JP4383435B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a VA mode liquid crystal display device excellent in viewing angle characteristics.

Liquid crystal display devices are increasingly used year by year as space-saving image display devices with low power consumption. Conventionally, the large viewing angle dependence of images has been a major drawback of liquid crystal display devices. However, high viewing angle liquid crystal display devices using the VA mode have come into practical use, and high-quality images such as televisions are required. In other markets, demand for liquid crystal display devices is rapidly expanding.
The VA mode liquid crystal display device has an advantage that the contrast is generally higher than that of other liquid crystal display modes, but has a problem that the contrast and the color change greatly depending on the viewing angle. Various optical compensation films have been proposed as a method for compensating for this. Among these, the method using two stretched cellulose acylates disclosed in Patent Document 1 as an optical compensation film allows the optical compensation film to also serve as a polarizing plate protective film. This is also a preferable method from the point of view.
However, in recent years, as display devices have become larger, especially for large TV applications, more precise display performance has been demanded. With the above method, compensation for color change due to viewing angle is insufficient, and further improvements are required. It was done.

JP 2003-170492 A

  An object of the present invention is to provide a liquid crystal display device which is simple and inexpensive to manufacture and has a low color viewing angle dependency.

The above problem is solved by the following means.
(1) A liquid crystal cell, a first polarizing plate and a second polarizing plate arranged on both sides of the liquid crystal cell, a first retardation film arranged between the first polarizing plate and the liquid crystal cell,
A second retardation film disposed between the second polarizing plate and the liquid crystal cell;
The absorption axis of the first polarizing plate and the slow axis of the first retardation film are substantially parallel,
The transmission axis of the second polarizing plate and the slow axis of the second retardation film are substantially parallel.
The liquid crystal display device in which the first retardation film satisfies the relationships of the following formulas (1) to (6), and the second retardation film satisfies the relationships of the following formulas (7) to (12).
10 nm <Re (548) <100 nm Formula (1)
20 nm <Rth (548) <400 nm Formula (2)
1.0 <Re (446) / Re (548) <2.0 Formula (3)
0.5 <Re (628) / Re (548) <1.0 Formula (4)
1.0 <Rth (446) / Rth (548) <2.0 Formula (5)
0.5 <Rth (628) / Rth (548) <1.0 Formula (6)
40 nm <Re (548) <300 nm Formula (7)
20 nm <Rth (548) <400 nm (8)
0.5 <Re (446) / Re (548) <1.5 Formula (9)
0.5 <Re (628) / Re (548) <2.0 Formula (10)
0.5 <Rth (446) / Rth (548) <2.0 Formula (11)
0.5 <Rth (628) / Rth (548) <1.5 Formula (12)
(2) The liquid crystal display device according to (1), wherein the first retardation film and the second retardation film satisfy the following relationship.
Formula (A)
λ1.0 (1 ^st ) −λ1.0 (2 ^nd )> 0
(In the formula (A), λ1.0 (1 ^st ) represents a wavelength at which the absorbance converted to a film thickness of 80 μm of the first retardation film is 1.0 in the wavelength range of 200 nm to 700 nm, and λ1.0 ( 2 ^nd) represents the wavelength at which the absorbance was converted into a film thickness of 80μm of the second retardation film is 1.0 in the wavelength range of 200 nm to 700 nm.)
(3) The liquid crystal display device according to (1) or (2), wherein at least one of the first retardation film and the second retardation film also serves as a protective film for a polarizing plate.
(4) The liquid crystal display device according to any one of (1) to (3), wherein at least one of the first retardation film and the second retardation film is a cellulose acylate film.
(5) The liquid crystal display device according to any one of (1) to (4), wherein the first retardation film contains a compound having at least one absorption maximum in a range of 200 nm to 380 nm. (6)
The liquid crystal display device according to any one of 1 to 5, wherein the first retardation film is a cellulose acylate film stretched in a longitudinal direction.
(7) The liquid crystal display device according to any one of (1) to (6), wherein the second retardation film is a cellulose acylate film stretched in the width direction.
(8) The liquid crystal display device according to any one of (1) to (8), wherein the liquid crystal cell is in a VA mode.

  According to the present invention, it is possible to provide a liquid crystal display device that is simple and inexpensive and has low dependence on the color viewing angle.

Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
In the present invention, “substantially parallel” means that an angle formed by two axes is −10 ° to + 10 °.

[Film retardation]
In this specification, Re (λ) and Rth (λ) respectively represent in-plane retardation and retardation in the thickness direction at a wavelength λ. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).
When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (in the absence of the slow axis, any in-plane value) The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (21) and (22).

注記：
上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値をあらわす。
式（２１）におけるｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘおよびｎｙに直交する方向の屈折率を表す。

Note:
The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In formula (21), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. .

Rth = ((nx + ny) / 2−nz) × d −−− Formula (22)
In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is the above-mentioned Re (λ), and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) from −50 degrees to +50 degrees with respect to the film normal direction. The light is incident at a wavelength of λ nm from each inclined direction in 10 degree steps, and measured at 11 points. KOBRA 21ADH or WR is measured based on the measured retardation value, the assumed average refractive index, and the input film thickness value. Is calculated.
In the above measurement, the assumed value of the average refractive index may be a value in a polymer handbook (John Wiley & Sons, Inc.) or a catalog of various optical films. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of the main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting these assumed values of average refractive index and film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

  Here, as the assumed value of the average refractive index, values of “Polymer Handbook” (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. If the average refractive index is not known, it can be measured with an Abbe refractometer.

Examples of the average refractive index values of main optical films are given below:
Cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59). By inputting the assumed value the average refractive index and a film thickness (refractive index of the film forming direction) n _x by KOBRA WR, n _y (refractive index in the width direction), n _z (refractive index in the thickness direction) Can be calculated.

<Liquid crystal display device>
The liquid crystal display device of the present invention includes a liquid crystal cell, first and second polarizing plates disposed on both sides of the liquid crystal cell, and a first position disposed between the first polarizing plate and the liquid crystal cell. Phase difference film,
A second retardation film disposed between the second polarizing plate and the liquid crystal cell;
The absorption axis of the first polarizing plate and the slow axis of the first retardation film are substantially parallel,
The transmission axis of the second polarizing plate and the slow axis of the second retardation film are substantially parallel.
The first retardation film satisfies the following expressions (1) to (6), and the second retardation film satisfies the following expressions (7) to (12).

10 nm <Re (548) <100 nm Formula (1)
20 nm <Rth (548) <400 nm Formula (2)
1.0 <Re (446) / Re (548) <2.0 Formula (3)
0.5 <Re (628) / Re (548) <1.0 Formula (4)
1.0 <Rth (446) / Rth (548) <2.0 Formula (5)
0.5 <Rth (628) / Rth (548) <1.0 Formula (6)
40 nm <Re (548) <300 nm Formula (7)
20 nm <Rth (548) <400 nm (8)
0.5 <Re (446) / Re (548) <1.5 Formula (9)
0.5 <Re (628) / Re (548) <2.0 Formula (10)
0.5 <Rth (446) / Rth (548) <2.0 Formula (11)
0.5 <Rth (628) / Rth (548) <1.5 Formula (12)

Hereinafter, the first retardation film and the second retardation film will be described in detail.
<First retardation film>
The retardation of the first retardation film in the present invention satisfies the following relationship.
10 nm <Re (548) <100 nm Formula (1)
20 nm <Rth (548) <400 nm Formula (2)
1.0 <Re (446) / Re (548) <2.0 Formula (3)
0.5 <Re (628) / Re (548) <1.0 Formula (4)
1.0 <Rth (446) / Rth (548) <2.0 Formula (5)
0.5 <Rth (628) / Rth (548) <1.0 Formula (6)

In the formula (1), 15 nm <Re (548) <80 nm is more preferable, and 20 nm <Re (548) <60 nm is most preferable.
In the formula (2), 30 nm <Rth (548) <300 nm is more preferable, and 50 nm <Rth (548) <250 nm is most preferable.
In Formula (3), 1.00 <Re (446) / Re (548) <1.70 is more preferable, and 1.05 <Re (446) / Re (548) <1.50. Most preferred.
In the formula (4), 0.60 <Re (628) / Re (548) <1.00 is more preferable, and 0.70 <Re (628) / Re (548) <0.97. Most preferred.
In Formula (5), it is more preferable that 1.00 <Rth (446) / Rth (548) <1.70, and 1.05 <Rth (446) / Rth (548) <1.50. Most preferred.
In the formula (6), it is more preferable that 0.6 <Rth (628) / Rth (548) <1.00, and 0.7 <Rth (628) / Rth (548) <0.97. Most preferred.
By using the retardation film in which Re (λ) and Rth (λ) are set in the above ranges, a liquid crystal display device having a small change in color depending on the viewing angle can be obtained.

The first retardation film of the present invention preferably has a certain absorption in the ultraviolet light region of 250 nm to 380 nm and substantially no absorption in the visible light region of wavelength 400 nm to 700 nm. Here, “having constant absorption” means, for example, an absorbance greater than 0.2 at a certain wavelength, and “having substantially no absorption” means, for example, at any wavelength. The absorbance is 0.2 or less.
The absorbance at a wavelength of 250 nm of the first retardation film of the present invention is preferably 1.0 or more, and more preferably 2.0 or more. The absorbance in the wavelength region of 400 nm to 700 nm is preferably 0.5 or less, and more preferably 0.2 or less.

The absorption in the ultraviolet light region of 250 nm to 380 nm of the first retardation film of the present invention is preferable for either absorption of the polymer itself or absorption of the dopant added in the polymer.
As the polymer having absorption in the ultraviolet light region of 250 nm to 350 nm, polycarbonate, polyimide and the like are preferable because of high transparency.

  When a dopant having absorption in the ultraviolet light region of 250 nm to 380 nm is added to the polymer film, various polymer films such as norbornene polymer film and cellulose acylate film can be used in addition to the polycarbonate and polyimide.

The first retardation film of the present invention preferably serves as a polarizing plate protective film from the viewpoint of reducing the thickness of the liquid crystal display device.
Among the polymer films, the cellulose acylate film is particularly preferable because it has properties as a polarizing plate protective film such as polarizing plate processing suitability and the raw material is inexpensive.
Hereinafter, a cellulose acylate film (hereinafter sometimes referred to as a first retardation cellulose acylate film) that is preferably used as the first retardation film of the present invention will be described in detail.

[Cellulose acylate]
First, the cellulose acylate that can be used for the first retardation cellulose acylate film of the present invention will be described.
The degree of substitution of cellulose acylate means the ratio of acylation of three hydroxyl groups present in the structural unit of cellulose (glucose having a (β) 1,4-glycoside bond). The degree of substitution (acylation degree) can be calculated by measuring the amount of bound fatty acid per unit mass of cellulose. The measuring method is carried out according to “ASTM D817-91”.

  The cellulose acylate in the present invention is preferably a cellulose acetate having an acylation degree of 2.00 to 2.90. The acylation degree is more preferably 2.20 to 2.90. Further, the ratio of the acylation degree at the 6-position to the total acylation degree is preferably 0.25 or more, and more preferably 0.3 or more.

  The cellulose acylate in the present invention preferably has a weight average degree of polymerization of 350 to 800, more preferably a weight average degree of polymerization of 370 to 600. The cellulose acylate in the present invention preferably has a number average molecular weight of 70,000 to 230,000, more preferably 75,000 to 230,000, and more preferably 78,000 to 120,000. Most preferably, it has a number average molecular weight of

  The cellulose acylate in the present invention can be synthesized using an acid anhydride or acid chloride as an acylating agent. When the acylating agent is an acid anhydride, an organic acid (for example, acetic acid) or methylene chloride is used as a reaction solvent. As the catalyst, a protic catalyst such as sulfuric acid is used. When the acylating agent is an acid chloride, a basic compound is used as a catalyst. In the most common synthetic method in the industry, cellulose is an organic acid corresponding to acetyl group and other acyl groups (acetic acid, propionic acid, butyric acid) or their acid anhydrides (acetic anhydride, propionic anhydride, butyric anhydride). Cellulose acylate is synthesized by esterification with a mixed organic acid component containing. In this method, cellulose such as cotton linter and wood pulp is activated with an organic acid such as acetic acid, and then esterified using a mixture of organic acid components as described above in the presence of a sulfuric acid catalyst. There are many cases to do. The organic acid anhydride component is generally used in an excess amount relative to the amount of hydroxyl groups present in the cellulose. In this esterification treatment, a hydrolysis reaction (depolymerization reaction) of the cellulose main chain β1 → 4 glycoside bond) proceeds in addition to the esterification reaction. When the hydrolysis reaction of the main chain proceeds, the degree of polymerization of the cellulose acylate is lowered, and the physical properties of the cellulose acylate film to be produced are lowered. For this reason, the reaction conditions such as the reaction temperature are preferably determined in consideration of the degree of polymerization and molecular weight of the cellulose acylate obtained.

  In order to obtain a cellulose acylate having a high degree of polymerization (high molecular weight), it is important to adjust the maximum temperature in the esterification reaction step to 50 ° C. or less. The maximum temperature is preferably adjusted to 35 to 50 ° C, more preferably 37 to 47 ° C. By setting the reaction temperature to 35 ° C. or higher, the esterification reaction can proceed more smoothly. By making reaction temperature 50 degrees C or less, the fall of the polymerization degree of a cellulose acylate can be suppressed more effectively. After the esterification reaction, when the reaction is stopped while suppressing the temperature rise, a decrease in the polymerization degree can be further suppressed, and a cellulose acylate having a high polymerization degree can be synthesized. That is, when a reaction terminator (for example, water or acetic acid) is added after completion of the reaction, the excess acid anhydride that did not participate in the esterification reaction is hydrolyzed to form a corresponding organic acid as a by-product. This hydrolysis reaction is accompanied by intense heat generation, and the temperature in the reactor rises. When the rate of addition of the reaction terminator is high, heat is rapidly generated exceeding the cooling capacity of the reactor. Therefore, the hydrolysis reaction of the cellulose main chain proceeds remarkably, and the degree of polymerization of the cellulose acylate obtained decreases. In addition, a part of the catalyst is bonded to the cellulose during the esterification reaction, and most of the catalyst is dissociated from the cellulose during the addition of the reaction terminator. However, when the rate of addition of the reaction terminator is high, there is not enough reaction time for the catalyst to dissociate, and a part of the catalyst remains in a state of being bound to cellulose. Cellulose acylate, in which a strong acid catalyst is partially bonded, has very poor stability, and is easily decomposed by heat during drying of the product and the degree of polymerization is lowered. For these reasons, after the esterification reaction, it is preferable to stop the reaction by adding a reaction terminator over a period of preferably 4 minutes or more, more preferably 4 to 30 minutes. In addition, it is preferable from a viewpoint of industrial productivity that the addition time of a reaction terminator shall be 30 minutes or less. As the reaction terminator, water or alcohol that decomposes an acid anhydride is generally used. However, in the present invention, a mixture of water and an organic acid is preferably used as a reaction terminator in order not to precipitate triesters having low solubility in various organic solvents. When the esterification reaction is carried out under the above conditions, a high molecular weight cellulose acylate having a weight average polymerization degree of 500 or more can be easily synthesized.

[Retardation expression agent]
The cellulose acylate film used for the first retardation cellulose acylate film of the present invention preferably contains a retardation enhancer. Here, the “retardation enhancer” is a compound that develops birefringence in the plane of the film and in the thickness direction.

  As the retardation enhancer in the present invention, a compound having an absorption maximum in a wavelength range of 200 to 380 nm is preferable, and in addition to the requirement, a compound having a molar extinction coefficient at 400 nm to 700 nm of 1000 or less (polarizability anisotropy) Of a large compound). By having the absorption characteristics, desired wavelength dispersion characteristics can be obtained without causing unnecessary coloration of the film.

  As the retardation developer in the present invention, a compound represented by the following general formula (I) can be preferably used.

（一般式（Ｉ）中、Ｘ¹は、単結合、−ＮＲ⁴−、−Ｏ−または−Ｓ−であり；Ｘ²は、単結合、−ＮＲ⁵−、−Ｏ−または−Ｓ−であり；Ｘ³は、単結合、−ＮＲ⁶−、−Ｏ−または−Ｓ−である。また、Ｒ¹、Ｒ²、およびＲ³は、それぞれ独立に、アルキル基、アルケニル基、芳香族環基または複素環基であり；Ｒ⁴、Ｒ⁵およびＲ⁶は、それぞれ独立に、水素原子、アルキル基、アルケニル基、アリール基または複素環基である。）

(In the general formula (I), X ¹ is a single bond, —NR ⁴ —, —O— or —S—; X ² is a single bond, —NR ⁵ —, —O— or —S—. X ³ is a single bond, —NR ⁶ —, —O—, or —S—, and R ¹ , R ² , and R ³ are each independently an alkyl group, an alkenyl group, or an aromatic ring. A group or a heterocyclic group; R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.)

  Hereinafter, the compound represented by formula (I) will be described in detail.

First, R ¹ , R ² , and R ³ will be described.
In general formula (I), R ¹ , R ² and R ³ each independently represents an alkyl group, an alkenyl group, an aromatic ring group or a heterocyclic group, preferably an aromatic ring group or a heterocyclic group. An aromatic ring group is more preferable. The aromatic ring group represented by each of R ¹ , R ² , and R ³ is preferably a phenyl group or a naphthyl group, and particularly preferably a phenyl group.

The aromatic ring group or heterocyclic group of R ¹ , R ² , and R ³ may have a substituent. Examples of the substituent include a halogen atom (for example, fluorine atom, chlorine atom), hydroxyl group, cyano group, nitro group, carboxyl group, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy Group, acyloxy group, alkoxycarbonyl group, alkenyloxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl group, alkyl-substituted carbamoyl group, alkenyl Examples thereof include a substituted carbamoyl group, an aryl-substituted carbamoyl group, an amide group, an alkylthio group, an alkenylthio group, an arylthio group, and an acyl group. Furthermore, these substituents may be substituted by the substituent.

When R ¹ , R ² , and R ³ represent a heterocyclic group, the heterocyclic ring preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (a 2-pyridyl group or a 4-pyridyl group as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent.

In the general formula (I), X ¹ represents a single bond, —NR ⁴ —, —O— or —S—, preferably —NR ⁴ —, and X ² represents a single bond, —NR ⁵ —, —O— or —S— represents —NR ⁵ —, X ³ represents a single bond, —NR ⁶ —, —O— or —S—, and —NR ⁶ — is preferred. R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and each independently preferably a hydrogen atom.

The alkyl group represented by each of R ⁴ , R ⁵ and R ⁶ may be a cyclic alkyl group or a chain alkyl group, but is preferably a chain alkyl group, rather than a chain alkyl group having a branch, A linear alkyl group is more preferred. The number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 10, further preferably 1 to 8, and 1 to 6. Is most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group) and an acyloxy group (for example, acryloyloxy group, methacryloyloxy group).

The alkenyl group represented by each of R ⁴ , R ⁵ and R ⁶ may be a cyclic alkenyl group or a chain alkenyl group, but is preferably a chain alkenyl group, more preferably than a branched chain alkenyl group. A linear alkenyl group is more preferred. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, and 2 to 6 Most preferably. The alkenyl group may have a substituent. Examples of the substituent are the same as those of the alkyl group described above.

The aromatic ring group and heterocyclic group represented by R ⁴ , R ⁵ and R ⁶ are the same as the aromatic ring group and heterocyclic group represented by R ¹ , R ² and R ³ , respectively, and the preferred ranges are also the same. is there. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as those of the aromatic ring and heterocyclic ring of R ¹ , R ² and R ³ .

  Preferred examples (I- (1) to IV- (10)) of the compounds represented by the general formula (I) are shown below, but the present invention is not limited to these specific examples.

As the retardation developer in the present invention, a compound represented by the following formula (1-1) is also preferable. Formula (1-1) described in detail below for the compound of formula (1-1)

（式（１−１）中、Ｒ^2-1、Ｒ^4-1、Ｒ^5-1はそれぞれ水素原子または置換基を表し、Ｒ^11-1、Ｒ^13-1はそれぞれ水素原子またはアルキル基を表し、Ｌ^1-1、Ｌ^2-1はそれぞれ単結合または２価の連結基を表す。Ａｒ^1-1はアリーレン基または芳香族へテロ環を表し、Ａｒ^2-1はアリール基または芳香族へテロ環を表し、ｎ−１は３以上の整数を表し、ｎ−１種存在するＬ^2-1、Ａｒ^1-1はそれぞれ同一であっても異なっていてもよい。ただしＲ^11-1、Ｒ^13-1は互いに異なっており、Ｒ^13-1で表されるアルキル基はへテロ原子を含まない。）
式（１−１）中、Ｒ^2-1、Ｒ^4-1、Ｒ^5-1はそれぞれ水素原子または置換基を表し、置換基は後述の置換基Ｔが適用できる。

(In formula (1-1), R ^2-1 , R ^4-1 and R ^5-1 each represent a hydrogen atom or a substituent, and R ^11-1 and R ^13-1 each represent a hydrogen atom or an alkyl group. L ^1-1 and L ^2-1 each represent a single bond or a divalent linking group, Ar ^1-1 represents an arylene group or an aromatic heterocyclic ring, and Ar ^2-1 represents an aryl group or an aromatic group. Represents a heterocycle, n-1 represents an integer of 3 or more, and L ^2-1 and Ar ^1-1 present in n-1 types may be the same or different, but R ^11-1 And R ^13-1 are different from each other, and the alkyl group represented by R ^13-1 does not contain a hetero atom.)
In formula (1-1), R ^2-1 , R ^4-1 and R ^5-1 each represent a hydrogen atom or a substituent, and the substituent T described below can be applied as the substituent.

^R2-1 is preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group or a hydroxyl group, more preferably a hydrogen atom, an alkyl group or an alkoxy group, still more preferably a hydrogen atom or an alkyl group (preferably 1 to 4 carbon atoms, more preferably a methyl group), an alkoxy group (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, particularly Preferably it is C1-C4. Particularly preferred are a hydrogen atom, a methyl group and a methoxy group, and most preferred is a hydrogen atom.

^R4-1 is preferably a hydrogen atom or an electron donating group, more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, or a hydroxyl group, and still more preferably a hydrogen atom or a carbon atom number of 1 to 4. An alkyl group having 1 to 12 carbon atoms (preferably having 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms), and particularly preferably hydrogen. An atom, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, and most preferably a hydrogen atom and a methoxy group.

^R5-1 is preferably a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an amino group, or a hydroxyl group, more preferably a hydrogen atom, an alkyl group, or an alkoxy group, still more preferably a hydrogen atom, an alkyl group. (Preferably 1 to 4 carbon atoms, more preferably a methyl group), an alkoxy group (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms). Particularly preferred is C 1-4). Particularly preferred are a hydrogen atom, a methyl group and a methoxy group. Most preferably, it is a hydrogen atom.

R ^11-1 and R ^13-1 each represent a hydrogen atom or an alkyl group, R ^11-1 and R ^13-1 are different from each other, and the alkyl group represented by R ^13-1 represents a ^hetero atom. Not included. Here, the heteroatom means an atom other than a hydrogen atom or a carbon atom, such as an oxygen atom, a nitrogen atom, a sulfur atom, phosphorus, silicon, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), boron, etc. Is mentioned.
The alkyl groups represented by R ^11-1 and R ^13-1 each represent a linear, branched, or cyclic alkyl group that is substituted or unsubstituted, preferably a substituted or unsubstituted carbon atom. An alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms (that is, a bicyclocarbon having 5 to 30 carbon atoms). A monovalent group in which one hydrogen atom is removed from an alkane.), And a tricyclo structure having many ring structures.

Preferred examples of the alkyl group represented by R ^11-1 and R ^13-1 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert-butyl, respectively. Group, n-pentyl group, iso-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, tert-octyl group, 2-ethylhexyl group, n-nonyl group, 1,1,3-trimethylhexyl Group, n-decyl group, 2-hexyldecyl group, cyclohexyl group, cycloheptyl group, 2-hexenyl group, oleyl group, linoleyl group, linolenyl group and the like. Examples of the cycloalkyl group include a cyclohexyl group, a cyclopentyl group, a 4-n-dodecylcyclohexyl group, and a bicycloalkyl group as a bicyclo [1,2,2] heptan-2-yl group and a bicyclo [2,2,2 ] An octan-3-yl group can be mentioned.

R ^11-1 is more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a methyl group.
R ^13-1 is particularly preferably an alkyl group containing 2 or more carbon atoms, and more preferably an alkyl group containing 3 or more carbon atoms.

Hereinafter, specific examples of the alkyl group represented by R ^13-1 will be described. However, the present invention is not limited to the following specific examples.

  In the above examples, # means the side bonded to the oxygen atom.

Ar ^1-1 represents an arylene group or an aromatic heterocyclic ring, and Ar ^1-1 in the repeating unit may all be the same or different. Ar ^2-1 represents an aryl group or an aromatic heterocyclic ring.
In the formula (1-1), the arylene group represented by Ar ^1-1 is preferably an arylene group having 6 to 30 carbon atoms, may be a single ring, or may be a condensed ring with another ring. It may be formed. Further, if possible, it may have a substituent, and the substituent T described later can be applied as the substituent. The arylene group represented by Ar ^1-1 preferably has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenylene group, a p-methylphenylene group, and a naphthylene group.
In the formula (1-1), the aryl group represented by Ar ^2-1 is preferably an aryl group having 6 to 30 carbon atoms, which may be a single ring, or may have another ring and a condensed ring. It may be formed. Further, if possible, it may have a substituent, and the substituent T described later can be applied as the substituent. The aryl group represented by Ar ^2-1 preferably has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyl group, a p-methylphenyl group, and a naphthalene group.

In formula (1-1), the aromatic heterocycle represented by Ar ^1-1 or Ar ^2-1 is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. More preferably an aromatic heterocycle containing at least one of a 5- to 6-membered ring oxygen atom, nitrogen atom or sulfur atom. Moreover, you may have a substituent further if possible. Substituent T described later can be applied as the substituent.

In the formula (1-1), specific examples of the aromatic heterocycle represented by Ar ^1-1 and Ar ^2-1 include, for example, a furan ring, a pyrrole ring, a thiophene ring, an imidazole ring, a pyrazole ring, and a pyridine ring. , Pyrazine ring, pyridazine ring, triazole ring, triazine ring, indole ring, indazole ring, purine ring, thiazoline ring, thiazole ring, thiadiazole ring, oxazoline ring, oxazole ring, oxadiazole ring, quinoline ring, isoquinoline ring, phthalazine ring , Naphthyridine ring, quinoxaline ring, quinazoline ring, cinnoline ring, pteridine ring, acridine ring, phenanthroline ring, phenazine ring, tetrazole ring, benzimidazole ring, benzoxazole ring, benzthiazole ring, benzotriazole ring, tetrazaindene ring, pyrrolo Triazole ring, pyra Such as Rotoriazoru ring, and the like. Preferred as the aromatic heterocycle are a benzimidazole ring, a benzoxazole ring, a benzthiazole ring, and a benzotriazole ring.

In formula (1-1), L ^1-1 and L ^2-1 each represent a single bond or a divalent linking group. L ^1-1 and L ^2-1 may be the same or different. Further, all L ^2-1 in the repeating unit may be the same or different.
Preferred as the divalent linking group is —O—, —NR ^1-1 — (R ^1-1 represents a hydrogen atom or an optionally substituted alkyl group or aryl group), —CO—, —SO ₂ —, —S—, an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, and a group obtained by combining two or more of these divalent groups, more preferably among them. -O -, - NR -, - CO -, - SO 2 NR 1-1 -, - NR 1-1 SO 2 -, - CONR 1-1 -, - NR 1-1 CO -, - COO-, and -OCO-, an alkynylene group. R ^1-1 preferably represents a hydrogen atom.

In the compound represented by the formula (1-1) in the present invention, Ar ^1-1 is bonded to L ^1-1 and L ^2-1 , but when Ar ^1-1 is a phenylene group, -L ^{1- 1} -Ar ^1-1 -L ^2-1 -, and -L ^2-1 -Ar ^1-1 -L ^2-1 - it is most preferable that a relation of mutually para position (1,4-position).

  In formula (1-1), n-1 represents an integer greater than or equal to 3, Preferably it is 3-7, More preferably, it is 3-7, More preferably, it is 3-6.

Of the compounds of the formula (1-1), compounds represented by the following formulas (2-1) and (3-1) can be particularly preferably used.
Formula (2-1)

（式（２−１）中、Ｒ^2-1およびＲ^5-1は、それぞれ水素原子または置換基を表し、Ｒ^11-1およびＲ^13-1は、それぞれ水素原子またはアルキル基を表し、Ｌ^1-1およびＬ^2-1は、それぞれ単結合または２価の連結基を表す。Ａｒ^1-1はアリーレン基または芳香族へテロ環を表し、Ａｒ^2-1はアリール基または芳香族へテロ環を表し、ｎ−１は３以上の整数を表し、ｎ種存在するＬ^2-1、Ａｒ^1-1はそれぞれ同一であっても異なっていてもよい。ただしＲ^11-1およびＲ^13-1は互いに異なっており、Ｒ^13-2で表されるアルキル基はへテロ原子を含まない。）

(In formula (2-1), R ^2-1 and R ^5-1 each represent a hydrogen atom or a substituent, R ^11-1 and R ^13-1 each represent a hydrogen atom or an alkyl group, and L ^1-1 and L ^2-1 each represent a single bond or a divalent linking group, Ar ^1-1 represents an arylene group or an aromatic heterocycle, and Ar ^2-1 represents an aryl group or an aromatic heterocycle. Represents a ring, n-1 represents an integer of 3 or more, and n types of L ^2-1 and Ar ^1-1 may be the same or different, provided that R ^11-1 and R ^{13- 1} is different from each other, and the alkyl group represented by R ^13-2 does not include a hetero atom.)

In formula (2-1), R ^2-1 , R ^5-1 , R ^11-1 and R ^13-1 have the same ^{meanings as} those in formula (1-1), and preferred ranges are also the same. ^{Further, L 1-1, L 2-1, Ar} 1-1, Ar 2-1 have the same meanings as those in formula (1-1), and preferred ranges are also the same.
Formula (3-1)

（式（３−１）中、Ｒ^2-1およびＲ^5-1は、それぞれ水素原子または置換基を表し、Ｒ^11-1、Ｒ^13-1およびＲ^14-1はそれぞれ水素原子またはアルキル基を表し、Ｌ^1-1およびＬ^2-1はそれぞれ単結合または２価の連結基を表す。Ａｒ^1-1はアリーレン基または芳香族へテロ環を表し、Ａｒ^2-1はアリール基または芳香族へテロ環を表し、ｎ−１は３以上の整数を表し、ｎ−１種存在するＬ^2-1、Ａｒ^1-1はそれぞれ同一であっても異なっていてもよい。ただしＲ^11-1、Ｒ^13-1は互いに異なっており、Ｒ^13-1で表されるアルキル基はへテロ原子を含まない。）

(In formula (3-1), R ^2-1 and R ^5-1 each represent a hydrogen atom or a substituent, and R ^11-1 , R ^13-1 and R ^14-1 each represent a hydrogen atom or an alkyl group. L ^1-1 and L ^2-1 each represent a single bond or a divalent linking group, Ar ^1-1 represents an arylene group or an aromatic heterocyclic ring, and Ar ^2-1 represents an aryl group or an aromatic group. N-1 represents an integer of 3 or more, and L ^2-1 and Ar ^1-1 present in n-1 types may be the same or different, but R ^{11- 1} and R ^13-1 are different from each other, and the alkyl group represented by R ^13-1 does not contain a hetero atom.)

In formula (3-1), R ^2-1 , R ^5-1 , R ^11-1 and R ^13-1 have the same ^{meanings as} those in formula (1-1), and preferred ranges are also the same. ^{Further, L 1-1, L 2-1, Ar} 1-1, Ar 2-1 have the same meanings as those in formula (1-1), and preferred ranges are also the same.
R ^14-1 represents a hydrogen atom or an alkyl group. As the alkyl group, alkyl groups shown as preferred examples of R ^11-1 and R ^13-1 are preferably used. R ^14-1 more preferably represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. . R ^11-1 and R ^14-1 may be the same or different, but both are particularly preferably methyl groups.

A compound represented by the formula (4-A) or the formula (4-B) is also preferable.
Formula (4-A)

（式（４−Ａ）中、Ｒ^2-1およびＲ^5-1はそれぞれ水素原子または置換基を表し、Ｒ^11-1およびＲ^13-1はそれぞれ水素原子またはアルキル基を表し、Ｌ^1-1およびＬ^2-1はそれぞれ単結合または２価の連結基を表す。Ａｒ^1-1はアリーレン基または芳香族へテロ環を表し、
ｎ−１は３以上の整数を表し、ｎ−１種存在するＬ^1-1およびＡｒ^1-1はそれぞれ同一であっても異なっていてもよい。ただしＲ^11-1およびＲ^13-1は互いに異なっており、Ｒ^13-1で表されるアルキル基はへテロ原子を含まない。）
式（４−Ａ）中、Ｒ^2-1、Ｒ^5-1、Ｒ^11-1、Ｒ^13-1、Ｌ^1-1、Ｌ^2-1、Ａｒ^1-1、ｎ−１は式（１−１）におけるそれらと同義であり、また好ましい範囲も同様である。

(In Formula (4-A), R ^2-1 and R ^5-1 each represent a hydrogen atom or a substituent, R ^11-1 and R ^13-1 each represent a hydrogen atom or an alkyl group, and L ^{1- 1} and L ^2-1 each represent a single bond or a divalent linking group, Ar ^1-1 represents an arylene group or an aromatic heterocyclic ring,
n-1 represents an integer of 3 or more, L ^1-1 and Ar ^1-1 is present n-1 species may each be the same or different. However, R ^11-1 and R ^13-1 are different from each other, and the alkyl group represented by R ^13-1 does not contain a hetero atom. )
Wherein ^{(4-A), R 2-1} , R 5-1, R 11-1, R 13-1, L 1-1, L 2-1, Ar 1-1, n-1 is the formula (1 -1) are the same as those in -1, and the preferred range is also the same.

  Formula (4-B)

（式（４−Ｂ）中、Ｒ^2-1およびＲ^5-1はそれぞれ水素原子または置換基を表し、Ｒ^11-1、Ｒ^13-1およびＲ^14-1はそれぞれ水素原子またはアルキル基を表し、Ｌ^1-1およびＬ^2-1はそれぞれ単結合または２価の連結基を表す。Ａｒ^1-1はアリーレン基または芳香族へテロ環を表し、ｎ−１は３以上の整数を表し、ｎ−１種存在するＬ^1-1、Ａｒ^2-1はそれぞれ同一であっても異なっていてもよい。ただしＲ^11-1、Ｒ^13-1は互いに異なっており、Ｒ^13-1で表されるアルキル基はへテロ原子を含まない。）

(In the formula (4-B), R ^2-1 and R ^5-1 each represent a hydrogen atom or a substituent, and R ^11-1 , R ^13-1 and R ^14-1 each represent a hydrogen atom or an alkyl group. L ^1-1 and L ^2-1 each represent a single bond or a divalent linking group, Ar ^1-1 represents an arylene group or an aromatic heterocyclic ring, and n-1 represents an integer of 3 or more. , L ^1-1 present n-1 kinds, Ar ^2-1 may each be the same or different. However R ^11-1, R ^13-1 are different from each other, with R ^13-1 (The alkyl group represented does not contain a heteroatom.)

Wherein ^{(4-B), R 2-1} , R 5-1, R 11-1, R 13-1, L 1-1, L 2-1, Ar 1-1, n-1 is the formula (1 -1) are the same as those in -1, and the preferred range is also the same.
R ^14-1 has the same meaning as R ^14-1 in the formula (3-1), and the preferred ranges are also the same.

The aforementioned substituent T will be described below.
The substituent T is preferably a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, or an n-propyl group. , Isopropyl group, tert-butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, for example, cyclohexyl group, cyclopentyl group) 4-n-dodecylcyclohexyl group), a bicycloalkyl group (preferably, a hydrogen atom is removed from a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a bicycloalkane having 5 to 30 carbon atoms. For example, bicyclo [1,2,2] heptan-2-yl group, bicycl [2,2,2] octane-3-yl group), alkenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as vinyl group, allyl group), cycloalkenyl group (preferably A substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms has been removed, for example, 2-cyclopentene-1- Yl group, 2-cyclohexen-1-yl group), bicycloalkenyl group (substituted or unsubstituted bicycloalkenyl group, preferably substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a double bond) A monovalent group obtained by removing one hydrogen atom from one bicycloalkene, for example, bicyclo [2,2,1] hept-2-en-1-yl , Bicyclo [2,2,2] oct-2-en-4-yl group), alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl group, propargyl group) An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, a p-tolyl group or a naphthyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted group) A monovalent group obtained by removing one hydrogen atom from an aromatic or non-aromatic heterocyclic compound, more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. For example, 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably A substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, for example, a methoxy group, an ethoxy group, an isopropoxy group, a tert-butoxy group, an n-octyloxy group, a 2-methoxyethoxy group), an aryloxy group ( Preferably, it is a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, such as phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylamino. Phenoxy group), a silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy group, tert-butyldimethylsilyloxy group), a heterocyclic oxy group (preferably having 2 to 30 carbon atoms) Substituted or unsubstituted heterocyclic oxy group, 1-phenyltetrazol-5-oxy Group, 2-tetrahydropyranyloxy group), acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 30 carbon atoms) A carbonyloxy group such as a formyloxy group, an acetyloxy group, a pivaloyloxy group, a stearoyloxy group, a benzoyloxy group, a p-methoxyphenylcarbonyloxy group), a carbamoyloxy group (preferably having 1 to 30 carbon atoms, Unsubstituted carbamoyloxy group, for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn- Octylcarbamoyloxy group), a Coxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, such as methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n-octylcarbonyloxy group) An aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms such as phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxy A phenoxycarbonyloxy group), an amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group , Methylamino group, Dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, carbon number 6 -30 substituted or unsubstituted arylcarbonylamino groups such as formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), aminocarbonylamino group (preferably having 1 to 30 carbon atoms) A substituted or unsubstituted aminocarbonylamino group, such as a carbamoylamino group, an N, N-dimethylaminocarbonylamino group, an N, N-diethylaminocarbonylamino group, a morpholinocarbonylamino group, an alkoxycarbonylamino group (preferably a carbon atom) Number 2-30 Substituted or unsubstituted alkoxycarbonylamino group, for example, methoxycarbonylamino group, ethoxycarbonylamino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino A group (preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms, for example, phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group), Sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms such as sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octyl group) Ruaminosulfonylamino group), alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino groups having 6 to 30 carbon atoms, for example, , Methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group), mercapto group, alkylthio group (preferably having 1 carbon atom) -30 substituted or unsubstituted alkylthio groups such as methylthio group, ethylthio group, n-hexadecylthio group), arylthio groups (preferably substituted or unsubstituted arylthio groups having 6 to 30 carbon atoms such as phenylthio group, p -Chlorofe Ruthio group, m-methoxyphenylthio group), heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, such as 2-benzothiazolylthio group, 1-phenyltetrazole- 5-ylthio group), a sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms, for example, N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably carbon atom) A substituted or unsubstituted alkylsulfinyl group of 1 to 30; a substituted or unsubstituted group of 6 to 30 Arylsulfinyl groups, for example, methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl and arylsulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl having 1 to 30 carbon atoms) Group, substituted or unsubstituted arylsulfonyl group of 6 to 30, for example, methylsulfonyl group, ethylsulfonyl group, phenylsulfonyl group, p-methylphenylsulfonyl group), acyl group (preferably formyl group, 2 to 2 carbon atoms) 30 substituted or unsubstituted alkylcarbonyl groups, substituted or unsubstituted arylcarbonyl groups having 7 to 30 carbon atoms, such as acetyl group and pivaloylbenzoyl group, aryloxycarbonyl groups (preferably having carbon atoms) 7-30 substitutions or Is an unsubstituted aryloxycarbonyl group, for example, phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxycarbonyl group), alkoxycarbonyl group (preferably having 2 carbon atoms) -30 substituted or unsubstituted alkoxycarbonyl groups such as methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group), carbamoyl group (preferably substituted with 1 to 30 carbon atoms or Unsubstituted carbamoyl groups such as carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (methylsulfonyl) carbamoyl group), aryl and hete A ring azo group (preferably a substituted or unsubstituted arylazo group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic azo group having 3 to 30 carbon atoms, such as a phenylazo group, a p-chlorophenylazo group, 5 -Ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably substituted or non-substituted with 2 to 30 carbon atoms) A substituted phosphino group, such as a dimethylphosphino group, a diphenylphosphino group, a methylphenoxyphosphino group, a phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having 2 to 30 carbon atoms, such as a phosphinyl group, Dioctyloxyphosphinyl group, diethoxyphosphinyl group), phosphinyloxy group (preferred Is a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as a diphenoxyphosphinyloxy group or a dioctyloxyphosphinyloxy group, a phosphinylamino group (preferably a carbon atom) A substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as a dimethoxyphosphinylamino group or a dimethylaminophosphinylamino group, a silyl group (preferably a substituted or unsubstituted carbon atom having 3 to 30 carbon atoms). A substituted silyl group such as a trimethylsilyl group, a tert-butyldimethylsilyl group, or a phenyldimethylsilyl group).

  Among the above-mentioned substituents, those having a hydrogen atom may be substituted with the above-mentioned group after removing this. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Examples thereof include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.

  Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

As a compound represented by the formula (4-A) or (4-B), R ^11-1 is a methyl group, R ^2-1 and R ^5-1 are both hydrogen atoms, R ¹³ is an alkyl group having 3 or more carbon atoms, and L ^1-1 and L ^2-1 are a single bond, —O—, —CO—, —NR—, —SO ₂ NR—, —NRSO, respectively. _{2 -, - CONR -, -} NRCO -, -. COO-, and -OCO-, alkynylene group (R is a hydrogen atom, an optionally substituted alkyl group, an aryl group is preferably a hydrogen atom And Ar ^1-1 is an arylene group and n-1 is 3-6.

  Hereinafter, the compound represented by formula (1-1) will be described in detail with specific examples, but the present invention is not limited to the following specific examples.

The compound represented by the formula (1-1) can be synthesized by first synthesizing a substituted benzoic acid and then by a general ester reaction or amidation reaction between the substituted benzoic acid and a phenol derivative or an aniline derivative. Any reaction may be used as long as it is a bond formation reaction. For example, a method in which a substituted benzoic acid is functionally converted to an acid halide and then condensed with a phenol derivative or aniline derivative, a method in which a substituted benzoic acid and a phenol derivative or aniline derivative are subjected to dehydration condensation using a condensing agent or catalyst, etc. It is done.
As a method for producing the compound represented by formula (1-1), a method in which a substituted benzoic acid is functionally converted to an acid halide and then condensed with a phenol derivative or an aniline derivative is preferable in consideration of the production process and the like.

  In the method for producing the compound represented by the formula (1-1), as a reaction solvent, a hydrocarbon solvent (preferably toluene or xylene), an ether solvent (preferably dimethyl ether, tetrahydrofuran, dioxane or the like) is used. Ketone solvents, ester solvents, acetonitrile, dimethylformamide, dimethylacetamide, and the like. These solvents may be used alone or in admixture of several kinds, and the solvent is preferably toluene, acetonitrile, dimethylformamide, or dimethylacetamide.

The reaction temperature is preferably 0 to 150 ° C, more preferably 0 to 100 ° C, still more preferably 0 to 90 ° C, and particularly preferably 20 ° C to 90 ° C.
Moreover, it is preferable not to use a base for this reaction. When a base is used, it may be either an organic base or an inorganic base, preferably an organic base, such as pyridine or tertiary alkylamine (preferably triethylamine, ethyldiisopropylamine, etc.).

  The compound represented by the formula (4-A) or the formula (4-B) can be synthesized by a known method. For example, in the case of a compound in which n-1 is 4, the following structure:

（式中、Ａ^1-1は水酸基、ハロゲン原子等の反応性基を表し、Ｒ^11-1、Ｒ^2-1、Ｒ^13-1、およびＲ^5-1は先に記載した通りであり、Ｒ^4-1は水素原子もしくは前述のＯＲ^14-1で表される置換基である。）
を有する原料化合物を、水酸基、アミノ基等の反応性部位を有する誘導体との反応に付して得られた中間体：

(In the formula, A ^1-1 represents a reactive group such as a hydroxyl group or a halogen atom, and R ^11-1 , R ^2-1 , R ^13-1 , and R ^5-1 are as described above, R ^4-1 is a hydrogen atom or a substituent represented by the aforementioned OR ^14-1 .)
An intermediate obtained by subjecting a raw material compound having a reaction with a derivative having a reactive site such as a hydroxyl group or an amino group:

（式中、Ａ’ ^1-1はカルボキシル基等の反応性基を表し、Ｒ^11-1、Ｒ^2-1、Ｒ^13-1、Ｒ^4-1、Ｒ^5-1、Ａｒ^1-1、およびＬ^1-1は先に記載した通りである。）
２分子を、

(In the formula, A ′ ^1-1 represents a reactive group such as a carboxyl group, R ^11-1 , R ^2-1 , R ^13-1 , R ^4-1 , R ^5-1 , Ar ^1-1 , And L ^1-1 is as described above.)
2 molecules

（式中、Ｂ^1-1およびＢ’ ^1-1は水酸基、アミノ基等の反応性基を表し、Ａｒ^2-1およびＬ^2-1は先に記載したＡｒ^1-1、Ｌ^2-1と同義である。）
１分子により連結することによって得ることができる。ただし、本発明における化合物の合成法はこの例に限定されない。

(In the formula, B ^1-1 and B ′ ^1-1 represent a reactive group such as a hydroxyl group and an amino group, and Ar ^2-1 and L ^2-1 represent Ar ^1-1 and L ^2-1 described above, respectively. Is synonymous with.)
It can be obtained by linking by one molecule. However, the synthesis method of the compound in the present invention is not limited to this example.

  The compounds represented by the above formulas (1-1) to (4-B) can be suitably used as a retardation enhancer for obtaining a biaxial film having excellent Re developability by stretching.

The retardation developer in the present invention can be used alone or in combination of two or more. The addition amount of the retardation enhancer in the present invention is preferably 1 to 30% by weight, and more preferably 2 to 25% by weight with respect to 100% by weight of cellulose acylate, for example. When mixing 2 or more types, it is preferable that a total amount is the said range.
The retardation developer in the present invention may be added to a cellulose acylate solution (dope) after being dissolved in an organic solvent such as alcohol, methylene chloride, or dioxolane, or may be added directly to the dope composition. .

  The retardation enhancers can be used alone or in combination of two or more.

(UV absorber)
In the first retardation cellulose acylate film of the present invention, a function as a retardation developer can be used in combination with an ultraviolet (UV) absorber.
Examples of the ultraviolet absorber used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. A benzotriazole-based compound with a low content is preferred. Further, ultraviolet absorbers described in JP-A-10-182621 and JP-A-8-337574 and polymer ultraviolet absorbers described in JP-A-6-148430 are also preferably used. When the cellulose acylate film in the present invention is used as a protective film for a polarizing plate, the ultraviolet absorber is excellent in the ability to absorb ultraviolet light having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of a polarizer or liquid crystal, and liquid crystal. From the viewpoint of display properties, those that absorb less visible light having a wavelength of 400 nm or more are preferred.

  Specific examples of the benzotriazole ultraviolet absorber useful in the present invention include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert). -Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl Phenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl) benzotriazole, 2,2 -Methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2 ' Hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy Examples include, but are not limited to, a mixture of -5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate. As commercially available products, TINUVIN 109, TINUVIN 171 and TINUVIN 326 (all manufactured by Ciba Specialty Chemicals Co., Ltd.) can be preferably used.

[Production of first retardation cellulose acylate film]
Next, the manufacturing method of the 1st phase difference cellulose acylate film employ | adopted by this invention is demonstrated in detail.
The first retardation cellulose acylate film in the present invention can be produced by a solvent cast method. In the solvent cast method, a film is produced using a solution (dope) in which cellulose acylate is dissolved in an organic solvent.

The organic solvent is selected from ethers having 3 to 12 carbon atoms, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 6 carbon atoms. It is preferable to include a solvent.
The ether, ketone and ester may have a cyclic structure. A compound having two or more functional groups of the ether, ketone and ester (that is, —O—, —CO— and COO—) can also be used as the organic solvent. The organic solvent may have another functional group such as an alcoholic hydroxyl group. In the case of an organic solvent having two or more types of functional groups, the number of carbon atoms is preferably within the above-described preferred range of carbon atoms of the solvent having any functional group.

Examples of the ether having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole.
Examples of the ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone.
Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.
Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.

The number of carbon atoms of the halogenated hydrocarbon having 1 to 6 carbon atoms is preferably 1 or 2, and more preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of halogen atoms substituted by halogen in the halogenated hydrocarbon is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably, it is most preferable that it is 40-60 mol%. Methylene chloride is a representative halogenated hydrocarbon.
Two or more kinds of organic solvents may be mixed and used.

  The cellulose acylate solution (dope) can be prepared by a general method comprising processing at a temperature of 0 ° C. or higher (ordinary temperature or high temperature). The cellulose acylate solution can be prepared using a dope preparation method and apparatus in a normal solvent cast method. In the case of a general method, it is preferable to use a halogenated hydrocarbon (particularly methylene chloride) as the organic solvent.

  The amount of cellulose acylate in the cellulose acylate solution (composition) is adjusted so that it is contained in an amount of 10 to 40% by mass in the resulting solution. The amount of cellulose acylate is more preferably 10 to 30% by mass. Arbitrary additives described later may be added to the organic solvent (main solvent).

  The cellulose acylate solution can be prepared by stirring cellulose acylate and an organic solvent at room temperature (for example, 0 to 40 ° C.). High concentration solutions may be stirred under pressure and heating conditions. Specifically, cellulose acylate and an organic solvent are placed in a pressure vessel and sealed, and stirred while heating to a temperature not lower than the boiling point of the solvent at normal temperature and in a range where the solvent does not boil. The heating temperature is preferably 40 ° C. or higher, more preferably 60 to 200 ° C., and still more preferably 80 to 110 ° C.

  Each component may be coarsely mixed in advance and then placed in a container. Moreover, you may put into a container sequentially. The container must be configured to allow stirring. The container can be pressurized by injecting an inert gas such as nitrogen gas. Moreover, you may utilize the raise of the vapor pressure of the solvent by heating. Or after sealing a container, you may add each component under pressure.

  When heating, it is preferable to heat from the outside of the container. For example, a jacket type heating device can be used. The entire container can also be heated by providing a plate heater outside the container and piping to circulate the liquid.

  Stirring is preferably performed using a stirring blade provided inside the container. The stirring blade preferably has a length that reaches the vicinity of the wall of the container. A scraping blade is preferably provided at the end of the stirring blade in order to renew the liquid film on the vessel wall.

  Instruments such as a pressure gauge and a thermometer may be installed in the container. Each component is dissolved in a solvent in a container. The prepared dope is taken out of the container after cooling, or taken out and then cooled using a heat exchanger or the like.

  A cellulose acylate solution can also be prepared by a cooling dissolution method. In the cooling dissolution method, the cellulose acylate can be dissolved in an organic solvent in which it is difficult to dissolve the cellulose acylate by a normal dissolution method. In addition, even if it is a solvent which can melt | dissolve a cellulose acylate with a normal melt | dissolution method, there exists an effect that a uniform solution can be obtained rapidly according to a cooling melt | dissolution method.

  In the cooling dissolution method, first, cellulose acylate is gradually added to an organic solvent with stirring at room temperature. The amount of cellulose acylate is preferably adjusted so as to be contained in the mixture in an amount of 10 to 40% by mass. The amount of cellulose acylate is more preferably 10 to 30% by mass. Furthermore, you may add the arbitrary additive mentioned later in a mixture.

  Next, the mixture is preferably cooled to −100 to −10 ° C. (more preferably −80 to −10 ° C., more preferably −50 to −20 ° C., most preferably −50 to −30 ° C.). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). The mixture of the cellulose acylate and the organic solvent is solidified by cooling.

  The cooling rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and most preferably 12 ° C./min or more. The higher the cooling rate, the better. However, 10,000 ° C./second is a theoretical upper limit, 1000 ° C./second is a technical upper limit, and 100 ° C./second is a practical upper limit. The cooling rate is a value obtained by dividing the difference between the temperature at the start of cooling and the final cooling temperature by the time from the start of cooling to the final cooling temperature.

  Further, when the cooled mixture is heated to preferably 0 to 200 ° C. (more preferably 0 to 150 ° C., further preferably 0 to 120 ° C., most preferably 0 to 50 ° C.), cellulose acylate is added to the organic solvent. Dissolves. The temperature may be increased by simply leaving it at room temperature or in a warm bath. The heating rate is preferably 4 ° C./min or more, more preferably 8 ° C./min or more, and most preferably 12 ° C./min or more. The higher the heating rate, the better. However, 10,000 ° C./second is a theoretical upper limit, 1000 ° C./second is a technical upper limit, and 100 ° C./second is a practical upper limit. The heating rate is the value obtained by dividing the difference between the temperature at the start of heating and the final heating temperature by the time from the start of heating until the final heating temperature is reached. is there.

  As described above, a uniform cellulose acylate solution is obtained. If the dissolution is insufficient, the cooling and heating operations may be repeated. Whether or not the dissolution is sufficient can be determined by merely observing the appearance of the solution with the naked eye.

  In the cooling dissolution method, it is desirable to use a sealed container in order to avoid moisture mixing due to condensation during cooling. In the cooling and heating operation, when the pressure is applied during cooling and the pressure is reduced during heating, the dissolution time can be shortened. In order to perform pressurization and decompression, it is desirable to use a pressure-resistant container.

  In addition, according to the measurement by a differential scanning calorimeter (DSC), the 20 mass% solution which melt | dissolved cellulose acetate (acetylation degree: 60.9%, viscosity average polymerization degree: 299) in methyl acetate by the cooling dissolution method is. In the vicinity of 33 ° C., there exists a quasi-phase transition point between a sol state and a gel state, and a uniform gel state is obtained below this temperature. Accordingly, this solution is preferably kept at a temperature equal to or higher than the pseudo phase transition temperature, preferably about 10 ° C. plus the gel phase transition temperature. However, this pseudo phase transition temperature varies depending on the degree of acetylation of cellulose acetate, the degree of viscosity average polymerization, the concentration of the solution, and the organic solvent used.

  A first retardation cellulose acylate film is produced from the prepared cellulose acylate solution (dope) by a solvent cast method. It is preferable to add a retardation developer to the dope. The dope is cast on a drum or band and the solvent is evaporated to form a film. The concentration of the dope before casting is preferably adjusted so that the solid content is 18 to 35%. The surface of the drum or band is preferably finished in a mirror state. The dope is preferably cast on a drum or band having a surface temperature of 10 ° C. or less.

  Regarding the drying method in the solvent cast method, US Pat. Nos. 2,336,310, 2,367,603, 2,492,078, 2,492,977, and 2,492,978 Nos. 2,607,704, 2,739,069 and 2,739,070, British Patent Nos. 640731 and 736892, and Japanese Patent Publication No. 45-4554 49-5614, JP-A-60-176834, JP-A-60-203430 and JP-A-62-115035. Drying on the band or drum can be performed by blowing an inert gas such as air or nitrogen.

  Further, the obtained film can be peeled off from the drum or band and further dried with high-temperature air whose temperature is successively changed from 100 ° C. to ˜160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting.

  Using the prepared cellulose acylate solution (dope), two or more layers can be cast to form a film. In this case, it is preferable to produce the first retardation cellulose acylate film by a solvent cast method. The dope is cast on a drum or band and the solvent is evaporated to form a film. It is preferable to adjust the concentration of the dope before casting so that the solid content is in the range of 10 to 40% by mass. The surface of the drum or band is preferably finished in a mirror state.

  When casting a plurality of cellulose acylate liquids of two or more layers, it is possible to cast a plurality of cellulose acylate solutions, and a plurality of casting ports provided at intervals in the direction of travel of the support Alternatively, a film may be produced while casting and laminating solutions containing cellulose acylate. For example, the methods described in JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be used. Also, a film can be formed by casting a cellulose acylate solution from two casting ports. For example, JP-B-60-27562, JP-A-61-94724, JP-A-61-947245, JP-A-61-104413, JP-A-61-158413, and JP-A-6-158413. The method described in each publication of No. 134933 can be used. Furthermore, a film casting method for wrapping a flow of a high-viscosity cellulose acylate solution described in JP-A-56-162617 with a low-viscosity cellulose acylate solution and simultaneously extruding the high- and low-viscosity cellulose acylate solution is provided. It can also be used.

  Also, using two casting ports, the film formed on the support by the first casting port is peeled off, and the second casting is performed on the side in contact with the support surface to produce a film. You can also For example, the method described in Japanese Patent Publication No. 44-20235 can be mentioned.

  As the cellulose acylate solution to be cast, the same solution may be used, or two or more different cellulose acylate solutions may be used. In order to give a function to a plurality of cellulose acylate layers, a cellulose acylate solution corresponding to the function may be extruded from each casting port. Further, the cellulose acylate solution in the present invention is cast simultaneously with other functional layers (for example, an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, an ultraviolet absorbing layer, a polarizing layer, etc.). You can also.

In the conventional monolayer liquid, in order to obtain a necessary film thickness, it is necessary to extrude a cellulose acylate solution having a high concentration and a high viscosity. In this case, the stability of the cellulose acylate solution is poor and solid matter is generated, which tends to cause problems due to defects in the surface and poor flatness. As a method of improving this problem, by casting a plurality of cellulose acylate solutions from the casting port, it is possible to extrude a highly viscous solution onto the support at the same time. Not only can the film be produced, but also the drying load can be further reduced by using a concentrated cellulose acylate solution, and the production speed of the film can be further increased.
A degradation inhibitor (for example, an antioxidant, a peroxide decomposer, a radical inhibitor, a metal deactivator, an acid scavenger, an amine, etc.) may be added to the first retardation cellulose acylate film. . The deterioration preventing agents are described in JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. Moreover, it is preferable that the addition amount of the said deterioration inhibitor is 0.01-1 mass% of the solution (dope) to prepare, and it is further more preferable that it is 0.01-0.2 mass%. If the addition amount is 0.01% by mass or more, the effect of the deterioration inhibitor is sufficiently exhibited, and if the addition amount is 1% by mass or less, the deterioration inhibitor bleeds out to the film surface (bleeding). And the like are less likely to occur. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

  These steps from casting to post-drying may be performed in an air atmosphere or an inert gas atmosphere such as nitrogen gas. The winder used for the production of the first retardation cellulose acylate film in the present invention may be a commonly used one, such as a constant tension method, a constant torque method, a taper tension method, a program tension control with a constant internal stress. It can be wound up by a winding method such as a method.

[Stretching treatment]
As the first retardation film in the invention, it is particularly preferable to use a stretched cellulose acylate film (stretched cellulose acylate film). A desired retardation can be imparted to the cellulose acylate film by stretching. The first retardation cellulose acylate film of the present invention is preferably stretched in the longitudinal direction. By stretching in the longitudinal direction, a retardation of the cellulose acylate film is expressed in the longitudinal direction, and a polarizing plate (hereinafter referred to as “polarizing plate”) is bonded so that the absorption axis of the polarizer and the slow axis of the first retardation film are parallel to each other. The first polarizing plate) can be manufactured roll-to-roll, which is preferable for improving the productivity of manufacturing the polarizing plate and reducing the cost.

  The film is stretched at room temperature or under heating conditions. The film can be stretched by a treatment during drying, and is particularly effective when the solvent remains. In the case of stretching in the longitudinal direction, for example, the film is stretched by adjusting the speed of the film transport roller so that the film winding speed is higher than the film peeling speed.

  The stretch ratio of the film (elongation with respect to the film before stretching) is preferably 1% to 50%, more preferably 2% to 30%.

[Thickness of cellulose acylate film]
The thickness of the first retardation cellulose acylate film in the invention is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm, and most preferably 30 μm to 100 μm.

<Second retardation film>
Next, the second retardation film in the present invention will be described in detail.
The retardation of the second retardation film in the present invention is characterized by satisfying the relationships of the following formulas (7) to (12).
40 nm <Re (548) <300 nm Formula (7)
20 nm <Rth (548) <400 nm (8)
0.5 <Re (446) / Re (548) <1.5 Formula (9)
0.5 <Re (628) / Re (548) <2.0 Formula (10)
0.5 <Rth (446) / Rth (548) <2.0 Formula (11)
0.5 <Rth (628) / Rth (548) <1.5 Formula (12)

In the formula (7), 50 nm <Re (548) <250 nm is more preferable, and 60 nm <Re (548) <200 nm is most preferable.
In the formula (8), 30 nm <Rth (548) <300 nm is more preferable, and 40 nm <Rth (548) <250 nm is most preferable.
In the formula (9), 0.5 <Re (446) / Re (548) <1.2 is more preferable, and 0.5 <Re (446) / Re (548) <1.1. Is most preferred.
In the formula (10), 0.8 <Re (628) / Re (548) <1.8 is more preferable, and 1.0 <Re (628) / Re (548) <1.5. Most preferred.
In the formula (11), 0.7 <Rth (446) / Rth (548) <1.7 is more preferable, and 0.8 <Rth (446) / Rth (548) <1.5. Most preferred.
In the formula (12), 0.6 <Rth (628) / Rth (548) <1.4 is more preferable, and 0.7 <Rth (628) / Rth (548) <1.2. Most preferred.
It is preferable to set Re (λ) and Rth (λ) within the above ranges because the effect of reducing the change in color depending on the viewing angle is increased. Furthermore, it is more preferable as a protective film for a polarizing plate.

Further, the absorption of the second retardation film of the present invention preferably satisfies the following relational expression A with respect to the absorption of the first retardation film of the present invention.
Formula (A)
λ1.0 (1 ^st ) −λ1.0 (2 ^nd )> 0
(In the formula (A), λ1.0 (1 ^st ) represents a wavelength at which the absorbance converted to a film thickness of 80 μm of the first retardation film is 1.0 in the wavelength range of 200 nm to 700 nm, and λ1.0 ( 2 ^nd) represents the wavelength at which the absorbance was converted into a film thickness of 80μm of the second retardation film is 1.0 in the wavelength range of 200 nm to 700 nm.)
In this invention, the light absorbency converted into the film thickness of 80 micrometers represents the value calculated by the following formula.
(Absorbance converted to a film thickness of 80 μm)
= (Absorbance of film) / (Film thickness (μm)) × 80
Formula (A) is more preferably λ _1st −λ _2nd > 10, and most preferably λ _1st −λ _2nd > 20.
By satisfying the relationship of the formula (A), the tint viewing angle reduction effect of the first retardation film and the tint viewing angle reduction effect of the second retardation film work synergistically, and more effectively the liquid crystal It becomes possible to reduce the color change due to the viewing angle of the display device.

It is preferable from the point of thickness reduction of a liquid crystal display device that the 2nd phase difference film of this invention serves as the function as a protective film of a polarizing plate.
Although various polymer films can be used as the second retardation film of the present invention, those having both a positive intrinsic birefringence component and a negative intrinsic birefringence component are particularly preferable. Specifically, modified polycarbonate films such as “Pure Ace” manufactured by Teijin Ltd., norbornene-based films disclosed in JP-A Nos. 2003-292539 and 2003-321535, and cellulose acylate films Etc. are preferred. Among these, cellulose acylate is particularly preferable from the viewpoint of suitability for polarizing plate processing.

[Cellulose acylate]
First, the cellulose acylate that can be used for the second retardation cellulose acylate film in the present invention will be described.
The degree of substitution of cellulose acylate means the ratio of acylation of three hydroxyl groups present in the structural unit of cellulose (glucose having a (β) 1,4-glycoside bond). The degree of substitution (acylation degree) can be calculated by measuring the amount of bound fatty acid per unit mass of cellulose. The measuring method is carried out according to “ASTM D817-91”.

  The cellulose acylate used in the second retardation film of the present invention is preferably cellulose acetate having an acylation degree of 2.00 to 2.90. The acylation degree is more preferably 2.2 to 2.8. Further, the ratio of the acylation degree at the 6-position to the total acylation degree is preferably 0.25 or more, and more preferably 0.3 or more. Moreover, it is preferable that the cellulose acylate used for the 2nd phase difference film of this invention contains 2 or more types of acyl groups.

  Another preferred example of the cellulose acylate used in the second retardation film of the present invention is an acyl group having an acylation degree of 2.0 to 2.9 and an acetyl group having 3 to 4 carbon atoms. It is a mixed fatty acid ester. The acylation degree of the mixed fatty acid ester is more preferably 2.20 to 2.85, most preferably 2.4 to 2.8. The degree of acetylation is preferably less than 2.5, more preferably less than 1.9.

  Yet another preferred cellulose acylate for use in the second retardation film of the present invention is a mixed acid ester having a fatty acid acyl group and a substituted or unsubstituted aromatic acyl group. Here, examples of the substituted or unsubstituted aromatic acyl group include groups represented by the following general formula (A).

First, the general formula (A) will be described. In general formula (A), X represents a substituent. Examples of the substituent include halogen atom, cyano group, alkyl group, alkoxy group, aryl group, aryloxy group, acyl group, carbonamido group, sulfonamido group, ureido group, aralkyl group, nitro, alkoxycarbonyl group, Aryloxycarbonyl group, aralkyloxycarbonyl group, carbamoyl group, sulfamoyl group, acyloxy group, alkenyl group, alkynyl group, alkylsulfonyl group, arylsulfonyl group, alkyloxysulfonyl group, aryloxysulfonyl group, alkylsulfonyloxy group and aryloxy A sulfonyl group, -S-R, -NH-CO-OR, -PH-R, -P (-R) ₂ , -PH-O-R, -P (-R) (-O-R), -P _{(-O-R) 2, -PH} (= O) -R-P (= O) (- R) 2, -P (= O) -O-R, -P (= O) (- R) (- O-R), - P (= O) (- O-R) 2, -O-PH (= O) -R -O-P (= O) (-R) _2- O-PH (= O) -O-R, -O-P (= O) (-R) (-O-R), -O-P (= O) (-O-R) ₂ , -NH-PH (= O) -R, -NH-P (= O) (-R) (-O-R), -NH-P (= O) _{(-O-R) 2, -SiH} 2 -R, -SiH (-R) 2, -Si (-R) 3, -O-SiH 2 -R, -O-SiH (-R) 2 and -O -Si (-R) ₃ is included. R is an aliphatic group, an aromatic group or a heterocyclic group.

  In the general formula (A), n is the number of substituents and represents an integer of 0 to 5. The number (n) of the substituents is preferably 1 to 5, more preferably 1 to 4, still more preferably 1 to 3, and most preferably 1 or 2. As the substituent shown above, a halogen atom, a cyano group, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an acyl group, a carbonamido group, a sulfonamide group and a ureido group are preferable, and a halogen atom, a cyano group, Alkyl groups, alkoxy groups, aryloxy groups, acyl groups and carbonamido groups are more preferred, halogen atoms, cyano, alkyl groups, alkoxy groups and aryloxy groups are more preferred, and halogen atoms, alkyl groups and alkoxy groups are most preferred.

  The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The alkyl group may have a cyclic structure or a branch. The number of carbon atoms in the alkyl group is preferably 1-20, more preferably 1-12, still more preferably 1-6, and most preferably 1-4. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, tert-butyl group, hexyl group, cyclohexyl group, octyl group and 2-ethylhexyl group. The alkoxy group may have a cyclic structure or a branch. The number of carbon atoms in the alkoxy group is preferably 1-20, more preferably 1-12, still more preferably 1-6, and most preferably 1-4. The alkoxy group may be further substituted with another alkoxy group. Examples of the alkoxy group include methoxy group, ethoxy group, 2-methoxyethoxy group, 2-methoxy-2-ethoxyethoxy group, butyloxy group, hexyloxy group and octyloxy group.

  The number of carbon atoms of the aryl group is preferably 6-20, and more preferably 6-12. Examples of the aryl group include a phenyl group and a naphthyl group. The aryloxy group preferably has 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms. Examples of the aryloxy group include a phenoxy group and a naphthoxy group. The number of carbon atoms in the acyl group is preferably 1-20, and more preferably 1-12. Examples of the acyl group include a formyl group, an acetyl group, and a benzoyl group. The number of carbon atoms of the carbonamide group is preferably 1-20, and more preferably 1-12. Examples of the carbonamido group include an acetamide group and a benzamide group. The number of carbon atoms in the sulfonamide group is preferably 1-20, and more preferably 1-12. Examples of the sulfonamide group include a methanesulfonamide group, a benzenesulfonamide group, and a p-toluenesulfonamide group. The number of carbon atoms in the ureido group is preferably 1-20, and more preferably 1-12. Examples of ureido groups include (unsubstituted) ureido.

  The number of carbon atoms in the aralkyl group is preferably 7-20, and more preferably 7-12. Examples of the aralkyl group include a benzyl group, a phenethyl group, and a naphthylmethyl group. The number of carbon atoms in the alkoxycarbonyl group is preferably 2-20, and more preferably 2-12. Examples of the alkoxycarbonyl group include methoxycarbonyl. The aryloxycarbonyl group preferably has 7 to 20 carbon atoms, and more preferably 7 to 12 carbon atoms. Examples of the aryloxycarbonyl group include a phenoxycarbonyl group. The number of carbon atoms in the aralkyloxycarbonyl group is preferably 8-20, and more preferably 8-12. Examples of the aralkyloxycarbonyl group include a benzyloxycarbonyl group. The number of carbon atoms of the carbamoyl group is preferably 1-20, and more preferably 1-12. Examples of the carbamoyl group include a (unsubstituted) carbamoyl group and an N-methylcarbamoyl group. The number of carbon atoms in the sulfamoyl group is preferably 20 or less, and more preferably 12 or less. Examples of the sulfamoyl group include a (unsubstituted) sulfamoyl group and an N-methylsulfamoyl group. The number of carbon atoms in the acyloxy group is preferably 1-20, and more preferably 2-12. Examples of the acyloxy group include an acetoxy group and a benzoyloxy group.

  The alkenyl group has preferably 2 to 20 carbon atoms, and more preferably 2 to 12 carbon atoms. Examples of the alkenyl group include a vinyl group, an allyl group, and an isopropenyl group. The number of carbon atoms in the alkynyl group is preferably 2-20, and more preferably 2-12. Examples of the alkynyl group include a thienyl group. The number of carbon atoms in the alkylsulfonyl group is preferably 1-20, and more preferably 1-12. The number of carbon atoms of the arylsulfonyl group is preferably 6-20, and more preferably 6-12. The alkyloxysulfonyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms. The number of carbon atoms of the aryloxysulfonyl group is preferably 6-20, and more preferably 6-12. The number of carbon atoms in the alkylsulfonyloxy group is preferably 1-20, and more preferably 1-12. The number of carbon atoms of the aryloxysulfonyl group is preferably 6-20, and more preferably 6-12.

  Next, the fatty acid ester residue in the cellulose mixed acid ester which is an example of the cellulose acylate used in the second retardation film of the present invention will be described. In the fatty acid ester residue in the cellulose mixed acid ester, the aliphatic acyl group preferably has 2 to 20 carbon atoms. Specific examples include acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, pivaloyl group, hexanoyl group, octanoyl group, lauroyl group, stearoyl group, etc., preferably acetyl group, propionyl group and butyryl group. Particularly preferred is an acetyl group. In the present invention, the aliphatic acyl group further includes those having a substituent. Examples of the substituent include those exemplified as X in the general formula (A).

  In the general formula (A), the number (n) of the substituents X substituted on the aromatic ring is 0 or 1 to 5, preferably 1 to 3, particularly preferably 1 or 2. .

  Furthermore, when the number of substituents substituted on the aromatic ring is 2 or more, the substituents may be the same or different from each other, and connected to each other to form a condensed polycyclic compound (for example, a naphthalene group, an indene group, An indane group, a phenanthrene group, a quinoline group, an isoquinoline group, a chromene group, a chroman group, a phthalazine group, an acridine group, an indole group, an indoline group, etc.). Specific examples of the aromatic acyl group represented by the general formula (A) are as shown below. 1, 3, 5, 6, 8, 13, 18, 28, more preferably 1, 3, 6, and 13.

  Substitution of an aromatic acyl group to a hydroxyl group of cellulose can be generally performed by a method using a symmetric acid anhydride and a mixed acid anhydride derived from an aromatic carboxylic acid claloid or an aromatic carboxylic acid. Particularly preferred is a method using an acid anhydride derived from an aromatic carboxylic acid (described in Journal of Applied Polymer Science, Vol. 29, 3981-3990 (1984)). As a method for producing the cellulose mixed acid ester compound cellulose acylate in the present invention as the above-mentioned method, (i) once the cellulose fatty acid monoester or diester is produced, the remaining hydroxyl group is represented by the general formula (A). Examples include a method of introducing an aromatic acyl group, and (ii) a method of reacting a mixed acid anhydride of an aliphatic carboxylic acid and an aromatic carboxylic acid directly with cellulose. In (i), the method for producing a cellulose fatty acid ester or diester is a well-known method, but the subsequent reaction for introducing an aromatic acyl group further differs depending on the type of the aromatic acyl group. At this time, the reaction temperature is preferably 0 to 100 ° C., more preferably 20 to 50 ° C., and the reaction time is preferably 30 minutes or more, more preferably 30 to 300 minutes. In the method (ii) using a mixed acid anhydride, the reaction conditions vary depending on the type of the mixed acid anhydride. Under the present circumstances, reaction temperature becomes like this. Preferably it is 0-100 degreeC, More preferably, it is 20-50 degreeC, Reaction time becomes like this. Preferably it is 30-300 minutes, More preferably, it is 60-200 minutes. Any of the above reactions may be performed in the absence of a solvent or in a solvent, but is preferably performed using a solvent. As the solvent, for example, dichloromethane, chloroform, dioxane and the like can be used.

  In the case of a cellulose fatty acid monoester, the substitution degree of the aromatic acyl group is preferably 2.0 or less, more preferably 0.1 to 2.0 with respect to the remaining hydroxyl group. In the case of cellulose fatty acid diester (cellulose diacetate), it is preferably 1.0 or less, more preferably 0.1 to 1.0, based on the remaining hydroxyl group. Although the specific example (No. 1-43) of the aromatic acyl group represented with general formula (A) below is shown, this invention is not limited to this. Examples of the aromatic acyl group represented by the general formula (A) include the following No. 1, 3, 5, 6, 8, 13, 18 and 28 are preferred. 1, 3, 6 and 13 are more preferred.

  The cellulose acylate used in the second retardation film of the present invention preferably has a mass average polymerization degree of 350 to 800, more preferably 370 to 600. The cellulose acylate used in the second retardation film of the present invention preferably has a number average molecular weight of 70000 to 230,000, more preferably 75000 to 230,000, and more preferably 78000 to 120,000. Most preferably, it has a molecular weight.

[Retardation expression agent]
The second retardation cellulose acylate film of the present invention preferably contains a retardation developer. The absorption maximum (λmax (2)) on the longest wavelength side of the retardation developer used in the second retardation film of the present invention is the longest wave side of the retardation developer used in the first retardation film of the present invention. It is preferable that it exists on the shorter wavelength side than the absorption maximum (λmax (1)).

More preferably, λmax (1) −λmax (2)> 10, and most preferably λmax (1) −λmax (2)> 20.
When the retardation developer satisfies the above relationship, the color viewing angle reduction effect by the first retardation film and the color viewing angle reduction effect by the second retardation film work synergistically, and the liquid crystal display device more effectively. It is possible to reduce the color change due to the viewing angle.

  As the retardation developer used for the second retardation film of the present invention, in addition to those described as the retardation developer used for the first retardation film, pages 11 to 14 of JP-A-2004-50516 The rod-shaped aromatic compounds described can be preferably used.

  As the retardation enhancer used in the present invention, a compound represented by the following general formula (I) is particularly preferred, and a compound represented by the following general formula (II) is most preferred.

(In the formula, L ¹ and L ² each independently represents a single bond or a divalent linking group. A ₁ and A ² each independently represent —O—, —NR— (R represents a hydrogen atom or a substituent). Represents a group selected from the group consisting of —S— and —CO—, R ¹ , R ² , and R ³ each independently represents a substituent, and X represents a nonmetallic atom of Groups 14 to 16 (However, a hydrogen atom or a substituent may be bonded to X. n represents an integer of 0 to 2.)

(In the general formula (II), L ¹ and L ² each independently represents a single bond or a divalent linking group. A ¹ and A ² each independently represent —O—, —NR— (R represents a hydrogen atom) Or a substituent selected from the group consisting of —S— and —CO—, wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently represents a substituent, n is Represents an integer from 0 to 2.)

In the general formula (I) or (II), the divalent linking group represented by L ¹ and L ² preferably includes the following examples.

  More preferred are -O-, -COO-, and -OCO-.

In general formula (I) or (II), R ¹ is a substituent, and when there are a plurality of R ^{1 s} , they may be the same or different and may form a ring. The following can be applied as examples of the substituent.

  A halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert- Butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms such as cyclohexyl group, cyclopentyl group, 4-n-dodecylcyclohexyl) Group), a bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. , Bicyclo [1,2,2] heptan-2-yl group, bicyclo [2,2,2] octane-3-yl group)

An alkenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group or an allyl group), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, That is, it is a monovalent group in which one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms is removed, for example, a 2-cyclopenten-1-yl, 2-cyclohexen-1-yl group), a bicycloalkenyl group (substituted or substituted). An unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. A bicyclo [2,2,1] hept-2-en-1-yl group, a bicyclo [2,2,2] oct-2-en-4-yl group), Rukiniru group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as ethynyl group, propargyl group),

An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, a p-tolyl group, a naphthyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic group A monovalent group obtained by removing one hydrogen atom from an aromatic or non-aromatic heterocyclic compound, and more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably substituted or unsubstituted having 1 to 30 carbon atoms) Alkoxy groups such as methoxy, ethoxy, isopropoxy, tert-butoxy, n-octyloxy, 2-methoxyethoxy), aryloxy Si group (preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms such as phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradeca Noylaminophenoxy group),

A silyloxy group (preferably a silyloxy group having 3 to 20 carbon atoms, such as trimethylsilyloxy group or tert-butyldimethylsilyloxy group), a heterocyclic oxy group (preferably a substituted or unsubstituted heterocycle having 2 to 30 carbon atoms) Ring oxy group, 1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy group), acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, carbon number 6-30 substituted or unsubstituted arylcarbonyloxy groups such as formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group), carbamoyloxy group (preferably Or substitution of 1 to 30 carbon atoms Is an unsubstituted carbamoyloxy group, for example, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn -Octylcarbamoyloxy group), alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms, for example, methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n- Octylcarbonyloxy group), aryloxycarbonyloxy group (preferably substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, such as phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group) , P-n-hexadecyloxycarbonyl phenoxycarbonyl group),

An amino group (preferably an amino group, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group, a methylamino group, a dimethylamino group; , Anilino group, N-methyl-anilino group, diphenylamino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted 6 to 30 carbon atoms, or Unsubstituted arylcarbonylamino group, for example, formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), aminocarbonylamino group (preferably substituted or unsubstituted amino acid having 1 to 30 carbon atoms) Carbonylamino group, for example, carbamoylamino group, N, N-dimethylamino Sulfonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group), alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms, such as methoxycarbonylamino group, ethoxycarbonyl) Amino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably substituted or unsubstituted aryloxy having 7 to 30 carbon atoms) Carbonylamino group, for example, phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group),

Sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms such as sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octylamino Sulfonylamino groups), alkyl and arylsulfonylamino groups (preferably substituted or unsubstituted alkylsulfonylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonylamino groups having 6 to 30 carbon atoms, such as methylsulfonyl An amino group, a butylsulfonylamino group, a phenylsulfonylamino group, a 2,3,5-trichlorophenylsulfonylamino group, a p-methylphenylsulfonylamino group, a mercapto group, and an alkylthio group (preferably a substituent having 1 to 30 carbon atoms) Or an unsubstituted alkylthio group such as Ruthio group, ethylthio group, n-hexadecylthio group), arylthio group (preferably a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, such as phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), A heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, for example, 2-benzothiazolylthio group, 1-phenyltetrazol-5-ylthio group),

Sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms such as N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′-phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably having 1 to 30 carbon atoms substituted or Unsubstituted alkylsulfinyl group, substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms, such as methylsulfinyl group, ethylsulfinyl group, phenylsulfinyl group, p-methylphenylsulfinyl group), alkyl and arylsulfonyl groups ( Preferably, it has 1 to 3 carbon atoms A substituted or unsubstituted alkylsulfonyl group, a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms, e.g., methylsulfonyl group, ethylsulfonyl group, phenylsulfonyl group, p- methylphenyl sulfonyl group),

An acyl group (preferably a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, such as an acetyl group or a pivaloylbenzoyl group), Aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxy Carbonyl group), alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group), carbamoyl Base Preferably, the substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms, for example, carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N-di-n-octylcarbamoyl group, N- (Methylsulfonyl) carbamoyl group),

Aryl and heterocyclic azo groups (preferably substituted or unsubstituted arylazo groups having 6 to 30 carbon atoms, substituted or unsubstituted heterocyclic azo groups having 3 to 30 carbon atoms, such as phenylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably substituted or non-substituted having 2 to 30 carbon atoms) Substituted phosphino groups such as dimethylphosphino group, diphenylphosphino group, methylphenoxyphosphino group), phosphinyl groups (preferably substituted or unsubstituted phosphinyl groups having 2 to 30 carbon atoms such as phosphinyl group, dioctyl Oxyphosphinyl group, diethoxyphosphinyl group), phosphinyloxy group (preferred Or a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, such as a diphenoxyphosphinyloxy group or a dioctyloxyphosphinyloxy group, or a phosphinylamino group (preferably having a carbon number) 2-30 substituted or unsubstituted phosphinylamino groups such as dimethoxyphosphinylamino group, dimethylaminophosphinylamino group, silyl groups (preferably substituted or unsubstituted groups having 3 to 30 carbon atoms) Silyl group, for example, trimethylsilyl group, tert-butyldimethylsilyl group, phenyldimethylsilyl group).

  Among the above substituents, those having a hydrogen atom may be substituted with the above groups after removing this. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Examples thereof include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.

R ¹ is preferably a halogen atom, alkyl group, alkenyl group, aryl group, heterocyclic group, hydroxyl group, carboxyl group, alkoxy group, aryloxy group, acyloxy group, cyano group, amino group, more preferably A halogen atom, an alkyl group, a cyano group, and an alkoxy group;

R ² and R ³ each independently represents a substituent. An example of R ¹ is given as an example. Preferred are a substituted or unsubstituted benzene ring and a substituted or unsubstituted cyclohexane ring. More preferred are a benzene ring having a substituent and a cyclohexane ring having a substituent, and more preferred are a benzene ring having a substituent at the 4-position and a cyclohexane ring having a substituent at the 4-position.

R ⁴ and R ⁵ each independently represents a substituent. An example of R ¹ is given as an example. Preferably, it is preferred that substituent constant sigma _p value of Hammett is greater than zero electron withdrawing group, sigma _p value has an electron withdrawing substituent of 0 to 1.5 Further preferred. Examples of such a substituent include a trifluoromethyl group, a cyano group, a carbonyl group, and a nitro group. R ⁴ and R ⁵ may be bonded to form a ring.
As for Hammett's substituent constants σ _p and σ _m , for example, Naoki Inamoto's “Hammett's rule-structure and reactivity-” (Maruzen), edited by the Chemical Society of Japan “New Experimental Chemistry Lecture 14 Reaction V "2605 (Maruzen), Tadao Nakatani" Theoretical Organic Chemistry "217 (Tokyo Kagaku Dojin), Chemical Review, 91, 165-195 (1991) .

A ¹ and A ² each independently represent a group selected from the group consisting of —O—, —NR— (wherein R is a hydrogen atom or a substituent), —S—, and —CO—. Preferred are —O—, —NR— (R represents a substituent, and examples thereof include R ¹ described above) and —S—.

X represents a nonmetallic atom belonging to Groups 14-16. However, a hydrogen atom or a substituent may be bonded to X. X is preferably ═O, ═S, ═NR, ═C (R) R (wherein R represents a substituent, and examples thereof include the examples of R ¹ described above).
n represents an integer of 0 to 2, preferably 0 or 1.

  Specific examples of the compound represented by formula (I) or (II) are shown below, but the present invention is not limited to the following specific examples. Regarding the following compounds, unless otherwise specified, the number in parentheses () indicates the exemplified compound (X).

  The synthesis of the compound represented by the general formula (I) or (II) can be performed with reference to known methods. For example, exemplary compound (1) can be synthesized according to the following scheme.

In the scheme, the synthesis from the compound (1-A) to the compound (1-D) is described in “Journal of Chemical Crystallography” (1997); 27 (9); p.515-526. It can be performed with reference to the method described in 1.
Further, as shown in the above scheme, methanesulfonic acid chloride was added to a tetrahydrofuran solution of the compound (1-E), N, N-diisopropylethylamine was added dropwise and stirred, and then N, N-diisopropylethylamine was added. Exemplary solution (1) can be obtained by adding dropwise a tetrahydrofuran solution of compound (1-D) and then adding a tetrahydrofuran solution of N, N-dimethylaminopyridine (DMAP).

Moreover, the retardation developing agent used for the 2nd phase difference film of this invention can be used individually or in mixture of 2 or more types. 0.1-20 mass% is preferable with respect to 100 weight% of cellulose acylates, and, as for the addition amount of the retardation developing agent used for the 2nd retardation film of this invention, 0.5-10 mass% is more preferable.
The retardation developer used in the second retardation film of the present invention is added to a cellulose acylate solution (dope) after dissolving the retardation developer in an organic solvent such as alcohol, methylene chloride or dioxolane. Or it may be added directly into the dope composition.

[Production of Second Retardation Cellulose Acylate Film]
The second retardation cellulose acylate film of the present invention can be produced by the same method as the first retardation cellulose acylate film.

[Stretching treatment]
The second retardation cellulose acylate film of the present invention is particularly preferably stretched. A desired retardation can be imparted to the cellulose acylate film by stretching. The stretching direction of the cellulose acylate film is preferably the width direction (lateral stretching). By stretching in the width direction, it becomes possible to produce a polarizing plate (hereinafter referred to as a second polarizing plate) in which the transmission axis of the polarizer and the slow axis of the second retardation film are parallel by roll-to-roll. By bonding the first polarizing plate and the second polarizing plate to the liquid crystal cell so that the absorption axes of the polarizers are orthogonal to each other, a liquid crystal display device having a small color change depending on the viewing angle can be obtained.
Methods for stretching in the width direction are described in, for example, JP-A-62-115035, JP-A-4-152125, JP-A-2842211, JP-A-298310, and JP-A-11-48271. Yes.

  The film is stretched at room temperature or under heating conditions. The film can be stretched by a treatment during drying, and is particularly effective when the solvent remains. Stretching in the width direction can be performed by conveying the film while holding the film with a tenter and gradually widening the width of the tenter. After the film is dried, it can be stretched using a stretching machine (preferably uniaxial stretching using a long stretching machine).

  The stretch ratio of the film (elongation relative to the film before stretching) is preferably 1% to 200%, more preferably 5% to 150%.

Furthermore, the 2nd phase difference cellulose acylate film of this invention can be preferably manufactured by including the shrinkage | contraction process shrink | contracted, holding a film in the width direction.
In the manufacturing method including a stretching process for stretching in the film width direction and a shrinking process for contracting in the film transport direction, the film is held by a pantograph or linear motor type tenter, and stretched in the film width direction while being stretched in the transport direction. The film can be shrunk by gradually reducing the interval between the clips.

  In addition, Ichikin Kogyo Co., Ltd. is a stretching apparatus that specifically performs a stretching process that stretches either the longitudinal direction or the width direction of the film as described above, simultaneously shrinks the other, and simultaneously increases the film thickness of the film. A company-made FITZ machine or the like can be desirably used. This apparatus is described in (Japanese Patent Laid-Open No. 2001-38802).

The stretching ratio in the stretching process and the shrinking ratio in the shrinking process can be arbitrarily selected depending on the values of the desired front retardation Re and retardation Rth in the film thickness direction. Is preferably 10% or more, and the shrinkage rate in the shrinking step is preferably 5% or more.
In addition, the shrinkage rate as used in the field of this invention means the ratio of the contracted length of the film after contraction with respect to the length of the film before contraction in the contraction direction.
The shrinkage rate is preferably 5 to 40%, particularly preferably 10 to 30%.

[Thickness of stretched cellulose acylate film]
The thickness of the second retardation cellulose acylate film after stretching in the present invention is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm, and most preferably 30 μm to 100 μm.

(Matting agent fine particles)
It is preferable to add fine particles as a matting agent to the second retardation film in the present invention. The fine particles used in the present invention include silicon dioxide (silica), titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, silica Mention may be made of aluminum oxide, magnesium silicate and calcium phosphate. Among these fine particles, those containing silicon are preferable in terms of low turbidity, and silicon dioxide is more preferable. The silicon dioxide fine particles preferably have a primary average particle size of 1 nm to 20 nm and an apparent specific gravity of 70 g / liter or more. Those having an average primary particle diameter of 5 to 25 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  These fine particles usually form secondary particles having an average particle size of 0.05 to 2.0 μm, and these fine particles are present in the film as aggregates of primary particles, and 0.05 μm on the film surface. Irregularities of ˜2.0 μm are formed. The secondary average particle size is preferably 0.05 μm to 1.0 μm, more preferably 0.1 μm to 0.7 μm, and further preferably 0.1 μm to 0.4 μm. As used herein, the primary or secondary particle size was determined by observing the particles in the film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles as the particle size. Also, 200 particles are observed at different locations, and the average value is taken as the average particle size.

  As fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.) can be used. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.), and can be used.

  Among these, Aerosil 200V and Aerosil R972V are fine particles of silicon dioxide having a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more, and the coefficient of friction is maintained while keeping the haze of the optical film low. It is particularly preferable because it has a great effect of reducing the effect.

  In the present invention, the mixing method of the matting agent is not particularly limited, but it is preferable to use an in-line mixer for mixing the matting agent dispersant and the additive solution and mixing the cellulose acylate liquid and the like. The concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and further preferably 15 to 20% by mass. A higher dispersion concentration is preferable because the turbidity with respect to the same amount of addition becomes low, and haze and aggregates are improved. The addition amount of the matting agent in the final cellulose acylate dope solution is preferably 0.001 to 1.0% by mass, more preferably 0.005 to 0.5% by mass, and 0.01 to 0.1%. More preferred is mass%.

[Saponification]
The first retardation cellulose acylate film and the second retardation cellulose acylate film of the present invention may be subjected to alkali saponification treatment. By performing a saponification treatment, adhesion to a polarizer material such as polyvinyl alcohol is imparted, and it can be preferably used as a protective film for a polarizing plate.

  The alkali saponification treatment of the cellulose acylate film in the present invention is preferably performed in a cycle in which the film surface is immersed in an alkali solution, neutralized with an acidic solution, washed with water and dried. Examples of the alkaline solution include a potassium hydroxide solution and a sodium hydroxide solution, and the concentration of hydroxide ions is preferably in the range of 0.1 to 5.0 mol / L, and 0.5 to 4.0 mol / L. More preferably, it is in the range of L. The alkaline solution temperature is preferably in the range of room temperature to 90 ° C, more preferably in the range of 40 to 70 ° C.

<Preparation of polarizing plate>
(Polarizer)
Next, the polarizer used for the polarizing plate in the present invention will be described.
The polarizer in the present invention is preferably composed of polyvinyl alcohol (PVA) and a dichroic molecule. However, as described in JP-A-11-248937, PVA and polyvinyl chloride are dehydrated and dechlorinated. Thus, a polyvinylene polarizer in which a polyene structure is produced and oriented can also be used.

The PVA is preferably a polymer material obtained by saponifying polyvinyl acetate, but may contain a component copolymerizable with vinyl acetate such as unsaturated carboxylic acid, unsaturated sulfonic acid, olefins and vinyl ethers. I do not care. In addition, modified PVA containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, or the like can also be used.
The degree of saponification of PVA is not particularly limited, but is preferably 80 to 100 mol%, particularly preferably 90 to 100 mol% from the viewpoint of solubility and the like. The degree of polymerization of PVA is not particularly limited, but is preferably 1000 to 10,000, and particularly preferably 1500 to 5000.
The syndiotacticity of PVA is preferably 55% or more in order to improve durability as described in Japanese Patent Registration No. 2978219, but as described in Japanese Patent Registration No. 3317494, it is 45 to 45%. 52.5% can also be preferably used.

After forming PVA into a film, it is preferable to introduce a dichroic molecule to constitute a polarizer. As a method for producing a PVA film, a method of forming a film by casting a stock solution obtained by dissolving a PVA resin in water or an organic solvent is generally preferably used. The density | concentration of the polyvinyl alcohol-type resin in a stock solution becomes like this. Preferably it is 5-20 mass%, and a PVA film with a film thickness of 10-200 micrometers can be manufactured by forming this stock solution with a casting method. The PVA film can be produced with reference to Japanese Patent Registration No. 3342516, Japanese Patent Application Laid-Open No. 09-328593, Japanese Patent Application Laid-Open No. 2001-302817, Japanese Patent Application Laid-Open No. 2002-144401, and the like.
The crystallinity of the PVA film is not particularly limited. However, in order to reduce the average crystallinity (Xc) of 50 to 75% by mass described in Patent Registration No. 3251073 and the in-plane hue variation, Japanese Patent Application Publication A PVA film having a crystallinity of 38% or less described in JP-A-236214 can be used.

The birefringence (Δn) of the PVA film is preferably small, and a PVA film having a birefringence of 1.0 × 10 ⁻³ or less described in Japanese Patent Registration No. 3342516 can be preferably used. However, as described in JP-A-2002-228835, in order to obtain a high degree of polarization while avoiding cutting during stretching of the PVA film, the birefringence of the PVA film may be 0.002 to 0.01. good to, as described in JP 2002-060505 value of _{(n x + n y) /} 2-n z may be 0.0003 to 0.01. The Re (1090) of the PVA film is preferably 0 nm to 100 nm, and more preferably 0 nm to 50 nm. The Rth (1090) of the PVA film is preferably 0 nm to 500 nm, and more preferably 0 nm to 300 nm.

In addition, the polarizing plate of the present invention is described in Japanese Patent Application Laid-Open No. 2001-316492, a PVA film having a 1,2-glycol bond amount of 1.5 mol% or less described in Japanese Patent Registration No. 3021494. A PVA film having 500 or less optical foreign matters of 5 μm or more per 100 cm ² , a PVA film having a hot-water cutting temperature spot in the TD direction of 1.5 ° C. or less of the film described in JP-A-2002-030163 Further, a film is formed from a solution in which 1 to 100% by weight of a trivalent or hexavalent polyhydric alcohol such as glycerin is mixed, or a plasticizer described in JP-A-06-289225 is mixed in an amount of 15% by mass or more. The PVA film made can be preferably used.

  Although the film thickness before extending | stretching of a PVA film is not specifically limited, 1 micrometer-1 mm are preferable and 20-200 micrometers is especially preferable from a viewpoint of stability of film holding | maintenance and the uniformity of extending | stretching. Further, as described in JP-A-2002-236212, a thin PVA film may be used in which the stress generated when stretching 4 to 6 times in water is 10 N or less.

Dichroic molecule I ₃ ^- or I ₅ ^- can be preferably used an iodine ion or a dichroic dye higher such. In the present invention, higher-order iodine ions are particularly preferably used. Higher-order iodine ions can be found in “Applications of Polarizing Plates” by Ryo Nagata, CMC Publishing and Industrial Materials, Vol. 28, No. 7, p. 39-p. As described in 45, PVA can be produced by immersing PVA in a solution obtained by dissolving iodine in an aqueous potassium iodide solution and / or an aqueous boric acid solution and adsorbing and orienting the PVA.

  When a dichroic dye is used as the dichroic molecule, an azo dye is preferable, and a bisazo dye and a trisazo dye are particularly preferable. The dichroic dye is preferably a water-soluble dye. For this reason, a hydrophilic substituent such as a sulfonic acid group, an amino group or a hydroxyl group is introduced into the dichroic molecule, so that a free acid, an alkali metal salt, an ammonium salt or an amine is introduced. It is preferably used as a salt.

  Specific examples of such dichroic dyes include C.I. I. Direct Red 37, Congo Red (C.I. Direct Red 28), C.I. I. Direct Violet 12, C.I. I. Direct Blue 90, C.I. I. Direct Blue 22, C.I. I. Direct Blue 1, C.I. I. Direct Blue 151, C.I. I. Benzidines such as Direct Green 1, C.I. I. Direct Yellow 44, C.I. I. Direct Red 23, C.I. I. Diphenylurea such as Direct Red 79, C.I. I. Stilbene series such as Direct Yellow 12, C.I. I. Dinaphthylamine type such as Direct Red 31, C.I. I. Direct Red 81, C.I. I. Direct Violet 9, C.I. I. Mention may be made of J acid systems such as Direct Blue 78.

In addition, C.I. I. Direct Yellow 8, C.I. I. Direct Yellow 28, C.I. I. Direct Yellow 86, C.I. I. Direct Yellow 87, C.I. I. Direct Yellow 142, C.I. I. Direct Orange 26, C.I. I. Direct Orange 39, C.I. I. Direct Orange 72, C.I. I. Direct Orange 106, C.I. I. Direct Orange 107, C.I. I. Direct Red 2, C.I. I. Direct Red 39, C.I. I. Direct Red 83, C.I. I. Direct Red 89, C.I. I. Direct Red 240, C.I. I. Direct Red 242, C.I. I. Direct Red 247, C.I. I. Direct Violet 48, C.I. I. Direct Violet 51, C.I. I. Direct Violet 98, C.I. I. Direct Blue 15, C.I. I. Direct Blue 67, C.I. I. Direct Blue 71, C.I. I. Direct Blue 98, C.I. I. Direct Blue 168, C.I. I. Direct Blue 202, C.I. I. Direct Blue 236, C.I. I. Direct Blue 249, C.I. I. Direct Blue 270, C.I. I. Direct Green 59, C.I. I. Direct Green 85, C.I. I. Direct Brown 44, C.I. I. Direct Brown 106, C.I. I. Direct Brown 195, C.I. I. Direct Brown 210, C.I. I. Direct Brown 223, C.I. I. Direct Brown 224, C.I. I. Direct Black 1, C.I. I. Direct Black 17, C.I. I. Direct Black 19, C.I. I. Direct Black 54 and the like are further disclosed in JP-A-62-70802, JP-A-1-161202, JP-A-1-172906, JP-A-1-172907, JP-A-1-183602, JP-A-1-248105, The dichroic dyes described in JP-A-1-265205 and JP-A-7-261024 can also be preferably used. In order to produce dichroic molecules having various hues, two or more of these dichroic dyes may be blended. When a dichroic dye is used, the adsorption thickness may be 4 μm or more as described in JP-A No. 2002-082222.
If the content of the dichroic molecule in the film is too small, the degree of polarization is low, and if it is too large, the single-plate transmittance is lowered. Therefore, the polyvinyl alcohol polymer constituting the film matrix is usually used. On the other hand, it is adjusted to a range of 0.01 to 5% by mass.
A preferable film thickness of the polarizer is preferably 5 μm to 40 μm, and more preferably 10 μm to 30 μm. Further, the ratio of the thickness of the polarizer and the thickness of the protective film described above is 0.01 ≦ A (polarizer film thickness) / B (protective film film thickness) ≦ described in JP-A-2002-174727. It is also preferable to set it to 0.16.
Furthermore, the crossing angle between the slow axis of the protective film and the absorption axis of the polarizer may be any value, but is preferably parallel or an azimuth angle of 45 ± 20 °.

<Polarizing plate manufacturing process>
Next, the manufacturing process of the polarizing plate in this invention is demonstrated. The polarizing plate of the present invention has a polarizer and a protective film provided on the surface of the polarizer.
The production process of the polarizing plate in the present invention is preferably composed of a swelling process, a dyeing process, a hardening process, a stretching process, a drying process, a protective film bonding process, and a post-bonding drying process. The order of the dyeing process, the hardening process, and the stretching process may be arbitrarily changed, or some processes may be combined and performed simultaneously. Further, as described in Japanese Patent No. 3331615, washing with water after the hardening step can be preferably performed.

  In the present invention, it is particularly preferable to sequentially perform the swelling process, the dyeing process, the hardening process, the stretching process, the drying process, the protective film bonding process, and the drying process after bonding in the order described. Further, an on-line surface inspection process may be provided during or after the aforementioned process.

The swelling step is preferably performed only with water. However, as described in JP-A-10-153709, the optical performance is stabilized and wrinkle generation of the polarizing plate substrate on the production line is avoided. In addition, the degree of swelling of the polarizing plate substrate can be controlled by swelling the polarizing plate substrate with an aqueous boric acid solution.
Moreover, although the temperature and time of a swelling process can be defined arbitrarily, 10 to 60 degreeC and 5 to 2000 second are preferable.

  For the dyeing step, the method described in JP-A-2002-86554 can be used. Further, as a dyeing method, not only immersion but any means such as application or spraying of iodine or a dye solution can be used. Further, as described in JP-A-2002-290025, a method of dyeing while stirring the iodine concentration, the dyeing bath temperature, the draw ratio in the bath, and the bath liquid in the bath may be used.

When high-order iodine ions are used as the dichroic molecule, in order to obtain a high-contrast polarizing plate, it is preferable to use a solution in which iodine is dissolved in an aqueous potassium iodide solution in order to obtain a high-contrast polarizing plate. In this case, iodine in the iodine-potassium iodide aqueous solution is preferably 0.05 to 20 g / l, potassium iodide is 3 to 200 g / l, and the mass ratio of iodine and potassium iodide is preferably 1 to 2000. The dyeing time is preferably 10 to 1200 seconds, and the liquid temperature is preferably 10 to 60 ° C. More preferably, iodine is 0.5 to 2 g / l, potassium iodide is 30 to 120 g / l, the mass ratio of iodine and potassium iodide is 30 to 120, dyeing time is 30 to 600 seconds, and liquid temperature is 20-50 degreeC is good.
Further, as described in Japanese Patent No. 3145747, boron compounds such as boric acid and borax may be added to the dyeing solution.

  In the hardening step, it is preferable to immerse in the crosslinking agent solution or apply the solution to contain the crosslinking agent. Further, as described in JP-A-11-52130, the hardening process can be performed in several steps.

  As the crosslinking agent, those described in US Pat. No. 2,328,977 can be used, and as described in Japanese Patent No. 3357109, a polyhydric aldehyde is used as a crosslinking agent in order to improve dimensional stability. However, boric acids are most preferably used. When boric acid is used as a crosslinking agent used in the hardening step, metal ions may be added to the boric acid-potassium iodide aqueous solution. Zinc chloride is preferable as the metal ion. However, as described in JP-A No. 2000-35512, zinc halide such as zinc iodide, zinc sulfate such as zinc acetate is used instead of zinc chloride. It can also be used.

  In the present invention, it is preferable to prepare a boric acid-potassium iodide aqueous solution to which zinc chloride has been added, and perform dura- tion by immersing the PVA film. Boric acid is preferably 1 to 100 g / l, potassium iodide is 1 to 120 g / l, zinc chloride is preferably 0.01 to 10 g / l, hardening time is preferably 10 to 1200 seconds, and liquid temperature is preferably 10 to 60 ° C. . More preferably, boric acid is 10 to 80 g / l, potassium iodide is 5 to 100 g / l, zinc chloride is 0.02 to 8 g / l, hardening time is 30 to 600 seconds, and liquid temperature is 20 to 50 ° C is preferable.

  The stretching step preferably uses a longitudinal uniaxial stretching method as described in US Pat. No. 2,454,515 or the like, or a tenter method as described in JP-A-2002-86554. Can do. A preferable draw ratio is 2 to 12 times, and more preferably 3 to 10 times. In addition, the relationship between the draw ratio, the original fabric thickness, and the polarizer thickness is described in JP-A No. 2002-040256 (polarizer film thickness after protective film bonding / original fabric film thickness) × (total draw ratio) )> 0.17, or the relationship between the width of the polarizer when leaving the final bath and the width of the polarizer when bonding the protective film is 0.80 ≦ (protection) described in JP-A-2002-040247 It is also preferable to set the polarizer width at the time of film bonding / the width of the polarizer when the final bath is removed) ≦ 0.95.

  As the drying step, a method known in JP-A-2002-86554 can be used, but a preferable temperature range is 30 ° C. to 100 ° C., and a preferable drying time is 30 seconds to 60 minutes. In addition, as described in Japanese Patent No. 3148513, heat treatment is performed so that the fading temperature in water is 50 ° C. or higher, or described in JP-A-07-325215 and JP-A-07-325218. As described above, aging in an atmosphere in which the temperature and humidity are controlled can be preferably performed.

  A protective film bonding process is a process of bonding the both surfaces of the above-mentioned polarizer which went out of the drying process with two protective films. A method of bonding with a pair of rolls is preferably used so that the adhesive liquid is supplied immediately before bonding and the polarizer and the protective film are overlapped. Further, as described in JP-A-2001-296426 and JP-A-2002-86554, in order to suppress the groove-like unevenness of the record due to the stretching of the polarizer, It is preferable to adjust the moisture content. In the present invention, a moisture content of 0.1% to 30% is preferably used.

  The adhesive between the polarizer and the protective film is not particularly limited, and examples thereof include PVA resin (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group) and boron compound aqueous solution. PVA resin is preferable. The thickness of the adhesive layer is preferably 0.01 to 5 μm, and particularly preferably 0.05 to 3 μm after drying.

Moreover, in order to improve the adhesive force of a polarizer and a protective film, it is preferable to adhere | attach, after surface-treating a protective film and hydrophilizing. The surface treatment method is not particularly limited, and a known method such as a saponification method using an alkaline solution or a corona treatment method as described above can be used. Further, an easy adhesion layer such as a gelatin undercoat layer may be provided after the surface treatment. As described in JP-A-2002-267839, the contact angle of the protective film surface with water is preferably 50 ° or less.
The drying conditions after bonding are in accordance with the method described in JP-A-2002-86554, but a preferable temperature range is 30 ° C. to 100 ° C., and a preferable drying time is 30 seconds to 60 minutes. It is also preferable to perform aging in an atmosphere with temperature and humidity control as described in JP-A-07-325220.

The element content in the polarizer is as follows: iodine 0.1-3.0 g / m ² , boron 0.1-5.0 g / m ² , potassium 0.1-2.00 g / m ² , zinc 0-2. It is preferably 00 g / m ² . Further, the potassium content may be 0.2% by mass or less as described in JP-A No. 2001-166143, and the zinc content in the polarizer is described in JP-A No. 2000-035512. It is good also as 0.04 mass%-0.5 mass% currently being carried out.

  As described in Japanese Patent No. 3323255, in order to increase the dimensional stability of the polarizing plate, an organic titanium compound and / or an organic zirconium compound is used in any of the dyeing process, the stretching process and the hardening process. In addition, at least one compound selected from an organic titanium compound and an organic zirconium compound can also be contained. Further, a dichroic dye may be added to adjust the hue of the polarizing plate.

<Characteristics of polarizing plate>
(1) Transmittance and degree of polarization The preferred single plate transmittance of the polarizing plate in the present invention is 42.5% to 49.5%, more preferably 42.8% to 49.0%. A preferable range of the degree of polarization defined by the following formula 4 is 99.900% to 99.999%, and more preferably 99.940% to 99.995%. A preferable range of parallel transmittance is 36% to 42%, and a preferable range of orthogonal transmittance is 0.001% to 0.05%.

  The above-described transmittance is defined by the following formula based on JISZ8701.

ここで、Ｋ、Ｓ（λ）、ｙ（λ）、τ（λ）は以下の通りである。

Here, K, S (λ), y (λ), and τ (λ) are as follows.

Ｓ（λ）：色の表示に用いる標準光の分光分布
ｙ（λ）：ＸＹＺ系における等色関数
τ（λ）：分光透過率

S (λ): spectral distribution of standard light used for color display y (λ): color matching function in XYZ system τ (λ): spectral transmittance

  Moreover, although the preferable range of the dichroism ratio defined by following formula 5 is 48-1215, More preferably, it is 53-525.

The iodine concentration and the single plate transmittance may be in the range described in [0017] of JP-A No. 2002-258051.
The parallel transmittance may be small in wavelength dependency as described in Japanese Patent Application Laid-Open No. 2001-083328 and Japanese Patent Application Laid-Open No. 2002-022950. The optical characteristics when the polarizing plates are arranged in crossed Nicols may be in the range described in JP-A-2001-091136 [0007], and the relationship between parallel transmittance and orthogonal transmittance is It may be within the range described in [0006] of Kaikai 2002-174728.

Further, as described in JP-A No. 2002-221618, the standard deviation of parallel transmittance every 10 nm between light wavelengths of 420 to 700 nm is 3 or less, and the light wavelength is 420 to 700 nm. The minimum value of (parallel transmittance / orthogonal transmittance) every 10 nm between 700 nm may be 300 or more.
The parallel transmittance and orthogonal transmittance at a wavelength of 440 nm of the polarizing plate, the parallel transmittance, the parallel transmittance and the orthogonal transmittance at a wavelength of 550 nm, and the parallel transmittance and the orthogonal transmittance at a wavelength of 610 nm are described in JP-A No. 2002-258042. [0012] and [0012] of JP-A No. 2002-258043 are also preferable.

(2) Hue The hue of the polarizing plate in the present invention is preferably evaluated using the lightness index L ^* and the chromaticness index a ^* and b ^* in the L ^* a ^* b ^* color system recommended as the CIE uniform perceptual space. Is done.
Definitions of L ^* , a ^* , and b ^* are described in, for example, Color Electronics, published by Tokyo Denki University Press.

The preferable range of a ^* for a single polarizing plate is −2.5 to 0.2, and more preferably −2.0 to 0. The preferable b ^* range of a single polarizing plate is 1.5 to 5, more preferably 2 to 4.5 or less. The preferable range of a ^* of the parallel transmitted light of the two polarizing plates is −4.0 to 0, and more preferably −3.5 to −0.5. The preferable range of b ^* of the parallel transmitted light of the two polarizing plates is 2.0 to 8, more preferably 2.5 to 7. The preferable range of a ^* of the orthogonally transmitted light of the two polarizing plates is −0.5 to 1.0, and more preferably 0 to 2. The preferable range of b ^* of the orthogonally transmitted light of the two polarizing plates is −2.0 to 2, more preferably −1.5 to 0.5.

The hue may be evaluated by the chromaticity coordinates (x, y) calculated from the aforementioned X, Y, and Z. For example, the chromaticity (x _p , y _p ) of the parallel transmitted light of the two polarizing plates. And the chromaticity (x _c , y _c ) of the orthogonal transmitted light is [0005] of Japanese Patent Laid-Open No. 2002-214436, [0007] of Japanese Patent Laid-Open No. 2001-166136, and [0005] of Japanese Patent Laid-Open No. 2002-169024. To the range described in [0005] to [0008], and the relationship between the hue and the absorbance is preferably within the range described in [0005] to [0006] of JP-A-2001-311827. Can do.

(3) Viewing angle characteristics When a polarizing plate is placed in crossed Nicol and light with a wavelength of 550 nm is incident, when vertical light is incident, the direction from 45 degrees to the polarization axis is 40 ° with respect to the normal line. It is also preferable that the transmittance ratio and the xy chromaticity difference when the light is incident at an angle of within the range described in Japanese Patent Application Laid-Open Nos. 2001-166135 and 2001-166137. Further, as described in JP-A-10-068817, the light transmittance (T ₀ ) in the vertical direction of the polarizing plate laminated body arranged in a crossed Nicols state and the light in the direction inclined by 60 ° from the normal line of the laminated body The ratio (T ₆₀ / T ₀ ) with the transmittance (T ₆₀ ) is 10000 or less, or as described in JP-A-2002-139625, the polarizing plate has an arbitrary range from the normal to an elevation angle of 80 °. When natural light is incident at an angle, the transmittance difference of transmitted light within the wavelength range of 20 nm within the wavelength range of 520 to 640 nm of the transmission spectrum is set to 6% or less, or described in JP-A-8-248201. It is also preferable that the difference in luminance of transmitted light at an arbitrary 1 cm distance on the film is within 30%.

(4) Durability (4-1) Damp heat durability The change rate of light transmittance and polarization degree before and after being left in an atmosphere of 60 ° C. and 95% relative humidity for 500 hours is 3% or less based on absolute values. It is preferable that In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less based on the absolute value. Further, as described in JP-A-7-077608, it is also preferable that the degree of polarization after standing at 80 ° C., relative humidity 90%, 500 hours is 95% or more and the single transmittance is 38% or more.

(4-2) Dry durability It is preferable that the light transmittance and the rate of change of the degree of polarization before and after leaving in a dry atmosphere at 80 ° C. for 500 hours are also 3% or less based on absolute values. In particular, the change rate of the light transmittance is preferably 2% or less, and the change rate of the polarization degree is preferably 1.0% or less, more preferably 0.1% or less based on the absolute value.

(4-3) Other durability Further, as described in JP-A-6-167611, the shrinkage rate after being left at 80 ° C. for 2 hours is 0.5% or less, or on both surfaces of the glass plate. The x-value and y-value after leaving the polarizing plate laminated body arranged in crossed Nicols in an atmosphere of 69 ° C. for 750 hours within the range described in JP-A-10-068818, 80 ° C., relative humidity 90 % of the change in spectral intensity ratio of the 105 cm ^-1 and 157cm ^-1 by Raman spectroscopy after 200 hours standing treatment in an atmosphere, the range described in JP-a-8-094834 and JP 9-197127 It can also be preferably performed.

(5) Orientation degree The higher the degree of orientation of PVA, the better the polarization performance, but the range of 0.2 to 1.0 is preferable as the order parameter value calculated by means such as polarization Raman scattering or polarization FT-IR. It is. Further, as described in JP-A-59-133509, the difference between the orientation coefficient of the polymer segment in the entire amorphous region of the polarizer and the orientation coefficient of the occupied molecule (0.75 or more) is at least 0. .15 and or, or the orientation coefficient of the amorphous region of the polarizer and 0.65 to 0.85, as described in JP-a-4-204907, I ₃ ^- and I ₅ - higher order iodine The degree of orientation of ions can also be preferably set to 0.8 to 1.0 as an order parameter value.

(6) Other properties As described in JP-A-2002-006133, the contraction force in the absorption axis direction per unit width when heated at 80 ° C. for 30 minutes is 4.0 N / cm or less, As described in JP-A-2002-236213, when the polarizing plate is placed under heating at 70 ° C. for 120 hours, the dimensional change rate in the absorption axis direction and the dimensional change rate in the polarizing axis direction of the polarizing plate. Can be preferably within ± 0.6%, or the moisture content of the polarizing plate can be 3% by mass or less as described in JP-A-2002-090546. Further, as described in JP-A No. 2000-249832, the surface roughness in the direction perpendicular to the stretching axis is set to 0.04 μm or less based on the center line average roughness, or described in JP-A No. 10-268294. As described above, the refractive index n _{0 in the} direction of the transmission axis is made larger than 1.6, or the relationship between the thickness of the polarizing plate and the thickness of the protective film is described in [0004] of JP-A-10-111411. It can also be preferably performed.

<Functionalization of polarizing plate>
The polarizing plate in the present invention is a function that is combined with an optical film having functional layers such as an antireflection film, a brightness enhancement film, a hard coat layer, a forward scattering layer, and an antiglare (antiglare) layer for improving display visibility. It is preferably used as a polarizing plate.

(Antireflection film)
The polarizing plate in the present invention can be used in combination with an antireflection film. As the antireflection film, either a film having a reflectivity of about 1.5% only by applying a single layer of a low refractive index material such as a fluorine-based polymer, or a film having a reflectivity of 1% or less using multilayer interference of a thin film is used. it can. In the present invention, a structure in which a low refractive index layer and at least one layer having a higher refractive index than that of the low refractive index layer (that is, a high refractive index layer and a middle refractive index layer) is laminated on a transparent support is preferably used. The In addition, Nitto Technical Report, vol. 38, no. 1, May, 2000, pages 26 to 28 and JP-A No. 2002-301783.
The refractive index of each layer satisfies the following relationship.

The refractive index of the high refractive index layer> The refractive index of the medium refractive index layer> The refractive index of the transparent support> The refractive index of the low refractive index layer. The transparent support used for the antireflection film is used for the protective film for the polarizer described above. A transparent polymer film can be preferably used.

  The refractive index of the low refractive index layer is preferably 1.20 to 1.55, more preferably 1.30 to 1.50. The low refractive index layer is preferably used as an outermost layer having scratch resistance and antifouling properties. In order to improve the scratch resistance, it is also preferable to impart slipperiness to the surface using a material such as a silicone-containing compound containing a silicone group or a fluorine-containing compound containing fluorine.

Examples of the fluorine-containing compound include JP-A-9-222503 [0018] to [0026], JP-A-11-38202 [0019] to [0030], JP-A 2001-40284 [0027] to [0027]. [0028] The compounds described in JP 2000-284102 A and the like can be preferably used.
The silicone-containing compound is preferably a compound having a polysiloxane structure, such as reactive silicone (for example, Silaplane (manufactured by Chisso Corporation), polysiloxane containing silanol groups at both ends (JP-A-11-258403), etc. Alternatively, an organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent may be cured by a condensation reaction in the presence of a catalyst (Japanese Patent Laid-Open No. 58-86). 142958, 58-147483, 58-147484, JP-A-9-157582, 11-106704, JP-A-2000-117902, 2001-48590, 2002 -53804 publication etc.).
The low refractive index layer has an average primary particle diameter of 1 to 150 nm such as fillers (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)) as additives other than the above. And a low refractive index inorganic compound, organic fine particles described in [0020] to [0038] of JP-A No. 11-3820, etc.), silane coupling agents, slip agents, surfactants, and the like are preferably included. Can do.

The low refractive index layer may be formed by a vapor phase method (vacuum deposition method, sputtering method, ion plating method, plasma CVD method, etc.), but can be formed by a coating method because it can be manufactured at low cost. preferable. As the coating method, dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, and micro gravure can be preferably used.
The film thickness of the low refractive index layer is preferably 30 to 200 nm, more preferably 50 to 150 nm, and most preferably 60 to 120 nm.

The medium refractive index layer and the high refractive index layer preferably have a configuration in which ultrafine particles of high refractive index having an average particle size of 100 nm or less are dispersed in a matrix material. Inorganic compound fine particles having a high refractive index include inorganic compounds having a refractive index of 1.65 or more, for example, oxides such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, and In, and metal atoms thereof. A composite oxide or the like can be preferably used.
Such ultrafine particles may be obtained by treating the particle surface with a surface treatment agent (silane coupling agent, etc .: JP-A Nos. 11-295503, 11-153703, 2000-9908, anionic compounds) Or an organic metal coupling agent: JP-A-2001-310432 or the like, or a core-shell structure with a high refractive index particle as a core (JP-A-2001-166104, etc.), or a specific dispersant (for example, JP-A-11-153703, U.S. Pat. No. 6,210,858B1, JP-A-2002-277760, etc.) can be used.

As the matrix material, conventionally known thermoplastic resins, curable resin films, and the like can be used, but JP-A-2000-47004, 2001-315242, 2001-31871, 2001-296401. It is also possible to use a curable film obtained from a polyfunctional material described in JP-A-2001-293818 or a metal alkoxide composition described in JP-A-2001-293818.
The refractive index of the high refractive index layer is preferably 1.70 to 2.20. The thickness of the high refractive index layer is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.
The refractive index of the medium refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.70.

  The haze of the antireflection film is preferably 5% or less, more preferably 3% or less. Further, the strength of the film is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K5400.

(Brightness enhancement film)
The polarizing plate in the present invention can be used in combination with a brightness enhancement film. The brightness enhancement film has a function of separating circularly polarized light or linearly polarized light, and is disposed between the polarizing plate and the backlight, and reflects or backscatters one circularly polarized light or linearly polarized light to the backlight side. Re-reflected light from the backlight part partially changes the polarization state and partially transmits when re-entering the brightness enhancement film and the polarizing plate, so the light utilization rate is improved by repeating this process. The front luminance is improved to about 1.4 times. As the brightness enhancement film, an anisotropic reflection system and an anisotropic scattering system are known, and both can be combined with the polarizing plate in the present invention.

  In the anisotropic reflection method, a brightness enhancement film having anisotropy in reflectance and transmittance is known by laminating a uniaxially stretched film and an unstretched film in multiple layers to increase the difference in refractive index in the stretching direction. Multilayer film systems using the principle of dielectric mirrors (described in the specifications of WO95 / 17691, WO95 / 17692, and WO95 / 17699) and cholesteric liquid crystals A system (European Patent No. 606940A2 specification, JP-A-8-271731) is known. DBEF-E, DBEF-D, and DBEF-M (all manufactured by 3M) are used as multi-layer brightness enhancement films using the principle of dielectric mirrors, and NIPOCS (Nitto Denko Corporation) as a cholesteric liquid crystal brightness enhancement film. )) Is preferably used in the present invention. For NIPOCS, see Nitto Giho, vol. 38, no. 1, May, 2000, pages 19 to 21 and the like.

  Further, in the present invention, the specifications of International Publication No. 97/32223, International Publication No. 97/32224, International Publication No. 97/32225, International Publication No. 97/32226, and Japanese Patent Application Laid-Open No. 9-274108. Used in combination with a brightness enhancement film of an anisotropic scattering method in which a positive intrinsic birefringent polymer and a negative intrinsic birefringent polymer are blended and uniaxially stretched as described in each publication of JP-A-11-174231 It is also preferable to do. As the anisotropic scattering system brightness enhancement film, DRPF-H (manufactured by 3M) is preferable.

(Other functional optical films)
The polarizing plate in the present invention is further combined with a functional optical film provided with a hard coat layer, a forward scattering layer, an antiglare (antiglare) layer, a gas barrier layer, a sliding layer, an antistatic layer, an undercoat layer, a protective layer and the like. It is also preferable to use it. These functional layers are also preferably used in combination with each other in the same layer as the antireflection layer or the optically anisotropic layer in the above-described antireflection film. These functional layers can be used by providing them on one side or both sides of the polarizer side and the side opposite to the polarizer (the side on the air side).

[Hard coat layer]
Since the polarizing plate in the present invention imparts mechanical strength such as scratch resistance, it is preferably combined with a functional optical film having a hard coat layer provided on the surface of the transparent support. When the hard coat layer is applied to the above-described antireflection film, it is particularly preferable to provide it between the transparent support and the high refractive index layer.
The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a curable compound by light and / or heat. The curable functional group is preferably a photopolymerizable functional group, or the hydrolyzable functional group-containing organometallic compound is preferably an organic alkoxysilyl compound. As a specific constituent composition of the hard coat layer, for example, those described in JP-A-2002-144913, JP-A-2000-9908, WO 00/46617, etc. can be preferably used.
The film thickness of the hard coat layer is preferably 0.2 μm to 100 μm.
The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

  As the material for forming the hard coat layer, a compound containing an ethylenically unsaturated group or a compound containing a ring-opening polymerizable group can be used, and these compounds can be used alone or in combination. Preferred examples of the compound containing an ethylenically unsaturated group include ethylene glycol diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol. Polyacrylates of polyols such as hexaacrylate; epoxy acrylates such as diacrylate of bisphenol A diglycidyl ether, diacrylate of hexanediol diglycidyl ether; obtained by reaction of polyisocyanate and hydroxyl group-containing acrylate such as hydroxyethyl acrylate Examples of preferred compounds include urethane acrylates. Moreover, as a commercially available compound, EB-600, EB-40, EB-140, EB-1150, EB-1290K, IRR214, EB-2220, TMPTA, TMPTMA (above, Daicel UCB Co., Ltd. product), UV -6300, UV-1700B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like.

  Preferred examples of the compound containing a ring-opening polymerizable group include ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether, glycerol triglycidyl ether as glycidyl ethers. Triglycidyl trishydroxyethyl isocyanurate, sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, polyglycidyl ether of phenol novolac resin, etc. Celoxide 2021P, Celoxide 2081, Epoxide GT-301, Epolide GT-401, EHPE3150CE (above, IXETA 121, OXT-221, OX-SQ, PNOX-1009 (above, manufactured by Toagosei Co., Ltd.) and the like as oxetanes, such as Issel Chemical Industry Co., Ltd.), polycyclohexyl epoxy methyl ether of phenol novolac resin, etc. Can be mentioned. In addition, a polymer of glycidyl (meth) acrylate or a copolymer of a monomer that can be copolymerized with glycidyl (meth) acrylate may be used for the hard coat layer.

  In the hard coat layer, oxide fine particles such as silicon, titanium, zirconium, and aluminum are used to reduce curing shrinkage of the hard coat layer, improve adhesion to the substrate, and reduce curling of the hard coat treated article in the present invention. It is also preferable to add crosslinked fine particles such as crosslinked fine particles such as polyethylene, polystyrene, poly (meth) acrylic acid esters, polydimethylsiloxane, etc., and fine organic particles such as fine crosslinked rubber particles such as SBR and NBR. The average particle size of these crosslinked fine particles is preferably 1 nm to 20000 nm. Further, the shape of the crosslinked fine particles can be used without particular limitation, such as a spherical shape, a rod shape, a needle shape, or a plate shape. The addition amount of the fine particles is preferably 60% by volume or less, more preferably 40% by volume or less of the hard coat layer after curing.

  In the case of adding the inorganic fine particles described above, since the affinity with the binder polymer is generally poor, it contains a metal such as silicon, aluminum, titanium, and the alkoxide group, carboxylic acid group, sulfonic acid group, phosphonic acid group, etc. It is also preferable to perform a surface treatment using a surface treatment agent having a functional group of

  The hard coat layer is preferably cured using heat or active energy rays. Among them, active energy rays such as radiation, gamma rays, alpha rays, electron rays, and ultraviolet rays are more preferred, and safety and productivity are improved. In view of the above, it is particularly preferable to use electron beams and ultraviolet rays. In the case of curing with heat, in consideration of the heat resistance of the plastic itself, the heating temperature is preferably 140 ° C. or lower, more preferably 100 ° C. or lower.

[Forward scattering layer]
The forward scattering layer is used to improve the viewing angle characteristics (hue and luminance distribution) in the vertical and horizontal directions when the polarizing plate of the present invention is applied to a liquid crystal display device. In the present invention, the forward scattering layer preferably has a configuration in which fine particles having different refractive indexes are dispersed in a binder. For example, Japanese Patent Application Laid-Open No. 11-38208 in which the forward scattering coefficient is specified, the relative refractive index between the transparent resin and the fine particles is in a specific range. Japanese Patent Laid-Open No. 2000-199809, Japanese Patent Laid-Open No. 2002-107512, etc. in which the haze value is defined as 40% or more can be used. Moreover, in order to control the viewing angle characteristics of haze, the polarizing plate in the present invention should be used in combination with “Lumisty” described in Sumitomo Chemical Co., Ltd. Technical Report “Optical Functional Film” on pages 31-39. Can also be preferably performed.

[Anti-glare layer]
The antiglare (antiglare) layer is used to scatter reflected light and prevent reflection. The antiglare function is obtained by forming irregularities on the outermost surface (display side) of the liquid crystal display device. The haze of the optical film having an antiglare function is preferably 3 to 30%, more preferably 5 to 20%, and most preferably 7 to 20%.
The method for forming irregularities on the film surface is, for example, a method of forming irregularities on the film surface by adding fine particles (for example, JP 2000-271878 A), relatively large particles (particle size 0.05-2 μm). ) Is added in a small amount (0.1 to 50% by mass) (for example, Japanese Patent Application Laid-Open Nos. 2000-281410, 2000-95893, 2001-100004, and 2001). No. 281407, etc.), a method of physically transferring the uneven shape onto the film surface (for example, as an embossing method, JP-A-63-278839, JP-A-11-183710, JP-A-2000-275401) Etc.) can be preferably used.

<Liquid crystal display device>
Next, a liquid crystal display device in which a polarizing plate including the optical compensation sheet of the present invention is preferably used will be described.

  FIG. 1 is a schematic view showing an example of the liquid crystal display device of the present invention. In FIG. 1, a liquid crystal display device 10 includes a liquid crystal cell having a liquid crystal layer 7 and a liquid crystal cell upper electrode substrate 5 and a liquid crystal cell lower electrode substrate 8 disposed above and below, and upper polarizing plates disposed on both sides of the liquid crystal cell. 1 and the lower polarizing plate 12. A color filter may be disposed between the liquid crystal cell and each polarizing plate. When the liquid crystal display device 10 is used as a transmission type, a cold cathode or hot cathode fluorescent tube, or a backlight having a light emitting diode, a field emission element, or an electroluminescent element as a light source is disposed on the back surface. Further, 2 and 13 indicate the direction of the upper or lower polarizing plate absorption axis, respectively, and 6 and 9 indicate the orientation control direction of the upper substrate or the lower substrate, respectively.

  The upper polarizing plate 1 and the lower polarizing plate 12 each have a structure in which a polarizer is sandwiched between two protective films, and the liquid crystal display device 10 of the present invention is a liquid crystal cell of one polarizing plate. The protective film on the side has the characteristics of the above formulas (1) to (6), and the protective film on the liquid crystal cell side of the other polarizing plate has the characteristics of the above formulas (7) to (12). The liquid crystal display device 10 of the present invention is preferably laminated in the order of the transparent protective film, the polarizer, and the cellulose acylate film of the present invention from the outside of the device (the side far from the liquid crystal cell). The liquid crystal display device 10 includes an image direct view type, an image projection type, and a light modulation type. The present invention is effective for an active matrix liquid crystal display device using a three-terminal or two-terminal semiconductor element such as TFT or MIM. Of course, it is also effective in a passive matrix liquid crystal display device typified by STN mode called time-division driving.

(VA mode)
The liquid crystal cell of the liquid crystal display device of the present invention is preferably in the VA mode.
In the VA mode, the dielectric anisotropy between the upper and lower substrates is negative, and a liquid crystal having Δn = 0.0813 and Δε = −4.6 is rubbed to provide a director indicating the alignment direction of the liquid crystal molecules, so-called tilt angle is about Fabricate at 89 °. The thickness d of the liquid crystal layer 7 in FIG. 1 is set to 3.5 μm. Here, the brightness at the time of white display changes depending on the magnitude of the product Δnd of the thickness d and the refractive index anisotropy Δn. Therefore, in order to obtain the maximum brightness, the thickness of the liquid crystal layer is set to be in the range of 0.2 μm to 0.5 μm.

  The absorption axis 2 of the upper polarizing plate 1 of the liquid crystal cell and the absorption axis 13 of the lower polarizing plate 12 are laminated substantially orthogonally. A transparent electrode (not shown) is formed inside each alignment film of the liquid crystal cell upper electrode substrate 5 and the liquid crystal cell lower electrode substrate 8, but in a non-driving state where no driving voltage is applied to the electrodes, the liquid crystal layer 7 The liquid crystal molecules therein are aligned substantially perpendicular to the substrate surface, and as a result, the polarization state of the light passing through the liquid crystal panel hardly changes. That is, the liquid crystal display device realizes an ideal black display in the non-driven state. On the other hand, in the driving state, the liquid crystal molecules are inclined in a direction parallel to the substrate surface, and the light passing through the liquid crystal panel changes the polarization state by the inclined liquid crystal molecules. In other words, in the liquid crystal display device, white display is obtained in the driving state.

Here, since an electric field is applied between the upper and lower substrates, a liquid crystal material having a negative dielectric anisotropy is used so that liquid crystal molecules respond perpendicularly to the electric field direction. When an electrode is disposed on one substrate and an electric field is applied in a lateral direction parallel to the substrate surface, a liquid crystal material having a positive dielectric anisotropy is used.
In addition, in a VA mode liquid crystal display device, the addition of a chiral agent generally used in a TN mode liquid crystal display device is rarely used to degrade dynamic response characteristics, but in order to reduce alignment defects. Sometimes added.

  The features of the VA mode are high-speed response and high contrast. However, the contrast is high in the front, but there is a problem that it is deteriorated in the oblique direction. During black display, the liquid crystal molecules are aligned perpendicular to the substrate surface. When observed from the front, the liquid crystal molecules have almost no birefringence, so the transmittance is low and high contrast can be obtained. However, when observed obliquely, birefringence occurs in the liquid crystal molecules. Further, the crossing angle of the upper and lower polarizing plate absorption axes is 90 ° perpendicular to the front, but is larger than 90 ° when viewed from an oblique direction. Because of these two factors, leakage light occurs in the oblique direction, and the contrast is lowered. In order to solve this, an optical compensation sheet is arranged.

  In addition, the liquid crystal molecules are tilted during white display, but the birefringence of the liquid crystal molecules when viewed from an oblique direction differs between the tilt direction and the opposite direction, resulting in differences in luminance and color tone. In order to solve this, a structure called a multi-domain in which one pixel of a liquid crystal display device is divided into a plurality of regions is employed.

[Multi-domain]
For example, in the VA system, the viewing angle characteristics are averaged by inclining liquid crystal molecules into a plurality of different regions within one pixel by applying an electric field. In order to divide the orientation within one pixel, the electrode is provided with slits or protrusions, and the electric field direction is changed or the electric field density is biased. In order to obtain a uniform viewing angle in all directions, the number of divisions may be increased, but a substantially uniform viewing angle can be obtained by dividing into four or eight or more. In particular, it is preferable that the polarizing plate absorption axis can be set at an arbitrary angle when dividing into eight.

  Also, the liquid crystal molecules are difficult to respond at the alignment division region boundary. For this reason, in normally black display, since black display is maintained, a reduction in luminance becomes a problem. Therefore, it is possible to reduce the boundary region by adding a chiral agent to the liquid crystal material.

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

[Reference Example 1]
(Preparation of the first retardation film 1)
The following cellulose acylate solution A composition was put into a mixing tank, stirred while heating to dissolve each component, and a cellulose acylate solution A was prepared.

(Cellulose acylate solution A composition)
100% by weight of cellulose acetate with a substitution degree of 2.86
Triphenyl phosphate (plasticizer) 7.8% by weight
Biphenyl diphenyl phosphate (plasticizer) 3.9% by weight
Methylene chloride (first solvent) 300% by weight
Methanol (second solvent) 54 wt%
1-butanol 11% by weight

  The following additive solution B-1 composition was put into another mixing tank and stirred while heating to dissolve each component to prepare additive solution B-1.

(Additive solution B-1 composition)
64% by weight of methylene chloride
Methanol 16% by weight
Retardation developer B-121 10% by weight
Retardation developer B-130 10% by weight

<Preparation of first retardation film 1>
A dope was prepared by adding 40% by weight of additive solution B-1 to 477% by weight of cellulose acylate solution A and stirring sufficiently. The dope was cast from a casting port onto a drum cooled to 0 ° C. When the solvent content was 70% by mass on a dry basis, the film was peeled off from the drum, and stretched 9% in the longitudinal direction by passing two rolls having different conveying speeds. Then, it dried further by conveying between the rolls of a heat processing apparatus, and produced the 1st phase difference film 1 with a thickness of 80 micrometers.

[Reference Example 2]
<Preparation of first retardation films 2-3>
The first retardation film 1 was prepared in the same manner as the first retardation film 1 except that the substitution degree of cellulose acetate, the type of retardation developing agent, the amount added, and the thickness were changed to those shown in Table 1. Retardation films 2 and 3 were produced.

[Reference Example 3]
<Preparation of the first retardation film 4>
As described below, the cellulose acylate solution C and the ultraviolet absorber solution D were prepared, and the first retardation film 4 was produced using them.

(Preparation of cellulose acylate solution C)
A mixture of the following cellulose acylate solution C composition was placed in a sealed container, gradually heated while slowly stirring, and then heated to 45 ° C. over 60 minutes for dissolution. The inside of the container was 1.2 atm. This dope was added to Azumi Filter Paper No. After filtering using 244, it left still for 24 hours and the bubble in dope was removed.

(Cellulose acylate solution C composition)
Cellulose acetate propionate 100% by weight
(Acetyl group substitution degree 2.00, propionyl group substitution degree 0.80, viscosity average polymerization degree 350)
Ethyl phthalyl ethyl glycolate 2% by weight
Triphenyl phosphate 8.5% by weight
290% by weight of methylene chloride
60% by weight of ethanol

(Preparation of UV absorber solution D)
Cellulose acetate propionate 5 wt%, Tinuvin 326 (Ciba Specialty Chemicals Co., Ltd.) 6 wt%, Tinuvin 109 (Ciba Specialty Chemicals Co., Ltd.) 4 wt%, Tinuvin 171 (Ciba Specialty Chemicals) Chemicals Co., Ltd. (5% by weight) was mixed with 94% by weight of methylene chloride and 8% by weight of ethanol and dissolved by stirring to prepare an ultraviolet absorber solution D.

  The UV absorber solution D is added at a ratio of 2.5% by weight to 100% by weight of the cellulose acylate solution C, and after sufficiently mixed by a static mixer, the dope temperature is 30 ° C. from the die onto the stainless belt. Cast at 1.6 m. Dry hot water at a temperature of 25 ° C. from the back surface of the stainless steel belt for 1 minute on the temperature-controlled stainless steel belt, and contact the back surface of the stainless steel belt with cold water at 15 ° C. for 15 seconds to remove residual solvent. It peeled from the stainless steel belt in an amount of 80% by mass.

  Subsequently, it extended | stretched by the magnification of 1.5 time in the width direction using the uniaxial stretching tenter. Furthermore, it was made to dry by conveying between rolls, and the 1st phase difference film 4 with a film thickness of 82 micrometers was produced.

  The ultraviolet absorbent (UV-1) used as an example in which the ultraviolet absorbent in the present invention is used in combination with a function as a retardation enhancer is as follows.

[Reference Example 4]
<Preparation of the second retardation film 1>
(Preparation of cellulose acylate solution 01)
The composition of the following cellulose acylate solution 01 was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution 01.

(Composition of cellulose acylate solution 01)
・ Cellulose acetate 100.0% by weight
(Degree of acetylation 2.70)
・ Plasticizer: Triphenyl phosphate 6.0% by weight
Plasticizer: Biphenyl phosphate 3.0% by weight
Methylene chloride (first solvent) 347.0% by weight
Methanol (second solvent) 52.0% by weight

(Preparation of matting agent solution 11)
The following matting agent solution 11 composition was put into a disperser and stirred to dissolve each component to prepare a matting agent solution 11.

(Matting agent solution 11 composition)
・ 2.0% by weight of silica particles having an average particle size of 20 nm
“AEROSIL R972” manufactured by Nippon Aerosil Co., Ltd., methylene chloride (first solvent) 75.0% by weight
Methanol (second solvent) 12.7% by weight
・ Cellulose acylate 01 solution 10.3% by weight

(Preparation of retardation developer 21 solution)
The composition of the following retardation developer solution 21 The composition of the matting agent solution 11 was put into a mixing tank, stirred while heating to dissolve each component, and the retardation developer solution 21 was prepared.

(Composition of the retardation developer solution 21)
Retardation expression agent (G) 10.0% by weight
Methylene chloride (first solvent) 67.1% by weight
・ Methanol (second solvent) 10.0% by weight
・ Cellulose acylate solution 01 12.8% by weight

  The cellulose acylate solution 01 (94.9% by weight), the matting agent solution 11 (1.3% by weight), and the retardation developer solution 21 (3.8% by weight) were filtered and mixed to obtain a band casting. It was cast using a machine. The obtained web was peeled from the band, and stretched laterally at a stretching ratio of 36% using a tenter under the condition of 140 ° C. Then, the clip was removed and dried at 130 ° C. for 40 minutes to produce a stretched cellulose acylate film (second retardation film 1). The finished stretched cellulose acylate film had a residual solvent amount of 0.2% by mass and a film thickness of 80 μm.

[Reference Example 5]
<Preparation of the second retardation film 2>
(Preparation of cellulose acylate solution 02)
The composition of the following cellulose acylate solution 02 was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution 02.

(Composition of cellulose acylate solution 02)
・ Cellulose acetate 100.0% by weight
(Degree of acetylation 2.78)
・ Plasticizer: Triphenyl phosphate 6.0% by weight
Plasticizer: Biphenyl phosphate 3.0% by weight
Methylene chloride (first solvent) 347.0% by weight
Methanol (second solvent) 52.0% by weight

(Preparation of matting agent solution 12)
The following matting agent solution 12 composition was put into a disperser and stirred to dissolve each component to prepare a matting agent solution 12.

(Matting agent solution 12 composition)
・ 2.0% by weight of silica particles having an average particle size of 20 nm
“AEROSIL R972” manufactured by Nippon Aerosil Co., Ltd., methylene chloride (first solvent) 75.0% by weight
Methanol (second solvent) 12.7% by weight
・ Cellulose acylate 02 solution 10.3% by weight

(Preparation of retardation developer 22 solution)
The composition of the following retardation developer solution 22 was put into a mixing tank, stirred while heating to dissolve each component, and a retardation developer solution 22 was prepared.

(Composition of the retardation developer solution 22)
UV absorber (UV-1 above) 20.0% by weight
Methylene chloride (first solvent) 58.5% by weight
-Methanol (second solvent) 8.7% by weight
・ Cellulose acylate solution 02 12.8% by weight

  The cellulose acylate solution 02 (91.9% by weight), the matting agent solution 12 (1.3% by weight), and the retardation developer solution 22 (6.8% by weight) were filtered and mixed, and the band casting was performed. It was cast using a machine. The obtained web was peeled from the band, and stretched laterally at a stretching ratio of 36% using a tenter under the condition of 140 ° C. Then, the clip was removed and dried at 130 ° C. for 40 minutes to produce a stretched cellulose acylate film (second retardation film 2). The finished stretched cellulose acylate film had a residual solvent amount of 0.2% by mass and a film thickness of 78 μm.

[Reference Example 6]
<Preparation of the second retardation film 3>
(Preparation of cellulose acylate solution 03)
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acylate solution 03.

(Composition of cellulose acylate solution 03)
・ Cellulose acetate 100.0 parts by mass (acetylation degree 2.80)
・ Plasticizer: 7.0 parts by weight of triphenyl phosphate ・ Plasticizer: 3.5 parts by weight of biphenyl phosphate ・ 347.0 parts by weight of methylene chloride (first solvent) ・ 52.0 parts by weight of methanol (second solvent)

(Preparation of matting agent solution 13)
The following composition was put into a disperser and stirred to dissolve each component to prepare a matting agent solution 13.

(Matting agent solution composition 13)
-Silica particles with an average particle size of 20 nm 2.0 parts by mass "AEROSIL R972" manufactured by Nippon Aerosil Co., Ltd.-Methylene chloride (first solvent) 75.0 parts by mass-Methanol (second solvent) 12.7 parts by mass-Cellulose Acylate 03 solution 10.3 parts by mass

(Preparation of retardation developer solution 23)
The following composition was put into a mixing tank, stirred while heating to dissolve each component, and a retardation developer solution 23 was prepared.

(Composition of the retardation developer solution 23)
-20.0 parts by mass of the retardation developer (20)-58.5 parts by mass of methylene chloride (first solvent)-8.7 parts by mass of methanol (second solvent)-12.8 parts by mass of cellulose acylate solution 03

  The cellulose acylate solution 03 (94.7 parts by mass), the matting agent solution 13 (1.3 parts by mass), and the retardation developer solution 23 (4.0 parts by mass) were respectively filtered and mixed, and then subjected to band casting. It was cast using a machine. The obtained web was peeled from the band, and stretched at a stretching ratio of 40% using a tenter under the condition of 135 ° C., and then relaxed by 10% in the longitudinal direction (conveying direction). Thereafter, the clip was removed and dried at 130 ° C. for 40 minutes to produce a second retardation film 3. The completed second retardation film 3 had a residual solvent amount of 0.2% by mass and a film thickness of 83 μm.

  About the 1st phase difference films 1-4 produced as mentioned above, and the 2nd phase difference films 1-3, it was 25 degreeC and relative by the automatic birefringence meter (KOBRA-WR, Oji Scientific Instruments Co., Ltd. product). Re and Rth at wavelengths of 446 nm, 548 nm, and 628 nm at a humidity of 60% were measured. The results are shown in Table 3 below.

[Reference Example 7]
(Saponification treatment of the first retardation film 1)
(Alkaline treatment of film)
The produced first retardation film 1 was immersed in an aqueous 2.3 mol / L sodium hydroxide solution at 55 ° C. for 3 minutes. It wash | cleaned in the room temperature water-washing bath, and neutralized using 0.05 mol / L sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. In this manner, the surface of the first retardation film 1 was saponified.

(Saponification treatment of first retardation films 2 to 4 and second retardation films 1 to 3)
Similarly to the first retardation film 1, the surfaces of the first retardation films 2 to 4 and the second retardation films 1 to 3 were saponified.

[Reference Example 8]
<Preparation of polarizing plate>
(Saponification treatment of polarizing plate protective film)
A commercially available cellulose acylate film (manufactured by Fuji Tac Co., Ltd., TD80) was immersed in a 1.5 mol / L aqueous sodium hydroxide solution at 55 ° C. for 1 minute. It wash | cleaned in the room temperature water-washing bath, and neutralized using 0.05 mol / L sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C.

(Production of polarizer)
A polarizer is prepared by adsorbing iodine to a stretched polyvinyl alcohol film, and a cellulose acylate film saponified in Reference Example 7 and Reference Example 8 using a polyvinyl alcohol-based adhesive. Was attached to both sides of the polarizer to produce a polarizing plate (A). It arrange | positioned so that the absorption axis of the polarizer of a 1st polarizing plate and the slow axis of the 1st phase difference film 1 might become parallel.

[Reference Example 9]
(Preparation of polarizing plates B to G)
Polarizing plates B to G were prepared in the same manner as in Reference Example 8 for the first retardation films 2 to 4 and the second retardation films 1 to 3. For polarizing plates B to C, the absorption axis of the polarizer and the slow axis of the retardation film are parallel, and for polarizing plates D to G, the transmission axis of the polarizer and the slow phase of the retardation film. They were placed so that the axes were parallel.

Example 1
(Production of liquid crystal display device)
In the VA mode liquid crystal cell, a polarizing plate A is provided as the upper polarizing plate 1 in FIG. 1, the first retardation film 1 is on the liquid crystal cell side, a polarizing plate G is provided on the lower polarizing plate 12, and The two retardation films 1 were attached to the viewer side and the backlight side one by one through an adhesive so that the two phase difference films 1 were on the liquid crystal cell side. The crossed Nicols were arranged so that the transmission axis of the polarizing plate on the viewer side was in the vertical direction and the transmission axis of the polarizing plate on the backlight side was in the horizontal direction. Thus, the liquid crystal display device 101 was produced.
Furthermore, the upper polarizing plate and the lower polarizing plate were changed to the contents shown in Table 2 below to produce the liquid crystal display devices 102 to 104 of the present invention and the liquid crystal display devices 201 and 202 of the comparative examples.

(Change in color viewing angle)
With respect to the liquid crystal display devices 101 to 104, 201, and 202 manufactured as described above, the hue change between an azimuth angle of 0 ° and an azimuth angle of 80 ° at a polar angle of 60 ° was measured by Ezcontrast manufactured by ELDIM, and on the xy chromaticity diagram. The absolute values Δx and Δy of the color change were obtained. The results are shown in Table 4.

From the results of Table 2, it can be seen that the liquid crystal display devices 101, 102, 103, and 104 of the present invention that satisfy the conditions of the present invention are preferable to the liquid crystal display device 201 of the comparative example because the change in color depending on the viewing angle is small.
The liquid crystal display device 202 satisfies the condition of the present invention, but does not satisfy the condition of the above formula (A). Therefore, it is preferable that the color change due to the viewing angle is small compared to the liquid crystal display device 201 of the comparative example, but the color change due to the viewing angle is inferior compared to the liquid crystal display devices 101, 102, 103, and 104. .

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

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper polarizing plate 2 Upper polarizing plate Absorption axis direction 5 Liquid crystal cell upper electrode substrate 6 Upper substrate orientation control direction 7 Liquid crystal layer 8 Liquid crystal cell lower electrode substrate 9 Lower substrate orientation control direction 10 Liquid crystal display device 12 Lower polarizing plate 13 Direction of absorption axis of lower polarizing plate

Claims (8)

A liquid crystal cell, a first polarizing plate and a second polarizing plate respectively disposed on both sides of the liquid crystal cell, a first retardation film disposed between the first polarizing plate and the liquid crystal cell,
A second retardation film disposed between the second polarizing plate and the liquid crystal cell;
The absorption axis of the first polarizing plate and the slow axis of the first retardation film are substantially parallel,
The transmission axis of the second polarizing plate and the slow axis of the second retardation film are substantially parallel.
The liquid crystal display device in which the first retardation film satisfies the relationships of the following formulas (1) to (6), and the second retardation film satisfies the relationships of the following formulas (7) to (12).
10 nm <Re (548) <100 nm Formula (1)
20 nm <Rth (548) <400 nm Formula (2)
1.0 <Re (446) / Re (548) <2.0 Formula (3)
0.5 <Re (628) / Re (548) <1.0 Formula (4)
1.0 <Rth (446) / Rth (548) <2.0 Formula (5)
0.5 <Rth (628) / Rth (548) <1.0 Formula (6)
40 nm <Re (548) <300 nm Formula (7)
20 nm <Rth (548) <400 nm (8)
0.5 <Re (446) / Re (548) <1.5 Formula (9)
0.5 <Re (628) / Re (548) <2.0 Formula (10)
0.5 <Rth (446) / Rth (548) <2.0 Formula (11)
0.5 <Rth (628) / Rth (548) <1.5 Formula (12) The liquid crystal display device according to claim 1, wherein the first retardation film and the second retardation film satisfy the following relationship.
Formula (A)
λ1.0 (1 ^st ) −λ1.0 (2 ^nd )> 0
(In the formula (A), λ1.0 (1 ^st ) represents a wavelength at which the absorbance converted to a film thickness of 80 μm of the first retardation film is 1.0 in the wavelength range of 200 nm to 700 nm, and λ1.0 ( 2 ^nd) represents the wavelength at which the absorbance was converted into a film thickness of 80μm of the second retardation film is 1.0 in the wavelength range of 200 nm to 700 nm.) The liquid crystal display device according to claim 1, wherein at least one of the first retardation film and the second retardation film also serves as a protective film for a polarizing plate. The liquid crystal display device according to claim 1, wherein at least one of the first retardation film and the second retardation film is a cellulose acylate film. 5. The liquid crystal display device according to claim 1, wherein the first retardation film contains a compound having at least one absorption maximum in a range of 200 nm to 380 nm. The liquid crystal display device according to claim 1, wherein the first retardation film is a cellulose acylate film stretched in the longitudinal direction. The liquid crystal display device according to claim 1, wherein the second retardation film is a cellulose acylate film stretched in the width direction. The liquid crystal display device according to claim 1, wherein the liquid crystal cell is in a VA mode.

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