JP2006268016A - Optical compensation sheet and liquid crystal display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical compensation sheet made of only one cellulose acylate film for optically compensating a liquid crystal cell. <P>SOLUTION: The optical compensation sheet consists of a cellulose acylate film prepared by incorporating 1 to 20 parts by mass of a retardation controlling agent to 100 parts by mass of cellulose acylate. The retardation controlling agent comprises at least two compounds different in Re/Rth ratios from each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical compensation sheet and a liquid crystal display device, and more particularly to an optical compensation sheet composed of only one cellulose acylate film, a polarizing plate using the same, and a liquid crystal display device.

  Among cellulose films, cellulose acetate films are characterized by high optical isotropy (low retardation value) compared to other polymer films. Therefore, it is common to use a cellulose acetate film for an application requiring optical isotropy, for example, a polarizing plate. On the other hand, optical anisotropy (high retardation value) is required for an optical compensation sheet (retardation film) such as a liquid crystal display device. Therefore, it is common to use a synthetic polymer film having a high retardation value such as a polycarbonate film or a polysulfone film as the optical compensation sheet.

  As described above, in the technical field of optical materials, when a polymer film requires optical anisotropy (high retardation value), a synthetic polymer film is used and optical isotropy (low retardation value) is used. In general, a cellulose acetate film has been used when the above is required.

However, in recent years, a cellulose acetate film having a high retardation value that can be used for applications requiring optical anisotropy has been required, and a technique corresponding to the cellulose acetate film has been proposed (for example, Patent Document 1). In the disclosed invention, in order to achieve a high retardation value with cellulose triacetate, an aromatic compound having at least two aromatic rings, particularly a compound having a 1,3,5-triazine ring, is added and subjected to stretching treatment. .
In general, cellulose triacetate is a polymer material that is difficult to stretch, and it is known that it is difficult to increase the birefringence. However, in Patent Document 1, birefringence is achieved by simultaneously orienting additives in the stretching process. The rate can be increased and a high retardation value is realized. Since this film can also serve as a protective film for a polarizing plate, there is an advantage that an inexpensive and thin liquid crystal display device can be provided.

In recent years, it has become essential to reduce the thickness of liquid crystal cells in order to reduce the weight of liquid crystal display devices, reduce manufacturing costs, and increase response speed. Therefore, the optical performance required for the optical compensation sheet has a higher Re retardation value and a film having a lower Rth retardation value.
However, as a result of intensive studies by the inventor in the method disclosed in Patent Document 1, the method can achieve both of the above-mentioned Re retardation value and Rth retardation value when setting them individually. It turns out that there is a problem that can not be. In addition to the above-mentioned Patent Document 1, there is a patent document that discloses a technique relating to the optical performance of a retardation film, for example, Patent Document 2, but a method for achieving both a desired Re value and an Rth value has not been disclosed. .

European Patent Application 0911656A2 JP 2001-116926 A

An object of the present invention is to provide an optical compensation sheet for optically compensating a liquid crystal cell composed of only one cellulose acylate film.
Specifically, the range of retardation for optical compensation is expanded, and an optical compensation sheet with a wide range of Re and Rth is provided.
Another object of the present invention is to provide a polarizing plate in which an optical compensation function optimal for a liquid crystal display device is added to the polarizing plate without increasing the number of constituent film elements.
Still another object of the present invention is to provide a liquid crystal display device optically compensated by a cellulose acylate film.

When considering a fixed film thickness, the retardation of the film is determined by the refractive index and the abundance of the material and the orientation state. In the case of the method disclosed in Patent Document 1, it is determined by the triaxial refractive index and orientation state of cellulose triacetate, the refractive index, addition amount, and orientation state of the discotic compound as an additive.
Since both the Re retardation value and the Rth retardation value are defined by the refractive index in the triaxial direction, the Re / Rth ratio is almost determined by the additive that greatly contributes to the retardation. As a result of examining the Re / Rth ratio with respect to the draw ratio, it was found that the relationship is proportional, and that the Re / Rth ratio increases as the draw ratio increases. The same proportional relationship is obtained when the addition amount is changed, and the Re / Rth ratio increases as the addition amount is increased. It was found that the slope of the Re / Rth ratio with respect to the draw ratio was determined by the additive material, and that the slope of the discotic compound specifically described in Patent Document 1 was small.

The orientation state of cellulose triacetate and additives that determine the retardation value also varies depending on the stretching method. In general, a roll stretching method or a tenter stretching method is known as a uniaxial stretching method. However, since the former causes shrinkage of the film width, Re is easily expressed. Since the latter is stretched in the width direction while the transport direction is regulated, Re is not easily increased, and the Re / Rth ratio with respect to the stretching ratio is smaller than the former. However, the tenter stretching method is effective for the film thickness and optical performance. Since it is easy to reduce in-plane variation, it is suitable as a method for manufacturing an optical compensation sheet for a liquid crystal display device. When this technique is applied to the example disclosed above, the increase amount of the Re / Rth ratio is approximately 0.01 or less per 1% of the draw ratio. When the Re target value is close to the Rth target value and the Re / Rth ratio is about 0.5, a draw ratio of 50% or more is required. It is practically difficult to stably realize this magnification in a cellulose triacetate film that is difficult to stretch.
In addition, with regard to the addition amount, it is difficult to achieve the target optical performance with an increase in the addition amount that is actually possible.

  In the present specification, Re and Rth respectively represent in-plane retardation and retardation in the thickness direction. Re is measured by making light with a wavelength of 590 nm incident in the normal direction of the film in KOBRA 21ADH (trade name, manufactured by Oji Scientific Instruments). Rth was measured by making light having a wavelength λ nm incident from a direction inclined + 40 ° with respect to the film normal direction with the Re, in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis). The retardation value and the retardation value measured by making light of wavelength λ nm incident from a direction inclined by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). KOBRA 21ADH is calculated based on the retardation value measured in the direction, 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 polymer handbook (JOHN WILEY & SONS, INC), catalog values of various optical films, and the like can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). KOBRA 21ADH calculates nx, ny, and nz by inputting these assumed values of average refractive index and film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

  In order to increase the Re / Rth control region with respect to the draw ratio when the present inventors achieve the optimum Re and Rth values as described above by the tenter drawing method, the disk described in Patent Document 1 is used. It has been found that the Re / Rth control region relative to the draw ratio can be increased by using a glassy compound and a compound represented by the following general formula (II) in combination as an additive, and it has not been realized by conventional methods. Based on this finding, the inventors have found that an optical compensation sheet with performance can be produced.

The object of the present invention has been achieved by the following optical compensation sheet and the following liquid crystal display device.
(1) An optical compensation sheet comprising a cellulose acylate film containing 1 to 20 parts by mass of a retardation control agent with respect to 100 parts by mass of cellulose acylate, wherein the retardation control agent has a different Re / Rth ratio. An optical compensation sheet comprising at least two kinds of compounds.
(2) The optical compensation sheet according to item (1), wherein the optical compensation sheet comprises a cellulose acylate film stretched at a stretch ratio of 3 to 100%.
(3) The optical compensation sheet according to item (1) or (2), wherein the content of the two compounds contained in the retardation control agent is 1 to 20 parts by mass in total with respect to 100 parts by mass of cellulose acylate. .
(4) In any one of (1) to (3), the Re / Rth ratio of the two compounds contained in the retardation controlling agent is less than 0.35 on one side and 0.35 or more on the other side. The optical compensation sheet as described.
(5) The optical compensation sheet according to item (4), wherein the compound having a Re / Rth ratio of less than 0.35 is a compound represented by the general formula (I).

(Wherein X ¹ represents a single bond, —NR ⁴ —, —O— or —S—; X ² represents a single bond, —NR ⁵ —, —O— or —S—; X ³ represents a single bond, —NR ⁶ —, —O— or —S—, and R ¹ , R ² and R ³ each independently represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. And R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
(6) The optical compensation sheet according to item (4), wherein the compound having a Re / Rth ratio of less than 0.35 is a compound represented by the general formula (II).

(In the formula, Ar ¹ , Ar ² , and Ar ³ each independently represent an aryl group or an aromatic heterocycle, and L ¹ and L ² each independently represent a single bond or a divalent linking group. N represents 3 The above integers are represented, and a plurality of Ar ² and L ² may be the same or different.
(7) The optical compensation sheet according to item (4), wherein the compound having a Re / Rth ratio of 0.35 or more is a compound represented by the general formula (III).

（一般式（IV）中、Ｒ⁴、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｒ⁸及びＲ⁹は各々独立して、水素原子又は置換基を表す。）
（９）セルロースアセテートフィルムの表面エネルギーが５５乃至７５ｍＮ／ｍであることを特徴とする（１）〜（８）のいずれか１項に記載の光学補償シート。
（１０）長手方向に搬送しながら長手方向と直交する方向に延伸し、延伸開始時のセルロースアシレートフィルムの残留溶剤量が２質量％〜５０質量％の状態であり、該フィルムの遅相軸が該フィルムの長尺方向に対して直交する方向にあることを特徴とする（１）〜（９）のいずれか１項に記載の光学補償シートの製造方法。
（１１）セルロースアシレートが、酢化度が５９．０〜６１．５％であるセルロースアセテートである（１）〜（９）のいずれか１項に記載の光学補償シートまたは（１０）に記載の光学補償シートの製造方法。
（１２）セルロースアシレートフィルムが、セルロースの水酸基がアセチル基および炭素原子数が３〜２２のアシル基で置換されたセルロースアシレートからなり、かつ該セルロースアシレートのアセチル基の置換度Ａおよび炭素原子数が３〜２２のアシル基の置換度Ｂが、下記式（III）を満たすことを特徴とする（１）〜（１１）のいずれか１項に記載の光学補償シートまたは（１０）もしくは（１１）に記載の光学補償シートの製造方法。
式（III）：２．０≧Ａ＋Ｂ≧３．０
（１３）セルロースアシレートの炭素原子数が３〜２２のアシル基が、ブタノイル基またはプロピオニル基であることを特徴とする（１２）に記載の光学補償シートまたは光学補償シートの製造方法。
（１４）液晶セルおよびその両側に配置された二枚の偏光板からなり、該偏光板が偏光膜およびその両側に配置された二枚の透明保護膜からなる液晶表示装置であって、該液晶セルと少なくとも一方の偏光膜との間に、（１）〜（１３）のいずれか１項に記載の光学補償シートが配置されており、該セルロースアシレートフィルムの遅相軸とセルロースアシレートフィルムに隣接する偏光膜の透過軸とが実質的に平行になるように配置されていることを特徴とする液晶表示装置。
（１５）液晶表示装置のモードがVAモードであることを特徴とする（１４）に記載の液晶表示装置。 Wherein Ar ¹¹ and Ar ¹² are each independently an aromatic group; L ¹² and L ¹³ are each independently from the group consisting of an alkylene group, —O—, —CO—, and combinations thereof. A divalent linking group selected; and X is 1,4-cyclohexylene, vinylene or ethynylene.)
(8) The optical compensation sheet according to any one of (1) to (7), wherein the retardation controlling agent is a compound represented by the general formula (IV).

(In the general formula (IV), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent.)
(9) The optical compensation sheet according to any one of (1) to (8), wherein the surface energy of the cellulose acetate film is 55 to 75 mN / m.
(10) The film is stretched in a direction perpendicular to the longitudinal direction while being conveyed in the longitudinal direction, and the residual solvent amount of the cellulose acylate film at the start of stretching is in a state of 2% by mass to 50% by mass, and the slow axis of the film The method for producing an optical compensation sheet according to any one of (1) to (9), wherein is in a direction orthogonal to the longitudinal direction of the film.
(11) The optical compensation sheet according to any one of (1) to (9) or (10), wherein the cellulose acylate is cellulose acetate having an acetylation degree of 59.0 to 61.5%. Manufacturing method of the optical compensation sheet.
(12) The cellulose acylate film is composed of cellulose acylate in which the hydroxyl group of cellulose is substituted with an acetyl group and an acyl group having 3 to 22 carbon atoms, and the substitution degree A and carbon of the acetyl group of the cellulose acylate The optical compensation sheet according to any one of (1) to (11), wherein the substitution degree B of the acyl group having 3 to 22 atoms satisfies the following formula (III), or (10) or The manufacturing method of the optical compensation sheet as described in (11).
Formula (III): 2.0 ≧ A + B ≧ 3.0
(13) The method for producing an optical compensation sheet or optical compensation sheet according to (12), wherein the acyl group having 3 to 22 carbon atoms of cellulose acylate is a butanoyl group or a propionyl group.
(14) A liquid crystal display device comprising a liquid crystal cell and two polarizing plates disposed on both sides thereof, the polarizing plate comprising a polarizing film and two transparent protective films disposed on both sides thereof, wherein the liquid crystal The optical compensation sheet according to any one of (1) to (13) is disposed between the cell and at least one polarizing film, and the slow axis of the cellulose acylate film and the cellulose acylate film A liquid crystal display device, characterized in that it is arranged so that a transmission axis of a polarizing film adjacent to the substrate is substantially parallel.
(15) The liquid crystal display device according to (14), wherein the mode of the liquid crystal display device is a VA mode.

In the present invention, “compounds having different Re / Rth ratios” means “Re / Rth ratio” values obtained from measured values of Re and Rth of triacetylcellulose produced, cast and stretched containing a compound. Different compounds.
Here, the value of the Re / Rth ratio is specifically determined by casting a dope prepared as described below on a glass plate, drying at 70 ° C. for 6 minutes, peeling off from the glass plate, and further increasing at 10 ° C. at 10 ° C. For 20 minutes with a fixed-end stretching device, and the cast film is dried, and the wavelength is 590 nm in KOBRA 21ADH (trade name, manufactured by Oji Scientific Instruments). It is a value of Re / Rth calculated from Re and Rth measured using light. Since these values vary depending on the addition amount of the compound and the draw ratio, the value of a film obtained by stretching 20% of the compound added by 2% by mass was used for comparison.
Triacetyl cellulose (degree of acetylation 60.9) 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Methylene chloride 318 parts by weight Methanol 47 parts by weight Compound (Retardation control agent) 2 parts by mass

By using the optical compensation sheet of the present invention, the liquid crystal cell can be optically compensated with an optical compensation sheet composed only of a cellulose acylate film. In addition, an optical compensation sheet in the range of the combination of Re and Rth that could not be achieved conventionally can be obtained.
When the optical compensation sheet of the present invention is used as one protective film of a polarizing plate, an optical compensation function can be added to the polarizing plate without increasing the number of components of the polarizing plate.
The optical compensation sheet composed only of the cellulose acylate film and the polarizing plate using the optical compensation sheet as a protective film can be used particularly advantageously in VA mode and OCB mode liquid crystal display devices.

In the present invention, preferably, the Re value of the cellulose acylate film is adjusted to 60 to 120 nm and the Rth retardation value is adjusted to 100 to 250 nm.
In the present invention, the amount of change in Re / Rth per 1% stretch ratio can be 0.01 to 0.1. Here, the amount of change in Re / Rth per 1% of the draw ratio can be obtained from the slope when the Re / Rth ratios for the draw ratios of at least three points with a draw ratio of 5% or more are linearly approximated.

The birefringence (nx-ny) of the cellulose acylate film is preferably 0.0002 to 0.0009, more preferably 0.00025 to 0.0009, and 0.00035 to 0.0009. Most preferred.
Further, the birefringence {(nx + ny) / 2−nz} in the thickness direction of the cellulose acylate film is preferably 0.0006 to 0.005, and more preferably 0.0008 to 0.005. 0.0012 to 0.005 is most preferable.

[Cellulose acylate film]
As the raw material cotton of cellulose acylate used in the present invention, a known raw material can be used (for example, Invention Association Open Technique 2001-1745). Cellulose acylate can also be synthesized by a known method (for example, Mita et al., Wood Chemistry 180-190 (Kyoritsu Shuppan, 1968)). The viscosity average degree of polymerization of cellulose acylate is preferably 200 to 700, more preferably 250 to 500, and most preferably 250 to 350. The cellulose ester used in the present invention preferably has a narrow molecular weight distribution of Mw / Mn (Mw is a weight average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. The specific value of Mw / Mn is preferably 1.5 to 5.0, more preferably 2.0 to 4.5, and most preferably 2.0 to 4.0. preferable.

Although there is no restriction | limiting in particular in the acyl group of this cellulose acylate film, It is preferable to use an acetyl group, a propionyl group, and a butyryl group, and an acetyl group is especially preferable. The substitution degree of all acyl groups is preferably 1.5 to 3.0, more preferably 2.7 to 3.0, and particularly preferably 2.8 to 2.95. In this specification, the substitution degree of an acyl group is a value calculated according to ASTM D817.
The acyl group is most preferably an acetyl group, and when cellulose acetate having an acyl group is an acetyl group is used, the acetylation degree is preferably 59.0 to 62.5%, and 59.0 to 61.5%. Is more preferable. When the acetylation degree is within this range, Re does not become larger than the desired value due to the conveying tension during casting, there is little in-plane variation, and there is little change in the retardation value due to temperature and humidity.
The substitution degree of the 6-position acyl group is preferably 0.9 or more from the viewpoint of suppressing variations in Re and Rth.

[Retardation control agent]
In the present invention, at least two compounds having different optical anisotropy (Re / Rth ratio) due to stretching are contained in the cellulose acylate film. The two types of compounds having different Re / Rth ratios to be used preferably have a Re / Rth ratio value of 0.05 or more, more preferably 0.10 or more. Preferably, the cellulose triacetate film to which the compound is added contains at least two compounds having a Re / Rth ratio value of less than 0.35 and 0.35 or more, respectively.

The compound having a Re / Rth ratio of less than 0.35 is preferably a compound represented by general formula (I) or general formula (II).
Below, the compound represented by general formula (I) is demonstrated.

Wherein, X ¹ is a single bond, -NR ⁴ -, - a O- or -S-; X ² is a single bond, -NR ⁵ -, - a O- or -S-; X ³ is A single bond, —NR ⁶ —, —O— or —S—; R ¹ , R ² and R ³ are each independently an alkyl group, an alkenyl group, an aryl group or a heterocyclic group; and R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
Here, the compound represented by the general formula (I) is a compound having a 1,3,5-triazine ring, and an aromatic compound having at least two aromatic rings can be preferably used.
The compound represented by the formula (I) is particularly preferably a melamine compound. In the melamine compound, in formula (I), X ¹ , X ² and X ³ are —NR ⁴ —, —NR ⁵ — and —NR ⁶ —, respectively, or X ¹ , X ² and X ³ Is a single bond, and R ¹ , R ² and R ³ are heterocyclic groups having a free valence on the nitrogen atom. ^{-X 1 -R 1, -X 2 -R} 2 and -X ³ -R ³ are preferably the same substituents. R ¹ , R ² and R ³ are particularly preferably aryl groups. R ⁴ , R ⁵ and R ⁶ are particularly preferably a hydrogen atom.

The alkyl group is preferably a chain alkyl group rather than a cyclic alkyl group. A linear alkyl group is preferred to a branched alkyl group.
The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, still more preferably 1 to 10 carbon atoms, still more preferably 1 to 8 carbon atoms. 6 is most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy, ethoxy, epoxyethyloxy) and an acyloxy group (eg, acryloyloxy, methacryloyloxy). The alkenyl group is preferably a chain alkenyl group rather than a cyclic alkenyl group. A linear alkenyl group is preferable to a branched chain alkenyl group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, and further preferably 2 to 6 is most preferred. The alkenyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy, ethoxy, epoxyethyloxy) and an acyloxy group (eg, acryloyloxy, methacryloyloxy).

  The aryl group is preferably phenyl or naphthyl, and particularly preferably phenyl. The aryl group may have a substituent. Examples of the substituent include a halogen atom, hydroxyl, cyano, nitro, carboxyl, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, alkenyloxycarbonyl group, Aryloxycarbonyl group, sulfamoyl, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamido group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide group, alkylthio group, alkenyl A thio group, an arylthio group and an acyl group are included. The alkyl group has the same definition as the alkyl group described above. The alkyl part of the alkoxy group, the acyloxy group, the alkoxycarbonyl group, the alkyl-substituted sulfamoyl group, the sulfonamide group, the alkyl-substituted carbamoyl group, the amide group, the alkylthio group and the acyl group is the same as the alkyl group described above.

  The alkenyl group has the same definition as the alkenyl group described above. The alkenyl part of the alkenyloxy group, acyloxy group, alkenyloxycarbonyl group, alkenyl-substituted sulfamoyl group, sulfonamide group, alkenyl-substituted carbamoyl group, amide group, alkenylthio group and acyl group is the same as the alkenyl group described above. Examples of the aryl group include phenyl, α-naphthyl, β-naphthyl, 4-methoxyphenyl, 3,4-diethoxyphenyl, 4-octyloxyphenyl and 4-dodecyloxyphenyl. Examples of the aryloxy group, acyloxy group, aryloxycarbonyl group, aryl-substituted sulfamoyl group, sulfonamido group, aryl-substituted carbamoyl group, amide group, arylthio group, and acyl group are the same as the above examples of the aryl group.

When X ¹ , X ² or X ³ is —NR ⁴ —, —NR ⁵ —, or —NR ⁶ —, the heterocyclic group represented by R ⁴ , R ⁵ and R ⁶ may have aromaticity. preferable. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably N, S or O, and particularly preferably N. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Heterocyclic group Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety. When X ¹ , X ² or X ³ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. In addition, the heterocyclic group may have a hetero atom other than the nitrogen atom (eg, O, S). The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.

  Below, the preferable example of a compound represented by general formula (I) is shown.

  The compound represented by general formula (I) can be synthesized, for example, according to the synthesis method described in JP-A-2003-344655.

  Next, the compound represented by formula (II) will be described.

In general formula (II), Ar ¹ , Ar ² and Ar ³ each independently represents an aryl group or an aromatic heterocycle, and L ¹ and L ² each independently represent a single bond or a divalent linking group. n represents an integer of 3 or more, and the plurality of Ar ² and L ² may be the same or different.

Ar ¹ , Ar ² , Ar ³ represent an aryl group or an aromatic heterocycle, and the aryl group represented by Ar ¹ , Ar ² , Ar ³ is preferably an aryl group having 6 to 30 carbon atoms, It may be present or may form a condensed ring with another ring. Further, if possible, it may have a substituent, and the substituent T described later can be applied as the substituent.
In the general formula ^{(II), Ar 1, Ar} 2, Ar 6~20 carbon atoms and more preferably an aryl group represented by ^3, particularly preferably 6 to 12 carbon atoms, such as phenyl, p- methylphenyl, And naphthyl.

In the general formula (II), the aromatic heterocycle represented by Ar ¹ , Ar ² , Ar ³ is any heterocycle as long as it is an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Although it may be a ring, it is preferably an aromatic heterocycle containing at least one of a 5- to 6-membered oxygen atom, nitrogen atom or sulfur atom. Moreover, you may have a substituent further if possible. Substituent T described later can be applied as the substituent.

  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, and examples thereof include amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like.

An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy, ethoxy, butoxy, etc.), an aryloxy group (preferably C6-C20, More preferably C6-C16, Most preferably C6-C12, for example, phenyloxy, 2-naphthyloxy, etc.), acyl groups (preferably C1-C1) 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, and more). Preferably it has 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonyl or ethoxycarbonyl. An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 10 carbon atoms, such as phenyloxycarbonyl). An acyloxy 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 acetoxy and benzoyloxy);

An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetylamino and benzoylamino), an alkoxycarbonylamino group (preferably Has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonylamino and the like, and an aryloxycarbonylamino group (preferably 7 to 7 carbon atoms). 20, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino, and the like, sulfonylamino groups (preferably 1 to 20 carbon atoms, more preferably carbon atoms) 1 to 16, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino Benzenesulfonylamino, etc.), sulfamoyl groups (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethyl) Sulfamoyl, 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, and examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl and the like), alkylthio. A 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 and ethylthio), an arylthio group (preferably having 6 to 6 carbon atoms). 20, More preferably, it is C6-C16, Most preferably, it is C6-C12, for example, phenylthio etc. are mentioned, A sulfonyl group (Preferably C1-C20, More preferably C1-C16 , Particularly preferably having 1 to 12 carbon atoms, such as mesyl and tosyl).

Sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably carbon 1 to 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 carbon atom) -20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphate amide and phenyl phosphate amide), hydroxy group, mercapto group, halogen atom (for example, 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 a carbon number of 1-30, more preferably 1-12. Examples of heteroatoms include nitrogen atoms, oxygen atoms, sulfur atoms, For example, imidazolyl, pyridyl, quinolyl, furyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 carbon atoms). To 30 and 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.

In the general formula (II), specific examples of the aromatic heterocycle represented by Ar ¹ , Ar ² , Ar ³ include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine. , Indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole Benzthiazole, benzotriazole, tetrazaindene, pyrrolotriazole, pyrazolotriazole and the like. Preferred examples of the aromatic heterocycle include benzimidazole, benzoxazole, benzthiazole, and benzotriazole.

In the general formula (II), L ¹ and L ^{2 each} represent a single bond or a divalent linking group, preferably as an example of a divalent linking group, preferably —NR ⁷ — (R ⁷ is a hydrogen atom, a substituent A group represented by -SO _2- , -CO-, an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, -O-, —S—, —SO—, and a group obtained by combining two or more of these divalent groups, more preferably —O—, —CO—, —SO ₂ NR ⁷ —, —NR ⁷ SO _2- , —CONR ⁷ —, —NR ⁷ CO—, —COO—, and —OCO—, an alkynylene group, most preferably —CONR ⁷ —, —NR ⁷ CO—, —COO—, and —OCO— , An alkynylene group.

In the compound represented by the general formula (II) of the present invention, when Ar ² is bonded to L ¹ and L ² but Ar ² is a phenylene group, L ¹ -Ar ² -L ² and L ² -Ar ² -L ² are most preferably in the relation of mutually para position (1,4-position).

n represents an integer of 3 or more, preferably 3 to 7, and more preferably 3 to 5.
Specific examples of the compound represented by the general formula (II) are shown below.

The compound represented by the general formula (II) can be synthesized by a known method. For example, the exemplary compound (II-41) will be described below, but is not limited thereto.
[Synthesis Example 1: Synthesis of Exemplified Compound (II-41)]
Exemplified compound (II-41) was synthesized according to the following scheme.

[Synthesis of Intermediate (S1)]
Methyl 2,4-dihydroxybenzoate (67.3 g), 2-ethylhexyl bromide (85.3 ml) and potassium carbonate (137.5 g) were added to DMF (500 ml), and the mixture was heated and stirred on a 90 ° C. hot water bath for 6 hours. Thereafter, 75.9 ml of dimethyl sulfate and 137 g of potassium carbonate were added, and heating and stirring were continued for 10 hours. After completion of the reaction, 500 ml of ethyl acetate was added, and the inorganic salt was separated by filtration under reduced pressure. Water was added to the filtrate, and the organic layer was extracted twice with ethyl acetate. The organic layer was washed successively with 1N aqueous hydrochloric acid, water and saturated brine, dried over magnesium carbonate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (developing solvent, ethyl acetate / n-hexane = 1/10) to obtain an intermediate methyl ester compound as an oily substance (70 g, yield 59%). This methyl ester was dissolved in 150 ml of methanol and 143 ml of 5N aqueous potassium hydroxide solution and heated to reflux for 2 hours. Thereafter, the mixture was added to a mixture of 500 ml of water and 59.3 ml of 12N hydrochloric acid, and then 500 ml of ethyl acetate was added to separate the organic layer. The organic layer was washed successively with water and saturated brine, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. In this way, 66 g of intermediate (S1) was obtained as an oil.

[Synthesis of Intermediate (S3)]
After 28 g of intermediate (S1), 100 ml of toluene, and 0.1 ml of dimethylformamide were heated to 70 ° C., 8.03 ml of thionyl chloride was slowly added dropwise, and the mixture was heated and stirred at 70 ° C. for 1 hour. Thereafter, a solution prepared by dissolving 13.81 g of 4-hydroxybenzoic acid (S2) in 20 ml of dimethylformamide was added to the reaction solution, and further reacted at 70 ° C. for 2 hours. After the reaction, the reaction mixture was cooled to room temperature, ethyl acetate and water were added, and the organic layer was separated. The organic layer was washed successively with 1N aqueous hydrochloric acid, water and saturated brine, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (developing solvent, methylene chloride / methanol = 20/1), dispersed in n-hexane, and filtered under reduced pressure to obtain 21.8 g of an intermediate (S3) as a white solid.

[Synthesis of Exemplary Compound (II-41)]
Intermediate (S3) 19.22 g, 3.72 g of 4,4′-biphenol and 0.98 g of dimethylaminopyridine were dissolved in 75 ml of methylene chloride and 25 ml of THF, and 10.73 g of dicyclohexylcarbodiimide was slowly added thereto. Subsequently, the solution was heated to reflux for 3 hours. Thereafter, the reaction solution was cooled to room temperature, the precipitated crystals (dicyclohexylurea) were filtered off, water was added to the filtrate, and the organic layer was separated. The obtained organic layer was washed successively with 1N aqueous hydrochloric acid, water and saturated brine, dried over magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography, and further recrystallized from methylene chloride / methanol to obtain 6.4 g of Compound (II-41) as a white solid.
The compound was identified by ¹ H-NMR (400 MHz).
¹ H-NMR (CDCl ₃ ): δ 0.89 (m, 12H), 1.28-1.60 (m, 16H), 1.76 (m, 2H), 3.92 (m, 10H), 6 .55 (m, 4H), 7.29 (d, 4H), 7.38 (d, 4H), 7.64 (d, 4H), 8.08 (d, 2H), 8.29 (d, 4H)
The melting point of the obtained compound was 94 ° C.

  A compound having a Re / Rth ratio of 0.35 or more is preferably a compound represented by the general formula (III).

In the formula, Ar ¹¹ and Ar ¹² are each independently an aromatic group; L ¹² and L ¹³ are each independently selected from the group consisting of an alkylene group, —O—, —CO—, and combinations thereof. And X is 1,4-cyclohexylene, vinylene or ethynylene.

In formula (III), L ¹² and L ¹³ are each independently a divalent linking group selected from the group consisting of an alkylene group, —O—, —CO—, and combinations thereof. The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure. The number of carbon atoms in the alkylene group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, still more preferably 1 to 4, and 1 or Most preferred is 2 (methylene or ethylene). L ¹² and L ¹³ are particularly preferably —O—CO— or —CO—O—.

  In the formula (III), X is 1,4-cyclohexylene, vinylene or ethynylene. X is preferably 1,4-cyclohexylene.

Ar ¹¹ and Ar ¹² each independently represents an aromatic group. In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group. An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine Rings, pyridazine rings, pyrimidine rings, pyrazine rings, and 1,3,5-triazine rings are included. As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include halogen atom (F, Cl, Br, I), hydroxyl, carboxyl, cyano, amino, alkylamino group (eg, methylamino, ethylamino) , Butylamino, dimethylamino), nitro, sulfo, carbamoyl, alkylcarbamoyl groups (eg, N-methylcarbamoyl, N-ethylcarbamoyl, N, N-dimethylcarbamoyl), sulfamoyl, alkylsulfamoyl groups (eg, N- Methylsulfamoyl, N-ethylsulfamoyl, N, N-dimethylsulfamoyl), ureido, alkylureido groups (eg, N-methylureido, N, N-dimethylureido, N, N, N′-trimethyl) Ureido), alkyl groups (eg, methyl, ethyl, propyl, butyl, pentyl) Heptyl, octyl, isopropyl, s-butyl, t-amyl, cyclohexyl, cyclopentyl), alkenyl groups (eg, vinyl, allyl, hexenyl), alkynyl groups (eg, ethynyl, butynyl), acyl groups (eg, formyl, acetyl, Butyryl, hexanoyl, lauryl), acyloxy groups (eg, acetoxy, butyryloxy, hexanoyloxy, lauryloxy), alkoxy groups (eg, methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy), aryloxy groups (Eg, phenoxy), alkoxycarbonyl group (eg, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, heptyloxycarbonyl), aryloxycar Nyl group (eg, phenoxycarbonyl), alkoxycarbonylamino group (eg, butoxycarbonylamino, hexyloxycarbonylamino), alkylthio group (eg, methylthio, ethylthio, propylthio, butylthio, pentylthio, heptylthio, octylthio), arylthio group (eg, , Phenylthio), alkylsulfonyl groups (eg, methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, pentylsulfonyl, heptylsulfonyl, octylsulfonyl), amide groups (eg, acetamido, butyramide, hexylamide, laurylamide) and non- Aromatic heterocyclic groups (eg, morpholyl, pyrazinyl) are included.

Examples of the substituent for the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom, cyano, carboxyl, hydroxyl, amino, alkyl-substituted amino group, acyl group, acyloxy group, amide group, alkoxycarbonyl group, alkoxy group, alkylthio And groups and alkyl groups are preferred. The alkyl part and the alkyl group of the alkylamino group, alkoxycarbonyl group, alkoxy group and alkylthio group may further have a substituent. Examples of alkyl moieties and substituents of alkyl groups include halogen atom, hydroxyl, carboxyl, cyano, amino, alkylamino group, nitro, sulfo, carbamoyl, alkylcarbamoyl group, sulfamoyl, alkylsulfamoyl group, ureido, alkylureido Group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, alkylsulfonyl group, amide group and non-aromatic An aromatic heterocyclic group is included. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, hydroxyl, amino, alkylamino group, acyl group, acyloxy group, acylamino group, alkoxycarbonyl group and alkoxy group are preferable.
Specific examples of the compound represented by the formula (III) are shown below.

Examples of the compound having a Re / Rth ratio value of less than 0.35 or 0.35 or more include compounds represented by the following general formula (IV).
The compound represented by general formula (IV) is demonstrated below.

In the general formula (IV), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a substituent.
R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are each a substituent represented by an alkyl group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably An alkyl group having 1 to 20 carbon atoms, for example, methyl group, ethyl group, isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl Group), an alkenyl group (preferably an alkenyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 20 carbon atoms, such as a vinyl group, an allyl group, 2 -Butenyl group, 3-pentenyl group and the like), alkynyl group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms). An alkynyl group, for example, a propargyl group, a 3-pentynyl group, and the like; an aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and particularly preferably 6 to 12 carbon atoms). Group, for example, a phenyl group, a p-methylphenyl group, a naphthyl group and the like, a substituted or unsubstituted amino group (preferably having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, and particularly preferably Is an amino group having 0 to 20 carbon atoms, and examples thereof include an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, and an anilino group).

An alkoxy group (preferably an alkoxy group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). Aryloxy group (preferably an aryloxy group having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 6 to 20 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably carbon number) To 20 alkoxy groups such as methoxycarbonyl group and ethoxycarbonyl group), aryloxycarbonyl groups (preferably having 7 to 40 carbon atoms, more preferably having 7 to 30 carbon atoms, and particularly preferably carbon atoms). An aryloxycarbonyl group having 7 to 20 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 carbon atoms). ˜20 acyloxy groups such as an acetoxy group and a benzoyloxy group)

An acylamino group (preferably an acylamino group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as an acetylamino group and a benzoylamino group), alkoxycarbonyl An amino group (preferably an alkoxycarbonylamino group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as a methoxycarbonylamino group), aryloxy Carbonylamino group (preferably an aryloxycarbonylamino group having 7 to 40 carbon atoms, more preferably 7 to 30 carbon atoms, particularly preferably 7 to 20 carbon atoms, such as a phenyloxycarbonylamino group) Sulfonylamino group (preferably having 1 to 40 carbon atoms, more preferred Or a sulfonylamino group having 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a methanesulfonylamino group and a benzenesulfonylamino group, and a sulfamoyl group (preferably having a carbon number of 0 to 40). More preferably, it is a sulfamoyl group having 0 to 30 carbon atoms, particularly preferably 0 to 20 carbon atoms, and examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, and a phenylsulfamoyl group. ), A carbamoyl group (preferably a carbamoyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, an unsubstituted carbamoyl group, a methylcarbamoyl group, diethylcarbamoyl group Group, phenylcarbamoyl group, etc.),

An alkylthio group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a phenylthio group), a sulfonyl group (preferably having 1 to 1 carbon atoms). 40, more preferably a sulfonyl group having 1 to 30 carbon atoms, particularly preferably a sulfonyl group having 1 to 20 carbon atoms, such as a mesyl group and a tosyl group, and a sulfinyl group (preferably having a carbon number of 1 to 40, more Preferably it is C1-C30, Most preferably, it is C1-C20 sulfinyl group, for example, a methane sulfinyl group, a benzene sulfinyl group, etc., a ureido group (preferably C1-C40, more preferable) Is a ureido group having 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as an unsubstituted ureido group or methylurea. And phosphoric acid amide groups (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms), For example, a diethylphosphoric acid amide group, a phenylphosphoric acid amide group etc. are mentioned), a hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a cyano group, a sulfo group, a carboxyl group , A nitro group, a hydroxamic acid group, a sulfino group, a hydrazino group, an imino group, a heterocyclic group (preferably a heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms such as a nitrogen atom, an oxygen atom, A heterocyclic group having a heteroatom such as a sulfur atom, such as an imidazolyl group, a pyridyl group, a quinolyl group, a furyl group, a piperidyl group Morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, 1,3,5-triazyl group, etc.), silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms). Particularly preferred is a silyl group having 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group. These substituents may be further substituted with these substituents. Further, when two or more substituents are present, they may be the same or different. If possible, they may be bonded to each other to form a ring.

The substituent represented by each of R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ is preferably an alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an alkylthio group or a halogen atom. It is.

  Although the specific example of a compound represented by general formula (IV) below is given, it is not limited to these.

These compounds are used in an amount of 0.01 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of cellulose acetate.
Further, when a compound having a Re / Rth ratio of less than 0.35 and a compound of 0.35 or more is represented by a mass ratio of a compound of less than 0.35: 0.35 or more, preferably 1: 9 to 9: 1, More preferably, it is used in a mixing ratio of 2: 8 to 8: 2.

  The compound represented by the general formula (IV) can be synthesized according to the synthesis method described in, for example, JP-A-2005-134484.

[Production of cellulose acetate film]
It is preferable to produce a cellulose acylate film by a solvent cast method. In the solvent cast method, a film is produced using a solution (dope) in which cellulose acylate is dissolved in an organic solvent.
Organic solvents include ethers having 3 to 12 carbon atoms, alcohols having 1 to 6 carbon atoms, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and 1 to 6 carbon atoms. It is preferable to include a solvent selected from the halogenated hydrocarbons.
The ether, ketone and ester may have a cyclic structure. A compound having two or more functional groups of ether, ketone and ester (that is, —O—, —CO— and —COO—) can also be used as the organic solvent. The organic solvent may have other functional groups. In the case of an organic solvent having two or more types of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group.

Examples of the ether having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole.
Examples of the alcohol having 1 to 6 carbon atoms include methanol, ethanol, 2-propanol, 2-propanol, 1-butanol, 2-butanol and the like.
Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone.
Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.

Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.
The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of halogenated hydrocarbon hydrogen atoms substituted with halogen is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably, it is 40 to 60 mol%, and most preferably. Methylene chloride is a representative halogenated hydrocarbon.

  Two or more kinds of organic solvents may be used as a mixture, and preferred solvents of the present invention include methylene chloride and methanol mixed solvents.

  The cellulose acylate of the present invention is preferably dissolved in an organic solvent at a concentration of 10 to 30% by mass, more preferably a concentration of 13 to 27% by mass, and particularly a concentration of 15 to 25% by mass. A cellulose acylate solution is preferred. The method for carrying out the cellulose acylate at these concentrations may be carried out so as to obtain a predetermined concentration at the stage of dissolution, or it is prepared as a low-concentration solution (for example, 9 to 14% by mass) and then concentrated as described later. You may adjust to a predetermined high concentration solution by a process. In addition, a cellulose acylate solution having a high concentration may be added to the cellulose acylate solution at a predetermined low concentration by adding various additives, and the cellulose acylate solution concentration of the present invention may be obtained by any method. There is no particular problem if it is implemented.

In this invention, it is preferable that the aggregate molecular weight of the cellulose acylate of the diluted solution which made the cellulose acylate solution 0.1-5 mass% with the organic solvent of the same composition is 150,000-15 million. More preferably, the associated molecular weight is 180,000 to 9 million. This associated molecular weight can be determined by a static light scattering method. In that case, it is preferable to dissolve so that the inertial square radius required at the same time is 10 to 200 nm. A more preferable inertial square radius is 20 to 200 nm. Furthermore, it is preferable to dissolve so that the second virial coefficient is −2 × 10 ⁻⁴ to 4 × 10 ^−4, and more preferably, the second virial coefficient is −2 × 10 ⁻⁴ to 2 × 10 ^−4. It is. Here, the definition of the association molecular weight, the inertial square radius, and the second virial coefficient in the present invention will be described.

  These were measured using the static light scattering method according to the following method. Although the measurement was performed in a dilute region for the convenience of the apparatus, these measured values reflect the behavior of the dope in the high concentration region of the present invention. First, cellulose acylate was dissolved in a solvent used for the dope to prepare 0.1 mass%, 0.2 mass%, 0.3 mass%, and 0.4 mass% solutions. In order to prevent moisture absorption, the cellulose acylate was dried at 120 ° C. for 2 hours, and was measured at 25 ° C. and 10% RH. The dissolution method was carried out according to the method employed at the time of dope dissolution (room temperature dissolution method, cooling dissolution method, high temperature dissolution method).

  Subsequently, these solutions and the solvent were filtered through a 0.2 μm Teflon (registered trademark) filter. Then, static light scattering of the filtered solution is measured at intervals of 10 degrees from 30 degrees to 140 degrees at 25 ° C. using a light scattering measuring device (DLS-700, trade name, manufactured by Otsuka Electronics Co., Ltd.). did. The obtained data was analyzed by the BERRY plot method. The refractive index necessary for this analysis is the value of the solvent obtained by Abbe's refractive system, and the refractive index concentration gradient (dn / dc) is a differential refractometer (DRM-1021, trade name, Otsuka Electronics Co., Ltd.). And the solvent and the solution used for the light scattering measurement.

  Next, with respect to the preparation of the cellulose acylate solution (dope) of the present invention, the dissolution method is not particularly limited, and may be room temperature, further a cooling dissolution method or a high temperature dissolution method, or a combination thereof. Regarding these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737, JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP-A-2000-53784, Kaihei 11-322946, JP-A-11-322947, JP-A-2-276830, JP-A-2000-273239, JP-A-11-71463, JP-A-04-259511, JP-A-2000-273184, JP-A-11-323017, JP-A-11-323017 11-302388 describes a method for preparing a cellulose acylate solution. The above-described method for dissolving cellulose acylate in an organic solvent is applicable to the present invention as long as it is within the scope of the present invention.

  These details are described in detail on pages 22 to 25 in the Japan Society for Invention and Technology (Publication No. 2001-1745, published on March 15, 2001, Japan Society for Inventions), especially for non-chlorine solvent systems. Be implemented in a way that Further, the cellulose acylate dope solution of the present invention is usually subjected to solution concentration and filtration. Similarly, the dope solution of the invention is published in the technical report of the Invention Association (public technical number 2001-1745, published on March 15, 2001, Invention Association). It is described in detail on the page. In addition, when it melt | dissolves at high temperature, it is the case where it is more than the boiling point of the organic solvent to be used, and in that case, it uses in a pressurized state.

[Cellulose derivative film]
Next, a method for producing the optical compensation sheet of the present invention (hereinafter also referred to as the cellulose acylate film of the present invention) will be described.

  For the 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. In the solution casting film forming method used for silver halide photographic light-sensitive materials and functional protective films for electronic displays, in addition to the solution casting film forming apparatus, an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. In many cases, a coating device is added to the surface processing of the film. Each of these manufacturing processes is described in detail on pages 25 to 30 in the Japan Institute of Invention Disclosure Technical Report (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention). (Including rolling), metal support, drying, peeling, stretching, etc.

  Here, although the space temperature of a casting part is not specifically limited in this invention, It is preferable that it is -50-50 degreeC. Furthermore, it is preferable that it is -30-40 degreeC, and it is especially preferable that it is -20-30 degreeC. In particular, the cellulose acylate solution cast at a low space temperature can be cooled on the support instantly to increase the gel strength, thereby holding the film containing the organic solvent. Thereby, without evaporating the organic solvent from the cellulose acylate, it can be peeled off from the support in a short time, and high-speed casting can be achieved. The means for cooling the space may be normal air, nitrogen, argon, helium or the like, and is not particularly limited. The humidity in that case is preferably 0 to 70% RH, and more preferably 0 to 50% RH. Moreover, in this invention, the temperature of the support body of the casting part which casts a cellulose acylate solution is -50-130 degreeC, Preferably it is -30-25 degreeC, Furthermore, it is -20-15 degreeC. In order to keep the casting part at the temperature of the present invention, it may be achieved by introducing a cooled gas into the casting part, or a cooling device may be arranged in the casting part to cool the space. At this time, it is important to take care not to attach water, and it can be carried out by a method such as using dry gas.

  In the present invention, the following configurations are particularly preferred for the contents and casting of each layer. That is, the cellulose acylate solution is a cellulose acylate solution containing 0.1 to 20% by mass of at least one liquid or solid plasticizer with respect to cellulose acylate at 25 ° C. and / or at least It is a cellulose acylate solution containing 0.001 to 5% by mass of one kind of liquid or solid UV absorber with respect to cellulose acylate, and / or an average particle size of 5 to 5 of at least one kind of solid. It is a cellulose acylate solution containing 0.001 to 5% by mass of fine particle powder of 3000 nm with respect to cellulose acylate, and / or at least one fluorosurfactant with respect to cellulose acylate A cellulose acylate solution containing 0.001 to 2% by mass and / or a small amount Both are cellulose acylate solutions containing 0.0001 to 2% by mass of one type of release agent with respect to cellulose acylate, and / or at least one type of deterioration inhibitor is 0.0001 with respect to cellulose acylate. A cellulose acylate solution containing ˜2 mass%, and / or containing 0.1-15 mass% of at least one optical anisotropy control agent with respect to cellulose acylate, and / or Or a cellulose acylate solution containing 0.1 to 5% by mass of at least one infrared absorber with respect to the cellulose acylate, and a cellulose acylate produced therefrom. A film is preferred.

  In the casting step, one type of cellulose acylate solution may be cast as a single layer, or two or more types of cellulose acylate solutions may be cast simultaneously and / or sequentially. In the case of having a casting process consisting of two or more layers, the composition of the chlorine-based solvent in each layer is either the same or different in each of the produced cellulose acylate solution and cellulose acylate film, and each layer The additive is one kind or a mixture of two or more kinds, the addition position of the additive to each layer is either the same layer or a different layer, The concentration in the solution is either the same or different in each layer, the aggregate molecular weight of each layer is either the same or a different aggregate molecular weight, Either the temperature is the same or a different temperature, the coating amount of each layer is the same or different, and the viscosity of each layer is the same Either one of the different viscosities, the film thickness after drying of each layer is the same or different, and the material present in each layer is the same or distribution or different or A cellulose acylate that is characterized by the distribution, the physical properties of each layer being the same or different, and the physical properties of each layer being either uniform or different. A rate solution and a cellulose acylate film produced from the solution are also preferred.

  A plasticizer can be added to the cellulose acylate film in order to improve mechanical properties or to increase the drying speed. As the plasticizer, phosphoric acid ester or carboxylic acid ester is used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP).

Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred.
The addition amount of the plasticizer is preferably 0.1 to 25% by mass, more preferably 1 to 20% by mass, and most preferably 3 to 15% by mass of the amount of the cellulose ester.

  Degradation inhibitors (eg, antioxidants, peroxide decomposers, radical inhibitors, metal deactivators, acid scavengers, amines) may be added to the cellulose acetate film. The deterioration preventing agents are described in JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. The amount of the deterioration inhibitor added is 0.01 to 1 of the solution (dope) to be prepared from the viewpoint that the effect of the addition of the deterioration inhibitor is manifested and the bleeding out of the deterioration inhibitor to the film surface is suppressed. The content is preferably mass%, more preferably 0.01 to 0.2 mass%. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

[Stretching treatment of cellulose acylate film]
The retardation of the cellulose acetate film can be adjusted by a stretching process. The draw ratio is preferably 3 to 100%. As the stretching method, an existing method can be used without departing from the scope of the claims, but tenter stretching is particularly preferably used from the viewpoint of in-plane uniformity. The cellulose acylate film of the present invention preferably has a width of at least 100 cm, the variation in the Re value of the entire width is preferably ± 5 nm, and more preferably ± 3 nm. Further, the variation of the Rth value is preferably ± 10 nm, and more preferably ± 5 nm. Further, it is preferable that the variation in the Re value and the Rth value in the length direction is also within the range of the variation in the width direction.

The stretching process may be performed in the middle of the film forming process, or the raw film that has been formed and wound may be stretched. In the former case, stretching may be performed in a state including the residual solvent amount, and the residual solvent amount at the start of stretching is preferably 2 to 50%. The amount of residual solvent at the start of stretching is the amount of residual solvent at the start of gripping both ends of the web (raw dry dope) with clips, if tenter stretching, and starts stretching at 5 to 50%. It is more preferable to start stretching at 10 to 45%. The residual solvent amount is calculated by the following formula.
(Residual solvent amount) = 100 × {(solvent amount in web) / (total amount of web)}
At this time, it is preferable to stretch the film in the direction perpendicular to the longitudinal direction while conveying the film in the longitudinal direction so that the slow axis of the film is orthogonal to the longitudinal direction of the film.
The stretching temperature can be selected appropriately depending on the amount of residual solvent and the film thickness during stretching.

When stretching in a state containing a residual solvent, it is preferable to dry after stretching. The drying method can be performed according to the method described in the film production.
The thickness of the cellulose acetate film after stretching is 110 μm or less, preferably 40 to 110 μm, more preferably 60 to 110 μm, and most preferably 80 to 110 μm. This film thickness corresponds to the film thickness of the optical compensation sheet of the present invention.

[Wavelength dispersion of cellulose acylate film]
Examples of the performance required for the optical compensation sheet include a wavelength dispersion shape having a Re retardation value and an Rth retardation value. The optical compensation sheet works as a negative retarder and compensates for the liquid crystal that is a positive retarder. To compensate for the polarization in the entire visible wavelength range, the Rth retardation value of the optical compensation sheet is the wavelength dispersion shape of the liquid crystal. It is necessary to be similar. At present, it is known that most of the wavelength dispersion shape of the liquid crystal sealed in the liquid crystal cell is forward dispersion. Therefore, the Re retardation value and Rth retardation value wavelength dispersion shape of the optical compensation sheet are also forward dispersion shapes. That is, the difference (Re700-Re400) between the Re retardation value at 700 nm (Re700) and the Re retardation value at 400 nm (Re400) is preferably from −25 nm to 10 nm, and from −25 nm to 5 nm More preferably it is. The difference (Rth700-Rth400) between the Rth retardation value at 700 nm (Rth700) and the Rth retardation value at 400 nm (Rth400) is preferably -50 nm to 20 nm, and further Rth700-Rth400 is -50 nm. It is particularly preferably 10 to 10 nm.

[Humidity dependence of Re retardation value and Rth retardation value]
It is desirable that the Re retardation value and the Rth retardation value are small in change due to environmental humidity.
Difference between Re retardation value, Rth retardation value measured under 25 ° C. and 10% RH environment and Re retardation value measured under 25 ° C. and 80% RH environment (Re10% −Re80% (25 ° C.)), Rth letter The difference in the retardation value (Rth 10% −Rth 80% (25 ° C.)) is also preferably small, and preferably within 25 nm and within 70 nm, respectively. Further, Re 10% -Re 80% (25 ° C.) is preferably within 15 nm, and Rth 10% -Rth 80% (25 ° C.) is preferably within 50 nm. In particular, Re 10% -Re 80% (25 ° C.) is within 10 nm. Rth 10% -Rth 80% (25 ° C.) is preferably within 40 nm.

[Moisture permeability]
In the present invention, a sample 70 mmφ was conditioned at 25 ° C. and 90% RH for 24 hours, and per unit area according to JIS Z-0208 using a moisture permeation tester (KK-70907, trade name, manufactured by Toyo Seiki Co., Ltd.). Calculate the amount of water (g / m ² ),
Rear weight moisture permeability = humidity - obtained in the humidity before the mass, it is preferred that the moisture permeability of at 25 ° C. 90% RH is a 20g / m ² · 24hr or ^{250g / m 2 · 24hr, 20g} / m 2 · It is particularly preferably 24 hr to 230 g / m ² · 24 hr.

[Dimension change rate]
In the present invention, three test pieces each having a width of 30 mm and a length of 120 mm are taken from the longitudinal direction and the transverse direction of the sample, holes of 6 mmφ are punched at both ends of the test piece at intervals of 100 mm, and this is 23 ± 3 Humidity is adjusted for 2 hours or more in a room with a relative humidity of 65 ± 5%, and the automatic pin gauge (manufactured by Shinto Kagaku Co., Ltd.) is used to measure the original punch distance (L1) to the minimum scale / 1000mm. The test piece is suspended in a 90 ° C ± 1 ° C incubator for 24 hours, heat-conditioned in a room at 23 ± 3 ° C and a relative humidity of 65 ± 5% for 2 hours or more, and then the punch interval after heat treatment with an automatic pin gauge. Dimension (L2) was measured, and the following formula size change rate = (L1-L2 / L1) × 100
The dimensional change rate calculated by the above is preferably 0.5% or less, more preferably 0.3% or less.

[High humidity dimensional change rate]
In the present invention, three test pieces each having a width of 30 mm and a length of 120 mm are taken from the longitudinal direction and the transverse direction of the sample, holes of 6 mmφ are punched at both ends of the test piece at intervals of 100 mm, and this is 23 ± 3 Humidity is adjusted for 2 hours or more in a room with a relative humidity of 65 ± 5%, and the automatic pin gauge (manufactured by Shinto Kagaku Co., Ltd.) is used to measure the original punch distance (L1) to the minimum scale / 1000mm. After suspending the test piece in a constant temperature and humidity chamber of 60 ° C. ± 1 ° C. and relative humidity of 90 ± 5% and heat-treating it for 24 hours and adjusting the humidity for 2 hours or more in a room of 23 ± 3 ° C. and relative humidity of 65 ± 5% The dimension (L3) of the punch interval after heat treatment is measured with an automatic pin gauge, and the following formula Dimensional change rate = (L1-L3 / L1) × 100
It is desired that the dimensional changes at 90 ° C Dry and 60 ° C 90% calculated by the above are both small, preferably within -0.2%, and more preferably within -0.15%. .

[Surface treatment of cellulose acetate film]
In order to set the surface energy of the cellulose acetate film to 55 to 75 mN / m, it is preferable to perform surface treatment. Examples of the surface treatment include saponification treatment, plasma treatment, flame treatment, and ultraviolet irradiation treatment. Saponification treatment includes acid saponification treatment and alkali saponification treatment. Plasma treatment includes corona discharge treatment and glow discharge treatment. In order to maintain the flatness of the film, in these surface treatments, the temperature of the cellulose acetate film is preferably set to a glass transition temperature (Tg) or lower, specifically 150 ° C. or lower. The surface energy of the cellulose acetate film after these surface treatments is preferably 55 to 75 mN / m.
The glow discharge treatment 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 preferable. A plasma-excitable gas is a gas that is plasma-excited under the above conditions, and examples thereof include chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, and 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, Invention Association). In the plasma treatment at atmospheric pressure, which has been attracting attention in recent years, for example, irradiation energy of 20 to 500 kGy is used under 10 to 1000 keV, and more preferably irradiation energy of 20 to 300 kGy is used under 30 to 500 keV. Among these, an alkali saponification treatment is particularly preferable, and it is extremely effective as a surface treatment of a cellulose acylate film.

  The alkali saponification treatment is preferably carried out by a method in which the cellulose acylate film is directly immersed in a saponification solution tank or a method in which the saponification solution is applied to the cellulose acylate film. Examples of the coating method include a dip coating method, a curtain coating method, an extrusion coating method, a bar coating method, and an E-type coating method. The solvent of the alkali saponification coating solution has good wettability because it is applied to the transparent support of the saponification solution, and the surface state remains good without forming irregularities on the surface of the transparent support by the saponification solution solvent. It is preferred to select a solvent to keep. Specifically, an alcohol solvent is preferable, and isopropyl alcohol is particularly preferable. An aqueous solution of a surfactant can also be used as a solvent. The alkali of the alkali saponification coating solution is preferably an alkali that dissolves in the above solvent, and more preferably KOH or NaOH. The pH of the saponification coating solution is preferably 10 or more, more preferably 12 or more. The reaction conditions during the alkali saponification are preferably 1 second to 5 minutes at room temperature, more preferably 5 seconds to 5 minutes, and particularly preferably 20 seconds to 3 minutes. After the alkali saponification reaction, it is preferable to wash the surface on which the saponification solution is applied with water or with an acid and then with water.

  The surface energy of the solid obtained by these methods can be obtained by the contact angle method, the wet heat method, and the adsorption method as described in “Basics and Application of Wetting” (issued by Realize 1989.12.10). . In the case of the cellulose acetate film of the present invention, it is preferable to use a contact angle method. Specifically, two types of solutions having known surface energies are dropped onto a cellulose acetate film, and at the intersection between the surface of the droplet and the film surface, the angle formed by the tangent line drawn on the droplet and the film surface The surface angle of the film can be calculated by defining the angle containing the droplet as the contact angle.

  By subjecting the cellulose acetate film to the above surface treatment, a cellulose acetate film having a surface energy of 55 to 75 mN / m can be obtained. By using this cellulose acetate film as a transparent protective film for a polarizing plate, the adhesion between the polarizing film and the cellulose acetate film can be improved. When the cellulose acetate film of the present invention is used in an OCB mode liquid crystal display device, the optical compensation sheet of the present invention forms an alignment film on the cellulose acetate film and includes a discotic compound or a rod-shaped liquid crystal compound on the alignment film. An optically anisotropic layer may be provided. The optically anisotropic layer is formed by aligning a discotic compound (or rod-shaped liquid crystal compound) on the alignment film and fixing the alignment state. Thus, when providing an optically anisotropic layer on a cellulose acetate film, conventionally, in order to ensure the adhesion between the cellulose acetate film and the alignment film, it was necessary to provide a gelatin undercoat layer between them. By using the cellulose acetate film having a surface energy of 55 to 75 mN / m according to the present invention, a gelatin undercoat layer can be dispensed with.

[Polarizer]
A polarizing plate consists of a polarizing film and two transparent protective films arrange | positioned at the both sides. As one protective film, an optical compensation sheet made of the above cellulose acylate film can be used. The other protective film may be a normal cellulose acetate film.
Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film.
It is preferable that the slow axis of the optical compensation sheet made of a cellulose acylate film and the transmission axis of the polarizing film are arranged so as to be substantially parallel.

[Antireflection layer]
It is preferable to provide an antireflection layer on the transparent protective film disposed on the opposite side of the polarizing plate from the liquid crystal cell. In particular, in the present invention, at least a light scattering layer and a low refractive index layer are laminated in this order on the transparent protective film, or a medium refractive index layer, a high refractive index layer, and a low refractive index layer are arranged in this order on the transparent protective film. The antireflection layer laminated with is preferably used.

[Liquid Crystal Display]
The polarizing plate using the optical compensation sheet of the present invention is advantageously used in a liquid crystal display device. The polarizing plate of the present invention can be used for liquid crystal cells in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal, AFLC) Various display modes such as HAN (Hybrid Aligned Nematic) have been proposed. Of these, the OCB mode or the VA mode can be preferably used.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to an Example.

Example 1
[Creation of cellulose acylate film]
Each component was put into a mixing tank at the following composition ratio, stirred while heating to dissolve each component, and a cellulose acetate solution was prepared.

(Cellulose acetate solution composition)
Cellulose acetate having an acetylation degree of 60.9 100 parts by weight Triphenyl phosphate (plasticizer) 7.8 parts by weight Biphenyl diphenyl phosphate (plasticizer) 3.9 parts by weight Methylene chloride (first solvent) 318 parts by weight Methanol ( Second solvent) 47 parts by mass Silica (particle size 0.2 μm) 0.1 parts by mass

In another mixing tank, 87 parts by mass of methylene chloride and 13 parts by mass of methanol are added to the retardation control agent A and retardation control agent B shown in Table 2, and the mixture is stirred while heating to form a retardation control agent solution. Was prepared.
The dope was prepared by mixing the retardation control agent solution with the cellulose acetate solution and stirring sufficiently. Table 2 shows the amounts of retardation modifiers A and B added to 100 parts by mass of cellulose acetate. Table 1 shows the Re / Rth ratio of the retardation adjusting agent measured by the above method.

  The obtained dope was cast using a band casting machine, and a film having a residual solvent amount of 32% by mass at the start of stretching was stretched laterally at a stretching ratio of 26% using a tenter at 130 ° C. The film was further dried at 130 ° C. for 20 minutes to produce a cellulose acetate film (thickness: 92 μm). The produced cellulose acetate film was measured for Re retardation value and Rth retardation value at a wavelength of 590 nm using KOBRA 21ADH (trade name, manufactured by Oji Scientific Instruments). The results are shown in Table 2.

As can be seen from Table 2, compounds such as general formulas (I) and (II) can increase Re when used alone, but at the same time Rth also increases. In addition, when a compound such as the general formula (III) was used alone, although Rth did not increase, a large Re could not be obtained, and the range of Re and Rth could not be obtained arbitrarily. On the other hand, in the present invention, optical compensation films having desired Re (60 to 90 nm) and Rth (128 to 190 nm) can be obtained by using a combination of compounds having different Re / Rth ratios.
The general formula (IV) includes (IV-1) which exhibits the same behavior as the general formulas (I) and (II) and (IV-4) which exhibits the same behavior as the general formula (III). Similarly, adjustment of Re and Rth alone is insufficient, but an optical compensation film in which Re and Rth are adjusted to a preferable range can be obtained by using in combination.

Furthermore, by processing these films into polarizing plates and using them for optical compensation, optical compensation of a wide variety of liquid crystal display devices can be easily performed.

Claims (9)

  An optical compensation sheet comprising a cellulose acylate film containing 1 to 20 parts by mass of a retardation control agent with respect to 100 parts by mass of cellulose acylate, wherein the retardation control agent is at least a compound having a different Re / Rth ratio. An optical compensation sheet comprising two types.   2. The optical compensation sheet according to claim 1, wherein the optical compensation sheet comprises a cellulose acylate film stretched at a stretch ratio of 3 to 100%.   The optical compensation sheet according to claim 1 or 2, wherein the content of the two kinds of compounds contained in the retardation control agent is 1 to 20 parts by mass in total with respect to 100 parts by mass of cellulose acylate. .   The Re / Rth ratio of the two kinds of compounds contained in the retardation control agent is such that one is less than 0.35 and the other is 0.35 or more. The optical compensation sheet as described. The optical compensation sheet according to claim 4, wherein the compound having a Re / Rth ratio of less than 0.35 is represented by the general formula (I).

(Wherein X ¹ represents a single bond, —NR ⁴ —, —O— or —S—; X ² represents a single bond, —NR ⁵ —, —O— or —S—; X ³ represents a single bond, —NR ⁶ —, —O— or —S—, and R ¹ , R ² and R ³ each independently represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. And R ⁴ , R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. The optical compensation sheet according to claim 4, wherein the compound having a Re / Rth ratio of less than 0.35 is a compound represented by the general formula (II).

(In the formula, Ar ¹ , Ar ² , and Ar ³ each independently represent an aryl group or an aromatic heterocycle, and L ¹ and L ² each independently represent a single bond or a divalent linking group. N represents 3 The above integers are represented, and a plurality of Ar ² and L ² may be the same or different. The optical compensation sheet according to claim 4, wherein the compound having a Re / Rth ratio of 0.35 or more is a compound represented by the general formula (III).

Wherein Ar ¹¹ and Ar ¹² are each independently an aromatic group; L ¹² and L ¹³ are each independently from the group consisting of an alkylene group, —O—, —CO— and combinations thereof. A selected divalent linking group; and X is 1,4-cyclohexylene, vinylene or ethynylene.) The optical compensation sheet according to any one of claims 1 to 3, wherein the retardation controlling agent is a compound represented by the general formula (IV).

(In the general formula (IV), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or a substituent.) A liquid crystal display device comprising a liquid crystal cell and two polarizing plates disposed on both sides thereof, wherein the polarizing plate comprises a polarizing film and two transparent protective films disposed on both sides thereof, the liquid crystal cell and at least The optical compensation sheet according to any one of claims 1 to 8, wherein the optical compensation sheet is disposed between the polarizing film and the polarizing film adjacent to the slow axis of the cellulose acylate film and the cellulose acylate film. A liquid crystal display device, characterized in that the liquid crystal display device is arranged so as to be substantially parallel to a transmission axis of the liquid crystal display.