JP2016033658A - Antiglare film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antiglare film that has excellent antiglare property in a wide observation angle while having a low haze and that can sufficiently suppress generation of white blue and glare when disposed in an image display device.SOLUTION: The antiglare film includes a transparent support and an antiglare layer formed thereon and having a fine surface rugged pattern, and has a total haze of 0.1% or more and 3% or less, and a surface haze of 0.1% or more and 2% or less. An average of inclination angles in the surface rugged pattern is 0.2° or more and 1.2° or less, and a standard deviation of the inclination angles is 0.1° or more and 0.8° or less. When polygons 27 are formed by Voronoi division on the surface of the antiglare layer using peaks of projections in the surface rugged pattern as base points 26, an average area of the polygons is 50 μmor more and 150 μmor less and a coefficient of variance in the areas of the polygons 27 is 40% or more and 80% or less.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an antiglare film having excellent antiglare properties.

  Image display devices such as liquid crystal displays, plasma display panels, cathode ray tube (CRT) displays, and organic electroluminescence (EL) displays are used to avoid deterioration in visibility due to external light reflected on the display surface. The antiglare film is disposed on the display surface.

  As an antiglare film, a transparent film having an uneven surface shape is mainly studied. Such an antiglare film reduces glare by scattering and reflecting external light (external light scattered light) with its surface irregularities, and exhibits antiglare properties. However, when the external light scattering light is strong, so-called “whiteness” may occur in which the entire display surface of the image display device becomes whitish or the display becomes cloudy. In addition, the pixel of the image display device and the surface unevenness of the anti-glare film interfere with each other, so that a so-called “glare” that is difficult to see due to a luminance distribution may occur. In view of the above, anti-glare films are required to sufficiently prevent the occurrence of these “blinks” and “glare” while ensuring excellent anti-glare properties.

  Thus, for example, Patent Document 1 discloses a fine antiglare film on a transparent substrate that does not generate glare even when placed in a high-definition image display device and is sufficiently prevented from being whitish. An uneven surface shape is formed, the average length PSm in an arbitrary cross-sectional curve of the uneven surface shape is 12 μm or less, and the ratio Pa / PSm of the arithmetic average height Pa to the average length PSm in the cross-sectional curve is 0 0.005 or more and 0.012 or less, the ratio of the surface having an inclination angle of 2 ° or less in the surface uneven shape is 50% or less, and the ratio of the surface having an inclination angle of 6 ° or less is 90% or more. An antiglare film is disclosed.

  The anti-glare film disclosed in Patent Document 1 eliminates the surface uneven shape having a period of around 50 μm, which makes it easy to generate glare, by making the average length PSm in an arbitrary cross-sectional curve very small. It can be effectively suppressed. However, in the antiglare film disclosed in Patent Document 1, when the haze is further reduced (when the haze is reduced), the display surface of the image display device in which the antiglare film is disposed is observed obliquely. There was a case where the antiglare property was lowered. Therefore, the antiglare film disclosed in Patent Document 1 has room for improvement in terms of antiglare properties at a wide observation angle.

JP 2007-188792 A

  The present invention provides an anti-glare film that has excellent anti-glare properties at a wide viewing angle while having a low haze, and can sufficiently suppress the occurrence of whitening and glare when placed in an image display device. The purpose is to do.

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention is an antiglare film comprising a transparent support and an antiglare layer having fine surface irregularities formed thereon,
The total haze is 0.1% or more and 3% or less,
The surface haze is 0.1% or more and 2% or less,
The average value of the inclination angle of the surface uneven shape is 0.2 ° or more and 1.2 ° or less, and the standard deviation of the inclination angle is 0.1 ° or more and 0.8 ° or less,
The average value of the area of the polygon formed when the surface is Voronoi divided with the vertex of the convex part of the surface uneven shape as a generating point is 50 μm ² or more and 150 μm ² or less, and the fluctuation of the area of the polygon Provided is an antiglare film having a coefficient of 40% or more and 80% or less.

In this anti-glare film,
The sum Tc of the transmission clarity measured using five types of optical combs in which the width of the light shielding portion and the transmission portion is 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, is 375%. That's it,
The sum Rc of the reflection sharpness measured at an incident angle of 45 ° using four types of optical combs in which the widths of the light-shielding portion and the light-transmitting portion are 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. (45) is 180% or less,
Rc of reflection sharpness Rc measured at an incident angle of light of 60 ° using four types of optical combs in which the width of the light shielding portion and the transmission portion is 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm, respectively. (60) is preferably 240% or less.

  According to the present invention, the anti-glare film has low glaze and sufficient anti-glare property at a wide observation angle, and is sufficiently suppressed in occurrence of whitening and glare when arranged in an image display device. Can be provided.

It is a schematic diagram for demonstrating the inclination angle of the surface uneven | corrugated shape of an anti-glare film. It is a schematic diagram for demonstrating the measuring method of the inclination angle of the surface of an anti-glare film. It is a Voronoi figure which shows the example of a Voronoi division | segmentation. It is a perspective view which shows typically the algorithm of the convex part determination of an anti-glare film. It is a figure which shows typically a preferable example of the first half part of the manufacturing method of a metal mold | die. It is a figure which shows typically a preferable example of the second half part of the manufacturing method of a metal mold | die. It is a figure which shows typically the example of arrangement | positioning of the apparatus used suitably when manufacturing an anti-glare film. It is a figure which shows typically the suitable pre-hardening process at the time of manufacturing an anti-glare film. It is a top view which shows typically the unit cell for glare evaluation. It is sectional drawing which shows typically the apparatus of glare evaluation. It is a figure showing a part of pattern used in Examples 1-3 and comparative example 1. FIG. It is a figure showing a part of pattern used in Example 4. FIG. 10 is a diagram illustrating a part of a pattern used in Example 5. FIG. 10 is a diagram illustrating a part of a pattern used in Comparative Example 2. FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as necessary, but the dimensions and the like shown in the drawings are arbitrary for ease of viewing.

In the antiglare film of the present invention, the average value of the inclination angle of the surface uneven shape is 0.2 ° or more and 1.2 ° or less, and the standard deviation of the inclination angle is 0.1 ° or more and 0.8 ° or less, The average value of the polygonal area formed when the surface is Voronoi divided with the top of the convex part of the surface irregularity as the base point, and the coefficient of variation of the polygonal area is 50 μm ² or more and 150 μm ² or less Is 40% or more and 80% or less.

  First, regarding the antiglare film of the present invention, the average value and standard deviation of the inclination angle, and how to determine the area of the polygon formed when the surface is Voronoi divided with the top of the convex portion of the surface uneven shape as the base point explain.

[Average of tilt angle and standard deviation]
In an image display device to which an antiglare film is applied, in order to give excellent antiglare performance and effectively prevent whitening, the surface unevenness of the antiglare film should exhibit a specific inclination angle distribution. Is effective. Therefore, in the antiglare film of the present invention, the average value of the inclination angle of the uneven surface shape is 0.2 ° to 1.2 °, and the standard deviation of the inclination angle is 0.1 ° to 0.8 °. To. When the average value of the inclination angle is less than 0.2 °, the unevenness of the surface becomes a substantially flat surface, and there is a possibility that sufficient antiglare performance cannot be exhibited. On the other hand, when the average value exceeds 1.2 °, each inclination angle becomes steep and it becomes easy to collect light from the surroundings. Therefore, an image display device provided with such an antiglare film Is prone to whitishness. Moreover, when the standard deviation of an inclination angle is less than 0.1 degree, surface uneven | corrugated shape becomes uniform and sufficient anti-glare performance may not be expressed. On the other hand, when the standard deviation exceeds 0.8 °, even if the average value is within a predetermined range, there will be a region with a steep inclination angle on the surface uneven shape, and such an antiglare film. The image display device provided with is likely to be whitish. The average value of the inclination angle of the surface uneven shape is preferably 0.5 ° or more and 1.2 ° or less, and the standard deviation of the inclination angle is preferably 0.3 ° or more and 0.7 ° or less.

  A method for obtaining the average value and standard deviation of the tilt angles will be described. FIG. 1 is a schematic perspective view showing the surface of the antiglare film. With reference to this figure, the anti-glare film 1 has fine irregularities 2 formed on the surface thereof. The “tilt angle of the surface irregularity shape” as used in the present invention refers to the main normal direction 5 of the film at an arbitrary point P on the surface of the antiglare film 1 shown in FIG. Means the angle ψ formed by the local normal 6. The angle ψ formed by the local normal 6 takes into account the influence of irregularities at the point P. In FIG. 1, the orthogonal coordinates in the film plane are indicated by (x, y), and the plane of the entire film is indicated by the projection plane 3. The inclination angle of the surface irregularity shape can be obtained from the three-dimensional information of the surface shape measured by an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM).

  FIG. 2 is a schematic diagram for explaining a method of measuring the inclination angle of the surface irregularity shape. A specific method of determining the tilt angle will be described. As shown in FIG. 2, a point of interest A on a virtual plane FGHI indicated by a dotted line on the film average plane 1 is determined, and a point of interest on the x-axis passing therethrough is determined. In the vicinity of point A, points B and D are approximately symmetrical with respect to point A, and in the vicinity of point of interest A on the y-axis passing through point A, points C and E are approximately symmetrical with respect to point A. The points Q, R, S, and T on the film surface corresponding to these points B, C, D, and E are determined. In FIG. 2, the orthogonal coordinates in the film plane are indicated by (x, y), and the coordinates in the film thickness direction are indicated by z. The plane FGHI is parallel to the x axis passing through the point C on the y axis, the straight line parallel to the x axis passing through the point E on the y axis, and the y axis passing through the point B on the x axis. And the intersections F, G, H, and I of the straight line passing through the point D on the x-axis and parallel to the y-axis. In FIG. 2, the position of the actual film surface is drawn with respect to the plane FGHI in the film average surface 1, but naturally, depending on the position taken by the point of interest A, The position may be higher than the plane FGHI in the film average plane 1 or may be lower.

  The inclination angle of the obtained surface shape data is the actual film surface corresponding to the point P on the actual film surface corresponding to the point of interest A and the four points B, C, D, E taken in the vicinity thereof. Obtained by averaging four normal planes 6a, 6b, 6c, 6d of four polygons PQR, PRS, PST, PTQ spanned by a total of five points Q, R, S, T above. It is obtained by calculating the polar angle of the average normal vector 6 obtained. Thus, after calculating | requiring an inclination angle about each measuring point, the average value and standard deviation of an inclination angle are calculated.

  When manufacturing an antiglare film by applying a resin solution in which fine particles are dispersed on a transparent support and exposing the fine particles to the coating film surface to form random unevenness on the transparent support, In order to obtain an antiglare film having an average inclination angle of 0.2 ° to 1.2 ° and a standard deviation of the inclination angle of 0.1 ° to 0.8 °, What is necessary is just to adjust a diameter, a dispersion state, and the film thickness of a coating film. In general, if the particle size of the fine particles is constant, the average value of the inclination angle becomes small by increasing the film thickness of the coating film. Further, the better the dispersion state of the fine particles, that is, the more the fine particles are uniformly arranged on the transparent support, the smaller the standard deviation of the tilt angle.

  On the other hand, when the UV embossing method, which is a preferable method for producing the antiglare film of the present invention to be described later, is adopted, the requirement of the present invention is adjusted by adjusting the etching amount in the second etching step for producing the mold. An antiglare film satisfying the above can be obtained. By increasing the etching amount in the second etching step, the average value and standard deviation of the tilt angle can be reduced.

[A polygonal area formed when the concavo-convex surface is divided into Voronois using the convex vertex as a base point]
Regarding the surface irregularity shape of the antiglare film, the polygonal area formed when the surface is Voronoi divided with the vertex of the convex portion as a base point will be described. First, the Voronoi division will be explained. When several points (called mother points) are arranged on a plane, the plane can be divided depending on which mother point is closest to any point in the plane. The figure is called Voronoi diagram, and the division is called Voronoi division. In FIG. 3, the example which carried out the Voronoi division | segmentation about the vertex of the convex part in the surface of an anti-glare film was made into the mother point. In this figure, square points 26 and 26 are generating points, and individual polygons 27 and 27 including one generating point are regions formed by Voronoi division and are called Voronoi regions or Voronoi polygons. In the following, it is called a Voronoi polygon. In this figure, the peripherally thinned portions 28, 28 will be described later. In the Voronoi diagram, the number of generating points coincides with the number of Voronoi polygons. The area of the polygon formed when the surface is Voronoi divided with the apex of the convex part of the surface uneven shape as the base point is the area of the Voronoi polygon.

  In calculating the average value and coefficient of variation of Voronoi polygons obtained by Voronoi division using the vertex of the convex part of the antiglare film surface as the generating point, confocal microscope, interference microscope, atomic force microscope ( The surface shape is measured by a device such as AFM) and the three-dimensional coordinate value of each point on the surface of the antiglare film is obtained. Then, the Voronoi division is performed by the algorithm shown below, and the average value of the area of the Voronoi polygon Calculate the coefficient of variation. In measuring the surface shape, the measurement region is 150 μm × 150 μm or more and preferably 500 μm × 500 μm or less in order to accurately measure the fine uneven surface of the antiglare film and reduce errors. Moreover, it is preferable to measure the area | region of 3 or more points, and make the average value the measured value.

  A method of Voronoi division using the top of the convex portion of the fine uneven surface of the antiglare film as a base point will be specifically described. First, the vertex of the convex part on the surface of the fine irregularities is obtained. That is, when an arbitrary point on the surface of the antiglare film is focused, if there is no point higher than the focused point around that point, the point is assumed to be the apex of the convex portion, and so on. The Voronoi division is performed with the vertex of the convex part obtained as described above as a generating point. More specifically, as shown in FIG. 4, paying attention to an arbitrary point 21 on the surface of the antiglare film, a circle having a radius of 2.5 μm parallel to the reference surface 23 of the antiglare film is drawn around the point 21. When the point on the antiglare film surface 22 included in the projection plane 24 of the circle does not have a point higher than the point 21 of interest, the point 21 is the vertex of the convex portion. Judge that there is. Here, the reason for comparing the altitude is within the range of the circle 24 having a radius of 2.5 μm in order to remove the influence of the high-frequency surface unevenness shape that hardly contributes to the antiglare property and glare of the antiglare film. .

  Next, the peak of the obtained convex part is projected on the anti-glare film reference plane 23. After that, all the three-dimensional coordinates obtained by measuring the surface shape are projected onto the reference plane, and all the projected points are assigned to the nearest base point to perform Voronoi division and obtained by division. By calculating the area of the polygon, the average value and coefficient of variation of the Voronoi polygon are determined. Here, the coefficient of variation is calculated as a percentage of a value obtained by dividing the standard deviation of the area of the Voronoi polygon by the average value. The reason for adopting the coefficient of variation instead of the standard deviation as an index for evaluating the variation in the area of the Voronoi polygon is to eliminate the influence of the average value of the area of the Voronoi polygon and evaluate the variation.

  As described above in part, FIG. 3 is a Voronoi diagram showing an example in which the surface is divided into Voronois with the apex of the convex portion of the antiglare film as a base point. A large number of generating points 26 and 26 are vertices of convex portions of the antiglare film, and one Voronoi polygon 27 is assigned to one generating point 26 by Voronoi division. In this figure, thinly filled Bonoi polygons 28 and 28 are Voronoi polygons in contact with the boundary of the visual field. The Voronoi polygon that touches the boundary of this field of view is not determined only by the vertex of the convex part that is the generating point, so it is used when calculating the average value and coefficient of variation of the area of the Voronoi polygon. do not do. In this figure, only some of the generating points and Voronoi polygons are provided with lead lines and symbols, but the fact that there are many generating points and Voronoi polygons is explained above and this figure. Will be easily understood.

The anti-glare film of the present invention has a synergistic effect with the haze described later, the average value of the inclination angle, and the standard deviation described above, by setting the average value and coefficient of variation of the Voronoi polygon described above to predetermined ranges, respectively. It exhibits excellent antiglare properties while preventing the occurrence of whitishness and glare. In order to effectively exhibit such an effect, the average value of the area of the Voronoi polygon is set to 50 μm ² or more and 150 μm ² or less. The average value of this area is more preferably 75 μm ² or more and 125 μm ² or less. For the same reason, the variation coefficient of the area of the Voronoi polygon is set to be 40% or more and 80% or less. The coefficient of variation is more preferably 50% or more and 70% or less, and further preferably 50% or more and 60% or less.

  When the average value of the area of the Voronoi polygon is less than the above range, the convex portions on the fine uneven surface of the antiglare film are too densely arranged, and it is difficult to obtain sufficient antiglare property. On the other hand, when the average value of the area of the Voronoi polygon exceeds the above range, the projections on the surface of the fine unevenness of the antiglare film are too sparsely arranged, and glare occurs when arranged on the image display device. Occur.

  When the variation coefficient of the area of the Voronoi polygon is less than the above range, the area distribution of the Voronoi polygon does not have a sufficient spread, the arrangement of the convex portions having an interval of 50 μm or more is insufficient, and the area is wide. It is difficult to obtain sufficient antiglare properties from the observation angle. On the other hand, when the variation coefficient of the area of the Voronoi polygon exceeds the above range, the area distribution of the Voronoi polygon is too wide, and the arrangement of dense convex portions cannot be obtained, resulting in glare.

[All haze and surface haze]
The antiglare film of the present invention exhibits antiglare properties and prevents whitishness, so that the total haze with respect to normal incident light is in the range of 0.1% to 3%, and the surface haze is 0.1. % To 2% or less. The total haze of the antiglare film can be measured according to a method defined in JIS K7136: 2000 “Plastics—How to determine haze of transparent material”. An antiglare film having a total haze or surface haze of less than 0.1% is not preferable because an image display device on which the haze is disposed does not exhibit sufficient antiglare properties. In addition, an antiglare film having a total haze of more than 3% or a surface haze of more than 2% is not preferable because the image display device on which the haze is disposed generates whiteness. Such an image display device also has a disadvantage that its contrast becomes insufficient.

  The lower the internal haze obtained by subtracting the surface haze from the total haze, the better. The image display apparatus in which the antiglare film having the internal haze exceeding 2.5% has a tendency to decrease the contrast.

[Transmission definition Tc, reflection definition Rc (45), and reflection definition Rc (60)]
The antiglare film of the present invention preferably has a sum Tc of transmission clarity required by the following method of 375% or more. That is, the transmission clarity sharpness Tc is measured by the transmission method using an optical comb having a predetermined width according to the method defined in JIS K7374: 2007 “Plastics—How to Obtain Image Sharpness”. It is obtained as their total value. Specifically, five types of optical combs having a ratio of a light shielding portion to a transmission portion of 1: 1 and a width of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are used. Then, the image sharpness by the transmission method is measured, and the total of them is obtained as Tc. When the antiglare film having a Tc of less than 375% is disposed in a higher-definition image display device, glare may easily occur. The upper limit of Tc is selected in the range of 500% or less, which is the maximum value. However, if this Tc is too large, an anti-glare property from the front tends to be an image display device that is not always good. It is preferable that it is 410% or less.

  In the antiglare film of the present invention, the reflection definition Rc (45) measured with incident light having an incident angle of 45 ° is preferably 180% or less, and more preferably 160% or less. The reflection definition Rc (45) is measured by the method defined in JIS K7374: 2007, as in the case of Tc. Here, among the above five types of optical combs, the width is 0.25 mm, and. Using four types of optical combs of 5 mm, 1.0 mm, and 2.0 mm, image sharpness at an incident angle of 45 ° is measured by a reflection method, and the total of them is obtained as Rc (45). According to JIS, five types of optical combs are defined as described above, and all of them are used or a width is selected as necessary. In the antiglare film defined in the present invention, the width is 0.125 mm. When the optical comb is used, the value of the reflection sharpness is small and the measurement error becomes large. Therefore, the reflection sharpness is obtained by adding the image sharpness measured using the above four types of optical combs. Degree. When Rc (45) is 180% or less, the image display device in which the antiglare film is disposed has favorable antiglare properties when observed from the front and oblique directions, and is preferably 160% or less. It is preferable because it becomes better. The lower limit of Rc (45) is not particularly limited, but is preferably 80% or more, for example, in order to satisfactorily suppress the occurrence of whitishness and glare.

  The antiglare film of the present invention preferably has a reflection definition Rc (60) measured by incident light having an incident angle of 60 ° of 240% or less, and more preferably 220% or less. The reflection definition Rc (60) is measured by the same method as JIS K7374: 2007 as the reflection definition Rc (45) except that the incident angle is changed. When Rc (60) is 240% or less, the image display device in which the antiglare film is disposed has favorable antiglare properties when observed obliquely, and is preferably 220% or less. This is preferable. The lower limit of Rc (60) is not particularly limited, but is preferably, for example, 150% or more in order to satisfactorily suppress the occurrence of whitishness and glare.

[General manufacturing method of anti-glare film]
The antiglare film of the present invention is produced, for example, as follows. The first method is to prepare a fine unevenness forming mold in which a surface unevenness shape based on a predetermined pattern is formed on a molding surface, transfer the shape of the uneven surface of the mold to a transparent support, In this method, the transparent support on which the shape of the surface is transferred is peeled off from the mold. The second method includes forming a composition containing fine particles, a binder resin, and a solvent, in which the fine particles are dispersed in a resin solution, applying the composition onto a transparent support, and drying as necessary. This is a method of curing a coating film containing fine particles. In the second method, the coating film thickness and the aggregation state of the fine particles are adjusted according to the composition of the composition and the drying conditions of the coating film, etc., thereby exposing the fine particles to the surface of the coating film and transparent random irregularities. Form on the support. From the viewpoint of production stability and production reproducibility of the antiglare film, it is preferable to produce the antiglare film of the present invention by the first method.

Here, the 1st method preferable as a manufacturing method of the anti-glare film of this invention is explained in full detail. In order to accurately form a surface uneven-shaped antiglare layer having the above-described properties, a prepared fine unevenness forming mold (hereinafter sometimes abbreviated as “mold”) is important. More specifically, the surface irregularity shape of the mold (hereinafter sometimes referred to as “mold irregularity surface”) is formed based on a predetermined pattern, and this predetermined pattern has its one-dimensional power spectrum. the average frequency is calculated 0.075 .mu.m ^-1 or more from 0.105Myuemu ^-1 or less, the standard deviation is preferably used not more than 0.095 m ^-1 or 0.125 .mu.m ^-1.
Here, the “pattern” means image data for forming the surface uneven shape of the antiglare layer of the antiglare film, a mask having a light transmitting part and a light shielding part, and is abbreviated as “pattern” hereinafter. I will do it.

  First, a method for defining a pattern for forming the surface irregularity shape of the antiglare layer of the antiglare film of the present invention will be described.

A method for obtaining a two-dimensional power spectrum of a pattern will be described, for example, when the pattern is image data. First, after converting the image data into binary image data of two gradations, the gradation is expressed by a two-dimensional function g (x, y). The resulting two-dimensional function g (x, y), and by Fourier transforming the two-dimensional function G (f _x, f _y) was calculated as the following equation (1), as shown in the following formula (2) , two-dimensional function G (f _x, f _y) obtained by squaring the absolute value of the two-dimensional power spectrum Γ (f _x, f _y) is determined. Here, x and y represent orthogonal coordinates in the image data plane. Further, f _x and f _y respectively represent the frequencies of the x and y directions, with the dimensions of the reciprocal of length.

  In Expression (1), π is a pi, i is an imaginary unit, and <g> is an average value of the two-dimensional function g (x, y).

Two resulting dimensional power spectrum Γ (f _x, f _y) represents the spatial frequency distribution of the pattern. Usually, since it is calculated | required that an anti-glare film is isotropic, the pattern for anti-glare film manufacture of this invention also becomes isotropic. Therefore, two-dimensional function representing the two-dimensional power spectrum of the pattern gamma (f _x, f _y) can be represented by one-dimensional functions that depend only on the distance f from the origin (0,0) Γ (f).

Next, a method of obtaining a two-dimensional function Γ (f _x, f _y) a one-dimensional function from a gamma (f). First, two-dimensional function gamma (f _x, f _y) is a two-dimensional power spectrum of the gradation pattern to be displayed in polar coordinates by the following equation (3).

Here, θ is a declination angle in Fourier space. The one-dimensional function Γ (f) can be obtained by calculating the rotational average of the two-dimensional function Γ (fcosθ, fsinθ) displayed in polar coordinates as in the following equation (4). Two-dimensional function Γ (f _x, f _y) is a two-dimensional power spectrum of the gradation pattern one-dimensional function is determined from the rotational mean of gamma and (f), also referred to as a one-dimensional power spectrum gamma (f) in the following.

To obtain anti-glare film of the present invention precisely is the average frequency <f> is calculated from the one-dimensional power spectrum of the pattern is at 0.075 .mu.m ^-1 or more 0.105Myuemu ^-1 or less, the standard deviation sigma _f it is preferable 0.095 m ^-1 or 0.125 .mu.m ^-1 or less. Here, the average frequency <f> and the standard deviation σ _f calculated from the one-dimensional power spectrum of the pattern are defined by the following equations (5) and (6), respectively.

  When obtaining a two-dimensional power spectrum of a pattern, the two-dimensional function g (x, y) of gradation is usually obtained as a discrete function. In that case, a two-dimensional power spectrum may be calculated by discrete Fourier transform. The one-dimensional power spectrum of the pattern is obtained in the same manner from the two-dimensional power spectrum of the pattern.

  In addition, in order to make the obtained surface unevenness shape a uniform and continuous curved surface, the average value of the two-dimensional function g (x, y) is the maximum value of the two-dimensional function g (x, y) and the two-dimensional function. It is preferably 30 to 70% of the difference from the minimum value of g (x, y). When the uneven surface of the mold is manufactured by a lithography method, the two-dimensional function g (x, y) is a pattern aperture ratio. In the case of manufacturing the concavo-convex surface of the mold by the lithography method, the pattern aperture ratio here is defined. The aperture ratio when the resist used in the lithography method is positive means the ratio of the exposed area to the entire surface area of the coating film when image data is drawn on the coating film of the positive resist. On the other hand, the aperture ratio when the resist used in the lithography method is negative means the ratio of the unexposed area to the entire surface area of the coating film when image data is drawn on the coating film of the negative resist. . The aperture ratio when the lithography method is batch exposure means the ratio of the light-transmitting portion of the mask having the light-transmitting portion and the light-shielding portion.

The antiglare film of the present invention produces a desired mold with the average frequency <f> calculated from the one-dimensional power spectrum of the pattern and the standard deviation σ _f within the above ranges, respectively, and uses the mold to It can be manufactured by the first method.

  In order to create a pattern of a one-dimensional power spectrum having such an intensity ratio, a random brightness distribution whose density is determined by a pattern created by randomly arranging dots or a random number or a pseudo-random number generated by a computer is used. A pattern (preliminary pattern) having the predetermined spatial frequency range is removed from the preliminary pattern. In order to remove components in this specific spatial frequency range, the preliminary pattern may be passed through a band pass filter.

  In order to produce an anti-glare film having an anti-glare layer having a surface uneven shape formed based on a predetermined pattern, the surface has an uneven surface for transferring the surface uneven shape formed based on the predetermined pattern to a transparent support. Manufacture molds. The first method using such a mold is an embossing method for producing an antiglare layer on a transparent support.

  This embossing method can be further classified into a photoembossing method using a photocurable resin and a hot embossing method using a thermoplastic resin. Of these, the photo-embossing method is preferable from the viewpoint of productivity.

  The photo-embossing method forms a photocurable resin layer on a transparent support (transparent support surface), and cures the photocurable resin layer while pressing the photocurable resin layer against the uneven surface of the mold. In this method, the shape of the surface is transferred to the photocurable resin layer. Specifically, light is applied from the transparent support side with the photocurable resin layer formed by applying a photocurable resin on the transparent support in close contact with the uneven surface of the mold (the light is photocured). Is used to cure the photocurable resin layer, and then the transparent support on which the cured layer of the photocurable resin is formed is peeled from the mold. In the antiglare film obtained by such a method, the cured layer of the photocurable resin becomes the antiglare layer. From the viewpoint of ease of production, an ultraviolet curable resin is preferable as the photocurable resin, and when the ultraviolet curable resin is used, ultraviolet light is used as the irradiation light. The embossing method using an ultraviolet curable resin as the photocurable resin is hereinafter referred to as “UV embossing method”. In order to produce an antiglare film integrated with a polarizing film, a polarizing film is used as a transparent support, and the embossing method described here may be used by replacing the transparent support with a polarizing film.

  The kind of the ultraviolet curable resin used for the UV embossing method is not particularly limited, and an appropriate one can be used from commercially available resins according to the kind of transparent support to be used and the kind of ultraviolet light. The term “ultraviolet curable resin” as used herein is a concept including monomers (polyfunctional monomers), oligomers and polymers that are photopolymerized by ultraviolet irradiation, and mixtures thereof. In addition, a resin that can be cured even with visible light having a wavelength longer than that of ultraviolet rays can be used by using a combination of photoinitiators appropriately selected according to the type of the ultraviolet curable resin. Suitable examples of this ultraviolet curable resin will be described later.

  Examples of the transparent support used in the UV embossing method include glass and plastic films. The plastic film can be used as long as it has appropriate transparency and mechanical strength. Specific examples include transparent resin films made of cellulose acetate resins such as triacetyl cellulose; acrylic resins; polycarbonate resins; polyester resins such as polyethylene terephthalate; polyolefin resins such as polyethylene and polypropylene. . These transparent resin films may be solvent cast films or extruded films.

  The thickness of the transparent support is, for example, 10 to 500 μm, preferably 10 to 100 μm, and more preferably 10 to 60 μm. When the thickness of the transparent support is within this range, an antiglare film having sufficient mechanical strength tends to be obtained, and the image display device provided with the antiglare film is more unlikely to cause glare. Become.

  On the other hand, the hot embossing method is a method in which a transparent resin film formed of a thermoplastic resin is pressed against an uneven surface of a mold while being heated and softened, and the uneven surface shape of the mold is transferred to the transparent resin film. It is. The transparent resin film used for the hot embossing method may be any as long as it is substantially optically transparent. Specifically, the transparent resin film used for the UV embossing method is exemplified above. Can be mentioned.

[Mold manufacturing method]
Next, a method for manufacturing a mold used for the embossing method will be described. As for the mold manufacturing method, the molding surface of the mold can transfer the surface uneven shape formed on the basis of the above-mentioned predetermined pattern onto the transparent support (the surface uneven shape formed on the basis of the predetermined pattern). In order to produce the anti-glare layer having an uneven surface shape with high accuracy and reproducibility, a lithography method is preferred. Further, the lithography method includes [1] first plating step, [2] first polishing step, [3] photosensitive resin film forming step, [4] exposure step, [5] development step, and [6] first step. It is preferable to include an etching step, [7] photosensitive resin film peeling step, [8] second etching step, [9] second plating step, and [10] protective film forming step in this order.

  FIG. 5 is a diagram schematically showing a preferred example of the first half of the mold manufacturing method (up to the development step [5] above). In this figure, the cross section of the metal mold | die in each process is shown typically. Hereafter, each process of the manufacturing method of the metal mold | die for glare-proof film manufacture is demonstrated in detail, referring FIG.

[1] First Plating Step First, a base material (mold base material) used for mold production is prepared, and copper plating is applied to the surface of the mold base material. Thus, by performing copper plating on the surface of the mold base, it is possible to improve the adhesion and gloss of nickel plating in the second plating step described later. Copper plating has a high covering property and a strong smoothing action, so that a flat and glossy surface can be formed by filling minute irregularities and voids of the mold base. Therefore, by performing copper plating on the mold substrate surface in this way, after performing nickel plating in the second plating step to be described later, it is caused by minute irregularities and voids existing on the substrate. Surface roughness that may occur is eliminated. Therefore, after forming a surface irregularity shape (fine irregularity surface shape) based on a predetermined pattern on the molding surface of the mold substrate, deviation due to the influence of the surface of the base (mold substrate) such as minute irregularities and voids It can be sufficiently prevented.

  The copper used for the copper plating in the first plating step may be a pure copper metal or an alloy (copper alloy) containing copper as a main component. Therefore, “copper” used for copper plating is a concept including copper and a copper alloy. Although copper plating may be electrolytic plating or electroless plating, it is preferable to use electrolytic plating for copper plating in the first plating step. Furthermore, the preferable plating layer in the first plating step is not limited to a copper plating layer but may be a laminate of a copper plating layer and a plating layer made of a metal other than copper.

  If the plating layer formed by copper plating on the surface of the mold base is too thin, the influence of the underlying surface (microscopic irregularities, voids, cracks, etc.) cannot be eliminated, so the thickness is 50 μm or more. It is preferable that The upper limit of the plating layer thickness is not critical, but is preferably about 500 μm or less in consideration of cost and the like.

  The mold base is a metal material, but from the viewpoint of cost, the metal material is preferably aluminum, iron, or the like. Further, from the viewpoint of convenience of handling the mold base, a lightweight aluminum base is particularly preferable as the mold base. In addition, aluminum and iron here do not need to be a pure metal, respectively, and may be an alloy containing aluminum or iron as a main component.

  The shape of the base material for molds should just be an appropriate thing according to the manufacturing method of an anti-glare film. Specifically, it is selected from a flat substrate, a columnar or cylindrical (roll shape) substrate, and the like. When manufacturing an anti-glare film continuously, it is preferable that a metal mold | die is a roll shape. Such a mold is manufactured from a roll-shaped mold substrate.

[2] First Polishing Step In the subsequent first polishing step, the surface (plating layer) of the mold base that has been subjected to copper plating in the first plating step described above is polished. In the manufacture of the mold used for manufacturing the antiglare film, it is preferable that the surface of the mold base is polished to a state close to a mirror surface through the first polishing step.
In order to achieve the desired accuracy, commercially available products such as flat base materials and roll-shaped base materials used as mold base materials are often subjected to machining such as cutting and grinding. Fine processed eyes remain. For this reason, even if the copper plating layer is formed by the first plating step, the above-mentioned processed eyes may remain. Moreover, even if copper plating is performed in the first plating step, the surface of the mold base does not always become completely smooth. That is, even if the mold substrate having a surface with such deep processing marks remaining is subjected to the steps [3] to [10] described later, the uneven shape of the mold surface obtained is a predetermined pattern. May be different from those based on, or may include irregularities derived from processed eyes or the like. When an anti-glare film is produced using a mold having effects such as processing eyes remaining, the target optical characteristics such as anti-glare property cannot be sufficiently exhibited, and there is a possibility of unexpected influence.

  The polishing method applied in the first polishing step is not particularly limited, and a method corresponding to the shape and properties of the mold base to be polished is selected. Specific examples of the polishing method applicable to the first polishing step include a mechanical polishing method, an electrolytic polishing method, and a chemical polishing method. Among these, as the mechanical polishing method, any of super finishing method, lapping method, fluid polishing method, buff polishing method and the like can be used. Moreover, it is good also considering the surface of the base material for metal mold | die as a mirror surface by carrying out mirror surface cutting using a cutting tool in a grinding | polishing process. The cutting tool in this case can use a carbide tool, a CBN tool, a ceramic tool, a diamond tool, etc. depending on the material of the mold base material (the type of metal material). Is preferably a diamond bite. The surface roughness after polishing is represented by a centerline average roughness Ra in accordance with JIS B0601: 2013 “Product Geometric Specification (GPS) —Surface Properties: Contour Curve Method—Terms, Definitions, and Surface Property Parameters” The thickness is preferably 0.1 μm or less, and more preferably 0.05 μm or less. If the center line average roughness Ra after polishing is larger than 0.1 μm, the surface roughness may remain on the uneven surface of the finally obtained mold. Further, the lower limit of the centerline average roughness Ra is not particularly limited, and may be determined from the viewpoint of processing time (polishing time) and processing cost in the first polishing step.

[3] Photosensitive Resin Film Forming Step Next, the photosensitive resin film forming step will be described with reference to FIG. FIG. 5A shows a state in which the surface of the mold base 40 becomes a polished plated surface 41 through the first plating step and the first polishing step. In the photosensitive resin film forming step, a solution (photosensitive resin solution) in which a photosensitive resin is dissolved in a solvent is applied to the polished plating surface 41 of the mold base 40 obtained by the first polishing step. Then, a photosensitive resin film (resist film) is formed by heating and drying. FIG. 5B schematically shows a state in which the photosensitive resin film 50 is formed on the polished plated surface 41 of the mold base 40.

  As the photosensitive resin, a conventionally known resin can be used, and a commercially available resist can be used as it is, or it can be used after being purified by filtration or the like, if necessary. . For example, as a negative photosensitive resin having a property that the photosensitive portion is cured, a monomer or prepolymer of (meth) acrylic acid ester having an acryloyl group or a methacryloyl group in the molecule, a mixture of bisazide and diene rubber, A polyvinyl cinnamate compound or the like can be used. Further, as a positive type photosensitive resin having a property that a photosensitive part is eluted by development and only an unexposed part remains, a phenol resin type or a novolac resin type can be used. Such a positive or negative photosensitive resin can also be easily obtained from the market as a positive resist or a negative resist. Moreover, the photosensitive resin solution may contain various additives such as a sensitizer, a development accelerator, an adhesion modifier, and a coating property improver, if necessary. What mixed with the commercially available resist can also be used as a photosensitive resin solution.

  In order to apply these photosensitive resin solutions to the polished plated surface 41 of the mold base 40, an optimum solvent is selected for forming a smooth photosensitive resin film, and the photosensitive resin is sensitive to such a solvent. It is preferable to use a photosensitive resin solution obtained by dissolving and diluting a resin. Such a solvent is selected according to the kind of the photosensitive resin and its solubility. Specifically, for example, a cellosolve solvent, a propylene glycol solvent, an ester solvent, an alcohol solvent, a ketone solvent, a highly polar solvent, or the like is selected. When a commercially available resist is used, an optimal resist may be selected and used as a photosensitive resin solution depending on the type of the solvent contained in the resist or by conducting an appropriate preliminary experiment.

  The method of applying the photosensitive resin solution to the polished plating surface 41 of the mold base includes meniscus coating, fountain coating, dip coating, spin coating, roll coating, wire bar coating, air knife coating, blade coating, The method is selected from known methods such as curtain coating and ring coating according to the shape of the mold base. The thickness of the photosensitive resin film after coating is preferably in the range of 1 to 10 μm after drying, and more preferably in the range of 6 to 9 μm.

[4] Exposure Step The subsequent exposure step is a step of exposing the photosensitive resin film 50 formed in the above-described photosensitive resin film forming step to transfer the target pattern to the photosensitive resin film 50. It is. The light source used in the exposure process may be appropriately selected according to the photosensitive wavelength and sensitivity of the photosensitive resin contained in the photosensitive resin film. For example, the g-line (wavelength: 436 nm) and h-line (wavelength: high-pressure mercury lamp). 405 nm) or i-line (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), or the like can be used. The exposure method may be a batch exposure method using a mask corresponding to a target pattern, or a drawing method. As described above, the target pattern is a pattern in which the average frequency <f> and the standard deviation σ _f calculated from the one-dimensional power spectrum of the pattern are within a predetermined preferable range.

In the production of a mold, in order to accurately form the surface unevenness of the mold, it is preferable to expose the target pattern on the photosensitive resin film 50 in a precisely controlled state.
In order to perform exposure in such a state, a target pattern is created as image data on a computer, and a pattern based on the image data is formed on the photosensitive resin film by laser light emitted from a computer-controlled laser head. It is preferable to draw (laser drawing).
For laser drawing, for example, an apparatus widely used in printing plate preparation can be used.
As a commercially available product of such a laser drawing apparatus, for example, Laser Stream FX [manufactured by Sink Laboratory Co., Ltd.] is exemplified.

  FIG. 5C schematically shows a state in which the pattern is exposed to the photosensitive resin film 50 in FIG. When the photosensitive resin film 50 contains a negative photosensitive resin (specifically, when a negative resist is used as the photosensitive resin solution), the exposed region 51 is exposed to exposure energy. The cross-linking reaction of the functional resin proceeds, and the solubility in the developer described later decreases. Therefore, the unexposed area 52 is dissolved in the developing solution in the developing process, and only the exposed area 51 remains on the substrate surface to become the mask 60 (see FIG. 5D). On the other hand, when the photosensitive resin film 50 contains a positive photosensitive resin (specifically, when a positive resist is used as the photosensitive resin solution), the exposed region 51 receives exposure energy. For example, the bond of the photosensitive resin is broken, so that it is easily dissolved in a developer described later. Therefore, the exposed region 51 is dissolved in the developer in the developing process, and only the unexposed region 52 remains on the substrate surface, and becomes the mask 60.

[5] Development Step In the development step, when the photosensitive resin film 50 contains a negative photosensitive resin, the unexposed region 52 is dissolved in the developer, and the exposed region 51 is the mold. The mask 60 remains on the substrate. On the other hand, when a positive photosensitive resin is contained in the photosensitive resin film 50, the exposed region 51 is dissolved in the developer, and the unexposed region 52 remains on the mold base. The mask 60 is obtained. In the mold base material in which the predetermined pattern is formed as the photosensitive resin film, the photosensitive resin film remaining on the mold base material acts as a mask in the first etching process described later.

  About the developing solution used at the image development process, an appropriate thing can be selected according to the kind of photosensitive resin used among conventionally well-known things. The developer includes, for example, inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; Secondary amines such as n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxyethylammonium Quaternary ammonium compounds such as hydroxide; alkaline aqueous solutions in which cyclic amines such as pyrrole and piperidine are dissolved; organic solvents such as xylene and toluene

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

  FIG. 5D schematically shows a state after the development process is performed using a negative type photosensitive resin. In FIG. 5C, the unexposed region 52 is dissolved in the developer, and only the exposed region 51 remains on the substrate surface, and the photosensitive resin film in this region becomes the mask 60 in FIG. 5D. . FIG. 5E schematically shows a state after the development process is performed using a positive type photosensitive resin. In FIG. 5C, the exposed region 51 is dissolved in the developer, and only the unexposed region 52 remains on the substrate surface, and the photosensitive resin film in this region becomes the mask 60 in FIG. 5E. .

[6] First Etching Step The first etching step is a region mainly having no mask on the surface of the mold base, using the photosensitive resin film remaining on the surface of the mold base as a mask after the development step described above. This is a step of etching the plating layer.

  FIG. 6 is a diagram schematically showing a preferred example of the latter half of the mold manufacturing method (after the first etching step [6] described above). FIG. 6A schematically shows a state after the plating layer mainly having no mask is etched by the etching process. The plating layer under the mask 60 is not etched because the photosensitive resin film acts as the mask 60, but etching from the region 45 without the mask proceeds with the progress of etching. Therefore, in the vicinity of the boundary between the region with the mask 60 and the region 45 without the mask, the plating layer under the mask 60 is also etched. Thus, the etching of the plating layer under the mask 60 in the vicinity of the boundary between the region with the mask 60 and the region 45 without the mask is called side etching.

The etching process in the first etching step usually uses an etchant such as an aqueous ferric chloride (FeCl ₃ ) solution, an aqueous cupric chloride (CuCl ₂ ) solution, or an alkaline etchant (Cu (NH ₃ ) ₄ Cl ₂ ). Then, it is carried out mainly by corroding the plating layer (metal surface) in the region where the mask 60 is not present on the surface of the mold base. In the etching process, a strong acid such as hydrochloric acid or sulfuric acid can be used as an etching solution. When the first plating process is performed by electrolytic plating, reverse electrolysis is performed by applying a potential opposite to that at the time of electrolytic plating. Etching can also be employed. The surface irregularities formed on the mold base by performing the etching process are the constituent material (metal material) or plating layer of the mold base, the type of the photosensitive resin film, and the etching in the etching process. Since it differs depending on the type of treatment, etc., it cannot be generally stated. However, when the etching amount is 10 μm or less, the etching is performed isotropically from the surface of the mold substrate in contact with the etching solution. The etching amount here is the thickness of the plating layer that is scraped off by etching.

  The etching amount in the first etching step is preferably 1 to 20 μm, more preferably 3 to 12 μm, and still more preferably 5 to 8 μm. When the etching amount is less than 1 μm, the surface irregularity shape is hardly formed on the mold, and the surface has a substantially flat surface. Therefore, even if an antiglare film is produced using the mold, the surface It has almost no concavo-convex shape. In an image display device in which such an antiglare film is disposed, sufficient antiglare properties are not exhibited. When the etching amount is too large, the finally obtained uneven surface of the mold tends to have a large height difference. When an antiglare film produced from such a mold is applied to an image display device, the occurrence of whitening may not be sufficiently prevented. The etching process may be performed by one etching process, or the etching process may be performed twice or more. Here, when the etching process is performed twice or more, it is preferable that the total etching amount in the two or more etching processes is 1 to 20 μm.

[7] Photosensitive resin film peeling step The subsequent photosensitive resin film peeling step is a step of acting as a mask 60 in the first etching step to remove the photosensitive resin film remaining on the mold base. In the step, it is preferable to completely remove the photosensitive resin film remaining on the mold base. In the photosensitive resin film peeling step, it is preferable to dissolve the photosensitive resin film using a peeling solution. As the stripper, those exemplified as the developer can be used by changing the concentration, pH, and the like. Alternatively, the same developer as that used in the development process is used, and the photosensitive resin film can be peeled off by changing the temperature, the immersion time, and the like in the development process. In the photosensitive resin film peeling step, the contact method (peeling method) between the peeling solution and the mold substrate is not particularly limited, and immersion peeling, spray peeling, brush peeling, ultrasonic peeling, and the like can be used.

  FIG. 6B schematically shows a state where the photosensitive resin film used as the mask 60 in the first etching process is completely dissolved and removed in the photosensitive resin film peeling process. The first surface irregularity 46 is formed on the surface of the mold base by the mask 60 made of a photosensitive resin film and the etching process.

[8] Second Etching Step The second etching step is a step for dulling the first surface irregularities 46 formed in the first etching step by further etching treatment (second etching treatment). This second etching process eliminates a portion having a steep surface inclination in the first surface uneven shape 46 formed by the first etching process (hereinafter, the surface inclination is steep in the surface uneven shape as described above). Dulling the part is called “shape blunting”). In FIG. 6 (c), the first surface irregularity shape 46 of the mold base 40 is blunted by the second etching process, so that a portion having a steep surface inclination is blunted and has a gentle surface inclination. A state in which the second uneven surface shape 47 is formed is shown. Thus, the metal mold | die obtained by blunting by a 2nd etching process has the effect of making the optical characteristic of the glare-proof film manufactured using the said metal mold more preferable.

  Also in the second etching step, an etching process using an etching solution similar to that in the first etching step or reverse electrolytic etching can be used. The degree of shape blunting after the second etching process (the degree of disappearance of the portion with the steep surface inclination after the first etching process) depends on the material of the mold base material, the means for the second etching process, Since it differs depending on the size and depth of the irregularities in the surface irregularity shape obtained by one etching process, it cannot be generally stated, but the biggest factor in controlling the dullness (the degree of blunting) is the second factor. This is the etching amount in the etching process. Similarly to the case of the first etching step, the etching amount here is also represented by the thickness of the base material to be cut by the second etching process. When the etching amount of the second etching process is small, the effect regarding the blunting of the surface uneven shape obtained by the first etching process becomes insufficient. Therefore, an antiglare film manufactured using a mold whose shape is not sufficiently blunted tends to have an average value and standard deviation of the inclination angle of the surface irregularity shape that easily exceeds the range defined in the present invention, resulting in whiteness. Injuries may occur. On the other hand, if the amount of etching in the second etching process is too large, the surface unevenness formed by the first etching process is almost eliminated, and the mold may have a substantially flat surface. The anti-glare film manufactured using such a mold having a substantially flat surface has an average value and standard deviation of the inclination angle of the surface irregularity shape that easily falls below the range defined in the present invention. Dazzle is often insufficient. Therefore, the etching amount in the second etching treatment is preferably in the range of 1 to 50 μm, more preferably in the range of 4 to 20 μm, and particularly preferably in the range of 9 to 12 μm. Similarly to the first etching step, the second etching step may be performed by one etching process, or the etching process may be performed twice or more. When the etching process is performed twice or more, it is preferable that the total etching amount in the two or more etching processes is in the range of 1 to 50 μm.

[9] Second Plating Step In the second plating step, the mold base material that has undergone the [6] first etching step and [7] photosensitive resin film peeling step, preferably the above [8] second etching step. Plating (preferably, bright nickel plating described later) is performed on the surface of the mold base material that has undergone the above. By performing the second plating step, it is possible to further blunt the surface irregularity shape 47 of the mold base and to protect the mold surface by the plating. FIG. 6D shows a final mold in which the surface unevenness is blunted by forming the nickel plating layer 71 on the second surface uneven shape 47 formed by the second etching process as described above. The state which became the uneven | corrugated surface 70 is shown.

  The plating layer formed in the second plating step is preferably nickel plating that is glossy and excellent in corrosion resistance. Among the nickel platings, nickel plating that expresses good gloss, called bright nickel plating, is particularly preferable. Nickel plating may be performed by electrolytic plating or electroless plating. When employing electroplating, an aqueous solution containing nickel sulfate, nickel chloride and boric acid is preferably used as the plating bath. The thickness of the nickel plating layer can be controlled by adjusting the current density and the electrolysis time. When using electroless plating, the plating baths include nickel salts (nickel sulfate, nickel chloride, nickel carbonate, nickel acetate, nickel sulfamate, nickel hypophosphite, etc.), reducing agents (hypophosphorous acid, hypophosphorous acid, etc.) Sodium phosphite, potassium hypophosphite, nickel hypophosphite, calcium hypophosphite, dimethylaminoboron, diethylaminoboron, sodium borohydride, etc.), complexing agents (amine compounds such as ethylenediamine, glycolic acid, lactic acid) , Monocarboxylic acids such as gluconic acid and propionic acid, dicarboxylic acids such as tartaric acid, malic acid, succinic acid and malonic acid, tricarboxylic acids such as citric acid, or carboxyls such as sodium, potassium and ammonium salts of these carboxylic acids Acid salts), stabilizers (Pb, Bi, Tl, In, Sn, etc.) Genus-based stabilizers; propargyl alcohol, thioether compounds, thiocyanate compounds, dithionite, an aqueous solution containing an organic-based stabilizer), such as dithionite salts are preferably used. The thickness of the nickel plating layer can be controlled by adjusting the concentration, temperature, processing time, etc. of the plating solution.

  By applying nickel plating to the unevenness on the surface of the mold base after the second etching treatment, a mold with a further reduced surface hardness and increased surface hardness can be obtained. In this case, the greatest factor in controlling the degree of blunting of the shape is the thickness of the nickel plating layer. If the nickel plating layer is thin, the degree of shape blunting becomes insufficient, and the antiglare film obtained from such a mold may cause whitening. On the other hand, when the nickel plating layer is too thick, the antiglare property is insufficient. In order to obtain an antiglare film that sufficiently prevents the occurrence of whitening and provides an image display device having excellent antiglare properties, a mold is manufactured so that the thickness of the nickel plating layer is within a predetermined range. Is found to be effective. That is, the thickness of the nickel plating layer is preferably in the range of 2 to 12 μm, and more preferably in the range of 5 to 10 μm.

[10] Protective film forming process The final stage of mold production is a protective film that forms a protective film on the surface (nickel plated layer) of the mold base that has been nickel plated in the second plating process described above. It is a forming process. Nickel plating is glossy and excellent in corrosion resistance, but the hardness is not sufficient, and if the antiglare film is continuously produced as it is, the surface may be worn or damaged. Therefore, it is preferable to provide a protective film forming step to form a protective film on nickel plating that has a high hardness and a low coefficient of friction and gives good releasability.

  The film formed in the protective film forming step is preferably a carbon film, and examples thereof include a diamond thin film, a diamond-like carbon film, and a hydrogenated amorphous carbon film (abbreviated as diamond-like carbon film, also referred to as a DLC film). Various vapor deposition methods are used to form such a carbon film. For example, a diamond thin film is formed by a microwave plasma CVD method, a hot filament CVD method, a plasma jet method, an ECR plasma CVD method, or the like, and a diamond-like carbon film and a DLC film. Is formed by plasma CVD, ion beam sputtering, ion beam evaporation, plasma sputtering, or the like. In forming these carbon films, at least one kind of ions selected from an inert gas, nitrogen, and carbon is implanted at the same time as the deposition (IBM (ion beam mixing)), or a mold base material to be implanted is applied with a pulse bias. By combining PBII (Plasma Based Ion Implantation), there is no clear interface between the film and the mold substrate, and adhesion can be improved. The thickness of these carbon films is preferably in the range of 0.1 to 5 μm, and more preferably in the range of 0.5 to 3 μm. If the carbon film is too thin, the durability as a mold may be insufficient. On the other hand, when the carbon film is too thick, productivity is deteriorated, which is not preferable.

[Production of anti-glare film using mold]
Below, the said photoembossing method preferable as a method for manufacturing the anti-glare film of this invention is demonstrated. As described above, the UV embossing method is particularly preferable as the photoembossing method. Here, the embossing method using an active energy ray-curable resin will be described in detail.

  In the case where the antiglare film is continuously produced by the photo-embossing method, it is preferable that at least the [P1] coating step and the [P3] main curing step are provided in this order among the following steps. Further, it is more preferable to provide a pre-curing step [P2] between both steps.

[P1] A coating process for forming a coating layer by applying a coating liquid containing an active energy ray-curable resin on a transparent support that is continuously conveyed,
[P2] A pre-curing step of irradiating active energy rays to both end regions in the width direction of the coating layer formed in the coating step, and [P3] pressing the mold surface against the surface of the coating layer A main curing step of irradiating active energy rays from the transparent support side in the applied state.

  Hereinafter, each step will be described in detail with reference to the drawings. FIG. 7 is a diagram schematically showing an arrangement example of an apparatus suitably used for continuously producing an antiglare film. In FIG. 7, the straight arrow represents the film conveyance direction, and the curved arrow represents the rotation direction of the roll.

[P1] Coating process In the coating process, a coating liquid containing an active energy ray-curable resin is applied onto a transparent support to form a coating layer. In the coating process, for example, as shown in FIG. 7, a coating liquid containing an active energy ray-curable resin is applied in the coating zone 83 to the transparent support 81 that is fed from the feed roll 80.

  Application of the coating liquid onto the transparent support 81 can be performed by, for example, a gravure coating method, a micro gravure coating method, a rod coating method, a knife coating method, an air knife coating method, a kiss coating method, a die coating method, or the like.

(Transparent support)
The transparent support 81 only needs to be translucent, and for example, glass or plastic film can be used. The plastic film should just have moderate transparency and mechanical strength. Specifically, any of those previously exemplified as the transparent support used in the UV embossing method can be used, and in addition, in order to continuously produce an antiglare film by the photoembossing method, moderate flexibility is required. What you have is selected.

  The surface of the transparent support 81 (the surface on which the coating solution is applied) may be subjected to various surface treatments for the purpose of improving the coatability and improving the adhesion between the transparent support and the coating layer. Good. Examples of the surface treatment include corona discharge treatment, glow discharge treatment, acid surface treatment, alkali surface treatment, and ultraviolet irradiation treatment. Further, another layer such as a primer layer may be formed on the transparent support 81, and a coating solution may be applied on the other layer.

  Furthermore, when it aims at bonding an anti-glare film to a polarizing film and making it an anti-glare polarizing plate, in order to improve the adhesiveness of a transparent support and a polarizing film, the surface ( It is preferable to hydrophilize the surface on the side opposite to the surface to which the coating solution is applied by various surface treatments. This surface treatment may be performed after the production of the antiglare film.

(Coating fluid)
The coating liquid contains an active energy ray-curable resin, and usually further contains a photopolymerization initiator (radical polymerization initiator). If necessary, it may contain various additives such as translucent fine particles, solvents such as organic solvents, leveling agents, dispersants, antistatic agents, antifouling agents, and surfactants.

(1) Active energy ray curable resin As an active energy ray curable resin, what contains a polyfunctional (meth) acrylate compound can be used preferably, for example. The polyfunctional (meth) acrylate compound is a compound having at least two (meth) acryloyloxy groups in the molecule. Specific examples of the polyfunctional (meth) acrylate compound include ester compounds of polyhydric alcohol and (meth) acrylic acid, urethane (meth) acrylate compounds, polyester (meth) acrylate compounds, epoxy (meth) acrylate compounds, and the like. is there.

  Examples of the polyhydric alcohol used for forming the ester compound include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and polypropylene glycol. Divalent alcohols such as propanediol, butanediol, pentanediol, hexanediol, neopentylglycol, 2-ethyl-1,3-hexanediol, 2,2'-thiodiethanol, 1,4-cyclohexanedimethanol 3 such as trimethylolpropane, glycerol, pentaerythritol, diglycerol, dipentaerythritol, ditrimethylolpropane It includes more than alcohol.

  As an ester compound of polyhydric alcohol and (meth) acrylic acid, specifically, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (Meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate Such as theft and the like.

  The urethane (meth) acrylate compound is a urethanation reaction product of a polyisocyanate having a plurality of isocyanato groups (—N═C═O) in one molecule and a (meth) acrylic acid derivative having a hydroxyl group. Can do. Examples of polyisocyanates having a plurality of isocyanato groups in one molecule include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate and the like. Examples thereof include diisocyanates having a group, triisocyanates having three isocyanato groups in one molecule obtained by isocyanurate-modified, adduct-modified or biuret-modified these diisocyanates. Examples of the (meth) acrylic acid derivative having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2- Examples thereof include hydroxy-3-phenoxypropyl (meth) acrylate and pentaerythritol tri (meth) acrylate.

  Preferred as the polyester (meth) acrylate compound is a compound obtained by reacting a hydroxyl group-containing polyester with (meth) acrylic acid. The hydroxyl group-containing polyester preferably used is a compound obtained by an esterification reaction between a polyhydric alcohol and a carboxylic acid or a compound having a plurality of carboxyl groups and / or an anhydride thereof. Examples of the polyhydric alcohol include the same compounds as those described above. In addition to polyhydric alcohols, polyhydric phenols such as bisphenol A can also be used. Examples of the carboxylic acid include formic acid, acetic acid, butyl carboxylic acid, benzoic acid and the like. The compounds having a plurality of carboxyl groups and / or anhydrides thereof include maleic acid, phthalic acid, fumaric acid, itaconic acid, adipic acid, terephthalic acid, maleic anhydride, phthalic anhydride, trimellitic acid, cyclohexanedicarboxylic anhydride Such as things.

  Among the polyfunctional (meth) acrylate compounds as described above, hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di ( Ester compounds such as (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate; hexamethylene diisocyanate and 2-hydroxy Adducts with ethyl (meth) acrylate, adducts of isophorone diisocyanate and 2-hydroxyethyl (meth) acrylate, tolylene diisocyanate and 2-hydroxyethyl (meth) acrylate Urethane (meth) acrylate compounds such as adducts with adsorbates, adducts modified with isophorone diisocyanate and 2-hydroxyethyl (meth) acrylate, and adducts with biuret-modified isophorone diisocyanate and 2-hydroxyethyl (meth) acrylate Is preferred. These polyfunctional (meth) acrylate compounds can be used alone or in combination of two or more.

  The active energy ray-curable resin may contain a monofunctional compound having only one polymerizable carbon-carbon double bond in one molecule in addition to the polyfunctional (meth) acrylate compound. A monofunctional (meth) acrylate compound is a typical monofunctional compound, and specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t- Butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (Meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) Chrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, ethyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, ethylene oxide modified phenoxy (meth) acrylate, propylene oxide modified phenoxy (meth) acrylate, nonylphenol (Meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, dimethylaminoethyl (meth) ) Acrylate, methoxytriethylene glycol (meth) acrylate, and the like. In addition, acryloylmorpholine, N-vinylpyrrolidone, and the like can be monofunctional compounds. These monofunctional compounds can be used alone or in combination of two or more.

  Further, the active energy ray curable resin may contain a polymerizable oligomer. By including the polymerizable oligomer, the hardness of the cured product can be adjusted. The polymerizable oligomer is, for example, the above polyfunctional (meth) acrylate compound, that is, an ester compound of a polyhydric alcohol and (meth) acrylic acid, a urethane (meth) acrylate compound, a polyester (meth) acrylate compound or an epoxy (meth) ) Dimer or trimer of acrylate.

  As another polymerizable oligomer, a urethane (meth) acrylate oligomer obtained by reacting a polyisocyanate having at least two isocyanato groups in the molecule with a compound having at least one (meth) acryloyloxy group and a hydroxyl group is used. Can be mentioned. Examples of the polyisocyanate used for this purpose include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate. In addition, compounds having at least one (meth) acryloyloxy group and hydroxyl group are many. Hydroxyl group-containing (meth) acrylic acid ester obtained by esterification reaction of a monohydric alcohol and (meth) acrylic acid, wherein a part of the alcoholic hydroxyl group of the polyhydric alcohol is esterified with (meth) acrylic acid And part of the alcoholic hydroxyl group remains in the molecule. Examples of the polyhydric alcohol used here include 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, and trimethylolpropane. Glycerol, pentaerythritol, dipentaerythritol, and the like.

  Furthermore, as another example of the polymerizable oligomer, a polyester (meta) obtained by reacting a compound having a plurality of carboxyl groups and / or an anhydride thereof with a compound having at least one (meth) acryloyloxy group and a hydroxyl group. ) Acrylate oligomers. Examples of the compound having a plurality of carboxyl groups used for this purpose and / or anhydrides thereof are the same as those mentioned in the polyester (meth) acrylate compound of the polyfunctional (meth) acrylate compound. Examples of the compound having at least one (meth) acryloyloxy group and a hydroxyl group are the same as those mentioned in the urethane (meth) acrylate oligomer.

  In addition to the above polymerizable oligomer, as an example of another urethane (meth) acrylate oligomer, it is obtained by reacting an isocyanate with a hydroxyl group of a hydroxyl group-containing polyester, a hydroxyl group-containing polyether or a hydroxyl group-containing (meth) acrylic ester. The compound which can be mentioned is mentioned. The hydroxyl group-containing polyester preferably used for this purpose is obtained by an esterification reaction of a polyhydric alcohol, a carboxylic acid, a compound having a plurality of carboxyl groups, and / or an anhydride thereof. Examples of the polyhydric alcohol and the compound having a plurality of carboxyl groups and / or anhydrides thereof are the same as those exemplified above for the polyester (meth) acrylate compound of the polyfunctional (meth) acrylate compound. . The hydroxyl group-containing polyether preferably used can be obtained by adding one or more alkylene oxides and / or ε-caprolactone to a polyhydric alcohol. The polyhydric alcohol may be the same as that which can be used for the hydroxyl group-containing polyester. Examples of the hydroxyl group-containing (meth) acrylic acid ester preferably used are the same as those exemplified in the urethane (meth) acrylate oligomer of the polymerizable oligomer. The isocyanate may be a compound having at least one isocyanato group in the molecule, but divalent isocyanate compounds such as tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are particularly preferable.

  These polymerizable oligomers can be used alone or in combination of two or more.

(2) Photoinitiator A photoinitiator can be suitably selected according to the kind of active energy ray applied to manufacture of an anti-glare film. Moreover, when using an electron beam as an active energy ray, the coating liquid which does not contain a photoinitiator may be used for manufacture of an anti-glare film. Examples of the photopolymerization initiator include acetophenone photopolymerization initiator, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, triazine photopolymerization initiator, and oxadiazole photopolymerization initiator. An initiator or the like is used. Examples of the photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenyl-1,2 ′. -Biimidazole, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, benzyl, 9,10-phenanthrenequinone, camphorquinone, methyl phenylglyoxylate, titanocene compounds and the like can also be used. The usage-amount of a photoinitiator is 0.5-20 weight part normally with respect to 100 weight part of active energy ray-curable resins, Preferably it is 1-5 weight part.

(3) Other optional components constituting the coating liquid The coating liquid may contain an organic solvent in order to improve the coating property to the transparent support.
Examples of the organic solvent include aliphatic hydrocarbons such as hexane, cyclohexane, and octane; aromatic hydrocarbons such as toluene and xylene; alcohols such as ethanol, 1-propanol, isopropanol, 1-butanol, and cyclohexanol; methyl ethyl ketone, Ketones such as methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate, butyl acetate and isobutyl acetate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Glycol ethers; ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, etc. Celluloses such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol; 2- (2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol, 2- (2- It can be selected from carbitols such as butoxyethoxy) ethanol in consideration of viscosity and the like. These solvents may be used alone or as a mixture of several kinds as required. When the coating liquid contains a solvent, it is necessary to evaporate the solvent after coating.
Therefore, it is desirable that the solvent has a boiling point in the range of 60 ° C to 160 ° C. The saturated vapor pressure at 20 ° C. is preferably in the range of 0.1 kPa to 20 kPa.

(Summary of other processes and coating processes optionally provided in the coating process)
When the coating liquid contains a solvent, it is preferable to provide a drying step of evaporating the solvent and drying after the coating step, before the main curing step, and before the preliminary curing step. Drying can be performed, for example, by passing the transparent support 81 after the coating layer is formed through the drying zone 84 as in the example shown in FIG. The drying temperature is appropriately selected depending on the solvent used and the type of transparent support. Generally, it is in the range of 20 ° C to 120 ° C, but is not limited thereto. When there are a plurality of drying furnaces, the temperature may be changed for each drying furnace. The thickness of the coating layer after drying is preferably 1 to 30 μm.

  Through the coating process as described above and, if necessary, a drying process, a laminate in which the coating layer is laminated on the transparent support is formed.

[P2] Pre-curing step The pre-curing step is a step of irradiating active energy rays to both end regions in the transparent support width direction of the coating layer and pre-curing both end regions prior to the main curing step described later. is there. FIG. 8 is a cross-sectional view schematically showing the preliminary curing step. In FIG. 8, end regions 82b existing at both ends in the width direction of the coating layer (direction perpendicular to the transport direction) are regions having a predetermined width from the end portion including the end portions of the coating layer.

In the preliminary curing step, by precuring both end regions, the adhesion with the transparent support 81 at that portion is further enhanced, and in the subsequent main curing step and subsequent steps, part of the cured resin is removed. It is possible to prevent the process from being peeled off and contaminated.
The end region 82b can be a region from 5 mm to 50 mm from the end of the coating layer 82, for example.

  The irradiation of the active energy ray to the end region of the coating layer is performed, for example, with reference to FIGS. 7 and 8, for example, the coating layer that has passed through the coating zone 83 (or the drying zone 84 when drying is performed). This is performed by irradiating the transparent support 81 having 82 with active energy rays using an active energy ray irradiating device 85 such as an ultraviolet ray irradiating device installed in the vicinity of both ends on the coating layer 82 side. Can do. The active energy ray irradiation device 85 may be any device as long as it can irradiate the end region 82b of the coating layer 82 with active energy rays, and may be installed on the transparent support 81 side.

About the kind and light source of an active energy ray, it is the same as that of the main hardening process mentioned later. When the active energy ray is ultraviolet, the integrated amount of light at UVA (wavelength 400～315Nm) of ultraviolet rays is preferably 10 mJ / cm ² or more 400 mJ / cm ² or less, 50 mJ / cm ² or more 400 mJ / cm ² or less More preferably. If irradiation is performed so that the integrated light amount is 50 mJ / cm ² or more, deformation in the subsequent main curing step can be more effectively prevented. On the other hand, if the integrated light quantity exceeds 400 mJ / cm ² , the curing reaction proceeds excessively, and as a result, resin peeling occurs at the boundary between the cured part and the uncured part due to a difference in film thickness or distortion of internal stress. Sometimes.

[P3] Main curing step The main curing step irradiates the surface of the coating layer with an active energy ray from the transparent support side in a state where a mold surface (molded surface) having a desired surface irregularity shape is pressed, This is a step of forming a cured resin layer on the transparent support by curing the coating layer. As a result, the coating layer is cured, and the uneven shape on the mold surface is transferred to the coating layer surface. The mold used here is a roll-shaped one when the antiglare film is continuously produced as a long object, and by using the roll-shaped mold base material in the mold manufacturing method already described. It is manufactured.

  For example, as shown in FIG. 7, this step is performed by applying a coating zone 83 (a drying zone 84 when a drying step is performed, or an active energy ray irradiation device when a preliminary curing step described above is performed). The active energy ray irradiating device 86 such as an ultraviolet irradiating device disposed on the transparent support 81 side is used for the laminated body having the coating layer after passing through the pre-curing zone irradiated with 85). This is performed by irradiating with active energy rays.

  First, a roll-shaped mold 87 is pressed against the surface of the coating layer of the laminate on which the coating layer has been formed using a crimping means such as a nip roll 88, and in this state, it is disposed on the transparent support 81 side. The active energy ray is irradiated from the active energy ray irradiating device 86 to cure the coating layer. Here, “curing the coating layer” means that the active energy ray-curable resin contained in the coating layer receives the energy of the active energy ray to cause a curing reaction. The use of the nip roll 88 is effective in preventing air bubbles from being mixed between the coating layer of the laminate and the mold. One or a plurality of active energy ray irradiation devices 86 can be used.

  After irradiation with the active energy ray, the laminate is peeled from the mold 87 with the nip roll 89 on the outlet side as a fulcrum. The laminate comprising the obtained transparent support and the cured coating layer becomes an antiglare film having the cured coating layer as an antiglare layer. The resulting antiglare film is usually wound up by a film winding device 90. At this time, for the purpose of protecting the antiglare layer, it may be wound up while a protective film made of polyethylene terephthalate, polyethylene or the like is attached to the surface of the antiglare layer through a pressure-sensitive adhesive layer having removability. Here, although the case where the metal mold | die to be used is roll shape was demonstrated, metal mold | dies other than roll shape can also be used. Moreover, you may perform additional active energy ray irradiation after peeling from a metal mold | die.

  The active energy ray used in this step is appropriately selected from ultraviolet ray, electron beam, near ultraviolet ray, visible light, near infrared ray, infrared ray, X-ray, etc., depending on the type of active energy ray curable resin contained in the coating liquid. Among these, ultraviolet rays and electron beams are preferable, and ultraviolet rays are particularly preferable because they are easy to handle and high energy can be obtained. Therefore, as described above, the UV embossing method is preferable as the photoembossing method.

  As the ultraviolet light source, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, an electrodeless lamp, a metal halide lamp, a xenon arc lamp, or the like can be used. An ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can also be used. Among these, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, an electrodeless lamp, a xenon arc lamp, and a metal halide lamp are preferably used.

  Further, as the electron beam, 50 to 1000 keV emitted from various electron beam accelerators such as Cockloft Walton type, Bande graph type, resonance transformation type, insulation core transformation type, linear type, dynamitron type, and high frequency type, preferably 100 Mention may be made of electron beams having an energy of ˜300 keV.

When the active energy ray is ultraviolet, the integrated amount of light at UVA (wavelength 400～315Nm) of ultraviolet rays is preferably at 100 mJ / cm ² or more 3000 mJ / cm ² or less, more preferably 200 mJ / cm ² or more 2000 mJ / cm ² It is as follows. In addition, since the transparent support may absorb ultraviolet rays on the short wavelength side, the integrated light amount of ultraviolet rays UVV (wavelength 395 to 445 nm) in the wavelength region including visible light is a preferable value for the purpose of suppressing the absorption. In this way, the dose may be adjusted. Integrated light intensity at UVV in this case, is preferably 100 mJ / cm ² or more 3000 mJ / cm ² or less, and more preferably 200 mJ / cm ² or more 2000 mJ / cm ² or less. If the integrated light quantity is less than 100 mJ / cm ² , the coating layer will be insufficiently cured, the resulting antiglare layer will have low hardness, or uncured resin will adhere to the guide roll, etc. There is a tendency to cause. On the other hand, when the integrated light quantity exceeds 3000 mJ / cm ² , the transparent support may contract due to heat radiated from the ultraviolet irradiation device and cause wrinkles.

[Use of anti-glare film]
The antiglare film of the present invention obtained as described above is used for an image display device or the like, and is usually used by being bonded to a polarizing film as a viewing side protective film of a viewing side polarizing plate. That is, the polarizing plate on which the antiglare film is bonded is disposed on the surface of the image display device. In addition, as described above, when a polarizing film is used as the transparent support, an antiglare film integrated with a polarizing film is obtained, and thus the antiglare film integrated with a polarizing film is applied to an image display device. You can also. The image display device provided with the antiglare film of the present invention has sufficient antiglare properties at a wide viewing angle, and can well prevent both whitening and glare.

  Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. The evaluation method of the metal mold | die or anti-glare film in the following examples is as follows. In addition, the anti-glare film of this invention is evaluated by the same method as the following evaluation method.

[1] Measurement of surface shape of antiglare film (inclination angle of surface unevenness)
The elevation of the surface of the antiglare film was measured using a three-dimensional microscope “PLμ2300” (manufactured by Sensofar). In order to prevent the measurement sample from warping, an optically transparent adhesive was used, and the surface opposite to the antiglare layer of the measurement sample was bonded to a glass substrate, and then subjected to measurement.
The magnification of the objective lens during measurement was 50 times. The horizontal resolutions Δx and Δy were both 0.332 μm and the measurement area was 255 μm × 191 μm. From the obtained measurement data, the average value of the inclination angles of the surface irregularities was determined based on the above-described algorithm, and the standard deviation was further determined therefrom.

[Average value and coefficient of variation of Voronoi polygons]
The surface shape of the antiglare film was measured using a three-dimensional microscope “PLμ2300” (manufactured by Sensofar). In order to prevent the sample from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent pressure-sensitive adhesive so that the uneven surface became the surface. At the time of measurement, the magnification of the objective lens was 50 times. The horizontal resolutions Δx and Δy were both 0.332 μm and the measurement area was 255 μm × 191 μm. From the obtained measurement data, using the algorithm described above, Voronoi division is performed with the convex portion of the fine uneven surface as the apex, and the average value and standard deviation of the area of the Voronoi polygon are obtained, and the coefficient of variation = (standard deviation) / Average value) × 100 (%).

[2] Measurement of optical properties of antiglare film [haze]
The total haze of the antiglare film is about an antiglare film bonded to the glass substrate by using an optically transparent adhesive and bonding the surface opposite to the antiglare layer of the measurement sample to the glass substrate. Then, light was incident from the glass substrate side, and the haze meter “HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd. was used in accordance with JIS K7136: 2000 described above. The surface haze was determined by calculating the internal haze of the antiglare film and subtracting the internal haze from the total haze by the following formula: surface haze = total haze-internal haze. The internal haze was measured in the same manner as the total haze after a triacetyl cellulose film having a haze of approximately 0 was attached to the antiglare layer surface of the measurement sample after measuring the total haze with glycerin.

(Transparency definition)
Based on the above-mentioned JIS K7374: 2007, the transmission clarity of the antiglare film was measured using an image clarity measuring device “ICM-1DP” manufactured by Suga Test Instruments Co., Ltd. Also in this case, in order to prevent the sample from warping, the surface opposite to the antiglare layer of the measurement sample was bonded to the glass substrate using an optically transparent adhesive, and then used for the measurement. In this state, light was incident from the glass substrate side and measurement was performed. The measured values here are values measured using five types of optical combs in which the widths of the light-shielding portion and the light-transmitting portion are 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. Is the sum of

[Reflection sharpness measured at 45 ° light incident angle]
Based on the above-mentioned JIS K7374: 2007, the reflection sharpness of the antiglare film was measured using an image clarity measuring device “ICM-1DP” manufactured by Suga Test Instruments Co., Ltd. Also in this case, in order to prevent the sample from warping and to prevent reflection from the back side, an optically transparent adhesive is used, and the surface opposite to the antiglare layer of the measurement sample is placed on the black acrylic resin substrate. It was used for the measurement after pasting. In this state, light was incident at 45 ° from the antiglare layer surface side, and measurement was performed. The measured values here are the total values of the values measured using four types of optical combs in which the widths of the light-shielding portion and the transmissive portion are 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively. is there.

[Reflection sharpness measured at a light incident angle of 60 °]
Except for changing the incident angle of light to 60 °, the reflection sharpness was measured by the same method as that measured at an incident angle of 45 ° of the upper light.

[3] Evaluation of anti-glare performance of anti-glare film [Visual evaluation of reflection and whitishness]
In order to prevent reflection from the back surface of the antiglare film, the surface opposite to the antiglare layer of the measurement sample was bonded to a black acrylic resin substrate using an adhesive, and in this state, a fluorescent lamp was attached. Visual observation was performed from the antiglare layer side in a bright room, and the degree of reflection of the fluorescent lamp and the degree of whitishness were evaluated. Regarding reflection, the anti-glare film was evaluated when observed from the front and when observed from an oblique angle of 30 °. Reflection and whitishness were evaluated according to the following criteria in three stages of 1 to 3, respectively.

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

Whiteness 1: No whiteness is observed.
2: A little whitish is observed.
3: The whitish is clearly observed.

[Evaluation of glare]
The glare was evaluated by the following procedure. That is, first, a photomask having a unit cell pattern shown in a plan view in FIG. 9 was prepared. In this figure, a unit cell 100 has a key-shaped chrome light-shielding pattern 101 having a line width of 10 μm formed on a transparent substrate, and a portion where the chrome light-shielding pattern 101 is not formed is an opening 102. Here, a unit cell having a size of 211 μm × 70 μm (vertical × horizontal in the figure) and an opening having a dimension of 201 μm × 60 μm (vertical × horizontal in the figure) was used. A large number of unit cells shown in the figure are arranged vertically and horizontally to form a photomask.

  Then, as shown in a schematic cross-sectional view in FIG. 10, the chromium light shielding pattern 111 formed on the glass substrate 112 of the photomask 113 is placed on the light diffusion plate 120 of the light box 115, and the glass plate 117 is placed. A sample obtained by bonding the antiglare film 110 with an adhesive so that the antiglare layer is on the surface is placed on the photomask 113. A light source 116 is disposed in the light box 115. In this state, by visually observing at a position 119 that is about 30 cm away from the sample, the degree of glare was sensory evaluated in seven stages. Level 1 corresponds to a state where no glare is observed, level 7 corresponds to a state where severe glare is observed, and level 4 refers to a state where only slight glare is observed.

[Evaluation of contrast]
The polarizing plates on both the front and back surfaces were peeled off from a commercially available liquid crystal television (“KDL-32EX550” manufactured by Sony Corporation). Instead of these original polarizing plates, the polarizing plate “Sumikaran SRDB831E” manufactured by Sumitomo Chemical Co., Ltd. is used on both the back side and the display side so that each absorption axis matches the absorption axis of the original polarizing plate. Further, the antiglare film shown in each of the following examples was laminated on the display surface side polarizing plate via an adhesive such that the concavo-convex surface was the surface. The liquid crystal television thus obtained was activated in a dark room, and the luminance in the black display state and the white display state was measured using a luminance meter “BM5A” manufactured by Topcon Corporation, and the contrast was calculated. Here, the contrast is represented by the ratio of the luminance in the white display state to the luminance in the black display state. On the other hand, the contrast was similarly obtained in the configuration in which the antiglare film was excluded from the above configuration (the state in which the antiglare film was not bonded to the display surface side polarizing plate), and the results were measured in the state in which the antiglare film was not bonded. It was shown by the ratio (%) of the contrast measured in the state where the antiglare film for the contrast was bonded.

[4] Evaluation of pattern for production of anti-glare film The created pattern data was made into binary image data of two gradations, and the gradation was expressed by a two-dimensional discrete function g (x, y). The horizontal resolutions Δx and Δy of the discrete function g (x, y) are both 2 μm. The resulting two-dimensional function g (x, y) of the discrete Fourier transform to two-dimensional function G (f _x, f _y) was determined. Two-dimensional function G (f _x, f _y) of a two-dimensional function gamma (f _x, f _y) of the absolute value squared by the two-dimensional power spectrum to calculate the one-dimensional power is a function of the distance f from the origin A one-dimensional function Γ (f) of the spectrum was calculated, and an average frequency <f> and a standard deviation σ _f were calculated.

<Example 1>
[Production of molds for production of anti-glare film]
An aluminum roll having a diameter of 300 mm (A6063 by JIS) was prepared by applying copper ballad plating to the surface. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the entire plating layer was about 200 μm. The copper plating surface was mirror-polished, a photosensitive resin was applied to the polished copper plating surface, and dried to form a photosensitive resin film. Next, a pattern in which the patterns shown in FIG. 11 were repeatedly arranged was exposed on a photosensitive resin film with a laser beam and developed. The laser beam exposure and development were performed using Laser Stream FX [manufactured by Sink Laboratory Co., Ltd.]. A positive type resin was used as the photosensitive resin. The pattern shown in FIG. 11 is created by passing a plurality of Gaussian function type bandpass filters from a pattern having a random brightness distribution, with an aperture ratio of 45%, calculated from the one-dimensional power spectrum of the pattern. the average frequency <f> and the standard deviation sigma _f being, respectively 0.091Myuemu ^-1 and 0.102μm ^-1.
Then, laser exposure was performed so that a black portion in the figure was an exposed portion and a white portion was a non-exposed portion. The relationship between the exposed portion and the non-exposed portion is the same in the following FIGS.

  Then, the 1st etching process was performed with cupric chloride aqueous solution. The etching amount at that time was set to 5 μm. The photosensitive resin film was removed from the roll after the first etching treatment, and the second etching treatment was performed again with an aqueous cupric chloride solution. The etching amount at that time was set to 10 μm. Subsequently, the plating thickness was set to 6 μm and nickel plating was performed. A DLC film was formed as a protective film on the roll plated with nickel by sputtering to produce a mold. At this time, the thickness of the DLC film was 0.5 μm.

(Preparation of antiglare film)
The following components were dissolved in ethyl acetate at a solid content concentration of 60%, and an ultraviolet curable resin composition capable of forming a film having a refractive index of 1.53 after curing was prepared.

Pentaerythritol triacrylate 60 parts Multifunctional urethanated acrylate 40 parts (Reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate)
2,4,6-Trimethylbenzoyldiphenylphosphine oxide 5 parts

This ultraviolet curable resin composition was applied on a 60 μm thick triacetylcellulose (TAC) film so that the thickness of the coating layer after drying was 5 μm, and dried in a dryer set at 60 ° C. for 3 minutes. It was. The dried film was brought into close contact with the mold forming surface (surface having an uneven shape) by pressing with a rubber roll so that the dried coating layer was on the mold side. In this state, from the TAC film side, light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² is irradiated so that the integrated light amount in terms of h-ray is 200 mJ / cm ² , the coating layer is cured, and the antiglare layer is formed. Formed. Thus, the film in which the antiglare layer was formed on the TAC film was peeled from the mold to obtain a transparent antiglare film. This is designated as an antiglare film A.

<Example 2>
A mold was fabricated in the same manner as the mold fabrication in Example 1 except that the etching amount in the second etching step was set to 9 μm. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film B.

<Example 3>
A mold was fabricated in the same manner as the mold fabrication in Example 1 except that the etching amount in the second etching step was set to 11 μm. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film C.

<Example 4>
A mold was produced in the same manner as in the production of the mold in Example 1 except that a pattern in which the patterns shown in FIG. 12 were repeatedly arranged was exposed on the photosensitive resin film with a laser beam. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film D. The pattern shown in FIG. 12 is created by passing a plurality of Gaussian function bandpass filters from a pattern having a random brightness distribution, with an aperture ratio of 45%, calculated from the one-dimensional power spectrum of the pattern. the average frequency <f> and the standard deviation sigma _f being, respectively 0.088Myuemu ^-1 and 0.101μm ^-1.

<Example 5>
A mold was produced in the same manner as in the production of the mold in Example 1 except that a pattern in which the patterns shown in FIG. 13 were repeatedly arranged was exposed on the photosensitive resin film with a laser beam. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film E. The pattern shown in FIG. 13 is created by passing a plurality of Gaussian function type bandpass filters from a pattern having a random brightness distribution, with an aperture ratio of 45%, calculated from the one-dimensional power spectrum of the pattern. the average frequency <f> and the standard deviation sigma _f being, respectively 0.092Myuemu ^-1 and 0.107μm ^-1.

<Comparative Example 1>
A mold F was fabricated in the same manner as the mold fabrication in Example 1, except that the etching amount in the second etching step was set to 8 μm. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film F.

<Comparative Example 2>
A surface of an aluminum roll having a diameter of 200 mm (A6063 by JIS) was prepared by applying copper ballad plating so that the total thickness of the plating layer was about 200 μm. Using this aluminum roll with copper ballad plating, a pattern obtained by repeatedly arranging the patterns shown in FIG. 14 was exposed on the photosensitive resin film with a laser beam in the same manner as in the production of the mold in Example 1. A mold was produced. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film G. The pattern shown in FIG. 14 is created by passing a plurality of Gaussian function bandpass filters from a pattern having a random brightness distribution, and is calculated from a one-dimensional power spectrum with a 45% aperture ratio. the average frequency <f> and the standard deviation sigma _f being, respectively 0.087Myuemu ^-1 and 0.094μm ^-1.

<Comparative Example 3>
The surface of an aluminum roll having a diameter of 300 mm (A5056 by JIS) was mirror-polished, and then the polished aluminum surface was subjected to zirconia beads “TZ-SX-17” using a blasting apparatus (manufactured by Fuji Seisakusho). Tosoh Co., Ltd., average particle size: 20 μm] is blasted at a blast pressure of 0.1 MPa (gauge pressure, the same applies hereinafter) and a bead usage of 8 g / cm ² (a used amount per 1 cm ² of surface area of the roll, the same applies hereinafter). The surface of the aluminum roll was uneven. The resulting aluminum roll with unevenness was subjected to electroless nickel plating to produce a mold. At this time, the electroless nickel plating thickness was set to 15 μm. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film H.

<Comparative example 4>
A surface of an aluminum roll having a diameter of 200 mm (A5056 by JIS) was prepared by applying copper ballad plating so that the thickness of the entire plating layer was about 200 μm. The copper plating surface is mirror-polished, and the same zirconia bead “TZ-SX-17” as used in Comparative Example 3 is blasted on the polished surface using a blasting device (manufactured by Fuji Seisakusho). Blasting was performed at a pressure of 0.05 MPa and a use amount of beads of 6 g / cm ² , and irregularities were formed on the surface of the aluminum roll. The resulting concavo-convex copper ballad plated aluminum roll was subjected to chrome plating to produce a mold. At this time, the chromium plating thickness was set to 6 μm. An antiglare film was produced in the same manner as the production of the antiglare film in Example 1 except that this mold was used. The obtained antiglare film is designated as an antiglare film I.

[Evaluation results]
Table 1 shows the evaluation results of the antiglare films obtained in the above Examples and Comparative Examples.

  Anti-glare films A to E (Examples 1 to 5) that satisfy the requirements of the present invention have excellent anti-glare properties regardless of whether the observation angle is front or oblique, despite having low haze. In addition, the effect of suppressing whitishness and glare was sufficient. On the other hand, the antiglare film F (Comparative Example 1) had whitening. The antiglare film G (Comparative Example 2) had insufficient antiglare properties when observed from an oblique direction. The glare-proof film H (Comparative Example 3) was easily glaring. The anti-glare film I (Comparative Example 4) had insufficient anti-glare properties when observed from an oblique direction, and whiteness was also generated.

DESCRIPTION OF SYMBOLS 1 ... Anti-glare film (or its average surface), 2 ... Surface unevenness, 3 ... Projection surface of film,
5 ... Main normal of the film, 6 ... Local normal with the unevenness,
6a, 6b, 6c, 6d ... normal vector of the polygon surface,
21: Arbitrary point on antiglare film surface, 22 ... Antiglare film surface,
23 ... Anti-glare film reference plane, 24 ... Circular projection plane centered on an arbitrary point 21,
26 ... Voronoi division mother point, 27 ... Voronoi polygon,
28 ... Voronoi polygon not counted as average value,
40 ... Base material for mold,
41 ... the plated surface polished through the first plating step and the polishing step,
45... Region without a mask etched by the first etching process,
46: first surface irregularities formed by the first etching process,
47 ... second surface irregularity shape blunted by the second etching process,
50 ... photosensitive resin film, 51 ... exposed area, 52 ... unexposed area,
60 ... mask,
70 ... The final mold uneven surface that has been blunted by nickel plating,
71 ... nickel plating layer,
80 ... feed roll, 81 ... transparent support,
82 ... coating layer, 82b ... end region of coating layer, 83 ... coating zone,
84 ... drying zone, 85 ... active energy ray irradiation device for pre-curing,
86 ... Active energy ray irradiation device, 87 ... Roll-shaped mold,
88, 89 ... nip roll, 90 ... film take-up device,
100: Unit cell, 101: Shading pattern, 102: Opening,
110 ... Anti-glare film, 111 ... Light shielding pattern, 112 ... Glass substrate,
113 ... Photomask, 115 ... Light box, 116 ... Light source,
117 ... Glass plate, 119 ... Glare observation position, 120 ... Light diffusion plate.

  The antiglare film of the present invention is useful for an image display device such as a liquid crystal display.

Claims (2)

An anti-glare film comprising a transparent support and an anti-glare layer having fine surface irregularities formed thereon,
The total haze is 0.1% or more and 3% or less,
The surface haze is 0.1% or more and 2% or less,
The average value of the inclination angle of the surface uneven shape is 0.2 ° or more and 1.2 ° or less, and the standard deviation of the inclination angle is 0.1 ° or more and 0.8 ° or less,
The average value of the polygonal area formed when the surface is Voronoi divided with the vertex of the convex part of the convexo-concave shape as a mother point is 50 μm ² or more and 150 μm ² or less, and the variation of the polygonal area is An antiglare film having a coefficient of 40% or more and 80% or less. The sum Tc of the transmission clarity measured using five types of optical combs in which the width of the light shielding portion and the transmission portion is 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm, respectively, is 375%. That's it,
The sum Rc of the reflection sharpness measured at an incident angle of 45 ° using four types of optical combs in which the width of the light-shielding portion and the light-transmitting portion are 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm, respectively. (45) is 180% or less,
Rc of reflection sharpness Rc measured at an incident angle of light of 60 ° using four types of optical combs in which the width of the light shielding portion and the transmission portion is 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm, respectively. The antiglare film according to claim 1, wherein (60) is 240% or less.

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