Anti-glare film and image display device
Patent Information
- Application Number
- JP2024059937
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2020-05-15
- Filing Date
- 2024-04-03
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2041-05-14
AI Technical Summary
Conventional anti-glare films provide insufficient suppression of reflections and often impair image clarity due to increased surface roughness, leading to blurred images and enhanced scattered light.
An anti-glare film with a specific uneven surface structure, characterized by amplitude spectrum parameters AM1 and AM2, and a composition including a binder resin and particles, which effectively suppresses reflections and scattered light while maintaining image clarity.
The film achieves excellent anti-glare properties by minimizing reflections and scattered light, providing a jet-black appearance and enhancing the perceived quality of image display devices.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present invention relates to an antiglare film and an image display device. [Background technology]
[0002] 2. Description of the Related Art Anti-glare films are often installed on the surfaces of image display devices such as televisions, notebook PCs, and desktop PC monitors in order to suppress reflections of lighting, people, and other background objects.
[0003] An antiglare film has a basic structure of having an antiglare layer having an uneven surface on a transparent substrate. Such antiglare films have been proposed, for example, in Patent Documents 1 to 4. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] JP 2005-234554 A [Patent Document 2] JP 2009-86410 A [Patent Document 3] JP 2009-265500 A [Patent Document 4] International Publication No. WO2013 / 015039 Summary of the Invention [Problem to be solved by the invention]
[0005] Conventional antiglare films such as those described in Patent Documents 1 to 4 provide antiglare properties to the extent that reflected images become blurred, and it is difficult to sufficiently suppress the reflection of lighting and people and other background objects. On the other hand, by increasing the degree of roughness of the surface irregularities of the antiglare layer, it is possible to sufficiently suppress reflection and improve the antiglare properties. However, simply increasing the degree of roughness of the surface irregularities increases the intensity of reflected and scattered light, which causes a problem of impairing the contrast of the image display device.
[0006] An object of the present invention is to provide an antiglare film having excellent antiglare properties and capable of suppressing reflected scattered light.
Means for Solving the Problems
[0007] The present invention provides the following antiglare films and display devices of [1] to
[14] . [1] An antiglare film having an antiglare layer, wherein the antiglare film has an uneven surface, and regarding the amplitude spectrum of the elevation of the uneven surface, the spatial frequencies are 0.005 μm -1 , 0.010 μm -1 , 0.015 μm -1 respectively, and when the sum of the amplitudes corresponding to 0.300 μm -1 is defined as AM1 and the amplitude at the spatial frequency of 0.300 μm -1 is defined as AM2, an antiglare film in which AM1 is 0.070 to 0.400 μm, AM2 is 0.0050 μm or more, and AM2 < AM1. [2] The antiglare film according to [1], wherein AM2 is 0.0055 to 0.0550 μm. [3] The antiglare film according to [1] or [2], wherein AM1 / AM2 is 1.0 to 60.0. [4] The antiglare film according to any one of [1] to [3], wherein the haze of JIS K7136:2000 is 60 to 98%. [5] The antiglare film according to any one of [1] to [4], wherein the antiglare layer contains a binder resin and particles. [6] The antiglare film according to [5], wherein when the thickness of the antiglare layer is defined as T and the average particle diameter of the particles is defined as D, D / T is 0.20 to 0.96. [7] The antiglare film according to [5] or [6], wherein the average particle diameter D of the particles is 1.0 to 5.0 μm. [8] The antiglare film according to any one of [5] to [7], which contains 40 to 200 parts by mass of the particles with respect to 100 parts by mass of the binder resin. [9] The antiglare film according to any one of [5] to [8], wherein the particles are organic particles.
[10] The antiglare film according to any one of [5] to [9], wherein the antiglare layer further contains inorganic fine particles.
[11] The antiglare film according to
[10] , comprising 40 to 200 parts by mass of the inorganic fine particles per 100 parts by mass of the binder resin.
[12] The antiglare film according to any one of [5] to
[11] , wherein the binder resin comprises a cured product of an ionizing radiation curable resin composition and a thermoplastic resin.
[13] The antiglare film according to any one of [1] to
[12] , further comprising an antireflection layer on the antiglare layer, the antireflection layer having the uneven surface.
[14] An image display device comprising an antiglare film according to any one of [1] to
[13] above a display element, the uneven surface side of the antiglare film facing away from the display element, and the antiglare film as the outermost surface. Effect of the Invention
[0008] The antiglare film and image display device of the present invention have excellent antiglare properties and can suppress reflected and scattered light. [Brief description of the drawings]
[0009] [Figure 1] 1 is a schematic cross-sectional view showing one embodiment of an antiglare film of the present invention. [Diagram 2] 4 is a schematic diagram for explaining the behavior of light incident on an antiglare layer. FIG. [Diagram 3] 1 is a cross-sectional view showing an embodiment of an image display device of the present invention. [Figure 4] 10A and 10B are diagrams for explaining a method for calculating an amplitude spectrum of the elevation of an uneven surface. [Diagram 5] 10A and 10B are diagrams for explaining a method for calculating an amplitude spectrum of the elevation of an uneven surface. [Figure 6] FIG. 2 is a diagram showing the relationship between the spatial frequency and the amplitude of the antiglare film of Example 1. [Figure 7] FIG. 13 is a diagram showing the relationship between the spatial frequency and the amplitude of the antiglare film of Example 2. [Figure 8]FIG. 13 is a diagram showing the relationship between spatial frequency and amplitude of the antiglare film of Example 3. [Figure 9] FIG. 13 is a diagram showing the relationship between spatial frequency and amplitude of the antiglare film of Example 4. [Figure 10] FIG. 13 is a diagram showing the relationship between spatial frequency and amplitude of the antiglare film of Example 5. [Figure 11] FIG. 2 is a graph showing the relationship between the spatial frequency and the amplitude of the antiglare film of Comparative Example 1. [Figure 12] FIG. 13 is a diagram showing the relationship between the spatial frequency and the amplitude of the antiglare film of Comparative Example 2. [Figure 13] FIG. 13 is a diagram showing the relationship between the spatial frequency and the amplitude of the antiglare film of Comparative Example 3. [Figure 14] FIG. 13 is a diagram showing the relationship between the spatial frequency and the amplitude of the antiglare film of Comparative Example 4. [Figure 15] FIG. 13 is a graph showing the relationship between the spatial frequency and the amplitude of the antiglare film of Comparative Example 5. [Figure 16] FIG. 13 is a graph showing the relationship between the spatial frequency and the amplitude of the antiglare film of Comparative Example 6. [Figure 17] FIG. 13 is a diagram showing the relationship between spatial frequency and amplitude of the antiglare film of Example 6. [Figure 18] FIG. 13 is a diagram showing the relationship between spatial frequency and amplitude of the antiglare film of Example 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] Hereinafter, an embodiment of the present invention will be described. In this specification, the notation AA to BB means AA or more and BB or less.
[0011] [Anti-glare film] The antiglare film of the present invention is an antiglare film having an antiglare layer, the antiglare film having a rough surface, and an amplitude spectrum of the elevation of the rough surface has a spatial frequency of 0.005 μm. -1 , 0.010μm -1 , 0.015μm -1The sum of the amplitudes corresponding to AM1 and spatial frequency 0.300 μm -1 When the amplitude at is defined as AM2, AM1 is 0.070 to 0.400 μm, AM2 is 0.0050 μm or more, and AM2 <AM1である、ものである。
[0012] As mentioned above, AM1 is the sum of the amplitudes of the three spatial frequencies and is expressed by the following formula: AM1 = spatial frequency 0.005 μm -1 Amplitude + spatial frequency at 0.010μm -1 Amplitude + spatial frequency at 0.015μm -1 Amplitude in
[0013] In addition, the spatial frequency is a discrete value that depends on the length of one side, so -1 , 0.010μm -1 , 0.015μm -1 , and 0.300 μm -1 In some cases, it may not be possible to obtain a spatial frequency that matches the value. If there is no spatial frequency that matches the value, the amplitude of the spatial frequency that is closest to the value may be extracted.
[0014] FIG. 1 is a schematic cross-sectional view of the cross-sectional shape of an antiglare film 100 of the present invention. The antiglare film 100 in Fig. 1 includes an antiglare layer 20 and has an uneven surface. In Fig. 1, the surface of the antiglare layer 20 is the uneven surface of the antiglare film. The antiglare film 100 in Fig. 1 includes the antiglare layer 20 on a transparent substrate 10. The antiglare layer 20 in Fig. 1 includes a binder resin 21 and organic particles 22. Fig. 1 is a schematic cross-sectional view. That is, the scale of each layer constituting the antiglare film 100, the scale of each material, and the scale of the surface irregularities are schematic for ease of illustration and differ from the actual scale. The same applies to Figs. 2 to 4.
[0015] The antiglare film of the present invention is not limited to the laminated structure shown in Fig. 1 (a laminated structure having an antiglare layer on a transparent substrate) as long as it has an antiglare layer with uneven surfaces where AM1 is from 0.070 to 0.400 μm, AM2 is 0.0050 μm or more, and AM2 < AM1. For example, the antiglare film may have a single-layer structure of the antiglare layer, or may have layers other than the transparent substrate and the antiglare layer (e.g., an antireflection layer, an antifouling layer, etc.). When there are other layers on the antiglare layer, it is sufficient that the surface of the other layer forms the uneven surface of the antiglare film. A preferred embodiment of the antiglare film has an antiglare layer on a transparent substrate, and the surface of the antiglare layer opposite to the transparent substrate is an uneven surface.
[0016] <Transparent substrate> From the viewpoints of ease of manufacturing the antiglare film and handleability of the antiglare film, it is preferable that the antiglare film has a transparent substrate.
[0017] As the transparent substrate, those having light transmissivity, smoothness, heat resistance, and excellent mechanical strength are preferable. Examples of such transparent substrates include plastic films such as polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane, and amorphous olefin (Cyclo-Olefin-Polymer: COP). The transparent substrate may be a laminate of two or more plastic films. Among the above, from the viewpoints of mechanical strength and dimensional stability, stretched polyester, particularly biaxially stretched polyester (such as polyethylene terephthalate, polyethylene naphthalate, etc.) is preferable. TAC and acrylic are suitable from the viewpoints of light transmissivity and optical isotropy. Also, COP and polyester are suitable in terms of excellent weather resistance.
[0018] The thickness of the transparent substrate is preferably 5 to 300 μm, more preferably 20 to 200 μm, and even more preferably 30 to 120 μm. When it is desired to make the antiglare film thinner, the preferable upper limit of the thickness of the transparent substrate is 60 μm, and the more preferable upper limit is 50 μm. Further, when the transparent substrate is a low moisture permeability substrate such as polyester, COP, or acrylic, the preferable upper limit of the thickness of the transparent substrate for thinning is 40 μm, and the more preferable upper limit is 20 μm. Even in the case of a large screen, if the upper limit of the thickness of the transparent substrate is within the above-mentioned range, it is also preferable in that it can hardly cause distortion. The thickness of the transparent substrate can be measured with a digital micrometer outside the standard (Mitutoyo Corporation, product number "MDC-25SX"). The thickness of the transparent substrate only needs to be such that the average value measured at any 10 points is the above numerical value.
[0019] On the surface of the transparent substrate, physical treatments such as corona discharge treatment or chemical treatments may be performed, or an easy-adhesion layer may be formed in order to improve adhesion.
[0020] <Uneven surface> The antiglare film needs to have an uneven surface. Further, with respect to the amplitude spectrum of the elevation of the uneven surface of the antiglare film, AM1 (the sum of the amplitudes corresponding to spatial frequencies of 0.005 μm -1 , 0.010 μm -1 , 0.015 μm -1 respectively) is 0.070 to 0.400 μm, AM2 (the amplitude at a spatial frequency of 0.30 μm -1 ) is 0.0050 μm or more, and it is required that AM2 < AM1. When there is no other layer on the antiglare layer, it is only necessary that the surface of the antiglare layer satisfies the conditions of the uneven surface. In addition, when there is another layer on the antiglare layer, it is only necessary that the surface of the other layer satisfies the conditions of the uneven surface.
[0021] As used herein, the "elevation of the uneven surface" means the straight-line distance in the direction of the normal V of the antiglare film (the normal direction in the virtual plane M) between an arbitrary point P on the uneven surface and a virtual plane M having the same height at the average height of the uneven surface (the elevation is 0 μm as a reference) (see Fig. 4). When the elevation of an arbitrary point P is higher than the average height, the elevation is positive, and when the elevation of an arbitrary point P is lower than the average height, the elevation is negative. Also, as used herein, unless otherwise specified, the term "elevation" means the elevation based on the above average height.
[0022] The spatial frequency and amplitude can be obtained by performing a Fourier transform on the three-dimensional coordinate data of the uneven surface. Details of the method for calculating the spatial frequency and amplitude from the three-dimensional coordinate data of the uneven surface will be described later.
[0023] 《AM1, AM2》 Regarding the amplitude spectrum of the elevation of the uneven surface, it can be generally said that the spatial frequency correlates with "the reciprocal of the distance between the convex portions" and the amplitude correlates with "the amount of change in the elevation of the convex portions with a predetermined interval". Note that a spatial frequency of 0.005 μm -1 indicates that the interval is about 200 μm, and a spatial frequency of 0.010 μm -1 indicates that the interval is about 100 μm, and a spatial frequency of 0.015 μm -1 indicates that the interval is about 67 μm, and a spatial frequency of 0.300 μm -1 indicates that the interval is about 3 μm. Also, it can be generally said that "the amount of change in the elevation of the convex portions with a predetermined interval" is proportional to the absolute value of the individual heights of the convex portions with a predetermined interval. Therefore, it can be indirectly stated that an uneven surface in which AM1 is 0.070 to 0.400 μm, AM2 is 0.0050 μm or more, and AM2 < AM1 includes the following convex portion groups i and ii. <Convex portion group i> A plurality of convex portions i are arranged at intervals of about 67 to 200 μm, and the absolute value of the height of the convex portion i is within a predetermined range. <Convex portion group ii> A plurality of protrusions ii are arranged at intervals of approximately 3 μm, and the absolute value of the height of the protrusions ii is equal to or greater than a predetermined value and is less than the absolute value of the height of the protrusion i.
[0024] It is considered that the uneven surface having the above-mentioned convex groups i and ii can exhibit excellent antiglare properties and suppress reflected scattered light mainly for the following reasons (x1) to (x5). Hereinafter, explanation will be given with reference to FIG. 2. In FIG. 2, the convex portion with a large interval between the convex portions indicates the convex portion i. In FIG. 2, the convex portion with a small interval between the convex portions existing between the convex portions i and the convex portions with a small interval between the convex portions existing at both the left and right ends of FIG. 2 indicates the convex portion ii. In FIG. 2, the outer edge of the convex portion with a large absolute value of height is drawn with a smooth line, but the outer edge may have fine unevenness. For example, it is considered that the antiglare film of the embodiment has fine unevenness on the outer edge of the convex portion with a large absolute value of height.
[0025] In the convex group (x1)i, the interval between adjacent convex portions i is not too long, and the convex portions i have a predetermined height. Therefore, most of the reflected light reflected on the surface of any convex portion i is incident on the adjacent convex portion i. Then, the light is totally reflected repeatedly inside the adjacent convex portion i, and finally travels in the opposite direction to the observer 200 (as shown by the solid line in FIG. 2). (x2) The reflected light of light incident on the steep slope of any convex portion i travels in the opposite direction to the observer 200, regardless of the adjacent convex portion i (image of the dashed line in FIG. 2). (x3) Usually, a substantially flat portion that generates specularly reflected light is likely to be formed in the region between the convex portions i. However, in this embodiment, the convex portion group ii is formed in the region between the convex portions i, so that the proportion of specularly reflected light in the reflected light reflected in the region can be reduced. (x4) The light reflected in the region between the convex portions i is likely to collide with the adjacent mountains. Therefore, the angular distribution of the light reflected in the region is not biased toward a specific angle, but is substantially uniform. (x5) The reflected light of the light incident on the gentle slope of the convex portion i travels toward the observer 200 (illustration of the dashed line in FIG. 2). Since the angle distribution of the gentle slope of the convex portion i is uniform, the angle distribution of the reflected light is also uniform without being biased toward a specific angle.
[0026] First, from the above (x1) to (x3), it is considered that the reflected scattered light can be suppressed, and thus the antiglare property can be improved to a predetermined level. Furthermore, from the above (x4) and (x5), even if a small amount of reflected scattered light is generated, the angular distribution of the reflected scattered light can be made uniform. Even if the reflected scattered light is微量, if the angular distribution of the reflected scattered light is biased toward a specific angle, it will be recognized as reflected light. Therefore, from the above (x4) and (x5), the antiglare property can be extremely improved. Also, from the above (x1) to (x5), since the observer can hardly feel the reflected scattered light, a deep black feeling can be imparted to the antiglare film, and thus a high-class feeling can be imparted to the image display device.
[0027] When AM1 is 0.070 to 0.400 μm, AM2 is 0.0050 μm or more, and AM2 < AM1, the actions of the above (x1) to (x5) are likely to occur, the antiglare property is excellent, the reflected scattered light is suppressed, and thus it is easy to impart a deep black feeling.
[0028] From the viewpoint of facilitating the occurrence of the actions of the above (x1) to (x5), AM1 is preferably 0.090 to 0.390 μm, more preferably 0.130 to 0.380 μm, and even more preferably 0.150 to 0.370 μm. If AM is too small, the antiglare property is particularly likely to be insufficient. On the other hand, if AM1 becomes too large, the resolution of the video tends to decrease. Also, if AM1 becomes too large, the ratio of the light that is totally reflected by the uneven surface among the light (mainly video light) incident from the side opposite to the uneven surface increases, and the transmittance tends to decrease. Also, if AM1 becomes too large, the convex portions with a large absolute value of height increase, and the ratio of the light reflected to the observer side increases, and the reflected scattered light may become conspicuous. Therefore, not making AM1 too large is also suitable from the viewpoints of suppressing the decrease in resolution and transmittance and further suppressing the reflected scattered light.
[0029] From the viewpoint of facilitating the above actions (x1) to (x5), AM2 is preferably 0.0055 to 0.0550 μm, more preferably 0.0060 to 0.0500 μm, even more preferably 0.0070 to 0.0450 μm, and even more preferably 0.0080 to 0.0400 μm. However, if AM2 becomes too large, the image resolution tends to decrease. Therefore, it is preferable to not make AM2 too large in order to prevent a decrease in resolution.
[0030] In addition, in the configuration elements shown in this specification, when multiple upper limit options and multiple lower limit options are shown, one selected from the upper limit options and one selected from the lower limit options can be combined to form an embodiment of the numerical range. For example, in the case of AM1, embodiments include numerical ranges of 0.070 to 0.400 μm, 0.070 to 0.370 μm, 0.090 to 0.400 μm, 0.090 to 0.370 μm, 0.130 to 0.390 μm, 0.130 to 0.370 μm, 0.150 to 0.40 μm, and 0.150 to 0.380 μm.
[0031] In this specification, numerical values relating to the amplitude spectrum of altitudes such as AM1 and AM2, optical properties (haze, total light transmittance, etc.), and surface shape (Sa, Smp, etc.) refer to average values of measurements at 16 points. In this specification, the 16 measurement points are preferably centered on 16 intersections of lines drawn from the outer edge of the measurement sample, dividing the inner area of the margin into 5 equal parts vertically and horizontally, with a margin of 1 cm from the outer edge of the measurement sample. For example, when the measurement sample is rectangular, it is preferable to measure the 16 intersections of dotted lines dividing the inner area of the margin into 5 equal parts vertically and horizontally, with a margin of 1 cm from the outer edge of the rectangle, and calculate the parameters from the average value. In addition, when the measurement sample is a shape other than a rectangle, such as a circle, an ellipse, a triangle, or a pentagon, it is preferable to draw a rectangle inscribed in these shapes and measure 16 points on the rectangle using the above method.
[0032] In this specification, various parameters such as numerical values related to the amplitude spectrum of altitudes such as AM1 and AM2, optical properties (haze, total light transmittance, etc.), and surface shape (Sa, Smp, etc.) are measured at a temperature of 23±5°C and a humidity of 40 to 65%, unless otherwise specified. Furthermore, before starting each measurement, the target sample is exposed to the above atmosphere for 30 minutes or more before the measurement is performed.
[0033] In this embodiment, AM1 is the sum of the amplitudes of three spatial frequencies. That is, AM1 takes into account three intervals as the intervals between the convex portions. In this embodiment, since AM1 takes into account multiple intervals, it is easy to suppress an increase in reflected light caused by the convex portions being spaced apart.
[0034] In this embodiment, the spatial frequency is 0.005 μm -1 , 0.010μm -1 , 0.015μm -1 When the average of the amplitudes corresponding to the above is defined as AM1ave, AM1ave is preferably 0.023 to 0.133 μm, more preferably 0.030 to 0.130 μm, further preferably 0.043 to 0.127 μm, and even more preferably 0.050 to 0.123 μm. AM1ave can be expressed by the following formula. AM1ave = (spatial frequency 0.005 μm -1 Amplitude + spatial frequency at 0.010μm -1 Amplitude + spatial frequency at 0.015μm -1 (amplitude at
[0035] In this embodiment, the spatial frequency is 0.005 μm -1 The amplitude corresponding to AM1-1 is 0.010 μm -1 The amplitude corresponding to AM1-2 is 0.015 μm -1When the amplitude corresponding to is defined as AM1-3, it is preferable that AM1-1, AM1-2, and AM1-3 are in the following ranges. By setting AM1-1, AM1-2, and AM1-3 in the following ranges, it is possible to easily prevent the intervals between the convex portions from becoming uniform, and therefore it is possible to easily prevent an increase in reflected light. AM1-1 is preferably 0.020 to 0.150 μm, more preferably 0.030 to 0.140 μm, even more preferably 0.040 to 0.130 μm, and even more preferably 0.050 to 0.120 μm. AM1-2 is preferably 0.020 to 0.145 μm, more preferably 0.030 to 0.135 μm, even more preferably 0.040 to 0.125 μm, and even more preferably 0.050 to 0.120 μm. AM1-3 is preferably 0.020 to 0.145 μm, more preferably 0.030 to 0.135 μm, even more preferably 0.040 to 0.125 μm, and even more preferably 0.050 to 0.120 μm.
[0036] In the antiglare film of the present invention, from the viewpoint of achieving a good balance between the convex portions having different periods and facilitating the above-mentioned actions (x1) to (x5), AM1 / AM2 is preferably from 1.0 to 60.0, more preferably from 2.0 to 50.0, even more preferably from 3.0 to 40.0, and even more preferably from 4.0 to 30.0.
[0037] -Calculation method for AM1 and AM2- In this specification, AM1 refers to the amplitude spectrum of the elevation of a rough surface with a spatial frequency of 0.005 μm -1 , 0.010μm -1 , 0.015μm -1 AM2 means the sum of the amplitudes corresponding to the spatial frequency 0.300 μm -1 The calculation method of AM1 and AM2 will be explained below.
[0038] First, as described above, in this specification, the "elevation of the uneven surface" means the straight-line distance in the direction of the normal V of the anti-glare film (the normal direction to the above-mentioned imaginary plane M) between any point P on the uneven surface and an imaginary plane M having that height at the average height of the uneven surface (the elevation is 0 μm as a reference) (see Figure 4).
[0039] If the Cartesian coordinates within the uneven surface of the anti-glare film are expressed as (x, y), the elevation of the uneven surface of the anti-glare film can be expressed as a two-dimensional function h(x, y) of the coordinates (x, y).
[0040] The elevation of the uneven surface is preferably measured using an interference microscope, such as Zygo's "New View" series. The horizontal resolution required for the measuring device is at least 5 μm or less, preferably 1 μm or less, and the vertical resolution is at least 0.01 μm or less, preferably 0.001 μm or less. The elevation measurement area has a spatial frequency resolution of 0.0050μm -1 Considering this, it is preferable that the size is at least 200 μm×200 μm or more.
[0041] Next, a method for calculating the amplitude spectrum of altitude from the two-dimensional function h(x,y) will be described. First, the amplitude spectrum Hx(fx) in the x direction and the amplitude spectrum Hy(fy) in the y direction are calculated from the two-dimensional function h(x,y) by the Fourier transform defined by the following equations (1a) and (1b).
[0042]
number
[0043] Here, fx and fy are the frequencies in the x and y directions, respectively, and have the dimension of the reciprocal of length. In addition, in equations (1a) and (1b), π is the circular constant, and i is the imaginary unit. The amplitude spectrum H(f) can be obtained by averaging the obtained amplitude spectrum Hx(fx) in the x direction and the amplitude spectrum Hy(fy) in the y direction. This amplitude spectrum H(f) represents the spatial frequency distribution of the uneven surface of the anti-glare film.
[0044] The method for determining the amplitude spectrum H(f) of the elevation of the uneven surface of the antiglare film will be described in more detail below. The three-dimensional information of the surface shape actually measured by the above-mentioned interference microscope is generally obtained as discrete values, i.e., elevations corresponding to a number of measurement points. Fig. 5 is a schematic diagram showing how the function h(x,y) representing the elevation can be obtained discretely. As shown in Fig. 5, the orthogonal coordinates within the antiglare layer are represented by (x,y), and the lines dividing the x-axis direction by Δx and the lines dividing the y-axis direction by Δy are shown by dashed lines on the projection plane Sp. In actual measurements, the elevation of the uneven surface is obtained as a discrete elevation value at each intersection of the dashed lines on the projection plane Sp.
[0045] The number of elevation values that can be obtained is determined by the measurement range, Δx, and Δy. As shown in Figure 5, if the measurement range in the x-axis direction is X = (M-1)Δx and the measurement range in the y-axis direction is Y = (N-1)Δy, the number of elevation values that can be obtained is M × N.
[0046] As shown in Figure 5, if the coordinates of point A of interest on the projection surface Sp are (jΔx, kΔy) (where j is 0 to M-1, and k is 0 to N-1), the elevation of point P on the uneven surface corresponding to point A of interest can be expressed as h(jΔx, kΔy).
[0047] Here, the measurement intervals Δx and Δy depend on the horizontal resolution of the measuring device, and in order to accurately evaluate a finely uneven surface, as described above, both Δx and Δy are preferably 5 μm or less, more preferably 2 μm or less, and the measurement ranges X and Y are preferably 200 μm or more, as described above.
[0048] In this way, in actual measurements, the function representing the elevation of the uneven surface is obtained as a discrete function h(x,y) having M×N values. By performing a discrete Fourier transform on the discrete function h(x,y) obtained by measurement in the x direction and the y direction, respectively, defined by the following formulas (2a) and (2b), N discrete functions Hx(fx) and M discrete functions Hy(fy) are obtained, and by calculating their absolute values (=amplitudes) using the following formula (2c), and averaging all of them, the amplitude spectrum H(f) is obtained. Note that in this specification, M=N and Δx=Δy. In the following formulas (2a) to (2c), "l" is an integer not less than -M / 2 and not more than M / 2, and "m" is an integer not less than -N / 2 and not more than N / 2. Also, Δfx and Δfy are frequency intervals in the x direction and the y direction, respectively, and are defined by the following formulas (3) and (4).
[0049]
number
[0050]
number
[0051]
number
[0052] The discrete function H(f) of the amplitude spectrum calculated as above represents the spatial frequency distribution of the uneven surface of the antiglare film. Figures 6 to 18 show the discrete functions H(f) of the amplitude spectrum of the elevation of the uneven surface of Examples 1 to 7 and Comparative Examples 1 to 6. In the figures, the horizontal axis represents the spatial frequency (unit: μm -1 "), and the vertical axis indicates amplitude (unit: "μm").
[0053] Sa, Smp The uneven surface of the antiglare film preferably has a three-dimensional arithmetic mean roughness Sa of 0.30 μm or more. The uneven surface of the antiglare film preferably has a three-dimensional mean mountain spacing Smp of 10.00 μm or less. By setting Sa and Smp in the above ranges, it becomes easier to obtain an uneven surface with high mountains at narrow intervals, and it becomes easier to set AM1 and AM2 in the above ranges.
[0054] Sa is preferably 0.40 μm or more, more preferably 0.50 μm or more, and even more preferably 0.55 μm or more. Furthermore, Sa is preferably 1.00 μm or less, more preferably 0.80 μm or less, and even more preferably 0.70 μm or less.
[0055] Smp is preferably 8.00 μm or less, more preferably 6.00 μm or less, even more preferably 4.50 μm or less, and even more preferably 3.50 μm or less. Also, Smp is preferably 1.00 μm or more, more preferably 1.50 μm or more, and even more preferably 2.00 μm or more.
[0056] The uneven surface of the antiglare film preferably has Sa / Smp of 0.05 or more, more preferably 0.10 or more, and even more preferably 0.13 or more. By making Sa / Smp 0.05 or more, the uneven surface of the antiglare layer can be made more likely to have high mountains at close intervals, and AM1 and AM2 can be made to fall within the above ranges. Furthermore, Sa / Smp is preferably 0.50 or less, more preferably 0.40 or less, and even more preferably 0.25 or less.
[0057] 《Sz / Sa》 In the antiglare film of the present invention, the ratio (Sz / Sa) of the three-dimensional ten-point average roughness Sz of the uneven surface to Sa is preferably 5.0 or more, more preferably 5.5 or more, and even more preferably 6.0 or more. By making Sz / Sa 5.0 or more, a certain degree of randomness is imparted to the uneven surface, and defects such as scratches on the uneven surface can be made less noticeable. If Sz / Sa is too large, there is a possibility that glare (a phenomenon in which minute variations in brightness are seen in the image light) will occur due to the presence of specific locations on the uneven surface, or that the feeling of jet blackness will be locally reduced. For this reason, Sz / Sa is preferably 10.0 or less, more preferably 8.0 or less, and even more preferably 7.5 or less.
[0058] 《Ssk》 The antiglare film of the present invention has a three-dimensional skewness Ssk of the uneven surface of preferably 0.60 or less, more preferably 0.20 or less, and even more preferably 0 or less. A small Ssk means that the uneven surface has a small proportion of low altitude areas where regular reflection can occur. Therefore, by making the Ssk 0.60 or less, the above-mentioned effects (antiglare properties, suppression of reflected and scattered light, and jet black feeling) can be more easily exhibited. If Ssk becomes too small, the reflected and scattered light tends to increase due to the effect of (x5) above. Also, if Ssk becomes too small, the lower parts of adjacent peaks may overlap, the slopes with large angles may disappear, and the effect of (x2) above may decrease. For this reason, Ssk is preferably -1.00 or more, more preferably -0.80 or more, and even more preferably -0.70 or more.
[0059] Ssk is an index that indicates the degree of positive and negative bias in the elevation distribution, based on the average elevation of the entire measurement surface. If the elevation distribution is normal, Ssk indicates 0. If the elevation distribution is negatively biased, Ssk indicates a positive value, and the greater the degree of negative bias, the larger the positive Ssk value becomes. On the other hand, if the elevation distribution is positively biased, Ssk indicates a negative value, and the greater the degree of positive bias, the larger the negative Ssk value becomes.
[0060] 《Tilt angle》 The uneven surface of the antiglare film preferably has a predetermined inclination angle distribution. Specifically, regarding the inclination angle of the uneven surface of the antiglare film, an inclination angle of more than 0 degrees and less than 1 degree is defined as θ1, an inclination angle of 1 degree or more and less than 3 degrees is defined as θ2, an inclination angle of 3 degrees or more and less than 10 degrees is defined as θ3, and an inclination angle of 10 degrees or more and less than 90 degrees is defined as θ4. When the total of θ1, θ2, θ3, and θ4 is taken as 100%, it is preferable that the proportions of θ1, θ2, θ3, and θ4 are in the following ranges. By having θ1, θ2, θ3, and θ4 in the following ranges, it is possible to easily set AM1 and AM2 in the above ranges. θ1≦3.0% 0.5%≦θ2≦15.0% 7.0%≦θ3≦40.0% 50.0%≦θ4≦90.0%
[0061] The ratio of θ1 is more preferably 2.0% or less, further preferably 1.5% or less, and even more preferably 1.2% or less. The lower limit of the ratio of θ1 is not particularly limited, but is usually 0.1% or more. The ratio of θ2 is more preferably 12.0% or less, further preferably 10.0% or less, and even more preferably 8.0% or less. The lower limit of the ratio of θ2 is more preferably 1.0% or more, further preferably 1.5% or more, and even more preferably 2.0% or more. The ratio of θ3 is more preferably 8.5% or more, even more preferably 10.0% or more, and even more preferably 12.0% or more. Also, the ratio of θ3 is more preferably 35.0% or less, even more preferably 32.0% or less, and even more preferably 30.0% or less. The ratio of θ4 is more preferably 55.0% or more, even more preferably 57.5% or more, and even more preferably 60.0% or more. The ratio of θ4 is more preferably 88.0% or less, even more preferably 86.5% or less, and even more preferably 85.0% or less.
[0062] In this specification, the three-dimensional arithmetic mean roughness Sa is a three-dimensional extension of the two-dimensional roughness parameter Ra described in JIS B0601:1994, and is calculated by the following formula (i) where A=Lx×Ly, where X and Y axes are orthogonal coordinate axes placed on a reference plane, Z(x,y) is the roughness curve, and Lx and Ly are the size of the reference plane.
[0063]
number
[0064] In this specification, the three-dimensional average peak spacing Smp is calculated as follows: If a portion of the three-dimensional roughness surface that is higher than the reference surface and surrounded by one area is defined as one peak, the number of peaks is defined as Ps, and the area of the entire measurement area (reference surface) is defined as A, Smp is calculated by the following formula (ii).
[0065]
number
[0066] In this specification, the three-dimensional ten-point average roughness Sz is a three-dimensional extension of the ten-point average roughness Rz, which is a two-dimensional roughness parameter described in JIS B0601:1994. A large number of straight lines passing through the center of the reference surface are placed radially through 360 degrees so as to cover the entire area, and a cross-sectional curve is obtained by cutting the three-dimensional roughness surface based on each straight line, and the ten-point average roughness (the sum of the average of the heights of the top five peaks from the highest peak and the average of the depths of the top five valleys from the deepest valley) of the cross-sectional curve is calculated. Sz is calculated by averaging the top 50% of the many ten-point average roughnesses thus obtained.
[0067] In this specification, the three-dimensional skewness Ssk is a three-dimensional extension of the roughness curve skewness Rsk, a two-dimensional roughness parameter described in JIS B0601:1994, and is calculated by the following formula (iii) where the orthogonal coordinate axes X and Y are placed on a reference surface, the measured surface shape curve is z=f(x,y), and the size of the reference surface is Lx,Ly. In formula (iii), "Sq" is the root mean square deviation of the surface height distribution defined by the following formula (iv).
[0068]
number
[0069]
number
[0070] In this specification, the distribution of the inclination angles of the uneven surface can be calculated from a three-dimensional roughness curve. The data of the three-dimensional roughness curve is expressed by points arranged in a lattice pattern at intervals of d on a reference surface (the horizontal direction is the x-axis and the vertical direction is the y-axis), and the heights at the positions of the points. The height at the position of the i-th point in the x-axis direction and the j-th point in the y-axis direction (hereinafter referred to as (i,j)) is Z i,j Then, at an arbitrary position (i, j), the tilt Sx in the x-axis direction with respect to the x-axis and the tilt Sy in the y-axis direction with respect to the y-axis are calculated as follows: Sx = (Z i+1,j -Z i-1,j ) / 2d Sy = (Z i,j+1 -Z i,j-1 ) / 2d Furthermore, the inclination St at (i, j) with respect to the reference plane is calculated as the following formula (v).
[0071]
number
[0072] And the inclination angle at (i,j) is tan -1 By performing the above calculation for each point, the inclination angle distribution of the three-dimensional roughness surface can be calculated.
[0073] The above Sa, Smp, and tilt angle distribution are preferably measured using an interference microscope. Examples of such interference microscopes include the "New View" series by Zygo. In addition, by using the measurement and analysis application software "MetroPro" that comes with the above-mentioned interference microscope "New View" series, Sa, Smp, and tilt angle distribution can be easily calculated.
[0074] <Anti-glare layer> The antiglare layer is a layer that plays a central role in suppressing reflected and scattered light and providing antiglare properties.
[0075] <<Method for forming anti-glare layer>> The antiglare layer can be formed, for example, by (A) a method using an embossing roll, (B) an etching treatment, (C) molding with a mold, (D) formation of a coating film by coating, etc. Among these methods, (C) molding with a mold is preferred from the viewpoint of facilitating obtaining a stable surface shape, and (D) formation of a coating film by coating is preferred from the viewpoints of productivity and compatibility with a wide variety of products. When forming a coating film (antiglare layer) by coating, for example, there are (d1) a method of coating a coating liquid containing a binder resin and particles to form unevenness by the particles, and (d2) a method of coating a coating liquid containing an arbitrary resin and a resin having poor compatibility with the resin to cause phase separation of the resin to form unevenness. (d1) is preferable to (d2) in that it is easier to achieve a good balance between AM1 and AM2. In addition, (d1) is preferable to (d2) in that it is easier to suppress the variation in Sa and Smp.
[0076] Thickness The thickness T of the antiglare layer is preferably from 2 to 10 μm, and more preferably from 4 to 8 μm, from the viewpoint of a balance between curl suppression, mechanical strength, hardness and toughness. The thickness of the antiglare layer can be calculated, for example, by averaging 20 arbitrary points selected from a cross-sectional photograph of the antiglare film taken by a scanning transmission electron microscope (STEM). The acceleration voltage of the STEM is preferably 10 kv to 30 kV, and the magnification of the STEM is preferably 1000 to 7000 times.
[0077] "component" The antiglare layer mainly contains a resin component, and optionally contains additives such as particles such as organic particles and inorganic fine particles, a refractive index adjuster, an antistatic agent, an antifouling agent, an ultraviolet absorber, a light stabilizer, an antioxidant, a viscosity adjuster, and a thermal polymerization initiator. The antiglare layer preferably contains a binder resin and particles. The particles include organic particles and inorganic particles, and organic particles are preferred. That is, the antiglare layer more preferably contains a binder resin and organic particles.
[0078] -particle- Examples of organic particles include particles made of polymethyl methacrylate, polyacrylic-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, silicone, fluorine-based resin, polyester-based resin, etc. Examples of inorganic particles include silica, alumina, zirconia, titania, etc., with silica being preferred. Since organic particles have a low specific gravity, when used in combination with inorganic fine particles described later, the organic particles tend to float near the surface of the antiglare layer. Therefore, when organic particles and inorganic fine particles are used in combination, the organic particles tend to form long-period irregularities, and the inorganic fine particles tend to form short-period irregularities, making it easier to make AM1 and AM2 within the above-mentioned range. In addition, when the organic particles tend to float near the surface of the antiglare layer, it makes it easier to make the surface shape of Sa, Smp, etc. within the above-mentioned range. When only organic particles are used as particles, it is preferable to increase the content of organic particles in the antiglare layer in order to make AM1 and AM2 fall within the above-mentioned range. By increasing the content of organic particles in the antiglare layer, the organic particles are spread over the entire surface, forming short-period irregularities (AM2) due to the organic particles, and further, a shape in which the organic particles are stacked in layers is partially formed in the shape in which the organic particles are spread over the entire surface, thereby forming long-period irregularities (AM1). In addition, the shape in which the organic particles are spread over the entire surface makes it easier to reduce Smp. Furthermore, the shape in which the organic particles are spread over the entire surface makes it easier to increase Sa, by partially forming a shape in which the organic particles are stacked in layers in the shape in which the organic particles are spread over the entire surface.
[0079] The average particle size D of particles such as organic particles and inorganic particles is preferably from 1.0 to 5.0 μm, more preferably from 1.5 to 3.5 μm, and even more preferably from 1.7 to 2.5 μm. By making the average particle diameter D 1.0 μm or more, it is possible to easily prevent AM1 from becoming too small and to easily make Sa 0.30 μm or more. Also, by making the average particle diameter D 5.0 μm or less, it is possible to easily prevent AM1 from becoming too large and to easily make Smp 10.00 μm or less.
[0080] The average particle size of particles such as organic particles and inorganic particles can be calculated by the following steps (A1) to (A3). (A1) The antiglare film is subjected to a transmission observation image taken with an optical microscope, preferably at a magnification of 500 to 2000 times. (A2) Randomly extract 10 particles from the observed image, and calculate the particle diameter of each particle. The particle diameter is measured as the distance between two parallel lines that is the maximum distance between the two lines when the cross section of the particle is sandwiched between the two lines. (A3) The same procedure is carried out five times on a separate observation image of the same sample, and the value obtained from the number average of the particle diameters of a total of 50 particles is regarded as the average particle diameter of the particles.
[0081] The ratio (D / T) of the thickness T of the antiglare layer to the average particle diameter D of the particles is preferably 0.20 to 0.96, more preferably 0.25 to 0.90, even more preferably 0.30 to 0.80, and even more preferably 0.35 to 0.70. By setting D / T in the above range, it becomes easier to set AM1 and AM2 in the above range. Furthermore, by setting D / T in the above range, it becomes easier to set the height of the peaks and the interval between the peaks of the uneven surface in an appropriate range, and it becomes easier to set the surface shape such as Sa and Smp in the above range.
[0082] The content of particles such as organic particles and inorganic particles is preferably 40 to 200 parts by mass, more preferably 55 to 170 parts by mass, and further preferably 60 to 150 parts by mass, based on 100 parts by mass of the binder resin. By making the particle content 40 parts by mass or more, it is easy to prevent AM1 from becoming too small. Also, by making the particle content 40 parts by mass or more, it is easy to make Sa 0.30 μm or more and Smp 10.00 μm or less. Also, by making the particle content 200 parts by mass or less, it is easy to prevent AM1 from becoming too large and easy to prevent particles from falling off from the antiglare layer. Note that, when inorganic fine particles described later are not used, in order to develop the above-mentioned "stacked" structure, it is preferable that the particle content is a relatively large amount within the above range.
[0083] -Inorganic fine particles- The antiglare layer preferably contains inorganic fine particles in addition to the binder resin and the particles, and more preferably contains inorganic fine particles in addition to the binder resin and the organic particles. By including inorganic fine particles in the antiglare layer, organic particles having a relatively low specific gravity tend to rise to the surface of the antiglare layer. Furthermore, by including inorganic fine particles in the antiglare layer, fine irregularities based on inorganic fine particles tend to be formed between the protrusions based on organic particles. As a result, AM1 and AM2 can be easily set to the above-mentioned range. Furthermore, by including organic particles tend to rise to the surface of the antiglare layer, the surface shape of Sa, Smp, etc. can be easily set to the above-mentioned range. Furthermore, by including inorganic fine particles in the antiglare layer, the difference between the refractive index of the organic particles and the refractive index of the composition other than the organic particles in the antiglare layer becomes smaller, which makes it easier to reduce internal haze.
[0084] Examples of inorganic fine particles include fine particles made of silica, alumina, zirconia, titania, etc. Among these, silica is preferable because it is easy to suppress the generation of internal haze.
[0085] The average particle size of the inorganic fine particles is preferably from 1 to 200 nm, more preferably from 2 to 100 nm, and further preferably from 5 to 50 nm.
[0086] The average particle size of the inorganic fine particles can be calculated by the following steps (B1) to (B3). (B1) The cross section of the antiglare film is imaged by TEM or STEM. The acceleration voltage of the TEM or STEM is preferably 10 kV to 30 kV, and the magnification is preferably 50,000 to 300,000. (B2) Randomly extract 10 inorganic microparticles from the observed image, and calculate the particle diameter of each inorganic microparticle. The particle diameter is measured as the distance between two parallel lines that is the maximum distance between the two lines when the cross section of the inorganic microparticle is sandwiched between the two lines. (B3) The same procedure is repeated five times on a separate observation image of the same sample, and the value obtained from the number average of the particle sizes of a total of 50 particles is regarded as the average particle size of the inorganic fine particles.
[0087] The content of the inorganic fine particles is preferably 40 to 200 parts by mass, more preferably 50 to 150 parts by mass, and further preferably 60 to 100 parts by mass, relative to 100 parts by mass of the binder resin. By setting the content of inorganic fine particles to 40 parts by mass or more, the above-mentioned effects based on the inorganic fine particles can be easily obtained, and by setting the content of inorganic fine particles to 200 parts by mass or less, the decrease in coating strength of the antiglare layer can be easily suppressed.
[0088] - Binder resin - From the viewpoint of improving mechanical strength, the binder resin preferably contains a cured product of a curable resin such as a cured product of a thermosetting resin composition or a cured product of an ionizing radiation curable resin composition, and more preferably contains a cured product of an ionizing radiation curable resin composition.
[0089] The thermosetting resin composition is a composition that contains at least a thermosetting resin, and is a resin composition that is cured by heating. Examples of the thermosetting resin include acrylic resin, urethane resin, phenol resin, urea melamine resin, epoxy resin, unsaturated polyester resin, silicone resin, etc. In the thermosetting resin composition, a curing agent is added to the curable resin as required.
[0090] The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter, also referred to as "ionizing radiation curable compound"). Examples of the ionizing radiation curable functional group include ethylenically unsaturated bond groups such as (meth)acryloyl group, vinyl group, and allyl group, as well as epoxy group and oxetanyl group. As the ionizing radiation curable compound, a compound having an ethylenically unsaturated bond group is preferred, a compound having two or more ethylenically unsaturated bond groups is more preferred, and among them, a polyfunctional (meth)acrylate-based compound having two or more ethylenically unsaturated bond groups is even more preferred. As the polyfunctional (meth)acrylate-based compound, either a monomer or an oligomer can be used. Here, ionizing radiation refers to electromagnetic waves or charged particle beams that have an energy quantum capable of polymerizing or crosslinking molecules. Usually, ultraviolet rays (UV) or electron beams (EB) are used, but other types of radiation, such as electromagnetic waves such as X-rays and gamma rays, and charged particle beams such as alpha rays and ion beams, can also be used.
[0091] Among the polyfunctional (meth)acrylate compounds, examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxydiacrylate, bisphenol A tetrapropoxydiacrylate, and 1,6-hexanediol diacrylate. Examples of trifunctional or higher (meth)acrylate monomers include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and isocyanuric acid-modified tri(meth)acrylate. The (meth)acrylate monomer may have a part of its molecular skeleton modified, and may be modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol, or the like.
[0092] Examples of the polyfunctional (meth)acrylate oligomer include acrylate polymers such as urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate. The urethane (meth)acrylate can be obtained, for example, by reacting a polyhydric alcohol and an organic diisocyanate with a hydroxy (meth)acrylate. In addition, preferred epoxy (meth)acrylates are (meth)acrylates obtained by reacting a tri- or higher functional aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with (meth)acrylic acid, (meth)acrylates obtained by reacting a di- or higher functional aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with a polybasic acid and (meth)acrylic acid, and (meth)acrylates obtained by reacting a di- or higher functional aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, or the like with a phenol and (meth)acrylic acid.
[0093] In addition, a monofunctional (meth)acrylate may be used in combination as an ionizing radiation curable compound for the purpose of adjusting the viscosity of the antiglare layer coating solution, etc. Examples of the monofunctional (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and isobornyl (meth)acrylate. The above ionizing radiation curable compounds may be used alone or in combination of two or more.
[0094] When the ionizing radiation curable compound is an ultraviolet ray curable compound, the ionizing radiation curable composition preferably contains additives such as a photopolymerization initiator and a photopolymerization accelerator. The photopolymerization initiator may be one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler's ketone, benzoin, benzyl dimethyl ketal, benzoyl benzoate, α-acyloxime ester, thioxanthones, and the like. The photopolymerization accelerator can reduce polymerization inhibition caused by air during curing and increase the curing speed, and examples of the accelerator include one or more types selected from p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, etc.
[0095] When the binder resin contains a cured product of an ionizing radiation curable resin composition, it preferably has the following structure (C1) or (C2).
[0096] The (C1) binder resin contains a thermoplastic resin in addition to a cured product of an ionizing radiation curable resin composition. (C2) The binder resin contains substantially only a cured product of an ionizing radiation curable resin composition, and the ionizing radiation curable compound contained in the ionizing radiation curable resin composition contains substantially only a monomer component.
[0097] In the case of the embodiment C1, the viscosity of the antiglare layer coating solution is increased by the thermoplastic resin, so that the organic particles are less likely to sink, and furthermore, the binder resin is less likely to flow down between the protrusions based on the organic particles. Therefore, in the case of the embodiment C1, it is easy to prevent AM1 and AM2 from becoming too small, and it is easy to make the surface shape of Sa, Smp, etc. within the above range.
[0098] Examples of thermoplastic resins include polystyrene-based resins, polyolefin-based resins, ABS resins (including heat-resistant ABS resins), AS resins, AN resins, polyphenylene oxide-based resins, polycarbonate-based resins, polyacetal-based resins, acrylic-based resins, polyethylene terephthalate-based resins, polybutylene terephthalate-based resins, polysulfone-based resins, and polyphenylene sulfide-based resins, with acrylic resins being preferred from the viewpoint of transparency.
[0099] The weight average molecular weight of the thermoplastic resin is preferably from 20,000 to 200,000, more preferably from 30,000 to 150,000, and even more preferably from 50,000 to 100,000. In this specification, the weight average molecular weight is an average molecular weight measured by GPC analysis and converted into standard polystyrene.
[0100] In the above embodiment C1, the mass ratio of the cured product of the ionizing radiation curable resin composition to the thermoplastic resin is preferably 60:40 to 90:10, and more preferably 70:30 to 80:20. By making the ratio of the thermoplastic resin to the cured product of the ionizing radiation curable resin composition 90 or more, the effect of increasing the viscosity of the antiglare layer coating liquid described above can be easily achieved. Also, by making the ratio of the thermoplastic resin to the cured product of the ionizing radiation curable resin composition 60 or less, it is possible to easily prevent the mechanical strength of the antiglare layer from decreasing.
[0101] In the case of the embodiment of C2, the organic particles are spread on the bottom of the antiglare layer, and in some regions, the organic particles are stacked, and the organic particles tend to be covered with a thin-skin-like binder resin. In the embodiment of C2, the stacked organic particles form a long-period unevenness (AM1), and the non-stacked organic particles form a short-period unevenness (AM2) between the long-period unevenness. Therefore, in the embodiment of C2, AM1 and AM2 can be easily set in the above range. In addition, in the embodiment of C2, the stacked organic particles can easily set Sa in the above range, and the spread organic particles can easily set Smp in the above range. In addition, in the embodiment of C2, in order to easily form the shape, it is preferable to make the content of the organic particles to the binder resin larger than that of the embodiment of C1.
[0102] In the above C2, the proportion of the cured product of the ionizing radiation curable resin composition relative to the total amount of the binder resin is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass. In the above C2, the ratio of the monomer component to the total amount of the ionizing radiation curable compound is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass. The monomer component is preferably a polyfunctional (meth)acrylate compound.
[0103] A solvent is usually used in the coating solution for the antiglare layer to adjust the viscosity and to make each component soluble or dispersible. Since the surface shape of the antiglare layer after coating and drying varies depending on the type of solvent, it is preferable to select the solvent in consideration of the saturated vapor pressure of the solvent, the permeability of the solvent into the transparent substrate, etc. Specifically, examples of the solvent include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), cyclohexanone, etc.), ethers (dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (isopropanol, butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), glycol ethers (propylene glycol monomethyl ether acetate, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), and mixtures of these may also be used.
[0104] The solvent in the coating solution for the antiglare layer is preferably a solvent with a high evaporation rate as a main component. By increasing the evaporation rate of the solvent, the organic particles are prevented from settling to the bottom of the antiglare layer, and the binder resin is less likely to flow down between the protrusions based on the organic particles. Therefore, by increasing the evaporation rate of the solvent, AM1 and AM2 can be easily adjusted to the above range, and the surface shape of Sa, Smp, etc. can be easily adjusted to the above range. The term "main component" means that the solvent accounts for 50% by mass or more of the total amount of the solvent, preferably 70% by mass or more, and more preferably 80% by mass or more.
[0105] In this specification, a solvent having a fast evaporation rate means a solvent having an evaporation rate of 100 or more, assuming that the evaporation rate of butyl acetate is 100. The evaporation rate of a solvent having a fast evaporation rate is more preferably 120 to 300, and further preferably 150 to 220. Examples of solvents with a fast evaporation rate include methyl isobutyl ketone (evaporation rate 160), toluene (evaporation rate 200), and methyl ethyl ketone (evaporation rate 370).
[0106] The solvent in the antiglare layer coating solution preferably contains a small amount of a solvent having a slow evaporation rate in addition to a solvent having a fast evaporation rate. By containing a solvent having a slow evaporation rate, the organic particles are appropriately aggregated, the area ratio of the convex parts based on the organic particles in the uneven surface is in an appropriate range, and it is easy to make AM1 and AM2 in the above range, and it is easy to make the surface shape such as Sa and Smp in the above range. The mass ratio of the solvent having a fast evaporation rate to the solvent having a slow evaporation rate is preferably from 99:1 to 80:20, and more preferably from 98:2 to 85:15.
[0107] In this specification, a solvent having a slow evaporation rate means a solvent having an evaporation rate of less than 100, where the evaporation rate of butyl acetate is taken as 100. The evaporation rate of a solvent having a fast evaporation rate is more preferably 20 to 60, and further preferably 25 to 40. Examples of solvents with slow evaporation rates include cyclohexanone (evaporation rate 32) and propylene glycol monomethyl ether acetate (evaporation rate 44).
[0108] When the antiglare layer is formed from the coating liquid for the antiglare layer, it is preferable to control the drying conditions. The drying conditions can be controlled by the drying temperature and the wind speed in the dryer. Specifically, the drying temperature is preferably 30 to 120° C., and the drying wind speed is preferably 0.2 to 50 m / s. In order to control the surface shape of the antiglare layer by drying, it is preferable to irradiate the antiglare layer with ionizing radiation after drying the coating solution.
[0109] <Optical properties> The antiglare film preferably has a total light transmittance according to JIS K7361-1:1997 of 70% or more, more preferably 80% or more, and even more preferably 85% or more. The light incident surface when measuring the total light transmittance and the haze described below is the side opposite to the uneven surface.
[0110] The antiglare film preferably has a haze according to JIS K7136:2000 of 60 to 98%, more preferably 66 to 86%, and even more preferably 70 to 80%. By setting the haze to 60% or more, it is possible to easily improve antiglare properties, and by setting the haze to 98% or less, it is possible to easily suppress a decrease in image resolution.
[0111] In order to facilitate good image resolution and contrast, the antiglare film preferably has an internal haze of 20% or less, more preferably 15% or less, and even more preferably 10% or less. The internal haze can be measured by a general-purpose method, for example, by laminating a transparent sheet onto the uneven surface via a transparent adhesive layer, thereby smoothing out the unevenness of the uneven surface.
[0112] <Other layers> The antiglare film may have layers other than the antiglare layer and the transparent substrate described above. Examples of the other layers include an antireflection layer, an antifouling layer, and an antistatic layer. A preferred embodiment having other layers includes an embodiment having an antireflection layer on the uneven surface of the antiglare layer, the surface of the antireflection layer being the uneven surface. It is more preferred that the antireflection layer has antifouling properties. That is, a more preferred embodiment has an antifouling antireflection layer on the antiglare layer, the surface of the antifouling antireflection layer being the uneven surface.
[0113] 《Anti-reflection layer》 Examples of the antireflection layer include a single-layer structure of a low refractive index layer, a two-layer structure of a high refractive index layer and a low refractive index layer, and a multi-layer structure of three or more layers. The low refractive index layer and the high refractive index layer can be formed by a general-purpose wet method or dry method. In the case of the wet method, the single-layer structure or two-layer structure is preferable, and in the case of the dry method, the multi-layer structure is preferable.
[0114] --Single-layer or two-layer structure-- The single layer structure or the two layer structure is preferably formed by a wet method. The low refractive index layer is preferably disposed on the outermost surface of the antiglare film. When the antireflection layer is to be provided with antifouling properties, it is preferable that the low refractive index layer contains an antifouling agent such as a silicone-based compound or a fluorine-based compound.
[0115] The lower limit of the refractive index of the low refractive index layer is preferably 1.10 or more, more preferably 1.20 or more, more preferably 1.26 or more, more preferably 1.28 or more, and more preferably 1.30 or more, and the upper limit is preferably 1.48 or less, more preferably 1.45 or less, more preferably 1.40 or less, more preferably 1.38 or less, and more preferably 1.32 or less.
[0116] The lower limit of the thickness of the low refractive index layer is preferably 80 nm or more, more preferably 85 nm or more, and more preferably 90 nm or more, and the upper limit is preferably 150 nm or less, more preferably 110 nm or less, and more preferably 105 nm or less.
[0117] The high refractive index layer is preferably disposed closer to the antiglare layer than the low refractive index layer. The lower limit of the refractive index of the high refractive index layer is preferably 1.53 or more, more preferably 1.54 or more, more preferably 1.55 or more, and more preferably 1.56 or more, and the upper limit is preferably 1.85 or less, more preferably 1.80 or less, more preferably 1.75 or less, and more preferably 1.70 or less.
[0118] The upper limit of the thickness of the high refractive index layer is preferably 200 nm or less, more preferably 180 nm or less, and even more preferably 150 nm or less, and the lower limit is preferably 50 nm or more, and more preferably 70 nm or more.
[0119] --In the case of a multi-layer structure of three or more layers-- The multilayer structure preferably formed by the dry method has a structure in which a total of three or more high refractive index layers and low refractive index layers are alternately laminated. Even in the multilayer structure, the low refractive index layer is preferably disposed on the outermost surface of the antiglare film.
[0120] The high refractive index layer preferably has a thickness of 10 to 200 nm and a refractive index of 2.1 to 2.4, and more preferably has a thickness of 20 to 70 nm. The low refractive index layer preferably has a thickness of 5 to 200 nm and a refractive index of 1.33 to 1.53, and more preferably has a thickness of 20 to 120 nm.
[0121] <Size, shape, etc.> The antiglare film may be in the form of a sheet cut to a predetermined size, or in the form of a roll obtained by winding a long sheet into a roll. The size of the sheet is not particularly limited, but the maximum diameter is about 2 to 500 inches. The "maximum diameter" refers to the maximum length when any two points on the antiglare film are connected. For example, when the antiglare film is rectangular, the diagonal line of the area is the maximum diameter. When the antiglare film is circular, the diameter is the maximum diameter. The width and length of the roll are not particularly limited, but generally, the width is about 500 to 3000 mm, and the length is about 500 to 5000 m. The antiglare film in the form of a roll can be cut into sheets according to the size of an image display device or the like. When cutting, it is preferable to remove the ends of the roll, which have unstable physical properties. The shape of the sheet is not particularly limited, and may be, for example, a polygon (triangle, square, pentagon, etc.), a circle, or a random, indeterminate shape. More specifically, when the antiglare film is square, the aspect ratio is not particularly limited as long as it does not cause any problems as a display screen. For example, the aspect ratio may be 1:1, 4:3, 16:10, 16:9, 2:1, etc., but in vehicle-mounted applications and digital signage that are rich in design, the aspect ratio is not limited to these.
[0122] The surface shape of the antiglare film opposite to the uneven surface is not particularly limited, but is preferably approximately smooth. Approximately smooth means that the arithmetic mean roughness Ra according to JIS B0601:1994 at a cutoff value of 0.8 mm is less than 0.03 μm, and preferably 0.02 μm or less.
[0123] [Image display device] The image display device of the present invention is configured by placing the above-mentioned anti-glare film of the present invention on a display element so that the surface with the uneven surface faces away from the display element, and by placing the anti-glare film on the outermost surface (see Figure 3).
[0124] Examples of the display element include a liquid crystal display element, an EL display element (an organic EL display element, an inorganic EL display element), a plasma display element, and further, an LED display element such as a micro LED display element. These display elements may have a touch panel function inside the display element. The liquid crystal display type of the liquid crystal display element includes the IPS type, VA type, multi-domain type, OCB type, STN type, TSTN type, etc. When the display element is a liquid crystal display element, a backlight is required. The backlight is placed on the opposite side of the liquid crystal display element from the side where the anti-glare film is placed.
[0125] The image display device of the present embodiment may be a touch panel-equipped image display device having a touch panel between the display element and the antiglare film. In this case, the antiglare film may be disposed on the outermost surface of the touch panel-equipped image display device, and the surface of the antiglare film having the concave and convex surface may be disposed so as to face the opposite side to the display element.
[0126] The size of the image display device is not particularly limited, but the maximum diameter of the effective display area is about 2 to 500 inches. The effective display area of an image display device is an area in which an image can be displayed. For example, when the image display device has a housing that surrounds a display element, the area inside the housing is the effective image area. The maximum diameter of the effective image area refers to the maximum length when any two points within the effective image area are connected. For example, if the effective image area is rectangular, the diagonal line of the area is the maximum diameter. Also, if the effective image area is circular, the diameter of the area is the maximum diameter. EXAMPLES
[0127] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, "parts" and "%" are based on mass unless otherwise specified.
[0128] 1. Measurement and Evaluation The antiglare films of the examples and comparative examples were measured and evaluated as follows. The atmosphere during each measurement and evaluation was set to a temperature of 23±5°C and a humidity of 40 to 65%. Before each measurement and evaluation, the target sample was exposed to the above atmosphere for 30 minutes or more before the measurement and evaluation. The results are shown in Table 1 or Table 2.
[0129] 1-1. Measurement of AM1 and AM2 The antiglare films of the examples and comparative examples were cut to 10 cm x 10 cm. The cut locations were selected randomly after visually checking for any abnormalities such as dust or scratches. Sample 1 was produced by bonding the transparent substrate side of the cut antiglare film to a glass plate (thickness 2.0 mm) measuring 10 cm long x 10 cm wide via an optically transparent adhesive sheet (product name: Panaclean PD-S1, thickness 25 μm) made by Panac Corporation. Using a white light interference microscope (New View7300, Zygo), Sample 1 was set so as to be fixed and in close contact with the measurement stage, and then the elevation of the uneven surface of the antiglare film was measured and analyzed under the following measurement condition 1 and analysis condition 1, and AM1 and AM2 were calculated. Note that the measurement and analysis software used was Microscope Application of MetroPro ver9.0.10.
[0130] (Measurement condition 1) Objective lens: 50x ImageZoom: 1x Measurement area: 218μm x 218μm Resolution (spacing per point): 0.22μm ·Instrument:NewView7000 Id 0 SN 073395 Acquisition Mode: Scan Scan Type:Bipolar Camera Mode: 992x992 48Hz Subtract Sys Err:Off Sys Err File: SysErr.dat AGC:Off Phase Res:High ·Connection Order:Location Discon Action: Filter Min Mod(%):0.01 Min Area Size:7 Remove Fringes:Off Number of Averages: 0 FDA Noise Threshold: 10 ·Scan Length:15um bipolar (6 sec) ·Extended Scan Length: 1000 μm FDA Res:High 2G
[0131] (Analysis condition 1) Removed: None Data Fill:On Data Fill Max:10000 Filter:HighPass FilterType:GaussSpline Filter Window Size:3 Filter Trim:Off ·Filter Low wavelength:800μm Min Area Size:0 Remove spikes: On Spike Height(xRMS):2.5 The low wavelength corresponds to the cutoff value λc in the roughness parameters.
[0132] (Calculation procedure for AM1 and AM2) The "Save Data" button was displayed on the Surface Map screen, and the three-dimensional curved surface roughness data after the analysis was saved in the "XYZ File (*.xyz)" format. Next, the data was exported to Microsoft Excel (registered trademark), and the two-dimensional function of altitude h(x,y) was obtained. The number of raw data obtained was 992 rows x 992 columns = 984064 points, with a side length (MΔx or NΔy) of 218 μm, but by repeatedly deleting the peripheral data 41 times, data with 910 rows x 910 columns = 828100 points and a side length of 200 μm was obtained. Next, using the statistical analysis software R (ver. 3.6.3), the one-dimensional amplitude spectrum of elevation Hx'(fx) and Hy'(fy) for each row and column of the two-dimensional function of elevation (910 rows x 910 columns) was calculated, and the one-dimensional amplitude spectrum of elevation H"(f) was obtained by averaging the amplitude values corresponding to each spatial frequency value. The one-dimensional function of elevation H"(f) was measured for 16 points on the surface of each sample, and the average of the amplitude values corresponding to each spatial frequency value was used as the one-dimensional amplitude spectrum of elevation H(f). Next, from the obtained data, AM2 (spatial frequency 0.300 μm -1 and AM1 (spatial frequency 0.005 μm -1 , 0.010μm -1 , 0.015μm -1 The sum of the amplitudes corresponding to the spatial frequency of 0.005 μm was calculated. -1 The amplitude corresponding to AM1-1 is 0.010 μm -1 The amplitude of AM1-2 corresponds to a spatial frequency of 0.015 μm. -1 The corresponding amplitudes, AM1-3, are shown in Table 1. 6 to 18 show the discrete functions H(f) of the amplitude spectrum of the elevation of the uneven surface of the antiglare films of Examples 1 to 7 and Comparative Examples 1 to 6. In the figures, the horizontal axis represents the spatial frequency (unit: μm -1 " ), and the vertical axis indicates amplitude (unit: "μm").
[0133] 1-2. Total light transmittance (Tt) and haze (Hz) The antiglare films of the examples and comparative examples were cut into 10 cm squares. The cut locations were randomly selected after visually checking for any abnormalities such as dust or scratches. The total light transmittance of each sample according to JIS K7361-1:1997 and the haze according to JIS K7136:2000 were measured using a haze meter (HM-150, manufactured by Murakami Color Research Laboratory). In order to allow the light source to stabilize, the device was powered on and then left for 15 minutes or more, and calibration was performed without setting anything at the entrance opening (where the measurement sample was placed), after which the measurement sample was placed at the entrance opening and measurement was performed. The light incident surface was set to the transparent substrate side.
[0134] 1-3. Anti-glare properties 1 (anti-glare properties in the direction of regular reflection) The antiglare films of the examples and comparative examples were cut to 10 cm x 10 cm. The cut locations were selected randomly after visually checking for any abnormalities such as dust or scratches. Sample 2 was produced by bonding the transparent substrate side of the cut antiglare film to a black board (Kuraray Co., Ltd., product name: Comoglass DFA2CG 502K (black) series, thickness 2 mm) measuring 10 cm long x 10 cm wide via an optically transparent adhesive sheet (product name: Panaclean PD-S1, thickness 25 μm) made by Panac Corporation. Sample 2 was placed on a horizontal table with a height of 70 cm so that the uneven surface was facing up, and the reflection of the illumination light on the uneven surface was evaluated in a bright room environment from the angle of the regular reflection direction of the illumination light according to the following evaluation criteria. In addition, during the evaluation, the position of sample 2 relative to the illumination was adjusted so that the angle of incidence of the light emitted from the center of the illumination to sample 2 was 10 degrees. In addition, a Hf32 type straight tube three-wavelength daylight fluorescent lamp was used as the illumination, and the illumination was positioned 2 m above the horizontal table in the vertical direction. In addition, the evaluation was performed in a range where the illuminance on the uneven surface of the sample was 500 to 1000 lux. In addition, the position of the observer's eyes was about 160 cm from the floor. The observer was a healthy person in his 30s with a visual acuity of 0.7 or higher. <Evaluation criteria> ◎: There is no outline of the light, and the position is unclear. 〇: There is no outline of the light, but the position is vaguely visible △: The outline and position of the light are vaguely visible. ×: The lighting outline is not very blurry and the position is clearly visible.
[0135] 1-4. Anti-glare properties 2 (Anti-glare properties at various angles) The reflection of the illumination light on the uneven surface was evaluated in the same manner as in 1-3, except that Sample 2 prepared in 1-3 was held with both hands and evaluated while changing the height and angle of Sample 2 (however, the incident angle of the light emitted from the center of the light to Sample 2 was changed within the range of 10 to 70 degrees).
[0136] 1-5. Reflected and scattered light (≒ jet black) Sample 2 prepared in 1-3 was placed on a horizontal table 70 cm high with the uneven surface facing up. The position of sample 2 relative to the lighting was adjusted so that the light with the strongest emission angle from the lighting was not just barely incident on sample 2. Due to this adjustment, the position of the sample relative to the observer was placed farther from the observer than the position of sample 1-3. Sample 2 was placed in the above position, and the degree of reflected and scattered light (≒ jet blackness) was evaluated using the following evaluation criteria. The observer's line of sight was approximately 160 cm from the floor. The observer was a healthy person in his / her 30s with a visual acuity of 0.7 or higher. <Evaluation criteria> ◎: No whiteness of scattered light is felt, and it is sufficiently black. 〇: There is a slight whiteness to the scattered light, but it is not noticeable. ×: The whiteness of the scattered light is noticeable
[0137] 1-6. Surface shape measurement Using a white light interference microscope (New View7300, Zygo), Sample 1 prepared in 1-1 was set on the measurement stage so as to be fixed and in close contact, and then the surface shape of the antiglare film was measured and analyzed. The measurement conditions and analysis conditions were the same as Measurement Condition 1 and Analysis Condition 1 in 1-1. The measurement and analysis software used was Microscope Application of MetroPro ver9.0.10 (64-bit). Examples 6 and 7 and Comparative Examples 3 and 6 were excluded from the surface shape measurement targets.
[0138] "Ra", "SRz", and "Rsk" were displayed on the Surface Map screen, and the respective values were taken as Sa, Sz, and Ssk for each measurement area. Next, the "Save Data" button was displayed on the above Surface Map screen, and the 3D curved surface roughness data after analysis was saved.Then, the saved data was read in the Advanced Texture Application, and the following analysis condition 2 was applied. (Analysis condition 2) High FFT Filter: off Low FFT Filter: off Calc High Frequency:On Calc Low Frequency:On Filter Trim:On Remove spikes: Off Spike Height(xRMS):5.00 Noise Filter Size:0 Noise Filter Type: 2 Sigma Fill Data:Off Data Fill Max:25 Trim:0 Trim Mode: All Remove:Plane Reference Band: 0μm ·Mim Peaks / Valleys Area:0μm 2 Max Peaks / Valleys Area: 0μm 2
[0139] Next, display the "Peaks / Valleys" screen and select "Reference Band: 0μm" and "Mim Peaks / Valleys Area: 0μm" 2 "Max Peaks / Valleys Area: 0μm 2" and the values displayed in "Peak Spacing" were taken as the Smp of each measurement area.
[0140] Next, the Slope Mag Map screen was displayed in the above analysis software (Microscope Application of MetroPro ver9.0.10 (64-bit)), and a histogram was displayed with the horizontal axis as Value (μm / mm) and the vertical axis as Counts on the screen. The horizontal axis was converted to an angle using the arctangent to obtain histogram data of the three-dimensional surface tilt angle distribution. Note that the value of nBins was changed and adjusted so that an angle distribution histogram with an increment of 1 degree or less was obtained for each measurement sample after conversion. Based on the obtained histogram data, the tilt angle (θ1) greater than 0 degrees and less than 1 degree, the tilt angle (θ2) of 1 degree or more and less than 3 degrees, the tilt angle (θ3) of 3 degrees or more and less than 10 degrees, and the tilt angle (θ4) of 10 degrees or more and less than 90 degrees were calculated.
[0141] 2. Preparation of anti-glare film [Example 1] The antiglare layer coating solution 1 having the following formulation was applied onto a transparent substrate (80 μm thick triacetyl cellulose resin film (TAC), Fujifilm Corporation, TD80UL), and dried at 70°C for 30 seconds with a wind speed of 5 m / s. After that, the coating solution was exposed to ultraviolet light in a nitrogen atmosphere (oxygen concentration 200 ppm or less) with an integrated light intensity of 100 mJ / cm. 2 An antiglare layer was formed by irradiating the film so as to obtain an antiglare film of Example 1. The thickness of the antiglare layer was 5.0 μm. The Ra of the side of the antiglare film opposite to the antiglare layer was 0.012 μm.
[0142] <Anti-glare layer coating solution 1> Pentaerythritol triacrylate 58.2 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) Urethane acrylate oligomer 18.2 parts (DIC, product name: V-4000BA) ·Thermoplastic resin 23.6 parts (Acrylic polymer, Mitsubishi Rayon, molecular weight 75,000) ·Organic particles 63.6 parts (Sekisui Plastics, spherical polyacrylic-styrene copolymer) (average particle size 2.0 μm, refractive index 1.515) (The ratio of particles with a diameter of 1.8 to 2.2 μm is 90% or more.) ·230 parts of inorganic fine particle dispersion (Nissan Chemical, silica with reactive functional groups on the surface, solvent: MIBK, solid content: 35.5%) (Average particle size 12nm) (Active ingredient of inorganic fine particles: 81.9 parts) Photopolymerization initiator 5.5 parts (IGM Resins BV, product name: Omnirad184) Photopolymerization initiator 1.8 parts (IGM Resins BV, product name: Omnirad907) Silicone leveling agent 0.2 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 346.8 parts Solvent (cyclohexanone) 17.9 parts
[0143] [Examples 2 to 7], [Comparative Examples 1 to 6] The antiglare films of Examples 2 to 7 and Comparative Examples 1 to 6 were obtained in the same manner as in Example 1, except that antiglare layer coating solution 1 was changed to the antiglare layer coating solution having the number shown in Table 1. The compositions of antiglare layer coating solutions 2 to 13 are shown below.
[0144] <Anti-glare layer coating solution 2> A coating solution having the same composition as anti-glare layer coating solution 1, except that the organic particles in anti-glare layer coating solution 1 have been changed to organic particles with "average particle size of 4.0 μm and refractive index of 1.515 (Sekisui Chemical Co., Ltd., spherical polyacrylic-styrene copolymer, with a particle size of 3.8 to 4.2 μm of 90% or more)."
[0145] <Anti-glare layer coating solution 3> Pentaerythritol triacrylate 100 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) ·Organic particles 129.8 parts (Sekisui Plastics, spherical polyacrylic-styrene copolymer) (average particle size 2.0 μm, refractive index 1.515) (The ratio of particles with a diameter of 1.8 to 2.2 μm is 90% or more.) Photopolymerization initiator 6.4 parts (IGM Resins BV, product name: Omnirad184) Photopolymerization initiator 1.0 parts (IGM Resins BV, product name: Omnirad907) Silicone leveling agent 0.1 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 498.4 parts Solvent (cyclohexanone) 55.4 parts
[0146] <Anti-glare layer coating solution 4> Pentaerythritol triacrylate 100 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) ·Organic particles 99.6 parts (Sekisui Plastics, spherical polyacrylic-styrene copolymer) (average particle size 2.0 μm, refractive index 1.515) (The ratio of particles with a diameter of 1.8 to 2.2 μm is 90% or more.) Silica particles 10 parts (Average particle size: 4.1μm) (Fuji Silysia Chemical, gel-process amorphous silica) Photopolymerization initiator 6.1 parts (IGM Resins BV, product name: Omnirad184) Photopolymerization initiator 1.1 parts (IGM Resins BV, product name: Omnirad907) Solvent (toluene) 452.9 parts Solvent (cyclohexanone) 50.3 parts Solvent (ethyl acetate) 2.6 parts
[0147] <Anti-glare layer coating solution 5> A coating solution having the same composition as antiglare layer coating solution 1, except that the amount of organic particles added in antiglare layer coating solution 1 was changed from 63.6 parts to 50.0 parts, and the amount of inorganic fine particle dispersion added was changed from 230 parts to 187 parts.
[0148] <Anti-glare layer coating solution 6> Pentaerythritol triacrylate 100 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) Silica particles 14 parts (Average particle size: 4.1μm) (Fuji Silysia Chemical, gel-process amorphous silica) Photoinitiator 5 parts (IGM Resins BV, product name: Omnirad184) Silicone leveling agent 0.2 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 150 parts Solvent (MIBK) 35 parts Solvent (ethyl acetate) 5.2 parts
[0149] <Anti-glare layer coating solution 7> Pentaerythritol triacrylate 65 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) · Urethane acrylate oligomer 35 parts (DIC, product name: V-4000BA) ·Organic particles 14 parts (Sekisui Plastics, spherical polyacrylic-styrene copolymer) (average particle size 3.5 μm, refractive index 1.550) Silica particles 6 parts (Average particle size: 12nm) (Fumed silica, manufactured by Nippon Aerosil Co., Ltd.) Photopolymerization initiator 5 parts (IGM Resins BV, product name: Omnirad184) Silicone leveling agent 0.025 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 100 parts Solvent (cyclohexanone) 20 parts Solvent (isopropyl alcohol) 55 parts
[0150] <Anti-glare layer coating solution 8> Pentaerythritol triacrylate 33 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) Isocyanuric acid EO modified triacrylate 52 parts (Toagosei, product name: M-313) ·Thermoplastic resin 15 parts (Acrylic polymer, Mitsubishi Rayon, molecular weight 75,000) ·Organic particles 16 parts (Sekisui Plastics, spherical polyacrylic-styrene copolymer) (average particle size 3.5 μm, refractive index 1.555) (The proportion of particles with a particle diameter of 3.2 to 3.8 μm is 90% or more) ·Inorganic fine particle dispersion liquid 158 parts (Nissan Chemical, silica with reactive functional groups on the surface, solvent: MIBK, solid content: 40%) (Average particle size: 12nm) Photopolymerization initiator 5 parts (IGM Resins BV, product name: Omnirad184) Silicone leveling agent 0.20 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 211 parts Solvent (propylene glycol monomethyl ether acetate) 165 parts
[0151] <Anti-glare layer coating solution 9> Pentaerythritol triacrylate 91.5 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) Urethane acrylate oligomer 8.5 parts (DIC, product name: V-4000BA) ·Organic particles 2 parts (Spherical polyacrylic-styrene copolymer, manufactured by Sekisui Plastics Co., Ltd.) (average particle size 5.0 μm, refractive index 1.550) Silica particles 15 parts (Average particle size: 4.1μm) (Fuji Silysia Chemical, gel-process amorphous silica) Photopolymerization initiator 1.9 parts (IGM Resins BV, product name: Omnirad184) Photopolymerization initiator 7 parts (IGM Resins BV, product name: Omnirad907) Silicone leveling agent 0.1 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 161.1 parts Solvent (cyclohexanone) 69 parts Solvent (ethyl acetate) 3.9 parts
[0152] <Antiglare layer coating solution 10> Pentaerythritol triacrylate 50.6 parts (Nippon Kayaku Co., Ltd., product name: KAYARAD-PET-30) Urethane acrylate oligomer 49.4 parts (DIC, product name: V-4000BA) ·Organic particles 3 parts (Sekisui Plastics, spherical polyacrylic-styrene copolymer) (average particle size 2.0 μm, refractive index 1.545 μm) Silica particles 1 part (Average particle size: 12nm (Fumed silica, manufactured by Nippon Aerosil Co., Ltd.) Photopolymerization initiator 1 part (IGM Resins BV, product name: Omnirad184) Photopolymerization initiator 0.2 parts (IGM Resins BV, product name: Omnirad907) Photopolymerization initiator 1.5 parts (Lamberti, ESACUREONE) Silicone leveling agent 0.1 parts (Momentive Performance Materials, product name: TSF4460) Solvent (toluene) 98.6 parts Solvent (cyclohexanone) 38.7 parts Solvent (isopropyl alcohol) 44.1 parts Solvent (MIBK) 2.4 parts
[0153] <Anti-glare layer coating solution 11> A coating solution having the same composition as Antiglare Layer Coating Solution 1, except that the amount of organic particles added was changed to 300 parts of Antiglare Layer Coating Solution 3.
[0154] <Anti-glare layer coating solution 12> A coating solution having the same composition as Antiglare Layer Coating Solution 3, except that the average particle size of the organic particles in Antiglare Layer Coating Solution 3 was changed to 3.5 μm.
[0155] <Anti-glare layer coating solution 13> A coating solution having the same composition as antiglare layer coating solution 3, except that the average particle size of the organic particles in antiglare layer coating solution 3 was changed to 1.5 μm and the amount of the organic particles added was changed to 160 parts.
[0156] [Table 1]
[0157] [Table 2]
[0158] From the results in Table 1, it can be seen that the antiglare films of the examples have excellent antiglare properties, suppress reflected and scattered light, and provide excellent jet black appearance. [Explanation of symbols]
[0159] 10: Transparent base material 20: Anti-glare layer 21: Binder resin 22:Organic particles 100:Anti-glare film 110: Display element 120: Image display device 200: Observer
Claims
1. An antiglare film having an antiglare layer, the antiglare film having a textured surface, The uneven surface has a three-dimensional average peak spacing Smp of 2.524 μm or more, The amplitude spectrum of the elevation of the uneven surface has a spatial frequency of 0.005 μm -1 , 0.010 μm -1 , 0.015 μm -1 The sum of the amplitudes corresponding to AM1 and the spatial frequency 0.300 μm -1 When the amplitude at the reflection wavelength is defined as AM2, AM1 is 0.070 to 0.400 μm and AM2<AM1.
2. The antiglare film according to claim 1, wherein, when the amplitude corresponding to a spatial frequency of 0.005 μm −1 is defined as AM1-1, the amplitude corresponding to a spatial frequency of 0.010 μm −1 is defined as AM1-2, and the amplitude corresponding to a spatial frequency of 0.015 μm −1 is defined as AM1-3, AM1-1 is 0.020 to 0.150 μm, AM1-2 is 0.020 to 0.145 μm, and AM1-3 is 0.020 to 0.145 μm.
3. 3. The antiglare film according to claim 1, wherein AM1 / AM2 is 2.0 to 60.
0.
4. 4. The antiglare film according to claim 1, which has a haze according to JIS K7136:2000 of 60 to 98%.
5. The antiglare film according to any one of claims 1 to 4, wherein the antiglare layer comprises a binder resin and particles.
6. 6. The antiglare film according to claim 5, wherein, when the thickness of the antiglare layer is defined as T and the average particle diameter of the particles is defined as D, D / T is 0.20 to 0.
96.
7. 7. The antiglare film according to claim 5, wherein the particles have an average particle diameter D of 1.0 to 5.0 μm.
8. The antiglare film according to any one of claims 5 to 7, comprising 40 to 200 parts by mass of the particles per 100 parts by mass of the binder resin.
9. The antiglare film according to any one of claims 5 to 8, wherein the particles are organic particles.
10. The antiglare film according to any one of claims 5 to 9, wherein the antiglare layer further comprises inorganic fine particles.
11. The antiglare film according to claim 10, comprising 40 to 200 parts by mass of the inorganic fine particles relative to 100 parts by mass of the binder resin.
12. The antiglare film according to any one of claims 5 to 11, wherein the binder resin comprises a cured product of an ionizing radiation curable resin composition and a thermoplastic resin.
13. An anti-glare film described in any of claims 1 to 12, wherein the uneven surface has a three-dimensional arithmetic mean roughness Sa of 0.30 μm or more and 1.00 μm or less.
14. An anti-glare film described in any of claims 1 to 13, wherein the uneven surface has a ratio Sa / Smp of the three-dimensional arithmetic mean roughness Sa to the three-dimensional average peak spacing Smp of 0.05 or more.
15. An anti-glare film described in any one of claims 1 to 14, having the anti-glare layer on a transparent substrate, and the surface of the anti-glare layer opposite the transparent substrate is the uneven surface.
16. An anti-glare film as described in claim 15, wherein the transparent substrate is a polyester film or a triacetyl cellulose film.
17. 17. The antiglare film according to claim 1, further comprising an antireflection layer on the antiglare layer, the antireflection layer having a surface with projections and recesses.
18. An anti-glare film as described in claim 17, comprising a low refractive index layer and a high refractive index layer as the anti-reflection layer.
19. An image display device comprising an anti-glare film according to any one of claims 1 to 18, arranged on a display element with the uneven surface side facing away from the display element, and the anti-glare film arranged as the outermost surface.