JP5801062B2 - Anti-glare film and anti-glare polarizing plate - Google Patents

Description

  The present invention relates to an antiglare (antiglare) film and an antiglare polarizing plate using the same.

  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 mobile phone or the like, an antiglare film for preventing reflection of external light is disposed on the surface of an image display device.

  As such an antiglare film, for example, in Japanese Patent Application Laid-Open No. 2006-53371 (Patent Document 1), a surface of a polished mold substrate is subjected to sand blasting and then subjected to electroless nickel plating. Is manufactured by manufacturing a mold having fine irregularities on the surface, and curing the photocurable resin layer formed on the triacetyl cellulose (TAC) film against the irregular surface of the mold while being cured. An antiglare film in which is transferred to a photocurable resin layer is described.

JP 2006-53371 A

  The antiglare film is required to have antiglare properties, exhibits good contrast when placed on the surface of the image display device, and the entire display surface is whitish due to scattered light when placed on the surface of the image display device. Suppresses the occurrence of so-called “whitening”, which causes the display to become turbid, and the pixel of the image display device and the uneven surface shape of the antiglare film when arranged on the surface of the image display device. There is a demand for suppressing the occurrence of so-called “glare” that interferes and results in a luminance distribution that is difficult to see. However, since the anti-glare film described in Patent Document 1 is produced using a mold having a concavo-convex shape formed by sandblasting, it is not sufficient in terms of the accuracy of the concavo-convex shape imparted to the anti-glare film. In particular, since there may be a relatively large uneven shape having a period of 50 μm or more, there is a problem that “glare” tends to occur. In addition, the antiglare film described in the same document is easily damaged and may not always be sufficient in terms of mechanical strength. Furthermore, the antiglare film described in the same document is not sufficient in moisture resistance, and when the antiglare film is bonded to a polarizing film and used, the polarizing film may be deteriorated.

  Accordingly, an object of the present invention is to prevent the deterioration of visibility due to the occurrence of “whiteness” and “glare” while exhibiting excellent antiglare properties and exhibiting good contrast, and mechanically. An antiglare film having excellent strength and moisture resistance, and an antiglare polarizing plate comprising a laminate of the antiglare film and a polarizing film, wherein the deterioration of the polarizing film is suppressed. It is to provide.

The present invention is an antiglare film comprising a base film and an antiglare layer having an uneven surface laminated on the base film, the base film containing an acrylic resin, and having a spatial frequency of 0. the energy spectrum H ₁ ² elevation of uneven surface in 01μm ^-1, the ratio H _{1 ²} / H ^{2 2} and the energy spectrum H ₂ ² elevation of uneven surface in the spatial frequency 0.04 .mu.m ^-1 3-20 The ratio H of the altitude energy spectrum H ₃ ² of the uneven surface at a spatial frequency of 0.1 μm ^{−1 to} the altitude energy spectrum H ₂ ² of the uneven surface at a spatial frequency of 0.04 μm ⁻¹ . ₃ ² / H ₂ ² is 0.1 or less, and the uneven surface provides an antiglare film containing 95% or more of a surface having an inclination angle of 5 ° or less. The thickness of the base film is preferably 20 μm or more and 100 μm or less.

  Moreover, this invention provides the anti-glare polarizing plate provided with the said anti-glare film and the polarizing film laminated | stacked on the surface on the opposite side to the anti-glare layer in a base film.

  The antiglare film of the present invention exhibits excellent antiglare properties, and can effectively prevent a decrease in visibility due to the occurrence of “blink” and “glare” while exhibiting good contrast. Further, the antiglare film of the present invention is excellent in mechanical strength and moisture resistance. In the antiglare polarizing plate of the present invention using such an antiglare film, deterioration of the polarizing film due to moisture absorption is effectively suppressed.

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 schematic diagram which shows the state from which the function h (x, y) showing an altitude is obtained discretely. It is the figure which represented the altitude of the fine uneven surface of the anti-glare layer with which the anti-glare film of this invention is provided with the two-dimensional discrete function h (x, y). The altitude energy spectrum H ² (f _x , f _y ) obtained by discrete Fourier transform of the two-dimensional function h (x, y) shown in FIG. 4 is shown in white and black gradation. Energy spectrum _{^{H 2 (f x, f y}} ) shown in FIG. 5 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 the anti-glare layer with which an anti-glare film is provided. It is a figure which shows a part of image data which is a pattern which can be used in order to produce the anti-glare film of this invention. Is a graph showing white and black gradation gradation two-dimensional discrete function g (x, y) the energy spectrum obtained by discrete Fourier transform _{^{G 2 (f x, f y}} ) a shown in FIG. 9 . Energy spectrum _{^{G 2 (f x, f y}} ) shown in FIG. 10 is a view showing a cross section taken along f _x = 0 in. It is a figure which shows typically a preferable example of the first half part of the manufacturing method of the metal mold | die preferably used for manufacture of the anti-glare film 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 preferably used for manufacture of the anti-glare film of this invention. 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 a figure which shows the pattern used in the case of metal mold | die preparation of Example 1. FIG. It is a figure which shows the pattern used in the case of metal mold | die preparation of Example 2. FIG. Energy spectrum _{^{G 2 (f x, f y}} ) in the pattern shown in FIG. 15 and FIG. 16 is a diagram showing a cross-section taken along f _x = 0 in.

<Anti-glare film>
FIG. 1 is a cross-sectional view schematically showing an example of the antiglare film of the present invention. As in the example shown in FIG. 1, the antiglare film of the present invention includes a base film 101 containing an acrylic resin and an antiglare layer 102 laminated on the base film 101. The surface of the antiglare layer 102 opposite to the base film 101 is a fine uneven surface (fine uneven surface 103). Hereinafter, the antiglare film of the present invention will be described in more detail.

(Anti-glare layer)
In the antiglare layer 102 antiglare film is provided according to the present invention, the energy spectrum H ₁ ² elevation of the fine uneven surface 103 in the spatial frequency 0.01 [mu] m ^-1, the altitude of the fine uneven surface 103 in a spatial frequency 0.04 .mu.m ^-1 The ratio H ₁ ² / H ₂ ^{2 to} the energy spectrum H ₂ ² is in the range of 3 to 20, and the altitude energy spectrum H ₃ ² of the fine uneven surface 103 at a spatial frequency of 0.1 μm ⁻¹ and the space The ratio H ₃ ² / H ₂ ^{2 to} the energy spectrum H ₂ ² of the altitude of the fine uneven surface 103 at a frequency of 0.04 μm ⁻¹ is 0.1 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. Therefore, the correlation between the glare and the fine uneven surface and the correlation between the anti-glare property and the fine uneven surface cannot be accurately evaluated, and an anti-glare film having both suppression of glare and sufficient anti-glare performance is produced. It was difficult.

In the antiglare film in which an antiglare layer having a fine uneven surface is laminated on a base film containing an acrylic resin, the fine uneven surface uses the “elevation energy spectrum of the fine uneven surface”. A specific spatial frequency distribution as defined above, that is, the energy spectrum ratio H ₁ ² / H ₂ ^{2 of} the altitude is in the range of 3 to 20, and H ₃ ² / H ₂ ² is 0.1 or less. The anti-glare film exhibits excellent anti-glare performance and can prevent deterioration of visibility due to whitening, and also when applied to a high-definition image display device, without causing glare It was found that high contrast was developed.

  First, the energy spectrum of the altitude of the fine uneven surface of the antiglare layer will be described. FIG. 2 is a perspective view schematically showing the surface of the antiglare film of the present invention. As shown in FIG. 2, the antiglare film 1 of the present invention includes an antiglare layer having a fine uneven surface composed of fine unevenness 2. Here, the “elevation of the surface of the fine unevenness” as used in the present invention means a virtual plane (elevation) having the height at the lowest point of the surface of the fine unevenness at an arbitrary point P on the surface of the antiglare film 1. Means the linear distance in the main normal direction 5 (normal direction in the virtual plane) of the antiglare film from 0 μm as a reference. As shown in FIG. 2, when the orthogonal coordinates in the antiglare film plane are displayed as (x, y), the elevation of the surface of the fine irregularities is a two-dimensional function h (x, y) of the coordinates (x, y). Can be expressed as In FIG. 2, the entire surface of the antiglare film is displayed on the projection surface 3.

The elevation of the surface of the fine irregularities 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 energy spectrum of the altitude needs to be 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 altitude from the two-dimensional function h (x, y) will be described. First, from the two-dimensional function h (x, y), a two-dimensional function H (f _x, f _y) by a two-dimensional Fourier transform defined by the following formula (1) is obtained.

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 (1), π is a pi and i is an imaginary unit. The resulting two-dimensional function H (f _x, f _y) by squaring the energy spectrum ^{_{H 2 (f x, f y}} ) of altitude can be obtained. The energy spectrum ^{_{H 2 (f x, f y}} ) represents the spatial frequency distribution of the fine uneven surface of the antiglare layer.

  Hereinafter, the method for obtaining the energy spectrum of the fine uneven surface of the antiglare layer 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. 3 is a schematic diagram showing a state in which the function h (x, y) representing the altitude is obtained discretely. As shown in FIG. 3, the orthogonal coordinates in the antiglare film plane are represented by (x, y), the line divided for each 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 obtained altitude values 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. 3, 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. Thus, a discrete function H (f _x, f _y) by a discrete Fourier transform defined by obtained by measuring discrete function h (x, y) and the following formula (2) is Motomari, discrete function H (f _x, f discrete function H ² (f _x of energy spectrum by squaring _y), f _y) is determined. In the formula (2), l is an integer from − (M + 1) / 2 to (M + 1) / 2, and m is an integer from − (N + 1) / 2 to (N + 1) / 2. Also, Delta] f _x and Delta] f _y are the spatial frequency intervals of the x and y directions, is defined by equation (3) and (4). Delta] f _x and Delta] f _y correspond to the horizontal resolution of the energy spectrum of the altitude.

  FIG. 4 is an example of a diagram in which the altitude of the fine uneven surface of the antiglare layer provided in the antiglare film of the present invention is represented by a two-dimensional discrete function h (x, y). In FIG. 4, the altitude is indicated by a gradation of white and black. The discrete function h (x, y) shown in FIG. 4 has 512 × 512 values, and the horizontal resolutions Δx and Δy are 1.66 μm.

FIG. 5 shows the energy spectrum H ² (f _x , f _y ) of the altitude obtained by discrete Fourier transform of the two-dimensional function h (x, y) shown in FIG. 4 in a white and black gradation. It is a thing. Elevation of the energy spectrum _{^{H 2 (f x, f y}} ) shown in FIG. 5 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 altitude 0.0012Myuemu ^-1 It is.

As in the example shown in FIG. 4, the fine uneven surface of the antiglare layer provided in the antiglare film of the present invention is composed of randomly formed unevenness, so the energy spectrum of the altitude is as shown in FIG. 5. , Symmetric about the origin. Therefore, energy spectrum H ₁ ² elevation in the spatial frequency 0.01 [mu] m ^-1, the energy spectrum H ₃ ² elevation in the energy spectrum H ₂ ² and the spatial frequency 0.1 [mu] m ^-1 elevation in the spatial frequency 0.04 .mu.m ^-1 is The energy spectrum H ² (f _x , f _y ), which is a two-dimensional function, can be obtained from a cross section passing through the origin. 6, showing a cross section of an f _x = 0 of the energy spectrum ^{_{H 2 (f x, f y}} ) shown in FIG. From FIG. 6, the altitude energy spectrum H ₁ ² at a spatial frequency of 0.01 μm ⁻¹ is 4.4, the altitude energy spectrum H ₂ ² at a spatial frequency of 0.04 μm ⁻¹ is 0.35, and the spatial frequency is 0.1 μm ^−. The energy spectrum H ₃ ² of the altitude at ¹ is found to be 0.00076, the ratio H ₁ ² / H ₂ ² is calculated to be 14, and the ratio H ₃ ² / H ₂ ² is calculated to be 0.0022.

As described above, in the antiglare layer of the present invention, the energy spectrum H ₁ ² elevation of the fine uneven surface in the spatial frequency 0.01 [mu] m ^-1, the energy spectrum of the altitude in the spatial frequency 0.04μm ^-1 H _{² 2} The ratio H ₁ ² / H ₂ ² is in the range of 3-20. When the ratio H ₁ ² / H ₂ ² of the energy spectrum of the altitude is less than 3, there are few irregular shapes with a long period of 100 μm or more contained in the fine irregular surface of the antiglare layer, and irregular shapes with a short period of less than 25 μm. It shows that there are many. In such a case, reflection of external light cannot be effectively prevented, and sufficient antiglare performance cannot be obtained. On the other hand, when the ratio H ₁ ² / H ₂ ² of the energy spectrum of the altitude exceeds 20, there are many irregular shapes having a long period of 100 μm or more included in the fine irregular surface, and a short period of less than 25 μm. It shows that there are few uneven | corrugated shapes. In such a case, the glare tends to occur when the antiglare film is disposed in a high-definition image display device. In order to suppress glare more effectively while exhibiting better anti-glare performance, the altitude energy spectrum ratio H ₁ ² / H ₂ ² is preferably in the range of 5 to 18, More preferably, it is in the range of -15.

The ratio of the antiglare layer of the present invention, the energy spectrum H ₃ ² elevation of the fine uneven surface in the spatial frequency 0.1 [mu] m ^-1, the energy spectrum H ₂ ² elevation in a spatial frequency 0.04 .mu.m ^-1 H ₃ ² / H ₂ ² is 0.1 or less, preferably 0.01 or less. When the ratio H ₃ ² / H ₂ ² is 0.1 or less, it indicates that the short period component of less than 10 μm contained in the fine irregular surface is sufficiently reduced. Can be effectively suppressed. Short-period components of less than 10 μm contained in the fine uneven surface do not contribute effectively to the antiglare property, but cause the light incident on the fine uneven surface to scatter and cause whitening.

In the conventional anti-glare film disclosed in Patent Document 1 and the like, the altitude energy spectrum H ₁ ^{2 on the} surface of fine irregularities at a spatial frequency of 0.01 μm ^{−1 and} the altitude energy at a spatial frequency of 0.04 μm ⁻¹ . the ratio H _{1 ²} / H ^{2 2} with spectrum H ₂ ² there is a problem that glare is likely to occur larger than the antiglare film of the present invention. Therefore, in order to set the ratio H ₁ ² / H ₂ ² within the range of 3 to 20, it is necessary to reduce the energy spectrum H ₁ ² of the altitude of the fine uneven surface at a spatial frequency of 0.01 μm ⁻¹ . The antiglare film having an energy spectrum H ₁ ² Decrease the fine uneven surface of the elevation of the fine concavo-convex surface in the spatial frequency 0.01 [mu] m ^-1 As is larger 0.04 .mu.m ^-1 less than 0 .mu.m ^-1 as described below By using a pattern showing an energy spectrum that does not have a maximum value within the range, it can be suitably produced. 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.

By forming a fine uneven surface of the antiglare film by using the pattern in this manner shows an energy spectrum that does not have the maximum value at greater than 0.04 .mu.m ^-1 within the range 0 .mu.m ^-1, effectively spatial frequency 0 It becomes possible to reduce the energy spectrum H ₁ ² of the altitude of the fine uneven surface at 0.01 μm ⁻¹ , and the ratio H ₁ ² / H ₂ ² can be in the range of 3-20.

Furthermore, the energy spectrum H ₃ ² elevation of the fine uneven surface in the spatial frequency 0.1 [mu] m ^-1, the ratio H _{3 ²} / H ^{2 2} and the energy spectrum H ₂ ² elevation in the spatial frequency 0.04 .mu.m ^-1 0 in order to obtain an antiglare film having fine uneven surface is .1 or less, it has a maximum value within the range energy spectrum is the spatial frequency of greater than 0.1 [mu] m ^-1 than 0.04 .mu.m ^-1 of the pattern Is preferred. By effectively forming the fine uneven surface of the antiglare film using a pattern having such an energy spectrum, the altitude energy spectrum H ₂ ² of the fine uneven surface at a spatial frequency of 0.04 μm ⁻¹ is effectively increased. The ratio H ₃ ² / H ₂ ² can be made 0.1 or less.

  As a method of forming a fine uneven surface of an antiglare film using such a pattern, a mold having an uneven surface is produced using the pattern, and the uneven surface of the mold is formed on a base film. A method of transferring to the surface of the resin layer (embossing method) is preferable.

  The inventors of the present invention are also more effective in effectively preventing whitish while exhibiting excellent anti-glare performance, so that the fine uneven surface of the anti-glare 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 contains 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. In order to suppress such a light collecting effect and prevent whitishness, the higher the proportion of the surface where the inclination angle of the fine uneven surface is 5 ° or less, the better, preferably 97% or more. 99% or more is more preferable.

  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 5 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. 7 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. 7, 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. 7, 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. 7, the actual position of the antiglare film surface is drawn with respect to the plane FGHI, but naturally, the actual position of the antiglare film surface depends on 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. 8 is a graph showing an example of a histogram of the inclination angle distribution of the fine uneven surface of the antiglare layer provided in the antiglare film. In the graph shown in FIG. 8, 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 FIG. 8, 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 is a distribution of a set whose inclination angle is in the range of 1 to 1.5 °. Indicates. 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 order to produce an antiglare film in which the fine uneven surface of the antiglare layer includes a surface having an inclination angle of 5 ° or less of 95% or more, a mold having an uneven surface using a pattern is also produced, It is preferable to employ a method (embossing method) for transferring the uneven surface of the mold onto the surface of the resin layer formed on the base film. In such an embossing method, the inclination angle of the fine uneven surface of the antiglare layer is determined by the production conditions of the mold having the uneven surface. Specifically, it can be controlled by changing the etching amount in the etching step in the mold manufacturing method described later. That is, by reducing the etching amount in the first etching step, it is possible to reduce the height difference of the first surface unevenness formed and to increase the proportion of the surface having the inclination angle of 5 ° or less. In order to obtain an antiglare film having a fine uneven surface including 95% or more of a surface having an inclination angle of 5 ° or less, the etching amount in the first etching step is preferably 2 to 8 μm. When the etching amount is less than 2 μm, almost no uneven shape is formed on the metal surface, and it becomes a substantially flat mold. Therefore, the antiglare film produced using such a mold is It will not show sufficient anti-glare properties. In addition, when the etching amount exceeds 8 μm, the height difference of the uneven shape formed on the metal surface becomes large, and the surface having an inclination angle of 5 ° or less may be less than 95%. An anti-glare film produced using such a mold may cause whitening.

  The inclination angle of the fine uneven surface of the antiglare layer can also be controlled by the etching amount in the second etching step. By increasing the etching amount in the second etching step, it is possible to effectively dull a portion having a steep surface inclination of the first surface irregularity shape, and increase the proportion of the surface whose inclination angle is 5 ° or less. Can be made. In order to obtain an antiglare film having a fine uneven surface including 95% or more of a surface having an inclination angle of 5 ° or less, the etching amount in the second etching step is preferably in the range of 4 to 20 μm. 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.

  In the present invention, the antiglare layer can be composed of a cured product of a curable resin such as a photocurable resin or a thermoplastic resin, and is preferably composed of a cured product of a photocurable resin. In the antiglare layer, fine particles having a refractive index different from that of a cured curable resin or a thermoplastic resin may be dispersed. By dispersing the fine particles, glare can be more effectively suppressed.

When the fine particles are dispersed in the antiglare layer, the average particle size of the fine particles is preferably 5 μm or more, and more preferably 6 μm or more. The average particle size of the fine particles can be about 10 μm or less, preferably 8 μm or less. When the average particle diameter is less than 5 μm, the intensity of scattered light on the wide-angle side due to the fine particles increases, and the contrast tends to decrease when applied to an image display device. The ratio n _b / n _r between the refractive index n _{b of the} fine particles and the refractive index n _r of the cured product of the curable resin or the thermoplastic resin is 0.93 or more and 0.98 or less, or 1.01 or more and 1.04. Or less, more preferably 0.97 or more and 0.98 or less, or 1.01 or more and 1.03 or less. When the refractive index ratio n _b / n _r is lower than 0.93 or higher than 1.04, the reflectance at the interface between the cured product of the curable resin or the thermoplastic resin and the fine particles increases, and as a result Scattering increases and the total light transmittance tends to decrease. The decrease in the total light transmittance increases the haze of the antiglare film and causes a decrease in contrast when applied to an image display device. Further, when the refractive index ratio n _b / n _r is more than 0.98 and less than 1.01, the internal scattering effect due to the fine particles is reduced, and therefore, a predetermined scattering characteristic is given to the antiglare layer to cause glare due to the fine particles. In order to obtain a suppressing effect, it is necessary to add a large amount of fine particles.

  The content of the fine particles is usually 50 parts by weight or less, preferably 40 parts by weight or less with respect to 100 parts by weight of the curable resin or the thermoplastic resin. Further, the content of the fine particles is preferably 10 parts by weight or more, and more preferably 15 parts by weight or more. When the content of the fine particles is less than 10 parts by weight, the glare suppressing effect by the fine particles may be insufficient.

  The material constituting the fine particles preferably satisfies the above preferable refractive index ratio. As described later, in the present invention, the UV embossing method is preferably used for forming the antiglare layer, and in the UV embossing method, an ultraviolet curable resin is preferably used. In this case, the cured product of the ultraviolet curable resin often has a refractive index of around 1.50. Therefore, the fine particles have a refractive index of about 1.40 to 1.60. It can be appropriately selected according to the above. As the fine particles, resin beads, which are also substantially spherical, are preferably used. Examples of such suitable resin beads are listed below.

Melamine beads (refractive index 1.57),
Polymethyl methacrylate beads (refractive index 1.49),
Methyl methacrylate / styrene copolymer resin beads (refractive index of 1.50 to 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.

(Base film)
The base film used in the antiglare film of the present invention is composed mainly of an acrylic resin that is excellent in transparency, moisture resistance, weather resistance, and mechanical strength, or consists of an acrylic resin. . Here, the acrylic resin in the present invention means a material obtained by mixing a methacrylic resin, an additive added as necessary, etc., and melt-kneading.

  The methacrylic resin is a polymer mainly composed of methacrylic acid ester. The methacrylic resin may be a homopolymer of one kind of methacrylic acid ester or a copolymer of methacrylic acid ester with other methacrylic acid ester or acrylic acid ester. Examples of the methacrylic acid esters include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate, and the alkyl group usually has about 1 to 4 carbon atoms. The acrylic ester that can be copolymerized with the methacrylic ester is preferably an alkyl acrylate, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. The number of carbon atoms in the group is usually about 1-8. In addition to these, the copolymer contains an aromatic vinyl compound such as styrene which is a compound having at least one polymerizable carbon-carbon double bond in the molecule, a vinyl cyanide compound such as acrylonitrile, and the like. Also good.

  The acrylic resin preferably contains acrylic rubber particles in terms of impact resistance and film-forming properties of the base film. The amount of acrylic rubber particles that can be contained in the acrylic resin is preferably 5% by weight or more, more preferably 10% by weight or more. The upper limit of the amount of acrylic rubber particles is not critical, but if the amount of acrylic rubber particles is too large, the surface hardness of the base film is lowered, and when surface treatment is applied to the base film, Solvent resistance to organic solvents decreases. Therefore, the amount of acrylic rubber particles that can be contained in the acrylic resin is preferably 80% by weight or less, and more preferably 60% by weight or less.

  The acrylic rubber particles are particles containing an elastic polymer mainly composed of an acrylate ester as an essential component. The acrylic rubber particles may have a single-layer structure consisting essentially only of the elastic polymer. It may have a multi-layer structure in which the coalescence is one layer. Specifically, as this elastic polymer, 50 to 99.9% by weight of an alkyl acrylate and at least one kind of other vinyl monomer copolymerizable therewith, 0 to 49.9% by weight, A cross-linked elastic copolymer obtained by polymerization of a monomer composition comprising 0.1 to 10% by weight of a polymerizable cross-linkable monomer is preferably used.

  Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like, and the alkyl group usually has about 1 to 8 carbon atoms. Examples of the other vinyl monomers copolymerizable with the alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule. Examples thereof include methacrylic acid esters such as methyl acid, aromatic vinyl compounds such as styrene, vinylcyan compounds such as acrylonitrile, and the like. Examples of the copolymerizable crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule. (Meth) acrylates of polyhydric alcohols such as (meth) acrylate and butanediol di (meth) acrylate, alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate and methallyl (meth) acrylate, divinyl Examples include benzene. In this specification, (meth) acrylate refers to methacrylate or acrylate, and (meth) acrylic acid refers to methacrylic acid or acrylic acid.

  In addition to the acrylic rubber particles, the acrylic resin contains normal additives such as ultraviolet absorbers, organic dyes, pigments, inorganic dyes, antioxidants, antistatic agents, surfactants, and the like. Also good. Among these, an ultraviolet absorber is preferably used for improving weather resistance. Examples of the ultraviolet absorber include 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (5 -Methyl-2-hydroxyphenyl) -2H-benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di -Tert-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5 -Di-tert-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-tert-amyl-2-hydroxypheny ) Benzotriazole ultraviolet absorbers such as -2H-benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) -2H-benzotriazole; 2-hydroxy-4-methoxybenzophenone, 2- Hydroxy-4-octyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4, Examples include 2-hydroxybenzophenone ultraviolet absorbers such as 4′-dimethoxybenzophenone; salicylic acid phenyl ester ultraviolet absorbers such as p-tert-butylphenyl salicylic acid ester and p-octylphenyl salicylic acid ester. It may be used two or more thereof. When the acrylic resin contains an ultraviolet absorber, the amount is usually 0.1% by weight or more, preferably 0.3% by weight or more, and preferably 2% by weight or less.

  The thickness of the base film is preferably 20 μm or more and 100 μm or less, and more preferably 40 μm or more and 80 μm or less. When the thickness of the base film is less than 20 μm, sufficient mechanical strength cannot be obtained, handling properties may be deteriorated, and curling may occur when an antiglare layer is formed. There is also. Moreover, it is not preferable that the thickness of the base film exceeds 100 μm from the viewpoint of the recent demand for thinning of the image display device and the cost.

  As a method for producing a base film used for the antiglare film of the present invention, for example, various generally known methods such as melt extrusion molding can be used. Especially, the method of melt-extrusion molding from T-die and making a film by making at least one surface of the molten film obtained into contact with the roll surface or the belt surface is preferable at the point from which a film with favorable surface property is obtained. In particular, from the viewpoint of improving the surface smoothness and surface gloss of the substrate film, a method of forming a film by bringing both surfaces of the molten film obtained by the above melt extrusion molding into contact with the roll surface or the belt surface is preferable. In the roll or belt used in this case, the surface of the roll or belt in contact with the acrylic resin is preferably a mirror surface in order to impart smoothness to the substrate film surface. The base film may have a multilayer structure, and examples of such a film include a laminated structure of a layer containing acrylic rubber particles and a layer containing no acrylic rubber particles. A base film having a multilayer structure can be suitably produced by, for example, multilayer melt extrusion using a feed block or a multi-manifold die. By making a base film into a multilayer structure, the characteristic which conflicts with a base film can be provided. For example, a base film with a multilayer structure having a layer containing acrylic rubber particles in the intermediate layer and a layer not containing acrylic rubber particles on the outermost surfaces of the front and back surfaces is impact resistant by the intermediate layer containing acrylic rubber particles. The surface hardness is improved by the surface layer containing no acrylic rubber particles.

  Moreover, the base film used for the antiglare film of the present invention may be obtained by subjecting a film composed of the acrylic resin obtained as described above to a stretching treatment. Further impact resistance can be imparted by the stretching treatment. The stretching method is arbitrary and is not particularly limited, but after transverse stretching with a tenter at a temperature of the glass transition temperature or higher, a method of performing heat setting treatment or after longitudinal stretching with a tenter at a temperature of the glass transition temperature or higher, A method of performing a heat setting treatment and then performing a heat setting treatment after transverse stretching can be mentioned.

<Method for producing antiglare film>
The antiglare film of the present invention can be suitably produced by a method including the following steps (A) and (B).
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 (A) 0 .mu.m ^-1, step to prepare a mold having an uneven surface and,
(B) The process of transferring the uneven | corrugated surface of a metal mold | die to the surface of the resin layer containing curable resins, such as photocurable resin, or a thermoplastic resin formed on the base film.

In large 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 by using a pattern showing an energy spectrum that does not have a maximum value, a fine irregular surface with a specific spatial frequency distribution as described above can be formed with high precision It becomes. Further, a fine uneven surface is produced by a method (embossing method) of producing a mold having an uneven surface using the pattern and transferring the uneven surface of the mold onto the surface of the resin layer formed on the base film. It is possible to obtain an antiglare layer having a good accuracy and reproducibility. 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.

If the energy spectrum of the pattern used in the step (A) is, for example, image data, the image data is converted into binary image data having two gradations, and then the gradation of the image data is converted into a two-dimensional function g (x , it expressed in y), resulting two-dimensional function g (x, y) Fourier transform to two-dimensional function G (f _x, calculates the f _y), the resulting two-dimensional function G (f _x, f _y ) is obtained by squaring. Here, x and y represent orthogonal coordinates of the image data plane, respectively f _x and f _y, representing the spatial frequencies 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 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 (5), discrete function G (f _x, f _y) is the energy spectrum by squaring the determined It is done. Here, π in the equation (5) 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, is defined by equation (6) and (7). In the equations (6) and (7), Δx and Δy 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. 9 is a diagram showing a part of image data, which is a pattern that can be used for producing the antiglare film of the present invention, and is expressed by a two-dimensional discrete function g (x, y) of gradation. It is. The image data which is the pattern shown in FIG. 9 has a size of 2 mm × 2 mm and was created at 12800 dpi.

Figure 10 is a two-dimensional discrete function g (x, y) of the gradation shown in Fig energy spectrum obtained by discrete Fourier transform ^{_{G 2 (f x, f y}} ) are shown in white and black gradation It is a figure. Since the pattern shown in FIG. 9 is obtained by randomly arranging dots, the energy spectrum is symmetric about the origin as shown in FIG. 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. Figure 11 is a view showing a cross section taken along f _x = 0 of the energy spectrum ^{_{G 2 (f x, f y}} ) shown in FIG. 10. Pattern shown now to Figure 9, but has a maximum value in the spatial frequency 0.045 .mu.m ^-1, is in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1 It can be seen that no maximum value.

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 specific fine uneven surface of the obtained antiglare film was the Since the spatial frequency distribution is not shown, it is impossible to combine glare elimination and sufficient antiglare properties.

Energy spectrum ^{_{G 2 (f x, f y}} ) pattern that has no local maximum value in the in large 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, as a pattern, for example as shown in Figure 9, the number of dots It can create by arrange | positioning at random and uniformly. One type of dot diameter may be randomly arranged, or a plurality of types may be used. In a pattern created by randomly arranging a large number of dots, the energy spectrum has a first maximum value (the maximum at the minimum spatial frequency where the spatial frequency is greater than 0 μm ^−1), which is the reciprocal of the average distance between dots. Value). Therefore, in the energy spectrum to create a pattern that does not have a maximum value in the larger 0.04 .mu.m ^-1 the range from 0 .mu.m ^-1, if create a pattern such that the average distance between the dots is less than 25μm Good. Further, the energy spectrum H ₃ ² elevation of the fine uneven surface in the spatial frequency 0.1 [mu] m ^-1 of the antiglare film, the ratio H ₃ ² / H of the energy spectrum H ₂ ² elevation in a spatial frequency 0.04 .mu.m ^-1 ₂ ² to 0.1 or less, the energy spectrum of the pattern preferably has a maximum value within the range spatial frequency of greater than 0.1 [mu] m ^-1 than 0.04 .mu.m ^-1. Such a pattern is obtained by creating an average distance between dots within a range of more than 10 μm and less than 25 μm.

A pattern obtained by passing a high-pass filter that removes a low spatial frequency component below a specific spatial frequency from a pattern created by randomly arranging a large number of dots can also be used. Furthermore, it was obtained by passing a band-pass filter that removes low spatial frequency components below a specific spatial frequency and high spatial frequency components above a specific spatial frequency from a pattern created by randomly arranging a large number of dots. A pattern can also be used. As shown in FIG. 11, the energy spectrum of a pattern created by randomly arranging a large number of dots shows a maximum value depending on the dot diameter of the dots to be arranged and the average distance between the dots. By passing such a pattern through the high-pass filter or the band-pass filter, unnecessary components can be removed. Energy spectrum of such a pattern which has passed through a high pass filter or band-pass filter is, since the removal of the component by the filter, the maximum value within the spatial frequency is greater 0.04 .mu.m ^-1 less than 0 .mu.m ^-1 I don't have it. Further, it is possible to create a pattern having a maximum value at a more efficient within a spatial frequency of less than larger 0.1 [mu] m ^-1 than 0.04 .mu.m ^-1. Here, the case of using a high-pass filter, in order to remove a maximum value within the range spatial frequency is greater than 0 .mu.m ^-1 0.04 .mu.m ^-1 following, the upper limit spatial frequency of the low spatial frequency components to be removed 0 0.04 μm ⁻¹ or less is preferable. Also, the case of using a band-pass filter to remove a maximum value within the range spatial frequency is increased 0.04 .mu.m ^-1 less than 0 .mu.m ^-1, and less than 0.1 [mu] m ^-1 than the spatial frequency 0.04 .mu.m ^-1 Is preferably 0.04 μm ⁻¹ or less, and the lower limit spatial frequency of the removed high spatial frequency component is 0. 0 μm ⁻¹ or less. It is preferably at least 08 μm ⁻¹ .

  When creating a pattern using a method that passes through a high-pal filter or band-pass filter, a random brightness distribution with the density determined by a random number or a pseudo-random number generated by a computer as the pattern before passing through the filter A pattern having can also be used.

  Details of a method for producing a mold using the pattern obtained as described above will be described later.

  The said process (B) is a process of forming the glare-proof layer which has a fine uneven surface on a base film by the embossing method. Examples of the embossing method include a UV embossing method using a photocurable resin and a hot embossing method using a thermoplastic resin. Among them, 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 base film, and the photocurable resin layer is cured by pressing the photocurable resin layer against the metal concave / convex surface so that the concave / convex surface of the mold is photocurable. Transferred to the surface of the resin layer. More specifically, a coating liquid containing a photocurable resin is applied onto the base film, and the coated photocurable resin is in close contact with the uneven surface of the mold, from the base film side. Irradiate light such as ultraviolet rays to cure the photocurable resin, and then peel the substrate film on which the cured photocurable resin layer is formed from the mold, so that the uneven shape of the mold is cured The antiglare film transferred to the photocurable resin layer (antiglare layer) is obtained.

  As the photocurable resin in the case of using the UV embossing method, an ultraviolet curable resin that is cured by ultraviolet rays is preferably used, but a visible initiator having a wavelength longer than that of ultraviolet rays can be obtained by combining the ultraviolet curable resin with an appropriately selected photoinitiator. It is also possible to use a resin that can be cured by light. 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 one or more polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, Irgacure 907 (manufactured by Ciba Specialty Chemicals), and Irgacure. It is a resin composition in which a photopolymerization initiator such as 184 (manufactured by Ciba Specialty Chemicals) or Lucillin TPO (manufactured by BASF) is mixed. A solvent or the like is added to these ultraviolet curable resins as necessary to prepare the coating solution.

<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 mold manufacturing method. In FIG. 12, the cross section of the metal mold | die in each process is shown typically. Hereinafter, the above steps will be described in detail with reference to 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. 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, it is preferable that the upper limit is about 500 μm in view of cost and the like.

  Examples of the metal material constituting the mold base include aluminum and iron from the viewpoint of cost. Furthermore, considering the convenience of handling, it is 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. Moreover, it is good also considering the base material surface 7 for metal mold | die as a mirror surface by carrying out mirror surface cutting using a cutting tool. The material and shape of the cutting tool at that time are not particularly limited, and carbide tools, CBN tools, ceramic tools, diamond tools, etc. can be used, but diamond tools should be used from the viewpoint of processing accuracy. Is preferred.

  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. Further, the lower limit of the center line average roughness Ra is not particularly limited, and is appropriately determined in consideration of processing time, processing cost, and the like.

[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) of high pressure mercury lamp, semiconductor laser (wavelength: 830 nm, 532 nm, 488 nm, 405 nm, etc.), YAG laser (wavelength: 1064 nm), KrF excimer laser (wavelength: 248 nm), ArF excimer laser (wavelength) 193 nm), F2 excimer laser (wavelength: 157 nm), 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 that a pattern is created as image data on a computer, and a pattern based on the image data is drawn by laser light emitted from a computer-controlled laser head. When performing laser drawing, a laser drawing apparatus for making a printing plate can be used. An example of such a laser drawing apparatus is Laser Stream FX (manufactured by Sink Laboratories).

  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 illustrating a preferred example of the latter half of the mold manufacturing method. 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 under the mask 12 is also etched, which is called side etching.

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, more preferably 2 to 10 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 uneven surface including 95% or more of a surface having an inclination angle of 5 ° or less, the etching amount in the first etching step is more preferably 2 to 8 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.

  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.

  Also, surface polishing after plating is 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 base film 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 the chrome plating is that there is an abnormality 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. 14, the first surface unevenness 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 unevenness 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 in order to obtain an antiglare film having a fine uneven surface including 95% or more of the surface having an inclination angle of 5 ° or less, it is 4 to 20 μm. More preferably, it is within the range. 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.

<Anti-glare polarizing plate>
The anti-glare film of the present invention exhibits excellent anti-glare properties, and can effectively prevent deterioration in visibility due to the occurrence of “blink” and “glare” while exhibiting good contrast. It is excellent in visibility when mounted on the apparatus. When the image display device is a liquid crystal display, this antiglare film can be applied to the polarizing plate. That is, the polarizing plate generally has a form in which a protective film is bonded to at least one surface of a polarizing film made of a polyvinyl alcohol-based resin film in which iodine or a dichroic dye is adsorbed and oriented. The antiglare film of the present invention is used. By bonding the polarizing film and the antiglare film of the present invention on the base film side of the antiglare film, an antiglare polarizing plate can be obtained. In this case, the other surface of the polarizing film may be in a state where nothing is laminated, a protective film or other optical film may be laminated, or an adhesive layer for bonding to a liquid crystal cell. May be laminated. Moreover, on the said protective film of the polarizing plate with which the protective film was bonded to the polarizing film at least one surface, the anti-glare film of this invention is bonded by the base film side, and it is set as an anti-glare polarizing plate. You can also. Furthermore, in the polarizing plate in which the protective film is bonded to at least one surface of the polarizing film, after the base film is bonded to the polarizing film as the protective film, an antiglare layer is formed on the base film. Moreover, it can also be set as an anti-glare polarizing plate.

  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 magnification of the objective lens was 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 spectrum of altitude H ₁ ² / H ₂ ² and H ₃ ² / H ₂ ² )
From the measurement data obtained above, the elevation of the fine uneven surface of the antiglare film is obtained as a two-dimensional function h (x, y), and the obtained two-dimensional function h (x, y) is subjected to discrete Fourier transform to obtain two dimension function H (f _x, f _y) was determined. Two-dimensional function H (f _x, f _y) a two-dimensional function ^{_{H 2 (f x, f y}} ) of energy spectrum was calculated by squaring, H ² (0 is a cross-sectional curve of f _x = 0, f _y ) than, determine the energy spectrum H ₂ ² in the energy spectrum H ₁ ² and the spatial frequency 0.04 .mu.m ^-1 in the spatial frequency 0.01 [mu] m ^-1, the ratio H _{1 ²} / H ^{2 2} energy spectrum was calculated. Further, an energy spectrum H ₃ ² at a spatial frequency of 0.1 μm ⁻¹ was obtained, and the energy spectrum ratio H ₃ ² / H 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] Measurement of mechanical strength (pencil hardness) and moisture permeability of antiglare film (pencil hardness)
The pencil hardness of the antiglare film was measured by the method defined in JIS K5600-5-4. Specifically, the measurement was performed with a load of 500 g using an electric pencil scratch hardness tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd.) compliant with this standard.

(Moisture permeability)
The moisture permeability of the antiglare film was measured under the conditions of a temperature of 40 ° C. and a relative humidity of 90% by the method defined in JIS Z0208.

[4] 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 and whitishness 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 corresponds to a state where severe glare is observed, and level 3 is a state where very slight glare is observed.

[5] Evaluation of pattern for production of antiglare film The gradation of the created pattern data was represented by a two-dimensional discrete function g (x, y). The horizontal resolutions Δx and Δy of the discrete function g (x, y) are both 2 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 ) than, to evaluate the presence or absence of the maximum value in the larger 0.04 .mu.m ^-1 less spatial frequency range from 0 .mu.m ^-1.

<Example 1>
(Production of molds for the production of anti-glare films)
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. 15 were continuously arranged repeatedly was exposed on a photosensitive resin film with a laser beam and developed. The laser beam exposure and development were performed using “Laser Stream FX” (manufactured by Sink Laboratories). A positive photosensitive resin was used for the photosensitive resin film. Pattern shown in Figure 15, the pattern in which the dot diameter was placed a dot is 12μm to many random, low spatial frequency components spatial frequency is 0.04 .mu.m ^-1 or less and 0.1 [mu] m ^-1 or more high spatial It is created by applying a bandpass filter that removes frequency components.

  Then, the 1st etching process was performed with the cupric chloride liquid. The etching amount at that time was set to 3 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 10 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.

(Preparation of base film)
First, an acrylic resin composition containing 70 parts by weight of a copolymer of methyl methacrylate / methyl acrylate = 96/4 (weight ratio) (refractive index: 1.49) and 30 parts by weight of acrylic rubber particles is first extruded. The mixture was melt-kneaded with a machine (screw diameter: 65 mm, uniaxial, with vent (manufactured by Toshiba Machine Co., Ltd.)) and supplied to the feed block. In addition, an acrylic resin composition in which 30 parts by weight of acrylic rubber particles is contained in 70 parts by weight of a copolymer (refractive index 1.49) of methyl methacrylate / methyl acrylate = 96/4 (weight ratio) is the second. Were melt-kneaded with an extruder (screw diameter: 45 mm, uniaxial, with vent (manufactured by Hitachi Zosen)), and supplied to the feed block. Co-extrusion molding is performed at 265 ° C. so that the resin supplied from the first extruder to the feed block becomes an intermediate layer, and the resin supplied from the second extruder to the feed block becomes a surface layer (both sides), A substrate film A having a three-layer structure having a thickness of 80 μm (intermediate layer 50 μm, surface layer 15 μm × 2) was produced through a roll unit set at 85 ° C.

(Formation of antiglare layer)
A photocurable resin composition GRANDIC 806T (manufactured by Dainippon Ink & Chemicals, Inc.) is dissolved in ethyl acetate to obtain a 50% strength by weight solution. Further, a photopolymerization initiator, Lucillin TPO (manufactured by BASF). Chemical name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide) was added in an amount of 5 parts by weight per 100 parts by weight of the curable resin component to prepare a coating solution. On the base film A, this coating solution was applied so that the coating thickness after drying was 6 μm, and dried for 3 minutes in a drier set at 60 ° C. The dried base film A was adhered to the concavo-convex surface of the previously obtained mold A with a rubber roll so that the photocurable resin composition layer was on the mold side. In this state, the photocurable resin composition layer was cured by irradiating light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² from the base film A side so that the amount of light in terms of h-line was 200 mJ / cm ² . . Thereafter, the base film A is peeled off from the mold together with the cured resin, and a transparent anti-glare film A made of a laminate of the cured resin (anti-glare layer) having the unevenness on the surface and the base film A is produced. did.

<Example 2>
In the exposure step, a pattern in which a plurality of patterns consisting of the image data shown in FIG. 16 are continuously arranged repeatedly is exposed on the photosensitive resin film with a laser beam so that the etching amount in the first etching process becomes 5 μm. A mold B was produced in the same manner as in Example 1 except that the etching amount in the second etching process was set to 12 μm. An antiglare film B was produced in the same manner as in Example 1 except that the obtained mold B was used. Pattern shown in Figure 16, the pattern in which the dot diameter was placed a dot is 12μm to many random, low spatial frequency components spatial frequency of 0.035 .mu.m ^-1 or less and 0.135Myuemu ^-1 or more high spatial It is created by applying a bandpass filter that removes frequency components.

<Comparative Example 1>
An antiglare film C was produced in the same manner as in Example 1 except that a triacetyl cellulose (TAC) film having a thickness of 80 μm was used instead of the base film A.

<Comparative Example 2>
The surface of a 300 mm diameter aluminum roll (JIS A5056) is mirror-polished, and the polished aluminum surface is coated with zirconia beads TZ-SX-17 (Tosoh Corp.) using a blasting device (Fuji Seisakusho). ), Average particle size: 20 μm) was blasted at a blast pressure of 0.1 MPa (gauge pressure) and a bead usage amount of 8 g / cm ² (amount used per 1 cm ² of surface area of the roll) to give unevenness to the surface. The obtained aluminum roll with unevenness was subjected to electroless nickel plating to produce a mold C. At this time, the electroless nickel plating thickness was set to 15 μm. An antiglare film D was produced in the same manner as in Example 1 except that the obtained mold C was used.

The measurement and evaluation results of [1] to [4] above for the obtained antiglare films A to D are summarized in Table 1. Also, showing a cross section of an f _x = 0 of the mold A and the mold energy spectrum G ² obtained from the pattern used for the preparation of the B (f _x, f _y) in FIG. 17. Than 17, the energy spectrum of the pattern used in the preparation of the mold A and B, it can be seen that not exhibit a maximum value to increase 0.04 .mu.m ^-1 less spatial frequency range from 0 .mu.m ^-1.

From the results shown in Table 1, the antiglare film A and the antiglare film B that satisfy all the requirements of the present invention did not cause glare at all, showed sufficient antiglare properties, and did not generate whiteness. In addition, since the haze is low, the contrast does not decrease even when it is arranged in an image display device. Furthermore, it has high pencil hardness and high mechanical strength, and also has low moisture permeability and high moisture resistance. On the other hand, although the anti-glare film C which did not use the base film which consists of acrylic resin showed the anti-glare performance, pencil hardness and moisture resistance were lower than the anti-glare film A and the anti-glare film B. In addition, the antiglare film D produced without using a predetermined pattern was glaring because the energy spectrum ratio H ₁ ² / H ₂ ² did not satisfy the requirements of the present invention.

  DESCRIPTION OF SYMBOLS 1 Anti-glare film, 2 Concavity and convexity which comprises fine uneven surface, 3 Projection surface of anti-glare film, 5 Main normal direction of anti-glare film, 6 Local normal which considered unevenness, 6a, 6b, 6c, 6d Polygon surface normal vector, ψ surface inclination angle, 7 mold substrate, 8 surface of substrate polished by polishing process, 9 photosensitive resin film, 10 photosensitive resin film exposed in exposure process, 11 Photosensitive resin film not exposed in the exposure step, 12 mask, 13 location without mask, 15 substrate surface after first etching step (first surface irregular shape), 16 chrome plating layer, 17 chrome plating surface, 18 Substrate surface (second surface irregular shape) after the second etching step, 101 substrate film, 102 antiglare layer, 103 fine irregular surface.

Claims (3)

An antiglare film comprising a base film and an antiglare layer having an uneven surface laminated on the base film,
The antiglare layer is a layer composed of a cured product of a curable resin or a thermoplastic resin and does not contain fine particles having a refractive index different from that of the cured product of the curable resin or the thermoplastic resin.
The base film includes an acrylic resin and acrylic rubber particles,
The ratio H ₁ ² / H ₂ ² between the energy spectrum H ₁ ² of the elevation of the irregular surface at a spatial frequency of 0.01 μm ⁻¹ and the energy spectrum H ₂ ² of the elevation of the irregular surface at a spatial frequency of 0.04 μm ⁻¹ . Is in the range of 3-20,
The ratio H ₃ ² / H ₂ ² between the energy spectrum H ₃ ² of the elevation of the uneven surface at a spatial frequency of 0.1 μm ⁻¹ and the energy spectrum H ₂ ² of the elevation of the uneven surface at a spatial frequency of 0.04 μm ⁻¹ . Is 0.1 or less, and
The uneven surface is an antiglare film containing 95% or more of a surface having an inclination angle of 5 ° or less.   The antiglare film according to claim 1, wherein the base film has a thickness of 20 μm to 100 μm.   An anti-glare polarizing plate comprising the anti-glare film according to claim 1 and a polarizing film laminated on a surface of the base film opposite to the anti-glare layer.