JP2007133236A - Optical film, polarizing plate and image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film which is formed of a single coating layer, is superior in anti-reflection properties, is suitable for mass production, and for which the problem of interference mottle has also been improved. <P>SOLUTION: In the optical film, low refractive index particulates are distributed unevenly on a surface side in a hardened layer, formed on a transparent plastic film base material and high refractive index particulates are distributed unevenly at a base material side therein. As the low refractive index particulates, particulates the surface free energy of which is reduced by chemical modification is used and as the high refractive index particulates, particulates, the surface free energy of which is higher than that of the surface of a hardened film formed by hardening only a binder resin, is used. After applying a curable composition onto the base material, the low refractive index particulates float and the high refractive index particulates are precipitated, and then the composition is hardened and the hardened layer is formed. Furthermore, by using silica particulates as the low refractive index particulates, the optical film becomes superior in abrasion resistance, and by using an electrically conductive particulate as the high refractive index particulate, the optical film is superior in preventing adhesion of contaminants. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical film formed by the upper portion of low refractive index fine particles and the lower portion of high refractive index fine particles, and a polarizing plate and an image display apparatus using such an optical film. In particular, an antireflective hard coat film formed from a curable composition comprising a low refractive index fine particle whose surface free energy is reduced by surface modification, a high refractive index fine particle having a high surface free energy and a curable resin, and The present invention relates to a polarizing plate and an image display device.

  Anti-reflection films are used in various image display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), electroluminescence displays (ELD), and cathode ray tube display devices (CRT). In order to prevent a decrease in contrast due to reflection, it is arranged on the surface of the display. Therefore, the antireflection film is required to have high transmittance and high physical strength (such as scratch resistance) in addition to high antireflection performance.

  Conventionally, an antireflection layer used for an antireflection film has been formed as a single-layer or multilayer thin film. In the case of a single layer, a layer having a lower refractive index than that of the substrate (low refractive index layer) may be formed with an optical film thickness of 1/4 of the design wavelength, and when further low reflection is required It is known that a layer (high refractive index layer) having a refractive index higher than that of the substrate may be formed between the substrate and the layer having a low refractive index.

  As such an antireflection film, a multilayer film obtained by laminating a transparent thin film of metal oxide has been widely used. A metal oxide transparent thin film has been usually formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method which is a kind of physical vapor deposition method.

  Such an antireflection film can also be formed by a wet coating method. Since it is suitable for mass production and cost reduction as compared with the vacuum deposition method, formation of an antireflection film by Roll To Roll by a wet coating method has been widely used in recent years. With increasing demand for antireflection films by this wet coating method, development of a production method of antireflection films having multiple functions at a lower cost is strongly desired.

When creating an antireflection film using a transparent plastic film as a base material, an antireflection layer is formed after a hard coat layer with a thickness of about 1 to 10 μm is formed on the base material to supplement the physical strength of the plastic film. A configuration is used.
Therefore, when producing an antireflection film using a wet coating method, it is necessary to repeat the coating, drying and curing of the curable composition at least twice, which significantly reduces productivity, and even in the wet coating method. This hinders further cost reduction.

  In recent years, there has been a growing demand for imparting antistatic properties to prevent dust, and imparting interference spot (unevenness) preventing properties to improve image quality. In order to meet these requirements, hard coat layers It is necessary to provide an antistatic layer or an interference spot preventing layer as shown in Patent Document 1 between the substrate and the base material, and it is necessary to repeat coating, drying and curing three times, which significantly reduces productivity.

  In addition, this coating method is a method of stacking the uncured layer after curing the lower layer, the lower layer has already been fixed by curing, and the reactive groups in the lower layer have already been consumed during curing, so the upper layer It is difficult to make a chemical bond. Therefore, it is difficult to ensure interlayer adhesion. Scratch resistance is deeply related to interlayer adhesion of the antireflection layer, and it is essential to obtain sufficient interlayer adhesion to obtain high scratch resistance. As mentioned earlier, the demand for scratch resistance has increased rapidly in recent years, and it is an extremely important issue to ensure interlayer adhesion and to obtain high scratch resistance.

  In order to solve such problems, Patent Document 2 discloses an apparatus for producing a multilayer coating film from the viewpoint of productivity. By using such a manufacturing apparatus, a certain result can be achieved in terms of productivity improvement. However, in order to realize such a method, a large capital investment is required. Also, when forming a coating film with a photo-radical curable resin, a nitrogen purge is necessary to prevent the inhibition of curing by oxygen, and this method of forming three layers separately performs a nitrogen purge three times as before. There is no improvement in terms of running cost. Furthermore, from the viewpoint of performance, even such a coating method is a coating method in which layers are stacked one by one, and thus the problem of interlayer adhesion remains.

By the way, Patent Documents 3 to 5 disclose a film in which a layer formed from one coating solution has a function of two layers. However, a film in which one coating layer has a substantially three-layer function has not been disclosed so far.
JP 2004-345333 A JP 2003-205264 A JP 2000-53921 A JP 2004-359930 A JP 2004-34399 A

  An object of the present invention is to provide an optical film that can have a substantially three-layer function in one coating layer, has high antireflection properties, and is suitable for mass productivity. And providing an optical film excellent in antistatic properties and / or interference unevenness preventing properties. Furthermore, it is providing the polarizing plate and image display apparatus which comprised this optical film.

  As a result of intensive studies, the inventor has obtained a curable composition containing a low refractive index fine particle having a reduced surface free energy by surface modification, a high refractive index fine particle having a high surface free energy, and a curable resin as a transparent plastic film base. By having the low refractive index fine particles unevenly distributed on the surface side of the coating layer and the high refractive index fine particles unevenly distributed on the substrate side before being cured after being coated on the material, there was substantially a three-layer function. An anti-reflective hard coat that can form an anti-reflective film, has excellent anti-reflective properties, is suitable for mass productivity, and has excellent scratch resistance, anti-static properties and / or anti-interference spots. I found that I could make a film.

That is, the present inventor has achieved the above object with the following configurations.
1. A cured layer containing a low refractive index fine particle, a high refractive index fine particle and a binder is formed on the transparent plastic film substrate, and the low refractive index fine particles are unevenly distributed on the surface side of the cured layer. An optical film characterized in that high refractive index fine particles are unevenly distributed.
2. 2. The optical film as described in 1 above, wherein the low refractive index fine particles have a refractive index of 1.50 or less.
3. 2. The optical film as described in 1 above, wherein the low refractive index fine particles have a refractive index of 1.46 or less.
4). 2. The optical film as described in 1 above, wherein the refractive index of the low refractive index fine particles is 1.43 or less.
5. 5. The optical film as described in any one of 1 to 4 above, wherein the refractive index of the high refractive index fine particles is 1.60 or more.
6). 5. The optical film as described in any one of 1 to 4 above, wherein the high refractive index fine particles have a refractive index of 1.70 or more.
7). 5. The optical film as described in any one of 1 to 4 above, wherein the refractive index of the high refractive index fine particles is 1.80 or more.

8). This is the ratio of the average filling rate (B) of the low refractive index fine particles in the 100 nm film thickness on the surface side of the hardened layer to the average filling rate (A) of the low refractive index fine particles in the entire hardened layer [(B / A ) × 100] is 150% or more. The optical film as described in any one of 1 to 7 above.
9. Said [(B / A) * 100] is 200% or more, The optical film in any one of said 1-8 characterized by the above-mentioned.
10. Said [(B / A) * 100] is 300% or more, The optical film in any one of said 1-9 characterized by the above-mentioned.
11. The ratio of the average filling rate (D) of the high refractive index fine particles in the film thickness of 100 nm on the substrate side of the cured layer to the average filling rate (C) of the high refractive index fine particles in the entire cured layer [[D / C) × 100] is 150% or more, the optical film as described in any one of 1 to 10 above.
12 Said [(D / C) x100] is 200% or more, The optical film in any one of said 1-10 characterized by the above-mentioned.
13. Said [(D / C) x100] is 300% or more, The optical film in any one of said 1-10 characterized by the above-mentioned.

14 14. The optical film as described in 1 to 13 above, wherein the surface of the low refractive index fine particles has a surface free energy reduced by chemical modification.
15. Any one of the above 1 to 14, wherein the surface of the low refractive index fine particles is chemically modified so that the surface free energy is lower than the surface of the cured film formed by curing only the binder resin. The optical film described in 1.
16. 16. The optical film as described in 15 above, wherein the surface free energy of the low refractive index fine particles is 2 mN / m or more lower than the surface of a cured film formed by curing only the binder resin.
17. 16. The optical film as described in 15 above, wherein the surface free energy of the low refractive index fine particles is 5 mN / m or more lower than the surface of a cured film formed by curing only the binder resin.
18. 18. The optical film as described in any one of 1 to 17 above, wherein an organic compound containing a perfluoroalkyl group and / or a silicone group is fixed on the surface of the low refractive index fine particles.

19. 19. The optical film as described in 18 above, wherein the surface of the low refractive index fine particles is surface-modified with an organosilane compound represented by the following general formula (III).
General formula (III)
_{^{(Rf-L 1) n -Si}} (R 11) n-4
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. L ¹ represents a divalent linking group having 10 or less carbon atoms. n represents an integer of 1 to 3. R ¹¹ represents a hydroxyl group or a hydrolyzable group.
20. 20. The optical film as described in 18 or 19 above, wherein the surface of the low refractive index fine particles is surface-modified with an organosilane compound represented by the following general formula (IV).
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.
21. 21. The optical film as described in any one of 18 to 20 above, wherein the surface of the low refractive index fine particles is surface-modified with an organosilane compound represented by the following general formula (V).
General formula (V)
_{(CH 3) 3 Si- (O} -Si (CH 3) 2) n1 - (CH 2) n2 -Si (R 12) 3
In the above formula, n ₁ represents an integer of ₁ to 50. n ₂ represents an integer of 0 to 17. R ¹² represents an alkoxy group having 1 to 5 carbon atoms or a halogen atom.

22. 22. The optical film as described in any one of 1 to 21 above, wherein the low refractive index fine particles are any one of silicon dioxide (silica), magnesium fluoride, calcium fluoride, and barium fluoride.
23. 23. The optical film as described in any one of 1 to 22 above, wherein the low refractive index fine particles are silica fine particles.
24. 24. The optical film as described in any one of 1 to 23 above, wherein the low refractive index fine particles are hollow silica fine particles.
25. 25. The optical film as described in any one of 1 to 24 above, wherein the average particle diameter of the low refractive index fine particles is 120 nm or less.
26. 25. The optical film as described in any one of 1 to 24 above, wherein the low refractive index fine particles have an average particle size of 100 nm or less.
27. 25. The optical film as described in any one of 1 to 24 above, wherein the low refractive index fine particles have an average particle size of 80 nm or less.

28. 28. The optical film as described in any one of 1 to 27 above, wherein the surface of the high refractive index fine particles has a surface free energy higher than that of a cured film formed by curing only a binder resin.
29. 29. The optical film as described in 28 above, wherein the surface free energy of the high refractive index fine particles is 2 mN / m or more higher than the surface of a cured film formed by curing only a binder resin.
30. 30. The optical film as described in 29 above, wherein the surface free energy of the high refractive index fine particles is 5 mN / m or more higher than the surface of a cured film formed by curing only a binder resin.

  31. 31. The optical film as described in any one of 1 to 30 above, wherein the high refractive index fine particles are conductive fine particles.

  32. The optical film as described in any one of 1 to 31 above, wherein the transparent plastic film substrate has been subjected to a treatment for increasing surface free energy before the curable composition is applied.

  33. The cured layer is formed by coating the curable composition on a transparent plastic film and then floating the low refractive index fine particles before settling, precipitating the high refractive index fine particles, and then curing. The optical film as described in any one of 1 to 32 above,

34. The average film thickness of the said hardened layer is 1.0-20.0 micrometers, The optical film in any one of said 1-33 characterized by the above-mentioned.
35. The average film thickness of the said hardened layer is 1.5-10.0 micrometers, The optical film in any one of said 1-34 characterized by the above-mentioned.
36. The average film thickness of the said hardened layer is 2.0-8.0 micrometers, The optical film in any one of said 1-35 characterized by the above-mentioned.
37. Any one of the above 1 to 36, wherein when the surface of the hardened layer is rubbed 10 reciprocally while applying a load of 1.96 N / cm ² using steel steel of # 0000, the rubbing trace is not visible. The optical film as described.

38. A polarizing plate, wherein the optical film according to any one of 1 to 37 is used as at least one of a protective film for a polarizing film.
39. Polarized light characterized in that the optical film according to any one of 1 to 37 is used for one of the protective films of the polarizing film and an optical compensation film having optical anisotropy is used for the other protective film of the polarizing film. Board.
40. An image display device, wherein the optical film according to any one of 1 to 37 or the polarizing plate according to any one of 38 to 39 is disposed on an image display surface.
41. 41. The image display device as described in 40 above, wherein the image display device is a transmissive, reflective or transflective liquid crystal display device in any one of TN, STN, IPS, VA and OCB modes.

  In the optical film of the present invention, low refractive index fine particles are unevenly distributed on the surface side of the cured layer, and high refractive index fine particles are unevenly distributed on the substrate side, so that substantially two to three layers are formed in one coating layer. It can be provided with a function and not only has excellent antireflection properties, but is also suitable for mass productivity and can improve the problem of interference spots (unevenness). In addition, when the low refractive index fine particles are high-hardness inorganic fine particles such as silica fine particles, it can be particularly excellent in scratch resistance, and when the high refractive index fine particles are conductive fine particles, It can be excellent.

  Moreover, the polarizing plate using the optical film of the present invention as a surface protective film is excellent in optical performance and physical strength, and can be provided in a large amount at a low cost.

  Furthermore, the image display device of the present invention includes the optical film or the polarizing plate, and is excellent in antireflection properties, scratch resistance and visibility.

Hereinafter, a method for producing the optical film of the present invention will be described.
In addition, in this specification, when a numerical value represents a physical property value, a characteristic value, or the like, the description “(numerical value 1) to (numerical value 2)” represents the meaning of “numerical value 1 or more and numerical value 2 or less”.

  The present invention relates to an optical film having a cured layer formed of a transparent resin on a transparent plastic film substrate, wherein the low refractive index fine particles and the high refractive index fine particles each have a concentration gradient in the thickness direction in the cured layer. Contained, the low refractive index fine particles have a high concentration on the surface side opposite to the transparent plastic film substrate, are unevenly distributed on the surface side, and the high refractive index fine particles have a high concentration on the substrate side, the substrate side It is related with the optical film characterized by being unevenly distributed.

  In the present invention, low refractive index fine particles are unevenly distributed on the surface side of the cured layer, whereby an apparent low refractive index layer (hereinafter referred to as “apparent low refractive index layer”) is formed on the surface side of the cured layer. ing. In addition, high refractive index fine particles are unevenly distributed on the substrate side of the cured layer, whereby an apparent high refractive index layer (hereinafter referred to as an “apparent high refractive index layer”) is formed on the substrate side of the cured layer. ing. As a result, the optical film of the present invention can ensure a low reflectance by the antireflection effect of the apparent low refractive index layer and the apparent high refractive index layer. Further, since the apparent low refractive index layer and the apparent high refractive index layer can be formed from a single cured layer at a time, the production efficiency is high and there is no problem of poor interlayer adhesion. In particular, when a radical polymerization system is used for the binder, there is a problem of curing inhibition by oxygen, so the effect is great. Moreover, the problem of interference spots can be improved by forming an “apparent high refractive index layer”. Further, by using high-hardness inorganic fine particles such as silica fine particles as the low refractive index fine particles, it is possible to simultaneously impart surface scratch resistance. Further, by using conductive fine particles as the high refractive index fine particles, antistatic properties can be imparted at the same time, and the dust adhesion preventing properties can be improved.

<Layer structure>
About the optical film of this invention, the following well-known layer structures can be applied to the structure of a hardened layer.
For example, representative examples are: A: Transparent plastic film substrate / (Anti-reflective anti-static hard coat layer)
B: Transparent plastic film substrate / (Antistatic layer / Hard coat layer / Low refractive index layer)
C: Transparent plastic film substrate / (interference spots prevention layer / hard coat layer / low refractive index layer)
There is.
Here, what was shown by () is the hardened layer of this invention.

  Other layers that may be provided between the transparent plastic film substrate and the cured layer or on the surface of the cured layer include a hard coat layer (when the above structure alone is insufficient in hardness), a moisture-proof layer, an adhesion improving layer, and the like. Can be mentioned.

<Hardened layer>
[Method of reducing reflectivity]
In the present invention, by reducing the surface free energy of the low refractive index fine particles, the low refractive index fine particles are unevenly distributed in the upper part of the cured layer, whereby antireflection properties can be imparted to the cured layer. As a method for controlling the refractive index distribution in the thickness direction by imparting low-refractive-index fine particles to the surface and imparting antireflection properties, the present invention includes the following two methods.
(1) Method of introducing a gradient refractive index structure into the hardened layer
(2) Method of introducing an apparent low refractive index layer on the surface of the cured layer

(1) Method of introducing a refractive index gradient structure into the hardened layer It is known that the reflectance of the surface can be reduced by providing a layer with a refractive index continuously reduced toward the outermost surface on a transparent substrate. It has been. With such an antireflection method, the reflectance can be reduced over a wide range in the visible light region.
In the present invention, the surface free energy of the low-refractive fine particles and the polarity of the solvent in the curable composition for forming a cured layer are controlled, and the low-refractive-index fine particles are gently added after being applied and cured. Such a refractive index gradient structure can be introduced into the cured layer by being cured after being levitated above the cured layer (on the surface side).
In order to introduce such a refractive index gradient structure, the thickness of the cured layer is preferably 1 μm or more, and as an application example of such a structure, a binder is selected so as to increase the hardness of the cured layer. Examples of the antireflection hard coat layer imparted with hard coat properties are given.

(2) Method of introducing an apparent low refractive index layer on the surface of the hardened layer An antireflection film can be formed by providing a low refractive index layer having an optical film thickness of λ / 4 on a hardened layer such as a hard coat layer. Widely known. In the present invention, an apparent low refractive index layer can be formed by concentrating the low refractive index fine particles on the upper portion of the cured layer. By controlling the amount of the low refractive index fine particles added, the optical film thickness can be made λ / 4.
In the present invention, the surface free energy of the low-refractive fine particles and the polarity of the solvent in the curable composition for forming the cured layer are controlled, and the low-refractive-index fine particles are drastically changed after the curable composition is applied and cured. After floating on top of the hardened layer (surface side) and curing, the boundary between the floating part of the low refractive index fine particles and the bulk region is clarified, and the film thickness is adjusted with the addition amount of the low refractive index fine particles By doing so, an apparent low refractive index layer can be introduced.

[Uneven distribution of high refractive index fine particles]
In the present invention, the surface free energy of the high refractive index fine particles is made higher than the surface free energy of the binder of the cured layer, and if necessary, the surface free energy of the base material is increased so that the high refractive index fine particles are Can be unevenly distributed to the side.
In a configuration in which a hard coat layer is laminated on a transparent plastic film substrate, interference observed under a three-wavelength fluorescent lamp when there is a refractive index difference of 0.03 or more between the substrate and the hard coat layer Spots (unevenness) occurs. Regarding the details of such problems, the present inventor described the details in Japanese Patent Application Laid-Open No. 2004-345333.
By causing the high refractive index fine particles in the cured layer to be unevenly distributed on the substrate side, the problem of interference spots can be improved.

(1) Method of introducing a refractive index gradient structure on the base material side of the hardened layer In the present invention, the surface free energy of the high refractive index fine particles, the surface free energy of the binder, and the surface free energy of the base material are controlled to be curable. After applying the composition, it is possible to introduce a refractive index gradient structure into the cured layer by slowly precipitating the high refractive index fine particles to the lower part (base material side) of the cured layer before curing. it can.
In the present invention, the refractive index of the hard coat layer is changed from the base material by providing a density gradient in the hard coat layer (cured layer) so as to increase the density of the high refractive fine particles toward the interface with the base material. It can be gradually changed, and the occurrence of interference spots due to light reflection at the interface between the base material and the hard coat layer can be suppressed.
Further, it is preferable to select conductive fine particles, which will be described later, as the high-refractive index fine particles, because the conductivity associated with the concentration of the conductive fine particles can be expressed.

(2) Method of introducing an apparent high refractive index layer on the base material side of the cured layer As described in the above Japanese Patent Application Laid-Open No. 2004-345333, the present inventor described that 0 between the base material and the hard coat layer. When there is a difference in refractive index of 0.03 or more, the problem of interference spots is that there is an intermediate refractive index between the base material and the hard coat layer, and the film thickness satisfies the following formula (1) This can be improved by providing an interference spot prevention layer.

Formula (1)
d _p = (2N−1) × λ / (4n _p )

Here, λ is any value in the range of 450 to 650 nm, N is a natural number, and n _p is the refractive index of the interference spot preventing layer.
In the present invention, it is possible to form an apparent interference prevention layer that satisfies the above conditions by concentrating the high refractive index fine particles on the substrate side.
In the present invention, the surface free energy of the high refractive index fine particles, the surface free energy of the binder, and the surface free energy of the base material are controlled. After settling to the lower part of the hardened layer (base material side) and then hardening, the boundary between the uneven distribution region and the bulk region of the high refractive index fine particles can be clarified, and an apparent interference spot preventing layer is formed. Can do.

In addition, when the refractive index difference between a base material and a hard-coat layer is 0.03 or less, it is preferable that the film thickness of an apparent interference spot prevention layer satisfy | fills the following Numerical formula (2).

Formula (2)
d _p = N × λ / (2n _p )

Here, λ is any value in the range of 450 to 650 nm, N is a natural number, and n _p is the refractive index of the interference spot preventing layer.
Also in the case of forming an apparent interference spot preventing layer, it is preferable to select conductive fine particles described later as the high refractive index fine particles so that the conductivity associated with the concentration of the conductive fine particles can be expressed.

[Distribution of low refractive index fine particles in the layer]
In the optical film of the present invention, a cured layer is formed by coating a composition containing a low refractive index fine particle, a high refractive index fine particle and a binder on a substrate, and the low refractive index in the entire cured layer. Expressed by the ratio of the average particle filling rate (B) of the low refractive index fine particles in the 100 nm film thickness on the surface side of the hardened layer (upper layer side opposite to the base material) with respect to the average particle filling rate (A) of the fine particles. [(B / A) × 100] is preferably 150% or more. The average particle packing ratios (A) and (B) in the present invention were determined by the following method.
The optical film was taken as a section having a thickness of 50 nm, and the cross section was photographed in 5 views using a transmission electron microscope at a magnification of 150,000 times. The number of particles was counted over a width 50 times longer than the layer thickness, and the average particle filling rate (A) was calculated as the number of particles per unit area in the cured layer on the cross-sectional photograph. Moreover, the average particle filling rate (B) in the 100 nm film thickness on the upper layer side opposite to the substrate of the cured layer was also calculated in the same manner as the average particle filling rate (A). Further, for example, when the particles are partially contained in the upper layer side 100 nm film thickness in the cured layer, the number of particles was calculated by multiplying the ratio of the area of the particles contained in the region on the cross-sectional photograph. That is, when 70% of the area of a certain particle is contained in the 100 nm film thickness on the upper layer side, it is counted as 0.7. In addition, in the case where particles were observed in a cross-sectional photograph of a section having a thickness of 50 nm, the overlapping amount was counted. In this case, the distribution of particles in the layer does not have directionality in the layer surface direction, and the average particle filling rate can be obtained based on the number of particles in a specific cross section selected as an intercept.
The range of [(B / A) × 100] of the present invention is preferably 150% or more, more preferably 200% or more, and most preferably 300% or more from the viewpoint of antireflection properties.

[Distribution of high refractive index fine particles in the layer]
In the optical film of the present invention, the average particle filling rate (C) of the high refractive index fine particles in the 100 nm film thickness on the substrate side of the cured layer (C) with respect to the average particle filling rate (C) of the high refractive index fine particles in the entire cured layer ( [(D / C) × 100] represented by the ratio of D) is preferably 150% or more. The average particle packing ratios (C) and (D) in the present invention were determined by the following method.
The optical film was taken as a section having a thickness of 50 nm, and the cross section was photographed in 5 views using a transmission electron microscope at a magnification of 150,000 times. The number of particles was counted over a width 50 times longer than the layer thickness, and the average particle filling rate (C) was calculated as the number of particles per unit area in the cured layer on the cross-sectional photograph. The average particle filling rate (D) in the 100 nm film thickness on the substrate side of the cured layer was also calculated in the same manner as the average particle filling rate (C). In addition, for example, when the particles are partially contained in the substrate-side 100 nm film thickness in the cured layer, the number of particles was calculated by multiplying the area ratio of the particles included in the region on the cross-sectional photograph. . That is, when 70% of the area of a certain particle is contained in the 100 nm film thickness on the base material side, it is counted as 0.7. In addition, in the case where particles were observed in a cross-sectional photograph of a section having a thickness of 50 nm, the overlapping amount was counted. In this case, the distribution of particles in the layer does not have directionality in the layer surface direction, and the average particle filling rate can be obtained based on the number of particles in a specific cross section selected as an intercept.
The range of [(D / C) × 100] of the present invention is preferably 150% or more, more preferably 200% or more, and most preferably 300% from the viewpoint of antistatic properties and / or interference spot prevention. That's it.

<Low refractive index fine particles>
As the low refractive index fine particles that can be preferably used in the present invention, low refractive index inorganic fine particles are preferable. Silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, aluminum fluoride, calcium fluoride, lithium fluoride, fluoride) Sodium, barium fluoride) and the like are preferable. More preferred are silicon dioxide (silica), magnesium fluoride, calcium fluoride, and barium fluoride, and particularly preferred is silicon dioxide (silica).

  The refractive index of the low refractive index fine particles is preferably 1.50 or less, more preferably 1.46 or less, and particularly preferably 1.43 or less. The lower the refractive index, the greater the antireflection effect obtained.

The mass average particle diameter of the primary particles of the low refractive index fine particles is preferably 1 to 120 nm, more preferably 1 to 100 nm, and particularly preferably 1 to 80 nm.
The mass average particle diameter of the primary particles can be determined from an electron micrograph.
It is preferable that the low refractive index fine particles are more finely dispersed in the curable composition for forming a cured layer.
The shape of the low refractive index fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a short fiber shape, a ring shape, a hollow shape, or an indefinite shape. A spherical shape, an indeterminate shape, and a hollow shape are more preferable, and a hollow shape is particularly preferable.
The low refractive index fine particles may be either crystalline or amorphous.

  Commercially available products as silicon oxide particle (for example, silica particle) dispersions include, for example, colloidal silica, methanol silica sol manufactured by Nissan Chemical Industries, Ltd., MA-ST-MS, IPA-ST, IPA- ST-MS, IPA-ST-L, IPA-ST-ZL, IPA-ST-UP, EG-ST, NPC-ST-30, MEK-ST, MEK-ST-L, MIBK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL, etc. ) Hollow silica CS60-IPA and the like. As powder silica, Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50, Silex H31, H32, H51, H52, H121, H122, Asahi Glass Co., Ltd., Nippon Silica Industry, Nippon Aerosil Co., Ltd. Examples include E220A and E220 manufactured by Fuji Electric, SYLYSIA470 manufactured by Fuji Silysia Co., Ltd., SG flake manufactured by Nippon Sheet Glass Co., Ltd., and the like.

When the low refractive index fine particles are silicon dioxide fine particles, it is particularly preferable to use hollow silicon dioxide fine particles.
The hollow silica fine particles preferably have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1.35, and most preferably 1.17 to 1.30. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica particles. At this time, when the radius of the void in the particle is a and the radius of the particle outer shell is b, the porosity x represented by the following formula (I) is preferably 10 to 60%, more preferably 20 to 60. %, Most preferably 30-60%.

Formula (I)
^{x = (4πa 3/3)} / (4πb 3/3) × 100

If the hollow silica particles are made to have a lower refractive index and a higher porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. Rate particles do not hold.
The refractive index of these hollow silica particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).
A method for producing hollow silica is described in, for example, Japanese Patent Application Laid-Open Nos. 2001-233611 and 2002-79616.

The coating amount of the hollow silica is preferably from ^{1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . If the amount is too small, the effect of lowering the refractive index and the effect of improving the scratch resistance will be reduced.
The average particle size of the hollow silica is preferably 30 nm to 120 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the silica particles is too small, the proportion of cavities will decrease and a decrease in refractive index cannot be expected. Getting worse. The silica fine particles may be either crystalline or amorphous, and monodisperse particles are preferred. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.
Here, the average particle diameter of the hollow silica can be determined from an electron micrograph.

In the present invention, silica particles having no voids can be used in combination with hollow silica. In this case, it is preferable that silica without voids is subjected to the same surface modification as hollow silica. The preferred particle size of silica without voids is 30 nm to 120 nm, more preferably 35 nm to 80 nm, and most preferably 40 nm to 60 nm.
In addition, at least one kind of silica fine particles having an average particle size of less than 25 nm of the thickness of the low refractive index layer (referred to as “silica fine particles having a small size particle size”) is used. It is preferably used in combination with “silica fine particles”.
Since the fine silica particles having a small particle size can exist in the gaps between the fine silica particles having a large particle size, they can contribute as a retaining agent for the fine silica particles having a large particle size.
The average particle size of the silica fine particles having a small size is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such silica fine particles is preferable in terms of raw material costs and a retaining agent effect.

[Chemical modification of the surface of low refractive fine particles]
Next, the surface chemical modification of the low refractive index fine particles in the cured layer will be described.
In the present invention, it is preferable that the surface free energy of the surface of the low refractive index fine particles is reduced by chemical modification, and it is preferable that the surface free energy is lower than the surface free energy of the cured film formed by curing only the binder resin. .

  Here, the surface free energy of the cured film formed by curing only the binder resin can be estimated from the contact angle between water and methylene iodide on the surface of the cured film using a known method. The cured film formed by curing only the binder resin means a cured film formed by removing at least a compound unevenly distributed on the surface from the composition for forming a cured layer. Examples of compounds that may be unevenly distributed on the surface include surfactants, silicone oils, and fine particles whose surface free energy has been reduced by chemical modification. Such a cured film is preferably formed by removing all dispersions such as fine particles from the composition for forming a cured layer.

  The difference between the free energy on the surface of the low refractive index fine particles thus measured and the surface free energy of the cured film formed by curing only the binder resin is preferably 2 mN / m or more, and preferably 5 mN / m or more. Is more preferable.

The surface free energy of the low refractive index inorganic fine particles can be determined by coating the surface of the coating film formed by removing the solvent after coating from the inorganic fine particle dispersion or the inorganic fine particle powder before dispersing in the solvent (removing the solvent from the dispersion). Can be estimated from the contact angle between water and methylene iodide on the surface of the tablet formed by a tablet shaper.
The method for estimating the surface free energy from the contact angle is not particularly limited, and examples thereof include the methods described in paragraphs [0044] to [0047] of JP-A-2002-148792.

In order to reduce the surface free energy on the surface of the low refractive index fine particles, an organic compound containing a hydrophobic group is preferably fixed on the surface of the low refractive index fine particles. When the low refractive index inorganic fine particles are silica particles, an organosilane represented by the following general formula (I) having a substituent capable of reacting with a silanol group on the surface can also be used.
For this purpose, the surface is chemically modified with a hydrolyzate of organosilane represented by the following general formula (I) and / or a partial condensate thereof. It is preferable to use either an acid catalyst and the following metal chelate compound or both.

[Organosilane compound]
The organosilane compound used in 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 group, ethyl group, propyl group, isopropyl group, hexyl group, t-butyl group, sec-butyl group, hexyl group, decyl group, hexadecyl group 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. As the hydrolyzable group, for example, an alkoxy group (preferably 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 and the like), and R ^{2 are used.} 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.

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) ), Acyloxy group (acetoxy group, acryloyloxy group, methacryloyloxy group, etc.), alkoxycarbonyl group Methoxycarbonyl 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. In particular, when the binder of the cured layer is formed of a compound having a vinyl polymerizable group, the substituted alkyl group or substituted aryl group preferably further has a vinyl polymerizable group, and in this case, represented by the general formula (I) This compound can be represented as an organosilane compound having a vinyl polymerizable substituent represented by the following general formula (II).

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 alkylene group having 3 to 10 carbon atoms having a linking group therein and an unsubstituted alkylene group, an unsubstituted arylene group, and an alkylene group having an ether linking group or an ester linking group therein. 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.
Specific examples of such compounds are shown in M-1 to M-38 and M-47 of [Chemical Formula 2] to [Chemical Formula 8] described later, but the present invention is not limited thereto.

  In order to reduce the surface free energy on the surface of the low refractive index fine particles, an organosilane compound containing a perfluoroalkyl group and / or a silicone group can be preferably used.

  Alternatively, the surface of the silica particles can be treated in advance with a silane coupling agent having a functional group, and then a compound having a perfluoroalkyl group and / or a silicone group can be immobilized. In this case, it is more preferable in terms of reactivity to use a silane coupling agent having any of an amino group, an epoxy group, and a vinyl group.

  Specific examples of the perfluoroalkyl group are not particularly limited, but perfluoromethyl group, perfluoropropyl group, perfluorobutyl group, perfluorohexyl group, perfluorooctyl group, perfluorodecyl group, perfluorododecyl group. And a perfluorotetradecyl group. Only one perfluoroalkyl group may be used, or two or more perfluoroalkyl groups may be appropriately combined. A part of the fluorine atom in the perfluoroalkyl group may be substituted with another atom such as a chlorine atom within a range not detracting from the effect of the present invention.

  Specific examples of the silicone group include, but are not limited to, a dimethyl silicone group, a diphenyl silicone group, a methyl phenyl silicone group, a diethyl silicone group, and a methyl ethyl silicone group. Only one type of silicone group may be used, or two or more types may be appropriately combined. Among them, it is preferable that the silicone group is at least one of a dimethyl silicone group and a diphenyl silicone group because introduction into an organic compound for immobilization on the surface of the low refractive index fine particles is easy.

As the organosilane compound used in the present invention, a fluorine-containing silane coupling agent represented by the following general formula (III) is preferable because it can reduce the surface energy of the inorganic fine particles.

General formula (III)
_{^{(Rf-L 1) n -Si}} (R 11) n-4

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 which 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 agents represented by the general formula (III), fluorine-containing silane coupling agents represented by the following general formula (IV) are 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 4 to 10, m is preferably 1 to 3, and R is preferably a methoxy group, an ethoxy group, or a chlorine atom.

  Specific examples of such a fluorine-containing silane coupling agent are shown in M-56 to M-87 of [Chemical 9] to [Chemical 10] described below, but the present invention is not limited thereto.

In the present invention, an organosilane compound having a silicone group capable of reducing the surface energy of silica fine particles is also preferably represented by the following general formula (V).

General formula (V)
_{(CH 3) 3 Si- (O} -Si (CH 3) 2) n1 - (CH 2) n2 -Si (R 12) 3

In the above formula, n ₁ represents an integer of ₁ to 50. n ₂ represents an integer of 0 to 17. R ¹² represents an alkoxy group having 1 to 5 carbon atoms or a halogen atom. R ¹² is preferably a methoxy group, an ethoxy group, or a chlorine atom.

In addition to the silane coupling agent for reducing the surface free energy of the low-refractive-index fine particles described so far, the film strength is increased by using a silane coupling agent having the same functional group as the binder that forms the cured layer. Can be preferable.
In this case, it is more preferable in terms of reactivity to use a silane coupling agent having any of an amino group, an epoxy group, and a vinyl group.

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.

Among these specific examples, (M-1), (M-2), (M-56), (M-57) and the like are particularly preferable. 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 silica 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 the hydroxyl group-based normality concentration (Formol) on the surface of the silica fine particles.
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 at the same time, or the reaction can be carried out by shifting the addition time. Also, it is preferable to add a plurality of kinds of compounds in the form of partial condensates in advance because the reaction control is easy.

In the present invention, the hydrolyzate of organosilane and / or a partial condensate thereof is allowed to act on the surface of the silica fine particles to reduce the surface free energy of the silica 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.

[Solvent for surface chemical modification]
The surface chemical modification of silica with the hydrolyzate and / or condensation reaction product of organosilane can be performed in the absence of 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 hydrolyzate and / or condensation reaction product of the organosilane 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 oxide 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 improving the affinity with the binder used at the time of coating and the stability of the dispersion itself.

[Surface chemical modification catalyst]
The treatment for improving the dispersibility by the hydrolyzate and / or condensation reaction product of the 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 oxide fine particle liquid, an acid catalyst is used in the present invention. (Inorganic acids, organic acids) and / or metal chelate compounds are used. Inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids preferably have an acid dissociation constant in water (pKa value (25 ° C.)) of 4.5 or less, and acid dissociation constants in hydrochloric acid, sulfuric acid and water of 3.0 or less. More preferred is an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid and water, more preferred is an organic acid having an acid dissociation constant of 2.5 or less in water, 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 composed of a metal selected from Zr, Ti, or Al having a ligand represented by an alcohol represented by the following general formula (1) and / or a compound represented by the following general formula (2). If it does, it can use suitably without a restriction | limiting especially. Within this category, two or more metal chelate compounds may be used in combination.

Formula (1): R ²¹ OH

General formula (2): R ²² COCH ₂ COR ²³

(In the formula, R ²¹ and R ²² may be the same or different and each represents an alkyl group having 1 to 10 carbon atoms, and R ²³ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. Show.)

The metal chelate compound suitably used in the present invention has the following general formula:
Zr (OR ²¹ ) _c1 (R ²² COCHCOR ²³ ) _c2 ,
Ti (OR ²¹ ) _d1 (R ²² COCHCOR ²³ ) _d2 and Al (OR ²¹ ) _e1 (R ²² COCHCOR ²³ ) _e2
Are preferably selected from the group of compounds represented by formula (I), which serve to promote the condensation reaction of the organosilane compound.

R ²¹ and R ²² in the metal chelate compound may be the same or different as described above, specifically an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, an n-propyl group, an i-propyl group, or n-butyl. Group, sec-butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R ²³ 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, an n-butoxy group, a sec-butoxy group, a t-butoxy group, and the like. Moreover, c1, c2, d1, d2, e1, and e2 in a metal chelate compound represent the integer determined so that it may become 4 or 6-dentate coordination.

  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 (acetylacetonato) titanium, di Titanium chelate compounds such as isopropoxy bis (acetylacetate) titanium and diisopropoxy bis (acetylacetone) titanium; Sopropoxyethyl acetoacetate aluminum, diisopropoxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum And aluminum chelate compounds such as monoacetylacetonate bis (ethylacetoacetate) aluminum.

  Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxy bis (acetylacetonate) 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 is preferably 0.01 to 50% by mass, more preferably 0.1 to 50% by mass with respect to 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. More preferably, it is used in a proportion of 0.5 to 10% by mass.

[Dispersion stabilizing additive]
The curable composition for layer formation used in the present invention includes a β-diketone compound and / or a β-ketoester compound represented by the following general formula (3) in addition to the organosilane compound and the acid catalyst or chelate compound. It is preferable to contain these, and these act as stability improvers of the curable composition for layer formation used in the present invention.

General formula (3): R ³¹ COCH ₂ COR ³²

That is, the compound represented by the general formula (3) is coordinated to a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), whereby organosilane and metal by these metal chelate compounds. It is considered that the action of promoting the condensation reaction of the chelate component is suppressed and the action of improving the storage stability of the resulting composition is achieved. R ³¹ and R ³² in the compound represented by the general formula (3) are the same as R ²² and R ²³ constituting the metal chelate compound.

Specific examples of the β-diketone compound and β-ketoester compound represented by the general formula (3) include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate. Acetic acid-n-butyl, acetoacetic acid-s-butyl, acetoacetic acid-t-butyl, 2,4-hexadione, 2,4-heptadione, 3,5-heptadione, 2,4-octadione, 2,4-nonadione, 5-methylhexadione and the like can be mentioned. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred.
These β-diketone compounds and β-ketoester compounds may be used alone or in combination of two or more.

  In the present invention, the β-diketone compound and β-ketoester compound are 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 2 mol or more, there is no possibility of being inferior in the storage stability of the composition obtained, and it is preferable.

<High refractive index fine particles>
High-refractive-index inorganic fine particles are preferred as high-refractive-index fine particles that can be preferably used in the present invention, and comprise an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, It is preferable that inorganic fine particles having an average particle diameter of 0.001 to 0.2 μm or less, preferably 0.001 to 0.1 μm, more preferably 0.001 to 0.06 μm or less are contained. Specific examples of such inorganic fine particles include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , antimony-doped tin oxide (ATO), tin-doped Indium oxide (ITO) and the like. TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index.

In the present invention, it is preferable that the high refractive index fine particles are conductive fine particles because antistatic properties can be imparted.
The conductive fine particles are preferably inorganic fine particles made of metal oxide or nitride. Examples of metal oxides or nitrides include tin oxide, indium oxide, zinc oxide and titanium oxide. Tin oxide and indium oxide are particularly preferred.

  The conductive fine particles are mainly composed of these metal oxides or nitrides, and may further contain other elements. The main component means a component having the largest content (mass%) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, S, B, Nb, In, V and a halogen atom are mentioned. In order to increase the conductivity of tin oxide and indium oxide, it is preferable to add Sb, P, B, Nb, In, V and a halogen atom. Particularly preferred are tin oxide containing Sb (ATO) and indium oxide containing Sn (ITO). The ratio of Sb in ATO is preferably 3 to 20% by mass. The ratio of Sn in ITO is preferably 5 to 20% by mass.

  The refractive index of the high refractive index fine particles is preferably 1.60 or more, more preferably 1.70 or more, and particularly preferably 1.80 or more. The greater the refractive index, the greater the effect of preventing interference spots.

The mass average diameter of the primary particles of the high refractive index fine particles is preferably 1 to 120 nm, more preferably 1 to 100 nm, and particularly preferably 1 to 80 nm.
The high refractive index fine particles are preferably more finely dispersed in the curable composition for forming a cured layer.

The conductive fine particles may be surface-treated. The surface treatment can be performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include alumina and silica. Silica treatment is particularly preferred. Examples of organic compounds used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Silane coupling agents are most preferred. Two or more kinds of surface treatments may be performed in combination.
The shape of the conductive fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape.

[Surface free energy of high refractive index fine particles]
In the present invention, the surface free energy of the surface of the high refractive index inorganic fine particles is preferably higher than the surface free energy of the surface of the cured film formed by curing only the binder resin. The surface free energy of the cured film formed by curing only the binder resin is as described in the above section [Chemical modification of the surface of the low refractive index fine particles].

The surface free energy of the high refractive index inorganic fine particles can be determined by coating the surface of the coating film formed by removing the solvent after coating from the inorganic fine particle dispersion or the inorganic fine particle powder before dispersing in the solvent (removing the solvent from the dispersion). Can be estimated from the contact angle between water and methylene iodide on the surface of the tablet formed with a tablet shaper.
The method for estimating the surface free energy from the contact angle is not particularly limited, and examples thereof include the methods described in paragraphs [0044] to [0047] of JP-A-2002-148792.

  The difference between the surface free energy of the surface of the high refractive index inorganic fine particles thus measured and the surface free energy of the cured film formed by curing only the binder resin is preferably 2 mN / m or more, and preferably 5 mN / m or more. More preferably.

[Hard coat layer]
Examples of the function of the cured layer of the present invention include a hard coat layer having scratch resistance. In this case, the hard coat layer has a scratch resistance such that when the surface of the hardened layer is rubbed 10 reciprocally while applying a load of 1.96 N / cm ² using # 0000 steel wool, the scratch marks are not visible. It is preferable that it is a hardened layer.
Components other than the low refractive index fine particles that can be contained in the hard coat layer of the present invention will be described below.
The hard coat layer of the present invention is formed from a curable composition, and the curable composition has the above-mentioned low refractive index fine particles, a binder for imparting hard coat properties as a binder, and other antiglare properties as necessary. It is formed from matte particles for imparting internal scattering properties and inorganic fine particles for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength.

<Curing resin>
The curable resin is preferably a binder polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a binder polymer having a saturated hydrocarbon chain as a main chain. The binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to make the binder polymer have a higher refractive index, the monomer structure contains an aromatic ring and at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms. A refractive index monomer, a monomer having a fluorene skeleton in the molecule, or the like can also be selected.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid [for example, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di ( (Meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (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, polyester polyacrylate], ethylene oxide-modified products and caprolactone-modified products of the above esters, vinylbenzene and its derivatives [eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2- Acryloyl ethyl ester, 1,4-divinylcyclohexanone], vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  Specific examples of the high refractive index monomer include (meth) acrylates having a fluorene skeleton, bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, etc. Is mentioned. Two or more of these monomers may be used in combination.

Polymerization of these monomers having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Therefore, the hard coat layer is composed of a monomer for forming a cured resin such as the above-mentioned ethylenically unsaturated monomer, a photo radical initiator or a thermal radical initiator, a low refractive index fine particle, and a low refractive index as described later if necessary. It can be formed by preparing a coating liquid containing an inorganic filler other than fine particles, matte particles, and a leveling agent, and curing the coating liquid on a transparent substrate by ionizing radiation or a polymerization reaction by heat. it can.

  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 is 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 It is.
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-trimethylbenzoyldiphenylphosphine oxide.
Examples of active esters include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], sulfonic acid esters, cyclic active ester compounds, and the like.
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.
Examples of active halogens 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.
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.
“Latest UV Curing Technology”, Technical Information Association, 1991, p. Various examples are also described in 159 and are useful in the present invention.
Commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 819, 907, 1870 (CGI-403 / Irg184 = 7/3 mixed initiator) manufactured by Ciba Specialty Chemicals, Inc., 500 , 369, 1173, 2959, 4265, 4263, etc.), OXE01), etc., KAYACURE (DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, manufactured by Nippon Kayaku Co., Ltd. , ITX, QTX, BTC, MCA, etc.), Esacure (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT) manufactured by Sartomer, etc. are preferable examples.

It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, 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.
Furthermore, 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 KAYACURE (DMBI, EPA) manufactured by Nippon Kayaku Co., Ltd.

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 ammonium sulfate, potassium persulfate and the like, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile), etc. And diazoaminobenzene, p-nitrobenzenediazonium and the like.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Accordingly, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, low refractive index fine particles, and, if necessary, an inorganic filler other than mat particles, leveling agents, and low refractive index fine particles, which will be described later. The coating liquid is applied onto a transparent substrate and then cured by a polymerization reaction with ionizing radiation or heat to form a hard coat layer.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

[Matte particles]
In order to impart antiglare property or internal scattering property to the hard coat layer, mat particles having an average particle diameter of 1 to 10 μm, preferably 1.5 to 7.0 μm, for example, inorganic compound particles or Resin particles are contained. Specific examples of the matting particles include silica particles, particles and crosslinked acrylic particles of an inorganic compound such as TiO ₂ particles, crosslinked acryl - styrene particles, crosslinked styrene particles, melamine resin particles, resin particles such as benzoguanamine resin particles preferably Can be mentioned. Of these, crosslinked acrylic particles, crosslinked acrylic-styrene particles, and crosslinked styrene particles are preferable. As the shape of the matte particle, either a true sphere or an indefinite shape can be used. Further, two or more different kinds of mat particles may be used in combination. The mat particles are formed on the anti-glare hard coat layer so that the amount of the mat particles in the anti-glare hard coat layer to be formed is preferably 10 to 1000 mg / m ² , more preferably 30 to 100 mg / m ^2. It should be contained. In a particularly preferred embodiment, cross-linked styrene particles are used as mat particles, and the cross-linked styrene particles having a particle size larger than one half of the film thickness of the hard coat layer occupy 40 to 100% of the entire cross-linked styrene particles. It is an aspect. Here, the particle size distribution of the mat particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

[Inorganic oxide fine particles]
Next, inorganic oxide fine particles other than the low refractive index fine particles that can be used in the present invention will be described.
The inorganic oxide particles are at least one selected from the group consisting of silicon, aluminum, zirconium, titanium, zinc, germanium, indium, tin, antimony and cerium from the viewpoint of the colorlessness of the cured film of the resulting curable composition. Elemental oxide particles are preferred.
These inorganic fine particles are introduced for the purpose of increasing the refractive index of the hard coat layer, preventing crosslinking shrinkage, increasing the strength, etc., and are preferably dispersed uniformly in the thickness direction in the cured film.

  Examples of these inorganic oxide particles include particles of silica, alumina, zirconia, titanium oxide, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, cerium oxide, and the like. be able to. Of these, particles of silica, alumina, zirconia and antimony oxide are preferred from the viewpoint of high hardness. These may be used alone or in combination of two or more. Furthermore, the inorganic oxide particles are preferably used as an organic solvent dispersion. When used as an organic solvent dispersion, the dispersion medium is preferably an organic solvent from the viewpoint of compatibility with other components and dispersibility. Examples of such an organic solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate, and γ-butyrolactone. , Esters such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; aromatic hydrocarbons such as benzene, toluene and xylene; dimethylformamide, dimethylacetamide, Examples thereof include amides such as N-methylpyrrolidone. Of these, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene and xylene are preferred.

  The number average particle diameter of the oxide particles is preferably 1 nm to 2000 nm, more preferably 3 nm to 200 nm, and particularly preferably 5 nm to 100 nm. When the number average particle diameter exceeds 2000 μm, the transparency when cured is reduced, and the surface state when coated is liable to deteriorate. Various surfactants and amines may be added to improve the dispersibility of the particles.

  Examples of products that are commercially available as silicon oxide particle dispersions (for example, silica particles) include colloidal silica, methanol silica sol manufactured by Nissan Chemical Industries, Ltd., MA-ST-MS, IPA-ST, IPA- ST-MS, IPA-ST-L, IPA-ST-ZL, IPA-ST-UP, EG-ST, NPC-ST-30, MEK-ST, MEK-ST-L, MIBK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL, etc. ) Hollow silica CS60-IPA and the like. As powder silica, Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50, Silex H31, H32, H51, H52, H121, H122, Asahi Glass Co., Ltd., Nippon Silica Industry, Nippon Aerosil Co., Ltd. Examples include E220A and E220 manufactured by Fuji Electric, SYLYSIA470 manufactured by Fuji Silysia Co., Ltd., SG flake manufactured by Nippon Sheet Glass Co., Ltd., and the like.

  Moreover, as an aqueous dispersion product of alumina, Nissan Chemical Industries, Ltd. alumina sol-100, -200, -520; As an alumina isopropanol dispersion product, Sumitomo Osaka Cement Co., Ltd. AS-150I; AS-150T manufactured by Sumitomo Osaka Cement Co., Ltd .; HXU-110JC manufactured by Sumitomo Osaka Cement Co., Ltd. as a toluene dispersion of zirconia; Nissan Chemical Industries, Ltd. as an aqueous dispersion of zinc antimonate powder Cellax: Alumina, titanium oxide, tin oxide, indium oxide, zinc oxide, etc., powder and solvent dispersion products, nanotech made by CI Kasei Co., Ltd .; SN-100D, manufactured by Mitsubishi Materials Corporation, and ITO The aqueous dispersion, mention may be made of Taki Chemical Co., Ltd. Nidoraru like.

The oxide particles have a spherical shape, a hollow shape, a porous shape, a rod shape, a plate shape, a fiber shape, or an indefinite shape, and preferably a spherical shape. The specific surface area of oxide particles (by BET method using nitrogen) is preferably at 10 to 1000 m ² / g, more preferably from 20 to 500 m ² / g, most preferably 50 to 300 m ² / g. These inorganic oxide particles can be obtained by dispersing a powder in a dry state in an organic solvent. Can be used.

[Distribution method]
In the present invention, a dispersant may be used to prepare the inorganic oxide fine particles by dispersing them from a powder in a solvent. In the present invention, it is preferable to use a dispersant having an anionic group.
As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (sulfo), a phosphoric acid group (phosphono), a sulfonamide group, or a salt thereof is effective, and in particular, a carboxyl group, a sulfonic acid group, A phosphoric acid group or a salt thereof is preferable, and a carboxyl group and a phosphoric acid group are particularly preferable. A plurality of anionic groups may be contained for the purpose of further improving dispersibility. The average number is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the anionic group contained in a dispersing agent may contain multiple types in 1 molecule.
The dispersant may further contain a crosslinking or polymerizable functional group. Crosslinkable or polymerizable functional groups include ethylenically unsaturated groups (for example, (meth) acryloyl groups, allyl groups, styryl groups, vinyloxy groups, etc.) that can undergo addition reactions and polymerization reactions with radical species, and cationic polymerizable groups (epoxies). Groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like, and functional groups having an ethylenically unsaturated group are preferred.
In the present invention, a disperser can be used to grind inorganic oxide particles. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

  The average film thickness of the hard coat layer is preferably 1.0 to 20.0 μm, more preferably 1.5 to 10.0 μm, and particularly preferably 2.0 to 8.0 μm. If it is too thin, the hard coat property is insufficient, and if it is too thick, curling and brittleness may be deteriorated and processing suitability may be lowered.

[Solvent of coating solution]
The organic oxide dispersion of inorganic oxide fine particles according to the present invention described above is used as a fine particle component and combined with a binder to form a coating composition, and a hard coat layer can be formed from this composition. Although there is no restriction | limiting in the solvent of a coating composition, It is preferable to contain at least 2 type of volatile solvent. For example, it is preferable to use a combination of at least two selected from alcohol and derivatives thereof, ethers, ketones, hydrocarbons, and esters. A solvent can be selected from the viewpoint of the solubility of the binder component, the stability of the inorganic fine particles, and the adjustment of the viscosity of the coating liquid. By using a combination of two or more solvents, the fine particles can be arranged in the film in a controlled manner as defined in the present invention. The boiling point of the solvent used in the present invention is preferably 50 ° C. or higher and 250 ° C. or lower, more preferably 65 ° C. or higher and 200 ° C. or lower. Further, the preferable dielectric constant is preferably 1 or more and 50 or less, more preferably 5 or more and 30 or less at 20 ° C. It is preferable in terms of dispersion stability that a solvent having a dielectric constant of 10 or more is contained in an amount of 10% by mass or more based on the inorganic fine particles.

Although the solvent which can be used for this invention below is mentioned, it is not limited to these.
Alcohol and its derivatives (methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec amyl alcohol, 3-pentanol , Tertiary amyl alcohol, n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-octanol, 2-ethylhexanol, 3,5,5- Trimethylhexanol, nonanol, benzyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol Diethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol isoamyl ether, methoxymethoxyethanol, methoxypropanol, butoxyethanol, ethylene glycol Monoacetate, ethylene glycol diacetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol Mono butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether)

・ Ethers (isopropyl ether, n-butyl ether, diisoamyl ether, methylphenyl ether, ethylphenyl ether)
Ketones (acetone, methylacetone, methylethylketone, methyl-n-propylketone, methyl-n-butyl, methylisobutylketone, methyl-n-amylketone, methyl-n-hexylketone, diethylketone, ethyl-n-butylketone, Di-n-propyl ketone, diisobutyl ketone, acetonyl acetone, diacetone alcohol, cyclohexanone, methylcyclohexanone)

Hydrocarbons (n-hexane, isohexane, n-heptane, n-octane, isooctane, n-decane, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene)
Esters (propyl formate, n-butyl formate, isobutyl formate, amyl formate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-amyl acetate) , Isoamyl acetate, methyl isoamyl acetate, methoxybutyl acetate, secondary hexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, benzyl acetate, methyl propionate, ethyl propionate , N-butyl propionate, isoamyl propionate, methyl butyrate, ethyl butyrate, n-butyl butyrate, isoamyl butyrate, ethyl oxyisobutyrate, methyl acetoacetate, ethyl acetoacetate, isoamyl isovalerate, methyl lactate, ethyl lactate, Lactic acid-n-butyl, isobutyl lactate, milk -n- amyl lactate, isoamyl, methyl benzoate, diethyl oxalate)

  A particularly preferred combination is the use of at least two, more preferably three, of alcohol and its derivatives, ketones and esters. As preferable examples, for example, two or three of methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-methoxypropanol, 2-butoxyethanol, isopropyl alcohol, and toluene can be used in combination.

  In general, inorganic fine particles subjected to chemical modification for reducing the surface free energy have low affinity with highly polar organic solvents. By utilizing this property, the surface composition of the low refractive index fine particles can be promoted by adding a highly polar solvent to the coating composition.

The polarity of the organic solvent can be represented by a solubility parameter (SP value). From the above viewpoint, the curable composition of the present invention is preferably formed from a curable composition containing a solvent having an SP value of 9.5 or more, more preferably 10.0 or more.
In the present invention, when the curable composition for forming a hard coat layer contains an organic solvent having an SP value of 9.5 or more, it is preferably contained in an amount of 5% by mass or more based on the curable composition. Is 10% by mass or more, more preferably 15% by mass or more.
Furthermore, in the present invention, when the curable composition for forming a hard coat layer contains an organic solvent having an SP value of 10.0 or more, it is preferably contained in an amount of 5% by mass or more based on the curable composition. Is 10% by mass or more, more preferably 15% by mass or more.

<Solubility parameter (SP value)>
The solubility parameter (SP value) in the present invention is σ = [(ΔH−RT) / VL] ^1/2 (where σ: solubility parameter, ΔH: heat of evaporation, VL: molar volume, R: gas) ΔH is a value calculated from the boiling point in accordance with Hidebrand rule and ΔH298 = 23.7Tb + 0.020Tb ² −2950 (where Tb is the boiling point). Therefore, the solubility parameter is also a value of 298 ° K. Specific examples of the solubility parameter determined by Hidebrand rule are described in, for example, J. Org. BRANDRUP, E.I. H. IMMERGUT, and E.I. A. GRULKE “POLYMER HANDBOOK FORTH EDITION” VII / 688-694 (1998), JOHN WILEY & SONS, INC. Are described in detail. Regarding the calculation method of solubility parameter by Hidebrand rule, see J.A. H. Hildebrand, “Solubility of Nonelectrolytes” 424-427 (1950), Reinhold Publishing Co. It is described in.
Table 1 shows the SP values of representative compounds.

  In the present invention, in order to control and arrange the inorganic fine particles in the layer, the binder is composed of at least one polymerizable composition having a weight average molecular weight of 5000 or more and at least one polymerizable compound having a weight average molecular weight of less than 5000. It is preferred that Specific examples of the composition having a mass average molecular weight of 5000 or more are preferably a copolymer having a (meth) acryloyl group in the side chain, or a high molecular weight compound containing a fluorocarbon or dimethylsiloxane. Further, as the compound having a mass average molecular weight of less than 5000, a polyfunctional acrylate monomer, a partial condensate of the compound of the general formula (II) having a (meth) acryloyl group, and the like are preferable.

(Other additives)
Furthermore, for the purpose of imparting antifouling properties, chemical resistance, slipperiness, etc. to the hard coat layer of the present invention, antifouling agents such as known polysiloxane compounds or fluorine compounds, slipping agents, etc. are appropriately added. You can also.

(Polysiloxane compound)
Preferable examples of the polysiloxane compound 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 a dimethylsilyloxy group 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 acryloyl group, methacryloyl group, vinyl group, allyl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, 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.

  When the hard coat layer is formed of a radical polymerizable binder, the polymerizable polysiloxane compound contained in the curable composition for forming the hard coat layer of the present invention is prevented from being a radical polymerizable polysiloxane compound. It is preferable from the viewpoint of stain durability.

  Specific examples of such compounds include terminal (meth) acrylate siloxane compounds such as X-22-164A, X-22-164B, X-22-164C, X-22-2404, X-22-174D, X -22-8201, X-22-2426 (Shin-Etsu Chemical Co., Ltd.) and the like.

  Further, when the hard coat layer is formed of a cationic polymerizable binder, it is preferably a cationic polymerizable polysiloxane compound from the viewpoint of antifouling durability.

  Specific examples of such compounds include KF-105, X-22-163A, X-22-163B, X-22-163C, X-22-173DX, KF-1001, KF-1001, KF-101, X -22-169AS, X-22-169B, KF-102, X-22-3667, X-22-4741 (Shin-Etsu Chemical Co., Ltd.) and the like.

The coating amount of the case of adding these additives is 0.4~45mg / m ^2, preferably from 1 to 30 mg / m ^2, more preferably ^{2~20mg / m 2, 3~8mg / m} 2 Gayori preferable.

  Moreover, the content of the active energy ray-curable silicone resin in the curable composition of the present invention is preferably 0.001 to 0.2 mass with respect to the total active energy ray-curable resin used in the curable composition. %, More preferably 0.005 to 0.1% by mass, and most preferably 0.01 to 0.05% by mass.

[Transparent plastic film substrate]
The antireflection hard coat film of the present invention is produced by forming an optical functional layer on a transparent plastic film substrate (hereinafter also referred to as “transparent support”). The light transmittance of the transparent plastic film substrate is preferably 80% or more, and more preferably 86% or more. The haze of the transparent plastic film substrate is preferably 2.0% or less, and more preferably 1.0% or less. The refractive index of the transparent plastic film substrate is preferably 1.4 to 1.7.

  Examples of transparent plastic film materials include cellulose esters, polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4. 4′-dicarboxylate, polybutylene terephthalate, etc.), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, polypropylene, polyethylene, polymethylpentene, etc.), polysulfone, polyethersulfone, polyarylate, polyetherimide, Polymethyl methacrylate and polyether ketone are included. Cellulose ester, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are preferred.

[Cellulose acylate film]
In particular, when the antireflection film of the present invention is used in a liquid crystal display device, a cellulose acylate film is preferable. Cellulose acylate is produced by esterifying cellulose. As the cellulose before esterification, linter, kenaf and pulp are used after purification.

(Cellulose acylate)
In the present invention, cellulose acylate refers to a fatty acid ester of cellulose, and a lower fatty acid ester is particularly preferable. Furthermore, a fatty acid ester film of cellulose is preferable.

  Lower fatty acid means a fatty acid having 6 or less carbon atoms. A cellulose acylate having 2 to 4 carbon atoms is preferred. Cellulose acetate is particularly preferred. It is also preferable to use mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate.

  The viscosity average degree of polymerization (Dp) of cellulose acylate is preferably 250 or more, and more preferably 290 or more. Cellulose acylate preferably has a narrow molecular weight distribution based on Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. A specific value of Mw / Mn is preferably 1.0 to 5.0. More preferably, it is 1.0-3.0, Most preferably, it is 1.0-2.0.

  As the transparent support, it is preferable to use cellulose acylate having an acetylation degree of 55.0 to 62.5%. The acetylation degree is more preferably 57.0 to 62.0%, and particularly preferably 59.0 to 61.5%. The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation is determined by measurement and calculation of the degree of acylation in ASTM: D-817-91 (testing method for cellulose acylate, etc.).

  In cellulose acylate, the hydroxyl groups at the 2-position, 3-position and 6-position of cellulose are not evenly substituted, but the substitution degree at the 6-position tends to be small. In the cellulose acylate used in the present invention, it is preferable that the degree of substitution at the 6-position of cellulose is the same or greater than that at the 2- and 3-positions. The ratio of the substitution degree at the 6-position to the total substitution degree at the 2-position, the 3-position, and the 6-position is preferably 30 to 40%, more preferably 31 to 40%, and more preferably 32 to 40%. Most preferably it is.

Various additives are added to the transparent support to adjust the mechanical properties (film strength, curl, dimensional stability, slipperiness, etc.) and durability (wet heat resistance, weather resistance, etc.) of the film. Can be used. For example, plasticizers (phosphate esters, phthalate esters, esters of polyols and fatty acids, etc.), UV inhibitors (eg, hydroxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, cyanoacrylate compounds) Etc.), deterioration inhibitors (eg, antioxidants, peroxide decomposers, radical inhibitors, metal deactivators, acid scavengers, amines, etc.), fine particles (eg, SiO ₂ , Al ₂ O ₃ , TiO ₂₎ BaSO ₄ , CaCO ₃ , MgCO ₃ , talc, kaolin, etc.), release agents, antistatic agents, infrared absorbers, and the like.

  These details are disclosed in JIII Journal of Technical Disclosure No. 2001-1745 (issued March 15, 2001, Invention Association), p. Materials described in detail in 17-22 are preferably used.

  The amount of these additives used is preferably 0.01 to 20% by mass of the transparent support, and more preferably 0.05 to 10% by mass.

[Surface treatment]
Surface treatment may be performed on the transparent support.
Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Specifically, for example, Invention Association Public Technical Bulletin No. 2001-1745 (issued March 15, 2001) p. The content described in 30-31, the content described in JP 2001-9973 A, and the like can be given. Preferably, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment, and more preferably glow discharge treatment and ultraviolet treatment.
By such treatment, the surface of the substrate becomes hydrophilic and the surface free energy increases, so that the high refractive index fine particles with high surface free energy contained in the hard coat layer forming coating liquid are likely to be unevenly distributed on the substrate surface. preferable.

[Saponification]
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. In addition, the hydrophilic surface makes it difficult for dust in the air to adhere to it, making it 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 caused by dust. It is.
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.

[Coating film forming method]
The optical film of the present invention can be formed by the following method, but is not limited to this method.
First, a coating solution containing components for forming each layer is prepared. The coating solution is applied onto a transparent support by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or extrusion coating (see US Pat. No. 2,681,294). Heat and dry. Among these coating methods, it is preferable to apply the gravure coating method because a coating solution with a small coating amount such as each layer of the antireflection film can be applied with high film thickness uniformity. Among the gravure coating methods, the micro gravure method has a high film thickness uniformity and is more preferable.
In addition, a coating solution with a small coating amount can be applied with high film thickness uniformity even by using a die coating method. Further, since the die coating method is a pre-measuring method, film thickness control is relatively easy, and the solvent in the coating part Is preferred because of less transpiration. Two or more layers may be applied simultaneously. The method of simultaneous application is described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, 3,526,528 and Yuji Harasaki, “Coating Engineering”, page 253, Asakura Shoten (1973). .

[Polarizer]
The polarizing plate is mainly composed of two protective films that sandwich the polarizing film from both sides. The optical film of the present invention is preferably used for at least one of the two protective films sandwiching the polarizing film from both sides. The manufacturing cost of a polarizing plate can be reduced because the optical film of the present invention also serves as a protective film. In addition, by using the optical film of the present invention as the outermost layer, reflection of external light and the like can be prevented, there are no interference spots, and a polarizing plate excellent in scratch resistance, dust adhesion prevention and the like can be obtained. .

As the polarizing film, a known polarizing film or a polarizing film cut out from a long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction may be used. A long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction is produced by the following method.
That is, a polarizing film stretched by applying tension while holding both ends of a continuously supplied polymer film by a holding means, stretched at least 1.1 to 20.0 times in the film width direction, The progress of the film is such that the difference between the moving speeds in the longitudinal direction of the holding device is within 3%, and the angle formed by the moving direction of the film at the exit of the step of holding both ends of the film and the substantial stretching direction of the film is inclined by 20 to 70 degrees. The film can be produced by a stretching method in which the direction is bent while holding both ends of the film. In particular, those inclined by 45 degrees are preferably used from the viewpoint of productivity.

  The method for stretching the polymer film is described in detail in paragraphs [0020] to [0030] of JP-A-2002-86554.

  When the optical film of the present invention is used as one side of a surface protective film of a polarizing film, it is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically. It can be preferably used for a transmissive, reflective, or transflective liquid crystal display device in a mode such as a compensated bend cell (OCB).

The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Proceed) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).
For a VA mode liquid crystal cell, a polarizing plate prepared by combining a triacetyl cellulose film stretched biaxially with the optical film of the present invention is preferably used. As for the method for producing a biaxially stretched triacetyl cellulose film, for example, the methods described in JP-A Nos. 2001-249223 and 2003-170492 are preferably used.

  The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. It is disclosed in the specifications of Japanese Patent Nos. 45882525 and 5410422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. For this reason, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

  In an ECB mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and is most frequently used as a color TFT liquid crystal display device, and is described in many documents. For example, it is described in “EL, PDP, LCD display” published by Toray Research Center (2001).

  In particular, for TN mode and IPS mode liquid crystal display devices, as described in JP-A-2001-100043, an optical compensation film having an effect of widening a viewing angle is used as a protective film having two polarizing films on both sides. Of these, a polarizing plate having an antireflection effect and a viewing angle widening effect can be obtained with the thickness of one polarizing plate by using it on the surface opposite to the optical film of the present invention.

  In order to describe the present invention in detail, the following examples are given for explanation, but the present invention is not limited thereto. Unless otherwise specified, “part” and “%” are based on mass.

(Preparation of silica dispersion A)
Hollow silica fine particle sol (isopropyl alcohol silica sol, average particle diameter 40 nm, shell thickness 6 nm, silica concentration 20 mass%, silica particle refractive index 1.30, size according to Preparation Example 4 described in JP-A-2002-79616 500 parts, 8 parts acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), 2 parts tridecafluorooctyltrimethoxysilane (manufactured by GE Toshiba Silicone), and diisopropoxy After adding 1.5 parts of aluminum ethyl acetate and mixing, 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.
While adding cyclohexanone to 500 g of this dispersion so that the silica content was almost constant, solvent substitution was performed by distillation under reduced pressure at a pressure of 20 kPa. There was no generation of foreign matter in the dispersion. Subsequently, the solid content concentration was adjusted by removing cyclohexanone, and the viscosity when the solid content concentration was 22% by mass was 9 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion A was analyzed by gas chromatography, it was 1.0%. Further, the refractive index of the particles was 1.42.

(Preparation of ATO dispersion)
20 parts by mass of commercially available conductive fine particle ATO “antimony-doped tin oxide T-1” (specific surface area 80 m ² / g, refractive index 2.0, manufactured by Mitsubishi Materials Corporation), 3.0 parts by mass of tetraalkoxysilane, 77 parts by mass of methyl isobutyl ketone was added and stirred.

  The ATO particles in the liquid were dispersed using a media disperser (using zirconia beads having a diameter of 0.1 mm). It was 55 nm as a result of evaluating the mass mean particle diameter of the ATO particle | grains in a dispersion liquid by the light-scattering method. In this way, an ATO dispersion was prepared.

[Preparation of coating solution for hard coat layer]
────────────────────────────────────
Composition of hard coat layer coating solution (HCL-1) ────────────────────────────────────
DPHA 450.0 parts Irgacure 907 12.0 parts Silica dispersion A 50.0 parts ATO dispersion 100.0 parts IPA-ST (30%) 600.0 parts Isopropyl alcohol 60.0 parts Methyl ethyl ketone 203.0 parts ───────────────────────────────────

────────────────────────────────────
Composition of antiglare hard coat layer coating solution (HCL-2) --------------------- ──
PETA 600.0 parts Irgacure 184 20.0 parts silica dispersion A 50.0 parts ATO dispersion 100.0 parts crosslinked polystyrene particle toluene dispersion (30%) 17.0 parts crosslinked acrylic-styrene particle toluene dispersion (30 133.0 parts Toluene 210.0 parts Cyclohexanone 98.0 parts ─────────────────────────────────── ──

The compounds used are shown below.
PETA: a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [KAYARAD PET-30: manufactured by Nippon Kayaku Co., Ltd.]
DPHA: a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate [KAYARAD DPHA: manufactured by Nippon Kayaku Co., Ltd.]
・ Irgacure 184: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
・ Irgacure 907: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]

IPA-ST: IPA dispersion of silica particles having an average particle size of 15 nm, solid content concentration of 30% by mass [manufactured by Nissan Chemical Co., Ltd.]
Crosslinked polystyrene particle toluene dispersion (30%): 30% toluene dispersion of SX-350H [average particle size 3.5 μm crosslinked polystyrene particles, refractive index 1.60, manufactured by Soken Chemical Co., Ltd.], polytron disperser Use after dispersion at 10,000 rpm for 20 minutes. Cross-linked acrylic-styrene particle toluene dispersion (30%): SX-350HL [average particle size 3.5 μm, refractive index 1.55, manufactured by Soken Chemical Co., Ltd.] 30% toluene Dispersed liquid, used after dispersion for 20 minutes at 10,000 rpm in a polytron disperser

<Creation of antireflection hard coat film>
Example 1-1 (film sample 101)
As a support (base material), a triacetyl cellulose film “TD80U” (manufactured by Fuji Photo Film Co., Ltd.) having a width of 1340 mm and a length of 2600 m and a thickness of 80 μm is unrolled in the form of a roll, and directly the surface-modified low refractive index. Using a microgravure roll with a diameter of 135 mm / inch and a gravure pattern with a depth of 60 μm and a doctor blade, the coating liquid for hard coat layer (HCL-1) to which fine particles are added is transported at a speed of 15 m / min. After coating at 25 ° C. for 60 seconds, drying at 60 ° C. for 150 seconds, and an oxygen-cooled metal halide lamp (eye graphic) of 160 W / cm under nitrogen purge so that the oxygen concentration is 1.0% by volume or less. using scan the Ltd.), hard coating layer illuminance 400 mW / cm ^2, the ultraviolet irradiation dose 250 mJ / cm ² was irradiated To form a hard coat layer (HC-1), and wound up. After curing, the gravure roll rotation speed was adjusted so that the average thickness of the hard coat layer was 6.0 μm.

Example 1-2 (film sample 102)
Before apply | coating the coating liquid for hard-coat layers with respect to Example 1-1, the surface of a triacetyl cellulose film is changed to perform a corona treatment (hydrophilization treatment) at 0.5 kW using a corona treatment apparatus. A sample of Example 1-2 was prepared in the same manner as Example 1-1 except that.

Comparative Example 1-1 (film sample 103)
Comparative example as in Example 1-1, except that the step of transporting at 25 ° C. for 60 seconds after application was omitted with respect to Example 1-1, and that the drying was performed immediately after application at 60 ° C. for 150 seconds. A sample 1-1 was prepared.

Example 2-1 (film sample 104)
As a support (base material), a triacetyl cellulose film “TD80U” (manufactured by Fuji Photo Film Co., Ltd.) having a width of 1340 mm and a length of 2600 m and a thickness of 80 μm is unrolled in the form of a roll. A coating liquid for anti-glare hard coat layer (HCL-2) to which fine particles are added is transported at a speed of 15 m using a micro gravure roll having a gravure pattern of 135 lines / inch and a depth of 60 μm and a doctor blade and a doctor blade. After coating at 25 ° C. for 60 seconds and drying at 60 ° C. for 150 seconds, 160 W / cm air-cooled metal halide under nitrogen purge so that the oxygen concentration is 1.0% by volume or less. by using a lamp (manufactured by eye graphics Co.), illuminance 400 mW / cm ^2, and an irradiation dose of 250 mJ / cm ² coating Curing the layer to form an antiglare hard coat layer (HC-2), and wound up. After curing, the gravure roll rotation speed was adjusted so that the average thickness of the antiglare hard coat layer was 6.0 μm.

Comparative Example 2-1 (film sample 105)
Comparative Example as in Example 2-1, except that the step of transporting at 25 ° C. for 60 seconds after application was omitted with respect to Example 2-1, and the drying was performed immediately after application at 60 ° C. for 150 seconds. A sample 2-1 was prepared.

Example 3-1 (film sample 106)
A coating liquid for hard coat layer (HCL-1) in which a polyethylene terephthalate (PET) film having a length of 2600 m and a thickness of 100 μm is unrolled as a support in the form of a roll and directly added with the above-mentioned fluorocopolymer product. Was applied using a microgravure roll having a diameter of 135 lines / inch and a gravure pattern with a depth of 60 μm and a doctor blade under a condition of a conveyance speed of 15 m / min, and conveyed at 25 ° C. for 60 seconds, followed by 60 ° C. After drying for 150 seconds at an illuminance of 400 mW / cm using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge so that the oxygen concentration is 1.0 volume% or less. ^2, and an irradiation dose of 250 mJ / cm ² to cure the coating layer, to form a hard coat layer, the winding It took. After curing, the gravure roll rotation speed was adjusted so that the average thickness of the hard coat layer was 8.0 μm.

Comparative Example 3-1 (film sample 107)
Comparative Example as in Example 3-1, except that the step of transporting at 25 ° C. for 60 seconds after application was omitted with respect to Example 3-1, and the drying was performed immediately after application at 60 ° C. for 150 seconds. A sample 3-1 was prepared.

[Measurement of surface free energy]
(1) Surface energy of low-refractive-index fine particles The solvent of the silica dispersion A was removed under reduced pressure using an evaporator to obtain silica fine powder. The obtained silica fine particle powder was made into a silica fine particle tablet using a tablet shaper / tablet shaper press (manufactured by JASCO Corporation). The contact angle of water and methylene iodide was measured using Contact-Angle meter (Kyowa Interface Chemical Co., Ltd. 10927). Further, surface free energy was obtained from the contact angle according to the method described in paragraphs [0044] to [0047] of JP-A-2002-148792. The results are shown in Table 3.
The following silica dispersion B was similarly made into a silica fine particle tablet, and its contact angle was measured to obtain surface free energy. The results are shown in Table 3.

(Preparation of silica dispersion B)
Hollow silica fine particle sol (Isopropyl alcohol silica sol, average particle diameter 40 nm, shell thickness 6 nm, silica concentration 20% by mass, silica particle refractive index 1.30, prepared by changing the size according to Preparation Example 4 of JP-A-2002-79616 ) 10 parts of acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.5 parts of diisopropoxyaluminum ethyl acetate were added to and mixed with 500 parts, and 9 parts of ion-exchanged water were added. After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 parts of acetylacetone was added.
While adding cyclohexanone to 500 g of this dispersion so that the silica content was almost constant, solvent substitution was performed by distillation under reduced pressure at a pressure of 20 kPa. There was no generation of foreign matter in the dispersion, and the viscosity when adjusted to a solid content concentration of 22% by mass with cyclohexanone was 9 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion B was analyzed by gas chromatography, it was 1.0%. Further, the refractive index of the particles was 1.42.

(2) Surface energy of high refractive index fine particles The dispersion of ATO fine particles was also made into tablets of ATO fine particles in the same manner as in (1), and the contact angle was measured to obtain surface free energy. The results are shown in Table 3.

(3) Surface energy of binder As a coating liquid for forming a layer using only the binder resin without using the low refractive index fine particles and the high refractive index fine particles of the hard coat layer coating liquid (HCL-1), the following hard coat layer use A coating solution (HCL-11) was prepared.
The following hard coat layer coating solution (HCL-12) is used as a layer forming coating solution containing only the binder resin without using the low refractive index fine particles, high refractive index fine particles, etc. of the hard coat layer coating solution (HCL-2). Was prepared.

[Preparation of coating solution for hard coat layer]
────────────────────────────────────
Composition of hard coat layer coating liquid (HCL-11) ------------------------
DPHA 450.0 parts Irgacure 907 12.0 parts Isopropyl alcohol 480.0 parts Methyl ethyl ketone 280.0 parts ─────────────────────────── ────────

────────────────────────────────────
Composition of hard coat layer coating solution (HCL-12) ------------------------
PETA 600.0 parts Irgacure 184 20.0 parts Toluene 392.0 parts Cyclohexanone 137.0 parts ───────────────────────────── ───────

Coating liquids (HCL-11) to (HCL-12) for hard coat layer were applied on a triacetylyl cellulose film “TD80U” (manufactured by Fuji Photo Film Co., Ltd.) with a bar coater so that the dry film thickness was 2 μm. After drying at 60 ° C. for 150 seconds, an air-cooled metal of 160 W / cm under a nitrogen purge is used with a ride lamp (manufactured by Eye Graphics Co., Ltd.) so that the oxygen concentration is 1.0% by volume or less. The hardened layers (HC-11) to (HC-12) were formed by curing the coating layer by irradiating with UV light of / cm ² and an irradiation amount of 250 mJ / cm ² . The contact angle of water and methylene iodide was measured using Contact-Angle meter (Kyowa Interface Chemical Co., Ltd. 10927) as the contact angle of the obtained hard coat layer to obtain surface free energy. The results are shown in Table 3.

(4) Surface energy of substrate The contact angle of the transparent plastic film substrate of Example 1-1 (triacetyl cellulose film “TD80U” (manufactured by Fuji Photo Film Co., Ltd.)) was similarly measured, and the surface Got free energy. The results are shown in Table 3.
Moreover, the contact angle was measured about the transparent plastic film base material (corona surface-treated) of Example 1-2, and surface free energy was obtained. The results are shown in Table 3.

  From the above results, the surface free energy of the silica fine particles contained in the silica dispersion A is surface-modified with a fluorine-containing silane coupling agent, so that a cured film HC-11 formed by curing only the binder resin of the hard coat layer, The surface free energy is lower than the surface of HC-12. It is considered that the surface uneven distribution of the silica fine particles occurs due to a decrease in the surface free energy of the silica fine particles.

[Saponification treatment of antireflection film]
After the production of the antireflection film samples, the following treatments were performed on these antireflection film samples.
A 1.5 mol / L aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / L dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The prepared antireflection film was immersed in this aqueous sodium hydroxide solution for 2 minutes and then immersed in water to thoroughly wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.

[Evaluation of antireflection film]
(1) Average reflectance Using a spectrophotometer (manufactured by JASCO Corporation), the spectral reflectance of each antireflection film sample at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. The average reflectance of 450-650 nm was used for the result.

(2) Steel Wool (SW) Scratch Resistance Evaluation A rubbing test was performed on the antireflection film sample using a rubbing tester under the following conditions.
Evaluation environmental conditions: 25 ° C., 60% RH.
Rubbing material: Steel wool (manufactured by Nippon Steel Wool Co., Ltd., “Grade No. 0000”) was wound around the rubbing tip (1 cm × 1 cm) of a tester in contact with the sample, and the band was fixed so as not to move.
Moving distance (one way): 13 cm, rubbing speed: 13 cm / sec, load: 1.96 N / cm ² .
Tip contact area: 1 cm × 1 cm, rubbing frequency: 10 reciprocations.

An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria.
A: Even when viewed very carefully, no scratches are visible.
○: Slightly weak scratches are visible when viewed very carefully.
Δ: Moderate scratches are visible.
X: There are scratches that can be seen at first glance.

(3) Measurement of [B / A] × 100, [D / C] × 100 It was measured by the method described in the specification.

(4) Evaluation of dust-proofing property The transparent support side of the optical film sample is attached to the CRT surface, and dust and tissue paper waste of 0.5 μm or more are applied to 0.028 m ^3, that is, 1 to ² million per 1 ft ³ (cubic feet). Used in a private room for 24 hours. The number of adhering dust and tissue paper waste per 100 cm ^{2 of the} optical film was measured, and the average value of each result was evaluated as follows.
◎: Less than 20 ○: 20-49 △: 50-199 ×: 200 or more

(5) Evaluation of interference spots (unevenness) A sample with a back surface rubbed with sandpaper and black magic applied to prevent reflection on the back surface is placed on a desk. -The sample was illuminated with ED-D / 18), interference spots were observed, and a three-stage evaluation was performed according to the following criteria.
◎: Interference spots were not visible ○: Interference spots were almost inconspicuous ×: Interference spots were clearly recognized

From the results shown in Table 4, the following is clear.
The antireflective film of the present invention using surface-modified low refractive index fine particles has a low reflectivity, excellent anti-dust adhesion and scratch resistance, and is free from interference spots after a single application of the curable composition. was gotten.
With respect to the antiglare hard coat film of Example 2-1, by using the curable composition of the present invention, it is possible to impart surface reflectance reduction, dust adhesion prevention, and scratch resistance.
Moreover, in the PET film which is a high refractive index plastic film from the result of the hard coat film shown in Example 3-1, there is a problem of interference spots due to the difference in refractive index between the base material and the hard coat layer (Comparative Example). 3-1) In the present invention, due to the uneven distribution of the high refractive index fine particles on the substrate surface, a refractive index gradient can be applied from the substrate surface toward the hard coat layer, and interference spots can be prevented.

When a cross section of Samples 101 to 107 was photographed at a magnification of 150,000 times using a transmission electron microscope, hollow silica particles that are low refractive fine particles in the example samples and in which cavities are seen are formed on the surface of the hard coat layer. We were able to observe the ubiquitous distribution. The degree of surface uneven distribution is as shown by the value of [B / A] × 100 in Table 4.
In addition, silica particles in which no cavity was found were uniformly dispersed in the hard coat layer.
Similarly, it was observed that ATO fine particles were unevenly distributed on the support side of the hard coat layer. The degree of uneven distribution on the support side is as indicated by the value of [D / C] × 100 in Table 4.
Further, Sample 101 of Example 1-1 and Sample 102 of Example 1-2 were observed to have a structure like a layer having a thickness of about 100 μm in which low refractive index fine particles were concentrated on the surface. Further, in Sample 102 of Example 1-2, a structure like a layer having a thickness of about 200 μm in which high refractive index fine particles were concentrated on the substrate side was observed.

<Production of polarizing plate, liquid crystal display device>
Examples 11-1 to 11-3
Next, after immersing the antireflection film samples 101, 102, and 104 of Examples 1-1 to 1-2 and 2-1 in a 1.5 mol / L, 55 ° C. NaOH aqueous solution for 2 minutes, respectively. Adhesion and protection on both sides of a polarizer made by adsorbing iodine to polyvinyl alcohol and stretching a 80 μm thick triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) washed with water and water. Each of the polarizing plates with antireflection was prepared by laminating the polarizing plate produced in the above manner.
Using this polarizing plate, a liquid crystal display device having an antireflection layer disposed on the outermost layer was produced. As a result, the reflectance was low, the reflection of external light was small, the reflected image was not noticeable, and excellent visibility was obtained. It was.

Example 21-1
A triacetyl cellulose film “TAC-TD80U” (manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 1.5 μm / L, immersed in an aqueous NaOH solution at 55 ° C. for 2 minutes, neutralized and washed with water. The polarizing plate was prepared by adhering and protecting the antireflection film sample 102 of Example 1-2 on both surfaces of a polarizing film prepared by adsorbing iodine to polyvinyl alcohol and stretching it.
The thus-prepared polarizing plate is a liquid crystal display device of a notebook personal computer equipped with a transmission type TN liquid crystal display device so that the antireflection film side becomes the outermost surface {Sumitomo 3M Co., Ltd., which is a polarization separation film having a polarization selection layer] When "D-BEF" made by the company is replaced with the polarizing plate on the viewing side of "D-BEF" between the backlight and the liquid crystal cell, both have low reflectivity, very little background reflection, and very high display quality. A display device that is high and has excellent dust prevention properties was obtained.

<Liquid crystal display device>
Examples 31-1 to 31-3
The protective film on the liquid crystal cell side of the polarizing plate on the viewing side and the protection on the liquid crystal cell side of the polarizing plate on the backlight side of the transmission type TN liquid crystal cell to which the antireflection film samples 101, 102 and 104 of the present invention are respectively attached. As a film, a wide viewing angle film “Wide View Film SA 12B” (manufactured by Fuji Photo Film Co., Ltd.) is used. A device was obtained.

Claims (18)

  A cured layer containing a low refractive index fine particle, a high refractive index fine particle and a binder is formed on a transparent plastic film substrate, and the low refractive index fine particles are unevenly distributed on the surface side of the cured layer. An optical film characterized by uneven distribution of high refractive index fine particles.   The optical film according to claim 1, wherein a refractive index of the low refractive index fine particles is 1.50 or less.   The optical film according to claim 1, wherein a refractive index of the high refractive index fine particles is 1.60 or more.   This is the ratio of the average filling rate (B) of the low refractive index fine particles in the 100 nm film thickness on the surface side of the hardened layer to the average filling rate (A) of the low refractive index fine particles in the entire hardened layer [(B / A ) × 100] is 150% or more. The optical film according to claim 1.   The ratio of the average filling rate (D) of the high refractive index fine particles in the film thickness of 100 nm on the substrate side of the cured layer to the average filling rate (C) of the high refractive index fine particles in the entire cured layer [[D / The optical film according to claim 1, wherein C) × 100] is 150% or more.   6. The optical film according to claim 1, wherein the surface of the low refractive index fine particles has a surface free energy reduced by chemical modification.   The optical surface according to claim 6, wherein the surface of the low refractive index fine particles is chemically surface-modified so that the surface free energy is lower than the surface of a cured film formed by curing only a binder resin. the film.   The optical film according to claim 1, wherein the low refractive index fine particles are silica fine particles.   The optical film according to claim 1, wherein the low refractive index fine particles are hollow silica fine particles.   The optical film according to claim 1, wherein the surface of the high refractive index fine particles has a surface free energy higher than that of a cured film formed by curing only a binder resin.   The optical film according to claim 1, wherein the high refractive index fine particles are conductive fine particles.   The optical film according to any one of claims 1 to 9, wherein the transparent plastic film substrate has been subjected to a treatment for increasing surface free energy before the curable composition is applied.   The cured layer is formed by coating the curable composition on a transparent plastic film and then floating the low refractive index fine particles before settling, precipitating the high refractive index fine particles, and then curing. The optical film according to claim 1, wherein the optical film is a film.   The average film thickness of the said hardened layer is 1.0-20.0 micrometers, The optical film in any one of Claims 1-13 characterized by the above-mentioned.   A polarizing plate comprising the optical film according to claim 1 as at least one of a protective film for a polarizing film.   Polarized light characterized in that the optical film according to any one of claims 1 to 14 is used for one of the protective films for the polarizing film, and an optical compensation film having optical anisotropy is used for the other protective film for the polarizing film. Board.   An image display device, wherein the optical film according to claim 1 or the polarizing plate according to any one of claims 15 to 16 is disposed on an image display surface.   18. The image display device according to claim 17, wherein the image display device is a transmissive, reflective, or transflective liquid crystal display device in any one of TN, STN, IPS, VA, and OCB modes.