JP2005227407A - Glare shield sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glare shield sheet restraining the lowering of glare shield characteristic caused by the adhesion of soil and also preventing reflection in display. <P>SOLUTION: In the glare shield sheet, its cross-sectional shape in a perpendicular direction to a sheet surface is rugged shape constituted of a maximal part constituted of a nearly circular-arc shaped curve and a minimal part constituted of a nearly circular-arc shaped curve. In the cross-sectional shape, the average radius of curvature R<SB>1</SB>of the circular-arc curve in the maximal area of the maximal part and the average radius of curvature R<SB>2</SB>of the circular-arc curve in the minimal area of the minimal part satisfy an expression (1): 1≤R<SB>1</SB>/R<SB>2</SB>≤5, and the average radius of curvature R<SB>1</SB>and the average space S<SB>m</SB>between the tops of projecting parts satisfy an expression (2): 4≤R<SB>1</SB>/S<SB>m</SB>≤15. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an antiglare sheet used for various displays (such as a liquid crystal display), a manufacturing method thereof, and a display device including the antiglare sheet.

  In recent years, various displays such as liquid crystal displays, plasma displays, organic EL (electroluminescence) displays, inorganic EL displays, and FED (field emission displays) have been developed. In particular, liquid crystal displays have made remarkable progress as display devices in television (TV) applications or moving image display applications, and are rapidly spreading. For example, the development of high-speed liquid crystal materials and the improvement of driving methods such as overdrive have overcome the conventional video display that LCDs were not good at, and production technology innovations that responded to larger displays Yes.

  In these displays, in applications such as televisions and monitors that place importance on image quality, and video cameras that are used outdoors with strong external light, the surface is usually treated to prevent reflection of external light. It is. One of the techniques is anti-glare treatment, and for example, the surface of a liquid crystal display is usually subjected to anti-glare treatment. The anti-glare treatment has an effect of blurring the reflected image by scattering the surface reflected light by forming a fine uneven structure on the surface. Therefore, unlike the clear antireflection film, the antiglare film does not reflect the shape of the viewer and the background, and thus the reflected light is unlikely to disturb the image.

  For example, WO95 / 31737 (Patent Document 1) discloses a film comprising a transparent film and an ionizing radiation curable resin layer provided on the transparent film, wherein the resin layer has a total light transmittance. Surface roughness with optical properties of 85% or more, haze degree of 3 to 35%, 60 degree glossiness of 90% or less, surface center line average roughness of 0.05 to 0.6 μm, and pitch between surface irregularities of 5 to 200 μm An anti-glare film for display is disclosed. In this document, a concavo-convex structure is formed in the resin layer by a method using a shaped substrate film containing fine particles having a particle diameter of 0.5 to 10 μm as a mold or a method in which the resin layer contains organic beads or inorganic beads. Has been.

  Japanese Patent Application Laid-Open No. 2002-189106 (Patent Document 2) is a film in which a transparent plastic layer is formed on the front surface of a transparent plastic, and an antiglare layer having a fine concavo-convex structure is laminated on the surface. An antiglare film is disclosed in which an antiglare layer has a surface three-dimensional 10-point average roughness of 0.9 to 3 μm and an average distance between adjacent convex portions of 20 to 50 μm. This document describes a method for forming a concavo-convex structure by using a concavo-convex mold in which a reverse shape of a desired concavo-convex shape is formed on one side and using a curable resin composition such as an ultraviolet curable resin. .

  In Japanese Patent Laid-Open No. 11-326611 (Patent Document 3), the 60 ° specular gloss is 10 to 70%, the center line average roughness is 0.1 to 0.35 μm, and the average peak-to-valley interval is 18 to 60 μm. A light diffusing layer comprising an ultraviolet curable resin film having a fine concavo-convex structure with a surface roughness of 1 on one side is disclosed. In this document, an ultraviolet curable resin film having a fine concavo-convex structure is formed by roughening the surface of a substrate by a method of dispersing and containing transparent particles in the resin or by a method such as sand plast, embossing roll, etching, etc. It is described that it can be obtained by a method of forming an ultraviolet curable resin film.

  However, these anti-glare films have a large scattering of light on the surface due to the uneven structure of the film surface, and the scattered light is mixed into a portion that originally appears black and becomes whitish. That is, in places where the outside light is strong, the screen is generally whitish and lacks contrast. In particular, it is difficult to display an image with a high contrast in a television (TV) application that requires an image with a strong contrast with black being tightened.

Therefore, an increasing number of liquid crystal TVs have a clear surface without being subjected to anti-glare treatment. However, viewers and clear backgrounds with a clear surface become noticeable, often hindering high-quality images. In particular, in a large display that can be used as a home theater or the like, contrast is greatly reduced and reflection is difficult, and it is difficult to form a high contrast image while preventing reflection.
WO95 / 31737 (Claims 1, 8, 9 and 12) JP 2002-189106 A (Claim 1, paragraph number [0018]) JP 11-326611 A (Claim 1, paragraph number [0014])

  Accordingly, an object of the present invention is to provide an antiglare sheet that can prevent reflection of external light on a display, reduce whiteness and whiteness (whiteness), and display an image with high contrast, and a method for manufacturing the same. It is to provide.

  Another object of the present invention is to provide an antiglare sheet capable of suppressing a decrease in antiglare properties even when dirt is attached, and a method for producing the same.

  Another object of the present invention is to provide an antiglare sheet capable of displaying a clear image with high contrast even for a large display and a method for producing the same.

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that the average curvature of the arc curve in the maximum region of the maximum portion in the roughness profile of the cross section on the surface of the sheet having the arc-shaped uneven structure continuous in the cross section. relationship between the average curvature radius R ₂ of arcuate curve at the minimum region of radius R ₁ and the minimum unit, further sheet in the range relationship particular the mean spacing S _m between the top of the average radius of curvature R ₁ and the convex portion The present inventors have found that external light can be prevented from being reflected on the display, whitishness and white floating (white blurring) can be reduced, and an image can be displayed with high contrast.

That is, the antiglare sheet of the present invention has a cross-sectional shape in a direction perpendicular to the sheet surface, which includes a maximum portion configured with a substantially arc-shaped curve and a minimum portion configured with a substantially arc-shaped curve. In the cross-sectional shape, the average curvature radius R ₁ of the arc curve in the maximum region of the maximum portion and the average curvature radius R ₂ of the arc curve in the minimum region of the minimum portion are expressed by the following formula (1). ) And the average radius of curvature R ₁ and the average distance S _m between the tops of the convex portions satisfy the following formula (2).

1 ≦ R ₁ / R ₂ ≦ 5 (1)
4 ≦ R ₁ / S _m ≦ 15 (2)

The sheet, in vertical cross section with respect to the sheet surface, the average distance S _m between the top portion of the convex portion is about 20 to 100 [mu] m, and the average line-square average roughness R _q is 0.05~0.3μm It may be a degree. When the top-to-top average distance _Sm and the average line square average roughness _Rq are within this range, whitening in a regular reflection region and whitening in a region having a large reflection angle can be simultaneously reduced. The sheet may have an average inclination angle Δa of the concavo-convex portion with respect to the sheet surface of about 0.5 to 2 °. The sheet has a cross-sectional shape in a direction perpendicular to the sheet surface, and the arithmetic average line height Z ₁ and the center line height Z ₂ of the concavo-convex part satisfy the following formula (3), and the center line height: The area of the curved surface having a thickness of Z ₂ or more may be 20% or more with respect to the entire surface.

| Z ₂ −Z ₁ | ≦ 0.1 μm (3)

  In addition, the sheet includes an alicyclic olefin resin, vinyl acetate resin, (meth) acrylic resin, styrene resin, polyester resin, polycarbonate resin, polyamide resin, cellulose derivative, epoxy (meth) acrylate, and the like. It may be comprised.

  The present invention also includes a method for producing the antiglare sheet by phase-separating a plurality of resins using spinodal decomposition. Furthermore, the present invention includes a display device including the antiglare sheet.

  In addition, the whitish of the image of the display in the conventional glare-proof sheet shows the reflected light scattering behavior that the reflected light intensity spreads exponentially with respect to the reflection angle. That is, in the conventional anti-glare sheet, as shown in FIG. 6, the reflected light intensity suddenly increases in the range where the reflection angle is small (regular reflection region), and white floating (white blurring or whiteness) occurs (see FIG. 6). Since the reflected light intensity continues to exist up to a range where the reflection angle is large even though it is weak (part B in the figure), whitening occurs even in a region where the reflection angle is large. Therefore, an anti-glare sheet with high contrast can be obtained by simultaneously reducing white floating in a regular reflection region and white floating in a region having a large reflection angle.

  In addition, the schematic which shows the relationship between a regular reflection direction and a reflection angle is shown in FIG. In FIG. 7, the light emitted from the light source 3 is reflected by the antiglare sheet 4 and reflected at the reflection angle θ with respect to the regular reflection direction 5.

Further, when the average distance (average distance) S _m between the tops of the convex portions of the anti-glare sheet having a concavo-convex structure and the square (square) average roughness R _q become a certain size or more, the reflected light scattering behavior is geometric optical. The light depending on the surface reflectance is reflected at a reflection angle of 2X ° (for example, when light is incident on a minute inclined region having an inclination angle X ° in the antiglare sheet). Reflected in the direction of

As a result of these studies, the anti-glare sheet with high contrast, that is, the average spacing S _m between the tops of the convex portions and the root mean square roughness R so that the behavior of the reflected light with respect to the reflection angle follows the principle of geometric optics. _As a sheet having a concavo-convex shape having _q , a sheet having a concavo-convex structure in which a parabola or a spherical convex portion was adjacent was prepared. A schematic cross-sectional view of a sheet having a spherical convex portion is shown in FIG. In FIG. 8, the convex part 6 which has the inclination angle of (theta) 1 degree with respect to the surface is formed adjacently. In such a sheet, the reflected light intensity does not have an exponential function with respect to the reflection angle, and as shown in FIG. 9, the reflected light intensity has a moderate intensity and a constant reflected light intensity within a specific reflection angle range. Since the intensity is zero at a wide angle beyond that, the whitening near the regular reflection (regular reflection region) and the whitening in the region having a large reflection angle can be improved at the same time.

  However, even with such an anti-glare sheet, the anti-glare property is very sensitive to dirt, and the anti-glare function of that part can be done by touching it slightly or wiping it with a slightly dirty cloth. Changes. Furthermore, the reflected light (light source) is reflected on the surface of the antiglare sheet more clearly than the conventional antiglare sheet.

  In other words, the problem of the former anti-glare function changing is that dust or oil tends to collect in the recesses that are the boundaries between the projections, and the apparent uneven shape changes, and the latter light source is reflected. The problem is that, while maintaining a constant reflected light intensity within a specific reflection angle range, discontinuous reflected light scattering behavior (C portion in FIG. 9) where the intensity suddenly becomes zero at a wider angle than that, The reason is that the boundary is conspicuous.

  In the present invention, since the uneven structure on the surface of the antiglare sheet is controlled to a specific gentle shape, reflection of outside light on the display can be prevented, whitishness and whitening can be reduced, and high contrast can be achieved. An image can be displayed. Moreover, even if dirt adheres, the fall of an anti-glare property can be suppressed. Furthermore, even a large display can display a clear image with high contrast.

[Uneven structure on antiglare sheet surface]
The antiglare sheet (or film) of the present invention has an uneven structure on the surface. Further, the curved surface on the surface is an uneven shape in which a continuous recess surrounds the periphery of the protrusion. In such a concavo-convex shape, the shape of the convex part and the concave part is represented by a curved surface. Further, in the uneven shape, it is preferable that at least the maximum portion and the minimum portion have a shape substantially along a spherical surface, and the shapes of the convex portion and the concave portion also have a shape substantially along the spherical surface.

  Specifically, in the direction perpendicular to the sheet surface, the cross-sectional shape (the roughness profile of the front cross-section in the longitudinal cross-section) is a maximum portion represented by a substantially arcuate curve and a substantially arcuate curve. It is the uneven | corrugated shape comprised by the minimum part represented. That is, in the surface profile roughness profile, the curve near the maximum value of the convex portion is substantially arc-shaped. In addition, a convex part refers to the area | region more than arithmetic average height on the basis of arithmetic average height in a table cross-sectional roughness profile. On the other hand, a recessed part points out the area | region except the convex part defined in this way.

  Further, in the roughness profile of the front cross section in the longitudinal cross section, the curve near the minimum value of the recess is also substantially arcuate. Therefore, as shown in FIG. 10, the profile of the surface cross-sectional roughness of the antiglare sheet of the present invention is represented by a maximum portion 11 represented by a substantially arcuate curve having different sizes and a substantially arcuate curve. The roughness profile of the cross section is formed by continuous connection (connection) with the minimum portion 12. The maximum portion and the minimum portion may each have a substantially uniform size.

  In the direction parallel to the sheet surface, the cross-sectional shape (the roughness profile of the front cross-section in the cross-section in the transverse direction or the planar shape of the concavo-convex portion in the slice surface) is, for example, a substantially circular convex at the arithmetic average height. Or a concavo-convex shape composed of a convex part (island part) formed by connecting a plurality of substantially circular convex parts and a concave part (sea part) continuously surrounding the convex part. Good.

In the roughness profile of the front cross section in the longitudinal section, the average curvature radius R ₁ of the arc curve in the maximum region (near the maximum value) of the maximum portion and the average of the arc curve in the minimum region (near the minimum value) of the minimum portion the ratio R ₁ / R ₂ of the radius of curvature R ₂ is 1-5, preferably 1-4, more preferably about 1.1 to 3. When R ₁ / R ₂ is smaller than 1, the ratio of the concave portions having a relatively small inclination angle increases and the intensity of the reflected scattered light in the vicinity of the regular reflection becomes strong, so that the whitening of the regular reflection area becomes strong. On the other hand, when R ₁ / R ₂ is greater than 5, the average radius of curvature of the minimum area of the recess or the minimum part becomes extremely small, and dust and oil easily remain in the minimum area of the recess or the minimum part. The wipeability of the kimono (fingerprints, etc.) is reduced, and traces of wiping with a cloth (wet rags, etc.) remain. Furthermore, if R ₁ / R ₂ is greater than 5, as shown in FIG. 9, the reflected light scattering behavior becomes discontinuous where the reflected light intensity suddenly decreases at an angle greater than a specific reflection angle. The reflection of is conspicuous. Therefore, in the present invention, by setting R ₁ / R ₂ in such a range in the roughness profile of the front cross section in the longitudinal cross section, the deterioration of the antiglare property due to the adhesion of dirt is small, and the light source on the surface It is possible to obtain an antiglare sheet in which the reflection is not conspicuous and the white reflection in the regular reflection region is small.

Moreover, the anti-glare sheet of this invention makes the curvature radius of a convex part (or the convex-shaped curved surface of each local maximum part which forms a convex part) sufficiently larger than the space | interval (distance) between adjacent convex parts. Is preferred. Specifically, in the roughness profile of the front cross section in the longitudinal high cross section, the ratio R ₁ / S _m between the average radius of curvature R ₁ and the average interval S _m between the tops of the convex portions is, for example, 4 to 15, preferably 4.5 to 12, more preferably about 5 to 10. When R ₁ / S _m is set in such a range, the intensity of the reflected scattered light in the regular reflection region can be suppressed.

The average curvature radii R ₁ and R ₂ and the average interval S _m between the tops of the convex portions can be measured by, for example, a roughness measuring method defined in JIS B 0601.

For example, an atomic force microscope system, a stylus step measurement system, or a confocal laser microscope analysis system can be used as a specific measurement method for the roughness of the surface of the antiglare sheet. With such a measurement system, the roughness profile of the front cross section in the longitudinal cross section is measured by a method in accordance with the above-mentioned JIS B 0601. From this profile, the mean curvature radii R ₁ , R ₂ , and the top of the convex portion The average interval S _m , the arithmetic average line height Z _{1 of} the uneven portion, and the center line height Z ₂ of the uneven portion can be calculated. For example, the average curvature radii R ₁ and R ₂ are obtained by measuring the roughness profile of the table cross section and then dividing the profile into a maximum portion and a minimum portion along the length direction. The point of inflection between the part and the minimum part or the point with the maximum slope may be used), and the radius of curvature is calculated by the least square method for each local maximum part and local minimum part, and the average value may be calculated. Good. Note that the shape of the convex or concave curved surface cannot be accurately measured only by the roughness profile of the front cross section in the longitudinal cross section, so three-dimensional from the measurements by the atomic force microscope system and confocal laser microscope analysis system It is preferable to create and evaluate an uneven surface profile.

Further, as shown in FIG. 10, the average radii of curvature R ₁ and R ₂ sunk the concave and convex curve of the surface concave and convex portion above the sheet surface and the curved arc curve 11 and below the sheet surface. By fitting the curved arc curve 12 alternately and repeatedly, the curvature radii may be measured for the individual concavo-convex portions and averaged as shown in the following equation. In FIG. 10, the average curvature radius R ₁ of the arc curve in the maximum region of the maximum portion is represented by R _1-1 , R _1-2 , R _1-3 , and the average curvature radius R in the minimum region of the minimum portion. _2, R _2-1, R _2-2, are represented by R _2-3.

In addition to the above characteristics, the antiglare sheet of the present invention preferably further controls the height and size of the uneven portion. Specifically, the average interval (average distance) S _m between the tops of the convex portions is 20 μm or more (for example, 20 to 100 μm), preferably 20 to 80 μm, and more preferably about 25 to 60 μm. The root mean square roughness R _q is 0.05 μm or more (for example, 0.05 to 0.3 μm), preferably 0.1 to 0.3 μm, and more preferably about 0.1 to 0.25 μm. If either of the top-to-top average distance S _{m or the} root mean square roughness R _q is too small, the light will not easily recognize the unevenness, and a mirror reflection similar to the smooth surface will occur despite the uneven surface. , The antiglare effect is reduced. On the other hand, when the top portion between the mean spacing S _m is too large, compete with the pixel size of the display device, glare occurs. On the other hand, if the root mean square roughness R _q is too large, the amplitude of the unevenness becomes larger than necessary, so that the reflected light is scattered at a wide angle and whitening occurs in a region where the reflection angle is large.

  Furthermore, in the antiglare sheet of the present invention, the average inclination angle of the concavo-convex portion with respect to the surface is, for example, 0.5 to 2 °, preferably 0.6 to 1.8 °, more preferably 0.7 to 1.5. It is about °. Increasing the slope of the concavo-convex portion can reduce whitening in the regular reflection region, but increases whitening in a region where the reflection angle is large. On the other hand, when the inclination is weakened, whitening in a region having a large reflection angle can be reduced, but whitening in a regular reflection region increases. In the present invention, whitening in the regular reflection region and the region having a large reflection angle can be simultaneously reduced by setting the tilt angle within the above range. In this invention, the average inclination | tilt angle of an uneven | corrugated | grooved part can be measured with the roughness measuring method described in ISO-4288-1985.

  In the present specification, the inclination angle is expressed as an angle of 0 to 90 ° with respect to the surface (horizontal plane) regardless of the measurement direction. In addition, the tilt angle may be a region of a convex portion or a concave portion.

In an antiglare sheet, if an extremely high convex portion exists, the inclination angle of the skirt of the convex portion becomes too large due to a step difference from the surroundings, and thus whitening occurs in a region where the reflection angle is large. In order to prevent the occurrence of such whitening, the root mean square roughness R _q is adjusted to the above range, but the centerline height Z ₂ is extremely smaller than the arithmetic mean line height Z _1. It is preferably not large. Specifically, in the roughness profile of the front cross section in the longitudinal cross section, for example, the absolute value (| Z ₂ −Z ₁ | of the difference between the center line height Z ₂ and the arithmetic mean line height Z ₁ of the concavo-convex portion ) Is 0.1 μm or less (for example, 0 to 0.1 μm, preferably 0 to 0.05 μm, more preferably about 0 to 0.03 μm). The arithmetic average line height Z ₁ is a height obtained by arithmetic averaging of the height frequency distribution, and the center line height Z ₂ is an intermediate height between the maximum height and the minimum height. .

Also, the area of the center line height Z ₂ or more at which the curved surface, is 20% or more of the total surface (e.g., 20-80%, preferably 25 to 70%, more preferably 30 to 60%) . In the present invention, the center line (surface) can be measured based on the measurement method related to roughness described in JIS B 0601, similarly to the measurement method related to the arithmetic average line height Z ₁ described above.

  Hereinafter, the uneven structure on the surface of the antiglare sheet will be described in detail using a specific example of the antiglare sheet of the present invention.

  FIG. 1 is a three-dimensional profile (three-dimensional image) of a typical antiglare sheet surface (uneven curved surface) in the present invention, and FIG. 2 is parallel to the sheet surface with respect to the uneven curved surface in this profile. It is the figure sliced by arithmetic mean height in a certain direction, and is comprised by the convex part 1 represented by the sliced cross section, and the recessed part 2 surrounding the circumference | surroundings. As shown in FIGS. 1 and 2, the surface of the antiglare sheet of the present invention is configured with a gentle uneven curved surface, and has a structure in which a continuous concave portion surrounds a convex portion or a series of convex portions. ing.

FIG. 3 is an unevenness (roughness) profile in a longitudinal section in the three-dimensional shape profile of FIG. In this concavo-convex profile, the mean square roughness R _q is 0.167 μm, the average interval S _m between the tops of the convex portions is 41.86 μm, the average inclination angle Δa of the concavo-convex portions is 0.895 °, and the maximum maximum region The average curvature radius R ₁ of the arc curve at 326 is 326 μm, and the average curvature radius R ₂ of the arc curve in the minimum region of the minimum portion is 236 μm.

FIG. 4 is a graph showing the height distribution of the protrusions obtained from the uneven profile of FIG. The vertical axis 50% in the graph represents the center line height Z ₂ (= 0.69 μm), and the line on the vertical axis 55% represents the average line height Z ₁ ( = 0.74 μm). The maximum height difference is 0.93 μm, and the difference (| Z ₂ −Z ₁ |) between the center line height Z ₂ and the average line height Z ₁ is 0.05 μm. Moreover, the area of the uneven | corrugated curved surface more than centerline height is 61% of the whole from a graph (b).

  As is clear from FIG. 4, the antiglare sheet of the present invention has a feature that the height distribution of the convex portions shows a substantially normal distribution. Moreover, it can be seen from the results of FIGS. 3 and 4 that this concavo-convex structure satisfies the above formulas (1) to (3). In addition, as seen in the uneven profile in the vicinity of 520 μm in FIG. 3, the antiglare sheet of the present invention is a small part of the uneven profile, and is continuous without forming a clear maximum or minimum with a substantially arc-shaped curve. It may draw a curve connected to. Such a curve is likely to occur at a portion where the heights of adjacent spherical convex shapes are greatly different, a bottom portion of a concave portion, or the like. However, such a curve is substantially the same as the concavo-convex profile of the present invention when it is only partially seen in the entire concavo-convex profile (for example, within 20% of the entire surface). Can be considered.

  FIG. 5 shows a result of simulation of light reflection / scattering behavior when a point light source is incident on the uneven curved surface (relationship between reflection angle and reflected light intensity). As is clear from the graph of FIG. 5, in the antiglare sheet of the present invention, there is no sudden increase in reflected light intensity in the regular reflection region observed in the conventional antiglare sheet, and the reflected light in a region where the reflection angle is large. Since there is no strength, both the whitening in the regular reflection area and the whitening in the area having a large reflection angle are superior to the conventional antiglare sheet. Furthermore, in the antiglare sheet of the present invention, the change in reflected light intensity with respect to the angle is continuous as compared to the antiglare sheet shown in FIG. Therefore, the antiglare sheet of the present invention is less noticeable even when reflected light is reflected, compared to the antiglare sheet shown in FIG.

  In addition, as a method of measuring the reflected scattered light behavior, that is, the reflected scattered light with respect to the reflected angle, for example, a measuring system that can change the light receiving angle of the light receiver and can measure the light intensity at any time (for example, Murakami Color Research Laboratory). Examples thereof include a method of measuring using a goniophotometer manufactured by Co., Ltd. In this method, the incident light angle is set to −10 ° from the normal line (line perpendicular to the sheet surface) with respect to the sheet on which the antiglare sheet is mounted using the apparatus so that the resolution is 1 ° or less. A sufficiently narrow light source (preferably a laser light source or the like) is incident on the sheet, the angle of the light receiver is changed, and the light intensity of the surface reflected light is measured. The light receiving angle is set to 0 ° at a position 10 ° from the sheet normal so that the reflected light is substantially symmetric about 0 °. In addition, by applying black ink to the back side of the sheet, the sheet is processed in advance so that the reflected light is only from the surface of the antiglare sheet.

[Optical characteristics of anti-glare sheet]
In the antiglare sheet of the present invention, the total light transmittance is, for example, 90% or more (for example, 90 to 100%), and preferably about 95 to 100%. The haze can be selected from a range of about 1 to 20%, for example, 4 to 20%, preferably 4 to 15%, and more preferably about 5 to 10%. The transmission definition is, for example, about 40 to 90%, preferably about 50 to 90%, and more preferably about 60 to 90%.

  In the antiglare sheet of the present invention, the total light transmittance and haze can be measured based on JIS-K-6714 using a haze meter (for example, NDH5000W manufactured by Nippon Denshoku Industries Co., Ltd.). Further, the transmission sharpness can be measured based on JIS K 7150 using an optical comb 0.5 mm width by a image clarity measuring instrument (for example, ICM-1DD type manufactured by Suga Test Instruments Co., Ltd.).

The refractive index of the antiglare sheet is preferably about 1.5 to 2, for example. In particular, when a low refractive index layer, which will be described later, is formed on the outermost surface, the refractive index of the antiglare sheet is, for example, 1.52 to 2, preferably 1, in order to reduce the reflectance by interfering with the low refractive index layer. About 53 to 1.8. In order to increase the refractive index (for example, 1.53 or more), for example, fine particles smaller than the wavelength of visible light (for example, an average particle diameter of 0.05 μm) are preliminarily added to the radiation curable resin constituting the antiglare sheet. The following fine particles) may be dispersed. The fine particles may be composed of, for example, an inorganic acid salt or oxide containing at least one selected from titanium, tin, zinc, zirconium, aluminum, indium, antimony and sulfur. When such fine particles are used, since the particle size of the fine particles is sufficiently smaller than the wavelength of light, unnecessary light scattering does not occur, and it behaves as an optically uniform substance. Become. Further, as the fine particles, conductive fine particles [for example, fine particles composed of indium-titanium-oxide (ITO), antimony-titanium-oxide (ATO), zinc oxide-aluminum, etc.) are used for the antiglare sheet. An antistatic effect may be imparted to the antiglare sheet by reducing the surface resistance (for example, 10 ⁹ or less). The addition amount of the fine particles may be about 3 to 90% (preferably 5 to 50%) with respect to the entire material forming the antiglare sheet.

[Structure and material of antiglare sheet]
The antiglare sheet having such characteristics may be formed as a single-layer antiglare sheet, or may be a laminated sheet in which a layer having a concavo-convex structure is formed on a base sheet.

  The antiglare sheet is not particularly limited as long as it is made of a transparent material, and may be made of an inorganic substance (glass, silica, alumina, etc.), but is usually made of at least a transparent resin. . Further, it may be composed of a plurality of components, for example, a combination of a plurality of transparent resins, an inorganic substance (for example, inorganic particles such as glass, alumina, aluminum hydroxide, mica, talc, montmorillonite, and clay) A combination with a transparent resin may be used. Further, the transparent resin may contain a non-transparent resin, a non-transparent inorganic substance, or the like as long as the transparency is not impaired. Among these, an antiglare sheet composed of a transparent resin or a combination of a plurality of transparent resins is preferable.

  Transparent resins include, for example, thermoplastic resins [cellulose derivatives, olefin resins (including alicyclic olefin resins), halogen-containing resins, vinyl alcohol resins, organic acid vinyl ester resins, (meth) acrylic resins. Styrene resin, polyester resin, polyamide resin, polycarbonate resin, polyether resin, polysulfone resin, thermoplastic polyurethane resin, polysulfone resin, polyphenylene ether resin, etc.], rubber or thermoplastic elastomer [polybutadiene, Diene rubber such as polyisoprene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, acrylic rubber, urethane rubber, silicone rubber, etc.], heat or photo-curing resin or precursor [epoxy resin, unsaturated polyester resin Diallyl phthalate resins, silicone resins, polyurethane resins, epoxy (meth) acrylate, allyl glycidyl ether, urethane (meth) acrylate, polyester (meth) acrylate, etc.] and the like. These transparent resins can be used alone or in combination of two or more.

Among these transparent resins, alicyclic olefin resins, vinyl acetate resins, (meth) acrylic resins, styrene resins, polyester resins, polycarbonate resins, polyamide resins, cellulose derivatives, and other thermoplastic resins, , Heat or photo-curing resins such as epoxy (meth) acrylate and allyl glycidyl ether, especially alicyclic olefin resins [cyclic olefins (norbornene, dicyclopentadiene, etc.) or copolymers, Copolymer with a polymerizable monomer (ethylene-norbornene copolymer, propylene-norbornene copolymer, etc.)], styrene resin [polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer ( AS resin), styrene-butadiene copolymer, etc.], (Meth) acrylic resins [poly (meth) methyl acrylate, etc.], cellulose derivatives [cellulose acetate (cellulose diacetate, cellulose triacetate, etc.), cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate Cellulose C _1-5 Organic Acid Esters, CMC (Carboxymethyl Cellulose), Ethyl Cellulose, Hydroxymethyl Cellulose, Hydroxy Ethyl Cellulose, and Other Cellulose Ethers], Epoxy (Meth) Acrylate [Epoxy Cyclohexenyl (Meth) Acrylate, etc. Epoxy Cyclo C _5-8 alkenyl (meth) acrylate, glycidyl (meth) acrylate, etc.] are preferred.

  The thickness of the antiglare sheet can be selected from a range of about 1 to 500 μm, preferably 3 to 300 μm, more preferably about 5 to 200 μm (particularly 10 to 100 μm).

  A low refractive index layer may be further formed on the surface of the antiglare sheet in order to reduce the surface reflectance. As the low refractive index layer, a conventional low refractive index layer, for example, a low refractive index layer described in JP-A-2001-100006 can be used. Such a low refractive index layer may be composed of, for example, a polymerized (or crosslinked) product such as a fluorine-containing monomer or a silane compound. Furthermore, the low refractive index layer may contain an inorganic filler in order to improve the coating film strength. When the inorganic filler is included, it is preferable that the inorganic filler is dispersed in the fluorine-containing monomer or silane compound polymerized by heat, moisture, ionizing radiation or the like.

Examples of the fluorine-containing monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.) Is mentioned. These fluorine-containing monomers are acrylic monomers having a reactive group (for example, hydroxy C _1-6 alkyl such as (meth) acrylic acid, glycidyl (meth) acrylate, methylol (meth) acrylate, hydroxyethyl (meth) acrylate). (Meth) acrylate, allyl (meth) acrylate, etc.) may be cross-linked, such as olefins (ethylene, propylene, etc.), acrylic monomers ((meth) acrylic acid, methyl (meth) acrylate, (Meth) acrylic acid ester such as 2-ethylhexyl acrylate) or a copolymerizable monomer of styrene monomer (such as styrene or divinylbenzene).

  Examples of the silane compound include a perfluoroalkyl group-containing silane compound [eg, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane].

  As the inorganic filler used in the low refractive index layer, for example, the filler described in JP-A-2001-100006 can be used, but a low refractive index filler such as silica or magnesium fluoride, particularly silica is preferable.

  The average particle size of the inorganic filler is 0.1 μm or less, preferably 0.05 μm or less (for example, 0.01 to 0.05 μm), more preferably about 0.01 to 0.04 μm.

  The proportion of the inorganic filler in the low refractive index layer may be, for example, 1% by weight or more, for example, about 5 to 90% by weight. The inorganic filler may be surface-modified with a coupling agent (titanium coupling agent, silane coupling agent).

  The refractive index of the low refractive index layer is, for example, about 1.3 to 1.5, preferably about 1.35 to 1.45.

  The thickness of the low refractive index layer is, for example, about 0.05 to 0.2 μm, preferably 0.06 to 0.15 μm, and more preferably about 0.07 to 0.12 μm.

  If necessary, the antiglare sheet is further provided with a thin film such as an antistatic layer (for example, a conductive thin film composed of a photocurable resin containing a conductive agent or a hydrophilic component) on the surface thereof. May be. The thickness of these thin films is, for example, about 0.01 to 10 μm, preferably about 0.03 to 1 μm, and more preferably about 0.05 to 0.1 μm.

[Production method of anti-glare sheet]
The production method of the antiglare sheet of the present invention is not particularly limited as long as the antiglare sheet having the above structure can be formed. For example, spherical fine particles are dispersed in a curable resin solution, applied to a substrate, dried, and cured. Therefore, it is difficult to produce the antiglare sheet of the present invention by the method of forming the concavo-convex structure on the surface. That is, as shown in FIG. 11, even if it is assumed that the fine particles are packed most closely, the ratio R ₁ / S _m between the average curvature radius R ₁ and the average interval S _m between the tops of the convex portions is R ₁ / S _m ≈0.5, and it is difficult to satisfy the formula (2). In actual cross-sectional profile measurement, the convex curve may deviate from the apex of the convex curved surface, and the curvature radius of the convex curved surface becomes the radius of the fine particles due to volume shrinkage accompanying the curing of the curable resin. In some cases, the above curvature is obtained. However, even in consideration of these cases, it can be estimated that R ₁ / S _m ≈3 is the limit in the method using fine particles. That is, it is difficult to produce the antiglare sheet of the present invention by such a method.

The method for producing an antiglare sheet according to the present invention includes, for example, processing the resin surface with laser light (for example, laser light such as YAG laser, CO ₂ laser, Ar laser, and excimer laser, particularly excimer laser light). A stamping method (such as a method described in Japanese Patent Laid-Open No. 9-193332) or the like, in which a plate having a certain concavo-convex structure is prepared in advance and transferred to a base film to form the concavo-convex structure. Also good. A method of forming a concavo-convex structure by phase separation of a plurality of resins is preferable because a (smooth) surface having the above characteristics can be easily formed. Further, these production methods may be a method of molding a resin composition containing the transparent resin or the like. However, from the viewpoint of simplicity, the transparent substrate (for example, the transparent material, particularly the transparent material). A method of forming a concavo-convex structure by applying a resin composition containing the transparent resin or the like on a substrate composed of a resin, in particular, a resin composition containing a plurality of resins on the transparent substrate. A method of forming (inducing) a concavo-convex structure by applying an object and phase-separating a plurality of resins is preferable.

  As such a method, for example, a plurality of incompatible polymers are each dissolved in a solvent, and a solution obtained by liquid-liquid phase separation in a sea-island structure is applied to a base sheet and dried, or a common solvent is used. Examples include a method in which a solution in which a plurality of incompatible polymers are compatible is applied to a substrate sheet, and a concavo-convex structure is formed by phase separation (spinodal decomposition) accompanying drying. In these methods, a thermal or photopolymerizable component (a reactive or photopolymerizable component such as a polymerizable oligomer and / or monomer) is used together with or in place of a polymer, and after film formation, an active energy ray ( It may be polymerized and cured by irradiation with ultraviolet rays, electron beams, or the like. Among these methods, in particular, by applying a solution in which a plurality of incompatible polymers are compatible with a common solvent to a base sheet, performing phase separation and drying after forming a sea-island structure, the above formula (1) and An uneven structure satisfying (2) can be easily formed. That is, when manufactured by this method, the three-dimensional shape of the island portion 13 is deformed into a disk shape (as shown in FIG. 12, an elliptical shape in the cross-sectional profile) due to the thickness shrinkage due to drying, and the surface has a smooth surface. A concavo-convex structure having

  Examples of the polymerizable oligomer include epoxy (meth) acrylate, polyurethane (meth) acrylate, and polyester (meth) acrylate. Examples of the polymerizable monomer include monofunctional monomers such as alkyl (meth) acrylate and vinyl pyrrolidone, alkylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Examples thereof include polyfunctional (meth) acrylates such as dipentaerythritol hexa (meth) acrylate.

  The ratio (weight ratio) between the polymer and the polymerizable component can be selected from the range of the former / the latter = 100/0 to 0.1 / 99.9, for example, 80/20 to 0.5 / 99.5. The ratio is preferably about 70/30 to 1/99, more preferably about 50/50 to 3/97 (particularly 70/30 to 5/95). In the polymerizable component, the ratio (weight ratio) between the oligomer and the monomer can be selected from the range of the former / the latter = 99/1 to 0/100, for example, 90/10 to 5/95, preferably 80 / It is about 20 to 10/90, more preferably about 70/30 to 20/80.

  Moreover, a solvent can be suitably selected according to the kind of a polymer or the said polymeric component, You may add a reaction initiator, a hardening | curing agent, etc. suitably. The characteristics of the concavo-convex structure can be adjusted by appropriately selecting the type and amount of drying time, curing time, solvent, polymer, polymerizable component, and additive. In particular, in the method of forming a concavo-convex structure by spinodal decomposition (wet spinodal decomposition), a method of phase separation at a low speed, for example, a method using a high-boiling solvent as a solvent, increasing the thickness of the coating film, and increasing the drying time Then, the gentle concavo-convex structure may be formed by a method of gradually evaporating the solvent or a method using a highly viscous coating solution.

  In addition, the sheet | seat in which the unevenness | corrugation was formed by phase separation in this way may be formed, and an anti-glare sheet may be manufactured with the said stamping method.

  The antiglare sheet of the present invention is used in various applications that require antiglare properties, such as a liquid crystal display (LCD) device, a plasma display device, a display device with a touch panel, an organic EL display device, an inorganic EL display device, and an FED device. It can be used for display devices such as. The anti-glare sheet of the present invention has high anti-glare properties, prevents reflection of external light, and has a high contrast on the display surface. The liquid crystal display device is particularly preferably used. When the antiglare sheet of the present invention is used in a liquid crystal display device, for example, an adhesive layer may be formed on one side and disposed on the outermost surface of the display, or may be used as a protective film for a polarizing plate.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the evaluation method at the time of mounting an anti-glare sheet in a liquid crystal display device is shown below.

Comparative Example 1
Cross-linked acrylic fine particles (average particle size 3 μm, dispersed particle size / average particle size = 1.1, refractive index 1.49) are dispersed in pentaerythritol triacrylate (PETA) and tripled (by weight) of ethyl acetate. Diluted with This solution is applied onto a cellulose triacetate film having a thickness of 80 μm (trade name “Fuji TAC-TD80U” manufactured by Fuji Photo Film Co., Ltd.), dried to a thickness of 5 μm, and then irradiated with ultraviolet rays (UV). A concavo-convex structure was formed. On the surface having this uneven structure, a heat-crosslinkable fluorine-containing resin solution having a refractive index of 1.42 (manufactured by JSR Corporation, trade name “OPSTA-TT1006”, solid content concentration 6% by weight) has an average thickness of 0.1 μm. Was applied in a thin film to produce an antiglare sheet. The antiglare sheet had a total light transmittance of 93.5%, a haze of 40%, and a transmission clarity of 35%.

Example 1
Acetic acid propionate cellulose ester (trade name “CAP482-20”, manufactured by Eastman Chemical Co., Ltd.) 4 parts by weight, reactive oligomer [(meth) acrylic acid- (meth) acrylic acid ester copolymer part of carboxyl group , 3,4-epoxycyclohexenyl methyl acrylate compound; Daicel UCB (UCB), Cyclomer P] 8.3 parts by weight, dipentaerythritol hexaacrylate (DPHA) 19.7 parts by weight 1.25 parts by weight of a reaction initiator (Ciba Specialty Chemicals, trade name “Irgacure 184”) to 68 parts by weight of a mixed solvent (methyl ethyl ketone / butanol (weight ratio) = 7.5 / 2.5) Dissolved to produce a clear and uniform solution. This solution was applied on a transparent film (trade name “ARTON”, manufactured by JSR Corporation) with a thickness of 80 μm using a wire coater # 50, dried for 5 minutes at room temperature, and further oven-dried at 80 ° C. for 2 minutes. A fine uneven structure was formed. By irradiating this film with ultraviolet rays from a metal halide lamp for about 30 seconds, the surface having a concavo-convex structure was cured.

  A heat-crosslinkable fluorine-containing resin solution (manufactured by JSR Corporation, trade name “OPSTA-TT1006”) was applied in a thin film shape with an average thickness of 0.1 μm to the surface having the uneven structure to produce an antiglare sheet. . The antiglare sheet had a total light transmittance of 93.5%, a haze of 7%, and a transmission clarity of 80%.

(Evaluation of anti-glare sheet)
A three-dimensional profile of the uneven surface of the antiglare sheet obtained in Comparative Example 1 measured with an atomic force microscope (AFM) is shown in FIG. Similarly, the three-dimensional profile about the uneven surface of the anti-glare sheet obtained in Example 1 is shown in FIG.

  FIG. 15 shows a table cross-sectional profile (a cross-sectional shape in a direction perpendicular to the sheet surface) in a vertical cross section measured with a contact-type step gauge on the uneven surface of the antiglare sheet obtained in Comparative Example 1. Similarly, the table | surface cross-sectional profile in the longitudinal direction cross section about the uneven | corrugated surface of the anti-glare sheet | seat obtained in Example 1 is shown in FIG.

  As apparent from FIGS. 13 to 16, the antiglare sheet obtained in Example 1 has a larger radius of curvature near the maximum of the convex portion than the antiglare sheet obtained in Comparative Example 1. Further, the antiglare sheet obtained in Example 1 has a relatively large radius of curvature near the maximum of the convex portion as compared to the radius of curvature near the minimum of the concave portion.

About the anti-glare sheet obtained in Comparative Example 1, the results of statistical analysis of the height distribution from the table cross-sectional profile created in the same manner as in FIG. 15 for 10 different places (total scan length of 5 mm) are shown in FIG. Table 1 shows the results of statistical analysis of various parameters. In the graph (a) of FIG. 17, the vertical axis normalizes the maximum height difference as 100%, shows the height from the minimum height position, the horizontal axis shows the frequency distribution of the height, In b), the horizontal axis indicates the integrated distribution. Thus, the 50% level of the vertical axis corresponds to the center line height Z _2. Similarly, the results of statistical analysis of the height distribution of the antiglare sheet obtained in Example 1 are shown in FIG. 18, and the results of statistical analysis of various parameters are shown in Table 1.

  Furthermore, the anti-glare sheet obtained in Example 1 and Comparative Example 1 was mounted on a cellulose triacetate film whose back surface was black-coated, and a variable angle photometer (Murakami Color Research Laboratory Co., Ltd., GP-200). The reflected light scattering behavior was measured by measuring the reflected light scattering. The incident light angle was set to −10 ° from the normal line of the film, a white light source with a diameter of 5 mm was incident on the film, the light receiver was turned, and the surface reflected scattered light was measured. The light receiving angle is set to 0 ° at a position 10 ° from the film normal so that the reflected light is substantially symmetric about 0 °. The measurement results are shown in FIG. In the figure, the vertical axis represents the luminous intensity, and is indicated by the gain of the reflected scattered light (meaning the brightness of the reflected scattered light with reference to the standard white plate, and the relative value when the reflected light of the standard white plate is 1). ing.

  The reflected light in the antiglare sheets obtained in Example 1 and Comparative Example 1 was angularly integrated, and the reflectance of incident light was analyzed, and both were 2.9%.

  As is clear from the results in FIG. 19, the antiglare sheet obtained in Example 1 has a specular reflection area and an antiglare sheet obtained in Example 1 in spite of the same reflectance. The reflected light intensity in the region where the reflection angle is large is suppressed.

The antiglare sheets obtained in Example 1 and Comparative Example 1 were respectively mounted on the surface of a VA (vertical alignment) LCD panel having a front luminance of 450 cd / m ² , a contrast of 400 to 1, 20 type, and a resolution of 60 ppi, Reflection of reflected light, white reflection in a specular reflection area (= sink of black display), white floating in a region having a large reflection angle, sharpness of characters and images, and fingerprint wiping properties were visually evaluated according to the following criteria. The results are also shown in Table 1.

  Here, with respect to whitening of the regular reflection area, a panel was placed under the fluorescent lamp so that the fluorescent lamp was reflected at the center of the panel, and the whitishness of the image near the regular reflection was evaluated. At the same time, the reflection was evaluated based on whether the shape of the fluorescent lamp was clearly visible at a position corresponding to the specular reflection direction. Further, as for whitening in a region where the reflection angle is large, the whitishness (blackness) of black display when a fluorescent lamp is illuminated at an angle of 45 ° from the front of the panel was evaluated.

(Reflection)
○: No reflection Δ: There is a slight reflection ×: The reflection is intense.

(Floating white in regular reflection area)
○: The image is not whitish and unnoticeable Δ: The image looks whitish ×: The image looks white.

(White floatation in areas with a large reflection angle)
○: Black display looks clear black △: Black display looks whitish ×: Black display looks white

(Clarity of text and images)
○: Visible clearly △: Visible ×: Difficult to see

(Fingerprint wiping)
○: Fingerprints can be easily wiped △: Fingerprints are difficult to wipe ×: Fingerprints cannot be wiped off

  As is clear from the results in Table 1, the antiglare sheet obtained in Example 1 has little whitening in the regular reflection region and the region where the reflection angle is large, and is excellent in contrast. On the other hand, the antiglare sheet obtained in Comparative Example 1 becomes whitish in the regular reflection region and the region where the reflection angle is large, and the sharpness is low. ,

FIG. 1 is a three-dimensional shape profile of the surface of the antiglare sheet of the present invention. FIG. 2 is a diagram obtained by slicing the concave / convex curved surface in the profile of FIG. 1 with the arithmetic average height in a direction parallel to the sheet surface. FIG. 3 is a concavo-convex profile in a longitudinal section in the three-dimensional shape profile of FIG. FIG. 4 is a graph showing the height distribution of the protrusions obtained from the uneven profile of FIG. FIG. 5 is a graph showing the relationship between the reflection angle and the reflected light intensity in the antiglare sheet of the present invention. FIG. 6 is a graph showing the relationship between the reflection angle and the reflected light intensity in a conventional antiglare sheet. FIG. 7 is a schematic view showing the relationship between the regular reflection direction and the reflection angle in the antiglare sheet. FIG. 8 is a schematic cross-sectional view of an antiglare sheet having a concavo-convex structure in which spherical convex portions are adjacent to each other. FIG. 9 is a graph showing the relationship between the reflection angle and the reflected light intensity in the antiglare sheet of FIG. FIG. 10 is a schematic diagram showing average radii of curvature R ₁ and R ₂ in the longitudinal cross section of the antiglare sheet of the present invention. FIG. 11 is a schematic diagram showing the relationship between the average radius of curvature R ₁ and the average interval S _m between the tops of the protrusions in the antiglare sheet obtained by the conventional manufacturing method. FIG. 12 is a schematic cross-sectional view of the antiglare sheet of the present invention. FIG. 13 is a three-dimensional shape profile of the antiglare sheet surface obtained in Comparative Example 1. FIG. 14 is a three-dimensional shape profile of the antiglare sheet surface obtained in Example 1. FIG. 15 is a table cross-sectional profile in a longitudinal section of the surface of the antiglare sheet obtained in Comparative Example 1. FIG. 16 is a cross-sectional profile in the longitudinal section of the surface of the antiglare sheet obtained in Example 1. FIG. 17 is a graph showing the height distribution of the antiglare sheet surface obtained in Comparative Example 1. FIG. 18 is a graph showing the height distribution of the antiglare sheet surface obtained in Example 1. FIG. 19 is a graph showing the relationship between the reflection angle and the reflected light intensity in the antiglare sheets obtained in Example 1 and Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Convex part 2 ... Concave part 3 ... Light source 4 ... Anti-glare sheet 5 ... Regular reflection direction

Claims (7)

The cross-sectional shape in the direction perpendicular to the sheet surface is a concavo-convex shape composed of a maximum portion constituted by a substantially arc-shaped curve and a minimum portion constituted by a substantially arc-shaped curve, The average curvature radius R ₁ of the arc curve in the maximum region of the maximum portion and the average curvature radius R ₂ of the arc curve in the minimum region of the minimum portion satisfy the following formula (1), and the average curvature radius: The antiglare sheet in which R ₁ and the average interval S _m between the tops of the convex portions satisfy the following formula (2).
1 ≦ R ₁ / R ₂ ≦ 5 (1)
4 ≦ R ₁ / S _m ≦ 15 (2) In vertical cross section with respect to the sheet surface, the average distance S _m between the top portion of the convex portion is 20 to 100 [mu] m, and claim 1 average line square average roughness R _q is 0.05~0.3μm The antiglare sheet as described.   The antiglare sheet according to claim 1, wherein an average inclination angle Δa of the concavo-convex portion with respect to the sheet surface is 0.5 to 2 °. In the cross-sectional shape in the direction perpendicular to the sheet surface, the arithmetic average line height Z ₁ and the center line height Z ₂ of the concavo-convex part satisfy the following formula (3), and the center line height Z ₂ or more The antiglare sheet according to claim 1, wherein the area of the curved surface is 20% or more with respect to the entire surface.
| Z ₂ −Z ₁ | ≦ 0.1 μm (3)   At least one selected from alicyclic olefin resins, vinyl acetate resins, (meth) acrylic resins, styrene resins, polyester resins, polycarbonate resins, polyamide resins, cellulose derivatives, and epoxy (meth) acrylates The antiglare sheet according to claim 1, which is composed of a transparent resin.   The method for producing an antiglare sheet according to claim 1, wherein a plurality of resins are phase-separated using spinodal decomposition.   A display device comprising the antiglare sheet according to claim 1.

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