KR20180056700A - Optical film, polarizing plate and image display device - Google Patents

Abstract

The optical film 16 has a film base 12 as a quarter-wave phase difference film and at least two cured layers located on one side of the film base 12. The cured layer closest to the film substrate 12 is referred to as a first cured layer 13 and the cured layer near the film substrate 12 next to the first cured layer 13 2 is a cured layer 14 and L1 <L2 when the thickness of the first cured layer 13 is L1 (占 퐉) and the thickness of the second cured layer 14 is L2 (占 퐉).

Description

Optical film, polarizing plate and image display device

The present invention relates to an optical film having at least two layers of a cured layer on one side of a film substrate as a 1/4 wavelength retardation film (hereinafter also referred to as? / 4 film), a polarizing plate having the optical film, To an image display apparatus.

When an observer observes an image displayed on a liquid crystal display device through polarizing glasses for viewing a stereoscopic image (3D image) or polarizing sunglasses (hereinafter also referred to as "polarizing glasses or the like"), The crosstalk (change in brightness, dark current) occurs because the transmission axis of the polarizing glasses or the like (the axis through which the linearly polarized light is transmitted) is inclined with reference to one state. In order to reduce the crosstalk and improve the visibility of the image, it is known to arrange a? / 4 film on the outermost surface of the viewer side of the liquid crystal display device.

That is, in the polarizing plate disposed on the viewer side with respect to the liquid crystal cell, a? / 4 film is provided on the viewer side of the polarizer so that the angle formed by the slow axis of the? / 4 film and the absorption axis of the polarizer is approximately 30 to 60 占By pasting, the linearly polarized light from the polarizer is converted into circularly polarized light or elliptically polarized light by the? / 4 film. In this way, when the observer observes the display image by attaching the polarizing glasses or the like, regardless of how the transmission axis of the polarizer (perpendicular to the absorption axis) and the transmission axis of the polarizing glasses or the like are out of alignment, Polarized light or elliptically polarized light) can be guided to the observer's eye by the observer's eye. Therefore, it is possible to suppress the display image from being hard to be seen in accordance with the viewing angle, and the crosstalk can be reduced. The polarizing plate in which the? / 4 film is attached to the polarizer is hereinafter also referred to as a circularly polarizing plate.

The? / 4 film is produced in a long shape by using, for example, a so-called oblique stretching method in which the polymer film is stretched in the direction of substantially 45 degrees with respect to the long side direction. A long circular polarizer plate is cut at a predetermined position by joining a long-shaped? / 4 film and a long-shaped polarizer in a roll-to-roll manner to produce a long circular polarizer plate, The productivity of the circularly polarizing plate is remarkably improved.

However, from the viewpoint of preventing physical damage to the circular polarizer plate, a structure for forming a cured layer on a? / 4 film is known (see, for example, Patent Document 1). In the case of producing a circularly polarizing plate using an optical film in which a cured layer is formed on a lambda / 4 film, a cured layer is formed on an obliquely drawn lambda / 4 film and then the optical film is once wound into a roll- The optical film is led out from the rolled body and joined with the long-shaped polarizer by the roll-to-roll method to produce a circularly polarizing plate.

Japanese Patent Application Laid-Open No. 2015-179204 (see claim 1, paragraphs [0026], [0029], [0033], figures 1, 2, etc.)

However, in the case where the optical film is formed by forming the cured layer as a single layer on the? / 4 film, if the liquid crystal display device is constituted by using the circularly polarizing plate including the optical film, the visibility (In particular, the contrast was lowered). The reason is presumed as follows.

The optical film obtained by forming the cured layer as a single layer on the? / 4 film is rolled up into a rolled body as described above and becomes a long rolled body and is stored or transported as such a rolled body. At this time, the residual stress generated by the oblique stretching of the lambda / 4 film is alleviated when the environment at the time of storage or transportation of the long winding body becomes high temperature and high humidity (or when subjected to a moist heat durability test under such a strict environment). As a result, the? / 4 film tends to decrease in its alignment direction (oblique stretching direction) (the? / 4 film tends to cause dimensional change).

At this time, if the single layer of the cured layer is thin, the curing failure tends to occur, and the original function of the cured layer, that is, the surface protection of the? / 4 film, can not be exhibited. For this reason, a certain thickness is required for the single-layered cured layer. However, if the thickness of the cured layer of the single layer is made thick, the region (brittle region) in which the mechanical strength is weakened by the solvent contained in the cured layer composition penetrates into the? / 4 film becomes thick in the film thickness direction, 4 Following the dimensional change of the film, a dimensional change occurs. For this reason, it is impossible to suppress the dimensional change of the? / 4 film by the entire cured layer. As a result, in the case of a long winding body of the optical film, twisting due to the dimensional change of the? / 4 film occurs, and by this twisting, blocking (sticking of the films together) or black band (strip- Is also likely to occur. When the optical film is not wound in a good state, the planarity of the optical film can not be ensured when the optical film is fed out from the long winding body in order to produce the circularly polarizing plate. , And when the optical film is applied to an image display apparatus, it is thought that it appears as a contrast unevenness.

Therefore, in order to suppress the contrast unevenness, it is possible to suppress the deformation of the wrapping state of the optical film due to the dimensional change of the lambda / 4 film under a high temperature and high humidity environment while the surface of the lambda / 4 film is protected by the cured layer, It is necessary to suppress deterioration of the flatness of the optical film when the film is fed out from the winding body. However, this point has not been examined at all conventionally.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an optical film which is obtained by changing the size of a quarter wavelength retardation film under a high temperature and high humidity environment, while protecting the surface of a quarter wavelength retardation film by a cured layer. And a polarizing plate having the optical film, and an image display apparatus having the polarizing plate, which is capable of suppressing the deformation of the winding state of the polarizing plate There is.

The inventors of the present invention have found that by setting the film thickness of the two-layered cured layer to be suitably set so as to have at least two cured layers on one side of the film substrate as the quarter-wave retardation film, The present invention has been accomplished on the basis of these findings. That is, the above object of the present invention can be achieved by the following arrangement.

An optical film according to one aspect of the present invention is an optical film having a film base as a quarter wave retardation film and at least two cured layers located on one side of the film base, Wherein the cured layer closest to the film base is referred to as a first cured layer and the cured layer next to the first cured layer is referred to as a second cured layer and the thickness of the first cured layer is defined as L1 (占 퐉), and the thickness of the second cured layer is L2 (占 퐉)

L1 < L2

to be.

It is preferable that the cured layer on the film base as the 1/4 phase difference film is constituted by a plurality of layers and the relationship between the film thicknesses of the two layers (the first cured layer and the second cured layer) , It is possible to suppress the deformation of the winding state of the optical film due to the dimensional change of the quarter wavelength retardation film under a high temperature and high humidity environment while the surface of the quarter wavelength retardation film is protected by the cured layer (particularly, the second cured layer) have. As a result, even when the optical film is fed out from the roll, the lowering of the flatness of the optical film can be suppressed.

Fig. 1 is a cross-sectional view showing a schematic configuration of an image display apparatus according to an embodiment of the present invention in an exploded manner, together with a configuration of an optical film used in the image display apparatus.
2 is a cross-sectional view showing another structure of the optical film.
3 is a cross-sectional view showing still another structure of the optical film.

An embodiment of the present invention will be described with reference to the drawings as follows. In the present specification, when numerical ranges A to B are represented, 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.

In order to solve the above-mentioned problems, the inventors of the present application have studied optical films having the following constitutions. That is, the optical film of the present embodiment is an optical film having a film base as a 1/4 wavelength retardation film (? / 4 film) and at least two cured layers located on one side of the film base, A cured layer closest to the film base material is referred to as a first cured layer and a cured layer next to the film base material next to the first cured layer is referred to as a second cured layer, When the thickness of the cured layer is L1 (占 퐉) and the thickness of the second cured layer is L2 (占 퐉)

L1 < L2

to be. This feature is a technical feature that is common to the invention relating to each claim in the claims.

Although the mechanism and mechanism for producing the effect of the constitution of the optical film are not clearly defined, they are presumed as follows.

the thickness L2 of the second cured layer nearer to the film substrate is smaller than the thickness L1 of the first cured layer closest to the film substrate in the structure having at least two cured layers on the film substrate as the? / 4 film This is big. Since the thickness of the second cured layer is thick, the surface of the? / 4 film (film substrate) can be protected by the second cured layer.

Further, since the first cured layer is thin, the solvent contained in the composition for forming the first cured layer is less likely to penetrate into the? / 4 film and the region where the mechanical strength becomes weak (the component forming the first cured layer and the? / 4 film In the mixed region in which the components forming the film are mixed, a relatively loose region) also becomes thinner in the film thickness direction. Therefore, in the entire cured layer including the first cured layer and the second cured layer, the region where the mechanical strength is relatively strong is increased. Therefore, the residual stress generated by the oblique stretching of the? / 4 film under the high temperature and high humidity environment is relaxed, whereby even if the? / 4 film is to be reduced in the alignment direction (oblique stretching direction) It is possible to suppress the dimensional change of the liquid. As a result, even when the optical film is wound in a roll form, twisting in the winding body, blocking of the optical film due to the twisting, and generation of black bands can be suppressed. That is, it is possible to suppress deformation of the optical film in the winding state. As a result, when the optical film is fed out from the winding body, the flatness of the optical film can be secured.

Since the planarity of the optical film is ensured in this way, the optical properties of the optical film are excellently exerted on the whole film surface. Therefore, even when the circular polarizer is formed using the optical film and the circular polarizer is applied to an image display device, It is possible to suppress deterioration of visibility (decrease of contrast) at the time of image observation by polarized sunglasses or the like.

In the polarizing plate of the present embodiment, the optical film is located on one side of the polarizer. According to the configuration of the optical film, even when the optical film is wound in a roll form, deformation in the winding state of the roll can be suppressed and the flatness of the optical film can be secured. Thus, even if a polarizing plate (for example, a circular polarizing plate) is formed by attaching the optical film to a polarizer, the planarity of the polarizing plate can be satisfactorily secured. As a result, when the polarizing plate is applied to an image display apparatus, deterioration of visibility (for example, non-uniformity of contrast) at the time of image observation by polarized sunglasses or the like can be suppressed.

In the image display device of the present embodiment, the polarizing plate is located on at least one side of the display cell. By configuring the image display device using the polarizing plate excellent in planarity, deterioration in visibility (for example, non-uniformity of contrast) at the time of image observation by polarized sunglasses or the like can be suppressed.

Hereinafter, a specific configuration of the image display apparatus to which the optical film of the present embodiment is applied will be described.

[Configuration of image display apparatus]

Fig. 1 is a cross-sectional view showing an outline configuration of an image display apparatus 1 according to an embodiment of the present invention. The image display apparatus 1 is, for example, a liquid crystal display apparatus and is provided with a filling layer 31 interposed between a polarizing plate 5 (specifically, on an optical film 16 described later) of the liquid crystal display panel 2 And a protective portion 3 are bonded. The filling layer 31 is an adhesive layer (void filler) containing a photo-curing resin such as acryl and is formed on the entire surface of the polarizing plate 5 of the liquid crystal display panel 2. [ The protective portion 3 protects the surface of the liquid crystal display panel 2 and is formed of, for example, a front face plate including acrylic resin or glass. Instead of the front face plate, a touch panel (electrostatic capacity type, resistive type, or the like) may be used as the protective portion 3.

The liquid crystal display panel 2 is constituted by disposing polarizing plates 5 and 6 on both sides of a liquid crystal cell 4 (display cell) sandwiched between a pair of substrates. The polarizing plate 5 is pasted on 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, TN (Twisted Nematic) type, VA (Vertical Alignment)

The polarizing plate 5 includes a polarizer 11 that transmits a predetermined linearly polarized light, a film base 12, a first cured layer 13, and a second base layer 14 that are sequentially stacked on the protective portion 3 side of the polarizer 11 2 cured layer 14 and a back surface protective film 15 laminated on the liquid crystal cell 4 side of the polarizer 11. [ The optical film 16 as a protective film formed on the viewer's side of the polarizer 11 is constituted by the film base 12, the first cured layer 13 and the second cured layer 14. The film substrate 12 includes, for example, a cellulose resin (cellulose ester resin) and is also referred to as a cellulose ester film substrate. The surface of the polarizing plate 5 can be protected by forming the cured layers (the first cured layer 13 and the second cured layer 14) on the film base 12.

The back surface protective film 15 is provided to protect the back surface of the polarizing plate 5. [ The backside protective film 15 may be made of the same material (for example, cellulose ester) as the film base 12, or may be made of other materials. Further, the back surface protective film 15 may be composed of a film (phase difference film) having an optical compensation function, or may be composed of a zero retardation film which gives almost no retardation to the transmitted light.

The polarizing plate 6 includes a polarizer 21 that transmits a predetermined linearly polarized light, a surface protective film 22 that is disposed on the liquid crystal cell 4 side of the polarizer 21, a liquid crystal cell 4 of the polarizer 21 And a back surface protective film 23 disposed on the opposite side of the back surface protective film 23. The polarizer 21 is arranged so that its transmission axis is perpendicular to the polarizer 11 (cross-Nicol state). The surface protective film 22 and the back surface protective film 23 are provided to protect the front surface and the back surface of the polarizing plate 6 but they may be made of the same material as the film base 12 of the polarizing plate 5 Cellulose ester), or may be composed of other materials.

The optical film 16 on the viewing side of the above-mentioned polarizing plate 5 will be further described below.

The film base 12 of the optical film 16 is bonded to the polarizer 11 by a water-shed, and the film thickness thereof is preferably within a range of, for example, 5 to 50 m. By making the film base 12 thin, the optical film 16 and the polarizing plate 5 can be made thin, contributing to the thinning of the entire image display device 1. [

The film substrate 12 is composed of a quarter wavelength retardation film (? / 4 film). The? / 4 film is a layer which imparts an in-plane retardation of about 1/4 of the wavelength of transmitted light, and is constituted by a film subjected to warp stretching in the present embodiment. (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, even when the transmission axis of the polarizing sunglass is shifted from the transmission axis (perpendicular to the absorption axis) of the polarizer 11 in the case where the observer attaches the polarizing sunglasses to observe the display image, The component of light included in the light (circularly polarized light or elliptically polarized light) and parallel to the transmission axis of the polarized sunglass can be guided to the observer's eyes. As a result, it is possible to suppress the display image from being hardly seen in accordance with the viewing angle. Further, 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 entering the observer's eye is directly incident on the observer's eye, The burden on the eyes can be reduced. Further, even in the case of observing a display image using polarized glasses instead of polarized sunglasses so as to observe a stereoscopic image, it is possible to suppress the display image from becoming hard to be seen in accordance with the viewing angle for the same reason as the above .

The thickness of the first cured layer 13 closest to the film base material 12 among the plurality of cured layers on the film base material 12 in the optical film 16 is defined as L1 (占 퐉) And the thickness of the second hardened layer 14 close to the second hardened layer 12 is L2 (mu m). In this embodiment,

L1 < L2

to be. By setting the magnitude relationship between L1 and L2 as described above, it is possible to protect the surface of the film base material 12 by the second cured layer 14 and to protect the surface of the optical film ( 16 can be suppressed. As a result, even when the optical film 16 is fed out from the roll, deterioration of the planarity of the optical film 16 can be suppressed. The detailed reason is as described above.

The second cured layer 14 includes a resin having an alicyclic structure and fine particles coated with a polymeric silane coupling agent and the first cured layer 13 includes a resin having an alicyclic structure of the second cured layer 14 The resin may be different from the resin and may include fine particles coated with a polymeric silane coupling agent.

The second hardened layer 14 (low moisture permeable layer) is realized by including the resin having the alicyclic structure. The second cured layer 14 is formed on the film base 12 with the first cured layer 13 interposed therebetween. That is, the first cured layer 13 is interposed between the second cured layer 14 and the film base 12. The first cured layer 13 includes fine particles coated with a polymeric silane coupling agent. When the optical film 16 is bonded as a protective film to one side of the polarizer 11 by means of water, moisture of the water film enters the film base 12 The moisture exits from the film substrate 12 to the first cured layer 13 due to the hygroscopicity of the first cured layer 13 (the fine particles). Thereby, it is possible to suppress the film substrate 12 from being deformed (expanded) by the function, and the tensile stress is applied to the second hardened layer 14 by the deformation, and a load due to the stress is generated Can be reduced.

Further, since the first cured layer 13 contains a resin different from the resin of the second cured layer 14 that realizes low moisture permeability (preferably, for example, a urethane acrylate resin) Even when an external impact is applied to the second cured layer 14 formed on the cured layer 13, the impact can be alleviated (absorbed) in the first cured layer 13. [ In addition, the hardness of the second hardened layer 14 can be increased by containing the fine particles coated with the polymer silane coupling agent in the second hardened layer 14 as well. In addition, in the second cured layer 14, low moisture permeability is realized by the resin having an alicyclic structure. Therefore, even if the second cured layer 14 contains the fine particles having hygroscopic property, (14) can be realized.

As described above, by suppressing deformation by the function of the film substrate 12 and absorbing the impact in the first cured layer 13 and securing the hardness of the second cured layer 14 to some extent, The second hardened layer 14 is unlikely to be cracked even when an external force is applied to the hardened layer 14 (for example, a bending stress due to the curved surface of the image display device 1 or an external impact). Therefore, even in the configuration in which the second moisture-curing layer 14 is formed, the cracks in the second hardened layer 14 can be reduced.

Since the water content of the water droplet that has entered the film base material 12 falls to the first cured layer 13 side, it is possible to suppress the phase difference variation due to the dimensional deformation and the function due to the function of the film base material 12. This makes it possible to further suppress a decrease in the contrast when the optical film 16 is applied to the image display device 1 and to prevent the deterioration of the contrast due to the phase difference variation of the film base 12 The crosstalk can be reduced.

Further, the resin (resin having an alicyclic structure) contained in the second cured layer 14 and the above-mentioned fine particles have poor compatibility. Therefore, when the second cured layer 14 is directly formed on the film base 12, the fine particles easily aggregate due to reaction with an extract (for example, an additive) from the film base 12, The layer is easily separated from the second cured layer 14. When the layer of the fine particles is formed, the reflected light of the external light at the surface of the second cured layer 14 and the reflected light of the external light at the layer of the fine particles interfere with each other, and nonuniformity occurs in black display.

On the other hand, when the first cured layer 13 is formed between the film base 12 and the second cured layer 14 as in the present embodiment, the presence of the first cured layer 13 causes the second The fine particles contained in the cured layer 14 are less likely to react with the extract from the film base 12 and the fine particles are less likely to aggregate. Therefore, the layer of the fine particles is hardly formed, and the above-described display unevenness due to the formation of the layer can be reduced.

When the fine particles are not contained in the first cured layer 13, a difference in refractive index occurs between the second cured layer 14 and the first cured layer 13 due to the presence or absence of the fine particles, Interference of light by the vehicle occurs. However, in the present embodiment, since the first cured layer 13 also contains the same fine particles as the fine particles contained in the second cured layer 14, the second cured layer 14 and the first cured layer 13, It is possible to reduce the difference in refractive index between the first and second refractive index layers, and reduce the interference of the light due to the refractive index difference.

The resin included in the first cured layer 13 (a resin different from the resin of the second cured layer 14) is preferably a urethane acrylate resin. If the first cured layer 13 is too soft, hardness hardly appears as the hardness of the optical film 16 even if the second cured layer 14 is formed thereon. By using the urethane acrylate resin together with the fine particles coated with the polymer silane coupling agent, the relatively hard first hardened layer 13 can be formed within a range that does not impair the buffer property. Therefore, the hardness of the optical film 16 can be easily increased by forming the second hardened layer 14 on the first hardened layer 13 including the urethane acrylate resin.

The thickness L1 of the first cured layer 13 is preferably 0.5 mu m or more and 3 mu m or less. When L1 is in the above range, the dimensional change of the film substrate 12 under a high temperature and high humidity environment can be surely suppressed while securing the hardness of the second cured layer 14. [

Incidentally, if L1 is less than 0.5 占 퐉, the first hardened layer 13 becomes too thin, and the hardening is liable to occur. When a hardening defect occurs in the first hardened layer 13, when the second hardened layer 14 is formed thereon, the extract from the first hardened layer 13 coagulates in the second hardened layer 14, The second hardened layer 14 hardly exhibits a predetermined hardness. On the other hand, if L1 is more than 3 m, the first cured layer 13 becomes too thick, and the solvent contained in the composition forming the first cured layer 13 penetrates the film substrate 12, It becomes difficult to suppress the dimensional change of the film substrate 12 under a high temperature and high humidity environment because the weakened region becomes thick in the film thickness direction.

The above optical film 16 can be used for purposes other than the polarizing plate. In this case, the first cured layer 13 and the second cured layer 14 may be formed on both sides of the film base 12. It is also possible to constitute the image display device 1 by disposing the two polarizing plates 5 on both sides of the liquid crystal cell 4.

2 is a cross-sectional view showing another structure of the optical film 16. The optical film 16 may have an antistatic layer 17 as a functional layer on the surface opposite to the first cured layer 13 with respect to the second cured layer 14. [ Though not shown, three or more cured layers may be formed on one side of the film substrate 12, or the antistatic layer 17 may be formed on the outermost cured layer.

3 is a sectional view showing still another structure of the optical film 16. As shown in Fig. The optical film 16 may have an antistatic layer 17 on both sides of one side (on the second cured layer) and the other side of the film base 12, The antistatic layer 17 may be provided only on the side opposite to the first cured layer 13 on the side opposite to the first cured layer 13.

As described above, since the optical film 16 further has the antistatic layer 17 on at least one side of the film base 12, the film can be prevented from being charged, blocking during film winding can be suppressed, It is possible to further suppress the deformation of the winding state of the stator 16. In addition, since the antireflection function can be given to the optical film 16, it is possible to provide a polarizing plate (for example, a touch (not shown) on the image display device 1 as the protective portion 3) It is very effective to apply the optical film 16 to the polarizing plate 5 on the touch panel side of the image display apparatus 1 in the configuration of installing the panel.

[Optical film]

Hereinafter, the details of the optical film 16 will be described.

<Second Cured Layer>

The second cured layer of the present embodiment contains an active energy ray curable resin having an alicyclic structure (hereinafter, simply referred to as a curable resin). Specific examples of the alicyclic structure include norbornyl, tricyclodecanyl, tetracyclododecanyl, pentacyclopentadecanyl, adamantyl, diamantanyl, and the like.

The active energy ray is defined as an energy ray capable of decomposing a compound (photopolymerization initiator) generating active species to generate active species. Examples of such active energy rays include visible light, ultraviolet (UV) light, electron beam (EB), infrared light, X-ray,? -Ray,? -Ray and? -Ray. However, ultraviolet rays are preferably used because they have a constant energy level, have a rapid curing rate, and are relatively inexpensive and compact.

The active energy ray-curable resin preferably has an ethylenically unsaturated double bond. As the ethylenically unsaturated double coupler (meth) acryloyl group, vinyl group, styryl group, there may be mentioned a polymerizable functional group such as an allyl group, particularly (meth) group and a -C (O) OCH = CH ₂ are acrylic desirable.

The active energy ray-curable resin having an alicyclic structure is preferably constituted by bonding a hydrocarbon group of an alicyclic structure and a group having an ethylenically unsaturated double bond via a linking group. Examples of the linking group include a single bond, an alkylene group, an amide group, a carbamoyl group, an ester group, an oxycarbonyl group, an ether group, or the like, or a combination thereof. Specifically, a polyol such as a diol or triol having an alicyclic structure, a carboxylic acid having a (meth) acryloyl group, a vinyl group, a styryl group or an allyl group, a carboxylic acid derivative, an epoxy derivative, Can be easily synthesized by a one-step or two-step reaction with a derivative compound or the like.

Hereinafter, specific compounds of the active energy ray-curable resin having an alicyclic structure are shown by the following general formulas (I) to (VII), but the present invention is not limited thereto.

(Wherein R 1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R 2 is an alkylene group or alkylene oxide group having 1 to 5 carbon atoms, R 3 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, n is an integer of 1 or 2 )

(Wherein R1, R3, and n are the same as in the general formula (I)

In the general formulas (I) and (II), R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom, a methyl group or an ethyl group. R2 represents an alkylene group or alkylene oxide group having 1 to 5 carbon atoms, preferably a methylene group, an ethylene group, a methylene oxide group, or an ethylene oxide group. R 3 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom, a methyl group or an ethyl group.

Hereinafter, preferred specific examples of the compound represented by the general formula (I) are shown, but the present invention is not limited thereto.

Hereinafter, preferred specific examples of the compound represented by the formula (II) are shown, but the present invention is not limited thereto.

Examples of commercially available products of the compounds represented by the above general formulas (I) and (II) include NK ester A-DCP (tricyclodecane dimethanol diacrylate, manufactured by Shin Nakamura Kagaku Kogyo Co., Ltd.) .

In the general formula (III), L and L 'each independently represent a divalent or higher-linking group and do not double at the same time. n represents an integer of 1 to 3;

In the general formula (IV), L and L 'each independently represent a divalent or higher-linking group and do not double at the same time. n represents an integer of 1 to 2;

In the general formula (V), L and L 'each independently represent a divalent or higher-valent linking group and do not double at the same time. n represents an integer of 1 to 2;

In the general formula (VI), L, L 'and L "each independently represent a divalent or higher linking group.

In the general formula (VII), L and L 'each independently represent a divalent or higher linking group, and do not double at the same time.

Specific examples of the compounds represented by the above general formulas (III) to (VII) are shown below, but are not limited thereto.

The second cured layer preferably contains an active energy ray-curable resin having an alicyclic structure in an amount of 30 mass% or more, and more preferably 50 mass% or more.

(Photopolymerization initiator)

The second cured 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 is 20: 100 to 0.01: 100 in terms of the 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, and for example, Irgacure 184, Irgacure 907, Irgacure 651 and the like of BASF Japan Co., Ltd. can be mentioned as preferable examples.

(Fine particles)

The second cured layer may contain fine particles. Examples of the fine particles include, but are not limited to, silica, alumina, zirconia, titanium oxide, antimony pentoxide, and the like, preferably silica. The silica fine particles may be hollow particles having cavities therein. Of these, fine particles coated with a polymeric silane coupling agent are particularly preferable because they provide a hardness suitable for the cured layer and exhibit good mechanical properties. The content is preferably such that the content of fine particles: active ray curable resin = 0.1: 100 to 400: 100.

(Polymeric silane coupling agent)

Polymer silane coupling agent means a reaction product of a polymerizable monomer and a silane coupling agent (reactive 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 (meth) acrylate, (Meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-heptyl (Meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, (meth) acrylate, decyl (meth) acrylate, dodecyl Hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl Acrylate, 2-aminoethyl acrylate, ethylene oxide adduct of (meth) acrylic acid, trifluoromethyl methyl (meth) acrylate, (Meth) acrylate, 2-perfluoroethyl (meth) acrylate, 2-perfluoroethyl (meth) acrylate, 2-perfluoroethyl (Meth) acrylate, perfluoromethyl (meth) acrylate, dipropylmethyl (meth) acrylate, 2-perfluoromethyl- (Meth) acrylic acid-based monomers such as 2-perfluorodecylethyl 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.

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

X-R-Si (OR)₃ (One)

(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 &gt; 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,? - (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane,? -Glycidoxymethyltrimethoxysilane,? -Glycidoxymethyltriethoxysilane,? -Glycidoxyethyltrimethoxysilane,? -Glycidyl Glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, , γ- (β-glycidoxyethoxy) propyltrimethoxysilane, γ- (meth) acryloxymethyltrimethoxysilane, γ- (meth) acryloxymethyltriethoxysilane, γ- ) Acryloxyethyltrimethoxysilane,? - (meth) acryloxyethyltriethoxysilane,? - (meth) acryloxypropyltrimethoxysilane,? - (Meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, 3-ureidoisopropylpropyltriethoxy Silane, perfluorooctylethyltrimethoxysilane, perfluorooctylethyltriethoxysilane, perfluorooctylethyltriisopropoxysilane, trifluoropropyltrimethoxysilane, N-beta (aminoethyl) gamma -Aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and mixtures thereof.

A polymeric silane coupling agent is prepared by reacting a polymerizable monomer with a reactive silane compound. 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, based on 100 parts by weight of the polymerizable monomer is prepared, a polymerization initiator is added thereto, Can be obtained.

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

Polymer silane coupling agent-coated fine particles can be specifically prepared by adding a polymer silane coupling agent to an organic solvent dispersion of fine particles and coating the fine particles with a polymer silane coupling agent in the presence of an alkali. The obtained polymeric silane coupling agent-coated fine particles preferably have an average particle diameter of 5 to 500 nm, more preferably 10 to 200 nm, in view of securing optical characteristics when used in an optical film.

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

(Conductive agent)

The second cured 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. Further, the antistatic layer may be formed on the second cured layer without containing the conductive agent in the second cured layer. Details of the antistatic layer will be described later.

(additive)

The second cured 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 applicability. It is easy to control the hydrophilicity by adjusting kinds and amounts of these additives. The HLB value refers to 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).

Specific compounds of compounds having an HLB value of 3 to 18 are illustrated below, but are not limited thereto. () Indicates the HLB value. Emulsion 102 (6.3), emulsion 103 (8.1), emulsion 104P (9.6), emulsion 105 (9.7), emulsion 106 (10.5), emulsion 108 (12.1) 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) Emulsion LS-110 (13.4), EMULGEN LS-114 (14.0), Nisshin Kagaku Kogyo K.K.: Surfynol 104E (4), Surfynol 104H (4) , Surfynol 104A (4), Surfynol 104BC (4), Surfynol 104DPM (4), Surfynol 104PA (4), Surfynol 104PG-50 ), Surinol 440 (8), Surinol 465 (13), Surinol 485 (17), Surinol SE (6), Shin Flats Kagaku Kogyo Kaisha as to whether or claim: X-22-4272 (7), X-22-6266 (8).

The fluorine-siloxane graft compound refers to a compound of a copolymer 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 graft compound can be prepared by a method 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 K.K.

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

KF-351, KF-354L, KF-355A, KF-615A, KF-945, KF-618, KF-6011, KF-351, KF-352, KF- BYK-UV3510, BYK-UV3510, BYK-UV3500, BYK-UV3510, and BYK-UV3510 available from Daicel Chemical Industries, Ltd .; These components are preferably added in an amount of 0.005 parts by mass or more and 10 parts by mass or less based on the solid component in the composition for forming a second cured layer. Two or more kinds of these components may be added as long as the total additive amount is in the range of 0.005 parts by mass or more and 10 parts by mass or less.

(Ultraviolet absorber)

The second cured layer may contain an ultraviolet absorber described in the following cellulose ester film. The content of the ultraviolet absorber is preferably such that the ratio of the ultraviolet absorber: curable resin = 0.01: 100 to 20: 100, in mass ratio.

(solvent)

The second cured layer is formed by applying a composition for forming a second cured layer by diluting a component forming the second cured layer with a solvent, applying the composition on the first cured layer in the following manner, drying and curing the composition .

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 application amount of the composition for forming the second cured layer 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 in the range of 2 to 12 占 퐉.

As a method of applying the composition for forming the second cured layer, known methods 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.

(Method of forming second hardened layer)

(Hereinafter, also referred to as &quot; UV curing treatment &quot;) is applied on the first cured layer to be described later, the composition for forming the second cured layer is applied, do. The heat treatment temperature after UV curing is preferably 60 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 second cured layer having excellent film strength can be obtained.

It is generally known that the drying process changes from a constant drying rate to a decreasing drying rate when drying begins. The section in which the drying rate is constant is referred to as the rate-drying section, and the section in which the drying rate is decreased is referred to as the rate-decreasing drying section.

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

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 the respective lamps, but the irradiation amount of the active rays is usually in the range of 50 to 1000 mJ / cm2, preferably in the range of 50 to 300 mJ / cm2. In addition, 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.

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

<First Cured Layer>

The first cured layer contains a resin different from the resin contained in the second cured layer. The resin of the first cured layer preferably contains an acrylic material. Examples of the acrylic material include a polyfunctional urethane (meth) acrylate synthesized from a monofunctional or polyfunctional (meth) acrylate compound such as a (meth) acrylic acid ester of a polyhydric alcohol, a diisocyanate and a polyhydric alcohol, and a hydroxy ester of (meth) Methacrylate compound may be used. In addition to these, polyether resins, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins and the like having an acrylate-based functional group can be used.

In the present embodiment, the term "(meth) acryl" refers to both "acrylic" and "methacrylic", and "(meth) acrylate" refers to both of "acrylate" and "methacrylate" , And "(meth) acryloyl" means both of "acryloyl" and "methacryloyl". For example, "urethane (meth) acrylate" represents both of "urethane acrylate" and "urethane methacrylate".

Examples of the monofunctional (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) (Meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate (Meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, (Meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, 2-ethoxyethyl (Meth) acrylate, phosphoric acid (meth) acrylate, (Meth) acrylate, ethylene oxide modified phenoxy (meth) acrylate, propylene oxide modified phenoxy (meth) acrylate, nonylphenol (meth) acrylate, ethylene oxide (Meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, (Meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethylhydrogenphthalate, 2 (Meth) acryloyloxypropylhydrogenphthalate, 2- (meth) acryloyloxypropylhexahydrohydrogenphthalate, 2- (meth) acryloyloxypropyltetrahydrophthalate, 2- (Meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, Adamantane derivatives such as adamantyl acrylate having a monovalent mono (meth) acrylate derived from 2-adamantane and adamantanediol, mono (meth) acrylate mono (meth) acrylate derived from monofunctional (Meth) acrylate, and the like.

Examples of the bifunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (Meth) acrylate, propoxylated hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate Acrylate, neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tripropylene glycol di Acrylate, di (meth) acrylate such as hydroxypivalic acid neopentyl glycol di (meth) acrylate, and the like.

Examples of trifunctional or more (meth) acrylate compounds include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) Tri (meth) acrylate such as 2-hydroxyethyl isocyanurate tri (meth) acrylate and glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (Meth) acrylate compounds such as trimethylolpropane tri (meth) acrylate and ditrimethylolpropane tri (meth) acrylate, and trifunctional (meth) acrylate compounds such as pentaerythritol tetra (Meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylol propane penta (meth) acrylate, dipentaerythritol penta (Meth) acrylate compounds such as trimethylolpropane hexa (meth) acrylate and ditrimethylolpropane hexa (meth) acrylate, and polyfunctional (meth) acrylate compounds in which part of these (meth) acrylates are substituted with an alkyl group or? -Caprolactone Substituted polyfunctional (meth) acrylate compounds, and the like.

Particularly, an ultraviolet curable acrylate resin, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin or an ultraviolet curable epoxy resin is preferably used Among them, an ultraviolet curable acrylate 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 methacryloyloxy groups in the molecule. Examples of the monomer of polyfunctional acrylate include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexane diol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylol Pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, Ditrimethylolpropane tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, glycerin triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol penta Acrylate, dipentaerythritol Trimethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, But are not limited to, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, pentaerythritol tetramethacrylate, But are not limited to, tetramethacrylate, glycerin trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate, polybasic acid Acrylate, and the like. 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 acrylates are available from Nippon Kasei Kogyo K.K., Shin Nakamura Kagaku Kogyo Co., Ltd., Osaka Yuki Kagaku Kogyo Co., Ltd., and the like.

It is possible to design a desired molecular weight and molecular structure among the acrylic materials and to make the first hardened layer have appropriate hardness and to balance the physical properties of the first hardened layer to be formed easily The functional urethane acrylate can be suitably used. The urethane acrylate is obtained by reacting a polyhydric alcohol, a polyvalent isocyanate and a hydroxyl group-containing acrylate.

As the solvent contained in the composition for forming the first cured layer used for forming the first cured layer, a solvent which dissolves or swells the film base is preferable. By dissolving or swelling the film base material in the solvent, the composition for forming the first cured layer is likely to penetrate into the inside from the surface of the film base material, and the adhesion between the film base material and the first cured layer can be improved.

In addition, a layer in which the resin component of the film base and the resin component of the first cured layer are mixed is formed near the surface layer of the film base, and the refractive index of the film base and the first cured layer can be inclined And it is possible to prevent occurrence of non-uniformity of interference.

Examples of the solvent for dissolving or swelling the surface of the film base material include cellulose ethers such as dibutyl ether, dimethoxy methane, dimethoxy ethane, diethoxy ethane, propylene oxide, 1, Ethers such as 4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole and phenetole, acetone, methyl ethyl ketone, diethyl ketone, Ketones such as methyl ethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone and methylcyclohexanone, and ketones such as ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, Esters such as n-butyl acetate, n-pentyl acetate and? -Butyrolactone, and cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve and cellosolve acetate, These can be used in combination. Further, it is preferable to use at least one of methyl acetate, ethyl acetate, methyl ethyl ketone, acetylacetone, acetone and cyclohexanone.

The first cured layer preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include 2,2-ethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, dibenzoyl, benzoin, benzoin methyl ether, benzoin ethyl ether, p-chlorobenzophenone, Methoxybenzophenone, Michler's ketone, acetophenone, 2-chlorothioxanthone and the like. These may be used alone or in combination of two or more.

The first cured layer preferably contains a photosensitizer. Examples of the photosensitizer include tertiary amines such as triethylamine, triethanolamine and 2-dimethylaminoethanol, alkylphosphines such as triphenylphosphine, and thioethers such as? -Thiodiglycol. Or a mixture of two or more of them may be used.

The first cured layer preferably includes a leveling agent. Among the leveling agents, it is most preferable to use an acrylic leveling agent. By using the leveling agent, it is possible to prevent defects such as film thickness unevenness and coating liquid cratering which may occur at the time of forming the first hardened layer. Further, by using the acrylic leveling agent, it is possible to improve the recoatability in the case of laminating the second cured layer on the first cured layer, the adhesion property between the first cured layer and the second cured layer Deterioration can be prevented.

Further, quaternary ammonium cations or conductive metal fine particles may be added to the first hardened layer to impart conductivity to the first hardened layer.

Examples of the application method of the composition for forming the first cured layer include dip coating method, spin coating method, flow coating method, spray coating method, roll coating method, gravure roll coating method, air doctor coating method, blade coating method, Coating method, slot-orifice coating method, calender coating method, die coating method, and the like can be adopted as a coating method, a coating method, a coating method, a knife coating method, a reverse coating method, a transfer roll coating method, a micro gravure coating method, Particularly, in the case of forming a uniform thin film layer, the micro gravure coating method is preferable, and when it is necessary to form a thick film layer, a die coating method is preferable.

The first cured layer contains the same fine particles as those contained in the second cured layer, that is, fine particles coated with a polymeric silane coupling agent. At this time, the ratio a / b of the content a of the fine particles contained in the second cured layer to the content b of the fine particles contained in the first cured layer may be 1, but is preferably 2 or more and 10 or less. The reason is as described above.

In addition, the first cured layer may contain additives similar to those of the second cured layer in addition to the fine particles. Further, the first cured layer can be formed on the film substrate in the same manner as the method of forming the second cured layer.

<Back Coating Layer>

A back coating layer may be formed on the surface opposite to the side where the cured layers (the first cured layer and the second cured layer) of the optical film are formed. The back coating layer is formed by coating, CVD, or the like so as to calibrate curl generated by forming a cured layer or other layers. In other words, by making the surface having the back coating layer formed inward to have a property of being rounded, the degree of curling can be balanced. It is also preferable that the back coating layer is formed by coating also with the anti-blocking layer. In this case, it is preferable that fine particles are added to the back coating layer coating composition so as to have an anti-blocking function.

Examples of the inorganic particles to be added to the back coating layer include inorganic particles such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, Zinc, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. It is preferable that the fine particles contain silicon, because haze is reduced, 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.). Fine particles of zirconium oxide 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, it is commercially available under the trade names of Tosepearl 103, 105, 108, 120, 145, 3120 and 240 (manufactured by Toshiba Silicone Co., 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 coefficient of dynamic friction on the back side of the optical film used in the present embodiment is preferably 0.9 or less, particularly 0.1 to 0.9.

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

The back coating layer is preferably formed by applying a composition containing a solvent for dissolving a transparent resin film (film substrate) or a solvent for swelling. The solvent used may include a solvent which does not dissolve in addition to the solvent to be dissolved and / or the solvent to be swollen, and a composition obtained by mixing them in an appropriate ratio depending on the degree of curling of the transparent resin film or the type of the resin and It may be formed in a coating amount.

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 alcohol , Propylene glycol monomethyl ether acetate, propylene carbonate, cyclopentanone, 3-pentanone, 1,2-dimethoxyethane, tetrahydrofuran, ethyl lactate, bis (2-methoxyethyl) ether, 2-methoxyethyl acetate, propylene glycol dimethyl ether, trichlorethylene, methylene chloride, ethylene chloride, tetrachloroethane, trichloroethane and chloroform. 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 back coating layer may contain a resin as a binder. Examples of the resin used as the binder of the back coating layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, copolymer of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymer, Vinyl polymers such as vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer and ethylene- 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), cellulose derivatives such as diacetyl cellulose and cellulose acetate butyrate resin, maleic acid and / or Acrylic acid copolymers, acrylic acid ester copolymers, acrylonitrile- Butadiene-styrene copolymers, acrylic resins, polyvinyl acetal resins, polyvinyl butyral resins, polyester polyurethane resins, polyvinyl butyral resins, polyvinyl butyral resins, polyvinyl butyral resins, Based resin, a silicone-based resin, a fluorine-based resin, and the like, such as a polyether resin, an ether polyurethane resin, a polycarbonate polyurethane resin, a polyester resin, a polyether resin, a polyamide resin, an amino resin, a styrene-butadiene resin and a butadiene- acrylonitrile resin But the present invention is not limited thereto. Examples of the acrylic resin include Acryphet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperp M-4003, M-4005, M-4006, M- BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77 and BR (manufactured by NAGAKI KOGYO KABUSHIKI KAISHA) -79, BR-80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, (Manufactured by Mitsubishi Rayon Co., Ltd.), BR-105, BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, Various homopolymers and copolymers prepared from acrylic and methacrylic monomers as raw materials are commercially available, and preferable ones can be selected appropriately. Preferably, it is a cellulose-based resin layer such as diacetyl cellulose and cellulose acetate propionate.

The order of application and formation of the back coating layer may be either before or after the formation of the cured layer on the side opposite to the back coating layer of the optical film. However, when the back coating layer also serves as the anti-blocking layer, Alternatively, the back coating layer may be applied two or more times before or after the coating formation of the cured layer.

<Optical Film Properties>

(Surface shape)

The arithmetic average roughness Ra (JIS B0601: 2001) of the cured layers (first cured layer and second cured 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 terms of 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 HB or higher, scratches are unlikely to occur in the polarizing plate forming process. The pencil hardness was measured by measuring the pencil hardness defined by JIS K5400 using a test pencil specified by JIS S 6006 under the conditions of a weight of 500 g and a humidity of more than 2 hours at a temperature of 23 캜 and a relative humidity of 55% And measuring them according to the evaluation method.

<Film substrate>

Examples of the resin constituting the film base of the optical film include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene, cellophane, cellulose resins or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, Polyether sulfone, polyether sulfone, polyether ketone imide, polyamide, fluorine resin, nylon, polymethyl methacrylate, polymethyl methacrylate, polymethyl methacrylate, Cycloolefin-based resins such as methacrylate, acrylic or polyarylate, urethane-modified acrylic, ARTON (trade name, manufactured by JSR) or APEL (trade name, manufactured by Mitsui Chemicals, Inc.). Preferably, the film substrate is composed mainly of a cellulose-based resin, in particular, a cellulose ester. Examples of the film substrate include a cellulose diacetate film, a cellulose triacetate film, a cellulose acetate propionate film, and a cellulose acetate butyrate film.

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-based resin)

The cellulose-based resin (cellulose ester, cellulose ester resin) 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, an acetyl group has a substitution degree of X, and a propionyl group or a butyryl group has a degree of substitution of Y, the following formula (I) And (II) are satisfied at the same time.

In formula (I) 2.6? X + Y? 3.0

The formula (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 using high performance liquid chromatography. The measurement conditions are as follows.

Solvent: methylene chloride

Column: Shodex K806, K805, K803G

(3 pieces of products manufactured by Showa Denko Co., Ltd. were connected and used)

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

(Thermoplastic acrylic resin)

The film substrate may be formed by using a thermoplastic acrylic resin in combination with a cellulose ester 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% by mass of methyl methacrylate units and 1 to 50% by 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 commercial products of 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.), KT75 (manufactured by Denki Kagaku Kogyo Co., 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 the? / 4 film is used, the optical film of the present embodiment is preferably introduced into an image display apparatus because it is excellent in visibility and crosstalk.

The? / 4 film is a film (1/4 wavelength retardation 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 range of the wavelength of visible light so as to obtain substantially complete circularly polarized light in the wavelength range of visible light.

The? / 4 film preferably has an in-plane retardation value Ro (550) measured at a wavelength of 550 nm in a range of 60 nm or more and 220 nm or less, more preferably 80 nm or more and 200 nm or less, More preferably in the range of &lt; RTI ID = 0.0 &gt; 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 among the refractive index at 23 DEG C and 55% RH at a wavelength of 550 nm, Is the refractive index in the orthogonal direction, 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 meter KOBRA-21ADH (manufactured by Oji Keisoku Kiki).

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

The circular polarization plate is obtained by laminating the slow axis of the lambda / 4 film and the transmission axis of the polarizer described later to an angle of substantially 45 degrees. 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 slow axis in the plane of the? / 4 film and the transmission axis of the polarizer is preferably from 41 to 49 °, more preferably from 42 to 48 °, still more preferably from 43 to 47 °, Is more preferable.

The? / 4 film is not particularly limited as long as it is an optically transparent resin, and examples thereof include acrylic resins, polycarbonate resins, cycloolefin resins, polyester resins, polylactic acid resins, polyvinyl alcohol resins, The above-mentioned cellulose resin or 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 carried out by adding the following retardation adjusting agent to the above-mentioned film substrate. 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. It is particularly preferred that the aromatic heterocycle is an aromatic heterocycle, which is generally an unsaturated heterocycle. Among them, 1,3,5-triazine ring is particularly preferable.

(Fine particles)

In order to improve the handling property, the film base material may be coated with an inorganic filler such as acrylic particles, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, It is preferable to contain a matting agent such as an inorganic fine particle such as calcium phosphate or a crosslinked polymer. 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 film base 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 preferably contains an ester compound or sugar ester represented by the following general formula (X) from the viewpoint of dimensional stability in environmental changes. First, the ester compound represented by the general formula (X) will be described.

In general formula (X) B- (G-A) 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- 2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl- Pentanediol-1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2- , 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, and the like, and these glycols are used as one kind 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.

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 in combination 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.

(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 sugars include glucose, galactose, mannose, fructose, xylose, arabinose, lactose, sucrose, nisthose, 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. The carboxylic acid to be used may be one kind or a mixture of two or more kinds. 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, But are not limited to, lauric 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 montanic acid, melissic acid and lactic acid, and unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and octenoic acid. Examples of preferred alicyclic monocarboxylic acids include 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-, p-toluenesulfonic acid, acetic acid, o-toluenesulfonic acid, m, p-homosalicylic acid, o-pyrocatecholic acid,? -resoric acid, vanillic acid, isobanilic acid, veratric acid, o-veratric acid, gallic acid, aspartic acid, mandelic acid, Acid, homo veratric acid, o-homo veratric acid, phthalic acid, and p-cumaric acid. However, benzoic acid is particularly preferred. Of the esterified ester compounds, an acetyl compound having an acetyl group introduced by esterification is preferable.

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 in an amount of 5 to 25 mass%, more preferably in an amount of 5 to 20 mass% Is particularly preferable.

(Plasticizer)

The film substrate 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 preferably a plasticizer containing an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid and having an aromatic ring or a cycloalkyl ring in the molecule. Preferably 2 to 20, aliphatic polyhydric alcohol esters.

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%, based on the cellulose acetate % Is particularly preferred.

(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 absorber is particularly preferable as long as the transmittance at a wavelength of 370 nm is 10% or less, more preferably 5% or less, still more preferably 2% or less. Specific examples of the ultraviolet absorber include, but are not limited to, oxybenzophenone compounds, benzotriazole compounds, salicylic ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex salt compounds, Inorganic powders and the like.

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. These may be used as a commercial product. For example, a tinuvin such as Tinuvin 109, Tinuvin 171, Tinuvin 234, Tinuvin 326, Tinuvin 327 and Tinuvin 328 available from BASF Japan can be preferably used.

The ultraviolet absorber preferably used is benzotriazole ultraviolet absorber, benzophenone ultraviolet absorber, triazine ultraviolet absorber, and particularly preferably benzotriazole ultraviolet absorber, benzophenone ultraviolet absorber and 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.

Examples of the benzotriazole ultraviolet absorber include TINUVIN 109 (octyl-3- [3- tert -butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol- ] Propionate with a mixture of 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol- TINUVIN 928 (2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol) . As the triazine type ultraviolet absorbent, TINUVIN 400 (2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) Phenyl and oxirane), TINUVIN 460 (2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) ), TINUVIN 405 (2- (2,4-dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine and (2-ethylhexyl) Reaction products of acid esters) and the like can be used.

The ultraviolet absorber may be added by dissolving an 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, Dope), or may be added directly to the dope composition. In the case where the inorganic powder is not dissolved in the organic solvent, 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 0.5 to 10% by mass, more preferably 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 decomposition of the cellulose acetate film due to halogen in the residual solvent amount in the cellulose acetate film or phosphoric acid of the phosphoric acid-based plasticizer. As the antioxidant, hindered phenolic compounds are 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-hexanediol (Bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- Di-t-butyl anilino) -1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis -Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5- Di-t-butyl-4-hydroxybenzyl) -isocyanurate and the like. The addition amount of these compounds is preferably from 1 ppm to 10000 ppm, more preferably from 10 to 1000 ppm, in terms of mass ratio with respect to the cellulose acetate film.

(fault)

It is preferable that the film base material has a defect of not less than 5 占 퐉 in diameter per square of 10 cm on one side. More preferably no more than 0.5 per square of 10 cm, and more preferably no more than 0.1 per square of 10 cm. 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 size of the shadow when the defect is observed as the transmitted light of the differential interference microscope when the defect is bubble or foreign matter. If 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 more than one per square of 10 cm on one side, for example, if tension is applied to the film at the time of processing in a subsequent process, etc., the film may be broken at the beginning of the defect and the productivity may be 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 is impossible to confirm with eyes, when a cured layer is formed, a coating film can not be uniformly formed, resulting in a defect (coating missing). Here, 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 forming, foreign matters in the film forming solution and foreign matter (foreign matter defect) . Further, the film substrate is preferably at least 10% or more preferably at least 20% in at least one direction in the measurement according to JIS-K7127-1999. The upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in a 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.

<Formation of Cellulose Ester Film>

Next, an example of a film-forming method of a cellulose ester film which is an example of a film substrate 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 soft 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 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 dipping the dope on a belt-type or drum-type metal support, a step of drying the dope as a web, A process of maintaining the process, stretching or width, a process of drying, and a process of winding the finished cellulose ester film.

As the metal support, a stainless steel belt or a drum finished by casting with a casting surface 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 캜 to a temperature at which the solvent does not foam by boiling. The higher the temperature, the faster the drying speed of the web can be. However, if the temperature 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 be 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 blowing hot air or cold air, or a method of bringing hot water to the side of the metal support. The use of hot water is preferable because the 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,

Particularly, it is preferable to change the temperature of the support and the temperature of the drying wind during the period from the time of pouring to the time of peeling, thereby efficiently performing drying.

The cellulose ester film preferably has a residual solvent amount of 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass, in particular when the web is peeled off from the metal support in order to obtain good flatness, 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 M after heating at 115 ° C for 1 hour.

In the drying step of the cellulose ester film, the web is preferably peeled off from the metal support and dried to make the residual solvent amount not more than 1% by mass, more preferably not more than 0.1% by mass, particularly preferably 0 to 0.01% % Or less.

In the film drying process, generally, a method of drying by conveying the web by a roller drying method (a method in which webs are alternately passed through a plurality of rollers arranged at upper and lower sides to be dried) or a tenter method is employed.

In the stretching step, stretching or simultaneous stretching can be performed with respect to the long-side 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 even more preferably in the range of 1.0 to 2.0 times. For example, there is a method in which a plurality of rollers are provided with a main speed difference, and the rollers are driven in the MD direction using a roller speed difference therebetween; 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 a 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 width direction in the film forming step is preferably performed by a tenter, and may be a pin tenter or a clip tenter.

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

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

The Tg of the cellulose ester film can be controlled by the kind of material 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 higher, more preferably 120 DEG C or higher. 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 stretching 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 soft-film-forming method refers to a method of heating and melting a composition including other additives such as a cellulose ester resin and a plasticizer to a temperature at which fluidity is exhibited, and thereafter flexing a melt containing a fluid cellulose ester.

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

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

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

Small amounts of additives such as particles and antioxidants are preferably mixed in advance in order 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 terms of kneading uniformity, an engaging 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 to the extruder by a feeder, and to form the film as it is without pelletizing.

The above pellets were extruded by using a uniaxial or biaxial type extruder and the extruded product was filtered at a temperature of about 200 to 300 DEG C by using a filter such as a leaf disc type filter 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 preferable to prevent the oxidative decomposition or the like under vacuum or in an inert gas atmosphere under reduced pressure.

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 obtained by integrally forming a stainless steel fiber body in an entangled state and then compressing and sintering the contact portions. The filtration accuracy can be adjusted by varying the density depending on the thickness of the fiber 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. To uniformly add, 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. For the roller having the surface of the elastic body used for this purpose, known rollers can be used.

The elastic touch roller is also referred to as a tightly closed rotating body. As the elastic touch roller, a commercially available one 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.

It is preferable that the cellulose ester film obtained as described above is passed through a process in contact with a cooling roller and then stretched by the above stretching operation.

As the stretching method, a known roller stretcher, a tenter or the like can be preferably used. 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 with a width that becomes a product, and knurling (embossing) may be performed at both ends in order to prevent attaching during winding and prevention of scratches in friction. The knurling process can be performed by heating or pressing using a metal ring having a concavo-convex pattern on its side surface. The grip portion of the clip at both ends of the film is usually cut and reused because the cellulose ester film is deformed and can not be used as a product.

(Production method of warp stretched film)

The? / 4 film can be produced by a method of producing an oblique stretched film. The method of producing an obliquely drawn film is a method of 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 unstretched film before the warp stretching, the above-mentioned cellulose ester film can be used.

Here, the angle with respect to the extending direction of the film is an angle within the film plane. Since the slow axis is usually expressed in the stretching direction or the direction perpendicular to the stretching direction, stretching at an angle of more than 0 DEG and less than 90 DEG with respect to the stretching direction of the film makes it possible to produce a stretched film having such a slow axis.

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

(Oblique stretching)

The oblique stretched film can be produced by using a warp stretching apparatus (warp stretching tenter). As the oblique stretching tenter, by varying the rail pattern, it is possible to freely set the orientation angle of the film, to align the orientation axis of the film right and left uniformly in the film width direction, It is preferable to use an apparatus capable of controlling the irradiation.

(Physical properties of film substrate)

The film thickness of the cellulose ester film base is preferably 5 to 200 占 퐉, more preferably 5 to 80 占 퐉, and particularly preferably 5 to 34 占 퐉. By forming the cured layer of the present embodiment on a cellulose ester film substrate of a thin film, the effect of this embodiment is more likely to be exerted. 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, it is possible to achieve an appropriate processability in the coating of the cured layer or the like and handling property of the film base material itself.

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.

&Lt; Other layer >

In the optical film of the present 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 coating the antireflection layer on the cured layer.

It is preferable that the antireflection layer is laminated in consideration of the refractive index, the film thickness, the number of layers, the layer order, and the like so that the reflectance is reduced 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 as a support or a high refractive index layer and a low refractive index layer having a refractive index higher than that of the protective film.

<Low Refractive Index Layer>

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 캜 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.

As for the composition for forming a low refractive index layer, it is preferable that the silica-based fine particles have at least one outer layer and at least one particle of porous or hollow particles therein. Particularly, it is preferable that the particles having the respective outer layers and the inside of which are porous or hollow are hollow silica-based fine particles.

The composition for forming a low refractive index layer may contain an organosilicon 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. As the organic silicon compound represented by the general formula, specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used.

Further, a compound having a thermosetting property and / or photo-curability, which mainly comprises 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. Specifically, it is a fluorine-containing polymer or a fluorine-containing sol-gel compound. As the fluorine-containing polymer, for example, a hydrolyzate or a dehydration condensation product of a perfluoroalkyl group-containing silane compound [for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane] , A fluorine-containing copolymer having a fluorine-containing monomer unit and a crosslinkable reactive unit as a constituent unit. In addition, a solvent, 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, if necessary.

&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.

<Antistatic Layer>

The optical film of this embodiment may have an antistatic layer (conductive layer) on the cured layer. The antistatic layer preferably contains a conductive compound. Examples of the conductive compound include metal oxide fine particles, a π conjugated conductive polymer compound, and an ionic compound. Among them, the metal oxide fine particles are preferable from the standpoint of stably maintaining the antistatic performance even after a more severe wet endurance test is performed.

&Lt; Metal oxide fine particles &

The metal oxide fine particles are not particularly limited and include at least one selected from Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, A metal oxide having one kind of element can be used as the metal oxide fine particles. These metal oxide fine particles may be doped with a small amount of atoms such as Al, In, Sn, Sb, Nb, a halogen element, and Ta. The metal oxide fine particles may be a mixture of metal oxides containing any of the above elements. Among them, at least one metal oxide fine particle selected from zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium tin oxide (ITO), antimony doped tin oxide (ATO) and zinc antimonate is used as a main component And particularly preferred are antimony compounds such as antimony doped tin oxide (ATO) and zinc antimonate.

The average particle diameter of the primary particles of the metal oxide fine particles is preferably 5 to 200 nm, more preferably 10 to 150 nm. The average particle diameter of the metal oxide fine particles can be measured from an electron microscope photograph by a scanning electron microscope (SEM) or the like. The average particle diameter may be measured by a particle size distribution analyzer using a dynamic light scattering method, a static light scattering method, or the like. If the particle diameter is too small, the metal oxide fine particles tend to agglomerate and the dispersibility deteriorates. If the particle size is excessively large, the haze remarkably increases, which is not preferable. The shape of the metal oxide fine particles is preferably a grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape or an irregular shape.

<Conjugated Conductive Polymer>

As the? -conjugated conductive polymer, an organic polymer having a main chain of? -conjugated system can be used. Examples thereof include polythiophenes, polypyrroles, polyanilines, polyphenylene, polyacetylenes, polyphenylene vinylene, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoints of ease of polymerization and stability, polythiophenes, polyanilines and polyacetylenes are preferred.

The? -conjugated conductive polymer may have sufficient conductivity and solubility in the binder resin even when it is in an unsubstituted state. In order to further improve conductivity and solubility, a functional group such as an alkyl group, a carboxyl group, a sulfo group, an alkoxy group, a hydroxyl group, may be introduced into the? -conjugated conductive polymer.

Specific examples of the π conjugated conductive polymer include polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene) (3-hexylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene) ), Poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3,4-dihydroxythiophene) Poly (3,4-dibutylthiophene), poly (3,4-dibutylthiophene), poly (3,4- 4-dioctyloxythiophene), (3,4-ethylenedioxythiophene), poly (3,4-dideoxylthiophene), poly (3,4- (3-methyl-4-methoxythiophene), poly (3-carboxythiophene), poly (3- Carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene), polypyrrole, poly (N-methylpyrrole), poly Poly (3-ethylpyrrole), poly (3-ethylpyrrole), poly (3-N-propylpyrrole) 3-dodecylpyrrol), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3-carboxypyrrole) (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole) ), Poly (3-butoxypyrrole), poly (2-methyl aniline), poly (3-isobutyl aniline), poly (2-aniline sulfonic acid), poly Poly (3-aniline sulfonic acid), polyphenylacetylene, and the like. These may be used singly or as a copolymer including two kinds of them.

A dopant component may be added to these? -Conjugated conductive polymers. Examples of the dopant component include low molecular weight dopants such as halogens, Lewis acids, proton acids, and transition metal halides, and polymers such as polyanions.

The polyanion is a polymer having an anionic group functioning as a dopant for a? -Conjugated conductive polymer and may be a substituted or unsubstituted polyalkylene, a substituted or unsubstituted polyalkenylene, a substituted or unsubstituted polyimide, a substituted or unsubstituted polyamide , Substituted or unsubstituted polyesters and copolymers thereof, and includes a structural unit having an anionic group and a structural unit having no anionic group.

The polyalkylene is a polymer in which the main chain is composed of repeating methylene, and examples thereof include polyethylene, polypropylene, polybutene, polypentene, polyhexene, polyvinyl alcohol, polyvinyl phenol, polyacrylonitrile, polyacrylate , Polystyrene, and the like.

The polyalkenylene is a polymer containing a constitutional unit having at least one unsaturated bond in its main chain, and examples thereof include propenylene, 1-methylprophenylene, 1-butylprophenylene, 1-decylpropenylene , 1-cyanoprophenylene, 1-phenylprophenylene, 1-hydroxyprophenylene, 1-butenylene, 1-methyl-1-butenylene, Butyl-1-butenylene, 2-hexyl-1-butenylene, 2-octyl-1-butenylene 2-butenylene, 1-ethyl-2-butenylene, 1-octyl-2-butenylene Butyl-2-butenylene, 2-hexyl-2-butenylene, 2-octyl-2-butenylene, 2-decyl- 2-butenylene, 2-pentenylene, 4-ethyl-2-pentenylene, 4-propyl-2-pentenylene, 4-butyl Pentenylene, 4-hexyl-2-pentenyl , 4-cyano-2-pentenylene, 3-methyl-2-pentenylene, 3-phenyl-2-pentenylene, 4-hydroxy-2-pentenylene, hexenylene and the like Units. &Lt; / RTI &gt;

Examples of the polyimide include pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, 2,2 ', 3,3'-tetracarboxydiphenyl ether dianhydride, 2,2' - [4,4'-di (dicarboxyphenyloxy) phenyl] propane dianhydride and diamines such as oxydiamine, paraphenylenediamine, metaphenylene diamine, and benzophenone diamine. .

Examples of the polyamide include polyamide 6, polyamide 6,6, polyamide 6,10 and the like. Examples of the polyester include polyethylene terephthalate and polybutylene terephthalate.

The anion group of the polyanion may be a functional group capable of chemical oxidation dope with respect to the π conjugated conductive polymer. From the viewpoint of ease of production and stability, the anionic group of the polyanion may be a monosubstituted sulfate group, a monosubstituted phosphate ester group, a phosphate group, Sulfo group and the like are preferable. Further, from the viewpoint of the doping effect of the functional group on the? -Conjugated conductive polymer, a sulfo group, a monosubstituted sulfate group and a carboxyl group are more preferable.

Specific examples of the polyanion include polyvinylsulfonic acid, polystyrenesulfonic acid, polyallylsulfonic acid, polyacrylic acid ethylsulfonic acid, polyacrylic acid butylsulfonic acid, poly (2-acrylamido-2-methylpropanesulfonic acid), polyisoprenesulfonic acid, polyvinylcarboxyl (2-acrylamido-2-methylpropanecarboxylic acid), polyisoprenecarboxylic acid, poly (2-acrylamido-2-methylpropanecarboxylic acid), polystyrenecarboxylic acid, polyacrylic carboxylic acid, polyacrylic carboxylic acid, polymethacrylic carboxylic acid, Acrylic acid and the like. These may be homopolymers or copolymers of two or more. Of these, polystyrenesulfonic acid, polyisoprenesulfonic acid, polyacrylic acid ethylsulfonic acid and polyacrylic acid butylsulfonic acid are preferable. These polyanions have high compatibility with the binder resin and can further improve the conductivity of the obtained antistatic layer.

In addition to the polyanion, donor or acceptor dopants such as the following can be used if the π-conjugated conductive polymer can be oxidized and reduced.

Examples of the donor dopant include alkali metals such as sodium and potassium; alkaline earth metals such as calcium and magnesium; alkaline earth metals such as tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium and dimethyldiethylammonium; Secondary amine compounds and the like.

Acceptor property dopants As, Cl _2, Br _2, I _2, halogen compounds such as ICl, IBr, IF, PF _5, AsF _5, SbF _5, Lewis, such as _{BF 5, BCl 5, BBr 5} , SO 3 acid, Organic cyanide compounds such as tetracyanoethylene, tetracyanoethylene oxide, tetracyano benzene, dichlorodicyanobenzoquinone, tetracyanoquinodimethane, tetracyanoazanaphthalene, protonic acid, organometallic compounds, fullerene, Fullerene hydride, fullerene hydroxide, fullerene oxide, fullerene sulfonate and the like can be used.

Examples of the proton acids include inorganic acids and organic acids. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, perchloric acid and the like. Examples of the organic acid include an organic carboxylic acid and an organic sulfonic acid.

As the organic carboxylic acid, an aliphatic, aromatic, cyclic aliphatic or the like containing one or two or more carboxyl groups can be used. For example, there may be mentioned inorganic acids such as formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, And phenylacetic acid.

Examples of the organic sulfonic acid include aliphatic, aromatic, cyclic aliphatic, and the like, which include one or more sulfo groups, or polymers containing sulfo groups.

1-heptanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1-nonanesulfonic acid, 1-butanesulfonic acid, 1-propanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, colistin methanesulfonic acid, 2-acrylamido Amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol-7-sulfonic acid, 3-aminopropanesulfonic acid, N-cyclohexyl- Examples of the sulfonic acid include sulfonic acid, benzenesulfonic acid, alkylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, Benzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4-dimethylbenzene Aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, 4-amino-2-chlorotoluene-5-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid Amino-2-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy- Chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methyl 4-amino-3-methylbenzene-1-sulfonic acid, Naphthalenesulfonic acid-formaldehyde condensate, melamine sulfonic acid-formalin polycondensate, anthraquinone sulfonic acid, pyrene, and the like. Sulfonic acid and the like. These metal salts may also be used.

Examples of two or more sulfo groups include ethanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, decanedisulfonic acid, o-benzenedisulfonic acid, m-benzenedisulfonic acid, p-benzenedisulfonic acid, Sulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, 3,4-dihydroxybenzene disulfonic acid, Dihydroxy-1,3-benzenedisulfonic acid, naphthalene disulfonic acid, methylnaphthalene disulfonic acid, ethyl naphthalene disulfonic acid, pentadecyl naphthalene disulfonic acid, 3-amino- Amino-1,4-benzenedisulfonic acid, 1-amino-3,8-naphthalenedisulfonic acid, 3-amino-1,5- Amino-5-naphthol-2,7-disulfonic acid, 4-acetamido-4'-isothiocyanatostilbene- 2,2'- Acid, 4-acetamido-4'-maleic, and the like already dill stilbene-2,2'-disulfonic acid, naphthalene tricarboxylic acid, dinaphthyl methane disulfonic acid, anthraquinone quinone sulfonic acid, anthracene sulfonic acid. These metal salts may also be used. The above-described conductive compound is preferably used in an amount of 0.01 to 300 parts by mass, more preferably 0.1 to 100 parts by mass, per 100 parts by mass of the resin used as a binder described later.

<Ionic Compound>

Examples of the ionic compound include imidazolium type, pyridium type, alicyclic amine type, aliphatic amine type, aliphatic phosphonium type cation and inorganic ion type such as BF ₄ ^- and PF ₆ ^- , CF ₃ SO ₂ ^- , (CF ₃ SO ₂ ) ₂ N ^- , CF ₃ CO ₂ ^-, and the like.

Examples of the ionic compound include anionic polymer compounds as disclosed in Japanese Patent Publication No. 49-23828, Japanese Patent Publication No. 49-23827, Japanese Patent Publication No. 47-28937, Japanese Patent Publication No. 55-734 , Japanese Unexamined Patent Publication No. 50-54672, Japanese Unexamined Patent Publication No. 59-14735, Japanese Unexamined Patent Publication No. 57-18175, Japanese Unexamined Patent Publication No. 57-18176, Japanese Unexamined Patent Publication No. 57-56059, Ionene-type polymers having a dissociation group in the main chain, Japanese Patent Publication 53-13223, Japanese Patent Publication 57-15376, Japanese Patent Publication 53-45231, Japanese Patent Publication 55-145783, Japanese Patent Publication 55 -65950, Japanese Patent Publication No. 55-67746, Japanese Patent Publication No. 57-11342, Japanese Patent Publication No. 57-19735, Japanese Patent Publication No. 58-56858, Japanese Patent Application Laid-open No. 61-27853, A cationic pen having a cationic dissociating group in the side chain, which is disclosed in JP-A-62-9346 Dendritic polymers and the like. It is also preferable to contain an ionene conductive polymer described in JP-A-9-203810 or a quaternary ammonium cation-conductive polymer having intermolecular crosslinking (for example, P-1 shown below). The above polymeric compounds are generally in the particle size range of about 0.05 탆 to 0.5 탆, preferably in the range of 0.05 탆 to 0.2 탆. The ratio of the polymer to the binder described below is preferably from 10 to 400 parts by mass based on 100 parts by mass of the polymer from the viewpoint of adhesion with the film substrate and particularly preferably from 100 parts by mass of the binder to 100 parts by mass of the polymer, Is 100 to 200 parts by mass.

Other examples include anionic antistatic agents, nonionic antistatic agents, and positive ionic antistatic agents.

Examples of the anionic antistatic agent include fatty acid salts, higher alcohol sulfuric acid ester salts, liquid fatty acid sulfuric acid ester salts, sulfates of aliphatic amines and aliphatic amides, aliphatic alcohol phosphoric acid ester salts, sulfonic acid salts of dibasic fatty acid esters, Examples of the cationic antistatic agent include aliphatic amine salts, quaternary ammonium salts, alkylpyridinium salts, and the like. Examples of the cationic antistatic agent include aliphatic amine salts, alkylarylsulfonic acid salts, and naphthalenesulfonic acid salts of formalin condensation.

Examples of the nonionic antistatic agent include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters and polyoxyethylene sorbitan alkyl esters .

Examples of the positive ionic antistatic agent include imidazoline derivatives, beta-type high alkylamino derivatives, sulfuric acid ester derivatives, and phosphoric acid ester derivatives.

Specific examples of the compound are described in Marumo Hideo &quot; Surface Modification of Antistatic Agent Polymer &quot;, Wai Shobo, supra, "Practical Manual for Additives for Plastics and Rubber Industries p333 to p455" published by Kagaku Kogyo, Japanese Patent Laid-Open No. 11-256143, 52-32572, JP-A-10-158484, and the like.

The surface resistivity of the antistatic layer is preferably a layer adjusted to 10 ¹³ Ω / sq (25 ° C, 55% RH) or less. More preferably 10 ¹⁰ ? / Sq (25 占 폚, 55% RH) or less and particularly preferably 10 ⁹ ? / Sq (25 占 폚, 55% RH) or less. The surface resistivity of the antistatic layer is preferably a layer adjusted to 10 ³ Ω / sq (25 ° C, 55% RH) or more. More preferably 10 ⁷ ? / Sq (25 占 폚, 55% RH) or more.

Here, the surface resistivity is a value measured using a resistivity meter after the sample is humidified for 24 hours under conditions of 25 캜 and 55% RH. As the resistivity meter, for example, Hiresta UP MCP-HT450 manufactured by Mitsubishi Kagaku Kogyo Co., Ltd. can be used.

Next, the binder which may be included in the antistatic layer will be described. The resin binder of the antistatic layer is preferably a curable resin. Of these, an active energy ray curable resin is preferable because it is excellent in film forming property and physical properties of the coating film and in adhesion to the laminated film. The active energy ray curable resin means a resin which is cured through crosslinking reaction or the like by irradiation of active rays such as ultraviolet rays or electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable resin layer is formed by curing by irradiating active rays such as ultraviolet rays or electron beams. As the active energy ray curable resin, ultraviolet curable resin, electron beam curable resin and the like can be exemplified, but an ultraviolet curable resin is particularly preferable.

As the ultraviolet ray hardening resin, for example, an ultraviolet ray hardening type urethane acrylate series resin, an ultraviolet ray hardening type polyester acrylate series resin, an ultraviolet ray hardening type epoxy acrylate series resin, an ultraviolet ray hardening type polyol acrylate series resin or an ultraviolet ray hardening type epoxy resin, Is used. Among them, an ultraviolet curable acrylate resin is preferable.

The ultraviolet curing type urethane acrylate resin is generally obtained by reacting a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer in addition to 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate Acrylate-based monomer having a hydroxyl group such as 2-hydroxypropyl acrylate) can be easily obtained by reacting an acrylate-based monomer having a hydroxyl group, such as 2-hydroxypropyl acrylate. For example, those described in Japanese Patent Application Laid-Open No. 59-151110, 100 parts of Unidick 17-806 (manufactured by Dainippon Ink and Chemicals, Incorporated) and 1 part of Coronate L (manufactured by Nippon Polyurethane Industry Co., Ltd.) Mixtures and the like are preferably used.

Examples of the ultraviolet curable polyester acrylate resin generally include those formed by reacting a polyester polyol with 2-hydroxyethyl acrylate or 2-hydroxyacrylate monomer, and JP-A 59- 151112 can be used.

Specific examples of the ultraviolet curable epoxy acrylate resin include those produced by reacting an epoxy acrylate as an oligomer with a reactive diluent and a photopolymerization initiator and reacting the epoxy acrylate as described in JP-A No. 1-105738 Can be used.

Specific examples of the UV curable polyol acrylate resin include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl modified Dipentaerythritol pentaacrylate, and the like.

These ultraviolet ray-curable resins are preferably used together with a photopolymerization initiator in terms of promoting the reaction.

Specific examples of the photopolymerization initiator include benzoin and derivatives thereof, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone,? -Amyloxime ester, thioxanthone, and derivatives thereof. It may be used together with a photosensitizer. The photopolymerization initiation system can be used as a photosensitizer.

When the epoxy acrylate photopolymerization initiator is used, a sensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine may be used. The photopolymerization initiator or photosensitizer used in the ultraviolet ray hardening resin composition is 0.1 to 20 parts by mass, preferably 1 to 15 parts by mass based on 100 parts by mass of the curable resin.

Examples of other monomers include monomers having one unsaturated double bond and common monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate and styrene . Examples of the monomer having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyldiacrylate, Isobornyl acrylate, and the like. The monomers described in JP-A-2006-3647 may also be preferably used.

KR-400, KR-410, KR-550, KR-566, KR-567 and BY-320B (manufactured by Asahi Denka Kabushiki Kaisha); C-501, M-101, M-102, T-102, D-102, NS-101, FT -102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Koei Kagaku Kogyo Co., Ltd.); DP-10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (manufactured by Dainichiseika Kogyo Co., Manufactured by K.K.); KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel-UCB Co., Ltd.); RC-5151, RC-5181, RC-5181 (manufactured by Dainippon Ink and Chemicals, Inc.) Manufactured by Inagaki Kogyo K.K.); Orex No.340 clear (manufactured by Jugoku Co., Ltd.); RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries, Ltd.); SP-1509, SP-1507 (manufactured by Showa Kobunshi Co., Ltd.); RCC-15C (manufactured by Grace Japan K.K.), Aronix M-6100, M-8030 and M-8060 (manufactured by Toagosei Co., Ltd.); NK hard B-420, NK Ester A-IB and B-500 (manufactured by Shin Nakamura Kagaku Kogyo K.K.) can be appropriately selected and used.

The curable resin also includes a thermosetting resin. Examples of the thermosetting resin include an unsaturated polyester resin, an epoxy resin, a vinyl ester resin, a phenol resin, a thermosetting polyimide resin, and a thermosetting polyamideimide.

As the unsaturated polyester resin, there can be used, for example, an unsaturated polyester resin, an isophthalic acid resin, a terephthalic acid resin, a bisphenol resin, a propylene glycol-maleic acid resin, dicyclopentadiene or a derivative thereof into an unsaturated polyester composition A styrene-butadiene copolymer, a low-shrinkable resin to which a thermoplastic resin (a polyvinyl acetate resin, a styrene-butadiene copolymer, a polystyrene, a saturated polyester or the like) is added, or an unsaturated polyester with a wax compound of a film- Directly brominated with Br ₂ , or copolymerized with heptanoic acid, dibromoneopentyl glycol, or a reactive type, a combination of a halide such as chlorinated paraffin or tetrabromobisphenol with an antimony trioxide, phosphorus compound, aluminum hydroxide or the like is used as an additive Additive type flame retardant resin, polyurethane And toughness resins (high strength, high elastic modulus, and high elongation) obtained by hybridization with carbon or silicon or IPN (Interpenetrating Polymer Networks).

Examples of the epoxy resin include glycidyl ether-based epoxy resins including bisphenol A type, novolac phenol type, bisphenol F type, and brominated bisphenol A type, glycidyl amine type, glycidyl ester type, And a special epoxy resin containing a heterocyclic epoxy system. As the vinyl ester resin, for example, there is usually one obtained by dissolving an oligomer obtained by subjecting an unsaturated monobasic acid such as an epoxy resin and methacrylic acid to a ring-opening reaction in a monomer such as styrene. There is also a special type such as having a vinyl group at the molecular end or side chain and a vinyl monomer.

Examples of the vinyl ester resin of the glycidyl ether-based epoxy resin include bisphenol-based, novolac-based, and brominated bisphenol-based resins. Specific examples of the vinyl ester resin include vinyl ester urethane, vinyl isocyanurate, side chain vinyl ester System. Phenol resins are obtained by polycondensation using phenols and formaldehyde as raw materials, and there are resole type and novolac type.

As the thermosetting polyimide resin, for example, there may be mentioned maleic acid series polyimide such as poly maleimide amine, polyamino bismaleimide, bismaleimide, diallyl bisphenol-A resin, bismaleimide triazine resin, Acid-modified polyimide, and acetylene-terminated polyimide.

The antistatic layer may contain inorganic particles or organic particles. The average particle diameter of these particles is preferably 0.01 to 5 占 퐉, more preferably 0.1 to 5.0 占 퐉, and particularly preferably 0.1 to 4.0 占 퐉. The antistatic layer may contain two or more kinds of particles having different particle diameters. The particles are preferably blended in an amount of 0.1 to 30 parts by mass with respect to 100 parts by mass of the curable resin.

In the antistatic layer, a polymer having a vinyl group and a carboxyl group in the side chain of the polyurethane resin and having a weight average molecular weight of 10000 or more and 30000 or less and a double bond equivalent of 500 or more and 2000 or less, or a vinyl group in the side chain of the polymer Acrylic polymer or polyfunctional thiol compound having a weight average molecular weight (Mw) of 10000 or more and 100000 or less, a double bond equivalent of 1000 or less, and a polymer Tg (glass transition temperature) of -50 DEG C or more and 120 DEG C or less . Examples of the polyfunctional thiol compound include 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate), 1,3,5-tris Butyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -thione. Examples of commercially available products include Carlens MT series manufactured by Showa Denko K.K.

The antistatic layer may contain a fluorine-acrylic copolymer resin. The fluorine-acrylic copolymer resin is a copolymer resin containing a fluorine monomer and an acrylic monomer. Particularly, a block copolymer containing a fluorine monomer segment and an acrylic monomer segment is preferable. The molecular weight of the fluorine-acrylic copolymer resin is preferably 5000 to 1000000, more preferably 10000 to 300000, and further preferably 10000 to 100000 as the number average molecular weight. The production of the fluorine-acrylic copolymer resin can be carried out by a known production process using a polymeric peroxide as a polymerization initiator (see, for example, Japanese Patent Application Laid-Open No. 5-41668 and Japanese Patent Application Laid-Open No. 5-59942) Can be manufactured.

Polymeric peroxydane is a compound having two or more peroxy bonds per molecule. As the polymeric peroxide, one kind or two or more kinds of various polymeric peroxides described in JP-A-5-59942 can be used.

Commercially available products of the fluorine-acrylic copolymer resin include Modifa F-200, Modifa F-600 and Modifa F-2020, which are trade names of Nippon Oil Co., Ltd.

The antistatic layer preferably contains a silicon-based surfactant or a fluorine-based compound in that productivity can be enhanced by imparting high-speed coating suitability while enhancing surface uniformity. Examples of the fluorine-based compound include fluorine-siloxane graft polymers.

The antistatic layer may contain a color tone adjusting agent (dye or pigment) having a color tone adjusting function, an electromagnetic wave shielding agent, an infrared absorbing agent, or the like as a color correcting filter for various display elements.

Further, in order to maintain easiness of adhesion with the overcoat layer, the antistatic layer may contain a cellulose ester resin or an acrylic resin.

As the coating composition for forming the antistatic layer, the following solvents are preferably used. As the solvent, a hydrocarbon, an alcohol, a ketone, an ester, a glycol ether, and other solvents can be appropriately mixed and used, but the present invention is not limited thereto.

Examples of the hydrocarbons include benzene, toluene, xylene, hexane, and cyclohexane. Examples of alcohols include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, 2-butanol, tert-butanol, pentanol, 2-methyl-2-butanol and cyclohexanol. Examples of the ketone include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of the esters include methyl formate, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, ethyl lactate, and methyl lactate. Examples of glycol ethers (C1 to C4) include methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether , Propylene glycol monobutyl ether, and propylene glycol mono (C1 to C4) alkyl ether esters (propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate and the like). Examples of other solvents include methylene chloride and N-methylpyrrolidone. Although not limited thereto, solvents suitably mixed with these are also preferably used.

As a coating method of the antistatic layer coating composition, a wet film thickness of 0.1 to 100 mu m is preferably formed on one surface of the film substrate by using a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater or spray coating, 0.5 to 30 占 퐉, and an average film thickness of 0.1 to 30 占 퐉, preferably 1 to 20 占 퐉, as a dry film thickness, followed by heating, drying, and curing if necessary. The curing process is performed by heat treatment or UV curing treatment.

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 the respective lamps, but the irradiation amount of the active rays is usually 5 to 500 mJ / cm 2, preferably 5 to 200 mJ / cm 2. In addition, when irradiating an active line, it is preferable that the film is carried out while applying a tensile force in the transport direction of the film, and more preferably, the tension is applied in the width direction. The tensile force to be imparted is preferably 30 to 500 N / m. The method of applying the tension is not particularly limited, and the tension may be applied in the carrying direction on the back roll, or in the width direction or the biaxial direction by the tenter. As a result, a film excellent in planarity can be obtained. The antistatic layer may be a single layer or a multilayer structure of two or more layers.

The antistatic layer may be formed by the above-described coating or may be formed by a method such as vapor deposition. The thickness of the antistatic layer is preferably 0.1 占 퐉 or more and 20 占 퐉 or less. More preferably not less than 0.1 mu m and not more than 10 mu m.

<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, an active energy ray-curable adhesive or the like may be used for bonding. However, it is also possible to bond the optical film to an alkali saponification treatment, and a polarizing film (polarizer) produced by immersing the treated optical film in an iodine solution, It is preferable to use a completely saponified polyvinyl alcohol aqueous solution (water-in-oil or water-based adhesive) to bond.

The optical film may be bonded to the other surface of the polarizer, or the above-mentioned film substrate or the like 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 100 mu m and more preferably in the range of 5 to 34 mu m from the viewpoint of adjusting the smoothness and the curl balance and further enhancing the effect of preventing the winding deviation. desirable.

A polarizing film as a main component of the polarizing plate is a device that allows only light of a polarization plane in a certain direction to pass therethrough. 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.

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

<Circular Polarizer>

A circular polarizer may be constituted by using an optical film. That is, the circular polarizer can be constituted by laminating a polarizer 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 shape? / 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 a dichroic 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 circularly polarizing plate 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 not only optically transparent but also exhibits appropriate viscoelasticity and adhesive property.

Specific examples of the adhesive layer include a polymer such as an adhesive 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 preferable because it is easy to control the adhesive property and has excellent transparency, weather resistance, durability and the like.

<Image Display Device>

The optical film of the present embodiment is preferable in that it is used in an image display device and 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, Display and the like. Among these image display devices, the liquid crystal display device is preferable in view of high visibility.

The protective portion may be disposed on the side closer to the cured layer of the optical film of the viewer-side polarizing plate. This protection section can be composed of a front face plate or a touch panel. The protective portion is bonded to the cured layer through a filler (photocurable resin) for filling the gap between the protective layer and the cured layer. The front face plate of the protection portion 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.

HRJ-60, HRJ-302, HRJ-53 (available from Kioretsu Kagaku Kogyo Co., Ltd., above) is preferable as a commercially available product. Examples of commercially available products include SVR1120, SVR1150, SVR1320, SVR1241H Manufactured by Kusanagi Kogyo Co., Ltd.). When a filler is used, one type may be used alone, or a plurality of types may be used in combination.

The bonding of 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 cured 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. By setting the surface free energy of the cured layer to 30 mN / m or more when the filler is applied to the surface of the cured layer, the filler is not repelled at the end of the cured layer and remains uniformly spread, Device can be obtained.

[Example]

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. In the examples, "part" or "%" is used, and "mass part" or "mass%" is used unless otherwise specified.

&Lt; Production of optical film 1 >

[Production of Cellulose Ester Film 1]

<Preparation of Dispersion of Silicon Dioxide>

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

ethanol   90 parts by mass

The mixture was stirred with a dissolver for 30 minutes and then dispersed with mannitol. 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 with a fine particle dispersion diluent filter (ADVANTEK TOYO Co., Ltd.: polypropylene wind cartridge filter TCW-PPS-1N).

<Preparation of Dope Composition 1>

(Cellulose ester resin)

Cellulose acetate A (cellulose acetate synthesized from a linter surface, acetyl group substitution degree 2.45, Mw = 200000) 90 parts by mass

(additive)

The ester (Exemplified Compound X-1) represented by the general formula (X) 5 parts by mass

The ester (Exemplified Compound X-12) represented by the general formula (X) 4 parts by mass

(Ultraviolet absorber)

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

(Fine particles)

Silicon dioxide dispersed diluent 4 parts by mass

(menstruum)

Methylene chloride 432 parts by mass

ethanol 38 parts by mass

The resulting solution was completely dissolved in a sealed vessel, heated and stirred, and filtered using Azumi Rossi No.24 manufactured by Azumi Co., Ltd. to prepare 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 residual solvent amount became 100% by mass and peeled off from the stainless band support. The web of the cellulose ester film was subjected to slanting at a temperature of 35 DEG C and slit to 1.15 m in width and subjected to oblique stretching at an elongation tenter at a stretching temperature of 175 DEG C and a stretching magnification of 1.5 times to obtain a tensile strength of 200 N / The stretching was performed in an oblique direction so that the orientation angle? (Angle formed by the film width direction and the slow axis) was 45 °. Thereafter, the inside of the drying device at 120 캜 was dried for 15 minutes while being conveyed by a plurality of rollers, slit at a width of 1.3 m, knurled at both ends of the film by 10 mm in width and 5 탆 in height, to obtain a cellulose ester film 1 as? / 4 film. The film thickness of the cellulose ester film 1 was 30 占 퐉, the winding length was 3900 m, the in-plane retardation Ro was 135 nm, the thickness direction retardation Rt was 140 nm, and the orientation angle?

[Preparation of Polymer Silane Coupling Coated Fine Particles]

30 mL of methyl methacrylate (Light Ester M, manufactured by Kyowa Chemical Co., Ltd.), 1 mL of 3-mercaptopropyltrimethoxysilane (KBM-803, Shin-Etsu Chemical Co., Ltd.) , 100 ml of tetrahydrofuran as a solvent and 50 mg of azoisobutyronitrile (AIBN manufactured by Kanto Kagaku K.K.) as a polymerization initiator were added and the mixture was purged with N ₂ gas and heated at 80 ° C for 3 hours to obtain a polymer silane To prepare a 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 KABA 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, Ethanol to prepare 100 g of an ethanol dispersion of fine silica particles (SiO ₂ concentration: 30% by weight).

20 g (25 ml) of acetone were dispersed in 100 g of this silica fine particle ethanol dispersion and 1.5 g of a polymer silane coupling agent. 20 mg of ammonia water having a concentration of 29.8% by weight was added thereto and stirred at room temperature for 30 hours to prepare a polymer silane coupling agent Lt; / RTI &gt;

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 adsorption to the unpolymerized polymeric silane coupling agent by centrifugation The silica particles having an average particle diameter of 5 mu m were removed. 1000 g of ethanol was added to the dispersion of fine silica particles adsorbed on the polymer silane coupling agent, and the fine silica particles were precipitated, separated, dried under reduced pressure, and then dried at 25 DEG C for 8 hours to obtain a polymer silane coupling agent-coated 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.

[Preparation of composition for forming first hardened layer]

The polymer silane coupling agent-coated silica (1) prepared above and the following compound were mixed with stirring to prepare a composition for forming the first cured layer.

(Fine particles)

Polymer Silane Coupling Agent Coated Silica (1) 10 parts by mass

(Active ray curable resin)

Urethane acrylate (U-4H, manufactured by Shin Nakamura Kagaku Kogyo Co., Ltd.) 35 parts by mass

(Photopolymerization initiator)

Irgacure 184 (manufactured by BASF Japan Ltd.) 5 parts by mass

(additive)

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

(solvent)

Propylene glycol monomethyl ether 80 parts by mass

Methyl acetate 20 parts by mass

[Preparation of composition for forming second cured layer]

The polymer silane coupling agent-coated silica (1) prepared above and the following compound were mixed with stirring to prepare a composition for forming the second cured layer.

(Fine particles)

Polymer Silane Coupling Agent Coated Silica (1) 50 parts by mass

(Active ray curable resin)

NK ester A-DCP (tricyclodecane dimethanol diacrylate, Shin Nakamura Kagaku Kogyo Co., Ltd.) 35 parts by mass

(Photopolymerization initiator)

Irgacure 184 (manufactured by BASF Japan Ltd.) 5 parts by mass

(additive)

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

(solvent)

Propylene glycol monomethyl ether 80 parts by mass

Methyl acetate 20 parts by mass

[Preparation of composition for forming antistatic layer]

&Lt; Preparation of particle dispersion liquid &

6.0 kg of isopropyl alcohol was gradually added to 6.0 kg of methanol-dispersed antimony double oxide colloid (solid content 60%, manufactured by Nissan Kagaku Kogyo K.K., antimony zinc zirconate, trade name: Cellax CX-Z610M-F2) To prepare a particle dispersion.

&Lt; Preparation of composition for forming antistatic layer >

The above-mentioned particle dispersion and the following compound were mixed with stirring to prepare a composition for forming an antistatic layer.

Particle dispersion 60 parts by mass

Dioxane glycol diacrylate (NK ester A-DOG, Shin Nakamura Kagaku Kogyo Co., Ltd.) 3 parts by mass

Urethane (meth) acrylate (UA-1100H, Shin Nakamura Kagaku Kogyo Co., Ltd.) 15 parts by mass

Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (Irgacure 907, manufactured by Shiba Japan K.K.) 2 parts by mass

Methyl ethyl ketone 22 parts by mass

KF-354L (polyether-modified silicone, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by mass

[Production of optical film 1]

The composition for forming the first cured layer was coated on the A side (the side not in contact with the flexible belt) of the prepared cellulose ester film 1 by using an extrusion coater, and the temperature of the constant rate drying section was set at 50 DEG C, After drying at a temperature of 50 캜, the coated layer was cured by irradiating the irradiated portion with an illuminance of 100 mW / cm 2 and irradiating an amount of 0.25 J / cm 2 using an ultraviolet lamp while purging with nitrogen to an atmosphere having an oxygen concentration of 1.0 vol% Thereby forming a first cured layer having a thickness of 0.5 mu m.

Subsequently, the composition for forming the second cured layer prepared above was applied to the first cured layer using a microgravure coater, and after drying at a temperature of 50 ° C for a constant rate drying section and 50 ° C for a reduced drying section temperature, The coating layer was cured by irradiating the irradiated portion with a light intensity of 100 mW / cm 2 and irradiating the light with a dose of 0.3 J / cm 2 using an ultraviolet lamp while nitrogen was purged so that the concentration was 1.0 volume% or less, Layer.

Then, the composition for forming the charging layer was treated with an ultrasonic homogenizer for 5 minutes, filtered through a polypropylene filter having a pore diameter of 30 mu m, applied with an extrusion coater, dried at 80 DEG C, , The irradiated portion was irradiated with an illuminance of 100 mW / cm 2, and the irradiated amount was irradiated with 0.2 J / cm 2 to form an antistatic layer having a dry film thickness of 1.0 탆. The produced optical film 1 was wound in a roll form.

&Lt; Production of optical films 2 to 10, 12 and 13 >

The resin constituting the first hardened layer, the film thickness of the first hardened layer, the presence or absence of fine silica particles in the second hardened layer, the film thickness of the second hardened layer, and the presence of the antistatic layer were changed as shown in Table 1 In addition, the optical films 2 to 10, 12, and 13 were produced in the same manner as in the production of the optical film 1. In the optical films 1 to 3 and 5 to 8 and 12, an antistatic layer was formed only on one side (second cured layer) of the film substrate. In the optical film 10, an antistatic layer .

&Lt; Production of optical film 11 >

The optical film 11 was produced in the same manner as in the production of the optical film 1 except that cellulose acetate A (90 parts by mass) of the dope composition 1 was replaced with 100 parts by mass of a cycloolefin resin (ATON G7810 Mw = 140000, JSR Corp.) Respectively.

<Production of Polarizing Plate 101>

The optical film 1 was attached to one side of the polarizing film, and a commercially available optical film KC4UZ (manufactured by Konica Minolta) was attached to the other side of the polarizing film to prepare a polarizing plate 101. More specifically, it is as follows.

(a) Production of a polarizing film

100 parts by mass of polyvinyl alcohol (hereinafter abbreviated as PVA) having a degree of saponification of 99.95 mol% and a polymerization degree of 2400 was impregnated with 10 parts by mass of glycerin and 170 parts by mass of water and melt-kneaded, Followed by melt-extrusion. Thereafter, the PVA film was obtained by drying and heat treatment. The obtained PVA film had an average thickness of 15 탆, a moisture content of 2.4%, and a film width of 3 m.

Then, the obtained PVA film was treated successively in the order of preliminary swelling, dyeing, uniaxial stretching by wet method, fixing treatment, drying and heat treatment in order to produce a polarizing film. That is, the PVA film was preliminarily swollen by immersing in water at 30 ° C for 30 seconds and immersed in an aqueous solution having an iodine concentration of 0.4 g / liter and a potassium iodide concentration of 40 g / liter at 35 ° C for 3 minutes. Subsequently, uniaxial stretching was carried out six times in the aqueous solution at a boric acid concentration of 4% at a temperature of 50 DEG C under a tension applied to the film of 700 N / m, and the concentration of potassium iodide was 40 g / liter, the boric acid concentration was 40 g / / Liter in an aqueous solution at a temperature of 30 DEG C for 5 minutes. Thereafter, the PVA film was taken out, subjected to hot air drying at a temperature of 40 占 폚, and then heat-treated at a temperature of 100 占 폚 for 5 minutes. The obtained polarizing film had an average thickness of 5 占 퐉, a polarizing performance of 43.0%, a polarization degree of 99.5% and a dichroism ratio of 40.1.

(b) Production of polarizing plate

A polarizing plate was produced according to the following steps 1 to 5.

Step 1: The above-mentioned polarizing membrane was immersed in a storage tank of a polyvinyl alcohol adhesive solution having a solid content of 2% by mass for 1 to 2 seconds.

Step 2: Optical film 1 and KC4UZ were subjected to alkali saponification treatment under the following conditions. Subsequently, in step 1, the excess adhesive adhered to the polarizing film immersed in the polyvinyl alcohol adhesive solution was lightly removed, and the polarizing film was laminated between the surface opposite to the cured layer of the optical film 1 and the KC4UZ.

(Alkali saponification treatment)

Saponification process 4M-KOH 50 ℃ 45 seconds

Washing process water 30 ℃ 60 seconds

Neutralization process 10 parts by mass HCl 30 ℃ 45 seconds

Washing process water 30 ℃ 60 seconds

After the saponification treatment, washing is carried out in the order of water washing, neutralization and washing, followed by drying at 100 ° C.

Step 3: The laminate was sandwiched between two rotating rollers and bonded at a speed of about 2 m / min at a pressure of 20 to 30 N / cm2. At this time, care was taken so that bubbles would not enter.

Step 4: The sample prepared in Step 3 was dried for 5 minutes in a drier at a temperature of 100 占 폚 to prepare a polarizing plate.

Step 5: A commercially available acrylic pressure-sensitive adhesive was coated on the protective film (KC4UZ) side of the polarizing plate prepared in Step 4 so that the thickness after drying was 5 占 퐉 and dried in an oven at 110 占 폚 for 5 minutes to form a pressure- A peelable protective film was stuck. This polarizing plate was cut (punched) to produce a polarizing plate 101.

<Fabrication of Liquid Crystal Display Device 201>

The upper polarizing plate of a commercially available liquid crystal display device (SONY Type 60 BRAVIA LX900) was peeled off, and the polarizing plate 101 was bonded to the liquid crystal cell as an upper polarizing plate. That is, the adhesive layer of the polarizing plate 101 and the glass of the liquid crystal cell were bonded such that KC4UZ of the polarizing plate 101 was on the liquid crystal cell side. At this time, the cross-Nicols were arranged such that the transmission axis of the upper polarizer (the polarizer 101) was in the vertical direction and the transmission axis of the lower polarizer was in the horizontal direction.

&Lt; Production of polarizing plates 102 to 113 >

The polarizing plates 102 to 113 were produced in the same manner as in the production of the polarizing plate 101 except that the optical film 1 of the polarizing plate 101 was changed to the optical films 2 to 13, respectively.

<Fabrication of Liquid Crystal Display Devices 202 to 213>

The liquid crystal display devices 202 to 213 were fabricated in the same manner as in the production of the liquid crystal display device 101 except that the polarizing plate 101 was changed to the polarizing plates 102 to 113.

<Evaluation>

(Evaluation of contrast unevenness)

Under ordinary fluorescent lamp lighting in a laboratory, a liquid crystal display device was placed on a predetermined die, and an incandescent lamp (100W) was arranged at a distance of about 50 cm above the liquid crystal display device at an oblique angle. Then, the brightness when the backlight of the liquid crystal display device was turned on and the white display was turned on while the incandescent lamp was turned on and the luminance when the backlight was turned off by turning off the backlight were measured using a colorimetric colorimeter (CS-100 manufactured by Konica Minolta Optics) , And the frontal contrast of the vertex (10 points) of the liquid crystal display device was calculated by the following equation.

Front contrast (%) = {(brightness when white display) / (brightness when black display)} x 100

In addition, the optical environment at the time of luminance measurement mimics a typical optical environment when the liquid crystal display device is actually used.

This front contrast calculation was performed for each of the liquid crystal display devices 201 to 213. [ Then, on the basis of the following criteria, the contrast unevenness was evaluated.

<< Evaluation Criteria >>

&Amp; cir &amp;: The variation of the front contrast is less than 1%, and there is no contrast unevenness.

?: The variation of the front contrast is 1% or more and less than 3%, and the contrast unevenness is very small.

?: Variation of front contrast was 3% or more and less than 5%, and contrast unevenness was small.

?: Variation of the front contrast is less than 5% and less than 10%, and there is little contrast unevenness, and there is no actual deterioration.

X: Variation of front contrast is 10% or more, contrast unevenness is large, and actual resolution is good.

(Blocking evaluation)

The produced optical films 1 to 13 were each wound at 2600 m, and after standing for 200 hours under high temperature and high humidity conditions (40 DEG C and 90% RH), the occurrence of blocking from the wound state was visually judged and evaluated based on the following criteria Respectively.

<< Evaluation Criteria >>

?: No blocking occurs.

○: Although it is possible to know the blocking only by the hand lamp, there is no actual deterioration.

?: The blocking can be detected even without a hand lamp, but there is no actual deterioration.

?: Although the blocking occurred weakly, there was no real deterioration.

X: The blocking occurred strongly, and there was real deterioration.

(Black band evaluation)

The produced optical films 1 to 13 were each wound 2600 m, and after standing for 200 hours under high temperature and high humidity conditions (40 DEG C and 90% RH), the occurrence of black bands was visually judged from the wound state and based on the following criteria Respectively.

<< Evaluation Criteria >>

?: No black band occurs.

○: Although it is possible to know the black band only by the hand lamp, there is no actual resolution.

?: The black band can be recognized even without a hand lamp, but there is no actual deterioration.

?: Although the black band was weakly generated, there was no actual deterioration.

X: The black band was strongly generated, and the actual band was deteriorated.

Table 1 shows the main compositions, parameters and evaluation results of the respective optical films 1 to 13. Further, in Table 1, CE indicates a cellulose ester, COP indicates a cycloolefin resin, UA indicates a urethane acrylate, and PETA indicates pentaerythritol tri / tetraacrylate.

From Table 1, good results (?) Were obtained in the optical films 1 to 11 in any evaluation of contrast non-uniformity, blocking, and black band. This is because, since the first cured layer is thinner than the second cured layer, the region of weak mechanical strength formed by penetrating the solvent at the time of forming the first cured layer becomes thin, and the film substrate shrinks in the alignment direction It is considered that the dimensional change of the film base material and the deformation of the winding state of the optical film are suppressed by the first cured layer and the second cured layer so that the planarity is secured when the optical film is fed to the plane.

From the results of the optical films 1 to 7 and the optical films 8 to 9, the second cured layer contains a resin having an alicyclic structure (for example, A-DCP) and fine silica particles, (For example, urethane acrylate resin, PETA) and silica fine particles, the effect of suppressing contrast nonuniformity is enhanced. This is presumably because deformation of the dimension due to the function of the film substrate can be suppressed by using the above-described constitution of the first cured layer and the second cured layer, so that the deformation of the winding state of the optical film can be further suppressed.

Further, from the results of the optical films 2 and 7, when the first cured layer contains a urethane-based resin, the effect of suppressing contrast nonuniformity, blocking, and black band is higher than when the first cured layer contains a urethane-based resin. This is because the first hardened layer contains the urethane resin and the fine silica particles to form the relatively hard first hardened layer and the second hardened layer is formed on the first hardened layer to increase the hardness of the entire hardened layer As a result, it is considered that the dimensional change of the film base material under the high temperature and high humidity environment and the deformation of the winding state of the optical film can be further suppressed.

In the case where the film thickness L1 of the first cured layer is 0.3 mu m like the optical film 5, the effect of suppressing the contrast nonuniformity is small. This is because if the first hardened layer is too thin, hardening of the first hardened layer is liable to occur, and it becomes difficult to impart a predetermined hardness to the second hardened layer thereon, and the first hardened layer and the second hardened layer The lack of hardness of the layer is considered to be because the effect of suppressing the dimensional deformation of the film base under a high temperature and high humidity environment is reduced and the effect of suppressing the deformation of the wrapping state of the optical film and suppressing the contrast unevenness is reduced. Therefore, it can be said that it is preferable that the film thickness L1 of the first cured layer is 0.5 mu m or more like the optical films 1 to 3.

Also, like the optical film 6, even when the thickness L1 of the first cured layer is 3.2 mu m, the effect of suppressing the contrast unevenness is small. This is because if the first cured layer becomes too thick, the region at which the solvent hardly penetrates into the film base material becomes too thick in the formation of the first cured layer, and the effect of suppressing the dimensional change of the film base under a high- Is small. Therefore, it can be said that the film thickness L1 of the first cured layer is preferably 3.0 m or less, which is a value between 2.8 m in the optical film 3 and 3.2 m in the optical film 6.

Further, from the results of the optical films 2 and 4, in the structure in which the optical film contains the antistatic layer, the effect of suppressing the contrast nonuniformity, blocking, and black band is higher than that of the structure not including the antistatic layer. This is considered to be because the film was prevented from being charged by forming the antistatic layer, blocking during film winding was suppressed, and deformation of the winding state of the optical film could be further suppressed.

Further, even when an optical film is formed by forming three or more cured layers on a film substrate, the film thickness of the cured layer nearest to the film substrate is made thinner than the film thickness of the cured layer next to the film substrate, It was confirmed that the dimensional change of the film substrate under the environment and the deformation of the winding state of the optical film can be suppressed. Furthermore, even when a film base is constituted of a resin other than a cellulose ester resin and a cycloolefin resin (acryl, polycarbonate, polyester, etc.), by setting the film thicknesses of the two cured layers on the film base material in the same manner as described above, It was confirmed that the film could be prevented from being deformed in the winding state.

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

1. A film substrate as a 1/4 wavelength retardation film,

An optical film having at least two cured layers located on one side of the film substrate,

A cured layer closest to the film base material is referred to as a first cured layer and a cured layer next to the film base material next to the first cured layer is referred to as a second cured layer among the at least two cured layers, 1 is a thickness of the first cured layer is L1 (mu m), and L2 is a thickness of the second cured layer,

L1 < L2

Is an optical film.

2. The method of claim 1,

A resin having an alicyclic structure, and fine particles coated with a polymeric silane coupling agent,

The first cured layer may include a first cured layer,

The optical film as described in 1 above, wherein the second cured layer comprises a resin different from the resin having the alicyclic structure, and fine particles coated with a polymeric silane coupling agent.

3. The optical film as described in 2 above, wherein the resin contained in the first cured layer is a urethane acrylate resin.

4. The optical film according to any one of 1 to 3 above, wherein the thickness L1 of the first cured layer is 0.5 占 퐉 or more and 3 占 퐉 or less.

(5) The optical film according to any one of (1) to (4) above, further comprising an antistatic layer on at least one side of the film base.

6. A polarizing plate characterized in that the optical film according to any one of 1. to 5. above is located on one side of the polarizer.

7. The image display apparatus according to item 6, wherein the polarizing plate is located on at least one side of the display cell.

&Lt; Industrial applicability >

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
4: Liquid crystal cell (display cell)
5: polarizer
11: Polarizer
12: Film substrate (1/4 wavelength retardation film)
13: First hardening layer
14: Second hardened layer
16: Optical film
17: Antistatic layer

Claims (7)

A film substrate as a 1/4 wavelength retardation film,
An optical film having at least two cured layers located on one side of the film substrate,
A cured layer closest to the film base material is referred to as a first cured layer and a cured layer next to the film base material next to the first cured layer is referred to as a second cured layer among the at least two cured layers, 1 is a thickness of the first cured layer is L1 (mu m), and L2 is a thickness of the second cured layer,
L1 < L2
Phosphorous, optical film. The method of claim 1, wherein the second cured layer comprises:
A resin having an alicyclic structure, and fine particles coated with a polymeric silane coupling agent,
The first cured layer may include a first cured layer,
A resin different from the resin having the alicyclic structure of the second cured layer; and fine particles coated with a polymeric silane coupling agent. The optical film according to claim 2, wherein the resin contained in the first cured layer is a urethane acrylate resin. The optical film according to any one of claims 1 to 3, wherein the thickness L1 of the first cured layer is 0.5 占 퐉 or more and 3 占 퐉 or less. The optical film according to any one of claims 1 to 4, further comprising an antistatic layer on at least one side of the film substrate. The polarizer according to any one of claims 1 to 5, wherein the optical film is located on one side of the polarizer. 7. The image display apparatus according to claim 6, wherein the polarizing plate is located on at least one side of the display cell.

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