KR20140091200A - Optical film - Google Patents

Abstract

The present invention relates to an optical film and to an optical film with high retardation and excellent water vapor permeability. The present invention provides the optical film with high retardation optical properties and excellent water vapor permeability. Also, the present invention provides the optical film with a haze reduced after stretching, compared to a haze before stretching.

Description

Optical film {OPTICAL FILM}

The present invention relates to an optical film, and relates to an optical film having high retardation and excellent moisture permeability.

A cellulose acetate film having high strength and excellent flame retardancy is used in various photographs or optical materials. The cellulose acetate film has a lower optical anisotropy compared to other polymer films and provides a relatively low retardation. Therefore, it is used in a polarizing plate or the like.

In the VA (Vertical Alignment) mode, transparent electrodes are formed on the upper and lower panels. However, unlike other modes, this mode uses a liquid crystal having a negative dielectric anisotropy and is vertically oriented, so that a liquid crystal director is rearranged by an applied electric field. Since the polarizing plate is attached to the outer surface of the upper and lower plates so that the polarizing plate is perpendicular to the polarizing plate, the polarizing plate is completely dark when the electric field is not applied in the initial alignment direction. When the electric field is applied, do. The optical compensation film of such a VA mode liquid crystal display device is required to have a high optical anisotropy, that is, a high retardation.

In particular, when the retardation in the thickness direction is high, the viewing angle and the contrast in the VA mode are effectively improved.

Additives that can be used in cellulose acetate films to improve their performance are known. Conventionally known compounds include a retardation increasing agent, which is a retardation increasing agent composed of a discotic compound. The retardation enhancer disclosed in Japanese Patent Application Laid-Open No. 2001-166144 (Patent Document 1) is a discotic compound, and as an example thereof, a compound having a structure including 1,3,5-triazine ring or porphyrin skeleton is disclosed . However, the conventional cellulose acetate film containing a retardation enhancer has a drawback that the haze increases during stretching, thereby adding a haze reducing agent separately, or a compatibility with cellulose acetate, resulting in bleeding out over time. Such a patent is disclosed in Japanese Patent Application Laid-Open No. 2009-223305 (Patent Document 2).

In recent years, a panel having a small display characteristic due to environmental humidity has been required as the screen size becomes larger.

Japanese Patent Application Laid-Open No. 2001-166144 Japanese Unexamined Patent Application Publication No. 2009-223305

The present invention aims to provide an optical film which exhibits a high phase difference optical special property and at the same time has excellent moisture permeability.

In addition, the present invention aims to provide an optical film having characteristics such that the haze after stretching is reduced as compared with the haze before stretching.

The present invention also provides an optical compensation sheet comprising the optical film, an optical filter for stereoscopic image, a polarizing plate, and a liquid crystal display device.

An object of the present invention is to provide a liquid crystal display device which is excellent in viewing angle characteristics and has less variation in display characteristics due to environmental humidity.

The present invention relates to an optical film having high retardation in the film thickness direction in the film and having reduced haze after stretching compared with the haze before stretching, and relates to an optical film excellent in moisture permeability.

The inventors of the present invention have studied to produce the above-mentioned film, and as a result, it is possible to increase the retardation in the thickness direction, and to achieve the above object in the case of producing a film using a compound that does not increase moisture permeability and haze And completed the present invention.

In the optical film according to the present invention, the retardation in the thickness direction in the film after stretching satisfies the following formula (1), and the haze change amount (DELTA H _ei ) satisfies the following formula (2).

[Formula 1]

50? Rth (550)? 500

0.8? Rth (400) / Rth (700)? 1.5

(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm.

[Formula 2]

-3 ≤ _{ΔH ei} ≤ 0

(Where H _ei = H _e - H _i , H _e is the haze value (%) after stretching, and H _i is the haze value (%) before stretching.

The optical film according to the present invention may be one used for an optical compensation sheet, an optical filter for stereoscopic image, a polarizing plate, and a liquid crystal display device.

A liquid crystal display device including the optical film according to the present invention is also included in the scope of the present invention.

The optical film according to the present invention exhibits high retardation and is excellent in optical properties and at the same time has an excellent moisture permeability.

The cellulose acylate film according to the present invention is more preferable as a film for optical use because the haze after stretching is reduced, the non-uniformity is reduced, and the light leakage is less than that before stretching.

Hereinafter, one embodiment of the optical film of the present invention will be described, but the present invention is not limited to the following embodiments.

In one embodiment of the optical film of the present invention, in the optical film, the retardation in the thickness direction in the film after stretching satisfies the following formula (1) and the haze change amount (DELTA H _ei ) satisfies the following formula (2).

[Formula 1]

50? Rth (550)? 500

0.8? Rth (400) / Rth (700)? 1.5

(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm.

[Formula 2]

-3 ≤ _{ΔH ei} ≤ 0

(Where H _ei = H _e - H _i , H _e is the haze value (%) after stretching, and H _i is the haze value (%) before stretching.

In one embodiment of the optical film of the present invention, the total light transmittance after stretching is 89 to 93%, and the total light transmittance change amount (DELTA TT) satisfies the following formula (3).

[Formula 3]

0.1?? TT? 3

TT _e is the total light transmittance value (%) after stretching, and TT _i is the total light transmittance value (%) before stretching.) In the above formula,? TT = TT _e -TT _i ,

In one embodiment of the optical film of the present invention, the optical film may have a moisture permeability of 30,000 to 60,000 g · m / m < 2 >

In one embodiment of the optical film of the present invention, the optical film may have a haze of 0.2 to 7% before stretching and a haze of 0 to 1% after stretching.

In one embodiment of the optical film of the present invention, the degree of drawing of the optical film may be 0 to 100%, and the thickness after stretching may be 20 to 140 탆.

In one embodiment of the optical film of the present invention, the optical film satisfies Re (?) And Rth (?) Before stretching and Re (?) And Rth .

[Formula 4]

0? Re (550)? 50

0? Rth (550)? 250

0.8? Rth (400) / Rth (700)? 1.5

[Formula 5]

20? Re (550)? 300

50? Rth (550)? 300

0.8? Rth (400) / Rth (700)? 1.5

(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm.

In one embodiment of the optical film of the present invention, the optical film may include a compound containing one aromatic ring as a mother nucleus and containing at least one ester (-COO-) group in the molecule.

In one embodiment of the optical film of the present invention, the optical film may include a compound having a cinnamate structure as a mother nucleus.

In one embodiment of the optical film of the present invention, the optical film may contain 1 to 15% by weight of a compound having a cinnamate structure as a mother nucleus.

In one embodiment of the optical film of the present invention, the optical film may comprise at least one compound selected from the following general formula (1).

[Chemical Formula 1]

(Wherein n is an integer selected from 1 to 3,

R ₁ is selected from the group consisting of hydrogen (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, heteroatom containing a heteroatom selected from N, ₃ -C ₂₀₎ cycloalkyl is selected from alkyl of said R _1, alkenyl, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, (C ₃ - C ₂₀₎ and one or both selected from cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino be further substituted,

에서 선택되고, Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, 상기 R₅는 (C₁-C₁₀)알킬, (C₁-C₁₀)알콕시에서 선택된다.)Each R 'is independently selected from the group consisting of hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

And R ₅ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy.

In one embodiment of the optical film of the present invention, the compound of formula (1) may be selected from the following formula (2).

(2)

Wherein R ₁ comprises a heteroatom selected from hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, N, O, S, heteroaryl Al (C ₃ -C ₂₀₎ cycloalkyl is selected from alkyl, alkenyl alkyl, seen in the R _1, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, which, (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃ and R ₄ are each independently selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl containing heteroatoms, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅ is (C ₁ -C ₁₀₎ are selected from alkyl, (C ₁ -C ₁₀₎ alkoxy,

And n is 1 or 2.)

In one embodiment of the optical film of the present invention, the compound of formula (2) may be selected from the following formulas (3) and (4).

(3)

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃₁ and R ₄₁ are each independently selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl containing heteroatoms, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,

[Chemical Formula 4]

(C ₃ -C ₂₀ ) cycloalkyl comprising a heteroatom selected from N, O and S, wherein R ₁₂ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₃ -C ₂₀ ) is selected from cycloalkyl, wherein R ₁₂ is alkyl, cycloalkyl, heterocycloalkyl (C ₁ -C ₁₀₎ alkyl, (C ₃ -C ₂₀₎ cycloalkyl, halogen, nitro, cyano, hydroxy, amino, One or more selected from imino may be further substituted,

Wherein R ₂₂ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, .

In one embodiment of the optical film of the present invention, the compound of formula (3) may be selected from the following formulas (5) to (7).

[Chemical Formula 5]

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택된다.)Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

.

[Chemical Formula 6]

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃₁ is a heteroatom containing a heteroatom selected from hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,

(7)

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃₁ is a heteroatom containing a heteroatom selected from hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >

에서 선택되고, Wherein R ₄₁ comprises a heteroatom selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, heterocyclic (C ₃ -C ₂₀₎ cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,

In one embodiment of the optical film of the present invention, in the general formula (5)

Wherein R ₁₁ is selected from (C ₁ -C ₅ ) alkyl, (C ₃ -C ₁₂ ) cycloalkyl, hetero (C ₃ -C ₁₂ ) cycloalkyl comprising a heteroatom selected from N, O, S,

에서 선택되는 것일 수 있다.It said alkyl, cycloalkyl, heterocycloalkyl of R ₁₁ is (C ₁ -C ₅₎ alkyl, (C ₃ -C ₁₂₎ cycloalkyl and alkyl may be further substituted,

. ≪ / RTI >

In one embodiment of the optical film of the present invention, the above-mentioned formula (5) may be selected from the following compounds.

In one embodiment of the optical film of the present invention, in the above formula (6)

Wherein R ₁₁ is hydrogen, (C ₁ -C ₅₎ alkyl, (C ₃ -C ₁₂₎ is selected from cycloalkyl, the R ₁₁ is alkyl, cycloalkyl (C ₁ -C ₅₎ alkyl, (C ₃ - Lt; / RTI > _C12 ) cycloalkyl,

Wherein R < ₂₁ > is hydrogen,

에서 선택되고, Wherein R ₃₁ is selected from the group consisting of hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy, nitro, cyano, amino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy.

In one embodiment of the optical film of the present invention, the above-mentioned formula (6) may be selected from the following compounds.

In one embodiment of the optical film of the present invention, in the general formula (7)

Wherein R ₁₁ is selected from hydrogen, (C ₁ -C ₅ ) alkyl,

Wherein R < ₂₁ > is hydrogen,

Wherein R ₃₁ is selected from hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy,

Wherein R ₄₁ is selected from hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy.

In one embodiment of the optical film of the present invention, the above-mentioned formula (7) may be selected from the following compounds.

In one embodiment of the optical film of the present invention, the compound of Formula 4 may be selected from the following compounds.

In one embodiment of the optical film of the present invention, the optical film may be based on a cellulose acylate resin.

In one embodiment of the optical film of the present invention, the cellulose acylate resin is a cellulose acylate resin in which all or a part of the hydrogen atoms of the hydroxyl groups existing at the second, third, and sixth positions of the glucose unit constituting the cellulose are acetyl group, , Butyryl group, and may have a degree of substitution of 2.0 to 3.0 according to ASTM D-817-91.

In one embodiment of the optical film of the present invention, the optical film may comprise 1 to 20 parts by weight of at least one compound selected from the following formula (1) based on 100 parts by weight of the cellulose acylate resin.

[Chemical Formula 1]

(Wherein n is an integer selected from 1 to 3,

R ₁ is selected from the group consisting of hydrogen (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, heteroatom containing a heteroatom selected from N, ₃ -C ₂₀₎ cycloalkyl is selected from alkyl of said R _1, alkenyl, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, (C ₃ - C ₂₀₎ and one or both selected from cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino be further substituted,

에서 선택되고, Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, 상기 R₅는 (C₁-C₁₀)알킬, (C₁-C₁₀)알콕시에서 선택된다.)Each R 'is independently selected from the group consisting of hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

And R ₅ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy.

In one embodiment of the optical film of the present invention, the optical film may be one used for an optical compensation sheet, an optical filter for stereoscopic image, a polarizing plate, and a liquid crystal display device.

One aspect of the optical compensatory sheet according to the present invention includes an optically anisotropic layer on at least one side of the optical film, and the optically anisotropic layer may contain a discotic compound subjected to a hybrid alignment treatment.

One aspect of a polarizing plate according to the present invention includes a polarizer; And at least one of the optical film and the optical compensation sheet. Wherein the optical compensatory sheet comprises an optically anisotropic layer on at least one side of the optical film and the optically anisotropic layer contains a discotic compound subjected to hybrid orientation treatment.

One aspect of the liquid crystal display device according to the present invention is a liquid crystal cell comprising: a liquid crystal cell; And a polarizing plate disposed on at least one side of the liquid crystal cell. Wherein the polarizer comprises a polarizer; And at least one of the optical film and the optical compensation sheet. In addition, the optical compensation sheet may include an optically anisotropic layer on at least one side of the optical film, and the optically anisotropic layer may contain a discotic compound subjected to a hybrid alignment treatment.

Hereinafter, the configuration of the present invention will be described in more detail.

In the present invention, the optical compensatory sheet is defined as using the optical film according to the present invention as a support and is essentially given an optical compensation function. The optical compensation sheet according to the present invention preferably includes the function of a transparent protective film as a protective function of a polarizing plate.

The optical film according to the present invention may be made of a transparent resin, and more specifically, a cellulose acylate resin may be used as a base resin.

The cellulose acylate resin used in the present invention is an ester of cellulose and acetic acid. The cellulose acylate resin used in the present invention is an ester of cellulose and acetic acid in which all or a part of the hydrogen atoms of the hydroxyl groups existing at the second, third and sixth positions of the glucose unit constituting cellulose are acetyl group, A butyryl group, and the like. More preferably, all or a part of the hydrogen atoms of the hydroxyl groups existing at the second, third and sixth positions of the glucose unit constituting the cellulose may be substituted with an acetyl group. Specifically, it includes, for example, diacetyl cellulose, triacetyl cellulose and the like.

The degree of substitution of the cellulose acylate resin is not limited, but is preferably 2.7 or more, and more preferably 2.7 to 3.0. The degree of substitution can be measured according to ASTM D-817-91.

The molecular weight range of the cellulose acylate resin is not limited, but the weight average molecular weight is preferably in the range of 200,000 to 350,000. The molecular weight distribution of the cellulose acylate resin is preferably Mw / Mn (Mw is weight average molecular weight, Mn is number average molecular weight) is 1.4 to 1.8, more preferably 1.5 to 1.7.

The optical film according to the present invention is preferably produced by a solvent cast method using a cellulose acylate dope solution. In the solvent cast method, a solution (dope) in which a cellulose acylate resin is dissolved in a solvent is cast on a support, and the solvent is evaporated to form a film.

As the raw material of the cellulose acylate doping solution, it is preferable to use cellulose acylate particles. At this time, 90 weight% or more of the cellulose acylate particles preferably have an average particle diameter of 0.5 to 5 mm. It is also preferable that at least 50% by weight of the cellulose acylate particles used has an average particle diameter of 1 to 4 mm.

It is preferable that the cellulose acylate particles have a shape as close to a sphere as possible, and that the cellulose acylate particles are dried to a water content of 2% by weight or less, more preferably 1% by weight or less, Do.

In the cellulose acylate dope solution used in the solvent casting method, additives such as plasticizers, ultraviolet inhibitors, deterioration inhibitors, fine particles, exfoliating agents, infrared absorbers, and optical anisotropy control agents may be added Can be added. The specific kind of such additives can be used without limitation as long as they are commonly used in the field, and the content thereof is preferably used within a range that does not deteriorate the physical properties of the film. The timing of adding the additives depends on the type of additive. A step of adding an additive to the end of the doping treatment may be performed.

The plasticizer is used to improve the mechanical strength of the film. When a plasticizer is used, the drying time of the film can be shortened. As the plasticizer, any conventionally used plasticizer can be used without limitation, and examples thereof include carboxylic acid esters selected from phosphoric acid esters and phthalic acid esters or citric acid esters. Examples of phosphoric acid esters include triphenyl phosphate (TPP), biphenyl diphenyl phosphate, and tricresyl phosphate (TCP). Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethylhexyl phthalate have. Examples of citric acid esters include o-acetyltriethyl citrate (OACTE) and o-acetyl tributyl citrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methyl acetyl ricinoleate, dibutyl sebacate and various trimellitic acid esters. Preferably, phthalate esters (DMP, DEP, DBP, DOP, DPP, DEHP) plasticizers are used. The plasticizer is used in an amount of 2 to 20 parts by weight, more preferably 5 to 15 parts by weight, based on 100 parts by weight of the cellulose acylate resin.

The UV inhibitor may be a hydroxybenzophenone compound, a benzotriazole compound, a salicylic ester compound, or a cyanoacrylate compound. The amount of the ultraviolet ray inhibitor is preferably 0.1 to 3 parts by weight, more preferably 0.5 to 2 parts by weight based on 100 parts by weight of the cellulose acylate resin.

As the deterioration preventing agent, for example, an antioxidant, a peroxide releasing agent, a radical inhibitor, a metal deactivator, an oxygen scavenger, and a photostabilizer (hindered amine) can be used. Particularly preferred examples of the deterioration inhibitor include butylated hydroxytoluene (BHT) and tribenzylamine (TBA). The amount of the deterioration inhibitor is 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the cellulose acylate resin.

The fine particles are added in order to keep the film in curl suppression, transportability, prevention of adhesion in a roll form, or good maintenance of the film, and any of inorganic compounds and organic compounds may be used. Examples of the inorganic compound include silicon compounds, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strontium oxide, antimony oxide, tin oxide, tin antimony, calcium carbonate, talc, Clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate are preferable, and an inorganic compound containing silicon and zirconium oxide are more preferably used. The fine particles have an average primary particle diameter of 80 nm or less, preferably 5 to 80 nm, more preferably 5 to 60 nm, and particularly preferably 8 to 50 nm. If the average primary particle diameter exceeds 80 nm, the surface smoothness of the film is impaired.

If necessary, an optical anisotropy adjusting agent, a wavelength dispersion adjusting agent and the like may further be added. Such additives can be used without limitation as long as they are conventionally used in the field.

The cellulose acylate dope solution for producing the optical film according to the present invention contains a compound containing one aromatic ring as a mother nucleus and containing at least one ester (-COO-) group in the molecule, The retardation, the moisture permeability, the haze, and the transmittance can be achieved. The optical film of the present invention is made into a film using a dope solution containing the above compound, whereby the compound of Formula 1 is present inside the film.

More specifically, the compound is preferably a compound containing a cinnamate structure as a mother nucleus. It is preferable that the compound is contained in the film in an amount of 1 to 15% by weight, thereby achieving a desired retardation, moisture permeability, haze and transmittance have. Preferably 2 to 10 parts by weight, more preferably 4 to 6 parts by weight. When the content is less than 1% by weight, the effect is insignificant, and when it is used in excess of 15% by weight, bleeding occurs to increase the haze and cause a change in the optical properties of the film. More specifically, the compound may be any one or more compounds selected from the following formula (1).

[Chemical Formula 1]

(Wherein n is an integer selected from 1 to 3,

R ₁ is selected from the group consisting of hydrogen (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, heteroatom containing a heteroatom selected from N, ₃ -C ₂₀₎ cycloalkyl is selected from alkyl of said R _1, alkenyl, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, (C ₃ - C ₂₀₎ and one or both selected from cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino be further substituted,

에서 선택되고, Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, 상기 R₅는 (C₁-C₁₀)알킬, (C₁-C₁₀)알콕시에서 선택된다.)Each R 'is independently selected from the group consisting of hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

And R ₅ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy.

The compound of the formula (1) of the present invention is a rod-like structure in which a double bond group is connected to one aromatic ring, and the retardation value (Rth) in the thickness direction of the optical film can be increased because it is oriented horizontally in the film. The effect of reducing the haze upon stretching can be obtained. Therefore, the viewing angle and the contrast of the optical film can be improved. The optical film according to the present invention can be suitably used for a VA mode liquid crystal display device.

 The substituents comprising alkyl, alkoxy and other alkyl moieties described in the present invention include both linear and branched forms and alkenyl includes both linear or branched forms containing from 2 to 8 carbon atoms and containing at least one double bond .

The (C3-C20) cycloalkyl described in the present invention includes both saturated monocyclic or saturated bicyclic ring structure forms having 3 to 20 carbon atoms. As well as various cyclic hydrocarbons such as substituted or unsubstituted adamantyl or substituted or unsubstituted (C7-C20) bicycloalkyl.

The hetero (C3-C20) cycloalkyl described in the present invention contains 1 to 3 heteroatoms selected from N, O, S as saturated cyclic hydrocarbon skeletal atoms and the remaining saturated monocyclic or bicyclic ring skeletal atoms Means a cycloalkyl group which may be substituted with at least one substituent selected from the group consisting of pyrrolidinyl, azetidinyl, pyrazolidinyl, oxazolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, , Valerolactamyl, oxiranyl, oxetanyl, dioxolanyl, dioxanyl, oxathiolanyl, oxathianyl, dithianyl, dihydrofuranyl, tetrahydrofuranyl, dihydropyranyl, tetrahydro Pyranyl, tetrahydropyridinyl, tetrahydropyrimidinyl, tetrahydrothiophenyl, tetrahydrothiopyranyl, diazepanyl and azepanyl.

Specifically, the compound of Formula 1 according to an embodiment of the present invention may be selected from Formula 2.

(2)

Wherein R ₁ comprises a heteroatom selected from hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, N, O, S, heteroaryl Al (C ₃ -C ₂₀₎ cycloalkyl is selected from alkyl, alkenyl alkyl, seen in the R _1, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, which, (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃ and R ₄ are each independently selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl containing heteroatoms, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅ is (C ₁ -C ₁₀₎ are selected from alkyl, (C ₁ -C ₁₀₎ alkoxy,

And n is 1 or 2.)

More specifically, the compound of formula (2) may be selected from the following formulas (3) and (4).

(3)

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃₁ and R ₄₁ are each independently selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl containing heteroatoms, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,

[Chemical Formula 4]

(C ₃ -C ₂₀ ) cycloalkyl comprising a heteroatom selected from N, O and S, wherein R ₁₂ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₃ -C ₂₀ ) is selected from cycloalkyl, wherein R ₁₂ is alkyl, cycloalkyl, heterocycloalkyl (C ₁ -C ₁₀₎ alkyl, (C ₃ -C ₂₀₎ cycloalkyl, halogen, nitro, cyano, hydroxy, amino, One or more selected from imino may be further substituted,

에서 선택된다.) Wherein R ₂₂ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano,

.

More specifically, the compound of formula (3) may be selected from the following formulas (5) to (7).

[Chemical Formula 5]

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택된다.)Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

.

[Chemical Formula 6]

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃₁ is a heteroatom containing a heteroatom selected from hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,

(7)

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,

에서 선택되고, Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >

에서 선택되고, Wherein R ₃₁ is a heteroatom containing a heteroatom selected from hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >

에서 선택되고, Wherein R ₄₁ comprises a heteroatom selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, heterocyclic (C ₃ -C ₂₀₎ cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,

More specifically, in Formula 5 according to an embodiment of the present invention, R ₁₁ represents a (C ₁ -C ₅ ) alkyl, (C ₃ -C ₁₂ ) cycloalkyl, a heteroatom selected from N, O and S (C ₃ -C ₁₂ ) cycloalkyl,

It said alkyl, cycloalkyl, heterocycloalkyl of R ₁₁ is (C ₁ -C ₅₎ alkyl, (C ₃ -C ₁₂₎ cycloalkyl and alkyl may be further substituted,

에서 선택되는 것일 수 있다.Wherein R < ₂₁ > is hydrogen, cyano,

. ≪ / RTI >

More specifically, the formula (5) may be selected from the following compounds, but is not limited thereto.

Than in the formula (6) More specifically, according to one embodiment of the present invention, the R ₁₁ is hydrogen, (C ₁ -C ₅₎ alkyl, (C ₃ -C ₁₂₎ is selected from cycloalkyl, the alkyl R _11, Cycloalkyl may be further substituted with one or more of (C ₁ -C ₅ ) alkyl, (C ₃ -C ₁₂ ) cycloalkyl,

Wherein R < ₂₁ > is hydrogen,

Wherein R ₃₁ is selected from the group consisting of hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy, nitro, cyano, amino, Lt; / RTI >

Wherein R ₅₁ is selected from (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy.

More specifically, the formula (6) may be selected from the following compounds, but is not limited thereto.

More specifically, in Formula 7 according to an embodiment of the present invention, R ₁₁ is selected from hydrogen, (C ₁ -C ₅ ) alkyl,

Wherein R < ₂₁ > is hydrogen,

Wherein R ₃₁ is selected from hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy,

Wherein R ₄₁ is selected from hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy.

More specifically, the formula (7) may be selected from the following compounds, but is not limited thereto.

More specifically, the formula (4) may be selected from the following compounds, but is not limited thereto.

Since the compound of the present invention has a single aromatic ring and a rod-like structure in which an ester group (-COO-) is linked to the aromatic ring through a double bond group, an optical film having excellent retardation and moisture permeability can be provided . In addition, there is an effect that the haze decreases after the opening and the total light transmittance increases.

In the optical film of the present invention, the stretching may be 0 to 100%, more specifically 0.1 to 100%, and further preferably 5 to 30%. Preferably in the transverse direction, and may be stretched in the machine direction or not stretched. And more preferably 5 to 30%, more preferably 10 to 20% in the width direction. The thickness after stretching is preferably 20 to 140 탆, more preferably 30 to 80 탆.

In the optical film comprising the compound, the retardation in the thickness direction in the film after stretching satisfies the following formula (1) and the haze change amount (DELTA H _ei ) satisfies the following formula (2).

[Formula 1]

50? Rth (550)? 500

0.8? Rth (400) / Rth (700)? 1.5

(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm.

[Formula 2]

-3 ≤ _{ΔH ei} ≤ 0

(Where H _ei = H _e - H _i , H _e is the haze value (%) after stretching, and H _i is the haze value (%) before stretching.

The optical film satisfying the retardation (Rth) and the haze change amount in the thickness direction of the film can provide a film excellent in contrast, transmittance and yellowishness when applied to an optical compensation sheet, a polarizing plate and a droplet display device have.

In the optical film of the present invention, the total light transmittance after stretching is 89 to 93%, and the total light transmittance change amount (DELTA TT) satisfies the following formula (3).

[Formula 3]

0.1?? TT? 3

TT _e is the total light transmittance value (%) after stretching, and TT _i is the total light transmittance value (%) before stretching.) In the above formula,? TT = TT _e -TT _i ,

The optical film having the total light transmittance and the total light transmittance variation amount can provide a film excellent in contrast, transmittance and yellowishness when applied to an optical compensation sheet, a polarizing plate and a liquid crystal display device.

The optical film of the present invention has a moisture permeability of 30,000 to 60,000 g 占 퐉 / m2 占 day. The moisture permeability is water vapor transmission rate measuring instrument (PERMATRAN-W Model 3/33, MOCON Co., Ltd.) as measured by using a, the pressure exerted on the film specimen 760mmHg, temperature 37.8 ℃, 100% RH (relative humidity) of the external cells, N ₂ carrier gas was measured from the outer cell through the film to the inner cell.

The optical film having the moisture permeability satisfying the above range can prevent the polarizer from being damaged when the polarizer is manufactured. Specifically, when the optical film is used as a protective film, the moisture permeability is a property that affects the production of the polarizing plate. Therefore, when the optical film and the polarizer are laminated, It is preferable to have a proper moisture permeability since it is possible to prevent the polarizer from being damaged by being removed. Therefore, the moisture permeability is preferably within the above range because an optical film excellent in post-processing can be provided.

In addition, it is possible to reduce the change in display characteristics in response to a change in the ambient humidity when the optical film is applied to an optical compensatory sheet, a polarizing plate, and a liquid crystal display device.

The optical film of the present invention preferably has a haze of 0.2 to 7% before stretching and a haze of 0 to 1% after stretching, more preferably 0 to 0.5% after stretching, specifically 0.1 to 0.5% %. ≪ / RTI > When the liquid crystal display device is applied to the optical compensatory sheet, the polarizing plate and the droplet display device in the above range, light emitted from the liquid crystal display device is not scattered, thereby increasing the contrast of the liquid crystal display device.

In the optical film of the present invention, Re (?) And Rth (?) Before stretching satisfy the following formula 4 and Re (?) And Rth (?) After stretching satisfy the following formula (5).

[Formula 4]

0? Re (550)? 50

0? Rth (550)? 250

0.8? Rth (400) / Rth (700)? 1.5

[Formula 5]

20? Re (550)? 300

50? Rth (550)? 300

0.8? Rth (400) / Rth (700)? 1.5

(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm.

A film excellent in contrast, transmittance and yellowishness when applied to an optical compensatory sheet, a polarizing plate and a liquid crystal display can be provided within the range satisfying the above-mentioned formulas 4 and 5.

Next, a method of producing the optical film of the present invention will be described. The optical film of the present invention may be a cellulose acylate film using a cellulose acylate resin as a base resin, and a manufacturing method will be described as an example of a cellulose acylate film.

To prepare the cellulose acylate film in the present invention, the following cellulose acylate composition, that is, a dope solution is prepared.

The cellulose acylate composition according to an embodiment of the present invention comprises 1 to 20 parts by weight of the compound of the formula 1 as a retardation controlling agent per 100 parts by weight of the cellulose acylate resin. When used in the above range, a target retardation range can be achieved.

In the present invention, the solid concentration of the dope is preferably 15 to 25% by weight, and more preferably 16 to 23% by weight. When the solid concentration of the dope is less than 15% by weight, the fluidity is too high to form a film, and when it exceeds 25% by weight, complete dissolution is difficult.

In one embodiment of the present invention, the content of the cellulose acylate is 70% by weight or more, preferably 70 to 90% by weight, and more preferably 80 to 85% by weight based on the entire solid content. The cellulose acylate may be a mixture of two or more kinds of cellulose acylates having different degree of substitution, degree of polymerization or molecular weight distribution.

When the film is produced by the solvent casting method, the solvent for preparing the cellulose acylate composition (dope) is preferably an organic solvent. As the organic solvent, it is preferable to use halogenated hydrocarbons, and halogenated hydrocarbons include chlorinated hydrocarbons, methylene chloride and chloroform, among which methylene chloride is most preferred.

If necessary, organic solvents other than halogenated hydrocarbons may be mixed and used. Organic solvents other than halogenated hydrocarbons include esters, ketones, ethers, alcohols and hydrocarbons. As the ester, methyl formate, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, pentyl acetate and the like can be used. As the ketone, acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone , Cyclopentanone, cyclohexanone, methylcyclohexanone and the like can be used. As the ether, diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetra Ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl- 2-butanol, cyclohexanol, 2-fluoroethanol, 2,2,2-trifluoroethanol and 2,2,3,3-tetrafluoro-1-propanol.

More preferably, methylene chloride may be used as the main solvent, and alcohol may be used as the minor solvent. Specifically, methylene chloride and alcohol may be mixed at a weight ratio of 80:20 to 95: 5.

The cellulose acylate composition can be prepared by room temperature, high temperature or low temperature dissolution.

The viscosity of the cellulose acylate composition is preferably 1 to 400 Pa · s at 40 ° C., more preferably 10 to 200 Pa · s.

The cellulose acylate film can be produced by a conventional solvent casting method. More specifically, the prepared dope (cellulose acylate composition) is once stored in a storage tank and defoamed in the foam contained in the dope. The defoamed dope is sent from a dope discharge port to a pressurized die through a pressurized metering gear pump capable of precisely pumping it at a high accuracy in accordance with the number of revolutions. The dope is transferred onto a metal support which is running from the slit of the pressurized die The casting film is uniformly cast so that the less-dried casting film is peeled off from the metal support at the peeling point at which the metal support almost rises. Both ends of the manufactured web are held in a clip and conveyed in a tenter while being held in a width, dried, conveyed to a roller of a drying device, dried and winded to a predetermined length by a winder. It is also possible to uniaxially and biaxially stretch in the machine direction and the width direction with the residual solvent amount in the casting film being 10 to 40% by weight. Or it may be stretched off-line after production of the casting film. The film may be stretched in the machine direction or the width direction, and simultaneously or sequentially biaxially stretched. The degree of drawing is preferably in the range of 0 to 100% (the% is the length%), specifically 0.1 to 100%, more preferably 0 to 50%, and most preferably 5 to 30% . In the stretching degree,% means length%. For example, 100% stretching with respect to a film having a length of 1 m before stretching means stretching to 2 m.

The stretching temperature is preferably the glass transition temperature (T _g ) of the optical film containing the compound of Formula 1 ± 10 ° C. The space temperature at the time of application of the solution is preferably -50 ° C to 50 ° C, more preferably -30 ° C to 40 ° C, and most preferably -20 ° C to 30 ° C. The cellulose acetate solution coated at a low spatial temperature is instantaneously cooled on the support to improve the gel strength, so that a film in which a large amount of organic solvent remains can be obtained. Therefore, the film can be peeled from the support in a short time without evaporating the organic solvent from the cellulose acylate. As the gas which cools the space, ordinary air, nitrogen, argon or helium can be used. The relative humidity is preferably 0 to 70%, more preferably 0 to 50%.

The temperature of the support (casting portion) to which the cellulose acylate solution is applied is preferably -50 to 130 占 폚, more preferably -30 占 폚 to 25 占 폚, and most preferably -20 占 폚 to 15 占 폚. In order to cool the casting portion, a gas cooled by the casting portion can be introduced. The cooling device may be disposed in the casting portion to cool the space. In cooling, it is important to be careful not to let water stick to the casting part. In the case of cooling with a gas, it is preferable to dry the gas.

Further, if necessary, the cellulose acylate film can be subjected to a surface treatment. The surface treatment is generally carried out in order to improve the adhesiveness of the cellulose acylate film. Examples of the surface treatment method include a glow discharge treatment, an ultraviolet ray irradiation treatment, a corona treatment, a flame treatment, and a saponification treatment.

The thickness of the cellulose acylate film is preferably in the range of 20 to 140 mu m, more preferably in the range of 30 to 80 mu m.

The cellulose acylate film according to the present invention can be used in a polarizing plate, an optical compensatory sheet, an optical filter for stereoscopic image, and a liquid crystal display device, and can be used in a laminate of one or two or more sheets. desirable.

The cellulose acylate film according to the present invention can be used in a polarizing plate, an optical compensatory sheet, an optical filter for stereoscopic image, and a liquid crystal display device, and can be used as one or two or more sheets.

More specifically, the cellulose acylate film of the present invention can be used as a protective film of a polarizing plate. One example of the polarizing plate of the present invention comprises a polarizing film and two polarizing plate protective films for protecting both surfaces thereof, and at least one of the protective films may be the cellulose acylate film of the present invention.

When the cellulose acylate film of the present invention is used as the polarizing plate protective film, the surface of the cellulose acylate film may be subjected to a surface treatment. The surface treatment may be a hydrophilic treatment, a glow discharge treatment, a corona discharge treatment, . ≪ / RTI >

In general, a liquid crystal display device has two polarizing plate protective films because liquid crystal cells are located between two polarizing plates. The cellulose acylate film of the present invention may be used for any of the four polarizing plate protective films, but is suitable for use as a protective film positioned between the polarizing film of the liquid crystal display and the liquid crystal cell. The protective film located on the opposite side of the cellulose acylate film of the present invention may form a transparent hard coating layer, a light-scattering coating layer, an antireflection coating layer, or the like.

An optical compensation film comprising a cellulose acylate film of the present invention, or a liquid crystal display device having a polarizing plate is also included in the scope of the present invention. The cellulose acylate film of the present invention can be used in a liquid crystal display device of various display modes, specifically, in modes such as TN, IPS, FLC, AFLC, OCB, STN, ECB, VA and HAN. The cellulose acylate film of the present invention is particularly preferably applied to a VA mode liquid crystal display device, and has excellent contrast and viewing angle compensation effect.

Hereinafter, the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

The physical properties of the film were measured by the following measuring method.

1) Optical anisotropy

Re was measured by using a birefringence meter (Axoscan, trade name, manufactured by Axometrics, Inc.) with wavelengths of 400 nm, 550 nm, and 700 m entering the normal direction of the film. Rth is the refractive index component of the refractive index ellipsoid obtained by measuring light of 400 nm, 550 nm, and 700 m, respectively, with the slow axis in the Re plane as the tilt axis at intervals of 10 degrees from 0 to 50 degrees with respect to the film normal direction Is the value obtained from the following equation using the following equation.

Rth = [(nx + ny) / 2-nz] xd

   nx: refractive index in a direction having a larger refractive index among two refractive indices of the plane

   ny: Refractive index in a direction with a small refractive index among two refractive indices of the plane

   nz: refractive index in the thickness direction

d: thickness of film

2) Water vapor permeability

(PERMATRAN-W Model 3/33, manufactured by MOCON). The moisture permeated from the outer cell through the film to the inner cell was measured for 24 hours under the conditions of a pressure of 760 mmHg, a temperature of 37.8 DEG C, a relative humidity of 100% of the outer cell, and N ₂ carrier gas.

3) Hayes

A cellulose acetate film sample 40 mm x 40 mm was measured with a hazemeter (Murakami Color Research Laboratory, HM-150) at 25 DEG C and a relative humidity of 60%.

The haze change amount (? H _ei ) was calculated by the following equation.

H _ei = H _e - H _i

(H _e is the haze value (%) after stretching, and H _i is the haze value (%) before stretching).

4) Total light transmittance

The total light transmittance was measured by a transmittance meter (Haze Meter HM-150, manufactured by Murakami Color Research Laboratory) according to ASTM D1003 Haze and Luminous Transmittance of Transparent Plastics.

The total light transmittance change amount (DELTA TT) was calculated by the following formula.

TT = TT _e - TT _i

(TT _e is the total light transmittance value (%) after stretching, and TT _i is the total light ray transmittance value (%) before stretching).

5) Film thickness

A cellulose acetate film sample (40 mm x 40 mm) was measured with a thickness gauge (TESA-μHITE Height Gauge, manufactured by Tesa technology). The thicknesses of the five points including the center of the film specimen were measured and the average value was obtained.

6) degree of substitution

The degree of substitution was measured according to ASTM D-817-91.

[Example 1]

1) Preparation of Cellulose Acetate Composition (Dope)

The following composition was put in a stirrer and dissolved at a temperature of 30 캜.

In the following composition, 2- (2H-Benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol was used as an ultraviolet inhibitor.

100 parts by weight of a cellulose acetate powder having a degree of substitution of 2.87

Compound 1 5 parts by weight

UV absorber 2 parts by weight

Silicon dioxide, average particle diameter 16 nm 0.5 part by weight

440 parts by weight of methylene chloride

Methanol 50 parts by weight

The resultant dope was heated to 30 DEG C and then sent to a gear pump. The resultant was filtered through a filter paper having an absolute filtration accuracy of 0.01 mm, and then filtered through a cartridge filtration apparatus having an absolute filtration accuracy of 5 mu m.

[Compound 1]

2) Preparation of Cellulose Ester Film: Preparation of Film Specimen Before Stretching

The dope obtained through the filtration process was cast on a glass plate and dried at room temperature for 7 minutes, after which the formed cellulose acetate film was peeled from the glass plate and dried at 140 DEG C for 60 minutes. After drying, the residual solvent was adjusted to be 0.5 wt% or less. The obtained cellulose acetate film had a dry thickness of 60 mu m.

The cellulose acetate film thus prepared was used as a film sample before stretching to measure its physical properties and is shown in Tables 1 and 2 below.

3) Preparation of cellulose ester film: Preparation of film specimen after stretching

The dope obtained through the filtration process was cast on a mirror-surface stainless steel support through a casting die and peeled off. The amount of the residual solvent at the time of peeling was adjusted to be 25 wt%. After peeling, the film was stretched at 0% in the direction of film advance in the stretching machine, and then connected to the tenter again, and stretched by 20% in the width direction of the film. After the film was removed from the tenter, the left and right ends of the film were removed 150 mm apart. The film having the terminals removed was dried through a drier. Both ends of the film from the dryer were trimmed to 3 cm, and 10 mm from the end thereof was subjected to a knurling process to a height of 100 탆. The dry thickness of the produced film was 40 탆. The cellulose acetate film thus prepared was used as a film specimen after stretching to measure its physical properties. The results are shown in Tables 1 and 2 below.

[Example 2]

A film was prepared in the same manner as in Example 1, except that Compound 2 was used instead of Compound 1.

The physical properties of the film before stretching and the film after stretching were measured and shown in Tables 1 and 2 below.

[Compound 2]

[Example 3]

A film was prepared in the same manner as in Example 1, except that Compound 3 was used instead of Compound 1.

The physical properties of the film before stretching and the film after stretching were measured and shown in Tables 1 and 2 below.

[Compound 3]

[Example 4]

A film was prepared in the same manner except that the following compound 4 was used in place of the compound 1 in Example 1.

The physical properties of the film before stretching and the film after stretching were measured and shown in Tables 1 and 2 below.

[Compound 4]

[Comparative Example 1]

1) Preparation of Cellulose Acetate Composition (Dope)

The following composition was put in a stirrer and dissolved at a temperature of 30 캜.

In the following composition, 2- (2H-Benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol was used as an ultraviolet inhibitor.

100 parts by weight of a cellulose acetate powder having a degree of substitution of 2.87

Triphenylphosphate 8 parts by weight

Biphenyl diphenyl phosphate 4 parts by weight

UV absorber 2 parts by weight

Silicon dioxide, average particle diameter 16 nm 0.5 part by weight

440 parts by weight of methylene chloride

Methanol 50 parts by weight

The resultant dope was heated to 30 DEG C and then sent to a gear pump. The resultant was filtered through a filter paper having an absolute filtration accuracy of 0.01 mm, and then filtered through a cartridge filtration apparatus having an absolute filtration accuracy of 5 mu m.

2) Preparation of Cellulose Ester Film: Preparation of Film Specimen Before Stretching

The dope obtained through the filtration process was cast on a glass plate and dried at room temperature for 7 minutes, after which the formed cellulose acetate film was peeled from the glass plate and dried at 140 DEG C for 60 minutes. After drying, the residual solvent was adjusted to be 0.5 wt% or less. The obtained cellulose acetate film had a dry thickness of 60 mu m.

The cellulose acetate film thus prepared was used as a film sample before stretching to measure its physical properties and is shown in Tables 1 and 2 below.

3) Preparation of cellulose ester film: Preparation of film specimen after stretching

The dope obtained through the filtration process was cast on a mirror-surface stainless steel support through a casting die and peeled off. The amount of the residual solvent at the time of peeling was adjusted to be 30 wt%. After peeling, the stretching machine stretched 0% in the film advancing direction and 20% in the width direction. After the film was removed from the tenter, the left and right ends of the film were removed 150 mm apart. The film having the terminals removed was dried through a drier. Both ends of the film from the dryer were trimmed to 3 cm, and 10 mm from the end thereof was subjected to a knurling process to a height of 100 탆. The dry thickness of the produced film was 40 탆. The cellulose acetate film thus prepared was used as a film specimen after stretching to measure its physical properties. The results are shown in Tables 1 and 2 below.

 [Table 1]

[Table 2]

As shown in Table 1, it can be seen that the embodiment of the present invention shows a high Rth value even before stretching. It was confirmed that not only the Re value but also the Rth value were increased before and after the stretching.

As shown in Table 2, unlike the comparative example, the haze value of the embodiment of the present invention tends to decrease after stretching, and the total light transmittance increases. In the case of the comparative example, the moisture permeability value is not known beyond the measurement range, but the embodiment shows that the moisture permeability is remarkably improved.

Claims (25)

Wherein the retardation in the thickness direction of the film after stretching satisfies the following expression (1) and the haze change amount (DELTA H _ei ) satisfies the following expression (2).
[Formula 1]
50? Rth (550)? 500
0.8? Rth (400) / Rth (700)? 1.5
(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm.
[Formula 2]
-3 ≤ _{ΔH ei} ≤ 0
(Where H _ei = H _e - H _i , H _e is the haze value (%) after stretching, and H _i is the haze value (%) before stretching. The method according to claim 1,
Wherein the optical film has a total light transmittance of 89 to 93% after stretching, and a total light transmittance change amount (DELTA TT) satisfies the following formula (3).
[Formula 3]
0.1?? TT? 3
(Wherein, < RTI ID = 0.0 > = TT _e - TT _i , TT _e is the total light transmittance value (%) after stretching, and TT _i is the total light transmittance value before stretching (%). The method according to claim 1,
Wherein the optical film has a moisture permeability of 30,000 to 60,000 g 占 퐉 / m2 占 day. The method according to claim 1,
Wherein the optical film has a haze before stretching of 0.2 to 7% and a haze after stretching of 0 to 1%. The method according to claim 1,
Wherein the optical film has an elongation of 0 to 100% and a thickness after stretching of 20 to 140 탆. The method according to claim 1,
Wherein the optical film satisfies the following expression (4): Re (?) And Rth (?) Before stretching and Re (?) And Rth (?) After stretching satisfy the following expression (5).
[Formula 4]
0? Re (550)? 50
0? Rth (550)? 250
0.8? Rth (400) / Rth (700)? 1.5
[Formula 5]
20? Re (550)? 300
50? Rth (550)? 300
0.8? Rth (400) / Rth (700)? 1.5
(Unit: nm), and Rth (?) Is a retardation value (unit: nm) in the film thickness direction at the wavelength? Nm. The method according to claim 1,
Wherein the optical film comprises a compound containing one aromatic ring as a mother nucleus and containing at least one ester (-COO-) group in the molecule. 8. The method of claim 7,
Wherein the compound is a compound comprising a cinnamate structure as a mother nucleus. 9. The method of claim 8,
And 1 to 15% by weight of a compound containing the cinnamate structure. 10. The method of claim 9,
Wherein the optical film comprises at least one compound selected from the following general formula (1).
[Chemical Formula 1]

(Wherein n is an integer selected from 1 to 3,
R ₁ is selected from the group consisting of hydrogen (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, heteroatom containing a heteroatom selected from N, ₃ -C ₂₀₎ cycloalkyl is selected from alkyl of said R _1, alkenyl, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, (C ₃ - C ₂₀₎ and one or both selected from cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino be further substituted,
Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >
Each R 'is independently selected from the group consisting of hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

And R ₅ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy. 11. The method of claim 10,
Wherein the formula (1) is selected from the following formula (2).
(2)

Wherein R ₁ comprises a heteroatom selected from hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, N, O, S, heteroaryl Al (C ₃ -C ₂₀₎ cycloalkyl is selected from alkyl, alkenyl alkyl, seen in the R _1, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, which, (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,
Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >
Wherein R ₃ and R ₄ are each independently selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl containing heteroatoms, nitro, cyano, amino, imino,

Lt; / RTI >
Wherein R ₅ is (C ₁ -C ₁₀₎ are selected from alkyl, (C ₁ -C ₁₀₎ alkoxy,
And n is 1 or 2.) 12. The method of claim 11,
Wherein the compound of formula (2) is selected from the following formulas (3) and (4).
(3)

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,
Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >
Wherein R ₃₁ and R ₄₁ are each independently selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl containing heteroatoms, nitro, cyano, amino, imino,

Lt; / RTI >
Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,
[Chemical Formula 4]

(C ₃ -C ₂₀ ) cycloalkyl comprising a heteroatom selected from N, O and S, wherein R ₁₂ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₃ -C ₂₀ ) is selected from cycloalkyl, wherein R ₁₂ is alkyl, cycloalkyl, heterocycloalkyl (C ₁ -C ₁₀₎ alkyl, (C ₃ -C ₂₀₎ cycloalkyl, halogen, nitro, cyano, hydroxy, amino, One or more selected from imino may be further substituted,
Wherein R ₂₂ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, . 13. The method of claim 12,
Wherein the compound of formula (3) is selected from the following formulas (5) to (7).
[Chemical Formula 5]

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,
Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

.
[Chemical Formula 6]

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,
Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >
Wherein R ₃₁ is a heteroatom containing a heteroatom selected from hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >
Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy,
(7)

Wherein R ₁₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, wherein the alkyl, alkenyl, cycloalkyl, heterocycloalkyl of R ₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl , (C ₃ -C ₂₀ ) cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino,
Wherein R ₂₁ is selected from the group consisting of hydrogen, (C ₁ -C ₁₀ ) alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >
Wherein R ₃₁ is a heteroatom containing a heteroatom selected from hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >
Wherein R ₄₁ comprises a heteroatom selected from hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, heterocyclic (C ₃ -C ₂₀₎ cycloalkyl, nitro, cyano, amino, imino,

Lt; / RTI >
Wherein R ₅₁ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, 14. The method of claim 13,
In Formula 5,
Wherein R ₁₁ is selected from (C ₁ -C ₅ ) alkyl, (C ₃ -C ₁₂ ) cycloalkyl, hetero (C ₃ -C ₁₂ ) cycloalkyl comprising a heteroatom selected from N, O, S,
It said alkyl, cycloalkyl, heterocycloalkyl of R ₁₁ is (C ₁ -C ₅₎ alkyl, (C ₃ -C ₁₂₎ cycloalkyl and alkyl may be further substituted,
Wherein R < ₂₁ > is hydrogen, cyano,

≪ / RTI > 14. The method of claim 13,
(5) is selected from the following compounds.

14. The method of claim 13,
In Formula 6,
Wherein R ₁₁ is hydrogen, (C ₁ -C ₅₎ alkyl, (C ₃ -C ₁₂₎ is selected from cycloalkyl, the R ₁₁ is alkyl, cycloalkyl (C ₁ -C ₅₎ alkyl, (C ₃ - Lt; / RTI > _C12 ) cycloalkyl,
Wherein R < ₂₁ > is hydrogen,
Wherein R ₃₁ is selected from the group consisting of hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy, nitro, cyano, amino,

Lt; / RTI >
Wherein R ₅₁ is (C ₁ -C ₅₎ alkyl, (C ₁ -C ₅₎ The optical film is selected from alkoxy. 14. The method of claim 13,
(6) is selected from the following compounds.

14. The method of claim 13,
In Formula 7,
Wherein R ₁₁ is selected from hydrogen, (C ₁ -C ₅ ) alkyl,
Wherein R < ₂₁ > is hydrogen,
Wherein R ₃₁ is selected from hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy,
Wherein R ₄₁ is selected from hydroxy, (C ₁ -C ₅ ) alkyl, (C ₁ -C ₅ ) alkoxy. 14. The method of claim 13,
(7) is selected from the following compounds.

13. The method of claim 12,
Wherein the compound of formula (4) is selected from the following compounds.

The method according to claim 1,
Wherein the optical film is based on a cellulose acylate resin. 22. The method of claim 21,
The cellulose acylate resin is a cellulose acylate resin in which all or a part of the hydrogen atoms of the hydroxyl groups existing at the second, third and sixth positions of the glucose unit constituting cellulose are substituted with any one or two selected from acetyl group, propylonyl group and butyryl group Or more and a degree of substitution of 2.0 to 3.0 according to ASTM D-817-91. 22. The method of claim 21,
Wherein the optical film comprises 1 to 20 parts by weight of at least one compound selected from the group consisting of the following formula (1) based on 100 parts by weight of the cellulose acylate resin.
[Chemical Formula 1]

(Wherein n is an integer selected from 1 to 3,
R ₁ is selected from the group consisting of hydrogen (C ₁ -C ₁₀ ) alkyl, (C ₂ -C ₁₀ ) alkenyl, (C ₃ -C ₂₀ ) cycloalkyl, heteroatom containing a heteroatom selected from N, ₃ -C ₂₀₎ cycloalkyl is selected from alkyl of said R _1, alkenyl, cycloalkyl, heterocycloalkyl is (C ₁ -C ₁₀₎ alkyl, (C ₂ -C ₁₀₎ alkenyl, (C ₃ - C ₂₀₎ and one or both selected from cycloalkyl, halogen, nitro, cyano, hydroxy, amino, imino be further substituted,
Wherein R ₂ is hydrogen, (C ₁ -C ₁₀₎ alkyl, cyano, hydroxy, amino, nitro,

Lt; / RTI >
Each R 'is independently selected from the group consisting of hydrogen, hydroxy, (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy, (C ₃ -C ₂₀ ) cycloalkyl, (C ₃ -C ₂₀ ) cycloalkyl, nitro, cyano, amino, imino,

And R ₅ is selected from (C ₁ -C ₁₀ ) alkyl, (C ₁ -C ₁₀ ) alkoxy. 24. The compound according to any one of claims 1 to 23,
Wherein the optical film is used in an optical compensation sheet, an optical filter for stereoscopic images, a polarizing plate, and a liquid crystal display device. A liquid crystal display device comprising an optical film according to any one of claims 1 to 23.