JP2002040232A - Optical film, polarizing plate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently provide an optical film using a UV absorbent which is excellent without causing defects such as sticking on a release roll or carrying roll, and to provide a polarizing plate or a display device which uses the above optical film. SOLUTION: The optical film contains a UV absorbent expressed by general formula 1. In formula, R11 is an oxygen atom, nitrogen atom, sulfur atom or a substituents on a benzene ring through a carbonyl group, R12 is a hydrogen atom, aliphatic group, aromatic group or heterocyclic group, each of R13 to R16 is a hydrogen atom, aliphatic group, aromatic group or heterocyclic group and groups R11 to R16 are not substituted by halogen atoms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical film used for optical applications, and particularly to a protective film for a polarizing plate used for a liquid crystal display device, a retardation film, a viewing angle widening film, and a plasma display. Various functional films such as anti-reflection film used,
The present invention relates to an optical film that can be used for various functional films used in an organic EL display and the like. More specifically, the present invention relates to an optical film containing a specific UV absorber, which is less colored during storage and excellent in productivity.

[0002]

2. Description of the Related Art In recent years, the development of higher definition, thinner and lighter notebook computers has been progressing. Along with this, the demand for higher performance and thinner protective films for liquid crystal polarizers has been increasing. As the protective film for a polarizing plate, generally, a cellulose ester film is widely used for reasons such as transparency and refractive index. However, simply forming the cellulose ester film into a thin film causes various problems.

That is, in a cellulose ester film conventionally used for a protective film for a polarizing plate, an ultraviolet absorber is used for the purpose of protecting a polarizer and a liquid crystal from ultraviolet rays. If this cellulose ester film is simply made thinner, it will not be possible to cut off ultraviolet rays sufficiently,
The amount of the ultraviolet absorber must be increased by the amount of the thin film.

[0004] With respect to ultraviolet absorbers, see JP-A-6-13.
Nos. 0226 and 7-11056 have been proposed.

[0005]

However, if the amount of the ultraviolet absorbers proposed in these methods is simply increased, the ultraviolet absorber adheres to the peeling roll and the transport roll in the cellulose ester film forming process, which causes a failure. It has been found that this causes a new problem that productivity is greatly reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an excellent ultraviolet absorber which is indispensable for a protective film for a polarizing plate and which does not have the defect that it does not adhere to the above-mentioned peeling roll or transport roll. An object of the present invention is to provide an optical film using an absorbent, and to provide a polarizing plate or a display device using the optical film.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies on an optical film containing an ultraviolet absorber which can solve the above-mentioned conventional problems. It has been found that the use of an ultraviolet absorber having the above structure and physical properties can improve the contamination of rolls, and completed the present invention. That is,
The above object of the present invention is achieved by the following means.

[0008] 1. An optical film comprising the ultraviolet absorbent represented by the general formula 1.

2. The molar extinction coefficient at 380 nm is 1
000 and the ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at 380 nm is 20
An optical film comprising the above ultraviolet absorber.

[0010] 3. 3. The optical film according to 2, wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber.

4. The optical film according to claim 3, wherein the benzotriazole-based ultraviolet absorber is represented by the general formula (2).

5. An optical film comprising the ultraviolet absorbent represented by the general formula (3).

6. The ultraviolet absorber has a molar extinction coefficient at 380 nm of 1000 or more and 380 n
6. The optical film according to 5, wherein the ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at m is 20 or more.

7. The optical device according to any one of items 1 to 6, further comprising silicon dioxide fine particles having a primary average particle diameter of 3 to 20 nm and an apparent specific gravity of 70 to 300 g / l. the film.

[8] The optical film according to any one of claims 1 to 7, wherein the optical film is a cellulose ester film.

9. 9. The optical film according to 8, wherein the cellulose ester film is a cellulose acetate propionate film.

10. Optical film thickness is 20-65μ
10. The optical film according to any one of 1 to 9, wherein m is m.

11. First optical film, polarizer, second
11. The polarizing plate having the optical film according to claim 1, wherein the first or second optical film is the optical film according to any one of 1 to 10. 11.

[12] In a display device using a polarizing plate,
A display device using the polarizing plate according to claim 11.

Hereinafter, the present invention will be described in more detail. (Ultraviolet absorber) In general formulas 1 and 3,
R ₁₁ and R ₃₁ each represent a group that is substituted on the benzene ring via an oxygen or nitrogen atom, a sulfur atom, or a carbonyl group.

Examples of the group which is substituted on the benzene ring via an oxygen atom include a hydroxyl group, an alkoxy group (for example, methoxy group, ethoxy group, t-butoxy group, 2-ethoxyethoxy group, etc.), an aryloxy group (for example, phenoxy group) Group, 2,4-di-t-amylphenoxy group, 4- (4-
Hydroxyphenylsulfonyl) phenoxy group, etc.), heterocyclic oxy group (eg, 4-pyridyloxy group, 2-hexahydropyranyloxy group, etc.), carbonyloxy group (eg, acetyloxy group, trifluoroacetyloxy group, pivaloyloxy group, etc.) , An aryloxy group such as a benzoyloxy group and a pentafluorobenzoyloxy group, etc.), a urethane group (eg, an alkylurethane group such as an N, N-dimethylurethane group, an N-phenylurethane group, an N- (p An aryl urethane group such as -cyanophenyl) urethane group, a sulfonyloxy group (e.g., an alkylsulfonyloxy group such as a methanesulfonyloxy group, a trifluoromethanesulfonyloxy group, an n-dodecanesulfonyloxy group, a benzenesulfonyloxy group; - an arylsulfonyloxy group such as toluenesulfonyloxy group) and others as mentioned,
An alkoxy group having 1 to 6 carbon atoms is preferred, and particularly an alkoxy group having 2 carbon atoms.
~ 4 alkoxy groups are preferred.

Examples of the group substituted on the benzene ring via a nitrogen atom include a nitro group, an amino group (for example, an alkylamino group such as a dimethylamino group, a cyclohexylamino group, and an n-dodecylamino group, an anilino group, and a p-t group). Arylamino groups such as -octylanilino group), sulfonylamino groups (e.g., methanesulfonylamino group, heptafluoropropanesulfonylamino group, alkylsulfonylamino group such as hexadecylsulfonylamino group, p-toluenesulfonylamino group, penta Arylsulfonylamino groups such as fluorobenzenesulfonylamino), sulfamoylamino groups (eg, alkylsulfamoylamino groups such as N, N-dimethylsulfamoylamino group,
An arylsulfamoylamino group such as an N-phenylsulfamoylamino group, an acylamino group (for example, an alkylcarbonylamino group such as an acetylamino group or a myristoylamino group, an arylcarbonylamino group such as a benzoylamino group), and a ureido group (for example. Examples thereof include an alkyl ureido group such as an N, N-dimethylamino ureide group, an aryl ureide group such as an N-phenyl ureide group, and an N- (p-cyanophenyl) ureide group, and an acylamino group is preferable.

Examples of the group substituted on the benzene ring via a sulfur atom include an alkylthio group (for example, methylthio group, t
-Octylthio group, etc.), arylthio group (eg, phenylthio group, etc.), heterocyclic thio group (eg, 1-phenyltetrazole-5-thio group, 5-methyl-1,3,4-oxadiazole-2-thio group, etc.) ), A sulfinyl group (for example, an alkylsulfinyl group such as a methanesulfinyl group and a trifluoromethanesulfinyl group, and an arylsulfinyl group such as a p-toluenesulfinyl group), and a sulfonyl group (for example, an alkylsulfonyl group such as a methanesulfonyl group and a trifluoromethanesulfonyl group) , And an arylsulfonyl group such as a p-toluenesulfonyl group), a sulfamoyl group (for example, a dimethylsulfamoyl group,
(Alkylsulfamoyl groups such as (2,4-di-t-amylphenoxy) butylaminosulfonyl group, and arylsulfamoyl groups such as a phenylsulfamoyl group). 4 ~
Twelve alkylsulfinyl groups are preferred.

Examples of the group substituted on the benzene ring via the carbonyl group include a carbonyl group (for example, an alkylcarbonyl group such as an acetyl group, a trifluoroacetyl group and a pivaloyl group, a benzoyl group, a pentafluorobenzoyl group, a 3,5- Arylcarbonyl groups such as di-t-butyl-4-hydroxybenzoyl group, etc.), oxycarbonyl groups (eg, methoxycarbonyl group, cyclohexyloxycarbonyl group, alkoxycarbonyl group such as n-dodecyloxycarbonyl group, phenoxycarbonyl group,
2,4-di-t-amylphenoxycarbonyl group, 1-
An aryloxycarbonyl group such as a naphthyloxycarbonyl group, and a heterocyclic oxycarbonyl group such as a 2-pyridyloxycarbonyl group and a 1-phenylpyrazolyl-5-oxycarbonyl group; a carbamoyl group (for example, a dimethylcarbamoyl group; Alkylcarbamoyl group such as 2,4-di-t-amylphenoxy) butylaminocarbonyl group, and arylcarbamoyl group such as phenylcarbamoyl group and 1-naphthylcarbamoyl group.

In the general formulas 1 and 3, R ₁₁ ,
The group represented by R ₃₁ is preferably a group substituted on the benzene ring via an oxygen atom, particularly preferably an alkoxy group having 1 to 12 carbon atoms, and more preferably an alkoxy group having 2 to 6 carbon atoms.

In the general formulas 1 and 3, R ₁₂ ,
R ₃₂ represents a hydrogen atom, an aliphatic group (eg, an alkyl group, an alkenyl group, an alkynyl group, etc.), an aromatic group (eg, a phenyl group, a p-chlorophenyl group, etc.), a heterocyclic group (eg, 2
-Tetrahydrofuryl group, 2-thiophenyl group, 4-imidazolyl group, indoline-1-yl group, 2-pyridyl group, etc.). R ₁₂ and R ₃₂ are preferably a hydrogen atom and an alkyl group.

In the general formulas 1 and 3, n is 1 to
Represents an integer up to 4, with 1 and 2 being preferred.

In the general formula 1, R _{13 to} R ₁₆ each independently represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, and specific substituents include those exemplified for R _12. Is mentioned. R ₁₃ and R ₁₅ are preferably a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, particularly preferably a branched alkyl group such as an i-propyl group, a t-butyl group and a t-amyl group. On the other hand, R ₁₄ and R ₁₆ are preferably a hydrogen atom.

The present inventors use an ultraviolet absorber having a structure having no halogen atom in the molecule and having a specific substituent represented by R _{11 to} R _{16 as} represented by the above general formula 1. By doing so, it was found that the roll contamination during transportation could be improved. However, as a result of further intensive studies, the use of an ultraviolet absorber having the following properties irrespective of the specific structure allows the use of an ultraviolet absorbent represented by the general formula 1. It has also been found that it is possible to improve the roll contamination during transportation in the same manner as the ultraviolet absorber to be used.

That is, the molar extinction coefficient at 380 nm is 1000 or more, and the ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at 380 nm is 2
By containing at least one UV absorber of 0 or more, roll contamination during transport can be improved, and an optical film with less pressing failure can be obtained.

Here, the pushing failure is a concave failure of about 30 to 500 μm on the surface of the optical film. Unlike a normal foreign substance failure, the failure nucleus is not observed even when the film is observed with a microscope or the like. It is.

The molar extinction coefficient at 380 nm is 100
When it is 0 or more, it indicates that the ultraviolet absorbing performance is good, and a sufficient effect to block ultraviolet light is obtained, and thus the problem that the optical film itself is colored yellow is also improved, The transparency of the film itself is improved.

As the ultraviolet absorber in the present invention, 3
It is preferable to use those having a molar extinction coefficient at 80 nm of 4000 or more, preferably 8000 or more, and more preferably 10,000 or more. If the molar extinction coefficient at 380 nm is less than 1000, a large amount of addition is required to obtain the desired UV absorption performance, and the transparency is significantly reduced due to an increase in haze or precipitation of an ultraviolet absorber. The strength tends to decrease.

As the above-mentioned ultraviolet absorber, for example, a salicylic acid-based ultraviolet absorber (phenyl salicylate, p-te
rt-butyl salicylate) or a benzophenone-based ultraviolet absorber (2,4-dihydroxybenzophenone,
2,2′-dihydroxy-4,4′-dimethoxybenzophenone, etc.), benzotriazole-based ultraviolet absorbers (2
-(2'-hydroxy-3'-tert-butyl-5 '
-Methylphenyl) -5-chlorobenzotriazole,
2- (2'-hydroxy-3 ', 5'-di-tert-
Butylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-tert-amyl-phenyl) benzotriazole, etc.), and a cyanoacrylate-based ultraviolet absorber (2'-ethylhexyl-2-)
Cyano-3,3-diphenyl acrylate, ethyl-2
-Cyano-3- (3 ', 4'-methylenedioxyphenyl) -acrylate, etc.), and triazine-based ultraviolet absorbers (2- (2'-hydroxy-4'-hexyloxyphenyl) -4,6-diphenyl) And the compounds described in JP-A-58-185677 and JP-A-59-149350.

Among the various types of known UV absorbers, the molar extinction coefficient at 380 nm is 100.
UV absorbers having a ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at 380 nm of not less than 0 are preferably used as an ultraviolet absorber for an optical film having the effects of the present invention. Can be When this ratio is less than 20, the coloring becomes large and it is not suitable for optical film applications.

That is, in order to suppress absorption of light near 400 nm, which is closer to the visible region, and to obtain a desired UV absorption performance,
In the present invention, it is preferable to contain an ultraviolet absorber having a performance capable of absorbing ultraviolet light as much as possible.

As the ultraviolet absorber used in the present invention, a benzotriazole-based ultraviolet absorber is preferred from the viewpoint of its own stability, and an ultraviolet absorber represented by the general formula 2 is particularly preferred.

In the general formula 2, R ₂₁ represents a group substituted on a benzene ring via a halogen atom (for example, a chlorine atom, a bromine atom or the like), an oxygen atom, a nitrogen atom or a sulfur atom. Oxygen atom, a nitrogen atom, or a substituent radicals on the benzene ring through a sulfur atom, the same groups as described in R ₁₁ of the general formula 1 is exemplified. When R ₂₁ is a halogen atom, a chlorine atom is preferred. R ₂₁ is preferably an alkoxy group having 1 to 12 carbon atoms, more preferably 2 to 6 carbon atoms.

R ₂₂ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. R ₂₂ is preferably a hydrogen atom or an alkyl group.

In the general formula 2, n represents an integer of 1 to 4. When a plurality of R ₂₁ or R ₂₂ are present depending on the number n, the plurality of R ₂₁ and R ₂₂ may be the same or different. Preferably n is 1 or 2.

In the general formulas 2 and 3, R_{twenty three}, R
_{twenty five}, R₂₆, R₃₃, R₃₅, R₃₆Are each independently a hydrogen atom, or
Represents a group that can be substituted on the benzene ring. R_{twenty three}, R_{twenty five}, R
₃₃, R₃₅Is a hydrogen atom or an alkyl having 1 to 12 carbons
A kill group is preferred, especially an i-propyl group, t-butyl
And a branched alkyl group such as a t-amyl group. R
₂₆, R₃₆Is preferably a hydrogen atom.

In the general formulas 2 and 3, R ₂₄ and R
₃₄ represents a group substituted on the benzene ring via an oxygen atom or a nitrogen atom. Specific substituents for R ₂₄ and R ₃₄ include the same substituents as those described on R ₁₁ in the general formula 1 which are substituted on the benzene ring via an oxygen atom or a nitrogen atom. R
_24, when R ₃₄ is a group substituting on the benzene ring via an oxygen atom, preferably an alkoxy group having 1 to 12 carbon atoms, in particular i- propoxy group, t-butoxy group, hexyloxy group and the like to the 2-ethyl Is preferred.
When R ₂₄ and R ₃₄ are groups that substitute on the benzene ring via a nitrogen atom, an acylamino group is preferred, and an N-alkylacylamino group is particularly preferred.

By using an ultraviolet absorber having a structure having no halogen atom in the molecule represented by the above general formula 3 and having a specific substituent represented by R _{31 to} R ₃₆ , In particular, roll contamination during transportation is improved. Even more surprisingly, the durability of the optical film itself is improved by using the ultraviolet absorbent represented by the general formula (3).

The method of adding the above-mentioned ultraviolet absorber to the optical film may be directly added, but in-line addition which is excellent in productivity is preferred. In the in-line addition, a small amount of a cellulose ester is preferably added to and dissolved in an organic solvent (eg, methanol, methylene chloride, etc.) in advance, and then added to the dope composition using an in-line mixer. The preferred amount of cellulose ester is solvent 1
1 to 10 parts by mass, more preferably 100 parts by mass,
It is 3 to 5 parts by mass. When a cellulose ester is added, the viscosity of the liquid containing the ultraviolet absorber increases, and it becomes easy to add a large amount in-line.

The amount of the above-mentioned ultraviolet absorber is not uniform depending on the kind of the compound and the conditions of use, but it is usually preferably 0.2 g to 2.0 g per 1 m ² of the optical film.
4 g to 1.5 g is more preferred, and 0.6 g to 1.0 g is particularly preferred.

The following are typical examples of the ultraviolet absorbent preferably used in the present invention, but the present invention is not limited thereto.

[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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The ultraviolet absorber and its intermediate used in the present invention can be synthesized with reference to known documents.
For example, U.S. Patent Nos. 3,072,585 and 4,02
8,331, 5,683,861; EP 86,300,416; JP-A-63-22775.
No. 5, 63-185969, Polymer Bu
lletin. V. 20 (2), 169-176 and C
Chemical Abstracts V.A. 109, N
o. 191389 and the like.

(Cellulose Ester) The cellulose ester used in the optical film of the present invention is preferably a lower fatty acid ester of cellulose. The lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms, for example, cellulose acetate, cellulose propionate, cellulose butyrate and the like, and JP-A-10-45804, 8- 2317
No. 61, U.S. Pat. No. 2,319,052 and the like, mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate can be used. Among the above, particularly preferred lower fatty acid esters of cellulose are cellulose triacetate and cellulose acetate propionate.

In the case of cellulose triacetate, from the viewpoint of film strength, those having a polymerization degree of 250 to 400 and an average acetylation degree (bound acetic acid amount) of 54.0 to 62.5% are preferably used, and more preferably. Has an average degree of acetylation of 5
8.0-62.5% cellulose triacetate.

The most preferred lower fatty acid ester of cellulose has an acyl group having 2 to 4 carbon atoms as a substituent. When the degree of substitution of an acetyl group is X and the degree of substitution of a propionyl group or a butyryl group is Y, It is a cellulose ester containing a cellulose ester satisfying the following formulas (I) and (II) at the same time.

Formula (I) 2.6 ≦ X + Y ≦ 3.0 Formula (II) 0 ≦ X ≦ 2.5 Among them, cellulose acetate propionate is particularly preferably used, and especially 1.9 ≦ X ≦ 2.5. And 0.
It is preferable that 1 ≦ Y ≦ 0.9. The portion not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by a known method.

As the cellulose ester, a cellulose ester synthesized from cotton linter, wood pulp, kenaf or the like can be used alone or as a mixture. If the releasability from the belt or drum becomes a problem, it is preferable to use a large amount of cellulose ester synthesized from cotton linter having good releasability from the belt or drum because the productivity is high. When a cellulose ester synthesized from wood pulp is mixed and used, the ratio of the cellulose ester synthesized from the cotton linter is preferably 40% by mass or more, since the effect of releasability becomes remarkable, and more preferably 60% by mass or more, It is most preferable to use the cotton linter alone from the viewpoint of the effect of peelability.

The polarizing film, which is a main component of the polarizing plate used in the present invention, is an element that transmits only light having a polarization plane in a certain direction, and a typical polarizing film currently known is a polyvinyl alcohol-based polarizing film. Polarizing films include polyvinyl alcohol-based films dyed with iodine and dichroic dyes. These are formed by forming a film of an aqueous polyvinyl alcohol solution and uniaxially stretching and dyeing the film, or dyeing the film and then uniaxially stretching the film, and then preferably performing a durability treatment with a boron compound.
A transparent plastic film, which is an optical film of the present invention, is laminated on the surface of the polarizing film as a protective film for a polarizing plate to form a polarizing plate.

A method for manufacturing an optical film will be described. The optical film of the present invention is obtained mainly by using a cellulose ester, and forming a film in which a solution containing an ultraviolet absorber and a dope solution in which the cellulose ester is dissolved are mixed and stirred in-line.

The dope solution in which the cellulose ester is dissolved in the present invention is a solution in which the cellulose ester is dissolved in a solvent (solvent). The dope solution contains a plasticizer and, if necessary, a plasticizer. Other additives can be added. The concentration of the cellulose ester in the dope solution is preferably from 10 to 30% by mass, more preferably,
18 to 20% by mass.

The solvents used in the present invention may be used alone or in combination, but it is preferable to use a mixture of a good solvent and a poor solvent from the viewpoint of production efficiency. More preferably, the mixing ratio of the good solvent and the poor solvent is The poor solvent is 30 to 5% by mass with respect to 70 to 95% by mass of the good solvent.

The good solvent and poor solvent used in the present invention include:
Those that dissolve the cellulose ester used alone are defined as good solvents, and those that swell or do not dissolve alone are defined as poor solvents. Therefore, a good solvent and a poor solvent vary depending on the amount of acetic acid bound to the cellulose ester. For example, when acetone is used as a solvent, a 55% cellulose acetate-bonded acetic acid becomes a good solvent, and the amount of bound acetic acid is 60%.
% Results in a poor solvent.

The good solvent used in the present invention includes organic halogen compounds such as methylene chloride and dioxolanes. Depending on the amount of acetic acid bonded to the cellulose ester, examples of the solvent that can be a good solvent or a poor solvent include acetone, methyl acetate, and ethyl acetate.

As the poor solvent used in the present invention, for example, methanol, ethanol, n-butanol, cyclohexane and the like are preferably used.

In preparing the above-mentioned dope solution, a general method can be used as a method for dissolving the cellulose ester, but a preferable method is to mix the cellulose ester with a poor solvent and wet or swell the solution. Further, there is a method of mixing with a good solvent. At this time, under pressure, the method of heating at a temperature not lower than the boiling point of the solvent at normal temperature of the solvent, and the solvent does not boil, and dissolving while stirring can prevent the generation of a massive undissolved substance called gel or mamaco, preferable.

Pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

The heating temperature after the addition of the solvent is preferably a temperature not lower than the boiling point of the solvent used and within a range not causing the solvent to boil, for example, preferably not lower than 60 ° C., particularly preferably in the range of 70 to 110 ° C. is there. The pressure is adjusted at the set temperature so that the solvent does not boil.

Next, the cellulose ester solution is filtered using a suitable filter medium such as filter paper. The filter material in the present invention preferably has a small absolute filtration accuracy in order to remove insolubles and the like, but if the absolute filter accuracy is too small, clogging of the filter material is likely to occur. For this reason, a filter medium having an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium having a range of 0.001 to 0.008 mm is more preferable, and a filter medium having a range of 0.003 to 0.006 mm is further preferable.

The material of the filter medium is not particularly limited, and a normal filter medium can be used. However, a plastic filter medium such as polypropylene or Teflon (registered trademark) or a metal filter medium such as stainless steel may cause fibers to fall off. Preferred.

Filtration of the dope solution can be carried out by a usual method, but a method of filtering under heating while heating at a temperature not lower than the boiling point of the solvent at normal pressure and not boiling the solvent, is performed before and after the filtration material. Differential pressure (hereinafter sometimes referred to as filtration pressure)
Is small and preferable. The preferred temperature range is 45 to
120 ° C., more preferably 45 to 70 ° C.
More preferably, it is in the range of 55 ° C.

The smaller the filtration pressure, the more preferable it is 1.6 × 10
It is preferably at most ⁶ Pa, more preferably at most 1.2 × 10 ⁶ Pa, even more preferably at most 1.0 × 10 ⁶ Pa.

After the dissolution, it is taken out of the container while cooling, or it is taken out of the container by a pump or the like, cooled by a heat exchanger or the like, and supplied to a film formation. The cooling temperature at this time may be cooled to room temperature, but it is more preferable to cool to a temperature lower by 5 to 10 ° C. than the boiling point and perform casting at that temperature because the viscosity of the dope solution can be reduced.

As the support in the casting step, a belt or drum-shaped stainless steel mirror-finished support is preferably used. The temperature of the support in the casting step can be cast in a general temperature range of 0 ° C. to a temperature lower than the boiling point of the solvent, but casting on the support at 0 to 30 ° C. causes the dope to gel. It is preferable because the peeling limit time can be shortened, and it is more preferable to cast on a support at 5 to 15 ° C. The separation time refers to the time during which the cast dope solution remains on the support at the limit of the casting speed at which a transparent and good flat optical film can be continuously obtained. It is preferable that the peeling limit time is short because the productivity is excellent.

The surface temperature of the support on the side to be cast (cast) is preferably 10 to 55 ° C., the temperature of the solution is preferably 25 to 60 ° C., and the temperature of the solution is equal to or higher than the temperature of the support. The temperature is preferably set to 5 ° C. or more.

The higher the temperature of the solution and the temperature of the support, the higher the drying speed of the solvent, which is preferable. However, if the temperature is too high, foaming or flatness may be deteriorated.

A more preferred range of the temperature of the support is 20.
~ 40 ° C, more preferred range of solution temperature is 35 ~ 45 ° C
It is.

The temperature of the support at the time of peeling is set to 10 to 40.
C., more preferably 15 to 30 ° C., because the adhesion between the optical film and the support can be reduced.

In order for the optical film at the time of production to exhibit good flatness, the amount of residual solvent when peeled from the support is 10%.
To 150% is preferable, and 80 to 150% is more preferable.
And particularly preferably 100 to 130%. The ratio of the good solvent contained in the residual solvent is preferably from 50 to 90%, more preferably from 60 to 90%, and particularly preferably from 70 to 80%.

The residual solvent amount can be measured by gas chromatography connected to a head space sampler. In the present invention, the measurement was performed under the following measurement conditions using a gas chromatography model 5890 SERISII manufactured by Hewlett-Packard Company and a headspace sampler HP7694 model.

Headspace Sampler Heating Condition: 12
0 ° C., 20 minutes GC introduction temperature: 150 ° C. Temperature rise: 40 ° C., hold for 5 minutes, then go to 100 ° C. (8 ° C./minute) Column: DB-WAX manufactured by J & W (0.32 mm inner diameter,
(Length: 30 m) In the present invention, the residual solvent amount is defined by the following formula.

Amount of residual solvent = (mass of solvent contained in optical film) / (mass of optical film after heat treatment) × 100
% The heat treatment when measuring the amount of residual solvent means that the optical film after measurement by gas chromatography is further heated to 115 ° C.
Represents that heat treatment is performed for one hour.

The peel strength at the time of peeling the optical film from the support is usually 196 to 245 N / m, but the content of the ultraviolet absorber per unit mass of the cellulose ester is large, and Since the optical film of the present invention, which is thinner than this, is likely to be wrinkled at the time of peeling, it is preferred that the optical film be peeled with a force within 167 N / m from the minimum peelable tension, and more preferably 137 N / m from the minimum tension. / M.

In the drying step of the optical film,
The optical film peeled from the support is further dried, and the amount of the residual solvent is preferably 3% by mass or less, more preferably 0.5% by mass or less.

In the optical film drying step, a method of drying while transporting the film by a roll hanging method or a pin tenter method is generally employed. For liquid crystal display members, it is preferable to dry while maintaining the width by a pin tenter method in order to improve dimensional stability. In particular, it is particularly preferable to maintain the width at a place where the amount of the residual solvent is large immediately after peeling off from the support, since the effect of improving the dimensional stability is further exhibited.

The means for drying the optical film is not particularly limited, and is generally performed using hot air, infrared rays, a heating roll, microwaves, or the like. It is preferable to use hot air in terms of simplicity. It is preferable that the drying temperature is divided into three to five stages in the range of 40 to 150 ° C., and the temperature is gradually increased.
It is more preferable to carry out in the range described above in order to improve dimensional stability.

In the present invention, the smaller the retardation R ₀ (nm) in the in-plane direction of the optical film formed as described above, the better. As the optical film of the present invention, one having a thickness of less than 1000 nm is appropriately used depending on the application. The polarizing plate protective film preferably has R ₀ of less than 20 nm, more preferably less than 10 nm. Particularly preferably, those having a thickness of 0 to 5 nm are used.

In the optical film of the present invention, the angle θ between the film forming direction (corresponding to the longitudinal direction) and the slow axis of the film is closer to 0 ° (longitudinal direction) or 90 ° (width direction). preferable. Here, θ is a narrow angle between the film forming direction and the slow axis.

More preferably, θ and the in-plane retardation R ₀ have the following relationship.

P ≦ 1−sin ² (2πθ / 180) · s
in ² (πR ₀ / λ) P is 0.999, and λ is a light wavelength of 590 nm at the time of three-dimensional refractive index measurement for obtaining R ₀ and θ. More preferably, when P is 0.9995, θ and R ₀ satisfy the above expression, and more preferably, P is 0.999
When it is 8, it is preferable that θ and R ₀ satisfy the above expression.

In the cellulose ester film of the present invention, the retardation Rt in the thickness direction is from 0 to 300 nm.
Is preferably used, more preferably 30 to 150 nm, and particularly preferably 40 to 120 nm. As Rt, a preferable value is appropriately used in accordance with the design of the liquid crystal display device.

Incidentally, R ₀ , Rt and θ can be obtained by the following method. Measurement of retardation value (Rt, R ₀ ) and slow axis angle Automatic birefringence meter KOBRA-21AD
H (manufactured by Oji Scientific Instruments) at 23.degree.
Under an environment of 5% RH, three-dimensional refractive index measurement is performed at a wavelength of 590 nm, and the slow axis angle θ and the refractive indexes Nx, Ny,
Find Nz. The retardation value Rt in the thickness direction and the retardation value R ₀ in the in-plane direction are calculated according to the following equations (1) and (2).

Formula (1) Rt value = ((Nx + Ny) / 2−Nz) × d Formula (2) R ₀ value = (Nx−Ny) × d In the formula, Nx is in the slow axis direction in the film plane. Refractive index, Ny
Represents the refractive index in the fast axis direction in the film plane, Nz represents the refractive index in the thickness direction of the film, and d represents the thickness (nm) of the film.

When the optical film of the present invention is used as a retardation plate (for example, １ ／ λ plate, １ ／ λ plate, etc.), R
Those having a value of ₀ to 100 to 500 nm are preferably used.
Is about 0 degrees (long direction), about 45 degrees, and about 90 degrees (width direction) is appropriately selected according to the application or method of use. For example, in a polarizing plate made by sandwiching a polarizer with two polarizing plate protective films, one of the polarizing plate protective films is a λλ plate, and the transmission axis direction of the polarizer and the retardation of the ４λ plate are used. A circularly polarizing plate can be obtained by arranging such that the phase axis direction is about 45 °.

The optical film of the present invention preferably contains a polymer other than the cellulose ester. The polymer used in the present invention is a polymer having a Mw of 400 to 5000 obtained by polymerizing a monomer, and includes a polymer called an oligomer. The weight average molecular weight Mw is 4
More preferably, it is from 400 to 2,000.
000 is more preferred.

The Mw / Mn of the polymer is not particularly limited, but is preferably in the range of 1 to 5, more preferably in the range of 2 to 5, and still more preferably in the range of 3 to 5.

The Mz / Mw of the polymer is not particularly limited, but is preferably in the range of 1 to 3, and is preferably in the range of 1 to 2.5.
Is more preferable.

Mw, Mn and Mz are GPC (Gel Pe)
It can be measured by an ordinary method by using an Rmeation Chromatography).

The amount of the polymer is not particularly limited, but is preferably 15 to 50% by mass, more preferably 15 to 45% by mass, and still more preferably 20 to 40% by mass based on the cellulose ester.

The type of the polymer used in the present invention is not particularly limited, and examples thereof include polyester, polyester ether, polyester urethane, polyurethane, vinyl polymer, acrylic acid polymer, methacrylic acid polymer, and copolymers thereof. Among these polymers, polyesters, polyester ethers and vinyl polymers are particularly preferred.

The type of polyester is not particularly limited, but for example, the following can be preferably used. Preferred polybasic acids include adipic acid, sebacic acid, phthalic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, 1,4-cyclohexanedicarboxylic acid, and combinations thereof. Examples of preferred polyhydric alcohols include ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol,
1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, Or a combination thereof. The terminal of the polymer may be modified with a monovalent acid or a monohydric alcohol.

The type of the polyester ether is not particularly limited. For example, a combination of the above polyester and an ether unit, a polyester ether obtained by polymerizing the above dibasic acid and an ether unit, and the like can be preferably used. The ether unit is not particularly limited,
For example, polytetramethylene ether glycol, polyethylene ether glycol, or a combination thereof can be used. The terminal of the polymer may be modified with a monovalent acid or a monohydric alcohol.

The type of the vinyl polymer is not particularly limited. For example, a vinyl polymer containing vinyl acetate can be preferably used. The vinyl polymer containing vinyl acetate may be a homopolymer of vinyl acetate or may be copolymerized with another monomer. The monomer used for the copolymerization is not particularly limited, and examples thereof include maleic acid ester, fumaric acid ester, vinyl chloride, vinyl alcohol, vinyl alcohol ester, acrylic acid ester, methacrylic acid ester and the like. Each monomer is preferably esterified with an acid or alcohol having an alkyl group having 1 to 4 carbon atoms or a benzene ring.

In the present invention, a low-molecular plasticizer may be added in addition to the polymer. The low-molecular plasticizer that can be used in the present invention is not particularly limited. For example, a phosphate plasticizer, a phthalate plasticizer, a glycolate plasticizer, and the like can be preferably used. Phosphate plasticizers include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like.Phthalate plasticizers include diethyl phthalate, dimethoxy Ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, dibenzyl phthalate, butyl phthalyl butyl glycolate as a glycolate plasticizer, ethyl phthalyl ethyl glycolate, methyl phthalyl Ethyl glycolate and the like can be preferably used. These plasticizers can be used alone or in combination of two or more.

The amount of the low-molecular plasticizer used depends on film performance,
From the viewpoint of processability and the like, 0 to 20
% By mass is preferred. For a liquid crystal display member, the content is more preferably 1 to 15% by mass, particularly preferably 2 to 12% by mass, from the viewpoint of dimensional stability.

The workability refers to the ease with which a base film or a liquid crystal display member is processed by slitting or punching. If the workability is poor, the cut surface becomes saw-toothed, and chips are generated. This is not preferable because it adheres to the surface and causes a foreign matter failure.

The optical film of the present invention is preferably used for a liquid crystal display member from the viewpoint of high dimensional stability and good ultraviolet cut performance. A liquid crystal display member is a member used for a liquid crystal display device, and includes, for example, a polarizing plate, a protective film for a polarizing plate, a retardation plate, a reflecting plate, a viewing angle widening film, an antiglare film, a non-reflective film, and reflection. Anti-film, anti-static film, brightness enhancement film and the like. Among the above descriptions, the optical film of the present invention is more preferably used in a polarizing plate, a protective film for a polarizing plate, a retardation plate, and a viewing angle widening film, which have strict requirements for dimensional stability.

Fine particles may be added to the optical film used in the present invention as a matting agent, if necessary. Among the fine particles used in the present invention, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, and hydrated calcium silicate. , Aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferred in that turbidity is reduced, and silicon dioxide is particularly preferred. The fine particles of silicon dioxide have a primary average particle diameter of 20 nm or less and an apparent specific gravity of 70.
Those having g / liter or more are preferred. The primary average particle size is preferably from 5 to 16 nm, more preferably from 5 to 12 nm. The smaller the average diameter of the primary particles, the lower the haze. The apparent specific gravity is preferably from 90 to 200 g / liter, more preferably from 100 to 200 g / liter. The larger the apparent specific gravity is, the higher the concentration of the dispersion can be made, and the haze and the aggregates are preferably improved.

The addition amount of the matting agent is 0.01 per m ^2.
To 1.0 g is preferable, 0.03 to 0.3 g is more preferable, and 0.04 to 0.1 g is most preferable.

The fine particles of silicon dioxide include, for example, Aerosil R972, R972V, R974, R812, 200,
200V, 300, R202, OX50, TT600
(These are manufactured by Nippon Aerosil Co., Ltd.) and can be used. Fine particles of zirconium oxide are commercially available, for example, under the trade names of Aerosil R976 and R811 (both manufactured by Nippon Aerosil Co., Ltd.).
Can be used.

Examples of the polymer include a silicone resin, a fluorine resin and an acrylic resin, and a silicone resin is preferable, and a polymer having a three-dimensional network structure is particularly preferable.
5, 108, 120, 145, 3120 and 240 (both manufactured by Toshiba Silicone Co., Ltd.) and can be used.

Of these, Aerosil 200V and Aerosil R972V are particularly preferred because of their great effect of lowering the coefficient of friction while keeping the turbidity of the optical film low.

(3) Manufacturing Method of Polarizing Plate The polarizing plate can be manufactured by a general method. For example, there is a method in which the optical film of the present invention is subjected to an alkali saponification treatment, and is immersed and stretched in an iodine solution, and bonded to both surfaces of the polarizing film using a completely saponified polyvinyl alcohol aqueous solution. The alkali saponification treatment refers to a treatment in which the cellulose ester film is immersed in a high-temperature strong alkaline solution in order to improve the wettability of the aqueous adhesive at this time and improve the adhesiveness.

In particular, it is preferable that the polarizing plate is formed of a first optical film, a polarizer, and a second optical film, and the first or second optical film is the above-described optical film of the present invention. . By using the first optical film or the second optical film as the optical film of the present invention, the polarizing film can be protected from ultraviolet rays. Further, it is preferable to use a polarizing plate made of the optical film of the present invention in a liquid crystal display device, since the liquid crystal cell can be protected from ultraviolet rays.

[0116]

EXAMPLES Hereinafter, the embodiments of the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. In the following, "parts" represents "parts by mass".

Table 1 shows the spectral absorption data of the ultraviolet absorbent used in the examples.

[0118]

[Table 1]

In Table 1, ε (380 nm) is 380
Represents the molar extinction coefficient in nm, ε (380 nm) /
ε (400 nm) represents the ratio of the molar extinction coefficient at 400 nm to the molar extinction coefficient at 380 nm.
The measurement of the spectral absorption was performed with a methylene chloride solvent.

The structures of Comparative UV-1 and Comparative UV-2 in the table are shown below.

[0121]

Embedded image

Example 1 <Preparation of Samples 1 to 11> (Silicon Oxide Dispersion) Aerosil 200V (manufactured by Nippon Aerosil Co., Ltd.) 10 parts (average primary particle diameter 12 nm, apparent specific gravity 100 g / liter) Ethanol 90 parts or more Was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Mentongorin. The liquid turbidity after dispersion is 93 pp
m.

(Preparation of Additive Liquid A) Ultraviolet-absorbing polymer Comparative UV-2 (described in Table 1) 10 parts Methylene chloride 100 parts The above was charged into a closed vessel, completely dissolved while heating and stirring, and filtered. did. To this, 10 parts of a silicon oxide dispersion was added with stirring, and the mixture was further stirred for 30 minutes.

(Preparation of dope solution A) Cellulose triacetate synthesized from linter cotton 85 parts Cellulose triacetate synthesized from wood pulp 15 parts Polyester of adipic acid-1,3 butylene glycol (Mw = 600) 11.5 parts Methylene 475 parts of chloride and 50 parts of ethanol were put into a closed container, and completely dissolved and filtered while heating and stirring to prepare a dope solution A.

(Film Forming Step) To 100 parts of the dope solution A, 2 parts of the additive solution A was added, and the mixture was sufficiently mixed with an in-line mixer (Toray static type in-tube mixer Hi-Mixer, SWJ) and filtered. Next, using a belt casting apparatus, the mixture was uniformly cast on a stainless steel band support at a temperature of 33 ° C. and a width of 1500 mm. The solvent was evaporated on the stainless steel band support until the residual solvent amount became 100%, and the peeling tension was 127.
Peeled from the stainless steel band support at N / m. The peeled cellulose triacetate film is 1300 mm
Slit to width and then 1.
The film was stretched by a factor of 05, and then dried while being conveyed by a number of rolls through a drying zone. The film was slit to a width of 1100 mm to obtain a cellulose triacetate film sample 1. At this time, the thickness of the cellulose triacetate film was 40 μm.

Comparative UV of UV absorber of coating solution A of sample 1
Samples 2 to 11 were prepared in the same manner except that the ultraviolet absorber as shown in Table 2 was used instead of -2.

<Evaluation> The obtained sample was evaluated according to the following measuring method. The results are shown in Table 2 below.

<< Measurement Method >> UV Performance Spectrophotometer U-3200
Using Hitachi (manufactured by Hitachi, Ltd.), the spectral absorption spectrum of the film was measured, the transmittance at 500 nm and 380 nm was determined, and the films were ranked as follows. The higher the transmittance at 500 nm, the better, and the lower the transmittance at 380 nm, the better. (500 nm transmittance) A: transmittance 92% or more B: transmittance 90% or more and less than 92% C ... transmittance 85% or more and less than 90% D ... transmittance less than 85% (transmission at 380 nm) A) Transmittance less than 3% B ... Transmittance 3% or more and less than 6% C ... Transmittance 6% or more and less than 10% D ... Transmittance 10% or more ・ Bright spot foreign matter Polarizing plate The two samples were placed in an orthogonal state (crossed Nicols), the sample was placed between them, the number of bright spot foreign substances (foreign substances that appeared as white spots) per 25 mm ² was measured with a microscope at 100 locations, and the average value was determined. . The microscope conditions at this time were a transmission light source at a magnification of 30 times. The smaller the number of bright spot foreign substances, the better the characteristics. -Durability The film sample was evaluated for YI before and after standing for 1000 hours in a high-temperature and high-humidity atmosphere of 80 ° C and 90% RH, and the YI change was classified into the following levels. The smaller the change, the better. (YI change) ・ ・ ・: Change is less than 0.3 ・ ・ ・: Change is 0.3 or more and less than 0.6 ・ ・ ・: Change is 0.6 or more and less than 1.0 X: Change is 1. 0 or more Note that the method for obtaining the YI is as follows: Spectrophotomet
er U-3200 (manufactured by Hitachi, Ltd.)
Y7 (Yellow) of the film specified in K7103
ness Index: yellowish index) is determined by the following equation.

YI = 100 (1.28X-1.06Z)
/ Y Here, X, Y and Z are tristimulus values of the light source color defined in JIS Z8701.

A: less than 1.0 B: 1.0 or more and less than 1.5 C: 1.5 or more Roll dirt: After preparing a 10,000 m cellulose ester film, it was peeled from the stainless steel band support. The degree of dirt on the first roll contacted by the film was visually observed and evaluated according to the following ranks. Note that A to C are levels at which production is continued, and D is a level at which production is interrupted to clean the rolls.

A: The roll is not dirty at all. B: The roll is slightly stained. C: The roll is completely stained. D: It is clearly seen that the roll is completely soiled.-Pushing failure At the time of producing a 10,000 m cellulose ester film, the film was sampled and 30 μm or more existing on 1 m ^{2 of the} obtained film was sampled. The number of pressed failures was counted and found. -Polarizing plate yield At the time of producing a 10,000 m cellulose ester film, a 1500 m roll of the raw material of the cellulose ester film was produced, and the alkali saponification treatment and the production of the polarizing plate described below were performed. The obtained polarizing plate was punched out to a size of 15 inches, and the appearance was visually inspected one by one. In the appearance inspection, a defective product was determined when three or more defects of 30 μm or more were present in one polarizing plate. The yield was determined by the following equation.

Yield (%) = (the number of good products / (the number of good products + the number of defective products)) × 100 (alkaline saponification treatment) Saponification step 2 mol / L-NaOH 50 ° C. for 90 seconds Rinse step Water 30 ° C. for 45 seconds Summing process 10% by mass HCl 30 ° C. 45 seconds Rinse step Water 30 ° C. 45 seconds Under the above conditions, the film sample was saponified, washed with water, neutralized, washed with water in this order, and then dried at 80 ° C. (Preparation of Polarizing Plate) A polyvinyl alcohol film having a thickness of 120 μm was immersed in 100 kg of an aqueous solution containing 1 kg of iodine and 4 kg of boric acid and stretched 6 times at 50 ° C. to form a polarizing film. Cellulose ester film samples which had been subjected to an alkali saponification treatment on both sides of the polarizing film were bonded to each other using a 5% aqueous solution of completely saponified polyvinyl alcohol as an adhesive to prepare a polarizing plate.・ Image quality 15 type TFT color liquid crystal display LA-1529
The polarizing plate made of HM (made by NEC) is peeled off, and the two polarizing plates prepared above are attached so as to sandwich the liquid crystal cell so that the polarizing axes of the polarizing plates do not change from the original, and are orthogonal to each other.
A 15-inch TFT color liquid crystal display was manufactured. One of the polarizing plates was subjected to anti-glare processing. For anti-glare processing, a working liquid in which 0.2 μm and 3.0 μm of silicon dioxide was dispersed in an acrylic ultraviolet curable resin was prepared, applied to a dry film thickness of 2 μm, and cured by an ultraviolet lamp. The anti-glare surface was attached so as to be the outermost surface of the liquid crystal display.

The liquid crystal display was displayed in white, and the image quality was visually evaluated based on the following criteria.

A: No unevenness of anti-glare processing
The screen is easy to see B: There is slight unevenness in anti-glare processing, and the screen is slightly invisible C: There is unevenness in anti-glare processing, and the screen is clearly hard to see

[0135]

[Table 2]

As is clear from Table 2, the samples using the ultraviolet absorbent according to the present invention are sufficiently suitable for practical use even when used as a polarizing plate. That is, there is an excellent effect that there is no defect such as non-adherence to the peeling roll and the transport roll while the ultraviolet absorbing performance is sufficient.
It is clear from the above that excellent effects can be obtained whether this is used as a polarizing plate or further as a liquid crystal display device.

[0137]

According to the present invention, a superior optical film is employed because it employs an excellent ultraviolet absorbent which has no defect that the ultraviolet absorbent is deposited on the peeling roll or the transport roll due to precipitation of the ultraviolet absorbent from the surface of the optical film. It has a remarkably excellent effect that it can be provided efficiently. In addition, when the optical film is used, it is possible to manufacture a polarizing plate or an excellent liquid crystal display device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G02B 5/30 G02B 5/30 F term (reference) 2H048 CA04 CA13 CA17 CA27 2H049 BA06 BA25 BA27 BB03 BB13 BB14 BB43 BB49 BB51 BB66 BC03 BC14 BC22 4F071 AA09 AB26 AC12 AE05 AE17 AH12 BA03 BB02 BC01 BC12 4J002 AB021 BF022 BG042 BG052 CF032 CF092 CK022 DE097 DE137 DE147 DE237 DH047 DJ007 DJ017 DJ037 DJ047 EU176 FD017FD020

Claims (12)

[Claims] 1. An optical film comprising an ultraviolet absorbent represented by the following general formula 1. Embedded image In the formula, R ₁₁ represents an oxygen atom, a nitrogen atom, a sulfur atom, or a group substituted on a benzene ring via a carbonyl group;
₁₂ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, each of R ₁₃ to R _16, represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group. Groups represented by R ₁₁ to R ₁₆ may have substituents, but not be substituted with halogen atoms. n represents an integer from 1 to 4. 2. A compound having a molar extinction coefficient at 380 nm of 10
An optical film comprising an ultraviolet absorber having a molar extinction coefficient at 400 nm to a molar extinction coefficient at 380 nm of not less than 00 and not less than 20. 3. The optical film according to claim 2, wherein the ultraviolet absorber is a benzotriazole-based ultraviolet absorber. 4. The optical film according to claim 3, wherein the benzotriazole-based ultraviolet absorber is represented by the following general formula 2. Embedded image In the formula, R ₂₁ represents a group substituted on the benzene ring via a halogen atom, an oxygen atom, a nitrogen atom, or a sulfur atom;
₂₂ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, a R _23, R ₂₅ and R ₂₆ each independently represent a hydrogen atom, or a group substitutable on the benzene ring, R ₂₄ is Oxygen atom,
Or a group substituted on a benzene ring via a nitrogen atom. n represents an integer from 1 to 4. 5. An optical film comprising an ultraviolet absorber represented by the following general formula 3. Embedded image In the formula, R ₃₁ represents an oxygen atom, a nitrogen atom, a sulfur atom, or a group substituted on a benzene ring via a carbonyl group;
₃₂ represents a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group, R _33, R ₃₅ and R ₃₆ each independently represent a hydrogen atom, or a group substitutable on the benzene ring, R ₃₄ is Oxygen atom,
Or a group substituted on a benzene ring via a nitrogen atom. n represents an integer from 1 to 4. 6. The ultraviolet absorbent according to claim 1, wherein said ultraviolet absorber has a molar extinction coefficient at 380 nm of 1000 or more, and 380 nm
6. The optical film according to claim 5, wherein a ratio of a molar extinction coefficient at 400 nm to a molar extinction coefficient in the above is 20 or more. 7. A primary average particle diameter of 3 to 20 nm,
7. The composition according to claim 1, further comprising silicon dioxide fine particles having an apparent specific gravity of 70 to 300 g / liter.
The optical film according to any one of the above. 8. The optical film according to claim 1, wherein the optical film is a cellulose ester film. 9. The optical film according to claim 8, wherein the cellulose ester film is a cellulose acetate propionate film. 10. The optical film has a thickness of 20 to 65 μm.
The optical film according to any one of claims 1 to 9, wherein 11. A polarizing plate having a first optical film, a polarizer, and a second optical film, wherein the first or second optical film is the optical film according to any one of claims 1 to 10. A polarizing plate, comprising: 12. A display device using a polarizing plate, wherein the polarizing plate according to claim 11 is used.