JPWO2010082411A1 - Optical film, polarizing plate, and liquid crystal display device - Google Patents

Abstract

An object of the present invention is to provide an optical film capable of providing uniform image quality on a large screen with high productivity. The optical film of the present invention comprises a sugar ester compound having at least one furanose structure or pyranose structure and esterifying all or part of the OH groups of the compound having 1 to 12 or more furanose structures or pyranose structures bonded thereto. It contains at least a cellulose ester having a repeating unit represented by the general formula (1) or (2). (In the formula, A and B represent a divalent hydrocarbon group having 1 to 12 carbon atoms or a divalent hydrocarbon group having 1 to 12 carbon atoms substituted by a hydroxyl group. However, A and B may be the same or different.

Description

  The present invention relates to an optical film with reduced frame failure and less foreign matter failure.

  Liquid crystal display devices have been increased in screen size, and there is a demand for more uniform image quality across the entire screen. In particular, liquid crystal display screens larger than 20 inches have been improved because a light leakage failure called a frame failure in which the peripheral portion of the display screen becomes bright like a frame during black display may occur.

  Therefore, for example, instead of the conventional triacetyl cellulose, the transparent protective film described in Patent Document 1 is used, and the optical compensation layer in which the liquid crystal compound for laminating the lack of retardation Rth in the thickness direction necessary for optical compensation is aligned is used. On the other hand, a proposal has been made to improve the so-called frame failure when a liquid crystal display device is formed by newly laminating a negative C plate layer such as a horizontal alignment layer of a discotic compound or a cholesteric liquid crystal layer ( For example, see Patent Document 1).

  In addition, it has been proposed that a novel cellulose ester film having a specific repeating unit can significantly improve frame failure (see, for example, Patent Document 2).

JP 2008-224763 A JP 2007-16137 A

  However, in the novel cellulose ester film having a specific repeating unit, the frame failure can be remarkably improved. However, there is a defect that foreign matter failure due to insolubilization of the material used during film formation increases.

  In recent years, with the rapid increase in demand for liquid crystal display devices, there are many foreign matter failures in response to demands for high productivity such as widening and long winding of polarizing plate protective films and retardation films. It is fatal because it greatly affects

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical film excellent in productivity that can reduce frame failure and with little foreign matter failure, and a polarizing plate using the same, and thereby a liquid crystal display device having uniform image quality on a large screen. Is to provide.

  The above object of the present invention can be achieved by the following configuration.

  1. A sugar ester compound having at least one furanose structure or a pyranose structure and esterifying all or part of the OH groups of the compound having the furanose structure or the pyranose structure bonded to 1 to 12, and at least the general formula (1) or An optical film comprising a cellulose ester having a repeating unit represented by (2).

(In the formula, A and B represent a divalent hydrocarbon group having 1 to 12 carbon atoms or a divalent hydrocarbon group having 1 to 12 carbon atoms substituted with a hydroxyl group, provided that A and B are the same. May be different.)
2. The optical film contains a benzotriazole compound represented by the following general formula (3), a benzophenone compound represented by the general formula (4), or a compound containing a cyano group represented by the general formula (5). 2. The optical film as described in 1 above.

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

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

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X ¹ and X ² represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, an aromatic group. Represents a heterocycle.)
3. 3. The optical film as described in 1 or 2 above, wherein the width of the optical film is 1.6 to 4 m.

  4). A polarizing plate comprising the optical film according to any one of 1 to 3 on at least one surface of a polarizer.

  5). 5. A liquid crystal display device using the polarizing plate according to 4 above on at least one surface of a liquid crystal cell.

  According to the present invention, it is possible to provide an optical film, a polarizing plate, and a liquid crystal display device with a large screen and uniform image quality, which can reduce frame failures and have few foreign matter failures and excellent productivity.

  As a result of intensive studies, the present inventors have found that the optical film excellent in productivity, which can reduce frame failure and reduce foreign matter failure, by containing the sugar ester compound of the present invention in the cellulose ester, It has been found that a polarizing plate using the same can be provided. Hereinafter, the configuration of the present invention will be described in detail.

(Sugar ester compound)
The optical film of the present invention has at least one furanose structure or pyranose structure, and is a compound (sugar ester) obtained by esterifying all or part of OH groups in a compound having 1 to 12 furanose structures or pyranose structures bonded thereto. Compound)). Preferred examples of the “compound having at least one furanose structure or pyranose structure and having 1 to 12 furanose structures or pyranose structures bonded to each other” include the following. It is not limited.

  Examples include glucose, galactose, mannose, fructose, xylose, arabinose, lactose, sucrose, cellobiose, cellotriose, maltotriose, raffinose, and the like, and particularly those having both a furanose structure and a pyranose structure are preferred. An example is sucrose.

  “Compound having at least one furanose structure or pyranose structure and esterifying all or part of OH groups in a compound having 1 to 12 furanose structures or pyranose structures bonded” (sugar ester compound) of the present invention There is no restriction | limiting in particular as monocarboxylic acid used when synthesize | combining, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. are mentioned. The carboxylic acid used may be one type or a mixture of two or more types.

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

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

  Examples of preferable aromatic monocarboxylic acids include aromatic monocarboxylic acids and cinnamic acids having 1 to 5 substituents such as alkyl groups or alkoxy groups introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid. , Aromatic monocarboxylic acids having two or more benzene rings such as benzyl acid, biphenyl carboxylic acid, naphthalene carboxylic acid, tetralin carboxylic acid, or derivatives thereof, and benzoic acid is particularly preferable.

  Details of the production methods of these compounds are described in JP-A Nos. 62-42996 and 10-237084.

  Specific examples are given below, but the present invention is not limited thereto.

The sugar ester compound of the present invention is preferably contained in the optical film in an amount of 1 to 35% by mass, particularly 5 to 30% by mass.
(Cellulose ester)
The optical film of the present invention contains a cellulose ester having a repeating unit represented by the general formula (1) or (2).

Specific examples of A are given below.
A-1-CH ₂ CH _{2-
A-2 -CH 2 CH 2 CH} 2 -
A-3 -CH = CH-
A-4

A-5

A-6 —CH ₂ C (CH ₃ ) ₂ —
Specific examples of B are given below.
B-1 _{-CH 2} CH 2 -
B-2-CH ₂ CH ₂ CH ₂ CH _2-
B-3

B-4

  The cellulose ester having a repeating unit represented by the general formula (1) or (2) in the present invention is an cellulose having an unsubstituted hydroxyl group or an acyl group such as an acetyl group, a propionyl group, a butyryl group, or a phthalyl group. Esterification reaction of polybasic acid or its anhydride and polyhydric alcohol in the presence of cellulose ester in which some hydroxyl groups are already substituted, or ring-opening polymerization of L-lactide and D-lactide, L-lactic acid , D-lactic acid can be obtained by self-condensation.

  Examples of the polybasic acid anhydride used in the esterification reaction include, but are not limited to, maleic anhydride, phthalic anhydride, and fumaric anhydride.

  Examples of the polyhydric alcohol that can be used in the esterification reaction include glycerin, ethylene glycol, and propylene glycol, but are not particularly limited.

  The esterification reaction can be performed without a catalyst, but a known Lewis acid catalyst or the like can be used. Examples of catalysts that can be used include metals such as tin, zinc, titanium, bismuth, zirconium, germanium, antimony, sodium, potassium, and aluminum, and derivatives thereof. Particularly, the derivatives include metal organic compounds, carbonates, oxides, halides. Is preferred. Specific examples include octyl tin, tin chloride, zinc chloride, titanium chloride, alkoxy titanium, germanium oxide, zirconium oxide, antimony trioxide, and alkyl aluminum. Moreover, an acid catalyst typified by p-toluenesulfonic acid can also be used as the catalyst. Moreover, in order to accelerate | stimulate the dehydration reaction of carboxylic acid and alcohol, you may add well-known compounds, such as carbodiimide and dimethylaminopyridine.

  Such a reaction may be a reaction in an organic solvent capable of dissolving cellulose ester and other compounds to be reacted, or a reaction using a batch kneader capable of heating and stirring while adding a shearing force. It may be by reaction using a uniaxial or biaxial extruder.

  The repeating unit of this invention can be suitably contained in 0.5-190 mass% with respect to the cellulose of the said part.

  Although the substitution degree of a cellulose ester can be selected suitably, it is preferable from the point of thermoplasticity and heat workability that it is 2.2-3.

  In the cellulose ester of the present invention, when the hydrogen atom of the hydroxyl group of cellulose is a fatty acid ester with an aliphatic acyl group, the aliphatic acyl group has 2 to 20 carbon atoms, specifically acetyl, propionyl, butyryl, Examples include isobutyryl, valeryl, pivaloyl, hexanoyl, octanoyl, lauroyl, stearoyl and the like.

The repeating unit of this invention is 300-10000 as a number average molecular weight with respect to the cellulose of the said part, and it is preferable from the point of thermal workability that it is 500-8000. The number average molecular weight of repeating unit in which the cellulose ester has is, GPC data or the cellulose ester after the reaction before and cellulose esters esterification reaction was in terms of ^{polystyrene, JNM-EX- 1 H-NMR} ( manufactured by JEOL 270: solvent: methylene dichloride).

  When the repeating unit of the present invention is introduced into cellulose, an oligomer or polyester having the repeating unit represented by the general formula (1) or (2) may be generated as a side reaction, but these compounds are used as a plasticizer. Since it acts, it does not necessarily need to be completely removed by purification, and may be contained in the cellulose ester. If content is 30 mass% or less with respect to a cellulose ester, there will be little change in the property of a cellulose ester. From the viewpoint of plasticity, it is preferably 0.5 to 20% by mass.

These oligomers and polyesters have a number average molecular weight of 300 to 10,000, and preferably 500 to 8,000 from the viewpoint of plasticity.
(Benzotriazole compounds, benzophenone compounds, compounds containing a cyano group)
It has been found that by adding a benzotriazole-based compound, a benzophenone-based compound, or a compound containing a cyano group that is preferably used in the present invention, the effect of reducing foreign matter failure due to insolubilization of the material used, which is the object of the present invention, has been increased.

  These compounds preferably have a molecular weight of 250 to 1000 from the viewpoint of volatility. More preferably, it is 260-800, More preferably, it is 270-800, Most preferably, it is 300-800. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used. The addition amount is preferably 0.01 to 30% by mass of the transparent film, more preferably 0.1 to 20% by mass, and particularly preferably 0.2 to 10% by mass. Moreover, these compounds may be used independently or may mix and use 2 or more types of compounds by arbitrary ratios. In addition, the compound may be added at any time during the dope preparation process, but it is preferably added at the initial stage of dope preparation from the viewpoint of solubility of the material.

Hereinafter, although a specific example is given, this invention is not limited to these.
Benzotriazole compounds:
Formula ^{(3) Q 1} -Q 2 -OH
(In the formula, Q ¹ represents a nitrogen-containing aromatic heterocycle Q ² represents an aromatic ring.)
Q ¹ is preferably a 5- to 7-membered nitrogen-containing aromatic heterocycle, more preferably a 5- to 6-membered nitrogen-containing aromatic heterocycle, such as imidazole, pyrazole, triazole, tetrazole, thiazole, oxazole, Selenazole, benzotriazole, benzothiazole, benzoxazole, benzoselenazole, thiadiazole, oxadiazole, naphthothiazole, naphthoxazole, azabenzimidazole, purine, pyridine, pyrazine, pyrimidine, pyridazine, triazine, triazaindene, tetrazaindene More preferably, it is a 5-membered nitrogen-containing aromatic heterocycle, specifically, imidazole, pyrazole, triazole, tetrazole, thiazole, oxazole, benzotriazole, benzothiazole. Azole, benzoxazole, thiadiazole and oxadiazole are preferred, and benzotriazole is particularly preferred. The nitrogen-containing aromatic heterocycle represented by Q ¹ may further have a substituent, and the substituent T described below can be applied as the substituent. In addition, when there are a plurality of substituents, each may be condensed to form a ring.

The aromatic ring represented by Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.

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

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

The aromatic ring represented by Q ² is preferably an aromatic hydrocarbon ring, more preferably a naphthalene ring or a benzene ring, and particularly preferably a benzene ring. Q ² may further have a substituent, and the substituent T described later is preferable.

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

  The compound represented by the general formula (3) is preferably a compound represented by the following general formula (3-A).

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , and R ⁸ each independently represents a hydrogen atom or a substituent)
As the substituent represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ^{9, the} above-described substituent T can be applied. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure. Preferred are a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, and more preferred are a hydrogen atom, an alkyl group, and an aryl group. A group, an alkyloxy group, an aryloxy group, and a halogen atom.

R ¹ and R ³ are more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and particularly preferably an alkyl group having 1 to 12 carbon atoms (preferably 4 to 12 carbon atoms).

R ² and R ⁴ are more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ⁵ and R ⁸ are more preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ⁶ and R ⁷ are more preferably a hydrogen atom or a halogen atom, and particularly preferably a hydrogen atom or a chlorine atom.

  The compound represented by the general formula (3) is more preferably a compound represented by the following general formula (3-B).

(In the formula, R ¹ , R ³ , R ⁶ and R ⁷ have the same meanings as those in general formula (3-A), and preferred ranges are also the same.)

  As the benzophenone compound used in the present invention, those represented by the general formula (4) are preferably used.

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X represents NR (R represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.)
The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be a single ring or may form a condensed ring with another ring.

The aromatic hydrocarbon ring represented by Q ¹ and Q ² is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring, a naphthalene ring, etc.). More preferably an aromatic hydrocarbon ring having 6 to 20 carbon atoms, still more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferably, it is a benzene ring.

The aromatic heterocycle represented by Q ¹ and Q ² is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the heterocyclic ring include, for example, furan, pyrrole, thiophene, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, Examples thereof include quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. Preferred examples of the aromatic heterocycle include pyridine, triazine, and quinoline.

The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 10 carbon atoms, still more preferably a substituted or unsubstituted benzene ring. is there.

Q ¹ and Q ² may further have a substituent, and the above-described substituent T is preferable, but the substituent does not contain a carboxylic acid, a sulfonic acid, or a quaternary ammonium salt. Further, if possible, substituents may be linked to form a ring structure.

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

  The compound represented by the general formula (4) is preferably a compound represented by the following general formula (4-A).

(In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or a substituent.)
As the substituent represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ^{9, the} above-described substituent T can be applied. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure. Preferred are a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom.

R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁸ and R ⁹ are more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, and more preferably a hydrogen atom. Atom, carbon 1-12 alkyl group, particularly preferably a hydrogen atom and a methyl group, and most preferably a hydrogen atom.

R ² is more preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, or a hydroxy group, More preferably, it is a C1-C20 alkoxy group, Most preferably, it is a C1-C12 alkoxy group.

R ⁷ is more preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, or a hydroxy group, More preferred are a hydrogen atom and an alkyl group having 1 to 20 carbon atoms (preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably a methyl group), and particularly preferred are a methyl group and a hydrogen atom. is there.

  The compound represented by the general formula (4) is more preferably a compound represented by the following general formula (4-B).

(Wherein R ¹⁰ represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, or a substituted or unsubstituted aryl group.)
As the substituent of R ^10, the above-described substituent T can be applied.

R ¹⁰ is preferably a substituted or unsubstituted alkyl group, more preferably a substituted or unsubstituted alkyl group having 5 to 20 carbon atoms, and still more preferably a substituted or unsubstituted alkyl group having 5 to 12 carbon atoms. (Including n-hexyl group, 2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group, etc.), particularly preferably a substitution of 6 to 12 carbon atoms or It is an unsubstituted alkyl group (2-ethylhexyl group, n-octyl group, n-decyl group, n-dodecyl group, benzyl group).

  The compound represented by the general formula (4) can be synthesized by a known method described in JP-A-11-12219.

  Moreover, as a compound containing the cyano group used for this invention, what is shown by General formula (5) is used preferably.

  Compound containing cyano group: General formula (5)

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

  The aromatic hydrocarbon ring is preferably (preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, benzene ring, naphthalene ring etc.), more preferably 6 carbon atoms. -20 aromatic hydrocarbon ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms.) More preferred is a benzene ring.

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

The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.

Q ¹ and Q ² may further have a substituent, and the above-described substituent T is preferable.

The substituent T described above can be applied to the substituents represented by X ¹ and X ² . The substituents represented by X ¹ and X ² may be further substituted with other substituents, and X ¹ and X ² may each be condensed to form a ring structure.

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

  The compound represented by the general formula (5) is preferably a compound represented by the following general formula (5-A).

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom or a substituent. X ¹ and X ² Are synonymous with those in formula (20), and the preferred range is also the same.)
As the substituent represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ , the above-described substituent T can be applied. Further, these substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure. Preferred are a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom.

R ¹ , R ² , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, a halogen atom, More preferably, they are a hydrogen atom and a C1-C12 alkyl group, Especially preferably, they are a hydrogen atom and a methyl group, Most preferably, it is a hydrogen atom.

R ³ and R ⁸ are more preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, hydroxy More preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms, and particularly preferably a hydrogen atom.

  The compound represented by the general formula (5) is more preferably a compound represented by the following general formula (5-B).

(In the formula, R ³ and R ₈ have the same meanings as those in formula (5-A), and preferred ranges are also the same. X ₃ represents a hydrogen atom or a substituent.)
As the substituent represented by X _{3, the} above-described substituent T can be applied, and if possible, the substituent may be further substituted with another substituent. X ₃ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring, more preferably a cyano group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring. More preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, an aryl having 6 to 12 carbon atoms). Group and a combination thereof)).

  The compound represented by the general formula (5) is more preferably a compound represented by the general formula (5-C).

(In the formula, R ³ and R ₈ have the same meanings as those in formula (5-A), and preferred ranges are also the same. R ²¹ represents an alkyl group having 1 to 20 carbon atoms.)
R ²¹ is preferably an alkyl group having 2 to 12 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, and still more preferably 6 carbon atoms when both R ³ and R ₈ are hydrogen. -12 alkyl groups, particularly preferably an n-octyl group, a tert-octyl group, a 2-ethylhexyl group, an n-decyl group, and an n-dodecyl group, and most preferably a 2-ethylhexyl group.

When R ³ and R ₈ are preferably other than hydrogen as R ²¹ , the compound represented by the general formula (5-C) has a molecular weight of 300 or more and an alkyl group having 20 or less carbon atoms. preferable.

  The compound represented by the general formula (5) of the present invention can be synthesized by the method described in Journal of American Chemical Society 63, 3452 (1941). Although the specific example of a compound represented by General formula (5) below is given, this invention is not limited to the following specific example at all.

(Other additives)
(Plasticizer)
The cellulose ester film or cellulose ester resin / acrylic resin film preferably contains the following plasticizer. Examples of plasticizers include phosphate ester plasticizers, phthalate ester plasticizers, trimellitic acid ester plasticizers, pyromellitic acid plasticizers, glycolate plasticizers, citrate ester plasticizers, and polyesters. A plasticizer, a polyhydric alcohol ester plasticizer, and the like can be preferably used.

  For phosphate plasticizers, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenylbiphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate ester plasticizers, diethyl phthalate, dimethoxy Ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, diphenyl phthalate, dicyclohexyl phthalate, and other trimellitic acid plasticizers include tributyl trimellitate, triphenyl trimellitate, triethyl For pyromellitic acid ester plasticizers such as trimellitate, tetrabutylpyromellitate, In the case of glycolate plasticizers such as lupyromelitate and tetraethylpyromellitate, triacetin, tributyrin, ethylphthalylethyl glycolate, methylphthalylethylglycolate, butylphthalylbutylglycolate, etc. Citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate and the like can be preferably used. Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  As the polyester plasticizer, a copolymer of a dibasic acid and a glycol such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid can be used. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid, and the like can be used. As glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more.

  The polyhydric alcohol ester plasticizer comprises an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid. Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, 2-n-butyl-2-ethyl- 1,3-propanediol, galactitol, mannitol, 3-methylpentane-1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol, and the like can be raised. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable. There is no restriction | limiting in particular as monocarboxylic acid used for polyhydric alcohol ester, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention. Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto. As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. It is more preferable that it is C1-C20, and it is especially preferable that it is C1-C10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid. Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laccelic acid, undecylenic acid, olein Unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid and arachidonic acid can be raised. Examples of preferable alicyclic monocarboxylic acid include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof. Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenyl carboxylic acid, naphthalene carboxylic acid, and tetralin carboxylic acid. Aromatic monocarboxylic acids or derivatives thereof can be raised. Particularly preferred is benzoic acid. The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably in the range of 300 to 1500, and more preferably in the range of 350 to 750. The larger one is preferable in terms of improvement in retention, and the smaller one is preferable in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified with carboxylic acid, or a part of the OH groups may be left as they are. These plasticizers are preferably used alone or in combination. The amount of these plasticizers used is preferably from 1 to 20% by mass, particularly preferably from 3 to 13% by mass, based on the cellulose ester, in terms of film performance, processability and the like.

  The addition amount of these plasticizers is 1-30 mass parts normally with respect to 100 mass parts of cellulose esters, Preferably it is 5-20 mass parts. If the amount of plasticizer used is too small, the plasticizing temperature is high, which is disadvantageous for workability, and if it is too large, there are problems such as bleeding from the film surface and reduced transparency. This is undesirable.

  The cellulose ester constituting the optical film of the present invention includes known antioxidants such as 2,6-di-t-butyl-4-methylphenol, 2,2'-dioxy-3,3'-di-t. -Butyl-5,5'-dimethylphenylmethane, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1,1,3-tris (2-methyl- 4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,2'-dioxy-3,3'-di-t-butyl-5,5'-diethylphenylmethane, 3,9-bis [1, -Dimethyl-2- [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl], 2,4,8,10-tetraoxpiro [5,5] undecane, tris ( 2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-) It can be stabilized by adding t-butyl-4-methylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, an ultraviolet absorber or the like.

  The addition amount of these antioxidants is 0.1-3 mass parts normally with respect to 100 mass parts of cellulose esters, Preferably it is 0.2-2 mass parts. If the amount of antioxidant used is too small, the effect of improving the durability is insufficient, and if it is too large, problems such as bleeding out from the film surface and reduced transparency occur. It is not preferable.

  In the optical film of the present invention, it is preferable to add a matting agent in order to facilitate transportability and winding.

  The matting agent is preferably as fine as possible. Examples of the fine particles include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, Examples thereof include inorganic fine particles such as magnesium silicate and calcium phosphate, and crosslinked polymer fine particles. Among these, silicon dioxide is preferable because it can reduce the haze of the film. In many cases, fine particles such as silicon dioxide are surface-treated with an organic substance, but such particles are preferred because they can reduce the haze of the film.

  Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes, silazane, siloxane and the like. The larger the average particle size of the fine particles, the greater the sliding effect, and the smaller the average particle size, the better the transparency. The average particle size of the secondary particles of the fine particles is in the range of 0.05 to 1.0 μm. The average particle size of the primary particles of preferable fine particles is preferably 5 to 50 nm, more preferably 7 to 14 nm. These fine particles are preferably used in the cellulose ester film in order to generate irregularities of 0.01 to 1.0 μm on the surface of the cellulose ester film. The content of the fine particles in the cellulose ester is preferably 0.005 to 0.3% by mass with respect to the cellulose ester.

  Examples of the fine particles of silicon dioxide include Aerosil 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600 manufactured by Nippon Aerosil Co., Ltd., preferably Aerosil 200V, R972. , R972V, R974, R202, R812. Two or more kinds of these fine particles may be used in combination. When using 2 or more types together, it can mix and use in arbitrary ratios. In this case, fine particles having different average particle sizes and materials, for example, Aerosil 200V or R972V and R812 can be used in a mass ratio of 0.1: 99.9 to 99.9: 0.1.

  Examples of the optical film of the present invention include U.S. Pat. Nos. 2,492,978, 2,739,070, 2,739,069, 2,492,977, and 2,336. 310, No. 2,367,603, No. 2,607,704, British Patent Nos. 64,071, 735,892, No. 45-9074, No. 49-4554, The film can be formed by referring to the methods described in JP 49-5614, JP 60-27562, JP 61-39890, and 62-4208.

  In the film forming process, the clip gripping portions at both ends of the cut film may be pulverized and reused as a film raw material of the same kind or as a film raw material of a different kind.

  The optical film of the present invention has a dimensional stability with a dimensional variation value of less than ± 2.0% at 80 ° C. and 90% RH, based on the dimensions of the film left at 23 ° C. and 55% RH for 24 hours. Yes, more preferably less than 1.0%, and even more preferably less than 0.5%. Furthermore, the width of the optical film of the present invention is preferably 1.6 to 4 m.

  The optical film of the present invention can be used for a protective film for a polarizing plate. When used as a protective film for a polarizing plate, the method for producing the polarizing plate is not particularly limited, and can be produced by a general method. The obtained optical film was treated with an alkali, and a polyvinyl alcohol film was immersed and stretched in an iodine solution, and a polarizer film was attached to both sides of the polarizer using a completely saponified aqueous polyvinyl alcohol solution on both sides of the polarizer. There is a method of combining, and at least one side is preferable from the viewpoint that the optical film which is the protective film for polarizing plate of the present invention can be directly bonded to the polarizer.

  Further, instead of the alkali treatment, easy-adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be applied to perform polarizing plate processing.

(Liquid crystal display device)
The polarizing plate of the present invention includes MVA (Multi-domain Vertical Alignment) mode, PVA (Patterned Vertical Alignment) mode, CPA (Continuous Pinweal Alignment) mode, OCB (Optical Compensated InP) Although it can be preferably used, it is not limited to a specific liquid crystal mode and the arrangement of polarizing plates.

  The polarizing plate of the present invention is used as a liquid crystal display device by laminating a known liquid crystal substrate, transparent electrode layer, liquid crystal alignment layer, gas barrier and the like. The liquid crystal display device using the polarizing plate of the present invention is used for a mobile phone, a digital information terminal, a pager (registered trademark), an in-vehicle liquid crystal monitor such as navigation, a light control panel, a display for OA equipment, a display for AV equipment, and the like. be able to.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited to a following example, unless the summary is exceeded. In the following, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

  Although the synthesis example of a cellulose ester is shown below, this invention is not limited to these.

(Synthesis Example 1) Synthesis of Cellulose Ester 1 70 parts of cellulose acetate (manufactured by Daicel Chemical Industries, Ltd., L-20, substitution degree 2.41) was added to the reactor, and 110 ° C., 4 hours, 4 Torr (about 1 Torr is about 1 Torr) 133 Pa) under reduced pressure. Thereafter, purging was performed with dry nitrogen, a reflux condenser was attached, 30 parts of ε-caprolactone and 67 parts of cyclohexanone that had been dried and distilled in advance were added, and the mixture was heated to 160 ° C. and stirred to dissolve cellulose acetate uniformly. To this reaction solution, 0.25 part of monobutyltin trioctylate was added and heated at 160 ° C. with stirring for 2 hours. Thereafter, the reaction solution was cooled to room temperature to terminate the reaction and obtain a reaction product. Furthermore, 10 parts of the reaction product was dissolved in 90 parts of chloroform, and then slowly dropped into 900 parts of a large excess of methanol, and the precipitated precipitate was filtered to remove the homopolymer of ε-caprolactone. . Furthermore, it heat-dried at 60 degreeC for 5 hours or more, and obtained the cellulose ester 1 which (epsilon) -caprolactone reacted with the cellulose acetate. And the primary structure of the cellulose ester obtained by < ¹ > H-NMR was analyzed. As a result, the average number of moles of ε-caprolactone reacted per mole of glucose unit was 0.86, the average degree of substitution was 0.12, and the average degree of polymerization was 7.4.

(Synthesis Example 2) Synthesis of Cellulose Ester 2 70 parts of cellulose acetate (L-20, substitution degree 2.41 manufactured by Daicel Chemical Industries, Ltd.) and 30 parts of L-lactide were added to the reactor, and 65 ° C, 12 hours. It dried under reduced pressure at 4 Torr. Thereafter, purging was performed with dry nitrogen, a reflux condenser was attached, 67 parts of cyclohexanone that had been dried and distilled in advance was added, and the mixture was heated to 160 ° C. and stirred to dissolve cellulose acetate uniformly. To this reaction solution, 0.25 part of monobutyltin trioctylate was added and heated at 160 ° C. with stirring for 2 hours. Thereafter, the reaction solution was cooled to room temperature to terminate the reaction and obtain a reaction product. Furthermore, 10 parts of the reaction product was dissolved in 90 parts of chloroform, and then slowly dropped into 900 parts of a large excess of methanol, and the precipitated precipitate was filtered off to remove the L-lactide homopolymer. . Furthermore, it heat-dried at 60 degreeC for 5 hours or more, and obtained the cellulose ester 2 which L-lactide reacted with the cellulose acetate. And the primary structure of the cellulose ester obtained by < ¹ > H-NMR was analyzed. As a result, the average number of moles of lactic acid units (lactic acid units) reacted per mole of glucose units was 0.85, the average degree of substitution DS was 0.22, and the average degree of polymerization was 3.9.

(Synthesis Example 3) Synthesis of Cellulose Ester 3 50 parts of cellulose acetate (manufactured by Daicel Chemical Industries, NAC, substitution degree 2.74) was added to the reactor, and dried under reduced pressure at 110 ° C. for 4 hours at 4 Torr. Thereafter, purging was performed with dry nitrogen, a reflux condenser was attached, 50 parts of ε-caprolactone and 67 parts of cyclohexanone that had been dried and distilled in advance were added, and the mixture was heated to 160 ° C. and stirred to dissolve cellulose acetate uniformly. To this reaction solution, 0.25 part of monobutyltin trioctylate was added and heated at 160 ° C. with stirring for 2 hours. Thereafter, the reaction solution was cooled to room temperature to terminate the reaction and obtain a reaction product. Furthermore, after dissolving 10 parts of the reaction product in 90 parts of chloroform, it was slowly dropped into 900 parts of a large excess of methanol, and the precipitated precipitate (graft) was separated by filtration. The coalescence was removed. Furthermore, it heat-dried at 60 degreeC for 5 hours or more, and obtained the cellulose ester 3 which (epsilon) -caprolactone reacted with the cellulose acetate. And the primary structure of the cellulose ester obtained by < ¹ > H-NMR was analyzed. As a result, the average number of moles of ε-caprolactone reacted per mole of glucose unit was 1.66, the average degree of substitution was 0.17, and the average degree of polymerization was 10.1.

(Synthesis Example 4) Synthesis of Cellulose Ester 4 20 parts of cellulose acetate (manufactured by Daicel Chemical Industries, Ltd., NAC, substitution degree 2.74) and 80 parts of L-lactide were added to a reactor, and 65 ° C., 24 hours, 4 Torr. And dried under reduced pressure. Thereafter, purging was performed with dry nitrogen, a reflux condenser was attached, and the mixture was heated to 140 ° C. and stirred to dissolve cellulose acetate uniformly. To this reaction liquid, 0.10 parts of tin octoate was added and heated at 140 ° C. with stirring for 1 hour. Thereafter, the reaction solution was cooled to room temperature to terminate the reaction and obtain a reaction product. Furthermore, 10 parts of the reaction product was dissolved in 90 parts of chloroform, and then slowly dropped into 900 parts of a large excess of methanol, and the precipitated precipitate was filtered off to remove the L-lactide homopolymer. . Furthermore, it heat-dried at 60 degreeC for 5 hours or more, and obtained the cellulose ester 4 which L-lactide reacted with the cellulose acetate. And the primary structure of the cellulose ester obtained by < ¹ > H-NMR was analyzed. As a result, the average number of moles of lactic acid units (lactic acid units) reacted per mole of glucose units was 14.1, the average degree of substitution was 0.23, and the average degree of polymerization was 60.5.
(Preparation of optical film-1)
(Preparation of optical film 1)
(Silicon dioxide dispersion)
Aerosil 972V (manufactured by Nippon Aerosil Co., Ltd.) 10 parts by mass (average primary particle diameter 16 nm, apparent specific gravity 90 g / liter)
90 parts by mass of ethanol or more was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. 88 parts by mass of methylene chloride was added to the silicon dioxide dispersion while stirring, and the mixture was stirred and mixed for 30 minutes with a dissolver to prepare a silicon dioxide dispersion dilution. Subsequently, it filtered with the fine particle dispersion | distribution dilution liquid filter 14 (Advantech Toyo Co., Ltd .: Polypropylene wind cartridge filter TCW-PPS-1N).

(Dope composition)
Cellulose ester (cellulose triacetate synthesized from linter cotton, degree of acetylation: 61.5%, Mw = 290000) 100 parts by mass Silicon dioxide dispersion 0.15 parts by mass Methylene chloride 430 parts by mass Ethanol 40 parts by mass Additive 2- a 8 parts by mass Here, the additive 2-a was completely dissolved with heating and stirring with methylene chloride in a sealed container, filtered, and added to the dope solution.

  The above was put into an airtight container, heated, stirred and completely dissolved, and Azumi Filter Paper No. No. 24 was used for filtration to prepare a dope solution.

  After forming the dope solution using a casting film forming apparatus, the dope solution was stretched 1.25 times in a direction perpendicular to the film transport direction in an atmosphere of 160 ° C. with a tenter stretching machine, and the width was 1.8 m. An optical film of 60 μm was obtained.

(Production of optical films 2 to 20)
Similarly to the optical film 1, optical films 2 to 20 were prepared using the resins and additives shown in Table 1. In addition, the additive was dissolved completely with heating and stirring with methylene chloride in a sealed container in the same manner as additive 2-a or 2-b, filtered, and added to the dope solution.

(Evaluation of foreign object failure)
About the optical film produced as mentioned above, the online defect inspection machine was installed just before the winding-up part of the belt casting film forming apparatus which is not shown in figure, and the number of the foreign materials more than 200 micrometers per 1 m < ² > film was measured.

  The evaluation results are shown in Table 1.

As a result, as shown in Table 1, it can be seen that foreign object failure is reduced by the present invention.

(Preparation of polarizing plate)
A 120 μm-thick polyvinyl alcohol film was immersed in an aqueous solution containing 1 part by mass of iodine, 2 parts by mass of potassium iodide, and 4 parts by mass of boric acid, and stretched 4 times at 50 ° C. to produce a polarizer. After saponifying the optical film 1-20 produced above on both surfaces of this polarizer, it bonded together using the polyvinyl alcohol-type adhesive agent, and produced the polarizing plates 101-120.

(Production of liquid crystal display device)
The polarizing plate was removed from a commercially available MVA liquid crystal display device (VL-1530S, manufactured by Fujitsu Limited), and instead the produced polarizing plates 101 to 120 were punched and pasted according to the size of the liquid crystal display device. About the produced MVA liquid crystal display device, after leaving a liquid crystal display device in a 60 degreeC80% RH thermostat for 24 hours, the occurrence condition of a frame failure was evaluated visually in the dark room. The frame failure was displayed in black on the entire surface, and the width that appeared bright along the outer periphery of the liquid crystal display device was measured.

  Table 2 shows the evaluation results of the frame failure.

  As a result, frame failure can be reduced by the present invention.

Claims (5)

A sugar ester compound having at least one furanose structure or a pyranose structure and esterifying all or part of the OH groups of the compound having the furanose structure or the pyranose structure bonded to 1 to 12, and at least the general formula (1) or An optical film comprising a cellulose ester having a repeating unit represented by (2).


(In the formula, A and B represent a divalent hydrocarbon group having 1 to 12 carbon atoms or a divalent hydrocarbon group having 1 to 12 carbon atoms substituted with a hydroxyl group, provided that A and B are the same. May be different.) The optical film contains a benzotriazole compound represented by the following general formula (3), a benzophenone compound represented by the general formula (4), or a compound containing a cyano group represented by the general formula (5). The optical film according to claim 1.

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

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

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X ¹ and X ² represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, an aromatic group. Represents a heterocycle.) The optical film according to claim 1, wherein a width of the optical film is 1.6 to 4 m. A polarizing plate comprising the optical film according to claim 1 on at least one surface of a polarizer. A liquid crystal display device comprising the polarizing plate according to claim 4 on at least one surface of a liquid crystal cell.