JP4961238B2 - Optical film, polarizing plate and image display device - Google Patents

Description

  The present invention relates to an optical film, a polarizing plate using the optical film, and an image display device. More specifically, the present invention has high antiglare properties and is applied to an antireflection, scratch resistance, and high-definition image display device. The present invention relates to an optical film excellent in anti-glare performance, a polarizing plate using the optical film, and an image display device.

  In general, in an image display device such as a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescence display (ELD) or a liquid crystal display (LCD), the contrast is reduced or the image is reflected due to reflection of external light. In order to prevent this, the surface is usually treated. As the method, there are a method of reducing the reflected light by providing fine irregularities on the film surface, scattering the reflected light on the surface, and blurring the reflected image and using the principle of optical interference. Unlike the clear antireflection film, the optical film having antiglare properties reduces the appearance of the viewer and the background on the image display device.

  As an optical film having antiglare properties, a method of imparting irregularities to the surface using a mixture of translucent fine particles and a binder resin is often used (for example, see Patent Document 1). In the produced anti-glare film, in a high-definition display device with a small pixel size, it was difficult to prevent deterioration in image quality such as display glare and blurred characters due to the uneven surface shape. .

  Then, the method of providing an unevenness | corrugation on the surface using the phase-separation structure which consists of several curable resin is proposed as an optical film which has the anti-glare property which can prevent reflection of external light efficiently (for example, patent documents) 2). However, when a low refractive index layer is applied on the antiglare layer using the phase separation structure, the wettability is poor (the occurrence of repelling), so that the coating composition for forming the low refractive index layer is uniformly formed in a desired film thickness. There is a problem that it is difficult to apply an object, and it is difficult to obtain a desired low-reflectivity layer, and thus a low reflectivity.

On the other hand, an antireflection film containing a polyfunctional fluorine-containing monomer and hollow silica fine particles has been proposed (see Patent Document 3). However, the resistance to chemical treatment was not sufficient to realize further lower reflectance. Accordingly, there has been a demand for an optical film having high antiglare properties and high scratch resistance even after chemical treatment with low reflectance.
JP 2000-338310 A JP 2004-306328 A JP 2006-28409 A

The object of the present invention is to use an antiglare layer provided with an antiglare property using a phase separation structure composed of a plurality of curable resins as an antiglare layer, and when a low refractive index layer is provided thereon, repelling occurs. It is an object of the present invention to provide an optical film that can form a uniform coating film, can achieve a desired low reflection, and has excellent scratch resistance (particularly scratch resistance after chemical treatment).
Another object of the present invention is to provide a polarizing plate and an image display device using such an optical film.

  As described above, an optical film having an antiglare layer having surface irregularities using a conventionally known mixture of translucent fine particles and a binder resin has high antiglare properties in a high-definition image display device. However, an optical film that has low reflectance and prevents reflection of external scenes on the display surface and glare has not been proposed yet.

  When an optical film having a low refractive index layer is used for a display, the low refractive index layer is located on the outermost surface of the optical film, and thus the low refractive index is required to have high scratch resistance. Since the low refractive index layer is usually a thin film having a thickness of about 100 nm, in order to realize high scratch resistance, the strength of the coating itself and the adhesion to the lower layer are required.

  Moreover, when using an optical film as an antireflection film, when making a polarizing plate using it as one of the surface protection films of two polarizing films, by making the surface of the side bonded with a polarizing film hydrophilic. It is preferable to improve the adhesion on the bonding surface, and for this purpose, a method of immersing the film in an alkaline solution is generally used. Therefore, in this case, the optical film needs to be resistant to the treatment with the alkaline solution, that is, the film is destroyed before and after the alkaline solution treatment, and the required performance such as scratch resistance is not deteriorated. The

As a result of intensive studies to solve the above-mentioned problems, the present inventors tried to coat a low-refractive index layer on an antiglare layer using a phase separation structure. It is difficult to apply a coating composition for forming a low refractive index layer with a desired film thickness, and the problem that it is difficult to obtain a desired low reflectance layer and thus a low reflectance is a problem that is caused by phase separation. It was found that the surface free energy on the surface of the glare layer is uneven (for example, the presence of a polymer caused by phase separation).
As a result of further studies based on the findings, the inventors have found that the above-described problems can be solved by the following configuration, and have completed the present invention.

1. An optical film having at least one antiglare layer and a low refractive index layer on a transparent support, wherein the antiglare layer has a phase separation structure composed of a plurality of resins, and the low refractive index The rate layer comprises (A) silica fine particles and (B) a coating composition containing a fluorine-containing polyfunctional monomer having at least two polymerizable groups and a fluorine content of 20.0% by mass or more. The content of the silica fine particles (A) is 40 to 65% by mass with respect to the total solid content in the coating composition, and the surface coverage of the silica fine particles in the low refractive index layer is 1% or more and less than 25%. Is an optical film.
2. The optical film according to 1, wherein the silica fine particles are surface-treated with a hydrolyzate of an organosilane compound and / or a partial condensate thereof.
3. The optical film according to 1 or 2 , wherein the coating composition further contains (C) at least one non-fluorinated polyfunctional monomer.
4. The optical film as described in 3, wherein the (C) at least one non-fluorinated polyfunctional monomer is an ester of a polyhydric alcohol and (meth) acrylic acid.
5. The optical film according to any one of 1 to 4 , wherein the silica fine particles have particles having pores therein.
6. The optical film according to any one of 1 to 5 , wherein the silica fine particles include particles having a particle size of 30 nm to 100 nm.
7. The coating composition according to any one of 1 to 6, wherein the coating composition contains at least one fluorine-based compound and / or at least one polysiloxane-based compound, and has a dynamic friction coefficient of 0.03 to 0.40. Optical film.
8 .1～ optical film according to any one of 7, two of which polarizing plate used in at least one of the protective films of the polarizing film in the polarizing plate.
9.1 to 7 image display device in which the polarizing plate is used on the outermost surface of a display according to an optical film or 8 according to any one of.
In addition, although this invention is related to said 1-9, the other matter was also described for reference.

The optical film of the present invention has high antiglare properties and is excellent in antireflection properties, scratch resistance, and antiglare properties when applied to a high-definition image display device.
Moreover, all the layers can be manufactured by a coating method, and can be manufactured at low cost.
In addition, a liquid crystal display device equipped with a polarizing plate using the optical film of the present invention as a protective layer is excellent in contrast, visibility, image sharpness, and the like, and is also free from glare. The same applies to a liquid crystal display device using the optical film of the present invention directly.

Hereinafter, the present invention will be described in more detail.
First, the first invention of the present invention will be described, and then the second invention will be described focusing on differences from the first invention.
The optical film of the first invention of the present invention is an optical film having at least one antiglare layer and a low refractive index layer on a transparent support, wherein the antiglare layer comprises a plurality of resins. The low refractive index layer is coated with (A) a coating composition containing silica fine particles, and the surface coverage of the silica fine particles in the low refractive index layer is 0% or more and less than 40%. It is characterized by being.

FIG. 1 shows a schematic diagram of a cross section of the optical film of the present invention. Note that FIG. 1 is merely an example of an embodiment of the present invention, and the present invention is not limited to these. For example, the aspect which has the other layer mentioned later may be sufficient.
The optical film 1 of the present invention has an antiglare layer 3 and a low refractive index layer 4 on a transparent support 2. The antiglare layer 3 has a phase separation structure composed of a plurality of resins and has irregularities. The low refractive index layer 4 contains silica fine particles 5. FIG. 2 is a schematic view of the optical film of the present invention as viewed from above. In the present invention, the surface coverage of the silica fine particles in the low refractive index layer refers to the abundance ratio of the silica fine particles 5 with respect to the material occupying the entire surface of the portion that protrudes from the surface of the low refractive index layer 4.

(Low refractive index layer)
In the present invention, the low refractive index layer provided on the antiglare layer is a layer formed by coating (A) a coating composition containing silica fine particles on the antiglare layer.

(A) Silica fine particles The silica fine particles that can be used in the low refractive index layer will be described. In the present invention, the use of silica fine particles in the low refractive index layer can reduce the refractive index and improve the scratch resistance.

  As for the size (particle size) of the silica fine particles, the average particle size is preferably 5 nm or more from the viewpoint of improving the scratch resistance, the surface of the low refractive index layer is not finely uneven, and the appearance such as black tightening From the viewpoint of good integrated reflectance, it is preferably 120 nm or less. More preferably, it is 10-100 nm, More preferably, it is 40-100 nm. The silica particles (A) preferably include at least one silica particle having an average particle size of 30 to 100 nm. The average particle diameter can be determined from an electron micrograph.

  The refractive index of the silica fine particles is preferably 1.45 or less, more preferably 1.40 or less, which is the refractive index of silica. Although nonporous silica fine particles having a refractive index of 1.45 to 1.46 can be used alone, at least one kind of silica-based fine particles having a porous structure or a cavity in the interior is preferable from the viewpoint of antireflection performance. It is preferable to use it.

  The refractive index of at least one kind of silica fine particles is preferably 1.10 to 1.40, more preferably 1.15 to 1.35, and most preferably 1.20 to 1.30. The refractive index here represents the refractive index of the entire particle. It is preferable that the refractive index of at least one kind of fine particles is 1.20 or more and 1.30 or less. Here, the refractive index of the entire particle is not the local refractive index of the particle but the refractive index of the entire particle including the void portion and the silica portion. The particles of the present invention are used for a low refractive index layer and are particles of 120 nm or less that do not substantially cause light scattering in visible light, and can be handled as particles having a single refractive index. The refractive index of the particles can be calculated by the method described in JP-A No. 2002-79616.

  The silica fine particles may be fine particles having any composition and structure as long as the particles are mainly composed of silica. In the present invention, silica fine particles having a porous or hollow structure inside the particles can also be used, but it is preferable to use hollow silica fine particles having pores inside. In the present invention, core / shell composite fine particles can also be suitably used.

  The silica fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.

  In the present invention, the silica fine particles are preferably 35 to 70% by mass with respect to the total solid content in the low refractive index layer coating composition from the viewpoint of scratch resistance and coating property improvement, and more preferably 40 to 65% by mass. %, And most preferably 40-60% by mass.

The coating amount of the silica fine particles is preferably 1 mg / m ² or more from the viewpoint of improving scratch resistance, fine irregularities cannot be formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are good. From the viewpoint of being, 100 mg / m ² or less is preferable. More preferably ^{10mg / m 2 ~80mg / m 2} , more preferably from ^{20mg / m 2 ~70mg / m 2} .

[Porous or hollow silica fine particles]
In order to reduce the refractive index, it is preferable that at least one of the fine particles is a porous or hollow silica fine particle. It is particularly preferable to use fine particles having a hollow structure having pores inside (hereinafter sometimes referred to as “hollow silica”). The porosity of these porous or hollow silica fine particles is preferably 10 to 80%, more preferably 20 to 60%, and most preferably 30 to 60%. It is preferable that the void ratio of the hollow fine particles be in the above range from the viewpoint of lowering the refractive index and maintaining the durability of the particles.

  A method for producing porous or hollow silica is described in, for example, Japanese Patent Application Laid-Open Nos. 2001-233611 and 2002-79616. In particular, particles having cavities inside the shell and having fine pores in the shell are particularly preferred. The refractive index of these hollow silica particles can be calculated by the method described in JP-A No. 2002-79616.

  The preferable coating amount of porous or hollow silica is as described above. If the amount is too small, the effect of reducing the refractive index and the effect of improving the scratch resistance are reduced. If the amount is too large, fine irregularities are formed on the surface of the low refractive index layer, and the appearance such as black tightening and the integrated reflectance are deteriorated.

  The average particle size of the porous or hollow silica is preferably 30 nm to 100 nm, more preferably 35 nm to 100 nm, and still more preferably 40 nm to 80 nm. In the present invention, the pore-containing fine particles may have a size distribution, and the coefficient of variation thereof is preferably 60% to 5%, more preferably 50% to 10%. In addition, two or more kinds of particles having different average particle sizes can be mixed and used. Here, the average particle diameter of the hollow silica can be determined from an electron micrograph.

The specific surface area of the hollow silica in the present invention is preferably from 20 to 300 m ² / g, more preferably 30~120m ² / g, most preferably 40~90m ² / g. The surface area can be obtained by the BET method using nitrogen.

  In the present invention, silica particles having no voids can be used in combination with hollow silica. The preferred particle size of silica without voids is 30 nm to 150 nm, more preferably 35 nm to 100 nm, and most preferably 40 nm to 80 nm.

[Preparation method of porous or hollow fine particles]
A preferred method for producing hollow fine particles is described below. The first step is the formation of core particles that can be removed by post-treatment, the second step is the formation of a shell layer, the third step is the dissolution of core particles, and the fourth step is the formation of an additional shell phase if necessary. Specifically, the hollow particles can be produced according to the method for producing hollow silica fine particles described in, for example, JP-A-2001-233611.

  A preferred method for producing porous particles is to produce porous core particles by controlling the degree of hydrolysis and condensation of alkoxide and the type and amount of coexisting substances as the first step, and a shell layer on the surface as the second step. It is a method of forming. Specifically, the production of the porous particles is, for example, a method described in JP-A-2003-327424, 2003-335515, 2003-226516, 2003-238140, or the like. Can be done.

  In the present invention, it is preferable to reduce the amount of adsorbed water of silica fine particles, which will be described later, and it can be controlled by changing the particle size, changing the shell thickness, hydrothermal treatment conditions, and the like. Also, the amount of adsorbed water can be reduced by firing the particles.

(Coating with silica fine particles)
In the present invention, the silica fine particles are preferable because the adsorption sites on the surface of the silica fine particles can be reduced by increasing the shell thickness and the amount of adsorbed water can be reduced. Furthermore, it is preferable to form a shell with a conductive component since conductivity can be imparted. Particularly preferred is a combination using ZnO ₂ , Y ₂ O ₃ , Sb ₂ O ₅ , ATO, ITO, SnO ₂ as the shell for porous or hollow silica fine particles. Hereinafter, preferable antimony oxide-coated silica-based fine particles will be described.

The antimony oxide-coated silica-based fine particles according to the present invention are obtained by coating porous silica-based fine particles or silica-based fine particles having pores therein with an antimony oxide coating layer. The porous silica-based fine particles include porous silica fine particles and composite oxide fine particles containing silica as a main component, and the surface of the porous inorganic oxide fine particles disclosed in JP-A-7-133105 is used. Low refractive index nanometer-sized composite oxide fine particles coated with silica or the like can be suitably used.
The silica-based fine particles having pores therein are disclosed in Japanese Patent Application Laid-Open No. 2001-233611, which is made of silica and an inorganic oxide other than silica and has a low refractive index nanometer size silica having a cavity inside. System fine particles can also be suitably used.

  Such porous silica-based fine particles or silica-based fine particles having cavities therein preferably have an average particle size in the range of 4 to 100 nm, more preferably 10 to 90 nm. If the average particle diameter is 4 nm or more, silica-based fine particles can be obtained without problems during production, and the obtained particles are also sufficiently stable, and can occur when small-sized particles are used. The problem that dispersed antimony oxide-coated silica-based fine particles cannot be obtained does not occur. If the average particle size is 100 nm or less, the average particle size of the obtained antimony oxide-coated silica-based fine particles can be suppressed to 120 nm or less, and when a transparent coating is formed using large-sized antimony oxide-coated silica-based fine particles. This is preferable because problems such as a possible decrease in transparency and an increase in haze can be suppressed.

  The refractive index of the porous silica-based fine particles or the silica-based fine particles having cavities therein is preferably 1.45 or less, more preferably 1.40 or less, which is the refractive index of silica. In addition, although nonporous silica fine particles having a refractive index of 1.45 to 1.46 can be used alone, it is preferable to use silica-based fine particles that are porous or have cavities inside from the viewpoint of antireflection performance. preferable.

  The average thickness of the antimony oxide coating layer is preferably in the range of 0.5 to 30 nm, more preferably in the range of 1 to 10 nm. If the average thickness of the coating layer is 0.5 nm or more, the silica-based fine particles are completely covered. This is preferable because the resulting antimony oxide-coated silica-based fine particles have sufficient conductivity. If the thickness of the coating layer is 30 nm or less, the effect of improving the conductivity can be sufficiently obtained, and problems such as insufficient refractive index when the average particle diameter of the antimony oxide-coated silica-based fine particles is small can be suppressed.

  The antimony oxide-coated silica-based fine particles according to the present invention preferably have an average particle size in the range of 5 to 120 nm, more preferably 10 to 100 nm. When the average particle diameter of the antimony oxide-coated silica-based fine particles is 5 nm or more, the fine particles can be obtained without problems during production, and aggregated particles in the obtained particles can be suppressed, which is preferable. In addition, there is a problem that transparency, haze, film strength, adhesion to the substrate, etc. may be insufficient when used for forming a transparent film due to insufficient dispersibility, which may occur with small particles. It is preferable. If the average particle diameter of the antimony oxide-coated silica-based fine particles is 120 nm or less, the formed transparent film is preferable because the transparency is sufficient and the haze is kept low. Further, the adhesion with the base material does not become insufficient.

  The refractive index of the antimony oxide-coated silica-based fine particles is preferably in the range of 1.25 to 1.60, more preferably 1.30 to 1.50. A refractive index of 1.25 or more is preferred because the particles can be obtained without problems during production. Moreover, there is no shortage in the strength of the obtained particles. On the other hand, if the refractive index is 1.60 or less, the antireflection performance of the transparent coating is also sufficient, which is preferable.

The volume resistance value of the antimony oxide-coated silica fine particles is preferably in the range of 10 to 5000 Ω / cm, more preferably 10 to 2000 Ω / cm. If the volume resistance value is 10 Ω / cm or more, the particles can be obtained without problems during production, which is preferable. Moreover, the refractive index of the obtained particle | grain becomes 1.6 or less, and the anti-reflective performance of a transparent film is sufficient, and it is preferable. On the other hand, if the volume resistance value is 5000 Ω / cm or less, the antistatic performance of the obtained transparent film is sufficient, which is preferable.
The antimony oxide-coated silica fine particles of the present invention can be used after surface treatment with a silane coupling agent according to a conventional method, if necessary.

(Adsorption water amount of fine particles)
In the present invention, the silica fine particles that can be used in the low refractive index layer have an adsorbed water amount of 6.1% by mass or less in terms of dispersibility in the coating solution, hardness of the coating film, and antifouling property. Is preferable.

(Measurement of water adsorbed on pore-containing fine particles)
In the present invention, the amount of adsorbed water of the pore-containing silica fine particles can be determined by the following measuring method.
The silica fine particle powder was dried for 1 hour under the conditions of 20 ° C. and about 1 hPa using a rotary pump. Thereafter, it was stored at 20 ° C. and 55% RH for 1 hour. Using “DTG-50” manufactured by Shimadzu Corporation, about 10 mg of the dried sample was weighed into a platinum cell, and the temperature was increased from 20 ° C. to 950 ° C. at a heating rate of 20 ° C./min. The amount of adsorbed water was calculated as a percentage of mass decrease when the temperature was raised to 200 ° C.
Adsorbed water amount (%) = 100 × (W ₂₀ −W ₂₀₀ ) / W ₂₀₀
here,
W ₂₀ : initial mass at the start of heating,
W ₂₀₀ : Mass when the temperature is raised to 200 ° C.

  When the particles are a dispersion, the solvent can be distilled off with an evaporator (25 ° C., reduced pressure to 10 hPa), and the residue can be ground in an agate mortar to obtain a powder, and then measured in the above step.

  In the present invention, the amount of adsorbed water is preferably 6.1% by mass or less, more preferably 5.5% by mass or less, and most preferably 5.0% by mass or less. Especially for particles with pores on the surface or inside, the amount of adsorbed water is reduced by increasing the thickness and density of the shell on the particle surface, or by coating the surface with different components such as the above-mentioned antimony oxide-coated particles. Can be made. Further, reducing the amount of adsorbed water is effective in improving the scratch resistance.

  In the present invention, the pore-containing fine particles may have a size distribution, and the coefficient of variation thereof is preferably 60% to 5%, more preferably 50% to 10%. In addition, two or more kinds of particles having different average particle sizes can be mixed and used.

(Silica fine particle surface treatment method)

The silica fine particles are preferably surface-treated with a hydrolyzate of organosilane and / or a partial condensate thereof in terms of improving dispersibility in the coating material for forming a low refractive index layer. In the surface treatment, it is more preferable to use either an acid catalyst or a metal chelate compound or both.
The structure of the organosilane is not particularly limited, but preferably has a (meth) acryloyl group at the terminal.
The organosilane compound that can be used for the surface treatment of the silica fine particles of the present invention will be described in detail.
Formula (I)
(R ¹⁰ ) _m -Si (X) _4-m
In the general formula (I), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, t-butyl, sec-butyl, hexyl, decyl, hexadecyl and the like. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include a phenyl group and a naphthyl group, and a phenyl group is preferable.

X represents a hydroxyl group or a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group (an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group and an ethoxy group), a halogen atom (for example, Cl, Br, I, etc.), and R ^2. COO groups (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples include CH ₃ COO groups and C ₂ H ₅ COO groups), preferably alkoxy groups, particularly preferably. Is a methoxy group or an ethoxy group. m represents an integer of 1 to 3. When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively. m is preferably 1 or 2, particularly preferably 1.
Moreover, the compound shown below as an example in case X is shown as a group which can be hydrolyzed is also preferable.
(R ¹⁰ ) ₃ —Si— (X) —Si— (R ¹⁰ ) ₃
Here, R ¹⁰ has the same meaning as R ¹⁰ above, and X represents a hydrolyzable group. Examples of X include -O- and -NH-.

The substituent contained in R ¹⁰ is not particularly limited, but is a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl group, ethyl group, i -Propyl group, propyl group, t-butyl group etc.), aryl group (phenyl group, naphthyl group etc.), aromatic heterocyclic group (furyl group, pyrazolyl group, pyridyl group etc.), alkoxy group (methoxy group, ethoxy group) , I-propoxy group, hexyloxy group, etc.), aryloxy group (phenoxy group, etc.), alkylthio group (methylthio group, ethylthio group, etc.), arylthio group (phenylthio group, etc.), alkenyl group (vinyl group, 1-propenyl group) Etc.), acyloxy group (acetoxy group, acryloyloxy group, methacryloyloxy group, etc.), alkoxycarbonyl group (meth) Xycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (phenoxycarbonyl group, etc.), carbamoyl group (carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N-methyl-N-octylcarbamoyl group) Etc.), acylamino groups (acetylamino group, benzoylamino group, acrylamino group, methacrylamino group, etc.) and the like, and these substituents may be further substituted. In the present specification, even if a hydrogen atom is replaced by a single atom, it is treated as a substituent for convenience.
When there are a plurality of R ¹⁰ , at least one is preferably a substituted alkyl group or a substituted aryl group. Among these, the substituted alkyl group or substituted aryl group preferably further has a vinyl polymerizable group. In this case, the compound represented by the general formula (I) is a vinyl polymerizable compound represented by the following general formula (II). It can be expressed as an organosilane compound having a substituent.
Formula (II)

In the general formula (II), R ¹ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. R ¹ is preferably a hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom or a chlorine atom, more preferably a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom or a chlorine atom, And methyl groups are particularly preferred.
Y represents a single bond, an ester group, an amide group, an ether group or a urea group. Single bonds, ester groups and amide groups are preferred, single bonds and ester groups are more preferred, and ester groups are particularly preferred.

  L is a divalent linking chain, specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and a linking group (for example, an ether group, an ester group, an amide group) inside. A substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group having a linking group therein, among which a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted carbon number 6 An arylene group of ˜20, an alkylene group having 3 to 10 carbon atoms having a linking group inside, an unsubstituted alkylene group, an unsubstituted arylene group, and an alkylene group having an ether linking group or an ester linking group inside are further included. An unsubstituted alkylene group and an alkylene group having an ether linking group or an ester linking group therein are particularly preferred. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

n represents 0 or 1. When there are a plurality of Xs, the plurality of Xs may be the same or different. n is preferably 0.
R ¹⁰ has the same meaning as R ^{10 in} formula (I), preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group.
X has the same meaning as X in formula (I), preferably a halogen, a hydroxyl group or an unsubstituted alkoxy group, more preferably a chlorine, a hydroxyl group or an unsubstituted alkoxy group having 1 to 6 carbon atoms, a hydroxyl group or a carbon number. 1-3 alkoxy groups are more preferable, and a methoxy group is particularly preferable.

As the organosilane compound used in the present invention, those represented by the following general formula (III) are also preferred.
Formula ^{(III) (Rf-L 1} ) n -Si (R 11) 4-n
In the above formula, Rf represents a linear, branched or cyclic fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated aromatic group having 6 to 14 carbon atoms. Rf is preferably a linear, branched or cyclic fluoroalkyl group having 3 to 10 carbon atoms, and more preferably a linear fluoroalkyl group having 4 to 8 carbon atoms. L ¹ represents a divalent linking group having 10 or less carbon atoms, preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms. The alkylene group is a linear or branched, substituted or unsubstituted alkylene group that may have a linking group (for example, ether, ester, amide) inside. The alkylene group may have a substituent, and preferable substituents in that case include a halogen atom, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group. R ¹¹ represents a hydroxyl group or a hydrolyzable group, preferably an alkoxy group having 1 to 5 carbon atoms or a halogen atom, more preferably a methoxy group, an ethoxy group, or a chlorine atom. n represents an integer of 1 to 3.

Next, among the fluorine-containing silane coupling agent represented by the general formula (III), the fluorine-containing silane coupling agent represented by the following general formula (IV) is preferable.
Formula _{(IV) C n F 2n +} 1 - (CH 2) m -Si (R) 3
In the above formula, n represents an integer of 1 to 10, and m represents an integer of 1 to 5. R represents an alkoxy group having 1 to 5 carbon atoms or a halogen atom. n is preferably from 4 to 10, m is preferably from 1 to 3, and R is preferably a methoxy group, an ethoxy group or a chlorine atom.

  Two or more kinds of the compounds represented by formula (I) may be used in combination. Specific examples of the compound represented by formula (I) are shown below, but the present invention is not limited thereto.

In addition, disiloxane-based and disilazane-based compounds can also be used as the surface treatment agent. For example, hexamethyldisiloxane, 1,3-dibutyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, 1,3 -Divinyltetramethyldisiloxane, hexaethyldisiloxane, 3-glycidoxypropylpentamethyldisiloxane, hexamethyldisilazane, hexaethyldisilazane and the like.
Among these specific examples, (M-1), (M-2), (M-49), (M-56), (M-57) and the like are particularly preferable. Further, the compounds of A, B, and C described in Reference Example of Japanese Patent No. 3474330 are also preferable because of excellent dispersion stability. In the present invention, the amount of the organosilane compound represented by the general formula (I) is not particularly limited, but is preferably 1% by mass to 300% by mass, more preferably 3% by mass to 100% by mass, per inorganic fine particle. %, Most preferably 5% by mass to 50% by mass. It is preferably 1 to 300 mol%, more preferably 5 to 300 mol%, and most preferably 10 to 200 mol% per normal concentration (Formol) based on hydroxyl groups on the surface of the inorganic oxide.
When the amount of the organosilane compound used is in the above range, a sufficient stabilizing effect of the dispersion can be obtained, and the film strength is also increased during coating film formation. It is also preferable to use a plurality of types of organosilane compounds in combination, and a plurality of types of compounds can be added simultaneously, or the addition time can be shifted for reaction. Also, it is preferable to add a plurality of types of compounds after making them into partial condensates in advance because the reaction control is easy.

In the present invention, it is preferable to improve the dispersibility of the inorganic fine particles by allowing the hydrolyzate of the organosilane compound and / or a partial condensate thereof to act on the surface of the inorganic fine particles.
In the hydrolysis condensation reaction, 0.3 to 2.0 mol, preferably 0.5 to 1.0 mol of water is added to 1 mol of the hydrolyzable group (X), and the acid catalyst used in the present invention. Or it is preferable to carry out by stirring at 15-100 degreeC in presence of a metal chelate compound.

[Surface treatment solvent]
The treatment for improving the dispersibility by the hydrolyzate and / or condensation reaction product of the organosilane can be carried out without a solvent or in a solvent. When a solvent is used, the concentration of the hydrolyzate of organosilane and / or the partial condensate thereof can be appropriately determined. As the solvent, an organic solvent is preferably used in order to uniformly mix the components. For example, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are preferable.
The solvent is preferably one that dissolves the organosilane hydrolyzate and / or condensation reaction product and the catalyst. In addition, it is preferable in the process that an organic solvent is used as a coating solution or a part of the coating solution, and those that do not impair the solubility or dispersibility when mixed with other materials such as a fluorine-containing polymer are preferable.

  Among these, examples of the alcohols include monohydric alcohols and dihydric alcohols. Among these, monohydric alcohols are preferably saturated aliphatic alcohols having 1 to 8 carbon atoms. Specific examples of these alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol. Examples thereof include monobutyl ether and ethylene glycol monoethyl ether acetate.

Specific examples of aromatic hydrocarbons include benzene, toluene and xylene, specific examples of ethers include tetrahydrofuran and dioxane, and specific examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Specific examples of esters such as diisobutylketone and the like include ethyl acetate, propyl acetate, butyl acetate, and propylene carbonate.
These organic solvents can be used alone or in combination of two or more. Although the density | concentration of the organosilane compound with respect to the solvent in this process is not specifically limited, Usually, it is the range of 0.1 mass%-70 mass%, Preferably it is the range of 1 mass%-50 mass%.
In the present invention, it is preferable to disperse the inorganic fine particles with an alcohol solvent and then perform a dispersibility improvement treatment, and subsequently replace the dispersion solvent with an aromatic hydrocarbon solvent or a ketone solvent. Substitution with a ketone solvent is preferable from the viewpoint of the affinity with the binder used at the time of coating and the improvement of the stability of the dispersion itself.

[Surface treatment catalyst]
The treatment for improving the dispersibility by the hydrolyzate and / or condensation reaction product of organosilane is preferably performed in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium. From the viewpoint of production stability and storage stability of the inorganic fine particle liquid, an acid catalyst (inorganic Acids, organic acids) and / or metal chelates. Among inorganic acids, hydrochloric acid, sulfuric acid, and organic acids preferably have an acid dissociation constant in water (pKa value (25 ° C.)) of 4.5 or less, and an acid dissociation constant in hydrochloric acid, sulfuric acid, or water of 3.0 or less. More preferred is an organic acid, hydrochloric acid, sulfuric acid, an organic acid having an acid dissociation constant of 2.5 or less in water is more preferred, an organic acid having an acid dissociation constant in water of 2.5 or less is more preferred, and methanesulfonic acid Further, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

  When the hydrolyzable group of the organosilane is an alkoxy group and the acid catalyst is an organic acid, the amount of water added can be reduced because the carboxyl group or sulfo group of the organic acid supplies protons. The amount of water added to 1 mol of the alkoxide group of the organosilane is 0 to 2 mol, preferably 0 to 1.5 mol, more preferably 0 to 1 mol, and particularly preferably 0 to 0.5 mol. Further, when alcohol is used as a solvent, it is also preferable that water is not substantially added.

The amount of the acid catalyst used is 0.01 to 10 mol%, preferably 0.1 to 5 mol%, based on the hydrolyzable group when the acid catalyst is an inorganic acid, and the acid catalyst is an organic acid. However, when water is added, the optimal amount of use is 0.01 to 10 mol%, preferably 0.1 to 5 mol%, based on the hydrolyzable group. When substantially no water is added, it is 1 to 500 mol%, preferably 10 to 200 mol%, more preferably 20 to 200 mol%, still more preferably 50 to 50 mol% with respect to the hydrolyzable group. 150 mol%, particularly preferably 50 to 120 mol%.
The treatment is carried out by stirring at 15 to 100 ° C., but is preferably controlled by the reactivity of organosilane.

[Metal chelate compounds]
The metal chelate compound is an alcohol represented by a general formula R ³ OH (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms) and / or a general formula R ⁴ COCH ₂ COR ⁵ (where R 3 ⁴ represents an alkyl group having 1 to 10 carbon atoms, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.) Zr, Any metal having a central metal selected from Ti or Al can be suitably used without particular limitation. Within this category, two or more metal chelate compounds may be used in combination. The metal chelate compound used in the present invention is
General formula Zr (OR ³ ) _p1 (R ⁴ COCHCOR ⁵ ) _p2 ,
Ti (OR ³ ) _q1 (R ⁴ COCHCOR ⁵ ) _q2 and Al (OR ³ ) _r1 (R ⁴ COCHCOR ⁵ ) _r2
Those selected from the group of compounds represented by the formula (1) are preferred, and these act to promote the condensation reaction of the organosilane compound.
R ³ and R ⁴ in the metal chelate compound may be the same or different and each has an alkyl group having 1 to 10 carbon atoms, specifically an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, a phenyl group, and the like. R5 is an alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and an n-butoxy group. , Sec-butoxy group, t-butoxy group and the like. In addition, p1, p2, q1, q2, r1, and r2 in the metal chelate compound represent integers determined so as to be tetradentate or hexadentate.

Specific examples of these metal chelate compounds include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetate). Zirconium chelate compounds such as acetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium, diiso Titanium chelate compounds such as propoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diisopropoxy Cetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonate bis (ethylacetate) And aluminum chelate compounds such as acetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

  The metal chelate compound of the present invention is preferably from 0.01 to 50% by mass, more preferably from 0.1 to 50% by mass, based on the organosilane compound, from the viewpoint of the speed of the condensation reaction and the film strength when it is used as a coating film. It is used in a proportion of 50% by mass, more preferably 0.5 to 10% by mass.

[Dispersion stabilization additive]
In addition to the organosilane, acid catalyst and / or chelate compound, the following component (c) is preferably added to the dispersion or coating composition used in the present invention.
Hereinafter, the component (c) will be further described. The component (c) used in the present invention is a β-diketone compound and / or β-ketoester compound represented by the general formula R ⁴ COCH ₂ COR ⁵ , and is used for the dispersion or coating composition used in the present invention. It acts as a stability improver. That is, by coordinating to a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), the action of promoting the condensation reaction of organosilane and metal chelate component by these metal chelate compounds is suppressed, It is considered that it acts to improve the storage stability of the resulting composition. (C) R4 and R5 constituting the component are the same as R4 and R5 constituting the metal chelate compound.

  Specific examples of the (c) component β-diketone compound and / or β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate- n-butyl, acetoacetate-sec-butyl, acetoacetate-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, Examples include 2,4-nonane-dione, 5-methyl-hexane-dione, and the like. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. These β-diketone compounds and / or β-ketoester compounds may be used alone or in combination of two or more. In the present invention, the β-diketone compound and / or β-ketoester compound as the component (c) is preferably used in an amount of 2 mol or more, more preferably 3 to 20 mol, per 1 mol of the metal chelate compound. If it is less than 2 mol, the storage stability of the resulting composition may be inferior, which is not preferable.

(Surface coverage of silica in the low refractive index layer)
The surface coverage of the silica fine particles in the low refractive index layer is 0% or more and less than 40%, preferably 0% or more and less than 30%, more preferably 0% or more and less than 25%. More preferably, it is less than 25%. If it exceeds 40%, the chemical resistance deteriorates and the scratch resistance decreases.

(Evaluation of surface coverage of silica in low refractive index layer)
Next, a method for measuring the surface coverage of silica in the low refractive index layer will be described.
Optical films are evaluated using “JPS-9000MX photoelectron spectrometer” (X-ray source: Mg Ka, voltage 10 kV, current 10 mA) manufactured by JEOL. The measurement is performed at a photoelectron take-off angle of 20 °, and photoelectron spectra of the outermost Si 2p, C 1s, O 1s and F 1s are obtained. Si 2p, C 1s, O 1s, and F 1s perform energy correction with the binding energy of C 1s (CH _x ) as the main component being 285.0 eV for the peak position of each photoelectron spectrum. In addition, the integral value of each peak is obtained, and the element composition ratio is obtained by normalizing with a sensitivity coefficient (Si 2p: 0.88, C 1s: 1.00, O 1s: 2.93, F 1s: 5.47). The element composition ratio of Si 2p at this time is A%.
For Si 2p, a Gauss-Lorentz function using SiPS derived from a silicone compound (bonding energy around 102 eV) and Si atom derived from silica fine particles (binding energy around 104 eV) using JEOL XPS software SpecXPS To obtain the ratio B% of the silica fine particle-derived material to the entire Si 2p.
The film surface coverage of silica is defined as {A × (B / 100) × 3}%, and the film surface coverage of silicone is defined as [{A × (100−B) / 100} × 4]%.

(B) Fluorine-containing polyfunctional monomer In the present invention, the coating composition for forming a low refractive index layer preferably contains (B) a fluorine-containing polyfunctional monomer having at least two polymerizable groups. The fluorine-containing polyfunctional monomer may be any compound as long as it has two or more polymerizable groups and the fluorine content is 20.0% by mass or more, and is not particularly limited.
The fluorine content is preferably 30.0% by mass or more, more preferably 40.0% by mass or more from the viewpoint of lowering the refractive index of the polymer.
Specifically, compounds f-1 to f-10 described in paragraph No. [0018] of JP-A-2006-28409 and X-1 to X-32 described in paragraph Nos. [0023] to [0027]. In addition, the following compounds (X-33), (X-34), and (X-35) can also be preferably used.

  In addition, the following compounds described in paragraph numbers 0135 to 0149 of WO2005 / 059601

(In the general formula (I), A ^{1 to} A ⁶ each independently represents an acryloyl group, a methacryloyl group, an α-fluoroacryloyl group, or a trifluoromethacryloyl group, and n, m, o, p, q, r Each independently represents an integer of 0 to 2, and R ^{1 to} R ⁶ each independently represents an alkylene group having 1 to 3 carbon atoms, or 1 or more carbon atoms in which one or more hydrogen atoms are substituted with fluorine atoms. Represents a fluoroalkylene group of ˜3.)

(In the general formula (II), A ^{11 to} A ¹⁴ each independently represents an acryloyl group, a methacryloyl group, an α-fluoroacryloyl group, or a trifluoromethacryloyl group, and s, t, u, and v each independently , Each of R ^{11 to} R ¹⁴ is independently an alkylene group having 1 to 3 carbon atoms, or fluoro having 1 to 3 carbon atoms in which one or more hydrogen atoms are substituted with fluorine atoms. (Which represents an alkylene group) can also be preferably used.

  Furthermore, the compounds described in paragraph Nos. 0014 to 0028 of JP-A-2006-291077 can also be suitably used.

(C) At least one non-fluorinated polyfunctional monomer In the present invention, the coating composition for forming a low refractive index layer preferably contains (C) at least one non-fluorinated polyfunctional monomer. In the present specification, “(meth) acrylate”, “(meth) acrylic acid”, and “(meth) acryloyl” are “acrylate or methacrylate”, “acrylic acid or methacrylic acid”, and “acryloyl or methacryloyl”, respectively. Represents.
Examples of the non-fluorinated polyfunctional monomer include compounds having a polymerizable functional group such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group, and among them, a compound containing a (meth) acryloyl group is preferable. Particularly preferably, a compound containing two or more (meth) acryloyl groups in one molecule described below can be used. These compounds are particularly preferred because they have a large combined effect for improving scratch resistance or scratch resistance after chemical treatment, particularly when a compound having a polymerizable unsaturated group is used in the polymer body.

As a specific example of the compound having a polymerizable unsaturated bond,
(Meth) acrylic acid diesters of alkylene glycol such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate;
(Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts such as 2,2-bis {4- (acryloxy · diethoxy) phenyl} propane and 2-bis {4- (acryloxy · polypropoxy) phenyl} propane ;
Etc.

  Furthermore, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable non-fluorinated polyfunctional monomer.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. For example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, EO Modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-chlorohexane tetramethacrylate, polyurethane polyacrylate Over DOO, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  Specific examples of polyfunctional acrylate compounds having a (meth) acryloyl group that are preferably used as non-fluorine-containing polyfunctional monomers include Nippon Kayaku Co., Ltd. KAYARAD DPHA, DPHA-2C, and PET- 30, TMPTA, TPA-320, TPA-330, RP-1040, T-1420, D-310, DPCA-20, DPCA-30, DPCA-60, GPO-303, Mention may be made of polyols such as V # 3PA, V # 400, V # 36095D, V # 1000, and V # 1080 manufactured by Osaka Organic Chemical Industry Co., Ltd. and esterified products of (meth) acrylic acid. Also, purple light UV-1400B, UV-1700B, UV-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7620EA, UV-7630B, UV-7630B, UV-7640B. UV-6630B, UV-7000B, UV-7510B, UV-7461TE, UV-3000B, UV-3200B, UV-3210EA, UV-3210EA, UV-3310EA, UV-3310B, UV-3500BA , UV-3520TL, UV-3700B, UV-6100B, UV-6640B, UV-2000B, UV-2010B, UV-2250EA, UV-2750B (manufactured by Nippon Synthetic Chemical Co., Ltd.), UL-503LN (manufactured by Kyoeisha Chemical Co., Ltd.), Unidic 17-80 17-813, V-4030, V-4000BA (Dainippon Ink Chemical Co., Ltd.), EB-1290K, EB-220, EB-5129, EB-1830, EB-4858 (Daicel UCB ( Ltd.), High Corp AU-2010, AU-2020 (manufactured by Tokushi Co., Ltd.), Aronix M-1960 (manufactured by Toagosei Co., Ltd.), Art Resin UN-3320HA, UN-3320HC, UN-3320HS, UN -904, a trifunctional or higher urethane acrylate compound such as HDP-4T, Aronix M-8100, M-8030, M-9050 (manufactured by Toagosei Co., Ltd., KRM-8307 (manufactured by Daicel Cytec Co., Ltd.)) A trifunctional or higher functional polyester compound such as a trade name] can also be preferably used.

  Furthermore, resins having three or more (meth) acryloyl groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins And oligomers or prepolymers such as polyfunctional compounds such as polyhydric alcohols.

  Furthermore, specific examples of the bifunctional (meth) acrylate compound used as the non-fluorinated polyfunctional monomer include compounds represented by the following formula, but are not limited thereto.

  As the non-fluorinated polyfunctional monomer, for example, dendrimers described in JP-A-2005-76005 and JP-A-2005-36105, and norbornene ring-containing monomers as described in JP-A-2005-60425 can also be used.

  Two or more kinds of non-fluorinated polyfunctional monomers may be used in combination. Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator. It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable.

  In the present invention, it is preferable that the coating composition contains at least one fluorine compound and / or at least one polysiloxane compound, and has a dynamic friction coefficient of 0.03 or more and 0.40 or less. The dynamic friction coefficient is more preferably 0.03 or more and 0.35 or less, and further preferably 0.03 or more and 0.30 or less.

(Fluorine compounds, polysiloxane compounds)
In the present invention, the coating composition contains at least one fluorine-based compound and / or at least one polysiloxane-based compound, which imparts properties such as antifouling property, slipperiness, water resistance, and chemical resistance. It is preferable for the purpose.
When these compounds are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferably 0.1 to 5% by mass.

[Polysiloxane compounds]
Next, the polysiloxane compound will be described. In the present invention, it is preferable to use a compound having a polysiloxane structure for the purpose of improving scratch resistance by imparting slipperiness and imparting antifouling property. There is no restriction | limiting in particular in the structure of a compound, What has a substituent in the terminal and / or side chain of a compound chain | strand which contains multiple dimethylsilyloxy units as a repeating unit is mentioned. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy.

  Although there is no restriction | limiting in particular in the molecular weight of the compound which has a polysiloxane structure, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000.

  From the viewpoint of preventing transcription, it preferably contains a hydroxyl group or a functional group that reacts with the hydroxyl group to form a bond. This bond formation reaction preferably proceeds rapidly under heating conditions and / or in the presence of a catalyst. Examples of such a substituent include an epoxy group and a carboxyl group. Although the following are mentioned as an example of a preferable compound, It is not limited to these.

(Including hydroxyl group)
“X-22-160AS”, “KF-6001”, “KF-6002”, “KF-6003”, “X-22-170DX”, “X-22-176DX”, “X-22-176D”, “X-22-176F” {manufactured by Shin-Etsu Chemical Co., Ltd.}; “FM-4411”, “FM-4421”, “FM-4425”, “FM-0411”, “FM-0421”, “ "FM-0425", "FM-DA11", "FM-DA21", "FM-DA25" {above, manufactured by Chisso Corporation}; "CMS-626", "CMS-222" {above, manufactured by Gelest} .

(Containing functional groups that react with hydroxyl groups)
"X-22-162C", "KF-105" {manufactured by Shin-Etsu Chemical Co., Ltd.}; "FM-5511", "FM-5521", "FM-5525", "FM-6611", " FM-6621 "," FM-6625 "{above, manufactured by Chisso Corporation}.

  In addition to the polysiloxane compound, another polysiloxane compound may be used in combination. Preferable examples include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include groups containing acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, oxetanyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is more preferable that it is 50,000 or less, It is especially preferable that it is 3000-30000, It is most preferable that it is 10,000-20000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.0 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferred silicone compounds include X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-1821 (above trade names) and Chisso (manufactured by Shin-Etsu Chemical Co., Ltd.). Co., Ltd., FM-0725, FM-7725, FM6621, FM-1121 and Gelest DMS-U22, RMS-033, RMS-083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, Examples thereof include, but are not limited to, FMS123, FMS131, FMS141, and FMS221 (hereinafter, trade names).

(Fluorine compounds)
As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.), even branched structures (eg, CH (CF ₃ ) ₂ , CH ₂ CF (CF ₃ ) ₂ , CH (CH ₃ ) CF ₂ CF ₃ , CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.), alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl group, perfluorocyclopentyl, etc. Group or an alkyl group substituted with these, and may have an ether bond (for example, CH ₂ OCH ₂ CF ₂ CF ₃ , CH ₂ CH ₂ OCH ₂ C ₄ F ₈ H, CH ₂ CH _{2 CH 2 CH 2 C 8 F 17} , CH 2 CH 2 OCF 2 CF 2 OCF 2 CF 2 H , etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.

  It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink Co., Ltd., Megafac F-171. , F-172, F-179A, and defender MCF-300 (named above), but are not limited thereto.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass. Examples of preferred compounds include, but are not limited to, Dainippon Ink Co., Ltd., MegaFace F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

(Polymerization initiator)
The polymerization initiator effective for curing the low refractive index layer of the present invention will be described. When the constituent component of the low refractive index layer is a radical polymerizable compound, the polymerization of these compounds can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.

(Photo radical initiator)
As radical photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds , Fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like.

  Examples of acetophenones include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxy-dimethylphenylketone, 1-hydroxy-dimethyl-p-isopropylphenylketone, 1-hydroxy Cyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 4-phenoxydichloroacetophenone, 4-t-butyl -Dichloroacetophenone and the like are included.

  Examples of benzoins include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. included.

  Examples of benzophenones include benzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone, 4,4'-dimethylaminobenzophenone (Michler ketone), 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone and the like are included.

  Examples of phosphine oxides include 2,4,6-trimethylbenzoyl diphenylphosphine oxide. Examples of the active esters include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], sulfonic acid esters, cyclic active ester compounds, and the like. Specifically, compounds described in Examples in JP-A No. 2000-80068 are particularly preferable.

  Examples of the onium salts include aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts. Examples of borate salts include ion complexes with cationic dyes.

  Specific examples of the active halogens include Wakabayashi et al., “Bull Chem. Soc Japan”, 42, 2924 (1969), US Pat. No. 3,905,815, JP-A-5-27830, M.M. P. Examples include compounds described in Hutt “Journal of Heterocyclic Chemistry”, Vol. 1 (No. 3), (1970), and in particular, oxazole compounds substituted with a trihalomethyl group: s-triazine compounds. More preferred are s-triazine derivatives in which at least one mono-, di- or trihalogen-substituted methyl group is bonded to the s-triazine ring. Specific examples include S-triazine and oxathiazole compounds, such as 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl). -4,6-bis (trichloromethyl) -s-triazine, 2- (p-styrylphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3-Br-4-di (ethyl) Acetate) amino) phenyl) -4,6-bis (trichloromethyl) -s-triazine, 2-trihalomethyl-5- (p-methoxyphenyl) -1,3,4-oxadiazole. Specifically, p.14 to p30 in JP-A-58-15503, p6-p10 in JP-A-55-77742, and p287 in JP-B-60-27673. 1-No. 8, No. pp. 443 to p444 of JP-A-60-239736. 1-No. 17, No. 4,701,399. Compounds such as 1-19 are particularly preferred.

  Specific examples of the active halogens are as follows.

Examples of inorganic complexes include bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis [2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl] titanium. . Examples of coumarins include 3-ketocoumarin.
These initiators may be used alone or in combination.

In the present invention, an oligomer type polymerization initiator is preferred as the compound having a high molecular weight and hardly volatilizing from the coating film. The oligomer type radiation polymerization initiator is not particularly limited as long as it has a site that generates a photo radical upon irradiation. In order to prevent volatilization by heat treatment, the molecular weight of the polymerization initiator is preferably 280 or more and 10,000 or less, more preferably 300 or more and 10,000 or less. More preferably, the mass average molecular weight is 400 to 10,000. A mass average molecular weight of 400 or more is preferable because of low volatility, and 10,000 or less is preferable because hardness of the resulting cured coating film is sufficient. Specific examples of the oligomer type radiation polymerization initiator include oligo [2-hydroxy-2-methyl-1- {4- (1-methylvinyl) phenyl} propanone] represented by the following general formula (5). .
General formula (5):

In the general formula (5), R ⁵¹ represents a monovalent group, preferably a monovalent organic group, and q represents an integer of 2 to 45.

  As a commercially available product of the oligo [2-hydroxy-2-methyl-1- {4- (1-methylvinyl) phenyl} propanone] represented by the general formula (5), trade name “Ezacure KIP150” manufactured by Fratelli Lamberti (CAS-No. 163702-01-0, q = 4-6), “Ezacure KIP65LT” (a mixture of “Ezacure KIP150” and tripropylene glycol diacrylate), “Ezacure KIP100F” (“Ezacure KIP150” and 2- Hydroxy-2-methyl-1-phenylpropan-1-one), “Ezacure KT37”, “Ezacure KT55” (above, “Ezacure KIP150” and a mixture of methylbenzophenone derivatives), “Ezacure KTO46” (“Ezacure KIP150”) ”Methylbenzofu Non-derivative and a mixture of 2,4,6-trimethylbenzoyldiphenylphosphine oxide), “Ezacure KIP75 / B” (a mixture of “Ezacure KIP150” and 2,2-dimethoxy-1,2-diphenylethane-1-one), etc. Can be mentioned.

“Latest UV Curing Technology” {Technical Information Association, Inc.} (1991), p. 159 and “UV Curing System” written by Kiyomi Kato (published by General Technology Center in 1989), p.65-14
Various examples are described in FIG. 8 and are useful in the present invention.

  Commercially available photocleavable photoradical polymerization initiators include “Irgacure 651”, “Irgacure 184”, “Irgacure 819”, “Irgacure 907”, “Irgacure 1870” (CGI) manufactured by Ciba Specialty Chemicals Co., Ltd. -403 / Irg184 = 7/3 mixing initiator), "Irgacure 500", "Irgacure 369", "Irgacure 1173", "Irgacure 2959", "Irgacure 4265", "Irgacure 4263", "Irgacure 127", "OXE01 “Kaya Cure DETX-S”, “Kaya Cure BP-100”, “Kaya Cure BDK”, “Kaya Cure CTX”, “Kaya Cure BMS”, “Kaya Cure 2-EAQ”, “Kaya Cure ABQ” manufactured by Nippon Kayaku Co., Ltd. ”,“ Kayaki Ar CPTX, Kaya Cure EPD, Kaya Cure ITX, Kaya Cure QTX, Kaya Cure BTC, Kaya Cure MCA, etc .; “Esacure (KIP100F, KB1, EB3, BP, X33, KTO46, KT37) manufactured by Sartomer , KIP150, TZT) ", etc., and combinations thereof are preferred examples.

  It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of binders, More preferably, it is the range of 1-10 mass parts.

  In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone. Further, one or more auxiliary agents such as an azide compound, a thiourea compound, and a mercapto compound may be used in combination.

  Examples of commercially available photosensitizers include “Kaya Cure (DMBI, EPA)” manufactured by Nippon Kayaku Co., Ltd.

(Thermal radical initiator)
As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.

Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Diazo compounds such as 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile) as azo compounds such as ammonium sulfate and potassium persulfate And diazoaminobenzene, p-nitrobenzenediazonium and the like.
The thermal radical initiator is preferably used in the range of 0.1 to 15 parts by mass, more preferably in the range of 1 to 10 parts by mass with respect to 100 parts by mass of the binder.

(Cationic polymerization initiator)
Examples of cationic polymerization initiators include proton acids such as toluenesulfonic acid and methanesulfonic acid, quaternary ammonium salts such as triethylbenzylammonium chloride and tetramethylammonium chloride, benzyldimethylamine, tributylamine, and tris (dimethylamino) methylphenol. A compound capable of generating a protonic acid by being decomposed by heating, such as a tertiary amine, an imidazole compound such as 2-methyl-4-ethylimidazole, 2-methylimidazole, toluenesulfonic acid cyclohexyl ester, toluenesulfonic acid isopropyl ester, Or the various compounds which generate | occur | produce an acid catalyst by the effect | action of the light described below can be mentioned.
In the present invention, a compound that generates an acid by the action of light is particularly preferred from the viewpoint of the pot life of the film-forming composition.

Various examples of compounds that generate an acid by the action of light are described in, for example, “Organic Materials for Imaging” p187-198, JP-A-10-282644, edited by the Society for Organic Electronics Materials (Bunshin Publishing). These known compounds can be used. Specifically, RSO ₃ ⁻ (R represents an alkyl group or aryl group), AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ , BF ₄ ^{− and the} like, a diazonium salt, an ammonium salt, a phosphonium salt having a counter ion, Various onium salts such as iodonium salts, sulfonium salts, selenonium salts, arsonium salts, organic halides such as oxadiazole derivatives and S-triazine derivatives substituted with a trihalomethyl group, o-nitrobenzyl esters of organic acids, benzoin esters, Examples thereof include iminoesters and disulfone compounds, preferably onium salts, particularly preferably sulfonium salts and iodonium salts.
A sensitizing dye can also be preferably used in combination with a compound that generates an acid by the action of light.

  The addition amount of the compound that initiates cationic polymerization by the action of heat or light is generally 0.1 to 15% by mass with respect to the total solid content in the low refractive index layer forming composition, like the radical initiator. More preferably, it is 0.5-10 mass%, Most preferably, it is 2-5 mass%.

(Curing conditions for low refractive index layer)
In the present invention, curing conditions suitable for the curable functional group of each component used in the low refractive index layer can be selected.
Preferred examples are described below.

(A) a hydroxyl group-containing fluorine-containing compound, a combined use system with a compound that reacts with a hydroxyl group,
The curing temperature is preferably 60 to 200 ° C, more preferably 80 to 130 ° C, and most preferably 80 to 110 ° C. A low temperature is preferred when the support is prone to degradation at high temperatures. The time required for thermosetting is preferably 30 seconds to 60 minutes, more preferably 1 minute to 20 minutes.
In particular, in the case where the lower surface is an ionizing radiation curable (meth) acrylate group-containing optical film constituting layer, the interface bond can be strengthened by adding a (meth) acrylate group-containing compound to the low refractive index layer. . Preferred curing conditions will be described later together with the case of the system (B).

(B) (meth) acrylate group-containing fluorine-containing compound-based system When the fluorine-containing compound contains a (meth) acrylate group, a compound containing a (meth) acrylate group may be used in combination with the low refractive index layer. It is preferable in terms of improving the strength of the coating film. It is effective to cure by combining irradiation with ionizing radiation and heat treatment before irradiation, simultaneously with irradiation or after irradiation.
Although the pattern of some manufacturing processes is shown below, it is not limited to these.
Before irradiation → At the same time as irradiation → After irradiation (-indicates that heat treatment is not performed)
(1) Heat treatment → ionizing radiation curing → −
(2) Heat treatment → ionizing radiation curing → heat treatment (3) − → ionizing radiation curing → heat treatment In addition, a step of performing heat treatment simultaneously with ionizing radiation curing is also preferable.

(Heat treatment)
In the present invention, as described above, heat treatment is preferably performed in combination with irradiation with ionizing radiation. The heat treatment is not particularly limited as long as it does not damage the constituent layers including the support of the optical film and the low refractive index layer, but is preferably 60 to 200 ° C, more preferably 80 to 130 ° C, and most preferably 80 to 110. ° C.

  By raising the temperature, the orientation and distribution of each component in the coating film can be adjusted, and the photocuring reaction can be controlled. Prior to curing with ionizing radiation or heat, each component is not immobilized and the orientation of each component occurs relatively quickly.However, after the initiation of curing, each component is fixed and orientation occurs only partially. Absent. The time required for the heat treatment varies depending on the molecular weight of the component used, interaction with other components, viscosity, etc., but is 30 seconds to 24 hours, preferably 60 seconds to 5 hours, and most preferably 3 minutes to 30 minutes.

  Although there is no limitation in particular in the method of setting the film surface temperature of a film to desired temperature, The method of heating a roll and contacting a film, the method of spraying heated nitrogen, irradiation of far infrared rays or infrared rays, etc. are preferable. A method described in Japanese Patent No. 2523574 may also be used, in which hot water or steam is passed through a rotating metal roll and heated. On the other hand, at the time of irradiation of ionizing radiation described below, when the film surface temperature of the film rises, a method of cooling the roll and bringing it into contact with the film can be used.

(Ionizing radiation irradiation conditions)
The film surface temperature during irradiation with ionizing radiation is not particularly limited, but is generally 20 to 200 ° C., preferably 30 to 150 ° C., and most preferably 40 to 120 ° C. in view of handling properties and in-plane performance uniformity. It is. If the film surface temperature is not more than the above upper limit value, the fluidity of the low molecular component in the binder is excessively increased and the surface state is not deteriorated, and the problem that the support is damaged by heat does not occur. Moreover, if it is more than this lower limit, the curing reaction proceeds sufficiently and the film has good scratch resistance, which is preferable.

There is no restriction | limiting in particular about the kind of ionizing radiation, Although an x-ray, an electron beam, an ultraviolet-ray, visible light, infrared rays etc. are mentioned, an ultraviolet-ray is used widely. For example, if the coating film is UV curable, it is to cure each layer by irradiating an irradiation amount of ultraviolet rays of 10mJ / cm ² ~1000mJ / cm ² by an ultraviolet lamp preferred. When irradiating, the energy may be applied at once, or divided and irradiated. In particular, from the viewpoint of reducing the performance variation in the surface of the coating film, it is also preferable to irradiate by dividing into about 2 to 8 times.

  The time during which the film is kept at the above temperature after irradiation with ionizing radiation is preferably from 0.1 seconds to 300 seconds, more preferably from 0.1 seconds to 10 seconds from the end of irradiation with ionizing radiation. If the film surface temperature of the film is kept in the above temperature range is too short, the reaction of the coating composition for forming a low refractive index layer that forms a film cannot be promoted. The above problem will occur.

(Oxygen concentration)
The oxygen concentration at the time of ionizing radiation irradiation is preferably 3% by volume or less, more preferably 1% by volume or less, and still more preferably 0.1% or less. In contrast to the step of irradiating with ionizing radiation at an oxygen concentration of 3% by volume or less, by providing a step of maintaining in an atmosphere at an oxygen concentration of 3% by volume immediately before or immediately after that, the curing of the film is sufficiently promoted, A film excellent in strength and chemical resistance can be formed.
The heat treatment step can be performed in an air atmosphere, but it is also preferable that the heat treatment step is performed by lowering the oxygen concentration as in the case of ionizing radiation irradiation. In particular, when the thermal stability of a polymerization initiator, a polymerizable compound, or the like is insufficient, the strength of the film after the completion of the entire curing process can be kept strong by performing a heat treatment while reducing the oxygen concentration.

  As a means for reducing the oxygen concentration, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another inert gas, and particularly preferably with nitrogen (nitrogen purge). It is. By carrying it in an atmosphere having a low oxygen concentration before the step of irradiating with ionizing radiation, the oxygen concentration inside the coating film surface and inside can be effectively reduced, and curing can be promoted. The oxygen concentration in the transport step before ionizing radiation irradiation is preferably 3% by volume or less, more preferably 1% volume or less, and still more preferably 0.1% or less.

(Fluorine-containing polymer binder)
Moreover, a fluorine-containing copolymer compound can also be used as a polymer binder for the low refractive index layer.
Examples of the fluorine-containing vinyl monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid moieties or fully fluorinated alkyl ester derivatives (for example, biscoat 6FM (trade name) , Osaka Organic Chemical Co., Ltd.) and R-2020 (trade name, manufactured by Daikin Co., Ltd.), fully or partially fluorinated vinyl ethers, and the like. Preferred are perfluoroolefins, refractive index, solubility, and transparency. From the viewpoint of availability, hexafluoropropylene is particularly preferable. Increasing the composition ratio of these fluorinated vinyl monomers can lower the refractive index but lowers the film strength. In the present invention, the fluorine-containing vinyl monomer is preferably introduced so that the fluorine content of the copolymer is 20 to 60% by mass, more preferably 25 to 55% by mass, and particularly preferably 30 to 50%. This is a case of mass%.

  For the purpose of imparting crosslinking reactivity to the above-mentioned fluorine-containing vinyl monomer, a copolymer of the following units (i), (ii) and (iii) can be preferably used.

(I): a structural unit obtained by polymerization of a monomer having a self-crosslinkable functional group in the molecule in advance such as glycidyl (meth) acrylate or glycidyl vinyl ether,
(Ii): Monomers having a carboxyl group, hydroxy group, amino group, sulfo group, etc. (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether) , Maleic acid, crotonic acid, etc.)
(Iii): reacting a compound having a crosslinkable functional group separately from the group that reacts with the functional group of (i) or (ii) in the molecule with the constituent unit of (i) or (ii) Examples of the structural unit to be obtained (for example, a structural unit that can be synthesized by a technique such as allowing acrylic acid chloride to act on a hydroxyl group).

  In the structural unit (iii), the crosslinkable functional group is preferably a photopolymerizable group. Examples of the photopolymerizable group include (meth) acryloyl group, alkenyl group, cinnamoyl group, cinnamylideneacetyl group, benzalacetophenone group, styrylpyridine group, α-phenylmaleimide group, phenylazide group, sulfonylazide. Group, carbonyl azide group, diazo group, o-quinonediazide group, furylacryloyl group, coumarin group, pyrone group, anthracene group, benzophenone group, stilbene group, dithiocarbamate group, xanthate group, 1,2,3-thiadiazole group, cyclo A propene group, an azadioxabicyclo group, etc. can be mentioned, These may be not only 1 type but 2 or more types. Of these, a (meth) acryloyl group and a cinnamoyl group are preferable, and a (meth) acryloyl group is particularly preferable.

Specific methods for preparing the photopolymerizable group-containing copolymer include, but are not limited to, the following methods.
a. A method of esterifying by reacting a (meth) acrylic acid chloride with a crosslinkable functional group-containing copolymer containing a hydroxyl group,
b. A method of urethanization by reacting a (meth) acrylic acid ester containing an isocyanate group with a crosslinkable functional group-containing copolymer containing a hydroxyl group,
c. A method of reacting (meth) acrylic acid with a crosslinkable functional group-containing copolymer containing an epoxy group,
d. A method in which a crosslinkable functional group-containing copolymer containing a carboxyl group is reacted with a containing (meth) acrylic acid ester containing an epoxy group for esterification.

  The amount of the photopolymerizable group introduced can be arbitrarily adjusted, and a certain amount of carboxyl groups, hydroxyl groups, etc., from the viewpoints of surface stability of the coating film, reduction of surface failure when coexisting with inorganic particles, and improvement of film strength. It is also preferable to leave.

  In the copolymer useful for the present invention, in addition to the repeating unit derived from the above-mentioned fluorine-containing vinyl monomer and the repeating unit having a (meth) acryloyl group in the side chain, it contributes to adhesion to the substrate and Tg of the polymer (film hardness). And other vinyl monomers can be copolymerized as appropriate from various viewpoints such as solubility in a solvent, transparency, slipperiness, dust resistance and antifouling properties. A plurality of these vinyl monomers may be combined depending on the purpose, and are preferably introduced in the range of 0 to 65 mol% in the copolymer in total, and in the range of 0 to 40 mol%. More preferably, it is particularly preferably in the range of 0 to 30 mol%.

  The vinyl monomer unit that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid) 2-ethylhexyl, 2-hydroxyethyl acrylate), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, etc.), styrene derivatives (styrene, p-hydroxymethylstyrene, p -Methoxystyrene, etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, etc.), vinyl esters (vinyl acetate) Vinyl propionate, vinyl cinnamate, etc.), unsaturated carboxylic acids (acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, etc.), acrylamides (N, N-dimethylacrylamide, N-tert-butylacrylamide, N -Cyclohexyl acrylamide, etc.), methacrylamides (N, N-dimethylmethacrylamide), acrylonitrile and the like.

  The fluorine-containing polymer particularly useful in the present invention is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing a crosslinking reaction alone (a radical reactive group such as a (meth) acryloyl group, a ring-opening polymerizable group such as an epoxy group or an oxetanyl group). These crosslinkable group-containing polymerized units preferably occupy 5 to 70 mol% of the total polymerized units of the polymer, particularly preferably 30 to 60 mol%. Regarding preferred polymers, JP-A-2002-243907, JP-A-2002-372601, JP-A-2003-26732, JP-A-2003-222702, JP-A-2003-294911, JP-A-2003-329804, JP-A-2004. -4444 and JP, 2004-45462, A can be mentioned.

  For the purpose of imparting antifouling properties, it is preferable that a polysiloxane structure is introduced into the fluoropolymer of the present invention. There is no limitation on the method of introducing the polysiloxane structure, but for example, as described in JP-A-6-93100, JP-A-11-189621, JP-A-11-228631 and JP-A-2000-313709, the initiation of silicone macroazo A method of introducing a polysiloxane block copolymer component using an agent, and a method of introducing a polysiloxane graft copolymer component using a silicone macromer as described in JP-A-2-251555 and JP-A-2-308806. preferable. Particularly preferred compounds include the polymers of Examples 1, 2, and 3 of JP-A-11-189621, and the copolymers A-2 and A-3 of JP-A-2-251555. These polysiloxane components are preferably 0.5 to 10% by mass in the polymer, and particularly preferably 1 to 5% by mass.

  The preferred molecular weight of the polymer that can be preferably used in the present invention is a mass average molecular weight of 5,000 or more, preferably 10,000 to 500,000, most preferably 15,000 to 200,000. By using polymers having different average molecular weights in combination, it is possible to improve the surface state of the coating film and the scratch resistance.

  As described in JP-A-10-25388 and JP-A-2000-17028, a curing agent having a polymerizable unsaturated group may be used in combination with the above polymer. Moreover, combined use with the compound which has a fluorine-containing polyfunctional polymerizable unsaturated group as described in Unexamined-Japanese-Patent No. 2002-145952 is also preferable. Examples of the compound having a polyfunctional polymerizable unsaturated group include the (B) fluorine-containing polyfunctional monomer and (C) at least one non-fluorine-containing polyfunctional monomer. These compounds are particularly preferred because they have a large combined effect for improving scratch resistance, particularly when a compound having a polymerizable unsaturated group is used in the polymer body.

  In the present invention, the component (A), the component (B), and the component (C) are not particularly limited, but the component (A) is 35 to 70% by weight, the component (B) is 5 to 50% by weight, (C ) It is preferable to have a low refractive index layer formed by coating a coating composition containing 5 to 40% by weight of the component.

  The component (A) is more preferably contained in an amount of 40 to 65% by weight, and further preferably 40 to 55% by weight.

  The component (B) is more preferably contained in an amount of 10 to 40% by weight.

  It is preferable to contain 5-30 mass% of said (C) component, and it is more preferable to contain 5-20 mass%. If the content of component (C) is too large, the refractive index of the low refractive index layer is undesirably high, and if it is too small, the scratch resistance tends to deteriorate.

  In the present invention, (A) silica fine particles, (B) a fluorine-containing polyfunctional monomer having at least two polymerizable groups, (C) a non-fluorine-containing polyfunctional monomer (hereinafter referred to as (A) component, (B) ) Component and (C) component)) are not particularly limited, but (A) component is 35 to 70% by weight, (B) component is 5 to 50% by weight, and (C) component is 5 to 5% by weight. It is preferable to have a low refractive index layer formed by coating a coating composition containing 40% by weight.

  The component (A) is more preferably contained in an amount of 40 to 65% by weight, and further preferably 40 to 60% by weight.

  The component (B) is more preferably contained in an amount of 10 to 40% by weight.

  The component (C) is preferably contained in an amount of 5 to 30% by weight, more preferably 5 to 20% by weight from the viewpoint of the refractive index of the low refractive index layer and the scratch resistance.

(Layer structure of optical film)
In general, the optical film of the present invention has a simplest configuration in which only an antiglare layer and a low refractive index layer are coated on a transparent support. Further, it is also preferable to combine the antistatic layers in order to impart dust resistance.

  The example of the preferable layer structure of the optical film of this invention is shown below. In the following configuration, what is described as (antistatic layer) is a configuration in which a layer having other functions also has the function of an antistatic layer. Since the number of layers to be formed can be reduced by providing the antistatic layer with a function other than antistatic, this structure is preferable because productivity is improved.

Support / antiglare layer (hard coat layer) / low refractive index layerSupport / antiglare layer (antistatic layer) / low refractive index layer / support / hard coat layer / antiglare layer (antistatic layer) / Low refractive index layer / support / hard coat layer / antistatic layer / antiglare layer / low refractive index layer / support / hard coat layer (antistatic layer) / antiglare layer / low refractive index layer

  As long as the reflectance can be reduced by optical interference, it is not limited to these layer configurations.

(Transparent support)
There is no limitation in particular as a transparent support body of the optical film of this invention, such as a transparent resin film, a transparent resin board, a transparent resin sheet, and transparent glass. Transparent resin films include cellulose acylate films (for example, cellulose triacetate film (refractive index 1.48), cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film), polyethylene terephthalate film, polyethersulfone. Films, polyacrylic resin films, polyurethane resin films, polyester films, polycarbonate films, polysulfone films, polyether films, polymethylpentene films, polyetherketone films, (meth) acrylonitrile films, and the like can be used.

<Cellulose acylate film>
Among them, a cellulose acylate film having high transparency, optically low birefringence, easy production, and generally used as a protective film for a polarizing plate is preferable, and a cellulose triacetate film is particularly preferable. The thickness of the transparent support is usually about 25 μm to 1000 μm.

In the present invention, it is preferable to use cellulose acetate having an acetylation degree of 59.0 to 61.5% for the cellulose acylate film.
The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation follows the measurement and calculation of the degree of acetylation in ASTM: D-817-91 (test method for cellulose acetate and the like).
The viscosity average degree of polymerization (DP) of cellulose acylate is preferably 250 or more, and more preferably 290 or more.
The cellulose acylate used in the present invention has a Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) value by gel permeation chromatography close to 1.0, in other words, a molecular weight distribution. Narrow is preferred. The specific value of Mw / Mn is preferably 1.0 to 1.7, more preferably 1.3 to 1.65, and most preferably 1.4 to 1.6. preferable.

In general, the hydroxyl groups at 2, 3, and 6 positions of cellulose acylate are not evenly distributed by 1/3 of the total substitution degree, and the substitution degree of the 6-position hydroxyl group tends to be small. In the present invention, it is preferable that the substitution degree of the 6-position hydroxyl group of cellulose acylate is larger than that of the 2- and 3-positions.
The hydroxyl group at the 6-position with respect to the total substitution degree is preferably substituted with 32% or more of an acyl group, more preferably 33% or more, and particularly preferably 34% or more. Furthermore, the substitution degree of the 6-position acyl group of cellulose acylate is preferably 0.88 or more. The 6-position hydroxyl group may be substituted with a propionyl group, butyroyl group, valeroyl group, benzoyl group, acryloyl group or the like, which is an acyl group having 3 or more carbon atoms, in addition to the acetyl group. The degree of substitution at each position can be determined by NMR.
In the present invention, as cellulose acylate, paragraphs “0043” to “0044” [Example] [Synthesis Example 1], paragraphs “0048” to “0049” [Synthesis Example 2], and paragraph “ Cellulose acetate obtained by the method described in “0051” to “0052” [Synthesis Example 3] can be used.

<Polyethylene terephthalate film>
In the present invention, a polyethylene terephthalate film is also preferably used because it is excellent in transparency, mechanical strength, flatness, chemical resistance and moisture resistance, and is inexpensive.
In order to further improve the adhesion strength between the transparent plastic film and the hard coat layer provided thereon, the transparent plastic film is more preferably subjected to an easy adhesion treatment.
Examples of commercially available PET films with an easily adhesive layer for optics include Cosmo Shine A4100 and A4300 manufactured by Toyobo Co., Ltd.

(Anti-glare layer)
An anti-glare layer is a layer provided in order to provide the optical film with the anti-glare property by surface scattering.
In the present invention, the antiglare layer preferably has hard coat properties and antistatic properties for improving the scratch resistance of the film.

  Examples of a method for imparting antiglare properties include a method of forming surface irregularities by utilizing phase separation in the process of evaporation of a solvent from a mixed solution of a plurality of resins as described in JP-A-2005-195919. These known methods can be used.

  The film thickness of the antiglare layer is preferably 1 to 20 μm, and more preferably 2 to 10 μm. By setting it within the above range, hard coat properties, curling, and brittleness can be satisfied.

  On the other hand, the center line average roughness (Ra) of the antiglare layer is preferably in the range of 0.09 to 0.40 μm from the viewpoint of glare or whitening of the surface when external light is reflected. Further, it is preferable that the value of the transmitted image definition is 5 to 60%.

  The strength of the antiglare layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test.

[Phase separation]
The antiglare layer can be formed using a technique for forming irregularities on the surface of the coating film by spinodal decomposition of a plurality of resins. Moreover, it becomes possible to provide favorable anti-glare property by giving a difference in the refractive index of the phase which isolate | separated especially the phase. The antiglare layer prepared by spinodal decomposition is composed of a plurality of resins having different refractive indexes, and is usually a phase having at least a co-continuous phase structure in an operating atmosphere (especially at room temperature of about 10 to 30 ° C.). A separation structure is formed. The co-continuous phase structure is formed by spinodal decomposition from a liquid phase containing a plurality of resins (a liquid phase at room temperature, for example, a mixed solution or a solution). The co-continuous phase structure is usually formed by spinodal decomposition using a composition containing a plurality of resins and forming a liquid phase at room temperature (for example, a mixed solution or a solution) and evaporating the solvent. Since such a light scattering layer is formed from a liquid phase, it has a uniform and fine co-continuous phase structure. When an optical film having such an antiglare property is used, incident light is scattered substantially isotropically, and directivity can be imparted to transmitted scattered light. Therefore, both high light scattering and directivity can be achieved.

  In order to enhance light scattering properties, a plurality of resins can be used in combination so that the difference in refractive index is, for example, about 0.01 to 0.2, and preferably about 0.1 to 0.15. If the difference in refractive index is less than 0.01, the intensity of the transmitted scattered light decreases. If the difference in refractive index is greater than 0.2, high directivity cannot be imparted to the transmitted scattered light.

Further, for the purpose of imparting light scattering properties, translucent particles can be used in combination in a plurality of resins. The translucent particles can be used in combination so that the difference in refractive index between the resin used and the translucent particles is, for example, about 0.01 to 0.2, preferably about 0.1 to 0.15. . If the difference in refractive index is less than 0.01, the intensity of the transmitted scattered light decreases. If the difference in refractive index is greater than 0.2, high directivity cannot be imparted to the transmitted scattered light.
Examples of the translucent particles include the following particles.
Preferred examples include inorganic compound particles such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. Of these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred. The shape of the light-transmitting particles can be either spherical or irregular.

  Moreover, you may use together and use 2 or more types of translucent particle | grains from which a particle diameter differs. For example, when an optical film is pasted on a high-definition display of 133 ppi or higher, a problem in display image quality called “glare” may occur. “Glitter” is derived from the fact that the pixels are enlarged or reduced due to the unevenness on the surface of the optical film, resulting in loss of luminance uniformity, but it is greatly improved by using translucent particles different from the refractive index of the binder. can do.

The translucent particles are contained in the antiglare layer so that the amount of matte particles in the formed antiglare hard coat layer is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ^2. The

  The plurality of resins include, for example, styrene resins, (meth) acrylic resins, vinyl ester resins, vinyl ether resins, halogen-containing resins, olefin resins (including alicyclic olefin resins), polycarbonate resins, and polyesters. Resin, polyamide resin, thermoplastic polyurethane resin, polysulfone resin (polyethersulfone, polysulfone, etc.), polyphenylene ether resin (2,6-xylenol polymer, etc.), cellulose derivatives (cellulose esters, cellulose carbamates) , Cellulose ethers, etc.), silicone resins (polydimethylsiloxane, polymethylphenylsiloxane, etc.), rubbers or elastomers (diene rubbers such as polybutadiene, polyisoprene, styrene-butadiene copolymers, Ronitoriru - butadiene copolymer, acrylic rubber, urethane rubber, silicone rubber, etc.) can be chosen a suitable combination and the like.

  Preferred resins include, for example, styrene resins, (meth) acrylic resins, vinyl ester resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, polycarbonate resins, polyester resins, polyamide resins, Cellulose derivatives, silicone resins, rubbers or elastomers are included. As the plurality of resins, a resin that is amorphous and is soluble in an organic solvent (particularly a common solvent capable of dissolving the plurality of resins) is usually used. In particular, resins with high moldability or film formability, transparency and weather resistance, such as styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) Etc. are preferable.

  These plural resins can be used in appropriate combination. For example, in a combination of resins, at least one resin may be selected from cellulose derivatives, particularly cellulose esters (eg, cellulose C2-4 alkyl carboxyls such as cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate). Acid esters) and may be combined with other resins.

  The glass transition temperature of the resin can be selected from the range of, for example, −100 ° C. to 250 ° C., preferably −50 to 230 ° C., more preferably about 0 to 200 ° C. (for example, about 50 to 180 ° C.). From the viewpoint of sheet strength and rigidity, the glass transition temperature of at least one of the constituent resins is 50 ° C. or higher (for example, about 70 to 200 ° C.), preferably 100 ° C. or higher (for example, 100 to 170 ° C.). It is advantageous that The weight average molecular weight of the resin can be selected from the range of, for example, about 1,000,000 or less (about 10,000 to 1,000,000), preferably about 10,000 to 700,000.

  Since the present invention employs a wet method in which a solvent is evaporated from a liquid phase containing a plurality of resins and spinodal decomposition is performed, in principle, a substantially isotropic common property is used regardless of the compatibility of the plurality of resins. A light scattering layer having a continuous phase structure can be formed. For this reason, it may be configured by combining a plurality of mutually compatible resins. However, in order to easily control the phase separation structure by spinodal decomposition and to form a co-continuous phase structure efficiently, incompatible (phase separation) In many cases, a plurality of resins are combined.

  The plurality of resins can be configured by a combination of the first resin and the second resin, and each of the first resin and the second resin may be composed of a single resin or a plurality of resins. Also good. A combination of the first resin and the second resin is not particularly limited. For example, when the first resin is a cellulose derivative (for example, cellulose esters such as cellulose acetate propionate), the second resin is a styrene resin (polystyrene, styrene-acrylonitrile copolymer, etc.), (meta ) Acrylic resins (such as polymethyl methacrylate), alicyclic olefin resins (such as polymers containing norbornene as monomers), polycarbonate resins, polyester resins (such as poly C2-4 alkylene arylate copolyester) Or the like.

  The ratio of the first resin to the second resin is, for example, the former / the latter = about 10/90 to 90/10 (weight ratio), preferably about 20/80 to 80/20 (weight ratio), and more preferably. Is about 30/70 to 70/30 (weight ratio), particularly about 40/60 to 60/40 (weight ratio). If the proportion of one resin is too large, the volume ratio between the separated phases is biased, so that the intensity of scattered light decreases. In addition, when forming a sheet | seat with three or more some resin, content of each resin is 1 to 90 weight% normally (for example, 1 to 70 weight%, Preferably it is 5-70 weight%, More preferably, it is 10 (About 70% by weight).

  The antiglare layer constituting the optical film of the present invention preferably has at least a co-continuous phase structure. The co-continuous phase structure is sometimes referred to as a co-continuous structure or a three-dimensional continuous or connected structure, and means a structure in which at least two constituent resin phases are continuous (for example, a network structure). . The light scattering layer only needs to have at least a co-continuous phase structure, and may have a structure in which a co-continuous phase structure and a droplet phase structure (independent or isolated phase structure) are mixed. In spinodal decomposition, a co-continuous phase structure is formed as the phase separation progresses, and when the phase separation is further advanced, the continuous phase becomes discontinuous due to its surface tension, and the droplet phase structure (spherical, true spherical) Sea island structure of independent phase). Therefore, depending on the degree of phase separation, an intermediate structure between the co-continuous phase structure and the droplet phase structure, that is, a phase structure in the process of shifting from the co-continuous phase to the droplet phase can be formed. In the present invention, the intermediate structure is also referred to as a co-continuous phase structure. When the phase separation structure is a mixed structure of a co-continuous phase structure and a droplet structure, the ratio of the droplet phase (independent resin phase) is, for example, 30% or less (volume ratio), preferably 10% or less ( Volume ratio). The shape of the co-continuous phase structure is not particularly limited, and may be a network shape, particularly a random network shape.

  The bicontinuous phase structure is generally isotropic with reduced anisotropy in the layer or sheet plane. Note that isotropic means that the average interphase distance of the co-continuous phase structure is substantially equal in any direction in the sheet plane.

  The bicontinuous phase structure usually has regularity in the interphase distance (distance between the same phases). For this reason, the light scattered on the sheet is directed to a specific direction by Bragg reflection. Therefore, even when mounted on a reflective liquid crystal display device, the transmitted scattered light can be directed in a certain direction, the display screen can be made highly bright, and a conventional particle-dispersed transmissive light scattering sheet Thus, a problem that cannot be solved, that is, reflection of a light source (for example, a fluorescent lamp) on the panel can be avoided.

  In the optical film, the average interphase distance between the co-continuous phases is, for example, about 0.5 to 20 μm (for example, 1 to 20 μm), preferably about 1 to 15 μm (for example, 1 to 10 μm). If the average interphase distance is too small, it is difficult to obtain high scattered light intensity, and if the average interphase distance is too large, the directivity of transmitted scattered light decreases.

  The average interphase distance of the co-continuous layer can be calculated from a photomicrograph (such as a transmission microscope, a phase contrast microscope, or a confocal laser microscope) of the light scattering layer or light scattering sheet. In addition, the scattering angle θ at which the scattered light intensity is maximized is measured by a method similar to the scattered light directivity evaluation method described later, and the average interphase distance d of the co-continuous phase is calculated from the following Bragg reflection condition equation. May be.

2d · sin (θ / 2) = λ
(Where d is the average interphase distance of co-continuous phases, θ is the scattering angle, and λ is the wavelength of light)

  In the present invention, an antiglare layer formed by coating a coating composition having the following composition is particularly preferably used in relation to the above-described low refractive index layer.

[Hard coat layer]
The optical film of the present invention can be provided with a hard coat layer in addition to the antiglare layer in order to impart the physical strength of the film.
The hard coat layer may be composed of two or more layers.

  The refractive index of the hard coat layer in the present invention is preferably in the range of 1.48 to 2.00, more preferably 1.52 to 1, from the optical design for obtaining an antireflection film. .90, more preferably 1.55 to 1.80. In the present invention, since there is at least one low refractive index layer on the hard coat layer, if the refractive index is too small, the antireflection property is lowered, and if it is too large, the color of the reflected light tends to be strong. is there.

From the viewpoint of imparting sufficient durability and impact resistance to the film, the thickness of the hard coat layer is usually about 0.5 μm to 50 μm, preferably 1 μm to 20 μm, more preferably 2 μm. 10 μm, most preferably 3 μm to 7 μm.
Further, the strength of the hard coat layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test.
Furthermore, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. For example, it may be formed by applying a coating composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer on a transparent support and subjecting the polyfunctional monomer or polyfunctional oligomer to a crosslinking reaction or a polymerization reaction. it can.
The functional group of the ionizing radiation curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable.

  The hard coat layer contains matte particles having an average particle diameter of 1.0 to 10.0 μm, preferably 1.5 to 7.0 μm, such as inorganic compound particles or resin particles, for the purpose of imparting internal scattering properties. May be.

  For the purpose of controlling the refractive index of the hard coat layer, a high refractive index monomer, inorganic particles, or both can be added to the binder of the hard coat layer. In addition to the effect of controlling the refractive index, the inorganic particles also have the effect of suppressing cure shrinkage due to the crosslinking reaction. In the present invention, a polymer formed by polymerizing the polyfunctional monomer and / or the high refractive index monomer after the hard coat layer is formed, and the inorganic particles dispersed therein are referred to as a binder.

  In order to maintain the sharpness of the image, it is preferable to adjust the clarity of the transmitted image in addition to adjusting the uneven shape of the surface. The clearness of the transmitted image of the clear antireflection film is preferably 60% or more. The transmitted image clarity is generally an index indicating the degree of blurring of an image reflected through a film, and the larger this value, the clearer and better the image viewed through the film. The transmitted image definition is preferably 70% or more, and more preferably 80% or more.

The refractive index of the low refractive index layer is preferably 1.20 to 1.46, more preferably 1.25 to 1.40, and particularly preferably 1.30 to 1.37.
The thickness of the low refractive index layer is preferably 30 to 500 nm, and more preferably 70 to 500 nm. In order to impart conductivity, it is preferable that the low refractive index layer has a thickness of 130 to 500 nm. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less. The specific strength of the low refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test under a 500 g load. Further, in order to improve the antifouling performance of the optical film, it is preferable that the contact angle of water on the surface is 90 degrees or more. More preferably, it is 95 degrees or more, and particularly preferably 100 degrees or more.

[Antistatic layer, conductive layer]
In the present invention, it is preferable to provide an antistatic layer from the viewpoint of preventing static electricity on the film surface. The antistatic layer can be formed by, for example, applying a conductive coating solution containing conductive fine particles and a reactive curable resin, or depositing or sputtering a metal or metal oxide that forms a transparent film. Conventionally known methods such as a method of forming a conductive thin film and a conductive polymer such as polythiophene or polyaniline can be mentioned. The conductive layer can be formed directly on the support or via a primer layer that strengthens adhesion to the support. Further, the antistatic layer can be used as a part of the antireflection film.

The thickness of the antistatic layer is preferably from 0.01 to 10 μm, more preferably from 0.03 to 7 μm, and even more preferably from 0.05 to 5 μm. The surface resistance of the antistatic layer is ^preferably from ¹⁰ 5 ~10 ¹² Ω / ^sq, more preferably from 10 5 ~10 ⁹ Ω / ^sq, most be 10 5 ~10 ⁸ Ω / sq preferable. The surface resistance of the antistatic layer can be measured by a four probe method.

The antistatic layer is preferably substantially transparent. Specifically, the haze of the antistatic layer is preferably 10% or less, more preferably 5% or less, further preferably 3% or less, and most preferably 1% or less. . The transmittance of light having a wavelength of 550 nm is preferably 50% or more, more preferably 60% or more, further preferably 65% or more, and most preferably 70% or more.
The antistatic layer of the present invention has excellent strength, and the specific antistatic layer has a pencil hardness of 1 kg, preferably H or higher, more preferably 2H or higher, more preferably 3H or higher. Is more preferable, and 4H or more is most preferable.

(Chemical treatment)
Examples of the chemical used for the chemical treatment include acids, alkalis, and solvents such as methanol, ethanol, toluene, etc., and preferably, treatment with alkali is used. When the optical film of the present invention is used in a liquid crystal display device, it is disposed on the outermost surface of the display by providing an adhesive layer on one side. When the transparent support is triacetyl cellulose, triacetyl cellulose is used as a protective film for protecting the polarizing layer of the polarizing plate. Therefore, it is preferable in terms of cost to use the optical film of the present invention as it is for the protective film.

  When the optical film of the present invention is disposed on the outermost surface of a display by providing an adhesive layer on one side or used as it is as a protective film for a polarizing plate, the optical film on the transparent support is sufficient for adhesion. It is preferable to perform a saponification treatment after forming an outermost layer mainly composed of a fluorine-containing polymer.

  The saponification treatment is performed by a known method, for example, by immersing the film in an alkali solution for an appropriate time. After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by dipping in a dilute acid so that the alkaline component does not remain in the film. By saponification treatment, the surface of the transparent support opposite to the side having the outermost layer is hydrophilized. The hydrophilized surface is particularly effective for improving the adhesion with a polarizing film containing polyvinyl alcohol as a main component. The hydrophilic surface makes it difficult for dust in the air to adhere to it, so that it is difficult for dust to enter between the polarizing film and the optical film when bonded to the polarizing film, and is effective in preventing point defects due to dust. .

  The saponification treatment is preferably carried out so that the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. More preferably, it is 30 ° or less, particularly preferably 20 ° or less.

  Specific means for the alkali saponification treatment can be selected from the following two means (1) and (2). (1) is superior in that it can be processed in the same process as a general-purpose triacetylcellulose film, but since the surface of the antireflection film is saponified, the surface is alkali-hydrolyzed and the film deteriorates. The point that it becomes dirty when the liquid remains can be a problem. In that case, although it becomes a special process, (2) is excellent.

(1) After the antireflection layer is formed on the transparent support, the back surface of the film is saponified by immersing it in an alkaline solution at least once.
(2) Before or after forming the antireflection layer on the transparent support, an alkaline solution is applied to the surface of the optical film opposite to the surface on which the optical film is formed, and is heated, washed and / or neutralized. Thus, only the back surface of the film is saponified.

  In the present invention, the conditions described below are standard saponification conditions. In the polarizing plate production process, a polarizing plate in a state of being saponified and processed into a polarizing plate generally by a continuous treatment is also referred to as “an optical film after saponification” It is defined as a “polarizing plate having”.

Saponification standard conditions: The optical film is treated and dried in the following steps.
Alkaline bath: 1.5 mol / dm ³ aqueous sodium hydroxide solution at 55 ° C. for 120 seconds.
First washing bath: tap water, 60 seconds.
Neutralization bath: 0.05 mol / dm ³ sulfuric acid, 30 ° C. for 20 seconds.
Second washing bath: tap water, 60 seconds.
Drying: 120 ° C., 60 seconds.
The dynamic friction coefficient of the optical film of the present invention is preferably 0.03 to 0.40, more preferably 0.03 to 0.35 or less, and most preferably 0.03 to 0.30. .
The optical film of the present invention is preferably made to have a specular reflectance of 2.0% or less because reflection of external light can be suppressed and visibility is improved. The specular reflectance is particularly preferably 1.4% or less.
The optical film of the present invention is particularly useful as a high-definition optical film having 80 to 200 pixels.

Next, the second invention will be described. In the following description, differences from the first invention will be mainly described. For the points not specifically described, the description in the first invention is applied as appropriate.
The optical film of the second invention of the present invention is an optical film having at least one antiglare layer and a low refractive index layer on a transparent support, wherein the antiglare layer has a phase separation structure comprising a plurality of resins. The low refractive index layer is coated with a coating composition containing (A) 35 to 70% by mass of silica fine particles based on the total solid content in the coating composition for forming a low refractive index. The silica fine particles are surface-treated with a hydrolyzate of an organosilane compound and / or a partial condensate thereof.
That is, in the optical film of the second invention of the present invention, it is essential that the silica fine particles in the low refractive index layer are surface-treated with a hydrolyzate of organosilane or the like, and the surface coverage is not an essential requirement. . Except this point, it is the same as the first invention described above.

Next, the polarizing plate of the present invention will be described.
The polarizing plate of the present invention is a polarizing plate having a polarizing film and protective films provided on both sides of the polarizing film, and at least one of the protective films is a polarizing plate that is the optical film of the present invention. .

  The use of the optical film or polarizing plate of the present invention is not particularly limited, but it can be suitably used as an antireflection film. Anti-reflection films such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescence display (ELD), cathode tube display (CRT), field emission display (FED), surface electric field display (SED) In various image display devices, it can be used to prevent a decrease in contrast due to reflection of external light or reflection of an image.

  The image display device (preferably a liquid crystal display device) of the present invention has the optical film or the polarizing plate of the present invention. The optical film or polarizing plate of the present invention is preferably disposed on the surface of the display (the viewing side of the display screen).

(Various evaluation of optical film)
First, evaluation methods in the following examples will be described.
(Steel wool scratch resistance evaluation)
Using a rubbing tester, a rubbing test was performed under the following conditions to obtain an index of scratch resistance.
Evaluation environmental conditions: 25 ° C., 60% RH
Rubbing material: Steel wool (Nippon Steel Wool Co., Ltd., gelled No. 0000)
Wrap around the tip (1cm x 1cm) of the scraper of the tester that comes into contact with the sample, and fix the band.
Travel distance (one way): 13cm
Rubbing speed: 13 cm / second,
Load: 500 g / cm ²
Tip contact area: 1 cm × 1 cm, rubbing frequency: 10 reciprocations.
An oil-based black ink is applied to the back side of the sample that has been rubbed, and scratches on the rubbed portion are visually observed with reflected light, and evaluation is made based on the difference in the amount of reflected light from other than the rubbed portion.

(Dynamic friction coefficient measurement)
The dynamic friction coefficient was evaluated as an index of surface slipperiness. As the dynamic friction coefficient, a sample was conditioned at 25 ° C. and a relative humidity of 60% for 2 hours, and then a value measured with a HEIDON-14 dynamic friction measuring machine at a 5 mmφ stainless steel ball, a load of 100 g, and a speed of 60 cm / min was used.

(Specular reflectance)
The specular reflectivity is measured by attaching an adapter “ARV-474” to a spectrophotometer “V-550” [manufactured by JASCO Corporation], and an emission angle at an incident angle of 5 ° in a wavelength region of 380 to 780 nm. The antireflection property can be evaluated by measuring a specular reflectance of −5 °, calculating an average reflectance of 450 to 650 nm.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.

(Preparation of particles having pores inside)
(Preparation of Dispersion B-1)
The preparation conditions were changed from Preparation Example 4 of JP-A-2002-79616 to prepare silica fine particles having cavities inside. In the final step, the solvent was replaced with methanol from the aqueous dispersion state to obtain a 20% silica dispersion. Particles having an average particle diameter of 45 nm, a shell thickness of about 7 nm, and silica particles having a refractive index of 1.30 were obtained. This is designated as dispersion (A-1).

  To 500 parts of the dispersion (A-1), 20 parts of acryloyloxypropyltrimethoxysilane and 1.5 parts of diisopropoxyaluminum ethyl acetate were added and mixed, and then 9 parts of ion-exchanged water was added. After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 parts of acetylacetone was added. The solvent was replaced by distillation under reduced pressure while adding MEK so that the total liquid volume was almost constant. Finally, a dispersion B-1 was prepared by adjusting the solid content to 20%.

(Production of optical film)
(Preparation of coating solution for low refractive index layer (Ln-1 to Ln-19))
Each component was mixed as shown in Table 1 and dissolved in MEK to prepare a coating solution for a low refractive index layer having a solid content of 5%.
In addition, Ln-15 shall be read as “reference example” as “present invention”.

In addition, the symbol in the said table | surface is as follows.
“P-1”: fluorine-containing copolymer P-3 described in JP-A No. 2004-45462 (weight average molecular weight of about 50000)
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, Nippon Kayaku Co., Ltd. PET-30: Mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [Nippon Kayaku Co., Ltd.]
M-8030: Aronix M-8030, Toa Gosei Co., Ltd. UN-3320HC: Art Resin UN-3320HC, Negami Kogyo Co., Ltd. Irg. 127: Irgacure 127, polymerization initiator (manufactured by Nippon Ciba Geigy Co., Ltd.)
Irg. 907: Irgacure 907, polymerization initiator (manufactured by Ciba Geigy Japan)
Irg. 184: Irgacure 184, polymerization initiator (manufactured by Ciba Geigy Japan)
I-1: Exemplary Compound 7 for Polymerization Initiator
I-2: Exemplary Compound 22 for Polymerization Initiator 22
X-22, X-31: Fluorine-containing polyfunctional acrylate X-33 described in JP-A-2006-28409: Illustrative compound X-35: fluorinated polyfunctional monomer RMS-033 : Methacryloxy modified silicone (manufactured by Gelest Co., Ltd.)

(Preparation of sol solution a)
In a 1,000 ml reaction vessel equipped with a thermometer, a nitrogen inlet tube, and a dropping funnel, 187 g (0.80 mol) of acryloxyoxypropyltrimethoxysilane, 27.2 g (0.20 mol) of methyltrimethoxysilane, 320 g of methanol ( 10 mol) and 0.06 g (0.001 mol) of KF were added, and 15.1 g (0.86 mol) of water was slowly added dropwise at room temperature with stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours, and then heated and stirred for 2 hours under methanol reflux. Then, 120 g of sol solution a was obtained by distilling off the low boiling point under reduced pressure and further filtering. As a result of GPC measurement of the substance thus obtained, the mass average molecular weight was 1500, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 30%.
Moreover, from the measurement result of ¹ H-NMR, the structure of the obtained substance was a structure represented by the following general formula.

Furthermore, the condensation rate α as determined by ²⁹ Si-NMR was 0.56. From this analysis result, it was found that the silane coupling agent sol was mostly composed of a linear structure.
From the gas chromatography analysis, the raw material acryloxypropyltrimethoxysilane had a residual rate of 5% or less.

(1) Preparation of coating solution for antiglare layer ───────────────────────────────
Composition of coating solution 1 for antiglare layer
───────────────────────────────
CAP482-20 2.4g
Cyclomer P 13.4g
DPHA 16.3g
Irgacure 184 1.2g
MEK 51.0g
Butanol 14.0g
Propylene glycol monomethyl ether 3.5g
───────────────────────────────

Composition of antiglare layer coating solution 2 ───────────────────────────────
PET-30 40.0g
DPHA 10.0g
Irgacure 184 2.0g
SX-350 (30%) 2.0g
Cross-linked acrylic-styrene particles (30%) 13.0 g
FP-13 0.06g
Sol solution a 11.0g
Toluene 38.5g
───────────────────────────────

  The coating solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare coating solutions 1 and 2 for hard coat layers.

The compounds used are shown below.
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate [manufactured by Nippon Kayaku Co., Ltd.]
PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [manufactured by Nippon Kayaku Co., Ltd.]
・ Irgacure 184: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
SX-350: average particle size 3.5 μm cross-linked polystyrene particles [refractive index 1.60, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion, used after dispersion for 20 minutes at 10,000 rpm in a polytron disperser]
Crosslinked acrylic-styrene particles: average particle size 3.5 μm [refractive index 1.55, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion, used after dispersion for 20 minutes at 10,000 rpm with a Polytron disperser]
・ FP-13: Fluorine surface modifier

CAP482-20: cellulose acetate propionate [manufactured by Eastman Chemical Co.]
・ Cyclomer P: Reactive oligomer [manufactured by Daicel UCB Co., Ltd.]

(Preparation of the antiglare layer 101)
A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) was unwound in a roll form, and the antiglare layer coating solution 1 was directly extruded and applied using a coater having a throttle die. After coating at a transfer speed of 30 m / min, drying at 70 ° C. for 180 seconds, and using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge, the irradiation amount is 90 mJ / cm. ^The coating layer was cured by irradiating ² ultraviolet rays to form an antiglare layer having an antiglare property having a thickness of 6.0 μm, and a roll-up antiglare layer 101 was produced.

(Coating of antiglare layer 102)
A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) was unwound in a roll form, and the coating solution 2 for the antiglare layer was directly extruded and applied using a coater having a throttle die. After applying at a transfer speed of 30 m / min, drying at 30 ° C. for 15 seconds and 90 ° C. for 20 seconds, and further using a 160 W / cm air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) under a nitrogen purge. The coating layer was cured by irradiating ultraviolet rays with an irradiation amount of 90 mJ / cm ² to form an antiglare layer having a thickness of 9.0 μm and having an antiglare property.

(Preparation of optical film sample 1)
On the anti-glare layer 101, the low refractive index layer coating liquid Ln-1 is used, and the thickness of the low refractive index layer is adjusted to 95 nm, and an optical film sample 1 is produced by a microgravure coating method. did.
Curing conditions Drying: 80 ° C.-120 seconds (2) UV curing: 60 ° C.-1 minute, 240 W / cm air-cooled metal halide lamp (eye graphic) while purging with nitrogen so that the oxygen concentration becomes 0.01 vol% or less. The irradiance was 120 mW / cm ² and the irradiation amount was 500 mJ / cm ² .

(Preparation of optical film samples 2 to 19)
Optical film sample 1 was prepared in the same manner as optical film sample 1 except that (Ln-2) to (Ln-19) were used instead of the coating solution for low refractive index layer (Ln-1). Films 2 to 19 were produced.
(Preparation of optical film samples 20 to 24)
In the production of the optical film sample 1, instead of using the anti-glare layer 102 instead of the anti-glare layer 101, the coating solution for low refractive index layer (Ln-1), (Ln-1), (Ln-3), Optical films 20 to 24 were produced in the same manner as the optical film sample 1 except that (Ln-17), (Ln-18), and (Ln-19) were used.

(Saponification of optical film)
The obtained optical film was treated and dried under the following saponification standard conditions.
Alkaline bath: 1.5 mol / dm ³ aqueous sodium hydroxide solution at 55 ° C. for 120 seconds.
First washing bath: tap water, 60 seconds.
Neutralization bath: 0.05 mol / dm ³ sulfuric acid, 30 ° C. for 20 seconds.
Second washing bath: tap water, 60 seconds.
Drying: 120 ° C., 60 seconds.

(Evaluation of optical film)
The following evaluation was performed using the saponified optical film.
(Evaluation 1) Presence / absence of repelling Oily black ink was applied to the back side of the sample and visually observed with reflected light, and repelling of the low refractive index layer was evaluated according to the following criteria.
A: Even if you look carefully, you can't see any repellency.
B: If you look carefully, you will see a slight repellency.
C: A repel can be visually recognized at a glance.
(Evaluation 2) Evaluation of surface coverage of silica The surface coverage of silica in the low refractive index layer was evaluated by the above method.
(Evaluation 3) Measurement of dynamic friction coefficient The dynamic friction coefficient was measured by the method described in the text.
(Evaluation 4) Steel wool scratch resistance evaluation Oil black ink was applied to the back side of the sample that had been rubbed and tested by the method described in the text, and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria. . The load was 500 g / cm ² and the number of times was 10 reciprocations.
A: Even if you look very carefully, no scratches are visible.
B: Slightly weak scratches can be seen when viewed very carefully.
C: A weak wound is visible.
D: A moderate crack is visible.
E: There is a scratch that can be seen at first glance.
(Evaluation 5) Measurement of specular reflectance The average reflectance of 450 to 650 nm was measured by the method described herein. As for the sample processed into the polarizing plate, the polarizing plate type is used as it is, and in the case of a display device that does not use the film itself or the polarizing plate, the back surface of the antireflection film is roughened and then blackened. Were subjected to light absorption treatment (transmittance at 380 to 780 nm was less than 10%) and measured on a black table.

In Table 2 above, sample No. 15 should be read as “reference example” instead of “present invention”.
From the results shown in Table 2 above, the optical film in which the low refractive index layer is coated on the antiglare layer having the phase separation structure composed of a plurality of resins obtained in the present invention has a silica surface coverage of 0 on the film surface. It was found that a coating film having no repellency after coating and having good scratch resistance after chemical treatment can be obtained by setting the content to be not less than 40% and less than 40%.

It is a schematic diagram of the cross section of the optical film of this invention. It is a schematic diagram at the time of seeing the optical film of this invention from the top.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical film 2 Transparent support 3 Anti-glare layer 4 Low refractive index layer 5 Silica microparticle

Claims (9)

An optical film having at least one antiglare layer and a low refractive index layer on a transparent support, wherein the antiglare layer has a phase separation structure composed of a plurality of resins, and the low refractive index layer There will be coated with a coating composition (a) silica particles and (B) a polymerizable group at least two having fluorine content contains a fluorine-containing polyfunctional monomer is at least 20.0 wt%, the (A) The content of silica fine particles is 40 to 65 mass% with respect to the total solid content in the coating composition, and the surface coverage of the silica fine particles in the low refractive index layer is 1% or more and less than 25%. Optical film.   The optical film according to claim 1, wherein the silica fine particles are surface-treated with a hydrolyzate of an organosilane compound and / or a partial condensate thereof. The optical film according to claim 1 or 2 wherein the coating composition further (C) containing at least one non-fluorine-containing polyfunctional monomer. The optical film according to claim 3, wherein the (C) at least one non-fluorinated polyfunctional monomer is an ester of a polyhydric alcohol and (meth) acrylic acid. The silica fine particles, optical film according to any one of claims 1 to 4 having a particle having an internal pore. The optical film according to any one of claims 1 to 5, wherein the silica fine particles, including particle size is 30nm or more 100nm or less particles. The coating composition, of at least one fluorine compound, and / or at least contain a kind of polysiloxane compound, claimed in any of claims 1-6 dynamic friction coefficient is 0.03 to 0.40 Optical film. The optical film according to any one of claims 1 to 7, in which a polarizing plate is used in at least one of two protective films of the polarizing film in the polarizing plate. An image display device in which the polarizing plate is used on the outermost surface of a display according to an optical film or claim 8 as claimed in any one of claims 1-7.

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