KR101777532B1

KR101777532B1 - Optical film, polarizing plate and image display device

Info

Publication number: KR101777532B1
Application number: KR1020167014710A
Authority: KR
Inventors: 히로유키 호리이
Original assignee: 코니카 미놀타 가부시키가이샤
Priority date: 2013-12-27
Filing date: 2014-12-18
Publication date: 2017-09-11
Also published as: TW201538331A; JPWO2015098685A1; CN105849600A; WO2015098685A1; CN105849600B; KR20160083051A; TWI599485B

Abstract

The optical film 15 has a film base 12 and a functional layer 13 formed on at least one of the surfaces of the film base 12 and satisfies the following conditional expressions (1) and (2) simultaneously. That is, conditional expression (1); a + b? 30 mN / m, conditional expression (2); 1? (A / b)? 10. Where a is the polar component (mN / m) of the surface free energy of the functional layer and b is the dispersion component (mN / m) of the surface free energy of the functional layer.

Description

[0001] OPTICAL FILM, POLARIZING PLATE AND IMAGE DISPLAY DEVICE [0002]

The present invention relates to an optical film having a functional layer (for example, a hard coating layer) on a film substrate, a polarizing plate having the optical film, and an image display apparatus having the polarizing plate.

BACKGROUND ART [0002] Conventionally, various liquid crystal display devices provided with a touch panel on a liquid crystal display panel have been proposed. In this type of liquid crystal display device, if there is an air gap layer between the liquid crystal display panel and the touch panel, reflection or scattering of light at the interface between the liquid crystal display panel and the air gap layer, or at the interface between the touch panel and the air gap layer, The contrast and the luminance are lowered. In order to avoid such a problem, it is preferable that the void layer is filled with a filler such as a photo-curing resin.

On the other hand, from the viewpoint of surface protection, an optical film having a hard coat layer on the outermost surface is generally used for a polarizing plate on the viewer side of a liquid crystal display panel. When the photocurable resin is applied to the surface of the hard coat layer as a filler in order to fill the void layer, the wettability of the filler is insufficient, so that the filler is repelled and can not be uniformly coated on the hard coat layer.

Thus, for example, in Patent Document 1, by controlling the viscosity of the filler and the silicon atom ratio of the film surface having the hard coat layer to be controlled to a specific relationship and controlling the silicon atom ratio of the surface of the film to a predetermined range, And attempts to apply the filler uniformly on the film.

Japanese Patent Laid-Open Publication No. 2013-101274 (claims 1, 2, paragraphs [0004], [0005], [0009], etc.)

Recently, however, demand for a display device with a touch panel is increasing as represented by a smart phone or a tablet-type display device. Such a display device is often used indoors, and when it is used outdoors, it has been found that a white turbidity phenomenon occurs at the end portion of the display and repeated touch (swipe), and visibility is lowered. In addition, it has been found that such white turbidity occurs particularly in the summer when the environment is high temperature.

As a result of intensive studies by the inventors of the present invention, it has been found that the whitening phenomenon of the display end portion in the summer is insufficient in the wettability of the filler when bonding the touch panel to the liquid crystal display panel via the filler, It is found that the filler is repelled at the end portion of the hard coat layer in the hard coating layer, and the minute bubble (micro bubble) generated at this time is expanded due to the high temperature, thereby causing the filler to peel off at the end portion of the hard coat layer. In addition, the whitening phenomenon at a place where repeated touching (swiping) is caused by the fact that the adhesiveness between the filler and the hard coat layer is lowered due to the ultraviolet rays contained in the sunlight and the shearing force acting at the time of repeated touch or swiping causes the filler It was found that the peeling from the hard coating layer was caused.

Although the above-mentioned Patent Document 1 attempts to improve the wettability of the filler, the wettability of the filler can not be improved so as to improve adhesion of the base to the film. Therefore, the technique of Patent Document 1 can not be said to improve the wettability and adhesion of the filler at the same time, and it is possible to sufficiently reduce the peeling of the filler, which causes the decrease in visibility due to turbidity under the high- Can not.

An object of the present invention is to provide an optical film capable of simultaneously improving the wettability and adhesion of the filler applied to the surface of the functional layer and thereby sufficiently reducing the peeling of the filler, A polarizing plate having the optical film, and an image display apparatus having the polarizing plate.

The above object of the present invention is achieved by the following constitution. That is, the optical film of the present invention is an optical film having a film substrate and a functional layer formed on at least one side of the film substrate, and satisfies the following conditional expressions (1) and (2) to be;

a + b? 30 mN / m (1)

1 &le; a / b &le; 10 &

only,

a: sum of the polar component of the surface free energy of the functional layer and the hydrogen bonding component (mN / m)

b: Dispersion component of surface free energy of functional layer (mN / m)

to be.

By satisfying the condition (1), the surface free energy of the functional layer of the optical film is increased. Therefore, when the filler is applied to the surface of the functional layer, the wettability of the filler can be improved. When the condition (2) is satisfied, the balance between the sum a of the polar component and the hydrogen bond component of the surface free energy of the functional layer and the dispersion component b becomes good, and the balance between the filler having a low polarity and the functional layer The degree of homogeneity becomes good. Whereby the wettability of the filler can be further improved. Since the wettability of the filler is greatly improved, the adhesion between the filler and the functional layer is also improved.

That is, by simultaneously satisfying the conditional expressions (1) and (2), the wettability and the adhesion of the filler can be simultaneously improved, whereby the peeling of the filler can be sufficiently reduced.

1 is a cross-sectional view showing a schematic structure of an image display apparatus according to an embodiment of the present invention.
2 is a plan view schematically showing a schematic configuration of an apparatus for producing an obliquely-drawn film used in the above embodiment.
3 is a plan view schematically showing an example of a rail pattern of the extending portion of the manufacturing apparatus.
4 is an explanatory view showing a state of the durability test.

An embodiment of the present invention will be described with reference to the drawings. In the present specification, when numerical ranges are denoted by A to B, values of lower limit A and upper limit B are included in the numerical range. The present invention is not limited to the following contents.

[Configuration of image display apparatus]

1 is a cross-sectional view showing a schematic structure of an image display apparatus 1 according to the present embodiment. The image display device 1 is constituted by joining the exterior member 3 with a filler 31 through a polarizing plate 5 (specifically, on an optical film 15 described later) of the liquid crystal display panel 2 have. The filler 31 is an adhesive layer (void filler) containing a photo-curable resin such as acryl and is formed on the entire surface of the polarizing plate 5 of the liquid crystal display panel 2. [

The liquid crystal display panel 2 is constituted by disposing a polarizing plate 5 占 on both sides of a liquid crystal cell 4 in which a liquid crystal layer is sandwiched between a pair of substrates. The polarizing plate 5 is attached to one side (for example, the viewer side) of the liquid crystal cell 4 with the adhesive layer 7 interposed therebetween. The polarizing plate 6 is attached to the other surface side (for example, the backlight 9 side) of the liquid crystal cell 4 with the adhesive layer 8 interposed therebetween. The driving method of the liquid crystal display panel 2 is not particularly limited, and various driving methods such as IPS (In Plane Switching) type and TN (Twisted Nematic) type can be adopted.

The polarizing plate 5 includes a polarizer 11 that transmits a predetermined linearly polarized light, a film base 12 and a functional layer 13 which are sequentially laminated on the exterior member 3 side of the polarizer 11, and a polarizer 11 And an optical film 14 laminated on the liquid crystal cell 4 side of the liquid crystal cell 4. The optical film 15 as the protective film formed on the viewing side surface of the polarizer 11 is constituted by the film base material 12 and the functional layer 13. [ The functional layer 13 is composed of a hard coat layer (cured layer), an antiglare layer (antiglare layer), and the like. The surface of the polarizing plate 5 can be protected by constituting the functional layer 13 with a hard coating layer. Further, the anti-glare function can be exerted by constituting the functional layer 13 with an anti-glare layer. The optical film (14) is provided to protect the back surface of the polarizing plate (5). The optical film 14 may be made of the same material as the film base material 12 (for example, a cellulose ester film), or may be made of other materials.

The film substrate 12 is formed of a? / 4 film in the present embodiment. The? / 4 film is a layer imparting an in-plane retardation of about 1/4 of the wavelength of transmitted light. In this embodiment, the? / 4 film is composed of a cellulose ester film subjected to warp stretching described later. (angle of intersection) between the slow axis of the? / 4 film and the absorption axis of the polarizer 11 is 30 ° to 60 ° so that the linearly polarized light from the polarizer 11 is a? / 4 film (12) to circularly polarized light or elliptically polarized light.

Therefore, in the case where the observer observes the display image with the polarizing sunglasses attached, the light emitted from the polarizing plate 5 is reflected by the polarizing plate 5 regardless of how the transmission axis (perpendicular to the absorption axis) of the polarizing element 11 is deviated from the transmission axis of the polarizing sunglass The component of the light parallel to the transmission axis of the polarizing sunglasses included in the circularly polarized light (circularly polarized light or elliptically polarized light) can be guided to the observer's eye. As a result, it is possible to suppress the display image from being hardly seen in accordance with the viewing angle. In addition, even when the observer does not mount the polarizing sunglasses, since the linear polarized light or the elliptically polarized light emitted from the polarizing plate 5 and incident on the observer's eye is directly incident on the observer's eye, Can be reduced.

The film substrate 12 may be a cellulose ester film containing a hindered amine compound. The optical film 15 having the functional layer 13 formed on the film substrate 12 is adhered (UV-adhered) to the polarizer 11 by, for example, ultraviolet irradiation, 12) and the functional layer 13 (resistance to light fastness) may be deteriorated. However, when the hindered amine compound is contained in the cellulose ester film constituting the film substrate 12, the above-mentioned light fastness can be improved.

The polarizing plate 6 includes a polarizer 21 that transmits a predetermined linearly polarized light, an optical film 22 disposed on the liquid crystal cell 4 side of the polarizer 21, a liquid crystal cell 4 of the polarizer 21, Is formed by laminating an optical film 23 disposed on the opposite side. The polarizer 21 is arranged such that its transmission axis is perpendicular to the polarizer 11 (cross-Nicol state). The optical films 22 and 23 are provided so as to protect the front and back surfaces of the polarizing plate 6, but they may be made of the same material (for example, cellulose ester) as the film base 12 of the polarizing plate 5 Or may be made of other materials.

The exterior member 3 is, for example, a capacitive touch panel, and includes a first electrode pattern including a transparent conductive film on a glass substrate, an interlayer insulating layer, and a second electrode pattern including a transparent conductive film, As shown in FIG. In this configuration, the surface of the glass substrate becomes the touch surface of the touch panel. Further, an insulating film may be formed so as to cover the second electrode pattern.

The first electrode pattern is formed to extend in one direction (e.g., X direction) on the glass substrate. The interlayer insulating layer is formed on the glass substrate so as to cover the first electrode pattern. The second electrode pattern is formed to extend in a direction (for example, Y direction) perpendicular to the direction in which the first electrode pattern extends. When the surface of the exterior member 3 is pressed with a finger, the first electrode pattern and the second electrode pattern are in contact with each other, and the capacitance between the first electrode pattern and the second electrode pattern is changed. The pressing position (coordinate) can be specified by detecting the change of the capacitance through the first electrode pattern and the second electrode pattern.

In addition, the touch panel is not limited to the above-described capacitance type, but may be of another type such as a resistance film type. Further, the exterior member 3 may be constituted by, for example, a front face plate including an acrylic resin.

The optical film 15 described above can also be used for applications other than the polarizing plate. In this case, the functional layer 13 may be formed on both sides of the film base 12. Therefore, in the optical film 15, the functional layer 13 may be formed on at least one surface of the film substrate 12. [

[Surface free energy]

In the present embodiment, the optical film 15 simultaneously satisfies the following conditional expressions (1) and (2). In other words,

a + b? 30 mN / m (1)

1 &le; a / b &le; 10 &

only,

b: Dispersion component of surface free energy of functional layer (mN / m)

to be. Details of the calculation methods of a and b will be described later.

The present inventors have found that the total sum of the sum a of the polar component and the hydrogen bonding component of the surface free energy of the surface layer of the functional layer 13 and the dispersed component b is 30 mN / m or more It was found that the wettability when the filler 31 was applied to the surface of the functional layer 13 was improved and the film 31 uniformity of the film was excellent.

As a result of further study, it was found that the ratio a / b of the polar component and the hydrogen bonding component of the surface free energy of the functional layer 13 satisfying the conditional formula (2) Is not less than 1 but not more than 10, the wettability of the filler (31) is further improved. This is considered to be due to the following reasons.

If the sum a of the polar component and the hydrogen bond component is larger than that of the dispersed component b, it is possible to improve the wettability of a substance having a low polarity such as the filler 31, It becomes difficult. Therefore, when the sum total of the polar component and the hydrogen bond component a and the dispersant component b is 30 mN / m or more, the ratio a of the polar component and the hydrogen bond component is preferably 10 It is necessary to relatively suppress (relatively increase the dispersion component b). On the other hand, if the ratio a / b is less than 1, the sum a of the polar component and the hydrogen bonding component is too small to satisfy the conditional expression (1) itself.

As described above, since the wettability of the filler 31 can be greatly improved by simultaneously satisfying the conditional expressions (1) and (2), the adhesiveness between the filler 31 and the functional layer 13 can be improved, Or by physical adhesion such as chemical bonding and intermolecular force. As a result, the adhesion between the filler (31) and the functional layer (13) can be reliably improved.

By improving the wettability and adhesion of the filler 31, the peeling of the filler 31 can be sufficiently reduced. As a result, even when the image display apparatus 1 with a touch panel is used under a high-temperature environment, it is possible to suppress the occurrence of clouding phenomenon at the end portion of the display screen and in a portion repeatedly touching (swiping) Can be suppressed.

From the viewpoint of further increasing the surface free energy of the functional layer 13 and further increasing the wettability of the filler 31, it is preferable that the optical film 15 further satisfies the following conditional expression (1a). In other words,

a + b? 40 mN / m (1a)

to be.

From the viewpoint of further suppressing the sum a of the polar component and the hydrogen bonding component and further enhancing the wettability of the filler 31, the optical film 15 preferably satisfies the following conditional expression (2a) Do. In other words,

1? (A / b)? 5 ... (2a)

to be.

From the viewpoint of further increasing the surface free energy of the functional layer 13 and further increasing the wettability of the filler 31, it is preferable that the optical film 15 also satisfies the following conditional formula (1b). In other words,

a + b? 50 mN / m (1b)

to be.

From the viewpoint that the polar component a is further suppressed and the effect of improving the wettability of the filler 31 is further enhanced, it is preferable that the optical film 15 also satisfies the following conditional formula (2b). In other words,

1? (A / b)? 4 ... (2b)

to be.

This effect is particularly effective when the filler 31 contains a photo-curable resin as in the present embodiment. That is, when the filler 31 contains a photo-curing resin, the wettability and adhesion of the filler 31 to the functional layer 13 can be reliably improved by satisfying the above-described conditional expressions.

Next, a method of calculating the sum a of the polar component and the hydrogen bond component of the surface free energy and the dispersion component b will be described. First, the optical film 15 was allowed to stand for 12 hours under the conditions of a temperature of 23 DEG C and a humidity of 55%, and then three kinds of droplets (pure water, ethylene glycol, diethylene glycol ) Was measured at a temperature of 23 캜 and a humidity of 55% using a drop master DM100 (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.). In addition, the contact angle of each droplet is measured five times each, and the average value thereof is used.

Subsequently, the Young's Fowkes equation is used to calculate the surface free energy.

_{(γ S d · γ L d} ) 1/2 + (γ S p · γ L p) 1/2 + (γ S h · γ L h) 1/2 = γ L (1 + cosθ) / 2

here,

γ _S d: dispersion component of surface free energy of solid (mN / m)

γ _L d: dispersion component of surface free energy of liquid (mN / m)

γ _S p: polar component of surface free energy of solid (mN / m)

γ _L p: Polarity component of surface free energy of liquid (mN / m)

γ _S h is the hydrogen bonding component of the surface free energy of the solid (mN / m)

γ _L h: hydrogen bonding component of the surface free energy of the liquid (mN / m)

γ _L: dispersion component of the surface free energy of the liquid, polar components, the sum of the hydrogen bond component (γ _L = γ _L d + γ _L p + γ _L h)

θ: contact angle (°)

The dispersive component? _L d, the polar component? _L p, and the hydrogen bonding component? _L h of the surface free energy of three kinds of droplets (pure water, ethylene glycol, diethylene glycol) 15, No. 3, p96 are used.

By solving the ternary simultaneous equations by substituting the value of the contact angle (average contact angle) into the Young-Fowkes equation, the dispersive component? _S d of the surface free energy of the solid, the polar component? _S p, Each value of the component γ _S h can be obtained. Thus, the sum a (=? _S p +? _S h) and the dispersion component b (=? _S d) of the polarity component and the hydrogen bonding component of the surface free energy of the functional layer can be obtained, (a + b) or ratio (a / b) can also be obtained. The sum a of the polar component and the hydrogen bond component is a component derived from a permanent dipole and the dispersed component b is a component not derived from a permanent dipole. Thus, the ratio a / b has a physical meaning as the ratio between the component derived from the permanent dipole and the component not derived.

[Contact angle]

The contact angle difference? Of the water before and after the alkali treatment in the functional layer 13 is preferably 10 ° or more, more preferably 20 ° or more in order to exert the effect of the present embodiment described above satisfactorily. It is also preferable that the contact angle difference DELTA [theta] is 55 DEG or less. Hereinafter, the contact angle difference? Before and after the alkali treatment will be described.

The contact angle difference?? (?) Of the water before and after the alkali treatment is determined by the contact angle? A (?) Of the water before the alkali treatment of the functional layer 13 of the optical film 15, ) Of the water contact angle? B (?). As the alkali treatment conditions, the optical film 15 is immersed in a sodium hydroxide solution of 2 mol / L at 50 캜 for 60 seconds. The water contact angle is a value obtained by performing the measurement five times by using the above-mentioned contact angle meter after leaving for 12 hours under the conditions of 23 占 폚 and 55% RH and averaging the measured values.

The surface free energy of the functional layer 13 rises after the alkali treatment and the adhesiveness at the interface between the filler 31 (photocurable resin) and the functional layer 13 is enhanced and the interlayer adhesion after the durability test is favorably obtained . In addition, the contact angle of the water after the alkali treatment is lowered is a preferred embodiment in the present embodiment.

The alkali treatment in the present embodiment includes a step of dipping at least the optical film 15 in an alkali solution (hereinafter also referred to as a saponification step), followed by washing with water and drying, and the conditions for the alkali treatment are the above conditions. After the alkali treatment, neutralization may be carried out in the acidic water process, followed by washing with water and drying.

The water contact angle difference? Before and after the alkali treatment can be adjusted so as to satisfy the above-mentioned range by adjusting the kind and amount of the additive such as a compound to be described later, and the curing condition (oxygen concentration adjustment, etc.) at the time of forming the functional layer.

[Optical film]

Hereinafter, the details of each layer constituting the optical film 15 will be described.

(Functional layer)

The functional layer of the present embodiment is a layer composed mainly of a resin. Specifically, it is preferable that an active ray-curable resin is contained because it has excellent mechanical strength (scratch resistance, pencil hardness). That is, it is a layer mainly composed of a resin which is cured by cross-linking reaction by irradiation of active rays (also referred to as active energy rays) such as ultraviolet rays or electron beams. As the active ray hardening resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and an active ray hardening resin layer is formed by irradiating an active ray such as ultraviolet rays or electron rays. As the active ray-curable resin, ultraviolet ray-curable resin, electron ray-curable resin and the like can be exemplified, but a resin which is cured by ultraviolet ray irradiation is particularly preferable in view of excellent mechanical film strength (scratch resistance, pencil hardness). Examples of the ultraviolet curable resin include ultraviolet curable acrylate resin, ultraviolet curable urethane acrylate resin, ultraviolet curable polyester acrylate resin, ultraviolet curable epoxyacrylate resin, ultraviolet curable polyol acrylate resin, Ultraviolet curing type epoxy resin and the like are preferably used, and among them, an ultraviolet curing type acrylate type resin is preferable.

As the ultraviolet curable acrylate resin, polyfunctional acrylate is preferable. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate and dipentaerythritol polyfunctional methacrylate Do.

Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups or methacryloyl groups in the molecule. Examples of the monomer of polyfunctional acrylate include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethyl Pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, , Ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, glycerin triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol Pentaacrylate Diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, neopentyl glycol dimethacrylate, neopentyl glycol dimethacrylate, Trimethylol propane trimethacrylate, trimethylol ethane trimethacrylate, tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, pentaerythritol dimethacrylate, But are not limited to, styrene dimethacrylate, styrene dimethacrylate, styrene dimethacrylate, pentaerythritol triacrylate, stearyl dimethacrylate, pentaerythritol tetramethacrylate, pentaerythritol tetramethacrylate, glycerin trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate, Pentamethacrylate, dipentaerythritol hexamethacrylate, active ener When the radiation curable isopropyl can be mentioned preferably a cyanurate, etc. derivatives, polybasic acid acrylate.

From the viewpoint of the object of the present embodiment, the functional layer of the optical film may contain polybasic acid acrylate. Examples of the polybasic acid acrylate include dipentaerythritol pentaacrylate succinic acid modified product, pentaerythritol triacrylate succinic acid modified product, dipentaerythritol pentaacrylate phthalic acid modified product, pentaerythritol triacrylate phthalic acid modified product, polybasic acid Modified acrylic oligomers and the like. Examples of commercially available products include Aronix M-510, Aronix M-520 (manufactured by Dojo Kasei), DPE6A-MS, PE3A-MP, DPE6A-MP and PE3A-MP (manufactured by Kyoeisha Chemical Co., Ltd.). With respect to the content, the resin component forming the film of the functional layer is preferably 100% by mass or more, more preferably 50% or more by mass ratio.

RC-700, RC-600, RC-500, RC-611 and RC-612 (manufactured by Sanyo Chemical Industries, Ltd. ARONIX M-313, ARONIX M-327 (manufactured by Toagosei Co., Ltd.), Aronix M-3100, Aronix M- NK-ester A-DOG, NK ester A-IBD-2E, A-9300, A-9300-1CL PE-3A (manufactured by Kyoeisha Chemical Co., Ltd.), and the like.

These active ray curable resins may be used singly or in combination of two or more kinds.

A monofunctional acrylate may also be used. Examples of monofunctional acrylates include isobornyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, isostearyl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxy ethyl acrylate, Acrylate, isooctyl acrylate, tetrahydrofurfuryl acrylate, behenyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, cyclohexyl acrylate, . Such a monofunctional acrylate is available from Nippon Kasei Kogyo K.K., Shin Nakamura Kagaku Kogyo K.K., Osaka Yukigagaku Kogyo K.K. and the like.

When a monofunctional acrylate is used, it is preferable that the mass ratio of the polyfunctional acrylate to the monofunctional acrylate is in the range of polyfunctional acrylate: monofunctional acrylate = 80:20 to 98: 2.

(Photopolymerization initiator)

The functional layer preferably contains a photopolymerization initiator for accelerating curing of the active ray curable resin. The content of the photopolymerization initiator is preferably such that the photopolymerization initiator: active ray curable resin = 20: 100 to 0.01: 100 in mass ratio. Specific examples of the photopolymerization initiator include alkylphenone, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone,? -Amyloxime ester, thioxanthone, etc., and derivatives thereof. It is not. As a photopolymerization initiator, a commercially available product may be used. For example, IRGACURE 184, IRGACURE 907, IRGACURE 651 and the like of BASF Japan Co., Ltd. can be mentioned as preferable examples.

(Fine particles)

It is preferable that the functional layer contains fine particles in that the surface free energy of the functional layer after the alkali treatment can be increased. The fine particles are not particularly limited as long as they are used in the functional layer, and examples thereof include silica, alumina, zirconia, titanium oxide, antimony pentoxide, and the like, preferably silica. The silica fine particles may be hollow particles having cavities therein. Since the functional layer contains fine particles formed by coating with a polymeric silane coupling agent, it is possible to exert a satisfactory performance particularly on adhesion after the durability test, which is preferable. The content is preferably such that the fine particle: active ray curable resin is 0.1: 100 to 400: 100 in order to maintain the aforementioned polar component ratio a / b in an appropriate range while increasing the surface free energy.

(Polymeric silane coupling agent)

Polymer silane coupling agent means a reaction product of a polymerizable monomer and a silane coupling agent (silane compound). Such a polymer silane coupling agent can be obtained, for example, in accordance with the production method of a reaction product of a polymerizable monomer and a reactive silane compound disclosed in Japanese Patent Application Laid-Open No. 11-116240.

Specific examples of the polymerizable monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl N-hexyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (Meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl Hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylate, Methacrylic acid, 2-aminoethyl acrylate, ethylene oxide adduct of (meth) acrylic acid, trifluoromethylmethyl (meth) acrylate, (Meth) acrylate, 2-perfluoroethyl (meth) acrylate, 2-perfluoroethyl (meth) acrylate, 2-perfluoroethyl Perfluoromethyl-2-perfluoroethylmethyl (meth) acrylate, perfluoromethyl (meth) acrylate, perfluoromethyl (meth) acrylate, dipropylmethyl (Meth) acrylic acid monomers such as hexyl ethyl, 2-perfluorodecyl (meth) acrylate and 2-perfluorohexadecyl (meth) acrylate; Styrene-based monomers such as styrene, vinyltoluene,? -Methylstyrene, chlorostyrene, styrenesulfonic acid and salts thereof; Fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; Silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; Monoalkyl esters and dialkyl esters of maleic anhydride, maleic acid, maleic acid; Monoalkyl esters and dialkyl esters of fumaric acid, fumaric acid; The content of nitrile groups such as maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide and cyclohexylmaleimide Vinyl monomers; Amide group-containing vinyl monomers such as acrylamide and methacrylamide; Vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate and vinyl cinnamate; Alkenes such as ethylene and propylene; Conjugated dienes such as butadiene and isoprene; Vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, acrylic resin monomers; (Meth) acrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, Methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl acrylate, n-stearyl acrylate, , 6-hexanediol dimethacrylate, perfluorooctylethyl methacrylate, trifluoroethyl methacrylate, urethane acrylate, and the like, and mixtures thereof.

It is also possible to use polymerizers (oligomers, prepolymers) of these polymerizable monomers. These polymerizable monomers may be used alone or in combination. (Meth) acryl means acryl or methacryl, and (meth) acrylate means acrylate or methacrylate.

As the reactive silane compound, it is preferable to use an organosilicon compound represented by the following formula (1).

XR-Si (OR) ₃ (1)

(Wherein R represents an organic group having 1 to 10 carbon atoms selected from a substituted or unsubstituted hydrocarbon group and X represents an organic group selected from a (meth) acrolyl group, an epoxy group (glycidyl group), a urethane group, an amino group and a fluoro group Lt; / RTI > or more functional groups)

Specific examples of the organosilicon compound represented by the formula (1) include 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane,? - Glycidoxymethyltriethoxysilane,? -Glycidoxyethyltrimethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropyltrimethoxysilane, Glycidoxypropyltrimethoxysilane, γ- (β-glycidoxyethoxy) propyltrimethoxysilane, γ- (γ-glycidoxypropyltrimethoxysilane), γ-glycidoxypropyltrimethoxysilane, (Meth) acryloxymethyltrimethoxysilane,? - (meth) acryloxymethyltriethoxysilane,? - (meth) acryloxyethyltrimethoxysilane,? - - (meth) acryloxypropyltrimethoxysilane,? - (meth) acryloxypropyltriethoxysilane, Perfluorooctylethyltrimethoxysilane, perfluorooctylethyltriethoxysilane, perfluorooctylethyltriisopropoxysilane, trifluoropropyltrimethoxysilane, perfluorooctyltrimethoxysilane, perfluorooctylethyltriethoxysilane, perfluorooctylethyltriisopropoxysilane, Silane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, And mixtures thereof.

The polymerizable monomer and the reactive silane compound are reacted to prepare a polymeric silane coupling agent. Specifically, an organic solvent solution prepared by mixing a reactive silane compound in an amount of 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight, per 100 parts by weight of the polymerizable monomer is prepared, and a polymerization initiator is added to the mixture to obtain .

Examples of the organic solvent include aromatic hydrocarbons such as benzene, toluene and xylene, esters such as ethyl acetate and ethylene glycol monomethyl ether, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethers such as tetrahydrofuran and dioxane Alcohols such as ethers, methanol and isopropanol, and halogenated hydrocarbons such as chloroform. They may be used in combination. The total concentration of the polymerizable monomer and the reactive silane compound at this time is preferably in the range of 1 to 40% by weight, more preferably 2 to 30% by weight, as solid content.

Examples of the polymerization initiator include azoisobutyl nitrile, lauroyl peroxide, benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyisobutyrate, Peroxide polymerization initiators such as peroxypivalate, t-butylperoxybenzoate and t-butylperoxyacetate, 2,2-azobisisobutyronitrile, 2,2-azobis (2,4-dimethylvalero Nitrile), and azo compounds such as 2,2-azobis (4-methoxy-2,4-dimethylvaleronitrile).

The reaction temperature is preferably in the range of 30 to 100 占 폚, more preferably 50 to 95 占 폚. If the reaction temperature is low, the reaction is delayed, and it may take a long time to produce a polymer silane coupling agent having a high molecular weight. If the reaction temperature is too high, the reaction rate becomes too high and the desired molecular weight can not be controlled in some cases. The molecular weight of the polymeric silane coupling agent is preferably in the range of 2,500 to 150,000, more preferably 2,000 to 100,000 in terms of polystyrene.

The coating layer thickness of the polymer silane coupling agent is preferably in the range of 1 to 10 nm, more preferably 1 to 5 nm. If the coating layer is thin, the dispersibility of the fine particles into the matrix component may be insufficient. In addition, if the coating layer is too thick, the productivity tends to deteriorate.

The content of the coating layer in the polymeric silane coupling agent-coated fine particles is preferably in the range of 0.5 to 20% by weight, more preferably 1 to 15% by weight, based on the solids content.

(Method for producing polymer-coated silane coupling agent-coated fine particles)

Polymer silane coupling agent-coated fine particles can be produced by specifically adding a polymer silane coupling agent to the organic solvent dispersion of fine particles and coating the fine particles with a polymer silane coupling agent in the presence of an alkali.

Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, 2-propanol (IPA), butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, hexylene glycol and isopropyl glycol; Esters such as acetic acid methyl ester, acetic acid ethyl ester and butyl acetate; Ethers such as diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and propylene glycol monomethyl ether; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl acetone and acetoacetic acid ester, methyl cellosolve, ethyl cellosolve, butyl cellosolve, toluene, cyclohexanone and isophorone.

The total concentration of the fine particles in the dispersion and the polymeric silane coupling agent is preferably from 1 to 30% by weight, more preferably from 2 to 25% by weight, as solid content.

Alkali is added to the dispersion to adsorb the polymer silane coupling agent to the fine particles. By the addition of the alkali, the surface of the fine particles is activated (OH group is generated), and the affinity between the polymer silane coupling agent and the fine particles is increased and bonded. Or the dehydration reaction of the OH group of the polymeric silane coupling agent with the OH group of the fine particles is promoted to promote the bonding.

As the alkali, basic nitrogen compounds such as ammonia and amines are used in addition to sodium hydroxide, potassium hydroxide and the like. Among them, the basic nitrogen compound is preferred because the adsorption and bonding of the polymer silane coupling agent to the fine particles are promoted, and the non-adsorbed polymer silane coupling agent is reduced.

The amount of the alkali to be used is preferably in the range of 0.001 to 0.2 parts by mass, more preferably 0.005 to 0.1 part by mass, of the fine particles, though it varies depending on the kind of the metal oxide particles, the average particle diameter and the like.

Subsequently, fine particles adsorbed by the polymer silane coupling agent are separated and dried to obtain polymer-coated silane coupling agent fine particles.

The average particle diameter of the resulting polymeric silane coupling agent-coated fine particles is preferably from 5 to 500 nm, more preferably from 10 to 200 nm, from the viewpoint of securing optical characteristics when used in an optical film.

The content of the polymeric silane coupling agent-coated fine particles in the functional layer is preferably 0.5 to 80 parts by mass, more preferably 1 to 60 parts by mass, in terms of solid content from the viewpoint of securing the film strength of the functional layer.

(Conductive agent)

The functional layer may contain a conductive agent for imparting antistatic properties. Preferable examples of the conductive agent include metal oxide particles or a π conjugated conductive polymer. An ionic liquid is also preferably used as the conductive compound.

(additive)

The functional layer may contain a fluorine-siloxane graft compound, a fluorine-based compound, a silicon-based compound, or a compound having an HLB value of 3 to 18 from the viewpoint of improving the coating property. It is easy to control the hydrophilicity by adjusting kinds and amounts of these additives.

The HLB value is a balance of Hydrophile-Lipophile-Balance, that is, a hydrophilic-lipophilic property, and is a value indicating the hydrophilicity or lipophilicity of the compound. The smaller the HLB value is, the higher the lipophilicity is, and the larger the value, the higher the hydrophilicity. The HLB value can be obtained by the following equation.

HLB = 7 + 11.7 Log (Mw / Mo)

In the formula, Mw represents the molecular weight of the hydrophilic group, Mo represents the molecular weight of the lipophilic group, and Mw + Mo = M (molecular weight of the compound). According to the Griffin method, the HLB value = 20 × total food / molecular weight of the hydrophilic part (J.Soc.Cosmetic Chem., 5 (1954), 294) and the like.

Specific compounds of compounds having an HLB value of 3 to 18 are exemplified below, but are not limited thereto. () Represents the HLB value.

Emulsion 102 (6.3), Emergene 103 (8.1), Emergene 104P (9.6), Emergen 105 (9.7), Emergene 106 (10.5), Emergene 108 Emergen 120 (15.3), Emergen 123P (16.9), Emergen 147 (16.3), Emergen 210P (10.7), Emergen 220 (14.2), Emergene 306P (9.4), Emergene 320P (13.9), Emergen 404 (8.8), Emergen 408 (10.0), Emergen 409PV (12.0), Emergen 420 (13.6), Emergen 430 (16.2), Emergene 705 (10.5), Emergene 707 Emergen 2020G-HA (13.0), Emergen 2025G (15.7), Emergene 1118S-70 (16.4) EMULGEN LS-114 (14.0) manufactured by Nisshin Chemical Industry Co., Ltd., Surfynol 104E (4), Surfynol 104H (4) manufactured by Nisshin Chemical Industry Co., , Surfynol 104A (4), Surfynol 104BC (4), Surfynol 104DPM (4), Surfynol 104PA (4), Surfynol 104PG-50 ), Surpynol 440 (8), Surfynol 465 (13), Surfynol 485 (17), Surfynol SE 6), X-22-4272 (7), X-22-6266 (8), manufactured by Shinetsu Chemical Industries Co., Ltd.

The fluorine-siloxane graft compound refers to a copolymer compound obtained by grafting at least a polysiloxane and / or an organopolysiloxane containing a siloxane and / or an organosiloxane group to a fluorine resin. Such a fluorine-siloxane grafted compound can be produced by a method as described in the following Examples. Examples of commercially available products include ZX-022H, ZX-007C, ZX-049 and ZX-047-D manufactured by Fuji Kasei Kogyo Co.,

Examples of the fluorine-based compound include Megapak series (F-477, F-487, F-569, etc.) manufactured by DIC Corporation, Optol DSX and Optol DAC manufactured by Daikin Industries.

Examples of the silicone compound include KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-618 and KF-6011 manufactured by Shinetsu Chemical Industries Co., , KF-6015, KF-6004, BYK-UV3576, BYK-UV3510, BYK-UV3505 and BYK-UV3500 manufactured by Big Chemie Japan KK. These components are preferably added in an amount of 0.005 parts by mass or more and 10 parts by mass or less with respect to the solid component in the functional layer composition. These components may be added in two or more kinds insofar as the total additive amount is 0.005 parts by mass or more and 10 parts by mass or less.

(Ultraviolet absorber)

The functional layer may further contain an ultraviolet absorber described in a cellulose ester film to be described later. As the film constitution when the ultraviolet absorber is contained, when it is composed of two or more layers, it is preferable that the ultraviolet absorber is contained in the functional layer in contact with the cellulose ester film.

The content of the ultraviolet absorber is preferably such that the mass ratio of the ultraviolet absorber: functional layer constituent resin is 0.01: 100 to 20: 100. When two or more layers are formed, the film thickness of the functional layer in contact with the cellulose ester film is preferably in the range of 0.05 to 2 mu m. The lamination of two or more layers may be formed as a simultaneous middle layer. The co-intermediate layer means that two or more functional layers are coated on a substrate by a wet on wet without a drying step to form a functional layer. In order to stack the second functional layer with wet on wet without performing the drying process on the first functional layer, the laminate is successively layered by an extrusion coater, or a simultaneous double layer is formed on the slot die having a plurality of slits do.

(solvent)

The functional layer is formed by applying the above-mentioned functional layer-forming component to the cellulose ester film as a functional layer composition by diluting the cellulose ester film with a solvent that swells or partially dissolves the cellulose ester film, and then drying and curing .

Examples of the solvent include ketones (methyl ethyl ketone, acetone and the like) and / or acetic acid esters (such as methyl acetate, ethyl acetate and butyl acetate), alcohols (ethanol, methanol, normal propanol, isopropanol), propylene glycol monomethyl ether, , Methyl isobutyl ketone and the like are preferable. The coating amount of the functional layer composition is such that the wet film thickness is 0.1 to 80 占 퐉, preferably 0.5 to 30 占 퐉 in wet film thickness. The dry film thickness is in the range of 0.01 to 20 占 퐉 in average film thickness, preferably in the range of 1 to 15 占 퐉. More preferably, it is in the range of 2 to 12 占 퐉.

As a method of applying the functional layer composition, a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, and an ink jet method may be used.

(Functional layer forming method)

After application of the functional layer composition, drying may be followed by curing (irradiation of active rays (also referred to as UV curing treatment)) and, if necessary, UV curing followed by heat treatment. The heat treatment temperature after UV curing is preferably 80 DEG C or higher, more preferably 100 DEG C or higher, and particularly preferably 120 DEG C or higher. By performing the heat treatment after UV curing at such a high temperature, a functional layer excellent in film strength can be obtained.

The drying is preferably carried out at a temperature of 30 DEG C or higher in the rate drying section. More preferably, the temperature of the reduced rate drying section is 50 DEG C or higher.

In general, it is known that when the drying process starts, the drying process changes from a constant state to a gradually decreasing state. The section where the drying rate is constant is referred to as the constant rate drying section, and the section where the drying rate is decreased is referred to as the rate reducing drying section.

As the light source for the UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp and the like can be used.

Irradiation conditions vary depending on each lamp, but the irradiation amount of the active ray is usually in the range of 50 to 1000 mJ / cm ² , preferably in the range of 50 to 300 mJ / cm ² . In the UV curing treatment, oxygen removal (for example, substitution with an inert gas such as nitrogen purge) may be performed in order to prevent reaction inhibition by oxygen. By adjusting the removal amount of the oxygen concentration, the cured state of the surface can be controlled. This makes it possible to control the presence of the additive on the surface of the functional layer, and as a result, it is easy to control the difference in contact angle? In the above-described range.

When irradiating the active line, it is preferable to perform the tension while applying a tensile force in the film transport direction, and more preferably, the tension is applied in the width direction. The applied tension is preferably 30 to 300 N / m. The method of applying the tension is not particularly limited. The tension may be applied in the carrying direction on the back roller, or in the width direction or the biaxial direction in the tenter. As a result, a film having excellent planarity can be obtained.

The optical film may be surface-modified with the functional layer. Examples of the surface modification method include a plasma irradiation treatment, a corona irradiation treatment, and a solvent treatment. These surface modification methods may be performed singly or in combination.

On the optical film, the functional layer may have at least one layer, or may be composed of a plurality of layers. The functional layer may be provided on both surfaces of the optical film, and the outermost surface of at least one surface may satisfy the conditional expressions (1) and (2).

(Back coat layer)

It is preferable to form the back coat layer on the side opposite to the side where the functional layer of the optical film (for example, hard coating film) of the present embodiment is formed. The backcoat layer is formed by coating, CVD, or the like so as to correct curl generated by forming a functional layer or other layer. That is, by making the back surface layer have the property of curling inward, the degree of curl can be balanced. It is also preferable that the backcoat layer is also formed by coating with an anti-blocking layer. In this case, fine particles are preferably added to the backcoat layer coating composition in order to provide an anti-blocking function. The backcoat layer may satisfy the conditional expressions (1) and (2).

Examples of the inorganic particles to be added to the back coat layer include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, indium oxide, , Hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. It is preferable that the fine particles contain silicon because the haze is lowered, and silicon dioxide is particularly preferable.

These fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50 and TT600 (manufactured by Nippon Aerosil Co., Ltd.). The zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used. Examples of the polymer fine particles include a silicone resin, a fluororesin, and an acrylic resin. Silicone resin is preferable, and it is particularly preferable to have a three-dimensional network structure. For example, Tosepearl 103, Copper 105, Copper 108, Copper 120, Copper 145, Copper 3120 and Copper 240 ), And can be used.

Of these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a high antiblocking effect while keeping the haze low. The optical film (for example, hard coating film) used in the present embodiment preferably has a coefficient of dynamic friction on the back side of the functional layer (e.g., hard coating layer) of 0.9 or less, particularly 0.1 to 0.9.

The fine particles contained in the back coat layer are preferably contained in an amount of 0.1 to 50 mass%, more preferably 0.1 to 10 mass%, based on the binder. When the backcoat layer is formed, the haze increase is preferably 1% or less, more preferably 0.5% or less, particularly preferably 0.0 to 0.1%.

Specifically, the backcoat layer is preferably formed by applying a composition containing a solvent for dissolving a transparent resin film or a solvent for swelling. The solvent to be used may further contain a solvent that does not dissolve in addition to a solvent to be dissolved and / or a solvent to be swollen. The composition may be a composition prepared by mixing these in appropriate proportions depending on the degree of curling of the transparent resin film or the type of resin, .

When it is desired to enhance the curl prevention function, it is effective to increase the mixing ratio of the solvent to dissolve the solvent composition and / or the swelling solvent to make the ratio of the solvent that does not dissolve small. The mixing ratio is preferably (solvent to be dissolved and / or swelling solvent): (solvent not to dissolve) = 10: 0 to 0.3: 9.7. Examples of the solvent for dissolving or swelling the transparent resin film contained in such a mixed composition include dioxane, acetone, methyl ethyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, cyclohexane, diacetone Propylene glycol monomethyl ether acetate, propylene carbonate, cyclopentanone, 3-pentanone, 1,2-dimethoxyethane, tetrahydrofuran, ethyl lactate, 2-methoxyethyl acetate, propylene glycol dimethyl ether, trichlorethylene, methylene chloride, ethylene chloride, tetrachloroethane, trichloroethane, chloroform and the like. Examples of the solvent that does not dissolve include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, propylene glycol monomethyl ether or hydrocarbons (toluene, xylene, cyclohexanol).

It is preferable that these coating compositions are applied to the surface of the transparent resin film at a wet film thickness of 1 to 100 mu m by using a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater or the like, desirable. The backcoat layer may contain a resin as a binder. Examples of the resin used as the binder of the back coat layer include a vinyl chloride-vinyl acetate copolymer, a vinyl chloride resin, a vinyl acetate resin, a copolymer of vinyl acetate and vinyl alcohol, a partially hydrolyzed vinyl chloride-vinyl acetate copolymer , A vinyl-based polymer such as a vinyl chloride-vinylidene chloride copolymer, a vinyl chloride-acrylonitrile copolymer, an ethylene-vinyl alcohol copolymer, a chlorinated polyvinyl chloride, an ethylene-vinyl chloride copolymer, or an ethylene- Cellulose derivatives such as nitrocellulose, cellulose acetate propionate (preferably having an acetyl group substitution degree of 1.8 to 2.3, a propionyl group substitution degree of 0.1 to 1.0), diacetyl cellulose and cellulose acetate butyrate resin, a maleic acid and / Or a copolymer of acrylic acid, an acrylic acid ester copolymer, Acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin, polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin Based resins such as polyether polyurethane resins, polycarbonate polyurethane resins, polyester resins, polyether resins, polyamide resins, amino resins, styrene-butadiene resins and butadiene-acrylonitrile resins, Resins, and the like, but the present invention is not limited thereto. Examples of the acrylic resin include acrylic resins such as Acryphet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperp M-4003, M-4005, M-4006, M- BR-75, BR-75, BR-75, BR-75, BR-60, BR-80, BR-80, BR-90, BR-90, BR-90, BR- (Manufactured by Mitsubishi Rayon Co., Ltd.), BR-105, BR-106, BR-107, BR-108, BR-112, BR- Various homopolymers and copolymers prepared by using acrylic and methacrylic monomers as raw materials are commercially available, and preferable ones can be appropriately selected.

Particularly preferred is a cellulose-based resin layer such as diacetyl cellulose and cellulose acetate propionate.

The order of applying and forming the backcoat layer may be either before or after the formation of the optical film opposite to the backcoat layer (the hardcoat layer or another layer such as the antistatic layer), but the backcoat layer may be blocked In the case where the protective layer also serves as an anti-blocking layer, it is preferable to first coat it. Alternatively, the backcoat layer may be applied in two or more divided portions before and after the application of the hard coat layer.

[Optical Film Properties]

(Surface shape)

The arithmetic average roughness Ra (JIS B0601: 2001) of the functional layer is preferably in the range of 2 to 100 nm, particularly preferably in the range of 2 to 20 nm. By setting the arithmetic average roughness Ra in the above range, visibility and clearability are excellent. The arithmetic average roughness Ra is a value measured by an optical interference type surface roughness meter (NewView, manufactured by ZYGO) according to JIS B0601: 2001.

(Hayes)

The haze of the optical film is preferably in the range of 0.05% to 10% in view of the visibility when used in an image display apparatus. The haze can be measured in accordance with JIS-K7105 and JIS K7136.

(Hardness)

As for the hardness of the optical film, it is preferable that the pencil hardness, which is an index of hardness, is equal to or higher than HB. If the pencil hardness is equal to or higher than HB, scratches are unlikely to occur in the polarizing step. The pencil hardness was measured by using a test pencil specified by JIS S 6006 under the conditions of a weight of 500g and a humidity of at least 23 hours at a temperature of 23 ° C and a relative humidity of 55% for 2 hours or more and a functional layer defined by JIS K5400 It is a value measured according to the pencil hardness evaluation method.

[Film substrate]

It is preferable that the film substrate is easy to manufacture, has good adhesiveness to the functional layer, is optically isotropic, transparent and the like.

The material of the film base material is not particularly limited as long as it has the above properties. For example, cellulose ester films such as a cellulose diacetate film, a cellulose triacetate film, a cellulose acetate propionate film and a cellulose acetate butyrate film, A polyester film such as a polyester film, a polycarbonate film, a polyarylate film, a polysulfone film (including a polyethersulfone) film, a polyester film such as polyethylene terephthalate and polyethylene naphthalate, a polyethylene film, (Manufactured by JSR Co., Ltd., Zeonex, Zeonoa, manufactured by Nippon Zeon Co., Ltd.)), polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, cycloolefin polymer film Polymethylpentene film, polyether Ketone film, polyether ketone may already include a de film, polyamide film, fluorocarbon resin film, a nylon film, polymethyl methacrylate film, an acrylic film, such as polylactic acid film or a glass plate. Among them, a cellulose ester film, a polycarbonate film, and a cycloolefin polymer film are preferable.

Examples of the cellulose ester film (hereinafter also referred to as cellulose acetate film) include triacetylcellulose film, cellulose acetate propionate film, cellulose diacetate film, and cellulose acetate butyrate film. In addition, the cellulose ester film can be produced by using a combination of a polyester resin such as polyethylene terephthalate and polyethylene naphthalate, a polycarbonate resin, a polyethylene resin, a polypropylene resin, a norbornene resin, a fluororesin and a cycloolefin polymer You can. Examples of commercially available products of the cellulose ester film include Konica Minolta Tact KC8UX, KC4UX, KC8UY, KC4UY, KC6UA, KC4UA, KC2UA, KC4UE and KC4UZ (manufactured by Konica Minolta Corporation). The refractive index of the cellulose ester film is preferably 1.45 to 1.55. The refractive index can be measured in accordance with JIS K7142-2008.

(Cellulose ester resin)

The cellulose ester resin (hereinafter also referred to as a cellulose ester or a cellulose resin) contained in the cellulose ester film is preferably a lower fatty acid ester of cellulose. The lower fatty acid means a fatty acid having 6 or less carbon atoms. Examples of the lower fatty acid ester of cellulose include cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate and cellulose butyrate, and mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate.

Particularly preferably used lower fatty acid esters of cellulose are cellulose diacetate, cellulose triacetate, and cellulose acetate propionate. These cellulose esters can be used alone or in combination.

The cellulose diacetate preferably has an average degree of acetalization (amount of bound acetic acid) of 51.0% to 56.0%. Commercially available products include L20, L30, L40 and L50 of Daicel Co., Ltd., Ca398-3, Ca398-6, Ca398-10, Ca398-30 and Ca394-60S available from Eastman Chemical Co.,

The cellulose triacetate preferably has an average degree of acetalization (amount of bonded acetic acid) of 54.0 to 62.5%, more preferably a cellulose triacetate having an average degree of acetatization of 58.0 to 62.5%.

The cellulose triacetate preferably contains cellulose triacetate A and cellulose triacetate B. Cellulose triacetate A is cellulose triacetate having a number average molecular weight (Mn) of 125000 to less than 155000, a weight average molecular weight (Mw) of 265000 to less than 310000 and an Mw / Mn of 1.9 to 2.1. Cellulose triacetate B is a cellulose triacetate having an acetyl group substitution degree of 2.75 to 2.90, a Mn of 155000 to less than 180,000, an Mw of 290000 to less than 360000, and an Mw / Mn of 1.8 to 2.0.

Cellulose acetate propionate has an acyl group having 2 to 4 carbon atoms as a substituent, a substitution degree of an acetyl group as X, and a substitution degree of a propionyl group or a butyryl group as Y, the following formulas (I) and (II) at the same time.

(I) 2.6? X + Y? 3.0

(II) 0? X? 2.5

Among them, it is preferable that 1.9? X? 2.5 and 0.1? Y? 0.9.

The degree of substitution of the acyl group can be measured according to ASTM-D817-96.

The number average molecular weight (Mn) and the molecular weight distribution (Mw) of the cellulose ester can be measured by high performance liquid chromatography. The measurement conditions are as follows.

Solvent: methylene chloride

Column: Shodex K806, K805, K803G

(I used three connection of the product made by Showa Denko Co., Ltd.)

Column temperature: 25 ° C

Sample concentration: 0.1 mass%

Detector: RI Model 504 (manufactured by GL Science)

Pump: L6000 (manufactured by Hitachi Seisakusho Co., Ltd.)

Flow rate: 1.0 ml / min

Calibration curve: Standard polystyrene STK A calibration curve with 13 samples of standard polystyrene (manufactured by Tosoh Corporation) Mw = 1000000 to 500 was used. 13 samples are preferably used at substantially equal intervals.

(Thermoplastic acrylic resin)

The cellulose ester film may be composed of a combination of a thermoplastic acrylic resin. When used in combination, it is preferable that the mass ratio of the thermoplastic acrylic resin to the cellulose ester resin is in the range of 95: 5 to 50:50 in the case of the thermoplastic acrylic resin: cellulose ester resin.

Acrylic resins also include methacrylic resins. The acrylic resin is not particularly limited, but it preferably contains 50 to 99 mass% of methyl methacrylate units and 1 to 50 mass% of other monomer units copolymerizable therewith. Examples of other copolymerizable monomers include alkyl methacrylates having 2 to 18 carbon atoms in the alkyl number, alkyl acrylates having 1 to 18 carbon atoms in the alkyl number, alpha, beta -unsaturated acids such as acrylic acid and methacrylic acid, Aromatic vinyl compounds such as styrene,? -Methylstyrene,?,? - unsaturated nitriles such as acrylonitrile and methacrylonitrile, maleic anhydride, maleimide , N-substituted maleimide, and glutaric anhydride. These may be used singly or in combination of two or more.

Of these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, and 2-ethylhexyl acrylate are preferable from the viewpoint of thermal decomposition resistance and fluidity of the copolymer, Methyl acrylate or n-butyl acrylate is particularly preferably used. The weight average molecular weight (Mw) is preferably in the range of 80000 to 500000, and more preferably in the range of 1100000 to 500000.

The weight average molecular weight of the acrylic resin can be measured by gel permeation chromatography. Examples of commercially available acrylic resins include Delpet 60N and 80N (manufactured by Asahi Kasei Chemicals Corporation), Dianal BR52, BR80, BR83, BR85 and BR88 (manufactured by Mitsubishi Rayon Co., Ltd.) and KT75 Ltd.) and the like. Two or more acrylic resins may be used in combination.

(? / 4 film)

As the film substrate, a? / 4 film may be used. When an optical film of this embodiment is incorporated into an image display apparatus by using a? / 4 film for the film substrate, it is preferable that the optical film is excellent in visibility and also in cross talk.

The? / 4 film is a film in which the in-plane retardation of the film is about 1/4 of the wavelength of a predetermined light (usually visible light region). The? / 4 film is preferably a wide-band? / 4 film having a phase difference of about 1/4 of the wavelength in the wavelength range of visible light so as to obtain substantially complete circularly polarized light in the wavelength range of visible light.

The retardation value Ro (550) measured at a wavelength of 550 nm of the? / 4 film is preferably in the range of 60 nm or more and 220 nm or less, more preferably 80 nm or more and 200 nm or less, more preferably 90 nm or more and 190 nm or less Is more preferable. The in-plane retardation value Ro is expressed by the following equation.

Ro = (nx-ny) xd

In the formula, nx and ny indicate the maximum refractive index (also referred to as the refractive index in the slow axis direction) in the plane of the film and the refractive index in the direction perpendicular to the slow axis in the film plane, of the refractive index at a wavelength of 550 nm Refractive index, and d is the thickness (nm) of the film.

Ro can be calculated by measuring the birefringence at each wavelength under an environment of 23 ° C and 55% RH using an automatic birefringence cobra (KOBRA) -21ADH (manufactured by Oji Chemical Industry Co., Ltd.).

In order to effectively function as a lambda / 4 film, it is preferable that the relation of Ro (590) -Ro (450) > = 2 nm is satisfied at the same time, , And Ro (590) -Ro (450)? 10 nm. In addition, Ro (A) denotes an in-plane retardation value measured at the wavelength Anm.

When the angle between the slow axis of the? / 4 film and the transmission axis of the polarizer described later is substantially 45, the circular polarizer can be obtained. Substantially 45 DEG is meant to be in the range of 30 DEG to 60 DEG, more preferably in the range of 40 DEG to 50 DEG. The angle between the in-plane slow axis of the? / 4 film and the transmission axis of the polarizer is preferably 41 to 49 °, more preferably 42 to 48 °, still more preferably 43 to 47 °, Deg.].

The? / 4 film is not particularly limited as long as it is an optically transparent resin, and examples thereof include acrylic resin, polycarbonate resin, cycloolefin resin, polyester resin, polylactic acid resin, polyvinyl alcohol resin , The aforementioned cellulose resin, and the like can be used. Among them, from the viewpoint of chemical resistance, the? / 4 film is preferably a cellulose resin or a polycarbonate resin. From the viewpoint of heat resistance, the? / 4 film is preferably a cellulose resin.

(Retardation adjusting agent)

The retardation adjustment of? / 4 can be performed by adding the following retardation adjusting agent to the above-mentioned resin film.

As the retardation adjusting agent, an aromatic compound having two or more aromatic rings as described in European Patent No. 911,656A2 can be used.

Two or more kinds of aromatic compounds may be used in combination. The aromatic ring of the aromatic compound includes, in addition to the aromatic hydrocarbon ring, an aromatic heterocycle. Especially preferred are aromatic heterocycles, and the aromatic heterocycle is generally an unsaturated heterocycle. Among them, 1,3,5-triazine ring is particularly preferable.

(Polycarbonate resin)

A polycarbonate resin may also be used for the? / 4 film. As the polycarbonate resin, various resins can be used without particular limitation, and aromatic polycarbonate resins are preferable from the viewpoints of chemical properties and physical properties, and bisphenol A polycarbonate resins are particularly preferable. Among them, it is more preferable to use a bisphenol A derivative having a benzene ring, a cyclohexane ring and an aliphatic hydrocarbon group introduced into bisphenol A. Particularly preferred is a polycarbonate resin having a structure in which the anisotropy in the unit molecule is reduced, obtained by using a derivative in which the functional group is introduced asymmetrically to the central carbon of bisphenol A. Examples of such polycarbonate resins include those obtained by replacing two methyl groups in the central carbon of bisphenol A with benzene rings and one hydrogen in each benzene ring of bisphenol A with asymmetric Is particularly preferably used.

Specifically, it is obtained from a 4,4'-dihydroxydiphenylalkane or a halogen substituent thereof by a phosgene method or an ester exchange method. For example, 4,4'-dihydroxydiphenyl methane, 4,4 ' Dihydroxydiphenyl ethane, 4,4'-dihydroxydiphenyl butane, and the like. Further, for example, Japanese Patent Application Laid-Open Nos. 2006-215465, 2006-91836, 2005-121813, 2003-167121, and Japanese Patent Polycarbonate resins described in JP-A-2009-126128, JP-A-2012-31369, JP-A-2012-67300, and WO00 / 26705.

The polycarbonate resin may be used in combination with a transparent resin such as a polystyrene type resin, a methyl methacrylate type resin and a cellulose acetate type resin. Further, a resin layer containing a polycarbonate resin may be laminated on at least one surface of a resin film formed using a cellulose acetate-based resin.

The polycarbonate resin preferably has a glass transition point (Tg) of 110 DEG C or more and a water absorption rate (value measured at 23 DEG C under water for 24 hours) of 0.3% or less. It is more preferable that the Tg is 120 ° C or more and the water absorption rate is 0.2% or less.

The polycarbonate resin film can be formed by a known method, and of these, the solution casting method and the melt casting method are preferable.

(Alicyclic Olefin Polymerization Resin)

As the? / 4 film, an alicyclic olefin polymerization system resin may be used. Examples of the alicyclic olefin polymerization-type resin include a cyclic olefin random multi-component copolymer disclosed in JP-A-05-310845, a hydrogenated polymer described in JP-A-05-97978, The thermoplastic dicyclopentadiene ring-opening polymer and hydrogenated product thereof described in JP-A-124429 may be employed.

The alicyclic olefinic polymer resin is a polymer having an alicyclic structure such as a saturated alicyclic hydrocarbon (cycloalkane) structure or an unsaturated alicyclic hydrocarbon (cycloalkene) structure. There is no particular limitation on the number of carbon atoms constituting the alicyclic structure, but the number of carbon atoms constituting the alicyclic structure is not particularly limited, but usually ranges from 4 to 30, preferably from 5 to 20, and more preferably from 5 to 15. When mechanical strength, heat resistance, The properties are highly balanced and suitable.

The proportion of the repeating unit containing an alicyclic structure in the alicyclic olefin polymer may be appropriately selected, but is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the proportion of the repeating unit having an alicyclic structure in the alicyclic polyolefin resin is within this range, the transparency and heat resistance of the optical material such as the retardation film obtained in the long warp stretched film of the present embodiment are improved, which is preferable.

Examples of the olefin polymerization system resin having an alicyclic structure include a norbornene resin, a monocyclic cycloolefin resin, a cyclic conjugated diene resin, a vinyl alicyclic hydrocarbon resin, and hydrides thereof. Among them, the norbornene resin can be suitably used because of its good transparency and moldability.

As the norbornene resin, for example, a ring-opening polymer of a monomer having a norbornene structure or a ring-opening copolymer of a monomer having a norbornene structure and another monomer or a hydride thereof, an adduct of a monomer having a norbornene structure Or addition copolymers of monomers having a norbornene structure with other monomers, or hydrides thereof. Among them, ring-opened (co) polymer hydrides of monomers having a norbornene structure can be suitably used particularly in view of transparency, moldability, heat resistance, low moisture absorption, dimensional stability and light weight.

As a method for molding a long film using the norbornene resin as described above, a solution casting method or a melt extrusion method is preferable. As the melt extrusion method, an inflation method using a die and the like can be mentioned. However, a method using a T-die is preferable in view of productivity and thickness accuracy.

As an extrusion molding method using a T die, a method of maintaining a molten thermoplastic resin in a stable state when it is brought into close contact with a cooling drum as described in Japanese Patent Application Laid-Open No. 2004-233604, It is possible to produce a long film having a small variation in optical characteristics such as angle.

Specifically, 1) a method in which, when a long film is produced by a melt extrusion method, a sheet-like thermoplastic resin extruded from a die is brought into close contact with a cooling drum under a pressure of 50 kPa or less to be pulled; 2) When a long film is produced by the melt extrusion method, the circumferential member is firstly covered with a surrounding member from the die opening to the close cooling drum, and the distance from the circumferential member to the die opening or the cooling drum Way; 3) a method of warming the temperature of the atmosphere within 10 mm from the sheet-like thermoplastic resin extruded from the die opening to a specific temperature when producing a long film by the melt extrusion method; 4) a method in which the sheet-like thermoplastic resin extruded from the die is brought into close contact with the cooling drum under a pressure of 50 kPa or less and is pulled thereon; 5) When a long film is produced by the melt extrusion method, there is a method of blowing air having a speed difference of 0.2 m / s or less from the drawing speed of the first cooling drum closely attached to the sheet-shaped thermoplastic resin extruded from the die opening have.

The long film may be a single layer or a laminated film of two or more layers. The laminated film can be obtained by a known method such as a coextrusion molding method, a shared softening molding method, a film lamination method, and a coating method. Of these, the co-extrusion molding method and the shared mold forming method are preferable.

(Fine particles)

In the film base material of this embodiment, in order to improve the handling property, for example, acrylic particles, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, It is preferable to contain a matting agent such as inorganic fine particles or crosslinked polymers such as aluminum, magnesium silicate and calcium phosphate. The acrylic particle is not particularly limited, but is preferably a multi-layered acrylic granular composite. Of these, silicon dioxide is preferable in that the haze of the cellulose ester film can be reduced. The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably in the range of 5 to 16 nm, and particularly preferably in the range of 5 to 12 nm.

(Ester compound)

The film substrate of the present embodiment preferably contains an ester compound or sugar ester represented by the following general formula (X) in view of dimensional stability in environmental changes. First, the ester compound represented by the general formula (X) will be described.

(X) B- (GA) n-G-B

(Wherein B is a hydroxy group or a carboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms or an aryl glycol residue having 6 to 12 carbon atoms or an oxyalkylene glycol residue having 4 to 12 carbon atoms, An alkylene dicarboxylic acid residue of 12 to 12 carbon atoms or an aryl dicarboxylic acid residue of 6 to 12 carbon atoms, and n represents an integer of 1 or more)

Examples of the alkylene glycol component having 2 to 12 carbon atoms in the general formula (X) include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, Propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2- Ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1, Pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1,3-hexanediol, 2-methyl 1,8-octanediol, Diol, 1,10-decanediol, 1,12-octadecanediol, and the like, and these glycols are used singly or as a mixture of two or more kinds. Particularly, alkylene glycol having 2 to 12 carbon atoms is particularly preferable because of its excellent compatibility with cellulose acetate. Examples of the aryl glycol component having 6 to 12 carbon atoms include hydroquinone, resorcin, bisphenol A, bisphenol F, and bisphenol. These glycols can be used alone or as a mixture of two or more thereof.

Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. These glycols may be used alone or as a mixture of two or more . Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid, Species or a mixture of two or more species. Examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalene dicarboxylic acid, and 1,4-naphthalene dicarboxylic acid. Specific examples (compounds X-1 to X-17) of the compound represented by formula (X) are shown below, but the present invention is not limited thereto.

[Chemical Formula 1]

(2)

(3)

(Ester ester compound)

Next, the sugar ester compound will be described. The sugar ester compound is an ester other than a cellulose ester, and is a compound obtained by esterifying all or a part of the sugar OH groups such as the following monosaccharides, 2 sugars, 3 sugars or oligosaccharides. Examples of the sugar include glucose, galactose, mannose, fructose, xylose, arabinose, lactose, sucrose, nisthos, 1F-fructosylnitose, stachyose, maltitol, lactitol, Oz, cellobiose, maltose, cellotriose, maltotriose, raffinose and kestose. In addition to these, gentiobiose, gentiootriose, gentiootetraose, xylotriose, galactosyl sucrose and the like can be mentioned. Of these compounds, compounds having a furanose structure and / or a pyranose structure are particularly preferable. Among these, sucrose, cestose, nisthose, 1F-fructosylnitose, stachyose and the like are preferable, and sucrose is more preferable. As the oligosaccharide, maltooligosaccharide, isomaltooligosaccharide, fructooligosaccharide, galactooligosaccharide, and xylooligosaccharide are also preferably used.

The monocarboxylic acid used for esterification of sugar is not particularly limited, and known aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, aromatic monocarboxylic acids and the like can be used. One carboxylic acid may be used, or two or more carboxylic acids may be used. Preferred aliphatic monocarboxylic acids are acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethylhexanecarboxylic acid, undecylic acid, But are not limited to, acid, tridecylic acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachic acid, behenic acid, lignoceric acid, , Unsaturated fatty acids such as malic acid and lactic acid, and unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linolic acid, linolenic acid, arachidonic acid and octenoic acid. Examples of preferred alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof. Examples of preferred aromatic monocarboxylic acids include benzoic acid, aromatic monocarboxylic acids having an alkyl group and an alkoxy group introduced into the benzene ring of benzoic acid, cinnamic acid, benzilic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid, tetralincarboxyl An aromatic monocarboxylic acid having two or more benzene rings such as benzenesulfonic acid, and an aromatic monocarboxylic acid having two or more benzene rings, or derivatives thereof, and more specifically, xylylic acid, hemelitic acid, mesitylene acid, O-, m-, p-anisic acid, o-toluic acid, o-toluic acid, hydro atonic acid, atropic acid, hydrocinnamic acid, salicylic acid, , m-, p-homosalicylic acid, o-pyrocatecholic acid,? -resoric acid, vanillic acid, isobanilic acid, veratric acid, o-veratric acid, gallic acid, asalonic acid, mandelic acid, Homobarinic acid, homo-veratric acid, o-homo veratric acid, phthalic acid, p-cumaric acid But, in particular, the acid is preferred. Of the esterified ester compounds, an acetyl compound having an acetyl group introduced by esterification is preferable. Specific examples of the sugar ester compound that can be used in the present embodiment are shown below, but the present invention is not limited thereto.

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

The sugar ester compound is preferably a compound represented by the general formula (Y). Hereinafter, the compound represented by the general formula (Y) will be described.

[Chemical Formula 9]

(Wherein R ₁ to R ₈ represent a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms, or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms, and R ₁ to R ₈ are the same , May be different)

Hereinafter, the compound represented by the general formula (Y) is represented more specifically (compounds Y-1 to Y-23), but is not limited thereto. In the following table, when the average degree of substitution is less than 8.0, any one of R ₁ to R ₈ represents a hydrogen atom.

[Chemical formula 10]

(11)

[Chemical Formula 12]

The substitution degree distribution can be adjusted to a desired substitution by controlling the esterification reaction time or by mixing compounds having different degrees of substitution.

The ester compound or sugar ester compound represented by the general formula (X) is preferably contained in the cellulose acetate film in an amount of 1 to 30 mass%, more preferably 5 to 25 mass%, more preferably 5 to 20 mass% Is particularly preferable.

(Plasticizer)

The film substrate of the present embodiment may contain a plasticizer, if necessary. Examples of the plasticizer include, but are not limited to, polyvalent carboxylic acid ester plasticizers, glycolate plasticizers, phthalate ester plasticizers, phosphate ester plasticizers, polyhydric alcohol ester plasticizers, and acrylic plasticizers. Of these, an acrylic plasticizer is preferable in that it is easy to control the cellulose ester film by a retardation value described later.

The polyhydric alcohol ester plasticizer is a plasticizer which is an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably 2 to 20, aliphatic polyhydric alcohol esters. Specific examples of polyhydric alcohol ester plasticizers are shown below, but are not limited thereto.

[Chemical Formula 13]

[Chemical Formula 14]

The glycolate-based plasticizer is not particularly limited, but alkyl phthalyl alkyl glycolates can be preferably used. Alkyl phthalyl alkyl glycolates include, for example, methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, Butyl phthalyl ethyl glycolate, butyl phthalyl ethyl glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, and octyl phthalyl ethyl glycolate.

Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl terephthalate, dicyclohexyl phthalate, dicyclohexyl terephthalate, .

Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyldiphenyl phosphate, octyldiphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like.

The polycarboxylic acid ester plasticizer is a compound which is an ester of a polyvalent carboxylic acid and an alcohol having a valence of 2 or more, preferably 2 to 20, Specific examples include triethyl citrate, tributyl citrate, acetyl triethyl citrate (ATEC), acetyl tributyl citrate (ATBC), benzoyl tributyl citrate, acetyltriphenyl citrate, acetyl tribenzyl citrate, Dibutyl, diacetyl dibutyl tartrate, tributyl trimellitate, tetrabutyl pyromellitate, and the like, but are not limited thereto.

The acrylic plasticizer is preferably an acrylic polymer, and the acrylic polymer is preferably a homopolymer or copolymer of acrylic acid or methacrylic acid alkyl ester. Examples of the monomer of the acrylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n-, i-), acrylonitrile (n-, i-), myristyl acrylate (n- , i-), acrylic acid (2-ethylhexyl), acrylic acid (? -caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl) Hydroxybutyl), acrylic acid (2-methoxyethyl), acrylic acid (2-ethoxyethyl) and the like, or the acrylic acid ester is replaced with methacrylic acid ester . The acrylic polymer is a homopolymer or a copolymer of the above monomers, but preferably has 30 mass% or more of acrylic acid methyl ester monomer units and more preferably 40 mass% or more of methacrylic acid methyl ester monomer units. In particular, a homopolymer of methyl acrylate or methyl methacrylate is preferred.

When the above-mentioned plasticizer is contained in the film base material of the present embodiment, it is preferably contained in an amount of 1 to 50 mass%, more preferably 5 to 35 mass%, and more preferably 5 to 25 mass% with respect to the cellulose acetate. Is particularly preferable.

(Ultraviolet absorber)

The film substrate of this embodiment may contain an ultraviolet absorber. Since the ultraviolet absorbent absorbs ultraviolet rays of 400 nm or less, the durability can be improved. The ultraviolet absorbent preferably has a transmittance of not more than 10% at a wavelength of 370 nm, more preferably not more than 5%, further preferably not more than 2%. Specific examples of ultraviolet absorbers include, but are not limited to, oxybenzophenone compounds, benzotriazole compounds, salicylic ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, , And inorganic powders.

More specifically, for example, 5-chloro-2- (3,5-di-sec-butyl-2-hydoxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol- ) -6- (straight chain and branched dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone and 2,4-benzyloxybenzophenone. For example, tinuvin such as Tinuvin 109, Tinuvin 171, Tinuvin 234, Tinuvin 326, Tinuvin 327 and Tinuvin 328 available from BASF Japan is preferably used. .

The ultraviolet absorber preferably used is a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, or a triazine ultraviolet absorber, particularly preferably a benzotriazole ultraviolet absorber, a benzophenone ultraviolet absorber, or the like.

In addition, a discotic compound such as a compound having a 1,3,5-triazine ring is also preferably used as an ultraviolet absorber. As the ultraviolet absorber, a polymer ultraviolet absorber can be preferably used, and a polymer-type ultraviolet absorber is preferably used.

As the benzotriazole-based ultraviolet absorber, commercially available TINUVIN 109 (octyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazole Phenyl] propionate and 2-ethylhexyl-3- [3- tert -butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol- Propionate), TINUVIN 928 (2- (2H-benzotriazol-2-yl) -6- (1-methyl- Tetramethylbutyl) phenol) and the like can be used. As the triazine type ultraviolet absorber, TINUVIN 400 (2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine-2- (Reaction product of a) -5-hydroxyphenyl and oxirane), TINUVIN 460 (2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dimethylphenyl) -1,3,5-triazine), TINUVIN 405 (2- (2,4-dihydroxyphenyl) , The reaction product of 3,5-triazine and (2-ethylhexyl) -glycidic acid ester), and the like.

The ultraviolet absorber may be added by dissolving the ultraviolet absorber in an alcohol such as methanol, ethanol or butanol, or an organic solvent such as methylene chloride, methyl acetate, acetone or dioxolane or a mixed solvent thereof, ), Or may be added directly to the dope composition. To dissolve in an organic solvent such as an inorganic powder, it is dispersed in an organic solvent and cellulose acetate using a dissolver or a sand mill, and then added to the dope.

The amount of the ultraviolet absorber to be used is preferably from 0.5 to 10% by mass, more preferably from 0.6 to 4% by mass, based on the cellulose acetate film.

(Antioxidant)

The film substrate of this embodiment may further contain an antioxidant (deterioration inhibitor). The antioxidant has a role of retarding or preventing the decomposition of the cellulose acetate film by halogen or a phosphoric acid of a phosphate-based plasticizer in the residual solvent amount in the cellulose acetate film. As the antioxidant, a hindered phenol-based compound is preferably used, and examples thereof include 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexane Di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4- Di-t-butyl anilino) -1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5- Propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5- (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5 Di-t-butyl-4-hydroxybenzyl) -isocyanurate. The amount of these compounds to be added is preferably 1 ppm to 10000 ppm, more preferably 10 ppm to 1000 ppm, in mass ratio with respect to the cellulose acetate film.

(Hindered amine compound)

The film substrate of this embodiment may contain a hindered amine compound. The hindered amine compound is a structure which functions as an antioxidant and has a bulky organic group (for example, a bulky branched alkyl group) in the vicinity of N atom. The hindered amine-based compounds include, for example, 2,2,6,6-tetraalkylpiperidine compounds, acid addition salts thereof, or complexes thereof with a metal compound. These compounds include the compounds of the following general formula (1).

[Chemical Formula 15]

Wherein R1 and R2 are a hydrogen atom or a substituent.

Specific examples of hindered amines include 4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1 4-hydroxy-2,2,6,6-tetramethylpiperidine, 1- (4-t-butyl-2-butenyl) -4- Tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine (3, < RTI ID = 0.0 > 4-methoxypyridin- Butyl-4-hydroxyphenyl) -propionate, 1-benzyl-2,2,6,6-tetramethyl-4-piperidinyl maleate, (di- Tetramethylpiperidin-4-yl) -adipate, (di-2,2,6,6-tetramethylpiperidin-4-yl) Methyl-2,6-diethyl-piperidin-4-yl) -s sebacate, (di- 4-yl) -phthalate, 1-acetyl-2,2,6,6-tetramethylpiperidine 4-yl-acetate, trimellitic acid-tri- (2,2,6,6-tetramethylpiperidin-4-yl) ester, 1-acryloyl-4-benzyloxy- , Dibutyl-malonic acid-di- (1,2,2,6,6-pentamethyl-piperidin-4-yl) -ester, dibenzyl-malonic acid- (1,2,3,6-tetramethyl-2,6-diethylpiperidin-4-yl) -ester, dimethyl-bis- (2,2,6,6-tetramethylpiperidin- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phosphite, tris- Tetramethylpiperidin-4-yl) -phosphate, N, N'-bis- (2,2,6,6-tetramethylpiperidin- Kiss (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl- - piperidyl) 1,2,3,4-butanetetracarboxylate, N, N'-bis- (2,2,6,6-tetramethylpiperidin- , 6-diacetamide, 1-acetyl N, N ', N'-tetramethylpiperidine, 4-benzylamino-2,2,6,6-tetramethylpiperidine, (2,2,6,6-tetramethylpiperidin-4-yl) -N, N'-dibutyl-adipamide, N, N'-bis- -Tetramethylpiperidin-4-yl) -N, N'-dicyclohexyl- (2-hydroxypropylene), N, N'-bis- (2,2,6,6-tetramethylpiperidine -4-yl) -p-xylylene-diamine, 4- (bis-2-hydroxyethyl) -amino-1,2,2,6,6-pentamethylpiperidine, 4- Methyl-β- [N- (2,2,6,6-tetramethylpiperidin-4-yl)] - 1,2,3,4-tetrahydro- -Amino-acrylic acid methyl ester.

In addition, N, N ', N ", N"' - tetrakis- [4,6-bis- [butyl- (N-methyl-2,2,6,6-tetramethylpiperidin- Amino] -triazin-2-yl] -4,7-diazadecane-1,10-diamine, dibutylamine and 1,3,5-triazine N, N'-bis (2,2,6 , 6-tetramethyl-4-piperidyl) -1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine (BASF CHIMASSORB 2020FDL manufactured by BASF), polycondensation of dibutylamine with 1,3,5-triazine and N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) Poly [{(1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl- Yl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (CHIMASSORB 944FDL manufactured by BASF), 1,6-hexanediamine- '- bis (2,2,6,6-tetramethyl-4-piperidyl) with morpholine-2,4,6-trichloro-1,3,5-triazine, poly [ -Morpholino-s-triazine-2,4-diyl) [(2,2,6,6-tetra (4-piperidyl) imino] -hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] and the like can be obtained by reacting the piperidine ring with a triazine skeleton Multiple bonded high molecular weight HALS (hindered amine light stabilizer); A complex of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6- The reaction of 6-pentamethyl-4-piperidino with 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane And high molecular weight HALS in which a piperidine ring is bonded via an ester bond, such as a mixed esterified product, but the present invention is not limited thereto. Among them, polycondensation products of dibutylamine with 1,3,5-triazine and N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) 1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) } Hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl- And a number average molecular weight (Mn) of 2,000 to 5,000.

Examples of preferred hindered amine-based compounds include the following HALS-1 and HALS-2. In the following HALS-1, n represents the number of repeating units.

[Chemical Formula 16]

Among these specific examples, CHIMASSORB 2020FDL (CAS-No.192268-64-7), CHIMASSORB 944FDL (CAS-No. 71878-19-8) and BASF (BASF Specialty Chemicals, TANUVIN 770DF (CAS-No.52829-07-9), Saiosub UV-3346 (CAS-No. 82541-48-7) manufactured by Sun Chemical Co., -No.193098-40-7) is commercially available and is suitable because of its excellent availability.

The hindered amine compound may be commercially available as described above, but may be prepared by synthesis. The method of synthesizing the hindered amine compound is not particularly limited and it can be synthesized by a method in ordinary organic synthesis. As the production method, distillation, recrystallization, re-precipitation, filtration, and a method using an adsorbent can be suitably used. In addition, commercially available products that are commercially available are not hindered amine compounds alone, but some of them are mixtures. In the present embodiment, commercially available products can be used without depending on the production method, composition, melting point, acid value, and the like.

(A polymer containing a repeating unit derived from a monomer represented by the general formula (2)

The optical film may contain a polymer containing a repeating unit derived from a monomer represented by the following general formula (2).

[Chemical Formula 17]

In the general formula (2), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ¹ is not particularly limited, but is preferably a hydrogen atom, a methyl group, or an ethyl group.

R ² represents a substituent, and the substituent is preferably an aliphatic group or an aromatic group. R ² is not particularly limited and is preferably an alkyl group, an alkenyl group, an alkynyl group or a cycloalkyl group as the aliphatic group, more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably a methyl group, , t-butyl group is particularly preferable. As the aromatic group, a phenyl group, a naphthyl group and a biphenyl group are preferable, and a phenyl group is particularly preferable.

n represents an integer of 0 to 4, preferably 0 to 2, more preferably 0 to 1. When n is 0, the substituent R ² is not present, but in the formula, it means that a hydrogen atom is present.

(A) represents an atomic group necessary for forming a 5 or 6-membered ring, and is preferably a 5 or 6-membered aromatic ring. The aromatic ring in the present specification is a concept including an aromatic ring containing no hetero atom and a saturated or unsaturated heterocyclic ring having a hetero atom. Specific examples of the specific polymer having a monomer-derived repeating unit represented by the general formula (2) are shown below, but are not construed as being limited thereto.

In the effect of suppressing the moisture permeability and water content of the film, the mass average molecular weight of the polymer represented by the general formula (2) is preferably from 200 to 10,000, more preferably from 300 to 8,000, and particularly preferably from 400 to 4,000 . In the effect of suppressing the moisture permeability and moisture content of the film, if it is not more than the upper limit value, improvement in compatibility with cellulose acylate can be expected.

The molecular weight and the degree of dispersion can be measured by GPC (gel filtration chromatography) method, and the molecular weight can be measured by the weight average molecular weight in terms of polystyrene, unless otherwise specified.

The gel filled in the column used in the GPC method is preferably a gel having an aromatic compound in a repeating unit, and examples thereof include a gel containing a styrene-divinylbenzene copolymer. It is preferable to use 2 to 6 columns connected. Examples of the solvent to be used include ether solvents such as tetrahydrofuran, and amide solvents such as N-methylpyrrolidinone. The measurement is preferably performed at a flow rate of the solvent in the range of 0.1 to 2 mL / min, and most preferably in the range of 0.5 to 1.5 mL / min. By performing the measurement within this range, measurement can be performed more effectively without causing a load on the apparatus. The measurement temperature is preferably 10 to 50 캜, and most preferably 20 to 40 캜. The column and the carrier to be used can be appropriately selected according to the physical properties of the polymer compound to be measured.

The amount of the polymer represented by the general formula (2) to be added is not particularly limited, but is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, and more preferably 1.0 to 30 parts by mass based on 100 parts by mass of the resin forming the film base material Particularly preferred is the part by mass.

Specific examples of the polymer having a monomer-derived repeating unit represented by the general formula (2) are shown, but the present invention is not construed as being limited thereto. In addition, the following structural formula shows the chemical structure and the composition ratio of the repeating unit of the main component, and other components may be contained as described above.

[Chemical Formula 18]

In addition, the polymer in the present specification means that, in addition to a polymer which is a general polymer compound in which a large number of monomers are polymerized, an oligomer such as a compound having a molecular weight of several hundreds or so, Also, unless otherwise stated, polymers, copolymers or copolymers are also included.

(Organic acid)

The optical film may contain an organic acid. The molecular weight of the organic acid is preferably 200 to 1000, more preferably 250 to 800, and particularly preferably 280 to 500. The organic acid preferably contains an aromatic ring structure, preferably contains an aryl group having 6 to 12 carbon atoms, and particularly preferably contains a phenyl group. The aromatic ring structure of the organic acid may form other rings and condensed rings. The aromatic ring structure of the organic acid may have a substituent, but is preferably a halogen atom or an alkyl group, more preferably a halogen atom or an alkyl group having 1 to 6 carbon atoms, particularly preferably a chlorine atom or a methyl group. The organic acid is preferably represented by the following general formula (3).

[Chemical Formula 19]

In the general formula (3), R ²⁶ represents an aryl group, and R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an alkyl group or an aryl group. R ²⁶ and R ²⁷ may each have a substituent. R ²⁶ is preferably an aryl group having 6 to 18 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and particularly preferably a phenyl group. R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (including a cycloalkyl group) or an aryl group having 6 to 12 carbon atoms, and is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms And more preferably a hydrogen atom, a methyl group, an ethyl group, a cyclohexane group or a phenyl group. Specific examples of the organic acid represented by the general formula (3) are illustrated below, but the present invention is not limited thereto.

[Chemical Formula 20]

The content of the organic acid is preferably 1 to 20% by mass based on the resin of the main component constituting the film base.

(fault)

It is preferable that the film substrate has a defect size of 5 mu m or more in diameter / 10 cm square or less. More preferably at most 0.5 / 10 cm square, further preferably at most 0.1 / 10 cm square. Here, the diameter of the defect refers to the diameter when the defect has a circular shape, and when the defect is not circular, the range of the defect is determined by observing with a microscope by the following method, and the maximum diameter is defined as the diameter of the circumscribed circle.

The range of the defect is the shadow size when the defect is observed as the transmitted light of the differential interference microscope when the defect is bubble or foreign matter. When the defect is a change in surface shape such as a transfer of a roller scratch or a scratch, the size can be confirmed by observing the defect as reflected light of a differential interference microscope.

If the number of defects is larger than 1/10 cm square, for example, if tension is applied to the film at the time of processing in a subsequent process or the like, the film breaks from the defect as a starting point, and the productivity is sometimes lowered. Further, when the diameter of the defect is 5 mu m or more, it can be visually confirmed by observing the polarizing plate or the like, and a bright spot may be generated when used as an optical member.

Further, even when it can not be visually confirmed, a coating film can not be uniformly formed when a functional layer is formed, and a defect (coating missing) may occur. Herein, the defect means defects such as voids (foaming defects) in the film caused by rapid evaporation of the solvent in the drying step of the solution film formation, foreign matter (foreign matter defect) in the film due to foreign matter contained in the membrane- It says. Further, in the measurement of the film substrate according to JIS-K7127-1999, the elongation at break in at least one direction is preferably 10% or more, and more preferably 20% or more. The upper limit of the elongation at break is not particularly limited, but is about 250% in practice. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter or foaming.

(Optical characteristics)

The film substrate preferably has a total light transmittance of 90% or more, and more preferably 92% or more. The practical upper limit is about 99%. The haze value is preferably 2% or less, and more preferably 1.5% or less. The total light transmittance and the haze value can be measured in accordance with JIS K7361 and JIS K7136.

The in-plane retardation value Ro of the film substrate is preferably 0 to 5 nm, and the retardation value Rth in the thickness direction is preferably -10 to 10 nm. The Rth is preferably in the range of -5 to 5 nm. Or the retardation Ro is preferably in the range of 30 to 200 nm, more preferably in the range of 30 to 90 nm. The retardation Rth in the thickness direction is preferably in the range of 70 to 300 nm.

The in-plane retardation Ro value is defined by the following formula (I), and the retardation value Rth in the thickness direction is defined by the following formula (II).

(I) Ro = (nx-ny) xd

(II) Rth = {(nx + ny) / 2-nz} xd

Ny is the index of refraction in the direction orthogonal to the slow axis in the film base surface, nz is the index of refraction in the thickness direction of the cellulose ester film, d is the refractive index of the cellulose ester film in the cellulose ester film, Thickness (nm), respectively)

The retardation can be obtained at a wavelength of 590 nm under an environment of 23 deg. C and 55% RH (relative humidity) using, for example, Cobra (KOBRA) -21ADH (Oji Keisei Kikuchi).

[Formation of cellulose ester film]

Next, an example of a film-forming method of a cellulose ester film as a film base will be described, but the film-forming method is not limited thereto. As the film forming method of the cellulose ester film, a manufacturing method such as an inflation method, a T-die method, a calendering method, a cutting method, a fusing method, an emulsion method and a hot press method can be used.

(Organic solvent)

The organic solvent useful for forming the resin solution (dope composition) in the case of producing the cellulose ester film by the solution casting film forming method described later can be used without limitation as long as it dissolves the cellulose ester resin and other additives at the same time. Examples of the chlorine-based organic solvent include methylene chloride and the non-chlorine-based organic solvent includes methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, Ethyl, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3 , 3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro- Propanol, iso-propanol, n-butanol, sec-butanol and tert-butanol, and methylene chloride, methyl acetate, ethyl acetate and acetone are preferably used have. The solvent is preferably a dope composition obtained by dissolving a cellulose ester resin and other additives in a total amount of 15 to 45 mass%.

(Solution flexible film-forming method)

In the solution casting film-forming method, a step of preparing a dope by dissolving a resin and an additive in a solvent, a step of dripping the dope on a belt-shaped or drum-shaped metal support, a step of drying the dope as a web, A process of holding the process, stretching or width, a process of further drying, and a process of winding the finished cellulose ester film.

As the metal support, a stainless steel belt or a drum finishing the surface of the cast iron is preferably used.

The width of the cast (flexible) can be 1 to 4 m. The surface temperature of the metal support of the flexible process is set at -50 占 폚 to a temperature at which the solvent does not foam by boiling. A higher temperature is preferable because it can speed up the drying speed of the web. However, if it is too high, the web may be foamed or the planarity may deteriorate.

The preferred support temperature is appropriately determined at 0 to 100 캜, more preferably 5 to 30 캜. Alternatively, it is preferable that the web is gelled by cooling to peel off the drum in a state containing a large amount of residual solvent. A method of controlling the temperature of the metal support is not particularly limited, but there is a method of spraying hot air or cold air, or a method of bringing hot water into contact with the back surface of the metal support. Use of hot water is preferable because heat transfer is performed efficiently and the time until the temperature of the metal support becomes constant is short.

In the case of using hot wind, in consideration of the temperature drop of the web due to the latent heat of evaporation of the solvent, the hot wind above the boiling point of the solvent may be used, while the foaming is also prevented while using wind at a temperature higher than the target temperature.

Particularly, it is preferable to change the temperature of the support and the temperature of the drying wind until the peeling from the softening, so that the drying is performed efficiently.

In order to obtain good flatness of the cellulose ester film, the amount of residual solvent when peeling the web from the metal support is preferably from 10 to 150% by mass, more preferably from 20 to 40% by mass or from 60 to 130% by mass, Preferably 20 to 30 mass% or 70 to 120 mass%. The amount of residual solvent is defined by the following formula.

Amount of residual solvent (mass%) = {(M-N) / N} 100

M is the mass of the sample taken from the web or film at any point during or after the production, and N is the mass after the mass M is heated at 115 占 폚 for 1 hour.

In the drying step of the cellulose ester film, it is preferable that the web is peeled off from the metal support and dried, so that the residual solvent amount is preferably 1 mass% or less, more preferably 0.1 mass% or less, particularly preferably 0 to 0.01 % Or less.

In the film drying step, a method of drying by conveying the web by a roller drying method (a method of alternately passing and drying webs through a plurality of rollers disposed up and down) or a tenter method is employed.

In the stretching step, stretching can be performed sequentially or simultaneously with respect to the longitudinal direction (MD direction) and the width direction (TD direction) of the film. The stretching magnifications in the biaxial directions orthogonal to each other are preferably set in the range of 1.0 to 2.0 times in the MD direction and 1.05 to 2.0 times in the TD direction, respectively, and 1.0 to 1.5 times in the MD direction and 1.05 And more preferably in the range of from 1.0 to 2.0 times. For example, there is a method in which a plurality of rollers are caused to have peripheral speeds and a roller peripheral speed is used to stretch them in the MD direction; a method in which both ends of the web are fixed with clips or pins, A method of stretching in the MD direction, a method of stretching in the transverse direction and stretching in the TD direction, or a method of simultaneously stretching the MD direction and the TD direction and stretching in both directions.

The stretching in the width direction or the stretching in the width direction in the film forming step is preferably performed by a tenter, and it may be a pin tenter or a clip tenter.

The film transport tension in the film forming process of the tenter or the like varies depending on the temperature, but is preferably 120 to 200 N / m, more preferably 140 to 200 N / m, and most preferably 140 to 160 N / m.

The temperature at the time of stretching is preferably from (Tg-30) to (Tg + 100) ° C, more preferably from (Tg-20) to (Tg + 80) ° C, (Tg-5) to (Tg + 20) 占 폚.

The Tg of the cellulose ester film can be controlled by the material species constituting the film and the ratio of the constituent material. The Tg of the cellulose ester film at the time of drying is preferably 110 DEG C or more, more preferably 120 DEG C or more. Particularly preferably 150 ° C or higher. The glass transition temperature is preferably 190 占 폚 or lower, more preferably 170 占 폚 or lower. The Tg of the cellulose ester film can be determined by the method described in JIS K7121. When the stretching temperature is 150 ° C or higher and the stretch ratio is 1.15 times or more, the surface is preferably roughened. Roughening the surface of the cellulose ester film is preferable because slipperiness is improved and surface formability is improved.

(Melt flexible film forming method)

The cellulose ester film may be formed by a melt soft-film forming method. The melt-blown film-forming method refers to a method in which a composition containing a cellulose ester resin and other additives such as a plasticizer is heated and melted to a temperature at which the fluidity is exhibited, and then the melt containing the fluid cellulose ester is softened.

In the melt soft-film-forming method, a melt-extrusion method is preferable in terms of mechanical strength and surface precision. The plurality of raw materials used for melt extrusion are usually kneaded in advance and pelletized.

The pelletization is carried out by a known method. For example, a dry cellulose ester, a plasticizer and other additives are fed to an extruder from a feeder, kneaded using a single- or twin-screw extruder, extruded from a die into a strand shape, Air cooling, and cutting.

The additives may be mixed before being fed to the extruder, or they may be fed to individual feeders.

Small amounts of additives such as particles and antioxidants are preferably mixed in advance to uniformly mix them.

The extruder is preferably processed at a low temperature as low as possible so as to suppress the shearing force and to make the resin pellet so as not to deteriorate the resin (deteriorate molecular weight, coloration, gel formation, etc.). For example, in the case of a twin-screw extruder, it is preferable to use a deep groove-type screw to rotate in the same direction. In the kneading uniformity, occlusal type is preferable.

Film formation is carried out using the pellets obtained as described above. Of course, it is also possible to feed the powder of the raw material directly from the feeder to the extruder without forming pellets, and to form the film as it is.

The pellets are extruded by using a uniaxial or biaxial type extruder and the melt temperature is set to about 200 to 300 DEG C by filtration with a filter such as a leaf disc type to remove foreign matter. The film is nipped with a cooling roller and an elastic touch roller, and is solidified on a cooling roller, thereby forming a cellulose ester film.

When introduced into the extruder from the feed hopper, it is desirable to prevent oxidative decomposition or the like under vacuum or under reduced pressure or under an inert gas atmosphere.

The extrusion flow rate is preferably adjusted stably by introducing a gear pump. A stainless steel fiber sintered filter is preferably used as a filter used for removing foreign matter. The stainless steel fiber sintering filter is formed by integrally forming a stainless steel fiber body in a state of being entangled with each other and then pressing and sintering the contact portions. The filtration accuracy can be adjusted by varying the density according to the thickness of the fibers and the amount of compression.

Additives such as plasticizers and particles may be mixed with the resin in advance, or may be put in the middle of the extruder. In order to uniformly add it, it is preferable to use a mixing device such as a static mixer.

It is preferable that the temperature of the cellulose ester film on the touch roller side when nipping the cellulose ester film with the cooling roller and the elastic touch roller is equal to or higher than Tg (Tg + 110 deg. C) of the film. A known roller may be used for the roller having the surface of the elastic body used for this purpose.

The elastic touch roller is also referred to as a tightly closed rotating body. A commercially available elastic touch roller may be used.

When the cellulose ester film is peeled from the cooling roller, it is preferable to control the tension to prevent deformation of the film.

The cellulose ester film obtained as described above is preferably stretched by the stretching operation after passing through a process in contact with a cooling roller.

A known roller stretching machine or tenter may be used for the stretching. The stretching temperature is preferably in the range of Tg to (Tg + 60) 占 폚 of the resin constituting the film.

Before winding, the end portion may be slit and cut with a width that becomes a product, and knurling (embossing) may be performed at both ends in order to adhere to the winding body and prevent scratching. The knurling process can be performed by heating or pressing using a metal ring having a concavo-convex pattern on its side surface. The clip holding portions at both ends of the film are usually cut and reused because the cellulose ester film is deformed and can not be used as a product.

[Method of producing oblique stretched film]

The above-mentioned? / 4 film can be produced by the following warp stretching. The oblique stretched film can be produced by producing a stretched film having a slow axis at an angle of more than 0 DEG and less than 90 DEG with respect to the stretching direction of the film. As the unoriented film before the warp stretching, the above-mentioned known film is used.

Here, the angle with respect to the extending direction of the film is an angle in the film plane. Since the slow axis is usually expressed in a stretching direction or a direction perpendicular to the stretching direction, stretching at an angle of more than 0 deg. And less than 90 deg. To the stretching direction of the film can produce a stretched film having such a slow axis.

The angle (orientation angle) between the extending direction of the film and the slow axis can be arbitrarily set to a desired angle in a range of more than 0 DEG and less than 90 DEG, more preferably 10 DEG to 80 DEG, 40 DEG to 50 DEG.

(Oblique stretching)

The warp stretched film can be produced by using a warp stretching apparatus (oblique stretching tenter). As the oblique stretching tenter, by varying the rail pattern, it is possible to freely set the orientation angle of the film, and to orient the orientation axis of the film evenly and horizontally across the film width direction, A device capable of controlling retardation can be preferably used. Next, a specific method of producing an oblique stretched film will be described with reference to the drawings.

Fig. 2 is a plan view schematically showing a schematic configuration of the obliquely-drawn film producing apparatus 51. Fig. The manufacturing apparatus 51 includes a film feed portion 52, a transport direction changing portion 53, a guide roll 54, a stretching portion 55, and a guide roll (not shown) in this order from the upstream side in the transport direction of the long film 56, a transport direction changing portion 57, a film cutting device 58, and a film winding portion 59. [ Details of the extending portion 55 will be described later.

The film feeding portion 52 uncovers the long film and feeds it to the stretching portion 55. The film feed portion 52 may be formed separately from the film forming apparatus of the long film, or may be integrally formed. In the former case, after the long film is formed, the long film is unwound from the film feeding portion 52 by winding the film on the winding core once and winding the film from the winding body (long film material) into the film feeding portion 52. On the other hand, in the latter case, after film formation of the long film, the film feed portion 52 uncovers the long film to the stretching portion 55 without winding.

The carrying direction changing section 53 changes the carrying direction of the long film to be unwound from the film feeding section 52 in the direction toward the entrance of the extending section 55 as the warp stretching tenter. The carrying direction changing section 53 includes a turn bar for changing the carrying direction by folding while conveying the film, and a rotary table for rotating the turn bar in a plane parallel to the film.

By changing the conveying direction of the long film in the conveying direction changing section 53 as described above, the width of the entire manufacturing apparatus 51 can be made narrower, and furthermore, the conveying position and angle of the film can be finely controlled And it becomes possible to obtain a long oblong stretched film having a small film thickness and a small optical value deviation. When the film feeding portion 52 and the conveying direction changing portion 53 are movable (slidable and swivelable), the stretching portion 55 is provided with the right and left clips It is possible to effectively prevent the sticking defects of the film on the film.

The film feed portion 52 may be slidable and pivotable so as to feed a long film at a predetermined angle to the entrance of the stretching portion 55. In this case, the configuration in which the transportation direction changing section 53 is omitted may be omitted.

At least one guide roll 54 is provided on the upstream side of the stretching portion 55 in order to stabilize the trajectory during traveling of the long film. Further, the guide roll 54 may be constituted by a pair of upper and lower rolls sandwiching the film therebetween, or may be constituted by a plurality of pairs of rolls. The guide roll 54 closest to the entrance of the stretching portion 55 is a driven roll for guiding the traveling of the film, and is rotatably supported by a bearing portion (not shown). As the material of the guide roll 54, known rollers can be used. In order to prevent the occurrence of scratches on the film, it is preferable to reduce the weight of the guide roll 54 by applying a ceramic coating to the surface of the guide roll 54, or chrome plating the light metal such as aluminum.

It is preferable that one of the rolls on the upstream side of the guide roll 54 closest to the entrance of the stretching portion 55 is nipped by pressing the rubber roll. By using such a nip roll, fluctuation of the unwinding tension in the film flow direction can be suppressed.

A pair of bearing portions at both ends (right and left) of the guide roll 54 closest to the entrance of the stretching portion 55 are provided with a film tension detecting device for detecting the tension generated in the film in the roll, 1 tension detecting device, and a second tension detecting device. As the film tension detecting device, for example, a load cell can be used. As the load cell, a known type of tensile or compression type can be used. The load cell is a device that converts a load acting on a point of contact to an electrical signal by a distortion gauge provided in the distortion generating body and detects the load.

The load cell is provided at the left and right bearing portions of the guide roll 54 closest to the entrance of the stretching portion 55 so that the force of the running film on the roll, that is, in the film advancing direction occurring near the both side edge portions of the film And independently detect the tension of left and right. Further, a strain gauge may be provided directly on a support constituting the bearing portion of the roll, and the load, i.e., the film tension may be detected based on the distortion generated in the support. The relationship between the generated distortion and the film tension is measured in advance and is assumed to be known.

When the position and transport direction of the film supplied from the film feed portion 52 or the transport direction changing portion 53 to the stretching portion 55 are shifted from the position toward the entrance of the stretching portion 55 and the transport direction, A difference occurs in the tension in the vicinity of both side edge portions of the film in the guide roll 54 closest to the entrance of the stretching portion 55, depending on the displacement amount. Therefore, by detecting the tension difference by installing the film tension detecting apparatus as described above, it is possible to determine the degree of the deviation. That is, when the transporting position and the transporting direction of the film are appropriate (the position and direction toward the inlet of the stretching portion 55), the load acting on the guide roll 54 becomes substantially equal at both ends in the axial direction, Otherwise, difference in film tension occurs between right and left.

Therefore, in order to equalize the left and right film tension differences of the guide roll 54 closest to the entrance of the stretching section 55, for example, the film direction and the film thickness direction are changed by the transport direction changing section 53, (The angle with respect to the entrance of the film 55) is properly adjusted, the holding of the film by the waveguide at the entrance of the stretching portion 55 is stabilized, and occurrence of disturbance such as separation of the waveguide can be reduced. Further, the physical properties in the film width direction after the warp stretching by the stretching portion 55 can be stabilized.

At least one guide roll 56 is provided on the downstream side of the stretching portion 55 in order to stabilize the trajectory of the obliquely stretched film at the stretching portion 55 during traveling.

The carrying direction changing portion 57 changes the carrying direction of the film after being drawn from the stretching portion 55 in the direction toward the film winding portion 59. [

Here, the film advancing direction at the entrance of the elongating section 55 and the film advancing direction at the exit of the elongating section 55 are set so as to correspond to the fine adjustment of the orientation angle (the direction of the slow axis in the film surface) It is necessary to adjust the angle. In order to adjust the angle, the direction in which the film is formed is changed by the transporting direction changing portion 53 to guide the film to the entrance of the stretching portion 55 and / or the film from the exit of the stretching portion 55 It is necessary to change the advancing direction of the film by the carrying direction changing portion 57 to return the film to the direction of the film winding portion 59. [

Further, it is preferable to continuously perform film formation and warp stretching in view of productivity and yield. In the case where the film forming process, the warp stretching process, and the winding process are continuously performed, the traveling direction of the film is changed by the carrying direction changing section 53 and / or the carrying direction changing section 57, The direction in which the film is unwound from the film feed portion 52 and the film advancing direction immediately before being wound by the film take-up portion 59 (as shown in Fig. 2) Winding direction), it is possible to reduce the width of the entire device with respect to the film advancing direction.

The film direction of the film is not necessarily coincident with the direction of the film in the film forming process and the winding process but may be changed in a direction in which the film feeding portion 52 and the film winding portion 59 do not interfere with each other, Or the carrying direction changing section 57 to change the traveling direction of the film.

The above-described transport direction changing unit 53 占 57 can be realized by a known method such as using an air flow roll or an air turn bar.

The film cutting device 58 cuts the stretched film (long oblong stretched film) in the stretching section 55 along a section including the width direction, and has a cutting member. The cutting member may be composed of, for example, a scissors or a cutter (including a slitter or a band-shaped blade (Thomson blade)), but is not limited thereto. In addition, a rotating circular saw or laser irradiator .

The film take-up portion 59 is for winding a film conveyed from the stretching portion 55 through the conveying direction changing portion 57 and is constituted by, for example, a winder device, an algebraic device, a drive device or the like. It is preferable that the film take-up portion 59 is a structure that can slide in the lateral direction to adjust the winding position of the film.

The film take-up portion 59 is capable of finely controlling the take-in position and angle of the film so as to take the film at a predetermined angle with respect to the exit of the stretching portion 55. This makes it possible to obtain a long oblong stretched film having a small variation in film thickness and optical value. In addition, the occurrence of wrinkles of the film can be effectively prevented, and the winding-up property of the film is improved, so that the film can be wound up a long time.

The film take-up portion 59 constitutes a pulling-out portion for stretching the film to be stretched by the stretching portion 55 with a predetermined tension. Between the stretching portion 55 and the film winding portion 59, a take-up roll for pulling the film at a constant tension may be provided. Further, the guide roll 56 described above may have a function as the pull roll.

In this embodiment, it is preferable that the film pulling tension T (N / m) after stretching is adjusted between 100 N / m <T <300 N / m, preferably 150 N / m <T <250 N / m. If the pulling tension is 100 N / m or less, loosening or wrinkling of the film tends to occur, and the profile of the retardation and orientation angle in the film width direction is also deteriorated. On the other hand, when the pulling tension is 300 N / m or more, the deviation of the orientation angle in the film width direction is deteriorated, and the width yield (width direction pickup efficiency) is deteriorated.

In the present embodiment, it is preferable to control the fluctuation of the take-up tension T at an accuracy of less than ± 5%, preferably less than ± 3%. If the variation of the take-up tension T is ± 5% or more, the deviation of the optical characteristics in the width direction and the flow direction (transport direction) becomes large. As a method for controlling the fluctuation of the take-up tension T within the above range, the load applied to the first roll (guide roll 56) on the outlet side of the stretching section 55, that is, the tension of the film is measured, , The rotation speed of the take-up roll of the take-up roll or film take-up unit 59 is controlled by a general PID control method. As a method for measuring the load, there is a method in which a load cell is provided in a bearing portion of a guide roll 56 and a load applied to the guide roll 56, that is, a tensile force of the film is measured. As the load cell, known tensile type or compression type can be used.

After stretching the film, the gripping of the stretching portion 55 is released and the film is discharged from the outlet of the stretching portion 55. After both ends (both sides) of the film held by the gripping portions are trimmed as necessary, Is cut by a cutting device 58 every predetermined length, and is wound on a winding core (winding roll) sequentially to become a warp stretched film winding body.

Further, before winding the obliquely-stretched film, the masking film may be wound on the obliquely-stretched film at the same time for the purpose of preventing blocking between the films, and at least one (preferably both) of the obliquely- A tape or the like may be wound while being bonded. The masking film is not particularly limited as long as it can protect the warped stretched film, and examples thereof include a polyethylene terephthalate film, a polyethylene film, and a polypropylene film.

(Details of extension section)

Next, the elongating unit 55 will be described in detail. 3 is a plan view schematically showing an example of the rail pattern of the extending portion 55. As shown in Fig. However, this is only an example, and the configuration of the extending portion 55 is not limited to this.

The long oblong stretched film in this embodiment is produced by using a tenter (warp stretching machine) capable of warp stretching as the stretching portion 55. The tenter is a device for heating a long film to an arbitrary stretchable temperature and obliquely stretching. This tenter is constituted by a plurality of wave cores Ci · Co (in the case of FIG. 3, only one set of gripping regions is shown as a center) for traveling the heating zone Z, a pair of rails Ri and Ro on the left and right, . Details of the heating zone Z will be described later. Each of the rails Ri and Ro is formed by connecting a plurality of rail portions by connecting portions (a white circle in Fig. 3 is an example of a connecting portion). The wave earth Ci · Co is constituted by a clip holding both ends in the width direction of the film.

In Fig. 3, the unwinding direction D1 of the long film is different from the winding direction D2 of the elongated oblong drawn film after stretching, and forms the unwinding angle &thetas; i between the winding direction D2. The unwinding angle &thetas; i can be set arbitrarily at a desired angle in a range of more than 0 DEG and less than 90 DEG.

As described above, since the unwinding direction D1 and the winding direction D2 are different from each other, the rail pattern of the tenter is asymmetrical in the left-right direction. The rail pattern can be manually or automatically adjusted in accordance with an orientation angle?, A stretching magnification, and the like applied to a long obliquely drawn film to be produced. In the warp stretching machine used in the manufacturing method of the present embodiment, it is preferable that the positions of the rail portions and the rail connecting portions constituting the rails Ri and Ro are freely set and the rail pattern can be arbitrarily changed.

In the present embodiment, the wave earth Ci · Co of the tenter is kept at a constant distance from the front and rear wave earths Ci · Co and travels at a constant speed. The traveling speed of the wave earth Ci · Co can be appropriately selected, but is usually 1 to 150 m / min. The traveling speed difference between the pair of left and right wave regions Ci · Co is usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less of the traveling speed. This is because if there is a difference in traveling speed between the left and right sides of the film at the exit of the stretching process, wrinkles and bunching occur at the exit of the stretching process, so that the speed difference between the left and right wave regions Ci and Co is required to be substantially the same. In a general tentering machine or the like, there is a speed variation occurring on the order of seconds or less depending on the sawing period of the sprocket for driving the chain, the frequency of the drive motor, etc., This does not apply to the speed difference described.

In the warp stretcher used in the production method of the present embodiment, a rail that regulates the trajectory of the crushing strip is often required to have a large bending rate, particularly at a position where the conveyance of the film becomes oblique. In order to avoid interference between waveguides due to abrupt bending or local concentration of stress, it is desired that the trajectory of the waveguide curve in the curved portion.

As described above, the oblique stretching tenters used for imparting the oblique directional orientation to the long film can freely set the orientation angle of the film by variously changing the rail pattern, and the orientation axis (slow axis) Can be uniformly and horizontally aligned in the width direction of the film, and the film thickness and retardation can be controlled with high precision.

Next, the drawing operation in the stretching portion 55 will be described. Both ends of the long film are gripped by the left and right wave regions Ci 占. O, and are transported in the heating zone Z in accordance with travel of the wave earth Ci 占. Co. The left and right wave regions Ci · Co are opposed to each other in a direction substantially perpendicular to the film advancing direction (unwinding direction D1) at the entrance portion (position A in the drawing) of the stretching portion 55, And runs on the rails Ri and Ro, respectively, and the film gripped at the exit portion (the position of B in the figure) at the end of drawing is opened. The film released from the wave region Ci 占 은 co is wound on the winding core in the film winding section 59 described above. The pair of rails Ri and Ro each have an endless continuous trajectory, and the wave Ci · Co, which opens the grip of the film at the exit of the tenter, travels on the outer rail and returns to the inlet.

In this case, since the rails Ri and Ro are asymmetric in the left and right directions, the left and right wave flanges Ci and Co, which were opposed to each other at the position A in Fig. 3, (On the course side) is the preceding positional relation to the wave earth Co running on the rail Ro side (out-course side).

That is, when one waveguide Ci first arrives at the position B at the end of the stretching of the film out of the waveguide Ci 占 Co, which has been opposed in the direction substantially perpendicular to the unwinding direction D1 of the film at the position A in the figure, The straight line connecting the waveguide Ci · Co is inclined only by an angle θL with respect to a direction substantially perpendicular to the winding direction D2 of the film. With the above action, the long film is obliquely elongated at the angle of? L with respect to the width direction. Here, the term " substantially perpendicular "

Next, details of the heating zone Z will be described. The heating zone Z of the stretching section 55 is constituted by a preheating zone Z1, a stretching zone Z2 and a heat fixing zone Z3. In the stretching section 55, the film held by the waveguide Ci 占 통과 passes through the preheating zone Z1, the stretching zone Z2, and the heat fixing zone Z3 in order. In the present embodiment, the preheating zone Z1 and the stretching zone Z2 are partitioned by partition walls, and the stretching zone Z2 and the heat fixing zone Z3 are partitioned by partition walls.

The preheating zone Z1 indicates a section in which the waveguide Ci 占 한 peewith holding both ends of the film at the entrance of the heating zone Z travels with left and right spacing (in the film width direction).

The stretching zone Z2 refers to a section from a gap between the waveguides Ci and Co holding both ends of the film to a predetermined interval. At this time, the oblique stretching as described above is performed, but if necessary, stretching may be performed longitudinally or transversely before and after oblique stretching.

The heat fixing zone Z3 is a section in which the interval between the wave zones Ci and Co becomes constant again after the stretching zone Z2 and refers to a section in which the wave zones Ci and Co at both ends run parallel to each other.

The stretched film may pass through a zone (cooling zone) where the temperature in the zone is set to be equal to or lower than the glass transition temperature Tg (占 폚) of the thermoplastic resin constituting the film after passing through the heat fixing zone Z3. At this time, in consideration of shrinkage of the film due to cooling, a rail pattern may be used in which the interval between the opposed wave cores Ci and Co is narrowed.

The temperature of the preheating zone Z1 is in the range of Tg to Tg + 30 占 폚, the temperature of the stretching zone Z2 is in the range of Tg to Tg + 30 占 폚, the temperature of the heat-fixing zone Z3 and the cooling zone is in the range of Tg- Tg + 20 占 폚.

The length of the preheating zone Z1 is usually 100 to 150% of the length of the stretching zone Z2, and the length of the heat-fixing zone Z3 is normally 100 to 150% 50 to 100%.

When the film width before stretching is W0 (mm) and the film width after stretching is W (mm), the stretching magnification R (W / W0) in the stretching step is preferably 1.3 to 3.0, 1.5 to 2.8. When the stretch ratio is within this range, thickness irregularity in the film width direction is reduced, which is preferable. In the stretching zone Z2 of the oblique stretching tenter, if the stretching temperature is made different in the width direction, it is possible to make the thickness unevenness in the width direction better. Further, the draw ratio R is the same as the magnification (W2 / W1) at the time when the interval W1 between both ends of the clip held by the tenter inlet portion becomes the interval W2 at the tenter outlet portion.

The oblique stretching method in the stretching portion 55 is not limited to the above-mentioned method. For example, as shown in Japanese Patent Application Laid-Open No. 2008-23775, . Simultaneous biaxial stretching is a method of grasping both end portions of a supplied long film in the transverse direction by each waveguide and transporting the long film while moving each wave earth while keeping the longitudinal direction of the long film constant , A method of stretching a long film in an oblique direction with respect to the width direction by making the moving speed of one wave earth different from the moving speed of the other wave earth. In addition, the oblique stretching may be carried out by a method as disclosed in Japanese Patent Laid-Open Publication No. 2011-11434.

(Physical properties of film substrate)

The film thickness of the film base is preferably 5 to 200 占 퐉, more preferably 5 to 80 占 퐉. Further, the length of the film base is preferably 500 to 10,000 m, and more preferably 1000 to 8000 m. By setting the length to the above range, the processability in coating of the functional layer or the like and the handling property of the film substrate itself are excellent.

The arithmetic average roughness Ra of the film substrate is preferably 2 to 10 nm, more preferably 2 to 5 nm. The arithmetic average roughness Ra can be measured in accordance with JIS B0601: 1994.

[Other floors]

In the optical film of this embodiment, other layers such as an antireflection layer and a conductive layer can be formed.

(Antireflection layer)

The optical film of the present embodiment can be used as an antireflection film having a function of preventing reflection of external light by forming an antireflection layer on the functional layer.

It is preferable that the antireflection layer is laminated in consideration of the refractive index, the film thickness, the number of layers, the order of layers, etc. so that the reflectance is decreased by optical interference. It is preferable that the antireflection layer is formed by combining a low refractive index layer having a refractive index lower than that of the protective film of the support or a high refractive index layer and a low refractive index layer having a refractive index higher than that of the protective film.

The low refractive index layer preferably contains silica-based fine particles, and the refractive index thereof is preferably in the range of 1.30 to 1.45 at a temperature of 23 DEG C and a wavelength of 550 nm.

The film thickness of the low refractive index layer is preferably in the range of 5 nm to 0.5 탆, more preferably in the range of 10 nm to 0.3 탆, and most preferably in the range of 30 nm to 0.2 탆.

With regard to the composition for forming a low refractive index layer, it is preferable that the silica-based fine particles, particularly the inside having an outer layer, contain at least one porous or hollow particle. Particularly, it is preferable that the porous or porous particles having the inside and outside of the layer are hollow silica-based particles.

The composition for forming a low refractive index layer may also contain an organic silicon compound represented by the following formula (OSi-1), a hydrolyzate thereof, or a polycondensate thereof.

(OSi-1): Si (OR) ₄

In the formulas, R represents an alkyl group having 1 to 4 carbon atoms. Specific examples of the organosilicon compound represented by the general formula include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, and the like.

Further, a compound having a thermosetting and / or photo-curable property, which mainly contains a fluorine-containing compound containing a fluorine atom in a range of 35 to 80 mass% and containing a crosslinkable or polymerizable functional group, It may be contained in the composition. Specific examples thereof include a fluorine-containing polymer, a fluorine-containing sol-gel compound, and the like. Examples of the fluorine-containing polymer include hydrolysates of perfluoroalkyl group-containing silane compounds [for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane], dehydration condensates A fluorine-containing copolymer having a fluorine-containing monomer unit and a crosslinking reactive unit as a constituent unit. If necessary, a silane coupling agent, a curing agent, a surfactant, and the like may be added to the composition for forming a low refractive index layer.

&Lt; High refractive index layer &

In the high refractive index layer, it is preferable to adjust the refractive index in the range of 1.4 to 2.2 in the measurement of the wavelength of 550 nm at 23 캜. The thickness of the high refractive index layer is preferably from 5 nm to 1 탆, more preferably from 10 nm to 0.2 탆, and most preferably from 30 nm to 0.1 탆. The adjustment of the refractive index can be achieved by adding metal oxide fine particles or the like. The refractive index of the metal oxide fine particles to be used is preferably 1.80 to 2.60, and more preferably 1.85 to 2.50.

The kind of the metal oxide fine particles is not particularly limited and is selected from among Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S A metal oxide having at least one kind of element may be used.

In the optical film, a conductive layer may be formed on the functional layer. As the conductive layer to be formed, generally known conductive materials can be used. For example, metal oxides such as indium oxide, tin oxide, indium tin oxide, gold, silver and palladium can be used. These can be formed as a thin film on an optical film by a vacuum evaporation method, a sputtering method, an ion plating method, a solution coating method or the like. It is also possible to form the conductive layer by using the above-mentioned organic conductive material as the? -Conjugated conductive polymer.

In particular, a conductive material containing any one of indium oxide, tin oxide, and indium tin oxide, which is excellent in transparency and conductivity and can be obtained at a relatively low cost, can be suitably used. Since the thickness of the conductive layer varies depending on the material to which it is applied, it can not be said to be uniform. However, the thickness is such that the surface resistivity is 1000 Ω or less, preferably 500 Ω or less, A range of 20 nm or more and 80 nm or less, and preferably 70 nm or less is suitable. In such a thin film, interference fringes of visible light due to thickness irregularity of the conductive layer are hard to occur.

[Polarizer]

Next, a polarizing plate using the optical film of this embodiment will be described. The polarizing plate can be manufactured by a general method.

For example, on one side of a polarizing film (polarizer) produced by alkali saponifying an optical film (for example, a hard coating film) of the present embodiment and immersing and stretching the treated optical film in an iodine solution, It is preferable to use a saponified polyvinyl alcohol aqueous solution.

The optical film may be bonded to the other surface of the polarizer, or a film base such as the above-mentioned cellulose ester film may be bonded. The film thickness of the film base to be bonded to the other surface is preferably in the range of 5 to 80 mu m from the viewpoint of adjusting the smoothness and the curl balance and further enhancing the effect of preventing the winding deviation.

The polarizing film as a main component of the polarizing plate is a device that passes only light of a polarization plane in a certain direction, and a typical polarizing film currently known is a polyvinyl alcohol polarizing film. The polarizing film includes a polyvinyl alcohol-based film stained with iodine and a dichroic dye stained, but the present invention is not limited thereto.

As the polarizing film, a film obtained by forming a polyvinyl alcohol aqueous solution, uniaxially stretching it, dyeing it, dyeing it, uniaxially stretching it, and preferably durability treatment with a boron compound is used. The film thickness of the polarizing film is 5 to 30 탆, preferably 8 to 15 탆.

On one side of the polarizing film, one side of the optical film of this embodiment is bonded to form a polarizing plate. Preferably by using an aqueous adhesive mainly composed of fully saponified polyvinyl alcohol or the like.

(Circularly polarizing plate)

The circular polarizer plate may be formed using the optical film (for example,? / 4 film + hard coating layer) of the present embodiment. That is, the circular polarizer can be constituted by laminating a polarizing plate protective film, a polarizer and a lambda / 4 film in this order. In this case, the angle formed by the slow axis of the? / 4 film and the absorption axis (or transmission axis) of the polarizing film is 45 °. A long shape polarizer protective film, a long shape polarizer, and a long lambda / 4 film (long obliquely stretched film) are preferably laminated in this order.

The circular polarizer can be produced by using a polarizer obtained by stretching polyvinyl alcohol doped with iodine or dichromatic dye and bonding it with a constitution of? / 4 film / polarizer. The film thickness of the polarizer is 5 to 40 占 퐉, preferably 5 to 30 占 퐉, and particularly preferably 5 to 20 占 퐉.

The circular polarizer can be manufactured by a general method. Namely, it is preferable to bond the? / 4 film treated with alkali saponification to one side of the polarizer produced by immersing and stretching the polyvinyl alcohol film in an iodine solution using a fully saponified polyvinyl alcohol aqueous solution.

[Adhesive layer]

In order to bond the polarizing plate to the substrate of the liquid crystal cell, the adhesive layer used for one side of the film of the polarizing plate is preferably optically transparent and exhibits appropriate viscoelasticity and adhesive property.

Specific examples of the adhesive layer include adhesives such as an acrylic copolymer, an epoxy resin, a polyurethane, a silicone polymer, a polyether, a butyral resin, a polyamide resin, a polyvinyl alcohol resin, A film can be formed by a drying method, a chemical hardening method, a thermosetting method, a thermal melting method, a photo-curing method, or the like, and curing can be performed. Among them, the acrylic copolymer is most preferable because it is easy to control the physical properties of the adhesive, and is excellent in transparency, weather resistance, durability and the like.

[Image display device]

The optical film of the present embodiment is preferable for use in an image display device because it exhibits excellent visibility. Examples of the image display device include reflective, transmissive and transflective liquid crystal display devices, liquid crystal display devices of various driving systems such as TN type, STN type, OCB type, VA type, IPS type and ECB type, organic EL display devices, And the like. Among these image display devices, a liquid crystal display device is preferable because of its high visibility.

An exterior member may be disposed on the viewer side of the functional layer of the optical film of the viewer-side polarizing plate. The exterior member can be composed of a front face plate or a touch panel. The exterior member is bonded to the functional layer via a filler (photocurable resin) for filling a gap between the exterior member and the functional layer. The front face plate of the exterior member is not particularly limited, and conventionally known ones such as an acrylic plate and a glass plate can be used. The material, thickness, etc. of the front face plate can be appropriately selected in accordance with the use of the image display apparatus.

Examples of commercially available products include SVR1120, SVR1150, SVR1320 (manufactured by Dexterial Co., Ltd.), HRJ-60, HRJ-302 and HRJ-53 Manufactured by SANKYO KABUSHIKI KAISHA), and the like. When a filler is used, one type may be used alone, or a plurality of types may be used in combination.

The bonding between the optical film and the front face plate can be performed, for example, as follows. First, filler is prepared. Then, a filler is applied to the surface of the functional layer of the optical film, and the front face plate is superimposed on the coating film of the filler. In this state, the filler is cured by light irradiation or the like to bond the optical film and the front face plate. When the filler is applied to the surface of the functional layer and the surface free energy of the functional layer (the sum of the polar component and hydrogen bond component plus a + the dispersed component b) is 30 mN / m or more, the filler does not bounce off the end of the functional layer, And an image display device having excellent visibility can be obtained. Further, by setting the ratio (a / b) of the sum a of the polar component and hydrogen bond component of the surface free energy of the functional layer to the dispersed component b to be not less than 1 and not more than 10, excellent adhesion can be obtained even after the durability test .

[Example]

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto. In the examples, "part" or "%" is used, but "mass part" or "mass%" is used unless otherwise specified.

[Production of Cellulose Ester Film 1]

&Lt; Preparation of silicon dioxide dispersion >

10 parts by mass of Aerosil R812 (manufactured by Nippon Aerosil Co., Ltd., average diameter of primary particles: 7 nm)

90 parts by mass of ethanol

The resulting mixture was stirred with a dissolver for 30 minutes and dispersed with Manton-Gaulin. 88 parts by mass of methylene chloride was added to the silicon dioxide dispersion while stirring, and the mixture was stirred with a dissolver for 30 minutes to prepare a silicon dioxide dispersion diluted solution. And filtered through a fine particle dispersion diluent filter (ADVAN Tech Co., Ltd .: Polypropylene Wind Cartridge Filter TCW-PPS-1N).

&Lt; Preparation of Dope Composition 1 &

(Cellulose ester resin)

Cellulose triacetate A (cellulose triacetate synthesized by a linter surface, acetyl group degree of substitution 2.88, Mn = 140000) 90 parts by mass

(additive)

5 parts by mass of the ester (Exemplary Compound X-1) represented by the general formula (X)

4 parts by mass of the ester (Exemplary Compound X-12) represented by the general formula (X)

(Ultraviolet absorber)

3 parts by mass of TINUVIN 928 (produced by BASF Japan Co., Ltd.)

(Fine particles)

Silicon dioxide dispersion diluted solution 4 parts by mass

(menstruum)

Methylene chloride 432 parts by mass

Ethanol 38 parts by mass

The above was put into a sealed container, heated and completely dissolved while stirring. 24 to obtain a dope (Dope Composition 1).

Subsequently, using a belt casting machine, the stainless steel band support was uniformly flexible. In the stainless steel band support, the solvent was evaporated until the amount of the residual solvent reached 100% by mass and peeled off on the stainless steel band support. The web of the cellulose ester film was evaporated at 35 캜 by evaporation, and the film was slit to a width of 1.15 m and dried at a drying temperature of 140 캜 while being stretched by 1.15 times in the TD direction (width direction of the film) in the tenter. Thereafter, the film was dried for 15 minutes while being conveyed by a plurality of rollers in a drying device at 120 DEG C, slit to a width of 1.3 m, knurled at both ends of the film by 10 mm in width and 5 m in height, To obtain a cellulose ester film 1. The film thickness of the cellulose ester film 1 was 25 占 퐉 and the winding length was 5000 m.

Further, the draw ratio in the MD direction calculated from the rotation speed of the stainless steel band support and the operation speed of the tenter was 1.01 times.

[Production of optical film 1]

The following functional layer composition 1 was coated on the A side (surface not in contact with the flexible belt) of the above-prepared cellulose ester film 1 using an extrusion coater, and the film was dried at a constant rate drying temperature of 50 deg. C, After drying, the coated layer was cured by irradiating the irradiated portion with an illuminance of 100 mW / cm ² and irradiating an amount of 0.2 J / cm ² using an ultraviolet lamp while nitrogen was purged so that the oxygen concentration became 1.0 volume% or less, A hard coat layer 1 having a thickness of 4 탆 was formed and wound in a roll shape to produce an optical film 1.

Subsequently, the produced optical film 1 was subjected to alkali treatment under the following conditions.

(Alkali treatment)

Saponification process 2mol / L-NaOH 50 캜 60 sec

Washing process water 25 ℃ 120 seconds

Drying process 100 ℃ 60 seconds

&Quot; Functional layer composition 1 "

&Lt; Composition of Functional Layer Composition 1 >

(Active ray curable resin)

100 parts by mass of pentaerythritol trie / tetraacrylate (NK ester A-TMM-3L, Shin-Nakamura Chemical Industry Co., Ltd.)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

Fluorine-siloxane graft compound (35 mass%) 2 mass parts

(solvent)

20 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

&Lt; Preparation of fluorine-siloxane graft compound >

The name of the commercial product used for the production of the fluorine-siloxane graft compound.

Radical Polymerizable Fluoropolymer (A): Cefral Coat CF-803 (having a hydroxyl number of 60, a number average molecular weight of 15000, manufactured by Central Garris Co., Ltd.)

One end radical polymerizable polysiloxane (B): Silaplane FM-0721 (number average molecular weight: 5000; manufactured by Chisso Corporation)

Radical polymerization initiator: Perbutyl O (t-butylperoxy-2-ethylhexanoate, manufactured by Nippon Oil Co., Ltd.)

Curing agent: Sumidor N3200 (buret-type prepolymer of hexamethylene diisocyanate; manufactured by Sumitomo Bayer Urethane Co., Ltd.)

(Synthesis of radically polymerizable fluororesin)

(1554 parts by mass), xylene (233 parts by mass) and 2-isocyanatoethyl methacrylate (manufactured by Mitsubishi Chemical Corporation) were added to a glass reactor equipped with a mechanical stirrer, a thermometer, a condenser and a dry nitrogen gas inlet, 6.3 parts by mass), and the mixture was heated at 80 占 폚 in a dry nitrogen atmosphere. After reacting at 80 DEG C for 2 hours and confirming disappearance of absorption of isocyanate by infrared absorption spectrum of the sample, the reaction mixture was taken out to obtain a radically polymerizable fluororesin of 50 mass% through urethane bonding.

(Preparation of fluorine-siloxane graft compound)

(26.1 parts by mass), xylene (19.5 parts by mass) and n-butyl acetate (16.3 parts by mass) were added to a glass reactor equipped with a mechanical stirrer, a thermometer, a condenser and a dry nitrogen gas inlet, (1.8 parts by mass), methyl methacrylate (2.4 parts by mass), n-butyl methacrylate (1.8 parts by mass), lauryl methacrylate (1.8 parts by mass, 2-hydroxyethyl methacrylate (5.2 parts by mass) and perbutyl O (0.1 part by mass) were charged and heated in a nitrogen atmosphere to 90 占 폚 and maintained at 90 占 폚 for 2 hours. Perbutyl O (0.1 part) was added, % Of the fluorine-siloxane grafted compound was obtained by HPLC (liquid chromatography, manufactured by Mitsubishi-Kagaku Kogyo KK). The weight average molecular weight of the fluoro-siloxane grafted compound was determined by HPLC ).

[Production of optical film 2]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 2. Otherwise, the optical film 2 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 2 "

&Lt; Composition of Functional Layer Composition 2 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

2 parts by mass of KF-351A (polyether-modified silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.)

Polymer silane coupling agent-coated silica (1) 10 parts by mass

(solvent)

20 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

&Lt; Preparation of Polymer Silane Coupling Coated Fine Particles >

30 ml of methyl methacrylate (Light Ester M, manufactured by Kyoeisha Chemical Co., Ltd.), 1 ml of 3-mercaptopropyltrimethoxysilane (KBM-803, Shin-Etsu Chemical Co., Ltd.) 50 mg of hydrofuran and 50 mg of azoisobutyronitrile (AIBN manufactured by KANTO CHEMICAL Co., Ltd.) as a polymerization initiator were added, and the mixture was substituted with N ₂ gas and heated at 80 ° C for 3 hours to prepare a polymer silane coupling agent . The polymer silane coupling agent thus obtained had a molecular weight of 16,000. The molecular weight was measured by a gel permeation chromatography apparatus. Subsequently, the silica sol (Si-45P made by NIKKISOKU KABASE CHEMICAL INDUSTRY CO., LTD., SiO ₂ concentration 30 wt%, average particle diameter 45 nm, dispersion medium: water) was ion-exchanged with an ion exchange resin and water Ethanol to prepare 100 g of an ethanol dispersion of fine silica particles (SiO ₂ concentration: 30 wt%).

100 g of the silica fine particle ethanol dispersion and 1.5 g of the polymer silane coupling agent were dispersed in 20 g (25 ml) of acetone, 20 mg of ammonia water having a concentration of 29.8% by weight was added thereto, and the mixture was stirred at room temperature for 30 hours to give a polymer silane coupling agent Absorbed.

Thereafter, silica particles having an average particle diameter of 5 탆 were added and stirred for 2 hours to adsorb the unadsorbed polymeric silane coupling agent in the solution to the silica particles, followed by centrifugation to obtain a polymeric silane coupling agent The adsorbed silica particles having an average particle diameter of 5 mu m were removed. 1000 g of ethanol was added to the silica fine particle dispersion adsorbed on the polymer silane coupling agent to precipitate silica fine particles, which were separated, dried under reduced pressure, and subsequently dried at 25 DEG C for 8 hours to obtain polymer-coated silane coupling agent silica (1) . The average particle diameter of the obtained polymeric silane coupling agent-coated silica (1) was 57 nm. The average particle diameter was measured by a laser particle diameter measuring apparatus.

[Production of optical film 3]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 3. Otherwise, the optical film 3 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 3 "

&Lt; Composition of Functional Layer Composition 3 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

2 parts by mass of KF-642 (polyether-modified silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.)

Polymer silane coupling agent 6 mass parts of silica (1)

(solvent)

20 parts by weight of n-propanol

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 4]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 4. Otherwise, the optical film 4 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 4 "

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

0.5 parts by mass of KF-351A (polyether-modified silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.)

0.25 parts by mass of KF-642 (polyether-modified silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.)

1.8 parts by mass of Emulgen 404 (manufactured by Kao Corporation)

1.4 parts by mass of V-8804 (silica fine particle dispersion, manufactured by Nippon Shokubai Kasei Kabushiki Kaisha)

(solvent)

20 parts by weight of n-propanol

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 5]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 5. Otherwise, the optical film 5 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 5 "

&Lt; Composition of Functional Layer Composition 5 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

Polymer silane coupling agent 3 mass parts of silica (1)

(solvent)

20 parts by weight of n-propanol

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 6]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 6, nitrogen purge was performed so that the atmosphere at the time of UV curing was 0.7% by volume or less, and no alkali treatment was performed. Otherwise, the optical film 6 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 6 "

&Lt; Composition of Functional Layer Composition 6 >

(Active ray curable resin)

(Photopolymerization initiator)

1.1 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

IRGACURE 907 (manufactured by BASF Japan Ltd.) 4.9 parts by mass

(additive)

1 part by mass of Surfynol 104E (manufactured by Nisshin Chemical Industry Co., Ltd.)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 7]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 7. Otherwise, the optical film 7 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 7 "

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

2 parts by mass of Megafac F-569 (fluorine-containing group-hydrophilic group-containing oligomer, manufactured by DIC Corporation)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 8]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 8. Otherwise, the optical film 8 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 8 "

&Lt; Composition of Functional Layer Composition 8 >

(Active ray curable resin)

(Photopolymerization initiator)

Irgacure 184 (manufactured by BASF Japan Ltd.) 12 parts by mass

(additive)

220 parts by mass of V-8804 (silica fine particle dispersion, manufactured by Nippon Shokubai Kasei Kabushiki Kaisha)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

N-propanol 240 parts by mass

[Production of optical film 9]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 9. Otherwise, the optical film 9 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 9 "

&Lt; Composition of Functional Layer Composition 9 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

Polymer Silane Coupling Agent 25 parts by mass of the coated silica (1)

(solvent)

25 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 10]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 10. Otherwise, the optical film 10 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 10 "

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

1.8 parts by mass of Emulgen 404 (manufactured by Kao Corporation)

(solvent)

25 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 11]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 11. Otherwise, the optical film 11 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 11 "

&Lt; Composition of Functional Layer Composition 11 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

(solvent)

25 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 12]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 12, and nitrogen purge was performed so that the atmosphere had an oxygen concentration of 0.7% by volume or less at the time of UV curing. Otherwise, the optical film 12 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 12 "

&Lt; Composition of Functional Layer Composition 12 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

0.5 parts by mass of KF-642 (polyether-modified silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.)

(solvent)

25 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 13]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 13. Otherwise, the optical film 13 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 13 "

&Lt; Composition of Functional Layer Composition 13 >

(Active ray curable resin)

80 parts by mass of urethane acrylate (UA-306H, manufactured by Kyoeisha Chemical Co., Ltd.)

(Photopolymerization initiator)

IRGACURE 184 (manufactured by BASF Japan) 8 parts by mass

(additive)

0.3 parts by mass of BYK-UV3510 (manufactured by Big Chemie Japan K.K.)

250 parts by mass of V-8804 (silica fine particle dispersion, manufactured by Nippon Shokubai Kasei Kabushiki Kaisha)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

120 parts by mass of methyl acetate

[Production of optical film 14]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 14. Otherwise, the optical film 14 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 14 "

(Active ray curable resin)

(Photopolymerization initiator)

IRGACURE 184 (manufactured by BASF Japan) 8 parts by mass

(additive)

1 part by mass of KF-351A (polyether-modified silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.)

1 part by mass of BYK-UV3505 (manufactured by Big Chemie Japan K.K.)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

120 parts by mass of methyl acetate

[Production of optical film 15]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 15, and nitrogen purge was performed so that the atmosphere had an oxygen concentration of 0.7% by volume or less at the time of UV curing. Otherwise, the optical film 15 was produced in the same manner as in the production of the optical film 1.

&Quot; Functional layer composition 15 "

(Active ray curable resin)

(Photopolymerization initiator)

1.1 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

IRGACURE 907 (manufactured by BASF Japan Ltd.) 4.9 parts by mass

(additive)

1.8 parts by mass of Emulgen 404 (manufactured by Kao Corporation)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

30 parts by mass of methyl acetate

70 parts by mass of methyl ethyl ketone

[Production of optical film 16]

In the production of the optical film 1, the functional layer composition 1 was changed to the following functional layer composition 16, and an optical film 16 'was produced in the same manner as in the production of the optical film 1. The following functional layer composition 17 was applied on this optical film 16 'using an extrusion coater. After drying at a temperature of 50 ° C for a constant rate drying zone and a temperature of 50 ° C for a reduced drying zone, the atmosphere was changed to an atmosphere having an oxygen concentration of 1.0% while, using an ultraviolet lamp and the illuminance of the irradiation unit 100mW / cm ^2, by curing the coating layer by the irradiation amount to 0.2J / cm ^2, wound in a roll shape to form a hard coat layer of 2㎛ dry film thickness, the optical film 16 was prepared. The optical film 16 was subjected to alkali treatment under the same conditions as those of the optical film 1.

&Quot; Functional layer composition 16 "

&Lt; Composition of Functional Layer Composition 16 >

(Active ray curable resin)

(Photopolymerization initiator)

Irgacure 184 (manufactured by BASF Japan Ltd.) 12 parts by mass

(additive)

(solvent)

20 parts by mass of propylene glycol monomethyl ether

N-propanol 240 parts by mass

&Quot; Functional layer composition 17 "

&Lt; Composition of Functional Layer Composition 17 >

(Active ray curable resin)

(Photopolymerization initiator)

6 parts by mass of Irgacure 184 (manufactured by BASF Japan Ltd.)

(additive)

1.8 parts by mass of Emulgen 404 (manufactured by Kao Corporation)

(solvent)

40 parts by weight of n-propanol

60 parts by mass of methyl acetate

Methyl ethyl ketone 140 parts by mass

[evaluation]

The following optical films 1-16 were evaluated as follows.

(1. Evaluation of wettability of filler)

The side opposite to the functional layer in the prepared optical films 1 to 16 was attached to a glass of 10 cm x 10 cm with an optical adhesive tape interposed therebetween.

Subsequently, HRJ-302 (manufactured by Koryu Tsuga Chemical Co., Ltd.), which is a filler, was dropped onto the functional layers of the optical films 1 to 16, and the film thickness of the filler was measured at 2500 rpm for 15 seconds using a spin coater 120 占 퐉.

Thereafter, a black PET film was bonded to the surface of the glass bonded with the optical film coated with the filler to the functional layer, to which the optical film was not adhered, and the back surface was blackened.

The film was allowed to stand horizontally for 100 hours under an environment of a temperature of 23 캜 and a relative humidity of 55% to measure the cratering width (mm), and the wettability was evaluated based on the following criteria.

(Evaluation standard)

◎ ◎: No crater ring at the end.

◎: Crater ring of 1 mm or less occurs on only one side.

?: The average value of the maximum cratering width on each side is less than 1 mm.

X: The average value of the maximum cratering width on each side is 1 mm or more and less than 5 mm.

××: The average value of the maximum cratering width on each side is 5 mm or more.

(2. Evaluation of durability)

On the opposite surface of the functional layers of the prepared optical films 1 to 16, they were adhered on glass of 10 cm x 10 cm with an optical adhesive tape interposed therebetween. Subsequently, HRJ-302 (manufactured by Koryu Tsuga Chemical Co., Ltd.) as a void filler was dropped onto each of the functional layers of the optical films 1 to 16, and the coating was carried out at 2500 rpm for 15 seconds using a spin coater And the entire surface was coated so as to have a thickness of 120 mu m.

Subsequently, glass was bonded to the surface coated with the void filler, light irradiation was performed at ² J / cm ² , and the glass and the optical film were bonded to each other through the gap filler. A weight (50 g) was put on a sample in which a glass and an optical film were bonded to each other with a gap filler interposed therebetween as shown in Fig. 4 and durability test was conducted by putting in a drier at 90 캜 for 500 hours. This sample was also allowed to stand outdoors in the sun for 100 days, and the light resistance test was conducted. With respect to the sample after the endurance test, the displacement strength was evaluated by the following criteria, and the durability of the sample was evaluated.

Dislocation Strength (Adhesion)

◎ ◎: Level with no deviation at all.

⊚: The level is within 0.2 mm, and there is no problem in practical use.

?: The level of deviation is 0.2 mm to 0.5 mm, and practically no problem occurs.

X: The level of deviation is 0.5 mm to 1 mm, which is a problem in practical use.

××: The level of deviation is 1 mm, which is a practical problem.

(3. Measurement of surface free energy of optical film)

The contact angles of pure water, ethylene glycol and diethylene glycol on the surfaces of the functional layers of the optical films 1 to 16 were measured five times and the average value thereof was determined. Using the Young-Fowkes formula described above, (Sum of a polar component and hydrogen bond component a + dispersed component b) and a ratio (a / b) of the surface free energy of the layer. The optical film 1 had a pure water contact angle of 97 deg., Ethylene glycol 74 deg., And diethylene glycol 51 deg.

The contact angle was measured by using a contact angle meter (trade name: DropMaster DM100, manufactured by Kyowa Chemical Industry Co., Ltd.) under an atmosphere of a temperature of 23 캜 and a relative humidity of 55% after leaving the sample in an atmosphere of a temperature of 23 캜 and a relative humidity of 55% , 1 占 퐇 of a liquid was dropped and measured after 10 seconds. Further, the measurement was carried out five times, and the average value was determined as the contact angle of the sample. For the optical film subjected to the alkali treatment, the contact angle of water was measured before and after the alkali treatment, and the difference (contact angle difference) ?? was obtained.

The results of the evaluation of the wettability and the adhesion of the filler and the total surface free energy (a + b), the ratio (a / b) of the surface free energy of the functional layer and the contact angle difference between water before and after the alkali treatment are shown in Table 1 . Table 1 also shows the correspondence relationship between the embodiment and the comparative example.

From Table 1, in both Comparative Examples 1 to 5, the wettability and adhesion of the filler were both poor (x or x). This is because the at least one of the sum (a + b) and the ratio (a / b) of the surface free energies of the functional layer is outside the range defined by the above-mentioned conditional formula (1) or (2) It is not possible to improve the adhesion and improve the adhesion.

On the other hand, in Examples 1 to 11, the wettability and adhesion of the filler were both good (?,?, Or?). This is because both of the sum (a + b) and the ratio (a / b) of the surface free energies of the functional layer are contained within the range specified by the conditional formula (1) or (2) , And the adhesion is sufficiently improved.

Further, a liquid crystal display was manufactured using the optical films 1 to 16 as the outermost surface, a filler was applied, a touch panel was placed on the filler, UV light of ² J / cm ² was irradiated, A liquid crystal display with a panel was manufactured. Subsequently, the display with the touch panel was allowed to stand under an atmosphere of 90 deg. C for 1000 hours. As a result, in the display using the optical films of Comparative Examples 1 to 5 in Table 1, clouding occurred at the edges. Observation with an optical microscope revealed that the cause of cloudiness was a set of minute spherical (bubble-like) particles, and when the display was disassembled, the bubble-like particles were voids.

The surface of the touch panel was rubbed 2,000 times from the fingers, and the optical film of Comparative Examples 1 to 5 had the rubbed portion of the rubbed portion The visibility deteriorated. The display was disassembled and, as a result, voids due to peeling of the filler were generated between the functional layer of the optical film and the filler at a portion where visibility was deteriorated.

On the other hand, in the display using the optical films of Examples 1 to 11, since the wettability and adhesion of the filler to the functional layer of the optical film were both good, cloudiness at the end portion was hardly observed, Little was confirmed. Particularly, in the optical films of Examples 1 to 4, 6 to 9, and 11, since the wetting property and the adhesion property with the filler are good and the contact angle before the alkali treatment is large (the difference in contact angle of water before and after the alkali treatment is large) , The adhesion of the film could be suppressed at the time of winding the optical film before the alkali treatment.

The optical film, the polarizing plate and the image display device of the present embodiment described above can be expressed as follows.

1. An optical film having a film substrate and a functional layer formed on at least one side of the film substrate,

And satisfies the following conditional expressions (1) and (2) simultaneously.

a + b? 30 mN / m (1)

1 &le; a / b &le; 10 &

only,

b: Dispersion component of surface free energy of functional layer (mN / m)

2. The optical film according to the above 1, wherein the following conditional formula (1a) is also satisfied.

a + b? 40 mN / m (1a)

3. The optical film according to the above 1 or 2, further satisfying the following conditional expression (2a).

1? A / b? 5 2a:

4. The optical film according to any one of the above items 1 to 3, further satisfying the following conditional formula (1b).

a + b? 50 mN / m (1b)

5. The optical film according to any one of items 1 to 4, wherein the optical film satisfies the following conditional expression (2b).

1? (A / b)? 4 (2b)

6. The optical film according to any one of items 1 to 5, wherein the functional layer has a contact angle difference? Of water before and after the alkali treatment under the following alkali treatment conditions is 10 ° or more.

[Alkali treatment condition]

Alkaline solution: 2 mol / L sodium hydroxide solution

Processing temperature: 50 ° C

Processing time: 60 seconds

7. The optical film as described in any one of items 1 to 6 above, wherein the functional layer has a contact angle difference? Of water before and after the alkali treatment under the following alkali treatment conditions is 20 ° or more.

[Alkali treatment condition]

Alkaline solution: 2 mol / L sodium hydroxide solution

Processing temperature: 50 ° C

Processing time: 60 seconds

8. The optical film according to any one of items 1 to 7, wherein the functional layer is a hard coating layer.

9. A polarizer, comprising a polarizer and a protective film formed on one side of the polarizer, wherein the protective film is the optical film according to any one of items 1 to 8 above.

10. An image display apparatus comprising: a display cell; and a polarizing plate disposed on a viewer side of the display cell, wherein the polarizing plate is the polarizing plate described in 9 above.

11. The polarizing plate according to any one of claims 1 to 9, further comprising an outer member joined to the polarizing plate via a filler,

The image display apparatus according to claim 10, wherein the exterior member comprises a touch panel or a front face plate.

12. The image display apparatus according to 11 above, wherein the filler is made of a photo-curable resin.

The optical film of the present invention can be used for an image display device such as a polarizing plate or a liquid crystal display device.

1 image display device
3 External member (touch panel, front face plate)
4 liquid crystal cell (display cell)
5 Polarizer
31 Filler
11 Polarizer
12 Film substrate (? / 4 film)
13 Functional layer (hard coat layer)
15 Optical film

Claims

An optical film having a film substrate and an active ray hardening resin layer formed on at least one side of the film substrate,
And satisfies the following conditional expressions (1) and (2) simultaneously.
a + b? 30 mN / m (1)
1 &le; a / b &le; 10 &
only,
(mN / m) of the polar component and the hydrogen bonding component of the surface free energy of the active line cured resin layer,
b: Dispersion component (mN / m) of the surface free energy of the active ray hardening resin layer

The method according to claim 1,
And the following conditional expression (1a) is satisfied.
a + b? 40 mN / m (1a)

3. The method according to claim 1 or 2,
Satisfies the following conditional expression (2a).
1? A / b? 5 2a:

3. The method according to claim 1 or 2,
(1b) < / RTI > below.
a + b? 50 mN / m (1b)

3. The method according to claim 1 or 2,
Satisfies the following conditional formula (2b).
1? (A / b)? 4 (2b)

3. The method according to claim 1 or 2,
Wherein the difference in contact angle? Of water before and after the alkali treatment in the following alkali treatment conditions in the active ray curable resin layer is 10 ° or more.
[Alkali treatment condition]
Alkaline solution: 2 mol / L sodium hydroxide solution
Processing temperature: 50 ° C
Processing time: 60 seconds

3. The method according to claim 1 or 2,
Wherein the difference in contact angle? Of water before and after the alkali treatment in the following alkali treatment conditions in the active ray curable resin layer is 20 ° or more.
[Alkali treatment condition]
Alkaline solution: 2 mol / L sodium hydroxide solution
Processing temperature: 50 ° C
Processing time: 60 seconds

3. The method according to claim 1 or 2,
Wherein the active ray curable resin layer is a hard coating layer.

A polarizer, and a protective film formed on one surface of the polarizer,
Wherein the protective film is the optical film according to any one of claims 1 to 3. The polarizing plate according to claim 1,

A display cell and a polarizing plate disposed on a viewer side of the display cell,
The image display apparatus according to claim 9, wherein the polarizing plate is the polarizing plate according to claim 9.

11. The method of claim 10,
Further comprising an exterior member which is bonded to the polarizing plate via a filler,
Wherein the exterior member is constituted by a touch panel or a front face plate.

12. The method of claim 11,
Wherein the filler is made of a photo-curable resin.