JP2006273898A - Cellulosic composition, cellulosic film, polarizing plate, liquid crystal display device, and silver halide photographic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cellulosic composition capable of forming a film having a retardation value desirable for an optical film. <P>SOLUTION: The cellulosic composition comprises a cellulosic, and at least one of a polymer and/or an oligomer each represented by formula (1) and each having a weight-average molecular weight of 500 to 15,000 or at least one of polymers and/or oligomers represented by formula (2) and/or formula (3). In the formulae, R<SP>11</SP>to R<SP>18</SP>are each independently a hydrogen atom or a substituent; As are each independently a single bond or a divalent bonding group; X is a divalent aromatic group; Y is a divalent bonding group; and Z is a divalent aromatic group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cellulose composition, a cellulose film comprising the cellulose composition, a polarizing plate protective film, a liquid crystal display device, and a silver halide photographic light-sensitive material.

  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.

Recently, however, cellulose acetate films having a high retardation value that can be used for applications requiring optical anisotropy have been proposed (for example, Patent Document 1 and Patent Document 2). 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 optical anisotropy. However, in Patent Documents 1 and 2, the additives are simultaneously oriented by stretching treatment. Therefore, it is possible to increase the optical anisotropy and realize a high retardation value.

  In recent years, it has become essential to reduce the thickness of a liquid crystal cell in order to reduce the weight of the liquid crystal display device and reduce the manufacturing cost. Therefore, higher optical anisotropy (Re: retardation value in the film plane) has been required for optical films including optical compensation sheets. However, the compounds having a 1,3,5-triazine ring described in Patent Documents 1 and 2 cause problems such as bleed-out when the addition amount is increased in order to obtain higher Re, and Re that can be realized is insufficient. there were.

  Therefore, development of new optical performance control technology, particularly technology for expressing higher Re has become necessary. This technique is advantageous in the field of optical films that require not so high Re because it enables a desired Re to be realized with a smaller amount of addition, and these techniques have been desired.

  On the other hand, there are known techniques for incorporating an acrylic polymer and / or oligomer into a cellulosic film (for example, Patent Document 3) and techniques for incorporating polyester (for example, Patent Document 4). Used and there is no mention of optical properties. As a result of the examination, it has been found that the polymers of Patent Document 3 and Patent Document 4 are insufficient for the expression of high Re, which is the object of the present invention.

European Patent Publication EP0911656A2 JP 2003-344655 A JP 2003-12859 A Japanese Patent Laid-Open No. Hei 5-97073

A first object of the present invention is to provide a cellulose composition that can form a film having a preferable retardation value as an optical film.
The second object of the present invention is to provide a cellulose film having a retardation value preferable as an optical film, and a polarizing plate protective film, a liquid crystal display device, and a silver halide photographic light-sensitive material produced using the cellulose film. It is to provide a support.

The object of the present invention has been achieved by the following means.
[1] A cellulose composition comprising a cellulose body and at least one polymer and / or oligomer represented by the following general formula (1) having a weight average molecular weight of 500 to 15000: object;

式中、R¹¹、R¹²、R¹³、R¹⁴、R¹⁵、R¹⁶、R¹⁷およびR¹⁸はそれぞれ独立に水素原子または置換基を表わし、Aはそれぞれ独立に単結合、または２価の連結基を表す。R¹¹、R¹²、R¹³、R¹⁴、R¹⁵、R¹⁶、R¹⁷、R¹⁸およびAは互いに結合して環を形成していても良い。

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or a substituent, and A each independently represents a single bond or a divalent group. Represents a linking group. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and A may be bonded to each other to form a ring.

[2] A cellulose composition comprising at least one of a cellulose and a polymer represented by the following general formula (2) and / or general formula (3), and / or an oligomer;

一般式（２）中、Xは２価の芳香族基を表し、Yは２価の連結基を表す。一般式（３）中、Zは２価の芳香族基を表す。

In general formula (2), X represents a divalent aromatic group, and Y represents a divalent linking group. In general formula (3), Z represents a divalent aromatic group.

[3] The cellulose composition according to [2], wherein the polymer and / or oligomer represented by the general formula (2) and / or the general formula (3) has a weight average molecular weight of 500 to 15000.
[4] The cellulose composition according to any one of [1] to [3], wherein cellulose acylate is contained as the cellulose derivative.
[5] A cellulose film comprising the cellulose composition according to any one of [1] to [4].
[6] A polarizing plate in which a protective film is bonded to both surfaces of a polarizer, wherein at least one of the protective films is the cellulose film of [5].
[7] The polarizing plate according to [6], which has an optically anisotropic layer on at least one surface of the protective film.
[8] A liquid crystal display device comprising a liquid crystal cell and two polarizing plates arranged on both sides thereof, at least one of the polarizing plates being a polarizing plate of [6] or [7].
[9] The liquid crystal display device according to [8], wherein the liquid crystal display is in a VA mode.
[10] The liquid crystal display device according to [8], wherein the liquid crystal display device is in an OCB mode.
[11] A silver halide photographic light-sensitive material using the cellulose film of [5] as a support.

  The cellulose composition of the present invention is useful for forming a film excellent in optical performance satisfying individually designated Re values. Therefore, the cellulose body film obtained from this is excellent in optical performance.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

One aspect of the cellulose body composition of the present invention relates to a composition containing a cellulose derivative, and is characterized by containing at least one polymer and / or oligomer represented by the general formula (1).
First, the polymer and / or oligomer represented by the general formula (1) will be described in detail.

In the general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or a substituent, and A each independently represents a single bond, Or a bivalent coupling group is represented. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and A may be bonded to each other to form a ring.

R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ preferably have a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group ( Preferably an alkyl group having 1 to 30 carbon atoms, for example, methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably carbon A substituted or unsubstituted cycloalkyl group having a number of 3 to 30 such as a cyclohexyl group, a cyclopentyl group, a 4-n-dodecylcyclohexyl group, or a bicycloalkyl group (preferably a substituted or unsubstituted bicyclo group having 5 to 30 carbon atoms). An alkyl group, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms, for example, bicyclo [1,2,2]. Butan-2-yl, bicyclo [2,2,2] octane-3-yl), an alkenyl group (preferably a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, such as a vinyl group or an allyl group), cyclo An alkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. For example, 2-cyclopentene -1-yl, 2-cyclohexen-1-yl), a bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a double bond). A monovalent group obtained by removing one hydrogen atom from one bicycloalkene, for example, bicyclo [2,2,1] hept-2-en-1-y , Bicyclo [2,2,2] oct-2-en-4-yl), an alkynyl group (preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, such as an ethynyl group or a propargyl group), An aryl group (preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, a p-tolyl group, a naphthyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic group A monovalent group obtained by removing one hydrogen atom from an aromatic or non-aromatic heterocyclic compound, and more preferably a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably 1 to 1 carbon atoms) 0 substituted or unsubstituted alkoxy groups such as methoxy group, ethoxy group, isopropoxy group, t-butoxy group, n-octyloxy group, 2-methoxyethoxy group), aryloxy group (preferably having 6 carbon atoms) To 30 substituted or unsubstituted aryloxy groups such as phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group), silyloxy group ( Preferably, the silyloxy group having 3 to 20 carbon atoms, for example, trimethylsilyloxy group, tert-butyldimethylsilyloxy group, heterocyclic oxy group (preferably substituted or unsubstituted heterocyclic oxy group having 2 to 30 carbon atoms) 1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy Group), acyloxy group (preferably formyloxy group, substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms, such as formyloxy group, Acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group), carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms such as N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octylcarbamoyloxy group), alkoxycarbonyloxy group ( Preferably, it has 2 carbon atoms To 30 substituted or unsubstituted alkoxycarbonyloxy groups such as methoxycarbonyloxy group, ethoxycarbonyloxy group, tert-butoxycarbonyloxy group, n-octylcarbonyloxy group), aryloxycarbonyloxy group (preferably having 7 carbon atoms) To 30 substituted or unsubstituted aryloxycarbonyloxy groups, for example, phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyloxyphenoxycarbonyloxy group), amino group (preferably amino group) A substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted anilino group having 6 to 30 carbon atoms, such as an amino group, a methylamino group, a dimethylamino group, an anilino group, N-methyl- Anilino group, dipheny Amino group), acylamino group (preferably formylamino group, substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, such as formylamino Group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group), aminocarbonylamino group (preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms such as carbamoylamino group, N, N-dimethylaminocarbonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group), alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms such as methoxycarbonylamino group) Group, ethoxycarbonylamino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably substituted or non-substituted having 7 to 30 carbon atoms) A substituted aryloxycarbonylamino group, for example, phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group), sulfamoylamino group (preferably having 0 to 30 carbon atoms) Substituted or unsubstituted sulfamoylamino groups such as sulfamoylamino group, N, N-dimethylaminosulfonylamino group, Nn-octylaminosulfonylamino group), alkyl and arylsulfonylamino groups (preferably carbon A substituted or unsubstituted alkylsulfonylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylsulfonylamino group having 6 to 30 carbon atoms, such as a methylsulfonylamino group, a butylsulfonylamino group, a phenylsulfonylamino group, 2, 3 , 5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group), mercapto group, alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms such as methylthio group, ethylthio group, n- Hexadecylthio group), arylthio group (preferably a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, such as phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), heterocyclic thio group (preferably carbon Substituted or unsubstituted F 2-30 Terocyclic thio group such as 2-benzothiazolylthio group, 1-phenyltetrazol-5-ylthio group, sulfamoyl group (preferably substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms such as N-ethyl Sulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl group, N- (N′phenylcarbamoyl) ) Sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms, for example, methylsulfinyl group Ethylsulfinyl group, phenylsulfinyl group, p-methylphenyl Sulfonylsulfinyl group), alkyl and arylsulfonyl groups (preferably substituted or unsubstituted alkylsulfonyl groups having 1 to 30 carbon atoms, substituted or unsubstituted arylsulfonyl groups having 6 to 30 carbon atoms such as methylsulfonyl group, ethylsulfonyl group) Group, phenylsulfonyl group, p-methylphenylsulfonyl group), acyl group (preferably formyl group, substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms) Group, for example, acetyl group, pivaloylbenzoyl group), aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms, such as phenoxycarbonyl group, o-chlorophenoxycarbonyl group , M-nitrophenoxycarbo Group, p-tert-butylphenoxycarbonyl group), alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms, for example, methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group), a carbamoyl group (preferably a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms, such as a carbamoyl group, an N-methylcarbamoyl group, an N, N-dimethylcarbamoyl group, an N, N -Di-n-octylcarbamoyl group, N- (methylsulfonyl) carbamoyl group), aryl and heterocyclic azo group (preferably substituted or unsubstituted arylazo group having 6 to 30 carbon atoms, substituted or substituted with 3 to 30 carbon atoms) Unsubstituted heterocyclic azo groups such as phenyl Zo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (preferably N-succinimide group, N-phthalimide group), phosphino group (preferably, C2-C30 substituted or unsubstituted phosphino group such as dimethylphosphino group, diphenylphosphino group, methylphenoxyphosphino group, phosphinyl group (preferably substituted or unsubstituted C2-C30 group) Phosphinyl group, for example, phosphinyl group, dioctyloxyphosphinyl group, diethoxyphosphinyl group), phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, for example, , Diphenoxyphosphinyloxy group, dioctyloxyphosphinyloxy group), phosphinyl An amino group (preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, such as a dimethoxyphosphinylamino group or a dimethylaminophosphinylamino group), a silyl group (preferably a carbon number of 3 Represents a substituted or unsubstituted silyl group of ˜30, for example, trimethylsilyl group, tert-butyldimethylsilyl group, phenyldimethylsilyl group).

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

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

The divalent linking group in A is preferably a group represented by —NR ²¹ — (R ²¹ represents a hydrogen atom, an alkyl group or an aryl group which may have a substituent), —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, Of these, —O—, —CO—, —SO ₂ —, an alkylene group, and a substituted alkylene group are more preferred, and —O—, an alkylene group, and a substituted alkylene group are most preferred.

  Moreover, the other aspect of the cellulose body composition of this invention is related with the composition containing a cellulose derivative, At least 1 of the polymer represented by General formula (2) and / or General formula (3), and / or an oligomer. It is characterized by containing one.

  In general formula (2), X represents a divalent aromatic group, and Y represents a divalent linking group. In general formula (3), Z represents a divalent aromatic group.

In the general formula (2), preferred examples of X include an arylene linking group or an aromatic heterocyclic linking group. The arylene linking group is preferably an arylene linking group having 6 to 30 carbon atoms, and is monocyclic. It may be present or may form a condensed ring with another ring. Further, if possible, it may have a substituent, and the above-mentioned substituents can be applied as the substituent.
In the general formula (2), the divalent aromatic group X is more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a p-phenylene group and a 2,6-naphthylene group. It is done.

  In the general formula (2), a preferable aromatic heterocyclic linking group represented by X can be an aromatic heterocyclic linking group containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom, preferably 5 or An aromatic heterocyclic linking group containing at least one of a 6-membered ring oxygen atom, nitrogen atom or sulfur atom. Moreover, you may have a substituent further if possible. As the substituent, the above-described substituents can be applied.

  In the general formula (2), specific examples of the aromatic heterocyclic linking group represented by X 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, benzimidazole, benzoxazole, benzthiazole, benzotriazole, Examples include tetrazaindene, pyrrolotriazole, and pyrazolotriazole.

  In the general formula (2), preferred examples of Y include an arylene linking group and an alkylene linking group, and more preferred examples of the arylene linking group are the same as those described for X. Group, propylene group and the like.

  Hereinafter, the polymer and / or oligomer represented by the general formulas (1), (2) and (3) will be described in detail with specific examples, but the present invention is not limited to the following specific examples. There is nothing.

  The polymer and / or oligomer represented by the general formula (1) can be synthesized by a known method, and is synthesized by a polycondensation reaction between a bisphenol derivative represented by the following general formula (4) and phosgene. However, the synthesis method of the compound of the present invention is not limited to this example.

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or a substituent, and A each independently represents a single bond or a divalent group. Represents a linking group. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and A may be bonded to each other to form a ring.

  The polymer and / or oligomer represented by the general formula (2) and / or the general formula (3) can also be synthesized by a known method, and the dicarboxylic acid represented by the following general formula (5) or It is synthesized by a polycondensation reaction between an ester or acid chloride and a diol represented by the general formula (6). However, the synthesis method of the compound of the present invention is not limited to this example.

  In the formula, in the general formula (5), X represents a divalent aromatic group, and in the general formula (6), Y represents a divalent linking group. In general formula (7), Z represents a divalent aromatic group.

  The content of the polymer and / or oligomer represented by the general formula (1) to the general formula (3) in the cellulose composition of the present invention is 0.1 to 20% by mass with respect to the cellulose derivative. More preferably, it is 0.5-16 mass%, More preferably, it is 1-12 mass%, Most preferably, it is 1-8 mass%, Most preferably, it is 1-5 mass%. A plurality of polymers and / or oligomers represented by general formula (1) to general formula (3) may be used in combination.

The weight average molecular weight of the polymer and / or oligomer represented by general formula (1) to general formula (3) used in the present invention is 500 or more and 15000 or less. By using the polymer and / or oligomer represented by the general formula (1) to the general formula (3) in the molecular weight range, it is possible to suppress the occurrence of white turbidity in the film. The weight average molecular weight of the polymer and / or oligomer represented by the general formula (1) to the general formula (3) is preferably 1000 to 15000, more preferably 2000 to 13000, and 3000 to 13000. More preferably.
In this specification, the weight average molecular weight of the polymer and / or oligomer represented by the general formula (1) to the general formula (3) is a polystyrene molecular weight standard product by GPC measurement in terms of polystyrene using tetrahydrofuran as a solvent. The value obtained by comparison with

  The polymer and / or oligomer represented by the general formula (1) to the general formula (3) can be used as a retardation control agent for an optical film, and in particular, to obtain a film having excellent Re developability by stretching. It can be suitably used as a retardation control agent. The polymers and / or oligomers represented by the general formula (1) to the general formula (3) are particularly useful as retardation control agents for cellulosic films. Details, such as a manufacturing method of the film containing these compounds, are mentioned below.

The cellulose body used in the cellulose body composition of the present invention will be described in detail.
In the present invention, the cellulose body means a compound having cellulose as a basic structure, and is not particularly limited, but among them, a cellulose ester is preferable, and a cellulose acylate is more preferable.

[Cellulose acylate raw cotton]
The cellulose used as the raw material of the cellulose acylate preferably used in the cellulose composition of the present invention includes cotton linter and wood pulp (hardwood pulp, softwood pulp) and the like, and any cellulose acylate obtained from any raw material cellulose is used. In some cases, a mixture may be used. Detailed descriptions of these raw material celluloses can be found in, 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.

[Substitution degree of cellulose acylate]
The cellulose acylate preferably used in the cellulose composition of the present invention is one in which the hydroxyl group of cellulose is acylated, and the substituent is an acyl group having 2 carbon atoms from an acetyl group having 2 carbon atoms. Any of the above can be used. In the cellulose acylate of the present invention, the degree of substitution of cellulose with a hydroxyl group is not particularly limited. You can get a degree. As a measuring method, it can carry out according to ASTM D-817-91.
Although the substitution degree of the hydroxyl group of cellulose is not particularly limited, the acyl substitution degree of the cellulose hydroxyl group is preferably 2.50 to 3.00, more preferably 2.75 to 3.00. .85 to 3.00 is particularly preferred.

  Among the acetic acid and / or the fatty acid having 3 to 22 carbon atoms substituted for the hydroxyl group of cellulose, the acyl group having 2 to 22 carbon atoms may be an aliphatic group or an allyl group, and is not particularly limited. It may be a mixture of more than one type. They are, for example, alkyl carbonyl esters, alkenyl carbonyl esters, aromatic carbonyl esters, aromatic alkyl carbonyl esters, and the like of cellulose, each of which may further have a 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, or cinnamoyl is preferable, and acetyl, propionyl, or butanoyl is more preferable.

  Among the acyl substituents substituted on the hydroxyl group of cellulose, in the case of consisting of at least two kinds substantially selected from an acetyl group, a propionyl group, and a butanoyl group, the total substitution degree is 2.50 to 3.00. It is preferable that 2.60 to 3.00 is more preferable, and 2.65 to 3.00 is particularly preferable.

[Degree of polymerization of cellulose acylate]
The degree of polymerization of cellulose acylate preferably used in the cellulose composition of the present invention is in the range of 180 to 700 in terms of viscosity average polymerization degree, more preferably 180 to 550, further preferably 180 to 400, and 180 to 350. Particularly preferred. If 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. This is described in detail in JP-A-9-95538.
The molecular weight distribution of cellulose acylate preferably used in the cellulose composition 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 preferably narrow. The specific value of Mw / Mn is preferably 1.0 to 3.0, more preferably 1.0 to 2.0, and particularly 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 water content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.7% by mass or less. It is a cellulose acylate having a water content. In general, cellulose acylate contains water and is known to be 2.5 to 5% by mass. In order to obtain a preferable moisture content of cellulose acylate, 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 page 7 to page 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.

  In the cellulose composition of the present invention, single or different two or more kinds of cellulose acylates can be mixed and used within the above-mentioned ranges such as substituent, substitution degree, polymerization degree, molecular weight distribution.

[Additive]
In the production of the cellulose composition of the present invention, the cellulose body (cellulose acylate) solution is represented by the general formula (1), (2) or (3) that expresses optical anisotropy in each preparation step. In addition to the compound, various additives (ultraviolet ray prevention agent, plasticizer, deterioration preventing agent, fine particles, optical property adjusting agent, etc.) according to the application can be added. In the present invention, the additive such as a modifier may be a single compound or a composition. The addition timing may be added 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.

[Matting agent fine particles]
Fine particles can be added as a matting agent to the film made of the cellulose composition of the present invention. The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silica Mention may be made of magnesium and calcium phosphates. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The fine particles of silicon dioxide preferably have a primary average particle diameter 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 to 1.5 μm, more preferably from 0.4 to 1.2 μm, particularly preferably from 0.6 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, and TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. Zirconium oxide fine particles are commercially available under the trade names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Among them, 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 friction coefficient is maintained while keeping the turbidity of the optical film low. This is particularly preferable because the effect of reducing is great.

In order to obtain a film having particles having a small secondary average particle size, several methods are conceivable when preparing a dispersion of fine particles. 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 preferable 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, after adding a small amount of cellulose ester to the solvent and dissolving with stirring, add the fine particles to this and disperse with a disperser to make this fine particle additive solution, and mix this fine particle additive solution with the dope solution using an inline mixer 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 compounds that optically reduce anisotropy and wavelength dispersion adjusting agents, the cellulose acylate film of the present invention includes various additives (for example, plasticizers, ultraviolet rays, etc.) in each preparation step. Inhibitors, deterioration inhibitors, release agents, infrared absorbers, etc.) can be added and they can be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of ultraviolet absorbing material at 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 Report (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention) are preferably used.

[Rate of compound addition]
In the cellulose composition of the present invention, the total amount of compounds having a molecular weight of 3000 or less is preferably 5 to 45% with respect to the mass of the cellulose body. More preferably, it is 10 to 40%, and even 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, etc. Is preferably 3000 or less, more preferably 2000 or less, and particularly preferably 1000 or less. When the total amount of these compounds is 5% or less, 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 is 45% or more, problems such as exceeding the limit of compound compatibility in the cellulose acylate film and depositing on the film surface to cause the film to become cloudy (crying out of the film) occur. It becomes easy.

[Organic solvent]
The cellulose composition of the present invention is preferably made into a cellulose acylate film by a solvent cast method, and can be produced as a film using a solution (dope) in which cellulose acylate is dissolved in an organic solvent. The organic solvent preferably used as the main solvent is preferably a solvent selected from esters, ketones, ethers having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 7 carbon atoms. Esters, ketones and ethers 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. 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.
When the cellulose composition of the present invention is used as a film, a chlorinated halogenated hydrocarbon may be used as a main solvent, or as described in JIII Journal of Technical Disclosure 2001-1745 (pages 12 to 16). A non-chlorine solvent may be used as the main solvent and is not particularly limited.

In addition, the cellulose body composition of the present invention and the solvent for the film thereof are disclosed in the following patents, including the dissolution method, and are 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, 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 also a preferred embodiment in the present invention.

[Manufacturing process of cellulosic film]
[Dissolution process]
In the preparation of the solution (dope) in the cellulose composition of the present invention, the dissolution method is not particularly limited, and may be room temperature, or a cooling dissolution method or a high temperature dissolution method, or a combination thereof. In the cellulose body composition of the present invention, regarding the preparation of the solution, and further the solution concentration and filtration steps accompanying the dissolution step, JIII Journal of Technical Disclosure (Publication No. 2001-1745, issued on March 15, 2001) The manufacturing process described in detail on pages 22 to 25 in the invention association) is preferably used.

  In the cellulose composition of the present invention, the dope transparency of the solution is preferably 85% or more, more preferably 88% or more, and particularly preferably 90% or more. In the cellulose composition of the present invention, it is preferable to confirm that various additives are sufficiently dissolved in the solution. As a specific method for calculating the dope transparency, the dope solution can be injected into a 1 cm square glass cell, and the absorbance at 550 nm can be measured with a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation). Only the solvent is measured in advance as a blank, and the transparency of the cellulose acylate solution can be calculated from the ratio to the absorbance of the blank.

[Casting, drying, winding process]
Next, in the cellulose composition of the present invention, a method for producing a film using the solution will be described. As a method and equipment for producing the cellulose composition of the present invention as a film, 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 fed 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. The dry-dried dope film (also referred to as a web) is peeled off from the metal support at the peeling point which is uniformly cast on the metal support and the metal support has almost gone around. The both ends of the obtained web are sandwiched between clips, transported by a tenter while holding the width and dried, and then the obtained film is mechanically transported by a roll group of a drying device, dried, and then rolled by a winder Wind up to a predetermined length. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film and the silver halide photographic light-sensitive material which are optical members for electronic displays, which is the main use of the cellulose body film, in addition to the solution casting film forming apparatus, In many cases, a coating apparatus is added for surface processing on a film such as an undercoat layer, an antistatic layer, an antihalation layer, or 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 body film, 20-100 micrometers is more preferable, and 30-90 micrometers is especially preferable.

[Evaluation of properties of cellulose acylate film]
Regarding the change in the optical performance due to the environmental change of the film made of the cellulose composition of the present invention, Re and Rth of the film treated at 60 ° C. and 90% RH (in the present invention, RH means relative humidity) for 240 hours. Is preferably 15 nm or less, more preferably 12 nm or less, and particularly preferably 10 nm or less.
[Change in optical performance of film after high temperature treatment]
Further, the amount of change in Re and Rth of the film treated at 80 ° C. for 240 hours is preferably 15 nm or less, more preferably 12 nm or less, and particularly preferably 10 nm or less.
[Compound volatilization after film heat treatment]
In the film comprising the cellulose composition of the present invention, the additive is preferably 30% or less, more preferably 0 to 25%, more preferably 0 to 20 in terms of the volatilization amount of the compound from the film treated at 80 ° C. for 240 hours. % Is particularly preferred. If the volatilization amount is too much, it becomes a main factor of process contamination and becomes a problem.
In addition, the amount of volatilization from the film is a compound in which a film treated at 80 ° C. for 240 hours and an untreated film are each dissolved in a solvent, a compound is detected by liquid high-performance chromatography, and the peak area of the compound is left in the film The amount can be calculated by the following formula.
Volatilization amount (%) = {(Amount of remaining compound in untreated product) − (Amount of remaining compound in treated product)} / (Amount of remaining compound in untreated product) × 100

[Glass Transition Temperature Tg of Film]
It is preferable that the glass transition temperature Tg of the film which consists of a cellulose body composition of this invention exists in the range of 80-165 degreeC, It is more preferable that Tg is 100-160 degreeC, It is 110-150 degreeC. Particularly preferred. The glass transition temperature Tg is measured with a differential scanning calorimeter (DSC2910, T.A. Instrument) measuring 10 mg of a film sample from room temperature to 200 ° C. at a temperature rising / falling rate of 5 ° C./min. Tg can be calculated.

[Haze of film]
The haze of the film comprising the cellulose composition of the present invention is preferably 0.01 to 2.0%, more preferably 0.05 to 1.5%, and 0.1 to 1.0%. It is particularly preferred that As an optical film, the transparency of the film is important. The haze can be measured according to JIS K-6714 with a film sample of 40 mm × 80 mm at 25 ° C. and 60% RH with a haze meter (HGM-2DP, Suga Test Instruments).

[Humidity dependency of Re and Rth of film]
The film made of the cellulose composition of the present invention preferably has a small change in humidity due to in-plane retardation Re and retardation Rth in the film thickness direction. Specifically, the difference between the Rth value at 25 ° C. and 10% RH and the Rth value at 25 ° C. and 80% RH (Rth 10% RH−Rth 80% RH) is preferably 0 to 50 nm, more preferably 0 to 40 nm. 0 to 35 nm is particularly preferable.

[Equilibrium moisture content of film]
The equilibrium moisture content of the film comprising the cellulose composition of the present invention is not impaired when used as a protective film for a polarizing plate, regardless of the film thickness, so as not to impair the adhesion with a water-soluble polymer such as polyvinyl alcohol. The equilibrium water content at 25 ° C. and 80% RH is preferably 0 to 4%, more preferably 0.1 to 3.5%, and particularly preferably 1 to 3%. An equilibrium water content of 0.4% or more is not preferable because the dependence of retardation due to humidity change becomes too large when used as a support for an optical compensation film.
As a method for measuring the moisture content, a film sample 7 mm × 35 mm can be measured by a Karl Fischer method with a moisture meter and a sample drying apparatus (CA-03, VA-05, both manufactured by Mitsubishi Chemical Corporation). It can be calculated by dividing the amount of water (g) by the sample weight (g).

[Water permeability of film]
The moisture permeability of the film using the cellulose composition of the present invention as an optical compensation sheet is measured under the condition of a temperature of 60 ° C. and a humidity of 95% RH based on JIS standard JISZ0208, and converted to a film thickness of 80 μm, 400 to 2000 g. / M ² · 24h is preferable. More preferably 500~1800g / m ² · 24h, and particularly preferably 600~1600g / m ² · 24h. If it exceeds 2000 g / m ² · 24 h, the tendency of the absolute value of the humidity dependence of the Re value and Rth value of the film to exceed 0.5 nm /% RH becomes strong. In addition, even when an optically anisotropic layer is laminated on a film made of the cellulose composition of the present invention to form an optical compensation film, the absolute value of the humidity dependence of the Re value and Rth value is 0.5 nm /% RH. The tendency to exceed becomes strong and is not preferable. When this optical compensation sheet or polarizing plate is incorporated in a liquid crystal display device, it causes a change in color and a decrease in viewing angle. In addition, when the moisture permeability of the cellulose acylate film is less than 400 g / m ² · 24 h, when the polarizing plate is prepared by being attached to both surfaces of the polarizing film, the cellulose acylate film prevents the drying of the adhesive, and adhesion Cause a defect.
If the film thickness of the cellulose acylate film is thick, the moisture permeability becomes small, and if the film thickness is thin, the moisture permeability becomes large. Therefore, it is necessary to convert the sample of any film thickness to a standard of 80 μm. The conversion of the film thickness was obtained as (water permeability in terms of 80 μm = measured moisture permeability × measured film thickness μm / 80 μm).
The measurement method of moisture permeability is “Polymer Physical Properties II” (Polymer Experiment Course 4, Kyoritsu Shuppan), pages 285-294: Measurement of vapor permeation amount (mass method, thermometer method, vapor pressure method, adsorption amount method) The film sample 70 mmφ was conditioned at 25 ° C. 90% RH and 60 ° C. 95% RH for 24 hours, respectively, and a moisture permeation test apparatus (KK-709007, manufactured by Toyo Seiki Co., Ltd.) ), The amount of water per unit area can be calculated (g / m ² ) in accordance with JIS Z-0208, and the water vapor transmission rate can be determined by the weight after humidity control-weight before humidity control.

[Dimensional change of film]
The dimensional stability of the film comprising the cellulose composition of the present invention is as follows: the dimensional change rate after standing for 24 hours under the condition of 60 ° C. and 90% RH (high humidity) and the condition of 90 ° C. and 5% RH In the case of standing still for 24 hours (high temperature), the dimensional change rate is preferably 0.5% or less, more preferably 0.3% or less, and particularly preferably 0.15% or less.
As a specific measurement method, two film samples 30 mm × 120 mm were prepared, humidity-controlled at 25 ° C. and 60% RH for 24 hours, and an automatic pin gauge (manufactured by Shinto Kagaku Co., Ltd.) with 6 mmφ at both ends. Holes are opened at an interval of 100 mm to obtain the original size (L0) of the punch interval. The dimension (L1) of the punch interval after one sample was processed at 60 ° C. and 90% RH for 24 hours was measured, and the punch interval after the other sample was processed at 90 ° C. and 5% RH for 24 hours. The dimension (L2) can be measured. It is possible to measure to a minimum scale of 1/1000 mm in all intervals. Dimensional change rate of 60 ° C. and 90% RH (high humidity) = {| L0−L1 | / L0} × 100, Dimensional change rate of 90 ° C. and 5% RH (high temperature) = {| L0−L2 | / L0} The dimensional change rate can be calculated as x100.

[Elastic modulus of film]
(Elastic modulus)
Elastic modulus of the film of cellulose composition of the present invention is preferably 200 to 500 kgf / mm ^2, more preferably 240~470kgf / mm ^2, particularly preferably at 270~440kgf / mm ² . As a specific measurement method, Toyo Baldwin Universal Tensile Tester STM T50BP is used to measure the stress at 0.5% elongation in a 23 ° C./70% atmosphere at a tensile rate of 10% / min to obtain the elastic modulus. be able to.

[Photoelastic coefficient of film]
(Photoelastic coefficient)
The photoelastic coefficient of the film made of the cellulose composition of the present invention is preferably 50 × 10 ⁻¹⁵ cm ² / dyne or less. It is more preferably 30 × 10 ⁻¹⁵ cm ² / dyne or less, and particularly preferably 20 × 10 ⁻¹⁵ cm ² / dyne or less. As a specific measuring method, a tensile stress is applied to the long axis direction of a 12 mm × 120 mm film sample, and the retardation at that time is measured with an ellipsometer (M150, manufactured by JASCO Corporation). The photoelastic coefficient can be calculated from the amount of change in retardation.

[Front retardation change before and after stretching, detection of slow axis]
The cellulose derivative film of the present invention may be stretched. It is particularly preferable that the film is stretched at an arbitrary magnification in order to exhibit optical anisotropy.
For the stretching, a known method can be used. For example, a tenter uniaxial stretching method, a simultaneous biaxial stretching method, a sequential method at a temperature between 10 ° C. and 50 ° C. higher than the glass transition temperature (Tg) of the cellulose derivative film. The film can be stretched by a biaxial stretching method or an inflation method. Moreover, in the case of film manufacture by the solution pouring method, the residual solvent can be stretched within a range of 1 to 30%, more preferably within a range of 5 to 20%. The draw ratio is preferably 1.01-2.
The front retardation of each sample before and after stretching can be measured using an automatic birefringence meter KOBRA21ADH. The detection of the slow axis can be determined from the orientation angle obtained in the above-described retardation measurement.

[Direction with slow axis]
When the film comprising the cellulose composition of the present invention is used as a protective film for a polarizer, since the polarizer has an absorption axis in the machine transport direction (MD direction), the cellulose acylate film has a slow axis in the vicinity of the MD direction or It is preferably in the vicinity of TD. Light leakage and color change can be reduced by making the slow axis parallel or orthogonal to the polarizer. “Near” means that the slow axis and the MD or TD direction are in the range of 0 to 10 °, preferably 0 to 5 °.

[Method for evaluating cellulose film]
As the evaluation of the cellulose body film of the present invention, each item can be measured by the following method.

(In-plane retardation Re, thickness direction retardation Rth)
A sample 30 mm × 40 mm was conditioned at 25 ° C. and 60% RH for 2 hours. Re (λ) was an automatic birefringence meter KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.). It can be measured by making it incident. Also, Rth (λ) is the Re (λ) and incident light of wavelength λnm with the in-plane slow axis as the tilt axis and the film normal direction as 0 °, and the sample tilted to 50 ° every 10 °. Based on the measured retardation value, it is possible to input and calculate the assumed average refractive index of 1.48 and the film thickness.

(Molecular orientation axis)
Sample 70mm x 100mm was conditioned at 25 ° C and 65% RH for 2 hours, and the phase difference when the incident angle at normal incidence was changed with an automatic birefringence meter (KOBRA21DH, manufactured by Oji Scientific Co., Ltd.) The molecular orientation axis can be calculated.
(Axis misalignment)
Moreover, an axis | shaft misalignment angle can be measured with an automatic birefringence meter (KOBRA-21ADH, Oji Scientific Instruments Co., Ltd. product). An average value of absolute values can be obtained by measuring 20 points at equal intervals over the entire width in the width direction. The range of the slow axis angle (axis deviation) is the measurement of 20 points at equal intervals over the entire width direction, and the difference between the average of the absolute value of the axis deviation and the average of the four points from the smaller absolute value. Is taken.

(Transmittance)
The transmittance of visible light (615 nm) can be measured for a sample of 20 mm × 70 mm at 25 ° C. and 60% RH with a transparency measuring instrument (AKA photoelectric tube colorimeter, manufactured by Kotaki Seisakusho).
(Spectral characteristics)
A sample 13 mm × 40 mm can be measured for transmittance at a wavelength of 300 to 450 nm with a spectrophotometer (U-3210, manufactured by Hitachi, Ltd.) at 25 ° C. and 60% RH. The inclination width can be obtained at a wavelength of 72% -5%. The limiting wavelength can be represented by a wavelength of (gradient width / 2) + 5%, and the absorption edge can be represented by a wavelength having a transmittance of 0.4%. From this, the transmittances at 380 nm and 350 nm can be evaluated.

[Film surface properties]
The film surface preferably has an arithmetic average roughness (Ra) of surface irregularities of the film based on JISB0601-1994 of 0.1 μm or less and a maximum height (Ry) of 0.5 μm or less. It is more preferable that the thickness (Ra) is 0.05 μm or less and the maximum height (Ry) is 0.2 μm or less. The concave and convex shapes on the film surface can be evaluated by an atomic force microscope (AFM).

[In-plane variation of retardation]
The cellulose acylate film of the present invention preferably satisfies the following formula.
| Re _(MAX) −Re _(MIN) | ≦ 3 and | Rth _(MAX) −Rth _(MIN) | ≦ 5
[In the formula, Re _(MAX) and Rth _(MAX) − are the maximum retardation values of 1 m square film cut out arbitrarily, and Re _(MIN) and Rth _(MIN) are the minimum values. ]

[Retention of film]
In the film comprising the cellulose composition of the present invention, the retention of various compounds added to the film is required. Specifically, the mass change of the film when the cellulose acylate film of the present invention is allowed to stand for 48 hours under the condition of 80 ° C./90% RH is preferably 0 to 5%. More preferably, it is 0 to 3%, and particularly preferably 0 to 2%.
<Reservation evaluation method>
The sample was cut into a size of 10 cm × 10 cm, the mass after being left for 24 hours in an atmosphere of 23 ° C. and 55% RH was measured, and the sample was left for 48 hours under conditions of 80 ± 5 ° C. and 90 ± 10% RH. The surface of the later sample is lightly wiped, and the mass after standing for 1 day at 23 ° C. and 55% RH is measured, and the retention property can be calculated by the following method.
Retention property (mass%) = {(mass before standing−mass after standing) / mass before standing} × 100

[Mechanical properties of film]
(curl)
The curl value in the width direction of the film is preferably −10 / m to + 10 / m. For the film comprising the cellulose composition of the present invention, the surface treatment described later, the rubbing treatment when applying the optically anisotropic layer, the alignment film, the coating and bonding of the optically anisotropic layer, etc. are long. When the scale is used, if the curl value in the width direction of the cellulose acylate film of the present invention is outside the above range, the handling of the film may be hindered and the film may be cut. In addition, the film is strongly in contact with the transport roll at the edge and center of the film, so it is easy to generate dust, and foreign matter adheres to the film. May exceed the value. Further, by setting the curl in the above-mentioned range, it is possible to reduce color spot failures that are likely to occur when the optically anisotropic layer is installed, and it is possible to prevent bubbles from entering when the polarizing film is bonded, which is preferable.
The curl value can be measured according to a measurement method (ANSI / ASCPH1.29-1985) defined by the American National Standards Institute.

(Tear strength)
The tear strength (Elmendorf tear method) based on the tear test method of JISK7128-2: 1998 is preferably 2 g or more when the film thickness of the cellulose acylate film of the present invention is in the range of 20 to 80 μm. More preferably, it is 5-25g, Most preferably, it is 6-25g. Moreover, 8 g or more is preferable at 60 micrometer conversion, More preferably, it is 8-15g. Specifically, it can be measured using a light load tear strength tester after conditioning a sample piece of 50 mm × 64 mm for 2 hours under conditions of 25 ° C. and 65% RH.

[Residual solvent amount of film]
It is preferable to dry on the conditions that the residual solvent amount with respect to a film becomes the range of 0.01-1.5 mass%. More preferably, it is 0.01-1.0 mass%. Curling can be suppressed by setting the residual solvent amount of the transparent support used in the present invention to 1.5% or less. More preferably, it is 1.0% or less. This is probably because free deposition is reduced by reducing the amount of residual solvent during film formation by the above-described solvent casting method.

[Hygroscopic expansion coefficient of film]
The hygroscopic expansion coefficient of the film is preferably 30 × 10 ⁻⁵ /% RH or less. The hygroscopic expansion coefficient is preferably 15 × 10 ⁻⁵ /% RH or less, and more preferably 10 × 10 ⁻⁵ /% RH or less. The hygroscopic expansion coefficient is preferably small, but usually it is 1.0 × 10 ⁻⁵ /% RH or more. The hygroscopic expansion coefficient indicates the amount of change in the length of the sample when the relative humidity is changed at a constant temperature. By adjusting this hygroscopic expansion coefficient, when a film made of the cellulose composition of the present invention is used as an optical compensation film support, while maintaining the optical compensation function of the optical compensation film, a frame-like transmittance increase, Light leakage due to distortion can be prevented.

[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 in 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, 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 No. 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]
Alkali saponification is one effective means of surface treatment when the cellulose acylate film of the present invention is used as a transparent protective film for a polarizing plate. In this case, the contact angle of the film surface after the alkali saponification treatment is preferably 55 ° or less. More preferably, it is 50 ° or less, and particularly 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.

(Light resistance)
In the cellulose composition of the present invention, the color difference ΔE * ab of the film irradiated with super xenon light for 240 hours is preferably 20 or less as an index of light durability. More preferably, it is 18 or less, and it is especially preferable that it is 15 or less. For the measurement of the color difference, UV3100 (manufactured by Shimadzu Corporation) can be used. The measurement can be carried out by adjusting the film to 25 ° C. and 60% RH for 2 hours or more, and then measuring the color of the film before irradiation with xenon light to determine initial values (L0 ^* , a0 ^* , b0 ^* ). Thereafter, the film alone was irradiated with xenon light for 240 hours under conditions of 150 W / m ² , 60 ° C. and 50% RH with a super xenon weather meter SX-75 (manufactured by Suga Test Instruments Co., Ltd.) After the lapse of time, the film is taken out from the thermostatic bath, adjusted to 25 ° C. and 60% RH for 2 hours, then subjected to color measurement again, and values (L1 ^* , a1 ^* , b1 ^* ) after irradiation can be obtained. From these, the color difference ΔE ^* ab = ((L0 ^* −L1 ^* ) ² + (a0 ^* −a1 ^* ) ² + (b0 ^* −b1 ^* ) ² ) ^0.5 can be obtained.

[Functional layer]
The film comprising the cellulose composition of the present invention is applied to optical applications and photographic light-sensitive materials. In particular, the optical application is preferably a liquid crystal display device, and the liquid crystal display device has a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and the liquid crystal It is more preferable that at least one optical compensation sheet is disposed between the cell and the polarizing element. As these liquid crystal display devices, TN, IPS, FLC, AFLC, OCB, STN, ECB, VA and HAN are preferable.
In that case, when using the film which consists of a cellulose body composition of this invention for the above-mentioned optical use, providing various functional layers is implemented. They are, for example, an antistatic layer, a cured resin layer (transparent hard coat layer), an antireflection layer, an easy adhesion layer, an antiglare layer, an optical compensation layer, an alignment layer, a liquid crystal layer, and the like. Examples of these functional layers and materials thereof include surfactants, slip agents, matting agents, antistatic layers, hard coat layers, and the like. It is described in detail on pages 32 to 45 in the publication of the Japan Society for Invention and Invention, and can be preferably used.

[Polarizer]
The cellulose composition of the present invention and the film thereof are useful for polarizing plate protective films. When using as a polarizing plate protective film, the manufacturing method of a polarizing plate is not specifically limited, It can manufacture by a general method. There is a method in which the obtained cellulose acylate film is treated with an alkali and bonded to both sides of a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. Instead of alkali treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed.
Examples of the adhesive used for bonding the protective film treated surface and the polarizer include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and the like.
The polarizing plate is composed of a polarizer and a protective film that protects both surfaces of the polarizer, and is further constructed by laminating a protective film on one surface of the polarizing plate and a separate film on the opposite surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the adhesive layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.
In a liquid crystal display device, a substrate containing liquid crystal is usually disposed between two polarizing plates. However, a polarizing plate protective film to which the optical film of the present invention is applied can provide excellent display properties regardless of the location. . In particular, the polarizing plate protective film on the outermost surface of the display side of the liquid crystal display device is provided with a transparent hard coat layer, an antiglare layer, an antireflection layer, and the like.

[Optical compensation film]
The cellulose composition and the film of the present invention can be used in various applications, and are effective when used as an optical compensation film for a liquid crystal display device. The optical compensation film is generally used for a liquid crystal display device, refers to an optical material that compensates for a phase difference, and is synonymous with a phase difference plate, an optical compensation sheet, and the like. The optical compensation film has birefringence and is used for the purpose of removing the color of the display screen of the liquid crystal display device or improving the viewing angle characteristics. When the cellulose-based composition film of the present invention is used as an optical compensation film, it is preferable that Re and Rth are 0 ≦ Re ≦ 10 nm and | Rth | ≦ 25 nm and the optical anisotropy is small, and ΔRe (| Re _{(400 )} −Re ₍₇₀₀₎ |) ≦ 10 nm and ΔRth (| Rth ₍₄₀₀₎ −Rth ₍₇₀₀₎ |) ≦ 35 nm are preferable. If it is such a film, only an optical performance of an optically anisotropic layer can be expressed when an optically anisotropic layer having birefringence is used in combination without causing excessive anisotropy.

Therefore, when the cellulose composition film of the present invention is used as an optical compensation film of a liquid crystal display device, Re and Rth of the optically anisotropic layer used in combination are Re = 0 to 200 nm and | Rth | = 0 to 400 nm. Any optically anisotropic layer within this range is preferable. The cellulosic material composition of the present invention and the optical performance and driving method of the liquid crystal cell of the liquid crystal display device in which the film is used are not limited, and any optically anisotropic layer required as an optical compensation film is used in combination. can do. The optically anisotropic layer used in combination may be formed from a composition containing a liquid crystalline compound or may be formed from a polymer film having birefringence.
The liquid crystal compound is preferably a discotic liquid crystal compound or a rod-like liquid crystal compound.

(Discotic liquid crystalline compounds)
Examples of discotic liquid crystalline compounds 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 optically anisotropic layer, the discotic liquid crystalline molecules are preferably fixed in an aligned state, and more preferably fixed by a polymerization reaction. 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 include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenyl Pyrimidines, phenyldioxanes, tolans and alkenylcyclohexylbenzonitriles are included. Not only the above low-molecular liquid crystalline compounds but also high-molecular liquid crystalline compounds can be used.

  In the optically anisotropic layer, the rod-like liquid crystalline molecules are preferably fixed in an aligned state, and more preferably fixed by a polymerization reaction. Examples of the polymerizable rod-like liquid crystalline compound 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.

(Optically anisotropic layer made of polymer film)
As described above, the optically anisotropic layer may be formed from a polymer film. The polymer film is formed from a polymer that can exhibit optical anisotropy. Examples of such polymers include polyolefins (eg, polyethylene, polypropylene, norbornene polymers), polycarbonates, polyarylate, polysulfone, polyvinyl alcohol, polymethacrylic acid esters, polyacrylic acid esters and cellulose esters (eg, cellulose triacetate, Cellulose diacetate). Further, a copolymer or a polymer mixture of these polymers may be used.

  The optical anisotropy of the polymer film is preferably obtained by stretching. The stretching is preferably uniaxial stretching or biaxial stretching. Specifically, longitudinal uniaxial stretching using a difference in peripheral speed between two or more rolls, tenter stretching for grasping both sides of the polymer film and stretching in the width direction, or biaxial stretching in combination of these is preferable. In addition, using two or more polymer films, the optical properties of the entire two or more films may satisfy the above conditions. The polymer film is preferably produced by a solvent cast method in order to reduce unevenness in birefringence. The thickness of the polymer film is preferably 20 to 500 μm, and more preferably 40 to 100 μm.

  Further, as the polymer film forming the optically anisotropic layer, at least one polymer material selected from the group consisting of polyamide, polyimide, polyester, polyetherketone, polyamideimide polyesterimide, and polyaryletherketone is used. A method in which a solution in which is dissolved in a solvent is applied to a substrate and the solvent is dried to form a film can also be preferably used. At this time, a method of stretching the polymer film and the base material to develop optical anisotropy and using it as an optically anisotropic layer can be preferably used. The cellulose body composition of the present invention and the film thereof are It can be preferably used as a substrate. In addition, the polymer film is prepared on another substrate, and after the polymer film is peeled off from the substrate, it is bonded to the film made of the cellulose composition of the present invention, together with the optically anisotropic layer. It is also preferable to use as. In this method, the thickness of the polymer film can be reduced, and is preferably 50 μm or less, and more preferably 1 to 20 μm.

(General liquid crystal display device configuration)
When the cellulose acylate film is used as an optical compensation film, the transmission axis of the polarizing element and the slow axis of the optical compensation film made of the cellulose acylate film may be arranged at any angle. The liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing element. The optical compensation film is arranged.
The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.

(Types of liquid crystal display devices)
The cellulose composition of the present invention and the film thereof can be used for liquid crystal cells in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroly Liquid Liquid Crystal), OCB (Optically Liquid BTS). Various display modes such as ECB (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The cellulose composition and the film thereof of the present invention are effective in any display mode liquid crystal display device. Further, it is effective in any of a transmissive type, a reflective type, and a transflective liquid crystal display device.

(TN type liquid crystal display device)
You may use the film which consists of a cellulose body composition of this invention as a support body of the optical compensation sheet | seat of a TN type liquid crystal display device which has a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. The optical compensation sheet used in the TN type liquid crystal display device is described in JP-A-3-9325, JP-A-6-148429, JP-A-8-50206, and JP-A-9-26572. Moreover, it is described in Mori et al. (Jpn. J. Appl. Phys. Vol. 36 (1997) p. 143 and Jpn. J. Appl. Phys. Vol. 36 (1997) p. 1068). is there.

(STN type liquid crystal display device)
You may use the film which consists of a cellulose body composition of this invention as a support body of the optical compensation sheet | seat of the STN type liquid crystal display device which has a liquid crystal cell of STN mode. In general, in a STN type liquid crystal display device, rod-like liquid crystalline molecules in a liquid crystal cell are twisted in the range of 90 to 360 degrees, and the refractive index anisotropy (Δn) and cell gap (d) of the rod-like liquid crystalline molecules. Product (Δnd) is in the range of 300 to 1500 nm. The optical compensation sheet used in the STN type liquid crystal display device is described in JP-A-2000-105316.

(VA type liquid crystal display device)
The film comprising the cellulose composition of the present invention is particularly advantageously used as a support for an optical compensation sheet of a VA liquid crystal display device having a VA mode liquid crystal cell. It is preferable that the Re retardation value of the optical compensation sheet used in the VA liquid crystal display device is 0 to 150 nm and the Rth retardation value is 70 to 400 nm. The Re retardation value is more preferably 20 to 70 nm. When two optically anisotropic polymer films are used in the VA liquid crystal display device, the Rth retardation value of the film is preferably 70 to 250 nm. When a single optically anisotropic polymer film is used for the VA liquid crystal display device, the Rth retardation value of the film is preferably 150 to 400 nm. The VA-type liquid crystal display device may be an alignment-divided system as described in, for example, JP-A-10-123576.

(IPS liquid crystal display device and ECB liquid crystal display device)
The film comprising the cellulose composition of the present invention is particularly suitable as a support for an optical compensation sheet of an IPS liquid crystal display device and an ECB liquid crystal display device having IPS mode and ECB mode liquid crystal cells, or as a protective film for a polarizing plate. It is advantageously used. In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules in parallel with the substrate surface in the absence of applied voltage. In these embodiments, the polarizing plate using the cellulose acylate film of the present invention contributes to improving the color tone, widening the viewing angle, and improving the contrast. In this aspect, of the protective films for the polarizing plates above and below the liquid crystal cell, the protective film (the protective film on the cell side) disposed between the liquid crystal cell and the polarizing plate is made of the cellulose composition of the present invention. A polarizing plate using a film is preferably used on at least one side. An optically anisotropic layer is disposed between the protective film of the polarizing plate and the liquid crystal cell, and the retardation value of the disposed optically anisotropic layer is set to not more than twice the value of Δn · d of the liquid crystal layer. Is more preferable.

(OCB type liquid crystal display device and HAN type liquid crystal display device)
The film comprising the cellulose composition of the present invention is also advantageously used as a support for an optical compensation sheet of an OCB type liquid crystal display device having an OCB mode liquid crystal cell or a HAN type liquid crystal display device having a HAN mode liquid crystal cell. . In the optical compensation sheet used for the OCB type liquid crystal display device or the HAN type liquid crystal display device, it is preferable that the direction in which the absolute value of retardation is minimum does not exist in the plane of the optical compensation sheet or in the normal direction. The optical properties of the optical compensation sheet used in the OCB type liquid crystal display device or the HAN type liquid crystal display device are also the optical properties of the optical anisotropic layer, the optical properties of the support, and the optical anisotropic layer and the support. Is determined by the arrangement of An optical compensation sheet used for an OCB type liquid crystal display device or a HAN type liquid crystal display device is described in JP-A-9-197397. Further, it is described in a paper by Mori et al. (Jpn. J. Appl. Phys. Vol. 38 (1999) p. 2837).

(Reflective liquid crystal display)
The film comprising the cellulose composition of the present invention is also advantageously used as an optical compensation sheet for a reflective liquid crystal display device of TN type, STN type, HAN type, and GH (Guest-Host) type. These display modes have been well known since ancient times. The TN type reflection type liquid crystal display device is described in JP-A-10-123478, WO98848320, and Japanese Patent No. 3022477. The optical compensation sheet used in the reflective liquid crystal display device is described in WO00-65384.

(Other liquid crystal display devices)
The film comprising the cellulose composition of the present invention is also advantageously used as a support for an optical compensation sheet of an ASM type liquid crystal display device having a liquid crystal cell in ASM (Axial Symmetrical Microcell) mode. The ASM mode liquid crystal cell is characterized in that the thickness of the cell is maintained by a resin spacer whose position can be adjusted. Other properties are the same as those of the TN mode liquid crystal cell. The ASM mode liquid crystal cell and the ASM type liquid crystal display device are described in a paper by Kume et al. (Kume et al., SID 98 Digest 1089 (1998)).

(Hard coat film, antiglare film, antireflection film)
The film comprising the cellulose composition of the present invention can be preferably applied to a hard coat film, an antiglare film, and an antireflection film. For the purpose of improving the visibility of flat panel displays such as LCD, PDP, CRT, EL, etc., any one of a hard coat layer, an antiglare layer and an antireflection layer on one or both sides of the film made of the cellulose composition of the present invention Or all can be provided. Preferred embodiments of such an antiglare film and antireflection film are described in detail in pages 54 to 57 of the Japan Institute of Invention and Technology (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Invention). The cellulose acylate film of the present invention can be preferably used.

(Photo film support)
Furthermore, the cellulose composition of the present invention and the film thereof can be applied as a support for a silver halide photographic light-sensitive material, and the above-described various materials, formulations, and processing methods can be applied. Regarding these techniques, Japanese Patent Application Laid-Open No. 2000-105445 details the color negative, and a film made of the cellulose composition of the present invention is preferably used. Further, application as a support for a color reversal silver halide photographic light-sensitive material is also preferable, and various materials, formulations and processing methods described in JP-A No. 11-282119 can be applied.

(Transparent substrate)
Since the film made of the cellulose composition of the present invention has an optical anisotropy close to zero and excellent transparency, it substitutes for a liquid crystal cell glass substrate of a liquid crystal display device, that is, encloses a driving liquid crystal. It can also be used as a transparent substrate.
Since the transparent substrate enclosing the liquid crystal needs to be excellent in gas barrier properties, a gas barrier layer may be provided on the surface of the cellulose acylate film of the present invention as necessary. The form and material of the gas barrier layer are not particularly limited, but SiO ₂ or the like is vapor-deposited on at least one surface of the cellulose acylate film of the present invention, or a relatively gas barrier property such as vinylidene chloride polymer or vinyl alcohol polymer. A method of providing a high polymer coat layer can be considered, and these can be used as appropriate.
In order to use as a transparent substrate for enclosing liquid crystal, a transparent electrode for driving the liquid crystal by applying a voltage may be provided. Although it does not specifically limit as a transparent electrode, A transparent electrode can be provided by laminating | stacking a metal film, a metal oxide film, etc. on the at least single side | surface of the film which consists of a cellulose body composition of this invention. Among these, a metal oxide film is preferable from the viewpoint of transparency, conductivity, and mechanical properties, and an indium oxide thin film mainly containing 2 to 15% of zinc oxide can be preferably used. Details of these techniques are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2001-125079 and 2000-227603.

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

[Synthesis Example 1: Synthesis of Exemplified Compound (PC-1)]
54 g of commercially available bisphenol A polycarbonate: Panlite AD5503 (manufactured by Teijin Chemicals Ltd.), 2.3 g of bisphenol A and 200 ml of 1,2,4-trichlorobenzene were heated and stirred at 100 ° C. to dissolve. 0.2 g of zinc acetate monohydrate was added thereto, and the mixture was further heated and stirred at 180 ° C. for 3 hours. After the reaction, the reaction solution was allowed to cool to room temperature and carefully poured into 1 L of methanol. The precipitated crystals were collected by filtration, washed with 200 ml of methanol and dried, and 52.8 g of the exemplified compound (PC-1) was obtained as a white solid.

[Measurement method]
<Weight average molecular weight>
It was determined by GPC measurement using polystyrene as a solvent in comparison with a polystyrene molecular weight standard product (HLC-8120GPC, manufactured by Tosoh Corporation).
Here, the weight average molecular weight of the obtained exemplary compound (PC-1) was 3200.

[Synthesis Example 2: Synthesis of Exemplified Compound (PC-10)]
10.6 g of 4,4'-biphenol and 0.8 g of t-butylphenol in 225 ml of methylene chloride were mixed with 0.2 g of hydrosulfite sodium and 17.8 g of sodium hydroxide in 200 ml of water. Added and stirred vigorously. Thereto was added a solution of triphosgene (6.92 g) in 25 ml of methylene chloride over 30 minutes. After the addition, the reaction was further continued for 1 hour, and then 0.2 ml of triethylamine was added. After further 4 hours of reaction, the organic layer was separated by a liquid separation operation. Further, it was washed twice with 300 ml of diluted hydrochloric acid, and methylene chloride was distilled off under reduced pressure. 80 ml of methylene chloride was added to the residue and dissolved, and after removing dust and filtering, it was slowly put into 400 ml of methanol. The precipitated resin was collected by filtration, washed with methanol, and dried to obtain 9.7 g of exemplary compound (PC-10) as a white solid.
The weight average molecular weight of the obtained resin was 7600.

Preparation of Cellulose Acetate Film Each component of the following cellulose acetate solution composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose acetate solution.

(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 (No. 2 solvents) 47 parts by mass

In another mixing tank, compound PC-1 (3200), PC-3 (4600), PC-10 (13600), PC-25 (5300), PC-26 (4800), or PE-8 (4700) Further, Panlite AD5503 (27000), Comparative compound (A) 16 parts by mass, Methylene chloride 87 parts by mass and Methanol 13 parts by mass were added as comparative compounds and stirred while heating to prepare a retardation control agent solution. . The exemplified compounds PC-3 (4600), PC-25 (5300), PC-26 (4800), and PE-8 (4700) are the same as the exemplified compounds PC-1 (3200) and PC-10 (7600). ). Here, the numerical value in parentheses attached after the compound name represents the weight average molecular weight by GPC measurement.
A dope was prepared by mixing 36 parts by mass of a retardation control (raising) agent solution with 474 parts by mass of the cellulose acetate solution and stirring sufficiently. Retardation control agents were added in parts by mass shown in Table 1 with respect to 100 parts by mass of cellulose acetate.

  The obtained dope was cast using a band casting machine. A film having a residual solvent amount of 15% by mass was horizontally stretched at a stretch ratio of 20% using a tenter under conditions of 130 ° C. to produce a cellulose acetate film (thickness: 92 μm). About the produced cellulose acetate film (optical compensation sheet), Re retardation value and Rth retardation value at a wavelength of 590 nm were measured. The results are shown in Table 1.

<Measurement of Re and Rth>
Re was measured by making light with a wavelength of 590 nm incident in the normal direction of the film in KOBRA 21ADH (manufactured by Oji Scientific Instruments). Rth was measured by making light having a wavelength of 590 nm incident from the direction inclined by + 40 ° with respect to the normal direction of the film, 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 injecting light having a wavelength of 590 nm from the direction tilted by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). It was calculated based on the retardation value measured in the direction, the assumed value of the average refractive index, and the input film thickness value.

  As can be seen from the results in Table 1, by adding the compounds represented by the general formulas (1) to (3), a film containing no comparative compound, a film containing 2 parts by mass of the comparative compound (A), and comparison It can be seen that a film having a high Re that could not be achieved with a film containing 5 parts by mass of the compound (A) can be produced. In addition, while the commercially available polymers known in the art cause film turbidity, the compounds represented by the general formulas (1) to (3) increase the addition amount further without causing the film to become cloudy. It becomes possible to express Re. Therefore, it can be seen that the compound of the present invention can produce a cellulose-based film satisfying a new Rth / Re region that could not be achieved conventionally.

  The cellulose-based film comprising the composition of the present invention can be suitably used as an optical film for a liquid crystal display device, particularly as an optical compensation sheet and a modified protective film. The cellulose film of the present invention can also be suitably used as a support for silver halide photographic light-sensitive materials.

Claims (11)

A cellulose body composition comprising a cellulose body and a polymer represented by the following general formula (1) having a weight average molecular weight of 500 or more and 15000 or less, and / or an oligomer;

In the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom or a substituent, and A each independently represents a single bond or a divalent group. Represents a linking group. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and A may be bonded to each other to form a ring. A cellulose body composition comprising a cellulose body and at least one of a polymer represented by the following general formula (2) and / or general formula (3), and / or an oligomer;

In general formula (2), X represents a divalent aromatic group, and Y represents a divalent linking group. In general formula (3), Z represents a divalent aromatic group.   The cellulose body composition according to claim 2, wherein the polymer and / or oligomer represented by the general formula (2) and / or the general formula (3) has a weight average molecular weight of 500 to 15,000.   Cellulose acylate is contained as said cellulose derivative, The cellulose body composition of any one of Claims 1-3 characterized by the above-mentioned.   The cellulose body film which consists of a cellulose body composition of any one of Claims 1-4.   The polarizing plate in which a protective film is bonded to both surfaces of a polarizer, wherein at least one of the protective films is the cellulose body film according to claim 5.   The polarizing plate of Claim 6 which has an optically anisotropic layer on the at least one surface of a protective film.   A liquid crystal display device comprising a liquid crystal cell and two polarizing plates disposed on both sides thereof, wherein at least one polarizing plate is the polarizing plate according to claim 6 or 7.   The liquid crystal display device according to claim 8, wherein the liquid crystal display is a VA mode.   The liquid crystal display device according to claim 8, wherein the liquid crystal display device is in an OCB mode.   A silver halide photographic light-sensitive material, wherein the cellulose film according to claim 5 is used as a support.