KR20110102838A - Anti-glare film and anti-glare polarizing plate - Google Patents

Abstract

In this invention, it is equipped with the base film and the anti-glare layer which has the uneven surface laminated | stacked on this, The said base film contains acrylic resin, The energy spectrum of the elevation of the elevation of the said uneven surface at the spatial frequency of 0.01 micrometer <^-1> (H) ₁ ² ) and the ratio (H ₁ ² / H ₂ ² ) of the energy spectrum (H ₂ ² ) at the spatial frequency of 0.04 μm ^{−1 is} in the range of 3 to 20, and the energy spectrum at the spatial frequency of 0.1 μm ⁻¹ (H ₃ ² ) and the ratio (H ₃ ² / H ₂ ² ) of the energy spectrum (H ₂ ² ) is 0.1 or less, and the uneven surface has an anti-glare film containing 95% or more of the inclination angle of less than 5 ° and An anti-glare polarizing plate using this is provided.

Description

Anti-glare film and anti-glare polarizing plate {ANTI-GLARE FILM AND ANTI-GLARE POLARIZING PLATE}

The present invention relates to an antiglare (anti-glare) 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 electroluminescent (EL) display, and the like, when external light shines on the display surface, visibility is remarkably impaired. Background Art [0002] Conventionally, in order to prevent such a background reflection of external light, an image display device is used in televisions and personal computers that focus on image quality, video cameras and digital cameras used outdoors with strong external light, and mobile phones which display using reflected light. The anti-glare film for preventing the background reflection of external light is arrange | positioned at the surface of the.

For example, Japanese Patent Laid-Open No. 2006-053371 discloses a mold having fine irregularities on its surface by sandblasting the polished mold base material and then electroless nickel plating, thereby producing a triacetyl cellulose (TAC) film. The anti-glare film which transferred the uneven surface of the said metal mold | die to the surface of the photocurable resin layer by hardening | curing while sticking the photocurable resin layer formed on the uneven surface of the said metal mold | die is described.

The antiglare film is required for anti-glare and exhibits a good contrast when disposed on the surface of the image display device, and the entire display surface becomes white due to scattered light when disposed on the surface of the image display device. Suppress the occurrence of so-called "whitening", which becomes hazy, and when placed on the surface of the image display device, the pixels of the image display device and the surface irregularities of the antiglare film interfere, resulting in a luminance distribution. It is desired to suppress the occurrence of the so-called "glare" which becomes difficult to see. However, since the anti-glare film described in JP 2006-053371 A is produced using a mold having a concave-convex shape formed by sand blasting, the accuracy of the concave-convex shape imparted to the anti-glare film is not sufficient. In particular, there is a problem that "glare" is likely to occur because of the fact that there may be a relatively large uneven shape having a period of 50 µm or more.

In addition, the anti-glare film described in this document tends to be flawed, and may not always be sufficient in terms of mechanical strength. Moreover, the anti-glare film described in this document is not enough in moisture resistance, and when the anti-glare film is bonded to a polarizing film and used, the polarizing film may deteriorate by moisture absorption.

Therefore, the objective of this invention is to show the outstanding anti-glare property, expressing favorable contrast, and can prevent the fall of the visibility by the occurrence of "whitening" and "glare", and an anti-glare film excellent in mechanical strength and moisture resistance, and its It is an anti-glare polarizing plate which consists of a laminated body of an anti-glare film and a polarizing film, Comprising: It is providing the anti-glare polarizing plate which can suppress deterioration of the said polarizing film effectively.

This invention is an anti-glare film provided with a base film and an anti-glare layer which has an uneven surface laminated | stacked on this base film, Comprising: The said base film contains acrylic resin, and the surface of the said uneven surface at the space frequency of 0.01 micrometer <^-1> the energy spectrum of the elevation (H ₁ ^2), a space ratio (H ² _1/2 H ²⁾ in the range of 3 to 20 of the energy spectrum of the altitude of the concave-convex surface (H _{² 2)} at a frequency of 0.04 ㎛ ^-1 I And the ratio (H ₂ ² ) of 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 of the surface at a spatial frequency of 0.04 μm ⁻¹ (H ₂ ² ). ₃ ² / H ₂ ² ) is 0.1 or less, and the uneven surface provides an antiglare film comprising 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 an anti-glare layer in a base film.

The anti-glare film of this invention can prevent the fall of the visibility by the occurrence of "whitening" and "glare" effectively, showing the outstanding anti-glare property and expressing favorable contrast. Moreover, the anti-glare film of this invention is excellent in mechanical strength and moisture resistance. In the anti-glare polarizing plate of the present invention using such an anti-glare film, deterioration of the polarizing film due to moisture absorption is effectively suppressed.

1: is sectional drawing which shows an example of the anti-glare film of this invention typically.
It is a perspective view which shows typically the surface of the anti-glare film of this invention.
3 is a schematic diagram showing a state where a function h (x, y) representing an elevation is obtained discretely.
It is an example of the figure which showed the elevation of the fine uneven surface of the anti-glare layer with which the anti-glare film of this invention is equipped with two-dimensional discrete function h (x, y).
FIG. 5 shows the energy spectrum H ² (f _x , f _y ) of the elevation obtained by the Discrete Fourier Transform of the two-dimensional function h (x, y) shown in FIG. 4 in white and black gradations.
FIG. 6 is a diagram showing a cross section at f _x = 0 of the energy spectrum H ² (f _x , f _y ) shown in FIG. 5.
It is a schematic diagram for demonstrating the measuring method of the inclination angle of a fine uneven 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 equipped.
It is a figure which shows a part of image data which is a pattern which can be used for producing the anti-glare film of this invention.
FIG. 10 is a diagram showing energy spectra G ² (f _x , f _y ) obtained by discrete Fourier transforming the two-dimensional discrete functions g (x, y) of the gray scale shown in FIG.
FIG. 11 is a diagram showing a cross section at f _x = 0 of the energy spectrum G ² (f _x , f _y ) shown in FIG. 10.
It is a figure which shows typically a preferable example of the front part of a metal mold | die manufacturing method.
It is a figure which shows typically a preferable example of the latter part of a metal mold manufacturing method.
It is a figure which shows typically the state in which the uneven surface formed by the 1st etching process is slowed by the 2nd etching process.
It is a figure which shows the pattern used when producing the metal mold | die of Example 1. FIG.
It is a figure which shows the pattern used when producing the metal mold | die of Example 2. FIG.
FIG. 17 is a diagram showing a cross section at f _x = 0 of the energy spectrum G ² (f _x , f _y ) of the patterns shown in FIGS. 15 and 16.

<Antiglare film>

1: is sectional drawing which shows an example of the anti-glare film of this invention typically. The anti-glare film of this invention is equipped with the base film 101 containing acrylic resin, and the anti-glare layer 102 laminated | stacked on the base film 101 like the example shown in FIG. The surface on the opposite side to the base film 101 in the antiglare layer 102 is composed of a fine uneven surface (fine uneven surface 103). EMBODIMENT OF THE INVENTION Hereinafter, the anti-glare film of this invention is demonstrated in detail.

(Antiglare layer)

In the antiglare layer 102 of the antiglare film of the present invention, the energy spectrum (H ₁ ² ) of the elevation of the fine concavo-convex surface 103 at the spatial frequency of 0.01 μm ^{−1 and} at the spatial frequency of 0.04 μm ⁻¹ The ratio H ₁ ² / H ₂ ² of the energy spectrum H ₂ ² of the elevation of the fine uneven surface 103 is in the range of 3 to 20, and the fine uneven surface 103 at a spatial frequency of 0.1 μm ⁻¹ . the energy spectrum of the altitude (H ₃ ²⁾ and a ^{_{non-(H 3 2 / H 2 2}} ) of the spatial energy spectrum (H ₂ ²⁾ of the elevation of the micro concavo-convex surface 103 of the frequency 0.04 ㎛ ^-1 is 0.1 or less to be.

Conventionally, about the period of the fine uneven | corrugated surface of an anti-glare film, the average length (RSm) of the roughness curve element described in JIS B 0601, the average length (PSm) of the cross-sectional curve element, the average length (WSm) of a wrinkle curve element, etc. Was being evaluated. However, such a conventional evaluation method could not accurately evaluate a plurality of cycles included in the fine uneven surface. Therefore, the correlation between the glare and the fine concave-convex surface and the correlation between the anti-glare and the fine concave-convex surface cannot be accurately evaluated, and the control of values such as RSm, PSm, WSm, and the like can provide an antiglare film having both glare suppression and sufficient antiglare performance. It was difficult to produce.

MEANS TO SOLVE THE PROBLEM In the anti-glare film which laminated | stacked the anti-glare layer which has a fine uneven | corrugated surface on the base film containing acrylic resin, this fine uneven | corrugated surface is the specific thing prescribed | regulated using "the energy spectrum of the elevation of the fine uneven surface." An anti-glare film that exhibits a spatial frequency distribution, that is, an energy spectral ratio (H ₁ ² / H ₂ ² ) of the elevation is in the range of 3 to 20, and H ₃ ² / H ₂ ² is 0.1 or less, exhibits excellent anti-glare performance, Moreover, it was found that the fall of the visibility by whitening can be prevented, and even when it is applied to the high-definition image display apparatus, high contrast is expressed, without generating glare.

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

The elevation of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, an atomic force microscope (AFM), or the like. The horizontal resolution required for the measuring device is at least 5 µm or less, preferably 2 µm or less, and the vertical resolution is at least 0.1 µm or less, preferably 0.01 µm or less. Examples of non-contact three-dimensional surface shape and roughness measuring instruments suitable for this measurement include the New View 5000 series (manufactured by Zygo Corporation, available from Zaigo Co., Ltd. in Japan), and three-dimensional microscope PLμ2300 (manufactured by Sensofar Corporation). Can be. Since the resolution of the energy spectrum of the elevation 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 or more.

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

Here, f _x and f _y are spatial frequencies in the x direction and the y direction, respectively, and have an inverse dimension of length. In the formula (1), pi is the circumference and i is an imaginary unit. By squaring the obtained two-dimensional functions H (f _x , f _y ), the energy spectrum H ² (f _x , f _y ) of the elevation can be obtained. This 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 of obtaining the energy spectrum of the elevation of the surface of the fine unevenness of the antiglare layer will be described in more detail. Three-dimensional information of the surface shape actually measured by the above confocal microscope, interference microscope, atomic force microscope, etc. is generally obtained as a discrete value, that is, an elevation corresponding to a plurality of measurement points. 3 is a schematic diagram showing a state where a function h (x, y) representing an elevation is obtained discretely. As shown in FIG. 3, the orthogonal coordinate in the antiglare film surface is represented by (x, y), and is divided on the projection surface 3 of the antiglare film by dividing every x in the x-axis direction in each x-axis direction and every y in the y-axis direction. When one line is represented by a broken line, in actual measurement, the elevation of the fine uneven surface is obtained as a discrete elevation value for each intersection point of each broken line on the projection surface 3 of the antiglare film.

The number of elevations obtained is determined by the measurement range and Δx and Δy. When the measurement range in the x-axis direction is X = MΔx and the measurement range in the y-axis direction is Y = NΔy, as shown in FIG. 3, The number of elevations obtained is (M + 1) x (N + 1) pieces.

As shown in FIG. 3, when 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, k is 0 or more and N or less). , The elevation of the point P on the antiglare film surface corresponding to the spot A can be represented by h (jΔx, kΔy).

Here, the measurement intervals Δx and Δy depend on the horizontal resolution of the measuring device, and in order to accurately evaluate the fine uneven surface, as described above, both Δx and Δy are preferably 5 μm or less, and more preferably 2 μm or less. desirable. In addition, as mentioned above, as for the measurement range X and Y, all are 200 micrometers or more, and it is more preferable that all are 500 micrometers or more.

In this way, in the actual measurement, a function representing the elevation of the fine uneven surface is obtained as a discrete function h (x, y) having (M + 1) × (N + 1) values. Accordingly, the discrete function H (f _x , f _y ) is obtained by the discrete Fourier transform obtained by the measurement and the discrete Fourier transform defined by the following formula (2), and the discrete function H (f _x , f By squaring _y ), the discrete function H ² (f _x , f _y ) of the energy spectrum is obtained. L in Formula (2) is an integer of-(M + 1) / 2 or more (M + 1) / 2 or less, m is an integer of-(N + 1) / 2 or more (N + 1) / 2 or less . Further, Δf _x and Δf _y are spatial frequency intervals in the x direction and the y direction, respectively, and are defined by equations (3) and (4), respectively. Δf _x and Δf _y correspond to the horizontal resolution of the energy spectrum of the elevation.

It is an example of the figure which showed the elevation of the fine uneven surface of the anti-glare layer with which the anti-glare film of this invention is equipped with two-dimensional discrete function h (x, y). In Fig. 4, the elevation is represented by a gradation of white and black. The discrete functions h (x, y) shown in FIG. 4 have 512 × 512 values, and the horizontal resolutions Δx and Δy are 1.66 μm.

5 shows the energy spectrum H ² (f _x , f _y ) of the elevation obtained by the discrete Fourier transform of the two-dimensional function h (x, y) shown in FIG. 4 in white and black gradations. The energy spectrum H ² (f _x , f _y ) of the elevation shown in FIG. 5 is also a discrete function having 512 × 512 values, and the horizontal resolution (Δf _x and Δf _y ) of the elevation of the energy spectrum is 0.0012 μm ⁻¹ . .

As shown in FIG. 4, since the fine uneven surface of the anti-glare layer of the anti-glare film of the present invention is formed of randomly formed unevenness, the energy spectrum H ² of the elevation is shown in FIG. 5. Likewise, it is symmetric about the origin. Therefore, the energy spectrum (H ₁ ² ) of the elevation at the spatial frequency of 0.01 μm ⁻¹ , the energy spectrum of the elevation at the spatial frequency of 0.04 μm ⁻¹ (H ₂ ² ) and the energy spectrum of the elevation at the spatial frequency of 0.1 μm ⁻¹ (H ₃ ² ) can be obtained from a cross section passing through the origin of the energy spectrum H ² (f _x , f _y ) which is a two-dimensional function. Figure 6, and shows a cross section of at f _x = 0 of the energy spectrum _{^{H 2 (f x, f y}} ) shown in Fig. From FIG. 6, the energy spectrum (H ₁ ² ) of the elevation at the spatial frequency of 0.01 μm ⁻¹ is 4.4, and the energy spectrum (H ₂ ² ) of the elevation at the spatial frequency of 0.04 μm ⁻¹ is 0.35 and the spatial frequency of 0.1 μm ⁻¹ It can be seen that the energy spectrum (H ₃ ² ) of the elevation at is 0.00076, the ratio (H ₁ ² / H ₂ ² ) is 14, and the ratio (H ₃ ² / H ₂ ² ) is 0.0022.

As described above, in the antiglare layer according to the present invention, the energy spectrum (H ₁ ² ) of the elevation of the fine uneven surface at the spatial frequency of 0.01 μm ⁻¹ and the energy spectrum of the elevation at the spatial frequency of 0.04 μm ⁻¹ ( ratio ^{_{(H 1 2 / H 2 2}} ) of H _{² 2)} is in the range of 3 to 20 is I. If the ratio (H ₁ ² / H ₂ ² ) of the energy spectrum of the elevation is less than 3, there are few long-period irregularities of 100 μm or more included in the surface of the fine unevenness of the antiglare layer, and the uneven-corrugated shape of less than 25 μm This shows a lot. In such a case, background reflection of external light cannot be prevented effectively, and sufficient anti-glare performance cannot be obtained. On the other hand, the ratio (H ₁ ² / H ₂ ² ) of the energy spectrum of the elevation above 20 indicates that the uneven shape of the long period of 100 μm or more included in the surface of the fine unevenness is many, and the short period of less than 25 μm It shows that there are few uneven | corrugated shapes. In such a case, there exists a tendency to generate glare when arrange | positioning an anti-glare film to a high definition image display apparatus. In order to suppress glare more effectively while showing superior anti-glare performance, the ratio (H ₁ ² / H ₂ ² ) of the energy spectrum of the elevation is preferably in the range of 5-18, more preferably in the range of 8-15. Do.

Further, in the antiglare layer according to the present invention, the energy spectrum (H ₃ ² ) of the elevation of the fine uneven surface at the spatial frequency of 0.1 μm ⁻¹ and the energy spectrum of the elevation at the spatial frequency of 0.04 μm ⁻¹ (H ₂ ²⁾ ) Ratio (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 indicates that the short-period component of less than 10 μm included in the surface of the fine unevenness is sufficiently reduced, whereby the occurrence of whitening can be effectively suppressed. The short-period component of less than 10 µm contained in the fine concavo-convex surface does not contribute effectively to the anti-glare property, but scatters the light incident on the fine concavo-convex surface to cause whitening.

In the conventionally known anti-glare film disclosed in Japanese Patent Application Laid-Open No. 2006-053371, etc., the energy spectrum (H ₁ ² ) of the elevation of the surface of the fine uneven surface at the spatial frequency of 0.01 μm ⁻¹ and the spatial frequency of 0.04 μm ^{− Since} the ratio (H ₁ ² / H ₂ ² ) of the energy spectrum (H ₂ ² ) of the elevation at ₁ is larger than that of the present application, there is a problem that glare is likely to occur. Thus, to within the ratio ^{_{(H 1 2 / H 2 2}} ) the range of 3 to 20, there is a need to reduce the energy spectrum of the altitude of the fine concavo-convex surface in the spatial frequency ^{_{0.01 ㎛ -1 (H 1 2)}} . Thus, an anti-glare film having a minute uneven surface fine concavo-convex surface by reducing the energy spectrum (H ₁ ²⁾ of the elevation in the spatial frequency is 0.01 ㎛ ^-1, of greater than 0 ㎛ ^-1 0.04 ㎛ ^-1 or less, as described below It can manufacture suitably by using the pattern which shows the energy spectrum which does not have a maximum in a range. Here, an "pattern" is typically an image composed of two gradations (for example, image data binarized in white and black) or three gradations created by a calculator, which is used to form a fine uneven surface of an antiglare film. Although it means data, data (matrix data etc.) which can be converted uniformly to the image data can also be included. Examples of data that can be uniformly converted into image data include data in which only coordinates and gradations of respective pixels are stored.

Thus, by forming a fine uneven surface of the anti-glare film by using a pattern showing an energy spectrum having no maximum value within the range of more than 0 μm ^{−1 and} 0.04 μm ⁻¹ or less, effectively forming the fine uneven surface at the spatial frequency of 0.01 μm ⁻¹ . It is possible to reduce the energy spectrum H ₁ ² of the elevation, and the ratio H ₁ ² / H ₂ ² can be set within the range of 3 to 20.

Furthermore, the ratio (H ₃ ² / H) of the energy spectrum (H ₃ ² ) of the elevation of the fine uneven surface at the spatial frequency of 0.1 μm ⁻¹ and the energy spectrum (H ₂ ² ) of the elevation at the spatial frequency of 0.04 μm ^{−1 ₂₂₎} in order to obtain the anti-glare film having a minute uneven surface more than 0.1, the energy spectrum of the pattern preferably has a maximum value in excess of 0.04 ㎛ ^-1 spatial frequency range below 0.1 ㎛ ^-1. By forming the fine uneven surface of the antiglare film using the pattern having such an energy spectrum, it is possible to effectively enlarge the energy spectrum (H ₂ ² ) of the elevation of the fine uneven surface at the spatial frequency of 0.04 μm ⁻¹ . (H ₃ ² / H ₂ ² ) can be 0.1 or less.

As a method of forming the fine concavo-convex surface of the antiglare film using such a pattern, a metal mold having a concave-convex surface is produced using the pattern, and the concave-convex surface of the metal mold is transferred to the surface of the resin layer formed on the base film. The method (embossing method) is preferable.

The inventors also found that it is more effective to effectively prevent whitening while exhibiting excellent anti-glare performance, so that the fine uneven surface of the anti-glare layer exhibits a specific inclination angle distribution. That is, in the anti-glare film of the present invention, the fine uneven surface of the anti-glare layer includes 95% or more of the surface having an inclination angle of 5 ° or less. When the ratio of the surface whose inclination-angle is 5 degrees or less is less than 95%, the inclination-angle of the uneven surface becomes sharp, it collects the light from the surroundings, and it becomes easy to produce the whitening which becomes white the display surface as a whole. In order to suppress such a light condensing effect and prevent whitening, the higher the ratio of the surface whose inclination-angle of the fine uneven | corrugated surface is 5 degrees or less is high, it is preferable that it is 97% or more, and it is more preferable that it is 99% or more.

Here, with reference to FIG. 2, the "inclined angle of the fine uneven | corrugated surface" referred to in this invention is the local normal 6 which added the uneven | corrugated thing in this point at arbitrary points P of the anti-glare film 1 surface. Means the angle (surface inclination angle) (ψ) made with respect to the main normal direction 5 of an anti-glare film. Similarly to the elevation, the inclination angle of the fine uneven surface can be obtained from three-dimensional information of the surface shape measured by a device such as a confocal microscope, an interference microscope, an atomic force microscope (AFM).

It is a schematic diagram for demonstrating the measuring method of the inclination angle of a fine uneven surface. A concrete method of determining the inclination angle will be described. As shown in Fig. 7, the point of interest A on the virtual plane FGHI indicated by the dotted line is determined, and the point A on the x-axis passing therethrough is in the vicinity. For example, the points B and D are held substantially symmetrically with respect to the point A, and near the point of interest A on the y-axis passing through the point A, the point C is almost symmetric with respect to the point A. And E), and determine the points Q, R, S, T on the antiglare film surface corresponding to these points B, C, D, and E. FIG. On the other hand, in FIG. 7, the orthogonal coordinate in the anti-glare film surface is represented by (x, y), and the coordinate of the anti-glare film thickness direction is represented by z. The plane FGHI is a straight line parallel to the x-axis passing through the point C on the y-axis, and similarly a straight line parallel to the x-axis passing through the point E on the y-axis and a point B on the x-axis. It is a surface formed by each intersection (F, G, H, I) with the straight line parallel to a y-axis, and similarly the straight line parallel to the y-axis which passes the point D on the x-axis. In addition, although the position of an actual anti-glare film surface is drawn upward with respect to the plane FGHI in FIG. 7, it is a matter of course according to the position which catches the attention point A, but the position of an actual anti-glare film surface is flat ( FGHI) may come up or down.

The inclination angle is the actual anti-glare corresponding to the point P on the actual anti-glare film surface corresponding to the point A and the four points B, C, D, E caught in the vicinity of the point A. Each normal vector 6a, 6b, 6c, 6d of a polygonal 4 plane, i.e. four triangles (PQR, PRS, PST, PTQ), unfolded by a total of five points on the film plane (Q, R, S, T) The average angle vector obtained by averaging the average angle of the anti-glare film with respect to the direction of the main normal of the antiglare film, which is obtained by averaging the average normal vector (the average normal vector is the same as the local normal 6 with the unevenness shown in FIG. 2). Obtained from information. After obtaining the inclination angle for each measurement point, the histogram is calculated.

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 equipped. In the graph shown in FIG. 8, the horizontal axis is an inclination angle, and is divided into 0.5 ° pitches. For example, the leftmost vertical bar indicates the distribution of the set in which the inclination angle is in the range of 0 to 0.5 °, and the angle increases by 0.5 ° as it goes to the right. In FIG. 8, the lower limit of a value is displayed for every two divisions of a horizontal axis, For example, the part which becomes "1" in a horizontal axis shows the distribution of the set in which the inclination-angle is in the range of 1-1.5 degrees. In addition, a vertical axis | shaft shows the distribution of an inclination-angle, and when it adds up, it is a value which becomes 1 (100%). In this example, the proportion of the face at the inclination angle of 5 degrees or less is approximately 100%.

In order to manufacture the anti-glare film in which the fine uneven | corrugated surface of an anti-glare layer contains 95% or more of inclination angles 5 degrees or less, a metal mold | die which has an uneven surface is also produced using a pattern, and the uneven surface of the said mold is a base film It is preferable to employ | adopt the method (embossing method) which transfers to the surface of the resin layer formed on. In such an embossing method, the inclination angle of the fine concavo-convex surface of the antiglare layer is determined according to the manufacturing conditions of the mold having the concave-convex surface. Specifically, it can control by changing the etching amount of an etching process in the manufacturing method of the metal mold | die mentioned 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 irregularities to be formed, and to increase the proportion of the surface having the inclination angle of 5 ° or less. In order to obtain the anti-glare film which has a fine uneven | corrugated surface containing 95% or more of the inclination-angles of 5 degrees or less, it is preferable that the etching amount in a 1st etching process is 2-8 micrometers. When the etching amount is less than 2 µm, almost no irregularities are formed on the surface of the metal, and almost flat molds are formed. Therefore, the anti-glare film produced using such a mold does not exhibit sufficient anti-glare property. Moreover, when the etching amount exceeds 8 micrometers, there exists a possibility that the height difference of the uneven | corrugated shape formed in a metal surface becomes large, and the surface whose inclination-angle is 5 degrees or less may become less than 95%. The anti-glare film produced using such a metal mold may cause whitening.

Moreover, also the inclination angle of the fine uneven surface of an anti-glare layer can be controlled also by the etching amount in a 2nd etching process. By increasing the amount of etching in the second etching step, it is possible to effectively slow down the portion where the surface inclination of the first surface unevenness is steeply inclined, thereby increasing the proportion of the surface having the inclination angle of 5 ° or less. In order to obtain the anti-glare film which has the fine uneven | corrugated surface containing 95% or more of surfaces inclination angle 5 degrees or less, it is preferable to make the etching amount in a 2nd etching process into the range of 4-20 micrometers. If the etching amount is small, the effect of blunting the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical properties of the antiglare film obtained by transferring the uneven shape are not very good. On the other hand, when the etching amount is too large, the uneven shape is almost eliminated and becomes an almost flat mold, so that the anti-glare property is not exhibited.

In this invention, an anti-glare layer can be comprised by hardened | cured material of curable resin, such as photocurable resin, or a thermoplastic resin, It is preferable to be comprised by hardened | cured material of photocurable resin especially. In the anti-glare layer, fine particles having a refractive index different from that of the cured resin or the thermoplastic resin may be dispersed. By dispersing the fine particles, glare can be more effectively suppressed.

When disperse | distributing the said microparticles | fine-particles to an anti-glare layer, it is preferable that the average particle diameter of microparticles | fine-particles is 5 micrometers or more, and it is more preferable that it is 6 micrometers or more. Moreover, the average particle diameter of microparticles | fine-particles can be about 10 micrometers or less, Preferably it is 8 micrometers or less. When the average particle diameter is less than 5 µm, the scattered light intensity on the wide-angle side due to the fine particles increases, which tends to reduce the contrast when applied to an image display device.

In addition, the refractive index of the fine particle (n _b) and the light refractive index of the cargo or the thermoplastic resin of the curable resin ratio of _{(n r) (n b /} n r) is 0.93 or more 0.98 or less or 1.01 or more 1.04 or less is preferred, and 0.97 or more 0.98 It is more preferable that it is below or 1.01 or more and 1.03 or less. When the refractive index ratio (n _b / n _r ) is less than 0.93 or more 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, the backscattering rises. This tends to lower the total light transmittance. The fall of the total light transmittance increases the haze of an anti-glare film, and causes the fall of contrast when it is applied to an image display apparatus. In addition, when the refractive index ratio (n _b / n _r ) is more than 0.98 and less than 1.01, since the internal scattering effect by the fine particles becomes small, in order to give a predetermined scattering characteristic to the antiglare layer and to obtain an anti-glare effect by the fine particles, It may be necessary to increase the amount of added.

Content of microparticles | fine-particles is 50 weight part or less normally with respect to 100 weight part of curable resin or a thermoplastic resin, Preferably it is 40 weight part or less. Moreover, it is preferable that it is 10 weight part or more, and, as for content of microparticles | fine-particles, it is more preferable that it is 15 weight part or more. When content of microparticles | fine-particles is less than 10 weight part, the glare suppression effect by microparticles | fine-particles may be inadequate.

It is preferable that the material which comprises microparticles | fine-particles satisfy | fills the said preferable refractive index ratio. As will be described later, in the present invention, the UV embossing method is preferably used for forming the antiglare layer, and the ultraviolet curable resin is preferably used in the UV embossing method. In this case, since the hardened | cured material of an ultraviolet curable resin often shows the refractive index around 1.50, as microparticles | fine-particles, it can select suitably according to the design of an anti-glare film among those whose refractive index is about 1.40-1.60. As microparticles | fine-particles, a resin bead and also what is almost spherical is used preferably. Examples of such suitable resin beads are given below.

Melamine beads (refractive index 1.57),

Polymethyl methacrylate beads (refractive index 1.49),

Methyl methacrylate / styrene copolymer resin beads (refractive index 1.50-1.59),

Polycarbonate beads (refractive index 1.55),

Polyethylene beads (refractive index 1.53),

Polystyrene beads (refractive index 1.6),

Polyvinyl chloride beads (refractive index 1.46),

Silicone resin beads (refractive index 1.46) and the like.

(Substrate film)

The base film used for the antiglare film of this invention consists of acrylic resin which is excellent in transparency, moisture resistance, and weather resistance, and also excellent in mechanical strength, or consists of acrylic resin. Here, in this invention, an acrylic resin means the material obtained by mixing and melt-kneading a methacryl resin and the additive added as needed.

The said methacrylic resin is a polymer mainly having methacrylic acid ester. The methacrylic resin may be a homopolymer of one kind of methacrylic acid ester, or may be a copolymer of methacrylic acid ester and other methacrylic acid ester or acrylic acid ester. As methacrylic acid ester, alkyl methacrylates, such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate, are mentioned, A carbon number of this alkyl group is about 1-4 normally. Moreover, as acrylate ester which can be copolymerized with methacrylic acid ester, alkyl acrylate is preferable, For example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. are mentioned, The carbon number of this alkyl group is usually 1-. 8 or so. In addition to these, the copolymer may contain an aromatic vinyl compound such as styrene, a vinyl cyan compound such as acrylonitrile, or the like, which is a compound having at least one polymerizable carbon-carbon double bond in the molecule.

It is preferable that acrylic resin contains acrylic rubber particle from a viewpoint of the impact resistance and film forming property of a base film. The amount of the acrylic rubber particles that can be included 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 the acrylic rubber particles is not critical, but if the amount of the acrylic rubber particles is too large, the surface hardness of the base film is lowered, and the content of the organic solvent in the surface treating agent when the surface film is subjected to the surface treatment. Defrosting is lowered. Therefore, the amount of acrylic rubber particles that may be included in the acrylic resin is preferably 80% by weight or less, and more preferably 60% by weight or less.

The said acrylic rubber particle is particle | grains which have an elastic polymer mainly as an acrylate ester as an essential component, may be the thing of the single layer structure which consists only of this elastomer substantially, or the thing of the multilayer structure which makes this elastic polymer one layer. good. As this elastic polymer, specifically, the monomer which consists of 50 to 99.9 weight% of alkyl acrylates, 0 to 49.9 weight% of at least 1 sort (s) of other vinyl monomers copolymerizable with this, and 0.1 to 10 weight% of copolymerizable crosslinkable monomers Crosslinked elastic copolymers obtained by polymerization of the composition are preferably used.

As said alkyl acrylate which forms an elastic polymer, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. are mentioned, for example, Carbon number of this alkyl group is about 1-8 normally. Moreover, as another vinylic monomer copolymerizable with the said alkyl acrylate, the compound which has one polymerizable carbon-carbon double bond in a molecule | numerator is mentioned, More specifically, methacrylic acid ester like methyl methacrylate, Aromatic vinyl compounds, such as styrene, and vinyl cyan compounds, such as an acrylonitrile, etc. are mentioned. Moreover, as said copolymerizable crosslinkable monomer, the crosslinkable compound which has at least 2 polymeric carbon-carbon double bond in a molecule | numerator is mentioned, More specifically, ethylene glycol di (meth) acrylate and butanediol di (Meth) acrylate of polyhydric alcohols, such as (meth) acrylate, alkenyl ester of (meth) acrylic acid, such as allyl (meth) acrylic acid and (meth) acrylic acid methacrylate, divinylbenzene, etc. are mentioned. In the present specification, (meth) acrylate refers to methacrylate or acrylate, and (meth) acrylic acid refers to methacrylic acid or acrylic acid.

The acrylic resin may contain, in addition to the acrylic rubber particles, ordinary additives such as ultraviolet absorbers, organic dyes, pigments, inorganic dyes, antioxidants, antistatic agents, surfactants, and the like. Especially, a ultraviolet absorber is used preferably in improving weather resistance. Examples of ultraviolet absorbers include 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] and 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-hydroxyphenyl) Benzotriazole ultraviolet absorbers such as -2H-benzotriazole and 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-hydroxybenzophenone ultraviolet absorbers such as 2,2'-dihydroxy-4-methoxybenzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone; The salicylic acid phenyl ester type ultraviolet absorbers, such as p-tert- butylphenyl salicylate ester and p-octylphenyl salicylate ester, etc. are mentioned, You may use 2 or more types of these as needed. When the ultraviolet absorber is included in the acrylic resin, the amount is usually at least 0.1% by weight, preferably at least 0.3% by weight, and preferably at most 2% by weight.

It is preferable that the thickness of a base film is 20 micrometers or more from a viewpoint of mechanical strength, handling property, and the prevention of the curl of a film at the time of anti-glare layer formation, and is 100 micrometers or less from a viewpoint of thickness reduction of an image display apparatus, cost, etc. It is preferable. The thickness of the base film is more preferably 40 µm or more and 80 µm or less.

As a manufacturing method of the base film used for the anti-glare film of this invention, various generally known methods, such as melt extrusion molding, can be used, for example. Especially, the method of carrying out film forming by contacting the roll surface or the belt surface with at least one surface of the molten film obtained by melt-extrusion from a T die is preferable at the point which can obtain the film with a favorable surface property. In particular, from the viewpoint of improving the surface smoothness and surface glossiness of the base film, a method of forming a film by bringing both surfaces of the molten film obtained by the melt extrusion molding into contact with the roll surface or the belt surface is preferred. In the roll or belt used at this time, the roll surface or the belt surface in contact with the molten film of acrylic resin is preferably mirror surface for imparting smoothness to the base film surface.

The base film may be made of a multilayer structure, and examples thereof include a laminated structure of a layer containing acrylic rubber particles and a layer not containing. The base film which has a multilayered structure can be suitably produced by multilayer melt extrusion molding using a feed block, a multi-manifold die, etc., for example. By making a base film into a multilayered structure, the characteristic which opposes to a base film can be provided. For example, the base film of the multilayer structure which has the layer containing acrylic rubber particle in an intermediate | middle layer, and has a layer which does not contain acrylic rubber particle in the outermost surface of front and back has high impact resistance by the intermediate | middle layer containing acrylic rubber particle. It has a high surface hardness by the surface layer which does not contain acrylic rubber particle | grains.

In addition, the base film used for the anti-glare film of this invention may be what extended | stretched the film comprised from the acrylic resin obtained by the above-mentioned formula. By extending | stretching process, impact resistance can be provided further. The stretching method is arbitrarily determined and is not particularly limited, but after transverse stretching with a tenter at a temperature above the glass transition temperature, the heat setting treatment is carried out, or longitudinal stretching with a tenter at a temperature above the glass transition temperature. After that, a heat setting treatment is performed, and then a method of performing heat setting treatment after transverse stretching is exemplified.

<Method for Producing Anti-glare Film>

The anti-glare film of the said invention can be manufactured suitably by the method containing the following process (A) and (B).

(A) a step of manufacturing a mold having an uneven surface based on a pattern showing an energy spectrum having no maximum value within a spatial frequency range of more than 0 µm ^{-1 and} 0.04 µm ^-1 or less, and

(B) The process of transferring the uneven surface of a metal mold | die to the surface of the resin layer containing curable resin, such as photocurable resin, or thermoplastic resin formed on the base film.

By using the pattern which shows the energy spectrum which does not have a maximum in the spatial frequency range of more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less, it becomes possible to form the fine uneven surface which has said specific spatial frequency distribution with high precision. Moreover, the anti-glare layer which has a fine uneven | corrugated surface is produced by the method (embossing method) which manufactures the metal mold | die which has an uneven surface based on the said pattern, and transfers the uneven surface of the metal mold | die to the surface of the resin layer formed on the base film. Can be obtained with high accuracy and reproducibility. Here, an "pattern" is typically an image composed of two gradations (for example, image data binarized in white and black) or three gradations created by a calculator, which is used to form a fine uneven surface of an antiglare film. Although it means data, data (matrix data, etc.) which can be converted uniformly to the said image data can also be included. Examples of data that can be uniformly converted into image data include data in which only coordinates and gradations of respective pixels are stored.

If the energy spectrum of the pattern used in the step (A) is, for example, image data, after converting the image data into binary gray image data of two gradations, the gradation of the image data is represented by a two-dimensional function g (x, y), The two-dimensional function g (x, y) obtained is Fourier transformed to calculate the two-dimensional function G (f _x , f _y ), and is obtained by squaring the obtained two-dimensional function G (f _x , f _y ). Here, x and y represent rectangular coordinates in the image data plane, and f _x and f _y represent the spatial frequency in the x direction and the spatial frequency in the y direction, respectively.

As in the case of obtaining the energy spectrum of the elevation of the fine uneven surface, also in the case of obtaining the energy spectrum of the pattern, the two-dimensional function g (x, y) of the gray scale is generally obtained as a discrete function. In this case, the energy spectrum is calculated by the Discrete Fourier Transform as in the case of obtaining the energy spectrum of the elevation of the fine uneven surface. Specifically, the energy spectrum G ² (f is calculated by calculating the discrete function G (f _x , f _y ) by the Discrete Fourier Transform defined by Equation (5), and by squaring the obtained discrete function G (f _x , f _y ). _x , f _y ) are obtained. Is the circumference and i is the imaginary unit. Further, M is the number of pixels in the x direction, N is the number of pixels in the y direction, l is an integer of -M / 2 or more and M / 2 or less, and m is an integer of -N / 2 or more and N / 2 or less. Furthermore, Δf _x and Δf _y are spatial frequency intervals in the x and y directions, respectively, and are defined by equations (6) and (7), respectively. (DELTA) x and (DELTA) y in Formula (6) and Formula (7) are horizontal resolution in an x-axis direction and a y-axis direction, respectively. On the other hand, when the pattern is image data, Δx and Δy are equal to the length in the x-axis direction and the length in the y-axis direction of one pixel, respectively. That is, when a pattern is created as image data of 6400 dpi, Δx = Δy = 4 μm, and when a pattern is created as image data of 12800 dpi, 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 represented by a two-dimensional discrete function g (x, y) of gray scale. The image data of the pattern shown in FIG. 9 was 2 mm x 2 mm in size, and was created at 12800 dpi.

FIG. 10 is a diagram showing energy spectra G ² (f _x , f _y ) obtained by discrete Fourier transforming the two-dimensional discrete functions g (x, y) of the gray scale shown in FIG. Figure 9 is the pattern shown in, because the randomly placed dots, the energy spectrum _{^{G 2 (f x, f y}} ) , as shown in Figure 10, is a symmetry around the origin. Therefore, the spatial frequency showing the maximum value of the energy spectrum G ² (f _x , f _y ) of the pattern can be obtained from the cross section passing through the origin of the energy spectrum. FIG. 11 is a diagram showing a cross section at f _x = 0 of the energy spectrum G ² (f _x , f _y ) shown in FIG. 10. From this, it can be seen that the pattern shown in FIG. 9 has a maximum value at a spatial frequency of 0.045 μm ⁻¹ but does not have a maximum value within a range of more than 0 μm ^{−1 and} 0.04 μm ⁻¹ or less.

When the anti-glare energy spectrum of the pattern to produce a film ^{_{G 2 (f x, f y}} ) having the maximum value in the spatial frequency range of greater than 0 ㎛ ^-1 0.04 ㎛ ^-1 or less, the fine uneven surface of the resultant anti-glare film, the Since it does not exhibit a specific spatial frequency distribution, it cannot combine glare elimination and sufficient anti-glare property.

A pattern in which the energy spectrum G ² (f _x , f _y ) does not have a maximum within the spatial frequency range of more than 0 μm ^{−1 and} less than 0.04 μm ⁻¹ is randomly arranged in a plurality of dots, for example, as shown in FIG. 9. Moreover, it can create by arrange | positioning uniformly. One type of dot diameter arrange | positioned at random may be sufficient, and two or more types may be sufficient as it. In a pattern created by arranging a large number of dots randomly, the energy spectrum shows a first maximum value (maximum value at the minimum spatial frequency of the spatial frequency exceeding 0 μm ⁻¹⁾ at a spatial frequency that is an inverse of the average distance between the dots. . Therefore, in order to produce the pattern which does not have a maximum in the range whose energy spectrum is more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less, what is necessary is just to create a pattern so that the average distance between dots may be less than 25 micrometers. In addition, the ratio (H ₃ ) of the energy spectrum (H ₃ ² ) of the elevation of the fine uneven surface at the spatial frequency of 0.1 μm ⁻¹ of the antiglare film and the energy spectrum (H ₂ ² ) of the elevation at the spatial frequency of 0.04 μm ⁻¹ to a _² / H ^{2 2)} to 0.1 or less, the energy spectrum of the pattern, it is preferable to have a maximum value in excess of 0.04 ㎛ ^-1 spatial frequency range below 0.1 ㎛ ^-1. Such a pattern is obtained by creating so that the average distance between dots may be more than 10 micrometers and less than 25 micrometers.

Moreover, the pattern obtained by passing the high pass filter which removes the low spatial frequency component below a specific spatial frequency from the pattern which arrange | positioned such a large number of dots at random can also be used. Further, a pattern obtained by passing a low-pass frequency component below a specific spatial frequency and a high-pass frequency component above a specific spatial frequency from a pattern created by arranging a plurality of dots randomly may be used.

As shown in FIG. 11, the energy spectrum of the pattern created by arranging many dots at random shows the maximum value which depends on the dot diameter of the arrange | positioning dot and the average distance between dots. By passing such a pattern through the high pass filter or the band pass filter, unnecessary components can be removed. The energy spectrum of the pattern which passed the high pass filter or the bandpass filter in this way does not have a maximum in the spatial frequency range of more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less, since the component is removed by the filter. Further, it is possible to write a pattern with a maximum value in excess of 0.04 ㎛ ^-1 spatial frequency range below 0.1 ㎛ ^-1 more efficiently. Here, when using the said high pass filter, in order to remove the local maximum in the spatial frequency range of more than 0 micrometer ^{-1 and} 0.04 micrometer ^-1 or less, it is preferable that the upper limit spatial frequency of the low spatial frequency component to remove is 0.04 micrometer ^-1 or less. Do. In addition, in the case of using the bandpass filter, in order to remove the maximum value within the spatial frequency range of more than 0 μm ^{−1 and} less than 0.04 μm ⁻¹ , and to have the maximum value within the spatial frequency range of more than 0.04 μm ⁻¹ and less than 0.1 μm ⁻¹ . The upper limit spatial frequency of the low spatial frequency component to be removed is preferably 0.04 µm ^-1 or less, and the lower limit spatial frequency of the high spatial frequency component to be removed is preferably 0.08 µm ^-1 or more.

In the case of creating a pattern using a method of passing a high pass filter, a band pass filter, or the like, a random brightness determined by a random number or pseudo random number generated by a calculator as a pattern before passing the filter. Patterns with distributions may also be used.

The detail of the method of manufacturing a metal mold | die based on the pattern obtained by the above formula is mentioned later.

The said process (B) is a process of forming the anti-glare layer which has a fine uneven surface by the embossing method on a base film. As an embossing method, the UV embossing method using a photocurable resin and the hot embossing method using a thermoplastic resin are illustrated, and UV embossing method is preferable especially from a viewpoint of productivity. In the UV embossing method, a photocurable resin layer is formed on the surface of the base film, and the photocurable resin layer is transferred to the photocurable resin layer surface by curing while pushing the photocurable resin layer onto the uneven surface of the mold. More specifically, the coating liquid containing photocurable resin is coated on a base film, and the photocurable resin was irradiated with light, such as an ultraviolet-ray, on the base film side in the state which adhere | attached the uneven surface of the metal mold | die, photocurable The anti-glare film in which the uneven | corrugated shape of the metal mold | die was transferred to the photocurable resin layer (anti-glare layer) after hardening can be obtained by hardening resin and peeling the base film in which the photocurable resin layer after hardening was formed from the metal mold | die after that.

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 curing is performed even with visible light having a longer wavelength than ultraviolet rays by combining an appropriately selected photoinitiator with the ultraviolet curable resin. Possible resins can also be used. The kind of ultraviolet curable resin is not specifically limited, A commercially available suitable thing can be used. Suitable examples of ultraviolet curable resins include one or two or more kinds of polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, Irgacure 907 (manufactured by Chiba Specialty Chemicals Co., Ltd.), Irgacure 184 ( It is a resin composition containing photoinitiators, such as Chiba Specialty Chemicals Corporation) and Lucirin TPO (BASF Corporation). Fine particles, a solvent, etc. are added to these ultraviolet curable resins as needed, and the said coating liquid is prepared.

<Method for producing mold for antiglare film production>

Hereinafter, the method of manufacturing the metal mold | die used for manufacture of the anti-glare film of this invention is demonstrated. The manufacturing method of the metal mold | die used for manufacture of the anti-glare film of this invention is not restrict | limited especially if it is a method which can obtain the predetermined surface shape based on the pattern mentioned above, In order to manufacture fine uneven surface precisely and reproducibly, [1] a first plating step, [2] polishing step, [3] photosensitive resin film forming step, [4] exposure step, [5] developing step, [6] first etching step, [7] It is preferable to basically include a photosensitive resin film peeling step and a [8] second plating step. It is a figure which shows typically a preferable example of the first half part of a metal mold | die manufacturing method, and FIG. 13 is a figure which shows a preferable example of the latter part of a metal mold | die manufacturing method typically. 12 and 13 schematically show cross sections of the mold in each step. Hereinafter, each process is explained in full detail, referring FIG. 12 and FIG.

[1] first plating process

In this process, copper plating or nickel plating is given to the surface of the base material used for a metal mold | die. Thus, by performing copper plating or nickel plating on the surface of the base material for metal mold | die, the adhesiveness and glossiness of chrome plating in a later 2nd plating process can be improved. This is because copper plating or nickel plating has a high coating property and a strong smoothing action, so as to fill a minute unevenness or cavity of the base material for a mold and to form a flat and glossy surface. By the characteristics of these copper plating or nickel plating, even if chromium plating is performed in the 2nd plating process mentioned later, the roughness of the chromium plating surface considered to originate in the minute unevenness | corrugation and the hole which existed in the base material is eliminated, and also Since the coating property of copper plating or nickel plating is high, generation | occurrence | production of a minute crack is reduced.

As the copper or nickel used in the first plating step, the respective pure metals may be used. In addition, an alloy mainly composed of copper or an alloy mainly composed of nickel may be used. Therefore, "copper" as used herein refers to copper and It is a meaning containing a copper alloy, and "nickel" is a meaning containing nickel and a nickel alloy. Copper plating and nickel plating may be performed by electrolytic plating or electroless plating, respectively, but electroplating is usually employed.

When carrying out copper plating or nickel plating, if the plating layer is too thin, the influence of the underlying surface cannot be excluded, and the thickness thereof is preferably 50 µm or more. Although the upper limit of the plating layer thickness is not critical, it is preferable to set it to about 500 micrometers in consideration of cost and the like.

As a metal material which comprises the base material for metal mold | die, aluminum, iron, etc. are mentioned from a cost viewpoint. Moreover, in consideration of the convenience of handling, it is preferable to use lightweight aluminum. It may be aluminum or a railroad here, and a pure metal, respectively, In addition, the alloy which mainly uses aluminum or iron may be sufficient.

In addition, the shape of the base material for a metal mold | die may be a suitable shape conventionally employ | adopted in the field | area, for example, a cylindrical or cylindrical roll other than a flat plate shape may be sufficient. When a metal mold | die is produced using a roll base material, there exists an advantage that an anti-glare film can be manufactured in a continuous roll shape.

[2] polishing process

In the subsequent polishing process, the surface of the base material subjected to copper plating or nickel plating in the above-described first plating process is polished. Through this step, the surface of the substrate is preferably polished in a state close to the mirror surface. In order to make a metal plate and a metal roll used as a base material with the desired precision, machining or cutting etc. are often performed, and the process mark remains on the surface of a base material, and copper plating or nickel plating was performed by this. This is because these processing marks may remain even in the state, and the surface is not completely smoothed in the plated state. In other words, even if the process described below is performed on the surface where such deep processing marks and the like remain, the irregularities such as the processing marks may be deeper than the irregularities formed after each process, and the influence of the processing marks and the like may remain. When an anti-glare film is manufactured using such a metal mold | die, it may have an unexpected influence on an optical characteristic. In FIG. 12 (a), the base material for flat metal mold 7 is subjected to copper plating or nickel plating on its surface in the first plating process (about the copper plating or nickel plating layer formed in this process). (Not shown), and also the state which had the surface 8 polished by the mirror process is shown typically.

The method for polishing the surface of the substrate subjected to copper plating or nickel plating is not particularly limited, and any of mechanical polishing, electrolytic polishing and chemical polishing can be used. Examples of the mechanical polishing method include ultrafinishing, lapping, fluid polishing, buff polishing, and the like. In addition, you may make the base material surface 7 for metal mold | die mirror-mirror by mirror-cutting using a cutting tool. The material, shape, etc. of the cutting tool at this time are not particularly limited. Carbide bites, CBN bites, ceramic bites, diamond bites and the like can be used, but diamond bites are preferably used from the viewpoint of processing precision.

As for the surface roughness after grinding | polishing, it is preferable that centerline average roughness Ra based on the specification of JISB0601 is 0.1 micrometer or less, and it is more preferable that it is 0.05 micrometer or less. If the centerline average roughness Ra after polishing is larger than 0.1 µm, there is a possibility that the influence of surface roughness after polishing remains on the uneven shape of the final mold surface. The lower limit of the center line average roughness Ra is not particularly limited and is appropriately determined in consideration of machining time, machining cost and the like.

[3] photosensitive resin film forming step

In the following photosensitive resin film formation process, the photosensitive resin is apply | coated as the solution which melt | dissolved photosensitive resin in the solvent, and heated and dried to the polished surface 8 of the base material 7 for mirrors which performed mirror polishing by the above-mentioned grinding | polishing process, To form a film. FIG. 12B schematically shows a state in which the photosensitive resin film 9 is formed on the polished surface 8 of the base material for metal mold 7.

Conventionally well-known photosensitive resin can be used as photosensitive resin. As a negative photosensitive resin which has a property which hardens a photosensitive part, the monomer and prepolymer of an acrylic ester which has an acryl group or a methacryl group in a molecule | numerator, a mixture of bis azide and diene rubber, a polyvinyl cinnamate type compound, etc. are used, for example. Can be. Moreover, a phenol resin type, a novolak resin type, etc. can be used as positive type photosensitive resin which has the property which a photosensitive part elutes by development and only an unphotosensitive part remains. Moreover, you may mix | blend various additives, such as a sensitizer, a development promoter, an adhesive modifier, and a coating property improving agent, with photosensitive resin as needed.

When applying these photosensitive resins to the polished surface 8 of the base material 7 for metal mold | die, it is preferable to dilute and apply in a suitable solvent, in order to form a favorable coating film. As the solvent, a cellosolve solvent, a propylene glycol solvent, an ester solvent, an alcohol solvent, a ketone solvent, a high polar solvent, or the like can be used.

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

[4] exposure step

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

In order to form the surface uneven shape of a metal mold | die and also the surface uneven | corrugated shape of an anti-glare layer with high precision, it is preferable at the exposure process to expose the said pattern on the photosensitive resin film in the state controlled precisely, Specifically, a computer It is preferable to create a pattern as image data on the image, and draw a pattern on the photosensitive resin film by the laser beam emitted from a computer-controlled laser head based on the image data. In laser drawing, the laser drawing apparatus for printing plate preparation can be used. Examples of such a laser drawing apparatus include Laser Stream FX (manufactured by Sink Laboratories).

FIG. 12C schematically shows a state in which a pattern is exposed on the photosensitive resin film 9. In the case where the photosensitive resin film is formed of negative photosensitive resin, crosslinking reaction of the resin proceeds in the exposed region 10 by exposure, and the solubility in the developer described later is lowered. Therefore, the area | region 11 which is not exposed in the image development process is melt | dissolved with a developing solution, and only the exposed area | region 10 remains on a surface of a base material, and becomes a mask. On the other hand, in the case where the photosensitive resin film is formed of a positive photosensitive resin, the bond of the resin is cut in the exposed region 10 by exposure, and the solubility in the developer described later increases. Therefore, the region 10 exposed in the developing step is dissolved by the developer, and only the region 11 that is not exposed remains on the substrate surface to become a mask.

[5] Development process

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

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

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

FIG. 12 (d) schematically shows a state in which the developing treatment is performed using a negative photosensitive resin on the photosensitive resin film 9. In FIG. 12C, the region 11 that is not exposed is dissolved by the developer, and only the exposed region 10 remains on the substrate surface to form the mask 12. FIG. 12E schematically shows a state where the development treatment is performed on the photosensitive resin film 9 by using a positive photosensitive resin. The region 10 exposed in FIG. 12C is dissolved by the developer, and only the region 11 that is not exposed remains on the substrate surface to become the mask 12.

[6] first etching process

In the following 1st etching process, the photosensitive resin film which remained on the surface of the metal mold | die base material after the above-mentioned image development process is used as a mask, the metal substrate for metal parts of a part without a mask is mainly etched, and an unevenness | corrugation is formed in the polished plating surface. FIG. 13A schematically shows a state in which the mold base 7 in the portion 13 without a mask is etched mainly by the first etching step. The mold base 7 under the mask 12 is not etched from the mold base surface, but etching proceeds from the portion 13 without the mask as the etching proceeds. Therefore, near the boundary between the mask 12 and the portion 13 without the mask, the base material 7 for the mold under the mask 12 is also etched. In the vicinity of the boundary between the mask 12 and the portion 13 without the mask, the etching of the mold base 7 under the mask 12 is also called side etching.

The etching treatment in the first etching step is usually performed using a ferric chloride (FeCl ₃ ) solution, cupric chloride (CuCl ₂ ) solution, alkaline etching solution (Cu (NH ₃ ) ₄ Cl ₂ ), or the like. Although it forms by corrosive, strong acid, such as hydrochloric acid and a sulfuric acid, can also be used, and the reverse electrolytic etching which reverses the electric potential of when electroplating can also be used. Since the concave shape formed in the base material for metal mold | die at the time of an etching process changes with the kind of base metal, the kind of photosensitive resin film, the etching method, etc., it cannot say uniformly, but when etching amount is 10 micrometers or less, It is etched approximately isotropically from the touching metal surface. Etching amount here is the thickness of the base material shaved by etching.

The etching amount in the first etching step is preferably 1 to 50 µm, more preferably 2 to 10 µm. In the case where the etching amount is less than 1 µm, since irregularities are hardly formed on the metal surface and become almost flat molds, anti-glare properties are not exhibited. Moreover, when etching amount exceeds 50 micrometers, the height difference of the uneven | corrugated shape formed in a metal surface becomes large, and there exists a possibility that whitening may arise in the image display apparatus which applied the anti-glare film produced using the obtained metal mold | die. In order to obtain the anti-glare film which has the fine uneven | corrugated surface containing 95% or more of surfaces in which the inclination angle is 5 degrees or less, it is more preferable that the etching amount in a 1st etching process is 2-8 micrometers. The etching process in a 1st etching process may be performed by one etching process, and you may divide an etching process into two or more times. When dividing an etching process two times or more, it is preferable that the sum total of the etching amount in two or more etching processes becomes in the said range.

[7] photosensitive resin film peeling step

In the following photosensitive resin film peeling process, the remaining photosensitive resin film used as a mask in a 1st etching process is melt | dissolved and removed completely. In the photosensitive resin film peeling process, a photosensitive resin film is melt | dissolved using a peeling liquid. As the peeling solution, the same developer as described above can be used. By changing the pH, temperature, concentration, and immersion time of the stripping solution, the negative photosensitive resin film is completely dissolved by removing the photosensitive resin film of the exposed part when the negative photosensitive resin film is used, and the photosensitive resin film of the non-exposed part when the positive photosensitive resin film is used. do. There is no restriction | limiting in particular also about the peeling method in the photosensitive resin film peeling process, and methods, such as an immersion phenomenon, a spray image development, a brush image development, and an ultrasonic image development, can be used.

FIG. 13B schematically shows a state in which 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 step. The 1st surface uneven | corrugated shape 15 is formed in the surface of the metal mold | die base material by the etching using the mask 12 which consists of a photosensitive resin film.

[8] second plating process

Subsequently, chromium plating is performed on the formed uneven surface (first surface uneven shape 15) to reduce the uneven surface shape. In (c) of FIG. 13, the surface by which the unevenness | corrugation became slower than the 1st surface uneven | corrugated shape 15 by forming the chromium plating layer 16 in the 1st surface uneven | corrugated shape 15 formed by the etching process of a 1st etching process. The state in which [the surface 17 of chromium plating] is formed is shown.

As chromium plating, it is preferable to employ | adopt chromium plating which has gloss, the hardness is high, the friction coefficient is small, and can give favorable mold release property on the surfaces, such as a flat plate and a roll. Although it does not restrict | limit especially as such chromium plating, It is preferable to use the chromium plating which expresses favorable gloss called so-called gloss chrome plating, decorative chromium plating, etc. Chromium plating is usually performed by electrolysis, and an aqueous solution containing chromic anhydride (CrO ₃ ) and a small amount of sulfuric acid is used as the plating bath. By adjusting the current density and the electrolysis time, the thickness of the chromium plating can be controlled.

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

In addition, surface polishing after plating is also undesirable. That is, it is preferable to use as the uneven surface of the metal mold | die which is transcribe | transferred to the resin layer surface on a base film as it is, without giving the process of grind | polishing the surface after a 2nd plating process. The reason for this is that, by polishing, flat portions are formed on the outermost surface, which may lead to deterioration of the optical characteristics, and because the control factor of the shape increases, making shape control with good reproducibility difficult.

Thus, by performing chromium plating on the surface in which the fine surface uneven | corrugated shape was formed, the uneven | corrugated shape can be slowed down and the metal mold | die with the high surface hardness can be obtained. The slowing state of the unevenness at this time varies depending on the type of the base metal, the size and depth of the unevenness obtained in the first etching step, the type and thickness of the plating, and the like, but it is not generally used to control the slowing state. The biggest factor in this is also the plating thickness. When the thickness of chromium plating is thin, the effect which can slow the surface shape of the unevenness | corrugation obtained before chrome plating process is inadequate, and the optical characteristic of the anti-glare film obtained by transferring the uneven | corrugated shape is not very good. On the other hand, when the plating thickness is too thick, the productivity is deteriorated, and a projection-type plating defect called nodule is generated, which is not preferable. Therefore, it is preferable to exist in the range of 1-10 micrometers, and, as for the thickness of chromium plating, it is more preferable to exist in the range which is 3-6 micrometers.

It is preferable that the chromium plating layer formed in the said 2nd plating process is formed so that Vickers hardness may be 800 or more, and it is more preferable to form so that it may become 1000 or more. When the Vickers hardness of the chromium plating layer is less than 800, the durability at the time of use of the mold decreases, and the decrease in the hardness due to chromium plating is likely to cause an abnormality in the plating bath composition, electrolytic conditions, etc. This is because there is a high possibility of adversely affecting the occurrence situation.

Moreover, in the manufacturing method of the metal mold | die for manufacturing the anti-glare film of this invention, the uneven surface formed by the 1st etching process between the above-mentioned [7] photosensitive resin film peeling process and [8] 2nd plating process. It is preferable to include the 2nd etching process which can slow down by an etching process. In a 2nd etching process, the 1st surface uneven | corrugated shape 15 formed by the 1st etching process which used the photosensitive resin film as a mask can be blunted by an etching process. By this 2nd etching process, in the 1st surface uneven | corrugated shape 15 formed by the 1st etching process, the part whose surface inclination is a steep inclination disappears and the optical characteristic of the anti-glare film manufactured using the obtained metal mold | die was made in the preferable direction. Is changed. In FIG. 14, the second surface unevenness of the mold base 7 is blunted by the second etching treatment, and the portion of the surface inclined sharply slanted is blunted to have a gentle surface slope. The state in which 18 is formed is shown.

Similarly to the first etching step, the etching treatment of the second etching step also includes ferric chloride (FeCl ₃ ) solution, cupric chloride (CuCl ₂ ) solution, alkaline etching solution (Cu (NH ₃ ) ₄ Cl ₂ ), and the like. Although it forms by corroding a surface, strong acids, such as hydrochloric acid and a sulfuric acid, can also be used, and reverse electrolysis etching which has a reverse electric potential at the time of electroplating can also be used. Since the slowing state of the unevenness after the etching treatment is different depending on the type of the underlying metal, the etching method and the size and depth of the unevenness obtained by the first etching step, and so on, it is not possible to say uniformly. The biggest factor is the etching amount. Etching amount here is also the thickness of the base material shaved by etching similarly to a 1st etching process. If the etching amount is small, the effect of blunting the surface shape of the unevenness obtained by the first etching step is insufficient, and the optical properties of the antiglare film obtained by transferring the uneven shape are not very good. On the other hand, when the etching amount is too large, the uneven shape is almost eliminated and becomes an almost flat mold, so that the anti-glare property is not exhibited. Therefore, it is preferable to carry out etching amount in the range of 1-50 micrometers, and to obtain the anti-glare film which has a fine uneven | corrugated surface containing 95% or more of the surface whose inclination-angle is 5 degrees or less, it must be in the range of 4-20 micrometers. It is more preferable. Similarly to the first etching step, the etching treatment in the second etching step may be performed by one etching treatment or may be performed by dividing the etching treatment into two or more times. When dividing an etching process two times or more, it is preferable that the sum total of the etching amount in two or more etching processes becomes in the said range.

<Anti-glare Polarizing Plate>

Since the anti-glare film of this invention shows the outstanding anti-glare property and expresses favorable contrast, visibility can be effectively prevented from the fall of the visibility by the occurrence of "whitening" and "the glare", when it is attached to an image display apparatus, It becomes excellent. When an image display apparatus is a liquid crystal display, this anti-glare film can be applied to a polarizing plate. That is, a 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. A protective film is comprised by the anti-glare film of this invention. It can be set as an anti-glare polarizing plate by bonding a polarizing film and the anti-glare film of this invention at the base film side of the anti-glare film. In this case, the other surface of the polarizing film may be in a state in which nothing is laminated, a protective film or another optical film may be laminated, or an adhesive layer for bonding to a liquid crystal cell may be laminated. Moreover, the anti-glare film of this invention can be bonded on the said base film side, and it can also be set as an anti-glare polarizing plate on the said protective film of the polarizing plate in which the protective film was bonded to at least one surface of the polarizing film. Moreover, in a polarizing plate in which a protective film was bonded to at least one surface of a polarizing film, after bonding the said base film to a polarizing film as this protective film, it can also be set as an anti-glare polarizing plate by forming an anti-glare layer on this base film. have.

Yes

Although an Example is given to the following and this invention is demonstrated in more detail, this invention is not limited to these Examples. The evaluation method of the anti-glare film and anti-glare film manufacture in the following examples is as follows.

[1] Measurement of surface shape of antiglare film

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

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

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

(Inclined angle of the fine uneven surface)

Based on the measurement data obtained above, it calculated based on the algorithm mentioned above, the histogram of the inclination-angle of the uneven surface was created, the distribution for every inclination-angle was calculated | required from it, and the ratio of the surface whose inclination-angle is 5 degrees or less was calculated.

[2] measurement of optical properties of antiglare film

(Haze)

The haze of the antiglare film was measured by the method specified in JIS K 7136. Specifically, haze was measured using a haze meter "HM-150 type" (manufactured by Murakami Shikisai Kijutsugenkusho Co., Ltd.) in accordance with this standard. In order to prevent curvature of an anti-glare film, it bonded to the glass substrate so that an uneven surface might become a surface using an optically transparent adhesive, and was made to use for a measurement. In general, when the haze increases, the image becomes dark when applied to the image display device, and as a result, the front contrast tends to decrease. For this reason, the lower the 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 specified in JIS K 5600-5-4. Specifically, it measured at the load of 500 g using the electric pencil Mohs hardness tester (made by Yasuda Seiki Seisakusho) in conformity with this standard.

(Moisture permeability)

The water vapor transmission rate of the anti-glare film was measured under the conditions of a temperature of 40 ° C. and a relative humidity of 90% by the method specified in JIS Z 0208.

[4] evaluation of antiglare performance of antiglare film

(Evaluate visually with background reflection, white flower)

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 is visually observed from the uneven surface side in a bright room with a fluorescent lamp, and the background reflection of the fluorescent lamp is present. The degree of whitening was visually evaluated. Background reflection and whitening were evaluated according to the following criteria in three stages of 1 to 3, respectively.

Background Reflection 1: No background reflection is observed.

2: A little background reflection is observed.

3: Background reflection is clearly observed.

Whitening 1: Whitening is not observed.

2: A little whitening is observed.

3: Whitening is observed clearly.

(Evaluation of the glare)

Glare was evaluated by the following method. That is, the polarizing plate of both front and back was peeled from the commercially available liquid crystal television (LC-32GH3 [manufactured by Sharp Co., Ltd.]. Instead of these original polarizing plates, both the back side and the display surface side were polarizing plates "Sumikaran SRDB31E" [Sumitomogagaku Co., Ltd.] ) Was bonded through an adhesive such that each absorption axis coincided with the absorption axis of the original polarizing plate, and on the display surface side polarizing plate, the antiglare film shown in each of the following examples was bonded together via the adhesive such that the uneven surface became a surface. In this state, the degree of glare was organoleptically evaluated by visual observation at a position about 30 cm from the sample, where level 1 is in a state where glare is not recognized at all, and level 7 is in a state where severe glare is observed. Correspondingly, level 3 is a state where glare is observed very rarely.

[5] Evaluation of pattern for antiglare film production

The gray level of the created pattern data was represented by the two-dimensional discrete function g (x, y). The horizontal resolutions (Δx and Δy) of the discrete functions g (x, y) were both 2 m. The obtained two-dimensional discrete function g (x, y) was discrete Fourier transformed to obtain a two-dimensional function G (f _x , f _y ). Two-dimensional function G (f _x, f _y) by the squared spectral two-dimensional function G ² of energy by (f _x, f _y) for calculation, and f _x = 0, the cross-sectional curve in G ² (0, f _y) from, 0 ㎛ ^-1 exceeds the maximum value was evaluated in the presence or absence in the spatial frequency range of 0.04 ㎛ ^-1 or less.

&Lt; Example 1 >

(Production of mold for anti-glare film production)

The thing which copper ballad plating was given to the surface of the aluminum roll (A5056 by JIS) of diameter 200mm was prepared. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the whole plating layer was set so that it might be set to about 200 micrometers. The copper plating surface was mirror-polished, the photosensitive resin was apply | coated to the polished copper plating surface, and it dried and formed the photosensitive resin film. Subsequently, the pattern which consisted of the pattern which consists of image data shown in FIG. 15 repeatedly and repeating in a row was exposed and developed by the laser beam on the photosensitive resin film. Exposure and development by a laser beam were performed using "Laser Stream FX" (manufactured by Sink Laboratories Co., Ltd.). Positive photosensitive resin was used for the photosensitive resin film. The pattern shown in FIG. 15 removes low-space frequency components having a spatial frequency of 0.04 μm ⁻¹ or less and high-space frequency components of 0.1 μm ⁻¹ or more with respect to a pattern in which a large number of dots having a dot diameter of 12 μm are randomly arranged. This is written by applying a bandpass filter.

Then, the 1st etching process was performed with the cupric chloride liquid (etching amount: 3 micrometers). The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was again performed with cupric chloride liquid (etching amount: 10 µm). Then, the chrome plating process was performed so that chrome plating thickness might be 4 micrometers, and the metal mold | die A was produced.

(Production of base film)

Methyl methacrylate / methyl acrylate = 96/4 (weight ratio) copolymer (refractive index 1.49) 70 parts by weight of the acrylic resin composition containing 30 parts by weight of acrylic rubber particles in the first extruder [screw diameter 65mm, uniaxial, vent (Toshiba Co., Ltd. product) was melt-kneaded, and it supplied to the feed block. Furthermore, the acrylic resin composition which contained 30 weight part of acrylic rubber particles in 70 weight part of copolymers of methyl methacrylate / methyl acrylate = 96/4 (weight ratio) (refractive index 1.49) is a 2nd extruder [screw diameter 45mm, uniaxial] And venting (Hitachijosen Co., Ltd.) were melt kneaded and supplied to a feed block. Through the roll unit co-extruded at 265 ° C and set to 85 ° C, the resin supplied to the feed block from the first extruder becomes the intermediate layer and the resin supplied to the feed block from the second extruder becomes the surface layer (both sides). The base film A of the three-layered structure whose thickness is 80 micrometers (intermediate layer 50 micrometers, surface layer 15 micrometers x 2) was produced.

(Formation of antiglare layer)

The photocurable resin composition "GRANDIC 806T" (manufactured by Dainippon Inkigagaku Kogyo Co., Ltd.) was dissolved in ethyl acetate to obtain a solution having a concentration of 50% by weight, and "Lucirine TPO" as a photopolymerization initiator (manufactured by BASF Corporation, Chemical Name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide) was added 5 parts by weight per 100 parts by weight of the curable resin component to prepare a coating solution. On the base film A, this coating liquid was apply | coated so that the coating thickness after drying might be 6 micrometers, and it dried for 3 minutes in the dryer set to 60 degreeC. The base film A after drying was pressed by the rubber roll so that the photocurable resin composition layer might become the metal mold | die side to the uneven surface of the metal mold A obtained previously. In this state, the light from the high pressure mercury lamp of 20 mW / cm <2> of intensity | strength was irradiated so that it might become 200 mJ / cm <2> by h-ray-converted light quantity, and the photocurable resin composition layer was hardened. Subsequently, the base film A was peeled from a metal mold | die for every cured resin, and the transparent anti-glare film A which consists of a laminated body of cured resin (antiglare layer) and base film A which have an unevenness | corrugation on the surface was produced.

<Example 2>

In the exposure process in metal mold | die manufacture, the pattern which consisted of the pattern which consists of image data shown in FIG. 16 in succession and repeating is exposed on the photosensitive resin film by laser beam, and the etching in a 1st etching process is carried out. A mold B was produced in the same manner as in Example 1 except that the amount was set to 5 µm and the etching amount in the second etching treatment was set to be 12 µm. An anti-glare film B was produced in the same manner as in Example 1 except that the obtained mold B was used. The pattern shown in FIG. 16 removes low-space frequency components with a spatial frequency of 0.035 μm ⁻¹ or less and high-space frequency components of 0.135 μm ⁻¹ or more for a pattern in which a large number of dots having a dot diameter of 12 μm are randomly arranged. This is written by applying a bandpass filter.

Comparative Example 1

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

Table 1 summarizes the measurement and evaluation results of the above-mentioned [1] to [4] regarding the obtained anti-glare films A to D. In addition, and shows a cross section in the Figure 17, Example 1 and Example 2 A mold of the energy spectrum resulting from a pattern used in the making of the mold _{^{B G 2 (f x, f}} y) in f _x = 0 in. It can be seen from FIG. 17 that the energy spectra of the patterns used in the production of the mold A of Example 1 and the mold B of Example 2 do not exhibit maximum values in the spatial frequency range of more than 0 μm ^{−1 and} 0.04 μm ⁻¹ or less. .

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Anti-glare Polarizer A B C D Base film A
(Acrylic resin) B
(Acrylic resin) TAC
film A
(Acrylic resin) mold A B A C surface
shape energy
Spectral
ratio H ₁ ² / H ₂ ² 19 4 19 41 H ₃ ² / H ₂ ² 0.002 0.001 0.002 0.003 Inclination angle 5 degrees or less
% Of cotton 100 100 100 100 optics
characteristic Haze (%) 0.4 0.6 0.4 0.4 Anti-glare
characteristic Background One One One One all sorts of flowers One One One One Glare One One One 6 Pencil hardness 4H 4H 3H 4H Water vapor permeability (g / ㎡ ・ 24hr) 52 48 287 50

From the results shown in Table 1, the glare-proof film A and the glare-proof film B which satisfy | fill all the requirements of this invention showed that glare did not generate | occur | produce at all, it showed that it was sufficient anti-glare property, and whitening did not generate | occur | produce either. In addition, since the haze is also low, the contrast is not caused even when placed in the image display device. Moreover, pencil hardness is also high, has strong mechanical strength, and also has low water vapor transmission rate, and has 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 outstanding anti-glare performance, pencil hardness and moisture resistance were lower than the anti-glare film A and the anti-glare film B. In addition, since the ratio (H ₁ ² / H ₂ ² ) of the energy spectrum did not satisfy the requirements of the present invention, glare was generated in the antiglare film D produced based on a predetermined pattern.

Claims (4)

As an anti-glare film provided with a base film and the anti-glare layer which has an uneven surface laminated | stacked on the said base film,
The base film contains an acrylic resin,
The ratio (H ₁ ² ) of the energy spectrum (H ₁ ² ) of the elevation of the uneven surface at the spatial frequency of 0.01 μm ⁻¹ and the energy spectrum (H ₂ ² ) of the elevation of the uneven surface at the spatial frequency of 0.04 μm ⁻¹ / H ₂ ² ) is in the range of 3-20,
The ratio of the spatial frequency 0.1 ㎛ ^-1 energy spectrum of the altitude of the concave-convex surface in the ₍₃ H ²⁾ and a spatial frequency energy spectrum of the altitude of the concave-convex surface in ^{_{0.04 ㎛ -1 (H 2 2)}} (H 3 2 / H ₂ ² ) is 0.1 or less,
The uneven surface is an anti-glare film containing 95% or more of the inclination angle of 5 ° or less. The antiglare film of Claim 1 whose thickness of the said base film is 20 micrometers or more and 100 micrometers or less. The antiglare film according to claim 1, wherein the base film contains acrylic rubber particles. The anti-glare polarizing plate provided with the anti-glare film of Claim 1, and the polarizing film laminated | stacked on the surface on the opposite side to the said anti-glare layer in the said base film.

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