JP5674292B2 - Antiglare film and method for producing the same, and method for producing a mold - Google Patents

Description

  The present invention relates to an antiglare (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. Moreover, this invention relates to the manufacturing method of the metal mold | die used suitably for the manufacturing method of the said anti-glare film.

  In an image display device such as a liquid crystal display, a plasma display panel, a cathode ray tube (CRT) display, an organic electroluminescence (EL) display, and the like, when external light is reflected on the display surface, visibility is significantly impaired. Conventionally, in order to prevent such reflection of external light, display is performed using a television or personal computer that emphasizes image quality, a video camera or digital camera that is used outdoors with strong external light, and reflected light. In a cellular phone or the like, a film layer for preventing reflection of external light is provided on the surface of an image display device. This film layer consists of a film that has been subjected to anti-reflection treatment using interference by the optical multilayer film, and anti-glare treatment that scatters incident light by blurring the incident light by forming fine irregularities on the surface. It is divided roughly into the thing which consists of the film which was given. The former non-reflective film is costly because it is necessary to form a multilayer film having a uniform optical film thickness. On the other hand, since the latter anti-glare film can be manufactured at a relatively low cost, it is widely used in applications such as large personal computers and monitors.

  Conventionally, such an antiglare film is based on random surface irregularities by, for example, applying a resin solution in which fine particles are dispersed on a substrate sheet while adjusting the film thickness and exposing the fine particles to the coating film surface. It is manufactured by a method of forming on a material sheet. However, the antiglare film manufactured using a resin solution in which such fine particles are dispersed has an influence on the arrangement and shape of surface irregularities depending on the dispersion state and application state of the fine particles in the resin solution. It is difficult to obtain surface irregularities as described above, and when the haze of the antiglare film is set low, there is a problem that a sufficient antiglare effect cannot be obtained. Furthermore, when such a conventional anti-glare film is disposed on the surface of the image display device, the entire display surface becomes whitish due to scattered light, and the display becomes cloudy, so-called “whiteness” is likely to occur. There was a problem. Also, with the recent high definition of image display devices, the pixels of the image display device and the surface uneven shape of the antiglare film interfere with each other, and as a result, a luminance distribution occurs and the display surface becomes difficult to see. There was also a problem that the “glare” phenomenon was likely to occur. In order to eliminate glare, there is an attempt to scatter light by providing a refractive index difference between the binder resin and the fine particles dispersed therein, but such an antiglare film is disposed on the surface of the image display device. In some cases, the contrast is likely to be lowered due to light scattering at the interface between the fine particles and the binder resin.

  On the other hand, there is also an attempt to develop anti-glare properties only by fine irregularities formed on the surface of the transparent resin layer without containing fine particles. For example, in Japanese Patent Laid-Open No. 2002-189106 (Patent Document 1), a three-dimensional 10-point average roughness on a transparent resin film and an average distance between adjacent convex portions on a three-dimensional roughness reference surface are described. Further, an antiglare film is disclosed in which a cured product layer of an ionizing radiation curable resin layer having fine surface irregularities each satisfying a predetermined value is laminated. This antiglare film is manufactured by curing the ionizing radiation curable resin in a state where the ionizing radiation curable resin is sandwiched between the embossing mold and the transparent resin film. However, even with the antiglare film disclosed in Patent Document 1, it has been difficult to achieve a sufficient antiglare effect, suppression of whitening, high contrast, and suppression of glare.

  It is also possible to use a film having fine irregularities on the surface as a light diffusion layer disposed on the back side of the liquid crystal display device, instead of an antiglare film disposed on the display surface of the display device. No. 6-34961 (Patent Document 2), Japanese Unexamined Patent Application Publication No. 2004-45471 (Patent Document 3), Japanese Unexamined Patent Application Publication No. 2004-45472 (Patent Document 4), and the like. Among these, in Patent Documents 3 and 4, as a method for forming irregularities on the surface of the film, an embossing roll having a shape with inverted irregularities is filled with an ionizing radiation curable resin liquid, and the filled resin is made of a roll intaglio. A transparent base material running in synchronization with the rotation direction is brought into contact, and when the transparent base material is in contact with the roll intaglio, the resin between the roll intaglio and the transparent base is cured, and at the same time as cured, a cured resin is cured. A method is disclosed in which a laminate of a cured resin and a transparent substrate is peeled off from a roll intaglio after the substrate and the transparent substrate are brought into close contact with each other.

  However, in the methods disclosed in Patent Documents 3 and 4, the composition of the ionizing radiation curable resin liquid that can be used is limited, and leveling as when applied by diluting with a solvent cannot be expected. It is expected that there is a problem in the uniformity of the film thickness. Furthermore, in the methods disclosed in Patent Documents 3 and 4, since it is necessary to directly fill the embossing roll intaglio with the resin liquid, in order to ensure the uniformity of the uneven surface, the embossing roll intaglio has high mechanical accuracy. There was a problem that it was required and it was difficult to produce an embossing roll.

  Next, as a method for producing a roll used for producing a film having irregularities on the surface, for example, in Patent Document 2 described above, a cylindrical body is made using a metal or the like, and electronic engraving, etching, sandblasting, or the like is performed on the surface. A method of forming irregularities by the above method is disclosed. Japanese Patent Application Laid-Open No. 2004-29240 (Patent Document 5) discloses a method for producing an embossing roll by a bead shot method, and Japanese Patent Application Laid-Open No. 2004-90187 (Patent Document 6) discloses a roll embossing roll. There has been disclosed a method for producing an embossing roll through a step of forming a metal plating layer on the surface, a step of mirror polishing the surface of the metal plating layer, and a step of peening if necessary.

  However, in such a state that the surface of the embossing roll is subjected to blasting treatment, the uneven diameter distribution caused by the particle size distribution of the blast particles is generated, and the depth of the dent obtained by blasting can be controlled. It was difficult to obtain an uneven shape excellent in antiglare function with good reproducibility.

  Further, Patent Document 1 described above describes that a concavo-convex surface is formed by a sandblasting method or a bead shot method, preferably using a roller having a chromium plating on the surface of iron. Furthermore, it is preferable to use the mold surface with such irregularities after applying chrome plating for the purpose of improving durability during use, thereby making it harder and preventing corrosion. There is also a statement that it is possible. On the other hand, in each of the examples of Patent Documents 3 and 4 described above, the surface of the iron core is chrome-plated and subjected to # 250 liquid sand blasting, and then chrome-plating again to form a fine uneven shape on the surface. It is described to do.

  However, in such an embossing roll manufacturing method, since blasting and shots are performed on chromium plating with high hardness, it is difficult to form unevenness, and it is difficult to precisely control the shape of the formed unevenness. It was. In addition, as described in Japanese Patent Application Laid-Open No. 2004-29672 (Patent Document 7), the chrome plating often has a rough surface depending on the material and the shape of the base, and is on the unevenness formed by blasting. Since fine cracks generated by chrome plating are formed on the surface, there is a problem that it is difficult to design what kind of irregularities can be formed. Furthermore, since there are fine cracks generated by chrome plating, there is also a problem that the scattering characteristics of the finally obtained antiglare film change in an unfavorable direction. Furthermore, since the finished roll surface varies in various ways depending on the combination of the embossing roll base material surface and plating type, in order to obtain the required surface irregularities accurately, the appropriate roll surface material and There was also a problem that an appropriate plating type had to be selected. Furthermore, even if the desired surface irregularity shape is obtained, the durability during use may be insufficient depending on the type of plating.

  Japanese Patent Application Laid-Open No. 2000-284106 (Patent Document 8) describes performing an etching step and / or a thin film laminating step after subjecting a base material to sandblasting. Japanese Patent Laid-Open No. 2006-53371 (Patent Document 9) describes that an electroless nickel plating is performed after a substrate is polished and sandblasted. Japanese Patent Application Laid-Open No. 2007-187852 (Patent Document 10) discloses that an embossed plate is produced by performing copper plating or nickel plating on a base material, polishing, sandblasting, and then chromium plating. It is described. Further, Japanese Patent Application Laid-Open No. 2007-237541 (Patent Document 11) discloses that after copper plating or nickel plating, polishing, sandblasting, etching, or copper plating, and then chromium plating. To produce an embossed plate. In these production methods using sandblasting, it is difficult to form the surface uneven shape in a precisely controlled state, so that a relatively large uneven shape having a period of 50 μm or more is also produced in the surface uneven shape. As a result, there is a problem that “glare” in which the large uneven shape and the pixels of the image display device interfere with each other and a luminance distribution is generated to make the display surface difficult to see occurs.

JP 2002-189106 A JP-A-6-34961 JP 2004-45471 A JP 2004-45472 A JP 2004-29240 A JP 2004-90187 A JP 2004-29672 A JP 2000-284106 A JP 2006-53371 A JP 2007-188792 A JP 2007-237541 A

  It is an object of the present invention to exhibit excellent anti-glare performance when applied to an image display device while having low haze, and to prevent deterioration in visibility due to whitishness, and to achieve high definition. Even when applied to an image display device, an antiglare film capable of expressing high contrast without causing glare, a method for producing the antiglare film, and a mold suitable for use in the method for producing the antiglare film Is to provide a method.

The present invention relates to an antiglare film comprising a transparent support and an antiglare layer having an uneven surface laminated on the transparent support, and the complex of the antiglare film at a spatial frequency of 0.016 μm ⁻¹ . The ratio T ₁ ² / T ₂ ² between the energy spectrum T ₁ ² of the transmission function and the energy spectrum T ₂ ² of the complex transmission function of the antiglare film at a spatial frequency of 0.155 μm ⁻¹ is 6000 or less, and the spatial frequency the energy spectrum T ₃ ² complex transmission function antiglare film in 0.108μm ^-1, the ratio T of the energy spectrum T ₂ ² complex transmission function antiglare film in the spatial frequency 0.155μm ^-1 ₃ ² / T ₂ ² is Ri der 3 to 20, uneven surface, the inclination angle comprises 5 ° in a plane 99% or less, antiglare layer, the average particle size does not include the above fine particles 0.4μm Anti-glare film I will provide a.

Antiglare Phil arm of the present invention preferably has a specific T _{3 ²} / T ^{2 2} is 4.0 or more 12.7 or less. The ratio T ₁ ² / T ₂ ² is preferably 1177 or more and 5161 or less .

Moreover, this invention provides the method of manufacturing the anti-glare film in any one of the said. Method for manufacturing the antiglare film of the present invention, by using a pattern showing an energy spectrum that does not have a maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, irregular surface of the antiglare film is formed It is characterized by that. The method for producing an antiglare film according to the present invention includes a step of producing a mold having an uneven surface using the pattern, and an uneven surface of the mold on the surface of a resin layer formed on a transparent support. It is preferable to include a transfer step.

  Furthermore, this invention provides the manufacturing method of the metal mold | die suitably used for the manufacturing method of the anti-glare film of the said invention. The method for producing a mold of the present invention includes a first plating process for performing copper plating or nickel plating on a surface of a mold base, a polishing process for polishing a surface plated by the first plating process, A photosensitive resin film forming step for forming a photosensitive resin film on the exposed surface, an exposure step for exposing the pattern on the photosensitive resin film, and a developing step for developing the photosensitive resin film on which the pattern is exposed. A first etching step of performing an etching process using the developed photosensitive resin film as a mask and forming irregularities on the polished plating surface; a photosensitive resin film peeling step of peeling the photosensitive resin film; And a second plating step of performing chromium plating on the uneven surface.

  The mold manufacturing method of the present invention includes a second etching step in which the uneven shape of the uneven surface formed by the first etching step is blunted by an etching process between the photosensitive resin film peeling step and the second plating step. It is preferable to include.

  It is preferable that the concavo-convex surface formed with the chromium plating formed in the second plating step is the concavo-convex surface of the mold transferred to the surface of the resin layer. That is, in the mold manufacturing method of the present invention, a mold in which an uneven surface subjected to chrome plating is directly transferred to the surface of the resin layer without providing a step of polishing the surface after the second plating step. It is preferable to use as an uneven surface.

  The chromium plating layer formed by chromium plating in the second plating step preferably has a thickness of 1 to 10 μm.

  According to the present invention, when applied to an image display device while having a low haze, it exhibits excellent anti-glare performance, and can prevent deterioration in visibility due to whitishness, and also has high definition. Even when applied to an image display device, it is possible to provide an antiglare film that exhibits high contrast without causing glare. Moreover, according to the manufacturing method of the anti-glare film of this invention, and the manufacturing method of a metal mold | die, the anti-glare film which shows the above outstanding optical characteristics can be manufactured with sufficient reproducibility.

It is sectional drawing which shows typically an example of the anti-glare film of this invention. It is a perspective view which shows typically the surface of the anti-glare film of this invention. It is a figure which shows typically the cross section of the anti-glare film of this invention. It is a schematic diagram which shows the state from which the function h (x, y) showing an altitude is obtained discretely. The complex transmission function of the anti-glare film of the present invention is represented by a two-dimensional discrete function t (x, y). The energy spectrum T ² (f _x , f _y ) of the complex transmission function obtained by performing discrete Fourier transform on the two-dimensional function t (x, y) shown in FIG. 5 is shown in white and black gradations. . Energy spectrum _{^{T 2 (f x, f y}} ) of the complex transmission function shown in FIG. 6 is a view showing a cross section taken along f _x = 0 in. It is a schematic diagram for demonstrating the measuring method of the inclination-angle of the fine uneven | corrugated surface. It is a graph which shows an example of the histogram of the inclination angle distribution of the fine uneven surface of an anti-glare film. It is the figure which represented a part of image data which is a pattern used in order to produce the anti-glare film of this invention with the two-dimensional discrete function g (x, y) of a gradation. Is a view showing a cross section taken along a f _x = 0 of the gradation of the two-dimensional discrete function g (x, y) of the discrete Fourier transform and the energy spectrum G ² obtained by (f _x, f _y) shown in FIG. 10 . It is a figure which shows typically a preferable example of the first half part of the manufacturing method of the metal mold | die of this invention. It is a figure which shows typically a preferable example of the second half part of the manufacturing method of the metal mold | die of this invention. It is a figure which shows typically the state which side etching advances in a 1st etching process. It is a figure which shows typically the state where the uneven surface formed by the 1st etching process dulls by the 2nd etching process. It is the figure which represented the gradation of the image data obtained from the pattern used in the case of metal mold | die preparation of Example 2 by the two-dimensional function g (x, y). It is the figure which represented the gradation of the image data obtained from the pattern used in the case of metal mold | die preparation of Example 3 with the two-dimensional function g (x, y). It is the figure which represented the gradation of the image data obtained from the pattern used at the time of metal mold | die preparation of the comparative example 1 by the two-dimensional function g (x, y). It is the figure which represented the gradation of the image data obtained from the pattern used in the case of metal mold | die preparation of Example 4 by the two-dimensional function g (x, y). It is the figure which represented the gradation of the image data obtained from the pattern used at the time of metal mold | die preparation of the comparative example 2 with the two-dimensional function g (x, y). It is a diagram showing a cross-section taken along f _x = 0 of Examples 2-4 and Comparative Example 1 to 3 antiglare film energy spectrum T ² obtained from the complex transmission function (f _x, f _y). Energy spectrum _{^{G 2 (f x, f y}} ) of the pattern to that used during the mold production of Examples 2-4 and Comparative Examples 1-2 is a diagram showing a cross-section taken along f _x = 0 in.

<Anti-glare film>
As shown in FIG. 1 as an example, the antiglare film of the present invention includes a transparent support 101 and an antiglare layer 102 laminated on the transparent support 101. The surface of the antiglare layer 102 opposite to the transparent support 101 is a fine uneven surface (fine uneven surface 103). In addition, the antiglare film of the present invention is characterized by exhibiting the spatial frequency distribution shown in the following [1] and [2] defined by using the energy spectrum of the complex transmission function.
[1] and energy spectrum T ₁ ² of the complex transmission function of the antiglare film in the spatial frequency 0.016μm ^-1, the ratio T _{1 ²} / T ^{2 2} the energy spectrum T ₂ ² in a spatial frequency 0.155Myuemu ^-1 6000 or less.
(2) an energy spectrum T ₃ ² in the spatial frequency 0.108μm ^-1, the ratio T ₃ ² / T ₂ ² the energy spectrum T ₂ ² in the spatial frequency 0.155Myuemu ^-1 is 3 or more and 20 or less.

  Conventionally, for the period of the fine uneven surface of the antiglare film, the average length RSm of the roughness curve element described in JIS B 0601, the average length PSm of the cross-section curve element, the average length WSm of the undulation curve element, etc. It was evaluated by. However, such a conventional evaluation method cannot accurately evaluate a plurality of periods included in the fine uneven surface. In addition, only the period of the fine concavo-convex surface does not consider the height information of the concavo-convex shape, and accurately evaluates the correlation between the glare and the fine concavo-convex surface and the correlation between the antiglare property and the fine concavo-convex surface. It was difficult to produce an antiglare film having both glare suppression and sufficient antiglare performance.

  In the antiglare film in which an antiglare layer having a fine uneven surface is laminated on a transparent support, the complex transmission function of the antiglare film exhibits a specific spatial frequency distribution, that is, the above [1] and The antiglare film having the spatial frequency distribution represented by [2] has been found to be able to sufficiently suppress glare while exhibiting excellent antiglare performance. It has been found that an anti-glare film can be provided that can prevent a reduction in visibility due to blurring and can exhibit high contrast without causing glare even when applied to a high-definition image display device. .

First, the energy spectrum of the complex transmission function of the antiglare film will be described with reference to FIGS. FIG. 2 is a perspective view schematically showing the surface of the antiglare film of the present invention, and FIG. 3 is a diagram schematically showing a cross section of the antiglare film of the present invention. As shown in FIGS. 2 and 3, the antiglare film 1 of the present invention has an antiglare layer 102 having a fine uneven surface composed of a transparent support 101 and fine unevenness 2 laminated on the transparent support 101. With. In this antiglare layer 102, a virtual plane 24 having the height at the height of the lowest point R on the surface of the fine unevenness and a virtual plane having the height at the height of the highest point Q of the surface of the fine unevenness. Attention is paid to a layer sandwiched by 25 (hereinafter referred to as a surface layer of an antiglare layer). The thickness of the surface layer is a linear distance h _max from the plane 24 to the plane 25 (see FIG. 3).

  The “complex transmission function” means that light 22 having a wavelength λ is incident on the surface layer of the antiglare layer 102 perpendicularly from the transparent support 101 side, and the light 22 is viewed on the surface side of the antiglare layer 102 (on the surface side of the fine irregularities). ) Means the transmittance including the phase of light. That is, when the light 22 perpendicularly incident on the surface layer of the antiglare layer 102 from the transparent support side is expressed by the following formula (1), the light 23 emitted from the viewing side of the surface layer of the antiglare layer 102 is expressed by the following formula (2 From this, the complex transmission function t is expressed by the following equation (3).

Here, u ₀ in the above formula (1) is the amplitude of the incident light 22, and k is defined by k≡2π / λ (π is the circumference and λ is the wavelength of the incident light 22). R ₀ is a position vector of a point where the light 22 is incident, and i is an imaginary unit. In the above formula (2), T is the amplitude transmittance, n is the refractive index of the constituent material of the antiglare layer, and h is the height of the lowest point R on the surface of the fine irregularities at the point where the light 22 is incident. It is the height from the virtual plane 24 having the surface to the surface of the antiglare layer 102.

  When it is assumed that the incident light 22 is not attenuated by passing through the surface layer of the antiglare layer 102, T = 1, so that the complex transmission function t is expressed by the following equation (4):

It is represented by Thus, the complex transmission function t is calculated from the virtual plane 24 having the height at the elevation of the fine uneven surface of each point of the antiglare layer, specifically, at the height of the lowest point R of the fine uneven surface. A straight line distance (elevation of the fine uneven surface at the highest point Q) h _{max at} the height of the highest point Q on the fine uneven surface to the virtual plane 25 having the height and the flat surface 24 at the point where the light 22 is incident. It can be calculated from the height to the surface of the glare layer 102 (elevation of the fine uneven surface at that point) h. The “elevation of the fine uneven surface” means the main method of the antiglare film from the virtual plane 24 having the height at the lowest point R of the fine uneven surface at an arbitrary point P on the surface of the antiglare layer. It means a straight line distance in the line direction 4 (normal direction in the virtual plane 24). In FIG. 2, the entire surface of the antiglare film is displayed on the projection surface 3.

  As shown in FIG. 2, when the orthogonal coordinates in the antiglare film plane are displayed as (x, y), the elevation of the fine uneven surface is a two-dimensional function h (x, y) of the coordinates (x, y). ) And a complex transmission function calculated therefrom can also be represented by a two-dimensional function t (x, y). The complex transmission function t (x, y) indicates the optical spatial frequency distribution on the surface of the fine unevenness in consideration of the height direction of the uneven shape in addition to the period of the uneven shape on the surface of the fine unevenness. Thus, the correlation between the glare and the fine uneven surface and the correlation between the antiglare property and the fine uneven surface can be accurately evaluated.

The elevation of the fine irregular surface for calculating the complex transmission function can be obtained from three-dimensional information of the surface shape measured by an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM). The horizontal resolution required for the measuring instrument is at least 5 μm or less, preferably 2 μm or less, and the vertical resolution is at least 0.1 μm or less, preferably 0.01 μm or less. Non-contact three-dimensional surface shape / roughness measuring instruments suitable for this measurement include New View 5000 series (manufactured by Zygo Corporation, available from Zygo Corporation in Japan), three-dimensional microscope PLμ2300 (manufactured by Sensofar), etc. Can be mentioned. Since the resolution of the altitude energy spectrum is preferably 0.01 μm ⁻¹ or less, the measurement area is preferably at least 200 μm × 200 μm, more preferably 500 μm × 500 μm.

Next, a method for obtaining the energy spectrum of the complex transmission function from the two-dimensional function t (x, y) will be described. First, a two-dimensional function T (f _x , f _y ) is obtained from the two-dimensional function t (x, y) by a two-dimensional Fourier transform defined by the following equation (5).

Here, f _x and f _y are the spatial frequencies of the x and y directions, with the dimensions of the reciprocal of length. Further, in Expression (5), π is a pi and i is an imaginary unit. The resulting two-dimensional function T (f _x, f _y) by squaring the energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function can be obtained. The energy spectrum ^{_{T 2 (f x, f y}} ) is based on a complex transmission function of the antiglare film, it represents the spatial frequency distribution of the fine uneven surface of the antiglare layer.

  Hereinafter, the method for obtaining the energy spectrum of the complex transmission function of the antiglare film will be described more specifically. The three-dimensional information of the surface shape actually measured by the above confocal microscope, interference microscope, atomic force microscope or the like is generally obtained as discrete values, that is, elevations corresponding to a large number of measurement points. FIG. 4 is a schematic diagram showing a state where functions h (x, y) representing altitude are obtained discretely. As shown in FIG. 4, the orthogonal coordinates in the antiglare film plane are displayed as (x, y), and the line divided by Δx in the x axis direction on the projection plane 3 of the antiglare film and Δy in the y axis direction. If the line divided | segmented for every is shown with a broken line, the elevation of the surface of fine unevenness | corrugation will be obtained as a discrete elevation value for every intersection of each broken line on the projection surface 3 of an anti-glare film in actual measurement.

  The number of altitude values obtained is determined by the measurement range and Δx and Δy, and is obtained when the measurement range in the x-axis direction is X = MΔx and the measurement range in the y-axis direction is Y = NΔy as shown in FIG. The number of elevation values is (M + 1) × (N + 1).

  As shown in FIG. 4, the coordinates of the point of interest A on the projection surface 3 of the antiglare film are (jΔx, kΔy) (where j is 0 or more and M or less, and k is 0 or more and N or less). Then, the altitude of the point P on the antiglare film surface corresponding to the point of interest A can be expressed as h (jΔx, kΔy).

  Here, the measurement intervals Δx and Δy depend on the horizontal resolution of the measuring device, and in order to accurately evaluate the fine uneven surface, both Δx and Δy are preferably 5 μm or less as described above, and are 2 μm or less. It is more preferable. Further, as described above, the measurement ranges X and Y are both preferably 200 μm or more, and more preferably 500 μm or more.

In this way, in actual measurement, a function representing the altitude of the fine uneven surface is obtained as a discrete function h (x, y) having (M + 1) × (N + 1) values. The discrete function t (x, y) is obtained from the discrete function h (x, y) obtained by the measurement. Also, discrete function t (x, y) and discrete function T (f _x, f _y) by a discrete Fourier transform defined by the following formula (6) is Motomari, discrete function T (f _x, f _y) squaring discrete function ^{_{T 2 (f x, f y}} ) of the energy spectrum by is determined. In formula (6), l 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 and (N + 1) / 2 or less. Also, Delta] f _x and Delta] f _y are the spatial frequency intervals of the x and y directions, is defined by equation (7) and Equation (8). Delta] f _x and Delta] f _y correspond to the horizontal resolution of the energy spectrum of the complex transmission function.

  FIG. 5 is a diagram showing the complex transmission function of the antiglare film of the present invention (specifically, the antiglare film of Example 1 described later) as a two-dimensional discrete function t (x, y). In FIG. 5, the size of the complex transmission function is represented by white and black gradation. The discrete function t (x, y) shown in FIG. 5 has 512 × 512 values, and the horizontal resolutions Δx and Δy are 0.83 μm.

FIG. 6 shows the energy spectrum T ² (f _x , f _y ) of the complex transmission function obtained by discrete Fourier transform of the two-dimensional function t (x, y) shown in FIG. It is shown by. Energy spectrum _{^{T 2 (f x, f y}} ) of the complex transmission function shown in FIG. 6 is also a discrete function having a 512 × 512 pieces of value, the horizontal resolution Delta] f _x and Delta] f _y of the energy spectrum of the complex transmission function 0 .0024 μm ⁻¹ .

Since the complex transmission function of the anti-glare film of the present invention is random as in the example shown in FIG. 5, the energy spectrum of the complex transmission function is symmetric about the origin as shown in FIG. Therefore, energy spectrum T ₁ ² of complex transmission function in the spatial frequency 0.016Myuemu ^-1, energy spectrum T ₃ ² in the energy spectrum T ₂ ^2, and spatial frequency 0.108Myuemu ^-1 in the spatial frequency 0.155Myuemu ^-1 is energy spectrum ^{_{T 2 (f x, f y}} ) is a two-dimensional function can be determined from the cross-section passing through the origin of. 7, showing a cross section of an f _x = 0 of the energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function shown in FIG. Than this, the energy spectrum T ₁ ² in a spatial frequency 0.016μm ^-1 277, the energy spectrum T ₂ ² in the spatial frequency 0.155Myuemu ^-1 was 0.054, the ratio T _{1 ²} / T ^{2 2} in 5161 I understand that there is. It can also be seen that the energy spectrum T ₃ ^{2 at} a spatial frequency of 0.108 μm ⁻¹ is 0.49, and the ratio T ₃ ² / T ₃ ² is 9.2.

As described above, the antiglare film of the present invention satisfies the above [1] and [2] regarding the energy spectrum of the complex transmission function. When the energy spectrum ratio T ₁ ² / T ₂ ² exceeds 6000, there are many long-period components of 62.5 μm or more included in the complex transmission function of the antiglare film, and few short-period components of less than 6.5 μm. Represents. Here, the complex transmission function includes information on the height direction of the concavo-convex shape in addition to the period of the concavo-convex shape on the fine concavo-convex surface as described above. This means an optical period including a difference in height, not a period between or convex periods. Therefore, when the energy spectrum ratio T ₁ ² / T ₂ ² exceeds 6000, it indicates that a lot of optical long-period components are contained in the fine concavo-convex shape. When this is arranged in a high-definition image display device, the luminance variation becomes large and the glare tends to occur. Further, the energy spectrum ratio T ₃ ² / T ₂ ² being less than 3 indicates that there are many short-period components optically less than 9.3 μm. In such a case, scattering is weak, Reflection of light cannot be effectively prevented, and sufficient antiglare performance cannot be obtained. On the other hand, an energy spectrum ratio T ₃ ² / T ₂ ² exceeding 20 indicates that there are optically many long-period components of 10 μm or more. When applied, the image becomes dark and as a result the front contrast tends to decrease. In order to suppress glare more effectively while exhibiting superior anti-glare performance, the energy spectrum ratio T ₁ ² / T ₂ ² of the complex transmission function is preferably in the range of 0 to 3000, more preferably Is in the range of 0-2000, and the ratio T ₃ ² / T ₂ ² is preferably in the range of 3-15, more preferably in the range of 3-11.

The inventors of the present invention are also more effective in effectively preventing whitish while exhibiting excellent antiglare performance if the fine uneven surface of the antiglare layer exhibits a specific inclination angle distribution. I found out. That is, in the antiglare film of the present invention, the fine uneven surface of the antiglare layer preferably includes 95% or more of a surface having an inclination angle of 5 ° or less. If the ratio of the surface with an inclination angle of 5 ° or less is less than 95%, the inclination angle of the uneven surface becomes steep, condensing light from the surroundings, and the display surface is whitened as a whole. It becomes easy to do. Suppressing such light condensing effect, in order to prevent Shirochake may higher the ratio of the inclination angle is 5 ° or less surface fine irregular surface, therefore, the present invention of the surface proportion to 99% or more.

  Here, the “inclination angle of the surface of the fine unevenness” as used in the present invention refers to FIG. 2 at an arbitrary point P on the surface of the antiglare film 1 with respect to the main normal direction 4 of the antiglare film. It means an angle (surface inclination angle) ψ formed by a local normal 6 with irregularities added. Similarly to the altitude, the inclination angle of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM).

  Here, FIG. 8 is a schematic diagram for explaining a method of measuring the inclination angle of the surface of the fine irregularities. A specific method for determining the tilt angle will be described. As shown in FIG. 8, a point of interest A on a virtual plane FGHI indicated by a dotted line is determined, and the point of interest on the x-axis passing there passes in the vicinity. The points B and D are approximately symmetrical with respect to the point A, and the points C and E are approximately symmetrical with respect to the point A in the vicinity of the point of interest A on the y-axis passing through the point A. , C, D, and E, the points Q, R, S, and T on the antiglare film surface are determined. In addition, in FIG. 8, the orthogonal coordinate in the anti-glare film surface is displayed by (x, y), and the coordinate of the anti-glare film thickness direction is displayed by z. The plane FGHI is parallel to the x axis passing through the point C on the y axis and parallel to the x axis passing through the point E on the y axis and to the y axis passing through the point B on the x axis. It is a plane formed by the respective intersections F, G, H, and I with a straight line and a straight line passing through the point D on the x-axis and parallel to the y-axis. Further, in FIG. 8, the actual position of the anti-glare film surface is drawn with respect to the plane FGHI, but the actual position of the anti-glare film surface is naturally determined by the position taken by the point of interest A. It may come above the plane FGHI or may come below.

  The angle of inclination is a point P on the actual anti-glare film surface corresponding to the point of interest A and a point Q on the actual anti-glare film surface corresponding to the four points B, C, D, E taken in the vicinity thereof. , R, S, and T, the average plane obtained by averaging the normal vectors 6a, 6b, 6c, and 6d of the four triangles PQR, PRS, PST, and PTQ. The polar angle of a vector (the average normal vector is synonymous with the local normal 6 with the irregularities shown in FIG. 2) can be obtained from the three-dimensional information of the measured surface shape. . After obtaining the tilt angle for each measurement point, a histogram is calculated.

  FIG. 9 is a graph showing an example of a histogram of the inclination angle distribution of the fine uneven surface of the antiglare film (specifically, the antiglare film of Example 1 described later). In the graph shown in FIG. 9, the horizontal axis is the inclination angle, and is divided in increments of 0.5 °. For example, the leftmost vertical bar shows the distribution of a set having an inclination angle in the range of 0 to 0.5 °, and the angle increases by 0.5 ° as going to the right. In the figure, the lower limit of the value is displayed for every two scales on the horizontal axis. For example, the portion with “1” on the horizontal axis indicates the distribution of the set whose inclination angle is in the range of 1 to 1.5 °. Show. In addition, the vertical axis represents the distribution of the tilt angle, which is a value that becomes 1 (100%) when summed up. In this example, the ratio of the surface having an inclination angle of 5 ° or less is approximately 100%.

In the antiglare film of the present invention, the antiglare layer may be one in which fine particles are dispersed, or may contain no fine particles. The glare can be more effectively eliminated by dispersing fine particles having a refractive index different from that of the binder resin constituting the antiglare layer, in particular, fine particles having an average particle diameter of 0.4 μm or more in the antiglare layer. However, when an anti-glare film in which such fine particles are dispersed in an anti-glare layer is disposed on the surface of the image display device, the contrast tends to decrease due to light scattering at the fine particle / binder resin interface. from the viewpoint, the antiglare film of the present invention is not intended to include 0.4μm or more particulate antiglare layer. Since the anti-glare film of the present invention exhibits the specific spatial frequency distribution described above, it exhibits sufficient glare-suppressing ability even when it does not contain fine particles.

  When the antiglare layer contains fine particles, the average particle diameter of the fine particles can be, for example, about 3 to 10 μm, preferably about 5 to 10 μm, and the content of the fine particles is a binder resin constituting the antiglare layer. For example, about 5 to 50 parts by weight, preferably about 10 to 50 parts by weight with respect to 100 parts by weight. As the fine particles, resin beads, which are also substantially spherical, are preferably used. Examples of such suitable resin beads include melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), methyl methacrylate / styrene copolymer resin beads (refractive index 1.50-1). .59), polycarbonate beads (refractive index 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46), silicone resin beads ( Refractive index 1.46) and the like.

  In the antiglare film of the present invention, the antiglare layer is not particularly limited as long as it is substantially optically transparent. For example, the antiglare layer is composed of a photocurable resin such as an ultraviolet curable resin, a thermosetting resin, or a thermoplastic resin. be able to. The thickness of the antiglare layer is not particularly limited, and can be, for example, about 1 to 50 μm, preferably 3 to 10 μm. Further, the transparent support is not particularly limited as long as it is a substantially optically transparent film. For example, a triacetyl cellulose film, a polyethylene terephthalate film, a polymethyl methacrylate film, a polycarbonate film, and a non-bornene compound are used as monomers. Resin films such as solvent cast films and extruded films of thermoplastic resins such as crystalline cyclic polyolefins. Although the thickness in particular of a transparent support body is not restrict | limited, Usually, it is 25-1000 micrometers, Preferably it is 25-100 micrometers.

<Method for producing antiglare film>
The antiglare film of the present invention, in order to accurately form a fine irregular surface with a specific spatial frequency distribution as described above, the energy does not have a local maximum in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It is preferable that the fine uneven surface is formed using a pattern showing a spectrum. Here, the “pattern” is typically used to form the fine uneven surface of the anti-glare film, and the two gradations created by a computer (for example, binarized into white and black) Image data) or image data composed of gradations of three or more gradations, but may also include data (such as matrix data) that can be uniquely converted to the image data. Examples of data that can be uniquely converted to image data include data in which only the coordinates and gradations of each pixel are stored.

For example, if the energy spectrum of the pattern is image data, the image data is converted into a gray scale of 256 gradations, and then the gradation of the image data is expressed by a two-dimensional function g (x, y). dimension function g (x, y) to Fourier transform two-dimensional function G (f _x, f _y) to calculate the two-resulting-dimensional function G (f _x, f _y) is determined by squaring. Here, x and y represent orthogonal coordinates of the image data plane, respectively f _x and f _y, it represents the spatial frequency of the spatial frequency and the y direction of the x-direction.

As in the case of obtaining the energy spectrum of the altitude of the fine uneven surface, the two-dimensional function g (x, y) of the gradation is generally obtained as a discrete function when obtaining the energy spectrum of the pattern. In that case, the energy spectrum of the pattern is calculated by discrete Fourier transform, as in the case of obtaining the energy spectrum of the altitude of the fine uneven surface. Specifically, computes the discrete function G (f _x, f _y) by a discrete Fourier transform defined by equation (9), discrete function G (f _x, f _y) is the energy spectrum by squaring the determined It is done. Here, π in the equation (9) is a pi, and i is an imaginary unit. M is the number of pixels in the x direction, N is the number of pixels in the y direction, l is an integer from −M / 2 to M / 2, and m is from −N / 2 to N / 2. It is an integer. Furthermore, Delta] f _x and Delta] f _y is the spatial frequency intervals of the x and y directions, it is defined by equation (10) and (11). Δx and Δy in Expression (10) and Expression (11) are horizontal resolutions in the x-axis direction and the y-axis direction, respectively. If the pattern is image data, Δx and Δy are equal to the length of one pixel in the x-axis direction and the length in the y-axis direction, respectively. That is, when a pattern is created as 6400 dpi image data, Δx = Δy = 4 μm, and when a pattern is created as 12800 dpi image data, Δx = Δy = 2 μm.

  FIG. 10 shows a two-dimensional discrete gradation of a part of image data which is a pattern used for producing the antiglare film of the present invention (a pattern used in the mold production of Example 1 described later). It is the figure represented with the function g (x, y). The two-dimensional discrete function g (x, y) shown in FIG. 10 has 512 × 512 values, and the horizontal resolutions Δx and Δy are 4 μm. Further, the image data which is the pattern shown in FIG. 10 has a size of 1.64 mm × 1.64 mm and was created at 6400 dpi.

Figure 11 is a two-dimensional gray scale shown in FIG. 10 discrete function g (x, y) the energy spectrum obtained by discrete Fourier transform ^{_{G 2 (f x, f y}} ) a cross section taken along f _x = 0 of FIG. The resulting discrete function ^{_{G 2 (f x, f y}} ) also has a 512 × 512 pieces of value, the horizontal resolution Delta] f _x and Delta] f _y is 0.00049μm ^-1. As shown in FIG. 10, since the pattern created in order to manufacture the anti-glare film of this invention is random, the obtained energy spectrum becomes symmetrical centering on the origin. Therefore, the spatial frequency indicating the maximum value of the energy spectrum of the pattern can be obtained from a cross section passing through the origin of the energy spectrum. From 11 shows the pattern in FIG. 10, but with a maximum value at a spatial frequency 0.061Myuemu ^-1, it can be seen that no maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 .

When having the maximum value in the range energy spectrum of 0.04 .mu.m ^-1 or less larger than 0 .mu.m ^-1 pattern for making an antiglare film, the resulting anti-glare film according to [1] and [2] Since the specific spatial frequency distribution represented by is no longer shown, it is not possible to combine the elimination of glare and sufficient anti-glare properties.

Pattern energy spectrum has no maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, for example, be random and uniformly arranged a number of dots having a dot diameter of less than 20 [mu] m (the dot diameter) Can be created. The dot diameter of the dots arranged at random may be one type or a plurality of types. Further, in order to more effectively remove a spatial frequency component having a spatial frequency of 0.04 μm ⁻¹ or less from a pattern formed by randomly arranging such a large number of dots, a spatial frequency of 0.04 μm ⁻¹ or less is used. A pattern obtained by passing through a high-pass filter that removes components may be used as a pattern for producing an antiglare film. Furthermore, in order to more effectively remove a spatial frequency component having a spatial frequency of 0.04 μm ⁻¹ or less from a pattern created by randomly arranging a large number of dots, a low spatial frequency component of 0.04 μm ⁻¹ or less and A pattern obtained by passing through a bandpass filter that removes a high spatial frequency component equal to or higher than a specific spatial frequency may be used as a pattern for producing an antiglare film.

Among the above, no maximum value to the energy spectrum in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, the energy spectrum G ₁ ² pattern in the spatial frequency 0.02 [mu] m ^-1, spatial frequency 0. The pattern in which the ratio G ₁ ² / G ₂ ² to the energy spectrum G ₂ ² of the pattern at 04 μm ⁻¹ is 1 or less, preferably 0.5 or less, more preferably 0.3 or less is the above [1] and [ The antiglare film showing the specific spatial frequency distribution shown in 2] is more preferably used because it can be produced with higher accuracy.

  The antiglare film having the fine uneven surface using the pattern described above can be produced by a printing method, a pattern exposure method, an embossing method, or the like. For example, in the printing method, the above-described pattern is printed on the surface of the resin layer formed on the transparent support by flexographic printing, screen printing, inkjet printing, or the like using a photocurable resin or a thermosetting resin. Thereafter, the antiglare film of the present invention can be produced by drying or curing by actinic rays or heating. In the pattern exposure method, after applying a photocurable resin or a thermosetting resin on a transparent support, direct drawing exposure by a laser using the above-described pattern or the entire surface through a mask having the above-described pattern. The antiglare film of the present invention can be produced by pattern exposure by exposure, development as necessary, and curing by actinic rays or heating. Further, in the embossing method, a mold having a fine uneven surface is produced using the pattern described above, the uneven surface of the produced mold is transferred to the resin layer surface formed on the transparent support, and then the uneven surface The antiglare film of the present invention can be produced by peeling off the transparent support having transferred thereto from the mold. Especially, it is preferable that the anti-glare film of this invention is manufactured by the embossing method from a viewpoint which manufactures a fine uneven | corrugated surface with sufficient precision and reproducibility.

  Examples of the embossing method include a UV embossing method using a photocurable resin and a hot embossing method using a thermoplastic resin. Among these, the UV embossing method is preferable from the viewpoint of productivity. In the UV embossing method, a photocurable resin layer is formed on the surface of a transparent support, and the photocurable resin layer is photocured by pressing the photocurable resin layer against the mold uneven surface. Transferred to the surface of the mold resin layer. More specifically, a coating liquid containing a photocurable resin is applied onto the transparent support, and the UV light is applied from the transparent support side in a state where the coated photocurable resin is in close contact with the uneven surface of the mold. Etc. by curing the photocurable resin by irradiating the light, etc., and then peeling the transparent support on which the cured photocurable resin layer is formed from the mold, so that the uneven shape of the mold is cured. An antiglare film transferred to the photocurable resin layer (antiglare layer) is obtained.

  In the UV embossing method, the above-mentioned transparent support can be suitably used. As the photocurable resin, an ultraviolet curable resin that is cured by ultraviolet rays is preferably used, but a resin that can be cured even with visible light having a wavelength longer than that of ultraviolet rays by combining the ultraviolet curable resin with an appropriately selected photoinitiator. It is also possible to use. The kind of ultraviolet curable resin is not specifically limited, A commercially available appropriate thing can be used. Suitable examples of the ultraviolet curable resin include polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, or a mixture of two or more of them, and Irgacure 907 (Ciba Special). This is a resin composition obtained by mixing a photopolymerization initiator such as Tea Chemicals Co., Ltd., Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.), or Lucillin TPO (BASF Co., Ltd.). Also in the hot embossing method, the same transparent support as that described in the UV embossing method can be used.

<Method for producing mold for producing antiglare film>
Below, the method to manufacture the metal mold | die used for manufacture of the anti-glare film of this invention is demonstrated. The method for producing a mold used for producing the antiglare film of the present invention is not particularly limited as long as it is a method capable of obtaining a predetermined surface shape using the above-described pattern, and the fine uneven surface is accurately and In order to manufacture with good reproducibility, [1] first plating step, [2] polishing step, [3] photosensitive resin film forming step, [4] exposure step, [5] development step, [ 6) It is preferable to basically include a first etching step, [7] photosensitive resin film peeling step, and [8] second plating step. FIG. 12 is a diagram schematically showing a preferred example of the first half of the method for producing a mold of the present invention. In FIG. 12, the cross section of the metal mold | die in each process is shown typically. Hereafter, each process of the manufacturing method of the metal mold | die of this invention is demonstrated in detail, referring FIG.

[1] First plating step In this step, copper plating or nickel plating is applied to the surface of the substrate used for the mold. Thus, by performing copper plating or nickel plating on the surface of the mold base, it is possible to improve the adhesion and gloss of chromium plating in the subsequent second plating step. In other words, when chrome plating is applied to the surface of iron or the like, or when chrome plating is applied again after forming irregularities on the chrome plating surface by the sandblasting method or the bead shot method, the surface tends to be rough and fine cracks occur. This makes it difficult to control the uneven shape on the surface of the mold. On the other hand, such inconvenience can be eliminated by first performing copper plating or nickel plating on the substrate surface. This is because copper plating or nickel plating has a high covering property and a strong smoothing action, so that a flat and glossy surface is formed by filling minute irregularities and voids of the mold base. is there. Due to these copper plating or nickel plating characteristics, even if chrome plating is applied in the second plating step, which will be described later, the rough surface of the chrome plating that appears to be caused by minute irregularities and voids that existed on the substrate is eliminated. In addition, the occurrence of fine cracks is reduced due to the high coverage of copper plating or nickel plating.

  The copper or nickel used in the first plating step may be a pure metal, or may be an alloy mainly composed of copper or an alloy mainly composed of nickel. “Copper” means to include copper and copper alloy, and “nickel” means to include nickel and nickel alloy. Copper plating and nickel plating may be performed by electrolytic plating or electroless plating, respectively, but electrolytic plating is usually employed.

  When copper plating or nickel plating is performed, if the plating layer is too thin, the influence of the underlying surface cannot be completely eliminated. Therefore, the thickness is preferably 50 μm or more. Although the upper limit of the plating layer thickness is not critical, the upper limit of the plating layer thickness is preferably about 500 μm in view of cost and the like.

  Examples of the metal material suitably used for forming the mold base include aluminum and iron from the viewpoint of cost. From the viewpoint of handling convenience, it is more preferable to use lightweight aluminum. The aluminum and iron here may be pure metals, respectively, or may be an alloy mainly composed of aluminum or iron.

  Moreover, the shape of the mold base material may be an appropriate shape conventionally employed in the field, and may be, for example, a plate-like shape, a columnar shape, or a cylindrical roll. If a mold is produced using a roll-shaped substrate, there is an advantage that the antiglare film can be produced in a continuous roll shape.

[2] Polishing Step In the subsequent polishing step, the surface of the substrate that has been subjected to copper plating or nickel plating in the first plating step described above is polished. It is preferable that the base material surface is grind | polished in the state close | similar to a mirror surface through the said process. This is because metal plates and metal rolls that serve as base materials are often subjected to machining such as cutting and grinding in order to achieve the desired accuracy, and as a result, machine marks remain on the base material surface. This is because even if copper plating or nickel plating is applied, those processed marks may remain, and the surface may not be completely smooth in the plated state. That is, even if a process described later is performed on the surface where such deep processed marks remain, unevenness such as processed marks may be deeper than the unevenness formed after each process is performed. Such effects may remain, and when an antiglare film is produced using such a mold, the optical characteristics may be unexpectedly affected. In FIG. 12 (a), a plate-shaped mold substrate 7 is subjected to copper plating or nickel plating on its surface in the first plating step (for the copper plating or nickel plating layer formed in this step). Further, a state in which the surface 8 is mirror-polished by a polishing process is schematically shown.

  There is no particular limitation on the method for polishing the surface of the substrate on which copper plating or nickel plating has been applied, and any of mechanical polishing, electrolytic polishing, and chemical polishing can be used. Examples of the mechanical polishing method include super finishing, lapping, fluid polishing, and buff polishing. As for the surface roughness after polishing, the center line average roughness Ra in accordance with the provisions of JIS B 0601 is preferably 0.1 μm or less, and more preferably 0.05 μm or less. If the centerline average roughness Ra after polishing is greater than 0.1 μm, the final unevenness of the mold surface may remain affected by the surface roughness after polishing. In addition, the lower limit of the center line average roughness Ra is not particularly limited, and there is no limit in particular because there is a natural limit from the viewpoint of processing time and processing cost.

[3] Photosensitive resin film forming step In the subsequent photosensitive resin film forming step, the photosensitive resin was dissolved in the solvent on the polished surface 8 of the mold substrate 7 that was mirror-polished by the polishing step described above. A photosensitive resin film is formed by applying as a solution, heating and drying. FIG. 12B schematically shows a state where the photosensitive resin film 9 is formed on the polished surface 8 of the mold base 7.

  A conventionally known photosensitive resin can be used as the photosensitive resin. Examples of the negative photosensitive resin having a property of curing the photosensitive part include, for example, a monomer or prepolymer of an acrylate ester having an acrylic group or a methacrylic group in the molecule, a mixture of bisazide and a diene rubber, polyvinyl Cinnamate compounds and the like can be used. Further, as a positive photosensitive resin having such a property that a photosensitive part is eluted by development and only an unexposed part remains, for example, a phenol resin type or a novolac resin type can be used. Moreover, you may mix | blend various additives, such as a sensitizer, a development accelerator, an adhesiveness modifier, and a coating property improving agent, with a photosensitive resin as needed.

  When these photosensitive resins are applied to the polished surface 8 of the mold base 7, it is preferable to dilute and apply in an appropriate solvent in order to form a good coating film. As the solvent, cellosolve solvents, propylene glycol solvents, ester solvents, alcohol solvents, ketone solvents, highly polar solvents, and the like can be used.

  As a method for applying the photosensitive resin solution, known methods such as meniscus coating, fountain coating, dip coating, spin coating, roll coating, wire bar coating, air knife coating, blade coating, and curtain coating may be used. it can. The thickness of the coating film is preferably in the range of 1 to 6 μm after drying.

[4] In the exposure step subsequent exposure step, the photosensitive that the energy spectrum is a pattern that has no local maximum value within the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, formed by the above-mentioned photosensitive resin film forming step The photosensitive resin film 9 is exposed. The light source used in the exposure process may be appropriately selected according to the photosensitive wavelength and sensitivity of the coated photosensitive resin. For example, the g-line (wavelength: 436 nm) of the high-pressure mercury lamp, the h-line (wavelength: 405 nm) of the high-pressure mercury lamp. ), I-line (wavelength: 365 nm), 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), or the like.

  In order to accurately form the surface unevenness of the mold, and thus the surface unevenness of the antiglare layer, in the exposure step, it is preferable to expose the pattern on the photosensitive resin film in a precisely controlled state, Specifically, it is preferable to create a pattern as image data on a computer and draw a pattern based on the image data with a laser beam emitted from a computer-controlled laser head. When performing laser drawing, a laser drawing apparatus for making a printing plate can be used. Examples of such a laser drawing apparatus include Laser Stream FX (manufactured by Sink Laboratory Co., Ltd.) and the like.

  FIG. 12C schematically shows a state in which the pattern is exposed to the photosensitive resin film 9. When the photosensitive resin film is formed of a negative photosensitive resin, the exposed region 10 undergoes a crosslinking reaction of the resin by exposure, and the solubility in a developing solution described later decreases. Therefore, the unexposed area 11 in the developing process is dissolved by the developer, and only the exposed area 10 remains on the substrate surface as a mask. On the other hand, in the case where the photosensitive resin film is formed of a positive photosensitive resin, the exposed region 10 is cut by bonding of the resin by exposure, and the solubility in a developer described later increases. Therefore, the area 10 exposed in the development process is dissolved by the developer, and only the unexposed area 11 remains on the substrate surface as a mask.

[5] Development Step In the subsequent development step, when a negative photosensitive resin is used for the photosensitive resin film 9, the unexposed region 11 is dissolved by the developer, and only the exposed region 10 is gold. It remains on the mold substrate and acts as a mask in the subsequent first etching step. On the other hand, when a positive photosensitive resin is used for the photosensitive resin film 9, only the exposed region 10 is dissolved by the developer, and the unexposed region 11 remains on the mold substrate. It acts as a mask in the subsequent first etching step.

  A conventionally well-known thing can be used about the developing solution used for a image development process. For example, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di-n-butylamine and the like Secondary amines, tertiary amines such as triethylamine, methyldiethylamine, alcohol amines such as dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, etc. Examples include alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines such as pyrrole and piperidine; and organic solvents such as xylene and toluene.

  The development method in the development step is not particularly limited, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

  FIG. 12D schematically shows a state in which development processing is performed using a negative photosensitive resin for the photosensitive resin film 9. In FIG. 12C, the unexposed area 11 is dissolved by the developer, and only the exposed area 10 becomes the remaining mask 12 on the substrate surface. FIG. 12E schematically shows a state in which a development process is performed using a positive photosensitive resin for the photosensitive resin film 9. In FIG. 12C, the exposed region 10 is dissolved by the developer, and only the unexposed region 11 becomes the remaining mask 12 on the substrate surface.

[6] First Etching Step In the subsequent first etching step, the mold base is mainly used in a portion where there is no mask, using the photosensitive resin film remaining on the mold base surface after the development step as a mask. The material is etched to form irregularities on the polished plated surface. FIG. 13 is a diagram schematically showing a preferred example of the latter half of the mold manufacturing method of the present invention. FIG. 13A schematically shows a state in which the mold base 7 in the portion 13 where no mask is mainly etched by the first etching step. The mold base 7 below the mask 12 is not etched from the mold base surface, but etching from the portion 13 without the mask proceeds with the progress of etching. Therefore, in the vicinity of the boundary between the mask 12 and the portion 13 without the mask, the mold base 7 under the mask 12 is also etched. In the vicinity of the boundary between the mask 12 and the portion 13 without the mask, the die base material 7 below the mask 12 is also etched, which is hereinafter referred to as side etching. FIG. 14 schematically shows the progress of side etching. A dotted line 14 in FIG. 14 shows the surface of the mold base material that changes as the etching progresses in stages.

The etching process in the first etching step is usually performed using a ferric chloride (FeCl ₃ ) solution, a cupric chloride (CuCl ₂ ) solution, an alkali etching solution (Cu (NH ₃ ) ₄ Cl ₂ ), etc. Although it is performed by corroding the surface, a strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that during electrolytic plating can also be used. The concave shape formed on the mold base material when the etching process is performed differs depending on the type of the base metal, the type of the photosensitive resin film, the etching technique, and the like. In the following cases, the etching is performed isotropically from the metal surface in contact with the etching solution. The etching amount here is the thickness of the base material to be cut 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 unevenness shape is hardly formed on the metal surface, and the die is almost flat, so that the antiglare property is not exhibited. In addition, when the etching amount exceeds 50 μm, the height difference of the concavo-convex shape formed on the metal surface becomes large, and in the image display device to which the antiglare film produced using the obtained mold is applied, it is white. There is a risk of injury. In order to obtain an antiglare film having a fine concavo-convex surface having a specific spatial frequency distribution represented by the above [1] and [2] and having a surface having an inclination angle of 5 ° or less and containing 95% or more The etching amount in the etching step is preferably in the range of 2 to 10 μm, more preferably in the range of 2 to 5 μm. The etching process in the first etching step may be performed by one etching process, or the etching process may be performed twice or more. In the case where the etching process is performed twice or more, it is preferable that the total etching amount in the two or more etching processes is within the above range.

[7] Photosensitive resin film peeling step In the subsequent photosensitive resin film peeling step, the remaining photosensitive resin film used as a mask in the first etching step is completely dissolved and removed. In the photosensitive resin film peeling step, the photosensitive resin film is dissolved using a peeling solution. As the stripper, the same developer as that described above can be used. By changing the pH, temperature, concentration, immersion time, etc. of the stripping solution, the exposure part is exposed when a negative photosensitive resin film is used, and the non-exposure is performed when a positive photosensitive resin film is used. Part of the photosensitive resin film is completely dissolved and removed. There is no particular limitation on the peeling method in the photosensitive resin film peeling step, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

  FIG. 13B schematically shows a state where the photosensitive resin film used as the mask 12 in the first etching process is completely dissolved and removed by the photosensitive resin film peeling process. The first surface irregularities 15 are formed on the surface of the mold substrate by etching using the mask 12 made of a photosensitive resin film.

[8] Second plating step Subsequently, the surface unevenness shape is blunted by performing chromium plating on the formed uneven surface (first surface unevenness shape 15). In FIG. 13 (c), by forming the chromium plating layer 16 on the first surface uneven shape 15 formed by the etching process of the first etching step, the unevenness is duller than the first surface uneven shape 15. The state where the surface (the surface 17 of chrome plating) is formed is shown.

As the chrome plating, it is preferable to employ a chrome plating that has a glossy surface, a high hardness, a low friction coefficient, and good mold releasability on the surface of a flat plate or a roll. The chrome plating is not particularly limited, but it is preferable to use a chrome plating that expresses good gloss, so-called gloss chrome plating or decorative chrome plating. Chromium plating is usually performed by electrolysis, and an aqueous solution containing chromic anhydride (CrO ₃ ) and a small amount of sulfuric acid is used as the plating bath. By adjusting the current density and electrolysis time, the thickness of the chromium plating can be controlled.

  JP-A-2002-189106, JP-A-2004-45472, JP-A-2004-90187, and the like disclosed above employ chrome plating. Depending on the type of chrome plating, the surface is often roughened after plating, or many fine cracks are generated due to chrome plating, and as a result, the optical characteristics of the antiglare film to be produced proceed in an undesirable direction. A mold having a rough plated surface is not suitable for producing an antiglare film. This is because the plating surface is generally polished after chrome plating in order to eliminate roughness, but as described later, polishing of the surface after plating is not preferable in the present invention. In the present invention, by applying copper plating or nickel plating to the base metal, such an inconvenience easily caused by chromium plating is solved.

  In the second plating step, it is not preferable to perform plating other than chromium plating. This is because plating other than chromium has low hardness and wear resistance, so that the durability as a mold is lowered, and unevenness is worn away during use or the mold is damaged. In an antiglare film obtained from such a mold, there is a high possibility that a sufficient antiglare function cannot be obtained, and there is a high possibility that defects will occur on the antiglare film.

  Further, surface polishing after plating as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2004-90187 is also not preferable. That is, without providing a step of polishing the surface after the second plating step, the concavo-convex surface subjected to chrome plating can be used as the concavo-convex surface of the mold transferred to the resin layer surface on the transparent support as it is. preferable. By polishing, a flat part is generated on the outermost surface, which may lead to deterioration of optical characteristics, and since shape control factors increase, shape control with good reproducibility becomes difficult. Depending on the reason.

  Thus, by performing chromium plating on the surface on which the fine surface irregularities are formed, a mold having an irregular shape that is dulled and whose surface hardness is increased can be obtained. The bluntness of the irregularities at this time varies depending on the type of the base metal, the size and depth of the irregularities obtained from the first etching process, and the type and thickness of the plating. The greatest factor in controlling is the plating thickness. If the thickness of the chrome plating is thin, the effect of dulling the surface shape of the unevenness obtained before the chrome plating process is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape are not so good. On the other hand, when the plating thickness is too thick, productivity is deteriorated and a projection-like plating defect called a nodule is generated, which is not preferable. Therefore, the thickness of the chrome plating is preferably in the range of 1 to 10 μm, and more preferably in the range of 3 to 6 μm.

  The chromium plating layer formed in the second plating step is preferably formed to have a Vickers hardness of 800 or more, and more preferably 1000 or more. When the Vickers hardness of the chrome plating layer is less than 800, the durability when using the mold is reduced, and the decrease in hardness due to chrome plating is due to abnormalities in the plating bath composition, electrolysis conditions, etc. during the plating process. This is because the possibility of occurrence is high, and the possibility of undesirably affecting the occurrence of defects is also high.

  Moreover, in the manufacturing method of the metal mold | die for producing the anti-glare film of this invention, between the [7] photosensitive resin film peeling process and the [8] 2nd plating process which were mentioned above by a 1st etching process. It is preferable to include the 2nd etching process of blunting the formed uneven surface by an etching process. In the second etching process, the first surface irregularities 15 formed by the first etching process using the photosensitive resin film as a mask are blunted by an etching process. By this second etching process, there is no portion with a steep surface inclination in the first surface irregularity shape 15 formed by the first etching process, and the optical characteristics of the antiglare film manufactured using the obtained mold are reduced. It changes in the preferred direction. In FIG. 15, the first surface irregularity shape 15 of the mold base 7 is blunted by the second etching process, the portion having a steep surface inclination is blunted, and the second surface irregularity having a gentle surface inclination is obtained. The state where the shape 18 is formed is shown.

Similarly to the first etching step, the etching process in the second etching step is usually ferric chloride (FeCl ₃ ) solution, cupric chloride (CuCl ₂ ) solution, alkaline etching solution (Cu (NH ₃ ) ₄ Cl ₂ ) or the like, and by corroding the surface, strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that during electrolytic plating can also be used. The bluntness of the unevenness after the etching process varies depending on the type of the underlying metal, the etching technique, and the size and depth of the unevenness obtained by the first etching process. The largest factor in controlling the amount is the etching amount. The etching amount here is also the thickness of the base material to be cut by etching, as in the first etching step. If the etching amount is small, the effect of dulling the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape are not so good. On the other hand, when the etching amount is too large, the uneven shape is almost lost and the die is almost flat, so that the antiglare property is not exhibited. Therefore, the etching amount is preferably in the range of 1 to 50 μm, and a surface having a specific spatial frequency distribution represented by the above [1] and [2] and having an inclination angle of 5 ° or less. In order to obtain an antiglare film having a fine uneven surface containing 95% or more, the etching amount in the second etching step is preferably in the range of 4 to 20 μm, more preferably in the range of 8 to 10 μm. Similarly to the first etching process, the etching process in the second etching process may be performed by one etching process, or the etching process may be performed twice or more. In the case where the etching process is performed twice or more, it is preferable that the total etching amount in the two or more etching processes is within the above range.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. The evaluation methods of the antiglare film and the pattern for producing the antiglare film in the following examples are as follows.

[1] Measurement of surface shape of antiglare film The surface shape of the antiglare film was measured using a three-dimensional microscope “PLμ2300” (manufactured by Sensofar). In order to prevent the sample from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent pressure-sensitive adhesive so that the uneven surface became the surface. At the time of measurement, the measurement was performed with the magnification of the objective lens being 20 times. The horizontal resolutions Δx and Δy were both 0.83 μm and the measurement area was 425 μm × 425 μm.

(Ratio of energy spectrum of complex transmission function T ₁ ² / T ₂ ² and T ₃ ² / T ₂ ² )
From the measurement data obtained above, the complex transmission function of the antiglare film is obtained as a two-dimensional function t (x, y), and the obtained two-dimensional function t (x, y) is subjected to discrete Fourier transform to obtain a two-dimensional function. T (f _x, f _y) was determined. Two-dimensional function T (f _x, f _y) of the energy spectrum by squaring the two-dimensional function ^{_{T 2 (f x, f y}} ) to calculate the, T ² (0 is a cross-sectional curve of f _x = 0, f _y ) than, determine the energy spectrum T ₂ ² in the energy spectrum T ₁ ² and the spatial frequency 0.155Myuemu ^-1 in the spatial frequency 0.016Myuemu ^-1, the ratio T _{1 ²} / T ^{2 2} energy spectrum was calculated. Further, an energy spectrum T ₃ ² at a spatial frequency of 0.108 μm ⁻¹ was obtained, and an energy spectrum ratio T ₃ ² / T ₂ ² was also calculated.

(Inclination angle of fine uneven surface)
Based on the measurement data obtained above, calculation is performed based on the above-described algorithm, a histogram of the inclination angle of the concavo-convex surface is created, a distribution for each inclination angle is obtained therefrom, and the inclination angle is 5 ° or less. The percentage of the surface was calculated.

[2] Measurement of optical properties of antiglare film (haze)
The haze of the antiglare film was measured by the method defined in JIS K 7136. Specifically, the haze was measured using a haze meter “HM-150 type” (manufactured by Murakami Color Research Laboratory) based on this standard. In order to prevent the anti-glare film from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent pressure-sensitive adhesive so that the uneven surface becomes the surface. In general, when haze increases, an image becomes dark when applied to an image display device, and as a result, front contrast tends to decrease. Therefore, a lower haze is preferable.

[3] Evaluation of anti-glare performance of anti-glare film (Visual evaluation of reflections and whitishness)
In order to prevent reflection from the back surface of the antiglare film, the antiglare film is bonded to the black acrylic resin plate so that the uneven surface becomes the surface, and visually observed from the uneven surface side in a bright room with a fluorescent lamp. Then, the presence or absence of reflection of a fluorescent lamp and the degree of whitening were visually evaluated. Reflection, whitishness and texture were evaluated according to the following criteria in three stages of 1 to 3, respectively.

Reflection 1: Reflection is not observed,
2: Reflection is slightly observed,
3: Reflection is clearly observed.

White 1: The white is not observed,
2: A little whitish is observed,
3: The whitish is clearly observed.

(Evaluation of glare)
The glare was evaluated by the following method. That is, the polarizing plates on both the front and back surfaces were peeled off from a commercially available liquid crystal television (LC-32GH3 (manufactured by Sharp Corporation). Instead of these original polarizing plates, the polarizing plate “Sumikaran SRDB31E” ( Sumitomo Chemical Co., Ltd.) is bonded via an adhesive so that each absorption axis coincides with the absorption axis of the original polarizing plate. The antiglare film shown in Fig. 1 was bonded via an adhesive so that the uneven surface was the surface, and in this state, the degree of glare was controlled in seven stages by visual observation from a position about 30 cm away from the sample. Level 1 is a state where no glare is observed, level 7 is a state where severe glare is observed, and level 4 is a state where slight glare is observed.

(Contrast evaluation)
The contrast was evaluated by the following method. That is, the polarizing plates on both the front and back surfaces were peeled from a commercially available liquid crystal television (LC-42GX1W (manufactured by Sharp Corporation)). Instead of these original polarizing plates, both the back side and the display side are attached with a polarizing plate "Sumikaran SRDB31E" (manufactured by Sumitomo Chemical Co., Ltd.) so that each absorption axis coincides with the absorption axis of the original polarizing plate. Further, the antiglare film shown in each of the following examples was laminated on the display surface side polarizing plate via an adhesive such that the uneven surface was the surface. In this state, in a dark room, the contrast is obtained by measuring the luminance at the time of white display and black display with a luminance meter ("BM-5A", manufactured by Topcon Technohouse Co., Ltd.) from a position approximately 1 m away from the sample. It was. Based on the contrast value in the state of only the polarizing plate not bonded with the anti-glare film, the ratio of the contrast value in the anti-glare film bonding state to this was evaluated.

[4] Evaluation of pattern for production of antiglare film The created pattern data was 256 gray scale image data, and the gray scale was expressed by a two-dimensional discrete function g (x, y). The horizontal resolutions Δx and Δy of the discrete function g (x, y) are both 4 μm. The resulting two-dimensional function g (x, y) and by discrete Fourier transform, two-dimensional function G (f _x, f _y) was determined. Two-dimensional function G (f _x, f _y) a two-dimensional function ^{_{G 2 (f x, f y}} ) of energy spectrum was calculated by squaring, G ² (0 is a cross-sectional curve of f _x = 0, f _y ), A local maximum value was obtained at a spatial frequency having a spatial frequency greater than 0 μm ⁻¹ and the smallest absolute value.

<Example 1>
An aluminum roll having a diameter of 200 mm (A5056 according to JIS) was prepared by applying copper ballad plating to the surface. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the entire plating layer was set to be about 200 μm. The copper plating surface was mirror-polished, and a photosensitive resin was applied to the polished copper plating surface and dried to form a photosensitive resin film. Next, a pattern in which a plurality of patterns composed of image data shown in FIG. 10 were repeatedly arranged in succession was exposed on a photosensitive resin film with a laser beam and developed. Exposure by laser light and development were performed using “Laser Stream FX” (manufactured by Sink Laboratories). A positive photosensitive resin was used for the photosensitive resin film.

Note that the pattern data shown in FIG. 10 is a band that removes other than a specific frequency region of 0.0415 to 0.0765 μm ^{−1 in} a first pattern in which a large number of one kind of dots having a dot diameter of 16 μm are randomly arranged. It was produced by applying a pass filter. Energy spectrum _{^{G 2 (f x, f y}} ) calculated from the pattern shown in FIG. 10 cross-section at f _x = 0 of is as shown in Figure 11. Pattern shown in Figure 10, shows the maximum value of the energy spectrum to the spatial frequency 0.061Myuemu ^-1, no maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1.

  Then, the 1st etching process was performed with the cupric chloride liquid. The etching amount at that time was set to 5 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed again with cupric chloride solution. The etching amount at that time was set to 8 μm. Then, the chrome plating process was performed and the metal mold | die A was produced. At this time, the chromium plating thickness was set to 4 μm.

A photocurable resin composition “GRANDIC 806T” (manufactured by Dainippon Ink & Chemicals, Inc.) is dissolved in ethyl acetate to obtain a 50% by weight solution. Further, a photopolymerization initiator, lucillin TPO (BASF) 5 parts by weight per 100 parts by weight of the curable resin component was added to prepare a coating solution. Chemical name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide) This coating solution was applied on a transparent support triacetylcellulose (TAC) film having a thickness of 80 μm so that the coating thickness after drying was 10 μm, and dried for 3 minutes in a dryer set at 60 ° C. . The dried film was brought into close contact with the uneven surface of the previously obtained mold A by pressing it with a rubber roll so that the photocurable resin composition layer was on the mold side. In this state, light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² was irradiated from the TAC film side so that the amount of light in terms of h-line was 200 mJ / cm ² to cure the photocurable resin composition layer. Then, the TAC film was peeled from the mold together with the cured resin, and a transparent antiglare film A composed of a laminate of a cured resin (antiglare layer) having irregularities on the surface and the TAC film was produced. Energy spectrum _{^{T 2 (f x, f y}} ) of the complex transmission function of the anti-glare film A section at f _x = 0 of is as shown in FIG.

<Example 2>
The pattern shown in FIG. 16 is used as a pattern exposed by laser light, and the etching amount of the first etching process is set to 4 μm, and the etching amount of the second etching process is set to 10 μm. Thus, a mold B was obtained. An antiglare film B was produced in the same manner as in Example 1 except that the obtained mold B was used. Energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function of the antiglare film B cross section in f _x = 0 in FIG. 21.

The pattern data shown in FIG. 16 was produced by randomly arranging a single type of dots having a dot diameter of 12 μm. The image data having the pattern shown in FIG. 16 has a size of 9.9 mm × 9.9 mm and is created at 12800 dpi. Energy spectrum ^{_{G 2 (f x, f y}} ) obtained from the pattern shown in FIG. 16 a cross section taken along f _x = 0 in FIG. 22. From FIG 22, the energy spectrum of the pattern shown in FIG. 16 shows a maximum value of the energy spectrum to the spatial frequency 0.062Myuemu ^-1, maxima in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It turns out that it does not have.

<Example 3>
The pattern shown in FIG. 17 is used as a pattern exposed by laser light, and the etching amount of the first etching process is set to 4 μm and the etching amount of the second etching process is set to 10 μm. Thus, a mold C was obtained. An antiglare film C was produced in the same manner as in Example 1 except that the obtained mold C was used. Energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function of the antiglare film C the cross section in the f _x = 0 in FIG. 21.

The pattern data shown in FIG. 17 was produced by randomly arranging one type of dot having a dot diameter of 20 μm. The image data having the pattern shown in FIG. 17 has a size of 9.9 mm × 9.9 mm and is created at 12800 dpi. Energy spectrum ^{_{G 2 (f x, f y}} ) obtained from the pattern shown in FIG. 17 a cross section taken along f _x = 0 in FIG. 22. From FIG 22, the energy spectrum of the pattern shown in FIG. 17 shows a maximum value of the energy spectrum to the spatial frequency 0.041Myuemu ^-1, maxima in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It turns out that it does not have.

< Comparative Example 1 >
The pattern shown in FIG. 18 is used as a pattern exposed by laser light, and the etching amount of the first etching process is set to 3 μm and the etching amount of the second etching process is set to 6 μm. Thus, a mold D was obtained. An antiglare film D was produced in the same manner as in Example 1 except that the obtained mold D was used. Energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function of the antiglare film D a cross section taken along f _x = 0 in FIG. 21.

The pattern data shown in FIG. 18 was prepared by randomly arranging one type of dot having a dot diameter of 12 μm. The image data which is the pattern shown in FIG. 18 has a size of 99.2 mm × 99.2 mm and was created at 12800 dpi. Energy spectrum obtained from the pattern shown in FIG. _{^{18 G 2 (f x, f}} y) a cross section taken along f _x = 0 in FIG. 22. From FIG 22, the energy spectrum of the pattern shown in Figure 18, shows the maximum value of the energy spectrum to the spatial frequency 0.058Myuemu ^-1, maxima in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It turns out that it does not have.

<Example 4 >
The pattern shown in FIG. 19 is used as a pattern exposed by laser light, and the etching amount of the first etching process is set to 5 μm, and the etching amount of the second etching process is set to 12 μm. Thus, a mold E was obtained. An antiglare film E was produced in the same manner as in Example 1 except that the obtained mold E was used. Energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function of the antiglare film E a cross-section in the f _x = 0 in FIG. 21.

The pattern data shown in FIG. 19 was created using an FM screen. The image data which is the pattern shown in FIG. 19 has a size of 1 mm × 1 mm and was created at 6400 dpi. Energy spectrum obtained from the pattern shown in FIG. _{^{19 G 2 (f x, f}} y) a cross section taken along f _x = 0 in FIG. 22. From FIG 22, the energy spectrum of the pattern shown in FIG. 19 shows a maximum value of the energy spectrum to the spatial frequency 0.05 .mu.m ^-1, maxima in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It turns out that it does not have.

<Comparative example 2 >
The pattern shown in FIG. 20 is used as a pattern exposed by laser light, and the etching amount of the first etching process is set to 10 μm and the etching amount of the second etching process is set to 30 μm. Thus, a mold F was obtained. An antiglare film F was produced in the same manner as in Example 1 except that the obtained mold F was used. Energy spectrum ^{_{T 2 (f x, f y}} ) of the complex transmission function of the antiglare film F a cross-section at f _x = 0 in FIG. 21.

The pattern data shown in FIG. 20 was prepared by randomly arranging one type of dot having a dot diameter of 36 μm. The image data which is the pattern shown in FIG. 20 has a size of 20 mm × 20 mm and was created at 2400 dpi. Energy spectrum obtained from the pattern shown in FIG. _{^{20 G 2 (f x, f}} y) a cross section taken along f _x = 0 in FIG. 22. From FIG 22, the energy spectrum of the pattern shown in FIG. 20, the range spatial frequency increases 0.04 .mu.m ^-1 less than 0 .mu.m ^-1, i.e., it can be seen that with a maximum value at 0.016μm ^-1.

<Comparative Example 3 >
The surface of a 200 mm diameter iron roll (STKM13A by JIS) was prepared by applying copper ballad plating. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the entire plating layer was set to be about 200 μm. The copper-plated surface is mirror-polished, and the polished copper-plated surface is subjected to zirconia beads TZ-SX-17 (manufactured by Tosoh Corp., average particle diameter) using a blasting device (manufactured by Fuji Seisakusho). 20 μm) is blasted with a blast pressure of 0.3 MPa (gauge pressure) and a use amount of beads of 8 g / cm ² (use amount per 1 cm ² of surface area of the roll). Etching was performed, and the resulting concavo-convex copper-plated iron roll was chrome-plated to produce a metal mold G. At this time, the etching amount was set to 10 μm, and the chromium plating thickness was set to 6 μm. An antiglare film G was produced in the same manner as in Example 1 except that the obtained mold G was used. Energy spectrum _{^{T 2 (f x, f y}} ) of the complex transmission function of the antiglare film G a cross section taken along f _x = 0 in FIG. 21.

  Table 1 shows the evaluation results of the surface shape and optical properties of the obtained antiglare film.

As shown in Table 1, the anti-glare films A to C and E of Examples 1 to 4 according to the present invention exhibit sufficient glare suppression ability and sufficient anti-glare property (reflection prevention ability), and are white. There was no injury and no reduction in front contrast. Antiglare film D of Comparative Example 1 showed sufficient glare suppressing ability and anti-glare, against irregularities formed in the first etching treatment, the etching amount of the second etching treatment is less For this reason, the tilt angle could not be reduced sufficiently, and the ratio of the surfaces having the tilt angle of 5 ° or less was less than 95%. Antiglare film of Comparative Example 2 in which the energy spectrum is generated using the pattern having the maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 F, the ratio of the energy spectrum T ₁ ² / T ₂ ² Was over 6000, causing glare. Moreover, since the anti-glare film G of Comparative Example 3 prepared without using a predetermined pattern has an energy spectrum ratio T ₃ ² / T ₂ ² of less than 3, sufficient anti-glare property (reflection prevention ability) Did not show.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Anti-glare film, 2 Concavity and convexity which comprises fine uneven surface, 3 Projection surface of anti-glare film, 4 Main normal direction of anti-glare film, 6 Local normal which considered unevenness, 6a-6d Polygon surface method Line vector, ψ surface inclination angle, 7 substrate for mold, 8 surface of substrate polished by polishing process, 9 photosensitive resin film, 10 photosensitive resin film exposed in exposure process, 11 exposed in exposure process Unmasked photosensitive resin film, 12 mask, 13 location without mask, 14 surface formed stepwise by etching, 15 substrate surface after first etching step (first surface irregular shape), 16 chromium plating layer, 17 Surface of chrome plating, 18 Substrate surface after second etching step (second surface irregular shape), 22 Light incident perpendicularly to the surface of the antiglare layer from the transparent support side, 23 Light emitted from the viewing side (fine uneven surface side) of the surface layer of the layer, 24 virtual plane having the lowest height of the fine uneven surface, 25 virtual plane having the highest height of the fine uneven surface 101 transparent support, 102 anti-glare layer, 103 fine uneven surface.

Claims (7)

An antiglare film comprising a transparent support and an antiglare layer having an uneven surface, laminated on the transparent support,
The energy spectrum T ₁ ² of the complex transmission function of the antiglare film in the spatial frequency 0.016μm ^-1, the ratio T of the energy spectrum T ₂ ² complex transmission function of the anti-glare film in a spatial frequency 0.155Myuemu ^-1 ₁ ² / T ₂ ² is 1177 or more and 5161 or less,
The energy spectrum T ₃ ² complex transmission function of the antiglare film in the spatial frequency 0.108μm ^-1, the ratio T of the energy spectrum T ₂ ² complex transmission function of the anti-glare film in a spatial frequency 0.155Myuemu ^-1 ₃ ² / T ₂ ² is 4.0 or more and 12.7 or less,
The uneven surface includes 99% or more of a surface having an inclination angle of 5 ° or less,
The antiglare layer is an antiglare film that does not contain fine particles having an average particle size of 0.4 μm or more. A method for producing the antiglare film according to claim 1 ,
Method for producing an antiglare film that the uneven surface is formed by using in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 a pattern showing an energy spectrum that does not have the maximum value. Using the pattern, producing a mold having an uneven surface;
The manufacturing method of the anti-glare film of Claim 2 including the process of transferring the uneven | corrugated surface of the said metal mold | die to the surface of the resin layer formed on the said transparent support body. A method for producing the mold according to claim 3 ,
A first plating step of performing copper plating or nickel plating on the surface of the mold base;
A polishing step of polishing the surface plated by the first plating step;
A photosensitive resin film forming step of forming a photosensitive resin film on the polished surface;
An exposure step of exposing the pattern on the photosensitive resin film;
A developing step of developing the photosensitive resin film exposed to the pattern;
A first etching step of performing an etching process using the developed photosensitive resin film as a mask and forming irregularities on the polished plated surface;
A photosensitive resin film peeling step for peeling the photosensitive resin film;
A second plating step of applying chromium plating to the formed uneven surface;
A method for manufacturing a mold, including: The manufacturing method of the metal mold | die of Claim 4 including the 2nd etching process of blunting the uneven | corrugated shape of the formed uneven surface by an etching process between the said photosensitive resin film peeling process and the said 2nd plating process. . The mold manufacturing method according to claim 4 or 5 , wherein the concavo-convex surface on which chromium plating is formed in the second plating step is an concavo-convex surface of the mold transferred to the surface of the resin layer. The method for manufacturing a mold according to any one of claims 4 to 6 , wherein a chromium plating layer formed by chromium plating in the second plating step has a thickness of 1 to 10 µm.