JP2008304638A - Anti-glare film and manufacturing method thereof, polarizer and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-glare film which can combine contrast with anti-glare performance, and to provide a manufacturing method thereof. <P>SOLUTION: The anti-glare film is equipped with a substrate and an anti-glare layer disposed on the substrate. The anti-glare layer includes fine particles and resin and is formed with a fine rugged shape by aggregation of fine particles. Average tilt angle θa on the surface is 0.2° to 1.5° and the arithmetic average roughness Ra is 0.05 to 0.4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an antiglare film, a method for producing the same, a polarizer, and a display device. Specifically, CRT (Cathode Ray Tube) displays, all liquid crystal displays (LCD) from small to large, plasma display panels (PDP), electro luminescence (EL) displays, surface conduction The present invention relates to an antiglare film used for a display surface of a display device such as a surface-conduction electron-emitter display (SED).

  Conventionally, in a display device such as a liquid crystal display or a plasma display, an antiglare film having a fine uneven shape is provided on the display surface side, and light is diffused by this film to reduce reflection due to surface reflection. Technology is adopted.

  In FIG. 7, the structure of the conventional anti-glare film 101 is shown. The antiglare film 101 includes a base material 111 and an antiglare layer 112 provided on the base material 111. The antiglare layer 112 includes fine particles 113, and the fine particles 113 protrude from the surface of the antiglare layer 112, whereby a fine uneven shape is formed on the surface. The antiglare film 101 is formed by applying a paint containing fine particles 113 such as silica fine particles and plastic fine particles on the substrate 111 and curing the paint. In the antiglare film having the above-described configuration, light incident on the antiglare layer 112 is scattered by the fine particles 113 protruding from the antiglare layer 112, so that reflection due to surface reflection is reduced.

  Conventionally, the fine uneven | corrugated shape for providing anti-glare property etc. effectively with respect to an anti-glare film is examined. For example, Patent Document 1 proposes that the center line average roughness of fine irregularities is selected to be 0.08 to 0.5 μm and the average peak-to-valley interval is 20 to 80 μm in order to prevent glare.

  In patent document 2, in order to implement | achieve favorable anti-glare property, rough unevenness | corrugation and fine unevenness | corrugation are provided, and the centerline average roughness Ra of the surface in which these unevenness | corrugation was provided is 0.1-1.0 micrometer, average The interval Sm is set to 20 to 120 μm, the center line average roughness Ra of rough unevenness is set to 0.5 to 1.5 μm, the average interval Sm is set to 100 to 300 μm, and the center line average roughness Ra of fine unevenness is set to 0. It has been proposed that the average spacing Sm is 20 to 70 μm.

  In Patent Document 3, in order to simultaneously realize excellent antiglare properties and image display power, a plurality of three-dimensional three-dimensional aggregated portions formed by five or more fine particles are present in the antiglare layer, and this It has been proposed to form a concavo-convex shape on the outermost surface of the antiglare layer so as not to gather a plurality of aggregated portions.

  In Patent Document 4, in order to realize excellent high hardness, scratch resistance, and antiglare property, the film thickness of the antiglare layer is 15 μm or more and 30 μm or less, and the average particle diameter of the fine particles is the film thickness of the antiglare layer. Further, it has been proposed that the average inclination angle θa according to JIS B 0601 of the uneven shape formed by the fine particles be 0.4 ° or more and 1.5 or less.

  In Patent Document 5, in order to suppress the decrease in display contrast of the display while maintaining the antiglare property, the average particle diameter of the fine particles is set to 6 μm to 15 μm, and the average inclination angle θa of the concavo-convex shape formed by the fine particles is set. It is proposed that the angle is 0.4 ° or more and 1.5 ° or less and further satisfies the relationship of (contrast ratio) / (contrast ratio of antiglare film not containing fine particles) × 100 ≧ 60%. .

Japanese Patent No. 3821156 Japanese Patent No. 3374299 JP 2005-316413 A JP 2007-47722 A JP 2007-41533 A

  However, the above-described proposed technique has a problem that the entire screen of the display device is faded, that is, the contrast is lowered. This is because each of the above proposals aims to scatter light at a wide angle, so that the fine uneven shape on the surface has a fine period and a steep angle component.

  In order to improve the cloudiness of the anti-glare film, as shown in FIG. 8, it is conceivable to increase the period of the fine irregularities on the surface. However, if the period is increased in this way, the reflection cannot be prevented. End up. That is, contrast and anti-glare properties are contradictory properties, and it is difficult to satisfy both properties at the same time.

  Moreover, as a film used for the display element surface, there exists a film which performed the hard coat process on the plastic substrate, and also the film which performed the antireflection process on the hard coat. Although any film can obtain good contrast, it is difficult to suppress reflection. For this reason, a film having both antiglare properties and contrast is demanded.

  Accordingly, an object of the present invention is to provide an antiglare film that can achieve both contrast and antiglare properties, a method for producing the same, a polarizer, and a display device.

  As a result of diligent study, the present inventors have optimized the reflection characteristics of external light by a fine uneven shape with a long period and a small angle component as well as surface scattering by individual particles protruding from the surface. It has been found that both antiglare properties and contrast can be achieved.

In order to solve the above-mentioned problem, the antiglare film of the present invention is
It has a fine uneven shape on the surface, the average inclination angle θa on the surface is 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is 0.05 to 0.4. To do.

The method for producing an antiglare film of the present invention comprises:
A method for producing an antiglare film having a fine uneven shape on the surface,
Provided with a step of forming a fine concavo-convex shape on the surface by a shape transfer method, sandblasting method or Benard cell formation method,
The average inclination angle θa on the surface is 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is 0.05 to 0.4.

  The polarizer of this invention is provided with the said anti-glare film. The display device according to the present invention includes the antiglare film on a display surface.

  The Benard cell generally indicates a convection phenomenon generated in a paint and a surface structure generated by convection in a solvent drying process. In the present invention, the fine particles form aggregates by the convection. In the present invention, the entire surface structure formed in the solvent drying process is called a Benard cell, and its shape is arbitrary, and it does not necessarily have to be a ring structure.

  In this invention, since the average inclination angle θa of the surface is 0.2 ° to 1.5 ° and the arithmetic average roughness Ra is 0.05 to 0.4, the cycle is long and the angle Light can be scattered by the fine concavo-convex shape in which the components are prepared. Further, by constituting the surface with a low-angle component, it is possible to suppress the cloudiness and obtain the antiglare property.

  As described above, according to the present invention, the contradictory properties of contrast and anti-glare properties can be achieved by adjusting the fine uneven shape of the surface, particularly the angle component.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals.

(1) First Embodiment (1-1) Configuration of Liquid Crystal Display Device FIG. 1 shows an example of the configuration of a liquid crystal display device according to a first embodiment of the present invention. As shown in FIG. 1, the liquid crystal display device includes a light source 3 that emits light, a liquid crystal panel 2 that temporally and spatially modulates the light emitted from the light source 3, and displays an image. And an antiglare film 1 provided on the display surface side.

  Examples of the light source 3 include a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), an organic electroluminescence (OEL), and a light emitting diode (Light Emitting Diode). LED) or the like is used.

  Examples of the liquid crystal panel 2 include a twisted nematic (TN) mode, a super twisted nematic (STN) mode, a vertically aligned (VA) mode, and a horizontal alignment (In-Plane Switching: IPS). Mode, Optically Compensated Birefringence (OCB) mode, Ferroelectric Liquid Crystal (FLC) mode, Polymer Dispersed Liquid Crystal (PDLC) mode, Phase Transition Guest Host (Phase) A panel of a display mode such as Change Guest Host (PCGH) mode can be used.

  For example, polarizers 2a and 2b are provided on both surfaces of the liquid crystal panel 2 so that their transmission axes are orthogonal to each other. The polarizers 2a and 2b allow only one of orthogonally polarized components of incident light to pass through and shield the other by absorption. Examples of the polarizers 2a and 2b include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, ethylene / vinyl acetate copolymer partially saponified films, iodine, dichroic dyes, and the like. Those obtained by adsorbing the dichroic material and uniaxially stretching can be used.

  One surface of the anti-glare film 1 is provided with a fine concavo-convex shape with a long period and a smooth angle component, and the fine concavo-convex shape is incident on the display surface of the liquid crystal display device. Light is scattered. This anti-glare film 1 is suitable for application to various display devices used in, for example, word processors, computers, televisions, in-vehicle instrument panels, and particularly to liquid crystal display devices.

(1-2) Configuration of Antiglare Film FIG. 2 shows an example of the configuration of the antiglare film 1 according to the first embodiment of the present invention. As shown in FIG. 2, the antiglare film 1 includes a base material 11 and an antiglare layer 12 provided on the base material 11. The antiglare layer 12 includes fine particles 13, and fine irregularities are formed on the surface of the antiglare layer due to aggregation of the fine particles 13. It is preferable that the base material 11 has a function as a protective film of the polarizer 2b. This is because it is not necessary to separately provide a protective film on the polarizer 2b, so that the polarizer 2b having the antiglare film 1 can be thinned.

  The surface haze is preferably 0 to 5%, more preferably 0 to 1%. When the surface haze is 5% or less, the cloudiness is reduced, and when it is 1% or less, the cloudiness is hardly felt. The surface haze is a value when surface scattering is detected, and the higher the surface haze, the greater the cloudiness. On the other hand, the internal haze is not particularly limited, and is determined by the fine particles 13 contained in the antiglare layer 12 or the like.

  The turbidity is preferably 2.0 or less, more preferably 0.5 to 1.5. When the turbidity is 2.0 or less, a decrease in contrast can be suppressed, and when it is 1.5 or less, excellent contrast can be realized.

(Base material)
As the base material 11, for example, a transparent film, sheet, substrate or the like can be used. As a material of the base material 11, for example, a known polymer material can be used. Specific examples of known polymer materials include triacetyl cellulose (TAC), polyester (TPEE), polyethylene terephthalate (PET), polyimide (PI), polyamide (PA), aramid, polyethylene (PE), poly Examples include acrylate, polyether sulfone, polysulfone, polypropylene (PP), diacetyl cellulose, polyvinyl chloride, acrylic resin (PMMA), polycarbonate (PC), epoxy resin, urea resin, urethane resin, and melamine resin. The thickness of the substrate 11 is preferably 38 to 100 μm from the viewpoint of productivity, but is not particularly limited to this range.

(Anti-glare layer)
The average film thickness of the antiglare layer 12 is preferably 3 to 30 μm, more preferably 4 to 15 μm. This is because, within this range, both optical characteristics (anti-glare properties, high contrast) and physical characteristics (low curl, high hardness) can be satisfied.

  The average inclination angle θa of the fine concavo-convex shape correlates with optical characteristics (contrast (white turbidity), anti-glare property). That is, it is possible to control the contrast (white turbidity) and the antiglare property by controlling the average inclination angle θa. Specifically, the average inclination angle θa is 0.2 to 1.5 °, preferably 0.4 to 1.2 °. By setting it within this range, both contrast and antiglare properties can be achieved. Specifically, when the angle is less than 0.2 °, the antiglare property is deteriorated because the surface is substantially flat. When it exceeds 1.5 °, the cloudiness increases and the contrast decreases.

FIG. 3 is a schematic diagram for explaining the average inclination angle θa of the present invention. The average inclination angle θa is defined by the following equation (1).
θa = tan ⁻¹ Δa (1)

In the above formula (1), Δa is the peak and valley of adjacent peaks in the reference length L of the roughness curve defined in JIS B 0601 (1994 version) as shown in the following formula (2). Is a value obtained by dividing the sum (h ₁ + h ₂ + h ₃ +... + H _n ) of the difference (height h) from the lowest point by the reference length L.
θa = tan ⁻¹ ((h ₁ + h ₂ + h ₃ +... + h _n ) / L) (2)

  The average inclination angle θa of the antiglare film 1 according to the first embodiment is smaller than that of the conventional antiglare film. In view of the fact that the average inclination angle θa is a parameter obtained by averaging the inclinations in a minute range, it can be seen that the following are specifically shown. That is, the antiglare film 1 according to the first embodiment has a continuous and gentle fine uneven shape as shown in FIG. 2, whereas the conventional antiglare film is shown in FIG. Thus, it has a fine uneven shape including a steep angle component. Therefore, in the antiglare film 1 according to the first embodiment, it is possible to suppress the light from diffusing over a wide angle and reduce the white turbidity of the display screen, whereas in the conventional antiglare film, the light is wide angle. The display screen becomes white turbid because it spreads over the entire area. In the conventional antiglare film as shown in FIG. 7, the fine uneven shape is determined by the size of the fine particles and the protruding amount of the fine particles.

  The antiglare layer 12 includes a resin and fine particles 13. The resin will be described later. As the fine particles 13, for example, at least one of inorganic fine particles and organic fine particles can be used. Further, as the shape of the fine particles 13, for example, a spherical shape or a flat shape can be used. The average particle diameter of the fine particles 13 is preferably 1 to 6 μm. By setting it within this range, it is possible to obtain a desired surface shape. That is, it is possible to form a continuous undulating fine uneven shape on the surface of the antiglare layer 12.

  As the organic fine particles, for example, those made of acrylic resin (PMMA), polystyrene (PS), acrylic-styrene copolymer, melamine resin, polycarbonate (PC) and the like can be used. The organic fine particles are not particularly limited in properties such as cross-linking and non-cross-linking, and any organic fine particles can be used as long as they are made of plastic. Moreover, as inorganic fine particles, what consists of silicon oxide, titanium oxide, aluminum oxide, zinc oxide, tin oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate etc. can be used, for example. It is preferable that the surface of these inorganic fine particles is made nonpolar by performing an organic treatment. This is because convection and agglomeration of the fine particles 13 occur moderately in the drying process described later, and a predetermined Benard cell is formed.

  The plurality of fine particles 13 are preferably aggregated to form an aggregate. This aggregate is preferably a two-dimensional aggregate in which the fine particles 13 are aggregated mainly in the in-plane direction of the antiglare layer 12 (mainly two-dimensional aggregation). This is because, since a continuous and gently undulating fine uneven shape can be formed on the surface of the antiglare layer 12, white turbidity can be reduced while maintaining antiglare properties. Here, “the fine particles 13 mainly aggregate in the in-plane direction of the anti-glare layer 12 (mainly two-dimensional aggregation)” (1) all the fine particles 13 overlap in the thickness direction of the anti-glare layer 12. In other words, it is aggregated only in the in-plane direction, or (2) most of the fine particles 13 are aggregated in the in-plane direction, and the remaining fine particles 13 do not cause an increase in the average inclination angle θa. It means that it overlaps in the thickness direction in the range. Aggregates exist, for example, without gathering on the surface of the antiglare layer, and fine aggregates are formed on the surface of the antiglare layer by the aggregate.

  Ideally, all the fine particles 13 are aggregated only in the in-plane direction without overlapping in the thickness direction of the anti-glare layer 12, but the average inclination angle θa even if some fine particles 13 overlap in the thickness direction. Will not increase. Since the average inclination angle θa is an averaged parameter, the fine particles 13 may overlap in a range that does not affect the increase in the average inclination angle θa. It is ideal that all the fine particles 13 are covered with the resin. However, a part of the fine particles 13 is not covered with the resin and exposed to the extent that the average inclination angle θa is not increased. Also good.

  FIG. 4 shows an example of the particle size distribution of the fine particles 13. In FIG. 4, a curve L1 shows a particle size distribution with a coefficient of variation of 8.4%, and a curve L2 shows a particle size distribution with a coefficient of variation of 30%. The fine particles 13 preferably have a particle size distribution as shown in FIG. This is because, since a continuous and gently undulating fine uneven shape can be formed on the surface of the antiglare layer 12, white turbidity can be reduced while maintaining antiglare properties. The fine uneven shape on the surface, for example, does not distribute the individual fine particles 13 uniformly, but intentionally forms an aggregate (aggregate) of the fine particles 13 by convection at the time of drying. And most or all of this is coated with a curable resin.

  In order to obtain anti-glare properties, it is extremely important to continuously form ridges between aggregates. From the viewpoint of continuously forming ridges between aggregates, it is preferable to use fine particles 13 having a particle size distribution with a coefficient of variation (standard deviation / average particle size) of 20 to 40%. When monodispersed fine particles are used, flat portions are easily formed between the aggregates, and the antiglare property is poor.

(1-2) Manufacturing method of anti-glare film Next, an example of the manufacturing method of the anti-glare film which has the above-mentioned composition is explained. In this method for producing an antiglare film, an aggregate of fine particles 13 is intentionally formed, and this aggregate is used as one mountain to form a surface shape (Benard cell) with a large period.

(Paint preparation)
First, for example, a resin and fine particles are added to a solvent and mixed to obtain a paint in which fine particles 13 are dispersed. At this time, in order to intentionally form an aggregate of the fine particles 13 in the drying step, which is a subsequent step, it is preferable to adjust the surface tension of the solvent contained in the paint and the surface energy of the fine particles 13.

  From the viewpoint of ease of production, it is preferable to use an ionizing radiation curable resin that is cured by light or an electron beam, or a thermosetting resin that is cured by heat. Most preferred. As such a photosensitive resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, polyester acrylate, polyol acrylate, polyether acrylate, and melamine acrylate can be used. For example, a urethane acrylate resin is obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer, and reacting the resulting product with an acrylate or methacrylate monomer having a hydroxyl group. The properties after curing can be appropriately selected. For example, those having excellent translucency are preferable from the viewpoint of image transparency, and those having high hardness are preferable from the viewpoint of scratch resistance. Note that the photosensitive resin is not particularly limited to the above-described example, and can be used as long as it has translucency. However, the hue and amount of transmitted light do not change significantly due to coloring or haze. Those are preferred.

  To the above photosensitive resin, urethane resin, acrylic resin, methacrylic resin, styrene resin, melamine resin, cellulosic resin, and further ionizing radiation curable oligomer and thermosetting oligomer, which become solid upon drying, are used as appropriate. Is preferred. It is possible to adjust the hardness and curl of the antiglare layer 12 by appropriately mixing the above resins. The resin is not limited to the above-described example, and for example, a polymer having a thermosetting group such as an ionizing radiation functional group such as an acrylic double bond or an —OH group can be used as the polymer. .

  As the photopolymerization initiator contained in the photosensitive resin, for example, a benzophenone derivative, an acetophenone derivative, an anthraquinone derivative, or the like can be used alone or in combination. In this photosensitive resin, a component for improving film formation, for example, an acrylic resin may be further appropriately selected and blended.

  As the solvent, those which dissolve the resin raw material to be used and have good wettability with the fine particles 13 and do not whiten the base material 11 are preferable. For example, acetone, diethyl ketone, dipropyl ketone, methyl ethyl ketone, methyl butyl Ketone, methyl isobutyl ketone, cyclohexanone, methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, sec-butyl acetate, amyl acetate, acetic acid Isoamyl, secondary amyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl lactate and other solvents such as ketones or carboxylic acid esters, methanol, ethanol, isopropanol, n-butanol, sec-butanol And alcohols such as tert-butanol. These solvents may be used singly or as a mixture of two or more components. Furthermore, solvents other than those exemplified above can be added within a range where the performance of the resin composition is not impaired.

  The surface tension of the solvent is preferably 23 mN / m or less at the coating temperature. This is because Benard cells can be formed reasonably in the subsequent drying step, and smooth undulation can be obtained on the surface of the antiglare layer. When the surface tension exceeds the above range, the fine particles 13 are agglomerated and the unevenness formed on the surface of the antiglare layer 12 becomes large. Therefore, although the antiglare property is excellent, the surface becomes cloudy and has a glaring surface. Examples of such an organic solvent include tertiary butanol having a surface tension of 20.0 mN / m at an environmental temperature of 20 ° C. and 22.1 mN / m of isopropyl acetate at an environmental condition of 22 ° C. If satisfied, the material is not particularly limited.

  The surface tension of the solvent can be calculated by, for example, the wilhelmy method by bringing the wilhelmy plate and the liquid sample into contact with each other to give a strain and measuring the force to pull the wilhelmy plate into the liquid. As the measuring device, for example, a dynamic surface tension measuring device (manufactured by UBM, trade name: Leosurf) can be used.

  You may make it add a light stabilizer, a ultraviolet absorber, an antistatic agent, a flame retardant, antioxidant, etc. to a coating material as needed. Further, silica fine particles or the like may be further added to the paint as a viscosity modifier.

(Coating)
Next, the coating material obtained as described above is applied onto the substrate 11. The paint is applied such that the average film thickness after drying is preferably 3 to 30 μm, more preferably 4 to 15 μm. When the film thickness is thinner than this numerical range, it becomes difficult to obtain a desired hardness, and when it is thicker than this numerical range, it may curl greatly. The coating thickness can be selected, for example, by appropriately preparing the solid content of the paint. The coating method is not particularly limited, and a known coating method can be used. Known coating methods include, for example, micro gravure coating method, wire bar coating method, direct gravure coating method, die coating method, dip method, spray coating method, reverse roll coating method, curtain coating method, comma coating method, knife coating. Method, spin coating method and the like.

(Dry)
Next, the solvent is volatilized by drying the paint applied on the substrate 11. And the aggregate of the fine particles 13 is intentionally formed by the convection generated at the time of drying, and a surface shape having a large period is formed by using this aggregate as one mountain. At this time, it is preferable that the fine particles 13 are aggregated mainly only in the in-plane direction of the antiglare layer 12, that is, mainly aggregated two-dimensionally. This is because if the fine particles 13 overlap in the thickness direction of the antiglare layer 12, a steep angle component is formed as the surface shape, and the average inclination angle θa increases.

  By preparing the solid content of the paint and controlling the convection, the fine particles 13 can be aggregated mainly only in the in-plane direction. Specifically, the solid content of the paint is preferably 30% or more and 60% or less. When the solid content of the paint is less than 30%, intense convection occurs, so that the fine particles 13 overlap in the thickness direction of the antiglare layer 12 and the average inclination angle θa increases. If the solid content of the paint exceeds 60%, it will be dried before the Benard cell (aggregate) is properly formed, resulting in a distribution close to monodispersion and a large cloudiness (large average inclination angle θa). The antiglare property is poor (arithmetic mean roughness Ra is small). The viscosity of the paint also affects the convection velocity. When the viscosity is high, that is, when the viscosity exceeds 100 mPa · s, the movement of the fine particles 13 by convection hardly occurs. Therefore, the viscosity of the coating is preferably 100 mPa · s or less from the viewpoint of obtaining an appropriate aggregate.

  Further, it is preferable to form smooth wavy fine irregularities on the surface of the coating film by a liquid resin meniscus formed in the Benard cell. In order to maintain the meniscus formed in the Benard cell even after drying, it is preferable to use a resin that is liquid until it is cured even after a drying process. This is because the smooth undulation of the surface can be maintained even when dried. In addition, since the base material surface is flat when the resin which becomes solid by drying (hereinafter referred to as dry cured resin) is included, the surface of the antiglare layer 12 formed on the base material 11 by the initial drying is also flat. Thus, it is considered that the substrate is flattened in accordance with the surface of the base material even after the inside is completely dried through the drying process.

  The drying conditions are not particularly limited, and may be natural drying or artificial drying by adjusting drying temperature, drying time, and the like. However, when wind is applied to the surface of the paint at the time of drying, it is preferable not to generate a wind pattern on the surface of the coating film. This is because when the wind ripples are generated, it is difficult to form a desired undulating fine uneven shape on the surface of the antiglare layer, and it is difficult to achieve both antiglare property and contrast. Further, the drying temperature and drying time can be appropriately determined depending on the boiling point of the solvent contained in the paint. In that case, it is preferable to select the drying temperature and the drying time in a range in which the base material 11 is not deformed by heat shrinkage in consideration of the heat resistance of the base material 11.

(Curing)
Next, the resin dried on the substrate 11 is cured by, for example, ionizing radiation irradiation or heating. Thereby, a fine uneven | corrugated shape (Benard cell) with a big period can be formed by making an aggregate into one mountain. That is, a fine uneven shape having a longer period and a gentle period (that is, the root mean square slope RΔq is appropriately small) is formed on the surface of the antiglare layer 12 as compared with the conventional case. As the ionizing radiation, for example, an electron beam, an ultraviolet ray, a visible ray, a gamma ray, an electron beam or the like can be used, and an ultraviolet ray is preferable from the viewpoint of production equipment. The integrated irradiation dose is preferably selected as appropriate in consideration of the curing characteristics of the resin, suppression of yellowing of the resin and the substrate 11, and the like. In addition, the irradiation atmosphere can be appropriately selected according to the degree of resin curing, and examples thereof include an atmosphere of an inert gas such as air, nitrogen, or argon.
Thus, the intended antiglare film 1 is obtained.

  As described above, according to the first embodiment, the average inclination angle θa of the fine irregularities on the surface of the antiglare layer is set to 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is set to 0.1. Since it is set to 05 to 0.4, it is possible to obtain a fine concavo-convex shape in which the cycle is long and gentle and the angle component is adjusted. Therefore, an antiglare film having high contrast and excellent antiglare properties can be realized.

(2) Second Embodiment (2-1) Configuration of Antiglare Film FIG. 5 shows an example of the configuration of an antiglare film according to the second embodiment of the present invention. The antiglare film 10 includes the low refractive index layer 14 having a lower refractive index than the antiglare layer 12 on the antiglare layer 12 in the first embodiment described above. In addition, the same code | symbol is attached | subjected to the part similar to the above-mentioned 1st Embodiment, and the description is abbreviate | omitted.

  The surface of the low refractive index layer 14 has a fine uneven shape. This fine concavo-convex shape has a undulation that is equal to or more than the fine concavo-convex shape on the surface of the antiglare layer, for example. The average inclination angle θa on the surface of the low refractive index layer is preferably 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is preferably 0.05 to 0.4. This is because high contrast and excellent antiglare properties can be obtained.

(2-2) Manufacturing method of anti-glare film Next, an example of the manufacturing method of the anti-glare film by 2nd Embodiment is demonstrated. The method for producing an antiglare film according to the second embodiment further includes a step of forming a low refractive index layer after the step of forming the antiglare layer in the first embodiment described above.
Hereinafter, the process of forming the low refractive index layer will be specifically described.

(Paint preparation)
First, for example, a paint in which a resin and a solvent are mixed is obtained. At this time, a light stabilizer, an ultraviolet absorber, an antistatic agent, a flame retardant, an antioxidant and the like may be further added as necessary.

  As the solvent, a solvent that dissolves the resin raw material to be used and does not dissolve the antiglare layer 12 serving as a base is preferable. Examples of such a solvent include organic solvents such as tertiary butanol, toluene, methyl ethyl ketone (MEK), isopropyl alcohol (IPA), and methyl isobutyl ketone (MIBK).

  As the resin, for example, it is preferable to use a resin containing at least a dry-curing resin that becomes a solid by drying. This is because by using a material containing a dry-curing resin, it is possible to prevent the paint from flowing into the recesses on the surface of the antiglare layer, filling the recesses, and flattening the surface. The dry resin is a thermosetting resin that is cured by applying heat in the drying process, for example. Specific examples of the dry curable resin include urethane resin, acrylic resin, methacrylic resin, styrene resin, melamine resin, and cellulose resin.

  As the resin, for example, at least one of ionizing radiation curable or thermosetting monomers, oligomers, and polymers can be used. In addition, a resin such as an ionizing radiation curable resin or a thermosetting resin may be appropriately mixed with the dry curable resin. In this case, the resin mixed with the dry curable resin is preferably one that undergoes a curing reaction with the dry curable resin. From the viewpoint of water and oil repellency, it is preferable to use a resin containing fluorine (F).

(Coating)
Next, the paint obtained as described above is applied onto the antiglare layer 12. The coating method is not particularly limited, and a known coating method similar to that of the first embodiment is used. By uniformly applying a predetermined amount of thickness on the antiglare layer 12, the surface of the coating layer is formed with a fine concavo-convex shape having a gentle undulation equal to or greater than that of the antiglare layer surface. be able to.

(Drying / curing)
Next, the paint applied on the antiglare layer 12 is dried and cured. Thereby, the low refractive index layer 14 which has the gentle fine uneven | corrugated shape on the surface is formed. In order to form gently wavy fine irregularities on the surface of the low refractive index layer, as described above, it is preferable that the paint contains at least a dry cured resin. When a coating made of only a resin material such as a monomer, oligomer, or polymer that does not contain any dry-curing resin, that is, in a liquid state after drying, is applied on the anti-glare layer 12, until the applied coating is dried and cured During these periods, these paints level, filling the recesses on the surface of the antiglare layer and flattening it, and the antiglare property is lowered. Moreover, since the convex part of the surface of an anti-glare layer remains as a protruding protrusion, it becomes a rough surface. By including a dry-curing resin in the paint, the dry surface formed by the initial drying covers the gentle undulations on the surface of the antiglare layer, so that leveling is suppressed and a gentle undulation component is formed.

Next, when the resin contains an ionizing radiation curable resin or a thermosetting resin, the coating material is cured by, for example, ionizing radiation irradiation or heating to form the low refractive index layer 14.
Thus, the intended antiglare film 10 is obtained.

  According to the second embodiment, since the low refractive index layer 14 is provided on the anti-glare layer 12, the reflectance can be further reduced as compared with the first embodiment described above, and the anti-glare layer can be prevented. Antifouling property can be imparted to the surface of the glare layer 12.

  Further, by appropriately adjusting the production process of the low refractive index layer, it is possible to form on the surface of the low refractive index layer a fine concavo-convex shape with a gentle undulation equivalent to or higher than the surface of the antiglare layer. Accordingly, the antiglare film 10 having such fine irregularities is used for various display devices such as a liquid crystal display, a plasma display, an electroluminescence display, a CRT (Cathode Ray Tube) display, etc., thereby maintaining the antiglare property. However, contrast superior to that of the first embodiment can be realized, and visibility can be further improved.

(3) Third Embodiment In the antiglare film according to the third embodiment, the antiglare layer 12 is composed of a first resin layer and a second resin layer in the first embodiment described above. It is. The first resin layer includes fine particles 13, and a part of the fine particles 13 is exposed from the surface of the first resin layer. The second resin layer covers the surface of the fine particles exposed from the surface of the first resin layer. Thus, since the fine particles exposed from the first resin layer can be covered by the second resin layer, the average inclination angle θa of the antiglare layer film surface can be reduced.
Hereinafter, an example of the manufacturing method of the anti-glare film which has such a structure is demonstrated.

  First, for example, a resin and fine particles are added to a solvent and mixed to obtain a paint in which fine particles 13 are dispersed. As the resin, fine particles, and solvent, for example, those similar to the antiglare layer 12 in the first embodiment described above can be used. Next, the coating material obtained as described above is applied onto the substrate 11. Next, the solvent is volatilized by drying the paint applied on the substrate 11. The fine particles 13 are naturally exposed on the surface by the convection generated during the drying. Next, the resin dried on the substrate 11 is cured by, for example, ionizing radiation irradiation or heating. Thereby, the first resin layer is formed on the substrate 11.

Next, for example, a paint in which a resin and a solvent are mixed is obtained. As the resin and the solvent, for example, those similar to the low refractive index layer 14 in the second embodiment described above can be used. Next, the coating material obtained as described above is applied onto the antiglare layer 12, dried and cured. Thereby, the second resin layer is formed on the first resin layer.
Thus, the intended antiglare film 1 is obtained.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

Each numerical value in the following examples and comparative examples was obtained as follows.
(Viscosity of paint)
Using a viscometer calibration standard solution (JIS Z8809), the viscosity of the paint was measured after calibration by a comparative method. As the viscometer, a vibration viscometer (manufactured by CBC Materials, trade name: Viscomate VA-10) was used.

(Dry film thickness of the antiglare layer)
First, arithmetic average roughness Ra was calculated | required based on JISB0601: 1994. In addition, the detail of the measuring method of this arithmetic mean roughness Ra is mentioned later. Next, the thickness of the whole glare-proof layer containing microparticles | fine-particles was measured using the thickness measuring device (the TESA Corporation make, electric micrometer). Next, the arithmetic average roughness Ra of the antiglare layer was subtracted from the thickness of the entire antiglare layer containing fine particles, and the value obtained thereby was taken as the thickness of the antiglare layer.
The film thickness of the antiglare layer determined as described above is obtained by observing a cross section of the antiglare film with a scanning electron microscope (SEM), and the thickness of the binder portion of the antiglare layer. It is confirmed that it almost agrees with the measured value.

(Average particle size)
The particle diameter was measured with a Coulter Multisizer, and the average value of the obtained data was defined as the average particle diameter of the fine particles (beads).

(Coefficient of variation)
The particle diameter was measured with a Coulter Multisizer, and the coefficient of variation was determined by the following equation (3) using the obtained data.
Coefficient of variation = standard deviation / average particle size (3)

(Solid content)
Solid content was calculated | required by the following formula | equation (4).
Solid content (%) = (weight of paint excluding solvent / weight of paint) × 100 (4)

Example 1
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 35 mPa · s. Next, the obtained paint was applied onto a TAC film (manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm with a bar coater. Next, after drying in a drying furnace at a temperature of 80 ° C. for 2 minutes, ultraviolet rays were irradiated at 500 mJ / cm ² to form an antiglare layer having a dry film thickness of 11.1 μm. Thus, the intended antiglare film was obtained.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol (t-BuOH) 167 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 6 weights Part

(Example 2)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 35 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 10.5 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 165 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 5 parts by weight

(Example 3)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 30%. The viscosity of the paint was 15 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 8.2 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: Toluene 257 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 5 parts by weight

Example 4
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 35 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 13.0 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 165 parts by weight Fine particles: acrylic styrene copolymer beads (average particle size 6.0 μm, coefficient of variation 40%) 5 parts by weight

(Example 5)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 40 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 3.4 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: Toluene 180 parts by weight Fine particles: Acrylic beads (average particle size 1.2 μm, coefficient of variation 20%) 15 parts by weight

(Example 6)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 35 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 10.0 μm was obtained in the same manner as in Example 1 except that this paint was used. Next, on the obtained anti-glare film, a polymer containing fluorine (F) was applied by 100 nm by a dipping method and then cured. As a result, a low refractive index layer (antireflection coating) was formed on the antiglare layer. Thus, the intended antiglare film was obtained.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 165 parts by weight Fine particles: Styrene beads (average particle size 6.0 μm, coefficient of variation 37%) 5 parts by weight

(Example 7)
First, the raw materials shown in the following paint composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a paint having a solid content of 60%. The viscosity of the paint was 98 mPa · s. Next, the obtained coating material was coated on PET (Toyobo Co., Ltd., Cosmo Shine A4300) having a thickness of 100 μm with a bar coater. Next, after drying in a drying furnace at a temperature of 80 ° C. for 2 minutes, ultraviolet rays were irradiated at 500 mJ / cm ² to form an antiglare layer having a dry film thickness of 9.5 μm. Thus, the intended antiglare film was obtained.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 73 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 5 parts by weight

(Comparative Example 1)
First, the raw materials shown in the following paint composition were blended and stirred for 30 minutes with a magnetic stirrer to obtain a paint having a solid content of 40%. The viscosity of the paint was 30 mPa · s. Next, the obtained paint was applied onto a TAC film (manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm with a bar coater. Next, after drying in a drying furnace at a temperature of 80 ° C. for 2 minutes, ultraviolet rays were irradiated at 500 mJ / cm 2 to form a hard coat layer having a dry film thickness of 10.0 μm. Thus, the intended hard coat film was obtained.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 73 parts by weight

(Comparative Example 2)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 35 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 8.5 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 168 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 7 parts by weight

(Comparative Example 3)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 40%. The viscosity of the paint was 40 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 3.5 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 173 parts by weight Fine particles: Styrene beads (average particle size 3.5 μm, coefficient of variation 15%) 10 parts by weight

(Comparative Example 4)
First, the raw materials shown in the following coating composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a coating having a solid content of 62%. The viscosity of the paint was 135 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 13.4 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 68 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 6 parts by weight

(Comparative Example 5)
First, the raw materials shown in the following paint composition were blended and stirred for 1 hour with a magnetic stirrer to obtain a paint having a solid content of 20%. The viscosity of the paint was 10 mPa · s. Next, an antiglare film having an antiglare layer having a dry film thickness of 18.0 μm was obtained in the same manner as in Example 1 except that this paint was used.
<Coating composition>
Resin: Hexafunctional urethane acrylic oligomer 100 parts by weight Initiator: Irgacure 184 5 parts by weight Solvent: t-butanol 440 parts by weight Fine particles: Styrene beads (average particle size 5.4 μm, coefficient of variation 35%) 5 parts by weight

(Roughness evaluation)
About the anti-glare films of Examples 1 to 7 and Comparative Examples 1 to 5 obtained as described above, the surface roughness is measured, the roughness curve is obtained from the two-dimensional cross-sectional curve, and arithmetic is performed as the roughness parameter. Average roughness Ra and average inclination angle θa were calculated. The results are shown in Table 2. Measurement conditions were in accordance with JIS B0601: 1994. The measurement apparatus and measurement conditions are shown below.
Measuring device: Fully automatic fine shape measuring machine (manufactured by Kosaka Laboratory Ltd., trade name: Surfcoder ET4000A)
Measurement conditions: Cut-off value (λc) 0.8 mm, evaluation length 4 mm (cut-off value × 5 times), data sampling interval 0.5 μm

(White turbidity)
The anti-glare films of Examples 1 to 7 and Comparative Examples 1 to 5 were measured for white turbidity. The results are shown in Table 2. The cloudiness is felt by detecting reflected light diffused on the surface of the antiglare layer. Here, a commercially available spectrocolorimeter was used, the above phenomenon was simulated and the quantified value was defined as the turbidity. In addition, it has been confirmed through experiments that the white turbidity in this measurement has a correlation with the visually felt white turbidity.

  A specific method for measuring white turbidity is shown below. First, in order to suppress the influence of back surface reflection and evaluate the diffuse reflection of the antiglare film itself, the back surface of the obtained antiglare film was bonded to black glass via an adhesive. Next, using an integrating sphere type spectrocolorimeter (product name: SP64, manufactured by X-Rite Co., Ltd.), a detector existing at a position inclined by 8 ° from the sample normal direction by irradiating the sample surface with diffuse light The measurement was performed with a d / 8 ° optical system that measures the reflected light. The measurement value was SPEX mode in which only the diffuse reflection component was detected except for the regular reflection component, and the measurement was performed at a detection viewing angle of 2 °.

(Anti-glare)
The antiglare properties of Examples 1 to 7 and Comparative Examples 1 to 5 were evaluated for antiglare properties. Specifically, a bare fluorescent lamp was copied onto the antiglare film, and the reflected image was blurred according to the following criteria. The results are shown in Table 2.
A: The outline of the fluorescent lamp is unknown (two fluorescent lamps appear to be one)
B: The fluorescent lamp can be recognized to some extent, but the outline is blurred. C: The fluorescent lamp is reflected as it is.

(Light place contrast)
About the anti-glare film of Example 1 and Comparative Example 2, the bright place contrast was measured as follows. An anti-glare film is bonded to the display surface of a liquid crystal television via an adhesive, and the screen brightness during all white display and all black display is measured using a luminance meter (product name: PR-650, manufactured by PHOTO REAERCH). The contrast was calculated from these ratios. At this time, the environmental illuminance measured using an illuminometer (manufactured by Konica Minolta, trade name: T-10) was 350 lx. The results are shown in Table 2.

(Distribution of fine particles)
About the anti-glare film of Example 1 and Example 5, distribution of microparticles | fine-particles was observed with the optical microscope. The results are shown in FIGS. 6A and 6B. 6A shows an optical micrograph (transmission image) of the antiglare film of Example 1. FIG. 6B shows an optical micrograph (transmission image) of the antiglare film of Comparative Example 5. FIG.

From Table 2, the following can be understood with respect to white turbidity and antiglare properties.
In the antiglare films of Examples 1 to 7, the average inclination angle θa of the fine irregularities on the surface is 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is 0.05 to 0.4. It exhibits moderate anti-glare properties, has low turbidity, and has good properties. On the other hand, in the hard coat film of Comparative Example 1, the average inclination angle θa and the arithmetic average roughness Ra both divide the above numerical range, and the antiglare property is not expressed. Moreover, in the anti-glare film of the comparative example 2, both average inclination angle (theta) a and arithmetic mean roughness Ra exceed the said numerical range, and white turbidity is large. Moreover, in the anti-glare film of Comparative Example 3, since particles having a small variation coefficient were used, the average inclination angle θa when adjusted to a thickness capable of exhibiting anti-glare properties exceeded the above numerical range, and the cloudiness increased. ing. When the thickness of the antiglare layer is increased and the average inclination angle θa is adjusted so as to fall within the numerical range, the arithmetic average roughness Ra divides the above numerical range, resulting in a film with poor antiglare property. Further, in the antiglare film of Comparative Example 4, since the viscosity and solid content are high, it is difficult for the fine particles to aggregate due to convection during drying, and the average inclination angle θa is within the above numerical range, but the arithmetic average roughness Ra is The above numerical range is divided, and the antiglare property is poor. In the antiglare film of Comparative Example 5, both the viscosity and the solid content are low, and the fine particles form a three-dimensional structure. Therefore, the average inclination angle θa is large and the turbidity is large.

From Table 2, the following can be seen regarding the contrast of light and dark.
The bright place contrast in the antiglare film of Example 1 is higher than that of Comparative Example 2. That is, even in the evaluation performed by mounting the antiglare film on the liquid crystal television, it is possible to clearly confirm the effect obtained by setting both the average inclination angle θa and the arithmetic average roughness Ra in the above numerical range.

From Table 2, FIG. 6A, and FIG. 6B, the following can be understood about the particle distribution and the fine uneven shape of the surface.
In the antiglare film of Example 1, the fine particles aggregate mainly only in the in-plane direction to form an aggregate having a two-dimensional structure. The average inclination angle θa is as small as 0.62 ° due to such aggregates. That is, a gentle uneven shape is formed on the surface. In contrast, in the antiglare film of Comparative Example 5, the fine particles aggregate in the in-plane direction and the thickness direction to form an aggregate having a three-dimensional structure. The average inclination angle θa is as large as 1.20 ° due to such aggregates. That is, a steep fine uneven shape is formed on the surface.

  From the above results, in order to achieve both the contrast and the antiglare property, the average inclination angle θa of the fine uneven shape on the antiglare film surface is set to 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is preferably 0.05 to 0.4.

  In order to achieve both the contrast and the antiglare property, it is preferable to aggregate the fine particles mainly in the in-plane direction to form an aggregate having a two-dimensional structure.

  Further, as in the conventional invention (for example, the invention described in Patent Documents 1 and 2), it is difficult to suppress the decrease in contrast while maintaining the antiglare property only by controlling the arithmetic average roughness Ra of the roughness curve. In addition, it is important to control both the arithmetic average roughness Ra and the average inclination angle θa of the roughness curve in order to achieve high contrast (low turbidity) while maintaining antiglare properties.

  Although the embodiments and examples of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and examples, and various modifications based on the technical idea of the present invention are possible. It is.

  For example, the numerical values given in the above-described embodiments and examples are merely examples, and different numerical values may be used as necessary.

  In the above-described embodiment, an example in which the present invention is applied to a liquid crystal display device has been described. However, the present invention is not limited to this. For example, the present invention is applied to various display devices such as a plasma display, an organic EL display, an inorganic EL display, a CRT display, a rear projection display, a surface conduction electron-emitting device display, a field emission display (FED), and an LED display. Can be applied.

  In the above-described embodiment, as an example of the method for producing an antiglare film, a method for forming an antiglare layer by applying a coating containing fine particles on a substrate and curing the coating is described. The method for producing an antiglare film is not particularly limited as long as a desired fine uneven shape can be obtained. For example, a roughening method such as a shape transfer method or a sand blast method can be used.

It is a schematic sectional drawing which shows an example of a structure of the liquid crystal display device by 1st Embodiment of this invention. It is a schematic sectional drawing which shows an example of a structure of the anti-glare film by 1st Embodiment of this invention. It is a schematic diagram for demonstrating average inclination | tilt angle (theta) a. It is a graph which shows an example of the particle size distribution of microparticles | fine-particles. It is a schematic sectional drawing which shows an example of a structure of the anti-glare film by 2nd Embodiment of this invention. 2 is an optical micrograph of an antiglare layer of Example 1 and Comparative Example 5. It is a schematic sectional drawing which shows the structure of the conventional anti-glare film. It is a schematic sectional drawing which shows the structure of the anti-glare film which lengthened the period of the fine unevenness | corrugation shape of the surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 Anti-glare film 2 Liquid crystal panel 2a, 2b Polarizer 3 Light source 11 Base material 12 Anti-glare layer 13 Fine particle 14 Low refractive index layer

Claims (15)

  It has a fine uneven shape on the surface, the average inclination angle θa on the surface is 0.2 ° to 1.5 °, and the arithmetic average roughness Ra is 0.05 to 0.4. Anti-glare film. A substrate;
Provided with at least one antiglare layer provided on the base material,
2. The antiglare film according to claim 1, wherein the fine uneven shape is provided on a surface of the antiglare layer. The antiglare layer contains fine particles and a resin,
The antiglare film according to claim 2, wherein the fine uneven shape is formed by aggregation of the fine particles.   4. The antiglare film according to claim 3, wherein the fine particles are aggregated mainly only in the in-plane direction of the surface.   4. The antiglare film according to claim 3, wherein most or all of the surface of the fine particles is covered with the resin.   4. The antiglare film according to claim 3, wherein the fine particles have an average particle size of 1 to 6 [mu] m.   4. The antiglare film according to claim 3, comprising the fine particles having a particle size distribution having a coefficient of variation (standard deviation / average particle size) of 20 to 40%.   The antiglare film according to claim 2, further comprising a low refractive index layer having a lower refractive index than the antiglare layer on the antiglare layer. A method for producing an antiglare film having a fine uneven shape on the surface,
Provided with a step of forming a fine concavo-convex shape on the surface by a shape transfer method, sandblasting method or Benard cell formation method,
The method for producing an antiglare film, wherein the average inclination angle θa on the surface is 0.2 ° to 1.5 ° and the arithmetic average roughness Ra is 0.05 to 0.4. The formation process of fine irregularities by the Benard cell formation method,
A coating process in which a coating material containing fine particles, a resin and a solvent is coated on a substrate;
A drying step of forming a Benard cell on the surface of the coating by drying the coating applied on the substrate;
A method for producing an antiglare film according to claim 9, further comprising: a curing step of forming the antiglare layer having the fine concavo-convex shape on the surface by curing the dried paint.   The method for producing an antiglare film according to claim 10, wherein in the drying step, fine particles contained in the paint are aggregated by convection of the applied paint.   12. The method for producing an antiglare film according to claim 11, wherein the fine particles are aggregated mainly only in the in-plane direction of the surface.   The method for producing an antiglare film according to claim 10, wherein the viscosity of the paint is 100 mPa · s or less, and the solid content of the paint is 30% or more and 60% or less.   A polarizer comprising the antiglare film according to claim 1.   A display device comprising the antiglare film according to any one of claims 1 to 8 on a display surface.