TW201534991A - Anti-glare film - Google Patents

Abstract

The present invention provides an anti-glare film, which has outstanding anti-glare performance even in a wide view angle and under low fog density, and can appropriately inhibit generation of glare. The present invention provides an anti-glare film, comprising a transparent support and fine surface irregularities formed thereon. The anti-glare film has a total fog density more than or equal to 0.1%, and less than or equal to 3%, a surface fog density more than or equal to 0.1%, and less than or equal to 2%, an average value of tilt angle of the surface irregularities more than or equal to 0.2 DEG, and less than or equal to 1.2 DEG, and a standard deviation of the tilt angle more than or equal to 0.1 DEG, and less than or equal to 0.8 DEG. Intensity ratios of specific two spatial frequencies in a power spectra of complex amplitude, which is calculated from the elevation of the surface irregularities and the refraction index of the anti-glare layer, falls within a specific range respectively.

Description

Anti-glare film

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

Image display devices such as liquid crystal display and plasma display panel, Braun tube (CRT) display, organic electroluminescence (EL) display, etc., are designed to prevent external light from being reflected on its display surface. Deterioration, an anti-glare film is disposed on the display surface.

As for the anti-glare film, a transparent film having a surface uneven shape is mainly reviewed. The anti-glare film reduces the reflection to reflect the anti-glare property by scattering the external light by the surface uneven shape (the external light scatters light). However, when the external light scatters light strongly, the display surface of the image display device may be whitish or the display may become turbid, that is, a so-called "whitening" occurs. Further, the pixels of the image display device interfere with the surface unevenness of the anti-glare film, and a luminance distribution is generated to make it difficult to see, that is, so-called "glare" occurs. From the above, it is expected that the anti-glare film ensures excellent anti-glare properties and sufficiently prevents the occurrence of "whitening" or "glare".

In the anti-glare film, for example, Patent Document 1 discloses an anti-glare film which is not disposed when placed on a high-definition image display device. An anti-glare film which is glare-free and sufficiently prevents the occurrence of whitening, has a fine surface uneven shape formed on a transparent substrate, and an average length PSm in an arbitrary cross-sectional curve of the surface uneven shape is 12 μm or less. The ratio of the arithmetic mean height Pa to the average length PSm, Pa/PSm, is 0.005 or more and 0.012 or less, and the surface unevenness is a ratio of a surface having an inclination angle of 2° or less of 50% or less and a ratio of the inclination angle of 6° or less. More than 90%.

The anti-glare film disclosed in Patent Document 1 can effectively suppress the glare by eliminating the surface unevenness having a period of about 50 μm which is likely to cause glare, by making the average length PSm in any cross-sectional curve extremely small. However, if the anti-glare film disclosed in Patent Document 1 is intended to have a smaller haze (if it is desired to have a low haze), the anti-glare may be observed when the display surface of the image display device in which the anti-glare film is disposed is obliquely observed. Sex will decrease. Therefore, the anti-glare film disclosed in Patent Document 1 still needs to be improved in terms of the anti-glare property of the observation angle.

[Previous 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 wide viewing angle even when it has a low haze, and can sufficiently suppress the occurrence of whitening and glare when disposed in an image display device.

The present inventors conducted an in-depth review to solve the above problems, and as a result, completed the present invention. That is, the present invention is as follows: an anti-glare film comprising a transparent support and an anti-glare layer having a fine surface uneven shape formed thereon, characterized in that the total haze is 0.1% or more 3% or less, the surface haze is 0.1% or more and 2% or less, and the average value of the inclination angle of the surface uneven shape of the antiglare layer is 0.2° or more and 1.2° or less, and the standard deviation of the inclination angle is 0.1° or more and 0.8°. Hereinafter, the power spectrum of the complex amplitude obtained by the power spectrum calculation method described below satisfies all of the following conditions (1) to (3).

Space (1) the spatial frequency power spectrum of the intensity of H 0.002μm ^-1 (0.002), the frequency and intensity of the power spectrum of the H 0.01μm ^-1 (0.01) ratio H (0.01) / H (0.002 ) 0.6 0.02 (2) The ratio of the spatial frequency of the power spectrum of 0.002 μm ^{-1 to} the intensity H (0.002) and the power spectrum of the spatial frequency of 0.02 μm ^{-1 to} the intensity H (0.02) H (0.02) / H (0.002) is 0.005 less than 0.05; and (3) the spatial frequency power spectrum of the intensity of H (0.002) 0.002μm ^-1, the frequency and intensity of the spatial power spectrum of the H 0.04μm ^-1 (0.04) ratio H (0.04) / H (0.002 ) is 0.0005 or more and 0.01 or less; <Power spectrum calculation method> (A) The average surface of the virtual plane is determined from the average of the elevation of the surface uneven shape; (B) The lowest elevation surface and the highest elevation surface are determined, and the lowest elevation surface is a virtual plane including a point at which the elevation of the surface unevenness shape is lowest and parallel to the average surface, the highest elevation surface including a point at which the elevation of the surface relief shape is highest and parallel to a virtual plane of the average surface; (C) a plane perpendicular to the main normal direction of the aforementioned lowest elevation surface and emitting a wavelength of 550 nm from the highest elevation surface , Of obtaining the complex time-varying amplitude of the power spectrum of the complex variable amplitude calculated from the highest elevation of the surface of the uneven surface shape of the refractive index and the elevation of the antiglare layer.

Further, in the anti-glare film of the present invention, it is preferable to use the penetration clarity measured by five types of 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. And Tc is 375% or more, and the sum of the reflection sharpness measured by the light incident angle of 45° is used for the four optical combs of the dark portion and the bright portion of the widths of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. ) is 180% or less, and the sum of the reflection intelligibility measured by the light incident angle of 60° using four kinds of optical combs of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm in the dark portion and the bright portion, respectively, Rc (60) It is 240% or less.

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

1‧‧‧Anti-glare film

2‧‧‧ bump

3‧‧‧film projection surface

5‧‧‧Main normal direction

6‧‧‧Average normal vector

6a, 6b, 6c, 6d‧‧‧ normal vector

40‧‧‧Mold base for mold

41‧‧‧The surface of the substrate for the mold after the first plating step and the grinding step (plating layer)

46‧‧‧First surface relief shape formed by the first etching process

47‧‧‧Shape-shaped surface relief shape through the second etching process

50‧‧‧Photosensitive resin film

60‧‧‧ mask

70‧‧‧ Surface embossed surface after chrome plating

71‧‧‧chrome plating

80‧‧‧Send rolls

81‧‧‧ Transparent support

83‧‧‧ Coating area

86‧‧‧Active energy line irradiation device

87‧‧‧Roll mold

88, 89‧‧‧ pinch roller

90‧‧‧film rewinding device

103‧‧‧ Lowest elevation surface

104‧‧‧highest elevation

Fig. 1 is a schematic view for explaining the inclination angle of the surface uneven shape of the anti-glare film.

Fig. 2 is a schematic view for explaining a method of measuring the inclination angle of the surface uneven shape of the antiglare film.

Fig. 3 is a view for simply explaining the elevation of the surface uneven shape of the anti-glare film.

Fig. 4 is a view for simply explaining the relationship between the elevation (x, y) of the surface unevenness of the anti-glare film, the reference surface of the elevation, and the highest elevation surface.

Fig. 5 is a view showing a state in which the elevation of the surface uneven shape of the anti-glare film can be obtained discretely.

Fig. 6 is a view showing a state in which a one-dimensional power spectrum is calculated from a two-dimensional power spectrum of a complex variable amplitude calculated from an elevation of a surface uneven shape obtained as a discrete function.

Fig. 7 is a graph showing the one-dimensional power spectrum H(f) of the complex amplitude calculated from the elevation of the surface uneven shape of the anti-glare film for the spatial frequency f.

Fig. 8 (a) to (e) are schematic views showing a preferred example of the method of manufacturing the mold (first half).

Fig. 9 (a) to (d) are schematic views showing a preferred example of the method of manufacturing the mold (the latter half).

Fig. 10 is a view showing a preferred example of a manufacturing apparatus which can be used in the method for producing an anti-glare film of the present invention.

Fig. 11 is a schematic view showing a suitable preliminary hardening step in the method for producing an antiglare film of the present invention.

Figure 12 is a schematic diagram of a unit cell for glare evaluation.

Figure 13 is a schematic diagram of a glare evaluation device.

Fig. 14 is a view showing a part of the pattern A used in the first to third embodiments.

Fig. 15 is a view showing a part of the pattern B used in the fourth embodiment.

Fig. 16 is a view showing a part of the pattern C used in the fifth embodiment.

Fig. 17 is a view showing a part of the pattern D used in Comparative Example 2.

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

The anti-glare film of the present invention is characterized in that the average value of the inclination angle of the surface uneven shape is 0.2° or more and 1.2° or less, and the standard deviation of the inclination angle is 0.1° or more and 0.8° or less, which is obtained by the power spectrum calculation method. complex amplitude of the spatial power spectrum of the frequency intensity 0.002μm ^-1, and the spatial frequency of 0.01μm ^-1, 0.02μm ^-1, and the ratio of the intensity of the respectively 0.04μm ^-1 range.

First, regarding the anti-glare film of the present invention, a method for determining the average value and standard deviation of the tilt angle and the power spectrum of the complex amplitude will be described.

[Average and standard deviation of the tilt angle]

Explain how to find the average and standard deviation of the tilt angle.

The present inventors have found that the surface unevenness shape of the anti-glare film is expressed as a specific oblique angle distribution, and is extremely effective for obtaining an image display device which has excellent anti-glare performance and can effectively prevent whitening. That is, the average value of the inclination angle of the surface uneven shape of the anti-glare film of the present invention The deviation of the inclination angle is 0.1° or more and 0.8° or less from 0.2° to 1.2°. When the average value of the inclination angle is less than 0.2, the unevenness of the surface uneven shape is a slightly flat surface, and there is a possibility that sufficient antiglare performance cannot be exhibited. When the average value of the inclination angle of the surface uneven shape is higher than 1.2°, the inclination angle thereof becomes steep, and the light from the surroundings is easily collected, so that the image display device having such an anti-glare film is liable to be whitened. Further, when the standard deviation of the inclination angle is less than 0.1, the surface unevenness shape becomes uniform, and sufficient antiglare performance may not be exhibited. When the standard deviation of the inclination angle is higher than 0.8°, even if the average value is within a specific range, the image display device having such an anti-glare film is liable to be whitened in a region where the surface unevenness shape has a sharp inclination angle.

The "inclination angle of the surface uneven shape" as used in the present invention means an arbitrary point P on the surface of the anti-glare film 1 shown in Fig. 1, and an angle formed by the local normal 6 to the main normal direction 5 of the film. . The angle 构成 formed by the local normal 6 reflects the influence of the unevenness of the point P. The inclination angle of the surface uneven shape can be obtained from the three-dimensional information of the measured surface shape by a device such as a confocal microscope, an interference microscope, or an atomic force microscope (AFM).

Fig. 2 is a schematic view for explaining a method of measuring the inclination angle of the surface uneven shape. Specifically, as shown in FIG. 2, the eye point A on the virtual plane FGHI indicated by the dotted line is determined, and the point of the eye point A on the x-axis passing through the point is determined. A is roughly symmetrical to take points B and D, and in the vicinity of the point of view A on the y-axis passing through point A, points C and E are taken in a manner that is substantially symmetrical with respect to point A, and point B is determined. , C, D, E corresponding to the film surface Points Q, R, S, T. Further, in Fig. 2, (x, y) indicates the orthogonal coordinates in the plane of the film, and z indicates the coordinates in the thickness direction of the film. The plane FGHI is a line parallel to the y-axis passing through a line parallel to the x-axis passing through a point C on the y-axis and passing through a point E on the y-axis, parallel to the x-axis, passing through a point B on the x-axis. And the surface formed by the respective intersections F, G, H, and I of the straight line parallel to the y-axis of the point D on the x-axis. Further, in Fig. 2, the position of the actual film surface is drawn upward with respect to the plane FGHI. However, in accordance with the position of the eye point A, of course, the position of the actual film surface may come. Above the plane FGHI, there will be a situation below.

Then, the inclination angle of the obtained surface shape data (surface shape data of the surface uneven shape) can be obtained by: a point P corresponding to the actual film surface corresponding to the point A of the eye point, corresponding to the vicinity of the point B The polygon 4 planes of the total of Q, R, S, and T on the actual film surface of C, D, and E are 5 points, that is, the normal vectors of the four triangles PQR, PRS, PST, and PTQ are obtained. 6a, 6b, 6c, and 6d are obtained by averaging the polar angles of the average normal vectors 6 obtained. After obtaining the inclination angle for each measurement point in this manner, the average value and the standard deviation of the inclination angle are calculated.

In order to set the average value of the inclination angle of the surface uneven shape to 0.2° or more and 1.2° or less, the standard deviation of the inclination angle is set to 0.1° or more and 0.8° or less: if the resin solution in which the fine particles are dispersed is applied to the transparent support In the method of exposing the fine particles to the surface of the coating film to form random irregularities on the transparent support, the particle size and dispersion state of the fine particles are adjusted. The film thickness of the coating film may be sufficient. Generally, when the particle diameter of the fine particles is constant, the average value of the inclination angle is lowered by increasing the film thickness of the coating film. Further, the dispersed state of the fine particles is good, and even if the fine particles are more uniformly disposed on the transparent support, the standard deviation of the inclination angle is smaller.

Further, in a preferred method for obtaining an anti-glare film of the present invention to be described later, an anti-glare film which satisfies the requirements of the present invention can be obtained by adjusting the etching amount in the second etching step. By increasing the amount of etching in the second etching step, the average value and standard deviation of the tilt angle can be reduced.

[Power spectrum of complex amplitude]

A power spectrum relating to the complex amplitude calculated from the elevation of the surface of the anti-glare film and the refractive index of the anti-glare layer. Fig. 3 is a cross-sectional view schematically showing an anti-glare film of the present invention. As shown in FIG. 3, the one-sided 様 (anti-glare film 1) of the anti-glare film 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 on the transparent support. The opposite side of the 101 has a surface uneven shape of the fine unevenness 2.

Here, the "elevation of the surface unevenness shape" in the present invention means the main normal direction 5 of the anti-glare film of the present invention at any point P on the surface uneven shape and the lowest elevation surface (the normal direction of the aforementioned lowest elevation surface) The straight line distance. The height of any point on the lowest elevation plane determined virtually is 0 μm, and is the reference for determining the elevation of an arbitrary point on the surface uneven shape, and is represented by the lowest elevation surface 103 in FIG.

Actually, as schematically shown in Fig. 1, the anti-glare film is provided with an anti-glare layer having a fine surface uneven shape on a two-dimensional plane. Therefore, as shown in Fig. 1, the elevation of the surface uneven shape is represented by (x, y) The in-plane orthogonal coordinates can be expressed as a two-dimensional function h(x, y) of the coordinates (x, y).

The elevation of the surface concavo-convex shape can be obtained by three-dimensional information on the surface shape measured by a device such as a conjugate focal microscope, an interference microscope, or an atomic force microscope (AFM). The horizontal resolution required for the measuring machine is preferably 5 μm or less, more preferably 2 μm or less, and the vertical resolution required for the measuring machine is preferably 0.1 μm or less, more preferably 0.01 μm or less. The non-contact three-dimensional surface shape/coarseness measuring machine suitable for the measurement includes a New View 5000 series (manufactured by Zygo Corporation), a three-dimensional microscope PL μ 2300 (manufactured by Sensofar Co., Ltd.), and the like. The resolution of the power spectrum for measuring the area height is required to be 0.002 μm ^-1 or less, so it is preferably at least 500 μm × 500 μm, more preferably 750 μm × 750 μm or more.

Figure 4 is a schematic representation of the elevation h(x, y) of the surface relief shape, and the lowest elevation surface 103 and The relationship between the highest elevation surface 104. Here, the elevation of the highest elevation surface 104 is set to h _max (μm). In addition, this fourth figure shows the structure which consists of the point which has the highest elevation of this anti-glare film, and the point of the point with the lowest elevation.

The optical path length d(x, y) between the lowest elevation surface 103 of the coordinate (x, y) and the highest elevation surface 104 can be expressed by the equation (1) using the two-dimensional function h(x, y) of the elevation. .

[Number 1] d ( x , y ) = n _AG h ( x , y ) + n _air [ h _max - h ( x , y )] (1)

Here, n _AG is the refractive index of the antiglare layer, and n _air is the refractive index of air. Further, if the refractive index n _{air of air is} approximately 1, the formula (1) can be expressed as in the formula (2).

[Number 2] d ( x , y )=( n _AG -1) h ( x , y )+ h _max (2)

Next, a plane wave of a single wavelength λ propagating in the main normal direction 5 (perpendicular to the main normal direction of the lowest elevation surface) is incident from the transparent support side (the lowest elevation surface 103 side) toward the anti-glare layer side ( The amplitude of the complex wave of the plane wave when the highest elevation surface 104 side is emitted will be described. The complex amplitude refers to the portion of the factor that does not contain time when the amplitude of the fluctuation is expressed in a complex number. The amplitude of a plane wave of a single wavelength λ can generally be expressed in plural according to the following formula (3).

Here, in the formula (3), A is the maximum amplitude of the plane wave, π is the pi, i is the imaginary unit, and z is the coordinate of the z-axis direction (the main normal direction 5) (the optical path length from the origin), ω is the angular frequency, t is the time, and φ ₀ is the initial phase.

The term that does not depend on time in equation (3) is the complex amplitude. Therefore, the complex amplitude ψ(x, y) in the coordinates (x, y) of the highest elevation surface 104 of the plane wave expressed by the equation (3) is in the term which does not depend on the time of the equation (3). It can be expressed by the equation (4) below the optical path length d (x, y).

Furthermore, since the maximum amplitude A of the plane wave and the initial phase φ ₀ in the equation (4) do not depend on the coordinates (x, y), the distribution of the uneven shape on the surface of the coordinate (x, y) is to be applied. The predetermined value in the present invention is constant, so the following is assumed to be A=1 and φ ₀ =0. Further, when the above formula (2) is substituted, the complex amplitude ψ(x, y) can be expressed by the following formula (5). Further, in the present invention, λ = 550 nm is used as a reference.

Next, a method for obtaining a power spectrum of a complex variable amplitude will be described. First, the two-dimensional function Ψ(f _x , f _y ) is obtained from the two-dimensional function ψ(x, y) expressed by the equation (5) by the two-dimensional Fourier transform defined by the equation (6).

Here, f _x and f _y are frequencies in the x direction and the y direction, respectively, and have a reciprocal dimension of length. Can be squared absolute values obtained by the two-dimensional function of Ψ (f _x, f _y), the two-dimensional power spectrum is obtained H (f _x, f _y) by the formula (7).

[ _Equation 7] H ( f _x , f _y )=|Ψ( f _x , f _y )| ² (1)

The two-dimensional power spectrum H(f _x , f _y ) represents a spatial frequency distribution of the complex amplitude calculated from the elevation of the surface uneven shape of the anti-glare film. Since the anti-glare film is isotropic, the two-dimensional function H(f _x , f _y ) representing the two-dimensional power spectrum of the complex amplitude can be used only in one dimension of the distance f from the origin (0, 0). The function H(f) is used to represent. Next, a method of obtaining a one-dimensional function H(f) from the two-dimensional function H(f _x , f _y ) is disclosed. First, the two-dimensional function H(f _x , f _y ) of the two-dimensional power spectrum of the complex amplitude is expressed by a polar coordinate according to the equation (8).

[ _Equation 8] H ( f _x , f _y )= H ( f cos θ, f sin θ)... (8)

Here, the angle in the θ-system Fourier space. The one-dimensional function H(f) can be obtained by calculating the rotation average of the two-dimensional function H (fcos θ, fsin θ) expressed by the polar coordinates according to the equation (9). One dimensional function H(f) is obtained from the rotational average of the two-dimensional function H(f _x , f _y ) of the two-dimensional power spectrum of the complex variable amplitude, hereinafter also referred to as the one-dimensional power spectrum H(f).

The anti-glare film of the present invention is characterized in that the spatial frequency of the one-dimensional power spectrum H(f) of the complex amplitude calculated from the elevation of the surface concavo-convex shape is the intensity H (0.002) in the 0.002 μm ^-1 and the spatial frequency of 0.01 μm. Ratio of intensity H (0.01) in ^-1 to H (0.01) / H (0.002), intensity H (0.002) and ratio of intensity H (0.02) in spatial frequency 0.02 μm ^-1 H (0.02) / H (0.002 Any one of the ratio H (0.04) / H (0.002) of the intensity H (0.002) and the intensity H (0.04) in the spatial frequency of 0.04 μm ^-1 is within the aforementioned specific range.

Hereinafter, a method of obtaining a two-dimensional power spectrum of a complex amplitude calculated from the elevation of the surface uneven shape of the anti-glare film will be further specifically described. By the above conjugated focus microscope, interference microscope, atomic force microscopy The three-dimensional information of the surface shape actually measured by a mirror or the like is generally a discrete value, that is, an elevation corresponding to a plurality of measurement points is obtained. Fig. 5 is a view showing a state in which the discreteness is obtained as a function of the function h(x, y) indicating the elevation. As shown in Fig. 5, the orthogonal coordinates in the plane of the film are indicated by (x, y), and on the film projection surface 3, the line divided by Δx in the x-axis direction is indicated by a broken line and at y. In the actual measurement, the elevation of the surface unevenness is obtained as the discrete elevation value of each area Δx × Δy divided by the broken lines on the film projection surface 3 in the actual measurement. .

The number of the obtained elevation values is determined by the measurement range and Δx and Δy. As shown in Fig. 5, the measurement range in the x-axis direction is X=MΔx, and the measurement range in the y-axis direction is taken as Y. When =NΔy, the number of the obtained elevation values is M×N.

As shown in Fig. 5, the coordinates of the eye point A on the film projection surface 3 are (m Δx, n Δy) [here, m is 0 or more and M-1 or less, and n is 0 or more and N. When -1 or less, 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 depend on the horizontal resolution of the measuring device, and in order to evaluate the surface unevenness with good precision, it is preferable that both Δx and Δy are 5 μm or less, and more preferably 2 μm or less. Further, the measurement ranges X and Y are preferably 500 μm or more, and more preferably 750 μm or more, as described above.

In such an actual measurement, the function indicating the elevation of the surface concavo-convex shape is obtained as a discrete function h(x, y) having M × N values. Therefore, according to the two-dimensional function h(x, y) of the surface concavo-convex shape, the complex amplitude ψ(x, y) obtained by the equation (5) can be obtained by the pattern of the discrete function, whereby the amplitude ψ( The two-dimensional function Ψ(f _x , f _y ) obtained by the two-dimensional Fourier transform of _x , _y ) is also obtained by the discrete Fourier transform which is discretely calculated by the equation (6) in the manner of the formula (10) The type of discrete function is obtained.

Here, j in the formula (10) 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. Further, Δf _x and Δf _y are frequency intervals in the x direction and the y direction, respectively, and are defined by the equations (11) and (12).

The two-dimensional power spectrum H(f _x , f _y ) is obtained by the square of the absolute value of the discrete function Ψ(f _x , f _y ) obtained by the equation (10), as shown in the equation (13). .

The two-dimensional power spectrum H(f _x , f _y ) obtained as a discrete function also represents the spatial frequency distribution of the complex variable amplitude calculated from the elevation of the surface uneven shape of the anti-glare film. Moreover, since the anti-glare film is isotropic, the two-dimensional discrete function H(f _x , f _y ) representing the two-dimensional power spectrum of the complex amplitude may also depend only on the distance f to the origin (0, 0). The one-dimensional discrete function H(f) is used to represent. When the one-dimensional discrete function H(f) is obtained from the two-dimensional discrete function H(f _x , f _y ), the rotation average may be calculated in the same manner as in the equation (9). The discrete rotation average of the two-dimensional discrete function H(f _x , f _y ) can be calculated by equation (14). The power function calculation method calculates a one-dimensional power spectrum represented by the one-dimensional discrete function H(f).

Here, in the case of 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, Δf is the interval between the distances to the origin and is set to Δf = (Δf _x + Δf _y )/2. Further, Θ(x) is a Heaviside function defined by the formula (15), and the distance from the origin of the f _jk system (j, k) is calculated by the equation (16).

The calculation shown in the equation (14) will be explained with reference to Fig. 6. The function Θ (f _jk -(1-1/2) Δf) is 0 when f _{jk is} less than (1-1/2) Δf, and is 1 when (1-1/2) Δf or more. Θ(f _jk -(1+1/2)Δf) is 0 when f _{jk is} less than (1+1/2) Δf, and is 1 when (1+1/2) Δf or more, therefore, Θ(f _jk -(1-1/2)Δf)-Θ(f _jk -(1+1/2)Δf) of the formula (14) is (1-1/2)Δf only at f _jk When it is less than (1-1/2) Δf, it becomes 1 and it becomes 0 in other cases. Here, in the frequency space, f _jk is the distance to the origin O (f _x =0, f _y =0), and therefore, the denominator of the equation (14) calculates the distance f _jk to the origin O as ( 1-1/2) The number of points (the black dots in Fig. 6) of Δf or more and less than (1 + 1/2) Δf. Further, the molecular system of the formula (14) calculates H (f) at a point where the distance f _jk to the origin O is (1-1/2) Δf or more and does not reach (1 + 1/2) Δf. The total value of _x , f _y ) (the total value of H(f _x , f _y ) in the black dot in Fig. 6).

In general, the one-dimensional power spectrum obtained by the aforementioned method contains the noise in the measurement. Here, in order to obtain the one-dimensional power spectrum, in order to remove the influence of the noise, it is preferable to measure the elevation of the surface unevenness shape at a plurality of points on the anti-glare film, and to use the elevation of the surface irregularities of the respective surfaces. The average of the one-dimensional power spectrum is taken as the one-dimensional power spectrum H(f). The number of the measurement points of the surface unevenness on the anti-glare film is preferably 3 or more, more preferably 5 or more.

Fig. 7 shows H(f) of the one-dimensional power spectrum of the complex variable amplitude calculated from the elevation of the surface uneven shape thus obtained. The one-dimensional power spectrum H(f) of Fig. 7 is obtained by averaging one-dimensional power spectra obtained from the elevations of the surface irregularities at five different points on the anti-glare film.

The anti-glare film of the present invention is characterized in that the spatial frequency of the one-dimensional power spectrum H(f) of the complex amplitude calculated from the elevation of the surface concavo-convex shape is the intensity H (0.002) in the space of 0.002 μm ^-1 and the space of the power spectrum. The ratio of the intensity H (0.02) of the frequency 0.01 μm ^-1 to H (0.01) / H (0.002) is 0.02 or more and 0.6 or less, and the ratio H of the strength H (0.002) and the spatial frequency of 0.02 μm ^-1 (H) is 0.02 ( 0.02)/H (0.002) is 0.005 or more and 0.05 or less, and the ratio H (0.04) / H (0.002) of the intensity H (0.002) and the intensity H (0.04) of the spatial frequency of 0.04 μm ^-1 is 0.0005 or more and 0.01 or less. Here, since the one-dimensional power spectrum H(f) is obtained as a discrete function, the intensity H(f ₁ ) in the specific spatial frequency f ₁ is obtained as long as it is expressed by the equation (17). Insert and calculate.

In the anti-glare film of the present invention, by setting the intensity ratios in the specific spatial frequencies to a predetermined range, the effects of the haze and the reflectance described later are well protected, and whitening and glare are well prevented. And it shows excellent anti-glare properties. In order to further exhibit this effect, the ratio of H (0.01) / H (0.002) is preferably 0.02 or more and 0.6 or less, and more preferably 0.03 or more and 0.3 or less. Similarly, the ratio of H (0.02) / H (0.002) is preferably 0.005 or more and 0.05 or less, more preferably 0.007 or more and 0.04 or less, and more preferably H (0.04) / H (0.002) is 0.0005 or more and 0.01 or less, and 0.001 or less. Above 0.005 or less is more preferable.

When the ratio H (0.01) / H (0.002) is lower than the above range, it is helpful for the antiglare effect when the antiglare film is observed at an inclination (30° or more) of about 100 μm (corresponding to a spatial frequency of 0.01 μm ^-1 ). The optical variation of the cycle is small, and the anti-glare property is insufficient. When the ratio of H (0.01) / H (0.002) is higher than the above range, the optical fluctuation of the period of about 100 μm is excessively large, the fine unevenness of the anti-glare film is rough, and the haze tends to increase, which is not preferable.

When the ratio H(0.02)/H(0.002) is lower than the above range, the antiglare effect when viewing the antiglare film from the inclination (10° to 30°) is about 50 μm (corresponding to the spatial frequency of 0.02 μm ^-1 ). The optical fluctuation of the cycle is small, and the anti-glare property is insufficient. When the ratio H (0.02) / H (0.002) is higher than the above range, the optical fluctuation of the period of about 50 μm is excessively large, and glare is generated.

When the ratio H (0.04) / H (0.002) is lower than the above range, the antiglare effect when the antiglare film is observed from the front (0° to 10°) is about 25 μm (corresponding to a spatial frequency of 0.04 μm ^{-1 ).} The optical variation of the cycle is small, and the anti-glare property is insufficient. When the ratio H (0.04) / H (0.002) is higher than the above range, scattering due to optical fluctuation of a short period of about 25 μm becomes strong, and whitening is likely to occur.

[Full haze, surface haze]

The anti-glare film of the present invention has a surface haze of 0.1% or more and 2% or less in order to exhibit anti-glare properties and prevent whitening, in the range of 0.1% or more and 3% or less of the total haze of normal incident light. The scope of the. The full haze of the anti-glare film can be measured by the method shown in JIS K7136. An image display device equipped with an anti-glare film having a full haze or a surface haze of less than 0.1% does not exhibit sufficient anti-glare property, which is not preferable. Further, when the total haze is higher than 3% or the surface haze is higher than 2%, the anti-glare film is not preferable because the image display device in which the anti-glare film is disposed becomes whitened. Moreover, the image display device also has a poor condition in which the contrast is insufficient.

The lower the internal haze obtained by subtracting the surface haze from the full haze, the better. An image display device equipped with an anti-glare film having an internal haze of more than 2.5% has a tendency to be lowered in contrast.

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

The antiglare film of the present invention preferably has a Tc of 375% or more as determined by the following measurement conditions. The sum of the penetration sharpness Tc is calculated by separately measuring the image sharpness according to the method of JIS K 7105 and using an optical comb of a predetermined width, and calculating the total. Specifically, five types of optical combs having a width ratio of a dark portion to a bright portion of 1:1 and widths of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are used to measure image sharpness, and the total is obtained as Tc. . When the anti-glare film having a Tc of less than 375% is disposed in a higher-definition image display device, glare sometimes becomes apt to occur. The upper limit of Tc is selected from the range of 500% or less of the maximum value. However, if 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 preferably has a reflection definition Rc (45) measured by incident light having an incident angle of 45° of 180% or less. The reflection sharpness Rc (45) is the same as the above Tc, and is measured by the method according to JIS K 7105. Four types of the optical combs are 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm. The optical comb measures the image sharpness separately, and finds the total as Rc (45). When the Rc (45) is 180% or less, the image display device in which the anti-glare film is disposed is more excellent in anti-glare property when viewed from the front and the oblique direction. The lower limit of Rc (45) is not particularly limited, but in order to be good It is preferable to suppress the occurrence of whitening and glare, for example, 80% or more.

The anti-glare film of the present invention preferably has a reflection definition Rc (60) of 240% or less as measured by incident light having an incident angle of 60°. The reflection sharpness Rc (60) is measured by a method according to JIS K 7105 in the same manner as the reflection sharpness Rc (45) except that the incident angle is changed. When Rc (60) is 240% or less, the image display device in which the anti-glare film is disposed is more excellent in anti-glare property at the time of oblique observation, which is preferable. The lower limit of Rc (60) is not particularly limited, but is preferably 150% or more in order to suppress whitening and glare more satisfactorily.

[Method for manufacturing anti-glare film]

The antiglare film of the present invention is produced, for example, in the following manner. In the first method, a mold for forming a fine unevenness having a surface unevenness shape according to a predetermined pattern is formed, and the shape of the uneven surface of the mold is transferred to the transparent support, and the transparent support having the shape of the uneven surface is transferred. The method of peeling the body from the mold. In the second method, a composition containing fine particles, a resin (binder) 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 make A method of hardening a formed coating film (a coating film containing fine particles). In the second method, the coating film thickness and the fine particle agglomerated state 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, and random formation is formed on the transparent support. Bump. From the viewpoint of production stability and production reproducibility of the antiglare film, it is preferred to produce the antiglare film of the present invention by the first method.

Here, a preferred first method as a method for producing an anti-glare film of the present invention will be described in detail.

In order to form the antiglare layer having the surface unevenness shape having the above-described characteristics with good precision, it is important to prepare a fine unevenness forming mold (hereinafter sometimes simply referred to as "mold"). More specifically, the surface uneven shape of the mold (hereinafter sometimes referred to as "mold uneven surface") is formed according to a predetermined pattern, which is preferably a spatial frequency of a one-dimensional power spectrum of 0.002 μm ^-1 The strength Γ(0.002) and the spatial frequency 0.01μm ^-1 intensity Γ(0.01) ratio Γ(0.01)/Γ(0.002) is 1.5 or more and 6 or less; the spatial frequency is 0.002μm ^-1 strength Γ(0.002) and space frequency intensity Γ (0.02) ratio of 0.02μm ^-1 Γ (0.02) / Γ (0.002 ) of 5 or less than 0.3; spatial frequency intensity of the Γ 0.002μm ^-1 (0.002), and spatial frequency of the intensity Gamma] 0.04μm ^-1 The ratio Γ(0.04)/Γ(0.002) of (0.04) is 3 or more and 13 or less. Here, the "pattern" means image data for forming a surface uneven shape of the antiglare layer of the antiglare film, a mask having a light transmitting portion and a light shielding portion, and the like, and may be simply referred to as a "pattern" hereinafter.

First, a method of determining a pattern for forming the uneven shape of the surface of the antiglare layer of the antiglare film of the present invention will be described.

A method of obtaining a two-dimensional power spectrum of a pattern is disclosed, for example, when the pattern is image data. First, after the image data is converted into binarized image data of 2nd order, the gradation is expressed by a two-dimensional function g(x, y). The obtained two-dimensional function g(x, y) is subjected to Fourier transform in the following equation (18) to calculate a two-dimensional function G(f _x , f _y ), as shown in the following formula (19), The square of the absolute value of the two-dimensional function G(f _x , f _y ) is obtained, and the two-dimensional power spectrum Γ(f _x , f _y ) is obtained. Here, x and y represent orthogonal coordinates within 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 reciprocal dimension of length.

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

[19] Γ( f _x , f _y )=| G ( f _x , f _y )| ² (19)

The two-dimensional power spectrum f(f _x , f _y ) represents the spatial frequency distribution of the pattern. In general, since the antiglare film is required to be isotropic, the pattern for producing an 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 pattern can be expressed only by one dimensional function Γ(f) from the distance f of the origin (0, 0). Next, a method of obtaining a 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 of the gradation of the pattern is expressed as a polar coordinate as in the equation (20).

[Number 20] Γ( f _x , f _y )=Γ( f cos θ, f sin θ)...(20)

Here, the angle in the θ-system Fourier space. The one-dimensional function Γ(f) can be obtained by calculating the rotation average of the two-dimensional function Γ (fcos θ, fsin θ) represented by the polar coordinates in the manner of the equation (21). The one-dimensional function Γ(f) is obtained from the rotational average of the two-dimensional function Γ(f _x , f _y ) of the two-dimensional power spectrum of the gradation of the pattern, hereinafter also referred to as the one-dimensional power spectrum Γ(f).

[Number 21]

In order to obtain a good precision the antiglare film of the present invention, the spatial dimension of one preferred power spectral line frequency 0.002μm intensity pattern Γ (0.002) ^-1 0.01μm in the spatial frequency intensity Γ (0.01) ^-1 of the in ratio Γ (0.02) ratio Γ (0.01) / Γ (0.002 ) of 1.5 or more and 6 or less, the spatial frequency intensity Γ (0.002) in the spatial frequency intensity 0.002μm ^-1 Γ (0.02) of the of 0.02μm ^-1 ratio Γ (0.04) / Γ (0.002 ) /Γ(0.002) is 0.3 or more and 5 or less, in the spatial frequency intensity Gamma] 0.002μm ^-1 (0.002) and the spatial frequency intensity Γ (0.04) of the of 0.04μm ^-1 It is 3 or more and 13 or less.

When the two-dimensional power spectrum of the pattern is obtained, the two-dimensional function g(x, y) of the gradation is usually obtained as a discrete function. At this time, the two-dimensional power spectrum can be calculated by the discrete Fourier transform. One dimensional power spectrum of the pattern is obtained in the same way from the two-dimensional power spectrum of the pattern.

In order to obtain the surface irregular shape as a uniform continuous curved surface, the average value of the two-dimensional function g(x, y) is preferably set to the maximum value of the two-dimensional function g(x, y) and the two-dimensional function g(x). , y) is 30 to 70% of the difference between the minimum values. When the concave-convex surface of the mold is produced by a lithography method, the two-dimensional function g(x, y) is the aperture ratio of the pattern. Regarding the case where the uneven surface of the mold is produced by the lithography method, the aperture ratio of the pattern described herein is defined. The aperture ratio of the photoresist used in the lithography method is a positive photoresist, and means the ratio of the exposed region to the total surface area of the coating film when the image data of the coating film of the positive photoresist is drawn. . On the other hand, the aperture ratio of the photoresist used in the lithography method is a negative photoresist, which means that the coating film of the negative photoresist is drawn. The ratio of the area of the unexposed area to the total surface area of the coated film in the image data. The lithography method is an aperture ratio at the time of exposure, and means a ratio of a light-transmitting portion having a light-transmitting portion and a mask of the light-shielding portion.

The anti-glare film of the present invention can be obtained by comparing the intensity ratio of one-dimensional power spectrum of the pattern to Γ(0.01)/Γ(0.002), Γ(0.02)/Γ(0.002), Γ(0.04)/Γ(0.002). In the above range, a desired mold is produced, and the mold is used to produce the mold by the first method.

In order to produce a pattern having such a power ratio of one-dimensional power spectrum, a pattern made by a random dot (dot) is pre-made, or a random luminance distribution having a random number or a pseudo-number generated by a computer is used to determine the shading. A pattern (preparation pattern) from which components of a specific spatial frequency range are removed. The removal of the components of the specific spatial frequency range may be performed by passing the preliminary pattern 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 predetermined pattern, a mold having a surface unevenness formed by transferring the surface uneven shape formed according to a predetermined pattern onto a concave-convex surface of a transparent support is manufactured. The first method using the mold is an imprint method characterized by forming an antiglare layer on a transparent support.

The imprint method is exemplified by a photoimprint method using a photocurable resin, a thermal imprint method using a thermoplastic resin, or the like. Among them, from the viewpoint of productivity, photolithography 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 layer is pressed while being pressed against the uneven surface of the mold, and the mold is embossed. A method in which the shape of the surface is transferred to the photocurable resin layer. Specifically, the photocurable resin layer formed by applying a photocurable resin to a transparent support is irradiated with light from the transparent support side in a state in which the surface of the mold is adhered to the surface of the mold (this light-based resin can be used as a photocurable resin) In the case of curing, the photocurable resin (photocurable resin contained in the photocurable resin layer) is cured, and then the transparent support on which the cured photocurable resin layer is formed is peeled off from the mold. The anti-glare film obtained by such a manufacturing method has an optical anti-glare layer after curing. 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 (ultraviolet curability is used as the photocurable resin). 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. In the imprint method described above, a transparent support may be used instead of a polarizing film.

The type of the ultraviolet curable resin used in the UV imprint method is not particularly limited, and it can be suitably used from commercially available resins depending on the type of transparent support used and the type of ultraviolet rays used. The ultraviolet curable resin contains a concept of a monomer (polyfunctional monomer), an oligomer, a polymer, and a mixture thereof which are photopolymerized by ultraviolet irradiation. Further, by using a photoinitiator appropriately selected in accordance with the kind of the ultraviolet curable resin, a resin which can be cured even if the wavelength is longer than ultraviolet light can be used. A suitable example of the ultraviolet curable resin and the like will be described later.

For the transparent support used in the UV imprint method, for example, a glass or a plastic film or the like can be used. As far as plastic film is concerned, as long as it has Appropriate transparency and mechanical strength can be used. Specifically, for example, an acetyl cellulose resin such as TAC (triethylene fluorene cellulose); an acrylic resin; a polycarbonate resin; a polyester resin such as polyethylene terephthalate; polyethylene, poly A transparent resin film made of a polyolefin resin such as propylene. 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 difficult to generate glare.

On the other hand, the hot stamping method is a method in which the transparent resin film formed of the thermoplastic resin is heated and softened, and pressed against the uneven surface of the mold 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 optically transparent, and specifically, a transparent resin film which is exemplified by the UV imprint method may be mentioned.

Next, a method of manufacturing a mold for use in an imprint method will be described.

In the method of manufacturing a mold, the molding surface of the mold is capable of transferring the surface uneven shape formed by the predetermined pattern onto the transparent support (an anti-glare layer capable of forming a surface uneven shape formed according to a predetermined pattern) The range of the uneven surface of the mold is not particularly limited, and a lithography method is preferred in order to produce the anti-glare layer having the surface unevenness with good precision and reproducibility. Furthermore, the lithography method preferably includes [1] a first plating step, [2] a first polishing step, [3] a photosensitive resin film forming step, [4] an exposure step, [5] Development step, [6] first etching step, [7] photosensitive resin film peeling step, [8] second etching step, [9] second plating step, and [10] second polishing step.

Fig. 8 is a view schematically showing an example of the first half of the method for manufacturing a mold. Figure 8 is a schematic representation of the mold profile in each step. Hereinafter, each step of the method for producing an anti-glare film producing mold of the present invention will be described in detail with reference to FIG.

[1] 1st 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 applying copper plating to the surface of the substrate for a mold, the adhesion and gloss of chrome plating in the second plating step described later can be improved. Since copper plating has high coating property and strong smoothing action, it can fill a small unevenness, a cavity, or the like of the substrate for a mold to form a flat and shiny surface. Therefore, by applying copper plating to the surface of the substrate for a mold, even if chrome plating is applied in the second plating step described later, it is possible to solve the chrome-plated surface which is thought to be caused by minute irregularities and voids existing in the substrate. Rough. Therefore, even if the surface unevenness shape (fine uneven surface shape) according to the predetermined pattern is formed on the substrate forming surface for the mold, the influence of the surface of the susceptor (substrate for the mold) such as minute irregularities, voids, and cracks can be sufficiently prevented. To the deviation.

For the copper used for the copper plating in the first plating step, a pure copper metal or an alloy containing copper as a main component (copper alloy) may be used. Therefore, the "copper" used in copper plating contains the concept of copper and copper alloy. The copper plating may be electroplating or electroless plating, but the copper plating in the first plating step is preferably electroplating. Furthermore, the preferred plating layer in the first plating step The system may be formed not only by a copper plating layer but also by a copper plating layer and a plating layer made of a metal other than copper.

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

The substrate for the mold is preferably a substrate made of a metal material. Further, from the viewpoint of cost, aluminum, iron, and the like are preferable in terms of the material of the metal material. Further, from the viewpoint of the convenience of handling of the substrate for a mold, it is particularly preferable to use a substrate made of lightweight aluminum as a substrate for a mold. Further, the aluminum or iron described herein does not need a pure metal, and may be an alloy mainly composed of aluminum or iron.

The shape of the substrate for a mold may be an appropriate shape in accordance with the method for producing an anti-glare film of the present invention. Specifically, it may be selected from a flat substrate, a cylindrical substrate, or a cylindrical (roller) substrate. When the antiglare film of the present invention is continuously produced, the mold is preferably in the form of a roll. Such a mold is produced from a substrate for a roll mold.

[2] First grinding step

In the subsequent polishing step, the surface (plating layer) of the substrate for mold for copper plating is applied to the first plating step. In the method for producing a mold for use in the method for producing an anti-glare film of the present invention, it is preferred that the surface of the substrate for a mold is polished to a state close to the mirror surface through the first polishing step. City using a flat substrate or a roll substrate as a substrate for a mold In order to form a desired precision, most of the products are subjected to machining such as cutting and polishing. Therefore, fine processing marks remain on the surface of the substrate for the mold. Therefore, even if a plating (preferably copper plating) layer is formed by the first plating step, the above-described processing marks remain. Moreover, even if the plating in the first plating step is applied, the surface of the substrate for a mold does not necessarily become completely smooth. In other words, in the substrate for a mold having a surface having such a deep processing mark or the like, even if the steps [3] to [10] described later are carried out, the surface unevenness of the surface of the obtained mold may be in accordance with a predetermined pattern. The surface irregularities are different, or may have irregularities due to processing marks or the like. When an anti-glare film is produced using a mold in which the influence of a work mark or the like is left, the optical characteristics such as anti-glare property are not sufficiently exhibited, and there is a concern that an unexpected effect is caused.

The polishing method to be applied in the first polishing step is not particularly limited, and a polishing method according to the shape/characteristic of the substrate for the mold to be polished is selected. Specific examples of the polishing method applicable to the first 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 a super finishing method, a lapping method, a fluid polishing method, and a polishing method can be used. Further, mirror surface cutting can be performed by using a cutting tool in the polishing step so that the surface of the substrate for the mold becomes a mirror surface. The material/shape of the cutting tool at this time may be a hard alloy drill, a CBN drill, a ceramic drill, a diamond drill or the like according to the type of the material (metal material) of the base material for the mold, and is preferably from the viewpoint of processing accuracy. A diamond drill bit is used. The surface roughness after the polishing is expressed by the center line average roughness Ra according to JIS B 0601, 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 greater than 0.1 In the case of μm, there is a possibility that the surface roughness is left 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 may be defined in terms of the processing time (polishing time) and the processing cost in the first polishing step.

[3] Photosensitive resin film forming step

Next, a photosensitive resin film forming step will be described with reference to Fig. 8 .

In the photosensitive resin film forming step, a solution (photosensitive resin solution) obtained by dissolving a photosensitive resin in a solvent is applied to a substrate 40 for a mirror which has been subjected to mirror polishing obtained by the first polishing step. The surface 41 is further heated/dried to form a photosensitive resin film (photoresist film). In the eighth embodiment, a state in which the photosensitive resin film 50 is formed on the surface 41 of the substrate 40 for a mold is schematically shown (Fig. 6(b)).

As the photosensitive resin, a conventionally known photosensitive resin can be used, and a commercially available one can be used as a photoresist, or it can be purified by filtration or the like as needed. For example, in the case of a negative-type photosensitive resin having a photosensitive partially hardened property, a monomer or prepolymer or a double layer for a (meth) acrylate having an acrylonitrile group or a methacryl fluorenyl group in a molecule can be used. A mixture of a nitride and a diene rubber, a polyvinyl cinnamate compound, or the like. In addition, a positive-type photosensitive resin having a property of dissolving a photosensitive portion by development and leaving only an unexposed portion may be a phenol resin-based or novolak resin-based resin. Such a positive-working or negative-type photosensitive resin can be easily obtained as a positive photoresist or a negative photoresist 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, as needed. The additive is mixed with a commercially available photoresist as a photosensitive resin solution.

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

The method of applying the photosensitive resin solution to the mirror-polished surface of the substrate for a mold can be applied from meniscus coating, spray coating, dip coating, spin coating, roll coating, wire coating, pneumatic Among known methods such as blade coating, blade coating, curtain coating, and ring coating, the shape of the substrate for a mold or the like is selected. The thickness of the photosensitive resin film after coating is preferably in the range of 1 to 10 μm after drying, more preferably in the range of 6 to 9 μm.

[4] Exposure step

Then, the exposure step is a step of transferring the target pattern to the photosensitive resin film 50 by exposing the photosensitive resin film 50 formed in the photosensitive resin film forming step. The light source used in the exposure step may be appropriately selected as long as it conforms to the photosensitive wavelength, sensitivity, and the like of the photosensitive resin contained in the photosensitive resin film, and for example, a g line (wavelength: 436 nm) of a high pressure mercury lamp, and an h line (wavelength: 405 nm), or i-line (wavelength: 365 nm), semi-conductive Body laser (wavelength: 830nm, 532nm, 488nm, 405nm, etc.), YAG laser (wavelength: 1064nm), KrF excimer laser (wavelength: 248nm), ArF excimer laser (wavelength: 193nm), F2 excimer Laser (wavelength: 157 nm) and the like. The exposure mode may be one of using a mask corresponding to the pattern of the purpose and the exposure mode, or may be a drawing mode. Furthermore, the pattern of the purpose is as described above, so that the intensity ratio of the spatial frequency of the one-dimensional power spectrum is Γ(0.01)/Γ(0.002), Γ(0.02)/Γ(0.002), and Γ(0.04)/Γ(0.002) ) are respectively set to predetermined preferred ranges.

In the method for producing a mold, in order to form the uneven shape of the surface of the mold with higher precision, it is preferable to expose the intended pattern on the photosensitive resin film in a state of being precisely controlled. In order to expose in such a state, it is preferable to make a target pattern as image data on a computer, and draw a laser according to the pattern of the image data by laser light emitted from a computer-controlled laser head (laser) Draw on the photosensitive resin film. When performing laser drawing, for example, a general-purpose laser drawing device such as a printing plate production can be used. A commercially available product of such a laser drawing device is, for example, a Laser Stream FX (Think Laboratory).

Fig. 8(c) is a view schematically showing a state in which the photosensitive resin film 50 is exposed to the pattern. When the photosensitive resin film 50 contains a negative-type photosensitive resin (for example, when a negative photoresist is used as a photosensitive resin solution), the exposed region 51 receives exposure energy and performs a crosslinking reaction of a photosensitive resin, which will be described later. The solubility of the developing solution is lowered. Therefore, the unexposed area 52 in the developing step is dissolved by the developing liquid, and only the exposed region 51 remains on the surface of the substrate to become the mask 60. On the other hand, in the photosensitive tree When the lipid film 50 contains a positive-type photosensitive resin (for example, when a positive photoresist is used as the photosensitive resin solution), the exposed region 51 receives exposure energy, and the bonding of the photosensitive resin is cut, thereby being easily dissolved. The developing solution will be described later. Therefore, in the developing step, the exposed region 51 is dissolved by the developing liquid, and only the unexposed region 52 remains on the surface of the substrate to become the mask 60.

[5] imaging steps

In the development step, when the photosensitive resin film 50 contains a negative-type photosensitive resin, the unexposed region 52 is dissolved by the developing solution, and the exposed region 51 remains on the substrate for the mold to form the mask 60. On the other hand, when the photosensitive resin film 50 contains a positive-type photosensitive resin, only the exposed region 51 is dissolved by the developing solution, and the unexposed region 52 remains on the substrate for the mold to form the mask 60. In the first etching step, the photosensitive resin film remaining on the substrate for a mold is used as a masking action in a first etching step to be described later, in the substrate for a mold which is formed by using a predetermined pattern as a photosensitive resin film.

The developing liquid used in the developing step can be selected from conventionally known ones depending on the type of photosensitive resin to be used. For example, examples of the developing liquid include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; a secondary amine such as a base amine or a di-n-butylamine; a tertiary amine such as triethylamine or methyldiethylamine; an alcohol amine such as dimethylethanolamine or triethanolamine; and tetramethylammonium hydroxide. a tetrabasic ammonium compound such as tetraethylammonium hydroxide or trimethylhydroxyethylammonium hydroxide; an aqueous alkaline solution such as a cyclic amine such as pyrrole or piperidine; or an organic solvent such as xylene or toluene.

The developing method in the developing step is not particularly limited, and Dip imaging, spray imaging, brushing, ultrasound imaging, etc.

Fig. 8(d) is a view schematically showing a state in which a negative film type is used as a photosensitive resin and a developing step is performed. In Fig. 8(d), the unexposed region 52 is dissolved by the developing solution, 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. 8(e) is a view schematically showing a state in which a positive type is used as a photosensitive resin and a developing step is performed. In Fig. 8(e), the exposed region 51 is dissolved by the developing solution, 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] First etching step

In the first etching step, the photosensitive resin film remaining on the surface of the substrate for a mold after the above-described developing step is used as a mask, and the plating layer mainly on the surface of the substrate for the mold is masked in the unmasked region. The steps.

Fig. 9 is a view schematically showing a preferred example of the latter half of the method of manufacturing the mold. Fig. 9(a) is a view schematically showing a state in which a plating layer mainly in a maskless region is etched by an etching step. The plating layer under the mask 60 is not etched by the action of the mask 60 by the photosensitive resin film, but is etched from the maskless region 45 as the etching progresses. Thus, in the vicinity of the boundary between the region having the mask 60 and the unmasked region 45, the plating layer under the mask 60 is also etched. Thus, in the vicinity of the boundary between the region having the mask 60 and the unmasked region 45, the case where the plating layer under the mask 60 is also etched is referred to as side etching.

The etching treatment in the first etching step is usually performed by using an iron (III) chloride (FeCl ₃ ) solution, a copper (II) chloride (CuCl ₂ ) solution, or an alkali etching solution (Cu(NH ₃ ) ₄ Cl ₂ ). The etching liquid is mainly used to etch the plating layer (metal surface) in the region of the maskless 60 in the surface of the substrate for the mold. In 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 plating, etching treatment may be performed by reverse electrolytic etching by applying a potential opposite to that at the time of plating. The surface unevenness shape formed by the base material for the mold during the etching treatment is based on the constituent material (metal material) of the base material for the mold, the type of the plating layer, the type of the photosensitive resin film, and the etching step. Since the type of the etching treatment differs depending on the type of the etching treatment, the etching amount is not more than 10 μm, and the surface of the substrate for the mold which is in contact with the etching liquid is slightly isotropically etched. The amount of etching referred to herein is the thickness of the plating layer which is removed by etching.

The etching amount in the first etching step is preferably from 1 to 20 μm, more preferably from 3 to 10 μm, still more preferably from 5 to 8 μm. When the etching amount is less than 1 μm, the mold has almost no surface unevenness and a mold having a substantially flat surface. Therefore, even if an anti-glare film is produced using the mold, the anti-glare film has almost no surface unevenness. An image display device equipped with such an anti-glare film does not exhibit sufficient anti-glare properties. Further, when the amount of etching is too large, the uneven surface of the finally obtained mold tends to have a large difference in unevenness. Even if an anti-glare film is produced using this mold, the image display device in which the anti-glare film is disposed may not sufficiently suppress the occurrence of whitening. The etching treatment in the etching step can be performed by one etching treatment, or the etching treatment can be carried out by dividing the 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 20 μm.

[7] Photosensitive resin film peeling step

Next, the photosensitive resin film peeling step is a step of removing the photosensitive resin film which acts as a mask 60 and remains on the substrate for a mold in the first etching step, and preferably by the In the step, the photosensitive resin film remaining on the substrate for the mold is completely removed. In the photosensitive resin film peeling step, it is preferred to dissolve the photosensitive resin film by using a peeling liquid. The peeling liquid system can be prepared by changing the concentration, pH, and the like of the developer as a developing solution. Alternatively, the photosensitive resin film may be peeled off by using the same temperature as that of the developing step used in the developing step, changing the temperature of the developing step of the developing step, the immersion time, and the like. 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. 9 is a view schematically showing a state in which the photosensitive resin film used as the mask 60 in the first etching step is completely dissolved and removed by the photosensitive resin film peeling step. The first surface uneven shape 46 is formed on the surface of the substrate for a mold by the mask 60 and the etching treatment by the photosensitive resin film.

[8] Second etching step

The second etching step is a step of passivating the first surface uneven shape 46 formed by the first etching step by an etching treatment (second etching treatment). By the second etching process, the portion of the first surface uneven shape 46 formed by the first etching process is steeply steeped (hereinafter, in the surface uneven shape, the portion whose surface is steeply inclined is passivated. "Shape passivation"). In Figure 9 (c), the second etching process is used to make the mode. The first surface uneven shape 46 of the substrate 40 has a passivation shape, and a portion having a steep surface inclination is passivated, and a state in which the second surface uneven shape 47 having a gentle inclination is formed is formed. As described above, the mold obtained by the second etching treatment has an effect of further improving the optical characteristics of the anti-glare film of the present invention produced by using the mold.

In the second etching treatment in the second etching step, etching treatment using the same etching liquid as in the first etching step or reverse electrolytic etching may be used. The degree of shape passivation after the second etching process (the degree of disappearance of the portion where the surface of the surface uneven shape after the first etching step is steeply inclined) is due to the material of the substrate for the mold, the means for the second etching treatment, and the first The size and depth of the unevenness of the surface unevenness obtained by the etching step are different, and cannot be generalized. However, in terms of controlling the passivation (degree of shape passivation), the largest factor is the etching amount of the second etching treatment. The etching amount here is also the same as that in the first etching step, and indicates the thickness of the substrate which is removed by the second etching treatment. When the etching amount of the second etching treatment is small, the effect of passivating the shape of the surface unevenness obtained by the first etching step becomes insufficient. Therefore, the anti-glare film produced by using a mold having insufficient shape passivation is likely to have an average value and a standard deviation of the inclination angle of the surface uneven shape to be higher than the requirements of the present invention, and as a result, whitening may occur. On the other hand, when the etching amount of the second etching treatment is too large, the unevenness of the surface unevenness formed by the first etching step is almost eliminated, and becomes a mold having a nearly flat surface. The anti-glare film produced by using such a mold having a substantially flat surface is less likely to have an average value and a standard deviation of the inclination angle of the surface uneven shape, and as a result, the anti-glare property may be insufficient. Therefore, the first The etching amount of the etching treatment is preferably in the range of 1 to 50 μm, more preferably in the range of 4 to 20 μm, and even more preferably in the range of 9 to 12 μm. The second etching treatment can be performed by one etching process as in the first etching step, or can be performed by two or more etching processes. 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 from 1 to 50 μm.

[9] 2nd plating step

In the second plating step, the substrate for the mold which has been subjected to the steps [6] and [7] described above is plated, preferably for the mold which has passed the steps of [6] to [8] above. The surface of the substrate is plated (preferably chrome plating described later). By performing the second plating step, the surface uneven shape 47 of the substrate for a mold can be passivated, and the surface of the mold can be protected by the plating. (d) of FIG. 9 shows a state in which the chrome plating layer 71 is formed on the second surface uneven shape 47 formed by the second etching treatment, and the surface uneven shape is passivated (the mold uneven surface 70).

The plating layer formed by the second plating step is preferably chrome-plated from the viewpoint of high gloss, high hardness, small friction coefficient, and good release property. Among the chrome plating, the special type is called chrome plating which exhibits good gloss such as gloss chrome plating and decorative chrome plating. The chrome plating is usually carried out by electrolysis, and in the case of the plating bath, an aqueous solution containing chromic anhydride (CrO ₃ ) and a small amount of sulfuric acid can be used as the plating solution. The thickness of the chrome plating layer can be controlled by adjusting the current density and the electrolysis time.

By applying chrome plating to the surface uneven shape of the surface of the substrate for a mold after the second etching treatment, the shape can be passivated and at the same time A mold whose surface hardness is improved. In terms of controlling the degree of passivation of the shape at this time, the largest factor is the thickness of the chrome plating layer. If the thickness is small, the degree of shape passivation becomes insufficient, and the anti-glare film obtained by using such a mold may be whitened. On the other hand, if the thickness of the chrome plating layer is too thick, the anti-glare property is insufficient. The present inventors have found that an anti-glare film for an image display device which is excellent in preventing the occurrence of whitening and which has excellent anti-glare properties is effective in producing a mold so that the thickness of the chromium plating layer becomes a predetermined range. That is, the thickness of the chrome plating layer is preferably in the range of 2 to 10 μm, more preferably in the range of 5 to 10 μm.

The chrome plating layer formed in the second plating step is preferably formed so that the Vickers hardness is 800 or more. More preferably, it is formed in a manner of becoming 1000 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.

[10] 2nd grinding step

The final stage of the mold manufacturing is a second polishing step in which the surface (chromium plating layer) of the chrome-plated mold substrate is applied in the second plating step. The chrome plating has a luster, a high hardness, a small coefficient of friction, and good release property, but micro cracks occur on the surface due to high internal stress when the chrome plating layer is formed. The mold manufacturing method used in the method for producing an anti-glare film of the present invention preferably passes through the second polishing step to solve a slight surface roughness caused by micro-cracking of chrome plating. When an anti-glare film is produced by using a mold having a rough surface shape due to chrome micro-cracking, the scattering of the surface becomes strong and whitening occurs. Also, the density of microcracks When there is a distribution, sometimes the anti-glare film produced by using the mold may have strong scattering and weak spots, and may cause streaks.

The polishing method to be applied in the second polishing step is preferably a method of selectively grinding the surface shape of the mold by the second plating step without slightly affecting the surface unevenness surface 70 formed by the second plating step. . Specific examples of such a polishing method include polishing, fluid polishing, sand blasting, and the like. The amount of polishing in which the amount of the chromium plating layer is removed in the second polishing step is preferably 0.03 μm or more and 0.2 μm or less. When the amount of polishing is less than 0.03 μm, the effect of solving the surface roughness caused by the microcracking of chrome plating is insufficient. On the other hand, when the amount of polishing is higher than 0.2 μm, the uneven surface 70 of the mold generates a flat region. When an anti-glare film is produced using a mold that produces a flat region, there is an insufficient anti-glare property.

The above-described photoimprint 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 preferred as the photoimprint method, but the imprint method using the active energy ray-curable resin is specifically described herein.

In order to continuously produce 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 have the following steps: [P1] coating a coating liquid containing an active energy ray-curable resin a coating step of forming a coating layer on a transparent support continuously transported; and [P2] mainly hardening the surface of the coating layer from the side of the transparent support by irradiating the active energy line in a state of pressing against the surface of the mold step.

Further, when the antiglare film of the present invention is produced by photoimprinting, it is more preferable to further include the following steps: [P3] The preliminary hardening step of irradiating the active energy ray in the end region of both of the width directions of the coating layer after the coating step [P1] and before the hardening step [P2].

Hereinafter, each step will be described in detail with reference to the drawings. Fig. 10 is a view schematically showing a preferred example of a manufacturing apparatus used in the method for producing an anti-glare film of the present invention. The arrows in Fig. 10 indicate the transport direction of the film or the direction of rotation of the rolls.

[P1] Coating step

In the coating step, a coating liquid containing an active energy ray-curable resin is applied onto a transparent support to form a coating layer. For example, as shown in FIG. 10, in the coating step, the coating liquid containing the active energy ray-curable resin composition is applied to the transparent support 81 sent from the delivery roller 80.

The application of the coating liquid to the transparent support 81 can be performed by, for example, a gravure coating method, a micro gravure coating method, a rod coating method, a knife coating method, a pneumatic blade coating method, or an anastomosis coating method (kiss Coating), mold coating method, etc. are carried out.

(transparent support)

As long as the transparent support 81 is translucent, for example, glass, a plastic film, or the like can be used. As far as the plastic film is concerned, it is only necessary to have moderate transparency and mechanical strength. Specifically, any of the transparent supports used as the UV imprint method can be used, and in order to further continuously manufacture the anti-glare film of the present invention by photoimprinting, it is selected to have moderate flexibility. By.

Improve coating properties, transparent support and coating For the purpose of the adhesion of the cloth layer, various surface treatments can be applied to the surface (coating layer side surface) of the transparent support 81. Examples of the surface treatment include corona discharge treatment, glow discharge treatment, acid surface treatment, alkali surface treatment, ultraviolet irradiation treatment, and the like. Further, another layer such as a primer layer may be formed on the transparent support 81, and a coating liquid may be applied to the other layer.

Further, when the antiglare film of the present invention is produced by integrating with a polarizing film, in order to improve the adhesion between the transparent support and the polarizing film, it is preferred to first surface (and coat) the transparent support by various surface treatments. The surface on the opposite side of the layer is 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 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 compound containing a polyfunctional (meth) acrylate compound can be suitably used. The polyfunctional (meth) acrylate compound refers to 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 a (meth) acrylate, a urethane (meth) acrylate compound, and a polyester (meth) acrylate compound. A polyfunctional polymerizable compound containing two or more (meth)acryl fluorenyl groups, such as an epoxy group (meth) acrylate 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, and propanediol. Butane diol, pentane diol, hexane diol, neopentyl glycol, 2-ethyl-1,3-hexane diol, 2,2'-thiodiethanol, 1,4-two A dihydric alcohol such as methanol; an alcohol having 3 or more yuan such as trimethylolpropane, glycerin, neopentyl alcohol, diglycerin, dipentaerythritol or trimethylolpropane.

Specific examples of the ester of a polyhydric alcohol and (meth)acrylic acid include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and 1,6-hexane two. Alcohol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, tetrahydroxyl Methyl methane tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, tetramethylol methane tetra(meth)acrylate, pentatriol tri(meth)acrylic acid Ester, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, glycerol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, Dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate.

The urethane (meth) acrylate compound may, for example, be an organic isocyanate having a plurality of isocyanate groups in one molecule and an urethanation reaction product with a (meth)acrylic acid derivative having a hydroxyl group. Examples of the organic isocyanate having a plurality of isocyanate groups in one molecule include hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, naphthalene diisocyanate, and diphenylmethane diisocyanate. An organic isocyanate having two isocyanate groups in one molecule such as phenyldimethyl diisocyanate or dicyclohexylmethane diisocyanate; the organic isocyanate is modified by isomeric cyanurate, the addition product is modified, and the biuret is obtained. An organic isocyanate having three isocyanate groups in one molecule of the modification. Examples of the (meth)acrylic acid derivative having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. 2-hydroxybutyl methacrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, neopentyl alcohol triacrylate.

In the case of the polyester (meth) acrylate compound, a polyester (meth) acrylate obtained by reacting a hydroxyl group-containing polyester with (meth) acrylic acid is preferred. Suitable hydroxyl group-containing polyesters are hydroxyl group-containing polyesters obtained by esterification of a polyol with a carboxylic acid or a compound having a plurality of carboxyl groups and/or an anhydride thereof. The polyol is the same as the aforementioned compound. Further, examples of the phenols other than the polyhydric alcohol include bisphenol A and the like. Examples of the carboxylic acid include formic acid, acetic acid, butyric acid, benzoic acid, and the like. Examples of the compound having a plurality of carboxyl groups and/or an acid anhydride thereof include maleic acid, citric acid, fumaric acid, itaconic acid, adipic acid, p-citric acid, maleic anhydride, phthalic anhydride, and benzoic acid. Formic acid, cyclohexane dicarboxylic acid anhydride, and the like.

Among the above polyfunctional (meth) acrylate compounds, hexane diol di(meth) acrylate and neopentyl glycol are preferred from the viewpoint of improvement in strength of the cured product and ease of availability. Di(meth)acrylate, diethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol three (a) Ester ester compound such as acrylate or dipentaerythritol hexa(meth) acrylate; An adduct of methylene diisocyanate and 2-hydroxyethyl (meth)acrylate; an adduct of isophorone diisocyanate and 2-hydroxyethyl (meth)acrylate; toluene diisocyanate and (methyl) An adduct of 2-hydroxyethyl acrylate; an adduct of an isofucanone diisocyanate and an ethyl 2-hydroxyethyl (meth)acrylate; and a biuret-modified isophorone diisocyanate An adduct of 2-hydroxyethyl methacrylate. Further, these polyfunctional (meth) acrylate compounds may be used alone or in combination of two or more.

The active energy ray-curable resin may further contain a monofunctional (meth) acrylate compound in addition to the above polyfunctional (meth) acrylate compound. The monofunctional (meth) acrylate compound may, for example, be methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate or isobutyl (meth) acrylate, ( Tert-butyl methacrylate, 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, tetrahydroanthracene (meth)acrylate Ester, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, ethionyl (meth)acrylate, benzyl (meth)acrylate , 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth) acrylate, phenoxy (meth) acrylate, ring Oxygen ethane modified phenoxy (meth) acrylate, propylene oxide (meth) acrylate, nonyl phenol (meth) acrylate, ethylene oxide modified (meth) acrylate, epoxy Propane modified nonylphenol (meth) acrylate, A Oxydiethylene glycol (meth) acrylate, 2-(methyl) propylene methoxyethyl 2-hydroxypropyl phthalate, (A) (meth) acrylate such as dimethylaminoethyl acrylate or methoxy triethylene 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. The polymerizable oligomer may be, for example, the aforementioned polyfunctional (meth) acrylate compound, that is, an ester compound of a polyhydric alcohol and a (meth) acrylate, a urethane (meth) acrylate compound, a polyester (methyl group). An oligomer such as a dimer or a trimer such as an acrylate compound or an epoxy (meth) acrylate.

The other polymerizable oligomers may be exemplified by a reaction of a polyisocyanate having at least two isocyanate groups in the molecule and a polyol having at least one (meth) acryloxy group. Ester (meth) acrylate oligomer. The polyisocyanate may, for example, be a polymer of hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate or benzodimethyl diisocyanate, and has at least one (A) The propylene oxy group-containing polyol may, for example, be a hydroxyl group-containing (meth) acrylate obtained by esterification of a polyhydric alcohol with (meth)acrylic acid, and the polyhydric alcohol may, for example, be 1, 3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, trihydroxyl Methylpropane, glycerol, neopentyl alcohol, dipentaerythritol, and the like. One part of the alcoholic hydroxyl group of the polyol-based polyol having at least one (meth)acryloxy group is reacted with the (meth)acrylic acid ester, and the alcoholic hydroxyl group remains in the molecule.

Furthermore, in the case of other polymeric oligomers, A polyester (meth) acrylate oligomer obtained by reacting a compound having a plurality of carboxyl groups and/or an acid anhydride thereof with a polyol having at least one (meth) acryloxy group can be mentioned. The compound having a plurality of carboxyl groups and/or an acid anhydride thereof may be the same as those described for the polyester (meth) acrylate of the above polyfunctional (meth) acrylate compound. In addition, the polyol having at least one (meth) acryloxy group may be the same as those described for the urethane (meth) acrylate oligomer.

Further, not only the above polymerizable oligomers, but also examples of the urethane (meth) acrylate oligomers may be exemplified for the hydroxyl group-containing polyester, the hydroxyl group-containing polyether or the hydroxyl group ( A compound obtained by reacting a hydroxyl group of a methyl acrylate to an isocyanate. Suitable hydroxyl group-containing polyesters are hydroxyl group-containing polyesters obtained by esterification of a polyol with a carboxylic acid or a compound having a plurality of carboxyl groups and/or an anhydride thereof. The polyol or a compound having a plurality of carboxyl groups and/or an acid anhydride thereof can be exemplified by the same as those described for the polyester (meth) acrylate compound of the polyfunctional (meth) acrylate compound. The hydroxyl group-containing polyether which is suitably used is a hydroxyl group-containing polyether obtained by adding one or more kinds of alkylene oxide and/or ε-caprolactone to a polyol. The polyol may be the same as the user of the aforementioned hydroxyl group-containing polyester. The hydroxyl group-containing (meth) acrylate which is suitably used may be the same as those described for the urethane (meth) acrylate oligomer 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 toluene 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 in accordance with the kind of active energy ray which is suitable for 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 may be 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, a benzophenone-based photopolymerization initiator, a thioxanthone system can be used. Photopolymerization initiator, three Photopolymerization initiator, A bisazole photopolymerization initiator or the like. Further, as the photopolymerization initiator, for example, 2,4,6-trimethylbenzimidyldiphenylphosphine oxide or 2,2'-bis(o-chlorophenyl)-4 can also be used. , 4',5,5'-tetraphenyl-1,2'-biimidazole, 10-butyl-2-chloroacridone, 2-ethylhydrazine, diphenylethylenedione, 9,10- Phenanthrene, camphorquinone, methyl phenylglyoxylate, titanium titanate compound, and the like. The photopolymerization initiator is usually used in an amount of from 0.5 to 20 parts by weight, preferably from 1 to 5 parts by weight, per 100 parts by weight of the active energy ray-curable resin.

In order to improve the applicability to a transparent support, the coating liquid may contain a solvent, such as an organic solvent. In terms of the organic solvent, the viscosity can be selected from the following: aliphatic hydrocarbons such as hexane, cyclohexane, and octane; aromatic hydrocarbons such as toluene and xylene; ethanol, 1-propanol, and the like. Alcohols such as propanol, 1-butanol and cyclohexanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate, butyl acetate and isobutyl acetate; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, Glycol ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; esterified glycol ethers such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; 2-methoxyethanol , 2-ethoxyethanol, 2-butoxyethanol, etc. Cyrus; 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, 2- A carbitol such as (2-butoxyethoxy)ethanol or the like. These solvents may be used singly or in combination of several kinds as needed. The above organic solvent must be evaporated after coating. Therefore, the boiling point is preferably in the range of 60 ° C to 160 ° C. Further, the saturated vapor pressure at 20 ° 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 the solvent and drying it after the coating step and before the first curing step. For example, in the example shown in Fig. 10, the drying can be carried out by passing the transparent support 81 having the coating layer through the drying zone 84. The drying temperature is appropriately selected depending on the type of solvent or transparent support to be used. Generally speaking, it is in the range of 20 ° C to 120 ° C, but is not limited thereto. Moreover, when there are a plurality of drying furnaces, the temperature can be changed for each drying furnace. The thickness of the coated layer after drying is preferably from 1 to 30 μm.

In this way, a laminate of the laminated transparent support and the coating layer can be formed.

[P2] hardening step

In this step, the active energy ray is irradiated from the transparent support side to the surface of the coating layer by pressing the concave-convex surface (forming surface) of the mold having the desired surface unevenness shape, and the coating layer is hardened to be transparent. A step of forming a hardened resin layer on the support. Thereby, the coating layer is hardened, and the surface uneven shape of the uneven surface of the mold is transferred to the surface of the coating layer. Made here The mold used in the form of a roll is manufactured by using a base material for a roll mold in the mold manufacturing method described above.

For example, as shown in Fig. 10, this step can be performed by, for example, irradiating the active energy ray irradiation device 86 with the passed coating region 83 (the drying region 84 when drying is performed, and the preliminary hardening step described later is performed). The laminate of the coating layer of the preliminary hardening zone is irradiated with the active energy ray by using the active energy ray irradiation device 86 such as an ultraviolet ray irradiation device disposed on the side of the transparent support 81.

First, the roll-shaped mold 87 is pressed against the surface of the coating layer of the laminated body subjected to the hardening step by using a crimping device such as the nip roller 88, and the active energy ray irradiation device 86 is used in this state to illuminate from the transparent support 81 side. The coating layer 82 is hardened by the active energy ray. Here, "curing the coating layer" means that the active energy ray-curable resin contained in the coating layer receives the energy of the active energy ray to cause a curing reaction. The use of the nip rolls is effective for preventing air bubbles from entering between the coating layer of the laminate and the mold. One or a plurality of active energy ray irradiation devices can be used.

After the active energy ray irradiation, 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 hardened coating layer are used as an antiglare layer to obtain an antiglare film of the present invention. The resulting anti-glare film is typically rewinded by a film rewinding device 90. In this case, for the purpose of protecting the anti-glare layer, the protective film made of polyethylene terephthalate or polyethylene may be attached to the surface of the anti-glare layer via a pressure-sensitive adhesive layer having removability. Rewind. Furthermore, although the case where the mold used is a roller is described here, a roller may be used. A mold other than the shape. Further, after being peeled off from the mold, additional active energy ray irradiation may be performed.

The active energy ray used in this step can be appropriately selected from ultraviolet rays, electron beams, near ultraviolet rays, visible rays, near infrared rays, infrared rays, and X-rays depending on the type of active energy ray-curable resin contained in the coating liquid. Etc., but among these, UV and electron beams are preferred. From the viewpoint of easy operation and high energy, ultraviolet light is preferred (as described above, in the case of photoimprinting, UV imprinting 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 synchrotron radiation may be used. Among these, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, an electrodeless lamp, a xenon arc lamp, and a metal halide lamp are preferably used.

Further, as for the electron beam, a Cockcroft-Walton type, a van de Graaff type, a resonance transformer type, an insulating core transformer type, and a straight type can be cited. An electron beam having an energy of 50 to 1000 keV (preferably 100 to 300 keV) emitted by various electron beam accelerators such as Dynamitron type and high frequency type.

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

[P3] preliminary hardening step

This step is a step of irradiating the both ends of the transparent support of the coating layer in the width direction to the active energy rays before the hardening step, and preliminarily hardening the both end regions. Figure 11 is a schematic cross-sectional view of the preliminary hardening step. In Fig. 11, the end portion 82b of the coating layer in the width direction (the direction orthogonal to the conveying direction) is a region including the end portion of the coating layer and having a predetermined width from the end portion.

In the preliminary hardening step, the adhesion to the transparent support 81 is further enhanced in the end region by hardening the end region in advance, and in the step after the hardening step, one of the hardened resins is prevented from being partially peeled off. The step caused by the drop is contaminated. The end region 82b can be, for example, a region of 5 mm or more and 50 mm or less from the end portion of the coating layer 82.

The irradiation of the active energy ray of the end region of the coating layer is referred to in Figs. 10 and 11 and may be provided, for example, by coating the coating layer 83 (drying zone 84 when dried). The transparent support 81 is made of ultraviolet rays respectively disposed near the both end portions of the coating layer 82 side. The active energy ray irradiation device 85 such as a radiation device is irradiated with the active energy ray. The active energy ray irradiation device 85 may be provided on the side of the transparent support 81 as long as it can illuminate the end region 82b of the coating layer 82 with an active energy ray.

The type of active energy line and the source of the light source are the same as the main hardening step. When the active energy ray is ultraviolet ray, the cumulative amount of light in the UVA of ultraviolet light 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 irradiating so as to be 50 mJ/cm ² or more, deformation in the main hardening step can be more effectively prevented. In addition, when it exceeds 400 mJ/cm ² and the hardening reaction progresses excessively, the boundary between the hardened portion and the uncured portion may be peeled off due to a difference in film thickness or internal stress.

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

The anti-glare film of the present invention obtained in the above manner can be used for an image display device or the like, and is usually used as a polarizing film as a visual-side protective film of a visual-side polarizing plate (that is, disposed on an image display device). surface). Further, when a polarizing film is used as the transparent support as described above, since the polarizing film-integrated anti-glare film can be obtained, the 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 at a wide viewing angle, and can well prevent whitening and glare.

(Example)

Hereinafter, the present invention will be described in more detail by way of examples. In the example, the "%" and "parts" of the content or the amount used are as long as there is no special At the time of annotation, it is the weight basis. The evaluation method of the mold or the anti-glare film in the following examples is as follows.

[1] Determination of the surface shape of an anti-glare film (the inclination angle of the surface uneven shape)

The elevation of the surface of the anti-glare film 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 of the measurement sample opposite to the anti-glare layer is bonded to the glass substrate, and measurement is performed. The magnification of the objective lens at the time of measurement was set to 50 times. The horizontal resolutions Δx and Δy were both 0.332 μm, and the measurement area was 255 μm × 191 μm. Based on the obtained measurement data, the average value and standard deviation of the inclination angle of the surface unevenness shape were calculated by the above-described calculation method.

(power spectrum of complex amplitude calculated from the elevation of the surface relief shape)

The elevation of the surface uneven shape of the antiglare layer of the antiglare film as 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 sample, an optically transparent adhesive is used, and the surface of the measurement sample opposite to the antiglare layer is bonded to the glass substrate, and then provided for measurement. At the time of measurement, the magnification of the objective lens was set to 10 times and the measurement was performed. The horizontal resolutions Δx and Δy were both 1.66 μm, and the measurement area was 1270 μm × 950 μm. From the central portion of the obtained measurement data, 512 × 512 (measurement area: 850 μm × 850 μm) data were sampled, and the elevation of the surface uneven shape (surface unevenness of the antiglare layer) of the antiglare film was determined as a two-dimensional The function h(x, y). Next, the two-dimensional function ψ(x, y) of the complex variable amplitude is calculated from the two-dimensional function h(x, y). The wavelength λ when calculating the complex amplitude is set to 550 nm. The two-dimensional function ψ(x, y) is discretely Fourier transformed to obtain a two-dimensional function Ψ(f _x , f _y ). Calculate the two-dimensional function H(f _x ,f _y ) of the two-dimensional power spectrum by squaring the absolute value of the two-dimensional function Ψ(f _x ,f _y ), and calculate the power spectrum of one of the functions of the distance f of the origin. One-dimensional function H(f). The elevation of the surface irregularities of each of the five samples was measured for each sample, and the average value of the one-dimensional power function H(f) of one-dimensional power spectrum calculated from the data was used as a one-dimensional function H of the one-dimensional power spectrum of each sample. (f).

[2] Determination of optical properties of anti-glare film (haze)

The full haze of the anti-glare film is bonded to the glass substrate by using an optically transparent adhesive, and the surface of the measurement sample opposite to the anti-glare layer is bonded to the glass substrate, and the anti-glare is adhered to the glass substrate. The film was incident on the glass substrate side, and the measurement was carried out by using a haze meter "HM-150" manufactured by Murakami Color Research Laboratory Co., Ltd. according to the method of JIS K 7136. The surface haze is obtained by subtracting the internal haze from the full haze by determining the internal haze of the anti-glare film: surface haze = full haze - internal haze internal haze is The antiglare layer of the measurement sample after the measurement of the full haze was measured by attaching a propylene glycol film having a haze of almost 0 to glycerol, and measuring it in the same manner as the full 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 K 7105. At this time, in order to prevent the warpage of the sample, an optically transparent adhesive is used. The coating was attached to a glass substrate on the side opposite to the antiglare layer of the measurement sample, and then provided for measurement. In this state, light was incident from the side of the glass substrate, and measurement was performed. Here, the measured values are the total values of the values measured by using five types of optical combs having a width of the dark portion and the bright portion of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively.

(reflection resolution measured at a light incident angle 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 K 7105. At this time, in order to prevent the warpage of the sample, an optically transparent adhesive was used, and the surface of the measurement sample opposite to the antiglare layer was bonded to the black acrylic substrate, and then it was measured. In this state, light was incident at 45° from the side of the anti-glare layer, and measurement was performed. Here, the measured value is a total value of four kinds of optical combs each 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.

(reflection resolution measured at a light incident angle 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 K 7105. At this time, in order to prevent the warpage of the sample, an optically transparent adhesive was used, and the surface of the measurement sample opposite to the antiglare layer was bonded to the black acrylic substrate, and then it was measured. In this state, light was incident at 60° from the side of the anti-glare layer, and measurement was performed. Here, the measured value is a total value of four kinds of optical combs each 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.

[3] Evaluation of anti-glare performance of anti-glare film (Visual inspection of reflective and whitening)

In order to prevent reflection from the back surface of the anti-glare film, the anti-glare film is bonded to the surface of the measurement sample which is opposite to the anti-glare layer and bonded to the black acrylic resin plate, and the fluorescent lamp is brightened. The indoor view was visually observed from the side of the anti-glare layer, and the degree of reflection of the fluorescent lamp and the degree of whitening were visually evaluated. Regarding the reflection, the degree of reflection of the antiglare film when viewed from the front and the degree of reflection when viewed from the inclination of 30° were evaluated, respectively. The reflective and ubiquitous systems were evaluated by the following criteria in stages of 1 to 3, respectively.

Reflective:

1: No reflection was observed.

2: A little reflection was observed.

3: Reflective observation is clearly observed.

Whitening:

1: No whitening was observed.

2: A little whitening was observed.

3: Clear whitening is clearly observed.

(evaluation of glare)

Glare is evaluated in the following order. That is, first, a reticle having a pattern of a unit cell as shown in plan view in Fig. 12 is prepared. In the figure, the unit cell 100 is formed on a transparent substrate, and a hook-shaped chrome-shielding pattern 101 is formed with a line width of 10 μm, and a portion where the chrome-shielding pattern 101 is not formed is an opening portion 102. Here, the unit unit size is 211 μm × 70 μm. (length of the figure × width), and the size of the opening is 201 μm × 60 μm (length × width of the figure). The unit cells shown in the figure are arranged in a large number in the longitudinal direction to form a reticle.

Then, as shown in the schematic cross-sectional view of Fig. 13, the chrome-shielding pattern 111 of the mask 113 is placed on the light box 115, and the anti-glare film 110 is adhered to the surface of the anti-glare layer by using an adhesive. A sample formed on the glass plate 117 is placed on the mask 113. A light source 116 is disposed in the light box 115. In this state, the degree of glare was evaluated by a seven-stage function from the position 119 at a distance of about 30 cm from the sample. In Stage 1, the state of glare was not confirmed at all, the state of strong glare was observed in Stage 7, and the state of a little glare was observed in Stage 4.

(evaluation of comparison)

The polarizing plate on both sides of the back of the watch was peeled off from a commercially available LCD TV [KY-32EX550" manufactured by SONY Co., Ltd.]. In place of the original polarizing plates, a polarizing plate "SUMIKALAN SRDB831E" manufactured by Sumitomo Chemical Co., Ltd. is attached to the back side and displayed by an adhesive so that the absorption axes thereof coincide with the absorption axes of the original polarizing plates. On the surface side, the antiglare film shown in each of the following examples was bonded to the display surface side polarizing plate with an uneven surface as a surface via an adhesive. The liquid crystal TV thus obtained was started in a dark room, and the brightness in the black display state and the white display state was measured using a TOPCON (luminaire) brightness meter "BM5A" type, and the contrast was calculated. Here, the contrast is expressed by the ratio of the brightness of the white display state to the brightness of the black display state. The results are shown by the ratio of the contrast measured in the state in which the antiglare film is bonded to the contrast measured in the state in which the antiglare film is not attached.

[4] Evaluation of patterns used in the manufacture of anti-glare films

The created pattern data is used as the second-order binary image data, and the gradation is represented by a two-dimensional discrete function g(x, y). The horizontal resolutions Δx and Δy of the discrete function g(x, y) are both set to 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 ). The square of the absolute value of the two-dimensional function G(f _x ,f _y ) is calculated, and the two-dimensional function Γ(f _x ,f _y ) of the two-dimensional power spectrum is calculated, and one of the functions of the distance f from the origin is calculated. One-dimensional function Γ(f).

<Example 1> (Production of mold for manufacturing anti-glare film)

A Ballard copper-plated person was prepared on the surface of an aluminum roll (JIS A6063) having a diameter of 300 mm. The Ballard copper plating system includes a copper plating layer/a thin silver plating layer/a surface copper plating layer, and the entire thickness of the 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 which has been polished, and dried to form a photosensitive resin film. Next, the pattern in which the pattern A shown in FIG. 14 is repeatedly arranged is exposed on the photosensitive resin film by laser light, and development is performed. This was carried out by using Laser Stream FX (manufactured by Think Laboratory) by exposure and development of laser light. As the photosensitive resin film, those containing a positive-type photosensitive resin are used. Here, the pattern A is produced by a plurality of Gaussian function type band pass filters having a pattern of random brightness distribution, the aperture ratio is 45%, and the spatial frequency of the one-dimensional power spectrum is 0.002 μm ^-1 (Γ2). ) 0.01 m ^-1 of the spatial frequency intensity Γ (0.01) the ratio Γ (0.01) / Γ (0.002 ) 3.8 system, the spatial frequency intensity of the Γ 0.002μm ^-1 (0.002) and the spatial frequency of 0.02μm intensity Gamma] ^-1 (0.02) the ratio Γ (0.02) / Γ (0.002 ) 0.5 lines, the intensity of the spatial frequency 0.002μm ^-1 Γ (0.002) of the spatial frequency intensity 0.04μm ^-1 Γ (0.04) the ratio Γ (0.04) / Γ (0.002) is 7.5.

Then, the first etching treatment is performed with a copper (II) chloride solution. The amount of etching at this time was set to be 5 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed with a copper (II) chloride solution. The amount of etching at this time was set to be 10 μm. Then, chrome processing is performed. At this time, the chrome plating thickness was set to be 6 μm. The chrome-plated roller was subjected to friction grinding under the following conditions to prepare a mold A.

Abrasive material: micro-polished (alumina abrasive with a particle size of 0.05 μm) (Musashino Sub-company company)

Grinding cloth: grinding cloth (red) (made by Musashino Electronics Co., Ltd.)

Roll rotation speed: 60rpm

Pressing pressure: 1.1kPa

(production of anti-glare film)

The following components were prepared by dissolving in ethyl acetate at a solid concentration of 60%, and after curing, an ultraviolet curable resin composition A having a film exhibiting a refractive index of 1.53 was formed.

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

The ultraviolet curable resin composition A was applied onto a triacetonitrile cellulose (TAC) film having a thickness of 60 μm so that the thickness of the dried coating layer was 5 μm, and it was set in a dryer set at 60 ° C. Dry for 3 minutes. The dried film was pressed against the molding surface (surface having the surface uneven shape) of the previously obtained mold A by using a rubber roller so that the dried coating layer became the mold side. In this state, the light from the high-pressure mercury lamp having a strength of 20 mW/cm ² was irradiated so that the amount of light in the h-line conversion was 200 mJ/cm ² from the TAC film side, and the coating layer was cured to produce an anti-glare film. Then, the obtained antiglare film was peeled off from the mold to prepare a transparent antiglare film A having an antiglare layer on the TAC film.

<Example 2>

A mold B was produced in the same manner as in the mold A of Example 1, except that the amount of etching in the second etching step was changed to 9 μm, and the same procedure as in Example 1 was carried out except that the mold A was replaced with the mold B. Anti-glare film. This anti-glare film is used as the anti-glare film B.

<Example 3>

A mold C was produced in the same manner as in the mold A of Example 1, except that the amount of etching in the second etching step was changed to 11 μm. The mold C was produced in the same manner as in Example 1 except that the mold A was replaced with the mold C. Anti-glare film. This anti-glare film is used as the anti-glare film C.

<Example 4>

A mold D was produced in the same manner as in the mold A of Example 1, except that the pattern in which the pattern B shown in Fig. 15 was repeatedly arranged was exposed to laser light on the photosensitive resin film, except that the mold A was used. An anti-glare film was produced in the same manner as in Example 1 except that the mold D was used. This anti-glare film is used as the anti-glare film D. Here, the pattern B is formed by a plurality of Gaussian function type band pass filters having a pattern of random brightness distribution, the aperture ratio is 45%, and the spatial frequency of the one-dimensional power spectrum is 0.002 μm ^-1 (Γ) 0.002) The ratio of the intensity Γ(0.01) of the spatial frequency 0.01μm ^-1 Γ(0.01)/Γ(0.002) is 2.7, the intensity of the spatial frequency 0.002μm ^-1 Γ(0.002) and the intensity of the spatial frequency 0.02μm ^-1 Γ (0.02) the ratio Γ (0.02) / Γ (0.002 ) 0.5 system, the spatial frequency intensity of the Γ 0.002μm ^-1 (0.002) of the spatial frequency intensity 0.04μm ^-1 Γ (0.04) the ratio Γ (0.04) / Γ (0.002) is 3.7.

<Example 5>

A mold E was produced in the same manner as in the mold A of Example 1, except that the pattern in which the pattern C shown in Fig. 16 was repeatedly arranged was exposed to laser light on the photosensitive resin film, except that the mold A was used. An anti-glare film was produced in the same manner as in Example 1 except that the mold E was replaced. This anti-glare film is used as the anti-glare film E. Here, the pattern C is formed by a plurality of Gaussian function type band pass filters having a pattern of random brightness distribution, the aperture ratio is 45%, and the spatial frequency of the one-dimensional power spectrum is 0.002 μm ^-1 (Γ) 0.002) The ratio Γ(0.01)/Γ(0.002) of the spatial frequency 0.01μm ^{-1 to} 0.01(0.01) is 3.5, the intensity of the spatial frequency 0.002μm ^-1 Γ(0.002) and the intensity of the spatial frequency 0.02μm ^-1 Γ (0.02) the ratio Γ (0.02) / Γ (0.002 ) 0.42 Department, spatial frequency intensity of the Γ 0.002μm ^-1 (0.002) of the spatial frequency intensity 0.04μm ^-1 Γ (0.04) the ratio Γ (0.04) / Γ (0.002) is 5.5.

<Comparative Example 1>

A mold F was produced in the same manner as in the mold A of Example 1, except that the amount of etching in the second etching step was changed to 8 μm, and the same procedure as in Example 1 was carried out except that the mold A was replaced with the mold F. Anti-glare film. This anti-glare film is used as the anti-glare film F.

<Comparative Example 2>

An aluminum roll having a diameter of 200 mm (A6063 of JIS) was subjected to laser light exposure except for the pattern in which the pattern D shown in FIG. 17 was repeatedly arranged on the photosensitive resin film, and the mold A of Example 1. The mold G was produced in the same manner, and an anti-glare film was produced in the same manner as in Example 1 except that the mold A was replaced with the mold G. This anti-glare film is used as the anti-glare film G. Here, the pattern D is formed by a plurality of Gaussian function type band pass filters having a pattern having a random brightness distribution, the aperture ratio is 45%, and the spatial frequency of the one-dimensional power spectrum is 0.002 μm ^-1 (Γ) 0.002) The ratio Γ(0.01)/Γ(0.002) of the spatial frequency 0.01μm ^{-1 to} 0.01(0.01) is 4.2, the intensity of the spatial frequency 0.002μm ^-1 Γ(0.002) and the intensity of the spatial frequency 0.02μm ^-1 Γ (0.02) the ratio Γ (0.02) / Γ (0.002 ) train 14, the spatial frequency of the intensity Γ 0.002μm ^-1 (0.002) of the spatial frequency intensity 0.04μm ^-1 Γ (0.04) the ratio Γ (0.04) / Γ (0.002) is 208.

<Comparative Example 3>

The surface of a 300 mm diameter aluminum roll (JIS A5056) was mirror-polished, and the zirconia beads TZ-SX-17 were placed on the ground aluminum surface using a blast apparatus (manufactured by Fujia Co., Ltd.). (TOSOH (manufactured by TOSOH), average particle diameter: 20 μm) at a spray pressure of 0.1 MPa (gauge pressure, hereinafter synonymous), and the amount of beads used was 8 g/cm ² (the amount used per 1 cm ² of the surface area of the roll, the following is synonymous) Blowing, causing irregularities on the surface of the aluminum roll. The obtained aluminum foil with irregularities was subjected to electroless nickel plating to prepare a mold H. At this time, the thickness of the electroless nickel plating was set to be 15 μm. An anti-glare film was produced in the same manner as in Example 1 except that the mold A was replaced with the mold H. This anti-glare film is used as the anti-glare film H.

<Comparative Example 4>

A Ballard copper-plated person was prepared on the surface of an aluminum roll (JIS A5056) having a diameter of 200 mm. Ballard copper plating includes a copper plating layer/thin silver plating layer/surface copper plating layer, and the entire thickness of the plating layer is about 200 μm. The copper-plated surface was mirror-polished, and the zirconia beads "TZ-SX-17" (TOSOH) were used for the polishing surface by using a blowing device (manufactured by Fujitsu Seisakusho Co., Ltd.). : 20 μm), blowing at a pressure of 0.05 MPa (gauge pressure, hereinafter synonymous), and a bead usage amount of 6 g/cm ^{2 to} cause irregularities on the surface of the aluminum roll. The obtained copper-plated aluminum roll with irregularities was subjected to chrome plating to prepare a mold 1. At this time, the chrome plating thickness was set to be 6 μm. An anti-glare film was produced in the same manner as in Example 1 except that the mold A was replaced with the mold 1. This anti-glare film was used as the anti-glare film I.

[evaluation result]

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

The anti-glare films A to E (Examples 1 to 5) satisfying the requirements of the present invention have an excellent anti-glare property regardless of the front or the inclination even if the haze is low haze, and the whitening and glare suppression effects are also Full. On the other hand, the anti-glare film F (Comparative Example 1) was whitened. Anti-glare film G (comparison Example 2) The antiglare property was insufficient at the time of oblique observation. The anti-glare film H (Comparative Example 3) is susceptible to glare. The antiglare film I (Comparative Example 4) had insufficient antiglare property when observed obliquely.

(industrial availability)

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

1‧‧‧Anti-glare film

2‧‧‧ bump

3‧‧‧film projection surface

5‧‧‧Main normal direction

6‧‧‧Average normal vector

Claims (2)

An anti-glare film comprising a transparent support and an anti-glare layer having a fine surface uneven shape formed thereon, wherein the total haze is 0.1% or more and 3% or less, and the surface haze is 0.1%. In the case of 2% or less, the average value of the inclination angle of the surface unevenness is 0.2° or more and 1.2° or less, and the standard deviation of the inclination angle is 0.1° or more and 0.8° or less, and the complex transformation is obtained by the following power spectrum calculation method. the amplitude of the power spectrum all the conditions of the following (1) to (3) as to satisfy: (1) the spatial frequency power spectrum of the intensity of H 0.002μm ^-1 (0.002), and spatial frequency power spectrum of the intensity of H 0.01μm ^-1 ( 0.01) the ratio H (0.01) / H (0.002 ) 0.02 to 0.6; (2) the spatial frequency power spectrum of the intensity of H 0.002μm ^-1 (0.002), and spatial frequency power spectrum of the intensity of 0.02μm ^-1 H (0.02) ratio H (0.02) / H (0.002) is 0.005 or more and 0.05 or less; and (3) the spatial frequency of the power spectrum is 0.002 μm ^-1 intensity H (0.002), and the power spectrum spatial frequency is 0.04 μm ^- the intensity of ¹ H (0.04) the ratio H (0.04) / H (0.002 ) 0.0005 0.01 or less; wherein <method of calculating the power spectrum> (a) from the surface of the concavo-convex shape of the elevation Determining the average plane belonging to the virtual plane; (B) determining the lowest elevation surface and the highest elevation surface, the lowest elevation surface comprising the lowest elevation point of the surface relief shape and parallel to the virtual plane of the average surface, the highest elevation surface a plane containing the highest elevation of the surface relief shape and parallel to the virtual plane of the average plane; (C) a plane wave having a wavelength of 550 nm emitted from the highest elevation plane from a direction perpendicular to the main normal direction of the lowest elevation plane A power spectrum of the complex amplitude when the complex amplitude of the highest elevation plane is calculated from the elevation of the surface relief shape and the refractive index of the antiglare layer is obtained. The anti-glare film according to claim 1, wherein the penetration clarity measured by using five kinds of optical combs having a width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm in the dark portion and the bright portion is used. The sum of Tc is 375% or more, and the sum of the reflection resolutions measured by the light incident angle of 45° is used for the four optical combs of the dark portion and the bright portion having the widths of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm. For the case of 180% or less, the sum of the reflection resolutions measured by the four types of optical combs having the width of the dark portion and the bright portion of 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm and the light incident angle of 60° is Rc (60). 240% or less.