KR20100045381A - Anti-glare film, anti-glare polarizing plate and visual display unit - Google Patents

Abstract

PURPOSE: An anti-glare film, an anti-glare polarizing plate, and a video display device are provided to improve durability without making a glittering phenomenon when the film is arranged on the surface of the video display device while preventing degradation of visibility. CONSTITUTION: An anti-glare film includes a resin base film(1) and a hard coating layer(2) with a minute concavo-convex shape on the surface, and is laminated on the top of the resin base film. The hard coating layer is made of light-transmitting resin in which at least one or more resin particle is dispersed. The surface haze of the hard coating layer is 1% ~ 10%. The inner haze is 10% ~ 20%. A volume change rate of the resin particle is 10% or more when the particle is dipped in ethyl acetate for 48 hours.

Description

Anti-glare film, anti-glare polarizing plate and image display device {ANTI-GLARE FILM, ANTI-GLARE POLARIZING PLATE AND VISUAL DISPLAY UNIT}

The present invention provides an anti-glare film having excellent durability and an anti-glare film that does not become cloudy and does not have glittering when applied to an image display device, and has excellent durability, and an anti-glare polarizing plate using the anti-glare film. It relates to an image display device.

In an image display device such as a liquid crystal display, a plasma display panel, a CRT display, or an organic electroluminescent (EL) display, visibility is remarkably impaired when external light shines on the display surface. Conventionally, in order to prevent such projection of external light, the surface of an image display apparatus is used in televisions and personal computers that value image quality, video cameras and digital cameras used outdoors with strong external light, and mobile phones which display using reflected light. The film layer which prevents projection of external light is provided in the inside. As this film layer, the anti-reflective processing technique using the interference by an optical multilayer film or the anti-glare processing technique which scatters incident light and applies a projected image by forming fine unevenness | corrugation on the surface are generally used. In particular, the technique of scattering incident light by forming the latter fine unevenness is relatively inexpensive, and thus is widely used for large-scale monitors and personal computers.

Such an anti-glare film is conventionally formed by applying a resin solution obtained by dispersing a filler onto a base sheet, adjusting the coating film thickness, and exposing the filler to the coating film surface to form random irregularities on the base sheet. It is manufactured by. Moreover, there exists an attempt to express anti-glare only by the fine unevenness | corrugation formed in the surface of a transparent resin layer, without containing a filler. For example, in Claims 1-6 and Paragraph 0043-0046 of Unexamined-Japanese-Patent No. 2002-189106 (patent document 1), the ionizing radiation is a state where the ionizing radiation curable resin is sandwiched between an embossing mold and a transparent resin film. The surface irregularities are formed on the transparent resin film by curing the curable resin and forming fine irregularities in which the average distance between adjacent convex portions on the three-dimensional ten-point average roughness and the three-dimensional roughness reference plane respectively satisfy a predetermined value. The anti-glare film in which the hardened | cured material layer of the ionizing radiation curable resin layer which has is laminated | stacked is disclosed. However, when such a conventional anti-glare film is disposed on the surface of the image display device, there is a problem that the entire display surface becomes white due to scattered light, so that a white cloudy color easily occurs.

In addition, when the image display device is highly precise, there is a problem that a so-called glittering phenomenon is likely to occur, in which the pixels of the image display device and the surface irregularities of the antiglare film interfere with each other, resulting in a luminance distribution that is difficult to see. In order to eliminate the glittering, there have been attempts to scatter light by setting the refractive index difference between the binder resin and the filler dispersed therein, but when such an antiglare film is used under high temperature, the binder resin and the filler deform or deteriorate, thereby There existed a problem that the surface shape of a film changes and a projection generate | occur | produces. In addition, even in the early stage of use, even if the glittering does not occur, the difference in refractive index between the binder resin and the filler changes when the use is continued under high temperature, so that scattering between the binder resin and the filler is reduced and there is also a problem that glittering occurs.

This invention is made | formed in view of such a reality, The objective is to show the outstanding anti-glare performance, and to prevent the fall of the visibility by cloudiness, and when it arrange | positions on the surface of a high-precision image display apparatus, it does not generate a glittering and high temperature. The present invention provides an anti-glare film having excellent durability that does not change its properties even when used for a long time, and further, to provide an anti-glare polarizing plate and an image display device to which the anti-glare film is applied.

The antiglare film according to the present invention is an antiglare film comprising a resin base film and a hard coating layer laminated on the resin base film surface and having a fine concavo-convex shape on the surface, wherein the hard coating layer is formed by dispersing at least one resin fine particle. It is made of a light-transmissive resin, and the surface haze of the hard coat layer is 1% or more and 10% or less, and the internal haze is 10% or more and 20% or less. The resin fine particles contained in the hard coat layer are 10% or more, preferably 50% or less, of a volume change rate when immersed in ethyl acetate at 23 ° C for 48 hours.

In the anti-glare film of the present invention, the difference between the refractive index of the translucent resin and the refractive index of the resin fine particles is preferably 0.02 or more and 0.06 or less. Moreover, it is preferable that the resin microparticles | fine-particles are contained in the hard-coat layer within the range whose weight average particle diameter is 2 micrometers or more and 10 micrometers or less, and is 1 weight part or more and 50 weight part or less with respect to 100 weight part of translucent resins.

The antiglare film of the present invention may further have a low reflection film on the uneven surface of the hard coat layer.

Moreover, the anti-glare polarizing plate in which the said polarizing film is arrange | positioned at the resin base film side of an anti-glare film is provided as an anti-glare polarizing plate which bonds the anti-glare film as described in any one of said, and a polarizing film.

The anti-glare film or anti-glare polarizing plate of the present invention can be used as an image display device in combination with an image display element such as a liquid crystal display element or a plasma display panel. That is, according to the present invention, the anti-glare film or the anti-glare polarizing plate and any one of the above-described anti-glare polarizing plates and the image display element are provided. There is provided an image display device arranged on the side.

When the anti-glare film of the present invention exhibits excellent anti-glare performance, a decrease in visibility due to cloudiness is prevented, and when disposed on the surface of a high-precision image display device, the anti-glare film does not generate glittering and is excellent in durability. The anti-glare polarizing plate which combined the anti-glare film of this invention with a polarizing film also expresses the same effect. And the image display apparatus which arrange | positioned the anti-glare film or anti-glare polarizing plate of this invention is high in anti-glare performance, and becomes excellent in visibility and durability.

<Antiglare film>

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows the preferable example of the anti-glare film of this invention. The anti-glare film shown in FIG. 1 is provided with the resin base film 1 and the hard-coat layer 2 laminated | stacked on the surface of the resin base film 1, and having a fine uneven | corrugated shape on the surface. The hard coat layer 2 is formed by dispersing the resin fine particles 3 in a translucent resin which is a binder resin. EMBODIMENT OF THE INVENTION Hereinafter, the anti-glare film of this invention is demonstrated in detail.

(Resin base film)

As a resin base film, if it is a film which has substantially optical transparency, it will not specifically limit, Various transparent resin films can be used. Specific examples thereof include cellulose resins such as triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, cycloolefin resins, polycarbonate, polymethyl methacrylate, polysulfone, polyether sulfone, polyvinyl chloride, The film etc. which consist of polyethylene terephthalate etc. are illustrated. Cycloolefin-type resin is resin which uses cyclic olefins, such as norbornene and dimethanooctahydronaphthalene, as a monomer, and as a specific commercial item, "Aton" (made by JSR Corporation), "Zeonor" (Nihon Xeon Co., Ltd.) ), "Xeonex" (made by Nihon Xeon Co., Ltd.), etc. are mentioned.

It is preferable that the thickness of a resin base film is 30 micrometers or more and 250 micrometers or less, More preferably, they are 40 micrometers or more and 170 micrometers or less. When the thickness of a resin base film is thin, it may be difficult to obtain sufficient hardness as an anti-glare film. Moreover, when the thickness of a resin base film is thick, it is unpreferable from a viewpoint, such as a request for thickness reduction of the recent image display apparatus, cost. From the viewpoint of reducing the thickness of the entire antiglare film, the thickness of the resin base film is more preferably 150 μm or less, more preferably 120 μm or less.

(Hard coating layer)

The hard coat layer which has a fine uneven | corrugated shape in the surface with which the antiglare film of this invention is equipped is laminated | stacked on the said resin base film surface, Comprising at least 1 type of translucent resin microparticles | fine-particles made of translucent resin (hard coating resin). . In the present invention, the term "transparent" means that light can be transmitted mostly, regardless of the presence or absence of scattering in the material.

In the present invention, the surface haze of the hard coat layer is 1% or more and 10% or less, and the internal haze is 10% or more and 20% or less. Here, the surface haze and the internal haze of the hard coat layer are measured as follows. That is, first, the hard coat layer is formed on a triacetyl cellulose film having a haze of almost 0%, and then the laminated film and the glass substrate are bonded together using a transparent adhesive so that the triacetyl cellulose film side becomes a bonding surface, Haze is measured based on JISK7136. The haze corresponds to the haze of the entire hard coating layer. Next, a triacetyl cellulose film having almost 0% haze is bonded to the uneven surface of the hard coat layer using glycerin, and the haze is measured again in accordance with JIS K 7136. The haze can be regarded as "internal haze" of the hard coat layer because the surface haze attributable to the surface irregularities is almost canceled by the triacetylcellulose film bonded on the surface irregularities. Therefore, "surface haze" of a hard coat layer is calculated | required from following formula (1).

Surface haze = whole haze-internal haze

By making the surface haze of a hard-coat layer into 10% or less, the cloudyness at the time of applying an anti-glare film to an image display apparatus can be suppressed effectively. In order to suppress cloudiness more effectively, it is preferable that the surface haze of a hard coat layer is 5% or less. However, when less than 1%, since sufficient anti-glare property is not shown, the surface haze of a hard coat layer will be 1% or more.

In addition, by making the internal haze of the hard coat layer 10% or more, the glittering when the antiglare film is applied to the image display device can be effectively eliminated. In order to more effectively eliminate the glittering, the internal haze of the hard coat layer is preferably 15% or more. Moreover, when an anti-glare film is applied to an image display apparatus by making internal haze of a hard coat layer into 20% or less, a screen becomes dark and it can prevent that visibility is impaired.

In the present invention, the hard coat layer provided with the surface irregularities satisfying the above optical characteristics is formed using at least one light-transmitting resin fine particle and a light-transmissive resin. More specifically, such a hard coat layer is applied by, for example, applying a light-transmissive resin solution obtained by dispersing light-transmitting resin fine particles as a filler onto a resin base film, adjusting the thickness of the coating film, and making the part of the light-transmissive resin fine particles convex. Can be formed. Moreover, the translucent resin solution which disperse | distributed translucent resin microparticles | fine-particles as a filler can be apply | coated on a resin base film, and surface irregularities can also be formed by the embossing method disclosed by the said patent document 1.

Here, the translucent resin microparticles | fine-particles used for the anti-glare film of this invention are 10% or more in volume change rate when immersed in ethyl acetate for 48 hours. By using the resin fine particle whose volume change rate when immersed in ethyl acetate for 48 hours is 10% or more, it becomes possible to obtain the anti-glare film which is excellent in durability, with little change of a characteristic (especially haze characteristic) also in use under high temperature.

According to the examination of the present inventors, when the anti-glare film provided with the hard-coat layer in which the resin microparticles | fine-particles were disperse | distributed under high temperature, the resin which comprises the translucent resin and the resin microparticles advances crosslinking reaction, respectively, As a result, a translucent resin and resin The refractive index of the microparticles rises, respectively. At this time, in general, since the resin constituting the translucent resin has a lower reactivity than the resin fine particles (lower crosslinking density), the translucent resin has a higher degree of progress in the crosslinking reaction due to high temperature exposure than the resin fine particles, resulting in a higher refractive index. It is bigger than this. As described above, when the antiglare film is exposed at a high temperature, the haze characteristics (particularly the internal haze) change because the translucent resin has a larger refractive index increase, so that the refractive index ratio (or refractive index difference) between the translucent resin and the resin fine particles is increased. It is thought that there is one cause for the deviation from the initially set value.

According to the present invention, when the resin fine particles having a volume change rate of 10% or more when immersed in ethyl acetate for 48 hours are used, these resin fine particles have a lower crosslinking density (lower reactivity) than the resin fine particles used in the past. The degree of progress of the crosslinking reaction at high temperature exposure, and hence the increase in refractive index, becomes larger. Thereby, since the change of the refractive index ratio (or refractive index difference) of translucent resin and resin microparticles | fine-particles at the time of high temperature exposure of an anti-glare film becomes small compared with the case where the conventional resin microparticles | fine-particles are used, especially the change of internal haze by high temperature exposure. It is possible to reduce the

The lower limit of the volume change rate of the light transmissive resin fine particles used in the antiglare film of the present invention when immersed in ethyl acetate for 48 hours is not particularly limited in terms of durability (particularly lowering of internal haze), but is light transmissive in which the resin fine particles are dispersed. It is preferable that it is 50% or less in terms of stability of a resin solution, It is more preferable that it is 30% or less, It is still more preferable that it is 20% or less.

In the present invention, the volume change rate when the resin fine particles are immersed in ethyl acetate for 48 hours is measured as follows. That is, first, the average particle diameter d ₀ of the resin fine particles before being immersed in ethyl acetate is measured. The average particle diameter d ₀ is the average particle diameter of the 20 resin fine particles obtained by image analysis with respect to 20 resin fine particles arbitrarily observed before immersion in ethyl acetate by the microscope. Next, the resin fine particles are immersed in ethyl acetate at 23 ° C. for 48 hours, and the average particle diameter d ₄₈ of the resin fine particles after immersion is similarly determined to obtain an image analysis. Using these average particle diameters, volume change rate (%) is calculated | required by following formula (2).

Volume change rate (%) = d ₄₈ ³ / d ₀ ³ × 100-100

The kind of resin which comprises the translucent resin microparticles | fine-particles disperse | distributed to a hard coat layer can adjust the optical characteristic (especially internal haze) of a hard coat layer in the said range, and the volume change rate when it immersed in ethyl acetate for 48 hours is said Although it does not restrict | limit especially if it is in a range, For example, melamine beads (refractive index: 1.57), polymethyl methacrylate beads (refractive index: 1.49), methyl methacrylate / styrene copolymer resin beads (refractive index: 1.50-1.59), Polycarbonate beads (refractive index: 1.55), polyethylene beads (refractive index: 1.53), polystyrene beads (refractive index: 1.6), polyvinyl chloride beads (refractive index: 1.46), silicone resin beads (refractive index: 1.46), and the like.

As the resin fine particles used in the present invention, in order to make the internal haze of the hard coating layer 10% or more and 20% or less, the difference between the refractive index of the resin fine particles and the refractive index of the translucent resin (hard coating resin) serving as the base material of the hard coating layer is 0.02 or more and 0.06. It is preferable to select the following resin fine particles.

Moreover, it is preferable that the weight average particle diameters of the resin fine particle used by this invention are 2 micrometers or more and 10 micrometers or less, and it is more preferable that they are 4 micrometers or more and 8 micrometers or less. If the weight average particle diameter is small, sufficient anti-glare property may not be obtained or the internal haze tends to be large. If the weight average particle diameter is large, the surface haze becomes large. As a result, the anti-glare film becomes cloudy and visibility is reduced, or sufficient internal haze is obtained. Tends not to be obtained. Here, a "weight average particle diameter" is a weight average particle diameter measured using the Coulter method. The weight average particle diameter using the Coulter method can be measured, for example using the precision particle size distribution measuring apparatus "Coulter Multisizer3" (made by Beckman Coulter).

Moreover, it is preferable that resin microparticles | fine-particles are contained in a hard-coat layer within the range of 1 weight part or more and 50 weight part or less with respect to 100 weight part of translucent resins. More preferably, it is contained within the range of 10 weight part or more and 40 weight part or less with respect to 100 weight part of translucent resins. When there is little content of resin microparticles | fine-particles, it will not show sufficient anti-glare property, or surface unevenness will generate | occur | produce, and a texture will fall, or internal haze tends to become small. Moreover, when there is much content of resin microparticles | fine-particles, haze will become large, and as a result, an anti-glare film tends to be cloudy, contrast will fall, and there exists a tendency for visibility to fall.

As light-transmissive resin which disperse | distributes resin microparticles | fine-particles, ultraviolet curable resin, a thermosetting resin, electron beam curable resin, etc. can be used, A ultraviolet curable resin is used preferably from a viewpoint of productivity, hardness, etc. As ultraviolet curable resin, what is marketed can be used. For example, single or 2 types or more of polyfunctional acrylates, such as a trimethylol propane triacrylate and pentaerythritol tetraacrylate, and "Irgacure 907" and "Irgacure 184" (above, Ciba specialty chemical The mixture with photoinitiators, such as the Z make) and "Lucirine TPO" (made by BASF Corporation), can be made into an ultraviolet curable resin. For example, when using an ultraviolet curable resin, after disperse | distributing resin microparticles | fine-particles to an ultraviolet curable resin, this resin composition is apply | coated on a resin base film and dried, and then irradiated with an ultraviolet-ray, a translucent resin (hard coating resin) A hard coat layer in which resin fine particles are dispersed can be formed.

In addition, when forming a fine uneven | corrugated shape in a hard-coat layer by the embossing method, as disclosed in the said patent document 1, etc., the shape of a metal mold | die was formed using the metal mold | die with which the fine uneven | corrugated shape was formed (namely, translucent resin). And a resin film composed of resin fine particles). It is preferable to perform transfer to the film of a mold shape by embossing, and the UV embossing method using an ultraviolet curable resin is preferable as embossing.

In the UV embossing method, an ultraviolet-curable resin layer (resin composition layer composed of a translucent resin and resin fine particles) is formed on the surface of the resin substrate film, and the ultraviolet-curable resin layer is cured while pressing the concave-convex surface of the mold to make the concave-convex surface of the mold. It is transferred to this ultraviolet curable resin layer. Specifically, the ultraviolet curable resin which disperse | distributed translucent resin microparticles | fine-particles was coated on the resin base film, ultraviolet-ray is irradiated from the resin base film side in the state which adhered the ultraviolet curable resin layer obtained by coating to the uneven surface of a metal mold | die, The ultraviolet curable resin layer is cured, and then the shape of the mold is transferred to the ultraviolet curable resin layer by peeling the resin base film on which the ultraviolet curable resin layer after curing is formed from the mold. The kind of ultraviolet curable resin is not specifically limited. In addition, by selecting the photoinitiator appropriately instead of the ultraviolet curable resin, it is also possible to use a visible light curable resin capable of curing with visible light having a longer wavelength than ultraviolet.

When forming a surface asperity shape in a hard-coat layer without using the embossing method, although the thickness of a hard-coat layer can adjust suitably so that surface haze may be in the said range, it is preferable that they are 2 micrometers or more and 20 micrometers or less. If the thickness of the hard coating layer is less than 2 μm, sufficient hardness is not obtained, and there is a tendency to be easily scratched, and if it is thicker than 20 μm, it tends to be broken, or the anti-glare film curls by hardening shrinkage of the hard coating layer, resulting in increased productivity. It tends to be lowered. Moreover, it is preferable that the thickness of a hard coat layer is 85% or more generally with respect to the weight average particle diameter of the translucent resin microparticles | fine-particles disperse | distributed, More preferably, it is 100% or more. When the thickness of a hard coat layer is less than 85% of the weight average particle diameter of resin fine particles, surface haze becomes large and, as a result, an anti-glare film tends to become cloudy and visibility falls.

When forming a surface uneven | corrugated shape in a hard coat layer using the embossing method, it is preferable that the thickness of a hard coat layer is 2 micrometers or more and 20 micrometers or less. If the thickness of the hard coating layer is less than 2 μm, sufficient hardness is not obtained, and it tends to be easily scratched. If the thickness of the hard coating layer is greater than 20 μm, it becomes brittle, or the anti-glare film curls due to hardening shrinkage of the hard coating layer, resulting in increased productivity. It tends to be lowered. In addition, the thickness of the hard coat layer is generally preferably 100% or more, more preferably 120% or more with respect to the weight average particle diameter of the translucent resin microparticles dispersed therein. When the thickness of the hard coat layer is thinner than the weight average particle diameter of the resin fine particles, the resin fine particles may have an unexpected effect on the surface irregularities of the hard coating layer, and a preferable surface haze value may not be obtained.

The anti-glare film of this invention may have a low reflection film in the outermost surface, ie, the uneven surface side of a hard-coat layer. Although sufficient anti-glare function is exhibited even in the absence of a low reflection film, anti-glare property can be further improved by providing a low reflection film on the outermost surface. The low reflection film can be formed on the hard coating layer by providing a layer of low refractive index material having a lower refractive index than that. As such a low refractive index material, specifically, inorganic fine particles such as lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), aluminum fluoride (AlF ₃ ), cryolite (3NaF.AlF ₃ or Na ₃ AlF ₆ ) Inorganic low reflection materials contained in acrylic resins, epoxy resins, and the like; Organic low reflection materials, such as a fluorine-type or silicone type organic compound, a thermoplastic resin, a thermosetting resin, and an ultraviolet curable resin, are mentioned.

<Anti-glare Polarizing Plate>

The anti-glare film of the present invention is excellent in anti-glare effect, effectively prevents turbidity, effectively suppresses the occurrence of glittering, and is excellent in durability. Therefore, by applying this to an image display device, image display having excellent visibility and durability can be obtained. Get the device. When an image display apparatus is a liquid crystal display, this anti-glare film can be applied to a polarizing plate. That is, in many cases, a polarizing plate generally has a form in which a protective film is bonded to at least one side of a polarizing film made of a polyvinyl alcohol-based resin film in which iodine or dichroic dye is adsorbed and oriented. It consists of an anti-glare film. It can be set as an anti-glare polarizing plate by bonding a polarizing film and the anti-glare film of this invention at the resin base film side of the anti-glare film. In this case, the other surface of a polarizing film may be a state in which nothing is laminated | stacked, another protective film or an optical film may be laminated | stacked, and the adhesive layer for bonding to a liquid crystal cell may be formed. . Moreover, the anti-glare film of this invention can be bonded on the resin base film side, and it can also be set as an anti-glare polarizing plate on the said protective film of the polarizing plate in which the protective film was bonded to at least one surface of the polarizing film. Moreover, in the polarizing plate in which the protective film was bonded on at least one surface, after joining the said resin base film to a polarizing film as this protective film, it can also be set as an anti-glare polarizing plate by forming the said hard-coat layer on a resin base film.

<Image display device>

The image display apparatus of this invention combines the anti-glare film or anti-glare polarizing plate of this invention with an image display element. Here, the image display element includes a liquid crystal cell in which a liquid crystal is enclosed between upper and lower substrates, and a liquid crystal panel which displays an image by changing the alignment state of the liquid crystal by voltage application is typical. The anti-glare film or anti-glare polarizing plate of the present invention can also be applied to various known displays such as a display and an organic EL display. In the image display apparatus of this invention, an anti-glare film is arrange | positioned rather than an image display element at the visual recognition side. At this time, it is arrange | positioned so that the uneven surface of an anti-glare film, ie, the hard-coat 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, the antiglare film may be bonded to the surface of the liquid crystal panel via a polarizing film. Thus, the image display apparatus provided with the anti-glare film of this invention can scatter an incident light by the unevenness | corrugation of the surface which an anti-glare film has, and can project a projected image, and provides outstanding visibility and excellent durability.

In addition, the antiglare film of the present invention, even when applied to a high-precision image display device, does not generate the glittering as seen in the conventional antiglare film, and has the performance of sufficient projection prevention, prevention of cloudiness, suppression of glittering, and excellent durability. It becomes.

Although an Example is described to the following and this invention is demonstrated to it further more concretely, this invention is not limited by these examples. In the examples,% and parts representing the content to the amount used are based on weight unless otherwise specified. In addition, the evaluation method of the anti-glare film in the following examples is as follows.

(1) Measurement of optical properties of antiglare film

(1-1) Surface and internal haze of the hard coat layer

First, after forming a hard-coat layer on the triacetyl cellulose film of which haze is almost 0%, the said laminated | multilayer film and a glass substrate are bonded together using a transparent adhesive so that a triacetyl cellulose film side may become a bonding surface, JIS K 7136 Haze of the whole was measured using the Haze meter "HM-150" type | mold by the Shikisai Gijutsu Genshusho Co., Ltd. which conformed to the. Next, a triacetylcellulose film having almost zero haze was bonded to the uneven surface of the hard coat layer using glycerin, and the internal haze was measured again in accordance with JIS K 7136. Surface haze was computed based on said Formula (1).

(1-2) transmission sharpness

The transmission sharpness of the anti-glare film was measured using a filament measuring instrument "ICM-1DP" manufactured by Suga Shikeki Co., Ltd. in accordance with JIS K 7105. In this case as well, in order to prevent the bending of the sample, an optically transparent adhesive was used to bond the glass substrate so that the uneven surface became a surface, and then the measurement was performed. Light was incident from the glass side in this state, and measurement was performed. The measured value here is the sum total of the values measured using the four types of optical combs whose width | variety of a dark part and a wrist is 0.125mm, 0.5mm, 1.0mm, and 2.0mm, respectively. In this case, the maximum value of transmission clarity is 400%.

(1-3) reflection sharpness

The reflection sharpness of the antiglare film was measured using the same filament measuring instrument "ICM-1DP". In this case as well, in order to prevent the bending of the sample, an optically transparent adhesive was used to bond the glass substrate so that the uneven surface became a surface, and then the measurement was performed. In addition, in order to prevent reflection from the back glass surface, a black acrylic resin plate having a thickness of 2 mm is adhered to water and adhered to the glass surface of the glass plate with the antiglare film, and light is incident from the sample (antiglare film) side in this state. The measurement was performed. The measured value here is the sum total of the value measured using the three types of optical combs whose width | variety of a dark part and a wrist is 0.5 mm, 1.0 mm, and 2.0 mm, respectively (maximum value 300%).

(2) Evaluation of antiglare performance of antiglare film

(2-1) Visual evaluation of projection and cloudiness

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 fluorescent lamps, and whether or not the projection of the fluorescent lamp is cloudy The degree of was visually evaluated. Projection and cloudiness were evaluated according to the following criteria in three steps of 1 to 3, respectively.

(a) projection; 1: No projection is observed. 2: The projection is slightly observed. 3: The projection is clearly observed.

(b) turbidity; 1: No turbidity is observed. 2: A little cloudiness is observed. 3: Cloudiness is observed clearly.

(2-2) Evaluation of Glittering

Glittering was evaluated by the following method. That is, first, a photomask having a pattern of unit cells as shown in plan view in FIG. 2 was prepared. In this figure, the unit cell 4 has a chromium light shielding pattern 5 in the form of a hook having a line width of 10 μm on a transparent substrate, and a portion where the chromium light shielding pattern 5 is not formed is an opening 6. It is. In this case, the unit cell 4 has a size of 254 μm × 84 μm (vertical × horizontal in the drawing), and thus, the opening 6 has a dimension of 244 μm × 74 μm (vertical in the drawing). The unit cell 4 shown in figure arranges many in the vertical and horizontal direction, and forms the photomask 7. As shown in FIG.

3, the chromium light shielding pattern 5 of the photomask 7 is placed on the light box 8 with the chrome shielding pattern 5 of the photomask 7 facing up, and the antiglare film 12 with the adhesive on the glass plate 10. The bonded sample is placed on the photomask 7 so that the uneven surface becomes a surface. The light source 9 is arranged in the light box 8. In this state, visual observation was carried out at a position 11 about 30 cm away from the sample. The degree of glittering was evaluated according to the following criteria in three steps of 1-3.

Glittering; 1: No glittering is seen. 2: Very little glittering is observed. 3: Very much glittering is observed.

(3) Evaluation of Durability of Anti-glare Film

The anti-glare film was stored in a dryer at 80 ° C. for 200 hours, and the optical properties and anti-glare performance after drying were evaluated by the above-described evaluation method.

(4) Volume change rate of resin fine particles when immersed in ethyl acetate for 48 hours

The resin fine particles before being immersed in ethyl acetate were observed with digital microscope VHX-500 (manufactured by Giens Co., Ltd.), and the average particle diameter d ₀ (average of 20 resin fine particles) was determined by image analysis. Then, it was immersed in ethyl acetate for 48 hours in 23 degreeC environment. The resin fine particles after immersion were again observed with a digital microscope, and in the same manner, the average particle diameter d ₄₈ was obtained by image analysis. The volume change rate was computed from the said Formula (2) using the obtained average particle diameter.

<Example 1>

(Production of Coating Liquid A)

Each of the following components was melt | dissolved in ethyl acetate at 60% of solid content concentration, and the ultraviolet curable resin composition A which shows the refractive index of 1.53 after hardening was prepared.

Pentaerythritol triacrylate 60 parts

Polyfunctional urethane acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) 40 parts

Next, with respect to 100 weight part of solid content of this ultraviolet curable resin composition A, the methyl methacrylate / styrene copolymer resin beads (weight average particle diameter 7.43 micrometer, refractive index 1.55, volume change rate when immersed in ethyl acetate for 48 hours at 23 degreeC for 48 hours). 11%) was added 40 weight part and 5 weight part of "Lucirine TPO" (made by BASF Corporation) which is a photoinitiator, and it diluted with ethyl acetate so that solid content might be 60%, and the coating liquid A was prepared.

(Production of embossing roll A)

The surface of the iron roll 200 mm in diameter (STKM13A by JIS) was prepared by which copper ballard plating was performed. Copper ballad plating consists of a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the whole plating layer was about 200 micrometers. The copper-plated surface was mirror-polished, and a blast device (manufactured by Fuji Seisakusho Co., Ltd.) was used as the polished surface thereof, and zirconia bead TZ-B125 (manufactured by Tosoh Corporation, average particle diameter was used as the first fine particles). 125 µm) was blasted at a blast pressure of 0.05 MPa (gauge pressure, the same below) and the use amount of beads 6 g / cm ² (the amount used per 1 cm ^{2 of} the roll surface, hereinafter the same) to form irregularities on the surface. A blast device (manufactured by Fuji Seisakusho Co., Ltd.) was used as the uneven surface, and zirconia bead TZ-SX-17 (manufactured by Tosoh Corporation, average particle diameter: 20 μm) was used as the second fine particles to have a blast pressure of 0.05. The surface irregularities were finely adjusted by blasting at 6 g / cm ² of MPa and beads. The obtained copper-plated iron roll with unevenness was subjected to etching treatment with cupric chloride liquid. The etching amount at that time was set to be 3 micrometers. Then, the chrome plating process was performed and the embossing roll A was produced. At this time, the chromium plating thickness was set to 4 µm.

(Production of anti-glare film A)

Coating liquid A was apply | coated so that the coating thickness after drying might be set to 15 micrometers on the triacetyl cellulose (TAC) film (made by Fujifilm, thickness of 80 micrometers), and it dried for 3 minutes in the dryer set to 60 degreeC. The film after drying was pressed by the rubber roll so that the ultraviolet-ray curable resin composition layer (layer of coating liquid A) might be the embossing roll side, and it adhered to the uneven surface of the embossing roll A. In this state, the light from the high pressure mercury lamp of 20 mW / cm <^2> intensity | strength was irradiated so that it might become 200 mJ / cm <^2> by h line conversion light quantity from the TAC film side, and the ultraviolet curable resin composition layer was hardened. Thereafter, the TAC film was peeled from the cured product layer embossing roll to obtain an antiglare film A made of a laminate of a hard coat layer having irregularities on the surface and a TAC film.

<Example 2>

Methyl methacrylate / styrene copolymer resin beads (weight average particle diameter 7.74 μm, refractive index 1.55, refractive index 1.55, 15% volume change when immersed in ethyl acetate for 48 hours at 100 parts by weight of the ultraviolet curable resin composition A) ) Was added 40 parts by weight, 5 parts by weight of "Lucirine TPO" (manufactured by BASF Corporation) as a photopolymerization initiator, and diluted with ethyl acetate to obtain a solid content of 60% to prepare a coating solution B.

Except having used this coating liquid B, it carried out similarly to Example 1, and obtained the anti-glare film B which consists of a laminated body of the hard-coat layer which has unevenness | corrugation on the surface, and a TAC film.

<Example 3>

Methyl methacrylate / styrene copolymer resin beads (weight average particle diameter 7.63 μm, refractive index 1.55, 63% volume change when immersed in ethyl acetate for 48 hours at 23 ° C.) with respect to 100 parts by weight of the solid content of the ultraviolet curable resin composition A ) Was added 40 parts by weight, 5 parts by weight of "Lucirine TPO" (manufactured by BASF Corporation) as a photopolymerization initiator, and diluted with ethyl acetate to obtain a solid content of 60% to prepare a coating solution C.

Except having used this coating liquid C, it carried out similarly to Example 1, and obtained the anti-glare film C which consists of a laminated body of the hard-coat layer which has unevenness | corrugation on the surface, and a TAC film.

Comparative Example 1

Methyl methacrylate / styrene copolymer resin beads (weight average particle diameter: 7.78 μm, refractive index: 1.55, volume change rate when immersed in ethyl acetate for 48 hours at 23 ° C. with respect to 100 parts by weight of the above-mentioned ultraviolet curable resin composition A) ) Was added 40 parts by weight, 5 parts by weight of "Lucirine TPO" (manufactured by BASF Corporation) as a photopolymerization initiator, and diluted with ethyl acetate to obtain a solid content of 60% to prepare a coating solution D.

Except having used this coating liquid D, it carried out similarly to Example 1, and obtained the anti-glare film D which consists of a laminated body of the hard-coat layer which has unevenness | corrugation on the surface, and a TAC film.

(I) Optical properties of the anti-glare films of Examples 1 to 3 and Comparative Example 1 before storage for 200 hours in the dryer, the average particle diameter before and after immersion in ethyl acetate, and 48 to 23 The volume change rate at the time of immersion, and (II) The optical characteristic after storing for 200 hours in 80 degreeC dryer are put together in Table 1 and 2, respectively. In addition, the breakdown of transmission clarity and reflection clarity of the anti-glare film of Example 1 shown in Table 1 is as follows.

                     Transmission Clarity Reflection Clarity

0.125 mm optical comb: 33.5%-

0.5 mm optical comb: 33.4% 12.8%

1.0 mm optical comb: 33.1% 13.8%

2.0 mm optical comb: 44.3% 22.3%

Total 144.3% 48.9%

As shown in Tables 1 and 2, the antiglare films (Examples 1 to 3) of the present invention and the antiglare films of Comparative Example 1 both exhibit excellent anti-glare performance before drying at 80 ° C. for 200 hours, and do not cause glittering or turbidity. It showed a favorable optical characteristic. However, the anti-glare film of Comparative Example 1 is due to the use of resin fine particles having a volume change rate of almost 0% when immersed in ethyl acetate at 23 ° C. for 48 hours in the hard coating layer, by drying at 80 ° C. for 200 hours. The internal haze of the hard coat layer was greatly lowered, and as a result, glittering occurred.

On the other hand, in the anti-glare films (Examples 1 to 3) of the present invention, deterioration of optical properties such as the surface of the hard coat layer and internal haze is effectively suppressed even by drying at 80 ° C for 200 hours. And had excellent durability. Moreover, the fall suppression effect of internal haze showed the tendency to become large, so that the volume change rate of the used resin fine particle is large. However, in the anti-glare film of Example 3, since the internal haze before drying at 80 degreeC for 200 hours is comparatively low as 10.8%, the fall of the internal haze by drying is very small, but the glittering occurs after drying at 80 degreeC for 200 hours. The result was. In the anti-glare film of Example 3, it is thought that the internal haze before drying at 80 degreeC for 200 hours is comparatively low because the stability of coating liquid C fell because the volume change rate of resin microparticles was 63% high. As described above, in terms of suppressing the reduction of internal haze of the hard coat layer, the volume change rate of the resin fine particles to be used is preferably larger, but considering the internal haze of the initial state (before high temperature exposure), the volume change rate of the resin fine particles is about 50%. It is preferable to set it as follows.

The embodiments and examples disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown by above-described not description but claim, and it is intended that the meaning of a claim and equality and all the changes within a range are included.

The antiglare film of the present invention is disposed on various displays such as a liquid crystal panel, a plasma display panel, a CRT display, an organic EL display, and the like so that the antiglare film is more visible than the image display element, without causing cloudiness and glittering. The image can be altered to provide excellent visibility.

BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram which shows the preferable example of the anti-glare film of this invention.

It is a top view which shows the unit cell of the pattern for glittering evaluation.

It is a cross-sectional schematic diagram which shows the state at the time of glittering evaluation.

<Explanation of symbols for the main parts of the drawings>

1: resin base film

2: hard coating layer

3: resin fine particles

4: unit cell of photomask

5: chrome shading pattern of photomask

6: opening of photomask

7: photomask

8: light box

9: light source

10: glass plate

11: Observation Position of Glittering

12: antiglare film

Claims (7)

It is an anti-glare film provided with a resin base film and the hard-coat layer laminated | stacked on the said resin base film surface, and having a fine uneven | corrugated shape on the surface, The hard coating layer is made of a light-transmissive resin in which at least one resin fine particle is dispersed, The surface haze of the said hard coat layer is 1% or more and 10% or less, The internal haze is 10% or more and 20% or less, The said resin fine particle is an anti-glare film whose volume change rate at the time of immersion in ethyl acetate at 23 degreeC for 48 hours is 10% or more. The anti-glare film of Claim 1 whose volume change rate when the said resin fine particle is immersed in ethyl acetate at 23 degreeC for 48 hours is 50% or less. The anti-glare film according to claim 1 or 2, wherein a difference between the refractive index of the translucent resin and the refractive index of the resin fine particles is 0.02 or more and 0.06 or less. The said resin fine particle has a weight average particle diameter of 2 micrometers or more and 10 micrometers or less, and is in the range of 1 weight part or more and 50 weight part or less with respect to 100 weight part of said translucent resins. Antiglare film contained in the hard coating layer. The anti-glare film according to any one of claims 1 to 4, further comprising a low reflection film on the uneven surface of the hard coating layer. It is an anti-glare polarizing plate formed by bonding the anti-glare film and polarizing film of any one of Claims 1-5, The said polarizing film is an anti-glare polarizing plate arrange | positioned at the said resin base film side of the said anti-glare film. The anti-glare film of any one of Claims 1-5, or the anti-glare polarizing plate of Claim 6, and an image display element are provided, The said anti-glare film or anti-glare polarizing plate is arrange | positioned at the visual recognition side of an image display element with the hard-coat layer side outside.

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