength of 550 nm. value. Re2 (550) and Rth2 (550) are Re2 (550) = {nx2 (550) - ny2 (550)} × d2 [nm], Rth2 (550) = [{nx2 (550) + ny2 (550)}, respectively. /2-nz2(550)] × d2 [nm]. Further, d2 is the thickness of the second optical anisotropic layer; nx2 (550) is the maximum principal refractive index in the second optical anisotropic layer of light having a wavelength of 550 nm; and ny2 (550) is orthogonal to nx2 ( The main refractive index of the orientation of 550); nz2 (550) is the thickness direction main refractive index of light having a wavelength of 550 nm; nz2 (550) > nx2 (550) = ny2 (550).

That is, the retardation value Re2 (550) in the plane of the vertical alignment liquid crystal film must be -10 nm to 10 nm, preferably 0 nm to 10 nm, more preferably 0 nm to 5 nm. Further, the retardation value Rth2 (550) in the thickness direction must be controlled to be -200 nm to -50 nm, preferably -190 nm to -70 nm, more preferably -180 nm to -90 nm.

By setting the Rth2 (550) value within the above range, when the film is improved as the viewing angle of the liquid crystal display device, the viewing angle can be increased while performing the color tone correction of the liquid crystal display. When the value of Rth2 (550) is more than -50 nm or less than -200 nm, there is a possibility that a sufficient viewing angle improvement effect cannot be obtained or unnecessary coloring occurs when viewed from an oblique direction. Moreover, by setting the Re2 (550) value to 10 nm or less, the front surface characteristics of the liquid crystal display element can be improved.

Next, the third optical anisotropic layer will be described.

The third optical anisotropic layer can be, for example, a polycarbonate resin, a polyvinyl alcohol resin, a cellulose resin, a polyester resin, a polyarylate resin, a polyimide resin, or a cyclic polymer. An olefin resin, a polyfluorene resin, a polyether oxime resin, a polyolefin resin, a polystyrene resin, a polyvinyl alcohol resin, and the like. Further, for example, a thermosetting resin such as an aminoester-based compound, an urethane urethane-based compound, an epoxy-based or a polyfluorene-based resin, or an ultraviolet curable resin can be used. Among these, a cellulose resin and a cyclic polyolefin resin are particularly preferably used. The third optical anisotropic layer may contain one or more optional additives as appropriate.

The cellulose resin is preferably an ester of cellulose and a fatty acid. Specific examples of such a cellulose ester-based resin may, for example, be triacetyl cellulose, diacetyl cellulose, tripropylene cellulose, dipropylene cellulose or the like. Among these, triacetyl cellulose is particularly preferable. A variety of products, such as triacetonitrile cellulose, are commercially available, and it is advantageous from the viewpoint of availability and cost. In the case where the triacetyl cellulose is delayed in the thickness direction by more than 10 nm, it is possible to obtain a cellulose resin film which not only reduces the frontal retardation but also reduces the thickness direction by using an additive which cancels the retardation or a film forming method, and is particularly suitable. . In the film forming method, for example, a base film such as polyethylene terephthalate, polypropylene, or stainless steel coated with a solvent such as cyclopentanone or methyl ethyl ketone may be bonded to a general cellulose-based film. After heating and drying (for example, about 3 to 10 minutes at 80 to 150 ° C), the method of peeling off the substrate film; A solution in which a solvent such as an olefin resin or a (meth)acrylic resin is dissolved in a solvent such as cyclopentanone or methyl ethyl ketone is applied to a general cellulose resin film and dried by heating (for example, at 80 to 150 ° C for 3~) After about 10 minutes, the method of coating the film is peeled off.

In addition, as the cellulose-based resin film having a small retardation in the thickness direction, a fatty acid cellulose-based resin film having a controlled degree of fat substitution can be used. Generally, the degree of acetic acid substitution of triacetyl cellulose is about 2.8, and it is preferable to reduce Rth by controlling the degree of substitution of acetic acid to 1.8 to 2.7. By adding a plasticizer such as dibutyl phthalate, p-toluenesulfonate, or triethyl citrate to the above-mentioned fatty acid-substituted cellulose resin, it is possible to control the reduction of Rth. The amount of the plasticizer to be added is preferably 40 parts by weight or less, more preferably 1 to 20 parts by weight, even more preferably 1 to 15 parts by weight based on 100 parts by weight of the fatty acid cellulose resin. Cellulose-based resin films having a small retardation in the thickness direction are commercially available as various products. Specific examples are, for example, "Z-TAC" manufactured by FUJIFILM Co., Ltd.; and "ZeroTAC" manufactured by KONICA MINOLTA ADVANCED LAYERS Co., Ltd.

The above cyclic polyolefin resin is preferably reduced An olefinic resin. The cyclic polyolefin-based resin is a general term for a resin which is polymerized by using a cyclic olefin as a polymerization unit, and is described in, for example, JP-A No. 1-240517, JP-A No. 3-148882, and JP-A No. 3-122137. Resin. Specific examples are, for example, a ring-opened (co)polymer of a cyclic olefin, an addition polymer of a cyclic olefin, an α-olefin such as a cyclic olefin and ethylene, propylene, and a copolymer thereof (representative random copolymer) And the modified graft polymer obtained by the unsaturated carboxylic acid or its derivative; and the hydride or the like. Specific examples of cyclic olefins can, for example, be lowered An olefinic monomer. Cyclic polyolefin resins are commercially available in various products. Specific examples are, for example, the product names "ZEONEX" and "ZEONOR" manufactured by Japan ZEON Co., Ltd.; the product name "Arton" manufactured by JSR Co., Ltd.; the product name "Topas" manufactured by TICONA Co., Ltd.; and the product name of Mitsui Chemicals Co., Ltd. "APEL".

The third optical anisotropic layer is used in the following [11] to [12].

[11]-10nm≦Re3(550)≦10nm

[12]-10nm≦Rth3(550)≦10nm

Wherein Re3 (550) refers to a retardation value in a third optical anisotropic layer at a wavelength of 550 nm; and Rth 3 (550) refers to a thickness direction of a third optical anisotropic layer at a wavelength of 550 nm. Delay value. Re3 (550) and Rth3 (550) are respectively Re3 (550) = (nx3 (550) - ny3 (550)) × d3 [nm], Rth3 (550) = {(nx3 (550) + ny3 (550)) /2-nz3(550)}×d3[nm]. Further, d3 is the thickness of the third optical anisotropic layer; nx3 (550) and ny3 (550) are principal refractive indices in the third optical anisotropic layer of light having a wavelength of 550 nm; nz3 (550) is a pair The main refractive index in the thickness direction of light having a wavelength of 550 nm; nx3 (550) ≧ ny 3 (550) ≧ nz 3 (550).

In other words, the in-plane retardation value Re3 (550) of the third optical anisotropic layer is -10 nm to 10 nm. It is preferably in the range of 0 nm to 10 nm, more preferably 0 nm to 5 nm. Further, the retardation value Rth3 (550) in the thickness direction is in the range of -10 nm to 10 nm, preferably -7 nm to 7 nm, more preferably 5 nm to 5 nm. By setting Re3 (550) and Rth3 (550) within the above range, a good viewing angle characteristic is exhibited.

The first polarizing plate and the second polarizing plate used in the present invention will be described.

In the first polarizing plate and the second polarizing plate used in the present invention, a protective film is provided on one side or both sides of the polarizing element. When the structure of the protective film is provided only on one side, the first optical anisotropic layer functions as a protective film. The laminated polarizing plate of the present invention is laminated such that the slow axis of the first optical anisotropic layer is slightly orthogonal to the absorption axis of the first polarizing plate (the angle of intersection is within 90° ± 5°). The negative biaxial optical anisotropic layer extending in the width direction can be integrally manufactured by the roller to the roller.

The polarizing element is not particularly limited, and various materials such as a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formaldehydeized polyvinyl alcohol film, or a partially saponified film of an ethylene vinyl acetate copolymer may be used. In the above, a dichroic substance such as iodine or a dichroic dye is adsorbed, and a uniaxially stretched one; or a polyene-based alignment film such as a dehydrated material of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride is adsorbed. Among these, it is preferable to use a polyvinyl alcohol-based film to stretch and adsorb a dichroic material (iodine, dye) and perform alignment. The thickness of the polarizing element is not particularly limited, and is generally about 5 to 80 μm.

A polarizing element which is dyed by iodine and which is uniaxially stretched by a polyvinyl alcohol-based film is dyed by, for example, immersing polyvinyl alcohol in an aqueous solution of iodine, and is formed by stretching 3 to 7 times the original length. . If necessary, it may be immersed in an aqueous solution of boric acid, potassium iodide or the like. this Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and subjected to water washing before dyeing. By washing the polyvinyl alcohol-based film with water, the surface of the polyvinyl alcohol-based film can be washed and the anti-adhesive agent can be washed. Further, by swelling the polyvinyl alcohol-based film, unevenness such as staining can be prevented. Effect. The extension system can be carried out after dyeing with iodine, or it can be stretched while dyeing, and can be dyed with iodine while extending. The extension may also be carried out in an aqueous solution of boric acid, potassium iodide or the like or in a water bath.

The protective film provided on one side or both sides of the polarizing element is preferably excellent in transparency, mechanical strength, thermal stability, moisture shielding property, and isotropic property. The material of the protective film may be, for example, a polyester-based polymer such as polyethylene terephthalate or polyethylene naphthalate; a cellulose-based polymer such as diethyl phthalocyanine or triacetyl cellulose; An acrylic polymer such as polymethyl methacrylate; a styrene polymer such as polystyrene or acrylonitrile ‧ styrene copolymer (AS resin); or a polycarbonate polymer. Further, examples of the polymer forming the protective film may be, for example, a polyolefin-based polymer such as polyethylene, polypropylene, ethylene or propylene copolymer; Polyolefin structure; vinyl chloride polymer; guanamine polymer such as nylon or aromatic polyamine; quinone imine polymer, fluorene polymer, polyether fluorene polymer, polyether ether ketone Polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, ethylene butyral polymer, aryl ester polymer, polyacetal polymer, epoxy polymer Or a blend of the above polymers. In addition, a thin film or the like may be used, such as a thermosetting type or an ultraviolet curing type resin such as an acrylic type, an urethane type, an urethane type, an epoxy type or a polyoxymethylene type. The thickness of the protective film is generally set to 500 μm or less, preferably 1 to 300 μm. Particularly preferably, the system is preferably 5 to 200 μm.

The protective film is preferably an optically isotropic substrate such as a FUJI tackifier (product of FUJIFILM Co., Ltd.) or a KONICA tackifier (product of KONICA MINOLTA OPTO Co., Ltd.), such as a triacetyl cellulose (TAC) film or an Arton film ( A cycloolefin polymer such as a JSR company product, a ZEONOR film, a ZEONEX film (product of Japan ZEON Co., Ltd.), a TPX film (product of Mitsui Chemicals Co., Ltd.), and an ACRYPLEN film (product of Mitsubishi Rayon Co., Ltd.), when an elliptically polarizing plate is formed, From the viewpoints of planarity, heat resistance, moisture resistance, and the like, triacetyl cellulose and a cycloolefin polymer are preferred.

Further, when a protective film is provided on both sides of the polarizing element, a protective film made of the same polymer material may be used for both the front and back surfaces, and a protective film formed of a different polymer material or the like may be used. The polarizing element and the protective film are usually adhered to each other by a water-based adhesive or the like. The water-based adhesive agent may, for example, be a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, an ethylene-based latex, an aqueous polyurethane, or an aqueous polyester.

The protective film may be a hard coat layer or treated by an anti-reflection treatment for the purpose of preventing sticking, diffusion or anti-glare.

The hard coat treatment is carried out for the purpose of preventing scratches on the surface of the polarizing plate. For example, it is formed of a suitable ultraviolet curable resin such as acrylic or polyoxygen, and a hardened film excellent in hardness and smoothness is attached to the surface of the protective film. Ways can be formed. The antireflection treatment is carried out for the purpose of external light antireflection on the surface of the polarizing plate, and can be achieved by formation of a conventional antireflection film or the like. Further, the anti-adhesive treatment is carried out for the purpose of preventing adhesion to an adjacent layer.

Further, the anti-glare treatment is performed to prevent the external light from being reflected by the surface of the polarizing plate, and to prevent the polarizing plate from penetrating the light, for example, by using a sand blasting method or an embossing method. An appropriate method such as a surface-forming method or a method of incorporating transparent fine particles can be formed by imparting a fine uneven structure to the surface of the protective film. For the fine particles contained in the formation of the surface fine concavo-convex structure, for example, ceria, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, cerium oxide, or the like having an average particle diameter of 0.5 to 50 μm can be used. The inorganic fine particles having conductivity or the transparent fine particles such as organic fine particles composed of a crosslinked or uncrosslinked polymer. When the surface fine uneven structure is formed, the amount of the fine particles used is generally from 2 to 50 parts by weight, preferably from 5 to 25 parts by weight, per 100 parts by weight of the transparent resin forming the surface fine uneven structure. The anti-glare layer may also have a diffusion layer (viewing angle expansion function, etc.) for diffusing the polarizing plate to penetrate the pupil and widening the viewing angle.

Further, the antireflection layer, the anti-adhesion layer, the diffusion layer, the antiglare layer, and the like may be directly provided on the protective film, and may be an optical layer separately provided in addition to the transparent protective layer.

The first and second optical anisotropic layers and the first polarizing plate are bonded to each other via an adhesive layer. The adhesive forming the adhesive layer is not particularly limited, and may be appropriately selected and used, for example, an acrylic polymer, a polyoxymethylene polymer, a polyester, a polyurethane, a polyamide, a polyether, or a fluorine. A polymer such as a system or a rubber system is a matrix polymer. In particular, it is preferably used, such as an acrylic adhesive, which is excellent in optical transparency, exhibits adhesive properties such as moderate wettability, cohesiveness, and adhesion, and is excellent in weather resistance and heat resistance.

The formation of the adhesive layer can be carried out in a suitable manner. For example, in a solvent formed by a single substance or a mixture of a suitable solvent such as toluene or ethyl acetate, the matrix polymer or a composition thereof is dissolved or dispersed to prepare an adhesive of about 10 to 40% by weight. The solution is directly attached to the solution by means of a suitable method such as a coating method or a coating method. a method of forming a liquid crystal layer; or a method of forming an adhesive layer on a separator and then moving it to the liquid crystal layer. Further, the adhesive layer may contain, for example, a resin of a natural product or a composition, particularly an adhesiveness-imparting resin; a filler, a pigment, and a coloring agent composed of glass fiber, glass beads, metal powder, other inorganic powder, or the like. An additive added to the adhesive layer, such as an agent or an antioxidant. Further, it may be an adhesive layer or the like which exhibits light diffusibility by containing fine particles.

Further, when the optical anisotropic layers are bonded to each other via the adhesive layer, the surface of the film is subjected to a surface treatment to improve the adhesion to the adhesive layer. The means for the surface treatment is not particularly limited, and surface treatment methods such as corona discharge treatment, sputtering treatment, low-pressure UV irradiation, and plasma treatment capable of maintaining the transparency of each of the optical anisotropic layers are preferably used. Among these surface treatment methods, corona discharge treatment is preferred.

In the horizontal alignment type liquid crystal display device of the present invention, the laminated polarizing plate of the present invention formed of at least a first polarizing plate, a first optical anisotropic layer, and a second optical anisotropic layer, and a horizontal alignment type are disposed in this order. Liquid crystal cell and second polarizing plate.

Further, in the horizontal alignment type liquid crystal display device of the present invention, the laminated polarizing plate of the present invention comprising at least a first polarizing plate, a first optical anisotropic layer, and a second optical anisotropic layer is disposed, The horizontal alignment type liquid crystal cell, the third optical anisotropic layer, and the second polarizing plate.

In the horizontal alignment type liquid crystal display device of the present invention, when the angle between the absorption axis of the first polarizing plate and the absorption axis of the second polarizing plate is s, s is preferably in the range of 85° to 95°, more preferably in the range of 88 to 92. °, especially good for 90 ° (orthogonal). When the s exceeds the upper and lower ranges, the light leakage of the horizontal alignment type liquid crystal display device is large, and the visibility is remarkably deteriorated, which is not preferable.

Further, when the angle between the absorption axis of the second polarizing plate and the liquid crystal axis of the horizontal alignment type liquid crystal cell is t, it is preferable to laminate the layer so as to satisfy -5°≦t≦5°. In the range, the horizontal alignment type liquid crystal display device has a large light leakage, which causes a significant deterioration in the visibility, which is not preferable.

[Examples]

The invention will be specifically described below by way of examples, but the invention is not limited thereto.

In addition, each analysis method used by the Example is as follows.

(1) Determination of ¹ H-NMR

The compound was dissolved in deuterated chloroform and measured by ¹ H-NMR (INOVA-400, manufactured by Variant Co., Ltd.) at 400 MHz.

(2) Determination of GPC

The compound was dissolved in tetrahydrofuran, and TSK-GEL SuperH1000, SuperH2000, SuperH3000, and SuperH4000 were connected in series by using an 8020 GPC system manufactured by TOSOH Co., Ltd., and measurement was carried out using tetrahydrofuran as an eluate. The calibration of the molecular weight uses polystyrene standards.

(3) Microscope observation

The alignment state of the liquid crystal was observed using a BH2 polarizing microscope manufactured by Olympus Optics Co., Ltd.

(4) Film thickness measurement method

SURFACE TEXTURE ANALYSIS SYSTEM Dektak 3030ST manufactured by SLOAN was used. Further, a method of obtaining a film thickness from interference wave measurement (U.S. Spectrophotometer, UV ‧ visible ‧ near-infrared spectrometer V-570) and refractive index data was also used in combination.

(5) Determination of parameters of liquid crystal film

The automatic complex refractometer KOBRA21ADH made by the prince measuring machine (stock) was used.

[Reference Example 1] (production of polarizing element)

The polyvinyl alcohol film was immersed in warm water and expanded, and then dyed in an iodine/potassium iodide aqueous solution, followed by uniaxial stretching treatment in an aqueous boric acid solution to obtain a polarizing element. The polarizing element was investigated for the monomer transmittance, the parallel transmittance, and the orthogonal transmittance by using a spectroscopic spectrometer, and the transmittance was 43.5% and the degree of polarization was 99.9%.

[Reference Example 2]

A liquid crystalline polymer represented by the following formula (8) is synthesized. The molecular weight was Mn = 8000 and Mw = 15,000 in terms of polystyrene. Further, the formula (8) is represented by the structure of the block polymer, and represents the composition ratio of the monomers.

1.0 g of the polymer of the formula (8) was dissolved in 9 ml of cyclohexanone, and a solution of a triallyl solution of a propylene carbonate hexafluoride 50% propylene carbonate (a reagent manufactured by Aldrich Co., Ltd.) was added in a dark place, and then used. A filter made of a polytetrafluoroethylene having a pore size of 0.45 μm was filtered to prepare a solution of a liquid crystal material.

The alignment substrate is prepared as follows. A polyethylene film of polyethylene naphthalate (manufactured by Teijin Co., Ltd.) having a thickness of 38 μm was cut into 15 cm squares, and a 5 mass% solution of an alkyl modified polyvinyl alcohol (PVA: KURARAY Co., Ltd., MP-203) was added. The solvent-based water and isopropyl alcohol were mixed in a mass ratio of 1:1. The coating was applied by a spin coating method, dried by a hot plate at 50 ° C for 30 minutes, and then heated in a 120 ° C oven for 10 minutes. Next, grinding was performed using a enamel polishing cloth. The film thickness of the obtained PVA layer was 1.2 μm. The peripheral speed ratio (grinding cloth moving speed / substrate film moving speed) at the time of polishing was set to 4.

On the alignment substrate obtained in this manner, the liquid crystal material solution was applied by spin coating. Next, it was dried by a hot plate at 60 ° C for 10 minutes, and then heat-treated in a 150 ° C oven for 2 minutes to align the liquid crystal material. Then, the sample was placed in close contact on an aluminum plate heated to 60 ° C, and a liquid crystal material was hardened by irradiating 600 mJ/cm ^{2 of} ultraviolet light (this is the amount of light measured by 365 nm) from a high-pressure mercury lamp thereon.

The polyethylene naphthalate film used as the substrate is not a preferred optical film because of its large birefringence, so that the liquid crystalline film on the obtained alignment substrate is interposed with the ultraviolet curing adhesive. Transfer onto a triethylene cellulose (TAC) film. That is, on the hardened liquid crystal material layer on the polyethylene naphthalate film, the adhesive is applied to a thickness of 5 pm, laminated with a TAC film, and irradiated with ultraviolet rays from the side of the TAC film to harden the adhesive. The polyethylene naphthalate film and the PVA layer were peeled off.

The obtained optical film (liquid crystal layer/adhesive layer/TAC film) was observed under a polarizing microscope, and it was found that it was not a misalignment but a uniform alignment of a single region, and it was observed by a conoscope that it had positive uniaxiality. Vertical alignment of the refractive index structure. The total in-plane retardation of the TAC film and the liquid crystal layer measured by KOBRA21ADH is 0.5 nm, and the thickness direction is extended. Late -119nm. Further, the TAC film single system has a negative uniaxiality and an in-plane retardation of 0.5 nm, and a thickness direction retardation of +35 nm. Therefore, it is estimated that the liquid crystal layer alone has a retardation system Re2 (550) of 0 nm and Rth2 (550) of -154 nm. After the first embodiment, when the film was bonded to another substrate, the TAC film of the substrate was removed, and only the vertical alignment liquid crystal layer was taken out. Further, the thickness of the vertical alignment liquid crystal layer was 0.9 μm. The refractive index of each orientation has a relationship of nz2 (550) > nx2 (550) = ny2 (550).

Further, the vertical alignment liquid crystal layer belongs to the second optical anisotropic layer.

[Example 1]

The structure of the laminated polarizing plate will be described with reference to Fig. 1 .

On one surface of the polarizing element obtained in Reference Example 1, a protective film 2 (a thickness of 40 μm, a front phase difference: 6 nm, and a thickness direction retardation: 60 nm) was adhered to each other via a polyvinyl alcohol-based adhesive. (TAC) film), the first polarizing plate 1 is formed. The polyvinyl alcohol-based adhesive is interposed on the other surface of the first polarizing plate 1 so that the angle between the absorption axis of the first polarizing plate and the slow axis of the first optical anisotropic layer 3 is 90 degrees. The first optical anisotropic layer 3 is formed by extending the uniaxial axis of the absorption axis of the first polarizing plate 1 having the absorption axis in the longitudinal direction of the roll, and has a slow axis in the roll width direction. In the olefin resin, the second optical anisotropic layer 4 produced in Reference Example 2 was bonded to the upper surface of the second optical anisotropic layer 4, and the laminated polarizing plate 5 was obtained. The first optical anisotropic layer 3 has a phase difference of Re1 (550) of 115 nm and Rth1 (550) of 103.5 nm, and Re1 (450) / Re1 (550) is 1.01, and Rth1 (450) / Rth1 ( 550) is 1.01, Re1 (650) / Re1 (550) is 0.99, and Rth1 (650) / Rth1 (550) is 0.99. The refractive index of each orientation has a relationship of nx1 (550) > ny1 (550) > nz1 (550).

[Embodiment 2]

The horizontal alignment type liquid crystal display device used in the second embodiment will be described with reference to Figs. 2 and 3 . A transparent electrode 7 having a high transmittance material formed of an ITO layer is formed on the substrate 6, and a liquid crystal layer 9 formed of a liquid crystal material having a negative dielectric constant anisotropy is sandwiched between the transparent electrode 7 and the substrate 8.

In the liquid crystal layer 9, a liquid crystal material having a positive dielectric constant anisotropy is used, and when an electric field is applied to the surface direction of the transparent electrode 7, the liquid crystal molecules rotate in the direction of the electric field.

The laminated polarizing plate 5 produced in the first embodiment is disposed on the display surface side (upper side in the drawing) of the horizontal alignment type liquid crystal cell 10. A linear polarizing plate (SQW-062 manufactured by Sumitomo Chemical Co., Ltd.) serving as the second polarizing plate 11 is disposed on the back side (the lower side in the drawing) of the horizontal alignment type liquid crystal cell 10. The Rth system of triacetyl cellulose used for the support substrate of the linear polarizing plate was 35 nm.

The absorption axis directions of the first polarizing plate 1 and the second polarizing plate 11 shown by the arrows in Fig. 3 are set to be 90 degrees in the plane and 0 degrees in the plane. The first optical anisotropic layer 3 is formed of an optical element having an optical axis in the plane and having a negative biaxial optical anisotropy. The slow axis orientation of the first optical anisotropic layer 3 shown by the arrow in Fig. 3 is 0 degree, and the phase difference of in-plane Re1 is 115 nm and Rth1 is 103.5 nm.

The second optical anisotropic layer 4 formed of the vertical alignment liquid crystal film has a phase difference of Re2 of 0 nm and Rth2 of -154 nm.

In Fig. 4, the transmittance ratio (white display) / (black display) of the black display 0V and the white display 5V is the contrast, and the contrast from the omnidirectional is shown. The contrast contours are sequentially set to 6000, 3000, 1000, 500, and 200 from the inside. Also, the concentric circles represent angles that are spaced 20 degrees from the center. Therefore, the outermost circle indicates 80 degrees from the center (the same applies to the following figures). When from all directions When viewing the contrast, it is known that the omnidirectional contrast is improved, and good viewing angle characteristics are obtained.

[Example 3]

In addition to the drop In the surface of the first optical anisotropic layer 3 formed of the olefin resin, Re1 is 125 nm, Rth1 is 87.5 nm, and the in-plane Re2 of the second optical anisotropic layer 4 composed of the vertical alignment liquid crystal film is provided. A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that 0 nm and Rth2 were set to -134 nm. Re1 (450) / Re1 (550) is 1.01, Rth1 (450) / Rth1 (550) is 1.01, Re1 (650) / Re1 (550) is 0.99, and Rth1 (650) / Rth1 (550) is 0.99. The refractive index of each orientation has a relationship of nx1 (550) > ny1 (550) > nz1 (550).

Figure 5 shows the contrast ratio (white display) / (black display) in black for 0V and white for 5V as contrast, showing the contrast from all directions. When the contrast is viewed from all directions, it is known that the omnidirectional contrast is improved, and good viewing angle characteristics can be obtained.

[Example 4]

In addition to the drop In the surface of the first optical anisotropic layer 3 made of an olefin resin, Re1 is 140 nm, Rth1 is 70.0 nm, and Re2 is provided in the plane of the second optical anisotropic layer 4 composed of the vertical alignment liquid crystal film. A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that 0 nm and Rth2 were -113 nm. Re1 (450) / Re1 (550) is 1.01, Rth1 (450) / Rth1 (550) is 1.01, Re1 (650) / Re1 (550) is 0.99, and Rth1 (650) / Rth1 (550) is 0.99. The refractive index of each orientation has a relationship of nx1 (550) > ny1 (550) > nz1 (550).

In Fig. 6, the transmittance ratio (white display) / (black display) of black display 0V and white display 5V is contrast, and the contrast from all directions is shown. When you look at the contrast from all directions, you know A full range of contrast enhancement improves the viewing angle characteristics.

[Example 5]

The horizontal alignment type liquid crystal display device used in the present embodiment is described in detail in FIGS. 7 and 8. The third optical anisotropic layer 12 disposed between the lower second polarizing plate 11 and the liquid crystal cell 10 is a cellulose-based resin film having a small retardation in the thickness direction (a Z-TAC polarizing film made of FUJIFILM). A horizontal alignment type liquid crystal display device was produced in the same manner as in the second embodiment except for the above. Re1 (450) / Re1 (550) is 1.01, Rth1 (450) / Rth1 (550) is 1.01, Re1 (650) / Re1 (550) is 0.99, and Rth1 (650) / Rth1 (550) is 0.99. The refractive index of each orientation has a relationship of nx1 (550) > ny1 (550) > nz1 (550). Further, in the third optical anisotropic layer 12, Re3 (550) is 1 nm and Rth 3 (550) is 2 nm. The refractive index of each orientation has a relationship of nx3 (550) ≧ ny 3 (550) ≧ nz 3 (550).

In Fig. 9, the transmittance ratio (white display) / (black display) of black display 0V and white display 5V is contrast, and the contrast from all directions is shown. When the contrast is viewed from all directions, it is known that the omnidirectional contrast is improved, and good viewing angle characteristics can be obtained.

[Comparative Example 1]

A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that Rth2 of the second optical anisotropic layer 4 composed of the vertical alignment liquid crystal film was set to -200 nm. The result was Rth1 + Rth2 = -96.5 nm.

In Fig. 10, the transmittance ratio (white display) / (black display) of black display 0V and white display 5V is contrast, and the contrast from all directions is shown. When the contrast is viewed from all directions, it is particularly low in four directions of the upper right, upper left, lower right, and lower left, and the viewing angle characteristics are deteriorated.

[Comparative Example 2]

Except for unused A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that the first optical anisotropic layer 3 made of an olefin resin was used.

In Fig. 11, the transmittance ratio (white display) / (black display) of black display 0V and white display 5V is contrast, and the contrast from all directions is shown. When the contrast is viewed from all directions, it is particularly low in four directions of the upper right, upper left, lower right, and lower left, and the viewing angle characteristics are deteriorated.

[Comparative Example 3]

A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that the second optical anisotropic layer 4 composed of the vertical alignment liquid crystal film was not used.

Figure 12 shows the contrast ratio (white display) / (black display) in black for 0V and white display for 5V, showing the contrast from all directions. When the contrast is viewed from all directions, it is particularly low in four directions of the upper right, upper left, lower right, and lower left, and the viewing angle characteristics are deteriorated.

[Comparative Example 4]

Except for unused A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that the first optical anisotropic layer 3 composed of an olefin resin and the second optical anisotropic layer 4 composed of a vertical alignment liquid crystal film were used. .

In Fig. 13, the transmittance ratio (white display) / (black display) of black display 0V and white display 5V is contrast, and the contrast from all directions is shown. When the contrast is viewed from all directions, it is particularly low in four directions of the upper right, upper left, lower right, and lower left, and the viewing angle characteristics are deteriorated.

[Comparative Example 5]

In addition to the drop A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that Re1 of the first optical anisotropic layer 3 composed of the olefin resin was 25 nm and Rth1 was 103.5 nm. It is determined that the black shows 0V, the white shows a contrast ratio of 5V (white display) / (black display), and as a result, when viewed from all directions, it is particularly low in the upper right and upper left directions, and the viewing angle is known. The characteristics deteriorated.

[Comparative Example 6]

In addition to the drop A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that Re1 of the first optical anisotropic layer 3 made of an olefin resin was 115 nm and Rth1 was 350 nm. The result was Rth1 + Rth2 = -196 nm. Further, it becomes Rth1 (550) / Re1 (550) = 3.0. It is determined that the black shows 0V, the white shows a contrast ratio of 5V (white display) / (black display), and as a result, when viewed from all directions, it is particularly low in the upper right and upper left directions, and the viewing angle is known. The characteristics deteriorated.

[Comparative Example 7]

In addition to the drop of the first optical anisotropic layer 3 A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that the olefin resin was changed to a polyfluorene-based resin. As a result, Re1 (450) / Re1 (550) = 1.2, Rth1 (450) / Rth1 (550) = 1.19, Re1 (650) / Re1 (550) = 0.7, and Rth1 (650) / Rth1 (550) = 0.68. The contrast ratio of the black display 0V and the white display 5V transmittance ratio (white display) / (black display) was measured, and the comparison range was the same as that of the second embodiment, and the overall range was high contrast, and good viewing angle characteristics were obtained. However, the values of Re1(450)/Re1(550), Rth1(450)/Rth1(550), Re1(650)/Re1(550), and Rth1(650)/Rth1(550) greatly exceed the optimal range. Therefore, the hue of the black display is reddish purple, and it is known that the color is quite large.

[Comparative Example 8]

A horizontal alignment type liquid crystal display device was produced in the same manner as in Example 2 except that Re2 of the second optical anisotropic layer 4 composed of the vertical alignment liquid crystal film was 50 nm and Rth2 = -154 nm. It is determined that the black shows 0V, the white shows a contrast ratio of 5V (white display) / (black display), and the result is particularly low in the two directions of the lower right and the lower left when viewed from all directions. The viewing angle characteristics deteriorate.

1‧‧‧1st polarizer

3‧‧‧1st optical anisotropic layer

4‧‧‧2nd optical anisotropic layer

5‧‧‧Laminated polarizing plate

Claims (12)

A laminated polarizing plate in which at least a first polarizing plate, a first optical anisotropic layer, and a second optical anisotropic layer are laminated, wherein the first optical anisotropic layer It satisfies the following [1] to [7], and the second optical anisotropic layer satisfies the following [8] to [9], the first optical anisotropic layer and the second optical anisotropy The layer satisfies the following [10]; [1] 50 nm ≦ Re1 (550) ≦ 200 nm [2] 30 nm ≦ Rth1 (550) ≦ 300 nm [3] 0.5 ≦ Rth1 (550) / Re1 (550) ≦ 1.5 [4 ] 0.7≦Re1(450)/Re1(550)<1.1[5]0.7≦Rth1(450)/Rth1(550)<1.1[6]0.95≦Re1(650)/Re1(550)<1.2[7]0.95 ≦Rth1(650)/Rth1(550)<1.2 (where Re1(450), Re1(550), and Re1(650) refer to the first optical anisotropic layer at wavelengths of 450nm, 550nm, and 650nm, respectively. The internal delay value; Rth1 (450), Rth1 (550), and Rth1 (650) refer to the thickness direction retardation value of the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm, respectively; Re1 (450) Re1 (550) and Re1 (650), and Rth1 (450), Rth1 (550), and Rth1 (650) are respectively Re1 (450) = (nx1 (450) - ny1 (450)) × d1 [nm], Re1(550)=(nx1(550)-ny1(550))×d1[nm] Re1(650)=(nx1(650)-ny1(650))×d1[nm], Rth1(450)={(nx1(450)+ny1(450))/2-nz1(450)}×d1[ Nm], Rth1(550)={(nx1(550)+ny1(550))/2-nz1(550)}×d1[nm], Rth1(650)={(nx1(650)+ny1(650) )/2-nz1(650)}×d1[nm]; further, d1 is the thickness of the first optical anisotropic layer; nx1 (450), nx1 (550), and nx1 (650) are respectively at a wavelength of 450, The most optically anisotropic layer of 550, 650 nm light Large principal refractive index; ny1 (450), ny1 (550), and ny1 (650) are principal refractive indices orthogonal to the orientations of nx1 (450), nx1 (550), and nx1 (650), respectively; nz1 (450), Nz1 (550) and nz1 (650) are the main refractive indices in the thickness direction of the wavelengths of 450, 550, and 650 nm, respectively; nx1 (550) > ny1 (550) > nz1 (550)) [8] - 10 nm ≦ Re2 (550) ≦10nm[9]-200nm≦Rth2(550)≦-50nm (where Re2(550) refers to the retardation value in the second optical anisotropic layer of light with a wavelength of 550 nm; Rth2(550) means the pair The thickness direction retardation value of the second optical anisotropic layer of light having a wavelength of 550 nm; Re2 (550) and Rth2 (550) are respectively Re2 (550) = {nx2 (550) - ny2 (550)} × d2 [nm] , Rth2(550)=[{nx2(550)+ny2(550)}/2-nz2(550)]×d2[nm]; again, d2 is the thickness of the second optical anisotropic layer; nx2(550 a maximum principal refractive index in a second optical anisotropic layer of light having a wavelength of 550 nm; ny2 (550) is a principal refractive index orthogonal to the orientation of nx2 (550); nz2 (550) is a light having a wavelength of 550 nm The main refractive index in the thickness direction; nz2 (550) > nx2 (550) = ny2) [10] - 60 nm ≦ Rth1 (550) + Rth2 (550) ≦ 60 nm. The laminated optically polarizing plate according to the first aspect of the invention, wherein the second optical anisotropic layer is formed by vertically aligning the liquid crystal composition having a positive uniaxiality in a liquid crystal state, and then being aligned and fixed. The alignment liquid crystal film is formed. The laminated polarizing plate of the second aspect of the invention, wherein the liquid crystal composition having a positive uniaxiality contains a side chain type liquid crystalline polymer having an oxetane group. The laminated polarizing plate according to any one of claims 1 to 3, wherein the first optical anisotropic layer contains polycarbonate or a cyclic polyolefin. The laminated polarizing plate according to any one of claims 1 to 4, wherein an angle between an absorption axis of the first polarizing plate and a slow axis of the first optical anisotropic layer is r At the time, it is laminated in such a manner that it satisfies 85°≦r≦95°. A horizontal alignment type liquid crystal display device in which at least a level of a first polarizing plate, a first optical anisotropic layer, a second optical anisotropic layer, a horizontal alignment type liquid crystal cell, and a second polarizing plate are disposed in order In the alignment type liquid crystal display device, the first optical anisotropic layer satisfies the following [1] to [7]; and the second optical anisotropic layer satisfies the following [8] to [9]; The first optical anisotropic layer and the second optical anisotropic layer satisfy the following [10]; [1] 50 nm ≦ Re1 (550) ≦ 200 nm [2] 30 nm ≦ Rth1 (550) ≦ 300 nm [ 3]0.5≦Rth1(550)/Re1(550)≦1.5[4]0.7≦Re1(450)/Re1(550)<1.1[5]0.7≦Rth1(450)/Rth1(550)<1.1[6] 0.95≦Re1(650)/Re1(550)<1.2[7]0.95≦Rth1(650)/Rth1(550)<1.2 (where Re1(450), Re1(550) and Re1(650) refer to The retardation value in the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm; Rth1 (450), Rth1 (550), and Rth1 (650) refer to the wavelengths at 450 nm, 550 nm, and 650 nm, respectively. 1 thickness direction retardation value of optical anisotropic layer; Re1 (450), Re1 (550) and Re1 (650), and Rth1 (450), Rth1 (550) and Rth1 (650) Others Re1(450)=(nx1(450)-ny1(450))×d1[nm], Re1(550)=(nx1(550)-ny1(550))×d1[nm], Re1(650) =(nx1(650)-ny1(650))×d1[nm], Rth1(450)={(nx1(450)+ny1(450))/2-nz1(450)}×d1[nm], Rth1 (550)={(nx1(550)+ny1(550))/2-nz1(550)}×d1[nm], Rth1(650)={(nx1(650)+ny1(650))/2- Nz1(650)}×d1[nm]; further, d1 is the thickness of the first optical anisotropic layer; Nx1 (450), nx1 (550), nx1 (650), ny1 (450), ny1 (550), and ny1 (650) are respectively in the first optical anisotropic plane of wavelengths of 450, 550, and 650 nm. The main refractive index; nz1 (450), nz1 (550), and nz1 (650) are the main refractive indices in the thickness direction of the wavelengths of 450, 550, and 650 nm, respectively; nx1 (550) > ny1 (550) > nz 1 (550)) [8]-10nm≦Re2(550)≦10nm[9]-200nm≦Rth2(550)≦-50nm (where Re2(550) refers to the second optical anisotropic layer at a wavelength of 550nm light The retardation value; Rth2 (550) refers to the thickness direction retardation value of the second optical anisotropic layer of light having a wavelength of 550 nm; Re2 (550) and Rth2 (550) are respectively Re2 (550) = {nx2 (550) - Ny2(550)}×d2[nm], Rth2(550)=[{nx2(550)+ny2(550)}/2-nz2(550)]×d2[nm]; again, d2 is the second optical non The thickness of the isotropic layer; nx2 (550) is the maximum principal refractive index in the second optical anisotropic layer of light having a wavelength of 550 nm; ny2 (550) is the principal refractive index of the orientation orthogonal to nx2 (550) Nz2 (550) is a thickness direction principal refractive index for light having a wavelength of 550 nm; nz2 (550) > nx2 (550) = ny2) [10] - 60 nm ≦ Rth1 (550) + Rth2 (550) ≦ 60 nm. A horizontal alignment type liquid crystal display device in which at least a first polarizing plate, a first optical anisotropic layer, a second optical anisotropic layer, a horizontal alignment type liquid crystal cell, and a third optical anisotropy are disposed in order The horizontal alignment type liquid crystal display device of the second layer and the second polarizing plate, wherein the first optical anisotropic layer satisfies the following [1] to [7]; and the second optical anisotropic layer satisfies the following [8] to [9]; the first optical anisotropic layer and the second optical anisotropy layer satisfy the following [10]; and the third optical anisotropic layer satisfies the following [ 11]~[12];[1]50nm≦Re1(550)≦200nm[2]30nm≦Rth1(550)≦300nm [3]0.5≦Rth1(550)/Re1(550)≦1.5[4]0.7≦Re1(450)/Re1(550)<1.1[5]0.7≦Rth1(450)/Rth1(550)<1.1[6 ]0.95≦Re1(650)/Re1(550)<1.2[7]0.95≦Rth1(650)/Rth1(550)<1.2 (where Re1(450), Re1(550) and Re1(650) refer to Delay values in the first optical anisotropic layer at wavelengths of 450 nm, 550 nm, and 650 nm; Rth1 (450), Rth1 (550), and Rth1 (650) refer to light at wavelengths of 450 nm, 550 nm, and 650 nm, respectively. The thickness direction retardation value of the first optical anisotropic layer; Re1 (450), Re1 (550), and Re1 (650), and Rth1 (450), Rth1 (550), and Rth1 (650) are Re1 (450), respectively. =(nx1(450)-ny1(450))×d1[nm], Re1(550)=(nx1(550)-ny1(550))×d1[nm], Re1(650)=(nx1(650) -ny1(650))×d1[nm], Rth1(450)={(nx1(450)+ny1(450))/2-nz1(450)}×d1[nm], Rth1(550)={( Nx1(550)+ny1(550))/2-nz1(550)}×d1[nm], Rth1(650)={(nx1(650)+ny1(650))/2-nz1(650)}× D1 [nm]; further, d1 is the thickness of the first optical anisotropic layer; nx1 (450), nx1 (550), and nx1 (650) are the first optical non-equal to the wavelengths of 450, 550, and 650 nm, respectively. The maximum principal refractive index in the directional plane; ny1 (450), ny1 (550), ny1 (650) respectively The principal refractive index of the orientation orthogonal to nx1 (450), nx1 (550), and nx1 (650); nz1 (450), nz1 (550), and nz1 (650) are the thicknesses of light at wavelengths of 450, 550, and 650 nm, respectively. Directional main refractive index; nx1(550)>ny1(550)>nz1(550))[8]-10nm≦Re2(550)≦10nm[9]-200nm≦Rth2(550)≦-50nm (where Re2( 550) refers to the retardation value in the second optical anisotropic layer at a wavelength of 550 nm; Rth2 (550) refers to the second optical anisotropic layer of light having a wavelength of 550 nm. Thickness direction delay value; Re2(550) and Rth2(550) are Re2(550)={nx2(550)-ny2(550)}×d2[nm], Rth2(550)=[{nx2(550)+ Ny2(550)}/2-nz2(550)]×d2[nm]; further, d2 is the thickness of the second optical anisotropic layer; nx2(550) is the second optical anisotropy of light having a wavelength of 550 nm The maximum principal refractive index in the sex plane; ny2(550) is the principal refractive index orthogonal to the orientation of nx2(550); nz2(550) is the thickness direction principal refractive index of the wavelength 550nm light; nz2(550)>nx2 (550)=ny2)[10]-60nm≦Rth1(550)+Rth2(550)≦60nm[11]-10nm≦Re3(550)≦10nm[12]-10nm≦Rth3(550)≦10nm (where Re3 (550) refers to the retardation value in the third optical anisotropic layer at a wavelength of 550 nm; Rth3 (550) refers to the thickness direction retardation value of the third optical anisotropic layer at a wavelength of 550 nm. Re3 (550) and Rth3 (550) are Re3 (550) = (nx3 (550) - ny3 (550)) × d3 [nm], Rth3 (550) = {(nx3 (550) + ny3 (550), respectively. / 2 - nz3 (550)} × d3 [nm]; further, d3 is the thickness of the third optical anisotropic layer; nx3 (550), ny3 (550) is the third optical non-equal to the wavelength of 550 nm light The main refractive index in the directional plane; nz3 (550) is the main direction of the thickness direction of the wavelength of 550 nm light Rate; nx3 (550) ≧ ny3 (550) ≧ nz3 (550)). The horizontal alignment type liquid crystal display device according to claim 6 or 7, wherein the second optical anisotropic layer is formed by vertically aligning the liquid crystal composition having a positive uniaxiality in a liquid crystal state. The alignment is formed by a vertically aligned vertical alignment liquid crystal film. The horizontal alignment type liquid crystal display device according to the eighth aspect of the invention, wherein the liquid crystal composition having a positive uniaxiality contains a side chain type liquid crystalline polymer having an oxetane group. A horizontal alignment type liquid crystal display device according to any one of claims 6 to 9, The first optical anisotropic layer contains polycarbonate or a cyclic polyolefin. The horizontal alignment type liquid crystal display device according to any one of claims 6 to 10, wherein an angle between an absorption axis of the first polarizing plate and a slow axis of the first optical anisotropic layer is r , layered in a manner that satisfies 85°≦r≦95°. The horizontal alignment type liquid crystal display device according to claim 11, wherein the angle between the absorption axis of the first polarizing plate and the absorption axis of the second polarizing plate is s, and satisfies 85° ≦ s ≦ 95°. Further, when the angle between the absorption axis of the second polarizing plate and the optical axis of the liquid crystal in the horizontal alignment type liquid crystal cell is t, the layer is laminated so as to satisfy -5°≦t≦5°.