KR20100107415A - Anti-glare film - Google Patents

Abstract

PURPOSE: An antiglare film according to the present invention is provided to improve the contrast by preventing the deterioration of the visibility due to whitening. CONSTITUTION: An antiglare film(1) has an antiglare layer. A fine convexo-concave(2) is formed on the antiglare layer. The height of the fine convexo-concave surface can be represented by two dimensional function on a coordinate. The overall surface of the film is displayed as a transparent surface(3).

Description

Anti-glare film {ANTI-GLARE FILM}

This invention relates to the anti-glare (anti glare) film which is low haze and is excellent in anti-glare characteristic.

In an image display device such as a liquid crystal display, a plasma display panel, a cathode ray tube (cathode ray tube: CRT) display, an organic electroluminescence (EL) display, and the like, when external light is projected on the display surface, visibility is remarkably impaired. In order to prevent such projection of external light, the surface of an image display device has conventionally been used in televisions and personal computers which value image quality, video cameras and digital cameras used outdoors with strong external light, and mobile phones which display using reflected light. The film layer which prevents projection of external light is provided in this. This film layer is largely classified into a film formed by an antireflective treatment using interference by an optical multilayer film and a film subjected to an antiglare treatment that scatters incident light by blurring incident light by forming fine irregularities on the surface. do. Among these, since the former antireflection film needs to form a multilayer film having a uniform optical film thickness, the cost is high. On the other hand, since the latter antiglare film can be produced relatively inexpensively, it is widely used for applications such as large personal computers and monitors.

Such anti-glare films are conventionally produced by a method of forming random irregularities on a sheet by, for example, applying a resin solution in which fine particles are dispersed on a base sheet, and adjusting the coating film thickness to expose the fine particles on the surface of the coating film. have. However, the antiglare film produced by dispersing such fine particles is difficult to obtain the unevenness as intended, because the arrangement and shape of the unevenness depends on the dispersed state, the coated state, and the like of the fine particles in the resin solution. There was a problem that a sufficient anti-glare effect could not be obtained. Moreover, when such a conventional anti-glare film was arrange | positioned on the surface of an image display apparatus, there existed a problem that what is called "whitening" which the whole display surface became white light by scattered light and became a cloudy color was easy to generate | occur | produce. . In addition, with the recent sharpening of image display apparatuses, the so-called "sparkling" phenomenon that the pixels of the image display apparatuses and the surface irregularities of the antiglare film interfere with each other, resulting in a luminance distribution that is difficult to see. There was a problem. In order to eliminate the glare, there are attempts to scatter the light by providing a refractive index difference between the binder resin and the dispersed fine particles, but when such an anti-glare film is placed on the surface of the image display device, the light at the fine particles and the binder resin interface There was also a problem that contrast tends to be lowered by scattering.

On the other hand, there exists an attempt to express anti-glare only by the fine unevenness | corrugation formed in the surface of a transparent resin layer, without containing microparticles | fine-particles. For example, Japanese Patent Laid-Open No. 2002-189106 (Patent Document 1) discloses a three-dimensional 10-point average roughness by curing the ionizing radiation curable resin in a state where an ionizing radiation curable resin is sandwiched between an embossing mold and a transparent resin film. Anti-glare of the form which the average distance of adjacent convex parts on a three-dimensional roughness reference plane forms fine unevenness which respectively satisfy | fills predetermined value, and provided the ionizing radiation curable resin layer in which the unevenness was formed on the said transparent resin film. Films are disclosed. However, even with the antiglare film disclosed in Patent Document 1, it was difficult to achieve sufficient antiglare effect, suppression of whitening, high contrast, and suppression of glare.

Further, for example, Japanese Patent Application Laid-Open No. 6-34961 also uses a film having fine irregularities formed on its surface as a light diffusion layer disposed on the back side of the liquid crystal display device, not an antiglare film disposed on the display surface of the display device. (Patent Document 2), Japanese Patent Laid-Open No. 2004-45471 (Patent Document 3), Japanese Patent Laid-Open No. 2004-45472 (Patent Document 4) and the like. Among these, Patent Literatures 3 and 4 are filled with an ionizing radiation curable resin liquid in an embossing roll having a shape in which irregularities are inverted as a method of forming irregularities on the surface of the film, and the filled resin is used in the direction of rotation of the roll recess plate. After contacting the transparent base material traveling synchronously, and when the transparent base material is in contact with the roll recess plate, the resin between the roll recess plate and the transparent base material is cured, and the cured resin and the transparent base material are brought into close contact with each other at the same time as the curing. The method of peeling the laminated body of a transparent base material from a roll recessed board is disclosed.

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 the same leveling as when diluted and applied with a solvent cannot be expected. It is expected to be. In addition, in the methods disclosed in Patent Documents 3 and 4, it is necessary to fill the resin liquid directly into the embossed roll recessed plate. Therefore, in order to ensure uniformity of the uneven surface, high mechanical precision is required for the embossed roll recessed plate, There was a problem that the production of emboss roll was difficult.

Next, as a manufacturing method of the roll used for manufacture of the film which has an unevenness | corrugation on the surface, the patent document 2 mentioned above manufactures a cylindrical body using a metal etc., for example, an electron engraving, an etching, a sandblast on the surface is carried out. The method of forming an unevenness | corrugation by the technique of these etc. is disclosed. In addition, Japanese Patent Laid-Open No. 2004-29240 (Patent Document 5) discloses a method for producing an emboss roll by a beads shot method, and Japanese Patent Laid-Open No. 2004-90187 (Patent In Document 6), an embossing roll is produced through a step of forming a metal plating layer on the surface of an embossing roll, a step of mirror polishing the surface of the metal plating layer, and a step of peening as necessary. Is disclosed.

However, in the state with the blasting process on the surface of the embossing roll in this way, distribution of the uneven | corrugated diameter resulting from the particle size distribution of a blast particle generate | occur | produces, and it is difficult to control the depth of the recessed part obtained by blasting. There existed a problem in obtaining reproducible shape of the uneven | corrugated material excellent in the anti-glare function.

In addition, Patent Document 1 described above preferably describes the formation of an uneven surface by a sand blasting method or a bead shot method using a roller chromium-plated on the surface of iron. Moreover, in order to improve the durability at the time of use, it is preferable to use it after the chromium plating etc. on the mold surface in which the unevenness | corrugation was formed in this way, and it can achieve hardening and corrosion prevention accordingly. There is also a description. On the other hand, in each of the above-described examples of Patent Documents 3 and 4, it is described that the surface of the iron core is chrome plated, the liquid sand blasting treatment of # 250 is performed, and then the chromium plating is performed again to form fine concavo-convex shapes on the surface. It is.

However, in the manufacturing method of such an embossing roll, since blasting and shot are performed on chromium plating with high hardness, unevenness | corrugation is hard to form and it was difficult to control the shape of the unevenness | corrugation formed precisely. In addition, as described in Japanese Patent Laid-Open No. 2004-29672 (Patent Document 7), chromium plating often has a rough surface depending on the material and its shape to form a base. Since fine cracks formed by chromium plating are formed on the formed unevenness, there is a problem that it is difficult to design what unevenness will occur. Moreover, since there exist the minute crack which arises by chromium plating, there also existed a subject that the scattering characteristic of the finally obtained anti-glare film changes to an undesirable direction. Furthermore, since the finished roll surface changes in various ways according to the combination of the material of the embossing roll base material surface and the plating type, in order to obtain the required surface irregularities precisely, the material of the appropriate roll surface Another problem was that an appropriate plating species must be selected. Moreover, even if desired surface irregularities were obtained, the durability at the time of use may become inadequate depending on the plating type.

Japanese Unexamined Patent Application Publication No. 2000-284106 (Patent Document 8) discloses performing a sand blasting process on a substrate and then performing an etching process and / or laminating a thin film, but forming a metal plating layer before the sand blasting process. There is neither description nor suggestion about what to do. In addition, Japanese Patent Laid-Open No. 2006-53371 (Patent Document 9) describes polishing of a substrate, sand blasting, and then electroless nickel plating. In addition, Japanese Patent Application Laid-Open No. 2007-187952 (Patent Document 10) discloses that a substrate is subjected to copper plating or nickel plating, then polished, sandblasted, and then chrome plated to produce an embossed plate. In addition, Japanese Unexamined Patent Publication No. 2007-237541 (Patent Document 11) discloses chromium plating after copper plating or nickel plating, followed by polishing, sandblasting, and then etching or copper plating. It is described to produce an embossed plate by carrying out. Since it is difficult to form a surface uneven | corrugated shape in the precisely controlled state by the manufacturing method using these sandblasting processes, the comparatively large uneven | corrugated shape which has a period of 50 micrometers or more in surface uneven | corrugated shape is also produced. As a result, there has been a problem that so-called sparkling is liable to occur because these large irregularities and the pixels of the image display device interfere with each other, and thus the luminance distribution occurs and becomes difficult to see.

SUMMARY OF THE INVENTION An object of the present invention is to provide an antiglare film that exhibits high contrast without causing glare when the excellent visibility of antiglare performance is prevented and the deterioration of visibility due to whitening is prevented and disposed on the surface of a high-definition image display device. do.

An anti-glare film of the present invention, the transparent support on, as an anti-glare film comprising an anti-glare layer is formed with a fine concavo-convex surface, the energy spectrum of the spatial frequency of 0.01 ㎛ ^-1 elevation (標高) of the fine concave-convex surface H ₁ ² and the ratio H ₁ ² / H ₂ ² of the energy spectrum H ₂ ^{2 at} the spatial frequency of 0.04 μm ⁻¹ are within the range of 3 to 15.

An anti-glare film of the present invention, the minute uneven surface of the energy spectrum of the spatial frequency of 0.1 ㎛ ^-1 elevation ₃ H ^2, and a ratio of the energy spectrum H H ₂ ² according to the spatial frequency of 0.04 ㎛ ^-1 ₃ ² / H ₂ is preferably ² or less is 0.01.

As for the anti-glare film of this invention, it is preferable that the ratio of the surface whose inclination-angle of the surface of a fine unevenness | corrugation is 5 degrees or less is 95% or more.

Moreover, it is preferable that the anti-glare film of this invention does not contain microparticles | fine-particles of 0.4 micrometer or more.

These and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention which is understood in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows typically the surface of the anti-glare film of this invention.
FIG. 2 is a schematic diagram showing a state in which a function h (x, y) representing elevation is obtained discretely. FIG.
Fig. 3 shows the elevation of the fine concavo-convex surface shape of the antiglare film of the present invention as a two-dimensional discrete function h (x, y).
FIG. 4 shows energy spectra H ² (f _x , f _y ) obtained by the Discrete Fourier Transform of the two-dimensional function h (x, y) shown in FIG. 3 as white and black gradations.
5 is a view showing a cross-section of the f _x = 0 of the energy spectrum _{^{H 2 (f x, f y}} ) shown in Fig.
It is a schematic diagram for demonstrating the measuring method of the inclination angle of a fine uneven | corrugated surface.
It is a graph which shows an example of the bar graph of the inclination-angle distribution of the fine uneven surface of an anti-glare film.
It is a figure which shows a part of image data which is a pattern used in order to produce the anti-glare film of this invention by the two-dimensional discrete function g (x, y) of gradation.
FIG. 9 is a diagram showing energy spectra G ² (f _x , f _y ) obtained by discrete Fourier transforming the two-dimensional discrete functions g (x, y) of the gray scale shown in FIG.
10 is a view showing a cross-section of the f _x = 0 of the energy spectrum _{^{G 2 (f x, f y}} ) shown in Fig.
It is a figure which shows typically a preferable example of the first half part of the manufacturing method of a metal mold | die.
It is a figure which shows typically a preferable example of the latter part of the manufacturing method of a metal mold | die.
It is a figure which shows typically the state in which side etching advances in a 1st etching process.
It is a figure which shows typically the state in which the uneven surface formed by the 1st etching process dulls by the 2nd etching process.
FIG. 15 is a diagram showing the gradation of image data obtained from the pattern used during fabrication of the mold of Example 2 as a two-dimensional function. FIG.
FIG. 16 is a diagram showing the gradation of image data obtained from the pattern used during fabrication of the mold of Comparative Example 1 as a two-dimensional function. FIG.
It is a figure which showed the gradation of image data obtained from the pattern used at the time of metal mold manufacture of the comparative example 2 as a two-dimensional function.
18 is a view showing a cross section of the f _x = 0 of the energy spectra obtained from the two-dimensional function of the elevation of the micro concavo-convex surface shape of the anti-glare film B~F.
19 is a view showing a cross-section according to the second embodiment and Comparative Example 1 and Comparative Example 2 f _x = 0 of the energy spectrum of the pattern used for.

<Antiglare film>

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described in detail.

The antiglare film of the present invention has an antiglare layer having a fine concavo-convex surface shape (fine concave-convex surface) on the transparent support, and has an energy spectrum H at a spatial frequency of 0.01 μm ⁻¹ at an elevation of the fine concavo-convex surface. ^_12, a non-H _{1 ²} / H ^{2 2} ₂ H ² of the energy spectrum of the spatial frequency is 0.04 ㎛ ^-1 characterized in that the range of 3 to 15. So far, the period of the fine uneven surface of the antiglare film includes the average length (RSm) of the roughness curve element, the average length (PSm) of the cross-sectional curve element, and the average length (WSm) of the undulation curve element described in JIS B 0601. It was evaluated. However, in such a conventional evaluation method, it was not possible to accurately evaluate a plurality of cycles included in the fine uneven surface. Therefore, the correlation between the glare and the fine concavo-convex surface and the correlation between the antiglare and the fine concavo-convex surface cannot be evaluated accurately, and it has been difficult to produce an antiglare film having both glare suppression and sufficient antiglare performance.

MEANS TO SOLVE THE PROBLEM In the anti-glare film in which the anti-glare layer in which the anti-glare layer which has a fine uneven surface was formed on the transparent support body is made to show a specific spatial frequency distribution, when the fine uneven surface expresses a sufficient anti-glare effect, it is understood that the glare is sufficiently prevented. Found. That is, according to the present invention, the energy spectrum of the spatial frequency of 0.01 ㎛ ^-1 elevation of the minute uneven surface H ₁ and ^2, the spatial frequency 0.04 ㎛ ^-1 ₁ ratio H ² / H of the energy spectrum in the H ₂ ² _{By setting 2} ² within a specific range, anti-glare film that exhibits high contrast without causing glare when the visibility of the high-definition image display device is prevented from being lowered due to whitening is prevented while exhibiting excellent anti-glare performance. This is provided.

First, the energy spectrum of the elevation of the fine uneven surface of an anti-glare film is demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows typically the surface of the anti-glare film of this invention. As shown in FIG. 1, the anti-glare film 1 of this invention has an anti-glare layer in which the fine unevenness | corrugation 2 was formed in the surface. Here, the "elevation of the fine concavo-convex surface" referred to in the present invention is an imaginary plane having the height at the height of the lowest point of the fine concavo-convex surface at an arbitrary point P on the surface of the film 1 (the elevation is used as a reference). The straight line distance in the main normal direction 5 (normal direction in the said imaginary plane) of the film from 0 micrometer is meant. As shown in FIG. 1, when the Cartesian coordinates in a film plane are represented by (x, y), the elevation of a fine uneven surface can be represented by the two-dimensional function h (x, y) of coordinates (x, y). In FIG. 1, the surface of the whole film is shown by the projection surface 3. As shown in FIG.

The elevation of the fine concavo-convex surface can be obtained from three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, an atomic force microscope (AFM). The horizontal resolution required for the measuring device 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. Examples of the non-contact three-dimensional surface shape and roughness measuring instrument suitable for this measurement include the New View 5000 series (manufactured by Zygo Corporation, available from Zaigo Co., Ltd. in Japan), three-dimensional microscope PLμ2300 (manufactured by Sensofar Corporation), and the like. Since the resolution of the energy spectrum of the elevation is required to be 0.01 μm ⁻¹ or less, the measurement area is preferably at least 200 μm × 200 μm or more, and more preferably 500 μm × 500 μm or more.

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

Where f _x and f _y are frequencies in the x and y directions, respectively, and have dimensions of the inverse of the length. In addition, (pi) in Formula (1) is a circumference and i is an imaginary unit. By squaring the obtained two-dimensional functions H (f _x , f _y ), the energy spectrum H ² (f _x , f _y ) can be obtained. The energy spectrum ^{_{H 2 (f x, f y}} ) denotes the spatial frequency distribution of the minute uneven surface of the antiglare film.

Hereinafter, the method of obtaining the energy spectrum of the fine uneven surface of an anti-glare film is demonstrated more concretely. 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 a discrete value, that is, an elevation corresponding to a plurality of measurement points. Fig. 2 is a schematic diagram showing a state where a function h (x, y) representing an elevation is obtained discretely. As shown in FIG. 2, the rectangular coordinates in the film plane are represented by (x, y), and the line divided by Δx in the x-axis direction and the line divided by Δy in the y-axis direction on the film projection surface 3. In broken lines, in actual measurement, the elevation of the fine uneven surface is obtained as a discrete elevation value for each intersection of each broken line on the film projection surface 3.

The number of elevation values obtained is determined by the measurement range and Δx and Δy. 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 obtained is (M + 1) x (N + 1) pieces.

As shown in FIG. 2, if the coordinate of the point A on the film projection surface 3 is (jΔx, kΔy) (where j is 0 or more and M or less and k is 0 or more and N or less), it corresponds to the point A. The elevation of the point P on the film surface can be represented by 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, it is preferable that both Δx and Δy are 5 μm or less, and more preferably 2 μm or less, as described above. In addition, as mentioned above, 200 micrometers or more are preferable and, as for the measurement range X and Y, all 500 micrometers or more are more preferable.

Thus, in the actual measurement, a function representing the elevation of the surface of the fine unevenness is obtained as a discrete function h (x, y) having (M + 1) × (N + 1) values. A discrete function h (x, y) and equation _{(2) (f x, f} y) that is obtained discrete function H (f _x, f _y) by a discrete Fourier transform, a discrete function H, defined as obtained by the measurement By squared, the discrete function H ² (f _x , f _y ) of the energy spectrum is obtained. L in Formula (2) is an integer of-(M + 1) / 2 or more (M + 1) / 2 or less, m is an integer of-(N + 1) / 2 or more (N + 1) / 2 or less . Δf _x and Δf _y are frequency intervals in the x direction and the y direction, respectively, and are defined by equations (3) and (4).

Figure 3 shows the elevation of the surface of the fine irregularities of the anti-glare film of the present invention by the discrete function h (x, y) of two dimensions. In FIG. 3, the elevation is shown by the gradation of white and black. The discrete functions h (x, y) shown in FIG. 3 have 512 × 512 values, and the horizontal resolutions Δx and Δy are 1.66 μm.

4 shows energy spectra H ² (f _x , f _y ) obtained by discrete Fourier transforming the two-dimensional functions h (x, y) shown in FIG. 3 in white and black gradations. The energy spectrum H ² (f _x , f _y ) shown in FIG. 4 is also a discrete function having 512 × 512 values, and the horizontal resolutions Δf _x and Δf _y are 0.0012 μm ⁻¹ .

As shown in FIG. 3, since the uneven surface of the anti-glare film of the present invention is irregularly formed at random, the energy spectrum of FIG. 4 is symmetric about the origin. Thus, the energy spectrum of the spatial frequency H ₁ ² 0.01 ㎛ ^-1, the zero point of the energy spectrum is a two-dimensional function, H ₂ ^{2 2} energy spectrum H (f _x, f _y) in the spatial frequency 0.04 ㎛ ^-1 It can be obtained from the cross section that passes. FIG. 5 shows a cross section at f _x = 0 of the energy spectrum H ² (f _x , f _y ) shown in FIG. 4. This shows that the energy spectrum H ₁ ² at the spatial frequency of 0.01 μm ⁻¹ is 4.8, the energy spectrum H ₂ ² at the spatial frequency of 0.04 μm ⁻¹ is 0.35, and the ratio H ₁ ² / H ₂ ² is 14. Can be.

As described above, according to the present invention an anti-glare film is, the energy spectrum of the spatial frequency of 0.01 ㎛ ^-1 elevation of the minute uneven surface H ₁ and ^2, the energy spectrum ₂ H ² in the spatial frequency 0.04 ㎛ ^-1 It characterized in that the ratio H _{1 ²} / H ^{2 2} is 3 to 15. When the ratio H ₁ ² / H ₂ ² of the energy spectrum is less than 3 indicates that there are few long-period irregularities of 100 μm or more included in the fine uneven surface of the antiglare film, and there are many short-period irregularities of less than 25 μm. have. In such a case, projection of external light cannot be prevented effectively, and sufficient anti-glare performance cannot be obtained. On the other hand, the ratio H ₁ ² / H ₂ ² of the energy spectrum exceeding 15 indicates that there are many long-period irregularities of 100 μm or more included in the fine uneven surface, and that there are few short-period irregularities of less than 25 μm. It is shown. In such a case, the antiglare film tends to generate glare when placed on a high definition image display device. Moreover, since the short period component of less than 10 micrometers contained in a fine uneven | corrugated surface does not contribute effectively to anti-glare property, and scatters the light incident on the fine uneven | corrugated surface, it becomes a cause of whitening, so it is preferable to use less. Specifically, when the energy spectrum at the spatial frequency of 0.1 μm ⁻¹ is H ₃ ² , the ratio H ₃ ² / H ₂ ² of the energy spectrum is preferably 0.1 or less, and more preferably 0.01 or less. In the energy spectrum shown in FIG. 5, the energy spectrum H ₃ ² at a spatial frequency of 0.1 μm ⁻¹ is 0.00076. This shows that ratio H ₃ ² / H ₂ ² is 0.0022.

The present inventors also found that, in the antiglare film, when the fine uneven surface shows a specific inclination angle distribution, it is more effective in effectively preventing whitening while exhibiting excellent antiglare performance. That is, it is preferable that the ratio of the surface whose inclination-angle of the surface of fine unevenness | corrugation is 5 degrees or less of the anti-glare film of this invention is 95% or more. When the ratio of the surface where the inclination angle of the fine uneven surface is 5 ° or less is less than 95%, the inclination angle of the uneven surface becomes steep, condensing light from the surroundings, and whitening of the display surface becomes white as a whole easily occurs. . In order to suppress such a light condensing effect and prevent whitening, the higher the ratio of the surface whose inclination-angle of the fine uneven | corrugated surface is 5 degrees or less is high, it is preferable that it is 97% or more, and it is more preferable that it is 99% or more.

Here, the "inclination angle of the fine uneven | corrugated surface" said by this invention is the unevenness | corrugation in the main normal direction 5 of a film in arbitrary point P of the anti-glare film 1 surface shown in FIG. It means the angle (ψ) formed by the local normal (6) with the addition of. Similarly to the elevation, the inclination angle of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, and an atomic force microscope (AFM).

Here, FIG. 6: is a schematic diagram for demonstrating the measuring method of the inclination-angle of the fine uneven | corrugated surface. Referring to Fig. 6, a method for determining a specific inclination angle is to determine a point A on an imaginary plane FGHI, which is indicated by a dotted line, and to the point A near the point A on the x-axis passing therethrough. Points B and D almost symmetrically, and near points of interest A on the y-axis passing through point A, take points C and E almost symmetrically with respect to point A, corresponding to these points B, C, D, E The points Q, R, S and T on the film plane are determined. In addition, in FIG. 6, the rectangular coordinates in a film plane are represented by (x, y), and the coordinate of the film thickness direction is represented by z. The plane FGHI is a straight line parallel to the x axis passing through point C on the y axis, and similarly a straight line parallel to the x axis passing through the point E on the y axis, a straight line parallel to the y axis passing through the point B on the x axis, and Similarly, it is a surface formed by the intersections F, G, H, and I of a straight line parallel to the y axis passing through the point D on the x axis. In addition, in FIG. 6, although the actual film surface position is drawn upwards with respect to the plane FGHI, although the position of the attention point A is taken as a matter of course, the actual film surface position may come above the plane FGHI in some cases. If you come down.

And the inclination angle of the surface shape data obtained is the point P on the actual film surface corresponding to the attention point A, the point Q on the actual film surface corresponding to 4 points B, C, D, E taken in the vicinity, An average normal vector obtained by averaging four normal planes of a polygon extending from five points of R, S, and T, that is, four normal vectors 6a, 6b, 6c, and 6d of four triangles PQR, PRS, PST, and PTQ. This can be obtained by obtaining the polar angle of 6). After obtaining the inclination angle for each measurement point, a bar graph is calculated.

It is a graph which shows an example of the bar graph of the inclination-angle distribution of the fine uneven surface of an anti-glare film. In the graph shown in FIG. 7, the horizontal axis is an inclination angle and is divided into 0.5 ° pitches. For example, the leftmost vertical bar represents the distribution of a set in which the inclination angle is in the range of 0 ° to 0.5 °, and the angle is increased by 0.5 ° as it goes to the right. In the figure, the lower limit of the value is displayed for every two divisions of the horizontal axis. For example, the portion labeled "1" on the horizontal axis shows the distribution of the set in which the inclination angle is in the range of 1 ° to 1.5 °. In addition, the vertical axis | shaft shows the distribution of the inclination-angle, and when it adds up, it is a value. In this example, the proportion of the face at the inclination angle of 5 degrees or less is approximately 100%.

It is preferable that the anti-glare film of this invention does not contain 0.4 micrometer or more in an anti-glare layer from a viewpoint which can express high contrast effectively, when arrange | positioned on the surface of an image display apparatus. The conventional anti-glare film is manufactured by the method of apply | coating the resin solution which disperse | distributed microparticles | fine-particles on a base sheet, adjusting a coating film thickness, and exposing microparticles | fine-particles to a coating film surface, and forming random unevenness | corrugation on a sheet | seat. The antiglare film produced by dispersing such fine particles often scatters light by providing a difference in refractive index between the binder resin and the fine particles in order to eliminate glare. When arrange | positioning such an anti-glare film on the surface of an image display apparatus, contrast falls by scattering of the light in a microparticle and binder resin interface. In the anti-glare film of the present invention, since the frequency distribution on the surface of the fine unevenness is appropriately designed, it is not necessary to scatter the light and eliminate the glare. Therefore, it is preferable not to contain microparticles | fine-particles 0.4 micrometers or more which cause a fall of contrast.

<Method for Producing Anti-glare Film>

In order to form the fine uneven | corrugated surface which has said frequency distribution with high precision, it is preferable to produce the anti-glare film of this invention using the pattern which does not have a local maximum in more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less. . Here, a "pattern" means the image data for forming the fine uneven surface of the anti-glare film of this invention, the mask which has a light transmission part, and a light shielding part.

If the energy spectrum of the pattern is, for example, image data, after converting the image data to 256 gray scales, the gray scale of the image data is represented by the two-dimensional function g (x, y), and the obtained two-dimensional function g (x, y) is represented. Fourier transform is used to calculate the two-dimensional function G (f _x , f _y ), and is obtained by squaring the obtained two-dimensional function G (f _x , f _y ). In the case of a mask having a light transmitting portion and a light shielding portion, the transmittance is represented by a two-dimensional function t (x, y), and the obtained two-dimensional function t (x, y) is Fourier transformed to calculate the two-dimensional function T (f _x , f _y ). Is obtained by squaring the obtained two-dimensional functions T (f _x , f _y ). Here, x and y represent rectangular coordinates in the image data plane or in the mask plane, and f _x and f _y represent frequencies in the x direction and frequencies in the y direction.

As in the case of obtaining the energy spectrum of the elevation of the fine uneven surface, also in the case of obtaining the energy spectrum of the pattern, the two-dimensional function g (x, y) of gray level and the two-dimensional function t (x, y) of transmittance are obtained as discrete functions. The case is common. In that case, the energy spectrum may be calculated by the Discrete Fourier Transform as in the case of obtaining the energy spectrum of the elevation of the fine uneven surface.

FIG. 8 is a diagram showing a part of image data that is a pattern (a pattern used in fabrication of the mold of Example 1 to be described later) used for producing the antiglare film of the present invention as a gray scale two-dimensional discrete function g (x, y). FIG. . The two-dimensional discrete functions g (x, y) shown in FIG. 8 have values of 512 × 512, and the horizontal resolutions Δx and Δy are 2 μm. In addition, the image data which is the pattern shown in FIG. 8 was 2 mm x 2 mm in size, and was created at 12800 dpi.

FIG. 9 is a diagram showing energy spectra G ² (f _x , f _y ) obtained by discrete Fourier transforming the two-dimensional discrete functions g (x, y) of the gray scale shown in FIG. The discrete functions G ² (f _x , f _y ) shown in FIG. 8 also have 512 × 512 values, and the horizontal resolutions Δf _x and Δf _y are 0.0010 μm ⁻¹ . As shown in FIG. 8, since the pattern created in order to manufacture the anti-glare film of this invention is random, the energy spectrum of FIG. 9 becomes symmetric about an origin. Therefore, the local maximum of the energy spectrum of the pattern can be obtained from the cross section passing through the origin of the energy spectrum. 10 is a view showing a cross-section of the f _x = 0 of the energy spectrum _{^{G 2 (f x, f y}} ) shown in Fig. This shows that the pattern shown in FIG. 8 has a maximum value at the spatial frequency of 0.045 μm ⁻¹ , but does not have a maximum value of more than 0 μm ^{−1 and} 0.04 μm ⁻¹ or less.

When the energy spectrum of the pattern for producing an antiglare film has a local maximum of more than 0 µm ^{-1 and} 0.04 µm ^-1 or less, the frequency distribution of the fine uneven surface of the resulting antiglare film does not satisfy the requirements of the present invention. Therefore, it cannot combine the elimination of glare and sufficient anti-glare.

What is necessary is just to arrange the dot diameter less than 20 micrometers randomly and uniformly in order to produce the pattern which does not have a maximum in the energy spectrum more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less. One type or two or more types of dot diameters which are arrange | positioned at random may be sufficient.

The anti-glare film which has a fine uneven surface using the pattern mentioned above can be manufactured by the printing method, the pattern exposure method, the embossing method, etc. For example, in the printing method, the above-described pattern is printed on the transparent support by flexographic printing, screen printing, inkjet printing using a photocurable resin or a thermosetting resin, and then produced, followed by drying or by actinic light or heating. By hardening, the anti-glare film of this invention can be manufactured.

For example, in flexographic printing, after producing a flexo plate, which is a convex plate based on the above-described pattern, applying a photocurable resin to the convex portion of the flexo plate, transferring the applied photocurable resin onto the transparent support, and then actinic light By hardening by, fine unevenness | corrugation based on the pattern mentioned above can be formed on a transparent support body. If it is screen printing, the screen which is a stencil based on the above-mentioned pattern is produced, and after printing the above-mentioned pattern on a transparent support body using the screen and photocurable resin, hardening a photocurable resin by actinic light. Thereby, fine unevenness | corrugation can be formed on a transparent support body. In the case of inkjet printing, fine irregularities can be formed on the transparent support by printing the above-mentioned pattern directly on the transparent support using a photocurable resin, and then curing the photocurable resin with actinic light. Since the fine concavo-convex formed by this printing method generally has a steep inclination and there is a portion where the resin layer is not formed on the transparent support, a photocurable resin is also coated on the fine concave-convex formed by the printing method. It is preferable to smooth the inclination angle and to form a resin layer on the entire surface on the transparent support.

In the pattern exposure method, after apply | coating photocurable resin on a transparent support body, pattern exposure is performed by direct drawing exposure by the laser which used the pattern mentioned above, or the front surface exposure through the mask which has the pattern mentioned above, and if necessary, After developing, the antiglare film of the present invention can be produced by curing by actinic light or heating. In the direct drawing exposure by a laser, after apply | coating photocurable resin on a transparent support body, the above-mentioned pattern is directly drawn and exposed by a laser beam, the site | part exposed by development remains or melt | dissolves, and the remaining photocurable By irradiating active light to resin and fully hardening, fine unevenness | corrugation based on the pattern mentioned above can be formed on a transparent support body. Since the fine indentations formed by the direct drawing exposure by such a laser generally have a steep inclination, it is preferable to coat the photocurable resin on the fine unevenness formed by the direct drawing exposure by a laser to smooth the inclination angle. desirable. In the whole surface exposure through a mask, after manufacturing the mask which has the above-mentioned pattern, apply | coated photocurable resin on a transparent support body, photocurable resin is exposed through the mask, and the site | part exposed by the development process remains. Alternatively, the fine concavo-convex based on the above-described pattern can be formed on the transparent support by dissolving and completely curing the remaining photocurable resin by irradiating active light. In the entire surface exposure through the mask, the inclination angle of the fine unevenness can be controlled by appropriately controlling the proximity gap, and can also be controlled by controlling the exposure degree by producing the mask as a gradation mask.

In the embossing method, a mold having a fine concavo-convex surface is produced using the above-described pattern, the concavo-convex surface of the manufactured mold is transferred onto a transparent support, and then the transparent support on which the concave-convex surface is transferred is peeled off from the mold. The anti-glare film of the invention can be produced. Here, it is preferable that the anti-glare film of this invention is manufactured by the embossing method from a viewpoint of manufacturing fine uneven | corrugated surface with high precision and reproducibility.

Here, as an embossing method, the UV embossing method using a photocurable resin and the hot embossing method using a thermoplastic resin are illustrated, Especially, a UV embossing method is preferable from a viewpoint of productivity.

The UV embossing method is a method in which the uneven surface of the mold is transferred to the photocurable resin layer by forming a photocurable resin layer on the surface of the transparent support and curing the photocurable resin layer while pushing the concave and convex surface of the mold. Specifically, the ultraviolet curable resin is coated on the transparent support, the ultraviolet curable resin is irradiated from the transparent support side in the state in which the coated ultraviolet curable resin is brought into close contact with the uneven surface of the mold, and the ultraviolet curable resin is cured. The shape of the metal mold | die is transferred to ultraviolet curable resin by peeling the transparent support body in which the ultraviolet curable resin layer after hardening was formed.

When the UV embossing method is used, the transparent support may be a substantially optically transparent film. For example, a triacetyl cellulose film, a polyethylene terephthalate film, a polymethyl methacrylate film, a polycarbonate film, or a norbornene-based compound may be used as a monomer. And resin films such as solvent cast films and extruded films of thermoplastic resins such as amorphous cyclic polyolefins.

Moreover, although the kind of ultraviolet curable resin in the case of using the UV embossing method is not specifically limited, A commercially available suitable thing can be used. Moreover, it is also possible to use the resin which can harden | cure even visible light which has a wavelength longer than an ultraviolet-ray by combining the photoinitiator suitably selected with ultraviolet curable resin. Specifically, polyfunctional acrylates, such as trimethylol propane triacrylate and pentaerythritol tetraacrylate, are used alone or in combination of two or more thereof, and Irgacure 907 (Ciba Specialty Chemicals, Inc.) is used. ), A mixture of photopolymerization initiators such as Irgacure 184 (manufactured by Chiba Specialty Chemicals) and Lucirin TPO (manufactured by BASF) can be suitably used.

On the other hand, the hot embossing method is a method in which a transparent support formed of a thermoplastic resin is pushed onto a mold in a heated state to transfer the surface shape of the mold to the transparent support. As a transparent support body used for a hot embossing method, what kind of thing may be sufficient as it is substantially transparent, For example, amorphous cyclic polyolefin etc. which make polymethyl methacrylate, a polycarbonate, a polyethylene terephthalate, a triacetyl cellulose, a norbornene-type compound as a monomer Solvent cast films, extruded films, and the like of thermoplastic resins may be used. These transparent resin films can also be used suitably also as a transparent support body for coating the ultraviolet curable resin in the UV embossing method demonstrated above.

<Method for producing mold for antiglare film production>

Hereinafter, the method of manufacturing the metal mold | die used for manufacture of the anti-glare film of this invention is demonstrated. The manufacturing method of the metal mold | die used for manufacture of the anti-glare film of this invention will not be restrict | limited especially if it is a method of obtaining the predetermined surface shape using the pattern mentioned above, In order to manufacture fine uneven | corrugated surface with high precision and reproducibility, [1] first plating step, [2] polishing step, [3] photosensitive resin film coating step, [4] exposure step, [5] developing step, [6] first etching step, [ 7] It is preferable to basically include a photosensitive resin film peeling process and a [8] 2nd plating process. It is a figure which shows typically a preferable example of the first half part of the manufacturing method of a metal mold | die. 11, the cross section of the metal mold | die in each process is shown typically. Each process of the manufacturing method of this metal mold is demonstrated in detail, referring FIG.

[1] first plating process

In the manufacturing method of this metal mold | die, first, copper plating or nickel plating is given to the surface of the base material used for a metal mold | die. Thus, by performing copper plating or nickel plating on the surface of the base material for metal mold | die, the adhesiveness and glossiness of chrome plating in a subsequent 2nd plating process can be improved. That is, as described above as a background art, when chromium plating is performed on the surface of iron or the like, or when chromium plating is performed again after the unevenness is formed on the surface of the chromium plating by sandblasting, bead shot, or the like, the surface is rough. It tends to be liable to occur and fine cracks occur, making it difficult to control the uneven shape of the mold surface. On the other hand, such a problem can be eliminated by giving copper plating or nickel plating to the surface of a base material first. This is because copper plating or nickel plating has a high coating property and a strong smoothing action, and thus forms a flat and glossy surface by filling minute irregularities, cavities, and the like of the base material for a mold. Due to the characteristics of these copper platings or nickel platings, even if chromium plating is performed in the second plating step described later, the roughness of the chromium plating surface, which is considered to be caused by the minute unevenness and cavity existing in the substrate, It is eliminated, and generation | occurrence | production of a fine crack is reduced by the high coating property of copper plating or nickel plating.

As copper or nickel used in a 1st plating process, besides what may be each pure metal, the alloy which mainly consists of copper, or the alloy which mainly consists of nickel may be sufficient. Therefore, "copper" said in this specification is copper And it is a meaning containing a copper alloy, and "nickel" is a meaning containing nickel and a nickel alloy. Copper plating and nickel plating may be performed by electrolytic plating or electroless plating, respectively, but electrolytic plating is employ | adopted normally.

When carrying out copper plating or nickel plating, if the plating layer is too thin, since the influence of the under surface cannot be excluded, the thickness is preferably 50 µm or more. The upper limit of the thickness of the plating layer is not critical, but from a relationship with cost or the like, it is generally sufficient to be about 500 µm.

Moreover, in the manufacturing method of this metal mold | die, aluminum and iron etc. are mentioned from a viewpoint of cost as a metal material used suitably for formation of a base material. Moreover, lightweight aluminum is more preferable from the convenience of handling. In addition to aluminum and a railway, it may be a pure metal, respectively, and may be an alloy mainly containing aluminum or iron.

In addition, the shape of a base material will not be restrict | limited especially if it is a suitable shape conventionally employ | adopted in the art, A flat form may be sufficient, and a cylindrical roll or a cylindrical roll may be sufficient. When a metal mold | die is produced using a roll-shaped base material, there exists an advantage that an anti-glare film can be manufactured in continuous roll shape.

[2] polishing process

In the subsequent polishing step, the surface of the base material subjected to copper plating or nickel plating in the above-described first plating step is polished. In the manufacturing method of this metal mold | die, it is preferable to grind the surface of a base material near a mirror surface through this process. This is because the metal plate and the metal roll serving as the base material are often machined such as cutting or grinding in order to achieve a desired precision, and thus, traces of processing remain on the surface of the base material, and copper plating or nickel plating is performed. It is because these processing traces may remain | survive even in the obtained state, and it cannot be said that the surface becomes completely smooth in the plated state. That is, even if the process described later is performed on the surface where such a deep processing trace etc. remain, the unevenness | corrugation, such as a process trace, may be deeper than the unevenness | corrugation formed after each process, and there exists a possibility that the influence of a process trace etc. may remain. In the case where an antiglare film is produced using such a mold, an unexpected effect may be exerted on the optical characteristics. In FIG. 11 (a), the base material 7 for flat metal mold | die is copper plating or nickel plating in the surface in a 1st plating process (The copper plating or nickel plating layer formed in the process is shown. Not shown) and the state which had the surface 8 polished by the mirror process is shown typically.

The method for polishing the surface of the substrate subjected to copper plating or nickel plating is not particularly limited, and any of mechanical polishing, electrolytic polishing and chemical polishing can be used. Examples of the mechanical polishing method include ultrafinishing, lapping, fluid polishing, buff polishing, and the like. As for the surface roughness after grinding | polishing, it is preferable that centerline average roughness Ra based on the specification of JISB0601 is 0.1 micrometer or less, and it is more preferable that it is 0.05 micrometer or less. If the centerline average roughness Ra after polishing is larger than 0.1 µm, there is a possibility that the influence of surface roughness after polishing remains on the uneven shape of the final mold surface. The lower limit of the center line average roughness Ra is not particularly limited, and since there is naturally a limit in terms of processing time and processing cost, there is no need to specify it in particular.

[3] photosensitive resin film coating step

In the following photosensitive resin film application | coating process, the photosensitive resin film is formed by apply | coating as a solution which melt | dissolved photosensitive resin in the solvent, and heating and drying it to the surface 8 of the base material 7 which performed mirror-polishing by the above-mentioned grinding | polishing process, and a photosensitive resin film is formed. . FIG. 11B schematically shows a state in which the photosensitive resin film 9 is formed on the surface 8 of the substrate 7.

Conventionally well-known photosensitive resin can be used as photosensitive resin. For example, a negative photosensitive resin having a property of curing the photosensitive portion may be a monomer or prepolymer of an acrylic ester having an acrylic group or a methacryl group, a mixture of a bisazide and a diene rubber, a polyvinyl cinnamate compound, or the like. Can be. Moreover, a phenol resin type, a novolak resin type, etc. can be used as a positive photosensitive resin which has the property which a photosensitive part elutes by development and only an unphotosensitive part remains. In addition, you may mix | blend various additives, such as a sensitizer, a development promoter, an adhesive modifier, and a coating property improving agent, with photosensitive resin as needed.

When applying these photosensitive resins to the surface 8 of the base material 7, in order to form a favorable coating film, it is preferable to dilute and apply in a suitable solvent, and it is a cellosolve solvent, a propylene glycol solvent, an ester solvent, Alcohol solvents, ketone solvents, high polar solvents and the like can be used.

As a method for applying the photosensitive resin solution, known methods such as meniscus coat, fountain coat, dip coat, rotary coating, roll coating, wire bar coating, air knife coating, blade coating, curtain coating, etc. may be used. Can be. It is preferable to make the thickness of a coating film into the range of 1 micrometer-6 micrometers after drying.

[4] exposure process

In the following exposure process, the pattern which does not have a maximum value above 0 micrometer < ^-1 > -0.04 micrometer <^-1> is exposed on the photosensitive resin film 9 formed in the photosensitive resin film application | coating process mentioned above. What is necessary is just to select suitably the light source used for an exposure process according to the photosensitive wavelength, sensitivity, etc. of the apply | coated photosensitive resin, For example, g line (wavelength: 436 nm) of high pressure mercury lamp, h line (wavelength: 405 nm) of high pressure mercury lamp, high pressure I-ray (wavelength: 365 nm), mercury lamp, semiconductor laser (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser (wavelength: 1064 nm), KrF excimer laser (wavelength: 248 nm), ArF Excimer laser (wavelength: 193 nm), F2 excimer laser (wavelength: 157 nm), and the like.

In order to form surface uneven | corrugated shape with high precision in the manufacturing method of this metal mold | die, it is preferable to expose the above-mentioned pattern in the state controlled precisely on the photosensitive resin film in an exposure process. In the manufacturing method of the metal mold | die of this invention, in order to expose the above-mentioned pattern on a photosensitive resin film with high precision, a pattern is created on a computer as image data, and the pattern based on the image data is generated from a computer-controlled laser head. It is preferable to draw by a laser beam. When performing laser drawing, the laser drawing apparatus for printing plate preparation can be used. Examples of such a laser drawing apparatus include Laser Stream FX (manufactured by Sync Laboratories).

FIG. 11 (c) schematically shows a state where the pattern is exposed on the photosensitive resin film 9. When the photosensitive resin film is formed of negative photosensitive resin, crosslinking reaction of resin advances in the exposed area | region 10 by exposure, and the solubility with respect to the developing solution mentioned later falls. Therefore, the area | region 11 which is not exposed in the image development process is melt | dissolved by the developing solution, and only the exposed area | region 10 remains on a surface of a base material, and becomes a mask. On the other hand, when the photosensitive resin film is formed of positive photosensitive resin, the bond of resin is cut | disconnected by exposure in the exposed area | region 10, and the solubility to the developing solution mentioned later increases. Therefore, the exposed region 10 in the developing step is dissolved by the developing solution, and only the unexposed region 11 remains on the substrate surface to become a mask.

[5] Development Process

In the subsequent developing step, when a negative photosensitive resin is used for the photosensitive resin film 9, the unexposed region 11 is dissolved by a developer, and only the exposed region 10 remains on the mold substrate. It acts as a mask in the subsequent first etching step. On the other hand, when positive type photosensitive resin is used for the photosensitive resin film 9, only the exposed area | region 10 is melt | dissolved with a developing solution, and the area | region 11 which is not exposed remains on the base material for metal mold | die, and the following agent It acts as a mask in one etching process.

As the developing solution used in the developing step, a conventionally known one can be used. For example, inorganic alkalis, such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and ammonia water, 1st amines, such as ethylamine and n-propylamine, diethylamine, di-n-butylamine, etc. Tertiary amines such as amines, triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and trimethylhydroxyethylammonium hydroxide And alkaline aqueous solutions such as cyclic amines such as quaternary ammonium salts, pyrrole and piperidine, and organic solvents such as xylene and toluene.

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

FIG. 11 (d) schematically shows a state in which the developing treatment is performed using a negative photosensitive resin for the photosensitive resin film 9. In FIG.11 (c), the area | region 11 which is not exposed melt | dissolves with a developing solution, and only the exposed area | region 10 remains on the surface of a base material, and becomes the mask 12. FIG. FIG. 11E schematically illustrates a state in which the developing treatment is performed using a positive photosensitive resin on the photosensitive resin film 9. In FIG. 11C, the exposed region 10 is dissolved by the developer, and only the unexposed region 11 remains on the substrate surface to form the mask 12.

[6] first etching process

In the following 1st etching process, the base material for metal mold | die of the site | part without a mask is mainly etched using the photosensitive resin film which remained on the surface of the metal mold | die base material after the above-mentioned image development process as a mask. It is a figure which shows typically a preferable example of the latter part of the manufacturing method of this metal mold | die. 12A schematically shows a state in which the mold base 7 in the portion 13 without a mask is etched mainly by the first etching step. The mold base 7 in the lower part of the mask 12 is not etched from the surface of the mold base, but etching proceeds from the region 13 without a mask as the etching proceeds. Therefore, in the vicinity of the boundary between the mask 12 and the maskless region 13, the base material 7 for the mold under the mask 12 is also etched. In the vicinity of the boundary between the mask 12 and the maskless region 13, the metal substrate 7 for the mold under the mask 12 is also etched, hereinafter referred to as side etching. 13, the progress of side etching is shown typically. The dotted line 14 of FIG. 13 has shown the surface of the metal mold | die base material which changes with progress of an etching step by step.

The etching treatment 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 ), or the like. Although it is performed by corroding a surface, strong acids, such as hydrochloric acid and a sulfuric acid, can also be used, and reverse electrolytic etching by applying the reverse electric potential at the time of electroplating can also be used. Since the concave shape formed on the base material for a metal mold | die at the time of an etching process differs with the kind of base metal, the kind of photosensitive resin film, the etching method, etc., it cannot say uniformly, but when etching amount is 10 micrometers or less, It is etched approximately isotropically from the metal surface in contact. Etching amount here is the thickness of the base material shaved by etching.

The etching amount in the first etching step is preferably 1 µm to 50 µm. In the case where the etching amount is less than 1 µm, almost no irregularities are formed on the metal surface and the mold becomes almost flat, so that the anti-glare property is not exhibited. In addition, when the etching amount exceeds 50 micrometers, since the height difference of the uneven | corrugated shape formed in a metal surface becomes large, and the anti-glare film produced using the obtained metal mold | die becomes white, it is unpreferable. The etching treatment in the first etching step may be performed by one etching treatment or may be performed by dividing the etching treatment into two or more times. In the case where the etching treatment is divided into two or more times, the total amount of etchings in the two or more etching treatments is preferably 1 µm to 50 µm.

[7] photosensitive resin film peeling step

In the following photosensitive resin film peeling process, the remaining photosensitive resin film used as a mask in a 1st etching process is melt | dissolved and removed completely. In the photosensitive resin film peeling process, a photosensitive resin film is melt | dissolved using a peeling liquid. As the stripping solution, the same developer as described above can be used, and by changing the pH, temperature, concentration, and immersion time, and the like, when the negative photosensitive resin film is used, the non-exposed part when the positive photosensitive resin film is used Of the photosensitive resin film is completely dissolved and removed. The peeling method in the photosensitive resin film peeling step is not particularly limited, and methods such as immersion development, spray development, brush development, and ultrasonic development can be used.

FIG. 12 (b) schematically shows a state in which the photosensitive resin film used as a mask in the first etching step is completely dissolved and removed by the photosensitive resin film peeling step. By the mask 12 and etching by the photosensitive resin film, the 1st surface uneven | corrugated shape 15 is formed in the surface of the metal mold | die base material.

[8] second plating process

Subsequently, the surface unevenness is blunted by chromium plating. 12 (c) shows a state in which the chromium plating layer 16 is formed on the surface irregularities formed by the etching process of the first etching step, thereby blunting the surface 17.

In the manufacturing method of this metal mold | die, chrome plating which has gloss, the hardness is high, the friction coefficient is small, and can give favorable mold release property is employ | adopted on the surfaces, such as a flat plate and a roll. Although the kind of chromium plating is not specifically limited, It is preferable to use chromium plating which expresses favorable gloss called so-called gloss chrome plating, decorative chromium plating, etc. 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 the electrolysis time, the thickness of the chromium plating can be controlled.

Although Japanese Patent Laid-Open Publication No. 2002-189106, Japanese Patent Laid-Open Publication No. 2004-45472, Japanese Patent Laid-Open Publication No. 2004-90187 and the like have been disclosed to employ chromium plating, they have been described with a base material before plating of a mold. Depending on the type of chromium plating, the surface becomes rough after plating or a large number of minute cracks due to chromium plating are often generated. As a result, the optical characteristics of the produced antiglare film proceed in an undesirable direction. The metal mold | die of the state with which the plating surface was rough is not suitable for manufacture of an anti-glare film. This is because, in general, polishing of the plating surface after chromium plating is performed in order to eliminate tackiness, but as described later, polishing of the surface after plating is not preferable in the present invention. In the manufacturing method of this metal mold | die, this problem which is easy to generate | occur | produce in chromium plating is eliminated by giving copper plating or nickel plating to a base metal.

In addition, it is not preferable to perform plating other than chromium plating in a 2nd plating process. Because in plating other than chromium, hardness and abrasion resistance are lowered, so that durability as a mold decreases, irregularities are worn out during use, and the mold is damaged. In the anti-glare film obtained from such a metal mold | die, it is highly unlikely that sufficient anti-glare function will be obtained, and also the possibility of a defect generate | occur | producing on a film will become high.

In addition, as disclosed in Japanese Patent Laid-Open No. 2004-90187 and the like, it is also not preferable to polish the surface after plating in the method of manufacturing the mold. By polishing, flat portions are generated on the outermost surface, which may lead to deterioration of the optical characteristics, and also because of the increase in the control factor of the shape, making it difficult to control shape with good reproducibility. All.

Thus, in the manufacturing method of this metal mold, after performing chromium plating, it is preferable to use a chromium plating surface as an uneven surface of a metal mold as it is, without grind | polishing the surface. This is because by performing chromium plating on the surface on which the fine surface irregularities are formed, the mold having the uneven shape becomes dull and the surface hardness thereof is increased. The unevenness at this time varies depending on the type of the underlying metal, the size and depth of the unevenness obtained from the first etching process, the type and thickness of the plating, and the like. The biggest factor is also the plating thickness. When the thickness of chromium plating is thin, the effect of blunting the surface shape of the unevenness obtained before chrome plating process is inadequate, and the optical characteristic of the anti-glare film obtained by transferring the uneven | corrugated shape to a transparent film does not improve very much. On the other hand, when the plating thickness is too thick, the productivity is poor, and a projection-like plating defect called nodule is generated, which is not preferable. Therefore, the thickness of the chromium plating is preferably in the range of 1 µm to 10 µm, and more preferably in the range of 3 µm to 6 µm.

It is preferable that the chromium plating layer formed in the 2nd plating process is formed so that Vickers hardness may be 800 or more, and it is more preferable to form so that it may be 1000 or more. When the Vickers hardness of the chromium plating layer is less than 800, the durability at the time of use of the mold decreases, and the decrease in the hardness due to the chromium plating is likely to cause an abnormality in the plating bath composition, electrolytic conditions, and the like during the plating treatment. This is because it is highly likely to have an undesirable effect on the occurrence situation of.

Moreover, in the manufacturing method of a metal mold | die for producing the anti-glare film of this invention, the uneven surface formed by the 1st etching process is etched between the above-mentioned [7] photosensitive resin film peeling process and [8] 2nd plating process. It is preferred to include a second etching process that blunts the treatment. In a 2nd etching process, the 1st surface uneven | corrugated shape 15 formed by the 1st etching process which used the photosensitive resin film as a mask is blunted by an etching process. By this 2nd etching process, the part in which the surface inclination in the 1st surface uneven | corrugated shape 15 formed by the 1st etching process is abrupt is eliminated, and the optical characteristic of the anti-glare film manufactured using the obtained metal mold | die in the preferable direction Change. In FIG. 14, the first surface uneven shape 15 of the substrate 7 is blunted by the second etching process, the portion having a sharp surface slope is blunted, and the second surface uneven shape 18 having a gentle surface slope. Is formed.

Similarly to the first etching step, the etching treatment of the second etching step also includes a ferric chloride (FeCl ₃ ) solution, cupric chloride (CuCl ₂ ) solution, and alkaline etching solution (Cu (NH ₃ ) ₄ Cl ₂ ) Although it is carried out by corroding the surface with the like, a strong acid such as hydrochloric acid or sulfuric acid may be used, or reverse electrolytic etching by applying a potential opposite to that of electroplating may be used. Since the dull state of the unevenness after the etching treatment is different depending on the type of the underlying metal, the etching method, and the size and depth of the unevenness obtained by the first etching step, it cannot be said uniformly. The biggest factor is the etching amount. Etching amount here is also the thickness of the base material shaved by etching similarly to a 1st etching process. If the etching amount is small, the effect of blunting the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical properties of the antiglare film obtained by transferring the unevenness shape to the transparent film are not very good. On the other hand, if the etching amount is too large, the uneven shape is almost eliminated, and the mold becomes almost flat. Therefore, the anti-glare property is not exhibited. Therefore, the etching amount is preferably in the range of 1 µm to 50 µm, and more preferably in the range of 4 µm to 20 µm. Also about the etching process in a 2nd etching process, you may perform by one etching process similarly to a 1st etching process, and may divide and perform an etching process in 2 or more times. In the case where the etching treatment is divided into two or more times, the total amount of etchings in the two or more etching treatments is preferably 1 µm to 50 µm.

Although an Example is given to the following and this invention is demonstrated in detail, this invention is not limited to these Examples. In the examples,% and parts representing the content to the amount used are based on weight unless otherwise specified. In addition, the evaluation method of the metal mold | die or anti-glare film in the following examples is as follows.

[1] Measurement of surface shape of antiglare film

The surface shape of the anti-glare film was measured using the three-dimensional microscope PLμ2300 (manufactured by Sensofar). In order to prevent curvature of a sample, it bonded to the glass substrate so that an uneven surface might become a surface using the optically transparent adhesive, and used for the measurement. In the measurement, the magnification of the objective lens was measured 10 times. The horizontal resolutions Δx and Δy were both 1.66 μm and the measurement area was 850 μm × 850 μm.

(Ratio of energy spectra H ₁ ² / H ₂ ² and H ₃ ² / H ₂ ² )

From the measurement data obtained above, the elevation of the fine concavo-convex surface of the antiglare film is obtained as the two-dimensional function h (x, y), the obtained two-dimensional function h (x, y) is discrete Fourier transformed, and the two-dimensional function H (f _x , f _y ) is obtained. Was obtained. Two-dimensional function H (f _x, f _y) square by calculating a two-dimensional function of the energy spectrum ^{_{H 2 (f x, f y}} ), f x = 0 cross-sectional curve in H ² (0, f _y) from, the space the energy spectrum and the spatial frequency H ₁ ^{2 -1} 0.04 ㎛ energy spectrum H ₂ seek to Figure ^2, non-H ^2, the energy spectrum _1/2 H ² in the calculated according to the frequency 0.01 ㎛ ^-1. In addition, the energy spectrum H ₃ ² at the spatial frequency of 0.1 μm ⁻¹ was obtained and calculated for the ratio H ₃ ² / H ₂ ² of the energy spectrum.

(Inclined angle of the fine uneven surface)

Based on the measurement data obtained above, calculation is made based on the algorithm described above, a bar graph of the inclination angle of the uneven surface is created, the distribution for each inclination angle is obtained therefrom, and the proportion of the surface having an inclination angle of 5 ° or less is calculated. It was.

[2] Measurement of optical properties of antiglare film

(Haze)

The haze of the antiglare film was measured by the method specified in JIS K 7136. Specifically, haze was measured using a haze meter HM-150 type (manufactured by Murakami Color Research Institute) in accordance with this standard. In order to prevent curvature of an anti-glare film, it bonded to the glass substrate so that an uneven surface might become a surface using the optically transparent adhesive, and used for the measurement. In general, when the haze increases, the image becomes dark when applied to the image display device, and as a result, the front contrast tends to decrease. For this reason, the lower one of the haze is preferable.

[3] Evaluation of antiglare performance of antiglare film

(Visual evaluation of projection and whitening)

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 concave-convex surface becomes the surface, and visually observed from the concave-convex surface side in a bright room where the fluorescent lamp is lit, and whether or not the projection of the fluorescent lamp is whitened. The degree was visually evaluated. Projection, whitening, and texture were evaluated according to the following criteria in three steps of 1 to 3, respectively.

Projection 1: No projection is observed.

      2: The projection is slightly observed.

      3: The projection is clearly observed.

Whitening 1: Whitening is not observed.

      2: Slight whitening is observed.

      3: Whitening is observed clearly.

(Evaluation of the flash)

Flashing was evaluated by the following method. That is, the polarizing plate of both front and back was peeled from commercial liquid crystal television LC-32GH3 (made by Sharp Co., Ltd.). Instead of these original polarizing plates, on both the back side and the display surface side, polarizing plates Sumikaran SRDB31E (manufactured by Sumitomo Kagaku Co., Ltd.) were bonded together via an adhesive so that each absorption axis coincided with the absorption axis of the original polarizing plate, and further, the display was performed. On the surface side polarizing plate, the anti-glare film shown in each of the following examples was bonded through the adhesive so that the uneven surface may be a surface. In this state, the degree of glare was sensory evaluated in seven steps by visual observation from a position about 30 cm away from the sample. Level 1 is a state where no glare is seen at all, level 7 corresponds to a state where severe flashes are observed, and level 3 is a state where very little flashes are observed.

[4] Evaluation of pattern for antiglare film production

The created pattern data was made into image data of 256 gray scales, and the gray scale was represented by the two-dimensional discrete function g (x, y). The horizontal resolutions Δx and Δy of the discrete functions g (x, y) were both 2 μm. The obtained two-dimensional function g (x, y) was discrete Fourier transformed, and the two-dimensional function G (f _x , f _y ) was obtained. Two-dimensional function G (f _x, f _y) square by calculating a two-dimensional function of the energy spectrum ^{_{G 2 (f x, f y}} ), f x = 0 cross section curve of G, the space from the ² (0, f _y) of The maximum value in the spatial frequency whose frequency is larger than 0 micrometer <^{-1> and} whose absolute value is the smallest was calculated | required.

&Lt; Example 1 >

The thing which copper ballard plating was performed to the surface of the aluminum roll (A5056 by JIS) of diameter 200mm was prepared. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the whole plating layer was set so that it might be set to about 200 micrometers. The copper plating surface was mirror-polished, the photosensitive resin was apply | coated to the polished copper plating surface, and it dried, and formed the photosensitive resin film. Subsequently, the pattern which repeated and arranged the pattern shown in FIG. 8 was exposed and developed by the laser beam on the photosensitive resin film. Exposure by laser light and development were performed using Laser Stream FX (manufactured by Sync Laboratories). Positive photosensitive resin was used for the photosensitive resin film.

Then, the 1st etching process was performed with the cupric chloride liquid. The etching amount at that time was set to be 7 micrometers. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was again performed with cupric chloride liquid. The etching amount at that time was set to be 18 micrometers. 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.

Photocurable resin composition GRANDIC 806T (manufactured by Dainippon Ink & Chemicals Co., Ltd.) was dissolved in ethyl acetate to obtain a solution having a concentration of 50% by weight, and further, lucirin TPO (manufactured by BASF Corporation, chemical name: 2) as a photopolymerization initiator. , 4,6-trimethylbenzoyldiphenylphosphine oxide] was added 5 parts by weight per 100 parts by weight of the curable resin component to prepare a coating solution. On the 80-micrometer-thick triacetyl cellulose (TAC) film, this coating liquid was apply | coated so that the coating thickness after drying might be set to 10 micrometers, and it dried for 3 minutes in the dryer set to 60 degreeC. The film after drying was pressed by the rubber roll so that the photocurable resin composition layer might become a metal mold | die to the uneven surface of the metal mold A previously obtained, and it was made to adhere. In this state, the light from the high-pressure mercury lamp of 20 mW / cm <2> intensity | strength was irradiated so that it might become 200 mJ / cm <2> by h-ray-converted light quantity, and the photocurable resin composition layer was hardened. Thereafter, the TAC film was peeled from the mold together with the cured resin to prepare a transparent anti-glare film A made of a laminate of a cured resin having irregularities on the surface and a TAC film.

<Example 2>

The metal mold | die B was obtained like Example 1 except having used the pattern shown in FIG. 15 as a pattern exposed by a laser beam. The image data which is the pattern shown in FIG. 15 was 1 mm x 1 mm in size, and was created at 6400 dpi. An anti-glare film B was produced in the same manner as in Example 1 except that the obtained mold B was used.

Comparative Example 1

The metal mold | die C was obtained like Example 1 except having used the pattern shown in FIG. 16 as a pattern exposed by a laser beam. The image data which is the pattern shown in FIG. 16 was 2 mm x 2 mm in size, and was created at 12800 dpi. An anti-glare film C was produced in the same manner as in Example 1 except that the obtained mold C was used.

Comparative Example 2

The pattern shown in FIG. 17 is used as a pattern to be exposed by laser light, except that the etching amount of the first etching treatment is set to 10 µm and the etching amount of the second etching treatment is set to 30 µm. Mold D was obtained in the same manner as in Example 1. The image data which is the pattern shown in FIG. 17 is 20 mm x 20 mm in size, and was created with 3200 dpi. An anti-glare film D was produced in the same manner as in Example 1 except that the obtained mold D was used.

Comparative Example 3

The thing which copper ballad plating was given to the surface of the aluminum roll (A5056 by JIS) of diameter 200mm was prepared. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the whole plating layer was set so that it might be set to about 200 micrometers. The copper-plated surface was mirror-polished and zirconia beads TZ-SX-17 (manufactured by Tosoh Corporation, average particle diameter: 20) was used on the polished copper plated surface using a blasting device (manufactured by Fuji Seisakusho Co., Ltd.). [Micro] m] was blasted at a blast pressure of 0.05 MPa (gauge pressure, the same as below) and the use amount of beads 8 g / cm 2 (the amount used per 1 cm 2 of the roll surface, the same below), to form irregularities on the surface. Chromium plating was performed to the copper plating aluminum roll which has the obtained unevenness | corrugation, and metal mold E was produced. At this time, the chromium plating thickness was set to 6 µm. An anti-glare film E was produced in the same manner as in Example 1 except that the obtained mold E was used.

<Comparative Example 4>

The surface of the aluminum roll (A5056 by JIS) with a diameter of 300 mm was mirror-polished, and zirconia beads TZ-SX-17 (Tosho) was used on a polished aluminum surface using a blasting device (manufactured by Fuji Seisakusho Co., Ltd.). (Manufacture), average particle diameter: 20 micrometers ", and it is blasted by blast pressure of 0.1 Mpa (gauge pressure or less, same), beads usage-amount 8 g / cm <2> (usage per 1 cm <2> of rolls, same or less), and uneven | corrugated to the surface Formed. The electroless nickel plating process was performed with respect to the obtained aluminum roll which has an unevenness | corrugation, and the metal mold | die F was produced. At this time, it set so that electroless nickel plating thickness might be set to 15 micrometers. An anti-glare film F was produced in the same manner as in Example 1 except that the obtained mold F was used.

The results are shown in Table 1. In addition, it shows a cross-section of the f _x = 0 of the energy spectra obtained from the two-dimensional function representing the elevation of the minute uneven surface of the antiglare film B~F in Fig. In addition, it shows a cross-section of the f _x = 0 of the energy spectrum resulting from a pattern used in the production of an anti-glare film B~D in Fig. From FIG. 19, it turns out that the energy spectrum of the pattern used for preparation of the anti-glare film B does not have a local maximum in the spatial frequency more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less. On the other hand, it can be seen that the energy spectrum of the pattern used for the production of the antiglare films C and D has a local maximum in the spatial frequency of more than 0 µm ^{-1 and} 0.04 µm ^-1 or less.

From the result shown in Table 1, the glare-proof films A and B which satisfy | fill all the requirements of this invention did not generate | occur | produce glare, showed sufficient anti-glare property, and also did not generate whitening. In addition, since the haze is also low, the degradation of the contrast does not occur even when disposed in the image display device. The anti-glare films C and D prepared from the patterns having an energy spectrum having a maximum value of more than 0 μm ^{−1 and} 0.04 μm ⁻¹ or less are sufficient because the ratio H ₁ ² / H ₂ ² of the energy spectrum does not satisfy the requirements of the present invention. It was anti-glare and whitening did not occur, but sparkling occurred. In addition, written without using the predetermined pattern antiglare film E and F, since the ratio H _{1 ²} / H ^{2 2} of the energy spectrum does not meet the requirements of the present invention, could not have both the inhibition of sufficient anti-glare and glare .

Claims (4)

An antiglare film in which an antiglare layer having a fine concavo-convex surface is formed on a transparent support, the energy spectrum H ₁ ^{2 at} a spatial frequency of 0.01 μm ⁻¹ of an elevation of the fine concavo-convex surface, and a space frequency of 0.04 μm ^-1 spectral energy ratio H ₂ ² H _{1 ²} / H ^{2 2} is within the range of 3 to 15 of the anti-glare film according to the. The method of claim 1, wherein the fine concavo-convex energy spectrum in the space frequency of 0.1 ㎛ ^-1 elevation of the surface ² and H _3, the spatial frequency ratio 0.04 ㎛ ^-1 H ₃ ² / H of the energy spectrum in the H ₂ ² _An antiglare film wherein ₂ ² is 0.01 or less. The anti-glare film of Claim 1 or 2 whose ratio of the surface in which the inclination-angle of the said fine uneven | corrugated surface is 5 degrees or less is 95% or more. The antiglare film according to claim 1, wherein the antiglare layer does not contain fine particles of 0.4 µm or more.

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