JP5135871B2 - Anti-glare film, anti-glare polarizing plate and image display device - Google Patents

Description

  The present invention is not anti-glare while exhibiting excellent anti-glare performance, and when applied to an image display device, the anti-glare (anti-glare) film that exhibits high contrast without causing glare and gives good visibility, The present invention relates to an antiglare polarizing plate and an image display device provided with the antiglare film.

  In an image display device such as a liquid crystal display, a plasma display panel, a cathode ray tube (CRT) display, and an organic electroluminescence (EL) display, visibility is significantly impaired when external light is reflected on the display surface. In order to prevent such reflection of external light, TVs and personal computers that emphasize image quality, video cameras and digital cameras used outdoors with strong external light, mobile phones that display using reflected light, etc. In the conventional art, a film layer for preventing the reflection of external light has been provided on the surface of the image display device. This film layer consists of a film that has been subjected to anti-reflection treatment using interference by the optical multilayer film, and anti-glare treatment that scatters incident light by blurring the incident light by forming fine irregularities on the surface. It is divided roughly into the thing which consists of the film which was given. Among these, the former non-reflective film needs to form a multilayer film having a uniform optical film thickness, and thus increases the cost. On the other hand, since the latter anti-glare film can be produced at a relatively low cost, it is widely used in applications such as large personal computers and monitors.

  Conventionally, such an antiglare film has, for example, a resin solution in which a filler is dispersed is applied on a base sheet, and the coating film thickness is adjusted to expose the filler on the surface of the coating film, thereby causing random unevenness on the sheet. It is manufactured by the method of forming on top. However, the antiglare film produced by dispersing such a filler has an unevenness as intended because the arrangement and shape of the unevenness depends on the dispersion state and application state of the filler in the resin solution. There is a problem that it is difficult to obtain, and sufficient anti-glare performance cannot be obtained if the haze is low. Furthermore, when such a conventional anti-glare film is disposed on the surface of an image display device, there is a problem that the entire display surface becomes whitish due to scattered light, and the display becomes cloudy, so-called whitening is likely to occur. It was.

  In addition, with recent high-definition image display devices, the pixels of the image display device and the surface irregularity shape of the antiglare film interfere with each other, and as a result, a so-called glare phenomenon that the luminance distribution is generated and is difficult to see easily occurs. There was also a problem. In order to eliminate glare, there is an attempt to scatter light by providing a difference in refractive index between the binder resin and the dispersion filler, but when such an antiglare film is applied to an image display device, scattered light is scattered. As a result, the luminance at the time of black display is increased, and as a result, there is a problem that the contrast is lowered and the visibility is remarkably lowered.

  On the other hand, there is also an attempt to develop anti-glare properties only by fine irregularities formed on the surface of the transparent resin layer without containing a filler. For example, Japanese Patent Application Laid-Open No. 2002-189106 (Patent Document 1) discloses that the ionizing radiation curable resin is cured in a state where the ionizing radiation curable resin is sandwiched between an embossing mold and a transparent resin film. An ionizing radiation curable resin in which fine irregularities are formed in which the average distance between adjacent convex portions on the original 10-point average roughness and the three-dimensional roughness reference surface satisfies predetermined values, respectively, and the irregularities are formed. An antiglare film having a layer provided on the transparent resin film is disclosed. This document describes that an uneven surface for embossing is formed by a sandblasting method or a bead shot method, preferably using a roller having a chromium plating on the surface of iron. Furthermore, it is preferable to use the mold surface with the unevenness after applying chrome plating for the purpose of improving durability during use, thereby achieving hardening and corrosion prevention. There is also a statement that it is possible.

  In such an embossing roll manufacturing method, since blasting or shot is performed on chromium plating with high hardness, it is difficult to form unevenness and it is difficult to precisely control the shape of the formed unevenness. In addition, as described in Japanese Patent Application Laid-Open No. 2004-29672 (Patent Document 2), the chrome plating often has a rough surface depending on the material and shape of the base, and the surface of the unevenness formed by blasting Since fine cracks generated by chrome plating are formed on the surface, there is a problem that it is difficult to design what kind of irregularities can be formed. Furthermore, since there are fine cracks generated by chrome plating, there is also a problem that the scattering characteristics of the finally obtained antiglare film change in an unfavorable direction.

  As another document disclosing the production method of a roll used for producing a film having irregularities on the surface, for example, JP 2004-29240 A (Patent Document 3) and JP 2004-90187 A (Patent Document 4). There is. The former document discloses a method for producing an embossing roll by a bead shot method, and the latter document includes a step of forming a metal plating layer on the surface of the embossing roll, and the surface of the metal plating layer is mirror-polished. There has been disclosed a method for producing an embossing roll through a step, a step of performing a blast treatment using ceramic beads on the mirror-polished metal plating layer surface, and a step of performing a peening treatment as necessary.

  Thus, in the state where the surface of the embossing roll has been subjected to blasting, the uneven diameter distribution resulting from the particle size distribution of the blast particles occurs, and it is difficult to control the depth of the indentation obtained by blasting. In addition, there is a problem in obtaining an uneven shape having an excellent antiglare function with good reproducibility.

  Japanese Patent Application Laid-Open No. 2006-53371 (Patent Document 5) relating to the application of the present applicant discloses that a metal is bumped on a polished metal surface to form irregularities, and then electroless nickel plating is applied to the gold metal. It is disclosed that an anti-glare film having excellent anti-glare performance while having low haze is obtained by forming a mold and transferring the uneven surface of the mold to a transparent resin film.

Furthermore, there are JP-A 2003-248101 (Patent Document 6) and JP-A 2004-126495 (Patent Document 7) as documents defining the transmitted scattered light intensity of the antiglare film. The former document is a film having an antiglare hard coat layer on a transparent support, which is inclined by 5 ° with respect to the amount of light (I ₀ ) that is incident from the transparent support side and travels straight through the transmitted light. The ratio (I ₅ / I ₀ ) of the light quantity (I ₅ ) scattered in the direction is 3.5% or more, and the ratio (I ₂₀ ) of the light quantity (I ₂₀ ) scattered in the direction inclined by 20 ° with respect to I ₀ An antiglare antireflection film having a / I ₀ ) of 0.1% or less is disclosed. The latter document discloses an antiglare film having a scattering angle showing a maximum value of scattered light intensity of 0.1 to 10 ° and a total light transmittance of 70 to 100%. Even with the antiglare films disclosed in these documents, it has been difficult to maintain high contrast, particularly when applied to a high-definition image display device.

JP 2002-189106 A (Claims 1 to 6, paragraphs 0043 to 0046) JP 2004-29672 A (paragraph 0030) JP 2004-29240 A (Claim 2) JP-A-2004-90187 (Claims 1 and 2) JP 2006-53371 A (Claims 1 and 2) JP 2003-248101 A (Claim 1) JP 2004-126495 A (Claim 1)

  The present invention shows excellent anti-glare performance, prevents deterioration of visibility due to whitening, and exhibits high contrast without causing glare when placed on the surface of a high-definition image display device. An object of the present invention is to provide an antiglare film and to provide an antiglare polarizing plate and an image display device to which the antiglare film is applied.

  As a result of intensive studies to solve the above problems, the present inventors have obtained an anti-glare film in which an antiglare layer having a fine uneven surface is formed on a transparent support, and an incident angle of 20 from the transparent support side. The anti-glare layer when the relative scattered light intensity T (20) in the normal direction of the anti-glare layer side when the light is incident at a temperature shows a specific value and the light is incident at an incident angle of 30 ° from the transparent support side. If the relative scattered light intensity T (30) in the side normal direction shows a specific value, glare is sufficiently prevented and the contrast hardly decreases when applied to an image display device. I found it. Further, in this antiglare film, when light is incident from the antiglare layer side at an incident angle of 30 °, the reflectance R (30) at a reflection angle of 30 °, the reflectance R (40) at a reflection angle of 40 °, and the reflection It has been found that if the reflectance R (50) at an angle of 50 ° is set to a specific value, it is more effective in effectively preventing whitening while exhibiting excellent antiglare properties. The present invention has been completed based on such findings and further various studies.

  That is, the antiglare film according to the present invention is formed by forming an antiglare layer having a fine uneven surface on a transparent support, and the antiglare layer side method when light is incident at an incident angle of 20 ° from the transparent support side. Relative scattering in the normal direction of the antiglare layer when the relative scattered light intensity T (20) in the linear direction is 0.0001% or more and 0.0005% or less and light is incident at an incident angle of 30 ° from the transparent support side. The light intensity T (30) is 0.00004% to 0.0025%.

  In this antiglare film, when light is incident at an incident angle of 30 ° from the antiglare layer side, the reflectance R (30) at a reflection angle of 30 ° is 0.05% or more and 2% or less. The reflectivity R (40) at 60 ° is 0.0001% or more and 0.005% or less, and the reflectivity R (50) at a reflection angle of 50 ° is 0.0001% or more and 0.0005% or less. preferable.

  Moreover, it is preferable that the surface haze when light is vertically incident on the antiglare film is 0.1% or more and 5% or less, and the total haze is 5% or more and 25% or less.

  This anti-glare film uses the three types of optical combs with the dark and bright widths of 0.5 mm, 1.0 mm and 2.0 mm to calculate the sum of the reflected sharpness measured at a light incident angle of 45 °. It can be 40% or less.

Furthermore, this anti-glare film has an arithmetic average height Pa of 0.05 μm or more and 0.2 μm or less in a cross-sectional curve of the uneven surface constituting the anti-glare layer, and a maximum cross-sectional height Pt of 0.2 μm or more and 1 μm or less. The average length PSm is preferably 15 μm or more and 30 μm or less. The uneven surface constituting the antiglare layer preferably has 50 or more and 100 or less protrusions in a 200 μm × 200 μm region, and is formed when the surface is Voronoi-divided with the protrusion vertices serving as mother points. average area of the polygon to be found is preferably 100 [mu] m ² or more 1,000 .mu.m ² or less.

  The antiglare layer in the antiglare film preferably has surface irregularities formed by transfer from a mold having an uneven surface. The antiglare layer is composed of 10 to 100 parts by weight of fine particles having an average particle diameter of 5 to 15 μm and a refractive index difference of 0.01 to 0.06 with respect to the binder resin with respect to 100 parts by weight of the binder resin. It is preferable that the fine particles are contained, and further, it is preferable that the fine particles are completely buried in the antiglare layer, and the fine particles do not affect the uneven shape of the surface.

  In this antiglare film, a low reflection film can be formed on the uneven surface of the antiglare layer.

  The antiglare film of the present invention can be used as an antiglare polarizing plate in combination with a polarizer comprising a polyvinyl alcohol-based resin. Specifically, the antiglare polarizing plate has a structure in which the transparent support side of the antiglare film is bonded to a polarizer.

  In addition, the antiglare film or the antiglare polarizing plate of the present invention can be combined with an image display element such as a liquid crystal display element or a plasma display panel to form an image display device. Therefore, an image display device according to the present invention includes the antiglare film or the antiglare polarizing plate and the image display means, and the antiglare film or the antiglare polarizing plate is disposed on the viewing side of the image display element. Is.

  The anti-glare film of the present invention has excellent anti-glare performance, prevents deterioration of visibility due to whitening, and does not cause glare when placed on the surface of a high-definition image display device. High contrast is exhibited. An antiglare polarizing plate in which this antiglare film is combined with a polarizer also exhibits the same effect. And the image display apparatus which has arrange | positioned the anti-glare film or anti-glare polarizing plate of this invention has high anti-glare performance, and becomes what was excellent in visibility.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The antiglare film of the present invention is such that an antiglare layer having a fine uneven surface is formed on a transparent support, and the antiglare layer when light is incident at an incident angle of 20 ° from the transparent support side. Anti-glare layer when the relative scattered light intensity T (20) observed in the side normal direction shows a value of 0.0001% or more and 0.0005% or less and light is incident at an incident angle of 30 ° from the transparent support side. The relative scattered light intensity T (30) observed in the side normal direction shows a value of not less than 0.00004% and not more than 0.0025%.

  In order to effectively suppress the whitish while exhibiting excellent anti-glare performance, when light is incident at an incident angle of 30 ° from the anti-glare layer side, the reflectance R (30 ) Is 0.05% or more and 2% or less, reflectance R (40) at a reflection angle of 40 ° is 0.0001% or more and 0.005% or less, and reflectance R (50) at a reflection angle of 50 ° Is preferably 0.0001% or more and 0.0005% or less.

[Relative scattered light intensity]
First, when light is incident from the transparent support side at an incident angle of 20 ° and when light is incident at an incident angle of 30 °, the relative scattered light intensities T (20) and T (30) in the normal direction of the antiglare layer side ).

  FIG. 1 shows the incident direction of light and transmitted scattering when light is incident from the transparent support side (opposite side of the uneven surface) and the scattered light intensity is measured in the normal direction of the antiglare layer side (uneven surface side). It is the perspective view which showed the light intensity measurement direction typically. With reference to this figure, the light 13 which is incident at an angle φ (incident angle) from the normal 12 on the transparent support side of the antiglare film 11 is transmitted in the normal direction 12 on the antiglare layer side. The intensity of the light 14 is measured, and a value obtained by dividing the transmitted scattered light intensity by the light intensity of the light source is defined as a relative scattered light intensity T (φ). That is, when the incident light 13 is incident on the transparent support side of the antiglare film 11 at an angle of 20 ° from the normal, the intensity of the emitted light 14 observed in the normal direction 12 of the antiglare layer side is set as the light intensity of the light source. When the incident light 13 is incident on the transparent support side of the antiglare film 11 at an angle of 30 ° from the normal 12 on the transparent support side of the antiglare film 11, it is observed in the normal direction 12 on the antiglare layer side. A value obtained by dividing the intensity of the emitted light 14 by the light intensity of the light source is T (30).

  When the relative scattered light intensity T (20) at 20 ° incidence exceeds 0.0005%, when this antiglare film is applied to an image display device, the luminance during black display increases due to the scattered light. This is not preferable because it reduces the contrast. Also, when the relative scattered light intensity T (20) at 20 ° incidence is less than 0.0001%, the scattering effect is low, and glare occurs when applied to a high-definition image display device. It is not preferable. Similarly, even when the relative scattered light intensity T (30) at 30 ° incidence exceeds 0.0025%, when this antiglare film is applied to an image display device, the luminance at the time of black display by the scattered light. Rises and lowers the contrast, which is not preferable. Also, when the relative scattered light intensity T (30) at 30 ° incidence is less than 0.00004%, the scattering effect is low, and glare occurs when applied to a high-definition image display device. Absent. In particular, when the antiglare film is applied to a liquid crystal display that is not a self-luminous type, the effect of increasing the brightness due to scattering caused by light leakage during black display is large, and therefore the relative scattered light intensities T (20) and T (30) are Exceeding the provisions of the invention results in a significant reduction in contrast and loss of visibility.

  References that have so far referred to transmitted and scattered light intensity include, for example, Patent Document 6 (Japanese Patent Laid-Open No. 2003-248101) and Patent Document 7 (Japanese Patent Laid-Open No. 2004-126495). However, unlike the scattering characteristics defined in the present invention, it was not necessarily sufficient to achieve high contrast and suppress glare when applied to an image display device.

  FIG. 2 is an example of a graph in which the relative scattered light intensity (logarithmic scale) measured by changing the incident angle φ from the transparent support side of the antiglare film 11 in FIG. 1 is plotted against the incident angle φ. Such a graph representing the relationship between the incident angle and the relative scattered light intensity, or the relative scattered light intensity for each incident angle read therefrom may be referred to as a transmission scattering profile. As shown in this graph, the relative scattered light intensity has a peak at an incident angle of 0 °, and the scattered light intensity tends to decrease as the angle from the normal direction of the incident light 13 deviates. The incident angles plus (+) and minus (-) are determined by the inclination of the incident light in the plane 19 including the direction 13 and the normal 12 of the incident light with the normal direction (0 °) as the center. It is. Therefore, the transmission / scattering profile usually appears symmetrically about the incident angle of 0 °. In the example of the transmission scattering profile shown in FIG. 2, the relative scattered light intensity T (0) at 0 ° incidence shows a peak at about 30%, and the relative scattered light intensity T (20) at 20 ° incidence is about The relative scattered light intensity T (30) at an incidence of 0.00002% and 30 ° is about 0.00004%.

  In measuring the relative scattered light intensity of the antiglare film, it is necessary to accurately measure the relative scattered light intensity of 0.001% or less. Therefore, it is effective to use a detector with a wide dynamic range. As such a detector, for example, a commercially available optical power meter can be used, and an aperture is provided in front of the detector of the optical power meter so that the angle at which the antiglare film is viewed is 2 °. Measurements can be made using an angle photometer. Visible light of 380 to 780 nm can be used as incident light, and a collimated light emitted from a light source such as a halogen lamp can be used as a measurement light source, or parallelism with a monochromatic light source such as a laser. Higher ones may be used. Moreover, in order to prevent the curvature of a film, it is preferable to use it for a measurement, after bonding to a glass substrate so that an uneven surface may become the surface using an optically transparent adhesive.

[Reflectance at 30 ° incidence]
Next, the reflectance for each angle when light is incident at an incident angle of 30 ° from the antiglare layer side will be described. FIG. 3 is a perspective view schematically showing an incident direction and a reflection direction of light from the antiglare layer side with respect to the antiglare film when the reflectance is obtained. Referring to this figure, the incident light 15 incident on the antiglare layer side of the antiglare film 11 at an angle of 30 ° from the normal 12 is reflected in the direction of the reflection angle of 30 °, that is, in the regular reflection direction 16. The light reflectance (that is, regular reflectance) is R (30). The reflected light at an arbitrary reflection angle θ is denoted by reference numeral 17, and the directions 16 and 17 of the reflected light when measuring the reflectance are in the plane 19 including the direction 15 of the incident light and the normal line 12. And The reflectance in the direction with a reflection angle of 40 ° is R (40), and the reflectance in the direction with a reflection angle of 50 ° is R (50).

  In the antiglare film of the present invention, the reflectance in the direction of the reflection angle of 30 °, that is, the regular reflectance R (30) is 0.05% or more and 2% or less with respect to the incident light having the incident angle of 30 °. It is preferable to do this. Further, the reflectance R (40) in the direction of the reflection angle 40 ° is 0.0001% to 0.005%, and the reflectance R (50) in the direction of the reflection angle 50 ° is 0.0001% to 0.0005%. The following is preferable.

  When the regular reflectance R (30) exceeds 2%, a sufficient antiglare function cannot be obtained, and the visibility is deteriorated. On the other hand, even if the regular reflectance R (30) is too small, it tends to cause whitishness, so it is preferably 0.05% or more. The regular reflectance R (30) is more preferably 1.5% or less, particularly 0.7% or less. On the other hand, if R (40) exceeds 0.005% or R (50) exceeds 0.0005%, the antiglare film will be whitish and visibility will be reduced. That is, for example, even when black is displayed on the display surface with an anti-glare film installed on the forefront of the display device, a whitish color occurs that picks up light from the surroundings and makes the display surface entirely white. There is a tendency. Therefore, it is preferable that R (40) and R (50) are not so large. On the other hand, R (40) is generally preferably 0.0001% or more and R (50) is generally 0, since sufficient antiglare properties are not exhibited even if the reflectance at these angles is too small. It is preferable that it is 0.0001% or more. R (50) is more preferably 0.0001% or less.

  4 shows the reflection angle and the reflectance (the reflectance is a logarithmic scale) of the reflected light 17 with respect to the incident light 15 incident at an angle of 30 ° from the normal 12 on the antiglare layer side of the antiglare film 11 in FIG. It is an example of the plotted graph. Such a graph representing the relationship between the reflection angle and the reflectance, or the reflectance for each reflection angle read from the graph may be referred to as a reflection profile. As shown in this graph, the regular reflectance R (30) is a reflectance peak with respect to the incident light 15 incident at 30 °, and the reflectance tends to decrease as the angle deviates from the regular reflection direction. In the example of the reflection profile shown in FIG. 4, the regular reflectance R (30) is about 0.2%, R (40) is about 0.0004%, and R (50) is about 0.00005%. .

  According to the investigations of the present inventors, most of the antiglare films currently on the market are of a type in which fillers are dispersed, and in such antiglare films, relative to 20 ° incidence The scattered light intensity T (20) is 0.0001% or more and 0.0005% or less, and the relative scattered light intensity T (30) at 30 ° incidence is 0.00004% or more and 0.0025% or less. There wasn't. In addition to the transmission scattering characteristics, the regular reflectance R (30) is 0.05% or more and 2% or less, and the reflectance R (40) at a reflection angle of 40 ° is 0.0001% or more and 0.005%. In the following, there was no case where the reflectance R (50) at a reflection angle of 50 ° was from 0.0001% to 0.0005%. As a result, there was no anti-glare film that did not cause glare, did not generate glare, showed high contrast, and exhibited sufficient anti-glare performance. On the other hand, it was found that the antiglare film defined in the present invention was excellent in that whitishness was suppressed while exhibiting sufficient antiglare performance.

  In measuring the reflectance of the antiglare film, it is necessary to accurately measure a reflectance of 0.001% or less as in the case of the relative scattered light intensity. Therefore, it is effective to use a detector with a wide dynamic range. As such a detector, for example, a commercially available optical power meter can be used, and an aperture is provided in front of the detector of the optical power meter so that the angle at which the antiglare film is viewed is 2 °. Measurements can be made using an angle photometer. As incident light, visible light of 380 to 780 nm can be used, and as a measurement light source, collimated light emitted from a light source such as a halogen lamp may be used, or a monochromatic light source such as a laser is used in parallel. A high degree may be used. In the case of an antiglare film having a smooth and transparent back surface, reflection from the back surface of the antiglare film may affect the measured value. For example, the smooth surface of the antiglare film is adhered to a black acrylic resin plate with an adhesive or It is preferable that only the reflectance on the outermost surface of the antiglare film can be measured by optical adhesion using a liquid such as water or glycerin.

[Haze]
In addition, the antiglare film of the present invention has a surface haze of 0.1% or more with respect to normal incident light in order to prevent whitening and to effectively suppress glare when applied to a high-definition image display device. The total haze is preferably 5% or more and 25% or less. The total haze of the antiglare film can be measured according to the method described in JIS K 7136. The surface haze and internal haze can be separated by measuring the overall haze, pasting a transparent film having a haze of almost 0 on the uneven surface, measuring the internal haze, and obtaining the surface haze by the following formula.

      Surface haze = Overall haze-Internal haze

  The haze value measured in a state where a transparent film having a haze of approximately 0 is pasted on the uneven surface of the antiglare film is considered to represent the internal haze in effect because the surface haze caused by the original unevenness is almost canceled. Good. The transparent film having substantially no haze is not particularly limited as long as the haze is small. For example, a triacetyl cellulose film may be used.

  If the surface haze exceeds 5%, whitening tends to occur. If the surface haze is less than 0.1%, sufficient antiglare property is not exhibited, which is not preferable. Further, the total haze is preferably 5% or more in order to effectively eliminate glare. However, if the total haze exceeds 25%, when applied to an image display device, the screen becomes dark as a result, and visibility is impaired.

[Reflection sharpness]
The antiglare film of the present invention also has a reflection sharpness measured at a light incident angle of 45 ° using three types of optical combs having a dark portion and a bright portion width of 0.5 mm, 1.0 mm, and 2.0 mm. Is preferably 40% or less. Reflection sharpness is measured by the method specified in JIS K 7105. In this standard, the ratio of the width of the dark part to the bright part is 1: 1 and the width is 0.125 mm, 0.5 mm, 1.0 mm, and 2.0 mm as an optical comb used for measuring the image definition. The type is specified. Among these, when an optical comb with a width of 0.125 mm is used, the measurement error when using an optical comb with a width of 0.125 mm is large because an error in the measured value becomes large in the antiglare film defined in the present invention. The value is not added to the sum, and the sum of image sharpness measured using three types of optical combs having widths of 0.5 mm, 1.0 mm, and 2.0 mm is referred to as reflection sharpness. In this definition, the maximum value of the reflection definition is 300%. When the reflection definition according to this definition exceeds 40%, an image of a light source or the like is clearly reflected, which is not preferable because of poor antiglare property.

  However, when the reflection sharpness is 40% or less, it is difficult to compare the superiority and inferiority of the antiglare property only from the reflection sharpness. This is because when the reflection definition according to the above definition is 40% or less, each reflection definition using an optical comb having a width of 0.5 mm, 1.0 mm, and 2.0 mm is at most about 10%, resulting in a measurement error. This is because the fluctuation of the reflection definition due to the above cannot be ignored. Therefore, in the present invention, for the antiglare film having a reflection definition of 40% or less, by defining the relative scattered light intensity, preferably by combining it with the reflectance at 30 ° incidence, This is an index that can be used to favorably evaluate glare performance.

[Surface shape]
Next, the surface shape of the antiglare layer uneven surface of the antiglare film will be described. The antiglare film of the present invention suppresses glare more effectively, and makes the texture when the appearance visually observed uniform and uniform. It is preferable to satisfy the requirements.

(1) In the cross-sectional curve of the concavo-convex surface constituting the antiglare layer, the arithmetic average height Pa is 0.05 μm or more and 0.20 μm or less, and the maximum cross-sectional height Pt is 0.2 μm or more and 1.0 μm or less. The average length PSm is not less than 15 μm and not more than 30 μm,
(2) The uneven surface constituting the antiglare layer has 50 to 100 protrusions in the region of 200 μm × 200 μm,
(3) the average area of a polygon convex apex of the concave-convex surface constituting the antiglare layer is formed when the Voronoi dividing the surface as a base point of 100 [mu] m ² or more 1,000 .mu.m ² or less.

  First, the arithmetic average height Pa, the maximum cross-sectional height Pt and the average length PSm in the cross-sectional curve of the uneven surface constituting the antiglare layer will be described. These values are defined in JIS B 0601 (= ISO 4287), and the arithmetic average height Pa is the same as the value called the center line average roughness.

  When the arithmetic average height Pa on the cross-sectional curve of the uneven surface is less than 0.05 μm, the antiglare film surface becomes almost flat and does not exhibit sufficient antiglare performance, which is not preferable. Further, when the arithmetic average height Pa is larger than 0.2 μm, the surface shape becomes rough, whitening occurs, and the texture when the appearance is visually observed becomes rough. When the maximum cross-sectional height Pt in the cross-sectional curve of the uneven surface is less than 0.2 μm, the anti-glare film surface is still almost flat and does not exhibit sufficient anti-glare performance, which is not preferable. On the other hand, when the maximum cross-sectional height Pt is larger than 1 μm, the surface shape becomes too rough, which causes problems such as whiteness and deterioration in texture, which is not preferable. When the average length PSm in the cross-sectional curve of the uneven surface is less than 15 μm, it is not preferable because sufficient antiglare property cannot be obtained. This is presumably because if the average length PSm is too small, the peak of the unevenness (the surface inclination angle is considered to be almost 0 °) is close, so that an image is formed when visually observed. On the other hand, when the average length PSm is larger than 20 μm, the texture when the appearance is visually observed becomes rough.

  The arithmetic average height Pa, the maximum cross-sectional height Pt, and the average length PSm in the cross-sectional curve of the uneven surface can be measured using a commercially available general contact surface roughness meter in accordance with JIS B 0601. . It is also possible to measure the surface shape with an apparatus such as a confocal microscope, an interference microscope, or an atomic force microscope (AFM), and obtain the value by calculation from the three-dimensional information of the surface shape. In addition, when calculating from three-dimensional information, in order to ensure sufficient reference length, it is preferable to measure three or more areas of 200 μm × 200 μm or more and use the average value as a measurement value.

  Next, the number of convex portions observed on the uneven surface will be described. If the number of projections on the uneven surface is small, it is not preferable because when used in combination with a high-definition image display device, glare occurs due to interference with the pixels, the image becomes difficult to see, and the texture also deteriorates. . Moreover, when the number of convex parts increases too much, as a result, the inclination angle of the surface irregularity shape becomes steep, and whitening tends to occur. Therefore, it is preferable that the uneven surface has 50 or more and 100 or less protrusions in a 200 μm × 200 μm region.

  In determining the number of protrusions on the concavo-convex surface of the antiglare film, the surface shape is measured with an apparatus such as a confocal microscope, an interference microscope, an atomic force microscope (AFM), etc. After obtaining a coordinate value, a convex portion is determined by the following algorithm, and the number of the convex portions is counted. That is, when an arbitrary point on the surface of the antiglare film is focused on, there is no point higher than the focused point around that point, and the altitude on the uneven surface of that point is the highest of the uneven surface. When the altitude of the point is higher than the middle of the lowest point, the point is assumed to be the vertex of the convex portion, and the number of convex vertices thus obtained is counted to obtain the number of convex portions.

  More specifically, as shown in FIG. 5, paying attention to an arbitrary point 21 on the surface of the antiglare film, a circle having a radius of 2 μm to 5 μm parallel to the reference surface 23 of the antiglare film is drawn around the point 21. The point on the antiglare film surface 22 included in the projection surface 24 of the circle does not have a point higher than the point 21 of interest, and the height of the uneven surface of the point is When the altitude is higher than the midpoint between the highest point and the lowest point, the point 21 is determined to be the apex of the convex portion, and the number of convex portions is obtained. At this time, the radius of the circle 24 is required to be a size that does not count fine irregularities on the sample surface and does not include a plurality of convex portions, and is preferably about 3 μm. At the time of measurement, in order to reduce errors, it is preferable to measure three or more areas of 200 μm × 200 μm and use the average value as a measured value.

  In the case of using a confocal microscope, it is preferable that the objective lens has a magnification of about 50 times and is measured with a reduced resolution. This is because if the measurement is performed at a high resolution, fine irregularities on the surface of the sample are measured, and the counting of the convex portions is hindered. Note that when the objective lens is set to a low magnification, the resolution in the height direction is also reduced, so that the surface shape may be difficult to measure in the case of a sample with few irregularities. In such a case, after measuring with a high-magnification objective lens, a low-pass filter is applied to the obtained data to remove high spatial frequency components so that the fine roughness observed on the uneven surface cannot be seen. Then, the number of convex portions may be counted.

  Next, the average area of the polygon formed when the surface is divided by Voronoi using the convex vertex of the irregular surface as a generating point will be described. First, the Voronoi division will be explained. When several points (called mother points) are arranged on a plane, the plane can be divided depending on which mother point is closest to any point in the plane. The figure is called Voronoi diagram, and the division is called Voronoi division. FIG. 6 shows an example in which the vertex of the convex portion on the surface of the antiglare film is used as a base point, and the surface is Voronoi-divided. Square points 26 and 26 are base points, and individual points including one base point are shown in FIG. The squares 27 and 27 are regions formed by Voronoi division, which are called Voronoi regions or Voronoi polygons, but are hereinafter called Voronoi polygons. In this figure, the peripherally thinned portions 28, 28 will be described later. In the Voronoi diagram, the number of generating points coincides with the number of Voronoi regions.

Thus, the average area of the Voronoi polygon vertices of the convex portion formed when Voronoi division as a base point is preferably not 100 [mu] m ² or more 1,000 .mu.m ² or less. When the average area at this time is less than 100 μm ² , the inclination angle of the antiglare film surface becomes steep, and as a result, whitening tends to occur, which is not preferable. On the other hand, when the average area of the Voronoi polygon is larger than 1,000 μm ² , the uneven surface shape becomes rough, glare is likely to occur, and the texture is deteriorated.

  In determining the average area of Voronoi polygons obtained by performing Voronoi division using the convex vertex of the surface of the antiglare film as a generating point, a confocal microscope, an interference microscope, an atomic force microscope (AFM) or the like is used. After measuring the surface shape and obtaining the three-dimensional coordinate value of each point on the surface of the antiglare film, Voronoi division is performed by the algorithm shown below to obtain the average area of the Voronoi polygon. That is, according to the algorithm described above with reference to FIG. 5, first, the vertex of the convex portion on the surface of the antiglare film is obtained, and then the vertex of the convex portion is projected onto the reference surface of the antiglare film. After that, all the three-dimensional coordinates obtained by measuring the surface shape are projected onto the reference plane, and all the projected points are assigned to the nearest base point to perform Voronoi division and obtained by division. By determining the area of the polygon, the average area of the Voronoi polygon is determined. In the measurement, in order to reduce the error, the Voronoi polygons that contact the boundary of the measurement field are counted as the number of the convex portions, but are not included when obtaining the average area. Moreover, in order to reduce a measurement error, it is preferable to measure three or more areas of 200 μm × 200 μm or more and use the average value as a measured value.

  As described above in part, FIG. 6 is a Voronoi diagram showing an example when Voronoi division is performed with the convex vertex of the antiglare film as a base point. A large number of generating points 26 and 26 are the vertices of the convex portions of the antiglare film, and one Voronoi polygon 27 is assigned to one generating point 26 by Voronoi division. In this figure, the Voronoi polygons 28 and 28 that are in contact with the boundary of the visual field and are thinly painted are not counted in the calculation of the average area as described above. In this figure, only some of the generating points and Voronoi polygons are provided with leading lines and symbols. However, the fact that there are a large number of generating points and Voronoi polygons is explained above and this figure. Will be easily understood.

[Transparent support and antiglare layer]
The antiglare film of the present invention is obtained by forming an antiglare layer having a fine uneven surface on a transparent support. The transparent support indicates an antiglare layer having an uneven surface and can be composed of a substantially optically transparent resin film. Examples of transparent supports include solvent cast films and extruded films made of thermoplastic resins such as amorphous cyclic polyolefins using triacetyl cellulose, polyethylene terephthalate, polymethyl methacrylate, polycarbonate, norbornene compounds as monomers. it can.

  The antiglare layer is formed on the transparent support as a layer provided with surface irregularities that satisfy the transmission scattering characteristics as described above. This anti-glare layer is coated with a resin solution in which fillers that have been widely used are dispersed on a transparent support, and the coating film thickness is adjusted to expose random fillers on the coating film surface. Although it can also be produced by a method of forming on a transparent support, the surface unevenness of the antiglare layer is preferably formed by transfer from a mold having an uneven surface. The antiglare layer contains 10 to 100 parts by weight of fine particles having an average particle diameter of 5 to 15 μm and a refractive index difference of 0.01 to 0.06 with respect to 100 parts by weight of the binder resin. Further, it is preferable that the fine particles are completely buried in the antiglare layer, and the fine particles do not affect the uneven shape of the surface. In this way, by independently controlling the surface fine unevenness shape and the internal scattering of the antiglare film, the surface fine unevenness shape of the antiglare film that mainly determines the reflection characteristics and the antiglare layer that mainly determines the transmission characteristics. The composition can be controlled separately. As a result, it becomes possible to easily achieve the above optical characteristics. The formation of such an antiglare layer will be described in detail later.

The antiglare film of the present invention exhibits a sufficient antiglare function even when there is no low reflection film on the outermost surface, that is, the uneven surface side, but it can also be used with a low reflection film on the outermost surface. . The low reflection film can be formed by providing a layer of a low refractive index material having a lower refractive index on the antiglare layer. Specific examples of such a low refractive index material include lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), cryolite (3NaF · AlF ₃ or Na ₃ AlF _6). ) And other inorganic low-reflective materials containing acrylic resin, epoxy resin, etc., fluorine-based or silicone-based organic compounds, thermoplastic resins, thermosetting resins, UV-curable resins Organic low reflection materials such as

[Manufacturing method of mold for manufacturing anti-glare film]
Next, a method for suitably producing the antiglare film according to the present invention and a method for producing a mold having irregularities formed on the surface for obtaining the antiglare film will be described. The antiglare film of the present invention uses a mold having irregularities formed in a predetermined shape, transfers the irregular surface of the mold to a transparent resin film, and then peels the transparent resin film having the irregular surface transferred from the mold. The method is advantageously produced. More specifically, after copper plating or nickel plating is applied to the surface of the metal and the plating surface is polished, fine particles are applied to the polished surface to form irregularities and the irregularities are dulled. The concavo-convex surface is subjected to chromium plating to form a mold, and the concavo-convex surface of the mold is transferred to the resin applied on the transparent support, and then the resin having the concavo-convex transferred is transferred from the mold together with the transparent support. Manufactured by a peeling method. In this method, in order to obtain a mold having irregularities, the surface of the metal substrate is subjected to copper plating or nickel plating, and after polishing the plated surface, bumps are formed on the polished surface to form irregularities, After performing the process which blunts the uneven | corrugated shape, chromium plating is given to the uneven surface, and it is set as a metal mold | die.

  First, the surface of the metal substrate on which the fine particles are hit to form irregularities and further the chrome plating layer is formed is subjected to copper plating or nickel plating. Thus, by performing copper plating or nickel plating on the surface of the metal constituting the mold, it is possible to improve the adhesion and gloss of chrome plating in the subsequent process. When chrome plating is applied to the surface of iron, etc., or when chrome plating is applied again after forming irregularities on the chrome plating surface by the sandblasting method or the bead shot method, as described in the background section above. The surface tends to be rough, and fine cracks are generated, which may adversely affect the shape of the antiglare film. On the other hand, it has been found that such inconvenience is eliminated by applying copper plating or nickel plating to the surface. This is because copper plating and nickel plating have a high covering property and a strong smoothing action, so that a flat and glossy surface is formed by filling minute irregularities and nests of the metal substrate. These copper plating and nickel plating characteristics eliminate the rough surface of the chrome plating that appears to be due to minute irregularities and nests that existed on the metal substrate. Therefore, it is considered that the occurrence of fine cracks is reduced.

  Copper or nickel as used herein may be a pure metal of each, or may be an alloy mainly composed of copper or an alloy mainly composed of nickel. Therefore, the term “copper” as used herein means to include copper and a copper alloy, and nickel means to include nickel and a nickel alloy. Copper plating and nickel plating may be performed by electrolytic plating or electroless plating, respectively, but electrolytic plating is usually employed.

  Examples of suitable metals for forming the mold include aluminum and iron from the viewpoint of cost. Furthermore, lightweight aluminum is more preferable from the convenience of handling. The aluminum and iron here may be pure metals, respectively, or may be an alloy mainly composed of aluminum or iron. After copper plating or nickel plating is applied to the surface of such a metal substrate, and the surface is further polished to obtain a smoother and more glossy surface, fine irregularities are formed by hitting the surface with fine particles. After performing the process of blunting the uneven shape, chrome plating is further applied thereto to form a mold.

  When copper plating or nickel plating is performed, if the plating layer is too thin, the influence of the base metal cannot be completely eliminated. Therefore, the thickness is preferably 10 μm or more. The upper limit of the plating layer thickness is not critical, but generally about 500 μm is sufficient from the viewpoint of cost and the like.

  The shape of the mold may be a flat metal plate or a cylindrical or cylindrical metal roll. If a metal mold | die is produced using a metal roll, an anti-glare film can be manufactured in a continuous roll shape.

  FIG. 7 is a cross-sectional view schematically showing a process until a mold is obtained, taking a case where a flat plate is used as an example. (A) of FIG. 7 shows the cross section of the base material after performing copper plating or nickel plating and mirror polishing, and a plating layer 32 is formed on the surface of the metal base material 31, and the surface is A polishing surface 33 is formed. Unevenness is formed by hitting fine particles against the surface of the plating layer 32 after such mirror polishing. FIG. 7B is a schematic cross-sectional view of the base material 31 after hitting the fine particles, and a fine concave surface 34 having a partial spherical shape is formed by hitting the fine particles. (C) in FIG. 7 is a schematic cross-sectional view of the base material 31 after the surface on which the unevenness due to the fine particles is formed is subjected to the process of dulling the uneven shape, and (C1) is blunted by the etching process. The state and (C2) represent the state dulled by copper plating, respectively. In (C1), the state of the partially spherical concave surface corresponding to (B) before being blunted by etching is indicated by a broken line. In the example employing the etching process of (C1), the concave surface 34 and the acute protrusion shown in (B) are etched away to form a shape 36a in which the acute protrusion on the partial spherical surface is blunted. ing. On the other hand, in the example employing the copper plating of (C2), the copper plating layer 35 is formed on the concave surface 34 shown in (B), and thereby the shape 36b in which the acute protrusion on the partial spherical surface is blunted is formed. Is formed.

  Then, the uneven | corrugated shape of the surface is further blunted by giving chromium plating. (D) in FIG. 7 is a schematic cross-sectional view after chrome plating, and (D1) is obtained by applying chrome plating on the uneven surface 36a blunted by the etching shown in (C1). (D2) is obtained by applying chromium plating to the copper plating layer 35 shown in (C2). In the example employing the etching process from (C1) to (D1), the chrome plating layer 37 is formed on the surface 36a that has been blunted by the etching shown in (C1), and the surface 38 is Compared with the uneven surface 36a of (C1), the state is further dulled by chrome plating, in other words, the uneven shape is relaxed. Moreover, in the example which employ | adopts the copper plating from (C2) to (D2), the copper plating layer 35 is formed on the fine concave surface formed in the copper or nickel plating layer 32 on the base material 31, and the further The chrome plating layer 37 is formed on the surface 38, and the surface 38 is further dulled by the chrome plating as compared with the concavo-convex surface 36b of (C2), in other words, the concavo-convex shape is relaxed. . As described above, the surface 36 (36a or 36b) subjected to the process of dulling the uneven shape after applying the fine particles to the surface of the copper or nickel plating layer 32 to form the unevenness is substantially subjected to chromium plating. Thus, a mold having no flat portion can be obtained. In addition, such a mold is suitable for obtaining an antiglare film exhibiting preferable optical characteristics.

  The plating layer made of copper or nickel on the substrate is hit with fine particles in a state where the surface is polished, but it is particularly preferable that the plating layer is polished close to a mirror surface. This is because the metal plate or metal roll as the base material is often subjected to machining such as cutting or grinding in order to obtain the desired accuracy, and as a result, the processing surface remains on the base material surface. It is. Even in the state where copper plating or nickel plating is applied, those processed marks may remain, and the surface may not be completely smooth in the plated state. In the state where deep processed eyes remain, even if the surface of the substrate is deformed by hitting the fine particles, the unevenness such as the processed eyes may be deeper than the unevenness formed by the fine particles, and the effects of the processed eyes remain. there is a possibility. When an antiglare film is produced using such a mold, the optical properties may be unexpectedly affected.

  There is no particular limitation on the method of polishing the surface of the substrate on which plating has been performed, and any of mechanical polishing, electrolytic polishing, and chemical polishing can be used. Examples of the mechanical polishing method include super finishing, lapping, fluid polishing, and buff polishing. The surface roughness after polishing is preferably 0.5 μm or less, more preferably 0.1 μm or less, expressed as the centerline average roughness Ra. If Ra is too large, even if the metal surface is deformed by hitting fine particles, the influence of the surface roughness before deformation may remain, which is not preferable. Also, the lower limit of Ra is not particularly limited, and there is no need to specify it because there is a natural limit from the viewpoint of processing time and processing cost.

  As a method for hitting the surface of the substrate plated with fine particles, an injection processing method is preferably used. Examples of the injection processing method include a sand blast method, a shot blast method, and a liquid honing method. The particles used in these processes are preferably in a shape close to a sphere rather than a shape having sharp corners, and particles of a hard material that are crushed during processing and do not produce sharp corners are preferable. . As particles satisfying these conditions, spherical zirconia beads and alumina beads are preferably used for ceramic particles. For metal particles, beads made of steel or stainless steel are preferred. Furthermore, particles in which ceramic or metal particles are supported on a resin binder may be used.

  It is preferable to use a fine particle having an average particle diameter of 10 to 150 μm, particularly a spherical fine particle, as the fine particle that strikes the surface of the substrate plated, thereby producing an anti-glare film exhibiting excellent anti-glare performance. be able to. If the average particle size of the fine particles is smaller than 10 μm, it becomes difficult to form sufficient irregularities on the plated surface, and it becomes difficult to obtain sufficient antiglare performance. On the other hand, if the average particle size of the fine particles is larger than 150 μm, the surface irregularities become rough, and glare is likely to occur or the texture is liable to deteriorate. Here, when processing using fine particles having an average particle size of 15 μm or less, it is preferable to employ a wet blasting method in which the particles are processed by being dispersed in a suitable dispersion medium so that the particles do not aggregate due to static electricity or the like.

Also, the pressure when hitting the fine particles, the amount of fine particles used, the distance from the nozzle that sprays the fine particles to the metal surface, etc. also affect the uneven shape after processing, and eventually the surface shape of the antiglare film, Fine particles to be used from a gauge pressure of about 0.05 to 0.4 MPa, an amount of fine particles of about 4 to 12 g per 1 cm ² of surface area of the metal to be treated, and a distance of about 200 to 600 mm from the nozzle for injecting the fine particles to the metal surface. According to the type, particle size, type of metal, shape of nozzle for injecting fine particles, desired uneven shape, and the like, it may be appropriately selected.

  The concavo-convex shape formed by hitting the surface of the substrate plated with fine particles has an arithmetic average height Pa of 0.1 μm or more and 1 μm or less in the cross section curve, and an arithmetic average height Pa in the cross section curve and The ratio Pa / PSm of the average length PSm is preferably 0.02 or more and 0.1 or less. When the arithmetic average height Pa is less than 0.1 μm or the ratio Pa / PSm is less than 0.02, the uneven surface is substantially flat when the uneven shape is blunted before the chrome plating process. It becomes difficult to obtain a mold having the desired surface shape. In addition, when the arithmetic average height Pa is greater than 1 μm or the ratio Pa / PSm is greater than 0.1, the process of dulling the concavo-convex shape before chrome plating must be performed under strong conditions. It tends to be difficult to control the shape.

  Thus, the process which blunts an uneven | corrugated shape is given to the base material with which the unevenness | corrugation was formed in the copper plating or nickel plating surface. As the processing for dulling the uneven shape, as described above with reference to FIGS. 7C and 7D, etching treatment or copper plating is preferable. By performing the etching process, the sharp portion of the uneven shape produced by hitting the fine particles is eliminated. Thereby, the optical characteristic of the anti-glare film produced when it uses as a metal mold | die changes in a preferable direction. Moreover, since the copper plating has a strong smoothing action, the effect of dulling the uneven shape is stronger than that of the chromium plating. Thereby, the optical characteristic of the anti-glare film produced when it uses as a metal mold | die changes in a preferable direction.

Etching is usually performed by corroding the surface using an aqueous ferric chloride (FeCl ₃ ) solution, an aqueous cupric chloride (CuCl ₂ ) solution, an alkaline etchant (Cu (NH ₃ ) ₄ Cl ₂ ), or the like. However, a strong acid such as hydrochloric acid or sulfuric acid can be used, or reverse electrolytic etching by applying a potential opposite to that during electrolytic plating can be used. The degree of unevenness after etching is different depending on the type of underlying metal and the size and depth of the unevenness obtained by blasting techniques. The largest factor is the etching amount. The etching amount here is the thickness of the plating layer to be cut by etching. If the etching amount is small, the effect of dulling the surface shape of the unevenness obtained by a technique such as blasting is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape to a transparent film are not so good. . On the other hand, when the etching amount is too large, the uneven shape is almost lost and the die is almost flat, so that the antiglare property is not exhibited. Therefore, the etching amount is preferably 1 μm or more and 20 μm or less, and more preferably 2 μm or more and 10 μm or less.

  When copper plating is used as the dulling process, the unevenness of the unevenness varies depending on the type of base metal, the size and depth of the unevenness obtained by techniques such as blasting, and the type and thickness of the plating. Although it cannot be said, the greatest factor in controlling the degree of rounding is the plating thickness. If the thickness of the copper plating layer is thin, the effect of dulling the surface shape of the unevenness obtained by techniques such as blasting is insufficient, and the optical properties of the antiglare film obtained by transferring the uneven shape to a transparent film are insufficient. It doesn't get much better. On the other hand, when the plating thickness is too thick, the productivity is deteriorated and the uneven shape is almost lost, so that the antiglare property is not exhibited. Therefore, the thickness of the copper plating is preferably 1 μm or more and 20 μm or less, and more preferably 4 μm or more and 10 μm or less.

  In this way, after dulling the surface shape of the substrate on which the unevenness was formed on the copper plating or nickel plating surface, by further applying chrome plating, the surface of the unevenness was further dulled and the surface hardness was reduced. Make an enhanced metal plate. The degree of unevenness at this time also differs depending on the type of base metal, the size and depth of the unevenness obtained by techniques such as blasting, and the type and thickness of the plating. The greatest factor in controlling is the plating thickness. If the thickness of the chrome plating layer is thin, the effect of dulling the surface shape of the unevenness obtained before the chrome plating process is insufficient, and the optical characteristics of the antiglare film obtained by transferring the uneven shape to a transparent film are It doesn't get much better. On the other hand, when the plating thickness is too thick, productivity is deteriorated and a protruding plating defect called a nodule is generated. Therefore, the thickness of the chrome plating is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 6 μm or less.

Chrome plating is glossy, has high hardness, has a low coefficient of friction, and provides good mold release properties. The type of chrome plating is not particularly limited, but it is preferable to use a chrome plating that expresses a good gloss, so-called gloss chrome plating or decorative chrome plating. Chromium plating is usually performed by electrolysis, and an aqueous solution containing chromic anhydride (CrO ₃ ) and a small amount of sulfuric acid is used as the plating bath. By adjusting the current density and electrolysis time, the thickness of the chromium plating can be controlled.

  The die surface to which chromium plating is applied preferably has a Vickers hardness of 800 or more, more preferably 1,000 or more. If the Vickers hardness is low, the durability when using the mold is reduced, and the decrease in hardness due to chrome plating is likely to cause abnormalities in the plating bath composition and electrolytic conditions during the plating process. There is a high possibility that the occurrence of defects will also have an undesirable effect.

  Patent Document 1 (Japanese Patent Laid-Open No. 2002-189106) and Patent Document 4 (Japanese Patent Laid-Open Publication No. 2004-90187) listed above as background art disclose that chromium plating is applied to the surface of a metal base material to be a mold. However, depending on the base before plating of the mold and the type of chrome plating, the surface is often roughened after plating or many fine cracks are generated due to chrome plating. The optical properties of the glare film proceed in an unfavorable direction. Those with a rough plating surface are not suitable for a mold for an antiglare film. This is because the plating surface is generally polished after chromium plating in order to eliminate roughness, but as described later, in the present invention, polishing of the surface after plating is not preferable. In the present invention, such inconvenience that is likely to occur in chromium plating is eliminated by applying copper plating or nickel plating to the base metal.

  In the case where the process of dulling the concavo-convex shape is not performed before the chrome plating, the chrome plating must be thickened in order to sufficiently dull the sharp portion of the concavo-convex shape produced by hitting fine particles. However, if the thickness of the chrome plating is too thick, nodules are likely to be generated, which is not preferable. In addition, when the thickness of the chrome plating is reduced, the uneven shape produced by hitting the fine particles cannot be sufficiently dulled, and a mold having the desired surface shape cannot be obtained. The produced anti-glare film does not exhibit excellent anti-glare performance.

  Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2002-189106) described above describes forming a concavo-convex surface on a roller chrome-plated on the surface of iron by a sandblasting method or a bead shot method, and then performing chrome plating. Patent Document 3 (Japanese Patent Laid-Open No. 2004-29240) and Patent Document 4 (Japanese Patent Laid-Open No. 2004-90187) describe that a bead shot method or a blast treatment is applied to the roll surface. However, there is no mention of a method of applying a process of actively dulling the surface shape after hitting fine particles to form a concavo-convex shape, and then applying a chrome plating process to dull the surface concavo-convex shape. According to these studies, an antiglare film exhibiting excellent antiglare performance could not be produced unless the surface shape was positively dulled as described above.

  In addition, it is not preferable to apply plating other than chromium plating to the metal surface with unevenness. This is because plating other than chromium has low hardness and wear resistance, so that the durability as a mold is lowered, and unevenness is worn away during use or the mold is damaged. In an antiglare film obtained from such a mold, there is a high possibility that a sufficient antiglare function cannot be obtained, and there is a high possibility that defects will occur on the film.

  After chrome plating, it is advantageous to use the chrome-plated surface as the uneven surface of the mold without polishing the surface. Patent Document 4 (Japanese Patent Application Laid-Open No. 2004-90187) describes polishing the surface after plating, but it is not preferable in the present invention to polish the chromium plating surface in this way. By polishing, a flat portion is generated on the outermost surface, which may cause deterioration of optical characteristics, and because shape control factors increase, it becomes difficult to control the shape with good reproducibility. It is. FIG. 8 shows a process of dulling the uneven shape obtained by hitting the fine particles, here, the surface subjected to the chromium plating shown in (D1) after performing the etching process shown in (C1) of FIG. FIG. 3 is a schematic cross-sectional view of a metal plate in which a flat surface is produced when polishing is performed. Due to the polishing, a part of the projections of the surface irregularities 38 of the chromium plating layer 37 formed on the surface of the copper or nickel plating layer 32 is cut, and a flat surface 39 is generated. FIG. 8 shows an example in which the post-etching chrome-plated surface shown in (D1) of FIG. 7 is polished, but also in the case of chrome-plating after copper plating shown in (D2) of FIG. If the surface is polished, a flat surface is similarly generated.

[Production method of anti-glare film]
Next, the process for producing an antiglare film using the mold thus obtained will be described. An antiglare film can be obtained by transferring the shape of the mold obtained by the method described above to a transparent resin film. The transfer to the mold-shaped film is preferably performed by embossing. Examples of embossing include a UV embossing method using a photocurable resin and a hot embossing method using a thermoplastic resin.

  In the UV embossing method, a photocurable resin layer is formed on the surface of a transparent support and cured while pressing the photocurable resin layer against the uneven surface of the mold so that the uneven surface of the mold becomes a photocurable resin. Transferred to the layer. Specifically, an ultraviolet curable resin is applied on a transparent support, and the cured UV curable resin is adhered to the concave and convex surface of the mold, and then UV is irradiated from the transparent support to cure the ultraviolet light. The mold resin is cured, and then the support on which the cured ultraviolet curable resin layer is formed is peeled off from the mold to transfer the mold shape to the ultraviolet curable resin. The kind of ultraviolet curable resin is not particularly limited. Moreover, although expressed as an ultraviolet curable resin, a resin that can be cured with visible light having a wavelength longer than that of ultraviolet rays can be obtained by appropriately selecting a photoinitiator. That is, the term “ultraviolet curable resin” as used herein is a generic name including such a visible light curable resin. On the other hand, in the hot embossing method, a transparent thermoplastic resin film is pressed against a mold in a heated state, and the surface shape of the mold is transferred to the thermoplastic resin film. Among these embossing methods, the UV embossing method is preferable from the viewpoint of productivity.

  The transparent support used for the production of the antiglare film may be a substantially optically transparent resin film. For example, triacetyl cellulose, polyethylene terephthalate, polymethyl methacrylate, polycarbonate, norbornene compound is used as a monomer. A solvent cast film or an extruded film made of a thermoplastic resin such as amorphous cyclic polyolefin can be used.

  A commercially available product can be used as the ultraviolet curable resin. For example, polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate are used alone or in admixture of two or more thereof, and “Irgacure 907”, “Irgacure 184” (above, Ciba A product obtained by mixing a photopolymerization initiator such as “Specialty Chemicals” or “Lucirin TPO” (BASF) can be used as an ultraviolet curable resin.

  The thermoplastic transparent resin film used in the hot embossing method may be any film as long as it is substantially transparent. For example, polymethyl methacrylate, polycarbonate, polyethylene terephthalate, triacetyl cellulose, norbornene compounds A solvent cast film or an extruded film of a thermoplastic resin such as amorphous cyclic polyolefin as a monomer can be used. These transparent resin films can also serve as a transparent support when the UV embossing method described above is employed.

  The antiglare film of the present invention uses a mold having irregularities formed in a predetermined shape, transfers the irregular surface of the mold to a resin coated on a transparent support, and then transfers the resin with the irregular surface transferred to the gold It is preferable to form the surface fine irregularities by a method of peeling from the mold. In the resin used for transfer, the average particle diameter is 5 μm or more and 15 μm or less, and the refractive index difference with the binder resin is 0.01 or more and 0.06 or less. It is preferable to contain 10 to 100 parts by weight of the fine particles with respect to 100 parts by weight of the binder resin.

  If the average particle size of the fine particles blended in the binder resin is less than 5 μm, the value on the wide-angle side of the transmission / scattering profile increases, and as a result, the contrast is lowered when applied to an image display device, which is not preferable. On the contrary, when the average particle diameter exceeds 15 μm, as described later, it is preferable to completely embed the particles in the binder resin, so that the film thickness tends to be increased in order to embed the particles. As a result, problems such as curling and aggregation are likely to occur during resin coating.

  In addition, when the refractive index difference between the fine particles and the binder resin is less than 0.01, the internal scattering effect due to the fine particles is reduced, so that the predetermined anti-glare layer is provided with predetermined scattering characteristics and haze to eliminate glare. It is necessary to add a large amount of fine particles to the binder resin, which is not preferable from the viewpoint of completely burying the fine particles in the binder resin. On the other hand, when the difference in refractive index exceeds 0.06, the difference in refractive index is large, so that the reflectance at the interface between the binder resin and the fine particles increases, resulting in an increase in backscattering and a decrease in the total light transmittance. This is not preferable. Since the ultraviolet curable resin as described above often has a refractive index of around 1.50, the fine particles have a refractive index of about 1.40 to 1.60. It can be selected appropriately according to the design. As the fine particles, resin beads, which are also substantially spherical, are preferably used. Examples of such suitable resin beads are listed below.

Melamine beads (refractive index 1.57),
Polymethyl methacrylate beads (refractive index 1.49),
Methyl methacrylate / styrene copolymer resin beads (refractive index 1.50 to 1.59),
Polycarbonate beads (refractive index 1.55),
Polyethylene beads (refractive index 1.53),
Polystyrene beads (refractive index 1.6),
Polyvinyl chloride beads (refractive index 1.46),
Silicone resin beads (refractive index 1.46).

  Further, it is preferable that these fine particles do not affect the uneven shape of the surface, that is, the particles are completely buried in the binder resin. This is because when the fine particles protrude from the surface, the surface irregularity shape changes depending on the shape of the fine particles, and the reflection characteristics (anti-glare performance, whitishness, etc.) of the anti-glare film are affected. When the fine particles protrude from the surface in this way, the surface shape must be designed in consideration of the shape, concentration, dispersibility, etc. of the particles in addition to the surface shape of the mold described above. It becomes difficult and difficult to obtain the expected characteristics. Therefore, it is preferable that the surface shape mainly affecting the reflection characteristics is controlled only by the mold, and the scattering characteristics are independently controlled by a combination of resin and particles.

[Anti-glare polarizing plate]
The anti-glare film of the present invention configured as described above has an anti-glare effect, is effectively prevented from being whitish, and can effectively suppress the occurrence of glare and the decrease in contrast. When it is done, it becomes excellent in visibility. When the image display device is a liquid crystal display, this antiglare film can be applied to the polarizing plate. That is, the polarizing plate generally has a shape in which a protective film is bonded to at least one surface of a polarizer composed of a polyvinyl alcohol resin film in which iodine or a dichroic dye is adsorbed and oriented. Is made of the antiglare film of the present invention, and the polarizer and the antiglare film of the present invention are bonded together on the transparent support side of the antiglare film, whereby an antiglare polarizing plate can be obtained. In this case, the other surface of the polarizer may be left as it is, another protective film or an optical film may be laminated, or an adhesive layer for bonding to a liquid crystal cell may be formed. Good. Moreover, it can also be set as the anti-glare polarizing plate by bonding the anti-glare film of this invention on the transparent support side to the polarizing plate by which the protective film was bonded to the polarizer at least one side. Furthermore, in the polarizing plate on which the protective film is bonded, the antiglare polarizing plate can be obtained by providing the antiglare unevenness as described above on the surface of the single-sided protective film.

[Image display device]
The image display device of the present invention is a combination of an antiglare film or an antiglare polarizing plate having a specific surface shape as described above and an image display element. Here, the image display element is typically a liquid crystal panel having a liquid crystal cell in which liquid crystal is sealed between upper and lower substrates and displaying an image by changing the alignment state of the liquid crystal by applying a voltage. The antiglare film of the present invention can also be applied to various known displays such as panels, CRT displays, and organic EL displays. And an image display apparatus is comprised by arrange | positioning an above-described anti-glare film to the visual recognition side rather than an image display element. Under the present circumstances, it arrange | positions so that the uneven surface of an anti-glare film, ie, the glare-proof layer side, may become an outer side (viewing side). The antiglare film may be directly bonded to the surface of the image display element, and when the liquid crystal panel is used as the image display means, for example, as described above, it is bonded to the surface of the liquid crystal panel via a polarizer. You can also. Thus, the image display device provided with the antiglare film of the present invention can scatter incident light due to the unevenness of the surface of the antiglare film and blur the reflected image, giving excellent visibility. Become.

  In addition, even when the antiglare film of the present invention is applied to a high-definition image display device, the glare as seen in the conventional antiglare film does not occur, sufficient reflection prevention, It has the functions of prevention, suppression of glare, and reduction of contrast reduction.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. Moreover, the evaluation method of the metal mold | die or anti-glare film in the following examples is as follows.

1. Measurement of Vickers hardness of mold
Vickers hardness was measured by a method based on JIS Z 2244 using an ultrasonic hardness tester “MIC10” manufactured by Krautkramer. The measurement was performed on the surface of the mold itself.

2. Measurement of optical properties of antiglare film (scattering profile)
The antiglare film is bonded to a glass substrate so that the uneven surface becomes the surface, and parallel light from a He-Ne laser is irradiated from the direction inclined at a predetermined angle with respect to the film normal on the glass surface side. The transmitted scattered light intensity in the film normal direction was measured on the uneven surface side of the antiglare film. For the measurement of reflectance, both “3292 03 Optical Power Sensor” and “3292 Optical Power Meter” manufactured by Yokogawa Electric Corporation were used.

(Reflection profile)
The uneven surface of the antiglare film is irradiated with parallel light from a He—Ne laser from a direction inclined by 30 ° with respect to the film normal, and the angle change of reflectance in a plane including the film normal and the irradiation direction is changed. Measurements were made. For the measurement of reflectance, both “3292 03 Optical Power Sensor” and “3292 Optical Power Meter” manufactured by Yokogawa Electric Corporation were used.

(Haze)
The haze of the antiglare film was measured using a haze meter “HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd. based on JIS K 7136. In order to prevent the sample from warping, it was bonded to a glass substrate using an optically transparent adhesive so that the concavo-convex surface became the surface, and the total haze was measured in that state. When measuring the internal haze, a triacetyl cellulose film having a haze of almost 0 was attached to the uneven surface of the antiglare film with glycerin.

(Reflection sharpness)
The reflection sharpness of the antiglare film was measured using an image clarity measuring device “ICM-1DP” manufactured by Suga Test Instruments Co., Ltd. based on JIS K 7105. Also in this case, in order to prevent the sample from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent adhesive so that the concavo-convex surface became the surface. In addition, in order to prevent reflection from the back glass surface, a 2 mm thick black acrylic resin plate is adhered to the glass surface of the glass plate on which the antiglare film is pasted, and the sample (antiglare film in this state) is attached. ) Side was used for measurement. As described above, the measured value here is a total value of values measured using three types of optical combs in which the widths of the dark part and the bright part are 0.5 mm, 1.0 mm, and 2.0 mm, respectively.

3. Measurement of surface shape of antiglare film
The surface shape of the antiglare film was measured using a confocal microscope “PLμ2300” manufactured by Sensofar. Also in this case, in order to prevent the sample from warping, it was subjected to measurement after being bonded to a glass substrate using an optically transparent adhesive so that the concavo-convex surface became the surface. At the time of measurement, the magnification of the objective lens was 50 times, and the measurement was performed with a reduced resolution. This is because if the measurement is performed at a high resolution, fine irregularities on the surface of the sample are measured, and the counting of the convex portions is hindered.

(Arithmetic mean height Pa, maximum cross section height Pt, and mean length PSm in the section curve)
Based on the measurement data obtained above, the arithmetic average height Pa, the maximum cross-sectional height Pt, and the average length PSm were obtained by calculation based on JIS B 0601.

(Number of convex parts)
Based on the three-dimensional coordinate value of each point on the surface of the antiglare film obtained by the above measurement, according to the algorithm described above with reference to FIG. 5, the convex portions existing in the 200 μm × 200 μm region I asked for a number.

(Average area of Voronoi polygon when Voronoi is divided)
Based on the three-dimensional coordinate value of each point of the antiglare film surface obtained by the above measurement, the average of the Voronoi polygon is calculated based on the algorithm described above with reference to FIGS. The area was determined.

4). Evaluation of anti-glare performance of anti-glare film (visual evaluation of reflection, whitishness and texture)
In order to prevent reflection from the back surface of the antiglare film, the antiglare film is bonded to the black acrylic resin plate so that the uneven surface becomes the surface, and visually observed from the uneven surface side in a bright room with a fluorescent lamp. Then, the presence or absence of reflection of a fluorescent lamp, the degree of whitishness, and the texture were visually evaluated. Reflection, whitishness and texture were evaluated according to the following criteria in three stages of 1 to 3, respectively.

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

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

Texture 1: Fine eyes and good texture.
2: The eyes are slightly rough and the texture is a little bad.
3: The eyes are clearly rough and the texture is poor.

(Evaluation of glare)
The glare was evaluated by the following method. That is, first, a photomask having a unit cell pattern as shown in a plan view in FIG. 9 was prepared. In this figure, a unit cell 40 has a key-shaped chrome light-shielding pattern 41 with a line width of 10 μm formed on a transparent substrate, and the portion where the chrome light-shielding pattern 41 is not formed is an opening 42. Here, a unit cell having a size of 254 μm × 84 μm (vertical × horizontal in the drawing), and therefore, an opening having a size of 244 μm × 74 μm (vertical × horizontal in the drawing) was used. A large number of unit cells shown in the figure are arranged vertically and horizontally to form a photomask.

  Then, as shown in a schematic cross-sectional view of FIG. 10, the chrome light-shielding pattern 41 of the photomask 43 is placed on the light box 45, and the antiglare film 11 is provided on the glass plate 47 with an adhesive on the surface. The sample bonded so as to become is placed on the photomask 43. A light source 46 is disposed in the light box 45. In this state, by visually observing at a position 49 about 30 cm away from the sample, the degree of glare was sensory evaluated in seven stages. Level 1 corresponds to a state where no glare is recognized, level 7 corresponds to a state where severe glare is observed, and level 3 refers to a state where only slight glare is observed.

(Contrast evaluation)
The polarizing plates on both the front and back surfaces were peeled off from a commercially available liquid crystal television (“LC-42GX1W” manufactured by Sharp Corporation). Instead of these original polarizing plates, the polarizing plate “Sumikaran SRDB831E” manufactured by Sumitomo Chemical Co., Ltd. is used on both the back side and the display side so that each absorption axis matches the absorption axis of the original polarizing plate. Further, the antiglare film shown in each of the following examples was laminated on the display surface side polarizing plate via an adhesive such that the concavo-convex surface was the surface. The liquid crystal television thus obtained was activated in a dark room, and the luminance in the black display state and the white display state was measured using a luminance meter “BM5A” manufactured by Topcon Corporation, and the contrast was calculated. Here, the contrast is represented by the ratio of the luminance in the white display state to the luminance in the black display state.

[ Comparative Example 10 (Old Example 1 ) ]
(A) Production of Embossing Die A surface of a 200 mm diameter iron roll (STKM13A according to JIS) with copper ballad plating was prepared. The copper ballad plating was composed of a copper plating layer / a thin silver plating layer / a surface copper plating layer, and the thickness of the entire plating layer was about 200 μm. The copper-plated surface is mirror-polished, and on the polished surface, a blasting device (Fuji Seisakusho Co., Ltd.) is used to make a zirconia bead “TZ-B53” (trade name, average particle diameter) 53 μm) is blasted under the conditions of a bead usage amount of 8 g / cm ² (per surface area of the roll), a blast pressure of 0.15 MPa (gauge pressure), and a distance of 450 mm from the nozzle for injecting fine particles to the metal surface. Wearing. The obtained copper-plated iron roll with unevenness was etched with an aqueous cupric chloride solution. The etching amount at that time was set to 8 μm. Thereafter, chrome plating was performed to produce an embossing die. At this time, the chromium plating thickness was set to 4 μm. The obtained mold had a surface Vickers hardness of 1,000.

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

  To this ultraviolet curable resin composition, 25 parts of methyl methacrylate / styrene copolymer resin beads having an average particle diameter of 8 μm and a refractive index of 1.565 are added per 100 parts of the ultraviolet curable resin, and then the solid content is added. A coating solution was prepared by adding ethyl acetate so that the concentration of resin beads (including resin beads) was 50%.

The above coating solution was applied onto a triacetyl cellulose (TAC) film having a thickness of 80 μm so that the coating thickness after drying was 10 μm, and was dried in a dryer set at 60 ° C. for 3 minutes. The dried film was brought into close contact with the uneven surface of the mold produced in (A) with a rubber roll so that the ultraviolet curable resin composition layer was on the mold side. In this state, the ultraviolet curable resin composition layer was cured by irradiating light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² from the TAC film side so that the amount of light in terms of h-line was 200 mJ / cm ² . Thereafter, the TAC film was peeled from the mold together with the cured resin to obtain a transparent antiglare film comprising a laminate of the cured resin having irregularities on the surface and the TAC film.

(C) Evaluation of anti-glare film About the obtained anti-glare film, optical characteristics, uneven surface shape, and anti-glare performance were evaluated by the above-described methods, and the results were used for mold preparation conditions and anti-glare layer preparation. Table 1 shows the types and amounts of fine particles. Further, a transmission / scattering profile graph is shown in FIG. 11, and a reflection profile graph is shown in FIG. In Table 1, (A) is a summary of the etching amount at the time of mold production and the type and amount of fine particles used for the production of the antiglare layer, (B) is a summary of the optical characteristics of the antiglare film, (C) summarizes the surface shape and antiglare performance of the antiglare film. The breakdown of the reflection definition in Table 1 (B) is as follows.

Reflection sharpness 0.5mm Optical comb: 1.4%
1.0mm optical comb: 5.4%
2.0mm optical comb: 9.6%
Total 16.4%

[ Comparative Example 11 (Old Example 2 ) ]
The amount of etching at the time of mold production was changed as shown in Table 1, and in the same manner as in Comparative Example 10 (Old Example 1 ) , an embossing mold having irregularities on the surface was produced. The obtained mold had a surface Vickers hardness of 1,000. Using this mold, a transparent antiglare film made of a laminate of a cured resin having a concavo-convex surface and a TAC film was produced in the same manner as in Comparative Example 10 (old Example 1 ) .

[Examples 3 and 4]
While using the same mold as Comparative Example 10 (Old Example 1 ) , the kind of fine particles used for the production of the antiglare layer and / or the addition amount with respect to 100 parts by weight of the ultraviolet curable resin were changed as shown in Table 1, and the others. In the same manner as in Comparative Example 10 (Old Example 1 ) , a transparent antiglare film composed of a laminate of a cured resin having irregularities on its surface and a TAC film was produced. The fine particles used in Example 3 are the same methyl methacrylate / styrene copolymer resin beads as in Comparative Example 10 (former Example 1 ), and the fine particles used in Example 4 have an average particle size of 8 μm. Polymethyl methacrylate beads having a refractive index of 1.490.

All of the antiglare films obtained in Comparative Example 11 (Old Example 2) and Examples 3 to 4 show the optical properties, surface shape and antiglare performance of these antiglare films in Comparative Example 10 (Old Example 1). ) And the data are shown in Table 1. Moreover, the graphs of the transmission scattering profile and the reflection profile of these antiglare films are shown in FIGS. 11 and 12 together with the data of Comparative Example 10 (old example 1 ) .

[Comparative Examples 1 and 2]
Comparative Example 1 uses the same mold as Comparative Example 10 (old Example 1 ), and Comparative Example 2 uses the same mold as Comparative Example 11 (old Example 2 ) , both of which are UV curable and do not contain resin beads. Using the resin composition, a transparent anti-glare film composed of a laminate of a cured resin having irregularities on the surface and a TAC film was produced in the same manner as in Comparative Example 10 (Old Example 1 ) . The optical characteristics, surface shape, and antiglare performance of the obtained antiglare film are shown in Table 1 together with the data of Comparative Example 10 (old example 1 ) . Moreover, the graph of the transmission / scattering profile of these anti-glare films is shown in FIG. 13, and the graph of the reflection profile is shown in FIG.

As shown in Table 1, Comparative Example 10 (old Example 1 ) and Comparative Example 11 (old Example 2 ) satisfying the requirements of the present invention showed excellent antiglare performance (low reflection and good texture). However, glare and whitish did not occur, and high contrast was exhibited when applied to an image display device. Further, in Examples 3 and 4 in which the internal haze was increased, the contrast was slightly reduced as compared with Comparative Example 10 (Old Example 1 ) and Comparative Example 11 (Old Example 2 ) , but the glare was more effective. It was found that it can be suppressed.

In contrast, Comparative Examples 1 and 2 have the same surface shape as Comparative Example 10 (Old Example 1 ) and Comparative Example 11 (Old Example 2 ) , respectively. Although no whitening occurs and the contrast is high, at least one of the relative scattered light intensities T (20) and T (30) is less than that of the present invention, the glare is strong, and the image display device When applied, the visibility was significantly reduced.

Here, comparative example 10 (old example 1 ) , 3 and 4 and comparative example 1 are producing the glare-proof film using the same metal mold, and comparative example 11 (old example 2 ) and comparative example 2 Has also produced an antiglare film using the same mold. And the reflection characteristic of the glare-proof film produced using these same metal mold | dies is substantially equivalent, From this result, it turns out that the added microparticles | fine-particles do not affect the surface shape.

Ultraviolet curing of porous silica fine particles having an average particle diameter of about 10 μm and a refractive index of 1.46 to the same ultraviolet curable resin composition (before addition of resin beads ) used in Comparative Example 10 (former Example 1 ) In addition to 10 parts per 100 parts of the curable resin, in Comparative Examples 4 and 5, methyl methacrylate / styrene copolymer resin beads having an average particle size of 3 μm and a refractive index of 1.57 were added per 100 parts of the ultraviolet curable resin. The coating solution was prepared by adding and dispersing ethyl acetate so that the solid content (including silica fine particles and resin beads) was 30%.

The above coating solution was applied onto a 80 μm thick triacetylcellulose (TAC) film so that the coating thickness after drying was 4 μm, and dried for 3 minutes in a drier set at 60 ° C. The UV-curable resin composition layer is irradiated with light from a high-pressure mercury lamp having an intensity of 20 mW / cm ² from the side of the dried film at a light-curing resin composition layer side so that the amount of light converted to h-ray is 200 mJ / cm ^2. Was cured to obtain a transparent antiglare film comprising a laminate of a cured resin having irregularities on the surface and a TAC film. In this antiglare film, the silica fine particles protrude from the surface of the antiglare layer, as can be seen from the relationship between the particle size of silica fine particles (about 10 μm) and the coating thickness (4 μm). About the obtained anti-glare film, optical characteristics, uneven surface shape, and anti-glare performance were evaluated by the method described above, and the results are shown in Table 2 together with the resin composition. In Table 2, (A) summarizes the fine particles blended in the curable resin, (B) summarizes the optical properties of the antiglare film, and (C) shows the surface shape and antiglare performance of the antiglare film. Is a summary. Further, a transmission / scattering profile graph is shown in FIG. 15, and a reflection profile graph is shown in FIG.

  As shown in Table 2, in Comparative Example 3, since the relative scattered light intensities T (20) and T (30) were below the definition of the present invention, the contrast did not decrease, but the glare was strong and the image display device was When applied, the visibility was significantly impaired. In Comparative Example 4, since the relative scattered light intensity T (20) incident at 20 ° exceeded the regulation of the present invention, the contrast was lowered to 1,800 or less, and the visibility was impaired. Further, among the surface shapes, the average length PSm is large, the number of convex portions is small, the average area of the Voronoi polygon is large, and the overall shape is larger than that defined in the present invention. Despite being strong, glare was not sufficiently suppressed. In Comparative Example 5, the relative scattered light intensities T (20) and T (30) greatly exceeded the provisions of the present invention, and thus no glare occurred, but the contrast was greatly reduced. In Comparative Examples 3 to 5, the average length PSm is generally large, the average area of the Voronoi polygon is larger than that of the present invention, and the number of convex portions is lower than that of the present invention, resulting in a rough texture. It looked stubborn.

[Comparative Examples 6-9]
Anti-glare film “AG3”, “AG5”, “SL6”, “SL6”, which is used as an anti-glare layer in the polarizing plate “Sumikaran” sold by Sumitomo Chemical Co., Ltd. CV2 "(respectively referred to as Comparative Examples 6 to 9) were evaluated for their optical properties, surface shape and antiglare performance by the methods described above, and the results are shown in Table 3. In Table 3, (B) summarizes the optical properties of the antiglare film, and (C) summarizes the surface shape and antiglare performance of the antiglare film. Further, a transmission / scattering profile graph is shown in FIG. 17, and a reflection profile graph is shown in FIG.

  In Comparative Example 6, since the relative scattered light intensities T (20) and T (30) were below the definition of the present invention, the contrast was not lowered, but the glare was strong and the visibility was remarkably lowered. Moreover, since all the requirements for the surface shape deviated from the provisions of the present invention, the texture was poor and the appearance was rugged. In Comparative Example 7, the relative scattered light intensity T (30) incident at 30 ° was lower than that of the present invention, and thus the result was that the glare occurred. In Comparative Examples 8 and 9, since the relative scattered light intensities T (20) and T (30) were generally large, no glare occurred, but the contrast was greatly reduced. In Comparative Example 8, the values of the reflectances R (40) and R (50) also exceeded the stipulations of the present invention, so that the screen became whitish as a whole.

  From the above results, it can be seen that it is important for achieving the optical characteristics that are the object of the present invention that the requirements defined in the present invention are well-balanced.

  By disposing the antiglare film of the present invention on various displays such as a liquid crystal panel, a plasma display panel, a CRT display, and an organic EL display so that the antiglare film is closer to the viewing side than the image display element. It is possible to blur the reflected image without generating a blur and a glare, and to provide excellent visibility.

A perspective view schematically showing the light incident direction and the transmitted scattered light intensity measurement direction when light is incident from the transparent support side of the antiglare film and the scattered light intensity observed in the normal direction of the antiglare layer is obtained. FIG. It is an example of the graph which plotted the relative scattered light intensity (logarithmic scale) measured by changing an incident angle with respect to an incident angle. It is a perspective view which shows typically the incident direction and reflection direction of the light from the glare-proof layer side when calculating | requiring a reflectance. It is an example of the graph which plotted the reflection angle and reflectance (a reflectance is a logarithmic scale) of the reflected light with respect to the light which injected at an angle of 30 degrees from the normal line of an anti-glare film. It is the perspective view which showed typically the algorithm of the convex part determination of an anti-glare film. It is a Voronoi figure which shows the example of a Voronoi division | segmentation. It is a cross-sectional schematic diagram which shows the manufacturing method of the metal mold | die for producing the anti-glare film which concerns on this invention for every process. It is a cross-sectional schematic diagram which shows the state which grind | polished the surface after chromium plating. It is a top view which shows the unit cell of the pattern for glare evaluation. It is a cross-sectional schematic diagram which shows the state of glare evaluation. It is a graph showing the transmission-scattering profile of the anti-glare film obtained in Examples 1-4. It is a graph showing the reflection profile of the anti-glare film obtained in Examples 1-4. It is a graph showing the transmission-scattering profile of the anti-glare film obtained in Comparative Examples 1 and 2. It is a graph showing the reflection profile of the anti-glare film obtained in Comparative Examples 1 and 2. It is a graph showing the transmission-scattering profile of the anti-glare film obtained by Comparative Examples 3-5. It is a graph showing the reflection profile of the anti-glare film obtained by Comparative Examples 3-5. It is a graph showing the transmission-scattering profile of the anti-glare film used in Comparative Examples 6-9. It is a graph showing the reflection profile of the anti-glare film used in Comparative Examples 6-9.

Explanation of symbols

11 ... Anti-glare film,
12 ... Film normal,
13: Direction of incident light when measuring transmitted scattered light intensity,
14: Measurement direction of transmitted scattered light intensity (normal direction),
15 ... Incident light direction when measuring reflectance,
16 …… Specular reflection direction,
17 …… Any reflection direction,
19 …… Surface including incident light direction and film normal,
φ: Angle of incidence when measuring transmitted scattered light intensity,
θ: Reflection angle when measuring reflectivity,
21 …… Any point on the antiglare film,
22 …… Anti-glare film surface,
23 …… Film reference plane,
24 …… A projected circle of a circle centered on an arbitrary point on the antiglare film on the film reference plane,
26 …… Projection point of convex part vertex (voron point of Voronoi division),
27 …… Voronoi polygon,
28 ...... Voronoi polygon that touches the measurement field boundary not counted as an average value,
31 …… Metal base material
32 …… Copper or nickel plating layer,
33 …… Polished surface,
34 ...... Concave surface formed by hitting fine particles,
35 …… Copper plating layer,
36a: a surface in which an uneven surface formed by hitting fine particles is blunted by etching,
36b... The surface formed by bumping the fine particles and dulled by copper plating,
37 …… Chrome plating layer,
38 …… Uneven surface remaining after chrome plating,
39. Flat surface generated when the surface after chrome plating is polished,
40 …… Photomask unit cell,
41 …… Chrome shading pattern of photomask,
42 …… Opening of photomask,
43 …… Photomask,
45 …… Light box,
46 …… Light source,
47 …… Glass plate,
49: Observation position of glare.

Claims (4)

An antiglare film in which an antiglare layer having a fine uneven surface is formed on a transparent support,
The relative scattered light intensity T (20) in the normal direction of the antiglare layer when light is incident at an incident angle of 20 ° from the transparent support side is 0.0001% or more and 0.0005% or less,
Ri 0.00025% der less relative scattered light intensity T (30) is 0.00004% or more in the antiglare layer side normal direction when the light enters at an incident angle of 30 ° from the transparent support side,
When light is incident at an incident angle of 30 ° from the antiglare layer side,
The reflectance R (30) at a reflection angle of 30 ° is 0.05% or more and 2% or less,
The reflectance R (40) at a reflection angle of 40 ° is 0.0001% or more and 0.005% or less,
The reflectance R (50) at a reflection angle of 50 ° is 0.00001% or more and 0.0005% or less,
Surface haze with respect to normal incident light is 0.1% or more and 0.9% or less,
The total haze is 21.1% to 25%,
The sum of reflection sharpness measured at a light incident angle of 45 ° using three types of optical combs having a dark part and a bright part width of 0.5 mm, 1.0 mm and 2.0 mm is 40% or less,
In the cross-sectional curve of the uneven surface constituting the antiglare layer,
The arithmetic average height Pa is 0.05 μm or more and 0.2 μm or less,
The maximum cross-sectional height Pt is 0.2 μm or more and 1 μm or less,
The average length PSm is 15 μm or more and 30 μm or less,
The uneven surface constituting the antiglare layer has 50 or more and 100 or less protrusions in a 200 μm × 200 μm region,
Average area of a polygon formed when Voronoi dividing the surface convex apex of the concave-convex surface constituting the antiglare layer as a base point is at 100 [mu] m ² or more 1,000 .mu.m ² or less,
The surface unevenness of the antiglare layer is formed by transfer from a mold having an uneven surface, and the antiglare layer has an average particle size of 5 μm to 15 μm with respect to 100 parts by weight of the binder resin. Containing 15 to 45 parts by weight of fine particles having a refractive index difference with the resin of 0.01 or more and 0.06 or less,
The anti-glare film is characterized in that the fine particles are completely buried in the anti-glare layer and do not affect the surface shape . Antiglare film according to claim 1, the uneven surface of the antiglare layer low reflection film is formed. An anti-glare polarizing plate, wherein a polarizer and the anti-glare film according to claim 1 or 2 are bonded together on the transparent support side of the anti-glare film. An antiglare film according to claim 1 or 2 , or an antiglare polarizing plate according to claim 3 , and an image display element, wherein the antiglare film or the antiglare polarizing plate is on the antiglare layer side. An image display device, wherein the image display device is disposed on the viewing side of the image display element with the outer side facing out.