WO2008105218A1

WO2008105218A1 - Elliptical polarizing plate for vertically aligned liquid crystal display and vertically aligned liquid crystal display using the same

Info

Publication number: WO2008105218A1
Application number: PCT/JP2008/051713
Authority: WO
Inventors: Gorou Suzaki; Tomoo Hirai; Tetsuya Uesaka
Original assignee: Nippon Oil Corporation
Priority date: 2007-02-28
Filing date: 2008-01-29
Publication date: 2008-09-04
Also published as: TW200905328A; JP2008209872A

Abstract

Disclosed is a thin elliptical polarizing plate for vertically aligned liquid crystal displays, wherein retardation in the thickness direction can be controlled over a wide range. The elliptical polarizing plate for vertically aligned liquid crystal displays is composed of a homeotropically aligned liquid crystal film and a linear polarizing plate. The homeotropically aligned liquid crystal film is obtained by homeotropically aligning at least a positive uniaxial liquid crystal material in a liquid crystal state and then fixing the alignment. Also disclosed is a vertically aligned liquid crystal display using such an elliptical polarizing plate, which is excellent in viewing angle characteristics.

Description

Description: Elliptical polarizing plate for vertical alignment type liquid crystal display device and vertical alignment type liquid crystal display device using the same

[Technical field]

The present invention relates to a vertical alignment type liquid crystal display device in which liquid crystal molecules are aligned perpendicular to a substrate when no voltage is applied, and in particular, an elliptically polarized light for a vertical alignment type liquid crystal display device that realizes a wide viewing angle and can be made thin. The present invention relates to a vertical alignment type liquid crystal display device in which an elliptically polarizing plate is disposed.

[Background]

One of the display modes in the liquid crystal display device is a vertical alignment mode in which liquid crystal molecules in the liquid crystal cell are aligned perpendicularly to the substrate surface in the initial state. When no voltage is applied, the liquid crystal molecules are aligned perpendicularly to the substrate surface, and a black display can be obtained by placing a linear polarizer perpendicular to both sides of the liquid crystal cell.

The optical characteristics in the liquid crystal cell are isotropic in the in-plane direction, and ideal viewing angle compensation is easily possible. In order to compensate for positive uniaxial optical anisotropy in the thickness direction of the liquid crystal cell, an optical element having negative uniaxial optical anisotropy in the thickness direction is inserted between one or both sides of the liquid crystal cell and the linear polarizer. When inserted into the, a very good black display viewing angle characteristic can be obtained.

When a voltage is applied, the orientation of liquid crystal molecules changes from a direction perpendicular to the substrate surface to a direction parallel to the substrate surface. At this time, it is difficult to make the liquid crystal alignment uniform. When the rubbing process on the substrate surface, which is a normal alignment process, is used, the display quality is significantly lowered.

In order to make the liquid crystal alignment uniform when applying a voltage, there are proposals such as devising the electrode shape on the substrate, generating an oblique electric field in the liquid crystal layer, and obtaining uniform alignment. According to this method, a uniform liquid crystal alignment can be obtained, but a microscopically non-uniform alignment region is generated, and this region becomes a dark region when a voltage is applied. Therefore, the transmittance of the liquid crystal display device is lowered.

According to Patent Document 1 (Japanese Patent Laid-Open No. 2 0 0 2-4 0 4 2 8), randomly oriented There has been proposed a configuration in which linearly polarizing plates arranged on both sides of a liquid crystal element having a liquid crystal layer including a state are replaced with circularly polarizing plates. By replacing the linearly polarizing plate with a circularly polarizing plate that combines a linearly polarizing plate and a 1 Z 4 wave plate, the dark area during voltage application can be eliminated, and a liquid crystal display device with high transmittance can be realized. However, the vertical alignment type liquid crystal display device using the circularly polarizing plate has a problem that the viewing angle characteristic is narrower than that of the vertical alignment type liquid crystal display device using the linear polarizing plate. According to Patent Document 2 (Japanese Patent Laid-Open No. 2 0 0 3—2 0 7 7 8 2), as a viewing angle compensation of a vertical alignment type liquid crystal display device using a circularly polarizing plate, a negative uniaxial optical anisotropic Optically anisotropic elements and biaxial optically anisotropic materials have been proposed. However, an optical anisotropic element with negative uniaxial optical anisotropy can compensate for positive uniaxial optical anisotropy in the thickness direction of the liquid crystal cell, but cannot compensate for the viewing angle characteristics of the 14 wavelength plate. A sufficient viewing angle characteristic cannot be obtained. Also, when manufacturing biaxial optically anisotropic materials, when the in-plane main refractive index of the resulting retardation plate is nx, ny, the refractive index in the thickness direction is nz, and nx> ny N z defined as N z = (nx— nz) / (nx— ny) is 1.0 and N z, 0.1, and there is a limit to stretching in the thickness direction. The phase difference cannot be controlled over a wide range. Moreover, in the said manufacturing method, since the elongate film is heat-shrinked with the heat-shrink film and it is extended | stretched in the thickness direction, the thickness of the obtained phase difference plate increases rather than a elongate film. The thickness of the retardation plate obtained by the manufacturing method is about 50 to 100 ^ um, which is not sufficient for reducing the thickness required for liquid crystal display devices and the like.

[Disclosure of the Invention]

An object of the present invention is to provide a vertical alignment type liquid crystal display device having excellent viewing angle characteristics. Another object of the present invention is to provide a thin elliptical polarizing plate capable of controlling the thickness direction retardation over a wide range as an elliptical polarizing plate for a vertical alignment type liquid crystal display device.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have achieved the above object by using an elliptically polarizing plate for a vertical alignment type liquid crystal display device shown below and a vertical alignment type liquid crystal display device using the same. The inventors have found that this can be achieved and have completed the present invention.

That is, according to the first aspect of the present invention, a liquid crystal material exhibiting at least positive uniaxiality is subjected to homeotropic pick orientation in a liquid crystal state, and then a vertical orientation comprising a homeotropic pick oriented liquid crystal film in which the orientation is fixed and a linear polarizing plate. An elliptically polarizing plate for an alignment type liquid crystal display, It is.

According to a second aspect of the present invention, the vertical alignment liquid crystal display device ellipse according to the first aspect of the present invention is characterized in that the homeotopically picked liquid crystal film satisfies the following [1] and [2]. A polarizing plate.

[1] 0 nm≤R e 1≤ 20 n m

[2]-500 nm≤R t h l≤- 30 nm

(Here, R e 1 means the in-plane retardation value of the home-mouth pick-aligned liquid crystal film, and R th 1 means the retardation value in the thickness direction of the home-top pick-aligned liquid crystal film. R e 1 and R th 1 are R e 1 = (N 1 −N y 1) X d 1 [nm], R th 1 = (N x 1 −N z 1) X d 1 [nm], respectively. D 1 is the thickness of the home-orifice pick-aligned liquid crystal film, Nx 1 and Ny 1 are the main refractive indexes in the plane of the home-orifice pick-oriented liquid crystal film, and N z 1 is the main refractive index in the thickness direction And N z 1> Nx 1≥Ny 1.)

According to a third aspect of the present invention, after the homeotropic alignment liquid crystal layer contains a liquid crystalline composition containing at least a liquid crystalline polymer compound having an oxetanyl group, the liquid crystal state is homeotropically aligned. 3. The elliptically polarizing plate according to the first or second aspect of the present invention, wherein the homeotropic orientation is fixed by reacting an oxetanyl group.

According to a fourth aspect of the present invention, the elliptically polarizing plate for a vertical alignment type liquid crystal display device has the first optical anisotropic element showing a phase difference of ¼ wavelength in the plane. 4. An elliptically polarizing plate for a vertical alignment type liquid crystal display device as described in the first to third items.

According to a fifth aspect of the present invention, the elliptically polarizing plate for a vertical alignment type liquid crystal display device is different from the first optical anisotropic element exhibiting a phase difference of 1Z 4 wavelengths in the plane with a negative uniaxial optical difference in the thickness direction. A vertically aligned liquid crystal according to any one of the first to fourth aspects of the present invention, comprising: a third optical anisotropic element characterized by satisfying the following [3] and [4] exhibiting a directivity: An elliptically polarizing plate for a display device.

[3] 0 nm≤R e 2≤ 20 n m

[4] 30 nm≤R t h 2≤ 500 nm

(Here, Re 2 means the in-plane retardation value of the third optical anisotropic element, and R th 2 means the retardation value in the thickness direction of the third optical anisotropic element. To do. R e 2 and R th 2 are respectively R e 2 = (N x 2 -Ny 2) X d 2 [nm], R th 2 = (N x 2 -N z 2) X d 2 [nm] is there. D 2 is the thickness of the third optical anisotropic element, Nx 2 and Ny 2 are the main refractive indices in the plane of the third optical anisotropic element, and N z 2 is the main refractive index in the thickness direction. Nx 2≥Ny 2> N z 2. )

According to a sixth aspect of the present invention, the third optical anisotropic element is at least one polymer material selected from the group consisting of a polyamide, a polyimide, a polyester, a polyether ketone, a polyamide imide, and a polyester imide. The elliptically polarizing plate according to the fifth aspect of the present invention, characterized in that

According to a seventh aspect of the present invention, in the first optical anisotropic element, the first optical anisotropic element exhibits a 1/4 wavelength phase difference in a plane and has negative biaxial optical anisotropy. The elliptically polarizing plate for vertical alignment type liquid crystal display devices as described in 1st-6th.

An eighth aspect of the present invention is the elliptically polarizing plate for a vertical alignment type liquid crystal display device according to any one of the first to seventh aspects, wherein the total film thickness is 400 m or less.

According to a ninth aspect of the present invention, there is provided a vertical alignment type liquid crystal cell including a liquid crystal molecule that is vertically aligned with respect to a substrate surface when no voltage is applied between a pair of substrates having electrodes, and the vertical alignment type liquid crystal cell substrate. 8. The vertical alignment type liquid crystal cell substrate side of the vertical alignment type liquid crystal cell substrate side of at least one side of the elliptically polarizing plate for vertical alignment type liquid crystal display device according to any one of claims 1 to 7, A vertical alignment type liquid crystal display device, wherein at least one first optical anisotropic element exhibiting a phase difference of 1Z4 wavelength in-plane is disposed between a liquid crystal cell substrate and the elliptically polarizing plate; It is.

A tenth aspect of the present invention is the vertical alignment type liquid crystal display device according to the ninth aspect of the present invention, wherein the surface from the substrate side is disposed on the substrate opposite to the substrate on which the elliptically polarizing plate for the vertical alignment type liquid crystal display device is disposed. The vertical alignment type liquid crystal display device according to the ninth aspect of the present invention, wherein at least one first optical anisotropic element exhibiting a phase difference of 1/4 wavelength and a linearly polarizing plate are disposed. ,

According to a first aspect of the present invention, there is provided a third optical element having negative uniaxial optical anisotropy in at least one thickness direction between the first optical anisotropic element and the vertical alignment type liquid crystal cell. The vertical alignment type liquid crystal display device according to the ninth or 10th aspect of the present invention, characterized by having an anisotropic element. A first aspect of the present invention includes the fourth optical anisotropic element having positive uniaxial optical anisotropy in an in-plane direction between the vertical alignment type liquid crystal cell and the linearly polarizing plate. A vertical alignment type liquid crystal display device according to any of 9th to 11th of the present invention.

A first aspect of the present invention is the present invention, wherein the first optical anisotropic element exhibits a phase difference of 1 Z 4 wavelength in a plane and has negative biaxial optical anisotropy. The vertical alignment type liquid crystal display device according to any one of Items 9 to 12.

A fourteenth aspect of the present invention is the ninth to thirteenth aspects of the present invention, wherein one substrate of the vertical alignment type liquid crystal cell is a substrate having a region having a reflection function and a region having a transmission function. The vertical alignment type liquid crystal display device described.

[The invention's effect]

When the elliptical polarizing plate for a vertical alignment type liquid crystal display device of the present invention using a homeotopic pick E-direction liquid crystal film is arranged in a vertical alignment type liquid crystal display device, the viewing angle can be widened. The vertical alignment type liquid crystal display device has a bright display and is capable of high contrast display in all directions.

[Best Mode for Carrying Out the Invention]

Hereinafter, the present invention will be described in detail.

The elliptically polarizing plate for vertical alignment type liquid crystal display device of the present invention will be described.

The elliptically polarizing plate for a vertical alignment type liquid crystal display device according to the present invention comprises a homeo-mouth-pick-aligned liquid crystal film in which a liquid crystal material exhibiting at least positive uniaxial property is home-mouth pick-aligned in a liquid crystal state and then the orientation is fixed. It consists of a linear polarizing plate. In the present invention, as a liquid crystal material used for obtaining a liquid crystal film in which the homeotropic orientation of the liquid crystal material is fixed, the alignment film is formed on the alignment substrate or on the alignment substrate and then formed. The liquid crystal material may be a positive uniaxial liquid crystal material that can be homeotropically aligned and fix the alignment, and may be a material composed of a low molecular liquid crystal compound, a liquid crystal polymer compound, or a mixture thereof.

As the low-molecular liquid crystal compound, a compound having a reactive group that reacts with light or heat is preferable because the alignment can be easily fixed. Examples of reactive groups include bur, attalyloyl, buroxy, oxylanyl, oxetanyl, and aziridinyl groups. However, other reactive groups such as an isocyanate group, a hydroxyl group, an amino group, an acid anhydride group, and a strong loxyl group can also be used depending on the reaction conditions. The liquid crystalline polymer compound includes a main chain type liquid crystal polymer and a side chain type liquid crystal polymer, both of which can be used. Examples of the main chain type liquid crystal polymer include polyester, polyester imide, polyamide, and polycarbonate. Among these, liquid crystalline polyesters are preferable from the viewpoint of ease of synthesis, orientation, glass transition point, and the like, and main chain type liquid crystalline polyesters bonded with cationic polymerizable groups are particularly preferable. Examples of the side chain type liquid crystal polymer include polyacrylate, polymalonate, polysiloxane and the like. The liquid crystal polymer preferably has the above-described reactive group bonded thereto.

The home-orientated pick-aligned liquid crystal film used in the present invention is, for example, developed by spreading the above-mentioned liquid crystal material on an alignment substrate, aligning the liquid crystal material, and then subjecting to light irradiation and Z or heat treatment as necessary, followed by cooling. By doing so, it can be manufactured by fixing the orientation state.

The main-chain liquid crystalline polyester includes an aromatic diol unit (hereinafter referred to as a structural unit (A)), an aromatic dicarboxylic acid unit (hereinafter referred to as a structural unit (B)), and an aromatic hydroxycarboxylic acid. A main-chain liquid crystalline polyester containing at least two types of units (hereinafter referred to as structural unit (C)) as essential units, and having a cationically polymerizable group at least at one end of the main chain It is a main chain type liquid crystalline polyester characterized by containing. Hereinafter, the structural units (A), (B) and (C) will be sequentially described.

As the compound for introducing the structural unit (A), a compound represented by the following general formula (a) is preferable. Specifically, catechol, resorcin, hydroquinone or the like, or a substituted product thereof, 4, bibienol, 2, 2, 6, 6, 6, tetramethyl 4, 4, bibienol, 2, 6-naphthalene diol, etc. Especially, catechol, resorcin, hydroquinone, etc. or their substitutes are preferred. Les.

However, 1 X in the formula is 1 H, 1 CH ₃ , 1 C ₂ H ₅ , 1 CH ₂ CH ₂ CH ₃ , 1 CH (CH ₃ ) ₂ , —CH ₂ CH ₂ CH ₂ CH ₃ , — CH ₂ CH (CH ₃ ) CH ₃ , — CH (CH ₃ ) CH ₂ CH ₃ , 1 C (CH ₃ ) ₃ , —〇CH ₃ , —OC ₂ H ₅ , — OC ₆ H ₅ , 1 OCH ₂ C ₆ One of H ₅ , 1 F, —CI ₂ , —Br, 1 N0 ₂ , and 1 CN ″, particularly a compound represented by the following formula (a ′) is preferable.

As the compound for introducing the structural unit (B), a compound represented by the following general formula (b) is preferable. Specifically, terephthalic acid, isophthalic acid, phthalic acid or the like, or a substituted product thereof, 4, 4, 1-stilbene dicarboxylic acid or its substitutes, 2, 6 1-naphthalenedicarboxylic acid, 4, 4 '1 biphenyl dicarboxylic acid, etc., especially terephthalic acid, isophthalic acid, phthalic acid etc. or their substitution I like the body

1 X in the formula is 1 H, 1 CH ₃ , 1 C ₂ H ₅ , 1 CH ₂ CH ₂ CH ₃ ,-CH (CH ₃ ) ₂ , — CH ₂ CH ₂ CH ₂ CH ₃ , — CH ₂ CH (CH ₃ ) CH ₃ , _C H (CH ₃ ) CH ₂ CH ₃ , 1 C (CH ₃ ) ₃ , —OCH ₃ , — OC ₂ H ₅ , 1 OC ₆ H ₅ , 1 OCH ₂ C ₆ H ₅ represents an F, _C 1, one B r, one N_〇 ₂ or a CN, whichever is the group.

As the compound for introducing the structural unit (C), a compound represented by the following general formula (c) is preferable. Specifically, hydroxybenzoic acid or a substituted product thereof, 4′-hydroxy 4-biphenyl Carboxylic acid or a substituted product thereof, 4′-hydroxy-1,4-stilbene carboxylic acid or a substituted product thereof, 6-hydroxy-2-naphthoic acid, 4-hydroxycinnamic acid, etc., particularly, hydroxybenzoic acid And a substituted product thereof, 4′-hydroxyl-4-biphenylcarboxylic acid or a substituted product thereof, and 4′-hydroxy-4-stilbene carboxylic acid or a substituted product thereof are preferable.

However, 1 X, 1 X and 1 X ₂ in the formula are respectively independently 1 H, _CH ₃ , 1 C ₂ H ₅ , — CH ₂ CH ₂ CH ₃ , — CH (CH ₃ ) ₂ , _ CH ₂ CH ₂ CH ₂ CH ₃ ,-CH ₂ CH (CH ₃ ) CH ₃ , 1 CH (CH ₃ ) CH ₂ CH ₃ , 1 C (CH ₃ ) ₃ ,-OCH ₃ , 1 OC ₂ H ₅ , 1 OC ₆ H ₅ , _ 0 CH ₂ C ₆ H ₅ , 1 F, 1 Cl, 1 Br, 1 N 0 ₂ , or 1 CN

The main chain type liquid crystalline polyester is preferably at least two kinds of structural units selected from (A) aromatic diol units, (B) aromatic dicarboxylic acid units, and (C) aromatic hydroxycarboxylic acid units. May further include a structural unit having a cationic polymerizable group (hereinafter referred to as “structural unit (D)”) at least at one of the ends of the main chain, as long as it exhibits thermomorphic liquid crystallinity. There is no particular limitation as long as the conditions are satisfied.

The proportion of the structural units (A;), (B) and (C) constituting the main-chain liquid crystalline polyester in the total structural units is that the structural units (A), (B) and (C) are diols or When expressed as a ratio of the total weight of dicarboxylic acid or hydroxycarboxylic acid to the total amount of monomers charged, it is usually 20 to 99%, preferably 30 to 95%, particularly preferably 40 to 90%. % Range. If it is less than 20%, the temperature range where liquid crystallinity is developed may be extremely narrow, and if it exceeds 99%, the number of units having a cationic polymerizable group will be relatively small, and the orientation will be maintained. Performance and mechanical strength may not be improved.

Next, the structural unit (D) having a cationic polymerizable group will be described. As the cationic polymerizable group, a functional group selected from the group consisting of an epoxy group, an oxetanyl group, and a vinyloxy group is preferable, and an oxetanyl group is particularly preferable. As a compound for introducing the structural unit (D), as shown in the following general formula (d), an aromatic compound having a phenolic hydroxyl group or a carboxyl group is added to an epoxy group, an oxetanyl group, and buroxy. Functional group having cationic polymerizability selected from a group Is a compound to which is bound. Further, an appropriate spacer portion may be provided between the aromatic ring and the cationic polymerizable group.

In the formula, 1 X, 1 X 1 X ₂ , 1 Y, and 1 表す each independently represent one of the following groups for each structural unit.

(1) — X, 1 X 1 ₂ : — Η, 1 CH ₃ , 1 C ₂ H ₅ , — CH ₂ CH ₂ CH ₃ , 1 CH (CH ₃ ) ₂ , — CH ₂ CH ₂ CH ₂ CH ₃ , —CH ₂ CH (CH ₃ ) CH ₃ , —CH (CH ₃ ) CH ₂ CH ₃ , —C (CH ₃ ) ₃ , 1 OCH ₃ , — OC ₂ H ₅ , — OC ₆ H ₅ , 1 OCH ₂ C ₆ H ₅ , 1 F, 1 C l, 1 Br, 1 N0 ₂ , or 1 CN

(2) — Y: single bond, — (CH ₂ ) _n —, _0—, — O— (CH ₂ ) _n —, one (CH ₂ ) _{n —} ○ _, one O— (CH ₂ ) _n — O —, — O— CO—, _c〇_o—, — O— CO— (CH ₂ ) _n —, —CO— O— (CH ₂ ) _n —, One (CH ₂ ) _n —〇_CO—, One (CH ₂ ) _n — CO—〇—, One O— (CH ₂ ) _n _0— CO—, — O— (CH ₂ ) _n — CO— O—, — O— CO— (CH ₂ ) _n — ○ One, one CO— O— (CH ₂ ) _{n —} ○ One, one O— CO— (CH ₂ ) _n — O— CO—, One O— CO— (CH ₂ ) _n — CO— O One, one CO—O— (CH ₂ ) _n —O—CO—, or one CO—O— (CH ₂ ) _n —CO—O— (where n represents an integer from:! To 1 2)

(3) Z:

i-

~. d--o-- ₀ '

In the structural unit (D), the bonding position of a cation polymerizable group or a substituent containing a cation polymerizable group and a phenolic hydroxyl group or carboxylic acid group is 1 when the skeleton to which these groups are bonded is a benzene ring. , 4—, in the case of a naphthalene ring, in the case of a 2, 6— positional relationship, in the case of a biphenyl skeleton or a stilbene skeleton, a 4, 4′_ positional relationship is preferred from the viewpoint of liquid crystallinity. More specifically, 4-bioxybenzoic acid, 4-buoxyphenol, 4-bioxyethoxybenzoic acid, 4-vinyloxyethoxyphenol, 4-glycidyloxybenzoic acid, 4-glycidyloxy Phenols, 4-I (oxetanylmethoxy) benzoic acid, 4-— (Oxetaninolemetoxy) Phenols, 4'Ivininoreoxy 4-Bibinenoleoxynorenoic acid, 4, -Vininoreoxy 1-Hydroxybiphenyl, 4'-Bulauxitoxy 4-biphenyl carboxylic acid, 4 'mono-bruchetoxy 4 4-hydroxy diphenyl, 4'-glycidyloxy 4- 4-phenyl carboxylic acid, 4'-glycidinoreoxy 4- 4-hydroxy biphenyl, 4 '-Oxetanilmethoxy 1-biphenolate norevonic acid, 4'-Oxetaninoremetoxy 4-Hydroxybiphenyl, 6-Buroxy-2, 1-Naphthalenecarboxylic acid, 6-Bieloxy-1, 2-Hydroxy Sinaphthalene, 6-Vinoxyethoxy-2-naphthalenecarboxylic acid, 6-Binyloxychetoxy 2-hydroxynaphthalene, 6-glycidyloxy-2-naphthalenecarboxylic acid, 6-glycidinoreoxy-1-hydroxynaphthalene, 6-oxetanylmethoxy-2-naphthalenecarboxylic acid, 6_oxetalum —Hydroxynaphthalene, 4-Buroxycinnamic acid, 4-Vinoxyxuccinamic acid, 4-Glycidyloxycinnamic acid, 4-Oxetanylmethoxycinnamic acid, 4′-Buroxy 1 4-Stilbene power Norebonic acid, 4, 1 Vinyloxy 1 3 '—Methoxy 4-stinolevene carboxylic acid, 4' Moninoreoxy 4 -Hydroxystinole 4'-Butoxyethoxy 4-stilbene carboxylic acid, 4'-vinyloxy succinoxy 3'-methoxy 4-stilbene-powered norevonic acid, 4, -vininoreoxytoxyl 4-hydroxy stynoleben, 4, 1 Glycidinore xylone 4 1 Stilbene strength Nolevonic acid, 4'-Glycidyloxy 1 3'-Methoxyl 1-Stilbene strength Norevonic acid, 4'-Glycidinoreoxy 1 4-Hydroxistinoleven 4'-oxetaninoremethoxy 4-mono-stilbene carboxylic acid, 4'-oxetanyl meth- oxy 3'-methoxy 4-stilbene carboxylic acid, 4'-oxetaermetoxy 4_hydroxystilbene and the like are preferable.

The proportion of the structural unit (D) having a cationic polymerizable group to the total structural units constituting the main-chain liquid crystalline polyester is similarly the weight proportion in the composition charged with the structural unit (D) as a carboxylic acid or phenol. When expressed, it is usually in the range of 1 to 60%, preferably 5 to 50%. If it is less than 1%, the orientation holding ability and mechanical strength may not be improved, and if it exceeds 60%, the crystallinity will increase and the liquid crystal temperature range will be narrowed. This is also not preferable.

Each structural unit of (A) to (D) has one or two carboxyl groups or phenolic hydroxyl groups, but the carboxyl groups and phenolic hydroxyl groups of (A) to (D) are It is desirable that the total number of equivalents of each functional group is roughly aligned at the preparation stage. That is, when the structural unit (D) is a unit having a free carboxyl group, ((A) moles X 2) = ((B) moles X 2) + ((D) moles Number), when the structural unit (D) is a unit having a free phenolic hydroxyl group, (number of moles of (A) X 2) + (number of moles of (D)) = (of (B) It is desirable to satisfy the following relationship: In the case of a feed composition that greatly deviates from this relational expression, a carboxylic acid or phenol other than the unit involved in cationic polymerization, or a derivative thereof becomes the molecular end, and sufficient cationic polymerization is not obtained. The presence of these acidic residues is not preferable because a polymerization reaction or a decomposition reaction may occur at a stage other than the desired stage in the process.

The main-chain liquid crystalline polyester can contain structural units other than (A), (B), (C) and (D). Other structural units that can be contained are not particularly limited, and compounds (monomers) known in the art can be used. For example, Naphthalenedicarboxylic acid, biphenyldicarboxylic acid, aliphatic dicarboxylic acid, compounds in which halogen groups or alkyl groups are introduced into these compounds, and bifunonol, naphthalenediol, aliphatic diols, and compounds in which halogen groups or alkyl groups are introduced And the like.

In addition, when an optically active compound is used as a raw material of a unit constituting the main chain type liquid crystalline polyester, a chiral phase can be imparted to the main chain type liquid crystalline polyester. There are no particular limitations on the powerful optically active compound. For example, an optically active aliphatic alcohol (C _n H _{2n + 1} OH, where n represents an integer of 4 to 14), an optically active aliphatic group Alkoxybenzoic acid (C _n H _{2n + 1} O 1 P h—COOH, where n is an integer from 4 to 14, P h represents a fuel group), menthol, camphoric acid, naproxen derivative, binaphthol, Examples include 1,2-propanediol, 1,3-butanediol, 2-methylbutanediol, 2-chlorobutanediol, tartaric acid, methylsuccinic acid, and 3-methyladipic acid.

The molecular weight of the main-chain liquid crystalline polyester is: logarithmic viscosity 77 measured at 30 ° C in phenol Z tetrachloroethane mixed solvent (mass ratio 60/40) is 0.03 to 0.5 0 d lZg Is more preferably 0.05 to 0.15 dl / g. When is less than 0.03 d 1, the solution viscosity of the main-chain liquid crystalline polyester is low, and a uniform coating film may not be obtained when forming a film. On the other hand, when it is larger than 0.50 d 1 Zg, the alignment treatment temperature required for liquid crystal alignment becomes high, and there is a risk that alignment and crosslinking occur simultaneously and alignment is lowered.

In the present invention, the molecular weight control of the main-chain liquid crystalline polyester is determined solely by the charged composition. Specifically, the monofunctional monomer that reacts in the form of sealing both ends of the molecule, that is, the main content obtained by the relative content of the compound for introducing the structural unit (D) in the total charged composition. The average degree of polymerization (average number of bonds of structural units (A) to (D)) of the chain-type liquid crystalline polyester is determined. Therefore, in order to obtain a main-chain liquid crystalline polyester having the desired logarithmic viscosity, it is necessary to adjust the charged composition according to the type of charged monomer.

The method for synthesizing the main chain type liquid crystalline polyester may be a method used for synthesizing ordinary polyester, and is not particularly limited. For example, A method in which a carboxylic acid unit is activated to an acid chloride or sulfonic anhydride and the like is reacted with a phenol unit in the presence of a base (acid chloride method), and a carboxylic acid unit and a phenol unit are converted to DCC (dicyclohexane). A direct condensation method using a condensing agent such as xylcarbodiimide), a method in which a phenol unit is acetylated, and this and a carboxylic acid unit are subjected to deacetic acid polymerization under melting conditions can be used. However, when using deacetic acid polymerization under melting conditions, the monomer units having a cationically polymerizable group may undergo polymerization or decomposition under the reaction conditions, so the reaction conditions must be strictly controlled. In many cases, an appropriate protecting group is used in some cases, or a compound having another functional group is reacted once and then a cation-polymerizable group is introduced later. Sometimes it is desirable. The crude main-chain liquid crystalline polyester obtained by the polymerization reaction may be purified by methods such as recrystallization and reprecipitation.

The main chain type liquid crystalline polyester thus obtained is analyzed by means such as NMR (nuclear magnetic resonance) to determine the proportion of each monomer present in the main chain type liquid crystalline polyester. Can be identified. In particular, the average number of bonds of the main chain type liquid crystalline polyester can be calculated from the amount ratio of the cationic polymerizable group.

It is also possible to mix other compounds with the main-chain liquid crystalline polyester containing the cationic polymerizable group as long as the scope of the present invention is not exceeded. For example, other high molecular compounds miscible with the main-chain liquid crystalline polyester used in the present invention and various low molecular compounds may be added. Such a low molecular weight compound may or may not have liquid crystallinity, and may or may not have a polymerizable group capable of reacting with a crosslinkable main chain liquid crystalline polyester. It is preferable to use a liquid crystalline compound having a polymerizable group, and examples thereof include the following.

Here, n represents an integer of 2 to 12, and 1 V— and 1 W each represent one of the following groups.

—V—: Single bond, 101, 1 O— C _m H _{2m —} 0 (where m is an integer from 2 to 12) — W:

When the added high molecular compound or low molecular compound is optically active, a chiral liquid crystal phase can be induced as a composition. Such a composition can be used for producing a film having a twisted nematic alignment structure or a cholesteric alignment structure.

As described above, the side chain type liquid crystal polymer includes poly (meth) acrylate, poly Malonate, polysiloxane, etc. are mentioned.

Poly (meth) acrylate with a reactive group bonded thereto is preferred.

In the formula (1), each R ³ independently represents hydrogen or a methyl group, and each R ⁴ independently represents hydrogen, methyl group, ethyl group, butyl group, hexyl group, octyl group, Noel Group, decyl group, dodecyl group, methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, cyano group, bromo group, black mouth group , A fluoro group or a carboxyl group, R ⁵ independently represents hydrogen, a methyl group or an ethyl group, R ⁶ represents a hydrocarbon group having 1 to 24 carbon atoms, and L ² represents Independently, a single bond, 10_, 1 O— CO_, —CO _0—, 1 CH═CH— or 1 C≡C—, p represents an integer from 1 to 10 and q represents 0 to 1 0 A, b, c, d, e and f are the molar ratio of each unit in the polymer (a + b + c + d + e + f = l. 0, where c + d + e = Not 0)

The molar ratio of each component constituting the side chain type polymer liquid crystal compound represented by the formula (1) is as follows: a + b + c + d + e + f = l.0, c + d + e = 0 It is necessary to exhibit liquid crystallinity. The molar ratio of each component may be arbitrary as long as this requirement is satisfied, but is preferably as follows.

a: preferably 0 to 0.80, more preferably 0.05 to 0.50 b Preferably 0 to 0.90, more preferably 0.1 0 to 0.70 c preferably 0 to 0.50, more preferably 0.1 0 to 0.30

d Preferably 0 to 0.50, more preferably 0.1 0 to 0.30

e Preferably 0 to 0.50, more preferably 0.1 0 to 0.30

f Preferably 0 to 0.30, more preferably 0.0 1 to 0.10

Each component in these poly (meth) acrylates does not need to be present in all six types as long as the above conditions are met.

R ⁴ is preferably hydrogen, a methyl group, a butyl group, a methoxy group, a cyano group, a promo group, or a fluoro group, particularly preferably hydrogen, a methoxy group, or a cyano group, and L ² is preferably a single bond, 10_, 1 O—CO— or 1 C 0—0, and R ⁶ is preferably of 2, 3, 4, 6, 8 and 18 Represents a hydrocarbon group.

Furthermore, the birefringence of the side chain type polymer liquid crystalline compound represented by the general formula (1) varies depending on the molar ratio of each component a to f and the orientation form, but the birefringence when nematic orientation is adopted. The rate is preferably 0.001 to 0 _: 300, more preferably 0.05 to 0.25.

Each (meth) acrylic compound corresponding to each component of the above-mentioned side chain type liquid crystal polymer can be obtained by an ordinary organic chemical synthesis method. A (meth) acrylic compound having an oxetanyl group can be easily obtained by a method similar to the synthesis of compounds corresponding to formulas (7), (8) and (9) described later.

Said side chain type liquid crystal polymer can be easily synthesized by copolymerizing the (meth) acrylic group of each (meth) acrylic compound obtained by the above method corresponding to each component by radical polymerization or cation polymerization. Can do. Polymerization conditions are not particularly limited, and normal conditions can be employed.

As an example of radical polymerization, a (meth) acrylic compound corresponding to each component is dissolved in a solvent such as dimethylformamide (DMF) or diethylene glycol dimethyl ether, and 2, 2, mono-bisisopropylonitrile (AI BN) or peroxynitrile is used. A method of reacting at 60 to 120 ° C. for several hours using benzoyl oxide (B 3 PO) or the like as an initiator can be mentioned. In order to make the liquid crystal phase appear stably, copper bromide (I) / 2,2'-bibilidyl series and 2, 2, 6, 6-tetramethylpiperidinoxy 'free radical A method of controlling the molecular weight and distribution by conducting living radical polymerization using a TEMPO system as an initiator is also effective. These radical polymerizations must be carried out under deoxygenated conditions.

As an example of anionic polymerization, the (meth) acrylic compound corresponding to each component is dissolved in a solvent such as tetrahydrofuran (THF) and reacted with a strong base such as an organolithium compound, an organic sodium compound, or a Grignard reagent as an initiator. Can be mentioned. It is also possible to control the molecular weight distribution by optimizing the initiator and reaction temperature for living anion polymerization. These anion polymerizations must be performed under dehydration and deoxygenation conditions.

The side chain type liquid crystal polymer preferably has a weight average molecular weight of 1,000 to 200,000, particularly preferably 3,000 to 50,000. Outside this range, the strength is insufficient or the orientation is deteriorated.

In the present invention, the liquid crystalline composition preferably contains a dioxetane compound represented by the following general formula (2).

In the formula (2), each R ⁷ independently represents hydrogen, a methyl group or an ethyl group, and each L ³ independently represents a single bond or one (CH ₂ ) _n — (n is 1 to 1 2 ′ X ¹ represents each independently a single bond, 10—, 10—CO— or _C〇_〇1, and M ¹ is represented by formula (3) or formula (4). In the formula (3) and the formula (^^, each independently represents a group selected from the formula (5), P ² represents a group selected from the formula (6), L ⁴ each independently represents a single bond, 1 CH═CH—, 1 C≡C—, 1 O—, 1 0—CO— or 1 CO—0.

One P ¹ ——— P ² —I—P ¹ — (3)

— P ¹ —Iichi P ¹ — (4)

In the formulas (5) and (6), E t represents an ethyl group, i Pr represents an isopropyl group, n B u represents a normal butyl group, and t B u represents a tertiary butyl group.

More specifically, the linking groups connecting the left and right oxetanyl groups as seen from the M ¹ group may be different (asymmetric) or the same (symmetric), especially when the two L ³ are different or other Depending on the structure of the linking group, it may not exhibit liquid crystallinity, but it is not a restriction on its use.

As the compound represented by the general formula (2), many compounds can be exemplified from the combination of ML ³ and X ¹ , but preferably, the following compounds can be listed.

These compounds can be synthesized according to ordinary synthesis methods in organic chemistry, and the synthesis method is not particularly limited.

In the synthesis, since the oxetanyl group has cationic polymerizability, it is necessary to select reaction conditions in consideration of the occurrence of side reactions such as polymerization and ring opening under strong acidic conditions. The oxetanyl group is less likely to cause a side reaction than the similar cationic polymerizable functional group oxylanyl group. Furthermore, various compounds such as similar alcohols, phenols, and carboxylic acids may be reacted successively, and the use of protecting groups may be considered as appropriate.

As a more specific synthesis method, for example, hydroxybenzoic acid is used as a starting compound, an oxetanyl group is bonded by Williamson's ether synthesis method, etc., and a diol suitable for the present invention and a diol suitable for the present invention are used. Are bonded using an acid chloride method using a condensation method using carbodiimide or the like, and conversely, the hydroxyl group of hydroxybenzoic acid is protected in advance with an appropriate protecting group, and after condensation with a diol suitable for the present invention, A compound having an appropriate oxetanyl group (oxetane compound) such as halo after removing the protecting group Examples include a method of reacting argyloxetane and the like with a hydroxyl group. For the reaction between the oxetane compound and the hydroxyl group, a reaction condition suitable for the form and reactivity of the compound to be used may be selected. Usually, the reaction temperature is 120 ° C. to 180 ° C., preferably A temperature of 10 ° C. to 1550 ° C. is selected, and the reaction time is 10 minutes to 48 hours, preferably 30 minutes to 24 hours. Outside these ranges, the reaction does not proceed sufficiently or side reactions occur, which is not preferable. The mixing ratio of the two is preferably 0.8 to 1.2 equivalents of oxetane compound per equivalent of hydroxyl group.

In the liquid crystal material used in the present invention, in addition to the side chain type liquid crystal polymer, various compounds that can be mixed without impairing liquid crystallinity can be contained. The compounds that can be contained include compounds having a cationic polymerizable functional group such as an oxetal group, an epoxy group, and a butyl ether group, various polymer materials having film-forming ability, and various low liquid crystal properties. Examples thereof include molecular liquid crystal compounds and polymer liquid crystal compounds. When the side chain liquid crystal polymer is used as a composition, the proportion of the side chain liquid crystal polymer in the entire composition is 10% by mass or more, preferably 30% by mass or more, and more preferably 50%. It is at least mass%. The content of the side chain type liquid crystal polymer is 10 mass. If it is less than ₀ , the film-forming ability is insufficient or the polymerizable group concentration in the composition is low, and the mechanical strength after polymerization becomes insufficient, which is not preferable.

Further, after the liquid crystal material is subjected to an alignment treatment, the liquid crystal state can be fixed by cationically polymerizing the oxetanyl group and crosslinking. For this reason, it is preferable that the liquid crystal material contains a light-power thione generator that generates cations by an external stimulus such as light and heat, and a hydrogen or thermal cation generator. If necessary, various sensitizers may be used in combination.

The photopower thione generator means a compound capable of generating a cation by irradiating with light of an appropriate wavelength, and examples thereof include organic sulfate salt systems, podonium salt systems, and phosphonium salt systems. Antimonates, phosphates, borates and the like are preferably used as counter ions of these compounds. Specific compounds include Ar ₃ S + S b F _6- , A r ₃ P + BF ₄ —, A r ₂ I + PF ₆ ^_ (where A r is a phenyl group or a substituted group) A dil group) and the like. In addition, sulfonic acid esters, triazines, diazomethanes, ketosulfone, iminosulfonate, benzoinsulfonate and the like can also be used. Thermal cation generators are compounds that can generate cations when heated to a suitable temperature, such as benzylsulfonium salts, benzylammoyuum salts, benzylpyridinium salts, benzylphosphonium. Salts, hydrazinium salts, carboxylic acid esters, sulfonic acid esters, ammine imides, antimony pentachloride acetyl chloride complex, diallydonium salt-dibenzyloxy copper, boron halide primary tertiary amine adduct, etc. Can be mentioned.

The amount of these cation generators added to the liquid crystal material varies depending on the structure of the mesogenic portion or spacer portion constituting the side chain type liquid crystalline polymer used, the oxetanyl group equivalent, the liquid crystal alignment conditions, etc. Therefore, it cannot be generally stated, but usually 100 mass ppm to 20 mass%, preferably 10 mass to pp 111 to 10 mass%, more preferably 0 to the side chain type liquid crystalline polymer substance. The range is from 2% to 7% by weight. If the amount is less than 100 ppm by mass, the amount of cations generated may not be sufficient and polymerization may not proceed. If the amount is more than 20% by mass, cations remaining in the liquid crystal film may be generated. It is not preferable because the decomposition residue of the agent increases and the light resistance may deteriorate. Next, the alignment substrate will be described.

As the alignment substrate, a substrate having a smooth plane is preferable, and examples thereof include a film or sheet made of an organic polymer material, a glass plate, and a metal plate. From the viewpoint of continuous productivity, it is preferable to use a material made of an organic polymer. Examples of organic polymer materials include polyvinyl alcohol, polyimide, polyphenol-oxide, polyphenylene norfide, polysenorephone, polyethenoreketone, polyethenoreethenoleketone, polyarylate, polyethylene terephthalate, polyethylene naphthalate, and other polyesters Examples thereof include a film made of a transparent polymer such as an acryl-based polymer, a ce / relose-based polymer such as diacetyl cellulose or triacetinoresenorelose, a polycarbonate polymer, or an acryl-based polymer such as polymethyl methacrylate. Also, styrene polymers such as polystyrene, acrylonitrile styrene copolymers, olefin polymers such as polyethylene, polypropylene, ethylene propylene copolymers, polycyclohexylene, vinyl chloride polymers, nylon and aromatic polyamides. Transparent polymers such as amide polymers A film made of mer is also included. These may be blends.

Among these, plastic films such as triacetyl cellulose, polycarbonate, polycyclohexylin and the like used as optical films are used. Examples of organic polymer film include norbornene such as ZENOA (trade name, manufactured by ZEON CORPORATION), ZEONEX (trade name, manufactured by ZEON CORPORATION), Arton (trade name, manufactured by JSR Corporation), etc. A plastic film made of a polymer material having a structure is preferable because it has excellent optical properties. Moreover, as a metal film, the said film formed from aluminum etc. is mentioned, for example.

In order to obtain homeotropic orientation with stability using the liquid crystal materials described above, the materials constituting these substrates are long-chain (usually 4 or more, preferably 8 or more) alkyl groups or fluorinated. It is more preferable to have a hydrocarbon group or to have a compound layer having these groups on the substrate surface. These organic polymer materials may be used alone as a substrate, or may be formed as a thin film on another substrate. The process of forming a compound layer (alignment film) having a long chain (usually 4 or more carbon atoms, preferably 8 or more) alkyl group or fluorinated hydrocarbon group will be described.

The material for forming the alignment film is preferably applied in a solution state from the viewpoint of controlling the alignment film thickness and surface properties. The solution can be appropriately performed using a solvent capable of dissolving the material. For example, the solvent for preparing the PVA solution is not particularly limited as long as it can dissolve the PVA, and usually a mixture of water, lower alcohol such as methanol, ethanol, isopropyl alcohol, or the like is used.

In the dissolution, various additives that do not adversely affect the coating and the alignment of the liquid crystal may be added. Moreover, you may heat in order to accelerate | stimulate melt | dissolution.

There are no particular restrictions on the coating method used to form the alignment film on the substrate. Especially, the coating method for large-area alignment films is flexographic printing using a soft resin plate, dispenser method, gravure coating method. , Micro gravure method, screen printing method, lip coating method, die coating method and the like. Of these, the gravure coating method, the lip coating method and the die coating method are preferable.

The applied alignment film is dried if necessary. The drying temperature is usually limited in the case of PVA due to its heat resistance, but may be higher depending on the purpose. Generally, it is 50 ° C to 180 ° C, preferably 80 ° C to 160 ° C. Also drying time Although there is no particular limitation, it is usually 10 seconds to 60 minutes, preferably 1 minute to 30 minutes. The relative moving speed between the film to be dried and the drying apparatus is preferably 60 m / min to 120 m mmin in terms of relative wind speed.

In the field of liquid crystals, rubbing is generally performed by rubbing the substrate with a cloth or the like in a certain direction. However, the home-orientation pick alignment liquid crystal film used in the present invention is anisotropic in the plane. Since it is an orientation structure that does not produce any basic properties, rubbing is not necessarily required. However, it is more preferable to apply a weak rubbing treatment from the viewpoint of suppressing repelling when a liquid crystal material is applied. An important setting value that defines the rubbing condition is the peripheral speed ratio. This represents the ratio of the movement speed of the cloth to the movement speed of the substrate when the rubbing cloth is wound around a roll and rubbed while the substrate is rubbed. In the present invention, the weak rubbing treatment usually has a peripheral speed ratio of 50 or less, more preferably 25 or less, and particularly preferably 10 or less. When the peripheral speed ratio is larger than 50, the effect of rubbing is too strong, and the liquid crystal material cannot be perfectly aligned vertically, and the alignment may fall in the in-plane direction from the vertical direction. Next, a method for producing a homeotopic picked liquid crystal film used in the present invention will be described. Although the method for producing the liquid crystal film is not limited to these, the above-mentioned liquid crystal material is spread on the above-mentioned alignment substrate, and after aligning the liquid crystal material, light irradiation and / or heat treatment is performed. Thus, it can be produced by fixing the orientation state.

The liquid crystal material is spread on the alignment substrate to form the liquid crystal material layer. The liquid crystal material can be applied directly on the alignment substrate in a molten state, or the liquid crystal material solution can be applied on the alignment substrate and then applied. The method of drying a film | membrane and distilling a solvent off is mentioned.

The solvent used for preparing the solution is not particularly limited as long as it can dissolve the liquid crystal material of the present invention and can be distilled off under suitable conditions. Generally, ketones such as acetone, methyl ethyl ketone, isophorone, and cyclohexanone are used. , Butoxychetinorea ^ call, hexyloxyethyl alcohol, ether alcohols such as methoxy-2-prononol, glycol ethers such as ethylene glycol dimethyl etherol and diethylene glycol dimethyl ether, ethyl acetate, lactyl acetate Estenoles, etc., Phenolic, Phenolics such as Black-headed Fuenore, N, N-Di Preferably used are amides such as methylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, halogens such as chlorophonolem, tetrachloroethane, dichlorobenzene, and the like, and mixtures thereof. In order to form a uniform coating film on the alignment substrate, a surfactant, an antifoaming agent, a leveling agent, a coloring agent, or the like may be added to the solution.

Furthermore, in order to facilitate the fixing of the alignment of the liquid crystalline polymer compound described above, two groups having the same reactivity as the polymerizable group bonded to the liquid crystal polymer compound are contained in one molecule. Various low molecular compounds (whether liquid crystalline or non-liquid crystalline) or various compounds that can improve adhesion can be added.

Regardless of the method of directly applying the liquid crystal material or the method of applying the solution, the application method is not particularly limited as long as it is a method that ensures the uniformity of the coating film, and a known method is adopted. Can do. Examples include spin coating, die coating, curtain coating, dip coating, and roll coating.

In the method of applying the liquid crystal material solution, it is preferable to include a drying step for removing the solvent after the application. As long as the uniformity of a coating film is maintained, this drying process can employ | adopt a well-known method, without being specifically limited. For example, there are methods such as a heater (furnace) and hot air blowing.

The film thickness of the liquid crystal film cannot be generally described because it depends on the method of the liquid crystal display device and various optical parameters, but is usually 0.2 μπι to 10 ηι, preferably 0.3 111 to 5 111, More preferably, it is 0.5 111 to 2 111. If the film thickness is thinner than 0.2 μm, it may not be possible to obtain a sufficient viewing angle improvement or brightness enhancement effect. Further exceeds 1 0 μ πι, a liquid crystal display device is a fear force ^s such browned unnecessarily.

Subsequently, the liquid crystal material layer formed on the alignment substrate is formed into a liquid crystal alignment by a method such as heat treatment, and is cured and fixed by light irradiation and / or heat treatment. In the first heat treatment, the liquid crystal is aligned by the self-alignment ability inherent in the liquid crystal material by heating to the liquid crystal phase expression temperature range of the liquid crystal material used. The conditions for the heat treatment vary depending on the liquid crystal phase behavior temperature (transition temperature) of the liquid crystal material to be used, because the optimum conditions and limit values are different — generally not 10 – 25 ° C, preferably 30 The temperature is in the range of ° C to 160 ° C, and the temperature is more than the glass transition point (T g) of the liquid crystal material, more preferably Heat treatment is preferably performed at a temperature higher by 1 ° C or more. If the temperature is too low, the liquid crystal alignment may not proceed sufficiently, and if the temperature is high, the cationically polymerizable reactive group in the liquid crystal material may adversely affect the alignment substrate. The heat treatment time is usually in the range of 3 seconds to 30 minutes, preferably 10 seconds to 20 minutes. If the heat treatment time is shorter than 3 seconds, the liquid crystal alignment may not be sufficiently completed, and if the heat treatment time exceeds 30 minutes, the productivity will be deteriorated. After the liquid crystal material layer is formed into a liquid crystal alignment by a method such as heat treatment, the liquid crystal material is cured by a polymerization reaction of oxetanyl groups in the composition while maintaining the liquid crystal alignment state. The purpose of the curing step is to fix the completed liquid crystal alignment by a curing (crosslinking) reaction and to modify it into a stronger film.

Since the liquid crystal material of the present invention has a polymerizable oxetal group, it is preferable to use a cationic polymerization initiator (cation generator) for polymerization (bridge) of the reactive group as described above. . Further, as the polymerization initiator, it is preferable to use a light power thione generator rather than a thermal cation generator.

When using a light thione generator, if the process from the addition of the light thione generator to the heat treatment for liquid crystal alignment is performed under drought conditions (light blocking conditions that do not allow the light thione generator to dissociate), The liquid crystal material can be aligned with sufficient fluidity without curing until the alignment stage. Then, cations are generated by irradiating light from a light source that emits light of an appropriate wavelength, and the liquid crystal material layer is cured.

The light irradiation method includes light from a light source such as a metal halide lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a xenon lamp, an arc lamp, or a laser that has a spectrum in the absorption wavelength region of the photoactive thione generator. Irradiate to cleave the light thione generator. The irradiation dose per square centimeter is usually in the range of 1 to 200 mj, preferably 10 to 100 mJ, as the integrated dose. However, this does not apply when the absorption region of the light-power thione generator and the spectrum of the light source are significantly different, or when the liquid crystal material itself has the ability to absorb light from the light source. In these cases, an appropriate photosensitizer or a mixture of two or more photopower thione generators having different absorption wavelengths can be used.

The temperature at the time of light irradiation needs to be within a temperature range in which the liquid crystal material takes liquid crystal alignment. In order to sufficiently improve the curing effect, the liquid crystal material is irradiated with light at a temperature equal to or higher than Tg. It is preferable to perform shooting.

The liquid crystal material layer produced by the above process is a sufficiently strong film. Specifically, the mesogens are three-dimensionally bonded by the curing reaction, which not only improves the heat resistance (upper limit temperature for maintaining liquid crystal alignment) compared to before curing, but also provides scratch resistance, abrasion resistance, and crack resistance. The mechanical strength such as property is also greatly improved.

In addition, the alignment substrate is not optically isotropic, or the liquid crystal film to be obtained is finally opaque in the intended use wavelength region, or the film thickness of the alignment substrate is too thick, which causes problems in actual use. If there is a problem such as the above, it is also possible to use a form formed on an alignment substrate, a polarizing plate, a substrate that does not become an obstacle in the intended wavelength range of use, and a stretched film having a retardation function. As a transfer method, a known method can be employed. For example, as described in Japanese Patent Application Laid-Open No. Hei 4 5 7 0 1 7 or Japanese Patent Application Laid-Open No. 5-3 3 3 3 1 3, a liquid crystal film layer is bonded to an alignment substrate via an adhesive or an adhesive. Examples include a method of transferring only a liquid crystal film by laminating different substrates and then peeling the alignment substrate from the stack.

The pressure-sensitive adhesive or adhesive used for transfer is not particularly limited as long as it is an optical grade as described later, and generally used materials such as acrylic, epoxy, and urethane can be used.

The homeotopically picked liquid crystal film layer obtained as described above can be quantified by measuring the optical phase difference of the liquid crystal layer at an angle inclined from normal incidence. In the case of home-orientated pick-aligned liquid crystal layers, this retardation value is symmetric with respect to normal incidence.

Several methods can be used to measure the optical phase difference. For example, an automatic birefringence measuring device (manufactured by Oji Scientific Instruments) and a polarizing microscope can be used. This homeomorphic liquid crystal layer looks black between the crossed Nicol polarizers. In this way, homeo-mouth pick orientation was evaluated.

The liquid crystal film used in the present invention has a liquid crystal film thickness of d 1, a main refractive index in the liquid crystal film plane of NX 1 and N y 1, and a main refractive index in the thickness direction of N z 1 and N zl> N xl≥N yl, the in-plane retardation value (R el = (N 1-N y 1) X d 1 [nm]) and the thickness direction retardation It is preferable to satisfy the following [1] and [2] which are equal to or less than Rd 1 (R th 1 = (N x 1 -N z 1) X d 1 [nm]) force.

[1] 0 nm≤R e 1≤ 20 n m

[2]-500 nm≤R t h l≤- 30 nm

The optical parameters R e 1 and R th 1 values of homeotopic alignment liquid crystal films depend on the type of liquid crystal display device and various optical parameters. On the other hand, the in-plane retardation value (R e 1) of the homeomorphic pick-up liquid crystal film is usually 0 nm to 20 nm, preferably O nm to: 10 nm, and more preferably 0 The retardation value (R th 1) in the thickness direction is usually from 500 nm to 30 nm, preferably from 400 nm to 50 nm, more preferably from 400 nm to 1 nm. Ten

It is controlled to 0 nm.

By setting the R e 1 value and the R t h 1 value in the above ranges, the viewing angle improving film of the liquid crystal display device can widen the viewing angle while correcting the color tone of the liquid crystal display. When the Re 1 value is larger than 20 nm, the front characteristic of the liquid crystal display device may be deteriorated due to the large in-plane retardation value. Also, if the R thl value is greater than –30 nm or less than 1500 nm, sufficient viewing angle improvement effects may not be obtained, or unnecessary coloring may occur when viewed from an oblique angle. .

In addition, the homeotopically picked liquid crystal film preferably satisfies the conditions represented by the following [5] and [6].

[5]-0. 厶 n≤— 0. 0005

[6] Δ n = N X 1 -N z 1

In the above [5] and [6], the delta eta, show birefringence in the thickness direction of the Homeoto port pick aligned liquid crystal full Ilm (birefringent layer), Nx l, Ny l Oyopi N _Z l is As described above, the refractive indexes in the three axial directions of the homeotopically picked liquid crystal film are shown. In view of improving productivity and reducing the thickness of the optical film including the birefringent layer, it is more preferably set to 0.2 ≦ Δ η ^ —0.005.

In addition, it has positive uniaxiality in the thickness direction in place of the home-to-mouth pick alignment liquid crystal film. Even if a stretched film is used as the optical anisotropic element, there is a limit to stretching in the thickness direction, and thus the retardation in the thickness direction cannot be controlled over a wide range. A method is also used in which a heat-shrinkable film is used to heat-shrink a long film and stretch it in the thickness direction. However, the thickness of the film obtained when the birefringence index in the thickness direction is 0.03 or less. Is about 50 to 100 μπι, which is thicker than the original long film, and it is difficult to meet the demand for thinning the entire elliptical polarizing plate as the liquid crystal display device becomes thinner. is there

The film thickness of the elliptically polarizing plate is desirably 40.000 or less, particularly preferably 300.mu.m or less, in view of the recent demand for thinning. Next, a vertical alignment type liquid crystal display device using the elliptically polarizing plate for the vertical alignment type liquid crystal display device of the present invention will be described.

A vertical alignment type liquid crystal display device according to the present invention includes a vertical alignment type liquid crystal cell including liquid crystal molecules that are vertically aligned with respect to a substrate surface when no voltage is applied between a pair of substrates provided with electrodes, and the vertical alignment type Placed on at least one side of the liquid crystal cell substrate so that the home-orientated pick-aligned liquid crystal film side of the elliptically polarizing plate for vertical alignment type liquid crystal display device of the present invention faces, between the vertical alignment type liquid crystal cell substrate and the elliptically polarizing plate, It is characterized in that at least one first optical anisotropic element exhibiting a phase difference of 1 Z 4 wavelength in the plane is arranged.

The first optical anisotropic element is a wideband 1/4 wavelength consisting of an optical element showing a phase difference of 1 Z 4 wavelength in the plane and a second optical anisotropic element showing a phase difference of 1/2 wavelength in the plane. It may consist of an optical element called a plate. Further, at least one third optical anisotropic element having negative uniaxial optical anisotropy in the thickness direction is disposed between the first optical anisotropic element and the vertical alignment type liquid crystal cell. In view of further widening the viewing angle, a fourth optical anisotropic element having positive uniaxial optical anisotropy in the in-plane direction is disposed between the vertical alignment type liquid crystal cell and the linearly polarizing plate. It is preferable.

As the linear polarizing plate constituting the elliptically polarizing plate of the present invention, one having a protective film on one side or both sides of the polarizer is usually used. There are no particular restrictions on the polarizer, and various types of polarizers can be used. For example, polybulal alcohol-based film, partially formalized polybulal alcohol-based film, ethylene / butyl acetate copolymer system part A dichroic material such as saponified dichroic dye is adsorbed on a hydrophilic polymer film such as a saponified film and uniaxially stretched. Dehydrated polybulal alcohol and polyvinyl chloride are removed. Polyethylene oriented films such as treated with hydrochloric acid are exemplified. Among these, those obtained by stretching a polybulal alcohol film and adsorbing and orienting a dichroic material (iodine, dye) are preferably used. The thickness of the polarizer is not particularly limited,

The range of 5 to 80 μΐη is common.

A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it, for example, is dyed by immersing polybulal alcohol in an aqueous solution of iodine, and is made by stretching it 3 to 7 times the original length. Can do. If necessary, it can be immersed in an aqueous solution of boric acid or potassium oxalate. Furthermore, if necessary, the polybulal alcohol film may be immersed in water and washed before dyeing. In addition to washing polyvinyl alcohol film surface stains and anti-blocking agents by washing the polyvinyl alcohol film with water, swelling of the polyvinyl alcohol film eliminates unevenness such as uneven coloring. There is also an effect to prevent. Stretching may be performed after dyeing with iodine, or may be performed while dyeing, or may be stretched and then dyed with iodine. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

The protective film provided on one side or both sides of the polarizer is preferably one having excellent transparency, mechanical strength, thermal stability, moisture shielding properties, isotropic properties, and the like. Examples of the material of the protective film include, for example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cenorelose polymers such as diacetyl cellulose and triacetylenorenorose, and acrylics such as polymethylenomethacrylate. Styrene polymers such as polystyrene polymers, polystyrene and acrylonitrile styrene copolymers (AS resin), polycarbonate polymers, and the like. In addition, polyolefin polymers such as polyethylene, polypropylene and ethylene / propylene copolymers, polyolefins having a neck or norbornene structure, chlorinated butyl polymers, amide polymers such as nylon and aromatic polyamides, Imido polymer, Snorephone polymer, Polyetherolenorephone polymer, Polyetherenoretone ketone polymer, Polyphenylene norfide polymer, Bull alcohol polymer, Vinylidene chloride polymer, Vinylptyra Examples of the polymer that forms a protective film include monolole polymers, arylate polymers, polyoxymethylene polymers, epoxy polymers, and blends of the above polymers. Other examples include films made from thermosetting or ultraviolet curable resins such as acrylic, urethane, acrylate urethane, epoxy, and silicone. The thickness of the protective film is generally

It is not more than 500 μm, and preferably 1 to 300 μm. In particular, it is preferably 5 to 200 μππι.

As the protective film, a cellulose-based polymer such as triacetyl cellulose is preferable from the viewpoints of polarization characteristics and durability. Triacetinole cellulose film is particularly preferred. In addition, when providing a protective film on both sides of the polarizer, a protective film made of the same polymer material may be used on the front and back, or a protective film made of a different polymer material or the like may be used. The polarizer and the protective film are usually in close contact via an adhesive or the like.

Examples of the adhesive include polybulal alcohol adhesives, gelatin adhesives, bullet latexes, aqueous polyurethanes, aqueous polyesters, and the like.

As the protective film, a hard coat layer, an antireflection treatment, an anti-sticking treatment, or a treatment subjected to treatment for diffusion or anti-glare can be used.

Hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate. For example, a protective film is applied to a cured film having excellent hardness and sliding properties by an appropriate UV curable resin such as acryl or silicone. It can be formed by a method of adding to the surface. The antireflection treatment is performed for the purpose of preventing reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the conventional art. In addition, the anti-sticking treatment is performed for the purpose of preventing adhesion with an adjacent layer.

The anti-glare treatment is performed for the purpose of preventing external light from being reflected on the surface of the polarizing plate and hindering the viewing of the light transmitted through the polarizing plate. For example, the anti-glare treatment can be performed using a sand plast method or an embossing method. It can be formed by imparting a fine concavo-convex structure to the surface of the protective film by an appropriate method such as a surface method or a compounding method of transparent fine particles. Examples of the fine particles to be included in the formation of the surface fine concavo-convex structure include silica, alumina, titania, zirconia, tin oxide having an average particle diameter of 0.5 to 50 ^ ηι, Transparent fine particles such as inorganic fine particles having conductivity, which are made of indium oxide, cadmium oxide, antimony oxide, or the like, and organic fine particles made of a crosslinked or uncrosslinked polymer are used. In the case of forming a surface fine uneven structure, the amount of fine particles used is generally about 2 to 50 parts by weight with respect to 100 parts by weight of the transparent resin forming the surface fine uneven structure, and 5 to 25 Part by weight is preferred. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

The antireflection layer, antisticking layer, diffusing layer, antiglare layer and the like can be provided on the protective film itself, or can be provided separately from the transparent protective layer as an optical layer.

A circularly polarizing plate is formed by combining a 1 Z 4 wavelength plate with a linear polarizing plate. The circularly polarizing plate has a function of changing linearly polarized light into circularly polarized light or changing circularly polarized light into linearly polarized light with a quarter wave plate.

A linearly polarizing plate is provided on both sides of the vertical alignment type liquid crystal cell, and the first optical anisotropic element having a phase difference of 1 Z 4 wavelength in the plane is provided between the linearly polarizing plate and the vertical alignment type liquid crystal cell. Therefore, when no voltage is applied, the phase difference in the observation direction of the liquid crystal layer is 0, so that the upper and lower polarizing plates can be made to be orthogonal, and when the voltage is applied, the phase difference in the observation direction is generated and bright display is possible. Become. In this case, the angle between the slow axis of the first optical anisotropic element having a phase difference of 1 Z 4 wavelength and the absorption axis of the linearly polarizing plate is 45 degrees, so that the liquid crystal layer has the simplest configuration. Circularly polarized light can be obtained.

In addition, in the case of a transflective vertical alignment type liquid crystal display device that has both a transmission function and a reflection function, in order to obtain a good display characteristic at the time of reflection, the first having a phase difference of 1 Z 4 wavelength at all wavelengths. Or a second optical anisotropic element having a phase difference of ½ wavelength in the plane between the linearly polarizing plate and the ¼ wavelength plate. Next, the first optical anisotropic element having a phase difference of 1/4 wavelength in the plane, the second optical anisotropic element having a phase difference of 1 Z 2 wavelength, and a positive uniaxial optical anisotropy in the in-plane direction. A fourth optical anisotropic element having a directivity will be described.

These optical anisotropic elements only have to have a desired retardation function, for example, polymer Examples thereof include a uniaxially or biaxially stretched film, a Z-axis oriented treatment, and an oriented film film in which a material exhibiting liquid crystallinity is applied and oriented.

As the optically anisotropic element, a method of uniaxially or biaxially stretching a film made of an appropriate polymer can be used, and a width of a long film can be reduced by a heat-shrinkable film as disclosed in Japanese Patent Application Laid-Open No. 5_157 911. A birefringent film manufactured by a method in which the direction is thermally shrunk to increase the retardation in the thickness direction is preferable, and examples of the raw material include films and sheets made of organic polymer materials. For example, polyester polymers such as poly (vinyl alcohol), polyimide, polyphenylene oxide, polyether ketone, polyether enoate ketone, polyethylene terephthalate and polyethylene naphthalate, and senorelose systems such as diacetyl cellulose and triacetyl styrene cellulose Examples include films made of transparent polymers such as polymers, polycarbonate polymers, and acrylic polymers such as polymethyl methacrylate. In addition, polystyrene, acrylonitrile 'styrene polymers such as styrene copolymers, polyethylene, polypropylene, polycyclohexylene, olefin polymers such as ethylene' propylene copolymer, butyl chloride polymers, nylon and aromatics. A film made of a transparent polymer such as an amide polymer such as polyamide may also be mentioned. In addition, imide polymers, sulfone polymers, polyetherolene sulfone polymers, polyetherenolethenoleketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinylenobutylene / repolymers, Examples thereof include films made of transparent polymers such as arylate polymers, polyoxymethylene polymers, epoxy polymers, and blends of the aforementioned polymers. Of these, plastic films such as triacetyl cellulose, polycarbonate, and polycyclohexylin, which have high hydrogen bonding properties and are used as optical films, are used. Examples of the organic polymer film include ZENOOR (trade name, manufactured by ZEON CORPORATION), ZEONEX (trade name, manufactured by ZEON CORPORATION), Arton (trade name, manufactured by JSR Corporation), etc. A plastic film made of a polymer material having a norbornene structure is preferably used. A retardation film formed by stretching the film described above has excellent optical properties.

For alignment films made of liquid crystal materials such as liquid crystal polymers, uniform and mono In-nematic alignment and liquid crystalline polymer that can easily fix the alignment state was heat-treated on the substrate or the substrate coated with the alignment film to form a uniform, monodomain nematic structure. After that, by cooling, the alignment film film produced by fixing without impairing the alignment in the liquid crystal state, or a liquid crystalline composition by blending the liquid crystal polymer with a photopolymerizable liquid crystal compound, the substrate or the alignment film An oriented film film that is applied and oriented and polymerized on a substrate coated with can be mentioned. When the X direction and the y direction are taken in the in-plane direction, and the thickness direction is the z direction, the positive uniaxial optical anisotropic element has a relationship of refractive index n X> ny = n _Z. Further, a positive biaxial optical anisotropic element has a relationship of refractive index n X>nz> ny. Negative uniaxial optically anisotropic element has a relationship of nx = ny> n _Z as a refractive index. A negative biaxial optical anisotropic element has a relationship of nx>ny> nz as a refractive index.

When biaxiality is defined as NZ coefficient = (η χ-η ζ) / (η χ-η y), NZ> 1 is negative 2 axes, NZ = 1 is positive 1 axis, NZ k 1 is positive It can be classified as two axes.

The first optical anisotropic element exhibiting a phase difference of 14 wavelengths in the plane has the thickness of the first optical anisotropic element d 3 and the main refractive index in the first optical anisotropic element surface Nx 3 And Ny 3, the in-plane retardation value (R e 3 = (Nx 3 -Ny 3) X d 3 when the main refractive index in the thickness direction is N z 3 and NX 3> N y 3 [nm]) is from 80 to: 1 70 nm, and the NZ coefficient (= (Nx 3 -N z 3) / (Nx 3 -Ny 3)) of the first optical anisotropic element is NZ 3 Those having a relationship of 1 to NZ 3 to 4 are preferred. The Re 3 and NZ 3 values, which are the optical parameters of the first optical anisotropic element, depend on the type of liquid crystal display device and various optical parameters. On the other hand, the retardation value (R e 3) in the first optical anisotropic element surface is usually 80 η π! ~ 170 nm, preferably 100 nm ~ 150 nm, more preferably 120 nm ~: 1 40 nm, and the NZ 3 value is 1 to NZ 3 to 4, preferably It is controlled at 0. 5 NZ 3 -3, more preferably 1≤NZ 3 -3.

The second optical anisotropic element showing a phase difference of 12 wavelengths in the plane is d 4 for the thickness of the second optical anisotropic element and Nx 4 for the main refractive index in the second optical anisotropic element plane. And Ny 4, the in-plane retardation value (R e 4 = (N 4 -Ny 4) X d 4 when the main refractive index in the thickness direction is N z 4 and NX 4> N y 4 [nm]) Force S200 ~ 3 50 nm When the NZ coefficient (= (NX 4 -N z 4) / (Nx 4— N y 4)) of the second optical anisotropic element is NZ 4, I prefer something that has. The Re 4 and NZ 4 values, which are the optical parameters of the second optical anisotropic element, cannot be generally described because they depend on the type of liquid crystal display device and various optical parameters. For monochromatic light, the in-plane retardation value (R e 4) of the second optically anisotropic element is usually 200 nm to 350 nm, preferably 250 ηπ! ~ 300 ηm, more preferred, 260 nm to 280 nm, and NZ4 values are _2, NZ4, 3, _1, NZ4, 2, more preferably 0 Controlled to ≤NZ 4 <1.5.

By setting the NZ3 and NZ4 values in the above range as well as the Re3, Re4 values, the viewing angle improvement film of the liquid crystal display device can widen the viewing angle while correcting the color tone of the liquid crystal display. Is possible. If the R e 3 and Re 4 values are out of the above range, the front characteristics of the liquid crystal display device may be deteriorated due to the effect of deviation of the in-plane retardation value. If the NZ 3 and NZ 4 values are out of the above range, sufficient viewing angle improvement effects may not be obtained, or unnecessary coloring may occur when viewed obliquely.

The fourth optical anisotropic element having positive uniaxial optical anisotropy in the in-plane direction has a thickness of the fourth optical anisotropic element d 5 and the main refractive index in the fourth optical anisotropic element plane. Nx 5 and Ny 5, the in-plane retardation value (R e 5 = (N 5 -N y 5) X d 5 [nm]) is preferably from 50 nm to 350 nm.

The Re 5 value, which is the optical parameter of the fourth optical anisotropic element, depends on the type of liquid crystal display device and various optical parameters, but it cannot be said unconditionally, but for 550 nm monochromatic light, The in-plane retardation value (Re5) of the fourth optical anisotropic element is usually in the range of 50 nm to 350 nm, preferably 70 nm to 300 nm, more preferably 90 nm to 280 nm. It is controlled. If the Re5 value is out of the above range, a sufficient viewing angle improvement effect may not be obtained, or unnecessary coloring may occur when viewed from an oblique direction. Next, a third optical anisotropic element having negative uniaxial optical anisotropy in the thickness direction will be described. The third optical anisotropic element is not particularly limited, but non-liquid crystal materials are excellent in heat resistance, chemical resistance, transparency, and rigidity. For example, cellulose triacylate, ZEONEX, ZEONOR (Both manufactured by Nippon Zeon Co., Ltd.) and Arton (manufactured by JSR Co., Ltd.), polyolefins, polyamides, polyimides, polyesters, polyether ketones, polyaryl ether ketones, polyamides, polyesters Polymers such as imides are preferred. These polymers may be used either alone or as a mixture of two or more with different functional groups, such as a mixture of polyaryletherketone and polyamide. Good. Among these polymers, polyimide is particularly preferable because of its high transparency and high orientation. As the polyimide, for example, a polyimide having high in-plane orientation and soluble in an organic solvent is preferable. Specifically, for example, the condensation of 9,9-bis (aminoaryl) fluorene and aromatic tetra force sulfonic acid dianhydride disclosed in Japanese Patent Publication No. 2 0 0 0—5 1 1 2 9 6 A polymerization product, specifically, a polymer containing one or more repeating units represented by the following formula (8) can be used.

In the formula (8), R ³ ~R ^e is hydrogen, halogen, Hue - group, 1 to 4 halo gen atom or Fuweniru group substituted with an alkyl group having a carbon number of 1-1 0, and carbonitrides It is at least one kind of substituent each independently selected from the group consisting of alkyl groups having 1 to 10 prime numbers. Preferably, R ^{3 to} R ⁶ are halogen, a phenyl group, a phenyl group substituted with 1 to 4 halogen atoms or an alkyl group having 1 to 10 carbon atoms, and 1 to 10 carbon atoms. And at least one kind of substituent each independently selected from the group consisting of alkyl groups.

In the above formula (8), Z is, for example, a tetravalent aromatic group having 6 to 20 carbon atoms, preferably a pyromellitic group, a polycyclic aromatic group, or a derivative of a polycyclic aromatic group. , Or below

In the formula (9), Z ′ is, for example, a covalent bond, C (R ⁷ ) ₂ group, CO group, O atom, S atom, S 0 ₂ group, S i (C ₂ H ₅ ) ₂ group, or NR ⁸ groups, and when plural, they are the same or different. W represents an integer from 1 to 10; Each R ⁷ is independently hydrogen or C (R ⁹ ) ₃ . R ⁸ is hydrogen, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and when there are a plurality thereof, they are the same or different. Each R ⁹ is independently hydrogen, fluorine, or chlorine.

Examples of the liquid crystal material include a cholesteric alignment film made of a liquid crystal material such as a cholesteric liquid crystalline polymer, a film in which a cholesteric alignment layer is supported by a film, and a discotic liquid crystal layer. First, the cholesteric alignment film preferably has a uniform blister orientation in which the cholesteric helical axis exists in the normal direction of the film by an appropriately selected method such as heat treatment, and the selective reflection wavelength s is 300 nm or less. Is preferred.

The material for realizing the cholesteric alignment is not limited to the liquid crystalline polymer, but a liquid crystal monomer molecule having a polymerizable group capable of realizing a cholesteric alignment alone, or a mixture of a liquid crystalline monomer having a polymerizable group and a chiral compound. Etc. are also preferably used. After these materials are cholesterically oriented by a method selected appropriately, such as heat treatment, the polymerizable group can be cured by a suitably used means such as heat or light, and the cholesteric orientation can be fixed.

Further, as a liquid crystal material other than the above that forms the negative uniaxial optically anisotropic layer, a polymerizable discotic liquid crystal compound that is homogeneously aligned is also preferably used. The third optical anisotropic element has a thickness of d 3 for the third optical anisotropic element, Nx 2 and Ny 2 for the main refractive index in the third optical anisotropic element surface, and main refraction in the thickness direction. When the rate is N z 2 and Nx 2≥Ny 2> N z 2, the in-plane retardation value (R e 2 = (NX 2 -Ny 2) X d 2 [nm]) is 0 to 20 nm, Thickness direction retardation value (R th 2 = (N x 2 -N z 2) X d 2 [nm]) is 30 to 500 nm Is preferred.

The R e 2 and R th 2 values, which are the optical parameters of the third optical anisotropic element, depend on the type of the liquid crystal display device and various optical parameters. The in-plane retardation value (R _e 2) for monochromatic light is usually 0 nm to 20 nm, preferably 0 n π! ˜10 nm, more preferably in the range of 0 nm to 5 nm, and the retardation value (R th 2) in the thickness direction is usually 30 to 500 nm, preferably 80 to 4 It is controlled at 0 nm, more preferably from 100 nm to 300 nm.

By setting the Re 2 value and the R th 2 value in the above ranges, the viewing angle improving film of the liquid crystal display device can widen the viewing angle while correcting the color tone of the liquid crystal display. If the Re 2 value is greater than 20 nm, the front characteristics of the liquid crystal display device may be deteriorated due to the large front phase difference value. Also, if the Rth2 value is less than 30 nm or greater than 500 nm, a sufficient viewing angle improvement effect cannot be obtained, or unnecessary coloring occurs when viewed obliquely. fear is a mosquito ^s.

The laminate composed of the linearly polarizing plate, the home-orientated pick-aligned liquid crystal film, and the first, second, third, and fourth optical anisotropic elements is bonded to each other via an adhesive layer. Can be produced. In addition, the homeotropic alignment liquid crystal film produced on the substrate is attached to the linearly polarizing plate or the first, second, or third optical anisotropic element through an adhesive layer, and then homeotropic. Stacking is also possible by stripping the alignment substrate used to achieve the photo-alignment and transferring only the liquid crystal part that has been home-orientated to the linearly polarizing plate or the first, second, or third optical anisotropic element. Can be made.

In addition, as a method of laminating the first, second, and third optical anisotropic elements, for example, a method of directly laminating both using an adhesive layer described later, a liquid crystal alignment capability on each optical anisotropic element. A method of providing a liquid crystalline polymer that exhibits uniform and monodomain liquid crystal orientation and that can easily fix the orientation state by means such as coating, provided on a film substrate For example, a method of transferring the liquid crystal compound to another optical anisotropic element using a pressure sensitive adhesive or an adhesive described later is preferably used.

The elliptically polarizing plate of the present invention is a homeotope pick with fixed homeotope pick orientation. It is an elliptically polarizing plate for vertically aligned liquid crystal display devices, in which an aligned liquid crystal film layer and a linearly polarizing plate are laminated. When manufacturing a liquid crystal display device, a light diffusing layer, a light control film, a light guide plate, a prism sheet are used as necessary. Such a member may be added.

The following (1) to (3) may be used in addition to the elliptically polarizing plate of the present invention in that the liquid crystal display device obtains optical characteristics with little viewing angle dependency. In the following, “Z” represents the interface of the layers (hereinafter the same).

(1) Ellipsoidal polarizing plate of the present invention / first optical anisotropy exhibiting a phase difference of 1 Z 4 wavelength in the plane Third optical anisotropy having negative uniaxial optical anisotropy in the Z-thickness direction Isotropic layer

(2) Ellipsoidal polarizing plate of the present invention / first optical anisotropy layer exhibiting a quarter-wave retardation in the plane

(3) The elliptically polarizing plate of the present invention / first optically anisotropic layer exhibiting negative biaxiality and having a phase difference of 1/4 wavelength in the plane

Further, examples of the configuration arranged in the vertical alignment type liquid crystal display device can include the following (4) to (15), and any configuration may be used.

(4) Ellipsoidal polarizing plate of the present invention / first optical anisotropy exhibiting a phase difference of 1 Z 4 wavelength in the plane, third optical anisotropy having negative uniaxial optical anisotropy in the Z-thickness direction Isotropic layer / vertical alignment type liquid crystal display cell / first optical anisotropic layer showing phase difference of 1/4 wavelength in the plane / fourth having positive uniaxial optical anisotropy in the in-plane direction Optical anisotropic element / linear polarizing plate

(5) Ellipsoidal polarizing plate of the present invention / first optical anisotropy exhibiting in-plane retardation of 1 Z 4 wavelength layer Z vertical alignment type liquid crystal display cell / negative uniaxial optical anisotropy in the thickness direction The third optically anisotropic layer / having a first optically anisotropic layer exhibiting a quarter wavelength retardation in the plane / the fourth optically uniaxial optical anisotropy in the in-plane direction Optical anisotropic element Linear polarizing plate

(6) Ellipsoidal polarizing plate of the present invention / first optical anisotropy exhibiting a phase difference of 1 Z 4 wavelength in the plane, third optical anisotropy having negative uniaxial optical anisotropy in the Z thickness direction Isotropic layer Z vertical alignment type liquid crystal display cell / third optical anisotropy layer having negative uniaxial optical anisotropy in the thickness direction The first optical exhibiting a 1/4 wavelength phase difference in the plane Anisotropic layer / fourth optical anisotropic element with positive uniaxial optical anisotropy in in-plane direction Z linear polarizing plate

(7) Ellipsoidal polarizing plate of the present invention / first optical anisotropy exhibiting a phase difference of 1 Z 4 wavelength in the plane, third optical anisotropy having negative uniaxial optical anisotropy in the Z thickness direction Isotropic layer Vertical alignment type liquid crystal display cell 1st optically anisotropic layer showing phase difference of 1 Z 4 wavelength in the plane Linearly polarizing plate (8) Ellipsoidal polarizing plate of the present invention The first optical anisotropy layer showing a 1/4 wavelength phase difference in the Z plane Z vertical alignment type liquid crystal display cell / negative uniaxial optical anisotropy in the thickness direction Third optically anisotropic layer having a first optically anisotropic layer / linearly polarizing plate exhibiting a phase difference of 1 Z4 wavelength in the Z plane

(9) Ellipsoidal polarizing plate of the present invention The first optical anisotropy exhibiting a 1/4 wavelength phase difference in the Z plane The third optical anisotropy having a negative uniaxial optical anisotropy in the layer / thickness direction Isotropic layer Z Vertically aligned liquid crystal display cell Z Third optically anisotropic layer with negative uniaxial optical anisotropy in the thickness direction First phase difference of 1/4 wavelength in the Z plane Optically anisotropic layer Z linear polarizer

(10) The elliptically polarizing plate of the present invention Z is a first optically anisotropic layer that exhibits negative biaxiality and exhibits a 1/4 wavelength retardation in the plane. Z 1st optical anisotropic layer showing phase difference of 4 wavelengths 4th optical anisotropic element / linearly polarizing plate with positive uniaxial optical anisotropy in Z-plane direction

(1 1) Ellipsoidal polarizing plate of the present invention The first optically anisotropic layer showing a phase difference of 1/4 wavelength in the Z plane, a vertically aligned liquid crystal display cell Z showing negative biaxiality and in-plane 1 First optical anisotropic layer showing phase difference of Z4 wavelength Fourth optical anisotropic element / linear polarizing plate with positive uniaxial optical anisotropy in the Z-plane direction

(1 2) The elliptically polarizing plate of the present invention / first optically anisotropic layer / vertical alignment type liquid crystal display cell / negative 2 exhibiting negative biaxiality and in-plane retardation of 1/4 wavelength First optically anisotropic layer showing axiality and in-plane phase difference of 1/4 wavelength / fourth optical anisotropic element with positive uniaxial optical anisotropy in in-plane direction Z linearly polarized light Board

(1 3) The first optically anisotropic layer / vertical alignment type liquid crystal display cell / in-plane 1/4 in the plane exhibiting negative biaxiality of the elliptically polarizing plate of the present invention and in-plane retardation of 1Z4 wavelength First optically anisotropic layer / linearly polarizing plate showing phase difference of 4 wavelengths

(14) The elliptically polarizing plate of the present invention / first optically anisotropic layer showing a phase difference of 1/4 wavelength in the plane / vertical alignment type liquid crystal display cell / showing negative biaxiality and in-plane 1 Z 1st optical anisotropic layer showing phase difference of 4 wavelengths Z linear polarizing plate

(15) The elliptically polarizing plate of the present invention Z is a first optically anisotropic layer exhibiting negative biaxiality and exhibiting a phase difference of 1Z4 wavelength in the plane.Vertical alignment type liquid crystal display cell First optically anisotropic layer showing a phase difference of 14 wavelengths in-plane Z linear polarizing plate

The adhesive used to form the linear polarizing plate, the home-orientated pick-up liquid crystal film, the layer of each optical anisotropic element, and the adhesive / adhesive layer used for transfer is optically isotropic and transparent. If it is a thing, it will not restrict | limit in particular. For example, those based on polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, and fluorine-based rubbers can be appropriately selected and used. A reactive material that reacts by an external stimulus such as light, electron beam, or heat to undergo polymerization or crosslinking can also be used. Among these, those having excellent optical transparency, such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance, heat resistance, etc. can be preferably used.

The adhesive layer can be formed by an appropriate method. For example, for example, a pressure-sensitive adhesive solution of about 10 to 40% by mass in which a base polymer or a composition thereof is dissolved or dispersed in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate. And the method of attaching it directly on the polarizing plate, the liquid crystal film or the optical element layer by an appropriate development method such as a casting method or a coating method, or an adhesive / adhesive on the separator according to the above. Examples include a method of forming a layer and transferring it onto the polarizing plate, the liquid crystal film or the optical element layer. The adhesive / adhesive layer includes, for example, natural and synthetic resins, in particular, tackifier resins, fillers made of glass fibers, glass beads, metal powders, other inorganic powders, pigments, It may contain additives that may be added to the adhesive layer, such as colorants and antioxidants. Further, it may be an adhesive layer containing fine particles and exhibiting light diffusibility.

The thickness of the adhesive layer is not particularly limited as long as the member to be adhered can be adhered and sufficient adhesion can be maintained, depending on the properties of the adhesive and the adhesive and the material to be adhered. Can be selected. Since the demand for reducing the total thickness of the elliptically polarizing plate is strong, it is preferable that the thickness of the adhesive is thinner, but usually 2 to 80 μπι, preferably 5 to 50 μm, more preferably 10 ~ 40 0 μπι. Outside this range, it is not preferable because the adhesive strength is insufficient, or oozes out from the end portion when laminating or storing the elliptically polarizing plate. In addition, when transferring a home-orientated pick-aligned liquid crystal film to the linearly polarizing plate or the first, second, or third optical anisotropic element via an adhesive layer, the transfer is facilitated as follows. Processes such as (A) to (C) can be used as appropriate.

(A) Home-to-mouth pick alignment in which the liquid crystal alignment formed on the alignment substrate is fixedAttach the liquid crystal layer directly to the linear polarizing plate or the optical anisotropic element through the adhesive layer 1, The alignment substrate is peeled off, and the homeotropic pick alignment liquid crystal layer is transferred to a linear polarizing plate or an optical anisotropic element.

(B) Home-to-mouth pick alignment in which the liquid crystal alignment formed on the alignment substrate is fixed. After the liquid crystal layer is adhered to the removable substrate 1 via the adhesive layer 1, the alignment substrate is peeled off and the homeotope is aligned. Transfer the mouth-pick orientation liquid crystal layer to the re-peelable substrate 1 and re-peel the substrate 1 Adhesive layer 1 Make the intermediate 1 consisting of the Z home-to-mouth pick-alignment liquid crystal layer, and then re-peel it through the adhesive layer 2 After adhering to the releasable substrate 2, the releasable substrate 1 is peeled off to produce an intermediate 2 consisting of an adhesive layer 1 home-orientated liquid crystal layer / adhesive layer 2 / removable substrate 2, and After the non-carrier paste with a separate film is bonded to the adhesive layer 1 side, the separate film is peeled off, and is appropriately attached to a polarizing plate or an optical anisotropic element, and the re-peelable substrate 2 is peeled off.

(C) Home-to-mouth pick alignment with fixed liquid crystal alignment formed on the alignment substrate After the liquid crystal layer is adhered to the re-peelable substrate 1 via the adhesive layer 1, the alignment substrate is peeled off and the homeotope is aligned. Transfer the lip-pickup alignment liquid crystal layer to the removable substrate 1, re-peelable substrate 1 / adhesive layer 1 produce intermediate 1 consisting of the Z homeotopick-pick alignment liquid crystal layer, and re-transfer through the adhesive layer 2 After adhering to the peelable substrate 2, the peelable substrate 1 is peeled off, and an intermediate 2 consisting of an adhesive layer 1 a homeomorphic liquid crystal layer Z adhesive layer 2 / removable substrate 2 is prepared, Furthermore, after pasting a non-carrier paste with a separate film on the adhesive layer 1 side, the releasable substrate 2 is peeled off, and the separate film Z adhesive layer / adhesive layer 1 / home-top orientation liquid crystal layer adhesive layer 2 Intermediate 3 made of Non-carrier paste with rate film is laminated Separate film adhesive layer Adhesive layer 1 Home-orientated pick liquid crystal layer Adhesive layer 2 / Adhesive layer Intermediate 4 consisting of Z separate film is prepared, and separate film And is attached to a polarizing plate or an optically anisotropic element as appropriate.

Furthermore, by adding additives such as a surface modifier as appropriate to the adhesive, the adhesion between the removable substrate and the home-orientated pick-aligned liquid crystal layer is reduced, and the removability is also achieved. By maintaining the adhesion between the substrate and the adhesive layer, the adhesive layer can be peeled off while being adhered to the removable substrate side. There are no particular limitations on the type and amount of the surfactant and additive used in this case as long as they do not adversely affect the optical defect inspection and peelability. In this way, the linear polarizing plate or the second polarizing plate When transferring to the first, second, or third optical anisotropic element, processes such as the following (D) and (E) can be used as appropriate to facilitate the transfer.

(D) Home-to-mouth pick alignment with fixed liquid crystal alignment formed on the alignment substrate After the liquid crystal layer is adhered to the removable substrate 1 via the adhesive layer 1, the alignment substrate is peeled off and Transfer the lip-pickup alignment liquid crystal layer to the removable substrate 1, re-peelable substrate 1, adhesive layer 1 / intermediate 1 composed of home-pick orientation alignment liquid crystal layer, and then re-transfer through the adhesive layer 2 After adhering to the peelable substrate 2, the releasable substrate 1 is peeled off, and the intermediate layer 2 consisting of the adhesive layer 1 Z homeotopick orientation liquid crystal layer Z adhesive layer 2 removable substrate 2 is prepared, Furthermore, after pasting a non-carrier paste with a separate film on the adhesive layer 1 side, the separate film is peeled off and appropriately stuck to a polarizing plate or an optical anisotropic element, and the releasable substrate 2 is attached to the adhesive layer 2. It peels in the state where it stuck.

(E) Home-to-mouth pick alignment in which the liquid crystal alignment formed on the alignment substrate is fixed. After the liquid crystal layer is adhered to the re-peelable substrate 1 via the adhesive layer 1, the alignment substrate is peeled off and the home is aligned. Transfer the lip-pickup alignment liquid crystal layer to the removable substrate 1, re-peelable substrate 1 / adhesive layer 1 produce intermediate 1 consisting of the Z homeotopick-pick alignment liquid crystal layer, and re-transfer through the adhesive layer 2 After adhering to the peelable substrate 2, the releasable substrate 1 is peeled off, and an intermediate 2 composed of the adhesive layer 1 liquid crystal orientation layer Z adhesive layer 2 removable substrate 2 is produced. Furthermore, after bonding a non-carrier paste with a separate film on the adhesive layer 1 side, the peelable substrate 2 is peeled off with the adhesive layer 2 adhered, and a separate film adhesive layer / adhesive layer 1 / Preparation of intermediate 5 consisting of homeostatic picked liquid crystal layer Non-carrier adhesive with separate vinyl is also pasted on the side of the liquid crystal alignment layer, separate film / adhesive layer Z adhesive layer 1 Z homeotropic alignment liquid crystal layer / adhesive layer 2 / adhesive layer Z separate An intermediate 6 made of a film is prepared, and the separate film is peeled off and appropriately attached to a polarizing plate or an optical anisotropic element.

In addition, when transferring the homeotropic alignment liquid crystal film to the linear polarizing plate or the first, second, or third optical anisotropic element via the adhesive layer, the surface of the homeotropic alignment liquid crystal film is surface-treated. Thus, the adhesiveness with the adhesive / adhesive layer can be improved. The surface treatment means is not particularly limited, but corona discharge treatment, sputtering treatment, low-pressure UV irradiation, brazing that can maintain the transparency of the liquid crystal film surface. A surface treatment method such as a zuma treatment can be suitably employed. Among these surface treatment methods, the corner discharge treatment is good.

Further, the above-mentioned liquid crystal material is applied to the above-mentioned alignment substrate on the above-mentioned linear polarizing plate or the first, second or third optically anisotropic element without using a home-orientation pick-alignment liquid crystal film via an adhesive layer. It is also possible to manufacture by aligning the liquid crystal material and then fixing the alignment state by light irradiation and Z or heat treatment. If necessary, install the alignment film on the linearly polarizing plate or the first, second, or third optical anisotropic element, and then develop the liquid crystal material on the alignment substrate. After aligning the liquid crystal material, it can also be produced by fixing the alignment state by irradiation with light Z or heat treatment.

Although there is no restriction | limiting in particular as a liquid crystal display device, Various liquid crystal display devices of a transmission type, a reflection type, and a transflective type can be mentioned. There are no particular restrictions on the driving method of the liquid crystal cell. The passive matrix method used in STN-LCD, the active matrix method using active electrodes such as TFT (Thin Film Transistor) electrodes, TFD (Thin Film Diode) electrodes, and plasma Any driving method such as an addressing method may be used. 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, a transparent substrate having the property of orienting liquid crystals by the substrate itself, a force that lacks the alignment ability of the substrate itself, a transparent substrate having an alignment film having the property of orienting liquid crystals, etc. Can also be used. Moreover, well-known things, such as ITO, can be used for the electrode of a liquid crystal cell. The electrode can usually be provided on the surface of the transparent substrate with which the liquid crystal layer is in contact, and when a substrate having an alignment film is used, it can be provided between the substrate and the alignment film.

The material exhibiting liquid crystallinity for forming the liquid crystal layer is not particularly limited as long as it has a negative dielectric anisotropy, and various ordinary low-molecular liquid crystal materials and polymers that can form various liquid crystal cells. Liquid crystal substances and mixtures thereof are mentioned. In addition, a dye, a chiral agent, a non-liquid crystal substance, and the like can be added to these as long as liquid crystallinity is not impaired. If a chiral agent is added to a vertically aligned liquid crystal layer using a liquid crystal material exhibiting negative dielectric anisotropy and the liquid crystal molecules are rotated when voltage is applied, the rotation of the liquid crystal molecules when voltage is applied should be stabilized. Can do. Furthermore, when the rubbing directions of the upper and lower substrates are applied in a direction other than the same direction, the trace of the alignment process is not the same direction, so that the streak is not noticeable. Also, If the liquid crystal layer is twisted 90 degrees, retardation will occur in the tilt direction of the liquid crystal molecules when it is aligned at a few degrees to prevent disclination when a voltage is applied. Since the tilted direction of the liquid crystal molecules forms an angle of 90 degrees near the upper and lower substrates, the generated retardation can be canceled out and a black display with less leakage light can be obtained.

Further, by using one substrate of the vertical alignment type liquid crystal cell as a substrate having a region having a reflection function and a region having a transmission function, a transflective vertical alignment type liquid crystal display device can be obtained.

The region having a reflective function (hereinafter sometimes referred to as a reflective layer) included in the transflective electrode used in the transflective vertical alignment type liquid crystal display device is not particularly limited, and is made of aluminum, silver. Examples thereof include metals such as gold, chromium and platinum, alloys containing them, oxides such as magnesium oxide, multilayer films of dielectrics, liquid crystals exhibiting selective reflection, or combinations thereof. These reflective layers may be flat or curved. In addition, the reflective layer is processed to have a surface shape, such as an uneven shape, to have diffuse reflectivity, to have the electrode on the electrode substrate opposite to the viewer side of the liquid crystal cell, or a combination thereof It may be.

The vertical alignment type liquid crystal display device of the present invention can be provided with other constituent members in addition to the constituent members described above. For example, by attaching a color filter to the liquid crystal display device of the present invention, a color liquid crystal display device capable of performing multicolor or full color display with high color purity can be manufactured.

[Example]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

The analysis methods used in the examples are as follows.

(1) iH—NMR measurement

The compound was dissolved in deuterated black-hole form and measured by ¹ H-NMR of 40 OMHz (I NOVA-400 manufactured by Variant).

(2) G PC measurement

Dissolve the compound in tetrahydrofuran and use Tosohichi 8020 GP C system. TSK—GEL Super H 1 000, Super H2000, Super H 3000, Super H4000 were connected in series and measured using tetrahydrofuran as the eluent. Polystyrene standards were used for molecular weight calibration.

(3) Microscopic observation

The alignment state of the liquid crystal was observed with a BH 2 polarizing microscope manufactured by Olympus Optical Co., Ltd.

(4) Liquid crystal film parameter measurement

An automatic birefringence meter K O B R A 2 1 A D H manufactured by Oji Scientific Instruments was used.

(5) DS C measurement (glass transition point (T g) measurement)

After scraping off the liquid crystal layer, a differential scanning calorimeter (DS C, DS C-7 manufactured by Perkin E1mer) was used and measured at a heating rate of 20 ° C / min.

(6) Measurement of viewing angle (equal contrast curve)

The viewing angle of the liquid crystal display device was measured by EZcontras t 16 60R manufactured by ELD IM, and an equal contrast curve was obtained.

A liquid crystal material solution was prepared as follows.

First, a liquid crystalline polymer of the following formula (1 0) was synthesized. The molecular weight was polystyrene conversion and had a number average molecular weight Mn = 8000 and a weight average molecular weight Mw = 15,000. Note that, for the sake of convenience, the formula (10) is represented by the structure of the block polymer, but the number represents the molar composition ratio of the monomer. 1.0 g of the polymer of formula (1 0) is dissolved in 9 ml of cyclohexanone, and in the dark, triarylsulfonium hexafluorate 50% propylene carbonate solution (available from Aldrich, reagent) After adding 0.1 g, the solution was filtered through a polytetrafluoroethylene filter having a pore size of 0.45 μπι to prepare a liquid crystal material solution.

An alignment substrate was prepared as follows.

Polyethylene naphthalate film (P EN film) with a thickness of 38 μηι (manufactured by Teijin DuPont Films Co., Ltd.) is cut into 15 cm squares, and the alkyl-modified polybutyl alcohol (Kuraray Co., Ltd., MP—203 (PVA)) 5% by weight solution (solvent is a mixed solvent of water and isopropyl alcohol at a mass ratio of 1: 1) is applied by spin coating, dried on a hot plate at 50 ° C for 30 minutes, and then 120 ° C at 120 ° C. Heated in an oven for 10 minutes. Subsequently, it was rubbed with a rayon rubbing cloth. The thickness of the obtained PVA layer was 1.2 μΐη. The peripheral speed ratio during rubbing (moving speed of rubbing cloth, moving speed of Z substrate film) was 4.

The liquid crystal material solution described above was applied to the alignment substrate thus obtained by spin coating. Next, it was dried on a hot plate at 60 ° C. for 10 minutes, and heat-treated at 15 ° 0 ° C. for 2 minutes to align the liquid crystal material. Next, place the sample in close contact with an aluminum plate heated to 60 ° C, and then irradiate it with ultraviolet light (measured at 365 nm) of 600 m J / cm ^{2 with} a high-pressure mercury lamp. material

(Thickness of the homeomorphic alignment liquid crystal layer 0.8 μπι) was cured.

(Production of laminates 1 and 2)

Laminates 1 and 2 were prepared as follows to measure the optical parameters of the obtained liquid crystal layer (homeotope orientation liquid crystal layer) and to protect the surface of the liquid crystal layer.

The liquid crystal layer on the obtained alignment substrate was transferred to a polyethylene terephthalate film (PET) through a commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.). In other words, UV-3400 was applied as adhesive layer 1 to a thickness of 5 on the cured liquid crystal layer on the PVA layer, and polyethylene terephthalate (P (ET) film is laminated, and the adhesive layer 1 is cured by irradiating UV light from the PET film side, then the PVA layer and the PEN film are peeled off, and an intermediate laminate with PET film ( PET film Z adhesive layer 1 liquid crystal layer).

A commercially available UV-curing adhesive (UV_3400, manufactured by Toagosei Co., Ltd.) was applied as an adhesive layer 2 on the homeotopick liquid crystal layer of the obtained intermediate laminate to a thickness of 5 m. After laminating with cetyl cellulose (TAC) film and irradiating UV rays from the TAC film side to cure the adhesive layer 2, the PET film is peeled off, and the laminate 1 (adhesive layer 1 no homeomorphic alignment liquid crystal Layer adhesive layer 2 ZT AC film).

After laminating a commercially available non-carrier paste with a separate film on the adhesive layer 1 side of the obtained laminate 1, peel off the TAC film and laminate 2 (separate film / adhesive layer Z adhesive) An agent layer 1 / home-orientated liquid crystal layer / adhesive layer 2) was obtained.

When the obtained laminate 1 is observed under a polarizing microscope in which the crossed Nicols are crossed, it has a uniform monodomain orientation with no disclination, and is homeomorphic with a positive uniaxial refractive index structure from conoscopic observation. I understood it. When this film was tilted, light was incident from an oblique direction, and the cross-col was observed in the same way, and light transmission was observed. The optical retardation of the film was measured with an automatic birefringence measuring device KOB RA2 1 ADH. The measurement light was made incident on the sample surface perpendicularly or obliquely, and the home-to-mouth pick orientation was confirmed from the chart of the optical phase difference and the incident angle of the measurement light. In home-to-mouth pick orientation, the phase difference (front phase difference) in the direction perpendicular to the sample surface is almost zero. Regarding this sample, when the phase difference was measured obliquely in the slow axis direction of the liquid crystal layer, the phase difference value increased with the increase of the incident angle of the measurement light, and the homeotopic orientation was obtained. I was able to judge. From the above, it was judged that the homeo-mouth pick orientation was good.

In addition, N X 1 of the homeotopic pick alignment liquid crystal film was 1.54, Ny: U¾l.54, and N z l were 1.73.

Further, only the liquid crystal material portion of the laminated film was scraped, and T g was measured using a differential calorimetry (DSC). The T g was 100 ° C. Also film liquid crystal The pencil hardness on the surface of the layer was about 2 H, and a sufficiently strong film was obtained.

(Production of elliptically polarizing plate 1)

Corona discharge treatment (25 OW'm in / m ² ) was applied to the adhesive layer 1 side of the laminate 1 and a linear polarizing plate (thickness: about 105 μηι, manufactured by Sumitomo Chemical Co., Ltd. SQW-06 06 2) ) Was peeled off, and the TAC film was peeled off to obtain an elliptically polarizing plate 1 (linear polarizing plate pressure-sensitive adhesive layer / adhesive layer 1 / homeotope orientation liquid crystal layer / adhesive layer 2).

(Preparation of laminate 3)

Corona discharge treatment (25 OW'm in / m ² ) is applied to the adhesive layer 1 side of the laminate 1 and a retardation film with an in-plane retardation of 140 nm is used as the first optical anisotropic element via an adhesive. (Zeonor film, manufactured by Nippon Zeon Co., Ltd.), then peel off the TAC film and laminate 3 (adhesive layer 2 / homeotopick orientation liquid crystal layer / adhesive layer 1 / adhesive layer Z zeonor film) Got.

(Production of laminate 4)

Corona discharge treatment (250 W · min / m ² ) is applied to the Xenoah film side of Laminate 3 and a TAC film (Fuji Film Co., Ltd.) has negative uniaxiality as a third optical anisotropic element via an adhesive. ) Manufactured) was pasted to obtain a laminate 4 (adhesive layer 2 / homeotopic picked liquid crystal layer / adhesive layer 1 / adhesive layer ZENOA film / adhesive layer / TAC film).

(Production of elliptically polarizing plate 2)

Corona discharge treatment (25 OW'm in / m ² ) was applied to the adhesive layer 2 side of the laminate 4 and a linear polarizing plate (thickness: about 105 μιη, manufactured by Sumitomo Chemical Co., Ltd. SQW-06 06 2) ) Is attached to the elliptical polarizing plate 2 (linear polarizing plate Ζadhesive layer adhesive layer 2 / homeoto mouth pick alignment liquid crystal layer / adhesive layer 1 Ζadhesive layer ΖZeoner film / adhesive layer A

C film). The layer thickness of the elliptically polarizing plate was 280 μπι.

(Production of vertical alignment type liquid crystal display device)

As shown in Fig. 1, the viewing side polarizing plate is shown in Fig. 1 for the backlight, back side polarizing plate, vertical alignment (VA) type liquid crystal cell, and viewing side polarizing plate. Instead of this, the elliptically polarizing plate 2 of the present invention was disposed. Figure 2 shows an equal contrast diagram. Compared to the case where this elliptical polarizing plate 2 is not used, the viewing angle is enlarged and obliquely It was found that a good image was obtained even when viewed. The concentric circles in Fig. 2 are drawn at 20 ° intervals. Therefore, the outermost circle shows 80 ° from the center (the same applies to the following figures). <Comparative Example 1>

Plane retardation 140 nm of the laminate 9 to corona discharge treatment to the adhesive layer 3 side (4 / T AC film adhesive layer 3 _ / nematic alignment liquid crystal layer adhesive layer) (2 5 0W 'min Zm 2) After applying a linear polarizing plate (thickness approx. 10 5 μπι, manufactured by Sumitomo Chemical Co., Ltd. 3 <2 "\ — 062) through the adhesive, the TAC film was peeled off and the elliptical polarizing plate 25 (direct A linear polarizing plate / adhesive layer / adhesive layer 3 nonnematic alignment liquid crystal layer Z adhesive layer 4) A commercially available VA type liquid crystal of the same type as that used in the production of the vertical alignment type liquid crystal display device of Example 2 For the television, the elliptically polarizing plate 25 was placed in place of the elliptically polarizing plate 2 used in Example 2. An equal contrast diagram is shown in Fig. 12. Compared with the case where the elliptically polarizing plate 2 of the present invention is used. The viewing angle expansion effect was small, and a good image was not obtained even when viewed from an oblique direction.

(Preparation of laminate 5)

Formula (1 1) polyether ketone represented by (Nippon Shokubai Ltd.: delta n = about 0.02) was dissolved in methyl isobutyl ketone to prepare the 20 weight ^_0/0 of the varnish. This varnish was applied to a retardation film having an in-plane retardation of 140 nm (Zeonor film, manufactured by Nippon Zeon Co., Ltd.) and heat-treated at 100 ° C. for 10 minutes. As a result, a laminate 5 was obtained in which a polyetherketone film having a transparent, smooth surface, a thickness of 6 m, and a negative optical anisotropy in the film thickness direction was formed on a ZENOA film.

(Production of laminate 6)

Corona discharge treatment (250 W. min / m ² ) was applied to the zenoir film side of the laminate 5, and the adhesive layer 2 side of the laminate 2 was adhered via an adhesive, and the laminate 6 (separate film Z Adhesive Layer Z Adhesive Layer 1 / Home-Oriented Pick Oriented Liquid Crystal Layer Adhesive Layer 2 Adhesive Layer Z Zeonor Film Z Polyetherketone Film) was obtained. (Production of elliptically polarizing plate 3)

The separate film of laminate 6 was peeled off, and a linear polarizing plate (thickness approx. 105 μm, SQW-06 2 manufactured by Sumitomo Chemical Co., Ltd.) was attached, and elliptical polarizing plate 3 (linear polarizing plate Z adhesive layer / adhesion) Adhesive layer 1 Noh homeo orientation liquid crystal layer / adhesive layer 2 Adhesive layer / Zeono film (Z polyetherketone film).

Example 4>

(Preparation of laminate 7)

The polyimide represented by the following formula (12) was dissolved in cyclohexanone to prepare a 15% by weight polyimide solution. This polyimide solution was applied to a retardation film having an in-plane retardation of 140 nm (Zeonor film, manufactured by Nippon Zeon Co., Ltd.) and heat-treated at 100 ° C. for 10 minutes. As a result, a polyimide film that is transparent, smooth on the surface, has a thickness of 6 μπι, and exhibits negative optical anisotropy in the direction perpendicular to the film surface is formed on the ZENOA film.

(Preparation of elliptically polarizing plate 4)

Corona discharge treatment (2 50 W · min / m ² ) is applied to the adhesive layer 2 side of the elliptical polarizing plate 1, and the ZENOA film side of the laminate 7 is adhered via an adhesive, and the elliptical polarizing plate 4 (linear polarization) Plate Z pressure-sensitive adhesive layer Z adhesive layer 1 / home-orientated pick liquid crystal layer adhesive layer 2 / pressure-sensitive adhesive layer nozono film / polyimide film) were obtained.

Example 5>

(Preparation of elliptical polarizing plate 5)

Terephthalic acid 50 mm o 1, methyl hydroquinone diacetate 25 mm o 1, catechol diacetate 25 mm o 1 and sodium acetate l O Omg under nitrogen atmosphere at 100 ° C for 30 min, 1 Polymerization was carried out while raising the temperature stepwise at 50 for 1 hour and 200 at 1 hour. Next, polymerization was continued for 2 hours at 250 ° C. with flowing nitrogen gas, and further for 1 hour at the same temperature under reduced pressure. The resulting poly The polymer was dissolved in tetrachloroethane and filtered, and then reprecipitated with methanol to obtain 9. O g of a purified polymer.

Using this polymer, a tetrachloroethane solution with a concentration of 15% by mass was purified and spun onto a 12 cm × 12 cm glass plate (manufactured by EBC) with a polyimide alignment film that was rubbed on one side. After applying by a coating method, it was dried.

Next, this sample was heat-treated at 200 ° C. for 10 minutes in an air thermostat, then taken out from the thermostat and allowed to cool to fix the alignment and obtain a nematic liquid crystal alignment layer. The obtained nematic liquid crystal alignment layer was a completely transparent and smooth film having a thickness of 0, 62 m. When the alignment state of this nematic liquid crystal alignment layer was observed under a crossed Nicol with a polarizing microscope, no defects were found over the entire region. Next, polarization analysis was performed to measure the retardation of this film (Δ η · d, Δ η is the birefringence, and d is the film thickness). The value was obtained and it was found that the nematic structure was fixed (Δ η = 0.227).

In order to transfer the obtained liquid crystal layer (nematic alignment liquid crystal layer) to the film substrate, a laminate 8 was prepared as follows.

The liquid crystal layer on the obtained alignment substrate was transferred to a polyethylene terephthalate film (PET) through a commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.). In other words, on the cured liquid crystal layer on the polyimide film, UV curable adhesive was applied as an adhesive layer 3 to a thickness of 5 m, laminated with PET film, and UV rays were applied from the PET film side. After curing the adhesive layer 3, the polyimide alignment film transparent glass substrate was peeled off to produce a laminate 8 (PET film adhesive layer 3 Z nematic alignment liquid crystal layer).

Further, a commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) was applied as an adhesive layer 4 on the liquid crystal layer of laminate 8 to a thickness of 5 μιη, and triacetyl cellulose ( TAC) Laminate with film and irradiate ultraviolet rays from TAC film side to cure adhesive layer 2, then peel off ΕΤ film and laminate 9 (adhesive layer 3 nematic alignment liquid crystal layer adhesive) Layer 4 ZT AC film). The elliptical polarizing plate 1 (linear polarizing plate adhesive layer / adhesive layer 1 Z homeotropic alignment liquid crystal layer-adhesive layer 2) has an edge discharge treatment (250 W min / m on the adhesive layer 2 side). ² ) and the laminated body 8 is used as a first optical anisotropic element via an adhesive. After adhering to the nematic alignment liquid crystal layer side, the PET film is peeled off and the elliptically polarizing plate 5 (Linear polarizing plate adhesive layer Adhesive layer 1 Z homeotopick alignment liquid crystal layer / adhesive layer

2 Z pressure-sensitive adhesive layer / nematic alignment liquid crystal layer Z adhesive layer 3) was obtained. The layer thickness of the elliptically polarizing plate 5 was 180 m.

(Production of film 1)

A film 1 as a third optical anisotropic element having negative uniaxiality in the film thickness direction was fabricated by the following method. Transparent polycarbonate film with a thickness of 110 m (manufactured by Sumitomo Chemical Co., Ltd.) 1 Heated to 70 ° C, stretched at a speed of 0.3 mm / sec, then re-heated 1 70 ° C However, the film was stretched at a speed of 0.5 mm / sec in a direction perpendicular to the first stretching direction. The polycarbonate film had a higher refractive index in the stretching direction due to the second stretching, and the refractive index was about the same as the direction perpendicular to the stretching direction. For this reason, the polycarbonate film became a negative uniaxial optical anisotropic body including the extraordinary refractive index of the medium in the direction perpendicular to the stretching direction (that is, the direction perpendicular to the film surface).

(Preparation of elliptically polarizing plate 6)

Corona discharge treatment (25 OW ′ min / m ² ) is applied to the adhesive layer 3 side of the elliptically polarizing plate 5, and the film having negative uniaxiality as a third optical anisotropic element through an adhesive 1 is attached, and elliptically polarizing plate 6 (linear polarizing plate Z adhesive layer Z adhesive layer 1 / home-to-mouth orientation liquid crystal layer Z adhesive layer 2 Z adhesive layer Z nematic alignment liquid crystal layer Z adhesive layer

3 Z adhesive layer / film 1) was obtained.

(Production of elliptically polarizing plate 7)

Corona discharge treatment (250 W 'min / m ² ) is applied to the adhesive layer 2 side of the laminate 3 (adhesive layer 2 Z home-mouth picked liquid crystal layer Z adhesive layer 1 / adhesive layer / Zeonor film), A linear polarizing plate (thickness: approx. 10 05 μπι, manufactured by Sumitomo Chemical Co., Ltd. 3 (3 ^ _ 06 2)) is bonded to the elliptical polarizing plate 7 (linear polarizing plate / adhesive layer / adhesive layer 2オ Homeo-mouth pick alignment liquid crystal layer adhesive layer 1 / adhesive layer / Zeonor film).

<Example 8> (Preparation of elliptically polarizing plate 8)

The elliptical polarizing plate 7 is subjected to corona discharge treatment (2550 W · min / m ² ) on the zenoir film side, and a negative uniaxial TAC film as a third optical anisotropic element through an adhesive (Fuji Film (manufactured by Co., Ltd.) is attached, and elliptically polarizing plate 8 (linearly polarizing plate Z adhesive layer Z adhesive layer 2 / homeotopick orientation liquid crystal layer Z adhesive layer 1 Z adhesive layer / ZEONOR film adhesive Layer ZTAC film).

Example 9>

(Production of film 2)

A retardation film (Pure Ace WR, manufactured by Teijin Ltd.) having an in-plane retardation was longitudinally uniaxially stretched at 230 ° C. to obtain a film 2 having negative biaxiality. The in-plane phase difference was 140 nm.

(Preparation of elliptically polarizing plate 9)

Corona discharge treatment on the adhesive layer 2 side of the elliptically polarizing plate 1 (linear polarizing plate Z adhesive layer Z adhesive layer 1 Z homeoto orientation liquid crystal layer / adhesive layer 2) m ² ), and the film 2 is pasted as a first optical anisotropic element through an adhesive, and an elliptically polarizing plate 9 (linearly polarizing plate Z adhesive layer Z adhesive layer 1 / homeotopic orientation liquid crystal Layer Z adhesive layer 2 Z pressure-sensitive adhesive layer Z film 2) was obtained. The layer thickness of the elliptically polarizing plate 9 was 1500 μm.

(Production of vertical alignment type liquid crystal display device)

For the commercially available VA type liquid crystal television arranged in the order of the backlight, the backlight side polarizing plate, the VA type liquid crystal cell, and the viewing side polarizing plate, as shown in FIG. 3, the present invention is used instead of the viewing side polarizing plate. The elliptically polarizing plate 9 was disposed. Figure 4 shows an equal contrast diagram. Compared to the case where the elliptical polarizing plate 9 is not used, the viewing angle is widened, and it was found that a good image can be obtained even when viewed obliquely.

Comparative Example 2>

For the commercially available VA type liquid crystal television of the same type as that used in the manufacture of the vertical alignment type liquid crystal display device of Example 9, instead of the elliptically polarizing plate 9, the elliptically polarizing plate obtained in Reference Example 14 described later 4 4 Arranged. Figure 14 shows an equi-contrast diagram. Compared with the case of using the elliptically polarizing plate 9 of the present invention, the effect of widening the viewing angle was small, and a good image was not obtained even when viewed from an oblique direction. <Example 1 0>

(Production of laminate 10)

After the corona discharge treatment (250 W · min / m ² ) is applied to the adhesive layer 1 side of the laminate 1 and the film 2 is adhered as a first optical anisotropic element via an adhesive, a TAC film The laminate 10 was peeled to obtain a laminate 10 (adhesive layer 2 homeomorphic orientation liquid crystal layer / adhesive layer 1Z pressure-sensitive adhesive layer film 2).

(Production of elliptically polarizing plate 10)

Corona discharge treatment (250 W · min / m ² ) was applied to the adhesive layer 2 side of the laminate 10, and a linear polarizing plate (thickness: about 10 μμιι, manufactured by Sumitomo Chemical Co., Ltd.) via an adhesive. SQ W-06 2) is pasted to obtain an elliptically polarizing plate 10 (linear polarizing plate Ζadhesive layer / adhesive layer 2 / homeotope picked liquid crystal layer Ζadhesive layer 1 Ζadhesive layer film 2) It was. Reference Example 1>

(Production of laminate 1 1)

In-plane retardation 1 05 nm retardation film (Zeonor film, manufactured by Nippon Zeon Co., Ltd.) was subjected to corona treatment (250 W · min / m2), and the laminate 8 (PET film Z adhesive) was bonded via an adhesive. After sticking the nematic alignment liquid crystal layer side of layer 3Z nematic alignment liquid crystal layer), the PET film was peeled off to produce laminate 1 1 (adhesive layer 3 / nematic alignment liquid crystal layer pressure-sensitive adhesive layer / Zeonor film).

(Production of elliptically polarizing plate 1 1)

The laminate 11 is subjected to a corona treatment (250 W 'min / m 2) on the zenoah film side, and a linear polarizing plate (thickness: about 105 μπι, manufactured by Sumitomo Chemical Co., Ltd., SQ W-06) 2) was pasted to make an elliptically polarizing plate 1 1 (adhesive layer 3Ζnematic alignment liquid crystal layer / adhesive layer / zeonor film / adhesive layer / linear polarizing plate).

(Production of elliptically polarizing plate 1 2)

A TAC film having negative uniaxiality as a third optical anisotropic element through a pressure-sensitive adhesive by applying corona discharge treatment (250 W · min / m ² ) to the adhesive layer 3 side of the elliptically polarizing plate 11 (Fuji Film Co., Ltd.) is attached, and elliptically polarizing plate 1 2 (TAC film / adhesive layer adhesive layer 3 Z nematic alignment liquid crystal layer adhesive layer ZEONOR film Z adhesive layer Z linear polarizing plate) Produced. Reference Example 3>

(Preparation of elliptically polarizing plate 1 3)

An in-plane retardation of 105 nm (Zeonor film, manufactured by Nippon Zeon Co., Ltd.) was subjected to corona discharge treatment (250 W · min / m ² ), and a linear polarizing plate (thickness approx. μιη and SQW-06 2) manufactured by Sumitomo Chemical Co., Ltd. were attached to produce an elliptically polarizing plate 1 3 (Zeonor film / adhesive layer Ζlinear polarizing plate).

Reference Example 4>

(Preparation of elliptically polarizing plate 14)

The elliptical polarizing plate 1 3 is subjected to corona treatment (250 W · mi η / m2) on the zenoah film side, and the laminate 9 (adhesive layer 3Z nematic alignment liquid crystal layer Z adhesive layer 4 / T AC film through an adhesive) stuck with adhesive layer 3 side), elliptically polarizing plate 1 4 (T AC film Z adhesive layer 4 / nematic alignment liquid crystal layer Z adhesive layer 3 / Zeonoafi Lum / adhesive layer _/ / linear polarizer) Obtained.

(Preparation of elliptical polarizing plate 15)

TAC film (Fuji Film) has a negative uniaxial property as the third optical anisotropic element through the adhesive by applying corona discharge treatment (250W · min Zm ² ) to the TAC film side of the elliptically polarizing plate 14 (Made by Co., Ltd.) and an elliptically polarizing plate 1 5 (TAC film Z adhesive layer ZT AC film / adhesive layer 4 Z nematic alignment liquid crystal layer Z adhesive layer 3 Z ZEONOR film Z adhesive layer / A linear polarizing plate) was obtained.

(Manufacture of elliptical polarizing plate 1 6) Corona discharge treatment (2500 W · min / m ² ) was applied, and the adhesive plate was attached to the elliptical polarizing plate 1 3 (Zeonor film / adhesive layer linear polarizing plate) on the zeonor film side. As a result, an elliptically polarizing plate 16 (polyimide film Xenoir film / adhesive layer / Zenoor film Z adhesive layer linearly polarizing plate) was obtained.

(Production of film 3)

First, film 3 having negative uniaxial anisotropy in the film thickness direction is produced by the following method. Made.

After saponifying the surface of the TAC film, an alignment film coating solution composed of 10 parts by weight of polyvinyl alcohol, 371 parts by weight of water, 19 parts by weight of methanol, and 0.5 parts by weight of glutaraldehyde is deposited on the film. It was applied with a spin coater. A film was formed by drying with warm air of 60 ° C for 60 seconds and further with warm air of 100 ° C for 120 seconds. Next, the formed film was rubbed in a direction parallel to the slow axis direction of the film to obtain an alignment film. Next, on the alignment film, 1.8 g of a discotic liquid crystalline compound represented by the following formula (13), ethylene oxide-modified trimethylolpropane tritalate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.) 0.2 g, photopolymerization initiator (Irgacure 9 07, manufactured by Chipagagi Co., Ltd.) 0.06 g, sensitizer (Cacure 1 DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02 g, 3.9 A solution of g in methyl ethyl ketone was applied with a spin coater. This was affixed to a metal frame and heated in a thermostat at 125 ° C for 3 minutes to align the discotic liquid crystal compound. Next, using a 120 W "cm high-pressure mercury lamp at 100 ° C, UV irradiation was performed for 30 seconds to crosslink the discotic liquid crystal compound. Then, the discotic liquid crystal compound was allowed to cool to room temperature. Thus, film 3 (discotic liquid crystal Layer alignment film / TAC film).

(Production of laminate 1 2)

A film having an in-plane retardation of 140 nm (Zeonor film, manufactured by Nippon Zeon Co., Ltd.) is attached as a first optical anisotropic element via an adhesive to the TAC film side of the film 3 and laminated. Body 1 2 (discotic liquid crystal layer alignment film ZTAC film pressure-sensitive adhesive layer Z-Zeonor film) was obtained.

(Preparation of laminate 1 3) In-plane retardation 1 05 nm retardation film (Zeonor film, manufactured by Nippon Zeon Co., Ltd.) was subjected to corona treatment (250 W min / m ² ), and the Zenoor film of the laminated body 1 2 was passed through an adhesive. The laminate 1 3 (discotic liquid crystal layer / alignment film no TAC film / adhesive layer nose oner film / adhesive layer Z zonah film) was obtained.

(Production of elliptically polarizing plate 1 7)

Corona discharge treatment (250 W · min / m ² ) was applied to the Xenoah film side of the laminate 13 and a linear polarizing plate (thickness: about 105 m, manufactured by Sumitomo Chemical Co., Ltd. 3 (3 06 2) was pasted to produce an elliptically polarizing plate 1 7 (discotic liquid crystal layer / alignment film TAC film pressure-sensitive adhesive layer / Zeono Aluminum Z pressure-sensitive adhesive layer nozeonofilm Z pressure-sensitive adhesive layer-linear polarizing plate).

(Preparation of laminate 14)

Corona discharge treatment (2 50 W · min / m ² ) was applied to a retardation film (Zenoah, manufactured by Nippon Zeon Co., Ltd.) with an in-plane retardation of 140 nm, and an in-plane retardation of 105 nm was applied via an adhesive. A phase difference film (Pure Ace, manufactured by Teijin Limited) is pasted and laminated.

14 (Zeonor film / adhesive layer Z pure ace film) was obtained.

(Production of film 4)

First, a film 4 having negative uniaxial anisotropy in the film thickness direction was produced by the following method.

Photopolymerizable mesogenic compound (LC 242 manufactured by BAS F) 90.5 parts by weight, polymerizable chiral agent (LC 75 6 manufactured by BAS F) 9.5 parts by weight and solvent (cyclohexanone) selectively reflected 3 weights of photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals Co., Ltd.) is added to the solution that is adjusted and blended so that the center wavelength is 300 nm. A coating solution with ₀ added (solid content 30 wt%) was prepared. The coating solution was applied on a stretched polyethylene terephthalate film (alignment substrate) using a spin coater so that the thickness after drying was 6 m, and the solvent was dried at 100 ° C for 2 minutes. . The obtained film was irradiated with the first ultraviolet ray at 5 OmW / cm ² for 1 second in an air atmosphere at 35 ° C. from the alignment substrate side. Then, it was heated at 80 ° C for 1 minute without UV irradiation. Next, the second UV irradiation is performed in an air atmosphere at 80 ° C. Performed at 5 mW / cm ² for 60 seconds. Next, irradiation of the third ultraviolet ray from the alignment substrate side at 8 OmW / cm ² was performed for 30 seconds in a nitrogen atmosphere at 50 ° C. to form a broadband cholesteric liquid crystal layer having a selected wavelength of 250 to 350 nm. Next, a triacetyl cellulose film was bonded to the cholesteric liquid crystal layer side with an acrylic adhesive and dried at 80 ° C. for 5 minutes. Next, the alignment substrate was gently peeled off to obtain film 4 (cholesteric liquid crystal layer pressure-sensitive adhesive layer / TAC film).

(Production of laminate 15)

Corona discharge treatment (250 W · min / m ² ) is applied to the zenoah film side of the laminate 14, and the TAC film side of the film 4 is adhered via an adhesive, and the laminate 15 (cholesteric liquid crystal layer) Z pressure-sensitive adhesive layer ZTAC film Z pressure-sensitive adhesive layer Z zeonor film / pressure-sensitive adhesive layer / pure ace film).

(Preparation of elliptically polarizing plate 18)

Corona discharge treatment (250 W · min / m ² ) was applied to the pure ace film side of the laminate 15 and a linear polarizing plate (thickness: about 105 μπι, manufactured by Sumitomo Chemical Co., Ltd. SQW-062) was applied via an adhesive. Adhesion was made to produce an elliptically polarizing plate 18 (cholesteric liquid crystal layer / adhesive layer ΖΤ AC film / adhesive layer / Zeonor film / adhesive layer Z Pure Ace film / adhesive layer / linear polarizing plate).

Reference Example 9>

(Production of film 5)

First, a film 5 having positive uniaxial anisotropy in the in-plane direction of the film was produced by the following method.

A photopolymerization initiator (Ciba Specialty Chemicals, Irgacure 907) was added to a solution in which 100 parts by weight of a photopolymerizable mesogenic compound (LC 242 manufactured by BAS F) and a solvent (cyclohexanone) were mixed. ) Was added to prepare a coating solution (solid content 30% by weight). The coating solution was applied onto a stretched polyethylene terephthalate film (alignment substrate) using a spin coater so that the thickness after drying was 6 μπι, and the solvent was dried at 100 ° C. for 2 minutes. The obtained film was irradiated with the first ultraviolet ray at 5 OmW / cm ² for 1 second in an air atmosphere at 35 ° C. from the alignment substrate side. Then, it was heated at 80 ° C for 1 minute without ultraviolet irradiation. Next, the second UV irradiation is performed at 5 mW / cm ² for 60 seconds in an air atmosphere at 80 ° C. And a nematic liquid crystal layer having positive uniaxial anisotropy was formed in the film plane. Next, a triacetyl cellulose film was bonded to the nematic liquid crystal layer side with an acrylic adhesive and dried at 80 ° C. for 5 minutes. Next, the alignment substrate was gently peeled to obtain film 5 (nematic liquid crystal alignment layer pressure-sensitive adhesive layer / TAC film).

(Production of film 6)

A retardation film having an in-plane retardation (Warton, manufactured by JSR Co., Ltd.) was longitudinally uniaxially stretched at 230 ° C. to obtain a film 6 having negative biaxiality. The in-plane retardation was 140 ηm.

(Production of laminate 16)

The film 6 is subjected to corona discharge treatment (250 W. min / m ² ), and the TAC film side of the film 5 having positive uniaxiality in the plane is pasted as a fourth optical anisotropic element through an adhesive. The laminate 16 (film 6Z adhesive layer / nematic liquid crystal alignment layer Z adhesive layer ZT AC film) was obtained.

(Production of elliptically polarizing plate 19)

Corona treatment (250 W · min / m 2) is applied to the TAC film side of the laminate 16 and a linear polarizing plate (thickness: about 105 im, SQ W-062 manufactured by Sumitomo Chemical Co., Ltd.) is applied via an adhesive. An elliptically polarizing plate 19 (film 6 / adhesive layer non-matic liquid crystal alignment layer / adhesive layer / TAC film / adhesive layer linear polarizing plate) was prepared. Reference Example 10>

(Production of elliptically polarizing plate 20)

The elliptical polarizing plate 13 (Zeonor film / adhesive layer Z linear polarizing plate) is subjected to a corona discharge treatment (250 W · minZm ² ) on the side of the zenoir film, and a negative 2 as a fourth optical anisotropic element through the adhesive. The axially polarizing film 6 was stuck to obtain an elliptically polarizing plate 20 (film 6 Z pressure-sensitive adhesive layer / Zeonoa film pressure-sensitive adhesive layer / linearly polarizing plate).

(Preparation of elliptically polarizing plate 21)

Corona discharge treatment (250W · minZm ² ) is applied to the Zeonor film side of the laminate 5 (Polyetherketone film Z Zeonor film), and a linear polarizing plate (thickness: about 105 m, manufactured by Sumitomo Chemical Co., Ltd.) is used. SQW—062) An elliptically polarizing plate 2 1 (polyether ketone film Z zeonor film / adhesive layer / linearly polarizing plate) was obtained.

Reference Example 1 2>

(Preparation of elliptically polarizing plate 22)

Corona discharge treatment (250W · min / m ² ) is applied to a retardation film with an in-plane retardation of 140 nm (Zeonor film, manufactured by ZEON CORPORATION), and a linear polarizing plate (thickness approx. 3 (3 \ ^-06 2) manufactured by Sumitomo Chemical Co., Ltd. was pasted to obtain an elliptically polarizing plate 22 (Zeonor film / adhesive layer Z linear polarizing plate).

Reference Example 1 3>

• (Production of elliptically polarizing plate 23)

The elliptical polarizing plate 22 (Zeonor film / adhesive layer linearly polarizing plate) is subjected to corona discharge treatment (250 W · min / m ² ) on the side of the zenoir film, and the third optical anisotropic element is formed via the adhesive. The film 1 having negative uniaxiality was stuck to obtain an elliptically polarizing plate 23 (film 1Z pressure-sensitive adhesive layer Z zeonor film Z pressure-sensitive adhesive layer / linearly polarizing plate).

Reference Example 14>

(Preparation of elliptically polarizing plate 24)

The film 6 having negative biaxiality as the first optical anisotropic element is subjected to a corona discharge treatment (250 W · min / m ² ), and a linear polarizing plate (thickness of about 10 5 M) via an adhesive. m, 3 <3 \ — 06 2) manufactured by Sumitomo Chemical Co., Ltd. was attached to obtain an elliptically polarizing plate 24 (film 6 / adhesive layer Z linear polarizing plate).

Using the VA type liquid crystal television of the same type as that used in Example 2, as shown in FIG. 5, the elliptically polarizing plates obtained in Examples 1 to 10 and Reference Examples 1 to 14 described above were used. The element and a vertical alignment type liquid crystal display cell were arranged to produce a vertical alignment type liquid crystal display device (see Table 1 for the number of elliptical polarizing plates used).

As a result, it was found that, compared with the case where the elliptically polarizing plate of the present invention was not used, the viewing angle was enlarged and a good image was obtained even when viewed obliquely.

Fig. 6 shows the equi-contrast diagram of Example 13.

<Comparative Example 3> For the commercially available VA liquid crystal TVs arranged in the order of backlight side polarizing plate, VA type liquid crystal cell, and viewing side polarizing plate, as shown in Fig. 15, instead of the viewing side polarizing plate, the elliptical polarization The plate 25 was provided with the elliptically polarizing plate 12 instead of the pack light side polarizing plate. As a result, the viewing angle expansion effect was small as compared with the case where the elliptically polarizing plate of the present invention was used, and a good image could not be obtained even when viewed obliquely.

An isocontrast diagram is shown in Figure 16.

A vertical alignment type liquid crystal display device shown in FIG. 5 was produced in the same manner as in Example 13 except that the retardation R th 2 in the thickness direction of the third optical anisotropic element of Example 13 was 10 nm. . As a result, the viewing angle expansion effect was small as compared with the case where the elliptically polarizing plate of the present invention was used, and a good image was not obtained even when viewed from an oblique direction.

An equal contrast diagram is shown in Figure 17.

Using the same type of VA-type liquid crystal television used in Example 2, except that the fourth optical anisotropic element was not arranged in the arrangement of FIG. A direct-alignment type liquid crystal display device was produced (see Table 1 for the number of elliptically polarizing plates used). As a result, it was found that, compared with the case where the elliptically polarizing plate of the present invention was not used, the viewing angle was enlarged and a good image was obtained even when viewed obliquely.

7 using the same type of VA type liquid crystal television as used in Example 2, except that the third optical anisotropic element was not arranged in the arrangement of FIG. A direct-alignment type liquid crystal display device was produced (see Table 1 for the number of elliptically polarizing plates used). As a result, it was found that, compared with the case where the elliptically polarizing plate of the present invention was not used, the viewing angle was enlarged and a good image was obtained even when viewed obliquely.

An equal contrast diagram for Example 19 is shown in FIG.

Using the same type of VA type liquid crystal television used in Example 2, as shown in FIG. 9, the elliptically polarizing plate and the optical anisotropic element obtained in Examples 1 to 10 and Reference Examples 1 to 14 are used. And a vertical alignment type liquid crystal display cell were arranged to produce a vertical alignment type liquid crystal display device (see Table 1 for the number of elliptically polarizing plates used). As a result, it was found that, compared with the case where the elliptically polarizing plate of the present invention was not used, the viewing angle was enlarged and a good image was obtained even when viewed obliquely.

An equivalent contrast diagram of Example 22 is shown in FIG.

Example 23>

(Preparation of laminate 17)

Commercially available UV curable adhesive (UV-3400, manufactured by Toagosei Co., Ltd.) and silicone-based surface modifier (Paintad) 32, manufactured by Toray Dakoi-Jung Co., Ltd.) was added as an adhesive layer 5 to a thickness of 5 μm, laminated with triacetyl cellulose (TAC) film, and TAC film After curing the adhesive layer 5 by irradiating ultraviolet rays from the side, the PET film was peeled off, and the laminate 1 Ί (adhesive layer 1 / homeotope orientation liquid crystal layer Z adhesive layer 5 ZT AC film) Got.

(Production of laminate 1 8)

Corona discharge treatment (2500 W · min / m ² ) was applied to the adhesive layer 1 side of the laminate 17 and an in-plane retardation of 140 nm was obtained as the first optical anisotropic element via the adhesive. After pasting the film (Zeonor Film, manufactured by Nippon Zeon Co., Ltd.), the TAC film was peeled off with the adhesive layer 5 adhered, and the laminate 1 8 (homeotope orientation liquid crystal layer Z adhesive layer 1 / adhesive layer Z zeno film).

(Production of laminate 1 9)

Corona discharge treatment (250 W. min / m ² ) was applied to the Xenoah film side of the laminate 18 and a negative uniaxial TAC film (Fuji Film ( Manufactured)) to obtain a laminated body 19 (homeotope orientation liquid crystal layer / adhesive layer 1 Z pressure-sensitive adhesive layer / Zeonor film / pressure-sensitive adhesive layer / TAC film).

(Preparation of elliptically polarizing plate 26)

Linear polarizer corona discharge treatment ^{(25 OW · min / m 2} ) applied to (a thickness of about ₁ 05 μ πι, Sumitomo Chemical Co., Ltd. SQW- 06 2), praise ot the laminate 1 9 with an adhesive Sticking with the mouth-pick orientation liquid crystal layer surface, an elliptically polarizing plate 26 (linear polarizing plate pressure-sensitive adhesive layer / homeoto mouth-pick orientation liquid crystal layer adhesive layer 1 pressure-sensitive adhesive layer Z ZEONOR film / pressure-sensitive adhesive layer ZT AC film) was obtained. . <Comparative Example 5>

Polystyrene was biaxially stretched in the in-plane direction of the film to produce an optically positive uniaxial film 7 having a thickness difference of 1195 nm. A vertical alignment type liquid crystal display device shown in FIG. 5 was produced in the same manner as in Example 2 except that the homeotropic alignment liquid crystal layer in Example 2 was replaced with film 7. As a result, the thickness was significantly increased compared to the elliptical polarizing plate of the present invention, and the total film thickness was 4500 m. table 1

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a vertical alignment type liquid crystal display device used in Example 2.

FIG. 2 is a diagram showing the contrast ratio when the vertical alignment type liquid crystal display device in Example 2 is viewed from all directions.

FIG. 3 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Example 9.

FIG. 4 is a graph showing the contrast ratio when the vertical alignment type liquid crystal display device in Example 9 is viewed from all directions.

FIG. 5 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Example 13. FIG. 6 is a graph showing the contrast ratio when the vertical alignment type liquid crystal display device in Example 13 is viewed from all directions. FIG. 7 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Example 19. FIG. 8 is a graph showing the contrast ratio when the vertical alignment type liquid crystal display device in Example 19 is viewed from all directions.

FIG. 9 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Example 22. FIG. 10 is a diagram showing the contrast ratio when the vertical alignment type liquid crystal display device in Example 22 is viewed from all directions.

FIG. 11 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Comparative Example 1. FIG. 12 is a diagram showing the contrast ratio when the vertical alignment type liquid crystal display device in Comparative Example 1 is viewed from all directions.

FIG. 13 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Comparative Example 2. FIG. 14 is a diagram showing the contrast ratio when the vertical alignment type liquid crystal display device in Comparative Example 2 is viewed from all directions.

FIG. 15 is a schematic cross-sectional view of the vertical alignment type liquid crystal display device used in Comparative Example 3. FIG. 16 is a diagram showing a small contrast ratio when the vertical alignment type liquid crystal display device in Comparative Example 3 is viewed from all directions.

FIG. 17 is a graph showing the contrast ratio when the vertically aligned liquid crystal display device in Comparative Example 4 is viewed from all directions.

(Explanation of symbols)

1 Linear polarizing plate

2 Home-to-mouth pick alignment liquid crystal film

3 First optical anisotropic element

4 First optical anisotropic element (negative biaxiality)

5 Third optical anisotropic element

6 Fourth optical anisotropic element

7 Vertical alignment type liquid crystal cell

Claims

The scope of the claims

1. An ellipse for a vertical alignment type liquid crystal display device comprising a home-orifice pick-alignment liquid crystal film in which a liquid crystal material exhibiting at least positive uniaxiality is home-orientated in a liquid crystal state and then the orientation is fixed, and a linear polarizing plate Polarizer.

2. The elliptically polarizing plate for a vertical alignment type liquid crystal display device according to claim 1, wherein the homeotope pick alignment liquid crystal film satisfies the following [1] and [2].

[1] 0 nm≤R e 1≤ 20 nm

[2]-500 nm≤R t h l≤-30 nm

(Here, R e 1 means the in-plane retardation value of the home-mouth pick-aligned liquid crystal film, and R th 1 means the retardation value in the thickness direction of the home-top pick-aligned liquid crystal film. R e 1 and R th 1 are R e 1 = (NX 1 −N y 1) X d 1 [nm] and R th 1 = (Nx 1−N z 1) X d 1 [nm], respectively. D 1 is the thickness of the liquid crystal film with home-orifice pick alignment, Nx 1 and Ny 1 are the main refractive index of the surface of the liquid crystal film with home-ortho-picked picking, and N z 1 is the main refractive index in the thickness direction. Yes, N zl> Nx l≥Ny l.)

3. A liquid crystalline composition comprising at least a liquid crystalline polymer compound having an oxetanyl group in the homeotropic alignment liquid crystal layer is homeotropically aligned in a liquid crystal state, and then reacted with the oxetanyl group. 3. The elliptically polarizing plate according to claim 1, wherein the homeotropic alignment is fixed.

4. The elliptically polarizing plate for a vertical alignment type liquid crystal display device has a first optical anisotropic element exhibiting a phase difference of 1 to 4 wavelengths in a plane. An elliptically polarizing plate for vertically aligned liquid crystal display devices according to claim 1.

5. The above-mentioned elliptically polarizing plate for a vertical alignment type liquid crystal display device exhibits negative uniaxial optical anisotropy in the thickness direction with the first optical anisotropic element showing a phase difference of 1/4 wavelength in the plane. Less than 5. An elliptical element for a vertical alignment type liquid crystal display device according to any one of claims 1 to 4, characterized by comprising a third optical anisotropic element characterized by satisfying [3] and [4]. Polarizer.

[3] 0 nm≤R e 2≤ 20 nm

[4] 30 nm≤R t h 2≤ 500 nm

(Here, Re 2 represents the in-plane retardation value of the third optical anisotropic element, and R th 2 represents the thickness direction retardation value of the third optical anisotropic element. It means that R e 2 and R th 2 are R e 2 = (Nx 2 -Ny 2) X d 2 [nm], R th 2 = (Nx 2-N z 2) X d 2 [nm, respectively. D 2 is the thickness of the third optical anisotropic element, Nx 2 and Ny 2 are the main refractive indices in the plane of the third optical anisotropic element, and N z 2 is the thickness. The principal refractive index in the direction, Nx 2≥Ny 2> N z 2.)

6. The third optically anisotropic element is at least one polymer material selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide. The elliptically polarizing plate according to claim 5.

7. The first optical anisotropic element according to any one of claims 1 to 6, wherein the first optical anisotropic element exhibits a phase difference of 1Z4 wavelength in a plane and has negative biaxial optical anisotropy. An elliptically polarizing plate for vertically aligned liquid crystal display devices.

8. The elliptically polarizing plate for a vertical alignment type liquid crystal display device according to claim 1, wherein the total film thickness is 400 μπι or less.

9. A vertical alignment type liquid crystal cell including liquid crystal molecules vertically aligned with respect to the substrate surface when no voltage is applied between a pair of substrates having electrodes, and vertical alignment on at least one side of the vertical alignment type liquid crystal cell substrate The liquid crystal cell substrate side of the vertical alignment type liquid crystal display device according to any one of claims 1 to 7 is disposed such that the home-orientated pick alignment liquid crystal film side faces the vertical alignment type liquid crystal cell substrate and the vertical alignment type liquid crystal cell substrate Between the elliptical polarizer, A vertical alignment type liquid crystal display device comprising at least one first optical anisotropic element having a phase difference of ¼ wavelength in a plane. .

10. The vertical alignment type liquid crystal display device according to claim 9, wherein the wavelength is 1/4 in-plane from the substrate side on the substrate opposite to the substrate on which the elliptically polarizing plate for the vertical alignment type liquid crystal display device is disposed. 10. The vertical alignment type liquid crystal display device according to claim 9, wherein at least one first optical anisotropic element exhibiting a phase difference of at least one and a linear polarizing plate are arranged.

11. A third optical anisotropic element exhibiting negative uniaxial optical anisotropy in at least one sheet in the thickness direction between the first optical anisotropic element and the vertical alignment type liquid crystal cell. The vertical alignment type liquid crystal display device according to claim 9 or 10, characterized by comprising:

12. A fourth optical anisotropic element having positive uniaxial optical anisotropy in an in-plane direction is provided between the vertical alignment type liquid crystal cell and the linearly polarizing plate. The vertical alignment type liquid crystal display device according to any one of the above.

1 3. Any one of claims 9 to 12, wherein the first optical anisotropic element exhibits a phase difference of ¼ wavelength in a plane and has negative biaxial optical anisotropy. Vertical alignment type liquid crystal display device described in Crab.

14. The substrate according to any one of claims 9 to 13, wherein one substrate of the vertical alignment type liquid crystal cell is a substrate having a region having a reflection function and a region having a transmission function. Vertical alignment type liquid crystal display device.