TW201532827A - Anti-glare film - Google Patents

Abstract

The present invention provides an anti-glare film, which has an excellent anti-glaring property at wide view angels even in low haze, and capable of suppressing the occurrence of whitening and glaring while provided in a picture display device. Provided is a anti-glare film comprising a transparent support body and a finely uneven surface formed thereon, and characterized in that: the total haze is 0.1% or more and 3% or less, the surface haze is 0.1% or more and 2% or less, the ratio of a visible reflectivity RSCI detected by including normal reflecting light and a visible reflectivity RSCE detected by comprising excluding reflecting light, RSCE/RSCI, is 0.1 or less, the intensity I(0.01), I(0.02), and I(0.1) of spatial frequency 0.01, spatial frequency 0.02, and spatial frequency 0.1 of the power spectrum of height of the structure of the uneven surface are defined in specific ranges, respectively.

Description

Anti-glare film

The present invention relates to a film excellent in anti-glare.

Image display devices such as liquid crystal displays, plasma display panels, cathode ray tube (CRT) displays, and organic electroluminescent (EL) displays are designed to avoid deterioration of the visibility caused by external light mapping on the display surface. The display surface is provided with an anti-glare film.

As for the anti-glare film, a transparent film having a surface uneven shape is mainly studied. Such an anti-glare film exhibits anti-glare property by scattering the external light by the surface uneven shape and reducing the mapping by (outer light scattered light). However, when the external light is scattered, the display surface of the image display device may be whitened or a turbid color may be displayed, that is, a so-called "discoloration" may occur. Further, there is a case where the pixels of the image display device interfere with the uneven surface of the anti-glare film, and a luminance distribution is generated and becomes difficult to recognize, that is, so-called "glare" is also generated. In view of the above, it is desirable to ensure excellent anti-glare properties in the anti-glare film, and to sufficiently prevent the occurrence of "whitening" and "glare".

As such an anti-glare film, for example, disclosed in Patent Document 1 An anti-glare film which is an anti-glare film which does not generate glare when it is disposed on a high-definition image display device and which sufficiently prevents whitening from occurring, forms a fine surface uneven shape on the transparent substrate, and the surface irregular shape The average length PSm of the arbitrary cross-sectional curve is 12 μm or less, and the ratio Pa/PSm of the arithmetic mean height Pa to the average length PSm of the cross-sectional curve is 0.005 or more and 0.012 or less, and the ratio of the surface unevenness angle of the surface is 2° or less. It is 50% or less, and the inclination angle is 6. The ratio of the following faces is 90% or more.

In the anti-glare film disclosed in Patent Document 1, since the average length PSm of an arbitrary cross-sectional curve is extremely small, the glare can be effectively suppressed by eliminating the surface unevenness of the period of 50 μm which is likely to cause glare. However, in the anti-glare film disclosed in Patent Document 1, if the haze is to be reduced (if a low haze is to be formed), the anti-glare property is observed when the display surface of the image display device in which the anti-glare film is disposed is observed from an oblique direction. Reduced situation. Therefore, in the antiglare film disclosed in Patent Document 1, there is still room for improvement in the point of preventing the glare of the wide viewing angle.

Prior technical literature Patent literature

Patent Document 1; Japanese Patent Laid-Open Publication No. 2007-187952

An object of the present invention is to provide an anti-glare film which has excellent anti-glare properties even at a low viewing angle even when it is low in haze, and can sufficiently suppress whitening and glare when disposed in an image display device.

The inventors of the present invention have completed the present invention in order to solve the above problems and to concentrate on the results of the research. That is, the anti-glare film of the present invention is provided with a transparent support and an anti-glare film having an anti-glare layer having a fine uneven surface formed thereon; characterized in that the total haze of the anti-glare film is 0.1%. Above 3% or less; surface haze is 0.1% or more and 2% or less; visual reflectance R _SCI measured by including specular reflection method and measured by not including specular reflection light (that is, removing specular reflection light) The ratio R _SCE /R _SCI of the visual reflectance R _SCE is 0.1 or less, and the power spectrum of the elevation of the surface shape of the concave-convex surface satisfies the conditions of any one of the following (1) to (3): (1) The spatial frequency is 0.01 μm. ^-1 intensity I (0.01) is 2 μm ⁴ or more and 10 μm ⁴ or less; (2) spatial frequency 0.02 μm ^-1 intensity I (0.02) is 0.1 μm ⁴ or more and 1.5 μm ⁴ or less; and, (3) spatial frequency is 0.1 μm the intensity I ^-1 (0.1) is more than 0.01μm ⁴ 0.0001μm ⁴ or less.

Furthermore, in the anti-glare film of the present invention, it is preferable to use the following five kinds of optical combs having a width of a dark portion and a bright portion of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. And the Tc is more than 375%; using four kinds of optical combs with the width of the dark portion and the bright portion of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, and the reflection of the light at an incident angle of 45 ° The degree of refraction and Rc (45) are less than 180%; the four kinds of optical combs with the width of the dark portion and the bright portion are 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, and the reflection is determined by the incident angle of light of 60°. The degree of Rc (60) is 240% or less.

Further, in the antiglare film of the present invention, the visual reflectance R _SCE measured by the above-described method including no specular reflection light is preferably 0.5% or less.

According to the present invention, it is possible to provide an anti-glare film which has excellent anti-glare properties even at a low viewing angle even at a low haze, and can sufficiently suppress the occurrence of whitening and glare when disposed in an image display device.

12 ‧ ‧ integral ball

13‧‧‧Light source

14‧‧‧Density reflectance measurement samples for anti-glare film

15‧‧‧Light trap

40‧‧‧Mold base for mold

41‧‧‧ Surface of the substrate for the mold after the first plating step and the polishing step (plating layer)

46‧‧‧First surface relief shape formed by etching treatment

50‧‧‧Photosensitive resin film

60‧‧‧ mask

70‧‧‧The surface irregularities after chrome plating are shape passivated surfaces

71‧‧‧Chromium plating

80‧‧‧Send the wheel

81‧‧‧Transparent support

83‧‧‧ coated area

86‧‧‧Active energy line irradiation device

87‧‧‧Roll-shaped mould

88, 89‧‧‧Clamping roller

90‧‧‧ film winding device

Fig. 1 (a) and (b) are schematic views of an optical system for measuring visual reflectances R _SCI and R _SCE .

Fig. 2 is a view for simply explaining the elevation of the surface uneven shape of the anti-glare film.

Fig. 3 is a view for simply explaining the relationship between the elevation of the surface uneven shape of the anti-glare film and the coordinates (x, y).

Fig. 4 is a view showing a state in which the surface unevenness of the surface of the anti-glare film is dispersedly obtained.

Fig. 5 is a view showing a state in which a one-dimensional power spectrum is calculated from a two-dimensional power spectrum of an elevation of a surface uneven shape obtained as a dispersion function.

Fig. 6 is a view showing a one-dimensional power spectrum I(f) indicating the surface unevenness of the anti-glare film with respect to the spatial frequency f.

Fig. 7 (a) to (e) are schematic views showing a preferred embodiment of the manufacturing method (front half) of the mold.

Fig. 8 (a) to (c) are schematic views showing a preferred embodiment of a method of manufacturing a mold (second half).

Fig. 9 is a schematic view showing a preferred embodiment of a manufacturing apparatus used in the method for producing an anti-glare film of the present invention.

Fig. 10 is a schematic view showing a suitable preliminary hardening step in the method for producing an antiglare film of the present invention.

Figure 11 is a schematic diagram of cells for glare evaluation.

Fig. 12 is a schematic view of a glare evaluation device.

Fig. 13 is a view showing a part of the pattern A used in the first to third embodiments and the comparative example 1.

Fig. 14 is a view showing a part of the pattern B used in Comparative Example 2.

Hereinafter, preferred embodiments of the present invention can be described with reference to the drawings as needed, but the dimensions and the like of the illustrations are of any size for ease of viewing.

The anti-glare film of the present invention has a ratio R _SCE /R _SCI of a visual reflectance R _SCI measured by a specular reflection method and a reflectance R _SCE measured without a specular reflection method of 0.1 or less. The spatial frequencies of the power spectrum of the surface unevenness are 0.01 μm ^-1 , 0.02 μm ^-1 , and 0.1 μm ^-1 , respectively, within a specific range.

First, regarding the anti-glare film of the present invention, a method of obtaining a power spectrum of the apparent reflectance R _SCI and the visual reflectance R _SCE and the level of the fine uneven surface will be described.

[Visual reflectance R _SCI and visual reflectance R _SCE ]

Fig. 1(a) is a schematic diagram of an optical system for measuring a visual reflectance R _SCI including a specular reflection method, and Fig. 1(b) is for measuring a visual reflectance R _SCE without including specular reflection. Schematic diagram of the optical system. Fig. 1(a) and Fig. 1(b) show an optical system of a diffused illumination system. The diffusion illumination method is a method of uniformly illuminating a measurement sample from all directions by using an integrating sphere or the like, and an integrating sphere 12 is provided in the first (a) and the first (b) diagrams (to almost completely diffuse the reflected light). A white paint such as barium sulfate is coated on the inner surface of 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 the first (b), a light trap 15 is provided at the position of the integrating sphere 12 in the specular reflection direction in the light receiving portion (in the first (b) diagram, a hollow auxiliary device having a conical shape is attached. The light that enters the conical hollow shape is absorbed in the cavity and becomes a structure that cannot be returned to the integrating sphere 12, and the light in the direction of the regular reflection of the light receiving portion is not reflected on the surface of the measurement sample.

An optical system that does not use an optical trap as shown in Fig. 1(a) is called a specular reflected light mode (SCI mode). On the other hand, an optical system using an optical trap as shown in Fig. 1(b) is referred to as a mode (SCE mode) that does not include specular reflected light (i.e., removes specular reflected light). The reflectance spectrum of the sample measured from the two modes, the visual reflectance calculated according to the method described in JIS Z 8722, is measured by the specular reflectance R _SCI measured by the method of specular reflection and by the method of not including specular reflection. Visual reflectance R _SCE .

When the ratio R _SCE /R _SCI of the apparent reflectance R _SCI measured by the specular reflection method and the apparent reflectance R _SCE measured without the specular reflection method exceeds 0.1, the surface of the anti-glare film is used. The ambient light of the environment becomes strong in the reflected light in the direction of the user, and as a result, the image display device having such an anti-glare film is whitened. Moreover, the image display device tends to reduce the contrast of the bright spots. It is more preferably 0.08 or less than R _SCE /R _SCI , and even more preferably 0.06 or less. Further, the visual reflectance R _SCE measured without including specular reflection light is preferably 0.5% or less, more preferably 0.4% or less, and still more preferably 0.3% or less.

[Power spectrum of the elevation of the surface irregular shape]

Hereinafter, the power spectrum of the elevation of the surface uneven shape of the anti-glare film will be described. Fig. 2 is a cross-sectional view schematically showing the surface of the anti-glare film of the present invention. As shown in FIG. 2, the anti-glare film 1 of the present invention has a transparent support 101 and an anti-glare layer 102 formed thereon, and the anti-glare layer 102 is provided with fine unevenness on the side opposite to the transparent support 101. 2 surface concave and convex shape.

Here, the "elevation of the surface unevenness" in the present invention means an arbitrary point P on the surface of the film 1, and a hypothetical plane 103 having the height in the average height of the surface unevenness (the height is based on 0 μm) The linear distance of the main normal direction 5 of the film (the normal direction of the assumed plane 103 above).

Actually, the anti-glare film is schematically shown in Fig. 3, and has an anti-glare layer in which fine irregularities are formed on a two-dimensional plane. Here, the elevation of the surface relief shape is as shown in Fig. 3. When the orthogonal coordinates in the plane of the film are represented by (x, y), they can be expressed as a two-dimensional function h(x, y) of the coordinates (x, y). ).

The elevation of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by a confocal microscope, an interference microscope, an atomic force microscope (AFM) or the like. The horizontal resolution required for the measuring machine is at least 5 μm or less, preferably 2 μm or less, and the vertical resolution is at least 0.1 μm or less, preferably 0.01 μm or less. The non-etching three-dimensional surface shape and the thickness measuring machine suitable for the measurement are, for example, New View 5000 series (manufactured by Zygo Corporation), three-dimensional microscope PL μ 2300 (manufactured by Sensofar Co., Ltd.), and the like. The measurement area must have an analytical power of the power spectrum of the standard height of 0.005 μm ^-1 or less, and therefore it is preferably at least 200 μm × 200 μm, more preferably 500 μm × 500 μm or more.

Next, a method of obtaining the power spectrum of the elevation from the two-dimensional function h(x, y) will be described. First, the two-dimensional function H(f _x , f _y ) is obtained from the two-dimensional function h(x, y) according to the two-dimensional Fourier transform defined by the equation (1).

Here, f _x and f _y are frequencies in the x direction and the y direction, respectively, and have a dimension of the inverse of the length. In the formula (1), the π is a pi, and i is an imaginary unit. By squaring the absolute value of the obtained two-dimensional function H(f _x , f _y ), the two-dimensional power spectrum I(f _x , f _y ) can be obtained according to the equation (2).

I ( f _x , f _y )=| H ( f _x , f _y )| ² (2)

This two-dimensional power spectrum I(f _x , f _y ) represents the spatial frequency distribution of the surface uneven shape of the anti-glare film. The anti-glare film is isotropic, so the two-dimensional function I(f _x , f _y ) of the two-dimensional power spectrum indicating the elevation of the surface concavo-convex shape can depend only on the distance f from the origin (0, 0). The dimension function I(f) is represented. Next, a method of obtaining the one-dimensional function I(f) from the two-dimensional function I(f _x , f _y ) is shown. First, the two-dimensional function I(f _x , f _y ) of the two-dimensional power spectrum of the elevation is expressed by polar coordinates according to equation (3).

I ( f _x , f _y )= I ( f cos θ, f sin θ)...(3)

Here, θ is the declination in the Fourier space. The one-dimensional function I(f) can be obtained by calculating the rotation average of the two-dimensional function I (fcos θ, fsins θ) represented by the polar coordinates according to the equation (4). The one-dimensional function I(f) is obtained from the rotational average of the two-dimensional function I(f _x , f _y ) as the two-dimensional power spectrum of the elevation, and is also referred to as a one-dimensional power spectrum I(f) hereinafter.

The anti-glare film of the present invention calculates the intensity I (0.01) of the spatial frequency of the one-dimensional power spectrum I(f) of 0.01 μm ^{-1 and} the intensity I of the spatial frequency of 0.02 μm ^-1 (0.02) from the elevation of the surface concavo-convex shape. And the intensity I (0.1) of the spatial frequency of 0.1 μm ^-1 is in a specific range.

Hereinafter, a method of obtaining a two-dimensional power spectrum of the elevation of the surface uneven shape of the anti-glare film will be more specifically described. The three-dimensional information of the surface shape actually measured by the above-described confocal microscope, interference microscope, atomic force microscope, or the like is generally a separated value, that is, corresponding to the elevation of a plurality of measurement points. Fig. 4 is a view showing a state in which the function h(x, y) of the elevation is dispersed. As shown in Fig. 4, (x, y) represents the orthogonal coordinates in the plane of the film, and is indicated by a broken line on the film projection surface 3 in the x-axis direction every Δx division line, and in the y-axis direction every △ y dividing line, actual In the measurement, the elevation of the surface uneven shape is obtained by the value of the dispersion of the area Δx × Δy divided by each broken line on the film projection surface 3.

The number of the obtained elevation values is determined according to the measurement range and Δx and Δy. As shown in Fig. 4, the measurement range in the x-axis direction is X=MΔx, and the measurement range in the y-axis direction is set. For Y = N Δy, the number of the obtained elevation values is M × N.

As shown in Fig. 4, the coordinates of the eye point A on the film projection surface 3 are (m Δx, n Δy) [where m is 0 or more and M-1 or less, and n is 0 or more and N-1. Hereinafter, the elevation of the point P corresponding to the film surface of the eye point A can be expressed as h (m Δx, n Δy).

Here, the measurement intervals Δx and Δy are based on the horizontal analysis ability of the measuring device, and the fine uneven surface is evaluated with high precision, and Δx and Δy are preferably 5 μm or less, more preferably 2 μm or less. Further, the measurement ranges X and Y are as described above, and are preferably 200 μm or more, more preferably 500 μm or more.

In such an actual measurement, the function indicating the elevation of the surface uneven shape is obtained by having a discrete function h(x, y) of M × N values. Therefore, the two-dimensional function H(f _x , f _y ) obtained by the two-dimensional Fourier transform of the two-dimensional function h(x, y) of the elevation of the fine concave-convex surface can also be discrete by the discrete equation (1) The Fourier transform is obtained as a discrete function as in equation (5).

Here, j in the formula (5) is an integer of -M/2 or more and M/2 or less, and k is an integer of -N/2 or more and N/2 or less. Δf _x and Δf _y are frequency intervals in the x direction and the y direction, respectively, and are defined by the formulas (6) and (7).

The two-dimensional power spectrum I(f _x , f _y ) is obtained by the square of the absolute value of the discrete function H(f _x , f _y ) obtained by the equation (5) as shown in the equation (8).

In the formula (8), |H(jΔf _x , kΔf _y )| ^{2 is} divided by MNΔxΔy for the purpose of actual measurement, and the integral range is different according to the measurement area. Therefore.

The two-dimensional power spectrum I(f _x , f _y ) obtained by the discrete function also indicates the spatial frequency distribution of the surface relief shape of the anti-glare film. Moreover, since the anti-glare film is an isotropic property, the two-dimensional discrete function I(f _x , f _y ) of the two-dimensional power spectrum indicating the elevation of the surface concavo-convex shape can also depend only on the origin (0, 0). The distance f is represented by a one-dimensional discrete function I(f). When the one-dimensional discrete function I(f) is obtained from the two-dimensional discrete function I(f _x , f _y ), the rotation average may be calculated in the same manner as in the equation (4). The discrete averaging of the two-dimensional discrete function I(f _x , f _y ) can be calculated by equation (9).

Here, when M≧N, 1 is an integer of 0 or more and N/2 or less, and when M<N, 1 is an integer of 0 or more and M/2 or less. Further, the interval between Δf and the distance from the origin is Δf = (Δf _x + Δf _y )/2. Further, Θ(x) is a Heaviside function defined by the formula (10), and f _jk is a distance from the origin of (j, k), which can be calculated according to the formula (11).

The calculation shown in the equation (9) will be explained using Fig. 5. The function Θ(f _jk -(1-1/2) Δf) is 0 when f _{jk is} less than (1-1/2) Δf. (1-1/2) When Δf or more is 1, the function Θ(f _jk -(1+1/2) Δf) is 0 when f _{jk is} less than (1+1/2) Δf. (1+1/2) is Δf or more, so Θ(f _jk -(1-1/2)Δf)-Θ(f _jk -(1+1/2)△ f) When f _jk is (1-1/2) Δf or more, when it is less than (1-1/2) Δf, it becomes 1 and when it is other, it becomes 0. Here, f _{jk is} in the frequency space from the origin O (f _x =0, f _y =0), so the denominator of equation (9) becomes the distance f _jk calculated from the origin O (1 - 1/2) The number of all points (the point of the black circle in Fig. 5) of Δf or more and less than (1 + 1/2) Δf. Further, the molecular system of the formula (9) is an I (f _x ) which calculates the distance f _jk from the origin O at (1 - 1/2) Δf or more and does not reach (1 + 1/2) Δf. , the total value of f _y ) (the total value of I(f _x , f _y ) in the point of the black circle in Fig. 5).

One-dimensional power spectrum packet is generally obtained according to the foregoing method. Contains noise during measurement. Here, when the one-dimensional power spectrum is obtained, in order to remove the influence of the noise, the elevation of the surface unevenness shape at a plurality of points on the anti-glare film is measured, and one dimension is obtained from the elevation of the individual surface uneven shape. The average of the power spectra is preferably used as the one-dimensional power spectrum I(f). The number of the elevations of the surface uneven shape on the antiglare film is preferably 3 or more, more preferably 5 or more.

Fig. 6 is a graph showing I(f) of one-dimensional power spectrum of the elevation of the surface uneven shape obtained in this manner. The one-dimensional power spectrum I(f) of Fig. 6 is obtained by averaging one-dimensional power spectrum from the elevation of the surface unevenness of the five points on the anti-glare film.

The anti-glare film of the present invention is calculated from the elevation of the surface concavo-convex shape, and the spatial frequency of the one-dimensional power spectrum I(f) is 0.01 μm ^{-1 and} the intensity I (0.01) is 2 μm ⁴ or more and 10 μm ⁴ or less, and the spatial frequency is 0.02 μm ^- intensity I (0.02) of ¹ to 0.1μm ⁴ less than 1.5μm ^4, the spatial frequency of the intensity I 0.1μm ^-1 (0.1) is more than 0.01μm ⁴ 0.0001μm ⁴ or less. Here, since the one-dimensional power spectrum I(f) is obtained as a discrete function, the intensity I(f ₁ ) in the specific spatial frequency f ₁ is obtained as shown in the equation (12), and is calculated as long as it is inserted. can.

The anti-glare film of the present invention is excellent in that the intensity in the specific spatial frequency described above is a specific range, and the overall effect of the haze and the average value of the inclination angle of the surface unevenness described later is good. It prevents the occurrence of whitening and glare, and shows excellent anti-glare properties. In order to exhibit such an effect, the strength I (0.01) is preferably 2.5 μm ⁴ or more and 9 μm ⁴ or less, more preferably 3 μm ⁴ or more and 8 μm ⁴ or less. Similarly, the intensity I (0.02) is preferably 0.2 μm ⁴ or more and 1.2 μm ⁴ or less, more preferably 0.25 μm ⁴ or more and 1 μm ⁴ or less, and the strength I (0.1) is 0.0003 μm ⁴ or more and 0.0075 μm ⁴ or less, preferably 0.0005 μm ^{4 .} better than 0.005μm ⁴ or less.

When I (0.01) is less than the above range, the periodic wave which contributes to the antiglare effect when the antiglare film is observed from the oblique direction is about 100 μm (the spatial frequency corresponds to 0.01 μm ^-1 ), and the antiglare property is insufficient. When I (0.01) is higher than the above range, the periodic wave of about 100 μm is excessively large, the fine unevenness of the antiglare film becomes thick, and the haze tends to increase, which is not preferable.

When I (0.02) is less than the above range, the periodic wave of about 50 μm (the spatial frequency corresponds to 0.02 μm ^-1 ) which contributes to the antiglare effect when the antiglare film is observed from the front side is small, and the antiglare property is insufficient. When I (0.02) is higher than the above range, the periodic wave of about 50 μm is too large to cause glare.

When I (0.1) is lower than the pre-recorded range, the short-period shape of the short period of about 10 μm (the spatial frequency is equivalent to 0.1 μm ^-1 ) is very small, and the surface uneven shape of the anti-glare film is formed only by the long-period uneven shape, so that the prevention The surface texture of the glare film becomes thick, so it is not good. When I (0.1) is higher than the range of the former, scattering due to the surface unevenness of a short period of about 10 μm becomes strong, so whitening is likely to occur.

[Total haze, surface haze]

The anti-glare film of the present invention exhibits anti-glare properties and prevents whitening, and the total haze of normal incident light is in the range of 0.1% or more and 3% or less, and the surface haze is in the range of 0.1% or more and 2% or less. The total haze of the anti-glare film can be rooted It was measured according to the method shown in JIS K7136. An image display device in which an anti-glare film having a total haze or a surface haze of less than 0.1% is disposed is inferior because it does not exhibit sufficient anti-glare properties. Further, when the total haze exceeds 3% or the surface haze exceeds 2%, the anti-glare film is an image display device in which the anti-glare film is disposed, and whitening is likely to occur, which is not preferable. Moreover, such an image display device has a lack of contrast in its comparison.

The internal haze obtained by subtracting the surface haze from the total haze is preferably lower, and specifically, it is preferably 2.5% or less. An image display device equipped with an anti-glare film having an internal haze of more than 2.5% has a tendency to decrease in contrast.

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

The antiglare film of the present invention preferably has a penetration clarity and a Tc of 375% or more as determined by the following measurement conditions. The penetration sharpness and the Tc were calculated according to the method of JIS K7105, and the image sharpness was measured using an optical comb of a predetermined width, and the sum was calculated. Specifically, five types of optical combs having a width ratio of a dark portion to a bright portion of 1:1 and a width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are used, and image sharpness is measured, and the sum is taken as Tc. An anti-glare film having a Tc of less than 375% may be apt to generate glare when disposed in a higher-resolution image display device. The upper limit of Tc is selected within a range of 500% or less of the maximum value. However, when the Tc is too high, an image display device which is easily degraded from the front side is obtained, and is preferably, for example, 450% or less.

The anti-glare film of the present invention is incident light having an incident angle of 45°. The measured reflection resolution Rc (45) is preferably 180% or less. The reflection sharpness Rc (45) is the same as the above Tc, and is measured according to the method of JIS K7105, and four types of optical combs having widths of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are used among the five kinds of optical combs. The image sharpness was measured separately, and the sum was taken as Rc (45). When Rc (45) is 180% or less, the image display device in which such an anti-glare film is disposed is preferable because it has good anti-glare property when viewed from the front side and the oblique direction. The lower limit of Rc (45) is not particularly limited, but is preferably 80% or more in order to satisfactorily suppress the occurrence of whitening and glare.

The anti-glare film of the present invention is preferably a reflection resolution Rc (60) measured by incident light having an incident angle of 60° of 240% or less. The reflection definition Rc (60) is the same as the reflection definition Rc (45) except that the incident angle is changed, and is measured in accordance with the method of JIS K7105. When the Rc (60) is 240% or less, the image display device in which such an anti-glare film is disposed is preferable because the anti-glare property when viewed from an oblique direction is further improved. The lower limit of Rc (60) is not particularly limited, but in order to suppress whitening and glare, for example, it is preferably 150% or more.

[Method for Producing Antiglare Film of the Present Invention]

The anti-glare film of the present invention is produced, for example, in the following manner. In the first method, a fine unevenness forming mold formed on the surface of the surface of the predetermined pattern is prepared, and the shape of the uneven surface of the mold is transferred to the transparent support, and the shape in which the uneven surface is transferred is transparent. The method of peeling the support from the mold. In the second method, a composition containing fine particles, a resin (adhesive), and a solvent, and the fine particles are dispersed in a resin solution, and the composition is applied onto a transparent support, and dried as needed to form a coating. A method of hardening a film (a coating film containing fine particles). In the second method, the coating film thickness and the aggregation state of the fine particles are adjusted by the composition of the composition, the drying conditions of the coating film, and the like so that the fine particles are exposed on the surface of the coating film to cause irregularities. The unevenness is formed on the transparent support. From the viewpoint of production stability and production reproducibility of the antiglare film, it is preferred that the antiglare film of the present invention is produced by the first method.

Here, a preferred first method as a method of producing the antiglare film of the present invention will be described in detail.

In order to form an anti-glare layer having a surface unevenness having the above-described characteristics, which is excellent in precision, a mold for forming a fine unevenness (hereinafter sometimes simply referred to as a "mold") is important. More specifically, the surface uneven shape (hereinafter sometimes referred to as "mold uneven surface") of the mold is formed according to a specified pattern, and the preferred one of the specified patterns is a spatial frequency of one-dimensional power spectrum of 0.01. Γ ^-1 is the intensity μm (0.01) of the spatial frequency intensity 0.02μm ^-1 Γ (0.02) the ratio Γ (0.02) / Γ (0.01 ) is 0.05 or more and 1.2 or less; spatial frequency intensity 0.01μm ^-1 Gamma] (0.01 The ratio Γ(0.1)/Γ(0.01) to the intensity Γ(0.1) of the spatial frequency of 0.1 μm ^-1 is 4 or more and 25 or less. Here, the term "pattern" refers to image data for forming a surface uneven shape of an anti-glare layer of an anti-glare film, and a mask having a light-transmitting portion and a light-shielding portion, and is simply referred to as "pattern" hereinafter.

First, a method of setting a pattern for forming the surface unevenness of the antiglare layer of the antiglare film of the present invention will be described.

For example, when the graphic is image data, a method of obtaining a two-dimensional power spectrum of the graphic is obtained. First, after the image data is converted into two-tone binary image data, the color tone is represented by a two-dimensional function g(x, y). The obtained two-dimensional function g(x, y) is Fourier transformed into the following formula (13), and the two-dimensional function G(f _x , f _y ) is calculated as shown in the following formula (14), by making the obtained The square of the absolute value of the two-dimensional function G(f _x , f _y ) is obtained to obtain a two-dimensional power spectrum Γ(f _x , f _y ). Here, x and y represent right angle coordinates in the plane of the image data. Further, f _x and f _y represent frequencies in the x direction and the y direction, respectively, and have a dimension of the reciprocal of the length.

π in the formula (13) is a pi, and i is an imaginary unit.

Γ( f _x , f _y )=| G ( f _x , f _y )| ² (14)

The two-dimensional power spectrum f(f _x , f _y ) represents the spatial frequency distribution of the figure. In general, since the antiglare film can be obtained isotropic, the pattern for producing the antiglare film of the present invention is also isotropic. Therefore, the two-dimensional function Γ(f _x , f _y ) representing the two-dimensional power spectrum of the figure can be dependent on the one-dimensional function Γ(f) of the distance f from the origin (0,0). Next, a method of obtaining the one-dimensional function Γ(f) from the two-dimensional function Γ(f _x , f _y ) will be described. First, the two-dimensional function Γ(f _x , f _y ) of the two-dimensional power spectrum as the hue of the pattern is expressed as a polar coordinate as shown in the equation (15).

Γ( f _x , f _y )=Γ( f cos θ, f sin θ)...(15)

Here, θ is the declination in the Fourier space. The one-dimensional function Γ(f) can be obtained by calculating the rotation average of the two-dimensional function Γ (fcos θ, fsins θ) represented by the polar coordinates as in equation (16). The one-dimensional function Γ(f) obtained from the rotational average of the two-dimensional function Γ(f _x , f _y ) of the two-dimensional power spectrum of the hue of the figure is also referred to as a one-dimensional power spectrum Γ(f) hereinafter.

For good resolution of the antiglare film of the present invention is formed, the one-dimensional power spectral spatial frequency intensity pattern of Γ 0.01μm ^-1 (0.01) and the spatial frequency intensity Γ (0.02) 0.02μm ^-1 of the ratio Γ (0.02 ) / Γ (0.01) is 0.05 or more and 1.2 or less, the spatial frequency of the intensity Γ 0.01μm ^-1 (0.01) and the spatial frequency of the intensity of 0.1μm ^-1 Γ (0.1) the ratio Γ (0.1) / Γ (0.01 ) 4 Those above 25 are preferred.

When the two-dimensional power spectrum of the graph is obtained, the two-dimensional function g(x, y) of the hue is usually obtained as a discrete function. In this case, the two-dimensional power spectrum can be calculated by discrete Fourier transform. The one-dimensional power spectrum of the graph is obtained by the two-dimensional power spectrum of the graph.

Moreover, in order to make the obtained surface uneven shape into a uniform continuous curved surface, the average value of the two-dimensional function g(x, y) is the maximum value of the two-dimensional function g(x, y) and the two-dimensional function g(x, y It is preferred that 30% to 70% of the difference between the minimum values is ). When the concave-convex surface of the mold is manufactured by the lithography method, the two-dimensional function g(x, y) becomes the aperture ratio of the pattern. When the concave and convex surface of the mold is manufactured by the lithography method, the aperture ratio of the pattern is first defined here. The aperture ratio when the photoresist used in the lithography method is a positive photoresist refers to the exposure of the entire surface area of the coating film when the image data of the coating film of the positive photoresist is drawn. The ratio of the regions. On the other hand, the aperture ratio when the photoresist used in the lithography method is a negative photoresist refers to the entire surface area of the coating film when the image data of the negative photoresist is drawn. Unexposed area ratio. The lithography method is an aperture ratio at the time of exposure, and refers to a ratio of a light-transmitting portion of a photomask having a light-transmitting portion and a light-shielding portion.

The one-dimensional power spectrum of the anti-glare film of the present invention has a strength ratio Γ(0.02)/Γ(0.01) and Γ(0.1)/Γ(0.01) in the above range, respectively, to produce a desired mold, which can be used according to the use. Manufactured by the first method of the mold.

In order to produce a pattern having such a power ratio to one-dimensional power spectrum, a pattern in which dots are randomly arranged, a random number, or a computer-generated random number is used to determine the shaded pattern having an irregular brightness distribution. (Preparation pattern), the component of the specific spatial frequency range is removed from the preliminary pattern. The component in the specific spatial frequency range is removed, and the preliminary pattern is passed through a band pass filter.

In order to manufacture an anti-glare film having an anti-glare layer formed with a surface uneven shape according to a prescribed pattern, a mold having a concave-convex surface for transfer to a transparent support according to the surface uneven shape formed by the specified pattern is manufactured. The first method using such a mold is characterized in that an embossing method for producing an antiglare layer on a transparent support is used.

As the imprint method, a photoimprint method using a photocurable resin, a hot stamp method using a thermoplastic resin, or the like is exemplified. Among them, from the viewpoint of productivity, photo imprinting is preferred.

In the photoimprint method, a photocurable resin layer is formed on a transparent support (the surface of the transparent support), and the photocurable resin is laminated on the uneven surface of the mold of the mold, and the mold is embossed. A method of transferring the shape of the surface to the photocurable resin layer. Specifically, The photocurable resin is applied to the transparent support, and the formed photocurable resin layer is adhered to the surface of the concave-convex surface of the mold, and the light is irradiated from the side of the transparent support (the light-based resin can be cured by using the light-based resin) The photocurable resin (photocurable resin contained in the photocurable resin layer) is cured, and then the transparent support in which the photocurable resin layer is formed after curing is peeled off from the mold. The anti-glare film obtained by such a production method is an anti-glare layer which is a photocurable resin layer after hardening. In addition, it is preferable that the photocurable resin is an ultraviolet curable resin, and when the ultraviolet curable resin is used, ultraviolet light is used for the light to be irradiated (the ultraviolet curable resin is used as the photocurability). The resin imprint method is hereinafter referred to as "UV imprint method"). In order to manufacture an anti-glare film integrated with a polarizing film, a polarizing film is used as a transparent support, and in the imprint method described here, the transparent support may be replaced by a polarizing film.

The type of the ultraviolet curable resin to be used in the UV imprinting method is not particularly limited, and a commercially available resin can be used depending on the type of the transparent support to be used and the type of the ultraviolet ray. The concept of such an ultraviolet curable resin includes a monomer (polyfunctional monomer), an oligomer, and a polymer which are photopolymerized by ultraviolet irradiation, and a mixture thereof. Further, depending on the type of the ultraviolet curable resin, a suitable photoactive initiator may be used in combination, and a resin which is harder than visible light having a longer wavelength than ultraviolet light may be used. Preferred examples of the ultraviolet curable resin and the like are described later.

As the transparent support used in the UV imprint method, for example, glass, a plastic film, or the like can be used. As a plastic film, as long as it has a moderate degree of penetration Both clarity and mechanical strength can be used. Specifically, for example, cellulose acetate resin such as TAC (triethyl fluorenyl cellulose); acrylic resin; polycarbonate resin; polyester resin such as polyethylene terephthalate; A transparent resin film made of a polyolefin resin such as polypropylene. The transparent resin film may be a solvent cast film or an extruded film.

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 more likely to cause glare.

On the other hand, the hot stamping method is a method in which a transparent resin film formed of a thermoplastic resin is heated and pressed against the uneven surface of the mold in a softened state to transfer the surface uneven shape of the uneven surface of the mold to the transparent resin film. The transparent resin film used in the hot stamping method may be substantially transparent, and specific examples thereof include an example of a transparent resin film used in the UV imprint method.

Next, a method of manufacturing a mold used in the imprint method will be described.

In the method of manufacturing a mold, the molding surface of the mold is a mold unevenness which can be transferred onto the transparent support (the anti-glare layer which can form a surface uneven shape formed by a predetermined pattern) by the surface uneven shape formed by the predetermined pattern. The range of the surface is not particularly limited, and a lithography method is preferable for producing an antiglare layer having a surface unevenness and excellent reproducibility. Furthermore, the lithography method includes [1] the first plating step, [2] Polishing step, [3] photosensitive resin film forming step, [4] exposure step, [5] developing step, [6] etching step, [7] photosensitive resin film peeling step, and [8] second plating step It is better.

Fig. 7 is a schematic view showing a preferred embodiment of the first half of the method for manufacturing the mold. Fig. 7 shows a cross section of the mold of each step. Hereinafter, each step of the method for producing a mold for producing an anti-glare film according to the present invention will be described in detail with reference to FIG.

[1] First plating step

First, a substrate (a substrate for a mold) used for mold production is prepared, and copper plating is applied to the surface of the substrate for the mold. In this way, by performing copper plating on the surface of the substrate for a mold, the adhesion and gloss of the chromium plating in the second plating step to be described later can be improved. Since copper plating has high coating property and strong smoothing action, it is possible to fill a fine uneven surface and a void of the substrate for a mold to form a flat and shiny surface. Therefore, in such a manner, copper plating is performed on the surface of the substrate for a mold, and in the second plating step to be described later, even if chrome plating is performed, chrome plating which is thought to be caused by fine irregularities or voids present in the substrate can be solved. The surface is rough and the coating of copper plating is high, which can reduce the occurrence of fine cracks. Therefore, even if the surface unevenness shape (fine uneven surface shape) according to the predetermined pattern is formed on the molding surface of the base material for the mold, the influence of the surface of the base (substrate for the mold) such as fine unevenness, voids, and cracks can be sufficiently prevented. The deviation caused.

As the copper used for the copper plating in the first plating step, pure copper may be used, or an alloy containing copper as a main component (copper alloy) may be used. Therefore, the concept of "copper" used in copper plating includes copper and copper. alloy. The copper plating may be electrolytic plating or electroless plating, but copper plating in the first plating step is preferably electrolytic plating. Further, the preferred plating layer in the first plating step may be a layer including a copper plating layer or a plating layer containing a metal other than copper.

When the copper plating layer formed by copper plating on the surface of the substrate for a mold is too thin, since the influence of the surface of the substrate (fine irregularities, voids, cracks, and the like) cannot be completely excluded, the thickness is preferably 50 μm or more. The upper limit of the thickness of the copper plating layer is not limited, and when it is considered to be a cost or the like, it is preferably about 500 μm or less.

The substrate for a mold is preferably a substrate containing a metal material. Further, from the viewpoint of cost, aluminum, iron, or the like is preferable as the material of the metal material. Further, in view of the ease of handling of the substrate for a mold, it is particularly preferable to use a lightweight substrate containing aluminum as a substrate for a mold. Further, the aluminum and iron referred to herein are not necessarily pure metals, and may be an alloy mainly composed of aluminum or iron.

The shape of the substrate for a mold may be a shape suitable for the method for producing an anti-glare film according to the present invention. Specifically, it can be selected from a flat substrate, a cylindrical substrate, a cylindrical (roller shape) substrate, or the like. In the continuous production of the antiglare film of the present invention, the mold is preferably in the shape of a roller. Such a mold can be manufactured from a substrate for a mold having a roll shape.

[2] Grinding step

Next, in the polishing step, the surface (plating layer) of the copper-plated mold base material subjected to the first plating step is polished. The method for producing a mold used in the method for producing an anti-glare film of the present invention, after the polishing In the step, it is preferable to polish the surface of the substrate for the mold to a state close to the mirror surface. In order to form a desired precision, a commercially available product of a flat substrate or a roll-shaped base material used as a base material for a mold is often subjected to machining such as cutting or polishing, whereby fineness remains on the surface of the base material for the mold. Processing traces. Therefore, even if a plating layer (preferably copper plating) is formed by the first plating step, the above-described processing marks remain. Further, even if the copper plating in the first plating step is performed, the surface of the substrate for a mold may not be completely smooth. In other words, in the substrate for a mold in which the surface of such a deep processing mark or the like remains, even if the steps [3] to [8] described later are carried out, the surface unevenness of the surface of the obtained mold may be in accordance with the specified pattern. The surface irregularities are different, or include irregularities from processing marks and the like. When an anti-glare film is produced using a mold in which the influence of a processing mark or the like is left, the optical characteristics such as the anti-glare property for the purpose cannot be sufficiently exhibited, and an unexpected influence may be caused.

The polishing method to be applied in the polishing step is not particularly limited, and the polishing method is selected in accordance with the shape and properties of the substrate for the 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. Among these, as the mechanical polishing method, any of an ultrafine processing method, a lapping method, a fluid polishing method, and a buffing polishing method can be used. Further, in the grinding step, the surface of the substrate for the mold can be used as a mirror surface by mirror cutting using a cutting tool. In the case of the material/shape of the cutting tool in this case, a super-hard turning tool, a CBN turning tool, a ceramic turning tool, a diamond turning tool, etc. can be used depending on the type of the material (metal material) of the base material for the mold, but the machining precision is used. The point of view is to use a diamond turning tool. Thick surface after grinding The roughness is expressed by the center line average roughness Ra according to JIS B0601, and is preferably 0.1 μm or less, more preferably 0.05 μm or less. If the center line average roughness Ra after grinding is more than 0.1 μm, the influence of such surface roughness may remain on the uneven surface of the mold of the finally obtained mold. Further, the lower limit of the center line average roughness Ra is not particularly limited. Therefore, the lower limit can be determined from the viewpoints of the processing time (polishing time) of the polishing step and the processing cost.

[3] Photosensitive resin film forming step

Next, referring to Fig. 7, a photosensitive resin film forming step will be described.

In the photosensitive resin film forming step, a solution (photosensitive resin solution) in which a photosensitive resin is dissolved in a solvent is applied onto the surface 41 of the substrate 40 for mirror polishing obtained by the polishing step. A photosensitive resin film (resist film) is formed by heating/drying. Fig. 7 is a view schematically showing a state in which the photosensitive resin film 50 is formed on the surface 41 of the substrate 40 for a mold (Fig. 7(b)).

As the photosensitive resin, a conventionally known photosensitive resin can be used, and a user who is commercially available as a photoresist or, if necessary, purified by filtration or the like can be used as it is. For example, as a negative photosensitive resin having a photosensitive portion hardening property, a monomer, a prepolymer, a double azide which is used for a (meth) acrylate having an acryl fluorenyl group or a methacryl fluorenyl group in a molecule can be used. A mixture with a diene rubber, a polyethylene cinnamate compound, or the like. Further, as the positive photosensitive resin having a property of eluting the photosensitive portion by development and leaving only the non-photosensitive portion, a phenol resin system, a novolak resin system or the like can be used. Such a positive or negative photosensitive resin, In terms of positive photoresist and negative photoresist, it can be easily obtained from the market. Further, the photosensitive resin solution may be formulated with various additives such as a sensitizer, a development accelerator, an adhesion modifier, and a coatability improver, and such additives may be mixed with a commercially available photoresist. Use a photosensitive resin solution.

In order to apply the photosensitive resin solution to the surface 41 of the substrate 40 for a mold, an optimum solvent is selected to form a smoother photosensitive resin film, and the photosensitive resin is dissolved/diluted in such a solvent. A photosensitive resin solution is preferred. Such a solvent is further selected depending on the kind of the photosensitive resin and its solubility. Specifically, for example, it is selected from a cellosolve solvent, a propylene glycol solvent, an ester solvent, an alcohol solvent, a ketone solvent, a highly polar solvent, or the like. When a commercially available photoresist is used, an optimum photoresist is selected depending on the type of solvent contained in the photoresist or an appropriate preliminary test, and it is used as a photosensitive resin solution.

A method of coating a photosensitive resin solution on a mirror-polished surface of a substrate for a mold, from meniscus coating, fountain coating, dip coating, spin coating, roller coating, wire bar coating, air knife coating A conventional method such as cloth, doctor blade coating, curtain coating, or ring coating is selected depending on the shape of the substrate for a mold or the like. The thickness of the photosensitive resin film after application is preferably in the range of 1 to 10 μm after drying, and more preferably in the range of 6 to 9 μm.

[4] Exposure step

Next, the exposure step is a step of exposing the photosensitive resin film 50 formed in the photosensitive resin film forming step and transferring the intended pattern to the photosensitive resin film 50. The light source used in the exposure step, as long as it contains The photosensitive resin, the sensitivity, and the like of the photosensitive resin film may be appropriately selected, and for example, a g-line (wavelength: 436 nm), an h-line (wavelength: 405 nm), or an i-line (wavelength: 365 nm) of a high-pressure mercury lamp can be used. ), semiconductor laser (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser (wavelength: 1064 nm), KrF excimer laser (wavelength: 248 nm), ArF excimer laser (wavelength: 193 nm), F2 Excimer laser (wavelength: 157 nm) and the like. The exposure method may be a method in which the photomask corresponding to the target is used for exposure, or a drawing method. Furthermore, the graph of the purpose has been described, and the intensity Γ(0.02)/Γ(0.01) of the spatial frequency of the one-dimensional power spectrum is respectively a specific preferred range.

In the method for producing a mold, in order to accurately form the surface unevenness of the mold, it is preferable to expose the intended pattern on the photosensitive resin film in a state of precise control. In order to expose in such a state, the image of the object is made into image data on the computer, and the laser light emitted from the laser light controlled by the computer is drawn on the photosensitive resin film according to the image of the image data (Ray Shooting is better. For laser drawing, a general-purpose laser drawing device such as a printing plate can be used. As a commercial item of such a laser drawing device, for example, Laser Stream FX (manufactured by Think Laboratory) or the like.

Fig. 7(c) is a view schematically showing a state in which the pattern on the photosensitive resin film 50 is exposed. When the photosensitive resin film 50 contains a negative photosensitive resin (for example, when a negative photoresist is used as a photosensitive resin solution), the exposed region 51 receives the energy of exposure and performs a crosslinking reaction of the photosensitive resin, and development is described later. The solubility of the liquid is lowered. Thus, in the development step, it is not exposed The light region 52 is dissolved by the developer, and only the exposed region 51 remains on the surface of the substrate to become the mask 60. On the other hand, when the photosensitive resin film 50 contains a positive photosensitive resin (for example, when a positive photoresist is used as the photosensitive resin solution), exposure energy is received in the exposed region 51, and the bonding of the photosensitive resin is cut off. This is easily dissolved in a developing solution to be described later. Therefore, the region 51 exposed in the developing step is dissolved by the developer, and only the unexposed region 52 remains on the surface of the substrate to become the mask 60.

[5] Development step

In the development step, 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 substrate for a mold to form the mask 60. On the other hand, when the photosensitive resin film 50 contains a positive photosensitive resin, only the exposed region 51 is dissolved by the developer, and the unexposed region 52 remains on the substrate for the mold to form the mask 60. The predetermined pattern is formed into a base material for a mold of a photosensitive resin film, and the photosensitive resin film remaining on the substrate for a mold in the etching step acts as a mask in an etching step to be described later.

The developer used in the development step can be selected from conventional ones according to the type of photosensitive resin to be used. For example, the developer is an inorganic base such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate or ammonia; a primary amine such as ethylamine or n-propylamine; and diethylamine. Diamines such as di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcoholamines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxide and hydroxide a tetra-ammonium compound such as tetraethylammonium or trimethylhydroxyethylammonium hydroxide; a cyclic amine such as pyrrole or piperidine; An alkaline aqueous solution, an organic solvent such as xylene or toluene, or the like.

The developing method in the developing step is not particularly limited, and immersion development, spray development, brush development, ultrasonic development, or the like can be used.

In Fig. 7(d), a state in which a negative type is used as a photosensitive resin and a development step is performed is schematically shown. In Fig. 7(d), the unexposed region 52 is dissolved by the developer, and only the exposed region 51 remains on the surface of the substrate, and the photosensitive resin film in this region serves as the mask 60. Fig. 7(e) is a view schematically showing a state in which a positive type is used as a photosensitive resin and a development step is performed. In Fig. 7(e), the exposed region 51 is dissolved by the developer, and only the unexposed region 52 remains on the surface of the substrate, and the photosensitive resin film in this region serves as the mask 60.

[6] etching step

The etching step is a step of using a photosensitive resin film remaining on the surface of the substrate for a mold after the development step as a mask, and etching the plating layer mainly in the region without the mask in the surface of the substrate for the mold. .

Fig. 8 is a view schematically showing a preferred example of the latter half of the method of manufacturing the mold. In Fig. 8(a), the etching step is mainly used to schematically show the state in which the plating layer of the region without the mask is etched. The plating layer on the lower portion of the mask 60 is not etched by the photosensitive resin film acting as the mask 60, but etching is performed while etching from the region 45 where no mask is present. Therefore, in the vicinity of the region having the mask 60 and the boundary without the mask region 45, the plating layer on the lower portion of the mask 60 is also etched. Thus, in the vicinity of the region having the mask 60 and the boundary without the mask region 45, the plating layer on the lower portion of the mask 60 is also etched, which is referred to as side etching.

In the etching treatment in the etching step, an etching solution such as a ferric chloride (FeCl ₃ ) solution, a copper chloride (CuCl ₂ ) solution, an alkali etching solution (Cu(NH ₃ ) ₄ Cl ₂ ), or the like, and a substrate for a mold are usually used. The surface is mainly made by etching a plating layer (metal surface) of the region without the mask 60. As the etching treatment, a strong acid such as hydrochloric acid or sulfuric acid may be used as the etching liquid, and when the plating layer is formed by electrolytic plating, etching treatment may be performed by reverse electrolytic etching which gives a potential opposite to that at the time of electrolytic plating. When the etching treatment is performed, the surface of the substrate for a mold has a concave-convex shape, and the type of the constituent material (metal material) or the plating layer of the substrate for the mold, the type of the photosensitive resin film, and the type of etching treatment in the etching step. The difference is not uniform, and when the etching amount is 10 μm or less, the surface of the substrate for the mold which is in contact with the etching liquid is etched in approximately the same direction. The amount of etching referred to herein means the thickness of the plating layer which is etched and removed.

The etching amount in the etching step is preferably from 1 to 12 μm, more preferably from 5 to 8 μm. When the etching amount exceeds 12 μm, the difference in the unevenness of the uneven shape formed on the surface of the mold becomes large. As a result, when the antiglare film is produced using the mold, the ratio of R _SCE /R _SCI may exceed 0.1. Therefore, the etching amount in the etching step is set to 12 μm or less, and it is preferable to manufacture a mold through a procedure described later, and an anti-glare film which can sufficiently prevent whitening can be obtained by using the mold to produce an anti-glare film. On the other hand, when the etching amount is less than 1 μm, the mold has almost no surface unevenness and a mold having almost a flat surface. Therefore, even if an anti-glare film is produced using the mold, such an anti-glare film has almost no surface unevenness. Therefore, an anti-glare film having sufficient anti-glare property cannot be obtained. Further, the etching treatment in the etching step may be performed by one etching treatment or may be performed by etching treatment twice or more. Here, when the etching treatment is carried out in two or more steps, the total etching amount of the etching treatment of two or more times is preferably 1 to 12 μm.

[7] Photosensitive resin film peeling step

Next, the photosensitive resin film peeling step is a step of removing the photosensitive resin film remaining on the substrate for a mold by the etching step, and by this step, the photosensitive residue remaining on the substrate for the mold is completely removed. A resin film is preferred. In the photosensitive resin film peeling step, it is preferred to use a release liquid to dissolve the photosensitive resin film. As the peeling liquid, those who are examples of the developing solution can be used, and the concentration, pH, and the like are changed to prepare them. Alternatively, the developing step may be performed by changing the temperature, the immersion time, or the like by using the same developer as that used in the developing step. In the photosensitive resin film peeling step, the contact method (peeling method) of the peeling liquid and the substrate for a mold is not particularly limited, and immersion peeling, spray peeling, brush peeling, ultrasonic peeling, or the like can be used.

(b) of FIG. 8 is a view schematically showing a state in which the photosensitive resin film used in the mask 60 is removed by the photosensitive resin film peeling step. The first surface uneven shape 46 is formed on the surface of the substrate for a mold by the mask 60 obtained by the photosensitive resin film and the etching treatment.

[8] 2nd plating step

The final stage of the mold production is a second plating step of performing plating (preferably chrome plating described later) on the surface of the substrate for a mold which has been subjected to the steps [6] and [7]. By performing the second plating step, the surface unevenness shape 46 of the substrate for a mold can be passivated, and the mold table can be protected by the plating. surface. Hereinafter, passivation of the surface uneven shape of the base material for a mold is referred to as "shape passivation". In the eighth embodiment (c), as described above, the chrome plating layer 71 is formed on the first surface uneven shape 46 formed by the etching treatment, and the shape of the surface uneven shape is passivated (the mold uneven surface 70).

The plating layer formed by the second plating step is preferably chrome plated in that it has high gloss, high hardness, and low friction coefficient, and good release property can be obtained. In chrome plating, chrome plating which is called gloss chrome plating, chrome plating for decoration, etc., which exhibits good gloss, is particularly preferable. The chromium plating is usually carried out by electrolysis, but as the plating tank, an aqueous solution containing anhydrous chromic acid (CrO ₃ ) and a small amount of sulfuric acid is used as the plating liquid. The thickness of the chrome plating layer can be controlled by adjusting the current density and the electrolysis time.

The plating of the second plating step in such a manner is preferably performed by chrome plating, and a mold for producing an anti-glare film of the present invention can be obtained. The surface unevenness shape of the surface of the substrate for the mold after the etching treatment can be passivated by chrome plating, and a mold having a high surface hardness can be obtained. The most important factor in controlling the degree of passivation at this time is the thickness of the chrome plating layer. If the thickness is thin, the degree of passivation of the shape becomes insufficient, and the anti-glare film obtained by using such a mold is liable to cause whitening. On the other hand, if the thickness of the chrome plating layer is too thick and the degree of passivation of the shape is too large, the antiglare film obtained by using such a mold tends to have insufficient antiglare property. The inventors of the present invention have found that it is effective to produce a mold in such a manner that the thickness of the chromium plating layer is within a specific range in order to obtain an anti-glare film of an image display device which is excellent in preventing the occurrence of whitening and having excellent anti-glare properties. That is, the thickness of the chrome plating layer is preferably in the range of 10 to 20 μm, more preferably in the range of 12 to 16 μm.

The chrome plating layer formed in the second plating step is preferably formed to have a Vickers hardness of 800 or more, and more preferably 1,000 or more. When the Vickers hardness of the chrome plating layer is less than 800, when the antiglare film is produced using a mold, the durability of the mold tends to be lowered.

The above-described imprint method which is preferable as a method for producing the antiglare film of the present invention will be described below. As described above, the UV imprint method is particularly preferable as the photoimprint method, but the imprint method using the active energy ray-curable resin will be specifically described here.

In order to continuously manufacture the anti-glare film of the present invention, when the anti-glare film of the present invention is produced by photoimprinting, it is preferred to include the following step: [P1] a coating step on a transparent support for continuous conveyance Applying a coating liquid containing an active energy ray-curable resin to form a coating layer; [P2] a curing step of irradiating the transparent support side from the surface of the coating layer while pressing the surface of the coating layer Energy line.

Further, when the antiglare film of the present invention is produced by a photoimprint method, it is more preferable to include a [P3] preliminary hardening step which is applied after the coating step [P1] and before the curing step [P2]. Both ends of the layer in the width direction are irradiated with active energy rays.

Hereinafter, each step will be described in detail with reference to the drawings. Fig. 9 is a schematic view showing a preferred example of a manufacturing apparatus used in the method for producing an anti-glare film of the present invention. The arrow in Fig. 9 indicates the conveying direction of the film or the direction of rotation of the roller.

[P1] coating step

The coating step is applied to the transparent support and coated with active energy ray hardening The coating liquid of the resin forms a coating layer. In the coating step, for example, as shown in FIG. 9, a coating liquid containing an active energy ray-curable resin composition is applied to the transparent support 81 which is continuously discharged from the delivery roller 80.

The application of the coating liquid on the transparent support 81 can be, for example, by gravure coating method, micro gravure coating method, bar coating method, knife coating method, air knife coating method, kiss coating method, slit coating method. Bufa et al.

(transparent support)

The transparent support 81 may be any one that transmits light, and for example, glass, a plastic film, or the like can be used. As the plastic film, it is sufficient as long as it has moderate transparency and mechanical strength. Specifically, any of the transparent supports exemplified as the UV imprint method can be used, and in order to continuously manufacture the anti-glare film of the present invention by photoimprint, it is possible to select moderate flexibility. By.

Various surface treatments can be performed on the surface (coating layer side surface) of the transparent support 81 for the purpose of improving the coating property of the coating liquid and improving the adhesion 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. Further, on the transparent support 81, for example, another layer such as an undercoat layer may be formed, and a coating liquid may be applied to the other layer.

Further, in the antiglare film of the present invention, in order to improve the adhesion between the transparent support and the polarizing film when the polarizing film is formed integrally, the surface of the transparent support (the opposite side to the coating layer) is formed by various surface treatments. The surface) is preferably hydrophilized. This surface treatment can also be carried out after the production of the anti-glare film.

(coating liquid)

The coating liquid contains an active energy ray-curable resin, and usually further contains a photopolymerization initiator (radical polymerization initiator). Various additives such as a solvent such as a light-transmitting fine particle or an organic solvent, a leveling agent, a dispersing agent, an antistatic agent, an antifouling agent, and a surfactant may be contained as needed.

(1) Active energy ray-curable resin

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

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, and butylene glycol. , pentanediol, hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2'-thiodiethanol, 2-hydroxyl of 1,4-cyclohexanedimethanol; An alcohol having 3 or more members of trimethylolpropane, glycerin, neopentyl alcohol, diglycerol, dipentaerythritol or di-trimethylolpropane.

Specific examples of the esterified product of a polyhydric alcohol and (meth)acrylic acid include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and 1,6-hexanediol di( Methyl) acrylate, neopentyl glycol di(a) Acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tetramethylolethanetris(meth)acrylate, 1,6-hexyl Diol (meth) acrylate, tetramethylol methane tetra (meth) acrylate, penta glycerol tri (meth) acrylate, neopentyl alcohol tri (meth) acrylate, neopentyl Alcohol tetra(meth)acrylate, glycerol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol Alcohol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate.

The ethyl urethane (meth) acrylate compound is, for example, an organic isocyanate having a plurality of isocyanate groups in one molecule, and an ethyl carbureate reaction product having a (meth)acrylic acid derivative having a hydroxyl group. Examples of the organic isocyanate having a plurality of isocyanate groups in one molecule include, for example, hexamethylene diisocyanate, isophorone diisocyanate, methylphenyl diisocyanate, naphthyl diisocyanate, and diphenylmethane diisocyanate. An organic isocyanate having two isocyanate groups in one molecule, such as benzoyl diisocyanate or dicyclohexylmethane diisocyanate, which are modified with isocyanurate, modified with an adduct, or reduced. An organic isocyanate having three isocyanate groups in one molecule of diurea modification. As a (meth)acrylic acid derivative having a hydroxyl group, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, (methyl) 2-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, neopentyl alcohol triacrylate.

Preferred as the polyester (meth) acrylate compound is a polyester obtained by reacting a hydroxyl group-containing polyester with (meth)acrylic acid. (Meth) acrylate. The hydroxyl group-containing polyester which is preferably used is a hydroxyl group-containing polyester obtained by esterification of a polyhydric alcohol with a carboxylic acid, a compound having a plurality of carboxyl groups, and/or an anhydride thereof. The polyol is, for example, the same as the above-mentioned compound. Further, in addition to the polyol, the phenol is, for example, bisphenol A or the like. Examples of the carboxylic acid include formic acid, acetic acid, butylcarboxylic acid, and benzoic acid. As a compound having a plurality of carboxyl groups and/or anhydrate thereof, for example, maleic acid, phthalic acid, fumaric acid, methylene succinic acid, adipic acid, terephthalic acid, butene Diacid anhydride, phthalic anhydride, trimellitic acid, cyclohexane dicarboxylic anhydride, and the like.

In the above polyfunctional (meth) acrylate compound, hexanediol di(meth) acrylate or neopentyl glycol diol is preferred from the viewpoint of improvement in strength of the cured product and easiness of obtaining the cured product. Methyl) acrylate, diethylene glycol di(meth) acrylate, tripropylene glycol di(meth) acrylate, trimethylolpropane tri(meth) acrylate, neopentyl alcohol tri(methyl) An ester compound of acrylate, dipentaerythritol hexa(meth)acrylate, or the like; an adduct of hexamethylene diisocyanate and 2-hydroxyethyl (meth)acrylate; isophorone diisocyanate and (A) An adduct of 2-hydroxyethyl acrylate; an adduct of methyl phenyl diisocyanate and 2-hydroxyethyl (meth) acrylate; an adduct modified isophorone diisocyanate and (methyl) An adduct of 2-hydroxyethyl acrylate; and an adduct of a biuret-modified isophorone diisocyanate and 2-hydroxyethyl (meth)acrylate. Further, these polyfunctional (meth) acrylate compounds may be used alone or in combination of two or more.

The active energy ray-curable resin may contain a monofunctional group (methyl) in addition to the above polyfunctional (meth) acrylate compound Acrylate compound. Examples of the monofunctional (meth) acrylate compound include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and isobutyl (meth) acrylate. Base) acrylic acid grade 3 butyl ester, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofuranmethyl (meth)acrylate, Cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, acetyl (meth)acrylate, benzyl (meth)acrylate, (A) 2-ethyl acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxy (meth) acrylate, ethylene oxide Phenyl (meth) acrylate, propylene oxide (meth) acrylate, nonyl phenol (meth) acrylate, ethylene oxide modified (meth) acrylate, propylene oxide modified sulfhydryl Phenol (meth) acrylate, A Diethylene glycol (meth) acrylate, 2-(methyl) propylene methoxyethyl 2-hydroxypropyl phthalate, dimethylaminoethyl (meth) acrylate, (Meth) acrylates such as methoxytriethylene glycol (meth) acrylate. These compounds may be used alone or in combination of two or more.

Further, the active energy ray-curable resin may contain a polymerizable oligomer. The hardness of the cured product can be adjusted by containing a polymerizable oligomer. Polymerizable oligomers such as the aforementioned polyfunctional (meth) acrylate compounds, that is, ester compounds of polyhydric alcohols and (meth)acrylic acid, ethyl urethane (meth) acrylate compounds, polyesters (methyl) An oligomer of a dimer or a trimer of an acrylate compound or an epoxy (meth)acrylate.

As another polymerizable oligomer, for example, a polyisocyanate having at least one isocyanate group in the molecule, and an ethyl urethane (meth)acrylate obtained by reacting with a polyol having at least one (meth) acryloxy group. Ester oligomer. As the polyisocyanate, for example, a polymer of hexamethylene diisocyanate, isophorone diisocyanate, methylphenyl diisocyanate, diphenylmethane diisocyanate or benzoyl diisocyanate, as having at least one ( The polyol having a methyl propylene oxy group is a hydroxyl group-containing (meth) acrylate obtained by an esterification reaction between a polyol and (meth)acrylic acid, and examples of the polyhydric alcohol include 1,3-butanediol. , 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, trimethylolpropane, glycerol, Neopentyl alcohol, dipentaerythritol, and the like. The polyol having at least one (meth) acryloxy group is an esterification reaction of a part of an alcoholic hydroxyl group of a polyol with (meth)acrylic acid, and the alcoholic hydroxyl group remains in the molecule.

Further, examples of the other polymerizable oligomers include, for example, a reaction of a compound having a plurality of carboxyl groups and/or an anhydride thereof with a polyol having at least one (meth)acryloxy group. Polyester (meth) acrylate oligomer. The polyester (meth) acrylate having a plurality of carboxyl groups, for example, the polyester (meth) acrylate of the above polyfunctional (meth) acrylate compound is described in the same manner. Further, the polyol having at least one (meth) acryloxy group, for example, the above-described urethane (meth) acrylate oligomer is described in the same manner.

In addition to the above polymerizable oligomer, further examples of the ethyl urethane (meth) acrylate oligomer include, for example, hydroxy group. A compound obtained by reacting a base polyester, a hydroxyl group-containing polyether or a hydroxyl group-containing (meth) acrylate hydroxyl group with an isocyanate. The hydroxyl group-containing polyester which is preferably used is a hydroxyl group-containing polyester obtained by esterification reaction of a polyhydric alcohol with a carboxylic acid, a compound having a plurality of carboxyl groups, and/or an anhydride thereof. The polyester (meth) acrylate compound of a polyfunctional (meth) acrylate compound is the same as the polyhydric alcohol, the compound which has a multiple carboxy group, and / or its an The hydroxyl group-containing polyether which is preferably used is a hydroxyl group-containing polyether obtained by adding one or two or more kinds of alkylene oxide and/or ε-caprolactone to a polyol. The polyol may be the same as those used in the aforementioned hydroxyl group-containing polyester. The hydroxyl group-containing (meth) acrylate which is preferably used is, for example, the same as the urethane (meth) acrylate of the polymerizable oligomer. The isocyanate is preferably a compound having one or more isocyanate groups in the molecule, and particularly preferably a divalent isocyanate compound such as methylphenyl diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate.

These polymerizable oligomer compounds may be used alone or in combination of two or more.

(2) Photopolymerization initiator

The photopolymerization initiator can be appropriately selected depending on the kind of active energy ray applied to the production of the antiglare film of the present invention. Further, when an electron beam is used as the active energy ray, a coating liquid containing no photopolymerization initiator is used in the production of the antiglare film of the present invention.

As the photopolymerization initiator, for example, an acetophenone-based photopolymerization initiator, a benzoin-based photopolymerization initiator, and a benzophenone-based photopolymer can be used. A initiator, a thioxanthone photopolymerization initiator, a triazine photopolymerization initiator, an oxadiazole photopolymerization initiator, and the like. Further, as the photopolymerization initiator, for example, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide or 2,2'-bis(o-chlorophenyl)-4,4' can also be used. ,5,5'-tetraphenyl-1,2'-bisimidazole, 10-butyl-2-chloroacridone, 2-ethyl fluorene, benzil, 9,10- Philippine (9,10-phenanthrenequinone), camphorquinone, methyl phenylglyoxylate, titanium ferrocene compound, and the like. The amount of the photopolymerization initiator to be used is usually 0.5 to 20 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the active energy ray-curable resin.

The coating liquid may contain a solvent such as an organic solvent in order to improve the coating property to the transparent support. Examples of the organic solvent include aliphatic hydrocarbons such as hexane, cyclohexane, and octane; aromatic hydrocarbons such as toluene and xylene; and alcohols such as ethanol, 1-propanol, isopropanol, 1-butanol, and cyclohexanol. Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; esters such as ethyl acetate, butyl acetate, isobutyl acetate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether , glycol ethers such as diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; esterified glycol ethers such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate; Cellosolve such as oxyethanol, 2-ethoxyethanol, 2-butoxyethanol; 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy) Ketone alcohols such as ethanol and 2-(2-butoxyethoxy)ethanol are used in consideration of viscosity and the like. These solvents may be used singly or in combination of plural kinds as needed. After coating, the above organic solvent must be evaporated. Therefore, the boiling point is desirably in the range of 60 ° C to 160 ° C. And, 20 The saturated vapor pressure at ° C is preferably in the range of 0.1 kPa to 20 kPa.

When the coating liquid contains a solvent, it is preferred to provide a drying step of evaporating and drying the solvent after the coating step and before the first curing step. The drying system is, for example, an example shown in Fig. 9, and the transparent support 81 having the coating layer is passed through the inside of the drying zone 84. The drying temperature is appropriately selected depending on the type of solvent to be used and the transparent support. It is generally in the range of 20 ° C to 120 ° C, but is not limited to this range. Moreover, when there are a plurality of drying furnaces, the temperature of each drying furnace can be changed. The thickness of the coating layer after drying is preferably from 1 to 30 μm.

Thereby, a laminate in which a transparent support and a coating layer are laminated is formed.

[P2] hardening step

This step is performed on the surface of the coating layer, and the coating layer is hardened by irradiating the active energy ray from the side of the transparent support while pressing against the uneven surface (forming surface) of the mold having the desired surface unevenness. The step of forming a hardened resin layer on the transparent support. Thereby, while the coating layer is hardened, the surface uneven shape of the uneven surface of the mold is transferred to the surface of the coating layer. The mold used here is a roller shape, and is a one manufactured by using a roller-shaped mold base material in the mold manufacturing method already described.

In this step, for example, as shown in FIG. 9, for example, preparation for irradiation by the active energy ray irradiation device 86 is performed in the application region 83 (the dry region 84 during drying, when performing the preliminary hardening step to be described later). The layered body having the coating layer in the hardened region is irradiated with active energy rays such as an ultraviolet irradiation device disposed on the side of the transparent support 81 Set 86, by irradiating the active energy line.

First, the roller-shaped mold 87 is held on the surface of the coating layer of the laminated body subjected to the hardening step by using a crimping device such as a grip roller 88, and the active energy ray irradiation device 86 is used in this state from the transparent support. The 81 side illuminates the active energy ray to harden the coating layer 82. Here, the term "curing the coating layer" means an active energy ray-curable resin contained in the coating layer, and receives energy of the active energy ray to cause a curing reaction. The use of the nip roller is effective in preventing air bubbles from being mixed between the coating layer of the laminate and the mold. The active energy ray irradiation device can use one machine or a plurality of machines.

After the active energy ray is irradiated, the laminated system is peeled off from the mold 87 with the nip roller 89 on the outlet side as a fulcrum. The obtained transparent support and the cured coating layer are used as an antiglare layer, and the antiglare film of the present invention can be obtained. The resulting anti-glare film is typically taken up by a film take-up device 90. In the case of protecting the anti-glare layer, a protective film containing polyethylene terephthalate or polyethylene is bonded to the surface of the anti-glare layer while being adhered to the surface of the anti-glare layer. Rolling. Here, although the mold to be used is described as a roller shape, a mold other than the shape of the roller may be used. Further, after being peeled off from the mold, additional active energy ray irradiation can be performed.

The active energy ray 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., depending on the type of active energy ray-curable resin contained in the coating liquid, but Among these, ultraviolet rays and electron beams are preferable, and from the viewpoint of easy handling and high energy, ultraviolet rays are particularly preferable (as described above, As the photoimprint method, a UV imprint method is preferred.

As the light source of the ultraviolet light, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, an electrodeless lamp, a metal halide lamp, a xenon arc lamp, or the like can be used. Further, an ArF excimer laser, a KrF excimer laser, an excimer lamp, or a synchrotron radiation may be used. Among these, it is preferable to use an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, an electrodeless lamp, a xenon arc lamp, a metal halide lamp or the like.

Moreover, as an electron beam, for example, from Cockroft-Waltons type, Van de Graaff type, resonance transformer type, insulated core transformer type, linear type, high frequency An electron beam having an energy of 50 to 1000 keV, preferably 100 to 300 keV, which is released by various electron beam accelerators of a high pressure (Dynamitron) type, a high frequency type or the like.

When the active energy ray is ultraviolet ray, the cumulative amount of UVA of the ultraviolet ray is preferably 100 mJ/cm ² or more and 3,000 mJ/cm ² or less, more preferably 200 mJ/cm ² or more and 2000 mJ/cm ² or less. In addition, since the transparent support absorbs ultraviolet rays on the short-wavelength side, the amount of accumulated UVV (395 to 445 nm) of ultraviolet light in the wavelength region including visible light is preferably adjusted to suppress the absorption. . The light accumulating amount of the UVV is preferably 100 mJ/cm ² or more and 3,000 mJ/cm ² or less, more preferably 200 mJ/cm ² or more and 2000 mJ/cm ² or less. When the amount of accumulated light is less than 100 mJ/cm ² , the hardening of the coating layer is insufficient, the hardness of the obtained antiglare layer is lowered, and the uncured resin adheres to the guide roller or the like, which tends to cause contamination of the step. When the amount of accumulated light exceeds 3000 mJ/cm ² , the heat radiated from the ultraviolet irradiation device may cause shrinkage of the transparent support and wrinkles.

[P3] preliminary hardening step

This step is a step of irradiating the active energy rays at both end portions in the width direction of the transparent support of the coating layer before the hardening step, and preliminarily hardening the both end portions. Figure 10 is a schematic view showing the preliminary hardening step. In Fig. 10, the end portion 82b of the coating layer in the width direction (direction perpendicular to the conveying direction) is a region from the specified width of the end portion including the coating layer.

In the preliminary hardening step, the end region is hardened in advance, and the adhesion to the transparent support 81 is further improved in the end portion, and in the step after the hardening step, a part of the cured resin is prevented from peeling off and the step is made. Infected. The end region 82b is formed, for example, from 5 mm to 50 mm from the end of the coating layer 82.

The end energy region of the coating layer is irradiated with an active energy ray, with reference to FIGS. 9 and 10, for example, a transparent support having a coating layer 82 passing through a coating region 83 (drying region 84 when dried) 81. The active energy ray irradiation device 85 such as an ultraviolet ray irradiation device provided in the vicinity of both end portions on the coating layer 82 side is irradiated with an active energy ray. The active energy ray irradiation device 85 may be provided on the transparent support 81 side as long as it can illuminate the end region 82b of the coating layer 82 with an active energy ray.

The type of the active energy ray and the light source are the same as the present hardening step. When the active energy ray is ultraviolet ray, the cumulative amount of UVA of the ultraviolet ray is preferably 10 mJ/cm ² or more and 400 mJ/cm ² or less, more preferably 50 mJ/cm ² or more and 400 mJ/cm ² or less. By the irradiation of 50 mJ/cm ² or more, the deformation of the present hardening step can be effectively prevented. In addition, when it exceeds 400 mJ/cm ² , the hardening reaction progresses excessively, and the boundary between the hardened portion and the uncured portion may be caused by deformation of the film thickness or deformation of the internal stress to cause peeling of the resin.

[Use of Anti-glare Film of the Present Invention]

The anti-glare film of the present invention obtained as described above is used in an image display device or the like, and is generally used as an identification-side protective film of the identification-side polarizing plate, and is bonded to a polarizing film (that is, disposed on the surface of the image display device). ). Further, as described above, when a polarizing film is used as the transparent support, since the polarizing film-integrated anti-glare film can be obtained, such a polarizing film-integrated anti-glare film can be used in an image display device. The image display device including the anti-glare film of the present invention has sufficient anti-glare property in a wide viewing angle, and can further prevent whitening and glare from occurring.

Example

Hereinafter, the present invention will be described in more detail by way of examples. In the examples, "%" and "parts" indicating the content or the amount used are based on weight unless otherwise specified.

The evaluation method of the mold or the anti-glare film of the following examples is as follows.

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

(power spectrum of the elevation of the surface relief shape)

The elevation of the surface uneven shape of the antiglare layer as the antiglare film of the measurement sample was measured using a three-dimensional microscope PL μ 2300 (manufactured by Sensofar Co., Ltd.). In order to prevent the warpage of the measurement sample, an optically transparent adhesive is used, and the surface opposite to the antiglare layer of the measurement sample is bonded to the glass substrate to provide a measurement. At the time of measurement, the measurement was performed at a magnification of 10 times the object lens. The horizontal resolution Δx and Δy were both 1.66 μm, and the measurement area was 1270 μm × 950 μm. The data of 512 × 512 (measurement area: 850 μm × 850 μm) was sampled from the center of the obtained measurement data, and the elevation of the surface uneven shape (surface unevenness of the anti-glare layer) of the anti-glare film was determined as a two-dimensional function. h(x, y). Then, the two-dimensional function h(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function H(f _x , f _y ). Calculating the two-dimensional function I(f _x , f _y ) of the two-dimensional power spectrum by squaring the absolute value of the two-dimensional function H(f _x , f _y ), and calculating the power spectrum of one of the functions of the distance f from the origin One-dimensional function I(f). For each sample, the elevation of the surface relief shape at five locations was measured, and the average of the one-dimensional function I(f) of the one-dimensional power spectrum calculated from the data of the samples was used as a one-dimensional function of the dimensional power spectrum of each sample. (f).

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

(haze)

The total haze of the anti-glare film is an optically transparent adhesive for the anti-glare film, and the surface opposite to the anti-glare layer of the measurement sample is bonded to the glass substrate, and the anti-glare film is bonded to the glass substrate. The light was incident from the side of the glass substrate, and the measurement was carried out by using a haze meter "HM-150" manufactured by Murakami Color Research Laboratory according to the method of JIS K7136. Surface haze is the internal haze of the anti-glare film, according to the following formula: surface haze = total haze - internal haze

Calculated by subtracting the internal haze from the total haze. Internal haze is measured The antiglare layer of the measurement sample after the haze was measured by using a glycerin-attached triacetyl cellulose film having a haze of almost 0, and then measuring the same as the total haze.

(penetration clarity)

The penetration clarity of the anti-glare film was measured by the image sharpness measuring device "ICM-1DP" manufactured by Suga Tester Co., Ltd. according to the method of JIS K7105. In this case, in order to prevent warpage of the sample, an optically transparent adhesive was used, and the surface opposite to the antiglare layer of the measurement sample was bonded to the glass substrate, and measurement was performed. In this state, light was incident from the glass substrate side, and measurement was performed. Here, the measured values are five kinds of optical combs each having a width of a dark portion and a bright portion of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, which are the total values of the respective measured values.

(reflection resolution measured at an incident angle of light of 45°)

The reflection sharpness of the anti-glare film was measured by the image sharpness measuring device "ICM-1DP" manufactured by Suga Tester Co., Ltd. according to the method of JIS K7105. At this time, in order to prevent warpage of the sample, an optically transparent adhesive was used, and the surface opposite to the antiglare layer of the measurement sample was bonded to the black acrylic substrate, and measurement was performed. In this state, light was incident at 45° from the side of the anti-glare layer, and measurement was performed. Here, the measured values are four kinds of optical combs having a width of a dark portion and a bright portion of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, and are the total values of the respective measured values.

(reflection resolution measured at an incident angle of light of 60°)

The reflection sharpness of the anti-glare film was measured by the image sharpness measuring device "ICM-1DP" manufactured by Suga Tester Co., Ltd. according to the method of JIS K7105. At this time, in order to prevent warpage of the sample, an optically transparent adhesive is used, The surface on the opposite side to the anti-glare layer of the measurement sample was attached to a black acrylic substrate, and measurement was performed. In this state, light was incident from the side of the anti-glare layer at 60°, and measurement was performed. Here, the measured values are four kinds of optical combs having a width of a dark portion and a bright portion of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, and are the total values of the respective measured values.

(Visual reflectance R _SCI and visual reflectance R _SCE )

The spectroscopic reflectance R _SCI measured by means of specular reflection light and the visual reflectance R _SCE measured by means of not including specular reflection light were measured using a spectrophotometer CM2002 (Konica Minolta Sensing System). . The reflection from the side opposite to the antiglare layer of the measurement sample was removed. In order to prevent warpage of the measurement sample, an optically transparent adhesive was used, and the surface opposite to the antiglare layer of the measurement sample was attached to a black acrylic plate to provide a measurement.

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

(Visual evaluation of mapping and whitening)

In order to prevent reflection from the back surface of the anti-glare film, the anti-glare film is bonded to the black acrylic plate on the surface opposite to the anti-glare layer of the measurement sample, and visually viewed from the side of the anti-glare layer in the room where the fluorescent lamp is lit. Observed, the degree of mapping of the fluorescent lamp and the degree of whitening were visually evaluated. Regarding the map, the degree of mapping when the anti-glare film was observed from the front side and the degree of mapping when viewed from the inclination of 30° were evaluated. The map and the whitening system were evaluated based on the following criteria using three stages of 1 to 3, respectively.

Map 1: no observed mapping

2: Observed a little mapping

3: Obviously observed mapping

Albino 1: no whitening observed

2: A little whitening was observed

3: Obviously observed whitening

(evaluation of glare)

The glare was evaluated by the following procedure. That is, first, a mask having a pattern of cells indicated by a plan view of Fig. 11 is prepared. In the figure, the cell 100 is formed on a transparent substrate to form a chrome-shielding pattern 101 having a key width of 10 μm, and a portion where the chrome-shielding pattern 101 is not formed is the opening 102. Here, since the size of the cell used is 211 μm × 70 μm (vertical × horizontal), the size of the opening is 201 μm × 60 μm (vertical × horizontal). The cells shown in the figure are arranged in a plurality of vertical and horizontal directions to form a photomask.

Then, as shown in the cross-sectional view of Fig. 12, the chrome-shielding pattern 111 of the mask 113 is placed upward, placed in the light box 115, and the anti-glare film 110 is attached to the glass in such a manner that the anti-glare layer becomes a surface. A sample of the plate 117 is placed on the reticle 113. In the light box 115, a light source 116 is disposed. In this state, the sensory evaluation was performed in seven stages from the position 119 at a distance of about 30 cm from the sample by visual observation. Level 1 is a state in which glare is completely unrecognizable, level 7 is a state in which severe glare is observed, and level 4 is a state in which a slight glare is observed.

(comparative evaluation)

The polarizing plates on both sides of the front and back sides were peeled off from a commercially available liquid crystal television ("KDL-32EX550" manufactured by SONY Co., Ltd.). In place of the original polarizing plates, the back side and the surface side are each adhered to a polarizing plate "SUMIKARAN SRDB831E" made by Sumitomo Chemical Co., Ltd. to absorb the axis and The absorption axis of the original polarizing plate was uniform, and the anti-glare film shown in each of the following examples was bonded to the polarizing plate on the display surface side via an adhesive so that the uneven surface became a surface. The liquid crystal television thus obtained was started in a dark room, and the brightness of the black display state and the white display state was measured using a TOPCON (Brightness) brightness meter "BM5A" type, and the contrast was calculated. Here, contrast refers to the ratio of the brightness of the white display state to the brightness of the black display state. As a result, the contrast measured by the anti-glare film in the bonded state was expressed by the ratio of the contrast measured in the state in which the anti-glare film was not attached.

[4] Evaluation of the pattern used in the manufacture of anti-glare film

The created graphic data is set to two-tone binary image data, and the color tone is represented by a two-dimensional discrete function g(x, y). The horizontal resolution Δx and Δy of the discrete function g(x, y) are both 2 μm. The obtained two-dimensional function g(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function G(f _x , f _y ). To square the absolute value of the two-dimensional function G(f _x ,f _y ), calculate the two-dimensional function 二维(f _x ,f _y ) of the two-dimensional power spectrum, and calculate the power spectrum of one of the functions of the distance f from the origin. One-dimensional function Γ(f).

<Example 1>

(Production of mold for manufacturing anti-glare film)

A copper ballard plated person was prepared on the surface of an aluminum roller (JIS A6063) having a diameter of 300 mm. The copper ballard plating layer includes a copper plating layer/a thin silver plating layer/a surface copper plating layer, and the thickness of the entire plating layer is set to be about 200 μm. The copper plating surface is mirror-polished, and a photosensitive resin is applied onto the surface of the copper plating to be polished, and dried to form a photosensitive resin film. Then, the pattern in which the pattern A shown in Fig. 13 is repeatedly arranged is exposed to laser light on the photosensitive resin film to be developed. The exposure and development of the laser light were carried out using Laser Stream FX (manufactured by Think Laboratory). As the photosensitive resin film, those containing a positive photosensitive resin are used. Here, the pattern A is made from a pattern having an irregular luminance distribution, and is formed by a complex Gaussian function type band pass filter, the aperture ratio is 45.0%, and the spatial frequency of the one-dimensional power spectrum is 0.01 μm ^-1 . (0.01) 0.02μm ^-1 of the spatial frequency intensity Γ (0.02) the ratio Γ (0.02) / Γ (0.01 ) was 0.09, the spatial frequency of the intensity Γ 0.01μm ^-1 (0.01) of the spatial frequency 0.1μm ^-1 The ratio Γ(0.1)/Γ(0.01) of the strength Γ(0.1) is 8.13.

Then, etching treatment is performed with a copper chloride solution. The etching amount at this time was set to 6 μm. After the etching treatment, the photosensitive resin film was removed from the roller, and chrome plating was performed to prepare a mold A. At this time, the thickness of the chromium plating was set to 13 μm.

(production of anti-glare film)

Each of the following components was dissolved in ethyl acetate at a solid concentration of 60% to prepare an ultraviolet curable resin composition A which can form a film having a refractive index of 1.53 after curing.

Neopentyl alcohol triacrylate 60 parts

Polyfunctional urethane acrylate 40 parts

(Reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate)

Diphenyl (2,4,6-trimethoxybenzylidene)phosphine oxide 5 parts

The ultraviolet curable resin composition A was applied to a triacetyl cellulose (TAC) film having 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 placed on the mold surface of the previously obtained mold A (surface having the surface uneven shape) by a rubber roller so that the dried coating layer became the mold side, and the film was adhered. In this state, light from a high pressure mercury lamp having a strength of 20 mW/cm ^{2 was} irradiated from the TAC film side so that the amount of converted h-line light became 200 mJ/cm ² , and the coating layer was cured to produce an antiglare film. Then, the obtained antiglare film was peeled off from the mold, and a transparent antiglare film A having an antiglare layer on the TAC film was produced.

<Example 2>

An anti-glare film was produced in the same manner as in Example 1 except that the mold B was replaced with the mold B except that the amount of etching in the etching treatment was changed to 5 μm. This anti-glare film is used as the anti-glare film B.

<Example 3>

An anti-glare film was produced in the same manner as in Example 1 except that the mold C was replaced with the mold C except that the amount of etching in the etching treatment was changed to 7 μm. This anti-glare film is used as the anti-glare film C.

<Comparative Example 1>

An anti-glare film was produced in the same manner as in Example 1 except that the mold D was replaced with the mold D except that the amount of etching in the etching treatment was changed to 9 μm. This anti-glare film is used as the anti-glare film D.

<Comparative Example 2>

A mold E was produced in the same manner as the mold A of Example 1 except that the pattern B shown in Fig. 14 was repeatedly arranged and exposed by laser light on the photosensitive resin film, except that the mold A was replaced by the mold E. An anti-glare film was produced in the same manner as in Example 1 except for the above. This anti-glare film was used as the anti-glare film E. Here, the pattern B is formed from a pattern having an irregular luminance distribution by a complex Gaussian function type band pass filter, the aperture ratio is 45.0%, and the spatial frequency of the one-dimensional power spectrum is 0.01 μm ^-1 . (0.01) 0.02μm ^-1 of the spatial frequency intensity Γ (0.02) the ratio Γ (0.02) / Γ (0.01 ) is 2.69, the spatial frequency of the intensity Γ 0.01μm ^-1 (0.01) of the spatial frequency 0.1μm ^-1 The ratio Γ(0.1)/Γ(0.01) of the strength Γ(0.1) was 278.67.

<Comparative Example 3>

The surface of the 300 mm diameter aluminum roller (JIS A5056) was mirror-polished, and the zirconia beads TZ-SX-17 (Dongcao) were sprayed on the polished aluminum surface using a spray device (manufactured by Fujitsu Fujia Co., Ltd.). (Tosoh) (average particle size: 20 μm) was sprayed at 0.1 MPa (gauge pressure, the same applies hereinafter), and the amount of beads used was 8 g/cm ² (the surface area of the roller was used per 1 cm ² , the same applies hereinafter). Spraying to impart unevenness on the surface of the aluminum roller. The obtained aluminum roller with irregularities was subjected to electroless nickel plating to prepare a mold F. At this time, the thickness of electroless nickel plating was set to 15 μm. An anti-glare film was produced in the same manner as in Example 1 except that the mold A was used instead of the mold A. This anti-glare film is used as the anti-glare film F.

<Comparative Example 4>

Prepared on the surface of a 200 mm diameter aluminum roller (JIS A5056) to perform copper ballard plating. The copper ballard plating layer is composed of a copper plating layer/a thin silver plating layer/a surface copper plating layer, and the entire plating layer has a thickness of about 200 μm. The copper-plated surface was mirror-polished, and on the polished surface, a zirconia bead TZ-SX-17 (made by Tosoh) was used by using a spray device (manufactured by Seiki Co., Ltd.). The average particle diameter: 20 μm) was sprayed at a pressure of 0.05 MPa (gauge pressure, the same applies hereinafter), and the amount of beads used was 6 g/cm ² to impart unevenness on the surface of the aluminum roller. The obtained copper-plated aluminum roller with irregularities was subjected to chromium plating to prepare a mold G. At this time, the thickness of the chromium plating was set to 6 μm. An anti-glare film was produced in the same manner as in Example 1 except that the mold A was used instead of the mold A. This anti-glare film is used as the anti-glare film G.

〔Evaluation results〕

The evaluation results of the above antiglare film are shown in Table 1 in the above examples and comparative examples.

The anti-glare films A to C (Examples 1 to 3) satisfying the requirements of the present invention, although low in haze, have excellent anti-glare properties, sufficient whitening and glare even if the viewing angle is front or oblique. The inhibitory effect. On the other hand, the anti-glare film D (Comparative Example 1) produced whitening. Anti-glare film E (Comparative Example 2), the anti-glare property when viewed from an oblique direction was insufficient. The anti-glare film F (Comparative Example 3) is susceptible to glare. The anti-glare film G (Comparative Example 4) was insufficient in anti-glare property when viewed from an oblique direction.

Industrial availability

The anti-glare film of the present invention can be used for an image display device such as a liquid crystal display.

12 ‧ ‧ integral ball

13‧‧‧Light source

14‧‧‧Density reflectance measurement samples for anti-glare film

15‧‧‧Light trap

Claims (3)

An anti-glare film comprising a transparent support and an anti-glare layer having a fine uneven surface formed thereon; wherein the anti-glare film has a total haze of 0.1% or more and 3% or less; and the surface haze is 0.1% or more and 2% or less; the ratio R _SCE /R _SCI of the visual reflectance R _SCI measured by the specular reflection method and the reflectance R _SCE measured by the method of not including the specular reflection method is 0.1 or less, The power spectrum of the elevation of the surface shape of the concave-convex surface satisfies the conditions of any one of the following (1) to (3): (1) the intensity I (0.01) of the spatial frequency of 0.01 μm ^-1 is 2 μm ⁴ or more and 10 μm ⁴ or less; 2) spatial frequency intensity I (0.02) 0.02μm ^-1 of 0.1μm ⁴ is less than 1.5μm ^4; and, (3) the intensity of the spatial frequency 0.1μm ^-1 I (0.1) 0.0001μm ⁴ is less than 0.01μm ⁴ . The anti-glare film according to claim 1, wherein the penetration is determined by using five optical combs having a dark portion and a bright portion having widths of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. The degree and Tc are 375% or more; four kinds of optical combs having a width of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, are used, and the incident angle of light is 45. The sum of the measured sharpness of the reflection is Rc (45) is 180% or less; the widths of the dark portion and the bright portion are 0.25 mm and 0.5 mm, respectively. Four types of optical combs of 1.0 mm and 2.0 mm have a reflection resolution of Rc (60) of 240% or less as measured by an incident angle of light of 60°. The anti-glare film according to claim 1 or 2, wherein the visual reflectance R _SCE is 0.5% or less.