JP2010054737A - Antiglare film, method for manufacturing the antiglare film, polarizing plate, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antiglare film in which image outline blurs, black tightness and interference fringes are improved and which has high darkroom contrast, weak curling and excelling appearance. <P>SOLUTION: The antiglare film has at least a transparent support and an antiglare layer formed on the transparent support. For the antiglare film, the film thickness is in the range of 8 to 18 μm; a coagulation part containing translucent particles of average particle size R of 5 μm<R<15 μm forms a surface rugged shape; and the coagulation ratio of the translucent particles expressed by the formula (A) is 15 to 40%. The formula (A) is represented by: (particle coagulation ratio)=(1-(particle occupancy area per mm<SP>2</SP>)/(the number of particles per mm<SP>2</SP>)×π×(the average particle size/2)<SP>2</SP>)×100. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an antiglare film, a method for producing an antiglare film, a polarizing plate, and an image display device.

  Image display devices such as CRT, plasma display (PDP), electroluminescence display (ELD), field emission display (FED), surface conduction electron-emitting device display (SED) and liquid crystal display (LCD) By preventing the reflection of an image on the display surface due to reflection, it is possible to improve the display performance in a bright room environment.

  As a method for preventing the reflection of an image on the display surface of an image display device, (1) the ability to blur the outline of the image reflected due to surface scattering (antiglare property) is imparted, making it difficult to recognize the reflected image. And (2) a method of making it difficult to recognize an image reflected by providing a low refractive index layer on the outermost surface of the display to provide a performance (antireflection) that reduces the amount of reflected light. (Patent Documents 1 and 2).

  2. Description of the Related Art In recent years, the market for applications that use a display device having a large screen, such as a liquid crystal television, to watch a moving image with high image quality from a relatively distant position, has been rapidly expanding. In such an application, the display is required to display a clearer image. If the anti-glare property is strong, the outline of the image will be blurred when objects placed around the display, fluorescent lamps, humans, etc. are reflected on the display surface, making it easier to recognize the image on the display. Reduced). On the other hand, the high antiglare property increases the feeling of whiteness on the display surface (blackening is worsened), and causes a decrease in contrast under the bright room. In general, these performances are considered to have a reciprocal relationship. On the other hand, with the recent expansion of the display market and the increase in the size of panels, there has been a strong demand for coexistence of image outline blurring and blackening. In addition, as the size and definition of panels increase, demands for surface films are increasing, reducing interference fringes generated inside the panels, appearance without unevenness and defects, and high contrast in dark rooms. It has become like.

  In order to solve these problems, in Patent Document 3, the surface irregularities are controlled by aggregating five or more particles having a particle diameter of 1.5 to 5 μm so as to achieve both the contour blur of the image and the black tightening. Further, in Patent Document 4, particles having a particle diameter of 7 to 15 μm are used, and the absolute value of the difference in refractive index between the particles and the resin is set to 0.01 to 0.06, so that the image outline blur, black tightening, interference fringes Meet the reduction.

Japanese Patent No. 3507719 JP 2003-270409 A JP 2005-316413 A JP 2007-334064 A

  However, when particles having a particle diameter of 1.5 to 5 μm are used as in Patent Document 3, the effect of reducing interference fringes generated inside the panel is not sufficient, and light scattering of the antiglare layer is required to reduce the interference fringes. When the amount is increased, there is a problem that the contrast in the dark room is lowered. Further, in Patent Document 4, since the above problem has been solved because particles having a particle diameter of 7 to 15 μm are used, in the prior art, the film thickness is designed to be 20 to 30 μm in order to improve black tightening. Since it was necessary, it turned out that the new problem that the cost improvement and curling worsen by that occurred.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and provide an antiglare film having excellent image blurring, blackening, interference fringe improvement, high darkroom contrast, weak curl, and excellent appearance, and a method for producing the same. There is. Another object of the present invention is to provide a polarizing plate and an image display device using the antiglare film.

  As a result of intensive studies, the present inventors have solved the above problems by adopting the following configuration.

1. An antiglare film having at least a transparent support and an antiglare layer formed on the transparent support, wherein the antiglare layer has a thickness of 8 to 18 μm and an average particle diameter R of 5 μm < An antiglare film in which a surface irregularity shape is formed by an agglomerated part containing translucent particles having R <15 μm, and the agglomeration rate represented by the following formula (A) of the translucent particles is 15 to 40%.
Formula (A) particle aggregation rate = (1- (1mm grain area occupied by the ² around) / (1 mm ² around the particle number × [pi × (average particle diameter / ^{2) 2))} × 100
2. The surface haze of the antiglare film is 2 to 7%, the internal haze is 10 to 30%, and the absolute value of the refractive index difference between the translucent particles and the translucent resin forming the antiglare layer is 2. The antiglare film according to 1 above, which is 0.01 to 0.10.
3. 3. The antiglare film as described in 1 or 2 above, which has at least one antireflection layer on the antiglare layer.
4). 4. The method for producing an antiglare film as described in any one of 1 to 3 above, wherein the coating solution for forming an antiglare layer having a solid content ratio of 20 to 60% by mass is applied on the transparent support, and then the coating is applied. The transparent support is held or transported in an inclined state of 30 to 90 ° for a time of half or more when the solid content ratio of the liquid is 75% by mass, and the solvent in the coating liquid is dried at a rate of 0.1 to 0. 0. A method for producing an antiglare film comprising a step of evaporating at 7 g / m ² · s and drying a coating film.
5). 5. The method for producing an antiglare film as described in 4 above, wherein the coating liquid for forming the antiglare layer has a viscosity at 25 ° C. of 2 to 20 mPa · s and a particle sedimentation rate of 0.1 to 5 μm / s.
6). A polarizing plate having a polarizer and protective films on both sides of the polarizer, wherein at least one of the protective films is the antiglare film according to any one of 1 to 3 above.
7). 7. An image display device provided with the antiglare film according to any one of 1 to 3 above or the polarizing plate according to 6 above on a surface thereof.

  According to the present invention, by controlling the film thickness of the antiglare layer, the particle diameter of the translucent particles, the aggregation rate, the outline blur of the image, black tightening, interference fringe improvement, high dark room contrast, weak curl, and An antiglare film excellent in appearance and a method for producing the antiglare film can be provided. Moreover, a polarizing plate and a liquid crystal display device using the antiglare film have excellent display characteristics.

  Hereinafter, the present invention will be described in more detail. In addition, in this specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”. In the present specification, the description “(meth) acrylate” means “at least one of acrylate and methacrylate”. The same applies to “(meth) acrylic acid” and the like.

<Layer structure of antiglare film>
The antiglare film of the present invention is an antiglare film having at least a transparent support and an antiglare layer formed on the transparent support, and the antiglare layer has a thickness of 8 to 18 μm. The surface irregularity shape is formed by the agglomerated portion made of translucent particles having an average particle diameter R of 5 μm <R <15 μm, and the agglomeration rate represented by the following formula (A) of the translucent particles is 15 to It is an anti-glare film characterized by being 40%.
(A) particle aggregation rate = (1- (1mm grain area occupied by the ² around) / (1 mm ² around the particle number × [pi × (average particle diameter / ^{2) 2))} × 100
Here, the area occupied by the particles is an area occupied by the particles around 1 mm ² when the film is observed with a transmission type optical microscope.

  The average particle diameter R of the translucent particles is preferably 5 μm <R <15 μm. When the average particle size is 15 μm or more, a large film thickness is required to improve black tightening, which is not preferable from the viewpoint of curling and cost. In addition, when the particle size is increased, the sedimentation rate of the particles is increased according to the Stokes equation. When the particle sedimentation rate is increased, the particles are deposited on the coating part and the pipe part of the coater, thereby causing non-uniformity in the flow rate, which may cause deterioration of the surface state. Further, when the particle diameter is 5 μm or less, for example, interference fringes generated inside the liquid crystal panel are not sufficiently reduced by the antiglare film. Therefore, when the amount of internal scattering of the antiglare film is increased in order to reduce interference fringes, darkroom contrast is deteriorated. To achieve both reduction of interference fringes and high darkroom contrast, it is important to increase the amount of light scattering on the front side of the liquid crystal panel and suppress the amount of scattering on the wide-angle side. If the particle size is small, the light scattering angle increases. Therefore, it is considered that the reduction of interference fringes and high darkroom contrast cannot be achieved at the same time.

In order to achieve both the contour blur of the image and the black tightening, the translucent particles in the translucent resin form aggregated portions, and the aggregation rate represented by the following formula (A) of the translucent particles is 15 to 40. %is required.
Formula (A) particle aggregation rate = (1- (1mm grain area occupied by the ² around) / (1 mm ² around the particle number × [pi × (average particle diameter / ^{2) 2))} × 100
This is considered to be because the contour of the image is blurred at the aggregated portion of the translucent particles, and the black tightening is improved at the portion where the surface where the aggregated portion does not exist is smooth.
The aggregation rate of the translucent particles is 15 to 40%, and more preferably 20 to 30%. When the agglomeration rate is less than 15%, the smooth portion of the surface decreases, and the black tightening deteriorates under the film thickness described below. On the other hand, if the particle agglomeration rate is larger than 40%, the unevenness becomes too large and the appearance deteriorates, which is not preferable.

  The film thickness of the antiglare layer of the present invention is preferably 8 to 18 μm, more preferably 10 to 16 μm. If the film thickness is smaller than 8 μm, the surface irregularity becomes too large when the particles having an average particle diameter R of 5 μm <R <15 μm are used, and the black tightening deteriorates. On the other hand, if the film thickness is larger than 18 μm, it is not preferable because the cost is increased and the curl is deteriorated. The film thickness of the antiglare layer can be measured by cutting the film and measuring the cross section with an optical microscope or SEM.

The surface haze of the antiglare film of the present invention is preferably 2 to 7%, and more preferably 3 to 5%. When the surface haze is smaller than 2%, the outline blur of the image is not sufficient, and when it is larger than 7%, the black tightening is deteriorated.
Further, the internal haze is preferably 10 to 30%, more preferably 15 to 25%. When the internal haze is smaller than 10%, the effect of reducing interference fringes generated inside the panel is not sufficient, and when the internal haze is larger than 30%, the dark room contrast is lowered.

  As for the absolute value of the refractive index difference of translucent resin which forms this translucent particle and an anti-glare layer, 0.01-0.10 are preferable. When the absolute value of the difference in refractive index is smaller than 0.01, the amount of particles added is increased in order to obtain a desired internal haze value, and black tightening is deteriorated. On the other hand, if the absolute value of the refractive index difference is larger than 0.10, the internal haze increases and the light scattering angle increases, and the dark room contrast decreases.

  In the present invention, at least one antireflection layer can be provided on the antiglare layer. In addition to the antiglare layer and the low refractive index layer, a low refractive index layer, a middle refractive index layer and / or a high refractive index layer can be provided. For example, although an intermediate refractive index layer, a high refractive index layer, and a low refractive index layer can be laminated, an antireflection film having a single antiglare layer and a single low refractive index layer in this order on a support. Form is preferred.

<Formation of antiglare film>
The antiglare layer of the present invention is formed by applying the antiglare layer-forming coating solution having a solid content ratio of 20 to 60% by mass on the transparent support, and then setting the solid content ratio of the coating solution to 75% by mass. For more than half of the time, the transparent support is held or transported while being inclined at 30 to 90 °, and the solvent in the coating solution is evaporated at a drying rate of 0.1 to 0.7 g / m ² · s, It is preferable to include a step of drying the coating film.

In general, when particles having a particle size larger than 5 μm are used, it is difficult to form a three-dimensional structure in the particles and to increase the particle aggregation rate to 15% or more. This is because as the particle size increases, the number of particles in the unit volume decreases, the collision and aggregation of particles due to Brownian motion decreases, and as the particle size increases, the porosity between particles increases. It is presumed that the contact area between each other decreases, so that the aggregate of particles once aggregated is easily broken.
In the present invention, after applying the antiglare layer-forming coating solution having a solid content ratio of 20 to 60% by mass on the transparent support, the solid content ratio of the coating solution is 75% by mass or more, By holding or transporting the transparent support at an angle of 30 to 90 °, the solvent in the coating solution is evaporated at a drying rate of 0.1 to 0.7 g / m ² · s, and the coating film is dried. It has been found that by forming an antiglare layer, the particle aggregation rate can be controlled to 15 to 40% even when particles having an average particle diameter R of 5 μm <R <15 μm are used.

  In addition to the method described above, the method for controlling the cohesiveness of the particles in the antiglare layer in advance in the coating liquid by adding the particle aggregating agent to the coating liquid or selecting the solvent to be used. It is also possible to agglomerate the particles. For example, by using a solvent such as methanol, ethanol, n-butanol, or isopropanol in an amount of 5 to 30% by mass of the solvent in the coating solution, the particle aggregability is 15 to 40%. It is possible to make it. However, if the particles are aggregated in advance in the coating solution by such a method, the sedimentation rate of the particles increases, and the surface condition of the coating film is deteriorated for the following reasons. In order to reduce the particle sedimentation rate, a method of increasing the coating solution viscosity is conceivable. However, when the coating solution viscosity is higher than 20 mPa · s, the leveling property is lowered and the surface condition is worsened. Will occur.

The antiglare layer is preferably formed by coating using a coating solution for forming an antiglare layer having a solid content ratio (solid content concentration) of 20 to 60% by mass. When solid content concentration is lower than 20 mass%, a viscosity will fall and surface property will deteriorate. When it is larger than 60% by mass, the viscosity is increased, the leveling property is lowered, and the surface state is deteriorated. In the drying step, the transparent support is held or transported in an inclined state of 30 to 90 ° and the drying speed is 0.1 to 0 in a time of half or more when the solid content ratio after coating is 75% by mass or more. It is preferable to evaporate the solvent at 0.7 g / m ² · s and dry the coating film. By drying the transparent support at an angle of 30 to 90 ° from the horizontal direction, the particles can be aggregated in the drying process. At this time, the position of the coating film relative to the transparent support may be either up or down. Moreover, you may change the angle of a transparent support body continuously. When the transparent support is inclined at an angle of 30 to 90 ° and dried, aggregation proceeds due to particle sedimentation in the drying process. When the angle of the transparent support is less than 30 °, the aggregation rate of the particles is 15% or more. It is not possible to achieve both low reflection and bright room contrast. In order to agglomerate the particles, the drying rate of the coating film is preferably 0.1 to 0.7 g / m ² · s. The adjustment of the drying speed can be controlled by adjusting the drying air speed, the drying temperature, the dew point, and the boiling point of the solvent. When the drying rate is slower than 0.1 g / m ² · s, the penetration of the solvent into the transparent support increases, and the appearance such as drying unevenness deteriorates. When the drying speed is greater than 0.7 g / m ² · s, the particle aggregation rate is less than 15%, and thus it is impossible to achieve both image outline blur and black tightening.

  The coating solution for forming an antiglare layer preferably has a viscosity at 25 ° C. of 2 to 20 mPa · s. If the viscosity is less than 2 mPa · s, the coating property and the surface condition are deteriorated, which is not preferable. On the other hand, when the viscosity exceeds 20 mPa · s, it is not preferable because the surface condition is deteriorated as the leveling property is lowered. The particle sedimentation rate in the coating solution is preferably 0.1 to 5 μm / s. If the particle sedimentation rate is less than 0.1 μm / s, particle aggregation does not proceed during the drying process, and the aggregation rate cannot be increased to more than 15%. On the other hand, if the particle sedimentation rate is greater than 5 μm / s, streaks or the like are generated and the surface shape is deteriorated. This is presumed that particles were deposited on the coating part and the pipe part of the coater, and the nonuniformity of the flow velocity caused streaks. In order to reduce the particle sedimentation rate, a method of increasing the viscosity of the coating solution is conceivable. However, it is not preferable that the viscosity is larger than 20 mPa · s for the reason described above.

  The antiglare film of the present invention can be formed by the following method, but is not limited to the following method as long as the above-described drying speed and the holding or transporting angle of the transparent support during drying are satisfied. First, a coating solution containing components for forming each layer is prepared. Next, a coating solution for forming various functional layers is applied onto the transparent support by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or die coating. The microgravure coating method, the wire bar coating method, and the die coating method (see US Pat. No. 2,681,294 and JP-A-2006-122889) are more preferable, and the die coating method is particularly preferable.

  The applied antiglare layer is dried and then irradiated with light or heated to polymerize and cure the monomer. Thereby, an anti-glare layer is formed. Here, if necessary, the antiglare layer may be a plurality of layers.

  Next, if necessary, a coating solution for forming a low refractive index layer is applied on the antiglare layer and irradiated or heated (irradiated with ionizing radiation such as ultraviolet rays, preferably irradiated with ionizing radiation under heating). And a low refractive index layer is formed. Thus, the antiglare film of the present invention is obtained.

<Translucent particles of antiglare layer>
The average particle diameter R of the translucent particles is preferably 5 μm <R <15 μm, and more preferably 5 μm <R <10 μm. When the average particle size is 15 μm or more, a large film thickness is required to improve black tightening, which is not preferable from the viewpoint of curling and cost. Further, if the average particle diameter is 5 μm or less, the light scattering angle becomes large, which is not preferable because reduction of interference fringes and high darkroom contrast cannot be achieved at the same time.
As the shape of the translucent particle, either a true sphere or an indefinite shape can be used. The particle size distribution is preferably monodisperse particles because of the haze value, controllability of diffusibility, and uniformity of the coated surface. For example, when particles having a particle diameter of 33% or more than the average particle diameter are coarse particles, the ratio of the coarse particles is preferably 1% or less, more preferably 0.8% or less of the total number of particles. More preferably, it is 0.4% or less. Particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

  For example, when particles having a particle diameter of 16% or more smaller than the average particle diameter are used as the fine particles, the proportion of the fine particles is preferably 10% or less of the total number of particles, more preferably 6% or less. More preferably, it is 4% or less. Particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

  The particle size distribution of the particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution. The average particle size is calculated from the obtained particle distribution. The average particle diameter of the translucent particles refers to the primary particle diameter regardless of whether two or more particles are present adjacent to each other in the coating film or independently. However, when the agglomerated inorganic particles having a primary particle size of about 0.1 μm are dispersed as a secondary particle in the coating liquid in a size satisfying the particle size of the present invention and then applied, the secondary particle The size of

  The types of translucent particles are poly ((meth) acrylate) particles, crosslinked poly ((meth) acrylate) particles, polystyrene particles, crosslinked polystyrene particles, crosslinked poly (acryl-styrene) particles, melamine resin particles, benzoguanamine resin particles. Preferably, resin particles such as

<Binder for matrix formation of antiglare layer>
The binder polymer that forms the matrix of the antiglare layer is preferably a translucent resin having a saturated hydrocarbon chain or a polyether chain as the main chain after curing with ionizing radiation or the like. Moreover, it is preferable that the main binder polymer after hardening has a crosslinked structure. Further, in order to produce a smooth surface, it is necessary to select a binder type so that the dispersibility of the particles becomes good when the above-mentioned particles are added into the binder.

  As the binder polymer having a saturated hydrocarbon chain as a main chain after curing, an ethylenically unsaturated monomer selected from compounds of the first group described below and a polymer thereof are preferable. Moreover, as a polymer which has a polyether chain as a principal chain, the epoxy-type monomer chosen from the compound of the 2nd group described below and the polymer by these ring-opening are preferable. Furthermore, a polymer of a mixture of these monomers is also preferable.

  In the present invention, as the first group of compounds, the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure is a (co) polymer of monomers having two or more ethylenically unsaturated groups. Is preferred. In order to obtain a high refractive index, the monomer structure preferably contains at least one selected from an aromatic ring, a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom.

  As a monomer having two or more ethylenically unsaturated groups used in a binder polymer for forming an antiglare layer, an ester of a polyhydric alcohol and (meth) acrylic acid {for example, ethylene glycol di (meth) Acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) ) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetrameta Relate, polyurethane polyacrylate, polyester polyacrylate}, vinylbenzene and its derivatives (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, , Divinylsulfone), (meth) acrylamide (for example, methylenebisacrylamide) and the like.

  Furthermore, resins having two or more ethylenically unsaturated groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins And oligomers or prepolymers such as polyfunctional compounds such as polyhydric alcohols. Two or more of these monomers may be used in combination, and the resin having two or more ethylenically unsaturated groups is preferably contained in an amount of 10 to 100% by mass based on the total amount of the binder.

  Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photoradical polymerization initiator or a thermal radical polymerization initiator. Therefore, it contains a monomer having an ethylenically unsaturated group, a photo radical polymerization initiator or a thermal radical polymerization initiator, and translucent particles, and if necessary, an inorganic filler, a coating aid, other additives, an organic solvent, etc. A coating solution to be prepared is prepared, the coating solution is coated on a transparent support, and then cured by a polymerization reaction with ionizing radiation or heat to form an antiglare layer. It is also preferable to perform ionizing radiation curing and thermal curing together. Commercially available compounds can be used as the photo- and thermal polymerization initiators, and they are described in “Latest UV Curing Technology” (p. 159, publisher: Kazuhiro Takahisa, publisher; Technical Information Association, 1991). Issued) and Ciba Specialty Chemicals catalog.

  In the present invention, it is preferable to use an epoxy compound described below as the second group of compounds in order to reduce curing shrinkage of the cured film. As these monomers having an epoxy group, monomers having two or more epoxy groups in one molecule are preferable, and examples thereof include JP-A Nos. 2004-264563, 2004-264564, and 2005-37737, Examples thereof include epoxy monomers described in JP-A-2005-37738, JP-A-2005-140862, JP-A-2005-140862, JP-A-2005-140863, and JP-A-2002-322430.

  The monomer having an epoxy group is preferably contained in an amount of 20 to 100% by mass with respect to all binders constituting the layer in order to reduce curing shrinkage, more preferably 35 to 100% by mass, and more preferably 50 to 100% by mass. It is more preferable to contain.

Examples of photoacid generators that generate cations by the action of light for polymerizing epoxy monomers and compounds include ionic compounds such as triarylsulfonium salts and diaryliodonium salts, and nitrobenzyl esters of sulfonic acids. Non-ionic compounds and the like can be used, and various known photoacid generators such as compounds described in “Organic Materials for Imaging” published by Bunshin Publishing Co., Ltd. (1997) can be used. . Among these, a sulfonium salt or an iodonium salt is particularly preferable, and PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ^{− and the} like are preferable as a counter ion.

  The polymerization initiator is preferably used in a range of 0.1 to 15 parts by mass with respect to 100 parts by mass of the compound of the first group or the second group in the total amount of the polymerization initiator. Is more preferable.

<High molecular compound of antiglare layer>
The antiglare layer of the present invention may contain a polymer compound. By adding a polymer compound, curing shrinkage can be reduced, and the viscosity of the coating solution can be adjusted.

  The polymer compound has already formed a polymer when added to the coating solution. Examples of the polymer compound include cellulose esters (for example, cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose acetate Pionate, cellulose acetate butyrate, cellulose nitrate, etc.), urethane acrylates, polyester acrylates, (meth) acrylic acid esters (for example, methyl methacrylate / (meth) methyl acrylate copolymer, methyl methacrylate / (Meth) ethyl acrylate copolymer, methyl methacrylate / (meth) butyl acrylate copolymer, methyl methacrylate / styrene copolymer, methyl methacrylate / (meth) acrylic acid copolymer, polymethyl methacrylate Etc.), poly Resins such as styrene are preferably used.

  The polymer compound is preferably from 1 to 50% by mass, more preferably from 5 to 40%, based on the total binder contained in the layer containing the polymer compound, from the viewpoint of the effect on curing shrinkage and the effect of increasing the viscosity of the coating solution. It is preferable to contain in the range of mass%. Further, the molecular weight of the polymer compound is preferably from 30,000 to 400,000 in terms of mass average, more preferably from 50,000 to 300,000, and even more preferably from 50,000 to 200,000.

<Inorganic filler for antiglare layer>
In addition to the above light-transmitting particles, the antiglare layer of the present invention can be used for adjusting the refractive index, adjusting the film strength, reducing curing shrinkage, and reducing the reflectance when a low refractive index layer is provided. Inorganic fillers can also be used. For example, it is composed of an oxide containing at least one metal element selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, and the average particle diameter of primary particles is generally 0.2 μm or less, preferably It is also preferable to contain a fine high refractive index inorganic filler that is 0.1 μm or less, more preferably 0.06 μm or less and 1 nm or more.

  When it is necessary to lower the refractive index of the matrix in order to adjust the difference in refractive index with the light-transmitting particles, a fine low refractive index inorganic filler such as silica fine particles or hollow silica fine particles is used as the inorganic filler. be able to. The preferred particle size is the same as that of the fine high refractive index inorganic filler.

  The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.

  The added amount of the inorganic filler is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and particularly preferably 30 to 75% by mass with respect to the total mass of the antiglare layer.

  In addition, since the inorganic filler has a particle size sufficiently shorter than the wavelength of light, scattering does not occur, and the dispersion in which the filler is dispersed in the binder polymer has the property of an optically uniform substance.

<Surfactant of antiglare layer>
In the antiglare layer of the present invention, in order to ensure surface uniformity such as coating unevenness, drying unevenness, point defect, etc., either a fluorine-based surfactant or a silicone-based surfactant, or both, is used for the antiglare layer. It is preferable to contain in the coating composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the antireflection film of the present invention appears in a smaller addition amount. The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity. Preferable examples of the fluorine-based surfactant include compounds described in paragraph numbers 0049 to 0074 of JP2007-188070A.

  The preferable addition amount of the surfactant (particularly the fluorine-based polymer) used in the antiglare layer of the present invention is in the range of 0.001 to 5% by mass, preferably 0.005 to 3% by mass with respect to the coating solution. %, And more preferably in the range of 0.01 to 1% by mass. When the addition amount of the surfactant is 0.001% by mass or more, the effect is sufficient, and by setting the addition amount to 5% by mass or less, the coating film is sufficiently dried and good performance as a coating film (for example, reflection) Rate, scratch resistance).

<Organic solvent of coating solution for antiglare layer>
An organic solvent can be added to the coating solution for forming the antiglare layer for forming the antiglare layer.
Examples of the organic solvent include alcohol, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, isoamyl alcohol, 1-pentanol, n-hexanol, methyl amyl alcohol. In the ketone system, methyl isobutyl ketone, methyl ethyl ketone, diethyl ketone, acetone, cyclohexanone, diacetone alcohol, etc., in the ester system, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, n-butyl acetate, Isoamyl acetate, n-amyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl acetate, methyl lactate, ethyl lactate, ether, acetal, 1,4 dioxane, te In hydrocarbons such as lahydrofuran, 2-methylfuran, tetrahydropyran, diethyl acetal, etc., hexane, heptane, octane, isooctane, ligroin, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene, styrene, divinylbenzene, etc., halogen hydrocarbons In, carbon tetrachloride, chloroform, methylene chloride, ethylene chloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, 1,1,1,2-tetrachloroethane In the case of polyhydric alcohols and derivatives thereof, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoacetate, diethylene glycol, In fatty acid systems such as lenglycol, dipropylene glycol, butanediol, hexylene glycol, 1,5-pentanediol, glycerin monoacetate, glycerin ethers, 1,2,6-hexanetriol, formic acid, acetic acid, propionic acid, In the case of nitrogen compounds such as entrained acid, isoentangled acid, isovaleric acid, and lactic acid, formamide, N, N-dimethylformamide, acetamide, acetonitrile, etc., and in the case of sulfur compounds, dimethyl sulfoxide and the like can be mentioned.

<Curing of antiglare layer>
The anti-glare layer can be formed by applying a coating solution for forming an anti-glare layer on a transparent support, and then carrying out light irradiation, electron beam irradiation, heat treatment or the like to cause crosslinking or polymerization reaction. In the case of ultraviolet irradiation, ultraviolet rays emitted from light such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, etc. can be used. Curing with ultraviolet rays is preferably carried out by nitrogen purge or the like in an atmosphere having an oxygen concentration of 4% by volume or less, more preferably 2% by volume or less, and most preferably 0.5% by volume or less.

<Low refractive index layer>
The antiglare film of the present invention preferably has a low refractive index layer in order to reduce the reflectance. The refractive index of the low refractive index layer is preferably 1.20 to 1.46, more preferably 1.25 to 1.46, and particularly preferably 1.30 to 1.40. The thickness of the low refractive index layer is preferably 50 to 200 nm, and more preferably 70 to 100 nm. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less.

As an aspect of a preferable cured product composition,
(1) A composition containing a fluorine-containing polymer having a crosslinkable or polymerizable functional group,
(2) a composition comprising as a main component a hydrolysis-condensation product of a fluorine-containing organosilane material;
(3) A composition containing a monomer having two or more ethylenically unsaturated groups and inorganic fine particles having a hollow structure.

(1) Fluorine-containing compound having a crosslinkable or polymerizable functional group As the fluorine-containing compound having a crosslinkable or polymerizable functional group, co-polymerization of a fluorine-containing monomer and a monomer having a crosslinkable or polymerizable functional group Coalescence can be mentioned. Specific examples of these fluoropolymers are described in JP2003-222702A, JP2003-183322A, and the like.

  As described in JP 2000-17028 A, a curing agent having a polymerizable unsaturated group may be used in combination with the above polymer. Moreover, combined use with the compound which has a fluorine-containing polyfunctional polymerizable unsaturated group as described in Unexamined-Japanese-Patent No. 2002-145952 is also preferable. Examples of the compound having a polyfunctional polymerizable unsaturated group include the above-described monomers having two or more ethylenically unsaturated groups. Moreover, the hydrolysis-condensation product of the organolane described in Unexamined-Japanese-Patent No. 2004-170901 is also preferable, and the hydrolysis-condensation product of the organosilane containing a (meth) acryloyl group is especially preferable. These compounds are particularly preferred because they have a large combined effect for improving scratch resistance, particularly when a compound having a polymerizable unsaturated group is used in the polymer body.

  When the polymer itself does not have sufficient curability, necessary curability can be imparted by blending a crosslinkable compound. For example, when the polymer body contains a hydroxyl group, various amino compounds are preferably used as the curing agent. The amino compound used as the crosslinkable compound is, for example, a compound containing one or both of a hydroxyalkylamino group and an alkoxyalkylamino group in total, specifically, for example, a melamine compound, Examples include urea compounds, benzoguanamine compounds, glycoluril compounds, and the like. For curing these compounds, an organic acid or a salt thereof is preferably used.

(2) Hydrolyzed condensate of fluorine-containing organosilane material A composition containing a hydrolyzed condensate of a fluorine-containing organosilane compound as a main component is also preferable because of its low refractive index and high hardness on the coating film surface. A condensate of a tetraalkoxysilane with a hydrolyzable silanol-containing compound at one or both ends with respect to the fluorinated alkyl group is preferred. Specific compositions are described in JP-A Nos. 2002-265866 and 2002-317152.

(3) A composition containing a monomer having two or more ethylenically unsaturated groups and inorganic fine particles having a hollow structure As yet another preferred embodiment, a low refractive index layer comprising low refractive index particles and a binder can be mentioned. . The low refractive index particles may be organic or inorganic, but particles having pores inside are preferable. Specific examples of the hollow particles are described in the silica-based particles described in JP-A-2002-79616. The particle refractive index is preferably 1.15 to 1.40, more preferably 1.20 to 1.30. Examples of the binder include monomers having two or more ethylenically unsaturated groups described on the page of the antiglare layer.

  It is preferable to add the polymerization initiator described on the page of the antiglare layer to the low refractive index layer of the present invention. When a radical polymerizable compound is contained, 1 to 10 parts by mass, preferably 1 to 5 parts by mass of a polymerization initiator can be used with respect to 100 parts by mass of the compound.

  In the low refractive layer of the present invention, inorganic particles can be used in combination. In order to impart scratch resistance, fine particles having a particle size of 15% to 150%, preferably 30% to 100%, more preferably 45% to 60% of the thickness of the low refractive index layer can be used. .

  In the low refractive index layer of the present invention, for the purpose of imparting properties such as antifouling property, water resistance, chemical resistance, and slipping property, a known polysiloxane-based or fluorine-based antifouling agent, slipping agent, etc. are appropriately used. Can be added.

  In the present invention, the preferred integrated reflectance of the antireflection antiglare film provided with a low refractive index layer or the like is preferably 3.0% or less, more preferably 2.0% or less, and most preferably 1.5%. % Or less and 0.3% or more. By reducing the integrated reflectance, sufficient antiglare properties can be obtained even if the light scattering on the surface of the antiglare film is reduced, so that an antiglare antireflection film excellent in blackening can be obtained.

<Transparent support>
As the transparent support of the antiglare film of the present invention, it is preferable to use a plastic film. Examples of the polymer forming the plastic film include cellulose acylate (eg, triacetyl cellulose, diacetyl cellulose, typically TAC-TD80U, TD80UF, etc., manufactured by Fuji Film), polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene). Naphthalate), polystyrene, polyolefin, norbornene resin (Arton: trade name, manufactured by JSR), amorphous polyolefin (ZEONEX: trade name, manufactured by ZEON CORPORATION), (meth) acrylic resin (ACRYPET VRL20A: product) Name, manufactured by Mitsubishi Rayon Co., Ltd., ring structure-containing acrylic resin described in JP-A No. 2004-70296 and JP-A No. 2006-171464), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable.

  When the antiglare film of the present invention is used in a liquid crystal display device, it is disposed on the outermost surface of the display by providing an adhesive layer on one side. Moreover, you may combine the anti-glare film of this invention and a polarizing plate. When the transparent support is triacetyl cellulose, triacetyl cellulose is used as a protective film for protecting the polarizing layer of the polarizing plate. Therefore, it is preferable in terms of cost to use the antiglare film of the present invention as it is for the protective film.

The antiglare film of the present invention is a transparent support for sufficient adhesion when it is disposed on the outermost surface of a display by providing an adhesive layer on one side or used as it is as a protective film for a polarizing plate. It is preferable to carry out a saponification treatment after the outermost layer is formed thereon. The saponification treatment is performed by a known method, for example, by immersing the film in an alkali solution for an appropriate time. After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by dipping in a dilute acid so that the alkaline component does not remain in the film.
By saponification treatment, the surface of the transparent support opposite to the side having the outermost layer is hydrophilized.

<Polarizing plate>
The polarizing plate is mainly composed of two protective films that protect both the front and back sides of the polarizer. The antiglare film of the present invention is preferably used for at least one of the two protective films sandwiching the polarizer from both sides. Since the antiglare film of the present invention also serves as a protective film, the manufacturing cost of the polarizing plate can be reduced. Further, by using the antiglare film of the present invention as the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate having excellent scratch resistance, antifouling property and the like can be obtained.

  The hydrophilized surface is particularly effective for improving the adhesion with a polarizer mainly composed of polyvinyl alcohol. In addition, the hydrophilic surface makes it difficult for dust in the air to adhere to it, so that it is difficult for dust to enter between the polarizing film and the antireflection film when bonded to the polarizer, thus preventing point defects due to dust. It is valid. The saponification treatment is preferably carried out so that the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. More preferably, it is 30 ° or less, particularly preferably 20 ° or less.

<Image display device>
The antiglare film of the present invention is used in image display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), electroluminescence displays (ELD), cathode ray tube display devices (CRT), and surface electric field displays (SED). Can be applied. Particularly preferably, it is used for a liquid crystal display (LCD) and an electroluminescence display (ELD). Since the antiglare film of the present invention has a transparent support, the transparent support side is adhered to the image display surface of the image display device.

  The antiglare film of the present invention, when used as one side of a polarizer surface protective film, is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optical It can be preferably used for a transmissive, reflective, or transflective liquid crystal display device in a mode such as a curry compensate bend cell (OCB).

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited thereto. Unless otherwise specified, “part” and “%” are based on mass.

<Preparation of antiglare film>
[Preparation of coating solution for each layer]
[Coating solution for antiglare layer formation]
Coating solutions A1 to A9 for Examples 1 to 9 and coating solutions B1 to B9 for Comparative Examples 1 to 9 were prepared as shown in Table 1.

  Each coating solution for forming the antiglare layer was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution.

  The refractive index of the antiglare layer film excluding the translucent particles was directly measured with an Abbe refractometer. Further, the refractive index of the translucent particles is changed by changing the mixing ratio of two kinds of solvents having different refractive indexes selected from methylene iodide, 1,2-dibromopropane, and n-hexane. The turbidity was measured by dispersing an equal amount of translucent particles in the solvent, and the refractive index of the solvent when the turbidity was minimized was measured by an Abbe refractometer.

The refractive index of the resin after curing was as follows.
PET-30 1.530
Viscoat 360 1.500

[Coating liquid for low refractive index layer]
Composition of coating liquid for low refractive index layer (L-1) Ethylenically unsaturated group-containing fluoropolymer (A-1) 3.9 g
Silica dispersion A (22%) 25.0 g
Irgacure 127 0.2g
DPHA 0.4g
MEK 100.0g
MIBK 45.5g

  The compounds used above are shown below.

PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate [manufactured by Nippon Kayaku Co., Ltd.];
Biscoat 360: trimethylolpropane PO-modified triacrylate [manufactured by Osaka Organic Chemical Industry Co., Ltd.];
Translucent particles: MIBK dispersion in which translucent particles having a desired average particle diameter and refractive index [both manufactured by Sekisui Chemical Co., Ltd.] are dispersed at 10,000 rpm for 20 minutes with a Polytron disperser Irgacure 127: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.];
CAB: Cellulose acetate butyrate CAB-531-1 manufactured by Eastman Chemical Co.
Ethylenically unsaturated group-containing fluoropolymer (A-1): fluoropolymer (A-1) described in Production Example 3 of JP-A-2005-89536;
DPHA: mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, Nippon Kayaku Co., Ltd. SP-13: The following fluorosurfactant (used after dissolving as a 5% by mass solution of MEK)

  The coating solution for low refractive index layer (L-1) was filtered through a polypropylene filter having a pore diameter of 1 μm to prepare a coating solution. The refractive index after curing of the low refractive index layer obtained by coating and curing the coating solution was 1.360.

(Silica dispersion A)
Hollow silica fine particle sol (Isopropyl alcohol silica sol, average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20 mass%, silica particle refractive index 1.31, change size according to Preparation Example 4 of JP-A-2002-79616. Prepared) 10 g of acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 1.0 g of diisopropoxyaluminum ethyl acetate were added and mixed, and then 3 g of ion-exchanged water was added. After making it react at 60 degreeC for 8 hours, it cooled to room temperature and added 1.0 g of acetylacetone. While adding cyclohexanone to 500 g of this dispersion so that the content of silica was almost constant, solvent substitution by vacuum distillation was performed. There was no generation of foreign matter in the dispersion, and the viscosity when the solid content concentration was adjusted to 22% by mass with cyclohexanone was 5 mPa · s at 25 ° C. It was 1.0 mass% when the residual amount of the isopropyl alcohol of the obtained dispersion liquid A was analyzed by the gas chromatography.

(Settling speed of coating solution)
30 ml of each coating solution was placed in a 100 ml beaker, sufficiently stirred, allowed to stand, and calculated from the sedimentation height with respect to the standing time (total coating solution height-supernatant liquid height).

[Examples 1-9, Comparative Examples 1-9]
Production of antiglare films of Examples 1 to 9 and Comparative Examples 1 to 9

(1) Coating of anti-glare layer A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm is unrolled in a roll form, and the anti-glare layer forming coating solution shown in Table 1 is used. Using a die coating method using a slot die as described in Example 1 of JP-A-2006-122889, coating was performed under the condition of a conveyance speed of 20 m / min, and the wind conditions and drying were performed so that the drying speed was a value shown in Table 2. Set the temperature and dry until the solid content ratio of the coating film reaches 75% by mass or more, then dry at 60 ° C. for 150 seconds, and further air-cooled metal halide of 160 W / cm with an oxygen concentration of about 0.1% under a nitrogen purge. Using a lamp (manufactured by Eye Graphics Co., Ltd.), the coating layer was cured by being irradiated with ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 100 mJ / cm ² and wound up. The coating amount was adjusted so that the film thickness of each antiglare layer was the value shown in Table 2. Here, the angle of the support during drying and the drying speed of the coating film were set as shown in Table 2. Here, the drying speed of the coating film is determined by measuring the time until the solid content ratio of the coating film reaches 75% by mass, calculating the change in the weight of the coating liquid around 1 m ² from there, and drying speed (g / m ² · s).

(2) Coating of low refractive index layer The triacetyl cellulose film coated with the antiglare layer is unwound again, and the coating solution for the low refractive index layer is conveyed by a die coating method using the slot die. After coating at 30 m / min and drying at 90 ° C. for 75 seconds, an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) having an oxygen concentration of 0.01 to 0.1% and 240 W / cm under a nitrogen purge was used. Then, an ultraviolet ray having an illuminance of 400 mW / cm ² and an irradiation amount of 240 mJ / cm ² is irradiated to form a low refractive index layer having a thickness of 100 nm and wound up, and the antiglare films of Examples 1 to 9 and Comparative Examples 1 to 9 Was made.

(Saponification treatment of antiglare film)
After coating, the sample was subjected to the following treatment.
A 1.5 mol / L aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / L dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The produced antiglare film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C. In this way, a saponified antiglare film was produced.

(Evaluation of anti-glare film)
(1) Haze [1] The total haze value (H) of the obtained antiglare film was measured according to JIS-K7136.
[2] A few drops of silicone oil are added to the front and back surfaces of the antiglare film, and two glass plates (micro slide glass product number S9111, made by MATSUNAMI) with a thickness of 1 mm are sandwiched from the front and back to completely The glass plate and the obtained anti-glare film are closely adhered, the haze is measured in a state where the surface haze is removed, and a value obtained by subtracting the haze measured by sandwiching only silicone oil between two separately measured glass plates. Calculated as the internal haze (Hi) of the film.
[3] A value obtained by subtracting the internal haze (Hi) calculated in [2] from the total haze (H) measured in [1] above was calculated as the surface haze (Hs) of the film.

(2) Curl The antiglare film sample was cut into a size of 20 cm × 20 cm and placed on a horizontal desk in an environment of 25 ° C. and 60% RH with the surfaces with the four corners raised upward. After 24 hours, the lifting distance from the desk surface at each of the four corners was measured with a ruler, and the average of the four corners was taken. The average values were classified and evaluated according to the following criteria.
A: Less than 5 mm.
○: 5 to less than 20 mm.
X: 20 mm or more.

(3) Measurement of particle agglutination rate particle aggregation rate observed a 1 mm ² film with a transmission optical microscope, particles aggregation rate = (1-(1 mm particles occupied area of ² around) / (1 mm ² around the number of particles Xπ (average particle diameter / 2) ² )) × 100 The particle occupation area is an area occupied by particles around 1 mm ² of the film when the film is observed from the coated surface side with a transmission type optical microscope.
(4) Planar A: No streak or defect is recognized.
○: Lines and defects can be recognized slightly, but I don't mind.
X: Streaks and defects are conspicuous.

[Examples 10 to 18, Comparative Examples 10 to 18]
(Preparation of polarizing plate)
An 80 μm-thick triacetylcellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.), which was neutralized and washed with an aqueous solution of NaOH of 1.5 mol / L and 55 ° C. for 2 minutes, and Example 1 Each film of Samples 9 to 9 and Comparative Examples 1 to 9 (saponified) was adsorbed with iodine on polyvinyl alcohol, and bonded and protected on both sides of a polarizer prepared to produce a polarizing plate.

(Production of liquid crystal display device)
A polarizing plate in which a polarizing plate and a retardation film provided in a VA type liquid crystal display device (LC-37GS10, manufactured by Sharp Corporation) are peeled off, and the polarizing plate produced above is pasted on the product instead. The liquid crystal display devices of Examples 10 to 18 and Comparative Examples 10 to 18 were produced. In addition, it affixed so that an anti-glare film might become a visual recognition side.

(Evaluation with liquid crystal display)
(1) Black tightening A sensory evaluation was performed on the feeling of blackening on a liquid crystal display device in which a polarizing plate with an antiglare film attached on the surface on the viewing side was arranged. The evaluation method is a method in which multiple displays are arranged in parallel and compared at the same time. From the front, the blackness when the power is turned off and the blackness (black image) when the power is turned on are compared for each film, and evaluated according to the following criteria. did. It was expressed by the standard that the stronger the blackness, the stronger the tightness of the screen.
A: Strong blackness and the screen looks very strong.
○: Black color is strong and the screen appears to be strong.
Δ: Black but gray, and the screen is not tight.
X: The taste is quite gray and the screen is not tight.

(2) Blur of image outline The liquid crystal display device in which a polarizing plate with an antiglare film attached to the surface on the viewing side was subjected to a sensory evaluation for a feeling of blackening. The evaluation method is a method in which a plurality of displays are arranged in parallel and compared at the same time. When the power is turned off, the fluorescent lamp is reflected on the surface of the antiglare film at an expected angle of 10 °, and the outline blur of the transferred fluorescent lamp image is shown below. Expressed by criteria.
A: The outline is strongly blurred.
○: The outline is blurred.
Δ: The outline blur is weak.
X: The outline is not blurred at all.

(3) Front contrast in dark room The front contrast was measured in a dark room using the liquid crystal display device produced above. Here, the contrast value of the liquid crystal display device was calculated by setting the contrast value when using a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd.) having a thickness of 80 μm as 100% as the front contrast value. .
A: 90% to 100%
○: 80% to 89%
Δ: 70% to 79%
×: 69% or less

(4) Interference fringes of image display device The display device produced above was displayed in halftone, the panel was observed from various angles, and the state of interference fringes was observed.
A: No interference fringes are visible.
○: Interference fringes look weak, but at a level that is not problematic for practical use.
(Triangle | delta): An interference fringe can be confirmed and there exists a problem practically.
X: Interference fringes appear very clearly, can be easily confirmed, and there is a problem.

  Table 2 shows the evaluation results of each sample.

  From the results shown in Table 2, the antiglare film of the present invention has a small curl and a good surface shape, and the image display device to which the antiglare film is applied has a good outline blur and a black tightness. It can be seen that this is a high-quality image display device with high front contrast under the dark room and in which interference fringes and the like caused by the image display device are difficult to see.

Claims (7)

An antiglare film having at least a transparent support and an antiglare layer formed on the transparent support, wherein the antiglare layer has a thickness of 8 to 18 μm and an average particle diameter R of 5 μm < An antiglare film in which a surface irregularity shape is formed by an agglomerated part containing translucent particles having R <15 μm, and the agglomeration rate represented by the following formula (A) of the translucent particles is 15 to 40%.
Formula (A) particle aggregation rate = (1- (1mm grain area occupied by the ² around) / (1 mm ² around the particle number × [pi × (average particle diameter / ^{2) 2))} × 100   The surface haze of the antiglare film is 2 to 7%, the internal haze is 10 to 30%, and the absolute value of the refractive index difference between the translucent particles and the translucent resin forming the antiglare layer is The antiglare film according to claim 1, which is 0.01 to 0.10.   The antiglare film according to claim 1 or 2, further comprising at least one antireflection layer on the antiglare layer. It is a manufacturing method of the glare-proof film in any one of Claims 1-3, Comprising: After apply | coating this coating liquid for glare-proof layer formation of 20-60 mass% of solid content on this transparent support body, The transparent support is held or transported in an inclined state of 30 to 90 ° for a time of half or more when the solid content ratio of the coating solution is 75% by mass, and the solvent in the coating solution is dried at a rate of 0.1 to 0. A method for producing an antiglare film, comprising a step of evaporating at 7 g / m ² · s and drying a coating film.   The method for producing an antiglare film according to claim 4, wherein the coating solution for forming an antiglare layer has a viscosity at 25 ° C of 2 to 20 mPa · s and a particle sedimentation rate of 0.1 to 5 µm / s.   A polarizing plate having a polarizer and protective films on both sides of the polarizer, wherein at least one of the protective films is an antiglare film according to claim 1.   The image display apparatus which provided the anti-glare film in any one of Claims 1-3, or the polarizing plate of Claim 6 on the surface.