JP4074872B2 - Optical compensation polarizing plate, image display device, and liquid crystal display device - Google Patents

Description

  The present invention relates to an optical compensation polarizing plate in which a transparent protective film and an optical compensation layer are laminated on a polarizer. The present invention also relates to an image display device using the optical compensation polarizing plate. In particular, the optical compensation polarizing plate of the present invention is suitable for a liquid crystal display device operating in a so-called IPS mode.

  A so-called TN mode in which the alignment state of nematic liquid crystal molecules having a positive dielectric anisotropy is twisted by 90 ° is used in currently mainstream liquid crystal display devices. A TN mode liquid crystal display device is composed of a substrate having a pair of transparent electrodes, a liquid crystal cell made of nematic liquid crystal sealed between the substrates, and a polarizing plate disposed on both sides thereof, compared with other types of LCDs. This is a powerful method because it has a relatively fast response speed of about several tens of milliseconds and exhibits high display contrast. However, due to the principle of the display method, it has a viewing angle characteristic that the display color and display contrast change depending on the viewing direction. However, the display performance of the CRT cannot be exceeded.

  The TN mode liquid crystal display device performs display by applying an electric field perpendicular to the substrate. When no electric field is applied, the molecular long axis of the liquid crystal changes substantially parallel to and substantially perpendicular to the substrate, that is, display is performed by changing the direction of the liquid crystal molecular long axis in a plane perpendicular to the substrate. For this reason, the retardation of the liquid crystal layer changes greatly depending on the direction of viewing the display screen, and the display color and display contrast change greatly. In order to improve the viewing angle characteristics, it has been proposed to install an optical compensation layer between the polarizer and the TN mode liquid crystal cell, and various optical compensation sheets have been proposed so far. The installation of the optical compensatory sheet has increased the viewing angle to some extent, but so far it has been difficult to achieve a wide viewing angle that can replace the CRT.

  There has been proposed a display method in which the direction in which the electric field is applied is not perpendicular to the substrate as described above but substantially parallel to the substrate (Patent Document 1, Non-Patent Document 1). Such a display method by applying an electric field substantially parallel to the substrate is called an IPS (In-Plane Switching) mode. In an IPS mode liquid crystal display device, in a non-driven state, liquid crystal molecules have a homogeneous alignment substantially parallel to the substrate surface, so that light passes through the liquid crystal layer with almost no change in its polarization plane, and as a result, the substrate By disposing polarizing plates above and below, almost complete black display is possible in a non-driven state.

  However, in the IPS mode, almost complete black display is possible in the normal direction of the panel, but when the panel is observed from a direction deviated from the normal direction, it is shifted from the optical axis direction of the polarizing plate arranged above and below the liquid crystal cell. In the direction, there is a problem that the viewing angle becomes narrow due to light leakage that is unavoidable due to the characteristics of the polarizing plate, and a non-negligible retardation value expressed by homogeneously aligned liquid crystal and a transparent protective film.

  In order to solve this problem, a polarizing plate is used in which a geometrical axis shift of the polarizing plate that occurs when observed from an oblique direction is compensated by an optical compensation sheet. A polarizing plate capable of obtaining such an effect is disclosed in, for example, Patent Document 2 and Patent Document 3. However, it is difficult to realize a sufficiently wide viewing angle with a conventionally known optical compensation sheet.

  In the polarizing plate described in Patent Document 2, an optical compensation sheet is used as a protective film for the polarizer. However, although the polarizing plate can obtain a good viewing angle characteristic in a normal use environment, the protective film directly laminated due to a change in the size of the polarizer is also deformed under a high temperature and a high humidity. Therefore, there is a problem that the retardation value of the optical compensation sheet used for the protective film is deviated from a desired value, and the effect cannot be maintained stably.

  In patent document 3, the optical compensation sheet is laminated | stacked on the polarizing plate to which the triacetyl cellulose film (TAC film) generally used as a protective film is applied. In this case, since no stress is directly applied to the optical compensation sheet, the retardation value of the optical compensation sheet is stable. However, the TAC film has a retardation value that cannot be ignored, so that it is difficult to design an optical compensation layer for compensation. Similarly to the above, the TAC film is stretched due to the dimensional change of the polarizer under a high temperature or high humidity, whereby a change in retardation value occurs, and the desired purpose cannot be achieved.

In Patent Document 4 and Patent Document 5, a film containing a norbornene-based resin or a film containing a resin having an imide group and a resin having a phenyl group or a nitrile group is laminated as a protective film. In this case, since the retardation value of the protective film can be reduced, it is easy to design the optical compensation layer. However, these synthetic resins are generally hydrophobic, have a problem in adhesion with a polarizer, and easily peel off. Further, in the step of laminating the protective film on both sides of the polarizer, there is a problem that moisture cannot be expected from being transmitted from the polarizer, so that moisture remains inside, resulting in deterioration of polarizing plate performance. Similarly to the above, the change in retardation value of the synthetic resin film occurs more than the TAC film due to the change in the size of the polarizer under high temperature or high humidity, and the desired purpose cannot be achieved.
JP 7-261152 A JP-A-4-305602 JP-A-4-371903 JP 2004-4641 A Japanese Patent Application Laid-Open No. 2004-4642 ASIA DISPLAY '95 (Published by The Institute of Television Engineers of Japan & The Society for Information Display, pages 777-580, pages 707-710)

The present invention relates to an optical compensation polarizing plate in which a polarizing plate and an optical compensation layer are laminated, and when applied to an image display device, particularly a liquid crystal display device, the display contrast and the viewing angle characteristics of display color without reducing the front contrast. It is an object of the present invention to provide an optical compensation polarizing plate that improves the above with high productivity.
Furthermore, in addition to the above-mentioned characteristics, an optical compensation polarizing plate is provided that has little deterioration in optical performance due to high temperature and high humidity.
Another object of the present invention is to provide an image display device provided with the above-mentioned optical compensation polarizing plate, particularly a liquid crystal display device excellent in viewing angle characteristics that can be replaced with a CRT.
A further object of the present invention is to provide a liquid crystal display device that operates in the IPS mode, which includes the optical compensation polarizing plate, has a high contrast ratio over a wide range, and can realize an easy-to-see display.

  As a result of intensive studies to solve the above problems, the present inventors have found the following optical compensation polarizing plate, image display device, and liquid crystal display device, and have completed the present invention.

[式中、Ｒ ¹ はアルキル基またはアリール基を表し、Ｒ ² およびＲ ³ は、それぞれ独立に、
水素原子、アルキル基またはアリール基を表す。Ｒ ¹ 、Ｒ ² およびＲ ³ の炭素原子数の総和
は１０以上である。]

[式中、Ｒ ¹ はアルキル基またはアリール基を表し、Ｒ ² およびＲ ³ はそれぞれ独立に水素
原子、アルキル基またはアリール基を表す。]

上記一般式（１９）において、Ｒ ⁴ 、Ｒ ⁵ およびＲ ⁶ はそれぞれ独立にアルキル基または
アリール基を表す。
（I）｜Ｒｅ｜≦１０
（II）｜Ｒｔｈ｜≦２５
（III）Ｎｚ＝（ｎｘ₁−ｎｚ₁）／（ｎｘ₁−ｎｙ₁）
（IV）Ｒｅ₁＝（ｎｘ₁−ｎｙ₁）×ｄ₁
（V）０．４≦Ｎｚ≦０．６
（VI）１００≦Ｒｅ₁≦３５０
［式中、Ｒｅ₁は波長590ｎｍにおける正面レターデーション値（単位：ｎｍ）であり、Ｎｚは波長590ｎｍにおけるＮｚファクターあり、またｎｘ₁はフィルム面内の遅相軸方向の屈折率、ｎｙ₁はフィルム面内の遅相軸と垂直な方向の屈折率、ｎｚ₁はフィルムの厚み方向の屈折率であり、ｄ₁はフィルムの厚さ（単位：ｎｍ）である。］
（２）前記偏光子が長手方向に平行な吸収軸を有する長尺状の偏光子であり、前記光学補償層が長手方向に直交する遅相軸を有する長尺状の光学補償層であることを特徴とする（１）に記載の光学補償偏光板。
（３）前記透明保護フィルムが、下記式（VII）を満たすことを特徴とする（１）または（２）に記載の光学補償偏光板。
（VII）｜Ｒｅ₍₄₀₀₎−Ｒｅ₍₇₀₀₎｜≦１０かつ｜Ｒｔｈ₍₄₀₀₎−Ｒｔｈ₍₇₀₀₎｜≦３５
［式中、Ｒｅ₍λ₎は波長λｎｍにおける正面レターデーション値（単位：ｎｍ）、Ｒｔｈ
₍λ₎は波長λｎｍにおける膜厚方向のレターデーション値（単位：ｎｍ）である。］
（４）前記透明保護フィルムの膜厚が１０〜１２０μｍであることを特徴とする（１）〜（３）のいずれかに記載の光学補償偏光板。
（５）前記透明保護フィルムが、下記式（VIII）をみたすことを特徴とする（１）〜（４）のいずれかに記載の光学補償偏光板。
（VIII）｜Ｒｅ(MAX)−Ｒｅ(MIN)｜≦6かつ｜Ｒｔｈ(MAX)−Ｒｔｈ(MIN)｜≦10
［式中、Ｒｅ(MAX)、Ｒｔｈ(MAX)は任意に切り出した1ｍ四方のフィルムの最大レターデ
ーション値（単位：ｎｍ）、Ｒｅ(MIN)、Ｒｔｈ(MIN)は最小レターデーション値（単位：
ｎｍ）である。］
（６）前記透明保護フィルムが、前記Ｒｔｈを低下させる化合物を、下記式（IX）、（X）をみたす範囲で含有することを特徴とする（１）〜（５）のいずれかに記載の光学補償偏光板。
（IX）（Ｒｔｈ（Ａ）−Ｒｔｈ（０））／Ａ≦１．０
（X）０．１≦Ａ≦３０
［式中、Ｒｔｈ（Ａ）はＲｔｈを低下させる化合物をＡ％含有したフィルムのＲｔｈ（
ｎｍ）、Ｒｔｈ（０）はＲｔｈを低下させる化合物を含有しないフィルムのＲｔｈ（ｎｍ
）、Ａ：フィルム原料ポリマーの質量を１００としたときの化合物の質量（％）である。］
（７）前記Ｒｔｈを低下させる化合物を、セルロースアシレート固形分に対して０．０１〜３０質量％含むことを特徴とする（１）〜（５）のいずれかに記載の光学補償偏光板。
（８）前記透明保護フィルムが、｜Ｒｅ₍₄₀₀₎−Ｒｅ₍₇₀₀₎｜および｜Ｒｔｈ₍₄₀₀₎−Ｒｔｈ₍₇₀₀₎｜を低下させる化合物を少なくとも１種、セルロースアシレート固形分に対して０．０１〜３０質量％含むことを特徴とする（１）〜（７）のいずれかに記載の光学補償偏光板。
（９）前記透明保護フィルムが、フィルムの機械搬送方向（ＭＤ方向）に対して垂直方向（ＴＤ方向）に遅相軸を有する長尺状のフィルムであることを特徴とする（１）〜（８）のいずれかに記載の光学補償偏光板。
（１０）前記透明保護フィルムが、アルカリ鹸化処理後のフィルム表面の接触角が５５°
以下であることを特徴とする（１）〜（９）のいずれかに記載の光学補償偏光板。
（１１）前記透明保護フィルムを６０℃９０％ＲＨで２４０時間処理した場合のＲｅおよびＲｔｈの変化量が１５ｎｍ以下であることを特徴とする（１）〜（１０）のいずれかに記載の光学補償偏光板。
（１２）前記透明保護フィルムを８０℃で２４０時間処理した場合のＲｅおよびＲｔｈの
変化量が１５ｎｍ以下であることを特徴とする（１）〜（１１）のいずれかに記載の光学
補償偏光板。
（１３）前記透明保護フィルムが延伸処理されたフィルムであって、かつ延伸後に光学補
償層が積層されたことを特徴とする（１）〜（１２）のいずれかに記載の光学補償偏光版。
（１４）前記透明保護フィルムが延伸処理されたフィルムであって、かつ光学補償層を積
層した後に延伸されたことを特徴とする（１）〜（１２）のいずれかに記載の光学補償偏
光版。
（１５）前記透明保護フィルムが、延伸処理の前後において、フィルム面内の正面レター
デーションが下記式（XI）を満たすことを特徴とする（１３）または（１４）に記載の光
学補償偏光板。
（XI）｜Ｒｅ(ｎ)-Ｒｅ(０)｜／ｎ≦１．０
[式中、Ｒｅ(ｎ)はｎ(％)延伸したフィルムの面内正面レターデーション(単位：ｎｍ)
、Ｒｅ(０)は延伸していないフィルムの面内正面レターデーション(単位：ｎｍ)]
（１６）前記透明保護フィルムが、アシル置換度２.７０〜３．００であるセルロースアセテートからなることを特徴とする（１）〜（１５）のいずれかに記載の光学補償偏光板。
（１７）前記透明保護フィルムが、下記式（XII）〜（XIV）をすべて満たすセルロースア
シレートからなることを特徴とする（１）〜（１５）のいずれかに記載の光学補償偏光板
。
（XII） ２．５０≦ＳＡ＋ＳＢ≦３．００
（XIII） ０≦ＳＡ≦２．５
（XIV） ０．５≦ＳＢ≦３．００
[式中、ＳＡはアセチル基の置換度を、ＳＢは炭素数３〜２２の置換アシル基の置換度を
表す。]
（１８）前記光学補償層が、棒状又は円盤状化合物を透明保護フィルム面に対して垂直配
向させてなる光学補償層であることを特徴とする（１）〜（１７）のいずれかに記載の光
学補償偏光板。
（１９）前記光学補償層が、ポリアミド、ポリイミド、ポリエステル、ポリエーテルケト
ン、ポリアミドイミドおよびポリエステルイミドから選択される固有複屈折値が正のポリ
マーを含有することを特徴とする（１）〜（１７）のいずれかに記載の光学補償偏光板。
（２０）前記光学補償層が、固有複屈折値が負のポリマーを含有することを特徴とする（
１）〜（１７）のいずれかに記載の光学補償偏光板。
（２１）前記透明保護フィルムと光学補償層とが接着剤層または粘着剤層で貼合されたこ
とを特徴とする（１）〜（２０）のいずれかに記載の光学補償偏光板。
（２２）ハードコート層、防眩層、反射防止層のいずれか少なくとも一層を有することを
特徴とする（１）〜（２１）のいずれかに記載の光学補償偏光板。
（２３）片面または両面に熱収縮フイルムが接着された長尺状のポリマーフイルムを加熱
処理して、該ポリマーフイルムを収縮させ長尺状の光学補償層を作製する工程と、作製し
た長尺状の光学補償層を、長尺状の透明保護フィルムを介して長尺状の偏光子と貼り合わ
せる工程とを含む（１９）〜（２２）のいずれかに記載の光学補償偏光板の製造方法。
（２４）前記光学補償層を作製する工程において、熱収縮フイルムとしてMD方向に優先的
に収縮する熱収縮フイルムを用いることを特徴とする（２３）に記載の光学補償偏光板の
製造方法。
（２５）前記光学補償層を作製する工程において、密ロールを使用することを特徴とする
（２３）に記載の光学補償偏光板の製造方法。
（２６）前記光学補償層を作製する工程において、テンタークリップの長手方向の間隔が
把持、搬送している間に狭くなる構造のテンターを用いて幅方向に延伸する工程を含むこ
とを特徴とする（２３）に記載の光学補償偏光板の製造方法。
（２７）（１）〜（２２）のいずれかに記載の光学補償偏光板を用いたことを特徴とする
画像表示装置。
（２８）画像表示装置がＩＰＳモードの液晶表示装置であり、視認側のセル基板には（１
）〜（２２）のいずれかに記載の光学補償偏光板が配置され、視認側と反対側のセル基板
には、偏光子の少なくとも片面に｜Ｒｅ（正面レターデーション値）｜≦１０且つ｜Ｒｔｈ（膜厚方向のレターデーション値）｜≦２５である透明保護フィルムが積層された偏光板が配置されており、かつ、電圧無印加状態において液晶セル内の液晶分子の長軸方向と偏光板の吸収軸が平行状態にあることを特徴とする液晶表示装置。
（２９）画像表示装置がＩＰＳモードの液晶表示装置であり、視認側のセル基板には偏光
子の少なくとも片面に｜Ｒｅ（正面レターデーション値）｜≦１０且つ｜Ｒｔｈ（膜厚方向のレターデーション値）｜≦２５である透明保護フィルムが積層された偏光板が配置され、視認側と反対側のセル基板には、（１）〜（２２）のいずれかに記載の光学補償偏光板が配置されており、かつ、電圧無印加状態において液晶セル内の液晶分子の長軸方向と光学補償偏光板の吸収軸が直交状態にあることを特徴とする液晶表示装置によって達成することができた。 That is, the present invention
(1) In an optical compensation polarizing plate in which an optical compensation layer is laminated on one side of a polarizing plate obtained by laminating a transparent protective film on both sides of a polarizer, at least one transparent protective film reduces the retardation Rth in the film thickness direction. Including at least one compound represented by any one of the general formulas (13), (18), and (19) as a compound to be treated , a front retardation value Re (unit: nm) and a retardation value Rth in the film thickness direction (Unit: nm) is a cellulose acylate film satisfying the following formulas (I) and (II), and Nz and Re ₁ defined by the following formulas (III) and (IV) of the optical compensation layer are: An optical compensation polarizing plate satisfying (V) and (VI).

[Wherein R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent
Represents a hydrogen atom, an alkyl group or an aryl group. Total number of carbon atoms of R ¹ , R ² and R ³
Is 10 or more. ]

[Wherein R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represents hydrogen.
An atom, an alkyl group or an aryl group is represented. ]

In the general formula (19), R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group or
Represents an aryl group.
(I) | Re | ≦ 10
(II) | Rth | ≦ 25
(III) Nz = (nx ₁ −nz ₁ ) / (nx ₁ −ny ₁ )
(IV) Re ₁ = (nx ₁ −ny ₁ ) × d ₁
(V) 0.4 ≦ Nz ≦ 0.6
(VI) 100 ≦ Re ₁ ≦ 350
[Where Re ₁ is the front retardation value (unit: nm) at a wavelength of 590 nm, Nz is the Nz factor at a wavelength of 590 nm, nx ₁ is the refractive index in the slow axis direction in the film plane, and ny ₁ is The refractive index in the direction perpendicular to the slow axis in the film plane, nz ₁ is the refractive index in the thickness direction of the film, and d ₁ is the thickness of the film (unit: nm). ]
(2) The polarizer is a long polarizer having an absorption axis parallel to the longitudinal direction, and the optical compensation layer is a long optical compensation layer having a slow axis perpendicular to the longitudinal direction. (1) The optical compensation polarizing plate according to (1).
(3) The optical compensation polarizing plate according to (1) or (2), wherein the transparent protective film satisfies the following formula (VII).
(VII) | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35
[Where Re ₍ λ ₎ is the front retardation value at wavelength λnm (unit: nm), Rth
₍ λ ₎ is the retardation value (unit: nm) in the film thickness direction at the wavelength λnm. ]
(4) The optical compensation polarizing plate according to any one of (1) to (3), wherein the transparent protective film has a thickness of 10 to 120 μm.
(5) The optical compensation polarizing plate according to any one of (1) to (4), wherein the transparent protective film satisfies the following formula (VIII).
(VIII) | Re (MAX) −Re (MIN) | ≦ 6 and | Rth (MAX) −Rth (MIN) | ≦ 10
[In the formula, Re (MAX) and Rth (MAX) are the maximum retardation values (unit: nm) of 1 m square film cut out arbitrarily, and Re (MIN) and Rth (MIN) are the minimum retardation values (unit:
nm). ]
(6) the transparent protective film, a compound for reducing the Rth, the following formula (IX), according to any one of and having containing a range satisfying the (X) (1) ~ (5) Optical compensation polarizing plate.
(IX) (Rth (A) −Rth (0)) / A ≦ 1.0
(X) 0.1 ≦ A ≦ 30
[Wherein Rth (A) represents Rth (A) of a film containing A% of a compound that lowers Rth
nm), Rth (0) is Rth (nm) of a film not containing a compound that lowers Rth.
), A: The mass (%) of the compound when the mass of the film raw material polymer is 100. ]
(7) The optical compensation polarizing plate according to any one of ( 1) to (5), wherein the compound for reducing Rth is contained in an amount of 0.01 to 30% by mass based on the solid content of cellulose acylate. .
( 8 ) The transparent protective film contains at least one compound that reduces | Re ₍₄₀₀₎ -Re ₍₇₀₀₎ | and | Rth ₍₄₀₀₎ -Rth ₍₇₀₀₎ | The optical compensation polarizing plate according to any one of (1) to ( 7 ), comprising 0.01 to 30% by mass.
( 9 ) The transparent protective film is a long film having a slow axis in a direction (TD direction) perpendicular to a machine transport direction (MD direction) of the film (1) to ( 8 ) The optical compensation polarizing plate in any one of.
( 10 ) The transparent protective film has a contact angle of 55 ° on the film surface after alkali saponification treatment.
The optical compensation polarizing plate according to any one of (1) to ( 9 ), wherein:
( 11 ) The optical component according to any one of (1) to ( 10 ), wherein the amount of change in Re and Rth when the transparent protective film is treated at 60 ° C. and 90% RH for 240 hours is 15 nm or less. Compensation polarizing plate.
( 12 ) The optical compensation polarizing plate according to any one of (1) to ( 11 ), wherein the amount of change in Re and Rth when the transparent protective film is treated at 80 ° C. for 240 hours is 15 nm or less .
( 13 ) The optically compensated polarizing plate according to any one of (1) to ( 12 ), wherein the transparent protective film is a stretched film, and an optical compensation layer is laminated after stretching.
( 14 ) The optically compensated polarizing plate according to any one of (1) to ( 12 ), wherein the transparent protective film is a stretched film and stretched after laminating an optical compensation layer .
( 15 ) The optically-compensating polarizing plate according to ( 13 ) or ( 14 ), wherein the transparent protective film has a front retardation in the film surface that satisfies the following formula (XI) before and after the stretching treatment.
(XI) | Re (n) -Re (0) | /n≦1.0
[In the formula, Re (n) is the in-plane front retardation of the stretched film (unit: nm).
, Re (0) is the in-plane front retardation of the unstretched film (unit: nm)]
( 16 ) The optical compensation polarizing plate according to any one of (1) to ( 15 ), wherein the transparent protective film is made of cellulose acetate having an acyl substitution degree of 2.70 to 3.00.
( 17 ) The optical compensation polarizing plate according to any one of (1) to ( 15 ), wherein the transparent protective film is made of cellulose acylate satisfying all of the following formulas (XII) to (XIV).
(XII) 2.50 ≦ SA + SB ≦ 3.00
(XIII) 0 ≦ SA ≦ 2.5
(XIV) 0.5 ≦ SB ≦ 3.00
[Wherein, SA represents the degree of substitution of the acetyl group, and SB represents the degree of substitution of the substituted acyl group having 3 to 22 carbon atoms. ]
( 18 ) The optical compensation layer according to any one of (1) to ( 17 ), wherein the optical compensation layer is an optical compensation layer obtained by vertically orienting a rod-like or discotic compound with respect to the transparent protective film surface. Optical compensation polarizing plate.
( 19 ) The optical compensation layer contains a polymer having a positive intrinsic birefringence value selected from polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide (1) to ( 17 ). The optical compensation polarizing plate according to any one of the above.
( 20 ) The optical compensation layer contains a polymer having a negative intrinsic birefringence value (
The optical compensation polarizing plate according to any one of 1) to ( 17 ).
( 21 ) The optical compensation polarizing plate according to any one of (1) to ( 20 ), wherein the transparent protective film and the optical compensation layer are bonded with an adhesive layer or an adhesive layer.
( 22 ) The optical compensation polarizing plate according to any one of (1) to ( 21 ), which has at least one of a hard coat layer, an antiglare layer and an antireflection layer.
( 23 ) A step of producing a long optical compensation layer by heat-treating a long polymer film having a heat-shrinkable film bonded to one side or both sides, and shrinking the polymer film; ( 19 ) The manufacturing method of the optical compensation polarizing plate in any one of ( 22 ) including the process of bonding an optical compensation layer with a elongate polarizer through a elongate transparent protective film.
( 24 ) The method for producing an optical compensation polarizing plate according to ( 23 ), wherein in the step of producing the optical compensation layer, a heat-shrinkable film that preferentially shrinks in the MD direction is used as the heat-shrinkable film.
( 25 ) The method for producing an optical compensation polarizing plate according to ( 23 ), wherein a dense roll is used in the step of producing the optical compensation layer.
( 26 ) The step of producing the optical compensation layer includes a step of stretching in the width direction using a tenter having a structure in which a distance between the longitudinal directions of the tenter clips is narrowed while gripping and transporting. ( 23 ) The manufacturing method of the optical compensation polarizing plate as described in ( 23 ).
( 27 ) An image display device using the optical compensation polarizing plate according to any one of (1) to ( 22 ).
( 28 ) The image display device is an IPS mode liquid crystal display device.
) To ( 22 ), the cell substrate on the side opposite to the viewing side is provided with | Re (front retardation value) | ≦ 10 and | Rth on at least one side of the polarizer. (Retardation value in the film thickness direction) A polarizing plate on which a transparent protective film satisfying | ≦ 25 is disposed, and the major axis direction of the liquid crystal molecules in the liquid crystal cell and the polarizing plate A liquid crystal display device characterized in that absorption axes are in a parallel state.
( 29 ) The image display device is an IPS mode liquid crystal display device, and the cell substrate on the viewing side has | Re (front retardation value) | ≦ 10 and | Rth (retardation in the film thickness direction) on at least one surface of the polarizer. Value) A polarizing plate on which a transparent protective film satisfying | ≦ 25 is disposed, and the optical compensation polarizing plate according to any one of (1) to ( 22 ) is disposed on the cell substrate opposite to the viewing side. In the liquid crystal display device, the major axis direction of the liquid crystal molecules in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate are orthogonal to each other when no voltage is applied.

The optical compensation polarizing plate of the present invention can eliminate light leakage in a direction shifted from the normal direction by the specific optical compensation layer when the polarizing plate is arranged in a crossed Nicol state in a liquid crystal cell. . In particular, an IPS mode liquid crystal display device has a function of compensating for a decrease in contrast in an oblique direction of a liquid crystal layer. The optical compensation layer has an Nz value of 0.4 to 0.6 and an in-plane retardation (Re ₁ ) of 100 to 350 nm. The Nz value is preferably 0.45 or more, more preferably 0.48 or more from the viewpoint of the compensation function. On the other hand, the Nz value is preferably 0.55 or less, more preferably 0.52 or less. The in-plane retardation Re ₁ is 230 nm or more, further 250 nm or more from the viewpoint of the compensation function.

  On the other hand, among the transparent protective films laminated on both sides of the polarizer of the optical compensation polarizing plate of the present invention, at least one transparent protective film is a cellulose acylate film having a small optical anisotropy (Re, Rth), | Re | ≦ 10 and Rth | ≦ 25. Preferably, | Re | ≦ 5 and | Rth | ≦ 10, and more preferably | Re | ≦ 2 and | Rth | ≦ 5. By laminating a cellulose acylate film having a small optical anisotropy and an optical compensation layer having a specific birefringence, the optical compensation performance of the optical compensation layer can be effectively expressed.

Further, the transparent protective film in the present invention is preferably small in in-plane optical anisotropy variation, particularly | Re (MAX) −Re (MIN) | ≦ 6 and | Rth (MAX) −Rth (MIN ) | ≦ 10 is desirable. More preferably, | Re (MAX) −Re (MIN) | ≦ 3 and | Rth (MAX) −Rth (MIN) | ≦ 5.
[In the formula, Re (MAX) and Rth (MAX) − are the maximum retardation values (unit: nm) of 1 m square film cut out arbitrarily, and Re (MIN) and Rth (MIN) are the minimum retardation values (units) : Nm). ]
By suppressing the variation in the optical anisotropy in the transparent protective film surface, the variation in the optical anisotropy of the optical compensation polarizing plate produced using the same can be reduced. The effect that can be reduced.
In the present invention, Re and Rth are small, that is, an optically isotropic film, because Re is small even when stretched, and in-plane variation can be kept small even if various transport tensions occur during production. In-plane optical anisotropy variation is small.

In the present invention, a cellulose acylate film having a small wavelength dispersion is preferable, and | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35. It is not good. More preferably, | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 5 and | Rth ₍₄₀₀₎ −
It is particularly desirable that Rth ₍₇₀₀₎ | ≦ 25, and | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 3 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 15.

  The transparent protective film is preferably a stretched film. The stretching treatment may be either uniaxial stretching or biaxial stretching. In particular, a biaxially stretched film is preferred.

  Generally, a film material can be improved in strength by stretching, and tougher mechanical properties can be obtained. However, in many materials, a phase difference is generated by stretching treatment, so that it cannot be used as a protective film for a polarizer.

On the other hand, the transparent protective film in the present invention is a cellulose acylate film having a small change in optical properties when stretched or undergoes a dimensional change due to stress after bonding, and is preferably used as a protective film for a polarizer. it can. | Re (n) −Re (0) | /n≦1.0 is more preferable, and | Re (n) −Re (0) | /n≦0.5 is more preferable.
[Where Re (n) is the in-plane front retardation (unit: nm) of the stretched film by n (%), and Re (0) is the in-plane front retardation of the unstretched film (unit: nm)]

Further, the transparent protective film in the present invention preferably has a thickness of 10 to 120 μm, more preferably 40 to 100 μm, and particularly preferably 60 to 80 μm.
Further, regarding the change in optical performance due to the environmental change of the transparent protective film in the present invention, the amount of change in Re and Rth when treated at 60 ° C. and 90% RH for 240 hours is preferably 15 nm or less, more preferably 10 nm. Hereinafter, it is more preferably 5 nm or less. The transparent protective film preferably has a change amount of Re and Rth of 15 nm or less, more preferably 5 nm or less when treated at 80 ° C. for 240 hours.

Thus, by reducing the optical anisotropy and the variation of the transparent protective film of the polarizer, the design of the optical compensation layer to be laminated becomes easy, and an optical compensation polarizing plate having a high compensation effect is obtained. Can do.
In the present invention, the thickness of the optical compensation layer is not particularly limited, but is usually about 2 to 200 μm, preferably 10 to 100 μm.

Furthermore, the present invention relates to an image display device using the optical compensation polarizing plate.
As the image display device of the present invention, an IPS mode liquid crystal display device is suitable. By disposing the optical compensation polarizing plate according to the present invention on the surface of any one of the IPS mode liquid crystal cells, it is possible to reduce light leakage at the time of black display, which has conventionally occurred in the IPS mode liquid crystal display device. it can. Such an IPS mode liquid crystal display device has a high contrast ratio in all directions, and can realize an easy-to-view display with a wide viewing angle.

Below, the suitable aspect of the liquid crystal display device of the IPS mode using the optical compensation polarizing plate which concerns on this invention is given.
(1) The optical compensation polarizing plate according to the present invention is arranged on the cell substrate on the viewing side, and | Re | ≦ 10 and | on at least one surface of the polarizer on the cell substrate on the opposite side to the viewing side. A polarizing plate formed by laminating a transparent protective film satisfying Rth | ≦ 25 is disposed, and the abnormal light refractive index direction of the liquid crystal substance in the liquid crystal cell and the absorption axis of the polarizing plate are parallel when no voltage is applied. A liquid crystal display device characterized by being in a state.

(2) A polarizing plate formed by laminating the transparent protective film satisfying | Re | ≦ 10 and | Rth | ≦ 25 is disposed on at least one surface of the polarizer on the viewing side cell substrate, opposite to the viewing side In the cell substrate on the side, the optical compensation polarizing plate according to the present invention is disposed, and in the state where no voltage is applied, the extraordinary refractive index direction of the liquid crystal substance in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate Is a liquid crystal display device characterized by being in an orthogonal state.
Of the two transparent protective films of the polarizing plate arranged on the opposite side of the optical compensation polarizing plate according to the present invention of the liquid crystal cell, at least one of the transparent protective films used in the optical compensation polarizing plate of the present invention Thus, a display having a high contrast ratio in all directions and easy to see at a wide viewing angle can be obtained.

  According to the optical compensation polarizing plate of the present invention, when applied to an image display device, particularly a liquid crystal display device, the display contrast and the viewing angle characteristics of the display color are improved without reducing the front contrast, and the wide viewing angle. High contrast image characteristics can be provided. The optical compensation polarizing plate of the present invention is suitable for a liquid crystal display device operating in the IPS mode. Furthermore, the optical compensation polarizing plate of the present invention has little deterioration in optical performance under high temperature and high humidity, and enables high productivity by laminating by roll-to-roll.

The optical compensation polarizing plate and the image display device of the present invention will be described below. The optical compensation polarizing plate of the present invention is an optical compensation polarizing plate in which an optical compensation layer is laminated on one side of a polarizing plate in which a transparent protective film is laminated on both sides of a polarizer, and at least one transparent protective film has a film thickness. The specific retardation is included as a compound for reducing the retardation Rth in the direction, and the front retardation value Re (unit: nm) and the retardation value Rth (unit: nm) in the film thickness direction are represented by the following formulas (I) and (II): Nz and Re ₁ defined by the following formulas (III) and (IV) of the optical compensation layer are the cellulose acylate films satisfying the following conditions (hereinafter referred to as “cellulose acylate film of the present invention”): It is characterized by satisfying (V) and (VI).
(I) | Re | ≦ 10
(II) | Rth | ≦ 25
(III) Nz = (nx ₁ −nz ₁ ) / (nx ₁ −ny ₁ )
(IV) Re ₁ = (nx ₁ −ny ₁ ) × d ₁
(V) 0.4 ≦ Nz ≦ 0.6
(VI) 100 ≦ Re ₁ ≦ 350
[In the formula, Re ₁ is the front retardation value (unit: nm) at a wavelength of 590 nm, N
z is the Nz factor at a wavelength of 590 nm, nx ₁ is the refractive index in the slow axis direction in the film plane, ny ₁ is the refractive index in the direction perpendicular to the slow axis in the film plane, and nz ₁ is the thickness of the film. The refractive index in the direction, d ₁ is the thickness of the film (unit: nm). ]

  Further, the absorption axis of the polarizer, the slow axis of the optical compensation layer, and the slow axis of the transparent protective film are laminated so as to be orthogonal or parallel to each other. It is preferable that the absorption axis of the polarizer and the slow axis of the optical compensation layer are laminated in parallel from the viewpoint of a continuous laminating step with a roll during lamination.

Hereinafter, the cellulose acylate film of the present invention will be described in detail.
[Cellulose acylate raw material cotton]
Cellulose acylate raw material cellulose used in the present invention includes cotton linter and wood pulp (hardwood pulp, softwood pulp), etc., and any cellulose acylate obtained from any raw material cellulose can be used, optionally mixed. May be. Detailed descriptions of these raw material celluloses are, for example, Plastic Materials Course (17) Fibrous resin (Maruzawa, Uda, Nikkan Kogyo Shimbun, published in 1970) and Invention Association Open Technical Report 2001-1745 (page 7). To page 8) can be used, and the cellulose acylate film of the present invention is not particularly limited.

[Substitution degree of cellulose acylate]
Next, the cellulose acylate of the present invention produced from the above-mentioned cellulose will be described. The cellulose acylate of the present invention is obtained by acylating a hydroxyl group of cellulose, and the substituent can be any acetyl group having 2 carbon atoms in the acyl group to those having 22 carbon atoms. In the cellulose acylate of the present invention, the degree of substitution of cellulose with a hydroxyl group is not particularly limited, but the degree of substitution is measured by measuring the degree of binding of acetic acid substituted with a hydroxyl group of cellulose or a fatty acid having 3 to 22 carbon atoms. Can be obtained. As a measuring method, it can carry out according to ASTM D-817-91.

  As described above, in the cellulose acylate of the present invention, the degree of substitution of the cellulose with a hydroxyl group is not particularly limited, but the degree of acyl substitution with the hydroxyl group of cellulose is preferably 2.70 to 3.00. Furthermore, the substitution degree is preferably 2.85 to 3.00, and more preferably 2.90 to 3.00.

The acyl group substituted on the hydroxyl group of cellulose may be an aliphatic group having 2 to 22 carbon atoms or an allyl group, such as alkylcarbonyl ester, alkenylcarbonyl ester or aromatic carbonyl ester, aromatic alkylcarbonyl ester, etc. of cellulose, Each may have a further substituted group. These preferred acyl groups include acetyl, propionyl, butanoyl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, Examples include oleoyl, benzoyl, naphthylcarbonyl, and cinnamoyl groups. Among these, acetyl, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are preferable, and acetyl, propionyl and butanoyl are more preferable.
Mixed cellulose acylate is also preferably used, and mixed cellulose acylate satisfying all the requirements defined by the following formulas (XII) to (XIV) is particularly preferable.
Formula (XII) 2.50 ≦ SA + SB ≦ 3.00
Formula (XIII) 0 ≦ SA ≦ 2.5
Formula (XIV) 0.5 ≦ SB ≦ 3.00
(In the formula, SA represents the degree of substitution of the acetyl group, and SB represents the degree of substitution of the substituted acyl group having 3 to 22 carbon atoms.)

  Here, the substitution degree of the acyl group means the total of the proportions of acylation of cellulose for each of the 2-position, 3-position and 6-position (100% acylation has a substitution degree of 1). In the present invention, preferably 2.60 ≦ SA + SB ≦ 3.00, and more preferably 2.67 ≦ SA + SB ≦ 2.97. Also, SA is preferably 0 ≦ SA ≦ 2.20, more preferably 0 ≦ SA ≦ 2.0, and SB is preferably 0.80 ≦ SB ≦ 2.97, and more Preferably, 1.25 ≦ SB ≦ 2.97. In the present invention, the substitution degree of each hydroxyl group at the 2-position, 3-position and 6-position of cellulose is not particularly limited, but the substitution degree at the 6-position of cellulose acylate is preferably 0.7 or more, more preferably It is 0.8 or more, more preferably 0.85 or more. As a result, not only the degradation of cellulose acylate due to electron beam irradiation but also solubility and heat-and-moisture resistance can be improved.

  Next, the C3-C22 acyl group represented by the substituent SB of the cellulose acylate of the present invention may be either an aliphatic acyl group or an aromatic acyl group. When the acyl group of the cellulose acylate of the present invention is an aliphatic acyl group, it is preferably 3 to 18 carbon atoms, more preferably 3 to 12 carbon atoms, and 3 to 8 carbon atoms. Further preferred. Examples of these aliphatic acyl groups include an alkylcarbonyl group, an alkenylcarbonyl group, and an alkynylcarbonyl group. When the acyl group of the cellulose ester of the present invention is an aromatic acyl group, it is preferably 6 to 22 carbon atoms, more preferably 6 to 18 carbon atoms, and further preferably 6 to 12 carbon atoms. preferable.

  Preferred examples of the cellulose acylate of the present invention include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose propanoate butyrate, cellulose acetate propionate butyrate, cellulose Acetate hexanoate, cellulose acetate octanoate, cellulose acetate cyclohexanoate, cellulose acetate decanoate, cellulose acetate adamantane carboxylate, cellulose acetate sulfate, cellulose acetate carbamate, cellulose propionate sulfate, cellulose acetate propionate sulfate, Cite cellulose acetate phthalate It can be. More preferably, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose propanoate butyrate, cellulose acetate hexanoate, cellulose acetate octanoate, etc. it can. More preferable examples include cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate. In this case, the substitution degree of the acetyl group and the acyl group having 3 or more carbon atoms is created within the above-described range, and desired characteristics can be obtained depending on the substitution degree.

[Degree of polymerization of cellulose acylate]
The degree of polymerization of the cellulose acylate of the present invention is preferably 180 to 700 in terms of viscosity average degree of polymerization. In cellulose acetate, 180 to 550 is more preferable, 180 to 400 is more preferable, and 180 to 350 is particularly preferable. . When the degree of polymerization is too high, the viscosity of the cellulose acylate dope solution becomes high, and film production becomes difficult due to casting. If the degree of polymerization is too low, the strength of the produced film will decrease. The average degree of polymerization can be measured by Uda et al.'S intrinsic viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Society, Vol. 18, No. 1, pages 105-120, 1962). This is described in detail in JP-A-9-95538.
Further, the molecular weight distribution of the cellulose acylate of the present invention is evaluated by gel permeation chromatography, and its polydispersity index Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) is small, and the molecular weight distribution is narrow. Is preferred. The specific value of Mw / Mn is preferably 1.0 to 3.0, more preferably 1.0 to 2.0, and most preferably 1.0 to 1.6. preferable.

  When the low molecular component is removed, the average molecular weight (degree of polymerization) increases, but the viscosity becomes lower than that of normal cellulose acylate, which is useful. Cellulose acylate having a small amount of low molecular components can be obtained by removing low molecular components from cellulose acylate synthesized by a usual method. The removal of the low molecular component can be carried out by washing the cellulose acylate with an appropriate organic solvent. In addition, when manufacturing a cellulose acylate with few low molecular components, it is preferable to adjust the sulfuric acid catalyst amount in an acetylation reaction to 0.5-25 mass parts with respect to 100 mass parts of cellulose. When the amount of the sulfuric acid catalyst is within the above range, cellulose acylate that is preferable in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. When used in the production of the cellulose acylate of the present invention, the moisture content of the cellulose acylate is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly 0.7% by mass. The following is preferable. In general, cellulose acylate contains water and is known to be 2.5 to 5% by mass. In order to obtain the moisture content of the cellulose acylate in the present invention, it is necessary to dry, and the method is not particularly limited as long as the desired moisture content is obtained. These cellulose acylates of the present invention are described in detail on pages 7 to 12 of the raw material cotton and the synthesis method in the Japan Society for Invention and Technology (public technical number 2001-1745, published on March 15, 2001, Japan Society for Invention). It is described in.

  The cellulose acylate of the present invention can be used as a single group or a mixture of two or more different types of cellulose acylates as long as the substituent, substitution degree, polymerization degree, molecular weight distribution and the like are within the above-mentioned ranges.

[Additive to cellulose acylate]
In the cellulose acylate solution (dope) of the present invention, various additives (for example, a compound that reduces optical anisotropy, a wavelength dispersion adjusting agent, an ultraviolet inhibitor, a plasticizer, Deterioration inhibitors, fine particles, optical property adjusting agents, etc.) can be added, and these will be described below. Further, the addition may be performed at any time in the dope preparation process, but may be performed by adding an additive to the final preparation process of the dope preparation process.
It is preferable to contain at least one compound that lowers the optical anisotropy of the cellulose acylate film of the invention, particularly the retardation Rth in the film thickness direction, within the range satisfying the following formulas (IX) and (X).
Formula (IX) (Rth (A) −Rth (0)) / A ≦ 1.0
Formula (X) 0.1 ≦ A ≦ 30
The above formulas (IX) and (X) are represented by the formula (XV) (Rth (A) −Rth (0)) / A ≦ −2.0.
Formula (XVI) 0.05 ≦ A ≦ 25
It is more desirable to be
Formula (XVII) (Rth (A) −Rth (0)) / A ≦ −3.0
Formula (XVIII) 0.1 ≦ A ≦ 20
It is even more desirable.
[Wherein Rth (A) is Rth (nm) of a film containing A% of a compound that lowers Rth, Rth (0) is Rth (nm) of a film not containing a compound that lowers Rth, A: film raw material It is the mass (%) of the compound when the mass of the polymer is 100. ]

[Structural characteristics of compounds that reduce optical anisotropy of cellulose acylate film]
The compound that reduces the optical anisotropy of the cellulose acylate film will be described. As a result of intensive studies, the inventors of the present invention have sufficiently reduced the optical anisotropy using a compound that suppresses the orientation of cellulose acylate in the film in the plane and in the film thickness direction. Zero and Rth were close to zero. For this purpose, it is advantageous that the compound that lowers the optical anisotropy is sufficiently compatible with cellulose acylate, and the compound itself does not have a rod-like structure or a planar structure. Specifically, when a plurality of planar functional groups such as aromatic groups are provided, a structure having these functional groups in a non-planar rather than the same plane is advantageous.
Examples of the compound that decreases the optical anisotropy of the cellulose acylate film include compounds represented by the following general formulas (1) to (19).

In the formula, each of R ^11-13 independently represents an aliphatic group having 1 to 20 carbon atoms. R ^11-13 may be linked to each other to form a ring.

In the general formulas (2) and (3), Z represents a carbon atom, an oxygen atom, a sulfur atom or —NR ²⁵ —, and R ²⁵ represents a hydrogen atom or an alkyl group. The 5- or 6-membered ring configured to include Z may have a substituent. Y ^21-22 each independently represents an ester group, alkoxycarbonyl group, amide group or carbamoyl group having 1 to 20 carbon atoms, and Y ^21-22 may be linked to each other to form a ring. m represents an integer of 1 to 5, and n represents an integer of 1 to 6.

In the general formulas (4) to (12), Y ^31-70 each independently represents an ester group having 1 to 20 carbon atoms, an alkoxycarbonyl group having 1 to 20 carbon atoms, or an amide group having 1 to 20 carbon atoms. Represents a carbamoyl group having 1 to 20 carbon atoms or a hydroxy group, and V ^31-43 each independently represents a hydrogen atom or an aliphatic group having 1 to 20 carbon atoms. L ^31-80 each independently represents a divalent saturated linking group having 0 to 40 atoms and 0 to 20 carbon atoms. Here, the ^{fact that} the number of atoms of L ^31-80 is 0 means that the groups at both ends of the linking group directly form a single bond. V ^31-43 and L ^31-80 may further have a substituent.

[Wherein, R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. The total number of carbon atoms of R ¹ , R ² and R ³ is 10 or more, and each of the alkyl group and aryl group may have a substituent. ]

[Wherein, R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. The total number of carbon atoms of R ⁴ and R ⁵ is 10 or more, and each of the alkyl group and aryl group may have a substituent. ]

[Wherein, R ¹ , R ² and R ³ each independently represents a hydrogen atom or an alkyl group. X represents a divalent linking group formed from one or more groups selected from the following linking group group 1. Y represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group.
(Linking group group 1) A single bond, —O—, —CO—, —NR ⁴ —, an alkylene group or an arylene group is represented. R ⁴ represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. ]

(Wherein Q ¹ , Q ² and Q ³ each independently represents a 5- to 6-membered ring. X represents B, CR (R represents a hydrogen atom or a substituent), N, P, P = Represents O)

(In the formula, X ² represents B, C—R (R represents a hydrogen atom or a substituent), N. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ³¹ , R ³² , R ³³ , R ³⁴ to R ³⁵ represent a hydrogen atom or a substituent.

[Wherein, R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Moreover, the alkyl group and the aryl group may have a substituent. ]

  Preferred as the general formula (18) is a compound represented by the following general formula (19).

In the general formula (19), R ⁴ , R ⁵ and R ⁶ each independently represents an alkyl group or an aryl group. Here, the alkyl group may be linear, branched or cyclic, preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and more preferably has 1 to 12 carbon atoms. Is most preferred. As the cyclic alkyl group, a cyclohexyl group is particularly preferable. The aryl group preferably has 6 to 36 carbon atoms, more preferably 6 to 24 carbon atoms.

The above alkyl group and aryl group may have a substituent, such as a halogen atom (for example, chlorine, bromine, fluorine and iodine), an alkyl group, an aryl group, an alkoxy group, an aryloxy group, acyl Group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, sulfonylamino group, hydroxy group, cyano group, amino group and acylamino group, more preferably halogen atom, alkyl group, aryl group, alkoxy group, aryloxy group A sulfonylamino group and an acylamino group, particularly preferably an alkyl group, an aryl group, a sulfonylamino group and an acylamino group.
Among the above, compounds represented by the general formulas (13), (18), and (19) are particularly preferable, and at least one of these is preferably used.

(Log P value)
In producing the cellulose acylate film of the present invention, octanol is among the compounds that reduce the optical anisotropy by inhibiting the cellulose acylate in the film from being oriented in the plane and in the film thickness direction as described above. -It is preferable to use a compound having a water partition coefficient (log P value) of 0 to 7. A compound having a log P value of more than 7 is poor in compatibility with cellulose acylate, and tends to cause film turbidity or powder blowing. In addition, since a compound having a log P value smaller than 0 has high hydrophilicity, the water resistance of the cellulose acylate film may be deteriorated. A more preferable range for the log P value is 1 to 6, and a particularly preferable range is 1.5 to 5.
The octanol-water partition coefficient (log P value) can be measured by a flask immersion method described in JIS Japanese Industrial Standard Z7260-107 (2000). Further, the octanol-water partition coefficient (log P value) can be estimated by a computational chemical method or an empirical method instead of the actual measurement. As a calculation method, Crippen's fragmentation method (J.Chem.Inf.Comput.Sci., 27,21 (1987).), Viswanadhan's fragmentation method (J.Chem.Inf.Comput.Sci., 29,163 (1989).) Broto's fragmentation method (Eur. J. Med. Chem.-Chim. Theor., 19, 71 (1984).) And the like are preferably used, but Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27 , 21 (1987). When the log P value of a certain compound varies depending on the measurement method or calculation method, it is preferable to determine whether or not the compound is within the desired range by the Crippen's fragmentation method.

[Physical properties of compounds that reduce optical anisotropy]
The compound that reduces optical anisotropy may or may not contain an aromatic group. The compound that reduces the optical anisotropy preferably has a molecular weight of 150 or more and 3000 or less, preferably 170 or more and 2000 or less, and particularly preferably 200 or more and 1000 or less. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.
The compound that reduces optical anisotropy is preferably liquid at 25 ° C. or a solid having a melting point of 25 to 250 ° C., more preferably liquid at 25 ° C. or a melting point of 25 to 200 ° C. It is a solid. Moreover, it is preferable that the compound which reduces optical anisotropy does not volatilize in the process of dope casting for cellulose acylate film production and drying.
The addition amount of the compound for reducing the optical anisotropy is preferably 0.01 to 30% by mass, more preferably 1 to 25% by mass, and more preferably 5 to 20% by mass with respect to the cellulose acylate solid content. % Is particularly preferred.
The compound that decreases the optical anisotropy may be used alone, or two or more compounds may be mixed and used in an arbitrary ratio.
The timing for adding the compound for reducing the optical anisotropy may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  The compound that reduces the optical anisotropy is such that the average content of the compound in the portion from the surface on at least one side to 10% of the total film thickness is the average content of the compound in the central portion of the cellulose acylate film. 80-99%. The abundance of the compound can be determined, for example, by measuring the amount of the compound at the surface and in the center by a method using an infrared absorption spectrum described in JP-A-8-57879.

Although the specific example of the compound which reduces the optical anisotropy of the cellulose acylate film preferably used by this invention below is shown, this invention is not limited to these compounds.
The compound of the general formula (1) will be described.
In the general formula (1), R ^11-13 each independently represents an aliphatic group having 1 to 20 carbon atoms. R ^11-13 may be linked to each other to form a ring.
R ^11-13 will be described in detail. R ^11-13 is an aliphatic group having 1 to 20 carbon atoms, preferably 1 to 16 carbon atoms, and more preferably 1 to 12 carbon atoms. Here, the aliphatic group is preferably an aliphatic hydrocarbon group, more preferably an alkyl group (including chain, branched and cyclic alkyl groups), an alkenyl group or an alkynyl group. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, t-amyl, n-hexyl, n-octyl, decyl, Dodecyl, eicosyl, 2-ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, 2,6-dimethylcyclohexyl, 4-t-butylcyclohexyl, cyclopentyl, 1-adamantyl, 2-adamantyl, bicyclo [2.2.2] octane-3 Examples of the alkenyl group include vinyl, allyl, prenyl, geranyl, oleyl, 2-cyclopenten-1-yl, and 2-cyclohexen-1-yl. Examples of the alkynyl group include , Ethynyl, propargyl and the like.

The aliphatic group represented by R ^11-13 may be substituted. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom), an alkyl group (straight chain, branched). A cyclic alkyl group including a bicycloalkyl group and an active methine group), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (regardless of the position of substitution), an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group , Heterocyclic oxycarbonyl group, carbamoyl group, N-acylcarbamoyl group, N-sulfonylcarbamoyl group, N-carbamoylcarbamoyl group, N-sulfamoylcarbamoyl group, carbazoyl group, carboxy group or salt thereof, oxalyl group, oxamoyl group , Cyano group, carbonimidoyl group (Carbonimidoyl group), formyl group, Roxy group, alkoxy group (including groups containing repeating ethyleneoxy group or propyleneoxy group units), aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) carbonyloxy group, carbamoyloxy group, sulfonyloxy Group, amino group, (alkyl, aryl or heterocyclic) amino group, acylamino group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group An ammonio group, an oxamoylamino group, an N- (alkyl or aryl) sulfonylureido group, an N-acylureido group, an N-acylsulfamoylamino group, a heterocyclic group containing a quaternized nitrogen atom (for example, a pyriyl group) Dinio group, imidazolio group, quinolinio group, isoquinolinio group), isocyano group, imino group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or a salt thereof, sulfamoyl group, N-acylsulfamoyl group Group, N-sulfonylsulfamoyl group or a salt thereof, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, silyl group and the like.
These groups may be further combined to form a composite substituent, and examples of such a substituent include ethoxyethoxyethyl group, hydroxyethoxyethyl group, ethoxycarbonylethyl group and the like. R ^11-13 can also contain a phosphate group as a substituent, and the compound of general formula (1) can also have multiple phosphate groups in the same molecule.

The compounds of general formulas (2) and (3) will be described.
In the general formulas (2) and (3), Z represents a carbon atom, an oxygen atom, a sulfur atom, or —NR ²⁵ —, and R ²⁵ represents a hydrogen atom or an alkyl group. The 5- or 6-membered ring configured to include Z may have a substituent, and a plurality of substituents may be bonded to each other to form a ring. Examples of 5- or 6-membered rings comprising Z include tetrahydrofuran, tetrahydropyran, tetrahydrothiophene, thiane, pyrrolidine, piperidine, indoline, isoindoline, chroman, isochroman, tetrahydro-2-furanone, tetrahydro-2- Examples include pyrone, 4-butane lactam, and 6-hexanolactam.
Further, the 5- or 6-membered ring composed of Z includes a lactone structure or a lactam structure, that is, a cyclic ester or cyclic amide structure having an oxo group at the adjacent carbon of Z. Examples of such cyclic ester or cyclic amide structures include 2-pyrrolidone, 2-piperidone, 5-pentanolide, and 6-hexanolide.

R ²⁵ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms (chain, branched and cyclic alkyl groups). Group). Examples of the alkyl group represented by R ²⁵ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, t-amyl, n-hexyl, and n-octyl. , Decyl, dodecyl, eicosyl, 2-ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, 2,6-dimethylcyclohexyl, 4-t-butylcyclohexyl, cyclopentyl, 1-adamantyl, 2-adamantyl, bicyclo [2.2.2] There may be mentioned octan-3-yl. The alkyl group represented by R ²⁵ may further have a substituent, and examples of the substituent include a group which may be substituted with R ^11-13 .

Y ^21-22 each independently represents an ester group, an alkoxycarbonyl group, an amide group or a carbamoyl group. The ester group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, acetoxy, ethylcarbonyloxy, propylcarbonyloxy, n -Butylcarbonyloxy, iso-butylcarbonyloxy, t-butylcarbonyloxy, sec-butylcarbonyloxy, n-pentylcarbonyloxy, t-amylcarbonyloxy, n-hexylcarbonyloxy, cyclohexylcarbonyloxy, 1-ethylpentylcarbonyl Oxy, n-heptylcarbonyloxy, n-nonylcarbonyloxy, n-undecylcarbonyloxy, benzylcarbonyloxy, 1-naphthalenecarbonyloxy, 2-naphthalenecarbonyloxy, 1-a Such as diamantane carbonyloxy may be exemplified. The alkoxycarbonyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, methoxycarbonyl, ethoxycarbonyl, n-propyloxy Carbonyl, isopropyloxycarbonyl, n-butoxycarbonyl, t-butoxycarbonyl, iso-butyloxycarbonyl, sec-butyloxycarbonyl, n-pentyloxycarbonyl, t-amyloxycarbonyl, n-hexyloxycarbonyl, cyclohexyloxycarbonyl, 2-ethylhexyloxycarbonyl, 1-ethylpropyloxycarbonyl, n-octyloxycarbonyl, 3,7-dimethyl-3-octyloxycarbonyl, 3,5,5-trimethylhexyl Xyloxycarbonyl, 4-t-butylcyclohexyloxycarbonyl, 2,4-dimethylpentyl-3-oxycarbonyl, 1-adamantaneoxycarbonyl, 2-adamantaneoxycarbonyl, dicyclopentadienyloxycarbonyl, n-decyloxycarbonyl, Examples thereof include n-dodecyloxycarbonyl, n-tetradecyloxycarbonyl, n-hexadecyloxycarbonyl and the like. The amide group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, acetamide, ethyl carboxamide, n-propyl carboxamide, isopropyl Carboxamide, n-butylcarboxamide, t-butylcarboxamide, iso-butylcarboxamide, sec-butylcarboxamide, n-pentylcarboxamide, t-amylcarboxamide, n-hexylcarboxamide, cyclohexylcarboxamide, 1-ethylpentylcarboxamide, 1-ethylpropyl Carboxamide, n-heptylcarboxamide, n-octylcarboxamide, 1-adamantancarboxamide, 2-adamantancarboxamide, n-nonylcarboxamide n- dodecyl carboxamide, n- penta-carboxamide, such as n- hexadecyl carboxamide can be exemplified. The carbamoyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, diethylcarbamoyl , N-propylcarbamoyl, isopropylcarbamoyl, n-butylcarbamoyl, t-butylcarbamoyl, iso-butylcarbamoyl, sec-butylcarbamoyl, n-pentylcarbamoyl, t-amylcarbamoyl, n-hexylcarbamoyl, cyclohexylcarbamoyl, 2-ethylhexyl Carbamoyl, 2-ethylbutylcarbamoyl, t-octylcarbamoyl, n-heptylcarbamoyl, n-octylcarbamoyl, 1-adamantancarbamoyl, 2-a Diamantane carbamoyl, n- dodecylcarbamoyl, n--dodecylcarbamoyl, n- tetradecylcarbamoyl, n- hex dodecylcarbamoyl, and others. Y21-22 may combine with each other to form a ring. Y21-22 may further have a substituent, and examples thereof include a group which may be substituted with R ^11-13 . m is 1-5, Preferably it is 1-3. Moreover, n is 1-6, Preferably it is 1-3.

The compounds of general formulas (4) to (12) will be described.
In General Formulas (4) to (12), Y ^31-70 each independently represents an ester group, an alkoxycarbonyl group, an amide group, a carbamoyl group, or a hydroxy group. The ester group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, acetoxy, ethylcarbonyloxy, propylcarbonyloxy, n -Butylcarbonyloxy, iso-butylcarbonyloxy, t-butylcarbonyloxy, sec-butylcarbonyloxy, n-pentylcarbonyloxy, t-amylcarbonyloxy, n-hexylcarbonyloxy, cyclohexylcarbonyloxy, 1-ethylpentylcarbonyl Oxy, n-heptylcarbonyloxy, n-nonylcarbonyloxy, n-undecylcarbonyloxy, benzylcarbonyloxy, 1-naphthalenecarbonyloxy, 2-naphthalenecarbonyloxy, 1-a Such as Man Tan carbonyloxy and the like. The alkoxycarbonyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, methoxycarbonyl, ethoxycarbonyl, n-propyloxy Carbonyl, isopropyloxycarbonyl, n-butoxycarbonyl, t-butoxycarbonyl, iso-butyloxycarbonyl, sec-butyloxycarbonyl, n-pentyloxycarbonyl, t-amyloxycarbonyl, n-hexyloxycarbonyl, cyclohexyloxycarbonyl, 2-ethylhexyloxycarbonyl, 1-ethylpropyloxycarbonyl, n-octyloxycarbonyl, 3,7-dimethyl-3-octyloxycarbonyl, 3,5,5-trimethylhexyl Ruoxycarbonyl, 4-t-butylcyclohexyloxycarbonyl, 2,4-dimethylpentyl-3-oxycarbonyl, 1-adamantaneoxycarbonyl, 2-adamantaneoxycarbonyl, dicyclopentadienyloxycarbonyl, n-decyloxycarbonyl , N-dodecyloxycarbonyl, n-tetradecyloxycarbonyl, n-hexadecyloxycarbonyl and the like. The amide group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, acetamide, ethyl carboxamide, n-propyl carboxamide, isopropyl Carboxamide, n-butylcarboxamide, t-butylcarboxamide, iso-butylcarboxamide, sec-butylcarboxamide, n-pentylcarboxamide, t-amylcarboxamide, n-hexylcarboxamide, cyclohexylcarboxamide, 1-ethylpentylcarboxamide, 1-ethylpropyl Carboxamide, n-heptylcarboxamide, n-octylcarboxamide, 1-adamantancarboxamide, 2-adamantancarboxamide, n-nonylcarboxamide n- dodecyl carboxamide, n- penta-carboxamide, such as n- hexadecyl carboxamide and the like. The carbamoyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. For example, methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, diethylcarbamoyl , N-propylcarbamoyl, isopropylcarbamoyl, n-butylcarbamoyl, t-butylcarbamoyl, iso-butylcarbamoyl, sec-butylcarbamoyl, n-pentylcarbamoyl, t-amylcarbamoyl, n-hexylcarbamoyl, cyclohexylcarbamoyl, 2-ethylhexyl Carbamoyl, 2-ethylbutylcarbamoyl, t-octylcarbamoyl, n-heptylcarbamoyl, n-octylcarbamoyl, 1-adamantancarbamoyl, 2-a Diamantane carbamoyl, n- dodecylcarbamoyl, n--dodecylcarbamoyl, n- tetradecylcarbamoyl, such as n- hex dodecylcarbamoyl the like. Y ^31-70 may further have a substituent, and examples thereof include a group which may be substituted with R ^11-13 .

V ^31-43 each independently represents a hydrogen atom or an aliphatic group having preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms. Here, the aliphatic group is preferably an aliphatic hydrocarbon group, more preferably an alkyl group (including chain, branched and cyclic alkyl groups), an alkenyl group or an alkynyl group. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, t-amyl, n-hexyl, n-octyl, decyl, dodecyl, and eicosyl. , 2-ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, 2,6-dimethylcyclohexyl, 4-t-butylcyclohexyl, cyclopentyl, 1-adamantyl, 2-adamantyl, bicyclo [2.2.2] octan-3-yl, etc. Examples of the alkenyl group include vinyl, allyl, prenyl, geranyl, oleyl, 2-cyclopenten-1-yl, and 2-cyclohexen-1-yl. Examples of the alkynyl group include ethynyl, Propargyl can be mentioned. V ^31-43 may further have a substituent, and examples thereof include a group which may be substituted with R ^11-13 .

L ^31-80 each independently represents a divalent saturated linking group having 0 to 40 atoms and 0 to 20 carbon atoms. Here, the ^{fact that} the number of atoms of L ^31-80 is 0 means that the groups at both ends of the linking group directly form a single bond. Preferred examples of L ^31-80 include alkylene groups (eg, methylene, ethylene, propylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, methylethylene, ethylethylene, etc.), cyclic divalent groups (eg, cis-1,4-cyclohexylene, trans-1,4-cyclohexylene, 1,3-cyclopentylidene, etc.), ether, thioether, ester, amide, sulfone, sulfoxide, sulfide, sulfonamide, ureylene, thioureylene, etc. Can be mentioned. These divalent groups may be bonded to each other to form a divalent composite group. Examples of the composite substituent include — (CH ₂ ) ₂ O (CH ₂ ) ₂ — and — (CH ₂ ). ₂ O (CH ₂ ) ₂ O (CH ₂ ) —, — (CH ₂ ) ₂ S (CH ₂ ) ₂ —, — (CH ₂ ) ₂ O ₂ C (CH ₂ ) ₂ — and the like can be mentioned. L ^31-80 may further have a substituent, and examples of the substituent include a group which may be substituted with R ^11-13 described above.

Preferred examples of the compound formed by the combination of Y ^31-70 , V ^31-43 and L ^{31-80 in} the general formulas (4) to (12) include citrate esters (for example, triethyl O- ^{acetylcitrate} , O-acetyl tributyl citrate, acetyl triethyl citrate, acetyl tributyl citrate, O-acetyl citrate tri (ethyloxycarbonylmethylene) ester, etc.), oleic acid ester (eg ethyl oleate, butyl oleate, oleic acid 2) -Ethylhexyl, phenyl oleate, cyclohexyl oleate, octyl oleate, etc.), ricinoleate (eg, methylacetyl ricinoleate), sebacate (eg, dibutyl sebacate), carboxylic acid ester of glycerin (eg For example, triacetin, tributyrin, etc.), glycolic acid esters (eg, butyl phthalyl butyl glycolate, ethyl phthalyl ethyl glycolate, methyl phthalyl ethyl glycolate, butyl phthalyl butyl glycolate, methyl phthalyl methyl glycolate, propyl) Phthalylpropyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, etc.), carboxylic acid ester of pentaerythritol (eg, pentaerythritol tetraacetate, pentaerythritol tetrabutyrate), carboxylic acid of dipentaerythritol Esters (eg, dipentaerythritol hexaacetate, dipentaerythritol hexabutyrate, dipentaerythritol tetraacetate, etc.), Limethylolpropane carboxylates (trimethylolpropane triacetate, trimethylolpropane diacetate monopropionate, trimethylolpropane tripropionate, trimethylolpropane tributyrate, trimethylolpropane tripivaloate, trimethylolpropane triacetate (T-butyl acetate), trimethylolpropane di-2-ethylhexanate, trimethylolpropane tetra-2-ethylhexanate, trimethylolpropane diacetate monooctanoate, trimethylolpropane trioctanoate, trimethylolpropane tri (cyclohexanecarboxy) Etc.), glycerol esters described in JP-A-11-246704, and JP-A-2000-63560. Diglycerol esters, citric acid esters described in JP-A No. 11-92574, pyrrolidone carboxylic acid esters (methyl 2-pyrrolidone-5-carboxylate, ethyl 2-pyrrolidone-5-carboxylate, 2-pyrrolidone- Butyl 5-carboxylate, 2-pyrrolidone-5-carboxylic acid 2-ethylhexyl), cyclohexane dicarboxylic acid ester (dibutyl cis-1,2-cyclohexanedicarboxylate, dibutyl trans-1,2-cyclohexanedicarboxylate, cis-1, 4-cyclohexanedicarboxylate dibutyl, trans-1,4-cyclohexanedicarboxylate dibutyl, etc.), xylitol carboxylate (xylitol pentaacetate, xylitol tetraacetate, xylitol pentapropionate, etc.) ) And the like.

  Examples of the compounds represented by the general formulas (1) to (12) that can be used in the present invention are listed below, but the present invention is not limited to these. For general formula (1), compounds (C-1 to C-76) are exemplified, and for general formulas (2) to (12), compounds (C-201 to C-231, C-401 to C- 448). The value of logP described in the table or in parentheses is determined by the Crippen's fragmentation method (J. Chem. Inf. Comput. Sci., 27, 21 (1987)).

(In the formula, R ^1-3 has the same meaning as R ^{11-13 in the} general formula (1), and specific examples are illustrated by C-1 to C-76 below.)

The compounds of the general formulas (13) and (14) will be described.
In the general formula (13), R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group, or an aryl group. Moreover, it is particularly preferable that the total number of carbon atoms of R ¹ , R ² and R ³ is 10 or more. In the general formula (14), R ⁴ and R ⁵ each independently represents an alkyl group or an aryl group. The total number of carbon atoms of R ⁴ and R ⁵ is 10 or more, and each of the alkyl group and aryl group may have a substituent. As the substituent, a fluorine atom, an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are preferable, and an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are particularly preferable. Further, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, and more preferably 6 to 20 (E.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, heptyl, octyl, bicyclooctyl, nonyl, adamantyl, decyl, t-octyl, undecyl, Dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, didecyl) are particularly preferred. As the aryl group, those having 6 to 30 carbon atoms are preferable, and those having 6 to 24 carbon atoms (for example, phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, triphenylphenyl) are particularly preferable. Although the preferable example of a compound represented by General formula (13) or General formula (14) is shown below, this invention is not limited to these specific examples.

The compound of the general formula (15) will be described.
In the general formula (15), R ¹ , R ² and R ³ each independently represent a hydrogen atom or an alkyl group. The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, propyl, isopropyl, butyl, amyl, isoamyl), and at least one of R ¹ , R ² and R ³ The above is particularly preferably an alkyl group having 1 to 3 carbon atoms (for example, methyl, ethyl, propyl, isopropyl). X represents a single bond, —O—, —CO—, —NR ⁴ — (R ⁴ represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group), an alkylene group (preferably having a carbon number of 1 to 6, more preferably selected from 1 to 3, such as methylene, ethylene, propylene) or an arylene group (preferably having 6 to 24 carbon atoms, more preferably 6 to 12, such as phenylene, biphenylene, naphthylene). It is preferably a divalent linking group formed from one or more groups selected, and is a divalent linking group formed from one or more groups selected from —O—, an alkylene group, or an arylene group. Is particularly preferred. Y is a hydrogen atom or an alkyl group (preferably having 2 to 25 carbon atoms, more preferably 2 to 20 carbon atoms. For example, ethyl, isopropyl, t-butyl, hexyl, 2-ethylhexyl, t-octyl, dodecyl, cyclohexyl , Dicyclohexyl, adamantyl), an aryl group (preferably having 6 to 24 carbon atoms, more preferably 6 to 18. For example, phenyl, biphenyl, terphenyl, naphthyl) or an aralkyl group (preferably having 7 to 30 carbon atoms). And more preferably 7 to 20. For example, benzyl, cresyl, t-butylphenyl, diphenylmethyl, triphenylmethyl) is preferable, and an alkyl group, an aryl group, or an aralkyl group is particularly preferable. As the combination of —X—Y, the total carbon number of —X—Y is preferably 0 to 40, more preferably 1 to 30, and most preferably 1 to 25. Although the preferable example of a compound represented by these General formula (14) is shown below, this invention is not limited to these specific examples.

  The compound of the general formula (16) will be described.

Q ¹ , Q ² and Q ³ each independently represents a 5- to 6-membered ring, which may be a hydrocarbon ring or a hetero ring, and may be a single ring, or may be further condensed with another ring. May be formed. The hydrocarbon ring is preferably a substituted or unsubstituted cyclohexane ring, a substituted or unsubstituted cyclopentane ring, or an aromatic hydrocarbon ring, and more preferably an aromatic hydrocarbon ring. The hetero ring is preferably a ring containing at least one of a 5- to 6-membered oxygen atom, nitrogen atom or sulfur atom. More preferably, the heterocycle is an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom.
Q ¹ , Q ² and Q ³ are preferably an aromatic hydrocarbon ring or an aromatic hetero ring. The aromatic hydrocarbon ring is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, benzene ring, naphthalene ring etc.), more preferably 6 carbon atoms. -20 aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferred is a benzene ring.

The aromatic heterocycle is preferably an aromatic heterocycle containing an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, Examples include quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline. Q ¹ , Q ² and Q ³ are more preferably an aromatic hydrocarbon ring, and more preferably a benzene ring. Q ¹ , Q ² and Q ³ may have a substituent, and examples of the substituent include the substituent T described later.
X represents B, CR (R represents a hydrogen atom or a substituent), N, P, P = O, X is preferably B, CR (R is preferably an aryl group, a substituted or unsubstituted amino group , Alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, hydroxy group, mercapto group, halogen atom ( For example, fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group, more preferably aryl group, alkoxy group, aryloxy group, hydroxy group, halogen atom, more preferably alkoxy group, hydroxy group , Particularly preferably a hydroxy group.), N, and more preferred as X It is CR, N, and particularly preferably from CR.
Preferred as the general formula (16) is a compound represented by the following general formula (17).

(Wherein X ² represents B, C—R (R represents a hydrogen atom or a substituent), N, P, P═O. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ³¹ , R ³² , R ³³ , R ³⁴ to R ³⁵ represent a hydrogen atom or a substituent.)

X ² represents B, C—R (R represents a hydrogen atom or a substituent), N, P, P═O, X ² is preferably B, C—R (R is preferably an aryl group, substituted) Or unsubstituted amino group, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, hydroxy group, Mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom) and carboxyl group, more preferably aryl group, alkoxy group, aryloxy group, hydroxy group and halogen atom, still more preferably alkoxy Group, a hydroxy group, particularly preferably a hydroxy group. , N, a P = O, more preferably a C-R, N, particularly preferably C-R.

R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ³¹ , R ³² , R ³³ , R ³⁴ to R ³⁵ are hydrogen atoms or substituents The substituent T described later can be applied as the substituent. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ , R ³¹ , R ³² , R ³³ , R ³⁴ to R ³⁵ are preferably alkyl groups, Alkenyl, alkynyl, aryl, substituted or unsubstituted amino, alkoxy, aryloxy, acyl, alkoxycarbonyl, aryloxycarbonyl, acyloxy, acylamino, alkoxycarbonylamino, aryloxycarbonyl Amino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, sulfonyl group, sulfinyl group, ureido group, phosphoric acid amide group, hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine) Atom, iodine atom), shear Group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, For example, a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), and a silyl group. An alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, and an aryloxy group are preferable, and an alkyl group, an aryl group, and an alkoxy group are more preferable.
These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  The aforementioned substituent T will be described below. Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

  Hereinafter, the compound represented by the general formula (16) will be described in detail with specific examples, but the present invention is not limited to the following specific examples.

  Although the preferable example of a compound represented by General formula (18) or General formula (19) below is shown below, this invention is not limited to these specific examples.

  Hereinafter, examples of the Rth reducing agent having an octanol-water partition coefficient (Log P value) of 0 to 7 will be shown, but the present invention is not limited to these specific examples.

(Polyhydric alcohol ester compound)
The polyhydric alcohol ester is an ester of a dihydric or higher polyhydric alcohol and one or more monocarboxylic acids. Examples of the polyhydric alcohol ester compound include the following, but the present invention is not limited thereto.

(Polyhydric alcohol)
Examples of preferable polyhydric alcohol include, for example, 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, Examples thereof include galactitol, mannitol, 3-methylpentane-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.

(Monocarboxylic acid)
There is no restriction | limiting in particular as monocarboxylic acid in a 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 preferable in terms of improving the moisture permeability, water content, and retention of the cellulose acylate film.

  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 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, 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-hexanecarboxylic 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, Examples thereof include unsaturated fatty acids such as oleic acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid. These may further have a substituent.

  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 carboxylic acid in 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. Preferably, it has 3 or more aromatic rings or cycloalkyl rings in the molecule.

  Examples of the polyhydric alcohol ester compound include the following compounds, but the present invention is not limited thereto.

(Carboxylic acid ester compound)
Examples of the carboxylic acid ester compound include the following compounds, but the present invention is not limited thereto. Specifically, phthalic acid esters such as phthalic acid esters and citric acid esters, phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dicyclohexyl phthalate, dioctyl phthalate and diethyl hexyl phthalate, etc. Mention may be made of acetyltributyl acid. In addition, butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, triacetin, trimethylolpropane tribenzoate and the like can also be mentioned. 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, methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, Octyl phthalyl octyl glycolate is preferable, and ethyl phthalyl ethyl glycolate is particularly preferably used. Two or more of these alkylphthalylalkyl glycolates may be used in combination.

  Examples of the carboxylic acid ester compound include the following compounds, but the present invention is not limited thereto.

(Polycyclic carboxylic acid compound)
The polycyclic carboxylic acid compound used in the present invention is preferably a compound having a molecular weight of 3000 or less, and particularly preferably a compound having a molecular weight of 250 to 2000. With respect to the cyclic structure, the size of the ring is not particularly limited, but it is preferably composed of 3 to 8 atoms, particularly preferably a 6-membered ring and / or a 5-membered ring. These may contain carbon, oxygen, nitrogen, silicon or other atoms, and a part of the ring bond may be an unsaturated bond. For example, the 6-membered ring may be a benzene ring or a cyclohexane ring. The compound used in the present invention contains a plurality of such cyclic structures. For example, the compound has both a benzene ring and a cyclohexane ring in the molecule, or has two cyclohexane rings. Or a derivative of naphthalene or anthracene. More preferably, it is a compound containing three or more such cyclic structures in the molecule. Moreover, it is preferable that at least one bond of the cyclic structure does not contain an unsaturated bond. Specifically, abietic acid derivatives such as abietic acid, dehydroabietic acid, and parastrinic acid are typical, and chemical formulas of these compounds are shown below, but are not particularly limited thereto.

(Bisphenol derivative)
The bisphenol derivative used in the present invention preferably has a molecular weight of 10,000 or less, and may be a monomer, an oligomer or a polymer within this range. Moreover, the copolymer with another polymer may be sufficient and the reactive substituent may be modified by the terminal. The chemical formulas of these compounds are shown below, but are not particularly limited thereto.

In the above specific examples of the bisphenol derivative, R ^{1 to} R ⁴ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. l, m, and n represent a repeating unit and are not particularly limited, but an integer of 1 to 100 is preferable, and an integer of 1 to 20 is more preferable.

[Wavelength dispersion adjusting agent]
The compound for reducing the wavelength dispersion of the cellulose acylate film of the present invention (hereinafter also referred to as a wavelength dispersion adjusting agent) will be described. In order to improve the Rth wavelength dispersion of the cellulose acylate film, a compound that reduces the Rth wavelength dispersion (ΔRth) represented by the following formula (XXI) is represented by the following formulas (XIX) and (XX). It is preferable to contain at least one type within the range.
(XIX) (ΔRth (B) −ΔRth (0)) / B ≦ −2.0
(XX) 0.01 ≦ B ≦ 30
(XXI) ΔRth = | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ |
[In the formula, ΔRth (B) is ΔRth (nm) of a film containing B% of a compound that reduces ΔRth, and ΔRth (0) is ΔRth (nm) of a film not containing a compound that reduces ΔRth. is there. B is the mass (%) of the compound when the mass of the film raw material polymer is 100. ]

The above formulas (XIX) and (XX) are (XXII) (ΔRth (B) −ΔRth (0)) / B ≦ −3.0
(XXIII) 0.05 ≦ B ≦ 25
More preferably,
(XXIV) (ΔRth (B) −ΔRth (0)) / B ≦ −4.0
(XXV) 0.1 ≦ B ≦ 20
More preferably.
The above-mentioned wavelength dispersion adjusting agent has absorption in the ultraviolet region of 200 to 400 nm, and 0.01 to 30% by mass of cellulose acylate solid content is added to reduce the wavelength dispersion of Re and Rth of the cellulose acylate film. Can be adjusted.

  In general, the Re and Rth values of the cellulose acylate film have a wavelength dispersion characteristic that the longer wavelength side is larger than the shorter wavelength side. Therefore, it is required to smooth the chromatic dispersion by increasing Re and Rth on the relatively short wavelength side. On the other hand, a compound having absorption in the ultraviolet region of 200 to 400 nm has a wavelength dispersion characteristic in which the absorbance on the long wavelength side is larger than that on the short wavelength side. If the compound itself is isotropically present inside the cellulose acylate film, it is assumed that the birefringence of the compound itself, and thus the wavelength dispersion of Re and Rth, is large on the short wavelength side as well as the wavelength dispersion of absorbance. .

  Therefore, as described above, by using the compound having absorption in the ultraviolet region of 200 to 400 nm and assuming that the wavelength dispersion of Re and Rth of the compound itself is large on the short wavelength side, the Re and Rth of the cellulose acylate film are used. Chromatic dispersion can be prepared. For this purpose, the compound for adjusting the wavelength dispersion is required to be sufficiently homogeneously compatible with the cellulose acylate. The absorption band range in the ultraviolet region of such a compound is preferably 200 to 400 nm, more preferably 220 to 395 nm, and even more preferably 240 to 390 nm.

In recent years, liquid crystal display devices such as televisions, notebook personal computers, and mobile portable terminals have been required to have excellent transmittance of optical members used in liquid crystal display devices in order to increase luminance with less power. In this respect, a cellulose acylate film is a compound having absorption in the ultraviolet region of 200 to ₄₀₀ nm and reducing | Re ₍₄₀₀₎ -Re ₍₇₀₀₎ | and | Rth ₍₄₀₀₎ -Rth ₍₇₀₀₎ | When it is added, it is required that the spectral transmittance is excellent. In the cellulose acylate film of the present invention, the spectral transmittance at a wavelength of 380 nm is preferably 45% to 95%, and the spectral transmittance at a wavelength of 350 nm is preferably 10% or less.

  As described above, the wavelength dispersion adjusting agent preferably used in the present invention preferably has a molecular weight of 250 to 1000 from the viewpoint of volatility. More preferably, it is 260-800, More preferably, it is 270-800, Most preferably, it is 300-800. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.

  It is preferable that the wavelength dispersion adjusting agent does not volatilize during the dope casting and drying process for producing the cellulose acylate film.

(Compound addition amount)
The addition amount of the wavelength dispersion adjusting agent preferably used in the present invention described above is preferably 0.01 to 30% by mass, and preferably 0.1 to 20% by mass with respect to the solid content of the cellulose acylate. More preferred is 0.2 to 10% by mass.

(Method of compound addition)
These wavelength dispersion adjusting agents may be used alone or in combination of two or more compounds at an arbitrary ratio.
Further, the timing of adding these wavelength dispersion adjusting agents may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  Specific examples of the wavelength dispersion adjusting agent preferably used in the present invention include, for example, benzotriazole compounds, benzophenone compounds, compounds containing a cyano group, oxybenzophenone compounds, salicylic acid ester compounds, nickel complex compounds, and the like. However, the present invention is not limited to these compounds.

  As the benzotriazole-based compound, those represented by the general formula (101) are preferably used as the wavelength dispersion adjusting agent in the present invention.

Formula ^{(101) Q 1} -Q 2 -OH

(In the formula, Q ¹ represents a nitrogen-containing aromatic heterocycle, and Q ² represents an aromatic ring.)

Q ¹ represents a nitrogen-containing aromatic heterocycle, preferably a 5- to 7-membered nitrogen-containing aromatic heterocycle, more preferably a 5- to 6-membered nitrogen-containing aromatic heterocycle, such as imidazole , Pyrazole, triazole, tetrazole, thiazole, oxazole, selenazole, benzotriazole, benzothiazole, benzoxazole, benzoselenazole, thiadiazole, oxadiazole, naphthothiazole, naphthoxazole, azabenzimidazole, purine, pyridine, pyrazine, pyrimidine, Examples thereof include pyridazine, triazine, triazaindene, tetrazaindene, and more preferably a 5-membered nitrogen-containing aromatic heterocycle, specifically imidazole, pyrazole, triazole, tetrazole, thiazole, oxa Lumpur, benzotriazole, benzothiazole, benzoxazole, thiadiazole, oxadiazole preferably, particularly preferably benzotriazole.
The nitrogen-containing aromatic heterocycle represented by Q ¹ may further have a substituent, and the substituent T described later can be applied as the substituent. In addition, when there are a plurality of substituents, each may be condensed to further form a ring.

The aromatic ring represented by Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (such as a benzene ring or a naphthalene ring), and more preferably having 6 to 20 carbon atoms. An aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms, and a benzene ring is most preferred.
The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.
The aromatic ring represented by Q ² is preferably an aromatic hydrocarbon ring, more preferably a naphthalene ring or a benzene ring, and particularly preferably a benzene ring. Q ² may further have a substituent, and the substituent T described later is preferable.
Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably C1-C16, Especially preferably, it is C1-C12, for example, a mesyl, tosyl etc. are mentioned), a sulfinyl group (preferably C1-C20)
More preferably, it has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methanesulfinyl, benzenesulfinyl and the like. ), A ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include ureido, methylureido, phenylureido, etc.), phosphoric acid. Amido group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenylphosphoric acid amide), hydroxy group , Mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group ( Preferably it is C1-C30, More preferably, it is 1-12, As a hetero atom, for example, a nitrogen atom, an oxygen atom, A yellow atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably Are those having 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyl and triphenylsilyl). These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

As the general formula (101), a compound represented by the following general formula (101-A) is preferable.
General formula (101-A)

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represents a hydrogen atom or a substituent)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represent a hydrogen atom or a substituent, and the substituent T described above can be applied as the substituent. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.
R ¹ and R ³ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably an alkyl group having 1 to 12 carbon atoms (preferably 4 to 12 carbon atoms).

R ² and R ⁴ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and a carbon 1-12 alkyl group, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁵ and R ⁸ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁶ and R ⁷ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and a halogen atom, and particularly preferably a hydrogen atom and a chlorine atom.

More preferable as the general formula (101) is a compound represented by the following general formula (101-B).
General formula (101-B)

(In formula, R < ¹ >, R < ³ >, R < ⁶ > and R < ⁷ > are synonymous with those in general formula (101-A), and their preferred ranges are also the same.)

  Specific examples of the compound represented by formula (101) are listed below, but the present invention is not limited to the following specific examples.

  Among the benzotriazole compounds exemplified in the above examples, when the cellulose acylate film of the present invention was produced without including those having a molecular weight of 320 or less, it was confirmed that it was advantageous in terms of retention.

In addition, as the benzophenone compound which is one of the wavelength dispersion adjusting agents used in the present invention, those represented by the general formula (102) are preferably used.
General formula (102)

(Wherein Q ¹ and Q ² each independently represents an aromatic ring. X represents NR (R represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.)

The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring represented by Q ¹ and Q ² is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (such as a benzene ring and a naphthalene ring). More preferably, it is a C6-C20 aromatic hydrocarbon ring, More preferably, it is a C6-C12 aromatic hydrocarbon ring, More preferably, it is a benzene ring.
The aromatic heterocycle represented by Q ¹ and Q ² is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, Examples include quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.
The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms, still more preferably a substituted or unsubstituted benzene ring. is there.
Q ¹ and Q ² may further have a substituent, and the substituent T described later is preferable, but the substituent does not contain a carboxylic acid, a sulfonic acid, or a quaternary ammonium salt. Further, when possible, the substituents may be linked to form a ring structure.

  X represents NR (R represents a hydrogen atom or a substituent. Substituent T described later can be applied as the substituent), an oxygen atom or a sulfur atom, and X is preferably NR (R is preferably an acyl group) A sulfonyl group, and these substituents may be further substituted.) Or an oxygen atom, particularly preferably an oxygen atom.

  Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, and n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

As the general formula (102), a compound represented by the following general formula (102-A) is preferable.
Formula (102-A)

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent.)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent, and the substituent T described above applies as the substituent it can. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁸ and R ⁹ are preferably hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, substituted or unsubstituted amino group, alkoxy group, aryl An oxy group, a hydroxy group and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, still more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms. And particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ² is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or a carbon number of 1 An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, and more preferably an alkoxy group having 1-20 carbon atoms. And particularly preferably an alkoxy group having 1 to 12 carbon atoms.

R ⁷ is preferably a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, substituted or unsubstituted amino group, alkoxy group, aryloxy group, hydroxy group, halogen atom, more preferably a hydrogen atom or carbon number 1 An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom, having 1-20 carbon atoms. An alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably a methyl group), particularly preferably a methyl group or a hydrogen atom.

More preferable as the general formula (102) is a compound represented by the following general formula (102-B).
General formula (102-B)

(Wherein R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group.)

R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group. Applicable.
R ¹⁰ is preferably a substituted or unsubstituted alkyl group, more preferably a substituted or unsubstituted alkyl group having 5 to 20 carbon atoms, and still more preferably a substituted or unsubstituted alkyl group having 5 to 12 carbon atoms. (Including n-hexyl group, 2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group, etc.), particularly preferably a substitution of 6 to 12 carbon atoms or An unsubstituted alkyl group (2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group).

The compound represented by the general formula (102) can be synthesized by a known method described in JP-A-11-12219.
Specific examples of the compound represented by the general formula (102) are given below, but the present invention is not limited to the following specific examples.

In the present invention, a compound containing a cyano group can be used as the wavelength dispersion adjusting agent. As the compound containing a cyano group, a compound represented by the general formula (103) is preferable.
General formula (103)

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X ¹ and X ² represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, an aromatic group. Represents an aromatic ring.) The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. These may be monocyclic or may form a condensed ring with another ring.

  The aromatic hydrocarbon ring is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (such as a benzene ring or a naphthalene ring), and more preferably having 6 to 20 carbon atoms. An aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms, and more preferably a benzene ring.

  The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, Examples include phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzthiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.

The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.
Q ¹ and Q ² may further have a substituent, and a substituent T described later is preferable. Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably carbon number). 2-8, for example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6-30 carbon atoms) More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, naphthyl and the like, and a substituted or unsubstituted amino group (preferably having 0 to 0 carbon atoms). 20, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, etc.), an alkoxy group (preferably having a carbon number) 1 to 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably 6 to 20 carbon atoms, more Preferably it has 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 2-naphthyloxy and the like. An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include acetyl, benzoyl, formyl, and pivaloyl). An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group ( Preferably it has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, and examples thereof include phenyloxycarbonyl, etc.), an acyloxy group (preferably 2 to 20 carbon atoms, More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms. Nzoyloxy and the like. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino), alkoxycarbonylamino group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino), aryloxycarbonylamino group (preferably having carbon number) 7 to 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, and sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. And sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, such as sulfamoyl and methylsulfamoyl). , Dimethylsulfamoyl, phenylsulfamoyl, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl). , Methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio, Ethylthio etc.), arylthio group (preferably Has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, and a sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl, tosyl, etc.), sulfinyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably Has 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 to 20 carbon atoms) More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, diethyl phosphoric acid amide, phenylphosphoric acid amide etc. are mentioned. ), Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, Heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, specifically, for example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl , Morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, and particularly preferably 3 to 24 carbon atoms). For example, trimethylsilyl, triphenylsilyl, etc.) . These substituents may be further substituted. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

X ¹ and X ² each represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, or an aromatic heterocycle. The substituent T described above can be applied to the substituents represented by X ¹ and X ² . In addition, the substituent represented by X ¹ and X ² may be further substituted with another substituent, and X ¹ and X ² may be condensed to form a ring structure.

X ¹ and X ² are preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group, or an aromatic heterocyclic ring, and more preferably a cyano group, a carbonyl group, a sulfonyl group, An aromatic heterocycle, more preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, 6 carbon atoms). ˜12 aryl groups and combinations thereof.

As the general formula (103), a compound represented by the following general formula (103-A) is preferable.
General formula (103-A)

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom or a substituent. X ¹ and X ² is synonymous with those in the general formula (20), and the preferred range is also the same.)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ each independently represent a hydrogen atom or a substituent, and the substituent is the above-described substituent. The group T can be applied. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ² , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, An alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, still more preferably a hydrogen atom and carbon 1-12. An alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ³ and R ⁸ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, and a hydroxy group, and more preferably a hydrogen atom and carbon They are a C1-C12 alkyl group and a C1-C12 alkoxy group, and particularly preferably a hydrogen atom.

More preferable as the general formula (103) is a compound represented by the following general formula (103-B).
General formula (103-B)

(Wherein R ³ and R ⁸ have the same meanings as those in formula (103-A), and preferred ranges thereof are also the same. X ₃ represents a hydrogen atom or a substituent.)

X ₃ represents a hydrogen atom or a substituent. As the substituent, the above-described substituent T can be applied, and if possible, the substituent may be further substituted with another substituent. X ₃ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group, or an aromatic heterocyclic ring, and more preferably a cyano group, a carbonyl group, a sulfonyl group, or an aromatic heterocyclic ring. More preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, aryl having 6 to 12 carbon atoms). Group and a combination thereof).

As the general formula (103), a compound represented by the general formula (103-C) is more preferable.
General formula (103-C)

(In the formula, R ³ and R ⁸ have the same definitions as those in formula (103-A), and preferred ranges are also the same. R ²¹ represents an alkyl group having 1 to 20 carbon atoms.)

R ²¹ is preferably an alkyl group having 2 to 12 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, and still more preferably 6 carbon atoms when both R ³ and R ⁸ are hydrogen. To 12 alkyl groups, particularly preferably n-octyl group, tert-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group, most preferably 2-ethylhexyl group. It is.

Preferably, when R ³ and R ⁸ are other than hydrogen as R ²¹ , the compound represented by the general formula (103-C) has a molecular weight of 300 or more and an alkyl group having 20 or less carbon atoms. preferable.

  The compound represented by the general formula (103) can be synthesized by the method described in Journal of American Chemical Society 63, 3452 (1941).

  Specific examples of the compound represented by the general formula (103) are given below, but the present invention is not limited to the following specific examples.

[Matting agent fine particles]
It is preferable to add fine particles as a matting agent to the cellulose acylate film of the present invention. The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and Mention may be made of calcium phosphate. Fine particles containing silicon are preferable from the viewpoint of low turbidity, and silicon dioxide is particularly preferable. The silicon dioxide fine particles preferably have a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more. Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm, and these fine particles are present as aggregates of primary particles in the film, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The secondary average particle size is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm. The primary and secondary particle sizes were determined by observing the particles in the film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles as the particle size. In addition, 200 particles were observed at different locations, and the average value was taken as the average particle size.

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

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

In order to obtain a cellulose acylate film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a fine particle dispersion. For example, a method of preparing a fine particle dispersion in which a solvent and fine particles are mixed with stirring in advance, adding this fine particle dispersion to a small amount of cellulose acylate solution separately prepared, stirring and dissolving, and further mixing with the main cellulose acylate dope solution There is. This method is a preferred preparation method in that the dispersibility of the silicon dioxide fine particles is good and the silicon dioxide fine particles are more difficult to reaggregate. In addition, a small amount of cellulose ester is added to the solvent, stirred and dissolved, and then the fine particles are added and dispersed with a disperser to make this fine particle additive solution. There is also a way to do it. The present invention is not limited to these methods, but the concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent or the like is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and 15 to 20%. Mass% is most preferred. A higher dispersion concentration is preferable because the liquid turbidity with respect to the added amount is lowered, and haze and aggregates are improved. The addition amount of the matting agent in the final cellulose acylate dope solution is preferably 0.01 to 1.0 g, more preferably 0.03 to 0.3 g, and 0.08 to 0.16 g per 1 m ^2. Most preferred.

  The solvent used is preferably lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the solvent used at the time of film forming of a cellulose ester.

[Plasticizer, degradation inhibitor, release agent]
In addition to the above-mentioned compound that optically reduces anisotropy and the wavelength dispersion adjusting agent, the cellulose acylate film of the present invention has various additives (for example, a plasticizer, an ultraviolet ray, etc.) in each preparation step. Inhibitors, degradation inhibitors, release agents, infrared absorbers, etc.), which may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of ultraviolet absorbing materials having melting points of 20 ° C. or lower and 20 ° C. or higher, and similarly, mixing of a plasticizer is described in, for example, Japanese Patent Application Laid-Open No. 2001-151901. Furthermore, infrared absorbing dyes are described, for example, in JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the dope preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a cellulose acylate film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ. For example, although it describes in Unexamined-Japanese-Patent No. 2001-151902 etc., these are techniques conventionally known. For these details, materials described in detail on pages 16 to 22 in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical No. 2001-1745, published on March 15, 2001, Japan Institute of Invention) are preferably used.

[Rate of compound addition]
In the cellulose acylate film of the present invention, the total amount of compounds having a molecular weight of 3000 or less is preferably 5 to 45% based on the mass of the cellulose acylate. More preferably, it is 10 to 40%, and more preferably 15 to 30%. As described above, these compounds include compounds that reduce optical anisotropy, wavelength dispersion regulators, ultraviolet inhibitors, plasticizers, deterioration inhibitors, fine particles, release agents, infrared absorbers, and the like. The molecular weight is preferably 3000 or less, more preferably 2000 or less, and even more preferably 1000 or less. When the total amount of these compounds is less than 5%, the properties of cellulose acylate alone are likely to be obtained, and there are problems such as that the optical performance and physical strength are likely to vary with changes in temperature and humidity. Moreover, when the total amount of these compounds exceeds 45%, it exceeds the limit that the compounds are compatible with each other in the cellulose acylate film, and these compounds are deposited on the film surface and the film becomes cloudy (crying out from the film). Problems are likely to occur.

[Organic solvent for cellulose acylate solution]
In the present invention, it is preferable to produce a cellulose acylate film by a solvent cast method, and the film is produced using a solution (dope) in which cellulose acylate is dissolved in an organic solvent. The organic solvent preferably used as the main solvent in the present invention is preferably a solvent selected from esters, ketones, ethers having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 7 carbon atoms. The ester, ketone and ether may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and —COO—) can also be used as a main solvent, such as an alcoholic hydroxyl group. It may have a functional group of In the case of the main solvent having two or more kinds of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group.

  As described above, chlorine-based halogenated hydrocarbons may be used as the main solvent for the cellulose acylate film of the present invention, and as described in JIII Journal of Technical Disclosure 2001-1745 (pages 12-16), A non-chlorine solvent may be used as the main solvent, and is not particularly limited.

  In addition, the solvent for the cellulose acylate solution and the film of the present invention is disclosed in the following patents, including its dissolution method, and is a preferred embodiment. They are, for example, JP 2000-95876, JP 12-95877, JP 10-324774, JP 8-152514, JP 10-330538, JP 9-95538, JP 9-95557, JP 10-10. -235664, JP-A-12-63534, JP-A-11-21379, JP-A-10-182853, JP-A-10-278056, JP-A-10-279702, JP-A-10-323853, JP-A-10-237186, JP-A-11-60807. JP-A-11-152342, JP-A-11-292988, JP-A-11-60752, and the like. According to these patents, not only the preferred solvent for the cellulose acylate of the present invention but also the physical properties of the solution and the coexisting substances to be coexisted are described, which is a preferred embodiment in the present invention.

[Manufacturing process of cellulose acylate film]
[Dissolution process]
The method for dissolving the cellulose acylate solution (dope) of the present invention is not particularly limited, and may be performed at room temperature, further by a cooling dissolution method or a high temperature dissolution method, or a combination thereof. Regarding the preparation of the cellulose acylate solution in the present invention, and further the steps of solution concentration and filtration associated with the dissolution step, the Technical Report of the Japan Society of Invention (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Invention) The manufacturing process described in detail on pages 22 to 25 is preferably used.

(Transparency of dope solution)
The dope transparency of the cellulose acylate solution of the present invention is preferably 85% or more. More preferably, it is 88% or more, and more preferably 90% or more. In the present invention, it was confirmed that various additives were sufficiently dissolved in the cellulose acylate dope solution. As a specific method for calculating the dope transparency, the dope solution was poured into a 1 cm square glass cell, and the absorbance at 550 nm was measured with a spectrophotometer (UV-3150, Shimadzu Corporation). Only the solvent was measured in advance as a blank, and the transparency of the cellulose acylate solution was calculated from the ratio with the absorbance of the blank.

[Casting, drying, winding process]
Next, a method for producing a film using the cellulose acylate solution of the present invention will be described. As a method and equipment for producing the cellulose acylate film of the present invention, a solution casting film forming method and a solution casting film forming apparatus conventionally used for producing a cellulose triacetate film are used. The dope (cellulose acylate solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dry-dried dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support and substantially rounds the metal support. Both ends of the obtained web are sandwiched between clips, transported by a tenter while keeping the width, dried, then transported by a roll group of a drying device, dried, and wound up to a predetermined length by a winder. The combination of the tenter and the roll group dryer varies depending on the purpose. The cellulose acylate film of the present invention preferably has a slow axis in the vertical direction (TD direction) to the machine transport direction (MD direction) of the film. In the solution casting film forming method used for the functional protective film or the silver halide photographic light-sensitive material which is an optical member for electronic display, which is the main use of the cellulose acylate film of the present invention, the solution casting film forming apparatus In addition, a coating apparatus is often added for surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, and a protective layer. These are described in detail on pages 25-30 in the Japan Society for Invention and Innovation Technical Report (Public Technical Number 2001-1745, issued on March 15, 2001, Japan Society for Invention). Including), metal support, drying, peeling and the like, and can be preferably used in the present invention.
Moreover, 10-120 micrometers is preferable, as for the thickness of a cellulose acylate film, 40-100 micrometers is more preferable, and 60-80 micrometers is further more preferable.

[Optical compensation layer]
As the optical compensation layer, those satisfying the Nz value and the in-plane retardation Re ₁ value can be used without particular limitation. For example, a birefringent film of a polymer film, an alignment film of a liquid crystal polymer, an alignment film of a low molecular liquid crystal and the like can be mentioned.

Examples of the polymer include acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile / styrene copolymer (AS resin), polyolefins such as polycarbonate and polypropylene, polyesters such as polyethylene terephthalate and polyethylene naphthalate. , Alicyclic polyolefins such as polynorbornene, polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyphenylene oxide, Polyallylsulfone, polyvinyl alcohol, polyamide Polyimide, polyvinyl chloride, cellulose polymers, or their binary and ternary various copolymers, graft copolymers, and any blend thereof. Among these, polymers having a negative intrinsic birefringence value such as polystyrene and polymethyl methacrylate are particularly preferable. In particular, a graft copolymer ((C)) obtained by addition polymerization of at least one monomer (referred to as (B)) with a styrene monomer to a polymer having an unsaturated double bond (referred to as (A)). Is particularly desirable. The polymer (A) may have an unsaturated double bond in either the main chain or the side chain.
It is also preferable to use a polymer having a positive intrinsic birefringence value such as polyamide, polyimide, polyester, polyetherketone, polyamideimide, and polyesterimide.

The polymer (A) constituting the so-called trunk of the graft copolymer (C) will be described.
Specifically, the polymer (A) is a polymer having a repeating unit of an unsaturated double bond in the main chain or side chain. This repeating unit is preferably derived by polymerization of a monomer having a conjugated diene structure.

  Preferred examples of the monomer having the conjugated diene structure include 1,3-butadiene, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, and 2-n-propyl-1,3-butadiene. 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl -1,3-butadiene, 2-chloro-1,3-butadiene, 1-bromo-1,3-butadiene, 1-chlorobutadiene, 2-fluoro-1,3-butadiene, 2,3-dichloro-1, Mention may be made of 3-butadiene, 1,1,2-trichloro-1,3-butadiene and 2-cyano-1,3-butadiene. Among these, 1,3-butadiene, isoprene, and 2-chloro-1,3-butadiene are particularly preferable.

Further, the polymer (A) constituting the trunk of the graft copolymer (C) may be a copolymer of the monomer having the diene structure and a hydrophobic monomer other than this monomer. Good.
Examples of such hydrophobic monomers include ethylene, propylene, 1-butene, isobutene, styrene, α-methylstyrene, vinyl ketone, monoethylenically unsaturated hydrocarbon (alkene) esters of aliphatic acids (eg acetic acid). Vinyl, allyl acetate), esters of ethylenically unsaturated mono- or dicarboxylic acids (eg methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, n-butyl acrylate, n- Hexyl acrylate, 2-ethylhexyl acrylate, t-butyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate Acrylate), ethylenically unsaturated monocarboxylic or dicarboxylic acid amides (eg t-butylacrylamide, t-butylmethacrylamide) and monoethylenically unsaturated compounds (eg acrylonitrile, methacrylonitrile). . Among these, ethylene, propylene, styrene, α-methylstyrene, esters of acrylic acid or methacrylic acid, acrylonitrile, and methacrylonitrile are particularly preferable.

  Two or more of the above-mentioned monomers having a conjugated diene structure and other hydrophobic monomers may be used. The unsaturated structure introduced into the polymer (A) by polymerization of a monomer having a conjugated diene structure may be a cis-1,4 bond, as well known in the art, It may be a 1,4-bond or a trans 1,2-bond.

  The optical compensation layer controls the refractive index in the thickness direction by a method of stretching the polymer film biaxially in the plane direction, a method of stretching uniaxially or biaxially in the plane direction, and stretching in the thickness direction, etc. Can be obtained. Further, it can be obtained by, for example, a method in which a heat-shrinkable film is adhered to a polymer film and the polymer film is stretched or / and contracted by tilting under the action of the shrinkage force by heating.

A method for producing an optical compensation layer using the heat-shrinkable film will be described in detail. Use of a heat-shrinkable film is preferable because it can be continuously produced in a long shape. Specifically, a long polymer film with a heat-shrinkable film bonded to one or both sides is heat-treated to produce an optical compensation layer that satisfies the desired optical characteristics by the action of the shrinkage force of the heat-shrinkable film. can do. You may perform an extending | stretching process at the time of heat processing. For example, when heat-treating a long polymer film having a heat-shrinkable film bonded to one side or both sides, a roll stretching machine having a roll speed ratio of 1 or less under the action of the shrinkage force of the heat-shrinkable film. The optical compensation layer can be continuously formed into a long shape by treating and shrinking the film and further stretching in the width direction.
Here, as the heat-shrinkable film, a uniaxial heat-shrinkable film that preferentially shrinks to MD can be preferably used. A uniaxial heat shrinkable film is a shrinkable film having a degree of shrinkage on one side larger than the other. By matching the contraction axis of the uniaxial heat-shrinkable film with the longitudinal direction of the retardation film, the longitudinal direction can be further contracted with respect to the width direction.
Furthermore, a heat-tight roll using a large number of rolls as shown in FIG. In FIG. 1, 51 indicates a heat-tight roll, and 52 indicates a heat-compressed film. For example, by arranging about 10 to 100 rolls having a diameter of 10 cm at intervals of 5 cm as the heat-tight roll, the shrinkage in the longitudinal direction can be made stronger in the width direction by suppressing the shrinkage in the width direction. It is also effective to increase the friction coefficient of the heat-tight roll.
Furthermore, it can also include a step of stretching the long optical compensation layer in the width direction using a tenter having a structure in which the distance between the tenter clips in the longitudinal direction is narrowed while being held and conveyed. It is particularly preferred because it can be stretched in the width direction and simultaneously contracted in the longitudinal direction.

  A heat-shrinkable film that adheres to one or both sides of the film is intended to control the phase difference characteristics, especially the refractive index in the thickness direction, by shrinking the target film by transmitting the shrinkage force due to heating. used. As the heat-shrinkable film, for example, an appropriate film that exhibits shrinkability by heat treatment made of a stretched product of a polymer film can be used, and there is no particular limitation. From the viewpoint of controllability of the phase difference in the translucent film, a heat-shrinkable film made of a polymer exhibiting the positive birefringence characteristics exemplified above can be preferably used.

  Moreover, it is preferable to use a heat-shrinkable film that exhibits heat-shrinkability in the vicinity of the glass transition temperature of the film, from the viewpoint of imparting shrinkage force. The shrinkage force of the heat-shrinkable film can be controlled by, for example, the stretching conditions such as the type of polymer and the stretching ratio, the film thickness, and the like. It is preferable to use a heat-shrinkable film whose shrinkage force by heating is as uniform as possible on the entire surface of the film because uniform orientation can be imparted to the target film.

  For the adhesion between the heat-shrinkable film and the target film, it is preferable to use an adhesive from the viewpoint of the propagation of shrinkage force due to good adhesion. As the adhesive, the shrinkage force of the heat-shrinkable film is well transmitted to the film during the shrinkage treatment, and after the treatment, the heat shrinkage after the treatment is performed without changing the optical properties as much as possible from the processed material of the film. What can isolate | separate a property film is used preferably.

  From the above point, an adhesive layer or the like is preferably used. As the adhesive layer, for example, an appropriate material such as acrylic, silicone, polyester, polyurethane, polyether, rubber, or the like can be used, and the type is not particularly limited. In the heat-shrinkable film, one layer or two or more layers of the same type or different types can be bonded to one side or both sides of the film.

  The heat-shrinkable film adhered to the film exhibits its shrinkage force by heat treatment, but the heat treatment can be performed by an appropriate method and is not particularly limited. In general, a heating method through a roll in a roll stretching machine, an atmospheric heating method, or a method using them in combination is adopted.

  From the viewpoint of stable processing by a roll stretching machine under the action of the shrinkage force of the heat-shrinkable film, the ratio of dimensional change based on the length direction (MD) / width direction (TD) of the heat-shrinkable film is It is preferable to perform the heat treatment under a temperature condition of 1.5 or less. Heat treatment with a dimensional change ratio exceeding 1.5 tends to cause meandering due to insufficient tension in the translucent film traveling between rolls, and does not cause deformation of the translucent film in accordance with the speed ratio of the roll. It is difficult to satisfy the condition of nx <nz.

  From the point of achieving the above dimensional change rate ratio, it is preferable to heat-treat in the temperature range of Tg ± 20 ° C. based on the glass transition temperature (Tg) of the polymer forming the heat-shrinkable film. The dimensional change rate ratio is defined as MD dimension / TD dimension after heat shrinkage, where the initial dimension before shrinkage of MD and TD is 1.

  In the above, the roll stretching machine used for the film shrinkage treatment is not particularly limited, and an appropriate type can be used. The processing conditions are preferably a roll speed ratio of 1 or less from the viewpoint of achieving film shrinkage. The retardation characteristics such as the refractive index of the obtained retardation film can be controlled by the kind of film, thickness, thickness change rate, shrinkage rate, processing temperature, and the like.

The long optical compensation layer thus produced is bonded to the long polarizing film via a transparent protective film. That is, after laminating the long optical compensation layer and the long transparent protective film, the long polarizing plate is bonded to the long polarizer or the transparent protective film is bonded, Bonded to the surface of the transparent protective film. According to the method using the heat-shrinkable film, it is possible to easily produce a long optical compensation layer whose slow axis is perpendicular to the longitudinal direction, and a long polarizer with a roll-to-roll. Can be pasted together.
When used in a liquid crystal display device, the optical compensation layer is cut into an appropriate size and then incorporated as an optical compensation polarizing plate. In the liquid crystal display device, the optical compensation layer is disposed on the liquid crystal cell side, and the slow axis of the optical compensation layer is arranged in parallel with the slow axis of the liquid crystal cell during black display.

  Examples of the liquid crystalline polymer include various main chain types and side chain types in which a conjugated linear atomic group (mesogen) imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. It is done. Specific examples of the main chain type liquid crystalline polymer include, for example, a nematic alignment polyester liquid crystalline polymer, a discotic polymer, and a cholesteric polymer having a structure in which a mesogen group is bonded to a spacer portion that imparts flexibility. . Specific examples of the side chain type liquid crystalline polymer include polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a nematic alignment imparting paraffin through a spacer portion composed of a conjugated atomic group as a side chain. Examples thereof include those having a mesogen moiety composed of a substituted cyclic compound unit. The alignment film of these liquid crystalline polymers is, for example, a liquid crystalline polymer on an alignment-treated surface such as a surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or an oblique deposition of silicon oxide. A solution in which the liquid crystal polymer is oriented by developing and heat-treating the above solution, and particularly in a tilted orientation, is preferred.

Examples of the low-molecular liquid crystal include rod-like or discotic (discotic) liquid crystalline compounds. It is preferable that the rod-like or discotic liquid crystalline compound is vertically aligned with respect to the transparent protective film surface.
(Discotic liquid crystalline compounds)
Examples of discotic liquid crystalline compounds that can be used in the present invention include various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by the Chemical Society of Japan). , Quarterly Chemical Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., Page 1794 (1985). J. Zhang et al., J. Am.Chem.Soc., Vol.116, page 2655 (1994)).

  In the optical compensation layer, the discotic liquid crystalline molecules are preferably fixed in an aligned state, and most preferably fixed by a polymerization reaction. In the present invention, it is preferable that the discotic liquid crystal molecules are oriented and fixed perpendicular to the transparent protective film surface. The polymerization of discotic liquid crystalline molecules is described in JP-A-8-27284. In order to fix the discotic liquid crystalline molecules by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline molecules. However, when the polymerizable group is directly connected to the disc-shaped core, it becomes difficult to maintain the orientation state in the polymerization reaction. Therefore, a linking group is introduced between the discotic core and the polymerizable group. JP-A-2001-4387 discloses a discotic liquid crystalline molecule having a polymerizable group.

(Bar-shaped liquid crystalline compound)
Examples of rod-like liquid crystalline compounds that can be used in the present invention include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, and cyano-substituted compounds. Phenyl pyrimidines, alkoxy substituted phenyl pyrimidines, phenyl dioxanes, tolanes and alkenyl cyclohexyl benzonitriles are included. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used.

  In the optical compensation layer, the rod-like liquid crystalline molecules are preferably fixed in an aligned state, and most preferably fixed by a polymerization reaction. In the present invention, it is preferable that the rod-like liquid crystal molecules are oriented and fixed perpendicularly to the transparent protective film surface. Examples of polymerizable rod-like liquid crystalline compounds that can be used in the present invention include Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), US Pat. Nos. 4,683,327, 5,622,648 and 5,770,107, World Patents (WO) 95/22586, 95/24455. No. 97/00600, No. 98/23580, No. 98/52905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and JP-A-2001-2001. And the compounds described in US Pat.

(Polarizer)
The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include hydrophilic polymers such as polyvinyl alcohol film, partially formalized polyvinyl alcohol film, and ethylene / vinyl acetate copolymer partially saponified film, and two colors such as iodine and dichroic dye. Examples include polyene-based oriented films such as those obtained by adsorbing a volatile substance and uniaxially stretched, polyvinyl alcohol dehydrated products, and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it can be immersed in an aqueous solution such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride and the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, or may be performed while dyeing, or may be performed with dyeing after iodine. The film can be stretched in an aqueous solution of boric acid or potassium iodide or in a water bath.

  The surface of the transparent protective film that does not adhere the polarizer (the surface on which the coating layer is not provided) was subjected to a treatment for the purpose of hard coat layer, antireflection treatment, sticking prevention, diffusion or antiglare (antiglare). It may be a thing. In this invention, it is preferable to have any one layer of a hard-coat layer, a glare-proof layer, and an antireflection layer.

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

The anti-glare treatment is applied for the purpose of preventing the outside light from being reflected on the surface of the polarizing plate and obstructing the visibility of the light transmitted through the polarizing plate. For example, the surface is roughened by a sandblasting method or an embossing method. It can be formed by imparting a fine concavo-convex structure to the surface of the transparent protective film by an appropriate method such as a blending method of transparent fine particles.
Examples of the fine particles to be included in the formation of the surface fine concavo-convex structure include conductive materials made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, and the like having an average particle diameter of 0.5 to 50 μm. In some cases, transparent fine particles such as inorganic fine particles, organic fine particles composed of a crosslinked or uncrosslinked polymer, and the like are used. When forming a surface fine concavo-convex structure, the amount of fine particles used is generally about 2 to 50 parts by mass and preferably 5 to 25 parts by mass with respect to 100 parts by mass of the transparent resin forming the surface fine concavo-convex structure. The antiglare layer may also serve as a diffusion layer (viewing angle expanding function or the like) for diffusing the light transmitted through the polarizing plate to expand the viewing angle.

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

[surface treatment]
The cellulose acylate film can achieve improved adhesion between the cellulose acylate film and each functional layer (for example, the undercoat layer and the back layer) by optionally performing a surface treatment. For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment here may be low-temperature plasma that occurs under a low pressure gas of 10 ^{−3 to} 20 Torr, and plasma treatment under atmospheric pressure is also preferred. A plasma-excitable gas is a gas that is plasma-excited under the above conditions, and includes chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, tetrafluoromethane, and mixtures thereof. It is done. Details of these are described in detail in pages 30 to 32 in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention), and are preferably used in the present invention. be able to.

[Contact angle of film surface by alkali saponification]
In the present invention, alkali saponification is one effective means for surface treatment of the transparent protective film. In this case, the contact angle on the film surface after the alkali saponification treatment is preferably 55 ° or less. More preferably, it is 50 ° or less, and more preferably 45 ° or less. The contact angle evaluation method can be used as an evaluation of hydrophilicity / hydrophobicity by an ordinary method in which a water droplet having a diameter of 3 mm is dropped on the surface of the film after the alkali saponification treatment and the angle formed by the film surface and the water droplet is determined.

  For the adhesion treatment between the polarizer and the transparent protective film, an isocyanate adhesive, a polyvinyl alcohol adhesive, a gelatin adhesive, a vinyl latex, an aqueous polyester, or the like is used after the surface treatment.

  The method for laminating the optical compensation layer and the polarizing plate is not particularly limited, and can be carried out by laminating the transparent protective film with an adhesive layer or an adhesive layer. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited. For example, an acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or rubber-based polymer is appropriately used as a base polymer. It can be selected and used. In particular, those having excellent optical transparency such as an acrylic pressure-sensitive adhesive, exhibiting appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and being excellent in weather resistance, heat resistance and the like can be preferably used.

[Preparation of polarizing plate]
A polarizing plate is obtained by laminating a transparent protective film on both sides of a polarizer. The method for laminating the transparent protective film is not particularly limited, but an adhesive or a pressure-sensitive adhesive is used when the transparent protective film and the polarizer are bonded together. The type of adhesive or pressure-sensitive adhesive is preferably a composition that has a low volatile content and does not require a high temperature during curing or drying, and can be processed in a short time, from the viewpoint of the moisture content of the polarizing plate and changes in properties.

  As a specific example of the adhesive or pressure-sensitive adhesive, an aqueous adhesive is preferable. For example, an isocyanate adhesive, a polyvinyl alcohol adhesive, a gelatin adhesive, a vinyl latex, a water-based polyester, or the like is used. The aqueous adhesive is usually used as an adhesive made of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content.

  The surface of the transparent protective film that adheres to the polarizer can be subjected to an easy adhesion treatment. Thereby, adhesive force can be improved. After the easy adhesion treatment, a dry treatment or an easy adhesion treatment material can be applied. Examples of the dry treatment include corona treatment, gas corona treatment, plasma treatment, and low-pressure UV treatment. Examples of the easy adhesion treatment material include cellulose ester-based resins, urethane-modified copolymerized polyester resins, and silane coupling agents. Dry treatment and easy adhesion coating may be used in combination. The transparent protective film can be saponified with a sodium hydroxide aqueous solution or the like to improve the adhesive force. Furthermore, a saponification treatment may be performed after the easy adhesion treatment.

  Bonding of a polarizer and a transparent protective film can be performed by a roll laminator or the like. Application of an adhesive or the like may be performed on either the transparent protective film or the polarizer, or may be performed on both sides. After the bonding, a drying process is performed to form an adhesive layer composed of a coating dry layer. The thickness of the adhesive layer is not particularly limited, but is usually about 0.1 to 5 μm.

  The polarizing plate of the present invention is dried after a transparent protective film and an optical compensation layer are bonded to both sides of the polarizer. Although it depends on the type of adhesive or the like, the drying temperature is usually 20 to 100 ° C., preferably 30 to 80 ° C. The drying time is 1 to 30 minutes, preferably 1 to 15 minutes. Under such drying conditions, the adhesive can be cured and moisture can be removed.

  Each layer such as an optical compensation polarizing plate and an adhesive layer is treated with an ultraviolet absorber such as a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate compound, or a nickel complex compound. What gave the ultraviolet absorptivity by a system etc. may be used.

  The optical compensation polarizing plate of the present invention is suitably used for an IPS mode liquid crystal display device. An IPS mode liquid crystal display device includes a pair of substrates sandwiching a liquid crystal layer, an electrode group formed on one of the pair of substrates, and a liquid crystal composition material layer having dielectric anisotropy sandwiched between the substrates. A liquid crystal comprising: an alignment control layer formed opposite to the pair of substrates for aligning a molecular arrangement of the liquid crystal composition material in a predetermined direction; and a driving means for applying a driving voltage to the electrode group Has a cell. The electrode group has an arrangement structure arranged so as to apply an electric field mainly parallel to the interface between the alignment control layer and the liquid crystal composition material layer.

  The optical compensation polarizing plate of the present invention is disposed on the viewing side or the light incident side of the liquid crystal cell. In the optical compensation polarizing plate, the optical compensation layer side is preferably the liquid crystal cell side. A polarizing plate is disposed on the opposite side of the liquid crystal cell on which the optical compensation polarizing plate is disposed. The absorption axis of the polarizing plate arranged on both sides of the cell substrate and the absorption axis of the optical compensation polarizing plate are arranged in an orthogonal state. As the polarizing plate, one obtained by laminating a transparent protective film on both surfaces of a polarizer similar to that used for the optical compensation polarizing plate is used. As the transparent protective film, a cellulose acylate film is preferably used, and a cellulose triacetate film is particularly preferably used. However, at least one of the polarizers may be used for the optical compensation polarizing plate of the present invention | Re | ≦ 10 and It is preferable to use a cellulose acylate film of | Rth | ≦ 25.

  When the optical compensation polarizing plate is disposed on the viewing side of the IPS mode liquid crystal cell, the liquid crystal molecules in the liquid crystal cell are not applied to the cell substrate on the opposite side (light incident side) to the viewing side. It is preferable that the long axis direction of the polarizing plate and the absorption axis of the polarizing plate be arranged in parallel.

  When the optical compensation polarizing plate is arranged on the light incident side of the IPS mode liquid crystal cell, the polarizing plate is arranged on the cell substrate on the viewing side, and the major axis direction of the liquid crystal molecules in the liquid crystal cell is not applied with voltage. It is preferable to arrange the optical compensation polarizing plate so that the absorption axes thereof are orthogonal.

  The optical compensation polarizing plate and the polarizing plate can be used by laminating other optical layers in practical use. The optical layer is not particularly limited. For example, the optical layer may be used for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, and a retardation plate (including a wave plate such as 1/2 or 1/4). One optical layer or two or more optical layers can be used. In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a polarizing plate is further laminated with a reflective plate or a semi-transmissive reflective plate, and a polarizing plate in which a luminance enhancement film is further laminated on the polarizing plate are preferable.

  A reflective polarizing plate is a polarizing plate provided with a reflective layer, and is used to form a liquid crystal display device or the like that reflects incident light from the viewing side (display side). Such a light source can be omitted, and the liquid crystal display device can be easily thinned. The reflective polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is attached to one surface of the polarizing plate via a transparent protective layer or the like as necessary.

  Specific examples of the reflective polarizing plate include those in which a reflective layer is formed by attaching a foil or a vapor deposition film made of a reflective metal such as aluminum on one side of a transparent protective film matted as necessary. Moreover, the transparent protective film contains fine particles so as to have a surface fine concavo-convex structure and a reflective layer having a fine concavo-convex structure thereon. The reflective layer having the fine concavo-convex structure has an advantage that incident light is diffused by irregular reflection to prevent directivity and glaring appearance and to suppress unevenness in brightness and darkness. The transparent protective film containing fine particles also has an advantage that incident light and its reflected light are diffused when passing through it, and light and dark unevenness can be further suppressed. The reflective layer of the fine concavo-convex structure reflecting the surface fine concavo-convex structure of the transparent protective film is formed by transparent the metal by an appropriate method such as a vapor deposition method such as a vacuum vapor deposition method, an ion plating method, a sputtering method, or a plating method. It can be performed by a method of directly attaching to the surface of the protective layer.

  Instead of the method of directly applying the reflecting plate to the transparent protective film of the polarizing plate, the reflecting plate can be used as a reflecting sheet provided with a reflecting layer on an appropriate film according to the transparent film. Since the reflective layer is usually made of metal, the usage form in which the reflective surface is covered with a transparent protective film, a polarizing plate or the like is used to prevent the reflectance from being lowered due to oxidation, and thus to maintain the initial reflectance for a long time. In addition, it is more preferable to avoid a separate attachment of the protective layer.

  The semi-transmissive polarizing plate can be obtained by using a semi-transmissive reflective layer such as a half mirror that reflects and transmits light with the reflective layer. A transflective polarizing plate is usually provided on the back side of a liquid crystal cell, and displays an image by reflecting incident light from the viewing side (display side) when a liquid crystal display device is used in a relatively bright atmosphere. In a relatively dark atmosphere, a liquid crystal display device or the like that displays an image using a built-in light source such as a backlight built in the back side of the transflective polarizing plate can be formed. In other words, the transflective polarizing plate is useful for forming a liquid crystal display device of a type that can save energy of using a light source such as a backlight in a bright atmosphere and can be used with a built-in light source even in a relatively dark atmosphere. It is.

  An optical compensation polarizing plate in which an optical compensation layer is laminated on a polarizing plate will be described. An optical compensation layer is used when changing linearly polarized light into elliptically polarized light or circularly polarized light, changing elliptically polarized light or circularly polarized light into linearly polarized light, or changing the polarization direction of linearly polarized light. In particular, a so-called quarter-wave plate (also referred to as a λ / 4 plate) is used as an optical compensation layer that changes linearly polarized light into circularly polarized light or changes circularly polarized light into linearly polarized light. A half-wave plate (also referred to as a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

  The optical compensation polarizing plate is effectively used for compensating (preventing) coloring (blue or yellow, etc.) caused by birefringence of the liquid crystal layer of the liquid crystal display device and displaying black and white without the coloring. Further, the one in which the three-dimensional refractive index is controlled is preferable because it can compensate (prevent) coloring that occurs when the screen of the liquid crystal display device is viewed from an oblique direction. The optical compensation polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflective liquid crystal display device in which the image is displayed in color, and also has an antireflection function.

  A polarizing plate obtained by bonding a polarizing plate and a brightness enhancement film is usually provided on the back side of a liquid crystal cell. The brightness enhancement film reflects a linearly polarized light with a predetermined polarization axis or a circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display device or reflection from the back side, and transmits other light. In addition, a polarizing plate in which a brightness enhancement film is laminated with a polarizing plate allows light from a light source such as a backlight to enter to obtain transmitted light in a predetermined polarization state, and reflects light without transmitting the light other than the predetermined polarization state. The The light reflected on the surface of the brightness enhancement film is further inverted through a reflective layer or the like provided behind the brightness enhancement film and re-incident on the brightness enhancement film, and part or all of the light is transmitted as light having a predetermined polarization state. Luminance can be improved by increasing the amount of light transmitted through the enhancement film and increasing the amount of light that can be used for liquid crystal display image display or the like by supplying polarized light that is difficult to be absorbed by the polarizer. That is, when light is incident through the polarizer from the back side of the liquid crystal cell without using a brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer is almost polarized. It is absorbed by the polarizer and does not pass through the polarizer. That is, although depending on the characteristics of the polarizer used, approximately 50% of the light is absorbed by the polarizer, and the amount of light that can be used for liquid crystal image display or the like is reduced accordingly, resulting in a dark image. The brightness enhancement film allows light having a polarization direction that is absorbed by the polarizer to be reflected once by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflective layer provided on the rear side thereof. Repeatedly re-enter the brightness enhancement film, and the brightness enhancement film transmits only polarized light whose polarization direction is such that the polarization direction of light reflected and inverted between the two can pass through the polarizer. Therefore, light such as a backlight can be efficiently used for displaying an image on the liquid crystal display device, and the screen can be brightened.

  A diffusion plate may be provided between the brightness enhancement film and the reflective layer. The polarized light reflected by the brightness enhancement film is directed to the reflective layer or the like, but the installed diffuser plate uniformly diffuses the light passing therethrough and simultaneously cancels the polarized state and becomes a non-polarized state. That is, the diffuser plate returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the natural light state is directed toward the reflection layer and the like, reflected through the reflection layer and the like, and again passes through the diffusion plate and reenters the brightness enhancement film. Thus, while maintaining the brightness of the display screen by providing a diffuser plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., the brightness unevenness of the display screen is reduced at the same time, A uniform and bright screen can be provided. By providing such a diffuser plate, it is considered that the first incident light has a moderate increase in the number of repetitions of reflection, and in combination with the diffusion function of the diffuser plate, a uniform bright display screen can be provided.

  The brightness enhancement film has a characteristic of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of dielectric material or a multilayer laminate of thin film films having different refractive index anisotropies. As shown (made by 3M, D-BEF, etc.), the orientation film of the cholesteric liquid crystal polymer and the oriented liquid crystal layer supported on the film substrate (made by Nitto Denko, PCF350, Merck, Transmax, etc.), Any suitable one can be used, such as one that reflects either left-handed or right-handed circularly polarized light and transmits other light.

  Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis as described above, the transmitted light is incident on the polarizing plate with the polarization axis aligned as it is, thereby efficiently transmitting while suppressing absorption loss due to the polarizing plate. Can be made. On the other hand, in a brightness enhancement film of a type that emits circularly polarized light such as a cholesteric liquid crystal layer, it can be incident on a polarizer as it is, but from the viewpoint of suppressing absorption loss, the circularly polarized light is linearly polarized through a retardation plate. It is preferable to make it enter into a polarizing plate. Note that circularly polarized light can be converted to linearly polarized light by using a quarter wave plate as the retardation plate.

  A retardation plate that functions as a quarter-wave plate in a wide wavelength range such as a visible light region exhibits, for example, a retardation layer that functions as a quarter-wave plate for light-color light having a wavelength of 550 nm and other retardation characteristics. It can be obtained by a method of superposing a retardation layer, for example, a retardation layer functioning as a half-wave plate. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or more retardation layers.

  In addition, the cholesteric liquid crystal layer can also be obtained by reflecting circularly polarized light in a wide wavelength range such as a visible light region by combining two or more layers having different reflection wavelengths and having an overlapping structure. Based on this, transmitted circularly polarized light in a wide wavelength range can be obtained.

  Further, the polarizing plate may be formed by laminating a polarizing plate and two or three or more optical layers like the above-described polarization separation type polarizing plate. Therefore, a reflective elliptical polarizing plate or a semi-transmissive elliptical polarizing plate in which the above-mentioned reflective polarizing plate or semi-transmissive polarizing plate and a retardation plate are combined may be used.

  The optical compensation layer can also be formed by a method of sequentially laminating separately in the manufacturing process of a liquid crystal display device or the like. There is an advantage that the manufacturing process of a liquid crystal display device or the like can be improved because of excellent stability and assembly work. For the lamination, an appropriate adhesive means such as an adhesive layer can be used.

  The liquid crystal display device can be formed according to the conventional method. A liquid crystal display device is generally formed by appropriately assembling components such as an illumination system as necessary and incorporating a drive circuit, but there is no particular limitation except that the optical film is used in the present invention. The conventional method can be applied. As the liquid crystal cell, in addition to the IPS mode exemplified above, any type such as VA type and π type can be used.

  As the liquid crystal display device, an appropriate liquid crystal display device such as one using an illumination system or a reflecting plate can be formed. Further, when forming a liquid crystal display device, for example, a single layer or a suitable layer such as a diffusing plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusing plate, a backlight, etc. Two or more layers can be arranged.

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

(Front retardation Re)
A 70 mm × 100 mm sample was conditioned at 25 ° C. and 60% RH for 2 hours, and the Re value at 590 nm was measured from the normal direction with an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.). Further, when measuring the wavelength dispersibility | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | or the like, the measurement may be performed at different wavelengths.

(Thickness direction retardation Rth)
A sample 30 mm × 40 mm was conditioned at 25 ° C. and 60% RH for 2 hours, and an automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.) normal direction at 590 nm and in-plane slow axis (KOBRA 21ADH Retardation measured by injecting light having a wavelength of 590 nm from a direction inclined at 10 °, 20 °, 30 °, 40 °, 50 ° with respect to the normal direction of the film with respect to the film normal direction. KOBRA 21ADH calculates the value, the assumed value of the average refractive index, and the input film thickness value. Here, as the assumed value of the average refractive index, the values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of the main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59).
Further, when measuring the wavelength dispersibility | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ |

(Measurement of Nz)
Automatic birefringence meter (KOBRA21DH, Oji Scientific Co., Ltd.) normal direction at 590 nm and in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis) with respect to the film normal direction Based on the retardation value measured by making light having a wavelength of 590 nm incident from the direction inclined by 10 °, 20 °, 30 °, 40 °, and 50 °, the assumed value of the average refractive index, and the input film thickness value, KOBRA 21ADH calculates nx, ny, and nz, and Nz = (nx−nz) / (nx−ny) is calculated from the calculated nx, ny, and nz.
(Haze of film)
It measured using the haze meter (Nippon Denshoku Co., Ltd. product).
(Measurement of moisture content of film)
Measurements were made using the Karl Fischer method.
(Moisture permeability measurement)
Measurements were made using the cup method.

[Example 1]
(Preparation of transparent protective film)
Cellulose triacetate powder (flakes) was gradually added to a 4000 L stainless steel dissolution tank having stirring blades while thoroughly stirring and dispersing in the following solvent mixed solution, and charged to a total of 2000 kg. Silica particles were added after being dispersed in a solvent in advance. Samples 101 to 106 were prepared by changing the compound for reducing optical anisotropy of the present invention and the compound for controlling wavelength dispersion (as described in Table 1).
Cellulose triacetate (degree of substitution described in Table 1) 100.0 parts by mass Methylene chloride (first solvent) 517.6 parts by mass Methanol (second solvent) 77.3 parts by mass Silica particles with an average particle size of 16 nm 0.13 parts by mass (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.)
Compound that reduces optical anisotropy (as described in Table 1) 11.7 parts by mass Wavelength dispersion modifier (as described in Table 1) 1.2 parts by mass Citric acid ester 0.01 parts by mass The in-plane retardation | Re | ≦ 10 nm and the thickness direction retardation | Rth | ≦ 25 nm.
Further, | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 nm, | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35 nm.

(Lamination of optical compensation layer)
After saponifying the surfaces of the cellulose acetate film samples 101 to 106, it was confirmed that the contact angle was 38 °. On this film, an alignment film coating solution having the following composition was coated at 20 ml / m ² with a wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. Next, the formed film was rubbed in a direction parallel to the slow axis direction of the film.
Composition of alignment film coating solution Modified polyvinyl alcohol 15 parts by weight Water 334 parts by weight Methanol 100 parts by weight Glutaraldehyde 1 part by weight Paratoluenesulfonic acid 0.3 parts by weight

Modified polyvinyl alcohol

  Next, 1.8 g of the following discotic liquid crystalline compound, 0.2 g of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), a photopolymerization initiator (IRGA) Cure 907, manufactured by Ciba-Geigy Co., Ltd.) 0.06 g, sensitizer (Kaya Cure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02 g, and the following air interface side vertical alignment agent 0.01 g were dissolved in 3.9 g of methyl ethyl ketone. The solution was applied with a # 3.4 wire bar. This was affixed to a metal frame and heated in a thermostatic bath at 125 ° C. for 3 minutes to align the discotic liquid crystal compound. Next, UV irradiation was performed for 30 seconds using a 120 W / cm high-pressure mercury lamp at 100 ° C. to crosslink the discotic liquid crystal compound. Then, it stood to cool to room temperature. Thus, the optical compensation layer was laminated.

Discotic liquid crystal compound

Air interface side vertical alignment agent

When the optical characteristics of only the discotic liquid crystal retardation layer were calculated, Re ₁ was 200 nm and the Nz value was 0.54, and it was confirmed that the discotic liquid crystal was aligned perpendicular to the film surface. The slow axis direction was parallel to the rubbing direction of the alignment film.

(Preparation of optical compensation polarizing plates 1 to 6)
Each of the transparent protective films (samples 101 to 106) having the optical compensation layer stack and a tack film TD80UF manufactured by Fuji Photo Film Co., Ltd. are stretched by adsorbing iodine to a polyvinyl alcohol film (polarizer: 20 μm) ) Were laminated using an adhesive to produce optical compensation polarizing plates 1 to 6, respectively.

(Preparation of polarizing plates 1 to 6)
Adhesives on both sides of the transparent protective film (samples 101 to 106) and a film (polarizer: 20 μm) obtained by stretching a tack film TD80UF manufactured by Fuji Photo Film Co., Ltd. by adsorbing iodine to a polyvinyl alcohol film. Were used to make polarizing plates 1 to 6, respectively.

(Production of liquid crystal display device 1)
The optical compensation layer side of the optical compensation polarizing plate 1 was laminated with an adhesive so as to be the surface on the viewing side of the IPS mode liquid crystal cell. On the other hand, the polarizing plate 1 was laminated with an adhesive on the opposite surface of the liquid crystal cell to produce a liquid crystal display device. The optical compensation polarizing plate 1 on the viewing side was laminated so that the extraordinary refractive index direction of the liquid crystal composition in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate 1 were orthogonal when no voltage was applied. Further, the absorption axis of the polarizing plate 1 and the absorption axis of the optical compensation polarizing plate were arranged to be orthogonal to each other.

(Evaluation)
In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction in the azimuth direction 45 degrees with respect to the optical axis of the front and orthogonal polarizing plates was measured using EZ Contrast (manufactured by ELDIM), the contrast ratio The front face was 370 and the 70 ° direction was 35. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.
(Production of liquid crystal display devices 2 to 6)
In the production of the liquid crystal display device 1, a liquid crystal display device was similarly obtained except that the polarizing plates 2 to 6 were used instead of the polarizing plate 1 and the optical compensation polarizing plates 2 to 6 were used instead of the optical compensation polarizing plate 1. When 2-6 were produced, the same performance as the above was obtained.

[Example 2]
(Preparation of transparent protective film)
A cellulose triacetate solution was prepared in the same manner as in Example 1 except that the composition was changed to the following composition, and a sample 114 was prepared.

Cellulose triacetate (substitution degree 2.86, viscosity average degree of polymerization 320, water content 0.4% by mass, viscosity of 6% by mass in methylene chloride solution 305 mPa · s, average particle size 1.5 mm with standard deviation 0.8. 5mm powder)
17.0 parts by mass, methylene chloride 67.4 parts by mass, methanol 12.7 parts by mass, butanol 0.5 parts by mass, triphenyl phosphate (TPP) 1.3 parts by mass, biphenyl-diphenyl phosphate (BDP) 0 .7 parts by mass-compound imparting optical isotropy (as described in Table 1) 2.0 parts by mass-compound controlling wavelength dispersion (as described in Table 1) 0.8 part by mass

(Preparation of polarizing plate 7)
A polarizing plate 7 was prepared by laminating the transparent protective film on both sides of a film (polarizer: 20 μm) obtained by adsorbing iodine to a polyvinyl alcohol film and using an adhesive.

(Lamination of optical compensation layer)
By stretching the polystyrene film, an optical compensation layer having a thickness of 60 μm, an in-plane retardation Re ₁ of 260 nm, and Nz = 0.50 was obtained. The optical compensation layer and the polarizing plate 7 were laminated using an adhesive so that the slow axis of the optical compensation layer and the absorption axis of the polarizing plate were in a parallel state, whereby the optical compensation polarizing plate 7 was produced.

(Production of liquid crystal display device 7)
The side having the optical compensation layer of the optical compensation polarizing plate 7 was laminated with a pressure-sensitive adhesive so as to be the surface on the viewing side of the IPS mode liquid crystal cell. On the other hand, a polarizing plate 7 was laminated with an adhesive on the opposite surface of the liquid crystal cell to produce a liquid crystal display device 7. The optical compensation polarizing plate 7 on the viewing side was laminated so that the extraordinary refractive index direction of the liquid crystal composition in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate 7 were orthogonal when no voltage was applied. Further, the absorption axis of the polarizing plate and the absorption axis of the optical compensation polarizing plate 7 were arranged so as to be orthogonal to each other.

(Evaluation)
In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front, the contrast ratio was 360 for the front and 35 for the 70 ° direction. Met. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.
Further, leakage light of the manufactured liquid crystal display device was measured. The average value of leakage light when observed from four oblique directions (azimuth angles: 45 degrees, 135 degrees, 225 degrees, 315 degrees, polar angle: 60 degrees) was 13%. Leakage light is measured using a brightness meter (SR-3 (manufactured by Topcon)), measuring the brightness (Lw) of the white image and the brightness (Lb) of the black image, and indicating Lb / Lw as leakage light (%). It was.

[Example 3]
(Preparation of transparent protective film)
A cellulose triacetate solution was prepared in the same manner as in Example 2 except that the composition was changed to the following composition, and a sample 115 was prepared.

Cellulose triacetate (substitution degree 2.86, viscosity average degree of polymerization 320, water content 0.4% by mass, viscosity of 6% by mass in methylene chloride solution 305 mPa · s, average particle size 1.5 mm with standard deviation 0.8. 5mm powder)
17.0 parts by mass, methyl acetate 62.4 parts by mass, acetone 6.5 parts by mass, ethanol 5.7 parts by mass, butanol 6.5 parts by mass, triphenyl phosphate (TPP) 1.3 parts by mass, biphenyl- Diphenyl phosphate (BDP) 0.7 parts by mass A compound imparting optical isotropy (as described in Table 1) 2.0 parts by mass A compound for controlling wavelength dispersion (as described in Table 1) 0.8 Parts by mass

(Preparation of polarizing plate 8)
A polarizing plate 8 was prepared by laminating the transparent protective film on both surfaces of a film (polarizer: 20 μm) obtained by adsorbing iodine on a polyvinyl alcohol film and stretching the film.

(Lamination of optical compensation layer)
After the surface of the cellulose acetate film sample 115 was saponified, it was confirmed that the contact angle was 38 °. On this film, an alignment film coating solution having the following composition was coated at 20 ml / m ² with a wire bar coater. Drying was performed with warm air of 60 ° C. for 60 seconds, and further with warm air of 100 ° C. for 120 seconds. Next, the formed film was rubbed in a direction parallel to the slow axis direction of the film. (Composition of alignment film coating solution)
The following modified polyvinyl alcohol 15 parts by mass Water 334 parts by mass Methanol 100 parts by mass Glutaraldehyde 1 part by mass Paratoluenesulfonic acid 0.3 parts by mass

Modified polyvinyl alcohol

  Next, on the alignment film, 1.8 g of the following discotic liquid crystalline compound, 0.2 g of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), a photopolymerization initiator (IRGA) Cure 907, manufactured by Ciba Geigy Co., Ltd.) 0.06 g, sensitizer (Kaya Cure DETX, manufactured by Nippon Kayaku Co., Ltd.) 0.02 g, and the following air interface side vertical alignment agent 0.01 g were dissolved in 3.9 g of methyl ethyl ketone. The solution was applied with a # 3.4 wire bar. This was affixed to a metal frame and heated in a thermostatic bath at 125 ° C. for 3 minutes to align the discotic liquid crystal compound. Next, UV irradiation was performed for 30 seconds using a 120 W / cm high-pressure mercury lamp at 100 ° C. to crosslink the discotic liquid crystal compound. Then, it stood to cool to room temperature. Thus, the optical compensation layer was laminated.

Discotic liquid crystal compound

Air interface side vertical alignment agent

When the optical characteristics of only the discotic liquid crystal retardation layer were calculated, Re ₁ was 200 nm and the Nz value was 0.54, and it was confirmed that the discotic liquid crystal was aligned perpendicular to the film surface. . The slow axis direction was parallel to the rubbing direction of the alignment film.

(Production of liquid crystal display device 8)
The side having the optical compensation layer of the optical compensation polarizing plate 8 was laminated with an adhesive so as to be the surface on the viewing side of the IPS mode liquid crystal cell. On the other hand, a polarizing plate 8 was laminated with an adhesive on the opposite surface of the liquid crystal cell to produce a liquid crystal display device. The optical compensation polarizing plate 8 on the viewing side was laminated so that the extraordinary refractive index direction of the liquid crystal composition in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate 8 were orthogonal when no voltage was applied. Further, the absorption axis of the polarizing plate 8 and the absorption axis of the optical compensation polarizing plate 8 were arranged so as to be orthogonal to each other.

(Evaluation)
In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the front and orthogonal polarizing plates, the contrast ratio was 370 for the front and 35 for the 70 ° direction. Met. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.

[Example 4]
(Preparation of transparent protective film)
A cellulose triacetate solution was prepared in the same manner as in Example 1 except that cellulose triacetate (substitution degree 2.94, viscosity average polymerization degree 320) having a higher degree of substitution than that in Example 1 was used, and Sample 116 was produced. The obtained roll-shaped transparent protective film was cut into a 10 cm × 2 cm strip and stretched 5% at a rate of 1 cm / min using Tensilon (manufactured by Orientec Co., Ltd.). Before and after stretching the obtained transparent protective film by 5%, the in-plane retardation of the film was | Re (5) −Re (0) | /5=0.5 nm.

(Lamination of optical compensation layer)
A polyester film having a dimensional change rate (MD / TD) of 1.15 at 165 degrees is adhered to both sides of a polycarbonate having a length of 100 m, a width of 180 mm, a thickness of 80 μm, and Re of 0 nm through an acrylic adhesive layer. The film was shrunk in the transport direction while being stretched 1.15 times in the width direction of the polycarbonate using a pin tenter whose pin spacing shrunk in accordance with transport in a high temperature atmosphere, and then the polyester film was peeled off to obtain an optical compensation layer.
Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependence of Re was measured, and when these optical characteristics were calculated, Re was 250 nm and Nz was 0. 0.5, and it was confirmed that the slow axis was in a direction perpendicular to the longitudinal direction.
(Preparation of polarizing plate 9) (Preparation of liquid crystal display device 9)
The transparent protective film and the optical compensation layer are laminated by roll-to-roll using an adhesive on both surfaces of a film (polarizer: 20 μm) obtained by adsorbing iodine to a polyvinyl alcohol film, polarizing plate 9, optical compensation A polarizing plate 9 and an IPS mode liquid crystal display device 9 were produced.

(Evaluation)
In this liquid crystal display device 9, when the contrast ratio in the direction of 70 degrees from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the orthogonal polarizing plate, the contrast ratio was 35. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.

[Example 5]
(Preparation of transparent protective film)
In the transparent protective film sample of the present invention produced in Example 1, the same procedure as in Example 1 was conducted except that cellulose triacetate was changed to the following cellulose acylates SEF-1, SEF-2 and SFE-3. Sample 117 of the invention was made and its characteristics were evaluated.
(Cellulose acylate SEF-1)
Cellulose acylate SEF-1 was synthesized from cellulose collected from cotton. Cellulose acylate SEF-1 has an acetyl substitution degree of 1.20, a butyryl substitution degree of 1.50, a total substitution degree of 2.70, a viscosity average polymerization degree of 280, a water content of 0.2% by mass, and a dichloromethane solution. It was a powder having a viscosity of 235 mPa · s, an average particle size of 1.5 mm, and a standard deviation of 0.6 mm. Further, the residual acetic acid content in the cellulose acylate solids is 0.1% by mass or less, the residual butanoic acid is 0.1% by mass or less, the Ca content is 85 ppm, the Mg content is 30 ppm, and the Fe content is 0. 0.3 ppm and further containing 130 ppm of sulfur as sulfate groups. Further, the substitution degree of the 6-position acetyl group was 0.40, and the substitution degree of the 6-position butyryl group was 0.48. The weight average molecular weight / number average molecular weight ratio (measured by GPC) is 2.6.

(Cellulose acylate SEF-2)
Cellulose acylate SEF-2 has an acetyl substitution degree of 2.58, a butyryl substitution degree of 1.30, a total substitution degree of 2.88, a viscosity average polymerization degree of 365, a water content of 0.2% by mass, and 6% by mass in a dichloromethane solution. It is a powder having a viscosity of 290 mPa · s, an average particle size of 1.4 mm, and a standard deviation of 0.6 mm.

(Cellulose acylate SEF-3)
Cellulose acylate SEF-3 has an acetyl substitution degree of 1.00, a propionyl substitution degree of 1.85, a total substitution degree of 2.85, a viscosity average polymerization degree of 280, a water content of 0.19% by mass, and 6% by mass in a dichloromethane solution. It is a powder having a viscosity of 105 mPa · s, an average particle size of 1.5 mm, and a standard deviation of 0.4 mm.
The obtained transparent protective film 117 was cut into a 10 cm × 2 cm strip and stretched 5% at a rate of 1 cm / min using Tensilon (manufactured by Orientec Co., Ltd.). Before and after stretching the obtained transparent protective film by 5%, the in-plane retardation of the film was | Re (5) −Re (0) | /5=0.5 nm.

(Lamination of optical compensation layer)
A polyester film having a length change of 165 ° (MD / TD) of 1.15 is adhered to both sides of a polycarbonate having a length of 100 m, a width of 180 mm, a thickness of 80 μm and a Re of 0 nm via an acrylic pressure-sensitive adhesive layer. The roll speed ratio was set to 0.96 with a stretching machine, and the polycarbonate was shrunk by treatment in a normal temperature atmosphere using 50 rolls with a diameter of 10 cm arranged at intervals of 5 cm and a roll temperature of 165 degrees. After that, the polyester film was peeled off. This roll-shaped polycarbonate film was stretched 1.06 times in the width direction under an atmosphere of 163 degrees to obtain an optical compensation layer, and laminated with the transparent protective film and roll-to-roll.
Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependence of Re was measured, and when these optical characteristics were calculated, Re was 180 nm and Nz was 0. 4 and it was confirmed that the slow axis was perpendicular to the longitudinal direction.
(Production of Polarizing Plate 10) (Production of Liquid Crystal Display Device 10)
The transparent protective film 117 is laminated by roll-to-roll using an adhesive on both surfaces of a film (polarizer: 20 μm) obtained by adsorbing iodine on a polyvinyl alcohol film, polarizing plate 10, optical compensation polarizing plate 10 An IPS mode liquid crystal display device 10 was produced.

(Evaluation)
In this liquid crystal display device 10, when the contrast ratio in the direction of 70 degrees tilted from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the orthogonal polarizing plate, the contrast ratio was 35. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed. It turns out that it is preferable to use a specific cellulose acylate in this invention.

[Example 6]
(Preparation of transparent protective film)
Cellulose triacetate powder (flakes) was gradually added to a 4000 L stainless steel dissolution tank having stirring blades while thoroughly stirring and dispersing in the following solvent mixed solution, and charged to a total of 2000 kg. Samples 107 to 113 and samples 118 to 121 were prepared by changing the compound that decreases the optical anisotropy and the compound that controls wavelength dispersion (as described in Table 1).
・ Cellulose triacetate (substitution degree 2.94, viscosity average degree of polymerization 320)
17.0 parts by mass / methylene chloride 70.5 parts by mass / methanol 10.5 parts by mass / compound imparting optical isotropy (as described in Table 1) 2.0 parts by mass / compound controlling wavelength dispersion ( 0.2 parts by mass The in-plane retardation Re of the transparent protective film was 1 ± 1 nm as a result of measuring an arbitrary 1 m square, and the thickness direction retardation Rth was 0 ± 3 nm. The amount of change in Re and Rth when the transparent protective film is treated at 60 ° C. and 90% RH for 240 hours is 3 nm and 5 nm, respectively, and the amount of change in Re and Rth when treated at 80 ° C. for 240 hours is respectively 2 nm and 5 nm.

(Polarizing plates 11 to 21)
Each of the transparent protective films (107 to 113, 118 to 121) and an antireflective film CV02L80 manufactured by Fuji Photo Film Co., Ltd. were saponified, and then the film was stretched by adsorbing iodine to a polyvinyl alcohol film (polarizer: 20 μm) ) Were laminated using an adhesive on both sides to prepare polarizing plates 11 to 21, respectively.

(Lamination of optical compensation layer)
A polyester film having a dimensional change rate (MD / TD) of 1.15 at 165 degrees is adhered to both sides of a polycarbonate having a length of 100 m, a width of 180 mm, a thickness of 80 μm, and Re of 0 nm through an acrylic adhesive layer. The film was shrunk in the transport direction while being stretched 1.15 times in the width direction of the polycarbonate using a pin tenter whose pin spacing shrunk in accordance with transport in a high temperature atmosphere, and then the polyester film was peeled off to obtain an optical compensation layer.
Using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments Co., Ltd.), the light incident angle dependency of Re was measured, and when these optical characteristics were calculated, Re was 210 nm and Nz was 0. It was confirmed that the slow axis was in a direction perpendicular to the longitudinal direction.
This optical compensation layer is applied to the polyvinyl alcohol film by using an adhesive so that the slow axis of the optical compensation layer and the absorption axis of the polarizing plate are parallel to the samples 107 to 113 side of the polarizing plates 11 to 17, respectively. Optical compensation polarizing plates 11 to 21 were produced by laminating both sides of a film stretched by adsorbing iodine (polarizer: 20 μm) using an adhesive with a roll to roll.

(Production of liquid crystal display device 11)
The optical compensation layer side of the optical compensation polarizing plate 11 was laminated with an adhesive so as to be the surface on the viewing side of the IPS mode liquid crystal cell. On the other hand, the polarizing plate 11 was laminated with an adhesive on the opposite surface of the liquid crystal cell to produce a liquid crystal display device 11. The optical compensation polarizing plate 11 on the viewing side was laminated so that the extraordinary refractive index direction of the liquid crystal composition in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate 11 were orthogonal when no voltage was applied. Further, the absorption axis of the polarizing plate 11 and the absorption axis of the optical compensation polarizing plate were arranged to be orthogonal to each other.

(Evaluation)
In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction in the azimuth direction 45 degrees with respect to the optical axis of the front and orthogonal polarizing plates was measured using EZ Contrast (manufactured by ELDIM), the contrast ratio The front face was 370 and the 70 ° direction was 35. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.
(Production of liquid crystal display devices 12 to 21)
In the production of the liquid crystal display device 11, a liquid crystal display device was similarly obtained except that the polarizing plates 12 to 21 were used instead of the polarizing plate 11 and the optical compensation polarizing plates 12 to 21 were used instead of the optical compensation polarizing plate 11. When 12 to 21 were produced, the same performance as above was obtained.

[Example 7]
(Preparation of transparent protective film)
Samples 118 to 121 prepared in Example 6 were stretched 1.1 times at 140 ° C. by lateral stretching at a fixed end, and then immersed in a 10% aqueous sodium hydroxide solution at 75 ° C. for 1 minute to perform a hydrophilization treatment. It was washed with water and then dried at 70 ° C. for 3 minutes to perform a hydrophilic treatment to obtain transparent protective films 122 to 125.

(Polarizing plates 22-25)
Each of the transparent protective films (122 to 125) and an antireflection film CV02L80 manufactured by Fuji Photo Film Co., Ltd. were saponified and iodine was adsorbed on a polyvinyl alcohol film and then stretched on both surfaces (polarizer: 20 μm). The polarizing plates 22 to 25 were produced by laminating using an adhesive.

(Lamination of optical compensation layer)
The optical compensation layer obtained by stretching the polycarbonate film in the same manner as in Example 6 was placed on the transparent protective film 122-125 side of the polarizing plates 22-25, and the slow axis of the optical compensation layer and the absorption axis of the polarizing plate were parallel to each other. Thus, it laminated | stacked using the adhesive and produced the optical compensation polarizing plates 22-25.

(Production of liquid crystal display device 22)
The optical compensation layer side of the optical compensation polarizing plate 22 was laminated with an adhesive so as to be the surface on the viewing side of the IPS mode liquid crystal cell. On the other hand, the polarizing plate 22 was laminated with an adhesive on the opposite surface of the liquid crystal cell to produce a liquid crystal display device 22. The optical compensation polarizing plate 22 on the viewing side was laminated so that the extraordinary refractive index direction of the liquid crystal composition in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate 22 were orthogonal when no voltage was applied. Further, the absorption axis of the polarizing plate 22 and the absorption axis of the optical compensation polarizing plate were arranged to be orthogonal.

(Evaluation)
In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction in the azimuth direction 45 degrees with respect to the optical axis of the front and orthogonal polarizing plates was measured using EZ Contrast (manufactured by ELDIM), the contrast ratio The front face was 370 and the 70 ° direction was 35. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.

(Production of liquid crystal display devices 23 to 25)
In the production of the liquid crystal display device 22, a liquid crystal display device was similarly obtained except that the polarizing plates 13 to 25 were used instead of the polarizing plate 22 and the optical compensation polarizing plates 13 to 25 were used instead of the optical compensation polarizing plate 22. When 23 to 25 were produced, the same performance as above was obtained.

[Example 8]
(Lamination of optical compensation layer)
After laminating an optical compensation layer on samples 118 to 121 produced in Example 6 through an alignment film in the same manner as in Example 1, the film was stretched 1.05 times by longitudinal uniaxial stretching at 140 ° C., and 75 ° C. It is immersed in a 10% aqueous sodium hydroxide solution for 1 minute to give a hydrophilic treatment, washed with pure water, then dried at 70 ° C. for 3 minutes to carry out the hydrophilic treatment, and the slow axis of the optical compensation layer and the polarizing plate Were laminated using an adhesive so that the absorption axes of the films were parallel, and protective films 26 to 29 with optical compensation layers were produced.

(Optical compensation polarizing plates 26-29)
Both surfaces of the protective films with optical compensation layers 26 to 29 and an antireflective film CV02L80 manufactured by Fuji Photo Film Co., Ltd. and then stretched by adsorbing iodine on a polyvinyl alcohol film (polarizer: 20 μm) The optical compensation polarizing plates 26 to 29 were respectively prepared by laminating them with an adhesive.

(Production of liquid crystal display device 26)
The optical compensation layer side of the optical compensation polarizing plate 26 was laminated with an adhesive so as to be the surface on the viewing side of the IPS mode liquid crystal cell. On the other hand, the polarizing plate 26 was laminated with an adhesive on the opposite surface of the liquid crystal cell to produce a liquid crystal display device 26. The optical compensation polarizing plate 26 on the viewing side was laminated so that the extraordinary refractive index direction of the liquid crystal composition in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate 26 were orthogonal when no voltage was applied. Further, the absorption axis of the polarizing plate 26 and the absorption axis of the optical compensation polarizing plate were arranged to be orthogonal to each other.

(Evaluation)
In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction in the azimuth direction 45 degrees with respect to the optical axis of the front and orthogonal polarizing plates was measured using EZ Contrast (manufactured by ELDIM), the contrast ratio The front face was 370 and the 70 ° direction was 35. In the black display, the degree of coloring in the direction of 70 degrees from the normal direction was compared at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree, but almost no change was observed. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then in-plane unevenness of black display was visually confirmed, almost no unevenness was observed. In addition, almost no deterioration of polarization performance was observed.

(Production of liquid crystal display devices 27 to 29)
In the production of the liquid crystal display device 26, a liquid crystal display device was similarly obtained except that the polarizing plates 27 to 29 were used instead of the polarizing plate 26 and the optical compensation polarizing plates 27 to 29 were used instead of the optical compensation polarizing plate 26. When 27 to 29 were produced, the same performance as described above was obtained.

[Comparative Example 1]
Polarized by laminating cellulose triacetate film (T80UZ manufactured by Fuji Photo Film Co., Ltd.) as a transparent protective film on both sides of a film (polarizer: 20 μm) stretched by adsorbing iodine on a polyvinyl alcohol film using an adhesive. A plate was made. The cellulose triacetate film had a thickness of 80 μm, an in-plane retardation Re of 4 nm, and a thickness direction retardation Rth of 45 nm.

  This polarizing plate was laminated on both surfaces of the same IPS mode liquid crystal cell as in Example 1 to produce a liquid crystal display device. The polarizing plates arranged on both surfaces of the liquid crystal cell were arranged so that the polarization axes were orthogonal to each other.

  In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the front and orthogonal polarizing plates, the contrast ratio was 370 on the front. The ° direction was 9. Further, in the black display, the degree of blue coloring in the direction of 70 degrees tilted from the normal direction was larger in the azimuth direction 45 degrees with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree.

[Comparative Example 2]
A film (polarizer: 20 μm) stretched by adsorbing iodine on a polyvinyl alcohol film is coated with Tac TD80UF manufactured by Fuji Photo Film Co., Ltd. as the transparent protective film, and ZEONOR manufactured by Nippon Zeon Co., Ltd. on the other surface. A film was laminated using an adhesive to produce a polarizing plate. The ZEONOR film had a thickness of 80 μm, an in-plane retardation Re of 1 nm, and a thickness direction retardation Rth of 4 nm.

  This polarizing plate was laminated on both surfaces of the same IPS mode liquid crystal cell as in Example 1 to produce a liquid crystal display device. The polarizing plates arranged on both surfaces of the liquid crystal cell were arranged so that the polarization axes were orthogonal to each other.

  In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front, the contrast ratio was 360 for the front and 10 for the 70 ° direction. Met. Also, in the black display, the blue coloration degree in the direction of 70 degrees tilt from the normal direction was larger in the azimuth direction 45 degrees with respect to the optical axis of the polarizing plate orthogonal to the front coloration degree. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then taken out, peeling occurred at the interface between the polarizer and ZEONOR, and unevenness and a decrease in contrast were observed.

[Comparative Example 3]
By stretching Tack TD80UF manufactured by Fuji Photo Film Co., Ltd. as a transparent protective film on one side of a film (polarizer: 20 μm) stretched by adsorbing iodine on a polyvinyl alcohol film, and a polycarbonate film on the other side By laminating the obtained retardation film having an in-plane retardation of 100 nm and Nz = 0.5 using an adhesive so that the slow axis of the retardation film and the absorption axis of the polarizing plate are in a parallel state. An optical compensation polarizing plate 17 was produced. The optical compensation polarizing plate produced in this manner was laminated with an adhesive so that the retardation film side would be the surface on the viewing side of the IPS mode liquid crystal cell, as in Example 1. On the other hand, the polarizing plate 1 used in Example 1 was laminated with an adhesive on the opposite surface to produce a liquid crystal display device 17.

  In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees tilted from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the front and orthogonal polarizing plates, the contrast ratio was 360 for the front and 15 for the 70 ° direction. Met. Further, in the black display, the degree of blue coloring in the direction of 70 degrees tilted from the normal direction was larger in the azimuth direction 45 degrees with respect to the optical axis of the polarizing plate orthogonal to the front coloring degree. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then taken out, peeling occurred at the interface between the polarizer and ZEONOR, and unevenness and a decrease in contrast were observed.

[Comparative Example 4]
Tack TD80UF manufactured by Fuji Photo Film Co., Ltd. as a transparent protective film is stretched on one side of a film (polarizer: 20 μm) stretched by adsorbing iodine on a polyvinyl alcohol film, and a polycarbonate film is stretched on the other side. The retardation film having an in-plane retardation of 120 nm and Nz = 1.0 obtained by the above is laminated using an adhesive so that the slow axis of the retardation film and the absorption axis of the polarizing plate are in a parallel state. Thus, an optical compensation polarizing plate 18 was produced. The optical compensation polarizing plate produced in this manner was laminated with an adhesive so that the retardation film side would be the surface on the viewing side of the IPS mode liquid crystal cell, as in Example 1. On the other hand, the polarizing plate 1 used in Example 1 was laminated with an adhesive on the opposite surface to produce a liquid crystal display device.

  In this liquid crystal display device, when the contrast ratio in the direction of 70 degrees from the normal direction was measured at 45 degrees in the azimuth direction with respect to the optical axis of the polarizing plate orthogonal to the front, the contrast ratio was 370 for the front and 8 for the 70 ° direction. Met. Also, in the black display, the blue coloration degree in the direction of 70 degrees tilt from the normal direction was larger in the azimuth direction 45 degrees with respect to the optical axis of the polarizing plate orthogonal to the front coloration degree. Further, when this liquid crystal display device was put in under conditions of 60 ° C. and 95% RH for 200 hours and then taken out, peeling occurred at the interface between the polarizer and ZEONOR, and unevenness and a decrease in contrast were observed.

It is a schematic diagram which shows the heat-tight roll used for shrinkage | contraction of a heat compression film.

Explanation of symbols

51 Heat-tight roll 52 Thermal compression film

Claims (29)

In an optical compensation polarizing plate in which an optical compensation layer is laminated on one side of a polarizing plate obtained by laminating a transparent protective film on both sides of a polarizer, at least one transparent protective film is a compound that decreases the retardation Rth in the film thickness direction. It contains at least one compound represented by any one of the general formulas (13), (18), and (19), and has a front retardation value Re (unit: nm) and a retardation value Rth in the film thickness direction (unit: nm) is a cellulose acylate film satisfying the following formulas (I) and (II), and Nz and Re ₁ defined by the following formulas (III) and (IV) of the optical compensation layer are represented by the following formula (V) , (VI), an optical compensation polarizing plate characterized by

[Wherein R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent
Represents a hydrogen atom, an alkyl group or an aryl group. Total number of carbon atoms of R ¹ , R ² and R ³
Is 10 or more. ]

[Wherein R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represents hydrogen.
An atom, an alkyl group or an aryl group is represented. ]

In the general formula (19), R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group or
Represents an aryl group.
(I) | Re | ≦ 10
(II) | Rth | ≦ 25
(III) Nz = (nx ₁ −nz ₁ ) / (nx ₁ −ny ₁ )
(IV) Re ₁ = (nx ₁ −ny ₁ ) × d ₁
(V) 0.4 ≦ Nz ≦ 0.6
(VI) 100 ≦ Re ₁ ≦ 350
[Where Re ₁ is the front retardation value (unit: nm) at a wavelength of 590 nm, Nz is the Nz factor at a wavelength of 590 nm, nx ₁ is the refractive index in the slow axis direction in the film plane, and ny ₁ is The refractive index in the direction perpendicular to the slow axis in the film plane, nz ₁ is the refractive index in the thickness direction of the film, and d ₁ is the thickness of the film (unit: nm). ] The polarizer is a long polarizer having an absorption axis parallel to the longitudinal direction, and the optical compensation layer is a long optical compensation layer having a slow axis perpendicular to the longitudinal direction. The optical compensation polarizing plate according to claim 1. The said transparent protective film satisfy | fills following formula (VII), Claim 1 or 2 characterized by the above-mentioned.
The optical compensation polarizing plate described in 1.
(VII) | Re ₍₄₀₀₎ −Re ₍₇₀₀₎ | ≦ 10 and | Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ | ≦ 35
[Where Re ₍ λ ₎ is the front retardation value at wavelength λnm (unit: nm), Rth
₍ λ ₎ is the retardation value (unit: nm) in the film thickness direction at the wavelength λnm. ] The film thickness of the transparent protective film is 10 to 120 μm.
The optical compensation polarizing plate according to any one of the above. The optical compensation polarizing plate according to claim 1, wherein the transparent protective film satisfies the following formula (VIII).
(VIII) | Re (MAX) −Re (MIN) | ≦ 6 and | Rth (MAX) −Rth (MIN) | ≦ 10
[In the formula, Re (MAX) and Rth (MAX) are the maximum retardation values (unit: nm) of 1 m square film cut out arbitrarily, and Re (MIN) and Rth (MIN) are the minimum retardation values (unit:
nm). ] The transparent protective film, optical compensation polarizer according to claim 1, a compound that reduces the Rth, the following formula (IX), and having free range satisfying the (X).
(IX) (Rth (A) −Rth (0)) / A ≦ 1.0
(X) 0.1 ≦ A ≦ 30
[Wherein Rth (A) represents Rth (A) of a film containing A% of a compound that lowers Rth
nm), Rth (0) is Rth (nm) of a film not containing a compound that lowers Rth.
), A: The mass (%) of the compound when the mass of the film raw material polymer is 100.
] The optical compensation polarizing plate according to any one of claims 1 to 5, wherein the compound for reducing Rth is contained in an amount of 0.01 to 30% by mass based on the solid content of cellulose acylate. The transparent protective film comprises at least one compound that reduces | Re ₍₄₀₀₎ -Re ₍₇₀₀₎ | and | Rth ₍₄₀₀₎ -Rth ₍₇₀₀₎ | the optical compensation polarizer according to any one of claims 1 to 7, characterized in that it comprises 30% by weight. The transparent protective film, any one of claims 1-8, characterized in that a long film having a slow axis in a direction perpendicular to the machine direction (MD direction) of the film (TD direction) The optical compensation polarizing plate described in 1. The transparent protective film, optical compensation polarizer according to any one of claims 1 to 9, the contact angle of the film surface after alkali saponification treatment is characterized in that it is 55 ° or less. The optical compensation polarizer according to any one of claims 1 to 10, characterized in that the variation of Re and Rth when treated the transparent protective film 240 hours at 60 ° C. 90% RH is 15nm or less. The optical compensation polarizer according to any one of claims 1 to 11, the variation of Re and Rth when treated the transparent protective film 240 hours at 80 ° C. The is characterized in that it is 15nm or less. The optical compensation polarizing plate according to any one of claims 1 to 12, wherein the transparent protective film is a stretched processed film, and wherein the optical compensation layer is laminated after stretching. The optically compensated polarizing plate according to any one of claims 1 to 12 , wherein the transparent protective film is a stretched film and is stretched after laminating an optical compensation layer. The optical compensation polarizing plate according to claim 13 or 14 , wherein the transparent protective film satisfies the following formula (XI) in front retardation in the film plane before and after the stretching treatment.
(XI) | Re (n) -Re (0) | /n≦1.0
[In the formula, Re (n) is the in-plane front retardation of the stretched film (unit: nm).
, Re (0) is the in-plane front retardation of the unstretched film (unit: nm)] The transparent protective film, optical compensation polarizer according to any one of claims 1 to 15, characterized in that the cellulose acetate is acyl substitution degree 2.70 to 3.00. The optical compensation polarizing plate according to any one of claims 1 to 15 , wherein the transparent protective film is made of cellulose acylate satisfying all of the following formulas (XII) to (XIV).
(XII) 2.50 ≦ SA + SB ≦ 3.00
(XIII) 0 ≦ SA ≦ 2.5
(XIV) 0.5 ≦ SB ≦ 3.00
[Wherein, SA represents the degree of substitution of the acetyl group, and SB represents the degree of substitution of the substituted acyl group having 3 to 22 carbon atoms. ] The optical compensation polarizing plate according to any one of claims 1 to 17 , wherein the optical compensation layer is an optical compensation layer obtained by vertically orienting a rod-like or disk-like compound with respect to the transparent protective film surface. The optical compensation layer, polyamide, polyimide, polyester, polyetherketone, to any one of claims 1 to 17, intrinsic birefringence is selected from polyamideimide and polyesterimide is characterized by containing a positive polymer The optical compensation polarizing plate described. The optical compensation layer contains a polymer having a negative intrinsic birefringence value.
The optical compensation polarizing plate according to any one of to 17 . The optical compensation polarizing plate according to any one of claims 1 to 20 , wherein the transparent protective film and the optical compensation layer are bonded with an adhesive layer or an adhesive layer. A hard coat layer, an antiglare layer, an optical compensation polarizer according to any one of claims 1 to 21, characterized in that it has either at least one layer of anti-reflection layer. A process for producing a long optical compensation layer by shrinking the polymer film by heat-treating a long polymer film having a heat-shrinkable film bonded to one or both sides, and the produced long optical compensation The method for producing an optical compensation polarizing plate according to any one of claims 19 to 22 , further comprising a step of bonding the layer to a long polarizer through a long transparent protective film. The method for producing an optical compensation polarizing plate according to claim 23 , wherein in the step of producing the optical compensation layer, a heat shrinkable film that shrinks preferentially in the MD direction is used as the heat shrinkable film. A dense roll is used in the step of producing the optical compensation layer.
24. A method for producing an optical compensation polarizing plate according to item 23 . In the step of producing the optical compensation layer, the longitudinal interval of the tenter clip is gripped,
The method for producing an optically compensatory polarizing plate according to claim 23 , further comprising a step of stretching in a width direction using a tenter having a structure that becomes narrow during conveyance. An image display device using the optical compensation polarizing plate according to any one of claims 1 to 22 . The image display device is an IPS mode liquid crystal display device, and the cell substrate on the viewing side has claims 1
22 is arranged, and on the cell substrate opposite to the viewing side, at least one surface of the polarizer has | Re (front retardation value) | ≦ 10 and | Rth (film thickness direction) The retardation value of the liquid crystal molecules in the liquid crystal cell is parallel to the absorption axis of the polarizing plate when no voltage is applied. A liquid crystal display device characterized by being in a state. The image display device is an IPS-mode liquid crystal display device, and the cell substrate on the viewing side has | Re (front retardation value) | ≦ 10 and | Rth (retardation value in the film thickness direction) | A polarizing plate on which a transparent protective film of ≦ 25 is laminated is disposed, and the optical compensation polarizing plate according to any one of claims 1 to 22 is disposed on the cell substrate on the side opposite to the viewing side, and A liquid crystal display device wherein the major axis direction of the liquid crystal molecules in the liquid crystal cell and the absorption axis of the optical compensation polarizing plate are orthogonal to each other when no voltage is applied.

Images