CN105637391A - Anti-glare film - Google Patents

Abstract

Provided is an anti-glare film which has excellent anti-glare properties over a wide viewing angle despite low haze, and which can sufficiently suppress the occurrence of whitening and glare when disposed on an image display device. An anti-glare film is provided, the anti-glare film is provided with a transparent support body and an anti-glare layer with fine concavities and convexities formed on the support body, for example, the root mean square roughness Rq (0.08 ) is not less than 0.01 μm and not more than 0.05 μm, the root mean square roughness when measured with a specified cut-off length is within the specified range, and the light reflectance R _SCI measured with the method of including regular reflected light is the same as that measured without regular reflected light The light reflectance R _SCE ratio R _SCE /R _SCI is 0.1 or less.

Description

Anti-glare film

technical field

The present invention relates to an antiglare film excellent in antiglare properties.

Background technique

For image display devices such as liquid crystal displays, plasma display panels, Braun tube (cathode ray tube: CRT) displays, and organic electroluminescent (EL) displays, in order to avoid In order to prevent degradation of visibility (visibility), an anti-glare film is disposed on the display surface.

As an anti-glare film, a transparent film having a surface unevenness has been mainly considered. Such an anti-glare film exhibits anti-glare properties by reducing the reflection of external light by scattering and reflecting external light (external light scattered light) by using the uneven shape of the surface. However, when the scattered light from external light is strong, the entire display surface of the image display device may be whitish and the displayed color may not be clear, so-called "whitening (白ちゃけ)" may occur. In addition, the pixel of the image display device interferes with the surface roughness of the anti-glare film, and a brightness distribution occurs, so-called "glare" that makes it difficult to see may occur. Based on the above background, anti-glare films are required to sufficiently prevent the occurrence of "whitening" and "glare" while ensuring excellent anti-glare properties.

As such an anti-glare film, for example, in Patent Document 1, the following anti-glare film is disclosed as an anti-glare film that does not cause glare even when it is arranged on a high-definition image display device, and can sufficiently prevent the generation of whitening. Film: It has fine surface irregularities formed on a transparent substrate, and the average length PSm of any profile curve of the surface irregularities is 12 μm or less, and the ratio of the arithmetic mean height Pa of the profile curve to the average length PSm is Pa/PSm 0.005 or more and 0.012 or less, the proportion of surfaces with an inclination angle of 2° or less is 50% or less, and the proportion of surfaces with an inclination angle of 6° or less is 90% or more.

The anti-glare film disclosed in Patent Document 1 can effectively suppress the glare by eliminating the surface irregularities with a period of approximately 50 μm that tend to cause glare by making the average length PSm of any profile curve very small. However, for the anti-glare film disclosed in Patent Document 1, if the haze is further reduced (reduced haze), it may cause the display surface of the image display device on which the anti-glare film is arranged to be viewed from an oblique direction. The anti-glare performance is reduced. Therefore, the antiglare film disclosed in Patent Document 1 still has room for improvement in terms of antiglare properties at wide viewing angles.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2007-187952

Contents of the invention

The problem to be solved by the invention

An object of the present invention is to provide an anti-glare film which has excellent anti-glare properties over a wide viewing angle despite low haze, and which can sufficiently suppress occurrence of whitening and glare when disposed on an image display device.

means of solving problems

The inventors of the present invention conducted intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the present invention relates to:

(1) An anti-glare film comprising a transparent support and an anti-glare layer formed on the transparent support and having a micro-concave-convex surface, characterized in that,

The total haze of the anti-glare film is not less than 0.1% and not more than 3%,

The surface haze is not less than 0.1% and not more than 2%,

The root mean square roughness Rq (0.08) when measured at a cut-off length (cutoff length) of 0.08 mm is not less than 0.01 μm and not more than 0.05 μm,

The root mean square roughness Rq (0.25) when measured at a cut-off length of 0.25 mm is not less than 0.05 μm and not more than 0.1 μm,

The root mean square roughness Rq (0.8) when measured at a cut-off length of 0.8 mm is not less than 0.07 μm and not more than 0.12 μm,

The root mean square roughness Rq(2.5) when measured at a cut-off length of 2.5 mm is not less than 0.08 μm and not more than 0.15 μm,

The ratio R _SCE /R _SCI of the light reflectance (luminous reflectance) R _SCI measured with the method containing regular reflection light, and the light reflectance R _SCE measured with the method of not including regular reflection light is 0.1 or less.

Moreover, in this invention, the antiglare film of following (2)-(4) is preferable.

(2) The antiglare film according to (1) above, wherein the average length Sm(0.25) measured at a cut length of 0.25 mm is 90 μm or more and 160 μm or less,

The average length Sm(0.8) when measured at a cut-off length of 0.8 mm is not less than 100 μm and not more than 300 μm,

The average length Sm(2.5) when measured at a cut length of 2.5 mm is 200 μm or more and 400 μm or less.

(3) The antiglare film as described in the above (1) or (2), which is measured using five kinds of optical combs with the widths of the dark part and the bright part being 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm, respectively. The sum Tc of transmission clarity is above 375%,

The sum Rc(45) of the reflection clarity measured at an incident angle of light of 45° using four kinds of optical combs whose widths of the dark part and bright part are 0.25mm, 0.5mm, 1.0mm and 2.0mm respectively is 180% or less,

The sum Rc(60) of the reflection clarity measured at an incident angle of light of 60° using four kinds of optical combs with dark and light widths of 0.25mm, 0.5mm, 1.0mm and 2.0mm respectively was 240% or less.

(4) The anti-glare film according to any one of the above (1) to (3), wherein the light reflectance R _SCE measured without regular reflected light is 0.5% or less.

The effect of the invention

According to the present invention, it is possible to provide an anti-glare film which has sufficient anti-glare properties over a wide viewing angle despite low haze, and which sufficiently suppresses occurrence of whitening and glare when disposed on an image display device.

Description of drawings

Figure 1: A diagram schematically showing the optical system used to measure the light reflectance R _SCI .

Fig. 2: A diagram schematically showing an optical system for measuring the light reflectance R _SCE .

Fig. 3: A diagram schematically showing a preferred example of a method of manufacturing a mold (first half).

Fig. 4: A diagram schematically showing a preferred example of a method of manufacturing a mold (second half).

FIG. 5 : is a diagram schematically showing a preferred example of a production apparatus used in the production method of the anti-glare film of the present invention.

Fig. 6: A diagram schematically showing a preferred pre-curing step in the method for producing the antiglare film of the present invention.

Fig. 7: A diagram schematically showing a unit cell used for glare evaluation.

Fig. 8: A diagram schematically showing a glare evaluation device.

FIG. 9 : A diagram showing a part of pattern A used in Examples 1 to 3 and Comparative Example 1. FIG.

FIG. 10 : A diagram showing a part of pattern B used in Comparative Example 2. FIG.

FIG. 11 : A diagram showing a power spectrum Γ(f) obtained by discrete Fourier transforming the patterns A and B. FIG.

detailed description

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as needed, but the dimensions and the like shown in the drawings are arbitrarily set for the convenience of observation.

The anti-glare film of the present invention is characterized in that the root mean square roughness Rq when measured with a specified cut-off length is within the above-mentioned ranges, and the light reflectance R _SCI measured with the method of including regular reflected light is the same as that without regular reflected light. The light reflectance R _SCE ratio R _SCE /R _SCI measured by the method is 0.1 or less.

First, the method of calculating the root mean square roughness Rq, the light reflectance _RSCI , and the light reflectance _RSCE of the antiglare film of the present invention will be described.

[root mean square roughness Rq]

In the antiglare film of the present invention, the root mean square roughness Rq (0.08 ), Rq(0.25), Rq(0.8) and Rq(2.5) are 0.01 μm to 0.05 μm, 0.05 μm to 0.1 μm, 0.07 μm to 0.12 μm, and 0.08 μm to 0.15 μm, respectively. These Rq(0.08), Rq(0.25), Rq(0.8), and Rq(2.5) can be measured by the method based on JISB0601 by setting the measurement conditions as follows.

Rq(0.08): interception length 0.08mm, assessment length 0.4mm

Rq(0.25): interception length 0.25mm, assessment length 1.25mm

Rq(0.8): interception length 0.8mm, assessment length 4mm

Rq(2.5): interception length 2.5mm, assessment length 12.5mm

The root mean square roughness when measured with a specified cut-off length refers to the roughness obtained by shielding the long-wavelength components above the specified cut-off length through a high-pass filter from the profile curve obtained by the measurement method specified by the above-mentioned JIS. The surface roughness obtained from the curve. Therefore, the root-mean-square roughness when measured with a cut-off length of 0.08 mm means that the root-mean-square roughness is calculated from the roughness curve when surface irregularities having a wavelength of 0.08 mm or more are removed from the above-mentioned profile curve. Evaluation was performed as a surface irregularity shape at a wavelength of 0.04 mm or less that cuts off the length 1/2. Similarly, the root mean square roughness when measured at a cut-off length of 0.25mm, 0.8mm, or 2.5mm refers to the use of surface irregularities with wavelengths of 0.25mm or more, 0.8mm or 2.5mm or more removed from the above profile curve. The surface roughness obtained by calculating the surface roughness curve is mainly evaluated for the surface roughness shape having a wavelength of 0.125 mm or less, 0.4 mm or less, or 1.25 mm or less as the intercept length 1/2.

A large Rq(0.08) means that the surface irregularities of the antiglare layer included in the antiglare film of the present invention have many surface irregularities having a wavelength of 0.04 mm or less. Similarly, a large Rq (0.25) means that the anti-glare layer has a large number of surface irregularities with a wavelength of 0.04 mm or more and 0.125 mm or less, and a large Rq (0.8) means that there are a large number of surface irregularities with a wavelength of 0.125 mm or more and 0.4 mm or less. As for the surface unevenness, a large Rq(2.5) means that there are many surface unevennesses having a wavelength of not less than 0.4 mm and not more than 1.25 mm. If Rq(0.08) is less than 0.01 μm, there are very few short-period surface irregularities with a wavelength of 0.04 mm or less, that is, an anti-glare film having an anti-glare layer formed only by long-period surface irregularities is formed. The texture becomes rough. If Rq (0.08) is greater than 0.05 μm, then form the anti-glare film with the anti-glare layer that strongly produces the scattering caused by the short-period surface irregularities with a wavelength of 0.04 mm or less, so the image display device with such an anti-glare film is easy to obtain. Produces whitening. Although Rq (0.08) of the anti-glare film of this invention is the said range, it is preferable that it is 0.02 micrometer or more and 0.04 micrometer or less.

If Rq (0.25) is less than 0.05 μ m, then form the anti-glare film that has the anti-glare layer with few surface irregularities with a wavelength of 0.04 mm or more and 0.125 mm or less. ~10° or so), the anti-glare property is insufficient. If Rq(0.25) is larger than 0.1 μm, the surface irregularities with a wavelength of not less than 0.04 mm and not more than 0.125 mm will increase. In particular, the surface irregularities in such wavelength bands have a strong correlation with the generation of glare, and therefore, an image display device including the anti-glare film is likely to generate glare. Although Rq(0.25) of the antiglare film of the present invention is within the range described above, it is preferably 0.06 μm or more and 0.08 μm or less.

If Rq (0.8) is less than 0.07 μ m, then form the anti-glare layer with few concavo-convex shapes with a wavelength of 0.125 mm or more and 0.4 mm or less, therefore, the image display device with the anti-glare film having the anti-glare layer is viewed from an oblique direction (10 ~30° or so), the anti-glare property becomes insufficient when observed. If Rq(0.8) is larger than 0.12 μm, there will be too many concavo-convex shapes with a wavelength of 0.125 mm or more and 0.4 mm or less, and an image display device that tends to cause whitening will be obtained. Although Rq(0.8) of the antiglare film of the present invention is within the above range, it is preferably 0.08 μm or more and 0.10 μm or less.

If Rq (2.5) is less than 0.08 μ m, then form the anti-glare layer with few concavo-convex shapes with a wavelength of more than 0.4 mm and less than 1.25 mm. ° or more), the anti-glare property at the time of observation becomes insufficient. If Rq(2.5) is larger than 0.15 μm, there will be too many long-period concavo-convex shapes with a wavelength of 0.4 mm to 1.25 mm, and the surface texture of the antiglare film will become rough. Although Rq(2.5) of the antiglare film of the present invention is within the above-mentioned range, it is preferably 0.09 μm or more and 0.11 μm or less.

[Light reflectance R _SCI and light reflectance R _SCE ]

Fig. 1 is a diagram schematically showing an optical system for measuring the light reflectance R _SCI with regular reflection light, and Fig. 2 is a schematic diagram showing an optical system for measuring light reflectance R _SCE without regular reflection diagram. Figure 1 and Figure 2 show the optical system of the diffuse illumination method. The diffuse illumination method is a method of uniformly illuminating the measurement sample from all directions by using an integrating sphere, etc. inside the ball). The light emitted from the light source 13 is diffused inside the integrating sphere 12 and reflected on the surface of the measurement sample 14 . In Fig. 2, an optical trap 15 is arranged at the position of the integrating sphere 12 in the regular reflection direction relative to the light receiving part (in Fig. 1, its structure is: a fixture with a conical cavity is installed, and the light entering the conical cavity absorbed in the cavity and will not return to the integrating sphere 12), the light in the regular reflection direction of the light receiving part cannot reach the surface of the measurement sample.

An optical system that does not use an optical trap as shown in FIG. 1 is called a specularly reflected light mode (SCI mode). On the other hand, an optical system using an optical trap as shown in FIG. 2 is called a specular reflection-free mode (SCE mode). The light reflectance calculated from the reflectance spectrum of the sample measured in two modes according to the method described in JISZ8722 is the light reflectance R _SCI measured with regular reflection light and the light reflectance measured without regular reflection light. R _SCE .

When the ratio R _SCE /R _SCI of the light reflectance R _SCI measured in a way containing regular reflected light to the light reflectance R _SCE measured in a way not including regular reflected light is greater than 0.1, the ambient light in the use environment will play a role in preventing Reflected light toward the user on the surface of the glare film increases, and as a result, whitening occurs in an image display device including the anti-glare film. In addition, this image display device tends to cause a reduction in bright room contrast. The ratio R _SCE /R _SCI is preferably 0.08 or less, more preferably 0.06 or less. In addition, the light reflectance R _SCE measured without regular reflected light is preferably 0.5% or less, more preferably 0.4% or less, and still more preferably 0.3% or less.

[total haze, surface haze]

In order to exhibit anti-glare properties and prevent whitening, the anti-glare film of the present invention has a total haze in the range of 0.1% to 3% and a surface haze in the range of 0.1% to 2% with respect to vertically incident light membrane. The total haze of the antiglare film can be measured according to the method shown in JISK7136. An image display device provided with an anti-glare film having a total haze or a surface haze of less than 0.1% is not preferable because sufficient anti-glare properties cannot be exhibited. In addition, when the total haze exceeds 3%, or when the surface haze exceeds 2%, the image display device in which the anti-glare film is arranged will cause whitening, which is not preferable. Such an image display device also suffers from insufficient contrast.

The lower the internal haze obtained by subtracting the surface haze from the total haze, the more preferable. An image display device provided with an anti-glare film having an internal haze higher than 2.5% tends to lower contrast.

[Average length Sm when measured at specified cut length]

In the anti-glare film of the present invention, the surface unevenness of the anti-glare layer is a surface unevenness with a root mean square roughness in the above-mentioned range when measured at a specified cut-off length, and preferably the average length when measured with the specified cut-off length is within the range shown below. Specifically, it is preferable that the average length Sm(0.25) when measured at a cut-off length of 0.25 mm is not less than 90 μm and not more than 160 μm, and that the average length Sm(0.8) when measured at a cut-off length of 0.8 mm is not less than 100 μm and not more than 300 μm. The average length Sm(2.5) when measured at 2.5 mm is 200 μm or more and 400 μm or less.

An anti-glare film having an Sm(0.25) of less than 90 μm has an anti-glare layer with many surface irregularities close to 50 μm, and an image display device provided with such an anti-glare film may be prone to glare. An anti-glare film with Sm(0.25) larger than 160 μm has an anti-glare layer with a long period of surface irregularities, and the surface texture of the anti-glare film may be rough. The anti-glare film with Sm(0.8) less than 100 μm has an anti-glare layer with a period of 100-200 μm, which contributes to the anti-glare property when viewed from an oblique direction (about 10-30°). The antiglare property of the image display device of an antiglare film may fall when viewed obliquely. An anti-glare film with Sm(0.8) larger than 300 μm has an anti-glare layer with a long period of surface irregularities, and the surface texture of the anti-glare film may be rough. The anti-glare film with Sm(2.5) less than 200 μm has an anti-glare layer with a period of 200 to 300 μm that contributes to the anti-glare property when the anti-glare film is viewed from an oblique direction (30° or more), and has a small surface irregularity. When the image display device of the antiglare film sees the antiglare film from an oblique direction (30 degrees or more), the antiglare property may fall. An anti-glare film having an Sm(2.5) of more than 400 μm has an anti-glare layer with excessively long-period surface irregularities, and the surface texture of the anti-glare film may be rough.

[Transmission clarity (sharpness) Tc, reflection clarity Rc (45) and reflection clarity Rc (60)]

The antiglare film of the present invention preferably has a sum Tc of transmitted clarity obtained under the following measurement conditions of 375% or more. The sum Tc of transmission sharpness can be calculated|required by measuring image sharpness separately using the optical comb of predetermined width by the method based on JISK7105, and calculating the addition. Specifically, five kinds of optical combs with a width ratio of 1:1 between the dark part and the bright part and whose widths are 0.125mm, 0.25mm, 0.5mm, 1.0mm and 2.0mm are used to measure the image sharpness respectively, and then calculate Take out its addition and set it as Tc. When an anti-glare film having a Tc of less than 375% is disposed on a higher-definition image display device, glare may easily occur. As far as the upper limit of Tc is concerned, it can be selected within the range of 500% or less of its maximum value, but if the Tc is too high, an image display device whose anti-glare property is easily reduced when viewed from the front will be obtained, so the Tc Preferably, it is, for example, 450% or less.

It is preferable that the reflection clarity Rc(45) of the antiglare film of this invention measured by the incident light of an incident angle of 45 degrees is 180 % or less. The reflection sharpness Rc(45) can be measured by the method based on JISK7105 in the same way as the above Tc, and the image sharpness is measured by using four kinds of optical combs with a width of 0.25mm, 0.5mm, 1.0mm and 2.0mm among the above five kinds of optical combs , and find its addition, which is set as Rc(45). When Rc(45) is 180% or less, the anti-glare properties when viewed from the front and oblique directions of the image display device in which such an anti-glare film is arranged will become more favorable, so it is preferable. The lower limit of Rc(45) is not particularly limited, but is preferably, for example, 80% or more in order to suppress occurrence of whitening and glare well.

It is preferable that the reflection clarity Rc(60) of the antiglare film of this invention measured by the incident light of an incident angle of 60 degrees is 240 % or less. Reflection clarity Rc(60) was measured by the method based on JISK7105 similarly to reflection clarity Rc(45) except having changed the incident angle. When Rc(60) is 240% or less, the anti-glare property when viewed from an oblique direction of the image display device in which the anti-glare film is arranged becomes more favorable, and it is preferable. The lower limit of Rc(60) is not particularly limited, but is preferably, for example, 150% or more in order to suppress occurrence of whitening and glare well.

[Manufacturing method of the anti-glare film of the present invention]

The antiglare film of the present invention can be produced as follows, for example. The first method includes: preparing a mold for forming fine unevenness based on a predetermined pattern on the molding surface; transferring the shape of the uneven surface of the mold to a transparent support; The transparent support was peeled from the mold. The second method includes: preparing a composition comprising microparticles, a resin (binder) and a solvent in which the microparticles are dispersed in a resin solution, coating the composition on a transparent support, and drying as necessary, so that The thus formed coating film (coating film containing fine particles) is cured. In the second method, the coating film thickness and the aggregation state of the microparticles are adjusted according to the composition of the above-mentioned composition, the drying conditions of the above-mentioned coating film, etc., thereby exposing the microparticles on the surface of the coating film, so that the microparticles are exposed on the transparent support. Irregular unevenness is formed. From the viewpoint of production stability and production reproducibility of the anti-glare film, the anti-glare film of the present invention is preferably produced by the first method.

Here, the 1st method preferable as the manufacturing method of the antiglare film of this invention is demonstrated in detail.

In order to form the anti-glare layer having the surface unevenness shape with the above characteristics with high precision, it is important to prepare a mold for forming fine unevenness (hereinafter also simply referred to as "mold"). More specifically, the concave-convex shape of the surface of the mold (hereinafter also referred to as "mold concave-convex surface") is formed based on a specified pattern, and the specified pattern preferably expresses its one-dimensional power in the form of intensity with respect to spatial frequency. The graph obtained for the spectrum has a pattern of one minimum value at a spatial frequency of 0.015 μm ⁻¹ or more and 0.05 μm ⁻¹ or less. Here, the "pattern" refers to image data for forming the fine uneven surface of the anti-glare layer of the anti-glare film, or a mask having a light-transmitting portion and a light-shielding portion, and is hereinafter simply referred to as a “pattern”.

First, the method of determining the pattern of the fine uneven surface for forming the anti-glare layer which the anti-glare film of this invention has is demonstrated.

For example, a method for calculating a two-dimensional power spectrum of a pattern will be described for a case where the pattern is image data. First, after converting the image data into binarized image data of 2 gradation levels, the gradation levels are represented by a binary function g(x, y). Perform Fourier transform on the obtained binary function g(x, y) as shown in the following formula (1) to calculate the binary function G(f _x , f _y ), and then as shown in the following formula (2) , take the quadratic of the absolute value of the obtained binary function G(f _x , f _y ), so as to calculate the two-dimensional power spectrum Γ(f _x , f _y ). Here, x and y represent orthogonal coordinates within the image data plane. In addition, f _x and f _y represent frequencies in the x-direction and y-direction, respectively, and have dimensions of the reciprocal length.

π in formula (1) is pi, and i is the imaginary unit.

Γ(f _x ,f _y )＝|G(f _x ,f _y )| ² …Formula (2)

This two-dimensional power spectrum Γ(f _x , f _y ) represents the spatial frequency distribution of the pattern. Usually, antiglare films are required to be isotropic, so the pattern for antiglare film production of the present invention is also isotropic. Thus, a binary function Γ(f _x , f _y ) representing the two-dimensional power spectrum of a pattern can be represented by a unary function Γ(f) that depends only on the distance f from the origin (0, 0). This unary function Γ(f) represents the one-dimensional power spectrum of the pattern. Next, a method of calculating the unary function Γ(f) from the binary function Γ(f _x , f _y ) will be described. First, a binary function Γ(f _x , f _y ) that is a two-dimensional power spectrum of an elevation is expressed in polar coordinates as in Equation (3).

Γ(f _x ,f _y )=Γ(fcosθ,fsinθ)...Formula (3)

Here, θ is the declination angle in Fourier space. The one-variable function Γ(f) can be obtained by calculating the rotation average of the two-variable function Γ(fcosθ, fsinθ) expressed in polar coordinates as in Equation (4).

In order to obtain the antiglare film of the present invention with high precision, it is preferable that the one-dimensional power spectrum Γ(f) of the pattern has a minimum value at a spatial frequency of 0.015 μm ⁻¹ or more and 0.05 μm ⁻¹ or less.

When obtaining the two-dimensional power spectrum of a pattern, the gray scale binary function g(x, y) is usually obtained as a discrete function. In this case, the two-dimensional power spectrum may be calculated by discrete Fourier transform. The one-dimensional power spectrum of the pattern can be similarly obtained from the two-dimensional power spectrum of the pattern.

In addition, in order to make the obtained surface uneven shape into a uniform and continuous curved surface, it is preferable to make the average value of the binary function g(x, y) equal to the maximum value of the binary function g(x, y) and the value of the binary function g(x, y). 30-70% of the difference between the minimum values of y). This binary function g(x, y) is the aperture ratio of the pattern in the case of producing the concave-convex surface of the mold by photolithography. For the case of manufacturing the concave-convex surface of the mold by photolithography, the aperture ratio of the pattern here is defined in advance. When the photoresist used in the photolithography method is a positive photoresist, the aperture ratio means: when image data is drawn on the coating film of the positive photoresist, the ratio is relative to the coating film. The proportion of the total surface area of the film that is exposed. On the other hand, when the photoresist used in photolithography is a negative photoresist, the aperture ratio means: when image data is drawn on the coating film of the negative photoresist, the aperture ratio is relative to the coating film of the negative photoresist. The ratio of the exposed area to the entire surface area of the cloth film. When the photolithography method is one-shot exposure, the aperture ratio refers to the ratio of the light-transmitting portion of a mask having a light-transmitting portion and a light-shielding portion.

The anti-glare film of the present invention can be obtained by making the one-dimensional power spectrum of the pattern have a minimum value at a spatial frequency of 0.015 μm- ¹ or more and 0.05 μm ^-1 or less, manufacturing a desired mold, and using the mold, using the above-mentioned The first method is to manufacture the antiglare film of the present invention.

In order to create a one-dimensional power spectrum pattern with a minimum value at a spatial frequency of 0.015 μm ^-1 or more and 0.05 μm ^-1 or less, a pattern in which points are randomly arranged, or a pseudo-random pattern generated by random numbers or using a computer is created in advance. A pattern (preparation pattern) having a random lightness distribution whose shading is determined by number, and components of a specific spatial frequency range are removed from the preliminary pattern. In order to remove components in this specific spatial frequency range, the above-mentioned preliminary pattern may be passed through a band-pass filter.

In order to produce an anti-glare film having an anti-glare layer formed with surface irregularities based on a predetermined pattern, a mold having an uneven surface for transferring the fine uneven surface formed based on the predetermined pattern to a transparent support is produced. The above-mentioned first method using such a mold is an embossing method characterized by forming an antiglare layer on a transparent support.

As said embossing method, the photo embossing method using a photocurable resin, the thermal embossing method using a thermoplastic resin, etc. are mentioned. Among them, the photo-embossing method is preferable from the viewpoint of productivity.

In the photoembossing method, a photocurable resin layer is formed on a transparent support (the surface of the transparent support), and the photocurable resin layer is pressed against the concave and convex surface of the mold while curing it. A method of transferring the shape of the concave-convex surface of the mold to the photocurable resin layer. The details are as follows: in the state where the photocurable resin layer formed by coating the photocurable resin on the transparent support is closely adhered to the concave-convex surface of the mold, light is irradiated from the transparent support side (the light uses a light that can curable resin curing light), so that the photocurable resin (photocurable resin contained in the photocurable resin layer) is cured, and then the transparent support formed with the cured photocurable resin layer is peeled from the mold . In the antiglare film obtained by such a manufacturing method, the photocurable resin layer after hardening becomes an antiglare layer. It should be noted that, from the viewpoint of ease of manufacture, as the photocurable resin, an ultraviolet curable resin is preferred, and in the case of using the ultraviolet curable resin, ultraviolet light is used for the light to be irradiated (hereinafter, the ultraviolet curable resin is used as The embossing method of photocurable resin is called "UV embossing method"). In order to manufacture the antiglare film integrated with a polarizing film, using a polarizing film as a transparent support body, what is necessary is just to replace a transparent support body with a polarizing film in the embossing method demonstrated here.

The type of ultraviolet curable resin used in the UV embossing method is not particularly limited, and an appropriate resin can be selected and used from commercially available resins according to the type of transparent support to be used and the type of ultraviolet rays. Such an ultraviolet curable resin is a concept including monomers (polyfunctional monomers), oligomers, polymers, and mixtures thereof that are photopolymerized by irradiation with ultraviolet rays. In addition, by using in combination a photoinitiator appropriately selected according to the type of ultraviolet curable resin, a resin that can be cured also by visible light having a wavelength longer than ultraviolet rays can also be used. Preferred examples and the like of the ultraviolet curable resin will be described later.

As the transparent support used in the UV embossing method, for example, glass, a plastic film, or the like can be used. As the plastic film, any one having appropriate transparency and mechanical strength can be used. Specific examples include: cellulose acetate resins such as TAC (cellulose triacetate); acrylic resins; polycarbonate resins; polyester resins such as polyethylene terephthalate; Transparent resin film made of polyolefin resin such as acrylic. These transparent resin films may be solvent cast films or extruded films.

The thickness of the transparent support is, for example, 10 to 500 μm, preferably 10 to 100 μm, more preferably 10 to 60 μm. When the thickness of the transparent support is within this range, an anti-glare film having sufficient mechanical strength tends to be obtained, and an image display device including the anti-glare film is less likely to be dazzled.

On the other hand, the thermal embossing method is a method in which a transparent resin film made of a thermoplastic resin is pressed against a mold concave-convex surface in a heated and softened state, and the surface concave-convex shape of the mold concave-convex surface is transferred to the transparent resin film. The transparent resin film used in the heat embossing method may be any film as long as it is substantially optically transparent, and specifically, the materials listed as the transparent resin film used in the UV embossing method are mentioned.

Hereinafter, the method of manufacturing the mold used for the embossing method is demonstrated.

Regarding the manufacturing method of the mold, as long as the molding surface of the mold can be manufactured, the above-mentioned surface unevenness formed based on a predetermined pattern can be transferred to a transparent support (an anti-glare layer with a surface unevenness formed based on a predetermined pattern can be formed) The range of the mold is not particularly limited, but in order to manufacture the anti-glare layer with the uneven surface with high precision and good reproducibility, photolithography is preferable. Further, the photolithography method preferably includes the following steps: [1] a first plating step, [2] a polishing step, [3] a photosensitive resin film forming step, [4] an exposure step, [5] a developing step, [ 6] First etching step, [7] Photosensitive resin film peeling step, [8] Second etching step, [9] Second plating step.

FIG. 3 schematically shows a preferred example of the first half of the mold manufacturing method. Fig. 3 schematically shows the cross section of the mold in each process. Hereinafter, each process of the manufacturing method of the mold for antiglare film manufacturing of this invention is demonstrated in detail with reference to FIG. 3. FIG.

[1] The first plating process

First, a base material (base material for mold) to be used for mold production is prepared, and copper plating is performed on the surface of the base material for mold. By performing copper plating on the surface of the base material for molds in this way, the adhesiveness and glossiness of the chromium plating in the 2nd plating process mentioned later can be improved. Copper plating has a high coating property and a strong smoothing effect, so it is possible to fill minute unevenness, cavities, etc. of the base material for a mold to form a flat and glossy surface. Thus, by performing copper plating on the surface of the base material for the mold in this way, even if chrome plating is performed in the second plating step described later, it is possible to eliminate the flaws on the chrome-plated surface that are thought to be caused by the fine unevenness and voids that exist in the base material. rough. In addition, since the coating of copper plating is high, the occurrence of fine cracks is reduced. Therefore, even if a surface irregularity shape (fine uneven surface shape) based on a predetermined pattern is formed on the molding surface of the base material for a mold, it is possible to sufficiently prevent damage caused by the influence of the surface of the base (base material for mold) such as minute unevenness, cavities, and cracks. deviation.

As copper used in the copper plating in the first plating step, a pure metal of copper may be used, or an alloy (copper alloy) mainly composed of copper may be used. Therefore, "copper" used for copper plating is a concept including copper and copper alloys. Copper plating may be electroplating or electroless plating, but it is preferable to use electroplating for copper plating in the first plating step. Furthermore, the preferred plating layer in the first plating step is not only a plating layer consisting of a copper plating layer, but a plating layer formed by laminating a copper plating layer and a plating layer made of a metal other than copper.

If the plating layer formed by copper plating on the surface of the base material for the mold is too thin, the influence of the base surface (micro unevenness, voids, cracks, etc.) cannot be completely eliminated, so the thickness is preferably 50 μm or more. The upper limit of the plating thickness is not critical, but it is preferably about 500 μm or less in terms of cost and the like.

The base material for a mold is preferably a base material made of a metal material. Furthermore, aluminum, iron, etc. are preferable as a material of this metal material from a viewpoint of cost. Furthermore, it is particularly preferable to use a lightweight aluminum base material as the base material for the mold from the viewpoint of the ease of handling the base material for the mold. It should be noted that the aluminum and iron here do not need to be pure metals, and may be alloys mainly composed of aluminum or iron.

The shape of the base material for molds should just be an appropriate shape with respect to the manufacturing method of the antiglare film of this invention. Specifically, it can be selected from a flat substrate, a cylindrical substrate, a cylindrical (tubular) substrate, and the like. In the case of continuously producing the antiglare film of the present invention, since the mold is preferably cylindrical, such a mold can be produced from a cylindrical mold base material.

[2] Grinding process

In the subsequent polishing step, the surface (plated layer) of the base material for a metal mold that has been copper-plated in the above-mentioned first plating step is polished. In the method for producing a mold used in the method for producing an antiglare film of the present invention, it is preferable to polish the surface of the base material for a mold to a state close to a mirror surface through the polishing step. Commercially available products such as flat bases and cylindrical bases used as bases for molds are often subjected to mechanical processing such as cutting and grinding in order to achieve the desired accuracy, and as a result, the base material for molds Fine processing traces remain on the surface. Thus, even if a plating (preferably copper plating) layer is formed by the 1st plating process, the said processing mark may remain. Moreover, even if plating in the 1st plating process is performed, the surface of the base material for molds may not necessarily become completely smooth. That is, even if the steps [3] to [9] described later are performed on a base material for a mold having such a surface on which deep processing traces and the like remain, the surface irregularities of the obtained mold surface may differ from the surface irregularities based on a predetermined pattern. There are differences in shape, or may include unevenness caused by processing traces, etc. When the anti-glare film is produced using a mold with residual effects such as processing traces, the desired optical properties such as anti-glare property may not be fully exhibited, resulting in unexpected effects.

The polishing method used in the polishing step is not particularly limited, and the polishing method can be selected according to the shape and properties of the base material for a mold to be polished. Specific examples of the polishing method applicable to the polishing step include a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method. However, as the mechanical polishing method, any method of superfinishing, buffing, fluid polishing, buff polishing, and the like can be used. In addition, the surface of the mold base material can also be made into a mirror surface by performing mirror surface cutting using a cutting tool in the polishing step. In terms of the material and shape of the cutting tool at this time, cemented tools, CBN tools, ceramic tools, diamond tools, etc. can be used depending on the type of material (metal material) of the base material for the mold, but from the viewpoint of machining accuracy, Preference is given to using diamond tools. The surface roughness after polishing is represented by center line average roughness Ra based on JIS B0601, and is preferably 0.1 μm or less, more preferably 0.05 μm or less. When the center line average roughness Ra after grinding is larger than 0.1 μm, the influence of the surface roughness may remain on the uneven surface shape of the finally obtained mold. In addition, the lower limit of the centerline average roughness Ra is not particularly limited. Therefore, the lower limit may be determined from the viewpoint of processing time (polishing time) in the polishing step and processing cost.

[3] Photosensitive resin film forming process

Hereinafter, the photosensitive resin film forming process will be described with reference to FIG. 3 .

In the photosensitive resin film forming step, a solution (photosensitive resin solution) in which a photosensitive resin is dissolved in a solvent is applied to the surface 41 of the mirror-polished mold substrate 40 obtained in the above-mentioned polishing step. , and heated and dried to form a photosensitive resin film (photoresist film). FIG. 3 schematically shows a state where the photosensitive resin film 50 is formed on the surface 41 of the mold base material 40 ( FIG. 3( b )).

As the photosensitive resin, a conventionally known photosensitive resin can be used, and a resin commercially available as a photoresist may be used as it is, or after being purified by filtration or the like if necessary. For example, as a negative-type photosensitive resin having a property that the photosensitive part is cured, monomers or prepolymers of (meth)acrylates having acryloyl or methacryloyl groups in the molecule, bisazide ( Bisazide) and diene rubber mixture, polyvinyl cinnamate compounds, etc. In addition, as a positive-type photosensitive resin having a property that the photosensitive part is eluted by development and only the non-photosensitive part remains, phenolic resins, novolac type resins, and the like can be used. Such a positive-type or negative-type photosensitive resin can also be easily obtained from the market as a positive-type photoresist or a negative-type photoresist. In addition, various additives such as a sensitizer, a development accelerator, an adhesion improver, and a coatability improver may be added to the photosensitive resin solution as needed, and such additives may be mixed with a commercially available photoresist Use it as a photosensitive resin solution after mixing.

In order to apply these photosensitive resin solutions to the surface 41 of the base material 40 for a mold, it is preferable to select the most suitable solvent from the viewpoint of forming a smoother photosensitive resin film, and to use a solvent in which the photosensitive resin is dissolved And dilute the obtained photosensitive resin solution. Such a solvent can also be selected according to the kind of photosensitive resin and its solubility. Specifically, it can be selected from, for example, cellosolve-based solvents, propylene glycol-based solvents, ester-based solvents, alcohol-based solvents, ketone-based solvents, and highly polar solvents. In the case of using a commercially available photoresist, the most suitable photoresist can be selected according to the type of solvent contained in the photoresist or through appropriate preliminary experiments, and can be used as a photosensitive resin solution.

As a method of coating the photosensitive resin solution on the mirror-polished surface of the base material for the mold, it can be selected from the following known methods according to the shape of the base material for the mold: meniscus coating, injection method, etc. Coating, dip coating, spin coating, roll coating, wire rod coating, air knife coating, knife coating, curtain coating, ring coating, etc. The thickness of the photosensitive resin film after coating is preferably in the range of 1 to 10 μm, more preferably in the range of 6 to 9 μm, as the thickness after drying.

[4] Exposure process

The next exposure step is a step of transferring a target pattern to the photosensitive resin film 50 by exposing the photosensitive resin film 50 formed in the photosensitive resin film forming step described above. The light source used for the exposure step may be appropriately selected according to the photosensitive wavelength and sensitivity of the photosensitive resin contained in the photosensitive resin film. For example, g-line (wavelength: 436 nm) and h-line (wavelength: : 405nm), or i-line (wavelength: 365nm), semiconductor laser (wavelength: 830nm, 532nm, 488nm, 405nm, etc.), YAG laser (wavelength: 1064nm), KrF excimer laser (wavelength: 248nm), ArF excimer laser (wavelength: 193nm), F2 excimer laser (wavelength: 157nm), etc. The exposure method may be a method of performing one-shot exposure using a mask corresponding to a target pattern, or a drawing method. It should be noted that the target pattern is, as already described, a graph when the one ^- dimensional power spectrum is expressed in the form of intensity with respect to the ^spatial frequency, which has a A pattern of minima.

In the method of manufacturing a mold, in order to form the uneven surface of the mold with higher precision, it is preferable to perform exposure in a state where a target pattern is precisely controlled on the photosensitive resin film. In order to perform exposure in such a state, it is preferable to generate image data of a target pattern on a computer, and draw (laser drawing) a pattern based on the image data on a photosensitive resin film using laser light emitted from a laser head controlled by a computer. . When performing laser drawing, for example, a laser drawing apparatus commonly used in printing plate production and the like can be used. As a commercial item of such a laser drawing apparatus, LaserStreamFX (made by the Corporation|KK Think Laboratory) etc. are mentioned, for example.

FIG. 3( c ) schematically shows a state in which a pattern is exposed to the photosensitive resin film 50 . When the photosensitive resin film 50 includes a negative photosensitive resin (for example, when a negative photoresist is used as a photosensitive resin solution), the exposed region 51 receives exposure energy to cause crosslinking of the photosensitive resin. reaction, so the solubility in the developer described later is reduced. Thus, in the development step, the unexposed region 52 is dissolved by the developer, and only the exposed region 51 remains on the surface of the base material to become the mask 60 . On the other hand, when the photosensitive resin film 50 includes a positive photosensitive resin (for example, when using a positive photoresist as a photosensitive resin solution), the exposed region 51 receives exposure energy to generate photosensitivity. Bond breaking of the resin, etc., thereby becomes easy to dissolve in the developer solution described later. Thus, in the developing step, the exposed region 51 is dissolved by the developer, and only the unexposed region 52 remains on the surface of the base material to become the mask 60 .

[5] Development process

In the development process, when the photosensitive resin film 50 contains a negative photosensitive resin, the unexposed region 52 is dissolved by the developer, and the exposed region 51 remains on the base material for the mold to become the mask 60. . On the other hand, when the photosensitive resin film 50 contains a positive-type photosensitive resin, only the exposed region 51 is dissolved by the developer, and the unexposed region 52 remains on the mold substrate to become the mask 60 . For the base material for the mold on which a predetermined pattern is formed in the form of a photosensitive resin film, in the first etching step, the photosensitive resin film remaining on the base material for the mold is used as a mask in the first etching step described later. Play a role.

As for the developer used in the development step, an appropriate developer can be selected from conventionally known developers according to the type of photosensitive resin to be used. Examples of the developing solution include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, primary amines such as ethylamine and n-propylamine, diethylamine, di-n-butylamine, etc. Secondary amines such as base amine, tertiary amines such as triethylamine and methyl diethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylammonium hydroxide Alkaline aqueous solutions of quaternary ammonium compounds such as hydroxyethyl ammonium hydroxide, cyclic amines such as pyrrole and piperidine, etc.; organic solvents such as xylene and toluene, etc.

The development method in the development step is not particularly limited, and dip development, jet development, brush development, ultrasonic development, and the like can be used.

FIG. 3( d ) schematically shows a state after performing a development process using a negative-type resin as a photosensitive resin. In FIG. 3( d ), the unexposed region 52 is dissolved by the developer, and only the exposed region 51 remains on the substrate surface, and the photosensitive resin film in this region becomes a mask 60 . FIG. 3( e ) schematically shows a state after performing a developing process using a positive-type resin as a photosensitive resin. In FIG. 3( e ), the exposed region 51 is dissolved by the developer, and only the unexposed region 52 remains on the substrate surface, and the photosensitive resin film in this region becomes the mask 60 .

[6] The first etching step

The first etching step is a step of etching the plated layer mainly in the maskless area on the surface of the mold base material using the photosensitive resin film remaining on the surface of the mold base material after the development process as a mask.

FIG. 4 schematically shows a preferred example of the second half of the mold manufacturing method. FIG. 4( a ) schematically shows the state after the plating layer in the maskless region is mainly etched by the first etching step. Since the photosensitive resin film functions as the mask 60, the plated layer below the mask 60 is not etched, but etching proceeds from the maskless region 45 as the etching progresses. Accordingly, the plated layer located under the mask 60 is also etched near the boundary between the region where the mask 60 exists and the region 45 without the mask. In this way, the case where the plating layer under the mask 60 is also etched near the boundary between the region where the mask 60 exists and the region 45 without the mask is called undercutting.

The etching treatment in the first etching step (first etching treatment) is usually performed by using ferric chloride (FeCl ₃ ) solution, copper chloride (CuCl ₂ ) solution, alkaline etching solution (Cu(NH ₃ ) ₄ Cl ₂ ) and other etching solutions to corrode the plating (metal surface) mainly located in the area without the mask 60 on the surface of the base material for the mold. As the etching treatment, a strong acid such as hydrochloric acid or sulfuric acid can be used as an etching solution, and when the plated layer is formed by electroplating, the etching treatment can also be performed by reverse electrolytic etching applying a potential opposite to that during electroplating. The surface irregularities formed on the base material for the mold during the etching process depend on the constituent material (metal material) or the type of plating of the base material for the mold, the type of the photosensitive resin film, and the type of etching treatment in the first etching step, etc. Although it cannot be generalized because the amount of etching is 10 μm or less, the surface of the base material for a mold that is in contact with the etchant is etched substantially isotropically. The etching amount here refers to the thickness of the plating layer reduced by etching.

The etching amount in the first etching step is preferably 1 to 10 μm, more preferably 2 to 5 μm. When the amount of etching exceeds 10 μm, the unevenness of the surface unevenness formed on the mold will increase in height difference. As a result, when an antiglare film is produced using this die, the ratio R _SCE /R _SCI may exceed 0.1. Therefore, it is preferable to set the etching amount in the first etching step to 10 μm or less, to manufacture a mold through the process described later, and to manufacture an antiglare film using the mold to obtain an antiglare film in which whitening is sufficiently prevented. On the other hand, when the amount of etching is less than 1 μm, almost no surface irregularities are formed on the mold, and a mold with a substantially flat surface is formed. Therefore, even if the antiglare film is produced using the mold, the antiglare film has almost no surface. Since the uneven shape cannot obtain an anti-glare film with sufficient anti-glare properties. It should be noted that the etching treatment in the first etching step may be performed by one etching treatment, or may be divided into two or more etching treatments. Here, when the etching treatment is divided into two or more times, the total amount of etching in the two or more etching treatments is preferably 1 to 10 μm.

[7] Photosensitive resin film peeling process

The next step of peeling off the photosensitive resin film is a step of removing the photosensitive resin film remaining on the base material for the mold which functions as the mask 60 in the first etching process. The photosensitive resin film on the material is completely removed. In the photosensitive resin film peeling process, it is preferable to dissolve the photosensitive resin film using a peeling liquid. As the stripping liquid, a solution prepared by changing the concentration, pH, and the like of the materials listed as the developer can be used. Alternatively, the photosensitive resin film may be peeled by changing the temperature, immersion time, and the like in the image development process using the same solution as the developer used in the image development process. In the step of peeling the photosensitive resin film, there is no particular limitation on the contact method (peeling method) between the stripping liquid and the base material for the mold, and immersion peeling, spray peeling, brush peeling, ultrasonic peeling, etc. can be used.

FIG. 4( b ) schematically shows a state where the photosensitive resin film used as the mask 60 in the first etching step is completely dissolved and removed by the photosensitive resin film peeling step. The first surface unevenness 46 is formed on the surface of the mold base material by the mask 60 made of a photosensitive resin film and etching.

[8] Second etching process

The second etching step is a step for passivating the first surface unevenness 46 formed in the first etching step by further etching treatment (second etching treatment). By this 2nd etching process, at the 1st surface uneven shape 46 formed by the 1st etching process, the part with steep surface inclination disappears (hereinafter, the case of passivating the portion with steep surface inclination in such a surface uneven shape called "shape passivation"). Fig. 4 (c) shows the following state: by utilizing the 2nd etching treatment, the first surface unevenness 46 of the base material 40 for the mold is passivated in shape, thereby, the part with steep surface inclination is passivated, forming a smooth surface. The second surface concave-convex shape 47 whose surface is inclined. The mold obtained by performing the second etching treatment as described above has the effect of making the optical characteristics of the antiglare film of the present invention manufactured using the mold more ideal.

As the second etching treatment in the second etching step, etching treatment using the same etching solution as in the first etching step and reverse electrolytic etching may be employed. The degree of passivation of the shape after the second etching process (the degree of disappearance of the steep portion of the surface in the surface uneven shape after the first etching process) depends on the material of the base material for the mold, the method of the second etching treatment, and The size and depth of the unevenness of the surface obtained by the etching process vary, so it cannot be generalized, but the most important factor in controlling the passivation (the degree of shape passivation) is the amount of etching in the second etching process . The etching amount here is expressed by the thickness of the base material cut by the second etching process as in the case of the first etching process. If the amount of etching in the second etching process is small, the effect of passivating the shape of the surface unevenness obtained in the first etching process will be insufficient. For this reason, whitening may occur in an anti-glare film manufactured using a mold whose shape is not sufficiently passivated. On the other hand, if the amount of etching in the second etching process is too large, the irregularities of the surface irregularities formed in the first etching process will almost disappear, and a mold having an almost flat surface may be obtained. An anti-glare film produced using such a mold having an almost flat surface may have insufficient anti-glare properties. Therefore, the etching amount of the second etching treatment is preferably within a range of 1 to 50 μm, more preferably within a range of 4 to 20 μm, and even more preferably within a range of 13 to 18 μm. Also about the second etching process, similarly to the first etching process, it may be performed by one etching process, or may be divided into two or more etching processes. However, when the etching process is divided into two or more times, it is preferable that the total amount of etching in the two or more times of etching processes is 1 to 50 μm.

[9] Second plating step

In the final stage of mold production, plating is performed on the surface of the base material for a mold that has passed through the steps [6] and [7] above, preferably the base material for a mold that has passed the steps [6] to [8] above. (Preferably chrome plating described later) the second plating step. By performing the second plating step, the surface unevenness 47 of the base material for a mold is further passivated, and the surface of the mold can be protected by this plating. FIG. 4( d ) shows a state where the surface roughness is passivated (surface 70 ) by forming the chromium plating layer 71 on the second surface roughness 47 formed by the second etching process as described above.

As the plated layer formed in the second plating step, chrome plating is preferable in terms of being glossy, having high hardness, having a small coefficient of friction, and being able to obtain good releasability. Among chrome platings, chrome plating exhibiting good gloss, such as so-called glossy chrome plating and decorative chrome plating, is particularly preferable. Chromium plating is usually performed by electrolysis, and as the plating bath, an aqueous solution containing anhydrous chromic acid (CrO ₃ ) and a small amount of sulfuric acid can be used as a plating solution. By adjusting the current density and electrolysis time, the thickness of the chromium plating layer can be controlled.

By carrying out the plating in the second plating step, preferably chrome plating, the mold for producing the anti-glare film of the present invention can be obtained. By performing chrome plating on the surface irregularities of the surface of the base material for the mold after the second etching treatment, it is possible to obtain a mold in which the shape is passivated and the surface hardness thereof is improved. The most important factor in controlling the degree of shape passivation at this time is the thickness of the chrome plating layer. If the thickness is thin, the degree of passivation of the shape is insufficient, and if the thickness of the chromium plating layer is too thick, the productivity will deteriorate, and protruding plating defects called nodules will occur, so it is not suitable as the anti-corrosion film of the present invention. Molds for glare film manufacturing. The thickness of the chromium plating layer is preferably within a range of 1 to 20 μm, more preferably within a range of 3 to 15 μm, and even more preferably within a range of 3 to 6 μm.

The chromium-plated layer formed through the second plating step is preferably formed so as to have a Vickers hardness of 800 or higher, and more preferably formed so as to have a Vickers hardness of 1,000 or higher. When the Vickers hardness of the chrome-plated layer is less than 800, the durability of the mold tends to decrease when the anti-glare film is produced using a mold.

Hereinafter, the said optical embossing method preferable as a method for manufacturing the antiglare film of this invention is demonstrated. As described above, the UV embossing method is particularly preferable as the photo embossing method, but here, the embossing method using an active energy ray-curable resin will be specifically described.

In order to continuously manufacture the antiglare film of the present invention and under the situation of producing the antiglare film of the present invention by the optical embossing method, preferably include the following steps:

[P1] Coating process: Coating a coating liquid containing an active energy ray-curable resin on the continuously conveyed transparent support to form a coating layer;

[P2] Main curing step: In a state where the surface of the mold is pressed against the surface of the coating layer, active energy rays are irradiated from the side of the transparent support.

In addition, in the case of producing the antiglare film of the present invention by the optical embossing method, it is more preferable to include the following steps:

[P3] Pre-curing step: After the coating step [P1] and before the curing step [P2], the end regions on both sides in the width direction of the coating layer are irradiated with active energy rays.

Hereinafter, each step will be described in detail with reference to the drawings. FIG. 5 schematically shows a preferable example of the manufacturing apparatus used for the manufacturing method of the antiglare film of this invention. Arrows in FIG. 5 indicate the conveyance direction of the film or the rotation direction of the roll.

[P1] Coating process

In the coating step, a coating liquid containing an active energy ray-curable resin is coated on the transparent support to form a coating layer. In the coating process, as shown in FIG. 5 , a coating liquid containing an active energy ray-curable resin composition is coated on the coating area 83 on the transparent support 81 led out from the lead-out roller 80 .

The coating of the coating liquid on the transparent support body 81 can be performed by, for example, a gravure coating method, a micro gravure coating method, a bar coating method, a knife coating method, an air knife coating method, a lick coating method, a die coating method, etc. .

(transparent support)

The transparent support body 81 should just be a light-transmitting support body, for example, glass, a plastic film, etc. can be used. As a plastic film, what is necessary is just to have moderate transparency and mechanical strength. Specifically, any of the supports listed above as transparent supports for the UV embossing method can be used. Moderately flexible material.

Various surface treatments may be applied to the surface of the transparent support 81 (coating layer side surface) for the purpose of improving the applicability of the coating liquid and improving the adhesiveness between the transparent support and the coating layer. Examples of the surface treatment include corona discharge treatment, glow discharge treatment, acid surface treatment, alkali surface treatment, and ultraviolet irradiation treatment. In addition, another layer such as an undercoat layer may be formed on the transparent support 81 and a coating liquid may be applied on the other layer.

In addition, when an antiglare film integrated with a polarizing film is produced as the antiglare film of the present invention, in order to improve the adhesiveness between the transparent support and the polarizing film, it is preferable to treat the transparent support with various surface treatments in advance. The surface (the surface opposite to the coating layer) is hydrophilized. This surface treatment can also be performed after manufacture of an anti-glare film.

(coating solution)

The coating liquid contains an active energy ray-curable resin, and usually further contains a photopolymerization initiator (radical polymerization initiator). Various additives such as translucent fine particles, solvents such as organic solvents, leveling agents, dispersants, antistatic agents, antifouling agents, and surfactants may be contained as needed.

(1) Active energy ray curable resin

As the active energy ray curable resin, for example, a resin containing a polyfunctional (meth)acrylate compound can be preferably used. The polyfunctional (meth)acrylate compound is a compound having at least two (meth)acryloyloxy groups in the molecule. Specific examples of polyfunctional (meth)acrylate compounds include ester compounds of polyhydric alcohol and (meth)acrylic acid, urethane (meth)acrylate compounds, polyester (meth)acrylic acid A polyfunctional polymerizable compound containing two or more (meth)acryloyl groups, such as an ester compound and an epoxy (meth)acrylate compound, etc.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, Propylene glycol, butanediol, pentylene glycol, hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2'-thiobis-ethanol, 1,4- Dihydric alcohols such as cyclohexanedimethanol; trihydric or higher alcohols such as trimethylolpropane, glycerol, pentaerythritol, diglycerol, dipentaerythritol, and ditrimethylolpropane.

As the esterified product of polyhydric alcohol and (meth)acrylic acid, specifically, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, 1,6-hexanediol di( Meth)acrylate, Neopentyl Glycol Di(meth)acrylate, Trimethylolpropane Tri(meth)acrylate, Trimethylolethane Tri(meth)acrylate, Tetramethylolmethane Tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, pentaglycerol tri(meth)acrylate, pentaerythritol tri( Meth)acrylate, Pentaerythritol tetra(meth)acrylate, Glycerin tri(meth)acrylate, Dipentaerythritol tri(meth)acrylate, Dipentaerythritol tetra(meth)acrylate, Dipentaerythritol penta(methyl)acrylate ) acrylate, dipentaerythritol hexa(meth)acrylate.

As a urethane (meth)acrylate compound, the urethanation reaction product of the organic isocyanate which has several isocyanate groups in 1 molecule, and the (meth)acrylic acid derivative which has a hydroxyl group is mentioned. Examples of organic isocyanates having a plurality of isocyanate groups in one molecule include hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate. Organic isocyanates having two isocyanate groups in one molecule, such as diisocyanate and dicyclohexylmethane diisocyanate, and one molecule of these organic isocyanates modified with isocyanurates, adducts, or biurets Organic isocyanates with 3 isocyanate groups, etc. Examples of (meth)acrylic acid derivatives having a hydroxyl group include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (meth)acrylate base) 2-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, pentaerythritol triacrylate.

As a polyester (meth)acrylate compound, polyester (meth)acrylate obtained by making hydroxyl-containing polyester and (meth)acrylic acid react is preferable. The preferably used hydroxyl-containing polyester is a hydroxyl-containing polyester obtained by esterification of a polyhydric alcohol with a carboxylic acid, or a compound having multiple carboxyl groups and/or an acid anhydride thereof. Examples of the polyol include the same polyols as those described above. Moreover, bisphenol A etc. which are phenols are mentioned other than a polyhydric alcohol. Examples of the carboxylic acid include formic acid, acetic acid, butylcarboxylic acid, benzoic acid and the like. Examples of compounds having a plurality of carboxyl groups and/or their anhydrides include maleic acid, phthalic acid, fumaric acid, itaconic acid, adipic acid, terephthalic acid, maleic anhydride, and phthalic acid. Anhydride, trimellitic acid, cyclohexanedicarboxylic anhydride, etc.

Among the polyfunctional (meth)acrylate compounds mentioned above, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and base) acrylate, diethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, di Pentaerythritol hexa(meth)acrylate and other ester compounds; adducts of hexamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate; isophorone diisocyanate and 2-hydroxyethyl (meth)acrylate Addition of ester; Addition of toluene diisocyanate and 2-hydroxyethyl (meth)acrylate; Addition of adduct modified isophorone diisocyanate and 2-hydroxyethyl (meth)acrylate and an adduct of biuret-modified isophorone diisocyanate and 2-hydroxyethyl (meth)acrylate. Furthermore, these polyfunctional (meth)acrylate compounds can be used individually or in combination of 2 or more types, respectively.

The active energy ray curable resin may contain a monofunctional (meth)acrylate compound other than the above-mentioned polyfunctional (meth)acrylate compound. Examples of monofunctional (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylate, Base) tert-butyl acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, ( 2-Hydroxy-3-phenoxypropyl methacrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl (meth)acrylate, (meth) Cyclohexyl acrylate, 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, acetyl (meth)acrylate, benzyl (meth)acrylate, 2-(meth)acrylate Ethoxyethyl ester, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxy (meth)acrylate, ethylene oxide modified phenoxy Propylene oxide modified (meth)acrylate, nonylphenol (meth)acrylate, ethylene oxide modified (meth)acrylate, propylene oxide modified nonyl Phenol (meth)acrylate, Methoxydiethylene glycol (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, (meth (meth)acrylates such as dimethylaminoethyl acrylate and methoxytriethylene glycol (meth)acrylate. These compounds can be used individually or in combination of 2 or more types, respectively.

In addition, the active energy ray curable resin may contain a polymerizable oligomer. By containing the polymerizable oligomer, the hardness of the cured product can be adjusted. The polymerizable oligomer may be, for example, the above-mentioned polyfunctional (meth)acrylate compound, that is, an ester compound formed of a polyhydric alcohol and (meth)acrylic acid, a urethane (meth)acrylate compound, a polyester (meth)acrylate compound, ) oligomers such as dimers and trimers of acrylate compounds or epoxy (meth)acrylates.

As other polymerizable oligomers, urethane ( Meth)acrylate oligomers. As polyisocyanate, can enumerate: the polymer etc. of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, as having at least 1 ( The polyhydric alcohol of meth)acryloyloxy group can be exemplified by the hydroxyl group-containing (meth)acrylic ester obtained by the esterification reaction of polyhydric alcohol and (meth)acrylic acid, and the polyhydric alcohol is, for example, 1,3-butanediol , 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, trimethylolpropane, glycerin, pentaerythritol, Dipentaerythritol, etc. The polyol having at least one (meth)acryloyloxy group is a polyol in which part of the alcoholic hydroxyl groups of the polyol undergoes an esterification reaction with (meth)acrylic acid, and the alcoholic hydroxyl group remains in the molecule.

In addition, examples of other polymerizable oligomers include polyesters obtained by reacting a compound having a plurality of carboxyl groups and/or an acid anhydride thereof with a polyol having at least one (meth)acryloyloxy group. (meth)acrylate oligomers. As a compound and/or its acid anhydride which have several carboxyl groups, the same compound and/or its acid anhydride as described in the polyester (meth)acrylate of the said polyfunctional (meth)acrylate compound are mentioned. Moreover, as a polyhydric alcohol which has at least 1 (meth)acryloyloxy group, the thing similar to what was described in the said urethane (meth)acrylate oligomer is mentioned.

In addition to the polymerizable oligomers described above, examples of urethane (meth)acrylate oligomers include: isocyanates and hydroxyl-containing polyesters, hydroxyl-containing polyethers, or hydroxyl-containing ( A compound obtained by reacting hydroxyl groups of meth)acrylates. The preferably used hydroxyl-containing polyester is a hydroxyl-containing polyester obtained by esterification of a polyhydric alcohol with a carboxylic acid or a compound having multiple carboxyl groups and/or an anhydride thereof. Examples of the compound having a polyhydric alcohol, a plurality of carboxyl groups, and/or an acid anhydride thereof include the same compounds as those described in the polyester (meth)acrylate compound of the polyfunctional (meth)acrylate compound, respectively. A preferably used hydroxyl-containing polyether is a hydroxyl-containing polyether obtained by adding one or more types of alkylene oxide and/or ε-caprolactone to a polyol. The polyol may be the same polyol as can be used for the above-mentioned hydroxyl-containing polyester. As a preferably used hydroxyl group-containing (meth)acrylate, the same hydroxyl group-containing (meth)acrylate as described in the urethane (meth)acrylate oligomer of a polymerizable oligomer is mentioned. As the isocyanates, compounds having one or more isocyanate groups in the molecule are preferred, and divalent isocyanate compounds such as toluene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are particularly preferred.

These polymerizable oligomer compounds can be used individually or in combination of 2 or more types, respectively.

(2) Photopolymerization initiator

A photopolymerization initiator can be suitably selected according to the kind of active energy rays used for antiglare film manufacture of this invention. Moreover, when using an electron beam as an active energy ray, the coating liquid which does not contain a photoinitiator may be used for manufacture of the antiglare film of this invention.

As the photopolymerization initiator, for example, acetophenone-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzophenone-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, triazine-based photopolymerization initiators, Photopolymerization initiators, oxadiazole-based photopolymerization initiators, and the like. In addition, as a photopolymerization initiator, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,2'-bis(o-chlorophenyl)-4,4',5 , 5'-tetraphenyl-1,2'-biimidazole, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, benzil, 9,10-phenanthrenequinone, camphorquinone, benzene Methyl formylformate, titanocene compounds, etc. The usage-amount of a photoinitiator is 0.5-20 weight part normally with respect to 100 weight part of active energy ray curable resins, Preferably it is 1-5 weight part.

In order to improve the coatability of the coating liquid on the transparent support, solvents such as organic solvents may also be contained in the coating liquid. As the organic solvent, the following solvents can be selected and used in consideration of viscosity, etc.: Aliphatic hydrocarbons such as hexane, cyclohexane, and octane; Aromatic hydrocarbons such as toluene and xylene; Ethanol, 1-propanol, isopropyl Alcohols such as alcohol, 1-butanol, and cyclohexanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, and isobutyl acetate; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and other glycol ethers; ethylene glycol monomethyl ether Esterified glycol ethers such as acid esters and propylene glycol monomethyl ether acetate; 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol and other cellosolves; 2-(2- Carbitols such as methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, 2-(2-butoxyethoxy)ethanol, and the like. These solvents may be used alone or in combination of two or more types as necessary. After coating, it is necessary to evaporate the above-mentioned organic solvent. For this reason, the boiling point is preferably in the range of 60°C to 160°C. In addition, it is preferable that the saturated vapor pressure at 20° C. is in the range of 0.1 kPa to 20 kPa.

When the coating liquid contains a solvent, it is preferable to provide a drying step of evaporating and drying the solvent after the above-mentioned coating step and before the first curing step. Drying can be performed by passing the transparent support 81 provided with the coating layer through the drying zone 84 as in the example shown in FIG. 5 . The drying temperature can be appropriately selected according to the type of solvent and transparent support to be used. It is usually in the range of 20°C to 120°C, but is not limited thereto. Moreover, when there are several drying furnaces, temperature can be changed for every drying furnace. The thickness of the dried coating layer is preferably 1 to 30 μm.

In this way, a laminate in which the transparent support and the coating layer are laminated is formed.

[P2] Curing process

In this step, the coating layer is cured by irradiating active energy rays from the transparent support side while pressing the concave-convex surface (molding surface) of the mold having the desired surface concave-convex shape on the surface of the coating layer to cure the coating layer. A step of forming a cured resin layer on a support. Thereby, while curing the coating layer, it is possible to transfer the surface irregularities on the concave-convex surface of the mold to the coating layer surface. The mold used here is a cylindrical mold manufactured using a cylindrical mold base material in the mold manufacturing method described above.

This step can be as shown in FIG. 5 , for example, by using an active energy ray irradiation device 86 such as an ultraviolet irradiation device disposed on the transparent support body 81 side to apply to the coating area 83 (in the case of drying, it is a drying area 84, In the case of performing a pre-curing step described later, it is performed by irradiating active energy rays to the layered body having the coating layer passing through the pre-curing zone (which is irradiated by the active energy ray irradiation device 86 ).

First, the cylindrical mold 87 is pressed against the surface of the coating layer of the laminated body after the curing step by means of a pressing device such as a nip roller 88, and in this state, the active energy ray irradiation device 86 is used to remove the heat from the transparent layer. The coating layer 82 is cured by irradiating the active energy ray on the side of the support body 81 . Here, "curing the coating layer" means that the active energy ray-curable resin contained in the coating layer receives the energy of the active energy ray to cause a curing reaction. Use of nip rolls is effective in preventing air bubbles from entering between the coating layer and the mold of the laminate. One or more active energy ray irradiation devices may be used.

After the active energy ray irradiation, the laminate is peeled from the mold 87 using the nip roll 89 on the exit side as a fulcrum. In the obtained transparent support and the cured coating layer, the cured coating layer becomes the anti-glare layer, and the anti-glare film of the present invention is obtained. The resulting antiglare film is usually wound up by a film winding device 90 . At this time, for the purpose of protecting the anti-glare layer, a protective film made of polyethylene terephthalate, polyethylene, etc. can be bonded on the surface of the anti-glare layer through a re-peelable adhesive layer winding at the same time. In addition, the mold used here has demonstrated the case of the cylindrical mold, but the mold other than a cylindrical mold can also be used. In addition, additional active energy ray irradiation may be performed after peeling from the mold.

The active energy rays used in this step can be appropriately selected from ultraviolet rays, electron beams, near ultraviolet rays, visible light, near infrared rays, infrared rays, X-rays, etc. according to the type of active energy ray curable resin contained in the coating liquid, Among these, ultraviolet rays and electron beams are preferable, and ultraviolet rays are particularly preferable from the viewpoint of easy handling and high energy availability (as described above, UV embossing is preferable as the photoembossing method).

As a light source of ultraviolet rays, for example, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultrahigh-pressure mercury lamps, carbon arc lamps, electrodeless lamps, metal halide lamps, xenon arc lamps, and the like can be used. Alternatively, an ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like may be used. Among these, an ultrahigh-pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, an electrodeless lamp, a xenon arc lamp, and a metal halide lamp are preferably used.

In addition, examples of the electron beam include a Cockcroft-Walton type, a Vande Graaff type, a resonant transformer type, an insulating core transformer type, a linear type, and a Dinamil ( Electron beams having energy of 50 to 1000 keV, preferably 100 to 300 keV, emitted from various electron beam accelerators such as Dynamitron type and high frequency type.

When the active energy ray is ultraviolet rays, the cumulative light intensity under UVA of ultraviolet rays is preferably 100 mJ/cm ² to 3000 mJ/cm ² , more preferably 200 mJ/cm ² to 2000 mJ/cm ² . In addition, since the transparent support sometimes absorbs ultraviolet rays on the short-wavelength side, the cumulative light intensity of ultraviolet rays in UVV (395 to 445 nm) is preferably 100 mJ/cm ² or more and 3000 mJ/cm ² or less, more preferably 200 mJ/cm 2 or less. cm ² or more and 2000mJ/cm ² or less. When the cumulative light intensity is less than 100 mJ/cm ² , the curing of the coating layer is insufficient, resulting in a reduction in the hardness of the anti-glare layer obtained, or uncured resin tends to adhere to guide rollers and the like, which tends to cause process contamination. In addition, when the cumulative light quantity exceeds 3000 mJ/cm ² , the heat radiated from the ultraviolet irradiation device may cause the transparent support to shrink and wrinkle.

[P3] Pre-curing process

This step is a step of irradiating active energy rays to end regions on both sides of the transparent support in the width direction of the coating layer prior to the curing step to precure the both end regions. Fig. 6 is a cross-sectional view schematically showing a pre-curing process. In FIG. 6 , an end region 82b in the width direction (direction perpendicular to the conveyance direction) of the coating layer is a region including the end of the coating layer and having a predetermined width from the end.

In the pre-curing step, by curing the end region in advance, the adhesion between the end region and the transparent support 81 can be further improved, thereby preventing a part of the cured resin from peeling off and falling off in the process after the curing step. polluting process. The end region 82 b can be, for example, a region of 5 mm or more and 50 mm or less from the end of the coating layer 82 .

The irradiation of the active energy ray to the end region of the coating layer is referred to FIG. 5 and FIG. 6 . 85 is performed by irradiating active energy rays to the transparent support body 81 having the coating layer 82 after passing through the coating zone 83 (drying zone 84 in the case of drying). The active energy ray irradiation device 85 may be provided on the transparent support 81 side as long as it can irradiate the end region 82b of the coating layer 82 with an active energy ray.

About the kind and light source of an active energy ray, it is the same as that of a main hardening process. When the active energy ray is an ultraviolet ray, the integrated light dose of the ultraviolet ray under UVA is preferably 10 mJ/cm ² to 400 mJ/cm ² , more preferably 50 mJ/cm ² to 400 mJ/cm ² . By irradiating with an integrated light quantity of 50 mJ/cm ² or more, deformation in the main curing process can be prevented more effectively. It should be noted that when the cumulative light intensity exceeds 400mJ/cm ² , the curing reaction proceeds excessively, and as a result, resin peeling may occur due to film thickness difference and distortion of internal stress at the boundary between the cured part and the uncured part.

As mentioned above, the 1st method of manufacturing the anti-glare film of this invention was demonstrated centering on preferable embodiment, However, the anti-glare film of this invention can also be manufactured by said 2nd method. Such a second method, as described above, is a method of applying a resin solution in which fine particles are dispersed on a transparent support to expose the fine particles on the surface of the coating film, thereby forming random irregularities on the transparent support. At this time, The particle diameter (average particle diameter) of the microparticles used, the film thickness of the coating film, and the dispersion state of the microparticles can be adjusted. In particular, by increasing the particle size of the particles and adjusting the thickness of the coating film to be more than the particle size, the scattered light caused by the fine particles is reduced, and the ratio R _SCE /R _SCI can be reduced and measured without regular reflection. The light reflectance ratio R _SCE . Also, even if the composition of the coating liquid and the production conditions are adjusted so that the fine particles aggregate to some extent, the ratio R _SCE /R _SCI and the light reflectance R _SCE can be reduced.

[Use of the anti-glare film of the present invention]

The anti-glare film of the present invention obtained as described above can be used in image display devices, etc., and can be used as a viewing-side protective film of a viewing-side polarizing plate and bonded to a polarizing film (that is, placed on the surface of an image display device). . Moreover, as mentioned above, when using a polarizing film as a transparent support body, in order to obtain the antiglare film integrated with a polarizing film, such an antiglare film integrated with a polarizing film can also be used for an image display apparatus. The image display device provided with the antiglare film of the present invention has sufficient antiglare properties over a wide viewing angle, and can prevent occurrence of whitening and glare well.

Example

Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, "%" and "part" showing content or usage-amount are based on weight unless otherwise specified.

The evaluation methods of molds or antiglare films in the following examples are as follows.

[1] Measurement of surface shape of anti-glare film

(Surface Roughness Parameters of Surface Concave and Convex Shapes)

The surface roughness parameter of the anti-glare film was measured by the method based on JISB0601 using the surface roughness meter SurftestSJ-301 made from Mitutoyo Corporation. In order to prevent warpage of the measurement sample, the surface of the measurement sample opposite to the anti-glare layer was bonded to a glass substrate using an optically transparent adhesive and used for measurement.

[2] Measurement of optical properties of anti-glare film

(haze)

The total haze of the anti-glare film is measured as follows: For the anti-glare film, an optically transparent adhesive is used, the surface of the measurement sample opposite to the anti-glare layer is attached to a glass substrate, and the surface of the anti-glare film attached to the glass The anti-glare film of the substrate was measured by a method based on JIS K7136 using a haze meter "HM-150" manufactured by Murakami Color Technology Laboratory Co., Ltd., by incident light from the glass substrate side. The surface haze can be obtained by obtaining the internal haze of the anti-glare film and subtracting the internal haze from the total haze according to the following formula.

Surface haze = total haze - internal haze

The internal haze was measured as follows: a cellulose triacetate film with a haze of almost zero was attached to the anti-glare layer of the measurement sample after measuring the total haze with glycerin, and then measured by the same method as the total haze .

(transmission clarity)

The transmission clarity of the anti-glare film was measured by the method based on JISK7105 using the imaging measuring instrument "ICM-1DP" by Suga Test Instruments Co., Ltd.. At this time, in order to prevent warping of the sample, the surface of the measurement sample opposite to the anti-glare layer was bonded to a glass substrate using an optically transparent adhesive and used for measurement. In this state, light was made to inject from the glass substrate side, and it measured. The measured value here is the total value of the values measured using five kinds of optical combs whose widths of the dark part and bright part are 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively.

(Reflection clarity measured at a light incident angle of 45°)

The reflection clarity of the anti-glare film was measured by the method based on JISK7105 using the imaging measuring instrument "ICM-1DP" by Suga Test Instruments Co., Ltd.. At this time, in order to prevent warping of the sample, the surface of the measurement sample opposite to the anti-glare layer was bonded to the black acrylic resin substrate using an optically transparent adhesive and used for measurement. In this state, light was incident at 45° from the anti-glare layer side, and the measurement was performed. The measured value here is the total value of the values measured using four kinds of optical combs whose widths of the dark portion and the bright portion are respectively 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm.

(Reflection clarity measured at a light incident angle of 60°)

The reflection clarity of the anti-glare film was measured by the method based on JISK7105 using the imaging measuring instrument "ICM-1DP" by Suga Test Instruments Co., Ltd.. At this time, in order to prevent warping of the sample, the surface of the measurement sample opposite to the anti-glare layer was bonded to the black acrylic resin substrate using an optically transparent adhesive and used for measurement. In this state, light was incident at 60° from the anti-glare layer side, and the measurement was performed. The measured value here is the total value of the values measured using four kinds of optical combs whose widths of the dark portion and the bright portion are respectively 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm.

(light reflectance R _SCI and light reflectance R _SCE )

Using a spectrophotometer CM2002 (manufactured by Konica Minolta Sensing), the light reflectance R _SCI measured with regular reflection included and the light reflectance R _SCE measured without regular reflection were measured. The reflection from the side opposite to the anti-glare layer of the measurement sample was excluded. In order to prevent warpage of the measurement sample, the surface of the measurement sample opposite to the anti-glare layer was bonded to a black acrylic plate using an optically transparent adhesive and used for measurement.

[3] Evaluation of anti-glare performance of anti-glare film

(Visual evaluation of reflection and whitening)

In order to prevent reflection from the back of the anti-glare film, the surface of the anti-glare film opposite to the anti-glare layer of the measurement sample was attached to a black acrylic resin plate, and the anti-glare The layer side was visually observed, and the degree of reflection of the fluorescent lamp and the degree of whitening were visually evaluated. Regarding the reflection, the degree of reflection when the anti-glare film was viewed from the front and the degree of reflection when the anti-glare film was observed from an oblique direction of 30° were evaluated. Reflection and whitening were evaluated on three scales of 1 to 3, respectively, based on the following criteria.

Reflection 1: No reflection was observed.

2: Reflection is slightly observed.

3: Reflection is clearly observed.

Whitening 1: No whitening was observed.

2: Whitening is slightly observed.

3: Whitening is clearly observed.

(dazzling evaluation)

Dazzle was evaluated according to the following procedure. That is, first, a photomask having a unit cell pattern as shown in plan view in FIG. 7 is prepared. In this figure, a unit cell 100 has a hook-shaped chrome light-shielding pattern 101 with a line width of 10 μm formed on a transparent substrate, and the portion where the chrome light-shielding pattern 101 is not formed serves as an opening 102 . Here, the size of the cell used is 211 μm×70 μm (vertical×horizontal in the figure), so the size of the opening is 201 μm×60 μm (vertical×horizontal in the figure). A photomask is formed by arranging a plurality of illustrated unit cells vertically and horizontally.

Then, as shown in the schematic cross-sectional view of FIG. 8 , the chrome light-shielding pattern 111 of the photomask 113 is placed on the light box 115 facing upward, and the antiglare film 110 will be made of an adhesive to make the antiglare layer become A sample bonded to a glass plate 117 in the form of a surface is placed on a photomask 113 . A light source 116 is arranged in the light box 115 . In this state, visual observation was performed at a position 119 about 30 cm away from the sample, and sensory evaluation was performed on the degree of glare in seven grades. Level 1 corresponds to a state in which no glare is observed at all, level 7 corresponds to a state in which glare is remarkably observed, and level 4 corresponds to a state in which glare is observed very slightly.

(evaluation of contrast)

The front and back polarizing plates were peeled off from a commercially available liquid crystal TV ["KDL-32EX550" manufactured by Sony Corporation]. Instead of these original polarizing plates, polarizing plates "Sumikaran SRDB831E" manufactured by Sumitomo Chemical Co., Ltd. were bonded to both the back side and the display side with an adhesive, and the absorption axes of these polarizing plates were aligned with those of the original polarizing plates. , and then, the anti-glare film shown in each of the following examples was bonded to the display surface side polarizing plate through an adhesive so that the uneven surface became the surface. The thus-obtained liquid crystal television was started up in a dark room, and the luminance in a black display state and a white display state were measured with a luminance meter "BM5A" manufactured by TOPCON Co., Ltd., and the contrast ratio was calculated. Here, the contrast is represented by the ratio of the luminance of a white display state to the luminance of a black display state. As a result, the ratio of the contrast measured with the antiglare film bonded to the contrast measured with the antiglare film not bonded is shown.

[4] Evaluation of patterns for anti-glare film production

The created pattern data is binarized image data of two gradations, and the gradations are represented by a binary discrete function g(x, y). The horizontal resolutions Δx and Δy of the discrete function g(x, y) are both 2 μm. The obtained binary function g(x, y) is subjected to discrete Fourier transform to obtain the binary function G(f _x , f _y ). Square the absolute value of the binary function G(f _x , f _y ), calculate the binary function Γ(f _x , f _y ) of the two-dimensional power spectrum, and calculate a function of the distance f from the origin The unary function Γ(f) of the dimensional power spectrum.

<Example 1>

(Preparation of molds for anti-glare film production)

A material obtained by performing ballard copper plating on the surface of an aluminum roll (A6063 based on JIS) with a diameter of 300 mm was prepared. Ballard copper plating consists of copper plating/thin silver plating/surface copper plating, and the overall thickness of the plating is set to about 200 μm. The copper-plated surface was mirror-polished, and a photosensitive resin was applied and dried on the polished copper-plated surface to form a photosensitive resin film. Next, a pattern obtained by repeatedly arranging pattern A shown in FIG. 9 was exposed on the photosensitive resin film with a laser, and developed. Exposure and development were performed by laser using Laser Stream FX (manufactured by Think Laboratory). As the photosensitive resin film, a resin film containing a positive photosensitive resin was used. Here, pattern A is made by passing a pattern with random lightness distribution through multiple Gaussian function bandpass filters, with an aperture ratio of 45.0%, and a one-dimensional power spectrum with a minimum value at a frequency of 0.0195μm ^-1 picture of.

Then, the 1st etching process was performed using copper chloride solution. The etching amount at this time was set to 4 μm. The photosensitive resin film was removed from the roller after the 1st etching process, and the 2nd etching process was performed again using copper chloride solution. The etching amount at this time was set to 13 μm. Then, a chrome plating process was performed, and the mold A was produced. At this time, the thickness of the chrome plating was set to 3 μm.

(Production of anti-glare film)

The following components were dissolved in ethyl acetate at a solid content concentration of 60%, and an ultraviolet curable resin composition A capable of forming a film showing a refractive index of 1.53 after curing was prepared.

60 parts of pentaerythritol triacrylate

40 parts of multifunctional urethanized acrylate

(reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate)

5 parts of diphenyl (2,4,6-trimethoxybenzoyl) phosphine oxide

This ultraviolet curable resin composition A was coated on a triacetate cellulose (TAC) film with a thickness of 60 μm so that the thickness of the dried coating layer was 5 μm, and dried in a dryer set at 60° C. 3 minutes. The dried film was pressed against the molding surface (surface having surface irregularities) of the above-obtained mold A with a rubber roller so that the dried coating layer was on the mold side, and brought into close contact. In this state, light from a high-pressure mercury lamp with an intensity of 20 mW/cm ² is irradiated from the TAC film side, and the light is 200 mJ/cm ² in terms of h-line conversion light quantity, and the coating layer is cured, thereby manufacturing the anti-glare membrane. Then, the obtained anti-glare film was peeled from the mold, and the transparent anti-glare film A provided with the anti-glare layer on the TAC film was produced.

<Example 2>

Mold B was produced in the same manner as that of Mold A in Example 1 except that the etching amount in the first etching process was set to 3 μm, and an anti-glare film was produced in the same manner as in Example 1 except that Mold A was replaced with Mold B. . This antiglare film was referred to as antiglare film B.

<Example 3>

Mold C was produced in the same manner as that of Mold A in Example 1 except that the etching amount in the first etching process was set to 5 μm, and an anti-glare film was produced in the same manner as in Example 1 except that Mold A was replaced with Mold C. . Let this antiglare film be antiglare film C.

＜Comparative example 1＞

Mold D was produced in the same manner as that of Mold A in Example 1 except that the etching amount in the first etching process was set to 6 μm, and an anti-glare film was produced in the same manner as in Example 1 except that Mold A was replaced with Mold D. . This anti-glare film was referred to as anti-glare film D.

＜Comparative example 2＞

Utilize the laser to expose on the photosensitive resin film and go out the pattern that repeatedly arranges the pattern B shown in Fig. 10, the etching amount of the first etching process is set to 5 μm, the etching amount of the second etching process is set to 13 μm, and the thickness of the chrome plating Except having set it as 4 micrometers, the mold E was produced similarly to the production of the mold A of Example 1, and the antiglare film was produced similarly to Example 1 except having replaced the mold A with the mold E. This anti-glare film was referred to as anti-glare film E. Here, pattern B is made by passing a pattern with random lightness distribution through multiple Gaussian function bandpass filters, the opening ratio is 45.0%, and the one-dimensional power spectrum of the pattern is above the frequency of 0.015μm ^-1 and A pattern with a minimum value below 0.05μm ^-1 .

<Comparative example 3>

Mirror-polish the surface of an aluminum roller (JIS-based A5056) with a diameter of 300 mm, and use a sand blasting device (manufactured by Fuji Seisakusho) to blast the polished aluminum surface with a blast pressure of 0.1 MPa (gauge pressure, the same below). ), the amount of beads used is 8 g/cm ² (the amount used for the unit surface area of the roller is 1 cm ² , the same below), and sandblasted zirconia beads TZ-SX-17 (manufactured by Tosoh Co., Ltd., average particle size: 20 μm) are aluminum Convexities and convexities were given to the surface of the roll. The obtained aluminum roll with unevenness was subjected to electroless nickel plating to prepare a die D. At this time, the thickness of the electroless nickel plating was set to 15 μm. Except having replaced mold A with mold F, it carried out similarly to Example 1, and produced the antiglare film. Let this antiglare film be antiglare film F.

<Comparative example 4>

The material which gave ballard copper plating to the surface of the aluminum roll (A5056 based on JIS) of diameter 200mm was prepared. Ballard copper plating consists of copper plating/thin silver plating/surface copper plating, and the overall thickness of the plating is about 200 μm. Mirror-polish the copper-plated surface, and then use a sandblasting device (manufactured by Fuji Manufacturing Co., Ltd.) to spray the abrasive surface with a sandblasting pressure of 0.05MPa (gauge pressure, the same below) and a bead consumption of 6g/ ^cm2 . Sand zirconia beads "TZ-SX-17" (manufactured by Tosoh Co., Ltd., average particle diameter: 20 μm) provided irregularities on the surface of the aluminum roll. The obtained copper-plated aluminum roll with unevenness was subjected to chrome plating, and a mold G was produced. At this time, the thickness of the chrome plating was set to 6 μm. Except having replaced mold A with mold G, it carried out similarly to Example 1, and produced the anti-glare film. Let this antiglare film be antiglare film G.

[One-dimensional power spectrum of the pattern used to make each mold]

FIG. 11 corresponds to a power spectrum Γ(f) obtained by performing discrete Fourier transform on the patterns A and B used in the production of the antiglare films A to E (Examples 1 to 3, and Comparative Examples 1 and 2). diagram.

[Evaluation results]

Table 1 shows the results of evaluating the above-mentioned anti-glare film about the above examples and comparative examples.

Table 1

Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Anti-glare film used A B C D. E. f G total haze 0.9 0.6 1.0 1.3 0.3 0.9 1.7 surface haze 0.8 0.5 0.9 1.1 0.3 0.8 1.7 Transmission Clarity 395.1 405.1 376.8 366.8 433.3 242.5 468.7 Rq(0.08) 0.04 0.03 0.03 0.04 0.03 0.05 0.04 Rq(0.25) 0.07 0.06 0.06 0.08 0.05 0.15 0.05 Rq(0.8) 0.10 0.08 0.10 0.10 0.06 0.15 0.06 Rq(2.5) 0.10 0.08 0.11 0.12 0.09 0.16 0.06 Sm(0.25) 105.0 123.2 127.9 134.2 91.2 81.4 55.2 Sm(0.8) 124.5 134.4 156.7 140.5 93.2 95.0 51.6 Sm(2.5) 206.1 226.1 247.1 255.6 202.0 140.8 137.5 R _SCE /R _SCI 0.06 0.05 0.07 0.11 0.05 0.08 0.08 Reflection Clarity (45°) 132.2 154.2 110.0 100.5 183.0 21.4 308.6 Reflection Clarity (60°) 196.6 233.4 180.1 158.7 275.1 58.3 346.7 R _SCE 0.32 0.23 0.40 0.52 0.20 0.35 0.36 Reflected (front) 1 1 1 1 1 1 1 Reflect (obliquely) 1 1 1 1 2 1 3 whitening 1 1 1 2 1 1 2 Dazzling 3 2 3 3 2 6 1 contrast 99 100 99 99 100 99 98

The anti-glare films A to C (Examples 1 to 3) satisfying the requirements of the present invention have low haze, but have excellent anti-glare properties regardless of the frontal or oblique viewing angles, and suppress whitening and glare The effect is enough, too. On the other hand, whitening occurred in the antiglare film D (comparative example 1). The anti-glare film E (comparative example 2) had insufficient anti-glare property when viewed obliquely. The anti-glare film F (Comparative Example 3) easily generated glare. Antiglare film G (Comparative Example 4) had insufficient antiglare property when viewed obliquely.

Symbol Description

12 integrating sphere, 13 light source, 14 light reflectance measurement sample of anti-glare film,

15 light traps,

40 mold base material,

41 through the mold substrate surface (plating layer) after the 1st plating process and grinding process,

46 the first surface uneven shape formed by the first etching treatment,

47 The surface roughness shape passivated by the second etching process,

50 photoresist film, 60 mask,

70 After chrome-plating, the concave-convex shape of the surface has a passivated surface,

71 chrome layer,

80 export rollers, 81 transparent supports, 83 coating areas,

86 active energy ray irradiation device, 87 cylindrical mold,

88, 89 nip roller, 90 film winding device.

Industrial applicability

The antiglare film of the present invention is useful for image display devices such as liquid crystal displays.

Claims (4)

1. An anti-glare film comprising a transparent support and an anti-glare layer formed on the transparent support with a micro-concave-convex surface, characterized in that, The total haze of the antiglare film is not less than 0.1% and not more than 3%, The surface haze is not less than 0.1% and not more than 2%, The root mean square roughness Rq (0.08) when measured at a cut-off length of 0.08 mm is not less than 0.01 μm and not more than 0.05 μm, The root mean square roughness Rq (0.25) when measured at a cut-off length of 0.25 mm is not less than 0.05 μm and not more than 0.1 μm, The root mean square roughness Rq (0.8) when measured at a cut-off length of 0.8 mm is not less than 0.07 μm and not more than 0.12 μm, The root mean square roughness Rq(2.5) when measured at a cut-off length of 2.5 mm is not less than 0.08 μm and not more than 0.15 μm, The ratio R _SCE /R _SCI of the light reflectance R _SCI measured with regular reflection light included and the light reflectance R _SCE measured without regular reflection light is 0.1 or less. 2. antiglare film as claimed in claim 1, is characterized in that, The average length Sm(0.25) when measured at a cut-off length of 0.25 mm is not less than 90 μm and not more than 160 μm, The average length Sm(0.8) when measured at a cut-off length of 0.8 mm is not less than 100 μm and not more than 300 μm, The average length Sm(2.5) when measured at a cut length of 2.5 mm is 200 μm or more and 400 μm or less. 3. antiglare film as claimed in claim 1 or 2, is characterized in that, The sum Tc of transmission clarity measured by using five kinds of optical combs whose widths of dark and bright parts are 0.125mm, 0.25mm, 0.5mm, 1.0mm and 2.0mm is more than 375%. The sum Rc(45) of the reflection clarity measured at an incident angle of light of 45° using four kinds of optical combs with a width of 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm in the dark and bright parts is 180% or less, The sum Rc(60) of reflection sharpness measured at an incident angle of light of 60° using four kinds of optical combs with dark and bright portions of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm in width was 240% or less. 4. The anti-glare film according to any one of claims 1 to 3, wherein the light reflectance R _SCE measured without regular reflected light is 0.5% or less.