JP5923948B2 - Rolled polarizing plate - Google Patents

Description

The present invention relates to a polarizer wrinkle be wound b Lumpur like is wound into a roll does not occur.

  A stretched film formed by stretching a resin film is used as an optical material such as a component of a display device by utilizing its optical anisotropy. For example, in a liquid crystal display device, the stretched film may be used as a retardation film for optical compensation such as anti-coloring and viewing angle expansion, or the stretched film and a polarizer may be bonded together to be used as a polarizing plate. It has been known.

  In recent years, the retardation film has been required for improving the display quality of organic EL display devices and stereoscopic display devices.

  In a stereoscopic display device, when viewing a 3D image of a liquid crystal display device by wearing polarized glasses, the image is displayed when the polarization angle of the polarized glasses and the polarization angle emitted from the liquid crystal display device deviate from an appropriate angle. There was a problem of overlapping. In order to prevent this, a retardation film having a retardation value (also referred to as “retardation value”) of ¼ of the wavelength of the ornamental light is required.

  Further, in the organic EL display device, there is a problem that external light is reflected by the electrode of the cell and the image becomes whitish. In order to prevent this, an attempt has been made to provide a retardation film having a retardation value of 1/4 (also referred to as λ / 4) of the wavelength of visible light on the viewing side.

  In order to produce a retardation film, it is necessary to stretch a film formed by casting or the like in a specific direction. However, in order to obtain a large retardation value such as λ / 4, the retardation required for widening the viewing angle is required. The stretch ratio must be larger than when obtaining the foundation value.

  In general, the higher the draw ratio of a plastic film, the larger the retardation value and the temperature / humidity change in dimensions after stretching. Therefore, improvement of the optical value and dimensional change after stretching of the λ / 4 retardation film is a priority issue.

  Patent Document 1 discloses that a polarizing plate which is less likely to curl due to changes in temperature and humidity can be produced by defining the moisture absorption and hygroscopic expansion coefficient of the protective film bonded to both sides of the polarizer to a certain value. Yes.

  The problem to be solved in Document 1 is curl due to a change in temperature and humidity of a polarizing plate produced by simply attaching protective films to both sides of a polarizer.

  The above-mentioned problem is described in addition to Document 1, and various solutions are described. Films and polarizing plates used for conventional liquid crystal display devices have been able to solve the curl problem by these means.

  However, it has been found that the λ / 4 retardation film required for a stereoscopic display device and an organic EL display device requires high magnification stretching to produce a problem that cannot be solved by the above solution. .

  When the polarizing plate is continuously produced, the roll-shaped protective film and the polarizer are respectively fed out from the roll and are subjected to appropriate bonding treatment while being transported, and the produced polarizing plate is wound into a roll. In the case of a polarizing plate bonded with a conventional λ / 4 retardation film, it has been found that a rolled shape is stored in the film while being rolled and stored. In the present case, this is hereinafter referred to as a roll.

  If the wrinkle occurs in the polarizing plate, it is difficult to arrange the polarizing plate on the display device thereafter, and there is a problem that unevenness occurs in the displayed image.

  This curl is a problem that appears particularly prominently in a polarizing plate in which λ / 4 retardation films are bonded to both surfaces of a polarizer.

JP 2008-107501 A

This invention is made | formed in view of the said problem and the situation, The solution subject is providing the polarizing plate wound by the roll shape which does not generate | occur | produce a curl even if it rolls in a roll shape .

  In order to solve the above-mentioned problems, the present inventor has studied the cause of the above-mentioned problem relating to a polarizing plate for laminating a retardation film having a retardation of λ / 4 on both sides of a polarizer, and as a result, the present invention has been applied to one surface. The difference in elastic modulus in the slow axis direction between the combined retardation film and the retardation film bonded to the other surface is in the range of 100 to 2000 MPa, and the polarizing plate is wound into a roll Sometimes, a polarizing plate wound with a film having a higher elastic modulus in the slow axis direction wound inside is found to be free from curling, and the present invention has been achieved.

  That is, the said subject which concerns on this invention is solved by the following means.

1. Two retardation films having an in-plane retardation value Ro satisfying the following formula (1) are a polarizing plate wound in a roll shape provided on both surfaces of a polarizer,
Is long,
One of the retardation film and the retardation film A, the other retardation film B,
When stored in roll form, the retardation film (A) is wound so as to be inside the roll, and
Each of the slow axis direction of the elastic modulus S, respectively, when the S (A) and S (B), that the two sheets of the retardation film is stuck so as to satisfy the following formula (2) A polarizing plate wound in a roll shape .
Formula (1): 100 nm ≦ Ro ≦ 160 nm
Formula (2): 100 MPa ≦ S (A) −S (B) ≦ 2000 MPa
( However, the in-plane retardation value Ro is an in-plane retardation value measured with light having a wavelength of 550 nm in an environment of a temperature of 23 ° C. and a relative humidity of 55%. )

2 . At least one of the retardation films contains a cellulose ester that satisfies the following formula (3). The polarizing plate wound in a roll shape according to the first item .
Formula (3): 0 ≦ X ≦ 1.8
( However, in the above formula, X represents the total substitution degree of propionyl group or butyryl group. )

3 . At least one of the retardation films contains a polycarbonate or a cycloolefin resin. The polarizing plate wound into a roll according to the first or second item.

By the above means of the present invention, it is possible to provide a polarizing plate wound in a roll shape that does not generate curl even when wound in a roll shape .

  Although the expression mechanism or action mechanism of the effect of the present invention is not clear, it is as follows when inferred from the configuration opposite to that of the present invention. That is, among the λ / 4 retardation films bonded to both surfaces of the polarizer, a polarizing plate wound in a roll shape with a film having a lower elastic modulus in the slow axis direction wound inside is a roll-shaped polarization Even if you cut a part from the plate and release it from the force that causes curl, the low elasticity film inside the winding with high curvature is easy to deform because of its low modulus, so it remembers large curl I guess it is because of

Schematic diagram of an obliquely stretched tenter according to an embodiment of the present invention Schematic diagram showing the basic configuration of a stereoscopic (3D) organic EL display system Schematic diagram showing a configuration example of a stereoscopic image display device

The polarizing plate wound in a roll shape of the present invention is a polarized light wound in a roll shape in which two retardation films having an in-plane retardation value Ro satisfying the formula (1) are provided on both surfaces of the polarizer. a plate, and an elongated, while the retardation film a of the retardation film and the other as a retardation film B, and when stored in the form of a roll, the retardation film (a) of the roll wound to become the inside and the elastic modulus S of each slow axis direction, respectively, S when the (a) and S (B), wherein the two so as to satisfy the formula (2) A retardation film is bonded. This feature is a technical feature common to the inventions according to claims 1 to 4 .

The embodiments of the present invention, from the viewpoint of the effect expression of the present invention, that at least one of the previous SL retardation film, contains a cellulose ester satisfying the formula (3), (1) the position Since the effect of the phase difference value expression property which satisfy | fills a phase difference value is acquired, it is preferable.

  Furthermore, in the present invention, it is also preferable that at least one of the retardation films contains a polycarbonate or a cycloolefin resin. This is because the difference in elastic modulus of the equation (2) can be made and the phase difference value of the equation (1) can also be obtained.

The polarizing plate wound into the roll shape of this invention can be comprised suitably for a display apparatus.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

(Outline of polarizing plate of the present invention)
The polarizing plate of the present invention is a polarizing plate in which two retardation films having an in-plane retardation value Ro satisfying the following formula (1) are provided on both surfaces of a polarizer, and one of the retardation films is When the retardation film A, the other is the retardation film B, and the respective elastic moduli S in the slow axis direction are S (A) and S (B), respectively, the following formula (2) is satisfied. The two retardation films are bonded to each other.
Formula (1): 100 nm ≦ Ro ≦ 160 nm
Formula (2): 100 MPa ≦ S (A) −S (B) ≦ 2000 MPa
However, the in-plane retardation value Ro is an in-plane retardation value measured with light having a wavelength of 550 nm in an environment of a temperature of 23 ° C. and a relative humidity of 55%.

  Here, the elastic modulus according to the present invention is a measured value measured by Tensilon RTA-100 manufactured by Tensile Tester Orientec Co., Ltd.

  In the present invention, when the polarizing plate is produced as a long polarizing plate and stored in a roll shape, the retardation film (A) may be wound so as to be inside the roll. It is preferable because it does not memorize a large curl.

  The polarizing plate of the present invention is manufactured by using a stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer, and laminating with a configuration of λ / 4 retardation film / polarizer / optical film. can do.

  In addition, when using the said polarizing plate for the liquid crystal display device which is a three-dimensional video display apparatus, the said (lambda) / 4 board is bonded on the visual recognition side, and when using the said polarizing plate for an organic electroluminescent display device, with the visual recognition side, Paste on the other side.

  In the present invention, it is preferable that the long retardation film is formed by laminating the long retardation film on at least one surface of the long polarizer.

  The polarizing plate of the present invention is particularly preferably used for a stereoscopic video display device or an organic EL display device. In that case, the lamination of the retardation film and the polarizer according to the present invention is preferably laminated so that the angle between the slow axis of the retardation film and the transmission axis of the polarizer is substantially 45 °. . “Substantially 45 °” means within a range of 40 ± 5 °.

  The film thickness of the polarizer is 5 to 40 μm, preferably 5 to 30 μm, and particularly preferably 5 to 20 μm.

  The polarizing plate can be produced by a general method. The retardation film of the present invention subjected to alkali saponification treatment is preferably bonded to at least one surface of a polarizer produced by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. . It is preferable to paste the optical film on the other surface.

  The polarizing plate can be constructed by further bonding a protective film on one surface of the polarizing plate and a separate film on the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection.

(Retardation film)
The retardation film according to the present invention is characterized in that it has an in-plane retardation value Ro that satisfies the formula (1).

  The in-plane retardation value Ro is obtained from the refractive index measured with light having a wavelength of 550 nm at 23 ° C. and 55% RH by the following formula.

_{Ro = (n x -n y)} × d
In the formula, _nx is the maximum refractive index in the film plane and is also referred to as the refractive index in the slow axis direction. n _y is a refractive index in a direction perpendicular to the slow axis in the film plane, also referred to as a fast axis direction of the refractive index. d represents the film thickness (nm) of the film.

  Using the refractive index, a retardation value Rt in the thickness direction is obtained from the following formula.

Rt = {(n _x + n _y ) / 2−n _z } × d
In the formula, _nz represents the refractive index in the thickness direction.

  The retardation film is used as a λ / 4 plate (Ro is about ¼ of the wavelength of visible light) that returns linearly polarized light to circularly polarized light with visible light centered at 550 nm.

  In addition, as a technique for adjusting the retardation development property of the film, there is a method using a retardation adjusting agent. Moreover, as another method, it is preferable to perform an extending | stretching process suitably. Examples of the stretching treatment capable of obtaining a large retardation value include a method of stretching in a state where the amount of residual solvent is reduced as much as possible, a method of stretching at a low temperature, a method of increasing the stretching ratio, and the like. The caulking method is effective and preferable.

  In addition, the display quality of display devices, such as a liquid crystal display device and an organic EL display device, especially front contrast can be improved, so that the haze of retardation film is small. The haze value of the retardation film according to the present invention is preferably less than 0.1%, more preferably 0.05% or less.

(Retardation film substrate)
In the retardation film according to the present invention, various thermoplastic resins can be used as a film substrate. For example, cellulose ester, polycarbonate, polyester, polyethersulfone, polyarylate, polyolefin and the like can be used. In addition, polyethylene terephthalate, polyimide, polymethyl methacrylate, polysulfone, polyethylene, polyvinyl chloride, alicyclic olefin polymer, acrylic polymer, and the like can be mentioned, among which cellulose ester is preferable.

In the present invention, at least one of the retardation films constituting the polarizing plate contains a cellulose ester satisfying the following formula (3), so that the retardation development property satisfying the retardation value of the formula (1) is satisfied. Because it has, it is preferable.
Formula (3): 0 ≦ X ≦ 1.8
However, in said formula, X represents the sum total of the substitution degree of a propionyl group or a butyryl group.

  Furthermore, in the present invention, it is also preferable that at least one of the retardation films contains a polycarbonate or a cycloolefin resin. This is because the difference in elastic modulus of equation (2) can be made and the phase difference value of equation (1) can also be obtained.

(Cellulose ester)
The retardation film according to the present invention can be produced using various resins as described above, but is preferably an embodiment containing a cellulose ester.

  The cellulose ester that can be used in the present invention is at least selected from cellulose (di, tri) acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose phthalate. One type is preferred.

  Among these, particularly preferable cellulose esters include cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate.

In the present invention, it is possible that at least one of the retardation films constituting the polarizing plate contains a cellulose ester satisfying the following formula (3) to obtain the effect of polarizing plate bonding suitability and surface processing suitability. Therefore, it is preferable.
Formula (3): 0 ≦ X ≦ 1.8
However, in said formula, X represents the sum total of the substitution degree of a propionyl group or a butyryl group.

  In the present invention, it is preferable to use a cellulose ester satisfying the above formula (3) for at least one of the retardation films constituting the polarizing plate, but for the other retardation film and the like, as the degree of substitution of the mixed fatty acid ester, In the case of having an acyl group having 2 to 4 carbon atoms as a substituent, the substitution degree X of the acetyl group and the substitution degree Y of the propionyl group or butyryl group satisfy the following formulas (4) and (5) at the same time. It is also preferable to use a cellulose ester.

Formula (4) 2.0 ≦ X + Y ≦ 3.0
Formula (5) 0 <= Y <= 1.5
(In the formulas (4) and (5), when the cellulose ester has a propionyl group and a butyryl group, Y represents the sum of the substitution degree of the propionyl group and the substitution degree of the butyryl group.)
Furthermore, the cellulose ester used in the present invention preferably has a weight average molecular weight Mw / number average molecular weight Mn ratio of 1.5 to 5.5, particularly preferably 2.0 to 5.0, Preferably it is 2.5-5.0, More preferably, the cellulose ester of 3.0-5.0 is used preferably.

  The cellulose ester raw material cellulose used in the present invention may be wood pulp or cotton linter, and the wood pulp may be softwood or hardwood, but softwood is more preferred. A cotton linter is preferably used from the viewpoint of peelability during film formation. The cellulose ester made from these can be mixed suitably or can be used independently.

  For example, the ratio of cellulose ester derived from cellulose linter: cellulose ester derived from wood pulp (coniferous): cellulose ester derived from wood pulp (hardwood) is 100: 0: 0, 90: 10: 0, 85: 15: 0, 50:50: 0, 20: 80: 0, 10: 90: 0, 0: 100: 0, 0: 0: 100, 80:10:10, 85: 0: 15, 40:30:30.

  In the present invention, 1 g of cellulose ester is added to 20 ml of pure water (electric conductivity of 0.1 μS / cm or less, pH 6.8), and the pH when stirred in a nitrogen atmosphere at 25 ° C. for 1 hr is 6 to 6. 7. It is preferable that the electric conductivity is 1 to 100 μS / cm.

  In addition, cellulose ester is industrially synthesized using sulfuric acid as a catalyst, but this sulfuric acid is not completely removed, and the remaining sulfuric acid causes various decomposition reactions during melt film formation, and is obtained. In order to affect the quality of the cellulose ester film, the residual sulfuric acid content in the cellulose ester used in the present invention is preferably in the range of 0.1 to 40 ppm in terms of elemental sulfur. These are considered to be contained in the form of salts. If the residual sulfuric acid content exceeds 40 ppm, the deposit on the die lip during heat melting increases, such being undesirable. Moreover, since it becomes easy to fracture | rupture at the time of slitting at the time of hot drawing or after hot drawing, it is not preferable. A smaller amount is preferable, but if it is less than 0.1 ppm, not only is it not preferable because the burden of the washing step of the cellulose ester becomes too large, but it is not preferable because it may easily break. This is not well understood, although an increase in the number of washings may affect the resin. Furthermore, the range of 0.1-30 ppm is preferable. The residual sulfuric acid content can be similarly measured by ASTM-D817-96.

  Further, the total residual acid amount including other (such as acetic acid) residual acids is preferably 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 100 ppm or less.

  For washing of cellulose ester, in addition to water, a poor solvent such as methanol or ethanol, or, as a result, a mixed solvent of a poor solvent and a good solvent can be used if it is a poor solvent. Organic impurities can be removed.

  In order to improve the heat resistance, mechanical properties, optical properties, etc. of cellulose ester, it can be dissolved in a good solvent of cellulose ester and then reprecipitated in a poor solvent to remove low molecular weight components and other impurities of cellulose ester. it can. Furthermore, another polymer or a low molecular weight compound may be added after the reprecipitation treatment of the cellulose ester.

  Moreover, it is preferable that the cellulose ester used by this invention is a thing with few bright spot foreign materials when it is made into a film. A bright spot foreign material is an arrangement in which two polarizing plates are arranged orthogonally (crossed Nicols), a cellulose ester film is placed between them, light from the light source is applied from one side, and the cellulose ester film is applied from the other side. This is the point where the light from the light source appears to leak when observed. At this time, the polarizing plate used for the evaluation is desirably composed of a protective film having no bright spot foreign matter, and a polarizing plate using a glass plate for protecting the polarizer is preferably used. The cause of bright spot foreign matter is considered to be one of the causes of unacetylated or low acetylated cellulose contained in cellulose ester. Use of cellulose ester with little bright spot foreign substance and filtration of molten cellulose ester or cellulose ester solution It is also possible to remove the bright spot foreign matter through the filtration step in the same manner once in the solution state in at least one of the process of synthesizing the cellulose ester and the process of obtaining the precipitate. Since the molten resin has a high viscosity, the latter method is more efficient.

(Polycarbonate resin)
Polycarbonates that can be used in the present invention are polyesters of carbonic acid and glycol or dihydric phenol, and are usually carbonic acid and 2,2′-bis (4-hydroxyphenyl) -propane (commonly called “bisphenol-A”). Aromatic polycarbonate having a structural unit as a structural unit is frequently used. However, the present invention is not limited to this, for example, 1,1-bis (4-hydroxyphenyl) -alkylcycloalkane, 1,1-bis (3-substituted-4-hydroxyphenyl) -alkylcyclohexane. At least one dihydric phenol selected from the group consisting of alkanes, 1,1-bis (3,5-substituted-4-hydroxyphenyl) -alkylcycloalkanes and 9,9-bis (4-hydroxyphenyl) fluorenes Homopolymers of polycarbonates having a monomer component, copolymer polymers having these dihydric phenols as one component, copolymer polycarbonates having the above dihydric phenol and bisphenol-A as monomer components, and mixtures of these polymers. .

  Specific examples of 1,1-bis (4-hydroxyphenyl) -alkylcycloalkane include 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4- Hydroxyphenyl) -3,3-dimethyl-5,5-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3-dimethyl-5-methylcyclopentane, and the like.

  1,1-bis (3-substituted-4-hydroxyphenyl) -alkylcycloalkane includes 1,1-bis (4-hydroxyphenyl) -alkyl substituted with an alkyl group having 1 to 12 carbon atoms or a halogen group. Cycloalkanes such as 1,1-bis (3-methyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3-ethyl-4-hydroxyphenyl) -3,3- Dimethyl-5,5-dimethylcyclohexane, 1,1-bis (3-chloro-4-hydroxyphenyl) -3,3-dimethyl-4-methylcyclohexane, 1,1-bis (3-bromo-4-hydroxyphenyl) ) -3,3-dimethyl-5-methylcyclopentane.

  As 1,1-bis (3,5-substituted-4-hydroxyphenyl) -alkylcycloalkane, 1,1-bis (4-hydroxyphenyl) substituted with an alkyl group having 1 to 12 carbon atoms or a halogen group -Alkylcycloalkanes such as 1,1-bis (3,5-dichloro-4-hydroxyphenyl) -3,3-dimethyl-5-methylcyclohexane, 1,1-bis (3-ethyl-5-methyl- 4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (3 5-dimethyl-4-hydroxyphenyl) -3,3-dimethyl-5-methylcyclopentane and the like.

  Examples of 9,9-bis (4-hydroxyphenyl) fluorenes include dihydric phenols represented by the following formula (I), such as 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis. (3-methyl-4-hydroxyphenyl) fluorene, 9,9-bis (3-ethyl-4-hydroxyphenyl) fluorene and the like.

さらに、上記以外のビスフェノール成分として、例えば２，２′−ビス（４−ヒドロキシフェニル）プロパン（ビスフェノール−Ａ）、４，４′−（α−メチルベンジリデン）ビスフェノール、ビス（４−ヒドロキシフェニル）メタン、２，２′−ビス（４−ヒドロキシフェニル）ブタン、３，３′−ビス（４−ヒドロキシフェニル）ペンタン、４，４′−ビス（４−ヒドロキシフェニル）ヘブタン、４，４′−ビス（４−ヒドロキシフェニル）２，５−ジメチルヘブタン、ビス（４−ヒドロキシフェニル）メチルフェニルメタン、ビス（４−ヒドロキシフェニル）ジフェニルメタン、２，２′−ビス（４−ヒドロキシフェニル）オクタン、ビス（４−ヒドロキシフェニル）オクタン、ビス（４−ヒドロキシフェニル）４−フルオロフェニルメタン、２，２′−ビス（３−フルオロー４−ヒドロキシフェニル）プロパン、ビス（３，５−ジメチル−４ヒドロキシフェニル）メタン、２，２′−ビス（３，５−ジメチル−４−ヒドロキシフェニル）プロパン、ビス（３，５−ジメチル−４−ヒドロキシフェニル）フェニルエタン、ビス（３−メチル−４−ヒドロキシフェニル）ジフェニルメタン等が挙げられる。これらは単独で又は二種類以上混合して用いることができる。

Further, as other bisphenol components, for example, 2,2′-bis (4-hydroxyphenyl) propane (bisphenol-A), 4,4 ′-(α-methylbenzylidene) bisphenol, bis (4-hydroxyphenyl) methane 2,2′-bis (4-hydroxyphenyl) butane, 3,3′-bis (4-hydroxyphenyl) pentane, 4,4′-bis (4-hydroxyphenyl) hebutane, 4,4′-bis ( 4-hydroxyphenyl) 2,5-dimethylhebutane, bis (4-hydroxyphenyl) methylphenylmethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2'-bis (4-hydroxyphenyl) octane, bis (4 -Hydroxyphenyl) octane, bis (4-hydroxyphenyl) 4-fluorophenyl Tan, 2,2'-bis (3-fluoro-4-hydroxyphenyl) propane, bis (3,5-dimethyl-4hydroxyphenyl) methane, 2,2'-bis (3,5-dimethyl-4-hydroxyphenyl) ) Propane, bis (3,5-dimethyl-4-hydroxyphenyl) phenylethane, bis (3-methyl-4-hydroxyphenyl) diphenylmethane and the like. These can be used alone or in admixture of two or more.

  The polycarbonates used in the present invention are particularly preferably polycarbonates composed of a repeating unit represented by the following formula (II) and a repeating unit represented by the following formula (III). These polycarbonates may be a copolymer or a mixture.

上記式（II）において、Ｒ_３〜Ｒ_１０は、それぞれ独立に、水素原子、ハロゲン原子及び炭素数１〜６の炭化水素基から選ばれる少なくとも一種の基である。かかる炭化水素基としては、メチル基、エチル基等のアルキル基、フェニル基等のアリール基が挙げられる。

In the above formula (II), R _{3 to} R ₁₀ are each independently at least one group selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group include alkyl groups such as a methyl group and an ethyl group, and aryl groups such as a phenyl group.

X is a linking group having a structure represented by the following formula. R ₁₉ and R ₂₀ are each independently at least one group selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 3 carbon atoms. Examples of the hydrocarbon group include alkyl groups such as a methyl group and an ethyl group, and aryl groups such as a phenyl group.

上記式（III）において、Ｒ_１１〜Ｒ_１８はそれぞれ独立に水素原子、ハロゲン原子及び炭素数１〜２２の炭化水素基から選ばれる少なくとも一種の基である。かかる炭化水素基としては、メチル基、エチル基等のアルキル基、フェニル基等のアリール基が挙げられる。

In the above formula (III), R _{11 to} R ₁₈ are each independently at least one group selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 22 carbon atoms. Examples of the hydrocarbon group include alkyl groups such as a methyl group and an ethyl group, and aryl groups such as a phenyl group.

  Y is at least one linking group selected from a linking group group having a structure represented by the following formula.

ここで、Ｒ_２１〜Ｒ_２３、Ｒ_２５及びＲ_２６は、それぞれ独立に、水素原子、ハロゲン原子及び炭素数１〜２２の炭化水素基から選ばれる少なくとも一種の基であり、Ｒ_２４及びＲ_２７は炭素数１〜２０の炭化水素基から選ばれる少なくとも一種の基である。炭素数１〜２２の炭化水素基としては、例えば、メチル基、エチル基等のアルキル基、フェニル基等のアリール基が挙げられる。炭素数１〜２０の炭化水素基としては、例えば、アルキレン基、アリーレン基が挙げられる。

Here, R _{21 to} R ₂₃ , R ₂₅ and R ₂₆ are each independently at least one group selected from a hydrogen atom, a halogen atom and a hydrocarbon group having 1 to 22 carbon atoms, and R ₂₄ and R _27. Is at least one group selected from hydrocarbon groups having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 22 carbon atoms include alkyl groups such as a methyl group and an ethyl group, and aryl groups such as a phenyl group. Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkylene group and an arylene group.

Ar _{1 to} Ar ₃ are each independently at least one group selected from aryl groups having 6 to 10 carbon atoms. Examples of the aryl group include a phenyl group and a naphthyl group.

  In the polycarbonates composed of the repeating units represented by the above formulas (II) and (III), the content of (II) is 50 to 70 mol% of the entire repeating units in order to have reverse dispersion characteristics. The approximate composition ratio is necessary.

  Among them, bisphenol-A is preferably used in the above formula (III), and further, a polycarbonate copolymer comprising bisphenol-A and 9,9-bis (4-hydroxyphenyl) fluorenes represented by the above formula (1) is used. The polymer is excellent in heat resistance, dimensional stability, and transparency. Furthermore, in the copolymer of bisphenol-A and 9,9-bis (4-hydroxyphenyl) fluorenes, the content of 9,9-bis (4-hydroxyphenyl) fluorenes is 60 to 70 mol%. Preferably, it is 60 to 67.5 mol%, and most preferably 60 to 65 mol%.

  The film thickness should preferably be thick to some extent for sufficient retardation and handling during processing, and the film should be thin to some extent to reduce the thickness of the display device and reduce costs. preferable. For this reason, the thickness of the film is preferably 20 μm or more and 70 μm or less, more preferably 25 μm or more and 65 μm or less, and most preferably 30 μm or more and 60 μm or less.

(Cycloolefin resin)
The cycloolefin resin that can be used in the present invention is a polymer resin having an alicyclic structure.

  A preferred cycloolefin resin is a resin obtained by polymerizing or copolymerizing cycloolefin. Examples of the cycloolefin include norbornene, dicyclopentadiene, tetracyclododecene, ethyltetracyclododecene, ethylidenetetracyclododecene, and tetracyclo [7.4.0.110, 13.02,7] trideca-2,4. Unsaturated hydrocarbons of polycyclic structures such as 6,11-tetraene and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, 3,4-dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclo Examples thereof include monocyclic unsaturated hydrocarbons such as octene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene, cycloheptene, cyclopentadiene, cyclohexadiene, and derivatives thereof. These cycloolefins may have a polar group as a substituent. Examples of the polar group include a hydroxy group, a carboxy group, an alkoxyl group, an epoxy group, a glycidyl group, an oxycarbonyl group, a carbonyl group, an amino group, an ester group, and a carboxylic acid anhydride group. Or a carboxylic anhydride group is preferred.

  Preferred cycloolefin resins may be those obtained by addition copolymerization of monomers other than cycloolefin. Addition copolymerizable monomers include ethylene, propylene, 1-butene, 1-pentene, and other ethylene or α-olefins; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl- Examples include dienes such as 1,4-hexadiene and 1,7-octadiene.

The cycloolefin resin is obtained by an addition polymerization reaction or a metathesis ring-opening polymerization reaction. The polymerization is carried out in the presence of a catalyst. Examples of the addition polymerization catalyst include a polymerization catalyst composed of a vanadium compound and an organoaluminum compound. As a catalyst for ring-opening polymerization, a polymerization catalyst comprising a metal halide such as ruthenium, rhodium, palladium, osmium, iridium, platinum, nitrate or acetylacetone compound, and a reducing agent; or titanium, vanadium, zirconium, tungsten, molybdenum And a polymerization catalyst comprising an acetylacetone compound and an organoaluminum compound. The polymerization temperature, pressure and the like are not particularly limited, but the polymerization is usually carried out at a polymerization temperature of −50 ° C. to 100 ° C. and a polymerization pressure of 0 to 490 N / cm ² .

  The cycloolefin resin used in the present invention is preferably a resin obtained by polymerizing or copolymerizing cycloolefin and then hydrogenating it to change the unsaturated bond in the molecule to a saturated bond. The hydrogenation reaction is performed by blowing hydrogen in the presence of a known hydrogenation catalyst. Examples of hydrogenation catalysts include cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, transition metal compounds such as titanocene dichloride / n-butyllithium, zirconocene dichloride / sec-butyllithium, tetrabutoxytitanate / dimethylmagnesium / alkyl. Homogeneous catalyst consisting of a combination of metal compounds; heterogeneous metal catalyst such as nickel, palladium, platinum; nickel / silica, nickel / diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth And a heterogeneous solid-supported catalyst in which a metal catalyst such as palladium / alumina is supported on a carrier.

  Or the following norbornene-type polymer is also mentioned as a cycloolefin resin. The norbornene-based polymer preferably has a norbornene skeleton as a repeating unit. Specific examples thereof include JP-A-62-252406, JP-A-62-2252407, and JP-A-2-133413. JP-A-63-145324, JP-A-63-264626, JP-A-1-240517, JP-B-57-8815, JP-A-5-39403, JP-A-5-43663 JP-A-5-43834, JP-A-5-70655, JP-A-5-279554, JP-A-6-206985, JP-A-7-62028, JP-A-8-176411, Although what was described in the Kaihei 9-241484 gazette etc. can be utilized preferably, it is not limited to these. Moreover, these may be used individually by 1 type and may use 2 or more types together.

  In the present invention, among the norbornene-based polymers, those having a repeating unit represented by any of the following structural formulas (I) to (IV) are preferable.

前記構造式（Ｉ）〜（IV）中、Ａ、Ｂ、Ｃ及びＤは、各々独立して、水素原子又は１価の有機基を表す。

In the structural formulas (I) to (IV), A, B, C and D each independently represent a hydrogen atom or a monovalent organic group.

  Among the norbornene-based polymers, a polymer obtained by metathesis polymerization of at least one compound represented by the following structural formula (V) or (VI) and an unsaturated cyclic compound copolymerizable therewith is provided. A hydrogenated polymer obtained by hydrogenation is also preferred.

前記構造式中、Ａ、Ｂ、Ｃ及びＤは、各々独立して、水素原子又は１価の有機基を表す。

In the structural formula, A, B, C and D each independently represent a hydrogen atom or a monovalent organic group.

  Here, A, B, C and D are not particularly limited, but preferably an organic group may be linked through a hydrogen atom, a halogen atom, a monovalent organic group, or at least a divalent linking group. These may be the same or different. A or B and C or D may form a monocyclic or polycyclic structure. Here, the at least divalent linking group includes a hetero atom typified by an oxygen atom, a sulfur atom, and a nitrogen atom, and examples thereof include ether, ester, carbonyl, urethane, amide, thioether, and the like. It is not limited. In addition, the organic group may be further substituted via the linking group.

  Examples of other monomers copolymerizable with the norbornene-based monomer include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, C2-C20 alpha olefins, such as 1-hexadecene, 1-octadecene, 1-eicocene, and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, cyclooctene, 3a, 5,6,7a-tetrahydro-4,7 -Cycloolefins such as methano-1H-indene, and derivatives thereof; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene, etc. Conjugated dienes; and the like are used. Among these, an α-olefin, particularly ethylene is preferable.

  These other monomers copolymerizable with the norbornene-based monomer can be used alone or in combination of two or more. In the case of addition copolymerization of a norbornene monomer and another monomer copolymerizable therewith, the ratio of the structural unit derived from the norbornene monomer and the structural unit derived from the other monomer copolymerizable in the addition copolymer However, it is appropriately selected so that the mass ratio is usually 30:70 to 99: 1, preferably 50:50 to 97: 3, more preferably 70:30 to 95: 5.

  When the unsaturated bond remaining in the molecular chain of the synthesized polymer is saturated by a hydrogenation reaction, the hydrogenation rate is 90% or more, preferably 95% or more, particularly from the viewpoint of light resistance deterioration, weather resistance deterioration, etc. Preferably it is 99% or more.

  In addition, examples of the cycloolefin resin used in the present invention include thermoplastic saturated norbornene resins described in paragraph Nos. [0014] to [0019] of JP-A-5-2108, and paragraph Nos. [0015] of JP-A-2001-277430. ] To [0031] thermoplastic norbornene polymers, JP 2003-14901 paragraph Nos. [0008] to [0045] thermoplastic norbornene resins, JP 2003-139950 paragraph Nos. [0014] to [0028] Norbornene-based resin composition, paragraph Nos. [0029] to [0037] described in JP-A No. 2003-161832, paragraph Nos. [0027] to [0036] described in JP-A No. 2003-195268 Norbornene resin, Japanese Patent Application Laid-Open No. 2003-211589 Paragraph numbers [0009] to [0023] alicyclic structure-containing polymer resin, norbornene polymer resin or vinyl alicyclic hydrocarbon polymer described in JP-A-2003-212588, paragraph numbers [0008] to [0024] Resin etc. are mentioned.

  Specifically, ZEONEX, ZEONOR manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Corporation, APPEL manufactured by Mitsui Chemicals, Inc. (APL8008T, APL6509T, APL6013T, APL5014DP, APL6015T) and the like are preferably used.

  The molecular weight of the cycloolefin resin used in the present invention is appropriately selected according to the purpose of use, but was measured by a gel permeation chromatographic method of a cyclohexane solution (a toluene solution when the polymer resin does not dissolve). When the polyisoprene or polystyrene-equivalent weight average molecular weight is usually in the range of 5,000 to 500,000, preferably 8,000 to 200,000, more preferably 10,000 to 100,000, the mechanical strength and molding processability of the molded body are high. Balanced and suitable.

  There is no particular limitation on the method for forming the cycloolefin resin film, and either a hot melt molding method or a solution casting method can be used. The heat-melt molding method can be further classified into an extrusion molding method, a press molding method, an inflation molding method, an injection molding method, a blow molding method, a stretch molding method, etc. Among these methods, mechanical strength, surface accuracy are included. In order to obtain an excellent film, an extrusion molding method, an inflation molding method, and a press molding method are preferable, and an extrusion molding method is most preferable. The molding conditions are appropriately selected depending on the purpose of use and the molding method. In the case of the hot melt molding method, the cylinder temperature is usually in the range of 150 to 400 ° C, preferably 200 to 350 ° C, more preferably 230 to 330 ° C. Is set as appropriate.

(Plasticizer)
To the retardation film according to the present invention, a compound known as a so-called plasticizer may be added for the purpose of improving mechanical properties, imparting flexibility, imparting water absorption resistance, reducing water vapor permeability, adjusting retardation, and the like. Preferably, for example, phosphate ester or carboxylic acid ester is used.

  The plasticizer is preferably contained in the cellulose ester film in an amount of 1 to 40% by mass, particularly 1 to 30% by mass.

  Examples of phosphate esters include triphenyl phosphate, tricresyl phosphate, phenyl diphenyl phosphate, and the like.

  Examples of the carboxylic acid ester include phthalic acid ester and citric acid ester. Examples of the phthalic acid ester include dimethyl phthalate, diethyl phosphate, dioctyl phthalate, and diethyl hexyl phthalate. Examples of the citrate ester include acetyl triethyl citrate and acetyl citrate. Mention may be made of tributyl. Other examples include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and triacetin. Alkylphthalylalkyl glycolates are also preferably used for this purpose. The alkyl in the alkylphthalylalkyl glycolate is an alkyl group having 1 to 8 carbon atoms. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl glycolate, Ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, propyl phthalyl ethyl glycolate, methyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl Phthalyl ethyl glycolate, propyl phthalyl butyl glycolate, butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl Collate, octyl phthalyl methyl glycolate, octyl phthalyl ethyl glycolate and the like can be mentioned, such as methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, Octyl phthalyl octyl glycolate is preferably used. These alkyl phthalyl alkyl glycolates may be used in combination of two or more.

  In addition, citrate plasticizers of the following compounds (CAE-1) to (CAE-3) described in Japanese Patent No. 3793184 can also be used as the plasticizer.

また、多価アルコールエステルも用いることができる。

Polyhydric alcohol esters can also be used.

  The polyhydric alcohol used in the retardation film of the present invention is represented by the following general formula (1).

Formula (1): R _1- (OH) _n
However, R ₁ represents an n-valent organic group, n represents a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxy group (hydroxyl group).

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol and the like. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  There is no restriction | limiting in particular as monocarboxylic acid used for polyhydric alcohol ester, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, or derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Although the specific compound of the polyhydric alcohol ester plasticizer used for this invention is shown below, this invention is not limited to this.

また、多価アルコールとして糖を用いた、下記一般式（２）で表される糖エステルも用いることができる。以下に一般式（２）で表される糖エステルの化合物例も示す。

Moreover, the sugar ester represented by the following general formula (2) using sugar as a polyhydric alcohol can also be used. Examples of the sugar ester compound represented by the general formula (2) are also shown below.

In General Formula (2), R _{1 to} R ₈ each independently represent a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group, or a substituted or unsubstituted arylcarbonyl group, and R _{1 to} R ₈ are mutually May be the same or different. In addition, the substituent described in the following table represents any one of R _{1 to} R ₈ . As the substituent for the alkylcarbonyl group and the arylcarbonyl group, substituents such as a phenyl group and an alkoxy group included in the alkylcarbonyl group and the arylcarbonyl group shown in the following table are preferable.

（一般式（２）で表される化合物の合成例）

撹拌装置、還流冷却器、温度計及び窒素ガス導入管を備えた四頭コルベンに、ショ糖３４．２ｇ（０．１モル）、無水安息香酸１８０．８ｇ（０．８モル）、ピリジン３７９．７ｇ（４．８モル）を仕込み、撹拌下に窒素ガス導入管から窒素ガスをバブリングさせながら昇温し、７０℃で５時間エステル化反応を行った。次に、コルベン内を４×１０^２Ｐａ以下に減圧し、６０℃で過剰のピリジンを留去した後に、コルベン内を１．３×１０Ｐａ以下に減圧し、１２０℃まで昇温させ、無水安息香酸、生成した安息香酸の大部分を留去した。そして、次にトルエン１Ｌ、０．５質量％の炭酸ナトリウム水溶液３００ｇを添加し、５０℃で３０分間撹拌後、静置して、トルエン層を分取した。最後に、分取したトルエン層に水１００ｇを添加し、常温で３０分間水洗後、トルエン層を分取し、減圧下（４×１０^２Ｐａ以下）、６０℃でトルエンを留去させ、化合物Ａ−１、Ａ−２、Ａ−３、Ａ−４及びＡ−５の混合物を得た。得られた混合物をＨＰＬＣ及びＬＣ−ＭＡＳＳで解析したところ、Ａ−１が７質量％、Ａ−２が５８質量％、Ａ−３が２３質量％、Ａ−４が９質量％、Ａ−５が３質量％であった。なお、得られた混合物の一部をシリカゲルを用いたカラムクロマトグラフィーにより精製することで、それぞれ純度１００％のＡ−１、Ａ−２、Ａ−３、Ａ−４及びＡ−５を得た。

(Synthesis example of the compound represented by the general formula (2))

A four-headed colben equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas inlet tube was mixed with 34.2 g (0.1 mol) of sucrose, 180.8 g (0.8 mol) of benzoic anhydride, 379. 7 g (4.8 mol) was charged, the temperature was raised while bubbling nitrogen gas from a nitrogen gas introduction tube with stirring, and an esterification reaction was carried out at 70 ° C. for 5 hours. Next, the inside of the Kolben was depressurized to 4 × 10 ² Pa or less, and after excess pyridine was distilled off at 60 ° C., the inside of the Kolben was depressurized to 1.3 × 10 Pa or less and the temperature was raised to 120 ° C. Most of the acid and benzoic acid formed were distilled off. Then, 1 L of toluene and 300 g of a 0.5% by mass aqueous sodium carbonate solution were added, and the mixture was stirred at 50 ° C. for 30 minutes and then allowed to stand to separate a toluene layer. Finally, 100 g of water is added to the collected toluene layer, and after washing with water at room temperature for 30 minutes, the toluene layer is separated, and toluene is distilled off at 60 ° C. under reduced pressure (4 × 10 ² Pa or less). A mixture of A-1, A-2, A-3, A-4 and A-5 was obtained. When the obtained mixture was analyzed by HPLC and LC-MASS, A-1 was 7% by mass, A-2 was 58% by mass, A-3 was 23% by mass, A-4 was 9% by mass, A-5. Was 3% by mass. A part of the obtained mixture was purified by column chromatography using silica gel to obtain A-1, A-2, A-3, A-4 and A-5 having a purity of 100%, respectively. .

  The total average degree of substitution of the sugar ester represented by the general formula (2) is preferably 6.1 to 6.9, and the range of the degree of substitution is particularly preferably 4.0 to 8.0. The substitution degree distribution may be adjusted to the desired substitution degree by adjusting the esterification reaction time or mixing compounds having different substitution degrees.

  It is preferable that these compounds are contained so that it may become 1-30 mass% with respect to a cellulose ester, Preferably it is 1-20 mass%. In order to suppress bleeding out during stretching and drying, a compound having a vapor pressure at 200 ° C. of 1400 Pa or less is preferable.

  These compounds may be added together with the cellulose ester or the solvent during the preparation of the cellulose ester solution, or may be added during or after the solution preparation.

  As the plasticizer, it is particularly preferable to use an aromatic terminal ester plasticizer represented by the following general formula (3).

General formula (3): B- (GA) _n -GB
(In the formula, B is a benzene monocarboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms, A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.)
The aromatic terminal ester plasticizer represented by the general formula (3) includes a benzene monocarboxylic acid residue represented by B and an alkylene glycol residue, oxyalkylene glycol residue or aryl glycol residue represented by G, A And is obtained by a reaction similar to that of a normal polyester plasticizer.

  Examples of the benzene monocarboxylic acid component of the aromatic terminal ester plasticizer used in the present invention include, for example, benzoic acid, para-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, There are normal propyl benzoic acid, aminobenzoic acid, acetoxybenzoic acid and the like, and these can be used as one kind or a mixture of two or more kinds, respectively.

  Examples of the alkylene glycol component having 2 to 12 carbon atoms of the aromatic terminal ester plasticizer used in the present invention include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, , 3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2 , 2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3propanediol (3,3-dimethylolheptane), 3-methyl- 1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl 1 There are 3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc., and these glycols are one kind or two or more kinds. Used as a mixture.

  Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the aromatic terminal ester include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, and the like. It can be used as a mixture of two or more.

  Examples of the aryl glycol component having 6 to 12 carbon atoms of the aromatic terminal ester include hydroquinone, resorcin, bisphenol A, bisphenol F, and bisphenol, and these glycols are used as one kind or a mixture of two or more kinds. it can.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic terminal ester include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. These are used as one kind or a mixture of two or more kinds. Examples of the aryl dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and the like.

  The aromatic terminal ester plasticizer has a number average molecular weight of preferably 300 to 2000, more preferably 480 to 1500. The acid value is 0.5 mgKOH / g or less, the hydroxy (hydroxyl group) value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less, and the hydroxy (hydroxyl group) value is 15 mgKOH / g or less. Is preferred.

  Hereinafter, synthesis examples of the aromatic terminal ester plasticizer will be described.

<Sample No. 1 (Aromatic terminal ester sample)>
Into a reaction vessel, 820 parts (5 moles) of phthalic acid, 608 parts (8 moles) of 1,2-propylene glycol, 610 parts (5 moles) of benzoic acid and 0.30 parts of tetraisopropyl titanate as a catalyst are charged all at once. While stirring in an air stream, a reflux condenser was attached to reflux excess monohydric alcohol, and heating was continued at 130 to 250 ° C. until the acid value became 2 or less, and water produced was continuously removed. Next, the distillate is removed under reduced pressure of 6.65 × 10 ³ Pa and finally 4 × 10 ² Pa or less at 200 to 230 ° C., and then filtered to obtain an aromatic terminal ester having the following properties. It was.

Viscosity (25 ° C., mPa · s); 19815
Acid value: 0.4
<Sample No. 2 (Aromatic terminal ester sample)>
A sample was used except that 500 parts (3.5 moles) of adipic acid, 305 parts (2.5 moles) of benzoic acid, 583 parts (5.5 moles) of diethylene glycol, and 0.45 parts of tetraisopropyl titanate as a catalyst were used in the reaction vessel. No. In the same manner as in No. 1, an aromatic terminal ester having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 90
Acid value: 0.05
<Sample No. 3 (Aromatic terminal ester sample)>
Sample No. except that 410 parts (2.5 moles) of phthalic acid, 610 parts (5 moles) of benzoic acid, 737 parts (5.5 moles) of dipropylene glycol and 0.40 parts of tetraisopropyl titanate as the catalyst were used in the reaction vessel. . In the same manner as in No. 1, an aromatic terminal ester plasticizer having the following properties was obtained.

Viscosity (25 ° C., mPa · s); 43400
Acid value: 0.2
Below, the specific compound of the aromatic terminal ester plasticizer used for this invention is shown.

（紫外線吸収剤）
本発明に係る位相差フィルムには、紫外線吸収剤を含有させることができる。外線吸収剤はフィルムが太陽光の照射により黄色に着色するのを防止することができる。また、偏光板保護フィルムとして本発明に係る位相差フィルムを使用した場合、太陽光による偏光子の色素破壊を防止することができる。また、本発明に係る位相差フィルムを液晶表示装置に使用した場合、カラーフィルターが太陽光により褪色するのを防止することができる。

(UV absorber)
The retardation film according to the present invention can contain an ultraviolet absorber. The external line absorbent can prevent the film from being colored yellow by irradiation with sunlight. Moreover, when the retardation film which concerns on this invention is used as a polarizing plate protective film, the pigment | dye destruction of the polarizer by sunlight can be prevented. In addition, when the retardation film according to the present invention is used in a liquid crystal display device, the color filter can be prevented from fading due to sunlight.

  Examples of ultraviolet absorbers that can be used include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, triazine compounds, and the like. A benzotriazole-based compound with little coloring is preferable. Further, ultraviolet absorbers described in JP-A-10-182621, JP-A-8-337574, JP-A-2001-72782, JP-A-6-148430, JP-A-2002-31715, JP-A-2002-169020, 2002-2002. Polymer ultraviolet absorbers described in 47357, 2002-363420, and 2003-113317 are also preferably used. As an ultraviolet absorber, from the viewpoint of preventing the deterioration of polarizers and liquid crystals, it is excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less, and from the viewpoint of liquid crystal display properties, the absorption of visible light having a wavelength of 400 nm or more is small. Is preferred.

  Specific examples of UV absorbers 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-butylphenyl)- 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'- ert-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-5- (5 -Chloro-2H-benzotriazol-2-yl) phenyl] propionate and the like can be mentioned, but not limited thereto. As commercially available products, TINUVIN 109, TINUVIN 171 and TINUVIN 326 (all manufactured by BASF Japan) can be preferably used. An example of the polymeric ultraviolet absorber is a reactive ultraviolet absorber RUVA-93 manufactured by Otsuka Chemical Co., Ltd.

  Specific examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy- 5-benzoylphenylmethane) and the like, but is not limited thereto.

  The ultraviolet absorber described above preferably used in the present invention is preferably a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber, which has high transparency and is excellent in the effect of preventing the deterioration of the polarizing plate and the liquid crystal element, and unnecessary coloring. A benzotriazole-based ultraviolet absorber with a lower content is particularly preferably used.

  The ultraviolet absorber can be added to the dope without limitation as long as it dissolves the ultraviolet absorber in the dope. In the present invention, the ultraviolet absorber is cellulose such as methylene chloride, methyl acetate, dioxolane and the like. Dope by dissolving in a good solvent for the ester, or a mixed solvent of a good solvent and a poor solvent such as a lower aliphatic alcohol (methanol, ethanol, propanol, butanol, etc.) and adding it to the cellulose ester solution as an ultraviolet absorber solution Is preferred. In this case, it is preferable to make the dope solvent composition and the solvent composition of the ultraviolet absorber solution the same or as close as possible. The content of the ultraviolet absorber is 0.01 to 5% by mass, particularly 0.5 to 3% by mass.

(Method for producing retardation film)
Hereinafter, as a typical example, a method for producing a retardation film using a cellulose ester will be described.

  The apparatus for producing the retardation film may be a solution casting apparatus using a casting band whose surface is mirror-finished or a solution casting apparatus using a casting drum.

<Extension>
In the present invention, it is preferable to stretch the cast dope in order to produce a retardation film of cellulose ester. Here, “dope” refers to a solution in which cellulose ester and other additives are dissolved.

  The stretching direction when stretching the dope after drying may be any of the film transport direction, the direction orthogonal to the transport direction, and the direction oblique to the transport direction. Since an elongate polarizing plate can be manufactured by roll-to-roll, the stretching in the oblique direction is preferable.

  In order to obtain an in-plane retardation value Ro (measured with light having a wavelength of 550 nm) of 128 to 148 nm, the stretching ratio is preferably 50 to 250%. As for the temperature of the film at the time of extending | stretching, 140-220 degreeC is preferable.

<Slant stretching>
Stretching of the film in the oblique direction is performed by the gripping means after stretching in the oblique direction so as to have an in-plane slow axis at an angle within a range of 10 to 45 ° with respect to the transport direction of the long retardation film. It is preferable to stretch the both ends of the film at an angle in the range of −90 to −70 ° with respect to the transport direction and at a stretch ratio in the range of 0 to 20%.

  In the present application, the “long shape” means a film having a length of at least about 5 times the width of the film, preferably a length of 10 times or more, specifically a roll. It can be a film roll having a length that can be stored or transported by being wound into a shape.

  In the manufacturing method of a long film, a film can be manufactured to desired length by manufacturing a film continuously. In addition, the manufacturing method of a stretched film may be wound around the core once after film formation, and may be supplied to the oblique stretching step after forming the wound body, or the film may be formed without winding up the film after film formation. You may supply to the diagonal stretch process continuously from the process. It is preferable to continuously perform the film forming step and the oblique stretching step because the film forming conditions can be changed by feeding back the film thickness after stretching and the results of optical values to obtain a desired stretched film.

  The angle (θ) formed by the film transport direction and the in-plane slow axis is more preferably 20 to 40 °, and still more preferably 25 to 35 °.

  After stretching in an oblique direction so as to have an in-plane slow axis at an angle in the range of 10 to 45 ° with respect to the transport direction of the long retardation film, both ends of the film are moved in the transport direction by gripping means. On the other hand, stretching and streaking can be prevented by stretching at an angle in the range of -90 to -70 ° and at a stretch ratio in the range of 0 to 20%.

  In FIG. 1, the schematic diagram of an example of the tenter which can be extended | stretched diagonally used for the manufacturing method of the elongate stretched film which concerns on this embodiment is shown.

  The long film original fabric 1 whose direction is controlled by the guide roller 9-1 on the tenter entrance side has a gripping tool (clip gripper) at the positions of the outer film holding start point 5-1 and the inner film holding start point 5-2. It is also gripped by.

  The pair of left and right film grippers are transported and stretched at an equal speed with each other in the oblique direction indicated by the trajectory 4-1 of the outer film gripping means and the trajectory 4-2 of the inner film gripping means by the oblique stretching tenter 3; The gripping is released by the outer film gripping end point 6-1 and the inner film gripping end point 6-2, and the conveyance is controlled by the guide roller 9-2 on the tenter outlet side, whereby the obliquely stretched film 2 is formed. In the drawing, the long film original is obliquely stretched at an angle (feeding angle θi) in the film stretching direction 11-2 with respect to the film feeding direction 11-1.

  In FIG. 1, the traveling speed of the gripping tool can be appropriately selected, but is usually 1 to 100 m / min. The phrase “the pair of left and right film grippers are at the same speed” means that the difference in travel speed between the pair of left and right grippers is substantially 1% or less of the travel speed.

(Fine particles)
The retardation film according to the present invention preferably contains fine particles having a volume average particle diameter of 0.01 μm or more and 1 μm or less. When the volume average particle diameter is 0.01 μm or more, the retardation film has moderate slipperiness and can prevent scratches that occur when winding. Haze can be suppressed low by being 1 micrometer or less.

  As the fine particles, it is preferable to use an inorganic compound. Examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate And calcium phosphate. Silicon dioxide, titanium dioxide and zirconium oxide are preferred, and silicon dioxide is particularly preferred. The fine particles of the inorganic compound can introduce a methyl group to the particle surface by surface treatment. For example, silicon oxide fine particles may be treated with dichlorodimethylsilane or bis (trimethylsilyl) amine.

  Silicon dioxide fine particles are already commercially available (eg, Aerosil R972, R972D, R974, R812, manufactured by Nippon Aerosil Co., Ltd.). There are also commercially available zirconium oxide microparticles (eg, Aerosil R976, R811, manufactured by Nippon Aerosil Co., Ltd.). The volume average particle diameter of the fine particles is preferably 0.1 to 1.0 μm, and more preferably 0.1 to 0.5 μm.

  The volume average particle diameter can be measured by a laser diffraction scattering method. For example, it can be measured using LS13320 manufactured by Beckman Coulter. The measurement is carried out by dispersing in an organic solvent, but it is preferable to carry out the measurement with the same composition as the solvent composition for film formation.

  It is preferable to adjust the surface roughness on the air side of a film formed by casting on a casting band or a casting drum to 1.0 to 3.0 nm by adding the fine particles. If the surface roughness is 1.0 nm or more, even when wound on a roll, it is difficult to be damaged, and if the surface roughness is 3.0 nm or less, haze of the film can be suppressed.

<Liquid crystal display device>
In the present invention, a liquid crystal display in which a sheet-like film formed by cutting a long retardation film or a sheet-like polarizing plate formed by cutting the long polarizing plate is provided. It can be a device. For example, the liquid crystal display device according to the present invention can be produced by using the liquid crystal display device in which the polarizing plate of the present invention is bonded to the surface on the viewing side of the liquid crystal cell.

  The polarizing plate according to the present invention is a reflective, transmissive, transflective LCD, or super twisted nematic (STN) mode, twisted nematic (TN) mode, in-plane switching (IPS) mode, vertical alignment (VA) mode. The liquid crystal display device is preferably used in a liquid crystal display device in an optically aligned birefringence (OCB) mode and a hybrid aligned nematic (HAN) mode.

  In the present invention, in particular, the liquid crystal display device is preferably a stereoscopic image display device or an organic EL display device.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
[Method for producing λ / 4 retardation film A-1]
Method for producing cellulose ester film (fine particle dispersion 1)
Fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.) 11 parts by weight Ethanol 89 parts by weight The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.

(Fine particle addition liquid 1)
The fine particle dispersion 1 was slowly added to the dissolution tank containing methylene chloride with sufficient stirring. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution 1.

Methylene chloride 99 parts by mass Fine particle dispersion 1 5 parts by mass A main dope having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose acetate C was added to a pressure dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope was prepared by filtration using 244.

<Composition of main dope>
Methylene chloride 340 parts by mass Ethanol 64 parts by mass Cellulose ester (cellulose acetate propionate: acetyl group substitution degree 1.5, propionyl group 0.9, total substitution degree 2.4
Weight average molecular weight 190000) 100 parts by mass Sugar ester compound (2-22) 7.0 parts by mass Polyester A 2.5 parts by mass TINUVIN 928 (manufactured by BASF Japan) 1.5 parts by mass Fine particle additive solution 1 1 part by mass Next, endless Using the belt casting apparatus, the obtained dope was uniformly cast on a stainless steel belt support at a temperature of 33 ° C. and a width of 2000 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

  The solvent is evaporated until the residual solvent amount in the cast (cast) film reaches 75% on the stainless steel belt support, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m. Was made.

  The produced raw film was stretched in an oblique direction using the apparatus of FIG. 1 at a temperature of 185 ° C. and a magnification of 1.6 times so that the slow axis was 45 ° with the film width direction.

  Next, drying was terminated while the drying zone was conveyed by a number of rolls. The drying temperature was 130 ° C. and the transport tension was 100 N / m.

  As described above, a retardation film A-1 having a dry film thickness of 40 μm was obtained.

<< Production Example 1: Method for producing retardation film B-1 >>
It was produced with reference to the description in paragraphs [0077] to [0078] of Japanese Patent Application Laid-Open No. 2010-204224.

  That is, pellets of the thermoplastic resin P1 (trade name “ZEONOR 1420”, manufactured by Nippon Zeon Co., Ltd., norbornene resin) are melted by an extruder and supplied to an extrusion die to form an original film.

  Next, the original film was obliquely stretched with a tenter stretching machine at a stretching temperature of 147 ° C. and a stretching ratio of 2.1 times so that the slow axis was inclined at 45 ° with respect to the longitudinal direction. An olefin resin film is obtained.

[Production of circularly polarizing plate]
A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times).

  This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide, and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid, and 100 g of water. This was washed with water and dried to obtain a polarizer.

  Film A-1 and film B-1 were bonded to one side of the polarizer using a completely saponified polyvinyl alcohol 5% aqueous solution as an adhesive. At that time, bonding was performed such that the transmission axis of the polarizer and the slow axis of the λ / 4 retardation film were 45 degrees.

  Next, after coating on the other surface where the film A-1 is not bonded to the retardation film B-1 coated with an acrylic adhesive, the circularly polarizing plate of the present invention is attached to a polarizer. Produced.

  At this time, at least one of the polarizer, the film A-1 and the film B-1 is a long film of 1000 m or more wound on a roll, and the produced circularly polarizing plate is also in a long roll state. .

  As a result of evaluating the curl of the produced circularly polarizing plate, there was no curl and the performance was satisfactory.

  The method for making the circularly polarizing plate and the method for evaluating the curl are the same as in Example 1 thereafter.

(Example 2)
<< Production Example 2: Method for producing retardation film B-2 and circularly polarizing plate >>
According to Example 1 described in the column of [Example] of the specification of Japanese Patent No. 4681334, that is, according to the method described in paragraphs [0085] to [0086], the retardation film B -2 was produced.

  That is, a sodium hydroxide aqueous solution and ion-exchanged water are charged into a reaction apparatus equipped with a stirrer, a thermometer, and a reflux condenser, and bisphenol A and biscresol fluorene are dissolved at a ratio of 36:64 (mol%), and a small amount Of hydrosulfide was added.

  Next, methylene chloride was added thereto, and phosgene was blown in at about 20 ° C. over about 60 minutes. Further, p-tert-butylphenol was added for emulsification, triethylamine was added, and the mixture was stirred at 30 ° C. for about 3 hours to complete the reaction. After completion of the reaction, the organic phase was collected, and methylene chloride was evaporated to obtain a copolymerized polycarbonate. The composition ratio of the obtained copolymer polycarbonate was almost equal to the amount of monomer charged.

  The polymer had a glass transition temperature (Tg) of 223 ° C. and a photoelastic constant of 43 Brewster.

  This copolymer polycarbonate was dissolved in methylene chloride to prepare an 18% by mass dope solution. This dope solution was cast on a steel drum, which was continuously peeled off and dried, and this was subjected to longitudinal uniaxial stretching of 2.2 times in the longitudinal direction at 228 ° C. with a roll stretching machine. The thickness of the obtained longitudinally uniaxially stretched film was 50 μm, and the residual solvent amount was 0.2% by mass. Further, as shown in Table 3, the optical properties of the film were Ro (550) = 138 nm and Rt (550) = 70 nm.

  A circularly polarizing plate was produced in the same manner as in Example 1 using the obtained film B-2 and the film A-1 produced in Example 1.

(Example 3)
[Lambda / 4 retardation film A-2 and method for producing circularly polarizing plate]
<Composition of main dope>
Cellulose acetate having an acetyl group substitution degree of 2.4 (weight average molecular weight 190,000) 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Methylene chloride (first solvent) 336 parts by mass Methanol (second solvent) 30 parts by mass UV absorber (Tinuvin 928 (manufactured by BASF Japan))
2.3 parts by mass Particulate additive solution 1 1 part by mass (preparing a retardation value increasing agent solution)
The following materials were put into another mixing tank and stirred while heating to prepare a phase difference value increasing agent solution.

Compound A 14 parts by mass Compound B 12 parts by mass Methylene chloride 92 parts by mass Methanol 8 parts by mass The cellulose acetate solution 474 parts by mass was mixed with 25 parts by mass of the retardation value increasing agent solution, and sufficiently stirred to prepare a dope.

  The λ / 4 retardation film may be abbreviated as a retardation film or simply a film.

  Next, using an endless belt casting apparatus, the obtained dope was uniformly cast on a stainless steel belt support at a temperature of 33 ° C. and a width of 2000 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

  The solvent is evaporated until the residual solvent amount in the cast (cast) film reaches 75% on the stainless steel belt support, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m. Was made.

  Except changing the produced raw film into the extending | stretching conditions of Table 2, it extended | stretched by the method similar to retardation film A-1 of Example 1, and produced film A-2.

  A circularly polarizing plate was produced in the same manner as in Example 1 using the obtained retardation film A-2 and the retardation film B-1 produced in Example 1.

Example 4
In Example 3, a circularly polarizing plate was produced in the same manner as in Example 3 except that the film B-1 was changed to the film B-2.

(Example 5)
[Lambda / 4 retardation film A-3 and method for producing circularly polarizing plate]
When producing retardation film A-2 in Example 3, film A-3 is produced in the same manner as A-2, except that the substitution degree of cellulose ester used for the main dope is changed as shown in Table 2. did.

  Thereafter, a circularly polarizing plate was produced in the same manner except that the retardation film A-1 used in Example 3 was changed to A-3.

(Examples 6 and 7)
[Λ / 4 Retardation Films A-4 and 5 and Method for Producing Circular Polarizing Plate]
When producing retardation film A-1 in Example 1, films A-4 and 5 were prepared in the same manner as A-1, except that the addition amount of the sugar ester used for the main dope was changed as shown in Table 2. Manufactured.

  Thereafter, a circularly polarizing plate was produced in the same manner except that the retardation film A-1 used in Example 1 was changed to A-4 and 5.

(Examples 8, 9, and 10)
[Lambda / 4 Retardation Films A-6, 7, 8 and Method for Producing Circular Polarizing Plate]
When producing retardation film A-1 in Example 1, retardation films A-6, 7, and 8 were produced in the same manner as A-1, except that the stretching conditions were changed as shown in Table 2. .

  Thereafter, a circularly polarizing plate was produced in the same manner except that the retardation film A-1 used in Example 1 was changed to A-6, 7, and 8.

  When the curl of the long roll-shaped circularly polarizing plate produced in the above Examples 1 to 10 was evaluated, a good circularly polarizing plate without curl was obtained.

(Comparative Examples 1, 2, and 3)
[Method for Producing λ / 4 Retardation Films C-1 and 2]
Retardation films C-1 and C-2 were produced in the same manner as in Examples 1 and 2, except that the substitution degree of the cellulose ester used for the main dope in Example 1 was changed as shown in Table 2.

  Since the retardation films C-1 and C-2 produced in Comparative Examples 1 and 2 have a high propionyl group substitution degree, the axial elastic modulus is lowered. Therefore, the evaluation of the curl was inferior.

[Production method of λ / 4 retardation film C-3]
In the production of the retardation film A-2 in Example 3, the retardation film C-3 was prepared in the same manner except that the substitution degree of the cellulose ester used in the main dope was changed to the cellulose ester having the value shown in Table 2. Produced.

  As shown in Table 2, it can be seen that the retardation film C-3 has a very high axial stretch ratio. This is probably because the cellulose ester used has a propionyl group substitution degree of 0 and a high acetyl group substitution degree.

  In Example 1, when evaluating the curl of the long roll-shaped circularly polarizing plate produced by changing the retardation film A-1 to the retardation film C-3, there was no curl, but the retardation Curling occurred on the film B-1 side.

(Comparative Example 4)
A circularly polarizing plate was produced in the same manner as in Example 1 except that the addition amount of the sugar ester compound used in the main dope in Example 1 was changed as shown in Table 2.

(Comparative Examples 5 and 6)
When winding the long circularly polarizing plate produced in Examples 1 and 2 in a roll shape, it is the same as Example 1 except that the film A-1 is wound outside and the films B-1 and B2 are wound inside. Thus, a long roll-shaped circularly polarizing plate was produced.

  Since the produced circularly polarizing plate was wound with a film having a low elastic modulus wound inside, the evaluation of the curl was inferior.

  The following were used for Compound A, Compound B and UV absorber.

（比較例７及び８）
実施例１において位相差フィルムＡ−１を作製する際に、延伸条件を表２のように変更する以外は、Ａ−１と同様にして位相差フィルムＤ−１を作製し、表２のような配置にする以外は実施例１と同様に円偏光板を作製した。

(Comparative Examples 7 and 8)
When producing retardation film A-1 in Example 1, retardation film D-1 was produced in the same manner as A-1, except that the stretching conditions were changed as shown in Table 2, and as shown in Table 2. A circularly polarizing plate was produced in the same manner as in Example 1 except that the arrangement was changed.

  In Comparative Example 7, curling and curling did not occur, but when the image was evaluated with a 3D-organic EL display system, crosstalk was seen. This is because the retardation film D-1 disposed on the viewing side with respect to the circularly polarizing plate in the display system does not have an in-plane retardation value R0 sufficient to suppress crosstalk. Is the cause.

  Moreover, in the case of the comparative example 8, when a wrinkle generate | occur | produced and the image was evaluated by 3D-organic EL display system, self and other backgrounds were visible from the display system by external light reflection. This is because the retardation film D-1 disposed on the organic EL light emitting element side with respect to the circularly polarizing plate in the display system has an in-plane retardation value Ro sufficient for suppressing external light reflection. The cause is not.

〔Evaluation method〕
(Round curl evaluation)
The roll-shaped circularly polarizing plate having a length of 1000 m or more was placed at 23 ° C./55% RH for 12 hours, and then the environment was changed to 23 ° C./80% RH for another 12 hours. The environment was again changed to 23 ° C. and 55% RH and left for 3 hours.

Thereafter, a 5 cm square sample was cut out from the roll-shaped circularly polarizing plate and further placed in an environment of 23 ° C. and 55% RH for 9 hours. Samples were then evaluated as follows.
A: No curl is left.
○: Almost no curl remains.
X: The curl remains.

Curl evaluation A 5 cm square was cut out from the rolled circularly polarizing plate to evaluate whether the polarizing plate was curled.
○: Not curled.
X: Curled.

<Measurement method of elastic modulus>
The elastic modulus was determined by conditioning the sample for 24 hours in an environment of 23 ° C. and 55% RH and using Tensilon RTA-100 manufactured by Orientec Co., Ltd. according to the method described in JIS K7127. The shape of the piece was a No. 1 type test piece, and the test speed was measured under the condition of 10 mm / min.

(Evaluation of 3D-organic EL display system)
<< Production of organic EL display device >>
An organic electroluminescence display device was produced by the following procedure.

  In the organic EL display device of this example, a reflective electrode made of chromium having a thickness of 80 nm is formed on a glass substrate by sputtering, ITO is formed on the reflective electrode as an anode by sputtering to a thickness of 40 nm, and the positive electrode is formed on the anode. Poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT: PSS) as the hole transport layer is 80 nm thick by sputtering, and a shadow mask is used on the hole transport layer, and each light emitting layer of RGB is 100 nm. The film thickness was formed.

As a red light emitting layer, tris (8-hydroxyquinolinate) aluminum (Alq ₃ ) and a luminescent compound [4- (dicyanomethylene) -2-methyl-6 (p-dimethylaminostyryl) -4H-pyran] (DCM ) Were co-evaporated (mass ratio 99: 1) to form a thickness of 100 nm.

As the green light emitting layer, Alq ₃ as a host and the light emitting compound coumarin 6 (Coumarin 6) were co-evaporated (mass ratio 99: 1) and formed to a thickness of 100 nm.

  The blue light-emitting layer was formed with a thickness of 100 nm by co-evaporating BAlq and a light-emitting compound Perylene as a host (mass ratio 90:10).

さらに、発光層上に電子が効率的に注入できるような仕事関数の低い第１の陰極としてカルシウムを真空蒸着法により４ｎｍの厚さで成膜し、第１の陰極上に第２の陰極としてアルミニウムを２ｎｍの厚さで成膜した。

Further, calcium is deposited to a thickness of 4 nm by vacuum deposition as a first cathode having a low work function so that electrons can be efficiently injected onto the light emitting layer, and a second cathode is formed on the first cathode. Aluminum was deposited to a thickness of 2 nm.

  Here, the aluminum used as the second cathode has a role to prevent calcium as the first cathode from being chemically altered when the transparent electrode formed thereon is formed by sputtering.

  As described above, an organic light emitting layer was obtained. Next, a transparent conductive film was formed to a thickness of 80 nm on the cathode by sputtering. Here, ITO was used as the transparent conductive film. Further, an insulating film was formed by depositing 200 nm of silicon nitride on the transparent conductive film by a CVD method.

  Next, after applying an adhesive layer on the surface of the retardation film B of each circularly polarizing plate produced as described above, as shown in FIGS. 2 and 3, using the organic EL display element produced as described above, The organic EL display device was produced by bonding glass and retardation film B through an adhesive layer.

  Using the organic EL display device produced above and the 3D glasses with the λ / 4 phase difference produced in Examples and Comparative Examples on the panel side of the liquid crystal shutter 3D glasses (SONY 3D glasses TDG-BR100) Thus, a 3D-organic EL display system was produced. The liquid crystal shutter-type 3D glasses are provided with retardation film / liquid crystal cell / polarizer in this order when viewed from the panel side.

  The following evaluation was performed about the produced said 3D-organic EL display system.

  The produced 3D-organic EL display device was evaluated for crosstalk when tilting the neck when viewing 3D video, and crosstalk without tilting the neck after continuous lighting.

《Evaluation of crosstalk prevention when tilting head when viewing 3D image》
Immediately after turning on the backlight of each liquid crystal display device in an environment of 23 ° C. and 55% RH, 3D glasses are worn, and 3D images are displayed with the neck tilted so that the glasses are tilted 25 °. It was viewed and crosstalk prevention was evaluated according to the following criteria.
○: No crosstalk at all ×: Crosstalk is clearly visible.

<< Evaluation of front antireflection function >>
The front antireflection function was evaluated based on the following criteria.
○: When the produced EL display device is viewed, the image of itself and the background are not so visible.
X: When the produced EL display device is viewed, the image of the user and the background can be clearly seen together with the image of the display device.

  The experimental requirements and evaluation results are summarized in Tables 1 to 3 above.

表３に示した評価結果から分かるように本発明の偏光板は、巻き癖が全く又はほとんど残っていず、カールしていないことが分かる。また、本発明の偏光板を用いた３Ｄ−有機ＥＬ表示システムは、クロストーク防止性及び正面の反射防止機能も優れていることが分かる。

As can be seen from the evaluation results shown in Table 3, it can be seen that the polarizing plate of the present invention has no or almost no curl and is not curled. Further, it can be seen that the 3D-organic EL display system using the polarizing plate of the present invention is excellent in crosstalk prevention and front antireflection function.

DESCRIPTION OF SYMBOLS 1 Long film original fabric 2 Long stretched film 3 Diagonal stretch tenter 4-1 Trajectory of outer film gripping means 4-2 Trajectory of inner film gripping means 5-1 Outer film gripping start point 5-2 Inner film Gripping start point 6-1 Outer film gripping end point 6-2 Inner film gripping end point 7-1 Outer oblique stretching start point 7-2 Inner oblique stretching start point 8-1 Outer oblique stretching end point 8-2 Inward oblique Stretching end point 9-1 Guide roller 9-2 on the tenter inlet side Guide roller 10 on the tenter outlet side Film stretching direction 11-1 Film transport direction 11-2 before oblique stretching Film transport direction Wo after oblique stretching Wo Diagonal Film width before stretching W Film width after oblique stretching A 3D-organic EL display system B Organic EL display device C 3D glasses a Transparent substrate (glass)
b metal electrode c organic light emitting layer d transparent electrode (indium tin oxide (ITO))
e Insulating layer f Broadband λ / 4 retardation film g Polarizer h λ / 4 retardation film i λ / 4 retardation film j Polarizer k Protective film l Liquid crystal m Protective film n Polarizer o Protective film 1a Transparent substrate 2a Metal Electrode 3aR Red light emitting layer 3aG Green light emitting layer 3aB Blue light emitting layer 4a Transparent electrode 5a Insulating film 6a Adhesive layer 7a λ / 4 plate T2
8a Polarizer 9a λ / 4 plate T1
10a Circularly polarizing plate 11a Organic EL display substrate

Claims (3)

Two retardation films having an in-plane retardation value Ro satisfying the following formula (1) are a polarizing plate wound in a roll shape provided on both surfaces of a polarizer,
Is long,
One of the retardation films is a retardation film A, the other is a retardation film B,
When stored in roll form, the retardation film (A) is wound so as to be inside the roll, and
When the elastic modulus S in each slow axis direction is S (A) and S (B), respectively, the two retardation films are bonded so as to satisfy the following formula (2). A polarizing plate wound in a roll shape.
Formula (1): 100 nm ≦ Ro ≦ 160 nm
Formula (2): 100 MPa ≦ S (A) −S (B) ≦ 2000 MPa
(However, the in-plane retardation value Ro is an in-plane retardation value measured with light having a wavelength of 550 nm in an environment of a temperature of 23 ° C. and a relative humidity of 55%.) The polarizing plate wound in a roll shape according to claim 1, wherein at least one of the retardation films contains a cellulose ester satisfying the following formula (3).
Formula (3): 0 ≦ X ≦ 1.8
(However, in said formula, X represents the sum total of the substitution degree of a propionyl group or a butyryl group.)   The polarizing plate wound in a roll shape according to claim 1 or 2, wherein at least one of the retardation films contains a polycarbonate or a cycloolefin resin.

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