TWI476456B - Antiglare film and method of manufacturing the same - Google Patents

Description

Anti-glare film and method of manufacturing same

The present invention relates to an antiglare film and a method for producing the same, and more particularly to an antiglare film in which an antiglare layer having a fine uneven surface is formed on a transparent support and a method for producing the same.

An image display device such as a liquid crystal display, a plasma display panel, a cathode ray tube (CRT), or an organic electroluminescence (EL) display, when external light is mapped to its display surface, Significantly compromises viewing. In order to prevent such mapping of external light, cameras and digital cameras used in outdoor environments where image quality is important, outdoor cameras used for outdoor use, and mobile phones that use reflected light for display have been used in the past. A film layer for preventing external light mapping is provided on the surface of the image display device. This film layer can be roughly classified into a film which is formed by a film which is subjected to the non-reflection treatment by the interference of the optical multilayer film, and which is formed by the formation of fine unevenness on the surface to scatter the incident light to blur the map image. The composition of the film treated with glare. The former non-reflective film has a high cost because it requires a multilayer film having a uniform optical film thickness. On the other hand, the latter anti-glare film can be manufactured relatively inexpensively, and is widely used in applications such as large-sized personal computers or displays.

Such an anti-glare film is conventionally applied to a substrate sheet by adjusting a film thickness by a resin solution in which fine particles are dispersed, and the particles are exposed on the surface of the coating film to form a film on the substrate sheet. A method of regular surface unevenness or the like is produced. However, the anti-glare film obtained by using the resin solution in which the fine particles are dispersed is difficult to obtain a desired surface unevenness because the arrangement or shape of the surface unevenness is affected by the dispersed state or the coated state of the fine particles in the resin solution. When the haze of the anti-glare film is set low, there is a problem that a sufficient anti-glare effect cannot be obtained. Further, when such a conventional anti-glare film is disposed on the surface of the image display device, the entire display surface is whitened by the scattered light, and thus there is a problem that the so-called "whitening" which becomes a cloudy color is likely to occur. Further, with the recent high definition of the image display device, the surface of the image display device and the surface of the anti-glare film are interfered with each other. As a result, there is a possibility that it is difficult to view the display surface due to the generation of the luminance distribution. The problem of "flashing" phenomenon. In order to eliminate flicker, although an attempt has been made to provide a refractive index difference between the binder resin and the fine particles dispersed therein to cause light to be scattered, when such an anti-glare film is disposed on the surface of the image display device, There is a problem that the contrast is easily lowered due to the scattering of light at the interface between the particles and the binder resin. Further, when the scattering of light is reduced in such a manner that the contrast is not lowered, there is a problem that the flicker eliminating effect is insufficient.

On the other hand, an attempt has been made to form an anti-glare property without containing fine particles and only by fine irregularities formed on the surface of the transparent resin layer. For example, Japanese Laid-Open Patent Publication No. 2002-189106 discloses an anti-glare film in which a cured layer of an ionizing radiation curable resin layer is laminated on a transparent resin film, and the ionizing radiation curable resin layer has a three-dimensional shape. The 10-point average roughness and the average distance between the convex portions adjacent to each other on the three-dimensional roughness reference surface satisfy the predetermined value of the fine surface unevenness. This anti-glare film is obtained by curing the ionizing radiation curable resin while sandwiching the ionizing radiation curable resin between the embossing mold and the transparent resin film. However, even with the anti-glare film disclosed in Japanese Laid-Open Patent Publication No. 2002-189106, it is difficult to achieve sufficient anti-glare effect, suppression of whitening, high contrast, and suppression of flicker.

Further, in order to produce a film having a fine unevenness on its surface, a method of transferring an uneven shape of a roll having an uneven surface to a film is known. For example, Japanese Laid-Open Patent Publication No. Hei 6-34961 discloses a method of producing a cylindrical body using metal or the like by electronic engraving, etching, sand blasting, or the like. The method of forming the unevenness on the surface. Further, in Japanese Laid-Open Patent Publication No. 2004-29240, a method of producing an embossing roll by a bead shot method has been disclosed, and a method has been disclosed in Japanese Laid-Open Patent Publication No. 2004-90187. A method of forming an embossing roll by a step of forming a metal plating layer on the surface of the embossing roll, a step of mirror-finishing the surface of the metal plating layer, and a process of performing a beading treatment.

However, in the state where the surface of the embossing roll is subjected to the blasting treatment, the distribution of the uneven diameter is caused by the particle size distribution of the blasting particles, and it is difficult to control the depth of the concave portion obtained by sand blasting, and therefore, it is necessary to There is still a problem in a well-behaved way to obtain an anti-glare function.

Japanese Laid-Open Patent Publication No. 2006-53371 describes the application of electroless nickel plating after polishing a substrate and applying sandblasting. In addition, Japanese Laid-Open Patent Publication No. 2007-187952 discloses the production of an embossed plate by subjecting a substrate to copper plating or nickel plating, polishing, and sandblasting, followed by chrome plating. In addition, Japanese Laid-Open Patent Publication No. 2007-237541 discloses that after copper plating or nickel plating, polishing and sandblasting are performed, an etching step or a copper plating step is applied, and then chrome plating is applied to produce a pressure. The content of the flower version. In such a method using sandblasting, since it is difficult to form a surface uneven shape in a state of precise control, a relatively large uneven shape having a period of 50 μm or more in the surface uneven shape is produced. As a result, such a large uneven shape interferes with the pixels of the image display device, and it is easy to cause a problem of so-called "flickering" of the display surface due to the occurrence of the luminance distribution.

An object of the present invention is to provide an anti-glare film having an anti-glare layer containing fine particles, which has low haze and which can exhibit excellent anti-glare performance when used in an image display device, and prevents whitening A reduction in visibility is caused, and even when used in a high-definition image display device, flicker does not occur, and a high-contrast anti-glare film and a method of manufacturing the same can be exhibited.

The present invention provides an anti-glare film comprising: a transparent support; and an anti-glare film laminated on the transparent support and having an anti-glare layer having an uneven surface, wherein the unevenness in a spatial frequency of 0.01 μm ^-1 spectrum of the surface of the elevation H ₁ ² in the spatial frequency spectrum of the elevation of the surface irregularities of 0.04μm ^-1 H _{² 2} ratio H _{1 ²} / H ^{2 2,} based in the range of 3 to 15; antiglare The layer is composed of a binder resin and fine particles dispersed in the binder resin; and the uneven surface of the antiglare layer is composed of a surface formed of a binder resin.

The antiglare layer preferably contains 10 to 50 parts by weight, based on 100 parts by weight of the binder resin, of an average particle diameter of 5 μm or more and 10 μm or less, and a refractive index ratio to the binder resin of 0.93 or more and 0.98 or less or 1.01. The fine particles of 1.04 or less or more; and the thickness of the antiglare layer is 1.1 times or more and 2 times or less of the average particle diameter of the fine particles.

The anti-glare film of the present invention is preferably an energy spectrum H ₃ ² of an elevation of the above-mentioned uneven surface in a spatial frequency of 0.1 μm ^-1 and an energy spectrum H ₂ ² of an elevation of the above-mentioned uneven surface in a spatial frequency of 0.04 μm ^-1 . The ratio H ₃ ² /H ₂ ² is 0.1 or less. Moreover, it is preferable that the uneven surface provided in the anti-glare film of the present invention contains a surface having an inclination angle of 5° or less of 95% or more.

Furthermore, the present invention provides a method for producing an anti-glare film, which is a method for producing the anti-glare film according to any one of the above aspects, comprising: exhibiting a spatial frequency greater than 0 μm ^-1 and being 0.04 μm ^{- a process} in which a pattern having an energy spectrum of a maximum value is not included in the range of ¹ or less, and a process of forming a mold having a concave-convex surface; and transferring the uneven surface of the mold to a surface of the resin layer in which the fine particles are formed on the transparent support Process.

According to the present invention, it is possible to obtain an anti-glare film which has low haze and which exhibits excellent anti-glare property when applied to an image display device and can be prevented from being caused by whitening in a reproducible manner. The visibility is lowered, and even when applied to a high-definition image display device, flicker does not occur and high contrast can be exhibited.

<anti-glare film>

As shown in FIG. 1, the anti-glare film of the present invention includes a transparent support 101 and an anti-glare layer 102 laminated on the transparent support 101. The anti-glare layer 102 is composed of a binder resin 103 and fine particles 104 dispersed in the binder resin 103, and the surface opposite to the transparent support 101 is a fine uneven surface of the surface formed by the binder resin 103 ( The fine uneven surface 105) is formed. The anti-glare film of the present invention will be described in more detail below.

(anti-glare layer)

In the antiglare layer provided in the antiglare film of the present invention, the energy spectrum H ₁ ² of the level of the fine uneven surface in the spatial frequency of 0.01 μm ^-1 and the level of the fine uneven surface in the spatial frequency of 0.04 μm ^-1 spectrum H ratio of H _{² 2 1 ²} / H ^{2 2,} based in the range of 3 to 15.

In the past, the period of the fine uneven surface of the anti-glare film is evaluated by the average length RSm of the roughness curve elements described in JIS B 0601, the average length PSm of the profiled curve elements, and the average length WSm of the curved curve elements. . However, in such a conventional evaluation method, the plurality of periods included in the surface of the fine uneven surface cannot be correctly evaluated. Therefore, the correlation between the flicker and the fine uneven surface and the correlation between the anti-glare property and the fine uneven surface cannot be correctly evaluated. Under the control of the values of RSm, PSm, and WSm, it is difficult to produce both flicker suppression and An anti-glare film with sufficient anti-glare properties.

The inventors of the present invention have found that in the antiglare film having the fine uneven surface and the antiglare layer in which the fine particles are dispersed, the fine uneven surface exhibits the use of the "energy spectrum of the surface of the fine uneven surface". The specific spatial frequency distribution specified, that is, the energy spectrum H ₁ ² of the elevation of the fine concave-convex surface in the spatial frequency of 0.01 μm ^-1 , and the energy spectrum H ₂ of the elevation of the fine concave and convex surface in the spatial frequency of 0.04 μm ^-1 H ² ratio of _{1 ²} / H ^{2 2} anti-glare film is located within the range of 3 to 15, preferably can show anti-glare effect and can sufficiently suppress flicker. Further, the fine concavo-convex surface is formed by a surface formed of a binder resin (the particles dispersed in the binder resin do not protrude from the surface of the anti-glare layer), thereby forming an anti-glare layer, thereby eliminating the protrusion The influence of the fine particles on the surface shape of the fine unevenness and the above-described specific spatial frequency distribution can be surely obtained, and an anti-glare film which exhibits the above-described preferable optical characteristics extremely can be obtained with excellent reproducibility. The anti-glare film of the present invention exhibits the above-mentioned specific spatial frequency distribution, can exhibit better anti-glare performance, and prevents deterioration of visibility due to whitening, even when applied to a high-definition image display device At the same time, no anti-glare film can be produced which is flickering and can exhibit high contrast.

Further, the anti-glare film of the present invention contains fine particles in the anti-glare layer, and is more effective in suppressing flicker than the anti-glare film not containing fine particles. In the past, when an anti-glare film having particles having a refractive index different from that of the binder resin is dispersed in the anti-glare layer and disposed on the surface of the image display device, light scattering at the interface between the particles and the binder resin is caused. However, there is a problem that the contrast is easily lowered, but according to the anti-glare film of the present invention, the scintillation suppressing effect by the microparticles can be obtained without causing a decrease in contrast.

First, the energy spectrum of the elevation of the fine uneven surface of the antiglare layer will be described. Fig. 2 is a perspective view schematically showing the surface of the anti-glare film of the present invention. As shown in FIG. 2, the anti-glare film 1 of the present invention includes an anti-glare layer having a fine uneven surface composed of fine unevenness 2. Here, the "elevation of the fine uneven surface" in the present invention means that the height of the lowest point of the fine uneven surface in the arbitrary point P on the surface of the anti-glare film 1 is from the virtual plane having the height (the elevation system) The linear distance in the main normal direction 5 (the normal direction of the imaginary plane) of the anti-glare film based on 0 μm. As shown in Fig. 2, when the orthogonal coordinates in the plane of the anti-glare film are represented by (x, y), the elevation of the fine concave-convex surface can be represented by the two-dimensional function h(x, y) of the coordinates (x, y). Said. In Fig. 2, the surface of the entire anti-glare film is indicated by the projection surface 3.

The elevation of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, or an atomic force microscope (AFM). The horizontal decomposition energy required for the measuring machine is at least 5 μm or less, preferably 2 μm or less, and the vertical decomposition energy is at least 0.1 μm or less, preferably 0.01 μm or less. A non-contact three-dimensional surface shape/roughness measuring machine suitable for the measurement includes a New View 5000 series (manufactured by Zygo Corporation, available from Zygo Co., Ltd. in Japan), and a three-dimensional microscope PLμ2300 (Sensofar Co., Ltd.) System) and so on. The measurement area is preferably at least 200 μm × 200 μm or more, and more preferably 500 μm × 500 μm or more, since the decomposition energy of the energy spectrum of the elevation must be 0.01 μm ^-1 or less.

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

Here, f _x and f _y are spatial frequencies in the x direction and the y direction, respectively, and have a dimension having a reciprocal of length. Further, π in the formula (1) is a pi, and i is an imaginary unit. Obtained by the two-dimensional function H (f _x, f _y) for calculating the square, the elevation is obtained spectrum ^{_{H 2 (f x, f y}} ). This energy spectrum H ² (f _x , f _y ) represents the spatial frequency distribution of the fine uneven surface of the antiglare layer.

Hereinafter, a method of obtaining an energy spectrum of the elevation of the fine uneven surface of the antiglare layer will be more specifically described. The three-dimensional information of the surface shape actually measured by the confocal microscope, the interference microscope, the atomic force microscope, or the like can be generally obtained as a discrete value, that is, corresponding to the elevation of a plurality of measurement points. Fig. 3 is a view showing a state in which the function h(x, y) indicating the elevation is discretely obtained. As shown in Fig. 3, the orthogonal coordinates in the plane of the anti-glare film are indicated by (x, y), and the line divided by Δx in the x-axis direction on the projection surface 3 of the anti-glare film is indicated by a broken line. And in the case of a line divided by Δy in the y-axis direction, in actual measurement, the elevation of the fine uneven surface can be used as a discrete elevation value of each intersection of each broken line on the projection surface 3 of the anti-glare film. obtain.

The number of the obtained elevation values is determined by the measurement range and Δx and Δy. As shown in Fig. 3, when the measurement range in the x-axis direction is X = MΔx, the measurement range in the y-axis direction is set to Y = When NΔy, the number of elevation values to be obtained is (M+1) × (N+1).

As shown in FIG. 3, when the coordinate of the eye point A on the projection surface 3 of the anti-glare film is (jΔx, kΔy) (here, j is 0 or more and M or less, and k is 0 or more and N or less), The elevation of the point P on the surface of the anti-glare film corresponding to the point of view A can be expressed as h(jΔx, kΔy).

Here, the measurement intervals Δx and Δy are determined according to the horizontal decomposition energy of the measuring device, and in order to evaluate the fine uneven surface with excellent precision, as described above, Δx and Δy are preferably 5 μm or less, and particularly preferably 2 μm or less. Further, the measurement range is preferably 200 μm or more, and more preferably 500 μm or more as described above.

As described above, in the actual measurement, the function indicating the elevation of the fine uneven surface can be obtained in the form of a discrete function h(x, y) of (M+1) × (N+1) values. Therefore, the discrete function H(f _x , f _y ) is obtained by the discrete function h(x, y) obtained by the measurement and the discrete Fourier transform defined by the following formula (2), and by discretizing The function H(f _x , f _y ) performs a quadratic operation to obtain a discrete function H ² (f _x , f _y ) of the energy spectrum. 1 in the formula (2) is an integer of -(M+1)/2 or more and (M+1)/2 or less, and m is an integer of -(N+1)/2 or more (N+1)/2 or less. Further, Δf _x and Δf _y are spatial frequency intervals in the x direction and the y direction, respectively, and are defined by the equations (3) and (4). Δf _x and Δf _y correspond to the horizontal decomposition energy of the energy spectrum of the elevation.

Fig. 4 is a diagram showing the elevation of the fine uneven surface of the antiglare layer of the antiglare film of the present invention (specifically, the antiglare film of Example 1 to be described later) by the two-dimensional discrete function h(x, y) Figure. In Fig. 4, the elevation is expressed in terms of white and black gradations. The discrete function h(x, y) shown in Fig. 4 has 512 × 512 values, and the horizontal decomposition energy Δx and Δy are 1.66 μm.

In addition, Fig. 5 shows the energy spectrum H ² (f _x , f _y ) of the elevation obtained by discrete Fourier transform of the two-dimensional function h(x, y) shown in Fig. 4 in white and black _gradation . Picture. The energy spectrum H ² (f _x , f _y ) of the elevation shown in Fig. 5 is also a discrete function having 512 × 512 values, and the energy level horizontal decomposition energies Δf _x and Δf _y of the elevation are 0.0012 μm ^-1 .

In the example shown in Fig. 4, since the fine uneven surface of the antiglare layer provided in the antiglare film of the present invention is composed of irregularly formed irregularities, the energy spectrum H ² of the elevation is as shown in Fig. 5. It is symmetrical with the origin as the center. Therefore, the energy spectrum H ₁ ² and the spatial frequency of 0.04 μm in the spatial frequency of 0.01 μm ^-1 can be obtained from the profile of the origin through the energy spectrum H ² (f _x , f _y ) belonging to the two-dimensional function. The energy spectrum H ₂ ² of the elevation in ^-1 . Fig. 6 is a cross-sectional view showing the energy spectrum H ² (f _x , f _y ) shown in Fig. 5 at f _x =0. As can be seen from the figure, the energy spectrum H ₁ ² of the elevation in the spatial frequency of 0.01 μm ^-1 is 4.8, and the energy spectrum H ₂ ² of the elevation in the spatial frequency of 0.04 μm ^-1 is 0.35, H ₁ ² /H ₂ The ratio of ² is 14.

As described above, in the antiglare layer of the present invention, the ratio H of the elevation spectrum H ₁ ² of the fine uneven surface in the spatial frequency of 0.01 μm ^-1 to the energy spectrum H ₂ ² of the elevation in the spatial frequency of 0.04 μm ^-1 ₁ ² /H ₂ ² is set in the range of 3 to 15. When the ratio H ₁ ² /H ₂ ² of the energy spectrum of the elevation is less than 3, it is shown that the uneven surface of the long period of 100 μm or more contained in the fine uneven surface of the antiglare layer is small, and the unevenness of the short period of 25 μm is less. More shapes. At this time, the mapping of external light cannot be effectively prevented, and sufficient anti-glare performance cannot be obtained. On the other hand, in the case where the ratio H ₁ ² /H ₂ ² of the energy spectrum of the elevation is higher than 15, the long-period shape of the long period of 100 μm or more contained in the surface of the fine uneven surface is large, and the short period of 25 μm or less is short. The shape of the bump is less. At this time, when the anti-glare film is disposed in a high-definition image display device, there is a tendency to cause flicker. In order to show better the anti-glare effect and effectively suppress flicker, elevation spectrum ratio H _{² 2} H _{1 ²} / H ^{2 2} preferably ranges from 3.5 to 14.5, more preferably in a range of 4 to 14 Inside.

Further, the short-period component of less than 10 μm contained in the fine uneven surface cannot effectively provide anti-glare property, and the light incident on the fine uneven surface is scattered to cause whitening, so that it is less preferable. Specifically, when the energy spectrum of the elevation at a spatial frequency of 0.1 μm ^-1 is H ₃ ² , the energy spectrum ratio H ₃ ² /H ₂ ^{2 is} preferably 0.1 or less, and more preferably 0.01 or less. In the energy spectrum shown in Fig. 6, the energy spectrum H ₃ ² of the elevation in the spatial frequency of 0.1 μm ^-1 is 0.00076. From the results, it was found that the energy spectrum ratio H ₃ ² /H ₂ ² was 0.0022.

The present inventors have further found that when the fine uneven surface of the antiglare layer is formed to exhibit a specific oblique angle distribution, it is possible to exhibit better antiglare performance and to more effectively prevent whitening. In other words, in the antiglare film of the present invention, the fine uneven surface of the antiglare layer is preferably a surface having an inclination angle of 95% or more of 5 or less. When the ratio of the surface having an inclination angle of 5 or less is less than 95%, the inclination angle of the uneven surface becomes steep, and the light from the surroundings is condensed, and whitening of the entire display surface is likely to occur. In order to suppress this condensing effect to prevent whitening, the higher the ratio of the surface of the fine uneven surface having an inclination angle of 5 or less, the better, preferably 97% or more, and more preferably 99% or more.

Here, the "inclination angle of the fine uneven surface" in the present invention means that the point B at the arbitrary point P on the surface of the anti-glare film 1 with respect to the main normal direction 5 of the anti-glare film is referred to in Fig. 2 The angle formed by the local normal 6 after the unevenness is added (surface tilt angle) ψ. The inclination angle of the fine uneven surface can be obtained from the three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, or an atomic force microscope (AFM), similarly to the elevation.

Fig. 7 is a schematic view for explaining a method of measuring the inclination angle of the fine uneven surface. As shown in Fig. 7, when the specific tilt angle determining method is described, the eye point A on the virtual plane FGHI indicated by the broken line is determined, and the vicinity of the eye point A on the x-axis passing through the point is taken as Point A is almost symmetrical with points B and D, and points C and E which are almost symmetrical with respect to point A near the point of view A on the y-axis passing through point A, and are determined to correspond to points B and C. The points Q, R, S, and T on the anti-glare film surface of D, E. In Fig. 7, the orthogonal coordinates in the plane of the anti-glare film are indicated by (x, y), and the coordinates in the thickness direction of the anti-glare film are indicated by z. The plane FGHI is a line parallel to the x-axis passing through the point C on the y-axis, and a line parallel to the x-axis passing through the point E on the y-axis, respectively, passing through the point B on the x-axis parallel to the y-axis The straight line and the line formed by the straight line parallel to the y-axis of the point D on the x-axis and the intersections F, G, H, and I. In addition, in Fig. 7, the position of the actual anti-glare film surface is drawn upward with respect to the plane FGHI, but of course, the actual anti-glare film surface can be made different depending on the position of the eye point A. Position above or below the plane FGHI.

The tilt angle can be obtained by determining the actual anti-glare of the point P corresponding to the actual anti-glare film surface of the eye point A and the 4 points B, C, D, E corresponding to the point taken near the eye point A. The four planes of the polygon formed by the total of five points Q, R, S, and T on the film surface, that is, from the three-dimensional information of the measured surface shape, the four triangles PQR, PRS, and PST are obtained. The average normal vector obtained by averaging the normal vectors 6a, 6b, 6c, and 6d of the PTQ (the average normal vector is synonymous with the local normal 6 after the unevenness shown in Fig. 2) Obtained from the polar angle of the main normal direction of the glare film. After obtaining the tilt angle for each measurement point, the histogram is calculated.

FIG. 8 is a view showing an example of a histogram of the oblique angle distribution of the fine uneven surface of the antiglare layer provided in the antiglare film (specifically, the antiglare film of Example 1 to be described later). In the graph shown in Fig. 8, the horizontal axis is an oblique angle and is divided by a scale of 0.5. For example, the leftmost straight column represents a distribution of a set of ranges in which the tilt angle is in the range of 0 to 0.5, and then the angle is increased by 0.5° each time as it moves to the right. In the figure, the lower limit value of the value of each of the two scales on the horizontal axis is shown. For example, the portion of "1" in the horizontal axis indicates the distribution of the set of the range in which the inclination angle is in the range of 1 to 1.5, and the vertical axis. The distribution indicating the inclination angle is a value of 1 (100%) in total. In this example, the ratio of the surface having an inclination angle of 5 or less is approximately 100%.

Next, the specific configuration of the antiglare layer provided in the antiglare film of the present invention will be described in detail. In the present invention, the antiglare layer is composed of a binder resin and fine particles dispersed in the binder resin, and is formed on the surface opposite to the transparent support 101, and is composed of a fine uneven surface 105. As described above, the fine uneven surface 105 can surely impart the above-described specific spatial frequency distribution, and can highly exhibit anti-glare performance, whitening suppression energy, scintillation suppressing performance, and contrast performance, and is formed by a surface formed of a binder resin. Composition. Here, the surface of the fine uneven surface formed of the surface formed of the binder resin means that the dispersed fine particles do not protrude from the surface of the antiglare layer, and the fine particles are completely embedded in the binder resin. By forming the surface of the fine uneven surface only by the surface formed by the binder resin, it is possible to eliminate the influence of the protruding fine particles on the surface of the fine uneven surface (for example, the change in the shape of the fine uneven surface caused by the change in the shape of the fine particles) Thereby, the fine uneven surface shape of the antiglare layer can be controlled with high precision.

In order to obtain an antiglare layer having a fine uneven surface composed of a surface formed of a binder resin, the fine particles preferably have an average particle diameter of 10 μm or less and a refractive index ratio to the binder resin (in terms of refractive index of the particles) n _b is, the refractive index of the resin binder is the time n _b n _r / n _r) of 1.01 or more 0.98 or less fine particles and the content of the fine particles with respect to 100 parts by weight of a binder resin 50 parts by weight or less, Further, the thickness of the antiglare layer is preferably set to 1.1 times or more of the average particle diameter of the fine particles. The average particle diameter of the fine particles is preferably 8 μm or less, and the content of the fine particles is preferably 40 parts by weight or less based on 100 parts by weight of the binder resin.

When the average particle diameter of the fine particles used exceeds 10 μm, the film thickness required for embedding the fine particles in the binder resin becomes thick, and as a result, defects such as curling or aggregation tend to occur during resin coating. Further, when the refractive index ratio n _b /n _r exceeds 0.98 and does not reach 1.01, the internal scattering effect achieved by the microparticles is small, and therefore, in order to impart predetermined scattering characteristics to the antiglare layer to eliminate flicker, a large amount of microparticles must be obtained. It is added to the binder resin, and there is a tendency that it is difficult to completely embed the particles in the binder resin. In addition, when the fine particles are contained in an amount of more than 50 parts by weight based on 100 parts by weight of the binder resin, it is difficult to completely embed the fine particles in the binder resin, which is not preferable. Further, when the thickness of the antiglare layer is less than 1.1 times the average particle diameter, the tendency of the fine particles to protrude from the binder resin is remarkable.

In the method of forming an antiglare layer having a fine uneven surface composed of a surface formed of a binder resin on a transparent support, it is preferred to use an embossing method (embossing) using the following resin composition The method will be described in detail later, and a resin layer (anti-glare layer) having the predetermined thickness described above is formed on a transparent support, and the resin composition contains an average particle diameter and a refractive index having the above preferred range in the above preferred content. Particles with a ratio of n _b /n _r .

The average particle diameter of the fine particles to be blended in the binder resin is preferably 5 μm or more, and more preferably 6 μm or more. When the average particle diameter is less than 5 μm, the scattered light intensity on the wide-angle side caused by the fine particles rises, and when applied to an image display device, the contrast tends to be lowered. Further, the refractive index ratio n _b /n _{r of the} fine particles and the binder resin is particularly preferably 0.93 or more and 0.98 or less, or 1.01 or more and 1.04 or less, more preferably 0.97 or more and 0.98 or less or 1.01 or more and 1.03 or less. When the refractive index ratio n _b /n _{r is} less than 0.93 or higher than 1.04, the reflectance at the interface between the fine particles and the binder resin is increased, and as a result, the back scattering is increased, and the total light transmittance is lowered. A decrease in the total light transmittance increases the haze of the anti-glare film, and a contrast reduction occurs when applied to an image display device. Further, the content of the fine particles is preferably 10 parts by weight or more, and particularly preferably 15 parts by weight or more based on 100 parts by weight of the binder resin. When it is less than 10 parts by weight, the scintillation suppressing effect achieved by the fine particles is insufficient. Further, the thickness of the antiglare layer is preferably 2 or less times the average particle diameter of the fine particles, and more preferably 1.5 times or less. When the thickness of the antiglare layer exceeds twice the average particle diameter, a loss such as curling tends to occur at the time of resin coating.

The material constituting the fine particles preferably satisfies the above preferred refractive index ratio. As described later, in the present invention, the formation of the antiglare layer is preferably carried out by UV embossing, and in the UV embossing method, the ultraviolet curable resin can be preferably used as a binder resin precursor. In this case, since the cured product (adhesive resin) of the ultraviolet curable resin exhibits a refractive index of about 1.50, the fine particles can be appropriately selected from the refractive index of 1.40 to 1.60 in accordance with the design of the antiglare film. The particles are preferably those which use resin particles and are almost spherical. Examples of the preferred resin particles are as disclosed below.

Melamine particles (refractive index 1.57), polybutyl methacrylate (refractive index 1.49), methyl methacrylate/styrene copolymer resin particles (refractive index 1.50 to 1.59), polycarbonate particles (refractive index 1.55), Polyethylene particles (refractive index: 1.53), polystyrene particles (refractive index: 1.6), polyvinyl chloride particles (refractive index: 1.46), neodymium resin particles (refractive index: 1.46), and the like.

(transparent support)

The transparent support is not particularly limited as long as it is substantially an optically transparent film, and examples thereof include a cellulose triacetate film, a polyethylene terephthalate film, and a polymethyl methacrylate film. A thermoplastic resin film such as a polycarbonate film or a film composed of a non-crystalline cyclic polyolefin having a decene-based compound as a monomer. These thermoplastic resin films may be solution cast films or extruded films. The thickness of the transparent support is not particularly limited, but is usually 10 to 250 μm, preferably 20 to 125 μm.

When the anti-glare film of the present invention irradiates light to the normal direction of the transparent support from the transparent support side, the relative scattered light observed in the direction of 20° from the normal direction of the transparent support on the anti-glare layer side The strength T (20) is preferably a value of 0.001% or less. Fig. 9 is a view schematically showing a direction in which light is incident on the transparent support from the normal direction of the transparent support, and the scattering measured in the direction from the normal direction of the transparent support at 20° on the side of the anti-glare layer is obtained. A perspective view of the direction of incidence of light at the time of light intensity and the direction of measurement of the intensity of transmitted scattered light. Referring to the figure, the side of the transparent support body of the anti-glare film 1 is incident with respect to the normal direction 5' from the transparent support (this direction is the same direction as the main normal direction 5 of the anti-glare film of Fig. 2). The light 20 is measured on a plane 22 which is in the direction of the light containing the incident light 20 and the normal direction 5' of the transparent support, and penetrates in a direction inclined by 20° from the normal direction 5' of the anti-glare layer side. The intensity of the scattered light 21 is divided, and the intensity of the transmitted scattered light is divided by the light intensity of the light source, and the percentage of the obtained value is set as the relative scattered light intensity T (20).

When the relative scattered light intensity T(20) exceeds 0.001%, when the anti-glare film is applied to an image display device, the brightness at the time of black display is increased by the scattered light, and the contrast is lowered, which is not preferable. In particular, when the anti-glare film is applied to a non-self-luminous type liquid crystal display, the effect of brightness rise due to scattering of light leakage during black display is large, so when the relative scattered light intensity T(20) exceeds 0.001%, This will result in a significant decrease in contrast and a loss of visibility. In the present invention, by using the specific average particle diameter and the particles having a specific refractive index ratio with respect to the binder resin as the particles contained in the antiglare layer, the relative scattered light intensity T(20) can be made 0.001%. the following.

When measuring the relative scattered light intensity of the anti-glare film, it is necessary to accurately measure the relative scattered light intensity of 0.001% or less. Therefore, the use of a wide dynamic range of detectors is effective. For such a detector, for example, a commercially available optical power meter or the like can be used, and an aperture can be set in front of the detector of the optical power meter, and a photometer with a viewing angle of 2° can be used. The anti-glare film was measured. For the incident light, visible light of 380 to 780 nm can be used, and the light source for measurement can be used for collimation correction of light emitted from a light source such as a halogen lamp, or a monochromatic light source such as a laser, and the parallelism is high. Further, in order to prevent warpage of the antiglare film, it is preferable to use an optically transparent adhesive so as to adhere the glass substrate to the surface of the uneven surface, and then provide the measurement.

In view of the above, in the present invention, the relative scattered light intensity T (20) is measured in the following manner. The anti-glare film is bonded to the glass substrate such that the uneven surface is a surface, and the parallel light from the He-Ne laser is irradiated from the normal direction of the anti-glare film (the normal direction of the transparent support) on the glass surface side. On the side of the uneven surface of the anti-glare film, the intensity of the transmitted scattered light in the direction inclined by 20° from the normal line of the anti-glare film was measured. For the measurement of the transmitted light intensity, "329203 Optical Power Sensor" and "3292 Optical Power Meter" manufactured by Yokogawa Electric Corporation were used.

Figure 10 shows a plot of relative scattered light intensity T(20) versus contrast. From Fig. 10, it can be seen that when the relative scattered light intensity T(20) exceeds 0.001%, the contrast is reduced by 10% or more, which tends to impair the visibility. In the production of Figure 10, the comparison was measured by the following method. First, the polarizing plate on the back side and the display side was peeled off from a commercially available liquid crystal TV ("LC-42GX1W" manufactured by Sharp Corporation), and the polarizing plate "Sumikalan SRDB31E" manufactured by Sumitomo Chemical Co., Ltd. was used for absorption. The axial direction is the same as the absorption axis of the original polarizing plate, and is adhered to the back side and the display surface side by an adhesive to replace the original polarizing plate, and then the anti-glare film of the present invention having various scattered light intensities is displayed. An anti-glare film having the same configuration (that is, a structure in which an anti-glare layer having fine surface irregularities and fine particles dispersed thereon is laminated on a transparent support) is attached to the display by an adhesive so that the uneven surface is a surface Face side polarizing plate. Then, the liquid crystal TV thus obtained is activated in a darkroom, and the brightness of the black display state and the white display state is measured using a brightness meter "BM5A" type manufactured by Topcon Corporation, and the brightness of the white display state is calculated with respect to the black display state. The ratio of brightness is used as a comparison.

In the anti-glare film of the present invention, since the spatial frequency distribution of the fine uneven surface of the anti-glare layer is appropriately controlled in the anti-glare layer, the relative scattered light intensity T(20) which is a main factor for the decrease in contrast is not The particles designed in a manner higher than the required degree are required to have sufficient anti-glare property, and even when disposed in an ultra-high-definition image display device, flicker does not occur, and the contrast can be effectively prevented from being lowered.

<Method for Producing Anti-Glare Film>

The antiglare film of the present invention described above is preferably produced by a method comprising the following steps (A) and (B).

(A) a step of producing a mold having a concave-convex surface based on a pattern showing an energy spectrum having a maximum value in a range of a spatial frequency of more than 0 μm ^-1 and not more than 0.04 μm ^-1 ;

(B) a step of transferring the uneven surface of the mold to the surface of the resin layer on which the fine particles are formed on the transparent support.

By using a pattern having an energy spectrum having a maximum value in a range of a spatial frequency of more than 0 μm ^-1 and not more than 0.04 μm ^-1 , it is possible to accurately form a fine uneven surface having the above-described specific spatial frequency distribution. Further, a method of producing a mold having an uneven surface according to the pattern and transferring the uneven surface of the mold to the surface of the resin layer on which the fine particles are formed on the transparent support (embossing method) can be produced. An anti-glare layer having a fine uneven surface (the particles are completely embedded in the binder resin) composed of a surface formed of a binder resin is obtained. Here, the "pattern" generally means a second-order tone (for example, binarized image data of white and black) which is used by a computer for forming a fine uneven surface of an anti-glare film. Or image data composed of gradations above the 3rd order, but may also contain information (array, etc.) that can be unambiguously converted into the image data. For data that can be unambiguously converted into image data, for example, coordinates of each pixel and data of only the tone are stored.

The energy spectrum of the pattern used in the above step (A), for example, if it is image data, can be represented by a two-dimensional function g(x, y) after converting the image data into a gray scale of 256-order tone. The tone of the image data, and the resulting two-dimensional function g(x, y) is subjected to discrete Fourier transform to calculate the two-dimensional function G(f _x , f _y ), and then the obtained two-dimensional function G(f _x , f _y ) is obtained by performing a quadratic operation. Here, x and y represent orthogonal coordinates in the image data plane, and f _x and f _y represent the spatial frequency in the x direction and the spatial frequency in the y direction, respectively.

The same as the time when the energy spectrum of the surface of the fine concave-convex surface is obtained, the two-dimensional function g(x, y) of the tone is generally obtained as a discrete function when the energy spectrum of the pattern is obtained. At this time, the energy spectrum can be calculated by discrete Fourier transform as in the case of obtaining the energy spectrum of the elevation of the fine uneven surface. Specifically, the discrete function G(f _x , f _y ) is calculated by the discrete Fourier transform defined by the equation (5), and then the obtained discrete function G(f _x , f _y ) is subjected to quadratic operation. The energy spectrum G ² (f _x , f _y ) is obtained. Here, π in the formula (5) is a pi, and i is an imaginary unit. Further, M is the number of pixels in the x direction, N is the number of pixels in the y direction, 1 is an integer of -M/2 or more and 2 or less, and m is an integer of -N/2 or more and N/2 or less. Further, Δf _x and Δf _y are spatial frequency intervals in the x direction and the y direction, respectively, and are defined by the equations (6) and (7). Δx and Δy in the equations (5) and (6) are horizontal decomposition energies in the x-axis direction and the y-axis direction, respectively. When the pattern is image data, Δx and Δy are equal to the length of the x-axis direction of one pixel and the length of the y-axis direction, respectively. That is, when a pattern is formed with image data of 6400 dpi, Δx = Δy = 4 μm, and when a pattern is formed with image data of 12800 dpi, Δx = Δy = 2 μm.

Fig. 11 is a view showing the image data of the pattern (the pattern used in the mold making of Example 1 to be described later) for producing the anti-glare film of the present invention by the two-dimensional discrete function g(x, y) of the tone. Part of the map. The two-dimensional discrete function g(x, y) shown in Fig. 11 has 512 × 512 values, and the horizontal decomposition energy Δx and Δy are 2 μm. Further, the image data of the pattern shown in Fig. 11 was 2 mm × 2 mm, and was produced at 12,800 dpi.

Figure 12 shows the energy spectrum G ² (f _x , f _y ) obtained by discrete Fourier transform of the two-dimensional discrete function g(x, y) of the tone shown in Fig. 11 in white and black _gradation . Picture. The energy spectrum function G ² (f _x , f _y ) shown in Fig. 12 also has 512 × 512 values, and the horizontal decomposition energies Δf _x and Δf _y are 0.0010 μm ^-1 . As shown in Fig. 11, the pattern produced by the anti-glare film of the present invention is irregularly arranged, so that the obtained energy spectrum G ² (f _x , f _y ) is as shown in Fig. 12. It is symmetrical with the origin as the center. Therefore, the spatial frequency representing the maximum value of the energy spectrum G ² (f _x , f _y ) of the pattern can be obtained from the profile passing through the origin of the energy spectrum. Fig. 13 is a cross-sectional view showing the f _x =0 of the energy spectrum G ² (f _x , f _y ) shown in Fig. 12. Known from the figure, the pattern shown in FIG. 11 in the spatial frequency 0.045μm ^-1 it has a maximum value, but greater than 0μm ^-1 and not to have a maximum value in the range of 0.04μm ^-1 or less.

When the energy spectrum G ² (f _x , f _y ) of the pattern for producing the anti-glare film has a maximum value in a range larger than 0 μm ⁻¹ and not more than 0.04 μm ⁻¹ , the obtained anti-glare film The fine uneven surface does not exhibit the above-described specific spatial frequency distribution, so that the elimination of flicker and sufficient anti-glare property cannot be achieved at the same time.

The energy spectrum G ² (f _x , f _y ) has a pattern having no maximum value in a range larger than 0 μm ⁻¹ and not more than 0.04 μm ⁻¹ , for example, by the pattern shown in FIG. 11 , A plurality of points having an average spot diameter (average of diameters of all points) of less than 20 μm were irregularly and uniformly arranged. The spot diameters that are irregularly arranged may be one or plural. Further, in order to more effectively remove the spatial frequency component having a spatial frequency of 0.04 μm ^-1 or less from the pattern formed by irregularly arranging such a plurality of dots, it is possible to remove the spatial frequency component of 0.04 μm ^-1 or less. The pattern obtained by the high-pass filter is used as a pattern for producing an anti-glare film. Furthermore, in order to more effectively remove spatial frequency components having a spatial frequency of 0.04 μm ^-1 or less from patterns irregularly arranged at a plurality of points, it is possible to remove low spatial frequency components of 0.04 μm ^-1 or less and A pattern obtained by a band pass filter of a spatial frequency component having a specific spatial frequency component or more is used as a pattern for producing an antiglare film.

A method of producing a mold according to the pattern obtained in the above manner will be described in detail later.

The step (B) is a step of forming an antiglare layer having a fine uneven surface and dispersing fine particles on the transparent support by an embossing method. In the embossing method, a UV embossing method using a photocurable resin and a hot embossing method using a thermoplastic resin can be exemplified, and from the viewpoint of productivity, a UV embossing method is preferred. In the UV embossing method, a photocurable resin layer containing fine particles is formed on the surface of the transparent support, and the photocurable resin layer is pressed against the uneven surface of the mold to be cured, thereby forming the uneven surface of the mold. A method of transferring to a photocurable resin layer. More specifically, the coating liquid of the photocurable resin in which the fine particles are dispersed is applied onto the transparent support, and the coated photocurable resin is adhered to the uneven surface of the mold, and is transparently supported. The body side is irradiated with light such as ultraviolet rays to cure the photocurable resin, and then the transparent support body on which the cured photocurable resin layer is formed is peeled off from the mold, whereby the uneven shape of the mold can be transferred to the hardened portion. An anti-glare film of the subsequent photo-curable resin layer (anti-glare layer).

In the UV embossing method, the transparent support is preferably used. The photocurable resin is preferably an ultraviolet curable resin which is cured by ultraviolet rays, or a photoselective agent which is appropriately selected may be combined with an ultraviolet curable resin, and can be used by visible light having a longer wavelength than ultraviolet rays. Hardened resin. The type of the ultraviolet curable resin is not particularly limited, and a commercially available suitable product can be used. A preferred example of the ultraviolet curable resin is one or more selected from the group consisting of polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, and Irgacure 907 (manufactured by Chiba Specialty Chemicals Co., Ltd.) and Irgacure 184. A resin composition of a photopolymerization initiator such as (Chiba Specialty Chemicals Co., Ltd.) or Lucirin TPO (manufactured by BASF Corporation). The coating liquid can be prepared by including the fine particles in the ultraviolet curable resin.

<Method for Producing Mold for Manufacturing Anti-Glare Film>

Hereinafter, a method of producing a mold used in the production of the antiglare film of the present invention will be described. The method for producing a mold used in the production of the anti-glare film of the present invention is not particularly limited as long as it can obtain a predetermined surface shape obtained according to the above-described pattern, but is excellent in accuracy and reproducibility. The fine uneven surface of the anti-glare film preferably contains [1] the first plating step, the [2] polishing step, the [3] photosensitive resin film forming step, the [4] exposure step, and the [5] developing step. [6] The first etching step, the [7] photosensitive resin film peeling step, and the [8] second plating step. Fig. 14 is a view schematically showing a preferred example of the first half of the method of manufacturing the mold. In Fig. 14, the cross section of the mold in each step is schematically shown. Hereinafter, each step of the method for producing the mold will be described in detail with reference to Fig. 14.

[1] First plating process

In this step, the surface of the substrate used for the mold is subjected to copper plating or nickel plating. As described above, by applying copper plating or nickel plating to the surface of the substrate for a mold, the adhesion and gloss of chrome plating in the subsequent second plating step can be improved. In other words, when chrome plating is applied to the surface of iron or the like, or the embossing is formed on the chrome-plated surface by blasting or particle blasting, and then chrome plating is applied, the surface is easily roughened and fine cracks are generated. It is difficult to control the uneven shape of the mold surface. On the other hand, first, such a defect can be eliminated by previously applying copper plating or nickel plating to the surface of the substrate. In this case, since copper plating or nickel plating has high coating property and strong smoothing effect, it is possible to form a flat and shiny surface by embedding fine irregularities or cavities of the substrate for a mold. By the characteristics of such copper plating or nickel plating, even if chrome plating is applied in the second plating step to be described later, chrome plating which is regarded as causing minute irregularities or cavities existing on the substrate can be eliminated. The surface is roughened, and since the coating property of copper plating or nickel plating is high, the generation of fine cracks can be reduced.

The copper or nickel used in the first plating step may be a copper-based alloy or a nickel-based alloy, in addition to a pure metal. Therefore, the term "copper" in the present specification includes copper. And the meaning of copper alloy, in addition, "nickel" contains the meaning of nickel and nickel alloy. Copper plating and nickel plating can be carried out by electrolytic plating or electroless plating, respectively, and electrolytic plating is generally used.

When copper plating or nickel plating is applied, when the plating layer is too thin, the influence of the underlying surface cannot be completely excluded, so the thickness thereof is preferably 50 μm or more. The upper limit of the thickness of the plating layer is not limited, but the upper limit of the thickness of the plating layer is preferably set to about 500 μm in consideration of cost and the like.

A metal material suitable for forming a substrate for a mold may, for example, be aluminum, iron or the like from the viewpoint of cost. In addition, in terms of handling convenience, it is particularly preferable to use lightweight aluminum. The aluminum or iron referred to herein may be an alloy mainly composed of aluminum or iron, in addition to pure metals.

Further, the shape of the substrate for a mold may be any shape conventionally used in the field, and may be, for example, a flat plate shape or a cylindrical or cylindrical roller. When a mold is produced using a roll-shaped base material, there is an advantage that an anti-glare film can be produced in a continuous roll shape.

[2] Grinding process

In the subsequent polishing step, the surface of the substrate to which copper plating or nickel plating is applied in the first plating step is polished. Preferably, the surface of the substrate is ground to a state close to the mirror surface through the process. Since this is a metal plate or a metal roll which is a base material, in order to achieve a desired precision, machining by cutting or grinding is often performed, and processing marks remain on the surface of the substrate, even if copper plating or nickel plating is applied. In the state, these processing marks may remain, or in the plated state, the surface may not be completely smooth. In other words, even if the step described later is applied to the surface on which the deep processing marks are left, the unevenness of the processing marks or the like can be made deeper than the unevenness formed after the respective steps are applied, and the possibility of residual processing marks may be affected. When such a mold is used to manufacture an anti-glare film, it may have an unpredictable effect on optical characteristics. In Fig. 14(a), a flat substrate 7 for a mold is schematically shown, and in the first plating step, the surface is subjected to copper plating or nickel plating (plating or plating formed in the step). The layer of nickel is not shown), and then has a mirror-polished surface 8 by a grinding process.

The method of polishing the surface of the substrate to which copper plating or nickel plating is applied is not particularly limited, and any of a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method can be used. Examples of the mechanical polishing method include a super finishing method, a polishing method, a fluid polishing method, and a polishing method. The surface roughness after polishing is preferably 0.1 μm or less, and particularly preferably 0.05 μm or less, in accordance with the center line average roughness Ra of JIS B 0601. When the center line average roughness Ra after grinding is more than 0.1 μm, the influence of the surface roughness after polishing may remain on the uneven shape of the finally formed mold surface. Further, the lower limit of the center line average roughness Ra is not particularly limited, and there is a limit in terms of processing time and processing cost, and therefore no special designation is required.

[3] Photosensitive resin film forming process

In the subsequent photosensitive resin film forming step, a solution in which a photosensitive resin is dissolved in a solvent is applied to the polished surface 8 of the substrate 7 for a mirror which is mirror-polished by the polishing step. The photosensitive resin film is formed by heating and drying. In the figure (b), the state in which the photosensitive resin film 9 is formed on the surface 8 to be polished of the substrate 7 for a mold is schematically shown.

As the photosensitive resin, a conventionally known photosensitive resin can be used. For example, as a negative photosensitive resin having a photosensitive portion to form a hardening property, for example, a monomer or prepolymer having an acrylate or methacryl oxime group in the molecule, a double azide and a diene can be used. A mixture of rubber, a polyvinyl cinnamate compound, and the like. In addition, as the positive photosensitive resin having a property of eluting the photosensitive portion by development and leaving only the non-photosensitive portion, for example, a phenol resin system, a phenol resin resin or the like can be used. Further, the photosensitive resin may be formulated with various additives such as a sensitizer, a development accelerator, an adhesion modifier, and a coatability modifier as necessary.

When the photosensitive resin is applied to the polished surface 8 of the substrate 7 for a mold, it is preferably diluted in an appropriate solvent to form a good coating film, and the solvent can be used. A fiber solvent, a propylene glycol solvent, an ester solvent, an alcohol solvent, a ketone solvent, a highly polar solvent, or the like.

The method of coating the photosensitive resin solution may use meniscus coating, spray coating, dip coating, spin coating, roll coating, wire bar coating, air knife coating, blade coating, and curtain coating. A generally known method such as coating. The thickness of the coating film is preferably in the range of 1 to 6 μm after drying.

[4] Exposure process

In the subsequent exposure step, the pattern is formed in the photosensitive resin film forming step by exposing the pattern to a pattern having no maximum value in a spatial frequency range of from 0 μm ⁻¹ to 0.04 μm ⁻¹ or less. On the photosensitive resin film 9. The light source used in the exposure step can be appropriately selected in accordance with the photosensitivity, sensitivity, and the like of the applied photosensitive resin. For example, g-ray (wavelength: 436 nm) of a high-pressure mercury lamp or h-ray of a high-pressure mercury lamp (wavelength: 405 nm) can be used. ), i-ray (wavelength: 365 nm) of high-pressure mercury lamp, semiconductor laser (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser (wavelength: 1064 nm), KrF excimer laser (wavelength: 248 nm), ArF Excimer laser (wavelength: 193 nm), F2 excimer laser (wavelength: 157 nm), and the like.

In order to accurately form the surface uneven shape of the mold and the surface uneven shape of the antiglare layer, it is preferable to expose the pattern to the photosensitive resin film in a state of being precisely controlled in the exposure step, specifically, A pattern is created in the computer as image data, and based on the image data, the pattern is drawn on the photosensitive resin film by laser light emitted from a computer-controlled laser head. For laser drawing, a laser drawing device for printing plate production can be used. Examples of such a laser drawing device include Laser Stream FX (manufactured by Think Laboratory).

In Fig. 14(c), the state in which the pattern is exposed to the photosensitive resin film 9 is schematically shown. When the photosensitive resin film is formed of a negative photosensitive resin, the exposed region 10 is subjected to a crosslinking reaction of the resin by exposure, so that the solubility with respect to the developer described later is lowered. Therefore, the unexposed area 11 in the developing process is dissolved by the developer, and only the exposed region 10 remains on the surface of the substrate to form a mask. On the other hand, when the photosensitive resin film is formed of a positive photosensitive resin, the exposed region 10 is cut by the exposure of the resin, and the solubility of the developer described later is increased. Therefore, the exposed region 10 in the developing step is dissolved by the developer, and only the unexposed region 11 remains on the surface of the substrate to form a mask.

[5] Development process

In the subsequent development process, when a negative photosensitive resin is used as the photosensitive resin film 9, the unexposed region 11 is dissolved by the developer, and only the exposed region 10 remains on the substrate for the mold, and In the subsequent first etching step, it acts as a mask. On the other hand, when a positive photosensitive resin is used as the photosensitive resin film 9, only the exposed region 10 is dissolved by the developer, and the unexposed region 11 remains on the substrate for the mold, and in the succeeding 1 acts as a mask in the etching process.

The developer used in the development step can be used as known. Examples thereof include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium metasilicate, and aqueous ammonia; first amines such as ethylamine and n-propylamine; and diethylamine and di-n-propylamine. Diamines; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethyl hydroxide a quaternary ammonium salt such as hydroxyethylammonium; an alkaline aqueous 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 methods such as immersion development, spray development, magnetic brush development, and ultrasonic development can be used.

In the fourth embodiment, the state in which the development process is performed using the negative photosensitive resin as the photosensitive resin film 9 is schematically shown. In Fig. 14(c), the unexposed region 11 is dissolved by the developer, and only the exposed region 10 remains on the surface of the substrate to become the mask 12. In the fourth embodiment, the state in which the development process is performed using the positive photosensitive resin as the photosensitive resin film 9 is schematically shown. In Fig. 14(c), the exposed region 10 is dissolved by the developer, and only the unexposed region 11 remains on the surface of the substrate to become the mask 12.

[6] First etching process

In the subsequent first etching step, after the development step, the photosensitive resin film remaining on the surface of the substrate for a mold is used as a mask, and the substrate for the mold without the mask is mainly etched. The unevenness is formed on the polished plated surface. Fig. 15 is a view showing a preferred example of the latter half of the manufacturing method of the mold. In Fig. 15(a), the state in which the substrate 7 for a mold without the mask 13 is mainly etched by the first etching step is schematically shown. The substrate 7 for the mold at the lower portion of the mask 12 is not etched from the surface of the substrate for the mold, but is etched from the unmasked portion 13 as the etching progresses. Therefore, in the vicinity of the boundary between the mask 12 and the unmasked portion 13, the substrate 7 for the mold at the lower portion of the mask 12 is also etched. Hereinafter, in the vicinity of the boundary between the mask 12 and the unmasked portion 13, the substrate 7 for the mold at the lower portion of the mask 12 is also etched, which is called side etching. Figure 16 is a schematic representation of the progress of the undercut. The broken line 14 of Fig. 16 is a stepwise display of the surface of the substrate for a mold which changes with the progress of etching.

In the etching treatment in the first etching step, generally, ferric chloride (FeCl ₃ ), copper chloride (CuCl ₂ ), an alkali etching solution (Cu(NH ₃ ) ₄ Cl ₂ ), or the like is used, and the metal surface is etched. This is carried out, but it is also possible to use a strong acid such as hydrochloric acid or sulfuric acid or a reverse electrolytic etching by applying a potential opposite to that at the time of electrolytic plating. The concave shape formed on the substrate for a mold during the etching treatment differs depending on the type of the underlying metal, the type of the photosensitive resin film, and the etching method, but the etching amount is 10 μm or less. The etching is performed substantially equilaterally from the surface of the metal that is in contact with the etching liquid. The amount of etching referred to herein means the thickness of the substrate removed by etching.

The etching amount in the first etching step is preferably 1 to 50 μm. When the etching amount is less than 1 μm, the metal surface hardly forms an uneven shape and becomes a nearly flat mold, so that the anti-glare property cannot be exhibited. Further, when the etching amount exceeds 50 μm, the difference in height of the uneven shape formed on the metal surface increases, and there is a concern that whitening occurs in the image display device using the anti-glare film produced by the obtained mold. In order to obtain an anti-glare film having a fine uneven surface containing 95% or more of the surface having an inclination angle of 5 or less, the etching amount in the first etching step is preferably 2 to 8 μm. The etching treatment in the first etching step can be performed by one etching treatment or by dividing the etching treatment into two or more. 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 within the above range.

[7] Photosensitive resin film peeling process

In the subsequent photosensitive resin film peeling step, the photosensitive resin film remaining as a mask in the first etching step is completely dissolved and removed. In the photosensitive resin film peeling step, a photosensitive resin film is dissolved using a peeling liquid. The peeling liquid can be used in the same manner as the above-mentioned developing solution, and by changing the pH, temperature, concentration, immersion time, and the like of the peeling liquid, when the negative photosensitive resin is used, the photosensitive resin film in the exposed portion can be completely dissolved. When a positive photosensitive resin is used, the photosensitive resin film in the non-exposed portion can be completely dissolved and removed. The peeling method in the photosensitive resin film peeling step is not particularly limited, and methods such as immersion development, spray development, magnetic brush development, and ultrasonic development can be used.

In the case of the photosensitive resin film peeling step, the photosensitive resin film used as the mask 12 in the first etching step is completely dissolved and removed. The first surface uneven shape 15 can be formed on the surface of the substrate for a mold by etching using the mask 12 formed of the photosensitive resin film.

[8] 2nd plating process

Next, chrome plating is applied to the formed uneven surface (first surface uneven shape 15) to passivate the uneven shape of the surface. In the first aspect, the chrome-plated layer 16 is formed on the surface of the first surface unevenness 15 formed by the etching treatment in the first etching step, and the surface having the unevenness and the first surface unevenness 15 is passivated ( The chrome-plated surface 17) is in a state of being passivated.

The chrome plating is preferably a chrome plating which is glossy on a surface such as a flat plate or a roll, has a high hardness, a small coefficient of friction, and imparts good release properties. Such chrome plating is not particularly limited, but it is preferably a chrome plating which exhibits a good gloss called so-called gloss chrome plating or decorative chrome plating. The chrome plating is generally carried out by electrolysis using an aqueous solution containing anhydrous chromic acid (CrO ₃ ) and a small amount of sulfuric acid. The thickness of the chrome plating can be controlled by adjusting the current density and the electrolysis time.

In the second plating step, plating other than chrome plating is not preferable. This is because, in the plating other than chrome plating, the durability as a mold is lowered due to the low hardness or wear resistance, and the unevenness may be worn or damaged during use. In the antiglare film produced by such a mold, it is difficult to obtain a sufficient antiglare function, and the possibility of occurrence of a defect in the antiglare film is also high.

Further, the surface polishing after plating as disclosed in Japanese Laid-Open Patent Publication No. 2004-90187 or the like is still not preferable. In other words, it is preferable that the step of polishing the surface is not provided after the second plating step, and the uneven surface after the chrome plating is directly used as the unevenness of the mold transferred to the surface of the resin layer on the transparent support. surface. This causes a flat portion to be formed on the outermost surface due to polishing, and there is a possibility that the optical characteristics are deteriorated, and the control factor of the shape is increased, and it is difficult to perform shape control such as reproducibility.

Thus, by applying chrome plating to the surface on which the fine surface unevenness is formed, the uneven shape can be passivated, and a mold whose surface hardness is improved can be obtained. The degree of passivation of the concavities and convexities at this time differs depending on the type of the underlying metal, the size and depth of the concavities and convexities obtained by the first etching step, and the type and thickness of the plating, and cannot be generalized, but the maximum factor for controlling the degree of passivation is still It is the plating thickness. When the thickness of the chrome plating is thin, the effect of passivating the surface shape of the unevenness obtained before the chrome plating is insufficient, and the optical characteristics of the anti-glare film obtained by transferring the uneven shape are not so good. On the other hand, when the chrome plating thickness is too thick, in addition to deterioration in productivity, a plating defect called a protrusion of a spur is generated, which is less preferable. Therefore, the chrome plating thickness is preferably in the range of 1 to 10 μm, particularly preferably in the range of 3 to 6 μm.

The chrome plating layer formed in the second plating step is preferably formed to have a Vickers hardness of 800 or more, and more preferably 1,000 or more. When the Vickers hardness of the chrome plating layer is less than 800, the durability at the time of use of the mold is lowered, and the hardness of the chrome plating layer is lowered, and the possibility of abnormality in plating bath composition, electrolysis conditions, and the like during plating treatment is increased. And for the occurrence of defects, the possibility of producing a less favorable effect is increased.

Moreover, in the manufacturing method of the mold for producing the anti-glare film of the present invention, it is preferable that the etching process is performed between the above-mentioned [7] photosensitive resin film peeling step and [8] second plating step. The second etching step of passivating the uneven surface formed in the first etching step. In the second etching step, the first surface uneven shape 15 formed by the first etching step using the photosensitive resin film as a mask is passivated by an etching treatment. By the second etching treatment, the portion of the first surface uneven shape 15 formed by the first etching step can be eliminated, and the optical characteristics of the anti-glare film obtained by using the obtained mold can be improved. The direction changes. In Fig. 17, it is schematically shown that the first surface uneven shape 15 of the mold base material 7 is passivated by the second etching treatment, and the portion having a steep surface inclination is passivated, and a gentle surface inclination is formed. The state of the second surface uneven shape 18.

The etching treatment in the second etching step is also the same as in the first etching step, and generally, a ferric chloride (FeCl ₃ ) solution, a copper chloride (CuCl ₂ ) solution, or an alkali etching solution (Cu(NH ₃ ) ₄ Cl ₂ ) is used. Etc., by performing etching on the surface, it is also possible to use a strong acid such as hydrochloric acid or sulfuric acid, or a reverse electrolytic etching by applying a potential opposite to that at the time of electrolytic plating. The degree of passivation of the unevenness after the etching treatment differs depending on the type of the underlying metal, the etching method, and the size and depth of the unevenness obtained by the first etching step, and cannot be generalized, but the maximum factor for controlling the degree of passivation is etching. the amount. The amount of etching referred to herein is the same as that of the first etching step, and refers to the thickness of the substrate removed by etching. When the etching amount is small, the effect of passivating the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical characteristics of the anti-glare film obtained by transferring the uneven shape are not good. On the other hand, when the etching amount is too large, the uneven shape almost disappears and becomes a nearly flat mold, so that the anti-glare property cannot be exhibited. Therefore, the etching amount is preferably in the range of 1 to 50 μm, and in addition, in order to obtain an anti-glare film having a fine uneven surface containing 95% or more of the surface having an inclination angle of 5 or less, it is preferably in the range of 4 to 20 μm. Inside. The etching treatment in the second etching step is performed in the same manner as in the first etching step, and can be performed by one etching treatment or by dividing the etching treatment into two 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 within the above range.

example

The invention is described in more detail in the following examples, but the invention is not limited thereto. The evaluation methods of the patterns for producing an anti-glare film and an anti-glare film of the following examples are as follows.

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

The surface shape of the anti-glare film was measured using a three-dimensional microscope "PLμ2300" (manufactured by Sensofar Co., Ltd.). In order to prevent the warpage of the sample, an optically transparent adhesive is applied to the glass substrate so that the uneven surface becomes a surface, and then it is provided for measurement. At the time of measurement, the measurement was performed by setting the magnification of the objective lens to 10 times. The horizontal decomposition energy Δx and Δy were both 1.66 μm, and the measurement area was 850 μm × 850 μm.

(The ratio of the energy spectrum of the elevation H ₁ ² /H ₂ ² and H ₃ ² /H ₂ ² )

From the above measured data, the elevation of the fine concave and convex surface of the anti-glare film is obtained as a two-dimensional function h(x, y), and the obtained two-dimensional function h(x, y) is subjected to discrete Fourier transform to obtain Two-dimensional function H(f _x , f _y ). The two-dimensional function H(f _x , f _y ) is quadratic to calculate the two-dimensional function H ² (f _x , f _y ) of the energy spectrum, and H ² (from the profile curve belonging to f _x =0) 0, f _y), the spatial frequency spectrum is _{obtained. 1} H 0.01μm ^{-1 2} and the spatial frequency spectrum of 0.04μm ^-1 H _{² 2,} and calculates a ratio spectrum H _{1 ²} / H ^{2 2} . Further, the energy spectrum H ₃ ² in the spatial frequency of 0.1 μm ^-1 was obtained, and the energy spectrum ratio H ₃ ² /H ₂ ² was calculated.

(the angle of inclination of the fine concave surface)

Based on the above measured data and calculated according to the above algorithm, a histogram of the inclination angle of the concave-convex surface is prepared, and the distribution of each inclination angle is obtained from the figure, and the inclination angle is calculated to be 5 or less. The proportion of the face.

(Evaluation of the protruding state (buried state) of the particles of the anti-glare film)

The anti-glare film produced in the same manner as the anti-glare layer is used as a comparison object, and when the spatial frequency distribution of the fine uneven surface and the histogram of the inclination angle of the uneven surface are the same as the comparison object, that is, when the level of the spectrum of two-dimensional function ^{_{H 2 (f x, f y}} ) of ^{_{f x = H 2 (0,}} f y) and the inclination angle of the sectional curve of the histogram 0 is substantially overlapped with the comparison target In the case of the anti-glare film containing the microparticles, the shape of the concave-convex surface is not affected by the microparticles. Therefore, it is judged that the microparticles do not protrude from the surface of the anti-glare layer (completely embedded in the binder resin), and the uneven surface is composed only of the binder. The surface formed by the resin is composed. In the following Table 1, the surface formed of only the binder resin is indicated by ○.

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

(haze)

The haze of the antiglare film was measured by the method specified in JIS K 7136. Specifically, the haze is measured using a haze meter "HM-150" (manufactured by Murakami Color Research Laboratory Co., Ltd.) according to this specification. In order to prevent the warpage of the anti-glare film, an optically transparent adhesive is applied to the glass substrate so that the uneven surface is a surface, and then it is provided for measurement. In general, when the haze is increased, the image applied to the image display device is darkened, and as a result, the front contrast is easily lowered. Therefore, the lower haze is better.

(relative scattered light intensity T (20))

The anti-glare film is bonded to the glass substrate so that the uneven surface is a surface, and the parallel light from the He-Ne laser is irradiated from the normal direction of the anti-glare film on the glass surface side, and the anti-glare film is uneven. On the surface side, the intensity of the transmitted scattered light in the direction inclined by 20° from the normal line of the anti-glare film was measured. For the measurement of the transmitted light intensity, "329203 Optical Power Sensor" and "3292 Optical Power Meter" manufactured by Yokogawa Electric Corporation were used. From the obtained transmitted scattered light intensity and the light intensity of the light source, the relative scattered light intensity T (20) (%) was calculated in accordance with the above definition.

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

(Visual assessment of mapping, whitening)

In order to prevent the reflection from the inner surface of the anti-glare film, the anti-glare film is bonded to the black acrylic resin plate so that the uneven surface is a surface, and is visually observed from the uneven surface side in the bright room where the fluorescent lamp is turned on. The degree of whitening of the mapping of the fluorescent lamps is evaluated visually. The mapping and whitening are evaluated in three stages of 1 to 3, respectively, by the following criteria.

Mapping 1: No mappings were observed.

2: A few mappings were observed.

3: The mapping is clearly observed.

Whitening 1: No whitening was observed.

2: A little whitening was observed.

3: Whitening was clearly observed.

(flashing evaluation)

Scintillation was evaluated in the following manner. In other words, the polarizing plate on both sides of the front and back sides was peeled off from a commercially available liquid crystal television (LC-32GH3 (manufactured by Sharp Corporation)). Then, the polarizing plate "Sumikalan SRDB31E" (manufactured by Sumitomo Chemical Co., Ltd.) is attached to the back side and the display side by an adhesive so that the absorption axis of the original polarizer matches the absorption axis of the original polarizing plate, instead of the original polarized light. The glare film shown in the following examples was attached to the display surface side polarizing plate through an adhesive so that the uneven surface became a surface. In this state, the uneven surface was visually observed from a position of about 30 cm from the sample, whereby the scintillation was evaluated for functionality in seven stages. Level 1 is the state in which no flicker is observed at all, level 7 is equivalent to the state in which very severe flicker is observed, and level 3 is a state in which a slight flicker is observed.

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

The created pattern data is used as the image data of the 256-step gray scale, and the two-dimensional discrete function g(x, y) is used to represent the tone. The horizontal decomposition energies Δx and Δy of the discrete function g(x, y) are both 2 μm. The obtained two-dimensional discrete function g(x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function G(f _x , f _y ). The two-dimensional function G(f _x , f _y ) is quadratic to calculate the two-dimensional function G ² (f _x , f _y ) of the energy spectrum, and the G ² (0) of the profile curve from f _x =0 , f _y ), the maximum value of the energy spectrum in the spatial frequency which is larger than 0 μm ^-1 and whose absolute value is the smallest.

<Example 1>

First, a copper ballard plater was prepared on the surface of an aluminum roll having a diameter of 200 mm (according to JIS A5056). The copper ballard plating is formed by a copper plating layer/thin silver plating layer/surface copper plating layer, and the thickness of the entire plating layer is set to be about 200 μm. The copper plating surface is mirror-polished, and a photosensitive resin is applied onto the polished copper plating surface, and dried to form a photosensitive resin film. Then, a plurality of patterns including the pattern shown in Fig. 11 are successively arranged in series, and exposure and development are performed by laser light on the photosensitive resin film. Exposure and development by laser light were carried out using "Laser Stream FX" (manufactured by Think Laboratory). A positive photosensitive resin is used for the photosensitive resin film. The cross section at f _x =0 in the energy spectrum G ² (f _x , f _y ) calculated from the pattern shown in Fig. 11 is as shown in Fig. 13. The pattern shown in Fig. 11 shows the maximum value of the energy spectrum at a spatial frequency of 0.045 μm ^-1 .

Then, the first etching treatment is performed with a copper chloride solution. The etching amount at this time was set to 7 μm. After the first etching treatment, the photosensitive resin film was removed from the roll, and the second etching treatment was performed again with the copper chloride liquid. The etching amount at this time was set to 18 μm. Then, chrome processing is performed to produce the mold A. At this time, the chrome plating thickness was set to 4 μm.

Then, an ultraviolet curable resin composition having a refractive index of 1.53 which was obtained by dissolving the following components in ethyl acetate so as to have a solid content of 60% by weight was prepared.

Pentaerythritol triacrylate 60 parts by weight

Polyfunctional amino formate acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) 40 parts by weight

Leveling agent

Methyl methacrylate/styrene copolymer resin particles (fine particles) having an average particle diameter of 8 μm and a refractive index of 1.565 are formed per 100 parts by weight of the ultraviolet curable resin (cured by the ultraviolet curable resin) The binder resin was added to the ultraviolet curable resin composition in an amount of 15 parts by weight in an amount of 15 parts by weight, and ethyl acetate was added thereto so as to have a solid content (containing resin particles) of 60% by weight. The coating liquid is discharged.

The coating liquid was applied to a cellulose triacetate (TAC) film having a thickness of 80 μm as a transparent support so as to have a coating thickness after drying of 10 μm, and was dried in a dryer set at 60 ° C for 3 minutes. Dry. The film after drying was pressed against the uneven surface of the previously obtained mold A by a rubber roller so that the ultraviolet curable resin composition layer became the mold side, and the film was adhered. In this state, light from a high-pressure mercury lamp having a strength of 20 mW/cm ² was irradiated from the TAC film side so that the amount of light converted into h-rays was 200 mJ/cm ² to cure the ultraviolet curable resin composition layer. Then, the TAC film was peeled off from the mold in units of each of the cured resins, and a transparent anti-glare film A composed of a laminate of a cured resin (anti-glare layer) having irregularities on the surface and a TAC film was produced.

<Example 2>

An anti-glare film B was produced in the same manner as in Example 1 except that the amount of the fine particles added was changed to 30 parts by weight.

<Comparative Example 1>

An anti-glare film C was produced in the same manner as in Example 1 except that no fine particles were added.

<Comparative Example 2>

A mold B was produced in the same manner as in Example 1 except that the pattern shown in Fig. 18 was used as the pattern for exposure by laser light. An anti-glare film D was produced in the same manner as in Example 1 except that the obtained mold B was used. The two-dimensional discrete function g(x, y) shown in Fig. 18 has 512 × 512 values, and the horizontal decomposition energy Δx and Δy are 2 μm. The image data of the pattern shown in Fig. 18 is a pattern in which a plurality of dots having a dot diameter of 22 μm are irregularly arranged, and has a size of 2 mm × 2 mm and is produced at 12,800 dpi. Fig. 20 is a view showing a cross section of f _x =0 of the energy spectrum G ² (f _x , f _y ) obtained from the pattern shown in Fig. 18. As can be seen from Fig. 20, the energy spectrum of the pattern shown in Fig. 18 is larger in the range of the spatial frequency of 0 μm ^-1 and less than 0.04 μm ^-1 , that is, the maximum value at 0.036 μm ^-1 . .

<Comparative Example 3>

In addition to the pattern shown in FIG. 19 as the pattern to be exposed by the laser light, the etching amount of the first etching treatment was set to 10 μm, and the etching amount of the second etching treatment was set to 30 μm, and other implementations were performed. In the same manner as in Example 1, a mold C was produced. An anti-glare film E was produced in the same manner as in Example 1 except that the obtained mold C was used. The two-dimensional discrete function g(x, y) shown in Fig. 19 has 512 × 512 values, and the horizontal decomposition energy Δx and Δy are 2 μm. The image data of the pattern shown in Fig. 19 is a pattern in which a plurality of dots having a dot diameter of 36 μm are irregularly arranged, and has a size of 20 mm × 20 mm and is produced at 3200 dpi. Fig. 20 is a view showing a cross section of f _x =0 of the energy spectrum G ² (f _x , f _y ) obtained from the pattern shown in Fig. 19. As can be seen from Fig. 20, the energy spectrum of the pattern shown in Fig. 19 is larger in the range of the spatial frequency of 0 μm ^-1 and less than 0.04 μm ^-1 , that is, the maximum value at 0.018 μm ^-1 . .

<Comparative Example 4>

First, the surface of an aluminum roller having a diameter of 300 mm (according to JIS A5056) was mirror-polished, and a sand blasting device (manufactured by Fuji Seisakusho Co., Ltd.) was used, with a blast pressure of 0.1 MPa (measured pressure, the same below), and a particle amount of 8 g/cm. ² (The amount of the roll surface area per 1 cm ^{2 is} the same as the following), and the zirconium dioxide particles TZ-SX-17 (manufactured by Tosoh Co., Ltd., average particle diameter: 20 μm) was sandblasted to the ground aluminum surface to form irregularities on the surface. The obtained aluminum roll with irregularities was subjected to electroless nickel plating to produce a mold D. At this time, the thickness of the electroless nickel plating was set to 15 μm. An anti-glare film F was produced in the same manner as in Example 1 except that the obtained mold D was used.

The first table shows the results of evaluation of the surface shape and optical characteristics of the obtained antiglare film. In addition, Fig. 21 and Fig. 22 show the energy spectrum H ² (f _x , f _y ) of the fine uneven surface of the antiglare layer of the antiglare film of the first embodiment, the second embodiment, and the comparative example 1, respectively. H ² (0, f _y ) of the profile curve of f _x =0 and a histogram of the tilt angle. From the 21st and 22nd, the spatial frequency distribution of the fine uneven surface of the anti-glare film of Examples 1 and 2 and the histogram of the inclination angle of the uneven surface are known, and the prevention of Comparative Example 1 containing no fine particles is obtained. The glare films overlap roughly.

As shown in the first table, the anti-glare films A and B of Examples 1 and 2 of the present invention showed no flicker at all, and showed sufficient anti-glare property (anti-mapping ability), and no whitening occurred. Further, since the relative scattered light intensity T(20) is also low, even when it is disposed in the image display device, the contrast is not lowered. The anti-glare film C of Comparative Example 1 which does not contain fine particles in the anti-glare layer exhibits sufficient anti-glare property and does not cause whitening, but generates some flicker. Further, the anti-glare films D and E of Comparative Examples 2 and 3 which were produced from a pattern having a maximum value in the spatial frequency range which is larger than 0 μm ^-1 and which is 0.04 μm ^-1 or less, showed sufficient The anti-glare property was also not whitened, but the flicker was generated because the energy spectrum ratio H ₁ ² /H ₂ ² did not satisfy the requirements of the present invention. Further, the anti-glare film F of Comparative Example 4 which was produced without using the predetermined pattern had flicker because the energy spectrum ratio H ₁ ² /H ₂ ² did not satisfy the requirements of the present invention.

1. . . Anti-glare film

2. . . Fine bump

3. . . Anti-glare film projection surface

5, 5’. . . Main normal direction

6. . . Normal

6a, 6b, 6c, 6d. . . Normal vector

7. . . Mold base

8. . . surface

9. . . Photosensitive resin film

10. . . Exposure area

11. . . Unexposed area

12. . . Mask

13. . . No mask

14. . . dotted line

15. . . First surface relief shape

16. . . Chrome plating

17. . . Chromed surface

18. . . Second surface relief shape

20. . . Light

101. . . Transparent support

102. . . Anti-glare layer

103. . . Adhesive resin

104. . . particle

105. . . Fine uneven surface

Fig. 1 is a cross-sectional view schematically showing an example of the antiglare film of the present invention.

Fig. 2 is a perspective view schematically showing the surface of the anti-glare film of the present invention.

Fig. 3 is a view showing a state in which the function h(x, y) indicating the elevation is discretely obtained.

Fig. 4 is a plan view showing the fine uneven surface of the antiglare layer provided in the antiglare film of the present invention by a two-dimensional discrete function h(x, y).

Fig. 5 is a graph showing the energy spectrum H ² (f _x , f _y ) of the elevation obtained by performing the discrete Fourier transform of the two-dimensional function h(x, y) shown in Fig. 4 in white and black gradations.

Fig. 6 is a cross-sectional view showing the energy spectrum H ² (f _x , f _y ) shown in Fig. 5 at f _x =0.

Fig. 7 is a schematic view for explaining a method of measuring the inclination angle of the fine uneven surface.

Fig. 8 is a schematic view showing a distribution of the inclination angle distribution of the fine uneven surface of the antiglare layer provided in the antiglare film.

Fig. 9 is a view schematically showing a direction in which the light is incident on the transparent support body from the side of the transparent support of the anti-glare film, and the direction of the anti-glare layer is 20° from the normal direction of the transparent support. A perspective view of the direction of incidence of light and the direction of measurement of the intensity of transmitted scattered light when the intensity of the scattered light is observed.

Figure 10 shows a plot of relative scattered light intensity T(20) versus contrast.

Fig. 11 is a partial view showing image data of a pattern used for producing the anti-glare film of the present invention by a two-dimensional discrete function g(x, y) of a tone.

Figure 12 shows the energy spectrum G ² (f _x , f _y ) obtained by discrete Fourier transform of the two-dimensional function g(x, y) of the tone shown in Fig. 11 in white and black gradation. Figure.

Fig. 13 is a cross-sectional view showing the f _x =0 of the energy spectrum G ² (f _x , f _y ) shown in Fig. 12.

Fig. 14 (a) to (e) are diagrams schematically showing a preferred example of the first half of the method of manufacturing the mold.

Fig. 15 (a) to (c) are diagrams schematically showing a preferred example of the latter half of the manufacturing method of the mold.

Fig. 16 is a view schematically showing a state in which side etching is performed in the first etching step.

Fig. 17 (a) and (b) are diagrams schematically showing a state in which the uneven surface formed in the first etching step is passivated by the second etching step.

Fig. 18 is a diagram showing the gradation of image data obtained from the pattern used in the mold making of Comparative Example 2 by a two-dimensional function g(x, y).

Fig. 19 is a diagram showing the gradation of image data obtained from the pattern used in the mold making of Comparative Example 3 by a two-dimensional function g(x, y).

Fig. 20 is a cross-sectional view showing the energy spectrum G ² (f _x , f _y ) of the pattern used in Comparative Example 2 and Comparative Example 3 at f _x =0.

Fig. 21 is a view showing the energy spectrum H ² (f _x , f _y ) of the level of the fine uneven surface of the antiglare layer of the antiglare film of the first embodiment, the second embodiment, and the comparative example 1 when f _x =0 Sectional view.

Fig. 22 is a histogram showing the oblique angle distribution of the fine uneven surface of the antiglare layer provided in the antiglare film of Example 1, Example 2, and Comparative Example 1.

101. . . Transparent support

102. . . Anti-glare layer

103. . . Adhesive resin

104. . . particle

105. . . Fine uneven surface

Claims (5)

An anti-glare film comprising: a transparent support; and an anti-glare film laminated on the transparent support and having an anti-glare layer having a concave-convex surface, wherein the surface of the concave-convex surface having a spatial frequency of 0.01 μm ^-1 is elevated spectra H ₁ ² with the spatial frequency of surface irregularities of 0.04μm elevation ^-1 H ratio of the spectrum of H _{² 2 1 ²} / H ^{2 2,} based in the range of 3 to 15; the antiglare layer, based The adhesive resin and the fine particles dispersed in the binder resin; the uneven surface of the anti-glare layer is formed by the surface of the surface of the adhesive resin forming the energy level of the uneven surface. H ² (f _x , f _y ) obtained by the quadratic of H(f _x , f _y ) obtained by the following formula Here, in the formula, h(x, y) is located at the elevation of the concave-convex surface of the coordinates (x, y), f _x and f _y are spatial frequencies in the x-direction and the y-direction, respectively, and π is the pi, i is Imaginary unit. The anti-glare film according to the first aspect of the invention, wherein the anti-glare layer contains 10 to 50 parts by weight of an average particle diameter of 10 to 50 parts by weight or less with respect to 100 parts by weight of the binder resin, and is bonded thereto. a refractive index ratio of the resin to be 0.93 or more and 0.98 or less or 1.01 or more and 1.04 or less; and The thickness of the antiglare layer is 1.1 times or more and 2 times or less the average particle diameter of the fine particles. The anti-glare film according to the first aspect of the invention, wherein the energy spectrum H ₃ ² of the elevation of the concave-convex surface in the spatial frequency of 0.1 μm ^-1 and the elevation of the concave-convex surface in the spatial frequency of 0.04 μm ^-1 The energy spectrum H ₂ ² ratio H ₃ ² /H ₂ ² is 0.1 or less. The anti-glare film according to claim 1, wherein the uneven surface contains 95% or more of a surface having an inclination angle of 5 or less. A method for producing an anti-glare film, which is a method for producing an anti-glare film according to claim 1, which comprises: exhibiting a range of more than 0 μm ^-1 and less than 0.04 μm ^-1 at a spatial frequency a process of producing a mold having an uneven surface without a pattern of a maximum energy spectrum; and transferring the uneven surface of the mold to a surface of a resin layer formed on the transparent support and dispersing the fine particles The energy spectrum of the pattern described above is obtained by the square of G(f _x , f _y ) obtained by the following formula: G ² (f _x , f _y ) Here, g(x, y) is a gradation of the pattern of coordinates (x, y), f _x and f _y are spatial frequencies in the x direction and the y direction, respectively, π is a pi, and i is an imaginary number. unit.