JP2009265651A - Optical film, polarizing plate, and image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film which has superior antiglare and black sharpness properties, definition and surface contrast, and stability of surface quality, to provide a polarizing plate with the optical film, and to provide an image display apparatus. <P>SOLUTION: The optical film has an antiglare layer on a transparent supporter, and the antiglare layer has a translucent resin and translucent particles, wherein the antiglare layer has a film thickness of 6 to 10 μm and the translucent particles have a particle size of 7 to 15 μm. Further, the absolute value of the difference in refractive index between the translucent particles and translucent resin is 0.001 to 0.050 and the antiglare layer contains 15 to 40 mass% of the translucent particles for the overall solid content in the antiglare layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical film, a polarizing plate having the optical film, and an image display device.

  In various image display devices such as liquid crystal display (LCD), plasma display panel (PDP), electroluminescence display (ELD), and cathode ray tube display (CRT), contrast reduction due to reflection of external light and image reflection In order to prevent this, an antiglare film or an antiglare antireflection film is used on the surface of the display. Widespread use in office and home environments, improved anti-glare properties to prevent indoor fluorescent lights and viewer images from appearing on the display surface, and display contrast (especially surface contrast) in bright places Further improvements are required.

  In order to improve the display contrast, there is a method for improving the surface contrast by reducing the light scattering property. However, it is also required that the display market size be uniform and the display quality with a fineness of about 100 ppi (hereinafter referred to as “glare”) not be impaired by the increase in the size of the display market.

  Anti-glare film that obtains anti-glare properties by scattering light by providing irregularities on the surface may reduce the image quality that black in bright places will not be tightened due to light scattering on the surface, and anti-glare properties It is desired to balance black tightening.

  As means for improving the antiglare property and the black tightening, an antiglare film containing fine particles having an average particle size of 1.5 μm to 7 μm (for example, see Patent Document 1) and fine particles having an average particle size of 6 μm to 15 μm. An antiglare film (for example, refer to Patent Document 2) containing benzene has been proposed.

  The anti-glare films shown in the examples of Patent Document 1 have a haze value indicating scattering of 8% or less or 50% or more. When low, the glare is poor, and when high, the display contrast is expected to decrease. Is done.

  The anti-glare film shown in the example of Patent Document 2 has a film thickness of 21 μm to 33 μm, so the surface quality due to the film thickness unevenness is not stable. Entering or curling is expected.

  When the anti-glare film of Patent Document 1 is used on the surface of a liquid crystal display (LCD), when a three-wavelength fluorescent lamp is reflected on the display surface, an rainbow color is generated around the reflected fluorescent lamp by internal reflection from the panel. Since the unevenness of the shape was visible, improvement was desired.

JP-A-2005-316450 JP 2007-41533 A

  An object of the present invention is an optical film that is excellent in antiglare property, black tightening property, glare and surface contrast, stability of surface quality, and is difficult to see unevenness of rainbow-colored surroundings of a reflected image and unevenness of a display device. Is to provide with good reproducibility. Another object of the present invention is to provide a polarizing plate and an image display device provided with the optical film.

  As a result of intensive studies, the inventors of the present invention set the translucent particles contained in the antiglare layer to a specific particle size and a specific refractive index in the optical film having the antiglare layer on the transparent support. The content is also specified, internal reflection from the panel is suppressed, and the film thickness of the antiglare layer is controlled within a specific range to stabilize / suppress the surface shape and curl, thereby providing antiglare and black tightening properties. The present inventors have found that an antiglare film excellent in glare and surface contrast can be produced with good reproducibility. Further, when the antiglare film of the present invention is used on the surface of an image display device such as a liquid crystal display device (LCD), even if a three-wavelength fluorescent lamp is reflected on the display surface, unevenness on the rainbow color does not occur. I found it.

That is, the present inventors achieved the above object with the following configurations.
1.
An optical film having an antiglare layer on a transparent support, the antiglare layer comprising (i) a translucent resin, (ii) a molecular weight of 3,000 to 400,000, and irradiation with ionizing radiation Or a polymer compound that does not cure by heating, and (iii) translucent particles, the film thickness of the antiglare layer is 6 μm to 10 μm, and the average particle diameter of the translucent particles is 7 μm to 15 μm. The absolute value of the difference in refractive index between the translucent particles and the translucent resin is 0.001 to 0.050, and the total of the translucent particles is based on the total solid content in the antiglare layer. An optical film of 15 to 40% by mass.
2.
2. The optical film as described in 1 above, wherein the antiglare layer further comprises (iv) a resin having a molecular weight of 600 to 50,000.
3.
3. The optical film as described in 2 above, wherein (iv) the resin having a molecular weight of 600 to 50,000 is a resin obtained by curing a compound having two or more ethylenically unsaturated groups.
4).
4. The optical film as described in any one of 1 to 3 above, comprising at least two kinds of the light transmissive particles, wherein the light transmissive particles have different refractive indexes.
5.
The translucent particles include at least two types of translucent particles A and translucent particles B, and the translucent particles A and translucent particles B satisfy any of the following conditions: Optical film.
(Refractive index of translucent particle A) − (refractive index of translucent resin) = 0.100 to 0.050
(Refractive index of translucent particle B) − (refractive index of translucent resin) = − 0.050 to −0.010
6).
5. The optical film according to any one of 1 to 4, wherein the translucent particles include at least two types of translucent particles A and translucent particles B, and the translucent particles A and the particles B satisfy the following conditions. .
Absolute value of difference between refractive index of translucent particle A and refractive index of translucent resin = 0.015 to 0.050
6. Absolute value of difference between refractive index of translucent particle B and refractive index of translucent resin = 0.001 or more and less than 0.015
7. The optical film as described in 5 or 6 above, wherein a mass ratio of the translucent particles A and the translucent particles B (translucent particles A: translucent particles B) is 20:80 to 80:20.
8).
8. The optical film as described in any one of 1 to 7 above, which contains at least two kinds of the light-transmitting particles, and the average particle diameter of the light-transmitting particles is different from each other.
9.
The optical film as described in any one of 1 to 8 above, which has an antiglare layer and an overcoat layer in this order on the transparent support.
10.
10. The optical film as described in any one of 1 to 9 above, further having a layer having a lower refractive index than the antiglare layer or the overcoat layer.
11.
11. The optical film as described in any one of 1 to 10 above, wherein the haze value resulting from surface scattering is from 0.2% to 10%.
12
The optical film as described in any one of 1 to 11 above, wherein the haze value resulting from internal scattering is 10 to 35%.
13.
13. The optical film as described in any one of 1 to 12 above, wherein the integrated reflectance is 3.0% or less.
14
14. The optical film as described in any one of 1 to 13 above, wherein the center line average roughness Ra is 0.05 μm or more and 0.25 μm or less, and the average interval Sm between the irregularities is 50 μm or more and 350 μm or less.
15.
15. The optical film as described in any one of 1 to 14 above, wherein the average inclination angle θa is 0.5 ° or more and 3.0 ° or less, and the maximum value of the inclination angle distribution is 0.3 ° or less.
16.
It is a polarizing plate which has a polarizing film and two protective films which protect both the front side and back side of this polarizing film, Comprising: At least one of this protective film is an optical film in any one of said 1-15. A polarizing plate.
17.
16. An image display device comprising the optical film according to any one of 1 to 15 or the polarizing plate according to 16.

  According to the present invention, an optical film that is excellent in antiglare and blackness, glare and surface contrast, surface quality stability, and is difficult to see irregularities in iridescent surroundings of reflected images and display devices. Can be provided. Further, according to the present invention, when used on the surface of a polarizing plate equipped with the optical film and a liquid crystal display (LCD), even when a three-wavelength fluorescent lamp is reflected on the display surface, iridescent unevenness occurs. It is possible to provide an image display device that is difficult to perform.

It is a figure explaining the method to measure the average inclination angle of the antireflection film of this invention.

  Hereinafter, the present invention will be described in more detail. In the present specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”. . In the present specification, the description “(meth) acrylate” means “at least one of acrylate and methacrylate”. The same applies to “(meth) acrylic acid” and the like.

<Layer structure of optical film>
The optical film of the present invention is an optical film having an antiglare layer on a transparent support, and the antiglare layer comprises (i) a translucent resin and (ii) a molecular weight of 3,000 to 400,000. And (iii) translucent particles, and the antiglare layer has a thickness of 6 μm to 10 μm, and the average particle of the translucent particles The diameter is 7 μm to 15 μm, the absolute value of the refractive index difference between the translucent particles and the translucent resin is 0.001 to 0.050, and the total of the translucent particles is the antiglare layer It is 15-40 mass% with respect to the total solid content.

  The optical film of the present invention has at least one antiglare layer on a transparent support. The antiglare layer of the present invention is a layer having a light diffusing function using surface scattering or internal scattering, or both, and the antiglare layer may be a single layer or a plurality of layers, for example, 2 to 4 layers. May be.

The example of the preferable layer structure of the optical film of this invention is shown below. In the following configuration, the base film refers to a transparent support composed of a film.
・ Base film / antiglare layer ・ Base film / antistatic layer / antiglare layer ・ Base film / antiglare layer / low refractive index layer ・ Base film / antiglare layer / antistatic layer / low refractive index layer -Base film / hard coat layer / antiglare layer / low refractive index layer- Base film / hard coat layer / anti-glare layer / antistatic layer / low refractive index layer-Base film / hard coat layer / antistatic layer / Anti-glare layer / Low refractive index layer -Base film / Anti-glare layer / High refractive index layer / Low refractive index layer -Base film / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer・ Antistatic layer / Base film / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer ・ Base film / Antistatic layer / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer ・ Antistatic layer / Base film / Anti-glare layer / High refractive index layer / Low refractive index layer / High refractive index layer / Low refractive index layer ・ Base film / Anti-glare layer Overcoat layer • Base film / antistatic layer / antiglare layer / overcoat layer • Base film / antiglare layer / overcoat layer / low refractive index layer • Base film / antiglare layer / overcoat layer / high Refractive index layer / low refractive index layer-base film / antiglare layer / overcoat layer / medium refractive index layer / high refractive index layer / low refractive index layer-antistatic layer / base film / antiglare layer / overcoat Layer / medium refractive index layer / high refractive index layer / low refractive index layer

  In the optical film of the present invention, layers other than the antiglare layer may be coated. Examples of these layers include a hard coat layer, an overcoat layer, an antistatic layer, a low refractive index layer, and an antifouling layer. Etc. More preferably, the antiglare layer has functions such as a hard coat layer, an antistatic layer, and an antifouling layer at the same time. It is preferable that at least one of the medium refractive index layer and the high refractive index layer having the above configuration also functions as an antistatic layer. In the case of a three-layer configuration of a medium refractive index layer / a high refractive index layer / a low refractive index layer, the medium refractive index layer also functions as an antistatic layer from the viewpoint of realizing desired antistatic properties and refractive index. Particularly preferred.

  In the present invention, an antireflection film comprising a medium refractive index layer / a high refractive index layer / a low refractive index layer is preferable from the viewpoint of low reflection. For example, JP-A-8-122504 and 8-110401 are preferable. The configurations described in Japanese Patent Laid-Open No. 10-300902, Japanese Patent Laid-Open No. 2002-243906, Japanese Patent Laid-Open No. 2000-11706, and the like can be given. In terms of simple production and high productivity, the preferred form of the present invention is an optical film having a single antiglare layer on a support, and a single antiglare layer and a single layer on a support. It is an antireflection film having a low refractive index layer in this order.

<Configuration of antiglare layer>
The antiglare layer of the present invention is applied and dried with a coating solution containing translucent particles having an average particle diameter of 7 μm to 15 μm, matrix-forming components (such as binder monomers) that form a translucent resin, and an organic solvent. It is a layer formed by curing.
In the present invention, the 50% volume diameter (median diameter) obtained from the obtained particle distribution is defined as the average particle diameter. This can be measured, for example, with a laser diffraction / scattering particle size distribution measuring apparatus [Mastersizer 2000 (trade name), manufactured by Malvern, Inc.].

  The coating liquid for forming the antiglare layer is, for example, a matrix-forming component that becomes a raw material of a translucent resin (translucent polymer) formed by curing with ionizing radiation, the translucent particles having the specific particle size, polymerization It contains an initiator, and preferably further contains a polymer compound for adjusting the viscosity of the coating solution, an inorganic filler for curling reduction and refractive index adjustment, a coating aid and the like.

  The thickness of the antiglare layer is 6 μm to 10 μm, more preferably 6.5 μm to 10 μm, and most preferably 7 μm to 9 μm. When the thickness is less than 6 μm, the surface unevenness becomes too large when the translucent particles described below are used, and the black tightening deteriorates, and when it exceeds 10 μm, the curl deteriorates.

  The film thickness of the antiglare layer can be expressed, for example, by observing the cross section of the antiglare layer with a scanning electron microscope and averaging the thickness in the normal direction from the substrate.

<Translucent particles of antiglare layer>
The average particle diameter of the translucent particles is 7.0 μm to 15 μm, more preferably 7.5 μm to 12 μm, and further preferably 8.0 μm to 12 μm. When the particle diameter is within this range, the antiglare property and black tightening are excellent.

In the present invention, the translucent particles can include at least two kinds from the viewpoint of the light scattering property described later. It is desirable that the average particle diameter and / or refractive index of at least two kinds of translucent particles are different from each other. Although the aspect containing only 2 types of the translucent particle | grains A and the translucent particle | grains B is preferable, the particle C of the same particle diameter as either one of the translucent particle | grains A or the translucent particle | grains B can further be included. . When the particles C are included, the absolute value of the difference in refractive index between the particles C and the translucent resin is preferably less than 0.001, or 0.051 to 0.100, more preferably less than 0.001 or 0.00. 051 to 0.080, and most preferably less than 0.001 or 0.051 to 0.070.
In the present invention, the translucent particles are dispersed in a coating solution for forming an antiglare layer, and this is coated, dried and cured on a support to form an antiglare layer. The average particle diameter of the translucent particles refers to the primary particle diameter regardless of whether two or more particles are present adjacent to each other in the coating film or independently. However, when the agglomerated inorganic particles having a primary particle size of about 0.1 μm are dispersed as secondary particles in the coating liquid in a size satisfying the particle size of the present invention, and then applied, the secondary particles The size of

  The average particle diameter of the translucent particles A and the translucent particles B is preferably different from each other, and the absolute value of the difference between the average particle diameter of the translucent particles A and the average particle diameter of the translucent particles B is It is 0.5-8 micrometers, More preferably, it is 1-6 micrometers, Most preferably, it is 2-5 micrometers. When the absolute value of the difference in average particle diameter is outside the above range, the surface form changes, which is not preferable from the viewpoint of antiglare property and blackening.

The present invention can be achieved by independently controlling the internal scattering property and the surface scattering property.
Control of internal scattering and surface scattering will be described later. Internal scattering is determined by haze due to internal scattering (hereinafter referred to as “internal haze”), and surface scattering is determined by haze due to surface scattering. (Hereinafter referred to as “surface haze”).

  In the present invention, in order to obtain necessary internal scattering properties, it is preferable to adjust the refractive indexes of the light-transmitting particles and the light-transmitting resin (matrix) of the antiglare layer. The absolute value of the difference in refractive index between the translucent particles and the translucent resin is preferably 0.001 to 0.050, more preferably 0.015 to 0.040, and most preferably 0.010 to 0. .030. When two or more kinds of translucent particles are used, the difference in refractive index between the particles A and the particles B may be 0, but they are preferably different.

  It is preferable that one of the particles A and the particles B has a lower refractive index than the matrix and the other has a higher refractive index than the matrix. For example, among the particles A and B, particles having a higher refractive index than the matrix preferably have a refractive index of 0.010 to 0.050 higher than that of the translucent resin, and those having a higher refractive index of 0.010 to 0.030 are more preferable. preferable. The particles having a refractive index lower than that of the matrix preferably have a refractive index of 0.010 to 0.050 lower than that of the translucent resin, and more preferably 0.010 to 0.030 lower. Since there is a difference in refractive index between the particles A and the particles B, the internal scattering and the surface shape can be easily controlled. In addition, by using the particles A and B with the refractive index up and down with respect to the matrix in this way, surprisingly, when used on the surface of a liquid crystal display device (LCD), it results from the image display unit. Unevenness does not occur. Further, the fluctuation of internal haze at high temperature or high temperature and high humidity is small.

  Apart from this, it is also preferable that the absolute value of the difference between the refractive index of at least two kinds of translucent particles and the refractive index of the translucent resin is different. For example, the absolute value of the difference between the refractive index of one of the particles A or the particles B and the refractive index of the translucent resin is preferably 0.015 to 0.050, and more preferably 0.015 to 0.040. Most preferably, it is 0.020-0.030. The absolute value of the difference between the refractive index of the other translucent particle and the refractive index of the translucent resin is preferably 0.001 or more and less than 0.015, and more preferably 0.005 to 0.010.

  The mass ratio of the particles A and the particles B is preferably 20:80 to 80:20, more preferably 25:75 to 75:25, from the viewpoint of reducing internal haze at high temperature or high temperature and high humidity. 30: 70-70: 30 is still more preferable.

  The addition amount of the translucent particles is 15 to 40% by mass in the total solid content of the antiglare layer, preferably 15 to 35% by mass, and more preferably 20 to 30% by mass. When the added amount is within this range, when used on the surface of an image display device such as a liquid crystal display device (LCD), even if a three-wavelength fluorescent lamp is reflected on the display surface, iridescent unevenness does not occur. Here, the total solid content is a component excluding the (organic) solvent in the coating solution. When at least two kinds of particles are used, the amount is preferably 0.2% by mass to 99.8% by mass, more preferably 1% by mass to 99% by mass, and most preferably based on the total particle A or A ′. Is 5% by mass to 95% by mass. When the particles have this ratio, it becomes easy to control the internal scattering property and the surface shape, which are the effects of the present invention.

The cause of iridescent unevenness is not clear, but is estimated as follows. When rainbow-colored irregularities are reflected in a display with a three-wavelength fluorescent lamp in a dark room, for example, internally reflected light reflected by a glass plate, polarizing plate, electric circuit, or black matrix in a liquid crystal display device This is presumed to occur around the regular reflection image. In addition, the unevenness caused by the image display unit can be observed as a striped or concentric display unevenness in a state of gray solid display depending on the liquid crystal display device. Although the cause is not clear, it is presumed to be a phenomenon caused by interference between the shadows of the backlight and the black matrix.
In order to prevent this phenomenon, it is necessary to increase the internal scattering property or the surface scattering property of the light scattering layer. However, when the internal scattering property is increased, there is a problem that the display contrast is lowered, and when the surface scattering property is increased, there is a problem that blackening is reduced. The particle diameter, refractive index, and filling amount of the present invention were able to prevent the occurrence of iridescent unevenness by reflection of a three-wave fluorescent lamp without deteriorating display contrast and blackening.

  The reason why the internal haze fluctuation is small at high temperature or high temperature and high humidity by using the particles A and B with the refractive index up and down with respect to the matrix is not clear, but the refractive index of the matrix fluctuated. It is estimated that the difference in refractive index between the matrix and the particles cancels out.

  The translucent particles can be selected from the particles described below according to the desired refractive index and average particle size.

  In the present invention, resin particles and / or inorganic fine particles are used as the translucent particles.

Specific examples of the resin particles include, for example, crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles, crosslinked polystyrene particles, crosslinked methyl methacrylate-methyl acrylate copolymer particles, crosslinked acrylate-styrene copolymer particles, Preferred examples include resin particles such as melamine / formaldehyde resin particles and benzoguanamine / formaldehyde resin particles. Of these, crosslinked styrene particles, crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles, and the like are preferable. Furthermore, the surface of these resin particles is a so-called surface-modified particle in which a compound containing a fluorine atom, a silicon atom, a carboxyl group, a hydroxyl group, an amino group, an sulfonic acid group, a phosphoric acid group or the like is chemically bonded, or a nano particle such as silica or zirconia. The particle | grains which couple | bonded the size inorganic particle to the surface are also mentioned preferably.
Moreover, inorganic fine particles can also be used as the translucent particles. Specific examples of the inorganic fine particles include silica particles and alumina particles, and silica particles are particularly preferably used.

  In the present invention, when uneven coating or interference non-uniformity is made inconspicuous, or from the viewpoint of cost, the refractive index of the matrix of the antiglare layer is 1.54 or less, particularly preferably 1.53 or less. The translucent particles are preferably crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles, and silica particles. When using crosslinked methyl methacrylate-styrene copolymer particles, the copolymerization ratio of styrene is preferably 10% or more and 90% or less.

  As the shape of the particle, either a true sphere or an irregular shape can be used. The particle size distribution is preferably monodisperse particles because of the haze value, controllability of diffusibility, and uniformity of the coated surface. The CV value representing the uniformity of the particle diameter is preferably 15% or less, more preferably 13% or less, and still more preferably 10% or less. Furthermore, when particles having a particle size of 33% or more than the average particle size are coarse particles, the proportion of the coarse particles is preferably 1% or less of the total number of particles, more preferably 0.8% or less. Yes, and more preferably 0.4% or less. If there are too many coarse particles, the roughening of the surface will be recognized with emphasis, and the rough feeling will deteriorate, which is not preferable.

  For example, when particles having a particle diameter of 16% or more smaller than the average particle diameter are used as the fine particles, the proportion of the fine particles is preferably 10% or less of the total number of particles, more preferably 6% or less. More preferably, it is 4% or less. Particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification. It is preferable to use a method such as an air classification method, a centrifugal classification method, a sedimentation classification method, a filtration classification method, or an electrostatic classification method for classification.

  The particle size distribution of the particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution. The average particle diameter is calculated from the obtained particle distribution, or the particles are observed with a transmission electron microscope (magnification of 500,000 to 2,000,000 times), and 100 particles are observed. There is a way to do it. In the present invention, the average particle diameter is a value obtained by the Cole counter method.

  The refractive index of the translucent particles is a solvent in which the refractive index is changed by changing the mixing ratio of two kinds of solvents having different refractive indexes selected from methylene iodide, 1,2-dibromopropane, and n-hexane. The turbidity is measured by dispersing an equal amount of translucent particles therein, and the refractive index of the solvent when the turbidity is minimized is measured by an Abbe refractometer.

[Surface form]
In the present invention, it is desirable to achieve both good antiglare property and black tightening. Regarding anti-glare properties, in practice, it is desirable to show good anti-glare properties when various light sources are reflected from various angles. As a result of diligent efforts by the inventors, it has been found that such reflections can be easily evaluated by changing the viewing angle when the light source is reflected. It is desirable to show good reflection with both a large-sized light source (for example, a fluorescent lamp) and a thin light source (for example, a linear light source made by simulating a fluorescent lamp with a cover). As for black tightening, it is desirable to achieve good black tightening both when viewed from the vertical direction of the display in a bright room environment and when viewed at an angle of about 45 °. In order to achieve an excellent antiglare property and black tightening by evaluating with such an index, it is desirable to achieve a specific surface form within the above film thickness range. Preferred ranges such as the average particle size and refractive index of the above particles are desirable requirements for achieving a specific surface morphology with the above film thickness. The preferable surface form (surface unevenness | corrugation) of the optical film of this invention is described below.

  In the optical film of the present invention, the haze value resulting from surface scattering is preferably 0.2 to 10%, and more preferably 0.5 to 5%. When the surface haze is too large, the black tightening is deteriorated, and when it is too small, the antiglare property is deteriorated.

  The center line average roughness Ra is preferably 0.05 μm or more and 0.25 μm or less, more preferably 0.10 μm or more and 0.20 μm or less, and most preferably 0.12 μm or more and 0.18 μm or less. The center line average roughness Ra can be measured in accordance with JIS-B0601 (1982). If Ra is too large, black tightening is caused, and bright room contrast is deteriorated. If Ra is too small, antiglare property is deteriorated.

In order to obtain a surface form suitable for achieving both antiglare properties and black tightening, the average interval Sm of the unevenness is also important. The average interval Sm of the irregularities is preferably 50 μm or more and 350 μm or less, more preferably 60 μm or more and 200 μm or less, or 250 μm or more and 350 μm or less, and most preferably 60 μm or more and 150 μm or less or 300 or more and 350 μm or less.
The average interval Sm of the unevenness can be measured in accordance with JIS-B0601 (1994). If Sm is too large, the reflection of a large light source becomes easy to see. If Sm is too small, the black tightening is deteriorated and the edge blur of a thin light source (line light source) is weak, which is not preferable. When Sm is 200 to 250 μm, surface roughness is strong and the appearance is not good.

In order to improve the bright room contrast, it is necessary to simultaneously control the average inclination angle θa to a specific range. The average inclination angle θa is preferably from 0.5 ° to 3.0 °, more preferably from 0.6 ° to 2.5 °, and most preferably from 0.6 ° to 2.0 °. . If the average inclination angle is too large, black tightening is deteriorated and edge blurring of a thin light source (line light source) is weakened. If the average inclination angle is too small, the reflection of a large-sized light source becomes easy to see, which is not preferable.
The maximum value of the inclination angle distribution is preferably 0.3 ° or less, more preferably 0.28 ° or less, and most preferably 0.25 ° or less.

  The average inclination angle of the optical film of the present invention is determined by the following method. That is, a triangle formed by three points where the vertex of a triangle having an area of 0.5 to 2 square micrometers is assumed on the transparent film substrate surface, and three perpendiculars extending vertically upward from the point intersect the film surface. The angle between the normal of the surface and the perpendicular extending vertically upward from the support is defined as the inclination angle of the surface, and an area of 250,000 square micrometers (0.25 square millimeters) or more on the substrate is divided into the triangles. The average value of all the measurement points when measured in this manner is calculated as the average inclination angle.

  A method for measuring the tilt angle will be described in more detail. The film is divided into meshes having an area of 0.5 to 2 square micrometers as shown in FIG. FIG. 1B is a diagram in which three points of the divided mesh are extracted. A perpendicular line is extended vertically upward from three points on the support, and points where the three points intersect the surface are designated as A, B, and C. An angle θ formed by a normal line DD ′ of the triangle ABC plane and a perpendicular line OO ′ extending vertically upward from the support is defined as an inclination angle. FIG. 1C is a cross-sectional view of the film taken along a plane P including the point O′DD ′. A line segment EF is an intersection line between the triangle ABC and the plane P. The measurement area is preferably 250,000 square micrometers (0.25 square millimeters) or more on the support, and this surface is divided into triangles on the support and measured to determine the inclination angle. There are several devices to measure, but an example will be described. A case will be described in which an SXM520-AS150 model manufactured by Micromap (USA) is used as the apparatus. For example, when the objective lens is 10 times, the measurement unit of the tilt angle is 0.8 square micrometers, and the measurement range is 500,000 square micrometers (0.5 square millimeters). If the magnification of the objective lens is increased, the measurement unit and the measurement range are reduced accordingly. The measurement data can be analyzed using software such as MAT-LAB to calculate the inclination angle distribution, and the average inclination angle can be calculated based on the data.

By setting the surface haze and surface roughness within these ranges, an optical film excellent in blackening can be obtained.
Moreover, it is preferable that the haze value resulting from internal scattering is 10 to 35%, more preferably 12 to 33%, and most preferably 15 to 30%. By setting the internal haze in this range, it is possible to satisfy practically two performances of lowering the surface contrast and preventing glare. These hazes can be adjusted by adjusting the type and amount of the light-transmitting particles.

The surface haze and internal haze can be measured by the following procedure.
(1) The total haze value (H) of the film is measured according to JIS-K7136.
(2) A few drops of silicone oil were added to the front and back surfaces of the low refractive index region side of the film, and sandwiched from the front and back using two 1 mm-thick glass plates (micro slide glass product number S 9111, manufactured by MATSUNAMI), Two glass plates and a film are optically closely adhered to each other, the haze is measured with the surface haze removed, and only the silicone oil is sandwiched between two separately measured glass plates to subtract the measured haze. The calculated value is calculated as the internal haze (Hi) of the film.
(3) A value obtained by subtracting the internal haze (Hi) calculated in (2) from the total haze (H) measured in (1) above is calculated as the surface haze (Hs) of the film.

<Translucent resin for antiglare layer (binder for matrix formation)>
The binder forming the matrix for forming the antiglare layer (also referred to as “binder”) is not particularly limited, but has a light-transmitting property having a saturated hydrocarbon chain or a polyether chain as the main chain after curing with ionizing radiation or the like. A resin is preferred. Moreover, it is preferable that the main binder polymer after hardening the below-mentioned monomer has a crosslinked structure.

  As the binder polymer having a saturated hydrocarbon chain as a main chain after curing, a polymer of an ethylenically unsaturated monomer selected from the first group of compounds described below is preferred. Moreover, as a polymer which has a polyether chain as a main chain, the polymer by ring-opening of the cyclic ether type monomer chosen from the 2nd group compound described below, for example, an epoxy-type monomer and an oxetane-type monomer, is preferable. Furthermore, a polymer of a mixture of these monomers is also preferable.

  In the present invention, as the first group of compounds, the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure is a (co) polymer of monomers having two or more ethylenically unsaturated groups. Is preferred. In order to increase the refractive index of the binder polymer, the monomer structure preferably contains at least one selected from an aromatic ring, a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom.

  As a monomer having two or more ethylenically unsaturated groups used in a binder polymer for forming an antiglare layer, an ester of a polyhydric alcohol and (meth) acrylic acid {for example, ethylene glycol 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-chlorohexanetetramethacrylate Rate, polyurethane polyacrylate, polyester polyacrylate}, vinylbenzene and its derivatives (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, , Divinylsulfone), (meth) acrylamide (for example, methylenebisacrylamide) and the like.

  Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photoradical polymerization initiator or a thermal radical polymerization initiator. Accordingly, a coating solution containing a monomer having an ethylenically unsaturated group, a photo radical polymerization initiator or a thermal radical polymerization initiator, and particles, and if necessary, an inorganic filler, a coating aid, other additives, an organic solvent and the like. After coating the coating solution on a transparent support, it is cured by a polymerization reaction with ionizing radiation or heat to form an antiglare layer. It is also preferable to perform ionizing radiation curing and thermal curing together. Commercially available compounds can be used as the photo and thermal polymerization initiators, and they are described in “Latest UV Curing Technology” (p. 159, publisher: Kazuhiro Takahisa, publisher; Technical Information Association, 1991). Issued), Ciba Specialty Chemicals Co., Ltd. “photopolymerization initiator” catalog (for example, IRGACURE series, DAROCUR series) and the like.

In the present invention, the epoxy compound described below is preferably used as the second group of compounds in order to reduce the curing shrinkage of the cured film. As these monomers having an epoxy group, monomers having two or more epoxy groups in one molecule are preferable, and examples thereof include JP-A Nos. 2004-264563, 2004-264564, and 2005-37737, Examples thereof include epoxy monomers described in JP-A-2005-37738, JP-A-2005-140862, JP-A-2005-140862, JP-A-2005-140863, and JP-A-2002-322430.
The monomer having an epoxy group is preferably contained in an amount of 20 to 100% by mass with respect to the entire binder matrix constituting the layer for reducing curing shrinkage, more preferably 35 to 100% by mass, and more preferably 50 to 100% by mass. % Content is more preferable.

Examples of photoacid generators that generate cations by the action of light for polymerizing epoxy monomers and compounds include ionic compounds such as triarylsulfonium salts and diaryliodonium salts, and nitrobenzyl esters of sulfonic acids. Non-ionic compounds and the like can be used, and various known photoacid generators such as compounds described in “Organic Materials for Imaging” published by Bunshin Publishing Co., Ltd. (1997) can be used. . Among these, a sulfonium salt or an iodonium salt is particularly preferable, and PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ^{− and the} like are preferable as a counter ion.

  The polymerization initiator is preferably used in a range of 0.1 to 15 parts by mass with respect to 100 parts by mass of the compound of the first group or the second group in the total amount of the polymerization initiator. Is more preferable.

<High molecular compound of antiglare layer>
In the present invention, the antiglare layer contains a polymer compound that is different from the binder and is not cured by irradiation with ionizing radiation or heating. By adding a polymer compound, curing shrinkage can be reduced, and the viscosity of the coating solution can be adjusted.

  The polymer compound has already formed a polymer when added to the coating solution. Examples of the polymer compound include cellulose esters (for example, cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose acetate). Propionate, cellulose acetate butyrate, cellulose nitrate, etc.), urethane acrylates, polyester acrylates, (meth) acrylic acid esters (for example, methyl methacrylate / methyl (meth) acrylate copolymer, methyl methacrylate) / (Meth) ethyl acrylate copolymer, methyl methacrylate / (meth) butyl acrylate copolymer, methyl methacrylate / styrene copolymer, methyl methacrylate / (meth) acrylic acid copolymer, polymethacrylic acid Methyl), Resins such as polystyrene are preferably used.

  The polymer compound is preferably 1 to 50% by mass, more preferably 2 to 2%, based on the total binder matrix contained in the layer containing the polymer compound, from the viewpoint of the effect on curing shrinkage and the effect of increasing the viscosity of the coating solution. It is preferable to contain in 30 mass%. The mass average molecular weight of the polymer compound is from 30,000 to 400,000, preferably from 50,000 to 300,000, and more preferably from 50,000 to 200,000.

<Resin having two or more ethylenically unsaturated groups>
In the present invention, the antiglare layer preferably further contains a resin having a molecular weight of 600 to 50,000. The molecular weight of the resin is more preferably 1,500 to 30,000, further preferably 3,000 to 20,000. The resin is preferably formed by curing a compound having two or more ethylenically unsaturated groups. In other words, in the present invention, two or more ethylenic resins are added to the antiglare layer coating solution. It is preferable to include a compound having an unsaturated group. Examples of the resin include polyfunctional compounds such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols. And oligomers or prepolymers thereof. These may be used in combination of two or more, and the resin having two or more ethylenically unsaturated groups is preferably contained in an amount of 10 to 100%, more preferably 15 to 80%, based on the total amount of the binder matrix, 20 to 60% is more preferable.

  Examples of preferable compounds of the resin having a molecular weight of 600 to 50,000 in the present invention include NK ester series (M-230G, 23G, BPE-500, BPE-1300), NK oligo series manufactured by Shin-Nakamura Chemical Co., Ltd. (U-6HA, UA-100, U-340A), (named above), manufactured by Nippon Kayaku Co., Ltd., Kayrad series (DPCA-20, DPCA-30, DPCA-60, UX-2201, UX- 3204, UX-5000, UXE-1000, UX-8101), (above product names), and the like, but are not limited thereto.

<Dispersant used for translucent particles>
You may use the dispersing agent which has an effect in the aggregation suppression of the above-mentioned translucent particle | grains. The dispersant used in the present invention is a copolymer having an amine value of 1 to 30 mgKOH / g. In the copolymer, amine groups act as adsorbing groups and are adsorbed on the surface of the translucent resin particles, thereby giving steric hindrance between the translucent resin particles. If the particles settle immediately after coating, the particles do not aggregate due to steric hindrance even if they collide with neighboring particles, so that no huge particle aggregation occurs, the surface irregularities of the antiglare layer are reduced, and the blackening effect is achieved. I think it will be obtained. Furthermore, when the low refractive index layer is coated on the antiglare layer, the surface unevenness is small, so the low refractive index layer can be applied uniformly, and the reflectance is lower than when no copolymer is added, The feeling of blackening is improved.

  The amine value of these copolymers in the present invention is 1 to 30 mgKOH / g, preferably 2 to 20 mgKOH / g. Even if the amine value is larger than this, even if the amine value is zero, the dispersibility of the particles is lowered, and it becomes difficult to obtain a darkening feeling. The amine value indicates the total amount of 1,2,3 amines, and is defined as the number of mg of caustic potash equivalent to hydrochloric acid required to neutralize 1 g of the sample. The measuring method is based on JIS K 7237. It is. Further, the addition amount of the copolymer having an amine value of 1 to 30 mgKOH / g is preferably 0.3 to 5.0 wt%, and more preferably 0.5 to 2.0 wt% with respect to the translucent resin particles. If the amount added is larger than this, the transparency of the coating film may be deteriorated, or the dispersion of particles may be caused. On the other hand, if the amount added is less than this, the dispersibility of the particles is lowered, and a darkening feeling cannot be obtained.

  The copolymer having an amine value of 1 to 30 mgKOH / g in the present invention is preferably a block copolymer, and more preferably a modified acrylic block copolymer. When a block copolymer is used, it is possible to combine goodness, dispersibility, and transparency of the coating film.

  Further, the acid value of this block copolymer depends on the presence and type of the acid group from which the acid value is based, but generally it is preferably lower, usually 20 mg-KOH / g or less, preferably 10 mg-KOH / g. g or less.

  The weight average molecular weight (Mw) of the block copolymer is usually in the range of 1000 or more and 100,000 or less. When the molecular weight of the block copolymer is too small, the dispersion stability is lowered, and when it is too large, the dispersibility tends to be lowered.

  Examples of these specific compounds include commercially available wetting and dispersing agents such as a wetting and dispersing agent manufactured by BYK Chemie, Disperbyk-161, Disperbyk-162, Disperbyk-163, Disperbyk-164, Disperbyk-166, Disperbyk-167, Disperbyk-168, Disperbyk-182, Disperbyk-183, Disperbyk-184, Disperbyk-185, Disperbyk-2000, Disperbyk-2001, Disper20k-2001, Disperbyk-2001, Disperk19-Disper20k Pigment dispersant manufactured by Enomoto Kasei Co., Ltd., Disparon DA-703-50, Disparon DA 325, DISPARLON DA-7300, Disparlon 1860, can be used DISPARLON 7004, and the like. Among these, a modified acrylic block copolymer is preferable from the viewpoint of side effects on particle dispersibility and film transparency, and Disperbyk-2000 is particularly effective. The above-mentioned copolymers may be used alone or in combination of two or more.

When the translucent particles contained in the antiglare layer of the present invention are set to a specific particle size and a specific refractive index, and the content thereof is also specified, internal reflection from the panel can be suppressed, and By making the film thickness of the antiglare layer in the range of 6 to 10 μm, the surface shape and curl can be stabilized / suppressed. However, the amount of filling of the particles increases and surface irregularities are easily formed, which causes deterioration of black tightening properties. .
When coarse particles (particle size of 20 μm or more) contained in the light-transmitting particles are present, they are recognized as point defects and become a problem. However, the antiglare layer has a molecular weight of 600 to 50,000, and two or more By containing a polymer having an ethylenically unsaturated group and a molecular weight of 3,000 to 400,000 and not cured by irradiation with ionizing radiation or heating, it becomes difficult to be recognized as a point defect. By using the above-mentioned dispersant (a copolymer having an amine value of 1 to 30 mgKOH / g), the particles are less likely to aggregate and further difficult to be recognized. The reason is not clear, but it is assumed that the particles are less likely to aggregate and difficult to form small surface irregularities, or that the surface viscosity of the film increases during coating and drying, making it difficult to produce small surface irregularities.

  In addition, when the particles aggregate from the coating to the drying process, the surface irregularities are likely to fluctuate during the drying process, but the molecular weight is 3,000 to 400,000, and the polymer is not cured by irradiation with ionizing radiation or heating. Variation of surface irregularities in the drying process by containing a compound and preferably a resin having a molecular weight of 600 to 50,000 and having two or more ethylenically unsaturated groups in the coating solution for the antiglare layer Becomes smaller. Furthermore, the effect is further increased by using the particles A and B having the refractive index up and down with respect to the matrix.

<Inorganic filler for antiglare layer>
In addition to the above light-transmitting particles, the antiglare layer of the present invention can be used for adjusting the refractive index, adjusting the film strength, reducing curing shrinkage, and reducing the reflectance when a low refractive index layer is provided. Inorganic fillers can also be used. For example, it is made of an oxide containing at least one metal element selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, and the average particle size of primary particles is generally 0.2 μm or less, preferably It is also preferable to contain a fine high refractive index inorganic filler that is 0.1 μm or less, more preferably 0.06 μm or less and 1 nm or more.

  When it is necessary to lower the refractive index of the matrix in order to adjust the difference in refractive index with the light-transmitting particles, a fine low refractive index inorganic filler such as silica fine particles or hollow silica fine particles is used as the inorganic filler. be able to. The preferred particle size is the same as that of the fine high refractive index inorganic filler.

  The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

  It is preferable that the addition amount of an inorganic filler is 2-40 mass% of the total mass of an anti-glare layer, More preferably, it is 5-30 mass%, Most preferably, it is 5-25 mass%.

  In addition, since the inorganic filler has a particle size sufficiently shorter than the wavelength of light, scattering does not occur, and the dispersion in which the filler is dispersed in the binder polymer has the property of an optically uniform substance.

The refractive index of the antiglare layer is preferably 1.46 to 1.65, more preferably 1.49 to 1.60, and particularly preferably 1.49 to 1.53. By setting the refractive index within this range, it is possible to make the coating village and interference unevenness inconspicuous and to obtain a high-hardness antiglare layer.
Here, the refractive index of the film of the light diffusion layer excluding the translucent particles can be quantitatively evaluated by directly measuring with an Abbe refractometer or by measuring a spectral reflection spectrum or spectral ellipsometry.

<Surfactant of antiglare layer>
In the antiglare layer of the present invention, in order to ensure surface uniformity such as coating unevenness, drying unevenness, point defect, etc., either a fluorine-based surfactant or a silicone-based surfactant, or both, is used for the antiglare layer. It is preferable to contain in the coating composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the optical film of the present invention appears with a smaller addition amount.
The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity. Preferable examples of the fluorine-based surfactant include compounds described in paragraph numbers 0049 to 0074 of JP2007-188070A.

  The preferable addition amount of the surfactant (particularly the fluorine-based polymer) used in the antiglare layer of the present invention is in the range of 0.001 to 5% by mass, preferably 0.005 to 3% by mass with respect to the coating solution. %, And more preferably in the range of 0.01 to 1% by mass. When the addition amount of the surfactant is 0.001% by mass or more, the effect is sufficient, and by setting the addition amount to 5% by mass or less, the coating film is sufficiently dried and good performance as a coating film (for example, reflection) Rate, scratch resistance).

<Organic solvent of coating solution for antiglare layer>
An organic solvent can be added to the coating composition for forming the antiglare layer.

  As an organic solvent, for example, in an alcohol system, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, isoamyl alcohol, 1-pentanol, n-hexanol, methyl amyl alcohol In the ketone system, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), diethyl ketone, acetone, cyclohexanone, diacetone alcohol, etc. In the ester system, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate , N-butyl acetate, isoamyl acetate, n-amyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl acetate, methyl lactate, ethyl lactate, ether, acetal 1,4-dioxane, tetrahydrofuran, 2-methylfuran, tetrahydropyran, diethyl acetal, etc. In the halogen hydrocarbon system, carbon tetrachloride, chloroform, methylene chloride, ethylene chloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, 1,1,1, In the case of polyhydric alcohol and derivatives thereof such as 2-tetrachloroethane, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoacetate, die Len glycol, propylene glycol, dipropylene glycol, butanediol, hexylene glycol, 1,5-pentanediol, glycerol monoacetate, glycerol ethers, 1,2,6-hexanetriol, etc. Examples of propionic acid, entangling acid, isoentangled acid, isovaleric acid, lactic acid, and the like for nitrogen compounds include formamide, N, N-dimethylformamide, acetamide, acetonitrile, and the like, and sulfur compounds include dimethyl sulfoxide and the like.

  Among organic solvents, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, acetone, toluene, xylene, ethyl acetate, 1-pentanol and the like are particularly preferable. In addition, an alcohol or a polyhydric alcohol solvent may be appropriately mixed with the organic solvent for the purpose of controlling cohesion. These organic solvents may be used alone or in combination, and the coating composition preferably contains 20% by mass to 90% by mass, and preferably 30% by mass to 80% by mass, as the total amount of the organic solvent. More preferably, it is most preferable to contain 40 mass%-70 mass%. In order to stabilize the surface shape of the antiglare layer, it is preferable to use a solvent having a boiling point of less than 100 ° C. and a solvent having a boiling point of 100 ° C. or more in combination.

<Curing of antiglare layer>
The anti-glare layer can be formed by applying a coating solution to a support, and then carrying out light irradiation, electron beam irradiation, heat treatment or the like to cause crosslinking or polymerization reaction. In the case of ultraviolet irradiation, ultraviolet rays emitted from light such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, etc. can be used. Curing with ultraviolet rays is preferably carried out by nitrogen purge or the like in an atmosphere having an oxygen concentration of 4% by volume or less, more preferably 2% by volume or less, and most preferably 0.5% by volume or less.

  Below, layers other than an anti-glare layer are demonstrated.

<Overcoat layer>
In order to adjust the uneven surface of the antiglare layer, an overcoat layer may be formed. The overcoat layer is a fine unevenness that exists along the uneven shape on a scale that is 1/10 or less of the uneven scale (uneven height and interval) of the surface that forms the uneven shape of the antiglare layer. It is possible to form smooth irregularities by applying smoothing, or to adjust the crest pitch, crest height, and crest frequency (number). The overcoat layer is formed for the purpose of imparting antistatic properties, refractive index adjustment, high curing, antifouling properties, and the like. The film thickness (at the time of curing) of the overcoat layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 8 μm.
In the present invention, an antiglare layer and an overcoat layer are preferable on the transparent support.

  The overcoat layer is selected from the group consisting of antistatic agents, refractive index adjusting agents, antifouling agents, water repellents, oil repellents, fingerprint adhesion preventing agents, high curing agents and hardness adjusting agents (buffering agents). One kind or a mixture of two or more kinds may be appropriately introduced.

  As the binder for forming the matrix of the overcoat layer, the polymer compound that can be added, the inorganic filler, the surfactant, and the organic solvent, those that can be used for the antiglare layer can be appropriately used.

<Low refractive index layer>
The optical film of the present invention preferably has a layer having a refractive index lower than that of the antiglare layer or the overcoat layer (also referred to as “low refractive index layer”) in order to reduce the reflectance. The refractive index of the low refractive index layer is preferably 1.20 to 1.46, more preferably 1.25 to 1.46, and particularly preferably 1.30 to 1.40. The thickness of the low refractive index layer is preferably 50 to 200 nm, and more preferably 70 to 100 nm. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less.

As a preferred embodiment of the curable composition for forming the low refractive index layer,
(1) A composition containing a fluorine-containing compound having a crosslinkable or polymerizable functional group,
(2) a composition comprising as a main component a hydrolysis-condensation product of a fluorine-containing organosilane material;
(3) a composition containing a monomer having two or more ethylenically unsaturated groups and inorganic fine particles (in particular, inorganic fine particles having a hollow structure are preferred);
Is mentioned.
Regarding (1) and (2), it is preferable to contain inorganic fine particles. If inorganic fine particles having a hollow structure with a low refractive index are used, from the viewpoints of lowering the refractive index, adjusting the amount of added inorganic fine particles, and adjusting the refractive index. Particularly preferred.

(1) Fluorine-containing compound having a crosslinkable or polymerizable functional group As the fluorine-containing compound having a crosslinkable or polymerizable functional group, co-polymerization of a fluorine-containing monomer and a monomer having a crosslinkable or polymerizable functional group Coalescence can be mentioned. Specific examples of these fluoropolymers are described in JP2003-222702A, JP2003-183322A, and the like.

  As described in JP 2000-17028 A, a curing agent having a polymerizable unsaturated group may be used in combination with the above polymer. Moreover, combined use with the compound which has a fluorine-containing polyfunctional polymerizable unsaturated group as described in Unexamined-Japanese-Patent No. 2002-145952 is also preferable. Examples of the compound having a polyfunctional polymerizable unsaturated group include the above-described monomers having two or more ethylenically unsaturated groups. Moreover, the hydrolysis-condensation product of the organolane described in Unexamined-Japanese-Patent No. 2004-170901 is also preferable, and the hydrolysis-condensation product of the organosilane containing a (meth) acryloyl group is especially preferable. These compounds are particularly preferred because they have a large combined effect for improving scratch resistance, particularly when a compound having a polymerizable unsaturated group is used in the polymer body.

  When the polymer itself does not have sufficient curability, necessary curability can be imparted by blending a crosslinkable compound. For example, when the polymer body contains a hydroxyl group, various amino compounds are preferably used as the curing agent. The amino compound used as the crosslinkable compound is, for example, a compound containing one or both of a hydroxyalkylamino group and an alkoxyalkylamino group in total, specifically, for example, a melamine compound, Examples include urea compounds, benzoguanamine compounds, glycoluril compounds, and the like. For curing these compounds, an organic acid or a salt thereof is preferably used.

(2) Composition mainly composed of hydrolyzed condensate of fluorine-containing organosilane material The composition mainly composed of hydrolyzed condensate of fluorine-containing organosilane compound also has a low refractive index and the hardness of the coating surface. Is preferable. A condensate of a tetraalkoxysilane with a hydrolyzable silanol-containing compound at one or both ends with respect to the fluorinated alkyl group is preferred. The specific composition is described in Unexamined-Japanese-Patent No. 2002-265866, 317152.

(3) A composition containing a monomer having two or more ethylenically unsaturated groups and inorganic fine particles having a hollow structure As yet another preferred embodiment, a low refractive index layer comprising low refractive index particles and a binder can be mentioned. . The low refractive index particles may be organic or inorganic, but particles having pores inside are preferable. Specific examples of the hollow particles are described in the silica-based particles described in JP-A-2002-79616. The particle refractive index is preferably 1.15 to 1.40, more preferably 1.20 to 1.30. Examples of the binder include monomers having two or more ethylenically unsaturated groups described on the page of the antiglare layer.

  It is preferable to add the above-mentioned photo radical polymerization initiator or thermal radical polymerization initiator to the composition for the low refractive index layer used in the present invention. When it contains a radically polymerizable compound, 1-10 mass% with respect to this compound, Preferably a 1-5 mass% polymerization initiator can be used.

  In the low refractive index layer used in the present invention, inorganic particles can be used in combination. In order to impart scratch resistance, fine particles having a particle size of 15% to 150%, preferably 30% to 100%, more preferably 45% to 60% of the thickness of the low refractive index layer can be used. .

  For the purpose of imparting antifouling properties, water resistance, chemical resistance, slipping properties, etc., a known polysiloxane-based or fluorine-based antifouling agent, slipping agent, etc. are appropriately added to the low refractive index layer. Can do.

  Examples of the additive having a polysiloxane structure include reactive group-containing polysiloxanes {for example, “KF-100T”, “X-22-169AS”, “KF-102”, “X-22-3701IE”, “X-22”. -164B "," X-22-5002 "," X-22-173B "," X-22-174D "," X-22-167B "," X-22-161AS "(product name), "AK-5", "AK-30", "AK-32" (trade name), manufactured by Toa Gosei Co., Ltd .; "Silaplane FM0725", "Silaplane FM0721" It is also preferable to add (trade name), manufactured by Chisso Corporation, etc.}. Moreover, the silicone type compound of Table 2 and Table 3 of Unexamined-Japanese-Patent No. 2003-112383 can also be used preferably.

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

It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833, Optool DAC (trade name), Dainippon Ink Co., Ltd. Examples include, but are not limited to, F-171, F-172, F-179A, defender MCF-300, MCF-323 (named above).
These polysiloxane fluorine-based compounds and compounds having a polysiloxane structure are preferably added in the range of 0.1 to 10% by mass, particularly preferably 1 to 5% by mass of the total solid content of the low refractive index layer. It is.

<High refractive index layer, medium refractive index layer>
In the antireflection film of the present invention, a high refractive index layer is provided between the transparent support of the antiglare layer and the low refractive index layer on the opposite side, and when the optical interference is used together with the low refractive index layer, the antireflection property is enhanced. be able to. Furthermore, it is preferable to provide an intermediate refractive index layer having a refractive index intermediate between the antiglare layer and the high refractive index layer between the antiglare layer and the high refractive index layer.
In the following specification, the high refractive index layer and the middle refractive index layer may be collectively referred to as a high refractive index layer. In the present invention, “high”, “medium”, and “low” in the high refractive index layer, medium refractive index layer, and low refractive index layer represent the relative refractive index relationship between the layers. In terms of the relationship with the antiglare layer, the refractive index preferably satisfies the relationship of antiglare layer> low refractive index layer, high refractive index layer> antiglare layer.
In the present specification, the high refractive index layer, the middle refractive index layer, and the low refractive index layer may be collectively referred to as an antireflection layer.

  In order to form an antireflection film by forming a low refractive index layer on a high refractive index layer, the refractive index of the high refractive index layer is preferably 1.55 to 2.40, more preferably 1.60 to 2.20, more preferably 1.60 to 2.00.

  When an antireflective film is produced by coating a medium refractive index layer, a high refractive index layer, and a low refractive index layer in order from the support, the refractive index of the high refractive index layer is 1.65 to 2.40. Preferably, it is 1.70 to 2.20. The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the medium refractive index layer is preferably 1.55 to 1.80, more preferably 1.55 to 1.70.

Specific examples of the inorganic particles used for the high refractive index layer and the medium refractive index layer include inorganic materials such as TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , and ITO. Inorganic particles mainly composed of oxides are preferred, and inorganic particles mainly composed of SiO ₂ can also be added for adjusting the refractive index. For use in the high refractive index layer, TiO ₂ and ZrO ₂ are particularly preferable from the viewpoint of increasing the refractive index. The inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment on the surface, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

The content of the inorganic particles in the high refractive index layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and particularly preferably 15 to 75% by mass with respect to the mass of the high refractive index layer. . Two or more inorganic particles may be used in combination in the high refractive index layer.
When the low refractive index layer is provided on the high refractive index layer, the refractive index of the high refractive index layer is preferably higher than the refractive index of the transparent support.

[Antistatic layer]
In the present invention, at least one thin film layer of the antireflection film can be used as an antistatic layer. In the present invention, when a fluorine-containing curable composition, particularly a fluorine-containing antifouling agent, is used, it is possible to express excellent antifouling properties at a low refractive index, but fluorine is oriented on the surface layer of the coating film. Therefore, the chargeability is poor and the dust resistance tends to deteriorate. Therefore, in the present invention, it is preferable to have an antistatic layer in terms of preventing static electricity on the film surface.
The materials used for the antistatic layer and the performance of the antistatic layer will be described in detail below.

  Methods for forming the antistatic layer include, for example, a method of applying a conductive coating solution containing conductive fine particles and a reactive curable resin, a method of applying a transparent conductive material made of a transparent and conductive polymer, or transparent A conventionally known method such as a method of forming a conductive thin film by vapor deposition or sputtering of a metal or metal oxide that forms a film can be used. The antistatic layer can be formed directly on the transparent support or via a primer layer that strengthens the adhesion to the transparent support. When an antistatic layer is provided as a layer close to the outermost surface layer of the antireflection film, it is preferable because sufficient antistatic properties can be obtained even if the layer is thin. In the present invention, it is preferable to have, as an antistatic layer, at least one thin film layer or a layer located between the transparent support and the thin film layer located closest to the transparent support among the thin film layers. The coating method is not particularly limited, and an optimal method may be selected from known methods such as roll coating, gravure coating, bar coating, extrusion coating, etc., depending on the characteristics of the coating solution and the coating amount. .

  The surface resistance of the antistatic layer preferably has a resistance value (SR) that satisfies the following formula (4).

  Formula (4): LogSR ≦ 12

In Formula (4), LogSR is more preferably 5 to 12, further preferably 5 to 9, and most preferably 5 to 8. The surface resistance (SR) of the antistatic layer can be measured by a four-probe method or a circular electrode method.
The antistatic layer is preferably substantially transparent. Specifically, the haze of the antistatic layer is preferably 10% or less, more preferably 5% or less, further preferably 3% or less, and most preferably 1% or less. . The transmittance of light having a wavelength of 550 nm is preferably 50% or more, more preferably 60% or more, further preferably 65% or more, and most preferably 70% or more.

(Conductive inorganic fine particles of antistatic layer)
The antistatic layer can be formed using a coating composition obtained by dissolving conductive fine particles and a reactive curable resin in a solvent. In this case, the conductive inorganic fine particles are preferably formed from a metal oxide or nitride. Examples of metal oxides or nitrides include tin oxide, indium oxide, zinc oxide and titanium nitride. Tin oxide and indium oxide are particularly preferred. The conductive inorganic fine particles are mainly composed of oxides or nitrides of these metals, and can 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 halogen atoms are included. In order to increase the conductivity of tin oxide and indium oxide, it is preferable to add at least one selected from Sb, P, B, Nb, In, V, and a halogen atom. More specifically, tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), phosphorus-doped tin oxide (PTO), zinc antimonate (AZO), indium-doped zinc oxide (IZO) ), Zinc oxide, ruthenium oxide, rhenium oxide, silver oxide, nickel oxide, and a combination of two or more metal oxides selected from the group consisting of copper oxide. Tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and phosphorus-doped tin oxide (PTO) are particularly preferred. The ratio of Sb in ATO is preferably 3 to 20% by mass. The ratio of In in ITO is preferably 5 to 20% by mass.

  The average primary particle diameter of the conductive inorganic fine particles used in the antistatic layer is preferably 1 to 150 nm, more preferably 5 to 100 nm, and most preferably 5 to 70 nm. The average particle diameter of the conductive inorganic fine particles in the antistatic layer to be formed is 1 to 200 nm, preferably 5 to 150 nm, more preferably 10 to 100 nm, and more preferably 10 to 80 nm. Most preferred. The average particle diameter of the conductive inorganic fine particles is an average diameter weighted by the mass of the particles, and can be measured by a light scattering method or an electron micrograph.

The conductive inorganic fine particles may be surface-treated. The surface treatment is 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. Specifically, the method described in {Surface Treatment Method for Inorganic Fine Particles} described in the component (C) inorganic fine particles of the present invention is preferably used. Further, the methods described in paragraph numbers [0101] to [0122] of JP-A-2008-31327 can also be preferably used. Two or more kinds of surface treatments may be performed in combination.
The shape of the conductive inorganic fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape.
Two or more kinds of conductive inorganic fine particles may be used in combination in the antistatic layer.

  The proportion of the conductive inorganic fine particles in the antistatic layer is preferably 20 to 90% by mass, more preferably 25 to 85% by mass, and most preferably 30 to 80% by mass in the total solid content. preferable.

  The conductive inorganic fine particles are used for forming an antistatic layer in the form of a dispersion. As the dispersion medium for the conductive inorganic fine particles, a liquid having a boiling point of 60 to 170 ° C. is preferably used. Examples of dispersion media include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ester (eg, methyl acetate, ethyl acetate, Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methyl) Carboxymethyl-2-propanol) are included. Toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are particularly preferred. The conductive inorganic fine particles can be dispersed in the medium using a disperser. 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 conductive inorganic compound particles are preferably reacted with an alkoxysilane compound in an organic solvent. By using a reaction liquid in which conductive inorganic compound particles and an alkoxysilane compound are reacted in advance, an effect of excellent storage stability and curability can be obtained.

  As a commercial item as a powder of the above-mentioned conductive inorganic oxide particles, for example, Mitsubishi Materials Corporation trade name: T-1 (ITO), Mitsui Kinzoku Co., Ltd. trade name: Pastoran (ITO, ATO) Product name: SN-100P (ATO) manufactured by Ishihara Sangyo Co., Ltd. Product name: Nanotech ITO, manufactured by Nissan Chemical Industries, Ltd. Product names: ATO, FTO, and the like.

  Conductive inorganic oxide particles having silicon oxide supported on the surface thereof are preferable because they react particularly effectively with alkoxysilane compounds. As a method for supporting such silicon oxide, for example, it is disclosed in Japanese Patent Publication No. 2858271, and after forming a coprecipitate of a hydrate of tin oxide and antimony oxide, a silicon compound is deposited. It can be manufactured by the steps of fractionation and firing.

  As a commercial item of the electroconductive inorganic oxide particle which carries the silicon oxide on the surface, for example, Ishihara Sangyo Co., Ltd. product name: SN-100P (ATO), SNS-10M, FSS-10M etc. Can be mentioned.

  Examples of commercial products in which conductive inorganic oxide particles are dispersed in an organic solvent include, for example, trade names: SNS-10M (MEK-dispersed antimony-doped tin oxide), FSS-10M (isopropyl alcohol-dispersed antimony) manufactured by Ishihara Sangyo Co., Ltd. Dope tin oxide), manufactured by Nissan Chemical Industries, Ltd. Trade name: Celnax CX-Z401M (methanol-dispersed zinc antimonate), Celnax CX-Z200IP (isopropyl alcohol-dispersed zinc antimonate), Catalyst Chemical Industry Co., Ltd. Product name: ELCOM JX-1001PTV (phosphorus-containing tin oxide dispersed in propylene glycol monomethyl ether) and the like.

(Organic solvent)
As described above, the organic solvent used in the curable composition for forming an antistatic layer is used as a dispersion medium for dispersing conductive inorganic oxide particles.
The blending amount of the organic solvent is preferably 20 to 4,000 parts by mass, and more preferably 100 to 1,000 parts by mass with respect to 100 parts by mass of the conductive inorganic oxide particles. When the amount of the solvent is less than 20 parts by mass, a uniform reaction may be difficult due to the high viscosity, and when it exceeds 4,000 parts by mass, the coatability may be deteriorated.
Examples of such an organic solvent include a solvent having a boiling point of 200 ° C. or less at normal pressure. Specifically, alcohols, ketones, ethers, esters, hydrocarbons, and amides are used, and these can be used alone or in combination of two or more. Of these, alcohols, ketones, ethers and esters are preferred.

Here, examples of alcohols include methanol, ethanol, isopropyl alcohol, isobutanol, n-butanol, tert-butanol, ethoxyethanol, butoxyethanol, diethylene glycol monoethyl ether, benzyl alcohol, phenethyl alcohol, and the like. . Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of ethers include dibutyl ether and propylene glycol monoethyl ether acetate. Examples of the esters include ethyl acetate, butyl acetate, and ethyl lactate. Examples of hydrocarbons include toluene and xylene. Examples of amides include formamide, dimethylacetamide, N-methylpyrrolidone and the like.
Of these, isopropyl alcohol, ethoxyethanol, butoxyethanol, diethylene glycol monoethyl ether, propylene glycol monoethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, propylene glycol monoethyl ether acetate, butyl acetate, and ethyl lactate are preferable.

(Antistatic layer binder)
As the binder for the antistatic layer, a curable resin used for the high refractive index layer, particularly an ionizing radiation curable polyfunctional monomer or a polyfunctional oligomer is preferably used, but it is crosslinked by reacting with a reactive curable resin. The polymer used can also be used as a binder. The crosslinked polymer preferably has an anionic group.
The polymer having a crosslinked anionic group has a structure in which the main chain of the polymer having an anionic group is crosslinked. The anionic group has a function of maintaining the dispersion state of the conductive inorganic fine particles. The crosslinked structure has a function of imparting a film forming ability to the polymer and strengthening the antistatic layer.

Examples of the polymer main chain include polyolefin (saturated hydrocarbon), polyether, polyurea, polyurethane, polyester, polyamine, polyamide and melamine resin. A polyolefin main chain, a polyether main chain and a polyurea main chain are preferable, a polyolefin main chain and a polyether main chain are more preferable, and a polyolefin main chain is most preferable.
The polyolefin main chain is composed of a saturated hydrocarbon. The polyolefin main chain is obtained, for example, by an addition polymerization reaction of an unsaturated polymerizable group. The polyether main chain has repeating units bonded by an ether bond (—O—). The polyether main chain is obtained, for example, by a ring-opening polymerization reaction of an epoxy group. In the polyurea main chain, repeating units are bonded by a urea bond (—NH—CO—NH—). The polyurea main chain is obtained, for example, by a condensation polymerization reaction between an isocyanate group and an amino group. The polyurethane main chain has repeating units bonded by urethane bonds (—NH—CO—O—). The polyurethane main chain is obtained, for example, by a polycondensation reaction between an isocyanate group and a hydroxyl group (including an N-methylol group). The polyester main chain has repeating units bonded by an ester bond (—CO—O—). The polyester main chain is obtained, for example, by a polycondensation reaction between a carboxy group (including an acid halide group) and a hydroxyl group (including an N-methylol group). In the polyamine main chain, repeating units are bonded by an imino bond (—NH—). The polyamine main chain is obtained, for example, by a ring-opening polymerization reaction of an ethyleneimine group. The polyamide main chain has repeating units bonded by an amide bond (—NH—CO—). The polyamide main chain is obtained, for example, by a reaction between an isocyanate group and a carboxy group (including an acid halide group). The melamine resin main chain is obtained, for example, by a polycondensation reaction between a triazine group (eg, melamine) and an aldehyde (eg, formaldehyde). In the melamine resin, the main chain itself has a crosslinked structure.

The anionic group is bonded directly to the main chain of the polymer or bonded to the main chain via a linking group. The anionic group is preferably bonded to the main chain as a side chain via a linking group.
Examples of the anionic group include a carboxylic acid group (carboxyl), a sulfonic acid group (sulfo), and a phosphoric acid group (phosphono), and a sulfonic acid group and a phosphoric acid group are preferable.
The anionic group may be in a salt state. The cation that forms a salt with the anionic group is preferably an alkali metal ion. Moreover, the proton of the anionic group may be dissociated.
The linking group that binds the anionic group and the polymer main chain is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof.

  The crosslinked structure chemically bonds (preferably covalently bonds) two or more main chains. The cross-linked structure is preferably covalently bonded to three or more main chains. The crosslinked structure is preferably composed of a divalent or higher valent group selected from —CO—, —O—, —S—, a nitrogen atom, a phosphorus atom, an aliphatic residue, an aromatic residue, and combinations thereof.

  The crosslinked polymer having an anionic group is preferably a copolymer having a repeating unit having an anionic group and a repeating unit having a crosslinked structure. The proportion of the repeating unit having an anionic group in the copolymer is preferably 2 to 96% by mass, more preferably 4 to 94% by mass, and most preferably 6 to 92% by mass. The repeating unit may have two or more anionic groups. The proportion of the repeating unit having a crosslinked structure in the copolymer is preferably 4 to 98% by mass, more preferably 6 to 96% by mass, and most preferably 8 to 94% by mass.

The repeating unit of the polymer having a crosslinked anionic group may have both an anionic group and a crosslinked structure. Further, other repeating units (repeating units having neither an anionic group nor a crosslinked structure) may be contained.
Other repeating units are preferably a repeating unit having an amino group or a quaternary ammonium group and a repeating unit having a benzene ring. The amino group or quaternary ammonium group has a function of maintaining the dispersed state of the inorganic fine particles, like the anionic group. In addition, even if the amino group, the quaternary ammonium group and the benzene ring are contained in a repeating unit having an anionic group or a repeating unit having a crosslinked structure, the same effect can be obtained.
In a repeating unit having an amino group or a quaternary ammonium group, the amino group or quaternary ammonium group is directly bonded to the main chain of the polymer or bonded to the main chain through a linking group. The amino group or quaternary ammonium group is preferably bonded to the main chain as a side chain via a linking group. The amino group or quaternary ammonium group is preferably a secondary amino group, a tertiary amino group or a quaternary ammonium group, more preferably a tertiary amino group or a quaternary ammonium group. The group bonded to the nitrogen atom of the secondary amino group, tertiary amino group or quaternary ammonium group is preferably an alkyl group, preferably an alkyl group having 1 to 12 carbon atoms, Is more preferably an alkyl group of 1 to 6. The counter ion of the quaternary ammonium group is preferably a halide ion. The linking group that connects the amino group or quaternary ammonium group to the main chain of the polymer is a divalent group selected from —CO—, —NH—, —O—, an alkylene group, an arylene group, and combinations thereof. Preferably there is. When the crosslinked polymer having an anionic group contains a repeating unit having an amino group or a quaternary ammonium group, the ratio is preferably 0.06 to 32% by mass, and 0.08 to 30% by mass. % Is more preferable, and 0.1 to 28% by mass is most preferable.

  The binder can be used in combination with the following reactive organosilicon compound described in, for example, JP-A No. 2003-39586. The reactive organosilicon compound is used in the range of 10 to 70% by mass with respect to the ionizing radiation curable resin as the binder. As the reactive organic silicon compound, an organosilane compound is preferable, and it is possible to form an antistatic layer using only this as a resin component.

〔solvent〕
The solvent for dissolving the coating composition for forming all the layers other than the antistatic layer is not particularly limited, but alcohol solvents and ketone solvents are preferably used. Specifically, acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexane, 2-heptanone, 4-heptanone, methyl isopropyl ketone, ethyl isopropyl ketone, diisopropyl ketone, methyl isobutyl ketone, methyl-t-butyl ketone, Examples include diacetyl, acetylacetone, acetonylacetone, diacetone alcohol, mesityl oxide, chloroacetone, cyclopentanone, cyclohexanone, acetophenone, and the like. Among these, methyl ethyl ketone and methyl isobutyl ketone are preferable. These solvents may be used alone or in a mixture at an arbitrary mixing ratio.

  As the auxiliary solvent, an ester solvent such as propylene glycol monomethyl ether acetate or a fluorinated solvent (such as a fluorinated alcohol) can be used as appropriate. These solvents may be used alone or in a mixture at an arbitrary mixing ratio.

  In the present invention, the preferable average reflectance of the antireflection antiglare film provided with a low refractive index layer or the like is preferably 3.5% or less, more preferably 3.0% or less, and still more preferably 2.0% or less. And most preferably 2.0% or less and 0.3% or more. Even if light scattering on the surface of the antiglare film is reduced by lowering the average reflectance, sufficient antiglare property can be obtained, so that an antiglare antireflection film excellent in black tightening can be obtained.

In the present invention, the integrated reflectance of the optical film provided with a low refractive index layer or the like is preferably 3.0% or less, more preferably 2.0% or less, and most preferably 1.5% or less 0.3. % Or more. Even if light scattering on the surface of the optical film is reduced by lowering the integrated reflectance, sufficient antiglare property can be obtained, so that an optical film excellent in blackening can be obtained.
The average reflectance was measured by roughening the back side of the film with sandpaper and then treating with black ink, and eliminating the back side reflection, and using a spectrophotometer with an integrating sphere, the front side was 380 to 780 nm. Spectral reflectance was measured in the wavelength region. The arithmetic average value of the reflectance of 450 to 650 nm was used.

<Transparent support>
A plastic film is preferably used as the transparent support of the optical film of the present invention. Examples of the polymer forming the plastic film include cellulose acylate (eg, triacetyl cellulose, diacetyl cellulose, typically TAC-TD80U, TD80UF, etc. manufactured by Fuji Film), polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene). Naphthalate), polystyrene, polyolefin, norbornene resin (Arton: trade name, manufactured by JSR), amorphous polyolefin (ZEONEX: trade name, manufactured by ZEON CORPORATION), (meth) acrylic resin (ACRYPET VRL20A: product) Name, manufactured by Mitsubishi Rayon Co., Ltd., ring structure-containing acrylic resin described in JP-A No. 2004-70296 and JP-A No. 2006-171464), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable.

  When the optical film of the present invention is used for, for example, a liquid crystal display device, it is disposed on the outermost surface of the display by providing an adhesive layer on one side. Moreover, you may combine the optical film and polarizing plate of this invention. 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 carry out a saponification treatment after forming the outermost layer. 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.

<Application 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. Next, the coating solution is applied on the transparent support by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or die coating, and heated and dried. A gravure coating method, a wire bar coating method, and a die coating method (see US Pat. No. 2,681,294 and JP-A-2006-122889) are more preferable, and a die coating method is particularly preferable.

Thereafter, the monomer for forming the functional layer is polymerized and cured by light irradiation such as ionizing radiation such as ultraviolet rays or heating, preferably irradiation with ionizing radiation under heating.
The functional layer is a layer provided as necessary in addition to the antiglare layer, such as the above-described antistatic layer, medium refractive index layer, and high refractive index layer. If necessary, the functional layer can be a plurality of layers.

  Next, in a preferred embodiment, a coating solution for forming a low refractive index layer is applied on the functional layer in the same manner, and is irradiated with light or heated (irradiated with ionizing radiation such as ultraviolet rays, preferably ionized radiation under heating. It is cured by irradiation, and a low refractive index layer is formed. In this way, the optical film of the present invention is obtained.

<Polarizing plate>
The polarizing plate is mainly composed of two protective films that protect both the front and back sides of the polarizing film. 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, and a polarizing plate having excellent scratch resistance, antifouling property and the like can be obtained.

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.

<Image display device>
The optical film of the present invention is applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), a cathode ray tube display device (CRT), and a surface electric field display (SED). can do. It is particularly preferably used for a liquid crystal display (LCD). Since the optical film of the present invention has a transparent support, it is used by bonding the transparent support side to the image display surface of the image display device.

  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).

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

[Example 1]
Composition of Coating Solution A-1 for Antiglare Layer PET-30 27.4g
Irgacure 127 1.2g
7μm cross-linked acrylic / styrene particles (30%) 36.0g
SP-13 0.1g
CAB 0.5g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution A-2 for antiglare layer PET-30 27.4 g
Irgacure 127 1.2g
8μm cross-linked acrylic / styrene particles (30%) 36.0g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of coating liquid A-3 for anti-glare layer PET-30 27.4 g
Irgacure 127 1.2g
8 μm cross-linked acrylic particles (30%) 9.0 g
8μm cross-linked acrylic / styrene particles (30%) 27.0g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of Coating Solution A-4 for Antiglare Layer PET-30 27.4g
Irgacure 127 1.2g
8 μm cross-linked acrylic particles (30%) 9.0 g
12 μm cross-linked acrylic / styrene particles (30%) 27.0 g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of coating liquid A-5 for anti-glare layer PET-30 27.4 g
Irgacure 127 1.2g
8 μm crosslinked acrylic particles (30%) 36.0 g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of coating solution A-6 for antiglare layer PET-30 33.4 g
Irgacure 127 1.2g
3.5 μm crosslinked styrene particles (30%) 16.0 g
SP-13 0.1g
CAB 0.5g
MIBK 30.8g
MEK 18.0g

Composition of Coating Solution A-7 for Antiglare Layer PET-30 27.4g
Irgacure 127 1.2g
6 μm cross-linked acrylic particles (30%) 9.0 g
6μm cross-linked acrylic / styrene particles (30%) 27.0g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of coating liquid A-8 for anti-glare layer PET-30 30.2 g
Irgacure 127 1.2g
8 μm cross-linked acrylic particles (30%) 6.7 g
8μm cross-linked acrylic / styrene particles (30%) 20.0g
SP-13 0.1g
CAB 0.5g
MIBK 23.3g
MEK 18.0g

Composition of coating liquid A-9 for antiglare layer PET-30 30.2 g
Irgacure 127 1.2g
8 μm cross-linked acrylic particles (30%) 6.7 g
12μm cross-linked acrylic / styrene particles (30%) 20.0g
SP-13 0.1g
CAB 0.5g
MIBK 23.3g
MEK 18.0g

Composition of coating solution A-10 for anti-glare layer PET-30 31.0 g
Irgacure 127 1.2g
5 μm cross-linked acrylic / styrene particles (30%) 12.0 g
3.5 μm crosslinked acrylic / styrene particles (30%) 12.0 g
SP-13 0.1g
CAB 0.5g
MIBK 25.2g
MEK 18.0g

Composition of Coating Solution A-11 for Anti-Glare Layer PET-30 25.6g
Irgacure 127 1.2g
7μm cross-linked acrylic / styrene particles (30%) 30.0g
Cohesive silica (30%) 12.0 g
SP-13 0.1g
CAB 0.5g
MIBK 12.6g
MEK 18.0g

Composition of Coating Solution A-12 for Antiglare Layer PET-30 27.4g
Irgacure 127 1.2g
8 μm cross-linked acrylic particles / styrene (2) (30%) 9.0 g
12 μm cross-linked acrylic / styrene particles (2) (30%) 27.0 g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of Coating Solution A-13 for Anti-Glare Layer PET-30 27.4g
Irgacure 127 1.2g
8 μm cross-linked acrylic particles / styrene (2) (30%) 5.4 g
12μm cross-linked acrylic / styrene particles (2) (30%) 30.6 g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of Coating Solution A-14 for Antiglare Layer PET-30 27.4g
Irgacure 127 1.2g
8μm cross-linked acrylic particles ・ Styrene (2) (30%) 12.6g
12 μm cross-linked acrylic / styrene particles (2) (30%) 23.4 g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Composition of coating liquid A-15 for anti-glare layer PET-30 27.4 g
Irgacure 127 1.2g
7μm cross-linked acrylic / styrene particles (30%) 36.0g
SP-13 0.1g
CAB 0.5g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution A-16 for anti-glare layer 26.5 g PET-30
Acrylic polymer (1) 1.4g
Irgacure 127 1.2g
7μm cross-linked acrylic / styrene particles (30%) 36.0g
SP-13 0.1g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution A-17 for anti-glare layer DPHA 26.5 g
Acrylic polymer (1) 1.4g
Irgacure 127 1.2g
7μm cross-linked acrylic / styrene particles (30%) 36.0g
SP-13 0.1g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution A-18 for antiglare layer PET-30 10.0 g
DPCA-60 16.5g
Acrylic polymer (1) 1.4g
Irgacure 127 1.2g
8μm cross-linked acrylic / styrene particles (30%) 36.0g
SP-13 0.1g
MIBK 16.8g
MEK 18.0g

Composition of coating liquid A-19 for antiglare layer PET-30 10.0 g
DPCA-60 16.5g
Acrylic polymer (1) 1.4g
Irgacure 127 1.2g
8 μm crosslinked acrylic particles (30%) 9.0 g
8μm cross-linked acrylic / styrene particles (30%) 27.0g
SP-13 0.1g
MIBK 16.8g
MEK 18.0g

Composition of coating liquid A-20 for anti-glare layer PET-30 17.0 g
UX-5003D 9.5g
Acrylic polymer (2) 1.4g
Irgacure 127 1.2g
8 μm crosslinked acrylic particles (30%) 9.0 g
8μm cross-linked acrylic / styrene particles (30%) 27.0g
SP-13 0.1g
MIBK 16.8g
MEK 18.0g

Composition of Coating Solution A-21 for Antiglare Layer PET-30 27.4g
Irgacure 127 1.2g
8 μm crosslinked styrene particles (30%) 36.0 g
SP-13 0.1g
CAB 0.5g
MIBK 16.8g
MEK 18.0g

Each coating solution for the antiglare layer was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution.
In the coating solution, the refractive index of the matrix after curing was 1.525.

  Here, the refractive index of the film (matrix) of the antiglare layer excluding the translucent particles was directly measured with an Abbe refractometer. Further, the refractive index of the translucent particles is changed by changing the mixing ratio of two kinds of solvents having different refractive indexes selected from methylene iodide, 1,2-dibromopropane, and n-hexane. The turbidity was measured by dispersing an equal amount of translucent particles in the solvent, and the refractive index of the solvent when the turbidity was minimized was measured by an Abbe refractometer.

The refractive index of the particles was as follows.
6 μm cross-linked acrylic particles 1.500
8 μm crosslinked acrylic particles 1.500
3.5μm cross-linked acrylic / styrene particles 1.530
5μm cross-linked acrylic / styrene particles 1.530
6μm cross-linked acrylic / styrene particles 1.555
7μm cross-linked acrylic / styrene particles 1.555
8μm cross-linked acrylic / styrene particles 1.555
12μm cross-linked acrylic / styrene particles 1.515
3.5 μm crosslinked styrene particles 1.600
8 μm cross-linked acrylic / styrene particles (2) 1.515
12μm cross-linked acrylic / styrene particles (2) 1.545
8 μm crosslinked styrene particles 1.600

Composition of coating liquid B-1 for overcoat layer PET-30 43.0 g
Irgacure 127 1.4g
SP-13 0.1g
CAB 0.5g
MIBK 31.5g
MEK 13.5g

Composition of coating liquid L-1 for low refractive index layer Ethylenically unsaturated group-containing fluorine-containing polymer (A-1) 3.9 g
Silica dispersion A (22%) 25.0 g
Irgacure 127 0.2g
DPHA 0.4g
MEK 100.0g
MIBK 45.5g

The coating solution for the low refractive index layer was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution.
The refractive index after curing of the low refractive index layer obtained by coating and curing the coating solution was 1.360.

The compounds used are shown below.
PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [manufactured by Nippon Kayaku Co., Ltd.];
DPHA: a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate [manufactured by Nippon Kayaku Co., Ltd.];
DPCA-60: polyfunctional acrylate resin [manufactured by Nippon Kayaku Co., Ltd.];
UX-5003D: urethane acrylate resin [manufactured by Nippon Kayaku Co., Ltd.];
3.5 μm crosslinked styrene particles (30%): MIBK dispersion in which average particle size 3.5 μm [manufactured by Soken Chemical Co., Ltd.] was dispersed for 20 minutes at 10,000 rpm with a Polytron disperser 6 μm crosslinked acrylic particles (30%): average MIBK dispersion in which a particle size of 6.0 μm [manufactured by Soken Chemical Co., Ltd.] was dispersed for 20 minutes at 10,000 rpm with a polytron disperser (crosslinked acrylic particles having other particle sizes were prepared in the same manner);
3.5 μm cross-linked acrylic / styrene particles (30%): MIBK dispersion in which average particle size 3.5 μm [manufactured by Sekisui Plastics Co., Ltd.] is dispersed for 20 minutes at 10,000 rpm with a Polytron disperser)
(Cross-linked acrylic / styrene particles of other particle sizes were prepared in the same manner.);
Aggregating silica (30%): MIBK dispersion in which secondary agglomeration diameter 8.9 μm [Nipsil SS-30P (manufactured by Tosoh Silica)] was dispersed for 20 minutes at 10,000 rpm with a Polytron disperser Irgacure 127: Polymerization initiator [ Ciba Specialty Chemicals Co., Ltd.];
CAB: cellulose acetate butyrate; weight average molecular weight 70,000
Acrylic polymer (1); polymethyl methacrylate: weight average molecular weight 93,000 [manufactured by Sigma-Aldrich]
Acrylic polymer (2); poly (methyl methacrylate-co-butyl methacrylate): weight average molecular weight 75,000 [manufactured by Sigma-Aldrich]
Ethylenically unsaturated group-containing fluoropolymer (A-1): fluoropolymer (A-1) described in Production Example 3 of JP-A-2005-89536;

  SP-13: Fluorine-based surfactant (used after dissolving as a 10% by mass solution of MEK)

(Silica dispersion A)
Hollow silica fine particle sol (Isopropyl alcohol silica sol, average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20% by mass, silica particle refractive index 1.31, prepared by changing the size according to Preparation Example 4 of JP-A-2002-79616 ) 10 g of acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.0 g of diisopropoxyaluminum ethyl acetate were added to and mixed with 500 g, and then 3 g of ion-exchanged water was added. After making it react at 60 degreeC for 8 hours, it cooled to room temperature and added 1.0 g of acetylacetone. While adding cyclohexanone to 500 g of this dispersion so that the content of silica was almost constant, solvent substitution by vacuum distillation was performed. There was no generation of foreign matter in the dispersion, and the viscosity when the solid content concentration was adjusted to 22% by mass with cyclohexanone was 5 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%.

  Production of optical film samples 101-124

  Optical film samples 101 to 124 were prepared using the coating liquid shown in Table 1.

(1) Coating of anti-glare layer An 80 μm-thick triacetyl cellulose film (TAC-TD80U, manufactured by FUJIFILM Corporation) is unwound in roll form, and the anti-glare layer coating solution shown in Table 1 is used. In the die coating method using a slot die described in Example 1 of JP-A-2006-122889, coating was performed under conditions of a conveyance speed of 30 m / min, drying at 60 ° C. for 150 seconds, and oxygen concentration under nitrogen purge was about 0. Using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 1%, the coating layer was cured by being irradiated with ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 100 mJ / cm ² . . The coating amount was adjusted so that the film thickness of each antiglare layer was the value shown in Table 1.

(1) Coating of overcoat layer The triacetyl cellulose film coated with the antiglare layer is unwound again, and the coating liquid for overcoat layer is transferred by a die coating method using the slot die at a conveyance speed of 30 m / After coating at 60 ° C. for 150 seconds, using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) with an oxygen concentration of about 0.1% under a nitrogen purge, an illuminance of 400 mW / cm ^2, was wound to cure the coating layer by an irradiation dose of 100 mJ / cm ^2. The coating amount was adjusted so that the film thickness of each overcoat layer was the value shown in Table 1.

(2) Coating of low refractive index layer The triacetyl cellulose film coated with the antiglare layer is unwound again, and the coating solution for the low refractive index layer is conveyed by a die coating method using the slot die. After coating at 30 m / min and drying at 90 ° C. for 75 seconds, an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) having an oxygen concentration of 0.01 to 0.1% and 240 W / cm under a nitrogen purge was used. Then, an ultraviolet ray having an illuminance of 400 mW / cm ² and an irradiation amount of 240 mJ / cm ² was irradiated to form a low refractive index layer having a thickness of 100 nm, and wound up to prepare an antiglare antireflection film.

(Saponification of optical film)
After coating, the sample was subjected to the following treatment. 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 produced optical film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently 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.
In this manner, saponified optical films (samples 101 to 124) were produced.

(Preparation of polarizing plate)
Iodine is adsorbed onto polyvinyl alcohol and stretched on one side of a polarizing film, soaked in a 1.5 mol / L, 55 ° C. NaOH aqueous solution for 2 minutes, neutralized, washed with water, and 80 μm thick triacetyl. A cellulose film (TAC-TD80U, manufactured by FUJIFILM Corporation) is placed on the other side of the present invention samples 101 to 107 and 113 to 123 (saponified) in Example 1 and comparative sample samples 108 to 112 and 124. The polarizing plates P-101 to 124 were prepared by bonding and protecting each of the (saponified) films.

(Evaluation of optical film and polarizing plate)
About these obtained optical film samples, the following items were evaluated. The results are shown in Table 2.

(1) Surface shape Surface roughness (Ra):
According to JIS-B0601 (1982), the center line average roughness (Ra) (μm) was measured using a surf coder MODEL SE-3F manufactured by Kosaka Laboratory.
The measurement conditions were an evaluation length of 2.5 mm, a cutoff of 0.25 mm, a speed of 0.5 mm / s, a probe diameter of 2 μm, and a load of 30 μN.

Average mountain valley distance Sm:
An average value Sm (μm) of intervals of one cycle of the valley and the valley obtained from the intersection where the roughness curve intersects the center line was measured. The measuring apparatus was manufactured by Kosaka Laboratory Co., Ltd., Surfcoder MODEL SE-3F, and the measurement was performed under the same conditions as Ra measurement conditions. In addition, the notation “-” in the table indicates that measurement is impossible.

(2) Haze [1] The total haze value (H) of the obtained optical film is measured according to JIS-K7136.
[2] A few drops of silicone oil are added to the front and back surfaces of the optical film, and two glass plates with a thickness of 1 mm (micro slide glass product number S9111, made by MATSUNAMI) are sandwiched from the front and back sides to completely separate the two glasses. The plate was adhered to the obtained optical film, the haze was measured in a state where the surface haze was removed, and the value obtained by subtracting the haze measured by sandwiching only silicone oil between two separately measured glass plates was measured. Calculated as internal haze (Hi).
[3] A value obtained by subtracting the internal haze (Hi) calculated in [2] from the total haze (H) measured in [1] above was calculated as the surface haze (Hs) of the film.

(3) Average reflectance The back side of the film was roughened with sandpaper, then treated with black ink, and the back side was removed, using the spectrophotometer (manufactured by JASCO Corporation). The spectral reflectance was measured in the wavelength region of 380 to 780 nm. The arithmetic average value of the integrated reflectance of 450 to 650 nm was used for the result.

(4) Blackening feeling A sensory evaluation was performed on the feeling of blackening on a liquid crystal display device in which a polarizing plate having an optical film attached to the viewing side surface was disposed. The evaluation method is a method in which multiple displays are arranged in parallel and compared at the same time. From the front, the blackness when the power is turned off and the blackness (black image) when the power is turned on are compared for each film, and evaluated according to the following criteria. did. It was expressed by the standard that the stronger the blackness, the stronger the tightness of the screen.
A: Strong black and the screen looks very strong.
○: Black color is strong and the screen looks strong.
Δ: Black but gray, and the screen is not tight.
×: The color is very gray and there is no tightness on the screen.

(5) Anti-glare The entire back side of the coated surface of the obtained film is painted with black magic ink, and the exposed fluorescent lamp (8000 cd / m ² ) without louver is projected from an angle of 5 degrees, from the direction of −5 degrees. The degree of blurring of the reflected image when observed from an angle of 45 degrees and observed from a direction of -45 degrees was evaluated according to the following criteria.
◎: Fluorescent lamp outline is slightly observed at -5 degrees and -45 degrees. ◯: Fluorescent lamp outline is slightly observed at -5 degrees, but the outline is relatively clear at -45 degrees. I understand.
Δ: The outline of the fluorescent lamp can be seen relatively clearly even at −5 degrees or −45 degrees.
X: The outline of the fluorescent light is clearly visible or dazzling at -5 degrees or -45 degrees.

(6) Brittleness test (crack resistance)
The obtained film sample was cut into 35 mm × 140 mm, left at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours, and then measured for the curvature diameter at which cracks start to occur when rolled into a cylinder. Cracks were evaluated according to the following criteria.
(Double-circle): Even if a curvature diameter is 30 mm, there is no crack or the length of a crack is less than 1 mm on average.
○: Even if the curvature diameter is 40 mm, there is no crack or the average length of the crack is less than 1 mm.
(Triangle | delta): There is no crack even if a curvature diameter is 50 mm, or the length of a crack is less than 1 mm on average.
X: The curvature diameter is 50 mm, and the average length of cracks is 1 mm or more.

(7) Glitter Evaluation was performed on a backlight viewer of a transmissive white surface light source through a matrix filter (thickness: 0.7 mm) with a resolution of 100 ppi based on a standard of less than glare in all directions in a dark room environment.
A: Almost no glare was observed in all directions.
○: Observed in all directions, slight glare was observed, but it was hardly noticed.
Δ: Glitter was observed as a whole when observed in all directions.
X: Strong glare was observed as a whole when observed in all directions.

(8) Planarity The planarity of the polarizing plate prepared above was evaluated under the following criteria under a three-wavelength fluorescent lamp.
○: Although coating unevenness is slightly observed, it is hardly noticed.
X: Coating unevenness was observed.
XX: Uneven coating was strongly observed.

(9) Iridescent unevenness A liquid crystal TV (LC-32GS10 type) manufactured by Sharp Corporation was disassembled, the polarizing plate was carefully peeled off, and the cell side on the backlight side was Example 1 of JP-A-2007-140497. A polarizing plate using a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm was bonded to the opposite side of the film described in Film 1 with an adhesive.
Moreover, the polarizing plate (P-101-112) produced above was bonded together with the adhesive on the visual recognition side.
The liquid crystal TV thus produced was reflected in a three-wavelength fluorescent lamp in a dark room and evaluated according to the following criteria.
○: Iridescent unevenness is not visible at the edge of the fluorescent lamp.
Δ: Iridescent unevenness appears slightly on the edge of the fluorescent lamp, but I don't mind.
X: Rainbow-like unevenness is seen at the edge of the fluorescent lamp to be reflected.

(10) Striped display unevenness (modification of LCD TV)
In order to forcibly generate unevenness due to the image display unit, the liquid crystal TV was modified as follows and evaluated. Sharp liquid crystal TV (LC-32GS10 type) was disassembled, and the optical sheet between the backlight and the liquid crystal panel was removed except for the diffusion plate. There, a prism sheet BEF2 made by 3M was placed so that the groove direction was the horizontal direction of the screen, and the TV was assembled again. Next, only the polarizing film on the viewing side (upper and lower polarizing plates) was carefully peeled off, and each film of the sample in Example 1 was laminated with an adhesive. In a state of gray solid display (gradation 126/255) on the liquid crystal TV, the degree of striped display unevenness was visually evaluated according to the following criteria.
I don't care about moire: A
I don't really care about moire: B
Moire is a little worrisome: C
I'm worried about moire: D

(11) Heat resistance test A change in internal haze (internal haze change value) after 100 hours in an environment of 100 ° C was measured.
(Internal haze change value) = (Internal haze before test) − (Internal haze after test)
The evaluation results of each sample are shown in Tables 2 and 3.

From the results shown in Tables 2 and 3, the following is clear. The optical film of the present invention desirably has optical / physical / display performance as an antiglare antireflection film (no blackening, antiglare, brittleness, glare, planar, iridescent unevenness). Is in range. In addition, the feeling of blackening is improved by providing an overcoat layer and / or a low refractive index layer.
Further, the present invention 119-122 and Comparative Examples 124 and subjected to optical microscopic observation (magnification: 100 times, observation area: ^{5 mm} 2). The ratio of aggregation (contact) of 5 or more translucent particles to the total number of particles observed was 50% or less for Inventions 119 and 120, 20% or less for Inventions 121 and 122, and Comparative Example 124. Was 90% or less.

[Example 2]
Composition of Coating Solution C-1 for Antiglare Layer PET-30 27.9g
Irgacure 127 1.2g
6 μm cross-linked acrylic / styrene particles (2) (30%) 36.0 g
SP-13 0.1g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating liquid C-2 for anti-glare layer PET-30 27.9 g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
SP-13 0.1g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution C-3 for anti-glare layer DPHA 27.9 g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
SP-13 0.1g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution C-4 for antiglare layer DPHA 27.4 g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
SP-13 0.1g
CAB 0.5g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating liquid C-5 for anti-glare layer PET-30 13.9 g
DPCA-60 13.0g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution C-6 for antiglare layer PET-30 13.9 g
UX-5002D-M20 13.0g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution C-7 for anti-glare layer PET-30 13.9 g
UX-5003D 13.0g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of Coating Solution C-8 for Antiglare Layer PET-30 13.9g
UX-5003D 13.0g
Irgacure 127 1.2g
8 μm cross-linked acrylic / styrene particles (4) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating liquid C-9 for antiglare layer PET-30 13.9 g
UX-5003D 13.0g
Irgacure 127 1.2g
12 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
8 μm cross-linked acrylic / styrene particles (5) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating solution C-10 for antiglare layer PET-30 13.9 g
UX-5003D 13.0g
Irgacure 127 1.2g
12 μm cross-linked acrylic / styrene particles (4) (30%) 36.0 g
8 μm cross-linked acrylic / styrene particles (6) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Composition of coating liquid C-11 for antiglare layer PET-30 13.9 g
UX-5003D 13.0g
Irgacure 127 1.2g
12 μm cross-linked acrylic / styrene particles (3) (30%) 36.0 g
8 μm cross-linked acrylic / styrene particles (5) (30%) 36.0 g
SP-13 0.1g
Acrylic polymer (2) 1.0g
Methyl isobutyl ketone (MIBK) 16.8g
Methyl ethyl ketone (MEK) 18.0g

Each coating solution for the antiglare layer was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution.
The refractive index of the matrix after curing in the coating solution was 1.525.

  Here, the refractive index of the film of the antiglare layer excluding the translucent particles was directly measured with an Abbe refractometer. Further, the refractive index of the translucent particles is changed by changing the mixing ratio of two kinds of solvents having different refractive indexes selected from methylene iodide, 1,2-dibromopropane, and n-hexane. The turbidity was measured by dispersing an equal amount of translucent particles in the solvent, and the refractive index of the solvent when the turbidity was minimized was measured by an Abbe refractometer.

The refractive index of the particles was as follows.
6 μm cross-linked acrylic / styrene particles (2) 1.550
8μm cross-linked acrylic / styrene particles (3) 1.550
8μm cross-linked acrylic / styrene particles (4) 1.550
8μm cross-linked acrylic / styrene particles (5) 1.510
8μm cross-linked acrylic / styrene particles (6) 1.510
12 μm cross-linked acrylic / styrene particles (3) 1.550
12 μm cross-linked acrylic / styrene particles (4) 1.550

The compounds used are shown below.
UX-5002D-M20: urethane acrylate resin [manufactured by Nippon Kayaku Co., Ltd.];
6 μm crosslinked acrylic / styrene particles (2) (30%); MIBK dispersion in which average particle size 6 μm [manufactured by Soken Chemical Co., Ltd.] was dispersed for 20 minutes at 10,000 rpm with a Polytron disperser 8 μm crosslinked acrylic / styrene particles (3) (30%); MIBK dispersion in which average particle size 8 μm [manufactured by Soken Chemical Co., Ltd.] was dispersed for 20 minutes at 10,000 rpm with a Polytron disperser 8 μm crosslinked acrylic / styrene particles (4) (30%); average particle size 8 μm [Manufactured by Soken Chemical Co., Ltd.] MIBK dispersion 8 μm crosslinked acryl / styrene particles (5) (30%) with 2 parts by mass Dispersbyk 2000 added to 100 parts by mass and dispersed in a polytron disperser at 10,000 rpm for 20 minutes; average MIBK dispersion in which a particle size of 8 μm [Kaken Chemical Co., Ltd.] was dispersed with a Polytron disperser at 10,000 rpm for 20 minutes Liquid 8 μm cross-linked acrylic / styrene particles (6) (30%); average particle size 8 μm [manufactured by Soken Chemical Co., Ltd.] 2 parts by mass of Disperbyk 2000 was added and dispersed with a Polytron disperser at 10,000 rpm for 20 minutes. MIBK dispersion 12 μm crosslinked acryl / styrene particles 12 μm crosslinked acryl / styrene particles (3) (30%); average particle size 12 μm [manufactured by Soken Chemical Co., Ltd.] dispersed at 10,000 rpm for 20 minutes with a Polytron disperser 12 μm crosslinked acryl / styrene Particle (4) (30%); average particle size 12 μm [manufactured by Soken Chemical Co., Ltd.] 2 parts by weight of Disperbyk2000 was added to 100 parts by weight and dispersed with a Polytron disperser at 10,000 rpm for 20 minutes Disperbyk2000: Block structural unit derived from methacrylic acid ester (B bromine And an AB block copolymer having a block structural unit (A block) derived from a monomer having a quaternary ammonium base having the following structure in the side chain derived from methacrylic acid. The weight average molecular weight (Mw) is about 3,500, and the amount of the quaternary ammonium base is 1.75 mmol per 1 g of the dispersant, the amine value is 4 mg-KOH / g, and the acid value is 0 mg-KOH / g. [Made by Big Chemie]

  Production of optical film samples 201 to 211

  Optical film samples 201 to 211 were produced using the coating liquid shown in Table 4.

(1) Coating of anti-glare layer It produced similarly to Example 1. FIG. The coating amount was adjusted so that the film thickness of each antiglare layer was the value shown in Table 4.

(Saponification of optical film)
In the same manner as in Example 1, saponified optical films (Samples 201 to 211) were produced.

(Preparation of polarizing plate)
In the same manner as in Example 1, polarizing plates P-201 to 211 were produced.

(Evaluation of optical film and polarizing plate)
About these obtained optical film samples, the following items were evaluated. The results are shown in Tables 5 and 6.

(12) Point defect The optical film produced above is observed through 10 m ² through a three-wavelength fluorescent lamp, and a thing recognized as a point defect (a size different from the normal part is 100 μm or more) is detected and evaluated according to the following criteria: did.
: Less than 0.1 / m ² ○: 0.1 / m ² or more, less than 0.5 / m ² Δ: 0.5 / m ² or more, less than 1.0 / m ² ×: 1.0 pieces / m ² or more, less than 2.0 pieces / m ² XX: 2.0 pieces / m ² or more (13) Change in antiglare property In order to see the change in antiglare property of samples 201 to 211 Samples 301 to 311 were prepared in the same manner except that the conveyance speed of Example 1 was changed to 15 m / min using the same antiglare layer coating solution, and the entire back side of the coated surface of the obtained film was treated with black magic. A change in the degree of blurring of the reflected image was evaluated according to the following criteria when painted with ink and exposed from a fluorescent lamp (8000 cd / m ² ) without a louver from an angle of 5 degrees and observed from a direction of −5 degrees.
A: No change in antiglare property is observed.
○: Almost no change in antiglare property is observed.
Δ: A slight change in anti-glare property is observed, but it is hardly noticed.
X: A slight change in anti-glare property is observed and anxious.
XX: The change in anti-glare property is large and I am very interested.

[Example 3]
An 80 μm-thick triacetylcellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.), which was neutralized and washed with an aqueous solution of NaOH of 1.5 mol / L and 55 ° C. for 2 minutes, and Example 1 A polarizing plate was prepared by adhering and protecting both sides of a polarizing film prepared by adsorbing iodine to polyvinyl alcohol and stretching each film of the sample of the present invention (saponified) in 2. 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 antiglare layer or the low refractive index layer is the outermost surface (a polarization separation film having a polarization selection layer). A display device with extremely low background reflection and very high display quality when the polarizing plate on the viewing side of D-BEF manufactured by Sumitomo 3M Co., Ltd. is placed between the backlight and the liquid crystal cell. was gotten.

[Example 4]
Protective film on the liquid crystal cell side of the polarizing plate on the viewing side of the transmission type TN liquid crystal cell to which the films of the samples of the present invention in Examples 1 and 2 were attached, and the protective film on the liquid crystal cell side of the polarizing plate on the backlight side As an optical compensation film (Wide View Film Ace, manufactured by FUJIFILM Corporation), it has excellent contrast in a bright room, very wide viewing angles in the top, bottom, left and right, extremely excellent visibility, and display quality. A liquid crystal display device having a high level was obtained.

  In the liquid crystal TV produced by the evaluation of (9) iridescent unevenness in Example 1, the comparative example 108 had higher black luminance in the dark room and lower front contrast than the present inventions 101 to 107.

[Example 5]
When each film of the sample of the present invention in Examples 1 and 2 was bonded to a glass plate on the surface of an organic EL display device via an adhesive, reflection on the glass surface was suppressed, and a display device with high visibility. was gotten.

[Example 6]
Using each film of the sample of the present invention in Examples 1 and 2, a polarizing plate having the optical film of the present invention on one side was prepared, and on the opposite side of the polarizing plate having the optical film of the present invention. When the λ / 4 plate is laminated and pasted on the glass plate on the surface of the organic EL display device so that the optical film side of the present invention becomes the outermost surface, the surface reflection and the reflection from the inside of the surface glass are cut and extremely A display with high visibility was obtained.

Claims (17)

  An optical film having an antiglare layer on a transparent support, the antiglare layer comprising (i) a translucent resin, (ii) a molecular weight of 3,000 to 400,000, and irradiation with ionizing radiation Or a polymer compound that does not cure by heating, and (iii) translucent particles, the film thickness of the antiglare layer is 6 μm to 10 μm, and the average particle diameter of the translucent particles is 7 μm to 15 μm. The absolute value of the difference in refractive index between the translucent particles and the translucent resin is 0.001 to 0.050, and the total of the translucent particles is based on the total solid content in the antiglare layer. An optical film of 15 to 40% by mass.   The optical film according to claim 1, wherein the antiglare layer further comprises (iv) a resin having a molecular weight of 600 to 50,000.   3. The optical film according to claim 2, wherein the resin having a molecular weight of (iv) 600 to 50,000 is a resin obtained by curing a compound having two or more ethylenically unsaturated groups.   The optical film according to claim 1, comprising at least two kinds of the light-transmitting particles, wherein the light-transmitting particles have different refractive indexes. The translucent particles include at least two kinds of translucent particles A and translucent particles B, and the translucent particles A and translucent particles B satisfy the following conditions. The optical film as described.
(Refractive index of translucent particle A) − (refractive index of translucent resin) = 0.100 to 0.050
(Refractive index of translucent particle B) − (refractive index of translucent resin) = − 0.050 to −0.010 The optical according to any one of claims 1 to 4, wherein the translucent particles include at least two kinds of translucent particles A and translucent particles B, and the translucent particles A and the particles B satisfy the following conditions. the film.
Absolute value of difference between refractive index of translucent particle A and refractive index of translucent resin = 0.015 to 0.050
Absolute value of difference between refractive index of translucent particle B and refractive index of translucent resin = 0.001 to less than 0.015   The optical film according to claim 5 or 6, wherein a mass ratio of the translucent particles A and the translucent particles B (translucent particles A: translucent particles B) is 20:80 to 80:20.   The optical film according to any one of claims 1 to 7, comprising at least two kinds of the translucent particles, wherein the translucent particles have different average particle diameters.   The optical film according to any one of claims 1 to 8, comprising an antiglare layer and an overcoat layer in this order on the transparent support.   The optical film according to claim 1, further comprising a layer having a lower refractive index than the antiglare layer or the overcoat layer.   The optical film according to claim 1, wherein a haze value resulting from surface scattering is 0.2% or more and 10% or less.   The optical film according to claim 1, wherein the haze value resulting from internal scattering is 10 to 35%.   The optical film according to claim 1, wherein the integrated reflectance is 3.0% or less.   14. The optical film according to claim 1, wherein the center line average roughness Ra is 0.05 μm or more and 0.25 μm or less, and the average interval Sm between the irregularities is 50 μm or more and 350 μm or less.   The optical film according to claim 1, wherein the average inclination angle θa is 0.5 ° or more and 3.0 ° or less, and the maximum value of the inclination angle distribution is 0.3 ° or less.   It is a polarizing plate which has a polarizing film and two protective films which protect both the front side and back side of this polarizing film, Comprising: At least one of this protective film is an optical film in any one of Claims 1-15 A polarizing plate.   An image display device comprising the optical film according to claim 1 or the polarizing plate according to claim 16.

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