JP5325409B2 - Antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a well-balanced antireflection film which has a wide viewing angle as a transmission characteristic, avoids reflection and substantially avoids dazzling. <P>SOLUTION: The antireflection film comprises a transparent film and an antireflection layer formed on the transparent film, wherein an average wavelength (S&lambda;a) of the antireflection layer side surface of the antireflection film is 50-300 &mu;m, a center plane average roughness (SRa) has irregularity represented by expression (1): 0.1+0.00065&times;S&lambda;a&lt;SRa&lt;0.003&times;S&lambda;a, and the irregularity is formed by transfer. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an antireflection film.

In various image display devices such as a liquid crystal display device (LCD) and a plasma display panel (PDP) that are thin and used for a large screen in recent years, it is difficult to see a display image by reflecting light incident from the outside on the screen. There are things to do. In particular, with the increase in the size of image display devices, it has become increasingly important to solve the above problems, and various antireflection methods have been proposed and installed.
In the LCD, antireflection is performed by forming fine irregularities on the surface. The antireflection method using fine irregularities is also called an antiglare treatment, and conventionally, sandblasting, embossing, and formation of a coating film containing fine particles have been performed. For example, as a method for producing an anti-glare hard coat film with controlled transmission light scattering characteristics and improved glare, an active energy ray curable resin is applied to a transparent plastic substrate and irradiated with active energy rays. There has been proposed a method of curing and forming an active energy ray-curable resin layer and then subjecting the coating to either sandblasting or embossing. (Patent Document 1)
In addition, when forming an antiglare layer of an antiglare film with a coating liquid composed of a light-transmitting fine particle, a light-transmitting resin, and a good solvent and a poor solvent of the light-transmitting resin, the light-transmitting effect is caused by the action of the poor solvent during the drying process Disclosed is a method for forming a good concavo-convex structure by gelling conductive fine particles and translucent resin. (Patent Document 2)

In addition, by applying a resin composition containing transparent fine particles such as styrene beads to a transparent plastic substrate, the surface of the coating film can be satisfactorily antiglare in the uneven state imparted to the coating film by the transparent fine particles. A method of forming a layer is disclosed. (Patent Document 3)
On the other hand, in the PDP, when an anti-glare process such as that used in an LCD is applied as an anti-reflection process, any of the methods disclosed in Patent Document 1, Patent Document 2, and Patent Document 3 described above can be applied to external light. However, there is a problem that the transmitted video itself that is originally intended to be projected is blurred, and the beauty of the video, which is a characteristic of PDP, is impaired.
The fact that the LCD technology cannot be applied is considered to be caused by the fact that the PDP uses an optical filter that is separated from the light emitting portion unlike the LCD.
As a solution to these problems, the conventional PDP uses light interference by a thin film with a low refractive index (hereinafter referred to as an antireflection film) as a method for reducing only the reflected image without losing its excellent transmission image. The reflectance of outside light has been lowered by the antireflection method. Specifically, in the case of a single-layer antireflection film, when the refractive index of the substrate is n _s , and the refractive index of the single-layer film is n and n _s > n, the reflectance R is set to a minimum value ( _ns − ^{_{n 2) 2 / (n s}} + n 2) 2 utilize to ^take, reducing the reflectance close to the refractive index n of the single-layer film such that n 2 = _{n s} in _(n ^{s) 1/2} It is something to be made. Currently, many commercially available optical members having an antireflection film have a luminous reflectance around 2% in the visible light region. There are various low-refractive-index materials for such an antireflection film. As a material for forming the antireflection film by a coating method, a fluororesin is generally known. (Patent Document 4)

As a method for forming an antireflection film, a hollow fine particle such as hollow silica having a cavity inside is dispersed in a binder containing an inorganic component obtained from a hydrolyzed polycondensate of alkoxysilane to form an antireflection film. A method (Patent Document 5) is disclosed.
However, in the antireflection film, the reflected light such as outside light or fluorescent lamp is clear, so that the visibility of what is desired to be displayed is not sufficient, and the antireflection method is insufficient.
Japanese Patent Laid-Open No. 11-352899 JP 2000-338310 A Japanese Patent Laid-Open No. 11-305010 JP 04-355401 A Japanese Patent Laying-Open No. 2005-099778

  That is, the object of the present invention is to solve the above-mentioned problems, have an excellent transmission image characteristic of PDP, have excellent antireflection characteristics, and have a balanced antireflection film with very little glare. Is to provide.

As a result of intensive studies, the present inventors have found that it is difficult to balance all the characteristics by simply forming the surface shape control using fine particles, and there is a trade-off relationship between the characteristics. . Various studies were conducted to overcome these problems, and it was found that a surface shape capable of exhibiting all these characteristics can be formed by forming a special shape without using fine particles, and the present invention was completed.
That is, the present invention
(1) An antireflection film comprising a transparent film and an antireflection layer formed on the transparent film, and the average wavelength (Sλa) of the antireflection layer side surface of the antireflection film is 50 to 300 μm, and the center plane average The roughness (SRa) has irregularities represented by the following formula (1),
0.1 + 0.00065 × Sλa <SRa <0.003 × Sλa Formula (1)
An antireflection film, wherein the unevenness is formed by transfer.
(2) The antireflection film as described in (1) above, wherein the irregularities have an irregular arrangement.
(3) The antireflection film as described in (1) above, wherein the unevenness is transferred based on the uneven shape by interference exposure.
(4) The antireflection film as described in (1) above, wherein the antireflection layer comprises a hard coat layer and a low refractive index layer.
It is.

  According to the present invention, it is possible to provide a film having no glare in various images, displaying a transmission image excellent in contrast and viewing angle, and having excellent antireflection characteristics. It is also useful for various image display devices such as organic EL. In particular, in the PDP, an excellent display can be achieved even in the front plate filter type, which is useful.

The present invention will be specifically described below.
As a transparent film that can be used in the present invention, for example, polyethylene film, polypropylene film, cellulose acetate film such as triacetyl cellulose, cellulose acetate propionate, polyester film such as stretched polyethylene terephthalate, polyethylene naphthalate, A polycarbonate film, a norbornene film, a polysulfone film, a polyethersulfone film, a polyarylate film, and the like. From the viewpoint of using transmitted light, the transparent film preferably has a haze of 2.0% or less, and more preferably 1.0% or less.

The antireflection film of the present invention can be provided with an antireflection function by sticking it to the surface to which an antireflection function is desired using an adhesive or the like. As the surface to which the antireflection function is to be imparted, glass is the most, and it can also be used for polycarbonate and acrylic resin. From the viewpoint of light transmittance and light utilization efficiency, the transparent film has a refractive index of 1.45 or more and 1.69 or less, such as a triacetyl cellulose film (hereinafter referred to as TAC film) or a polyethylene terephthalate film (hereinafter referred to as PET film). And the like are preferably used.
The thickness of the TAC film or PET film is preferably 12 μm or more from the viewpoint of the uniformity of the thickness of the antireflection layer and the handleability as an optical substrate. The upper limit with preferable thickness of a TAC film or PET film is 200 micrometers from a viewpoint of light transmittance and the utilization efficiency of light.

As the transparent film of the present invention, a film containing an ultraviolet absorber may be used. It can be preferably used for protecting the pigment used in the constituent elements of the PDP front plate filter, particularly the color tone correction layer. As the ultraviolet absorber, an ultraviolet absorber that absorbs a short wavelength side of 420 nm or less can be used, and in particular, an ultraviolet absorber having a wavelength of 350 to 400 nm can be used.
The antireflection film of the present invention comprises a transparent film and an antireflection layer formed on the transparent film. The antireflection layer is a layer having irregularities on the surface on a transparent film, and may have an antireflection film utilizing light interference.
The structure of the antireflection layer is composed of a hard coat having irregularities on the surface, a layer having a low refractive index layer provided on the hard coat layer having irregularities on the surface, and a layer for reducing the reflectance, and the surface A layer with a high refractive index layer and a low refractive index layer provided in this order on a hard coat layer with unevenness, and a layer that lowers the reflectivity by providing a multilayer thin film on the hard coat layer with unevenness on the surface There are things. Further, a resin layer having unevenness may be provided on the transparent film, and a hard coat layer or a multilayer reflectance lowering layer may be provided on the transparent film while substantially maintaining the uneven shape. The antireflection film of the present invention is characterized by the shape of the outermost surface on the antireflection layer side.

The shape of the antireflection layer side surface of the antireflection film of the present invention can be measured with a stylus type surface shape measuring instrument. For example, the surface shape can be measured by measuring a region of 1 mm × 1 mm to 3 mm × 3 mm using a surface shape measuring instrument “Surfcoder ET4000” of Kosaka Laboratory. At this time, the raw data is leveled by the least square method, and the surface shape parameter is calculated without using the cut-off.
Here, the center plane average roughness (SRa) is the three-dimensional plane of the center line average roughness (Ra) of the two-dimensional roughness parameters described in JIS B0601-1994, ISO 4287-1997, ASME-1995. Is calculated as

Sm = Lx × Ly
When the orthogonal coordinate axes X and Y axes are placed on the center plane of the roughness curved surface and the axis orthogonal to the center plane is the Z axis, the roughness curved surface is f (x, y), and the reference plane sizes Lx and Ly are: This is the value given by the above formula.
The average slope SΔa is obtained by calculating the two-dimensional arithmetic mean slope Δa described in ASME-1995 as a plane in three dimensions.

The orthogonal coordinate axes X and Y are placed on the center surface of the roughness surface, the axis orthogonal to the center surface is the Z axis, the roughness surface is f (x, y), and the sizes of the reference surfaces are Lx and Ly. Is the value given by the above equation.
The average wavelength Sλa is obtained by calculating the two-dimensional arithmetic average wavelength λa as a three-dimensional surface.

The value given by.
Since these parameters such as SRa, SΔa, Sλa are standard data processing, they are incorporated in the standard data processing software of “Surfcoder ET4000” and can be automatically calculated and output.
As for the shape of the antireflection layer side surface of the antireflection film of the present invention, the average wavelength (Sλa) is 50 to 300 μm, and the center plane average roughness (SRa) has irregularities represented by the following formula (1). doing.
0.1 + 0.00065 × Sλa <SRa <0.003 × Sλa Formula (1)
If the average wavelength (Sλa) is small, reflection of a reflected fluorescent lamp or the like tends to be clearly seen and the surface becomes whitish, which is not preferable. A large average wavelength (Sλa) is not preferable because the glare increases. Among these, 60-200 micrometers, especially 70-150 micrometers can be preferably used as an average wavelength.
In the present invention, the relationship between Sλa and SRa is important. When SRa is smaller than (0.1 + 0.00065 × Sλa ) μm, external light on the surface and reflection of a fluorescent lamp increase. On the other hand, if SRa is larger than (0.003 × Sλa) μm, the image when the image is viewed obliquely is blurred, and a sufficient viewing angle cannot be maintained.

In the present invention, it is preferable that the irregularities forming the surface shape have an irregular arrangement. In the case of geometrically aligned irregularities, moire may be seen on the screen depending on the period. As one index, a surface shape particle analysis method can be used.
For example, in the mountain particle analysis, when the slice level is set to SRa μm and the cut area is evaluated by a histogram obtained by classifying every 100 μm ² , the distribution of the cut area spreads over 1000 μm ² as a width. Is preferred. If it is a single distribution, moire may be seen, which is not preferable. Since the distribution is non-uniform, the arrangement can be non-uniform.
On the other hand, in the formation of irregularities due to the aggregation structure of fine particles such as silica fine particles, this distribution is wide and many projections are often provided at 0 to 100 μm ² . When there are many projections with such a small area, the screen becomes whitish, which is not preferable, and the angle dependency, which is one of the transmission characteristics of the film, tends to decrease. The number of protrusions with a cut area of 0 to 100 μm ² sliced with SRa is preferably 50 or less in the range of 1 mm × 1 mm, and particularly preferably 30 or less.

  The antireflection layer of the antireflection film of the present invention preferably has a hard coat layer. By having a hard coat layer, the scratch resistance of the antireflection film is improved and it can be used for various applications. By selecting the thickness, material, and curing conditions of the hard coat layer, the scratch resistance can be controlled. A pencil hardness test can be used as one index of scratch resistance. As the antireflection film of the present invention, those having a pencil hardness of HB or more, preferably H or more, and more preferably 2H or more can be most preferably used. The thickness of the hard coat layer can be 0.5 μm to 10 μm. Of these, those having a thickness of 1 to 6 μm are often used because they are particularly easy to exhibit characteristics.

  The material of the hard coat layer is preferably a hard coat material that can perform heat curing, ultraviolet curing, and electron beam curing. The hard coat material preferably contains a photopolymerization initiator, a thermal polymerization initiator, an additive, a solvent and the like depending on the curing method. Typical examples of the hard coat material include melamine type, acrylic radical type, acrylic silicone type, and alkoxysilane type. Among the above hard coat materials, the acrylic radical system is preferably a polyfunctional acrylate monomer, oligomer, and / or polymerized polyfunctional acrylate monomer. Examples of the polyfunctional acrylate monomer include dipentaerythritol hexaacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, and ditrimethylolpropane tetraacrylate.

Polyfunctional acrylate oligomers include epoxy acrylates that are acrylate-modified novolak-type and bisphenol-type epoxy resins, urethane acrylates that are acrylate-modified products of urethane compounds obtained by reacting polyisocyanates and polyols, and polyester acrylates that are acrylate-modified polyester resins. Etc.
In the acrylic silicone type, those in which an acrylic group is covalently bonded to a silicone resin are preferable.
Moreover, in the alkoxysilane type | system | group, what contains the condensate which has the silanol group obtained by carrying out the hydrolysis polycondensation of alkoxysilane is preferable. A silanol group is converted into a siloxane bond by thermosetting after coating, and a cured film is obtained.

These hard coat materials may be used alone or in combination. It is preferable to mix a plurality of hard coat materials by adjusting the refractive index. Among these, acrylic radicals are preferably used from the viewpoint of simplicity of production method, cost, performance, etc., and polyfunctional acrylate oligomers are more preferably used.
As hard coat materials, commercially available silicone hard coats, (meth) acrylic hard coats, epoxy hard coats, urethane hard coats, epoxy acrylate hard coats, urethane acrylate hard coats, etc. should be used. Can do. Specifically, Shin-Etsu Chemical Co., Ltd. UV curable silicone hard coat agent X-12 series, GE Toshiba Silicone Co., Ltd. UV curable silicone hard coat agent UVHC series, thermosetting silicone hard coat agent SHC series, stock Company Nippon Dacro Shamrock's thermosetting silicone hard coat agent Solgard NP series, Nippon Synthetic Chemical Industry Co., Ltd. UV curable hard coat agent purple light series, Kyoeisha Chemical Co., Ltd. UV curable hard coat agent light procoat series, Japan A UV curable hard coat agent KAYANOVA FOP series manufactured by Kayaku Co., Ltd. is preferable. These commercially available hard coat materials may be used alone or in combination. It is preferable to mix a plurality of hard coat materials by adjusting the refractive index. In addition, it can be formed by applying a coating liquid containing a polyfunctional monomer and a polymerization initiator and polymerizing the polyfunctional monomer.

  It is effective to add a polymerization initiator as an additive to the hard coat material. As the polymerization initiator, known ones such as a thermal radical generator, a photo radical generator, a thermal acid generator, and a photo acid generator are selected according to the reactive functional group of the hard coat material and the reaction form of the polymerizable monomer. be able to. Specific examples of the heat / photo radical generator include Irgacure (registered trademark) and Darocur (registered trademark) acetophenone-based, benzophenone-based, phosphine oxide-based, and titanocene-based commercially available from Ciba Specialty Chemicals Co., Ltd. Each polymerization initiator, a thioxanthone polymerization initiator, a diazo polymerization initiator, an o-acyloxime polymerization initiator, and the like can be mentioned. Among these, benzophenone-based polymerization initiators such as Irgacure (registered trademark) 184 are particularly preferable. Specific examples of the heat / photoacid generator include Sun Aid (trademark) SI series commercially available from Sanshin Chemical Industry Co., Ltd., WPI series, WPAG series, and Sigma Aldrich commercially available from Wako Pure Chemical Industries, Ltd. Examples thereof include sulfonium-based, iodonium-based, and diazomethane-based polymerization initiators represented by the PAGs series commercially available from Japan Corporation.

The hard coat layer contains various additives such as an antistatic agent, an ultraviolet absorber, an infrared absorber, a leveling agent, a dye, a metal salt, a surfactant, and a release agent as long as the optical properties are not impaired. It is also possible. Moreover, an additive can be contained according to various purposes, such as adjustment of refractive index, adjustment of shrinkage ratio, and adjustment of pencil hardness. Various additives can be used according to various purposes, but fine particles, molecules, and ions can be used so as not to impair the optical characteristics. In the case of fine particles, metal oxide fine particles, inorganic fine particles, and resin fine particles having a particle diameter of 100 nm or less, particularly 50 nm or less can be used as primary particles.
Providing an antistatic function in the hard coat layer is one of the preferable measures. By mixing the conductive fine particles and the inorganic particles having a low refractive index, the antistatic function and the refractive index can be adjusted, and the surface shape can be used within a range that is not impaired. The pencil hardness can also be H or higher.

As the antistatic agent for imparting antistatic properties, a known antistatic agent such as a surfactant or an ionic polymer, or conductive fine particles dispersed in a binder is used. Examples of the conductive fine particles include oxide or composite oxide fine particles such as indium, zinc, tin, molybdenum, antimony, and gallium, copper, silver, nickel, low melting point alloy (solder, etc.) metal fine particles, and a metal-coated polymer. Known materials such as fine particles, various kinds of carbon black, conductive polymer particles such as polypyrrole and polyaniline, metal fibers, and carbon fibers can be used. Among these, ITO (tin-containing indium oxide) particles, ATO (tin-containing antimony oxide) particles, and antimony pentoxide particles are particularly preferable because they can exhibit high transparency and conductivity. The surface resistivity of the antistatic hard coat layer is preferably 10 ⁶ Ω / □ to 10 ¹⁸ Ω / □.

  As the antireflection film of the present invention, a film in which a low refractive index layer is formed on a hard coat layer is preferably used. By forming the low refractive index layer, the visibility can be further improved by improving the contrast of the transmitted image and reducing the reflectance of the reflected image due to external light. The low refractive index layer is a layer having a refractive index lower than that of the hard coat layer, and preferably has a refractive index of 1.25 to 1.45 at a wavelength of 550 nm. The refractive index of the low refractive index layer is preferably controlled by controlling the type and amount of fine particles and the type and amount of binder so that the minimum reflectance at an incident angle of 5 degrees is 2% or less. The thickness of the low refractive index layer is used in the range of 50 nm to 250 nm, and from the viewpoint of antireflection performance in the visible light region, the thickness is usually set to have a minimum reflectance wavelength of 500 to 750 nm at an incident angle of 5 degrees. What was adjusted is preferable.

The low refractive index layer preferably has a configuration containing silica fine particles and a binder. Silica fine particles may or may not have cavities inside. In view of dispersibility, surface properties of the resulting layer, and mechanical strength, it is preferable to use those having an average particle size of 200 nm or less. When the average particle diameter exceeds 200 nm, haze increases and white blurring of the surface tends to occur.
The use of hollow silica fine particles having cavities inside the particles as the silica fine particles is preferable because the refractive index of the low refractive index layer can be lowered. Since the cavity is surrounded by the outer shell, the binder does not enter the cavity. The presence of the cavity can reduce the refractive index, and the blocking of the binder from entering the cavity can prevent an increase in the refractive index. A reduction in the refractive index of the prevention layer can be realized.

The average particle diameter of the hollow silica fine particles is preferably 40 to 200 nm. When the hollow silica fine particle diameter is larger than 200 nm, the refractive index decreases when the thickness of the outer shell surrounding the cavity is almost constant, but the strength of the hollow silica fine particle tends to be weak, and the surface When the unevenness becomes too large, the transmitted image is blurred and white blurring of the antiglare film surface tends to occur. If the hollow silica fine particles are smaller than 40 nm, the strength is increased, but it is difficult to lower the refractive index. The refractive index is a very large factor because it correlates with the cube of the particle diameter. From these viewpoints, those having an average particle diameter of 60 to 200 nm are particularly preferably used.
The refractive index of the hollow silica fine particles is preferably 1.40 or less from the viewpoint of lowering the refractive index of the antireflection layer. When the refractive index is greater than 1.40, the effect of reducing the refractive index is low. A refractive index of 1.10 to 1.35 is preferably used.
Two or more types of silica fine particles or hollow silica fine particles may be used in combination.

Next, the binder contained in the low refractive index layer will be described.
The binder may be used alone or in combination.
The following are mentioned as a preferable binder.
(1) Tetramethoxysilane, tetraethoxysilane, tetra (i-propoxy) silane, trimethoxysilane, triethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxy Silane, propyltriethoxysilane, isobutyltriethoxysilane, methyltri-iso-propoxysilane, ethyltri-iso-propoxysilane, dimethoxysilane, diethoxysilane, methyldimethoxysilane, methyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane Diethyldimethoxysilane, diethyldiethoxysilane, diethyldi (i-propoxy) silane, methylethyldimethoxysilane, methylethyldiethoxysilane , Methylethyldi (i-propoxy) silane, methylpropyldimethoxysilane, methylpropyldiethoxysilane, methylpropyldi (i-propoxy) silane, methoxysilane, ethoxysilane, methylmethoxysilane, methylethoxysilane, dimethylmethoxysilane, dimethyl Ethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, trimethyl (i-propoxy) silane, triethylmethoxysilane, triethylethoxysilane, triethyl (i-propoxy) silane, tripropylmethoxysilane, tripropylethoxysilane, tripropyl (i- Propoxy) silane, methyldiethylmethoxysilane, methyldiethylethoxysilane, methyldiethyl (i-propoxy) silane, methyldipropylmeth Sisilane, methyldipropylethoxysilane, methyldipropyl (i-propoxy) silane, ethyldimethylethoxysilane, ethyldimethyl (i-propoxy) silane, ethyldipropylmethoxysilane, ethyldipropylethoxysilane, ethyldipropyl (i- Propoxy) silane, propyldimethylmethoxysilane, propyldimethylethoxysilane, propyldimethyl (i-propoxy) silane, propyldiethylmethoxysilane, propyldiethylethoxysilane, propyldiethyl (i-propoxy) silane, bis (trimethoxysilyl) methane, Bis (triethoxysilyl) methane, bis (trimethoxysilyl) ethane, bis (triethoxysilyl) ethane, 1,3-bis (trimethoxysilyl) propane, 1,3-bis ( Triethoxysilyl) propane, hexamethoxydisiloxane, hexaethoxydisiloxane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3- Mercaptopropyltriethoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltri Ethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, tetraacetoxysilane, tetrakis (trichloroacetoxy) silane, tetrakis (trifluoroacetate) Xyl) silane, triacetoxysilane, tris (trichloroacetoxy) silane, tris (trifluoroacetoxy) silane, methyltriacetoxysilane, methyltris (trichloroacetoxy) silane, methyltris (trifluoroacetoxy) silane, methyldiacetoxysilane, methylbis ( Trichloroacetoxy) silane, methylbis (trifluoroacetoxy) silane, dimethylbis (trichloroacetoxy) silane, dimethylbis (trifluoroacetoxy) silane, methylacetoxysilane, methyl (trichloroacetoxy) silane, methyl (trifluoroacetoxy) silane, dimethyl Acetoxysilane, dimethyl (trichloroacetoxy) silane, dimethyl (trifluoroacetoxy) silane, trimethylacetoxy Run, trimethyl (trichloroacetoxy) silane, trimethyl (trifluoroacetoxy) silane, tetrachlorosilane, tetrabromosilane, tetrafluorosilane, trichlorosilane, tribromosilane, trifluorosilane, methyltrichlorosilane, methyltribromosilane, methyltri Fluorosilane, methyldichlorosilane, methyldibromosilane, methyldifluorosilane, dimethyldichlorosilane, dimethyldibromosilane, dimethyldifluorosilane, methylchlorosilane, methylbromosilane, methylfluorosilane, dimethylchlorosilane, dimethylbromosilane, dimethylfluorosilane, trimethyl Hydrolyzable silanes such as chlorosilane, trimethylbromosilane, and trimethylfluorosilane.
(2) 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriacetoxysilane, 3-acryloxypropyltris (trichloroacetoxy) silane, 3-acryloxypropyltris (trifluoroacetoxy) silane, 3-methacryloxypropyltriacetoxy Silane, 3-methacryloxypropyltris (trichloroacetoxy) silane, 3-methacryloxypropyltris (trifluoroacetoxy) silane, 3-glycidoxypropyltriacetoxysila 3-glycidoxypropyltris (trichloroacetoxy) silane, 3-glycidoxypropyltris (trifluoroacetoxy) silane, 3-acryloxypropyltrichlorosilane, 3-acryloxypropyltribromosilane, 3-acryloxypropyl Trifluorosilane, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropyltribromosilane, 3-methacryloxypropyltrifluorosilane, 3-glycidoxypropyltrichlorosilane, 3-glycidoxypropyltribromosilane, A reactive silane compound having both a polymerizable functional group and a functional group capable of forming a covalent bond with silica particles in the same molecule, such as 3-glycidoxypropyltrifluorosilane.

(3) Silicic acid, trimethylsilanol, triphenylsilanol, dimethylsilanediol, diphenylsilanediol, silanol terminated polydimethylsiloxane, silanol terminated polydiphenylsiloxane, silanol terminated polymethylphenylsiloxane, silanol terminated polymethyl ladder siloxane, silanol terminated poly Silicon compounds containing silanol groups such as phenyl ladder siloxane and octahydroxy octasilsesquioxane.
(4) Water glass, sodium orthosilicate, potassium orthosilicate, lithium orthosilicate, sodium metasilicate, potassium metasilicate, lithium metasilicate, tetramethylammonium orthosilicate, tetrapropylammonium orthosilicate, tetramethylammonium metasilicate, metasilicate Active silica obtained by bringing a silicate such as tetrapropylammonium into contact with an acid or ion exchange resin.
(5) Polyethers such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, polyacrylamide derivatives, polymethacrylamide derivatives, amides such as poly (N-vinylpyrrolidone) and poly (N-acylethyleneimine), polyvinyl Organic polymers such as alcohols, polyvinyl acetate, polyacrylic acid derivatives, polymethacrylic acid derivatives, esters such as polycaprolactone, polyimides, polyurethanes, polyureas, and polycarbonates. These organic polymers may have a polymerizable functional group at the terminal or main chain.

(6) alkyl (meth) acrylate, alkylene bis (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, Polymerized acrylic monomers such as dipentaerythritol hexa (meth) acrylate. Polymerizable monomers such as alkylene bisglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol triglycidyl ether, pentaerythritol tetraglycidyl ether, vinylcyclohexene diepoxide. Here, (meth) acrylate refers to both acrylate and methacrylate. These are polymers.
(7) Curable resin. For example, (meth) acrylic UV curable resin, moisture curable silicone resin, thermosetting silicone resin, epoxy resin, phenoxy resin, novolac resin, silicone acrylate resin, melamine resin, phenol resin, unsaturated polyester resin , Polyimide resin, urethane resin, urea resin and the like.

(8) The alkyl groups and hydrogen groups in the above (1) to (7) can be substituted with fluorine. Those substituted with fluorine have a low refractive index and excellent optical performance. However, since it may be mechanically weak alone, it can be used by mixing with inorganic fine particles.
The binder may be used alone or in combination. In particular, a reactive silane compound having both a polymerizable functional group and a functional group capable of forming a covalent bond with a silica particle in the same molecule listed in (2), a polymerizable monomer listed in (6), or The combined use of the fluorine-substituted products (2) and (6) is effective in improving the mechanical strength.

The kind of the polymerizable monomer is appropriately selected according to the form and speed of the reaction. When using a polymerizable monomer or one having a functional group, it is effective to add a polymerization initiator as an additive. As the polymerization initiator, a known one such as a thermal radical generator, a photo radical generator, a thermal acid generator, or a photo acid generator can be selected according to the reaction mode of the above polymerizable functional group or polymerizable monomer. it can.
Specific examples of the heat / photo radical generator include Irgacure (registered trademark) and Darocur (registered trademark) acetophenone-based, benzophenone-based, phosphine oxide-based, and titanocene-based commercially available from Ciba Specialty Chemicals Co., Ltd. Each polymerization initiator, a thioxanthone polymerization initiator, a diazo polymerization initiator, an o-acyloxime polymerization initiator, and the like can be mentioned. Among these, polymerization initiators having an amino group and / or a morpholino group in the molecule such as Irgacure (registered trademark) 907, Irgacure (registered trademark) 369, and Irgacure (registered trademark) 379 are particularly preferable. Specific examples of the heat / photoacid generator include Sun Aid (trademark) SI series commercially available from Sanshin Chemical Industry Co., Ltd., WPI series, WPAG series, and Sigma Aldrich commercially available from Wako Pure Chemical Industries, Ltd. Examples thereof include sulfonium-based, iodonium-based, and diazomethane-based polymerization initiators represented by the PAGs series commercially available from Japan Corporation.

The silanes represented by (1) and (2) are preferably used after partial hydrolysis / dehydration condensation. Partial hydrolysis and dehydration condensation reactions are carried out by reacting hydrolyzable silane with water, but as catalysts, acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, formic acid, acetic acid, ammonia, trialkylamine Alkalis such as sodium hydroxide, potassium hydroxide, choline and tetraalkylammonium hydroxide, and tin compounds such as dibutyltin dilaurate may be used. In that case, the hydrolysis / dehydration condensation reaction may be performed in the presence of silica fine particles or hollow silica fine particles.
From the viewpoint of mechanical strength and antireflection performance of the low refractive index layer, the amount of the binder is preferably 0.5 or more and 5.0 or less in a weight ratio when the combined weight of the silica fine particles and the hollow silica fine particles is 1. .

The binder itself preferably has a refractive index of 1.3 to 1.55. By using a material having a relatively low refractive index, an antireflection layer having a very low refractive index can be obtained.
In the low refractive index layer, various additives such as an antistatic agent, an ultraviolet absorber, an infrared absorber, a leveling agent, a dye, a metal salt, a surfactant, and a release agent are added within a range that does not impair the gist of the present invention. It can also be included.
The thickness of the low refractive index layer is 50 to 300 nm, but from the viewpoint of antireflection performance in the visible light region, it is usually preferable that the minimum reflectance wavelength at an incident angle of 5 degrees is in the range of 500 to 750 nm. . The refractive index of the low refractive index layer is preferably controlled by controlling the amount of silica fine particles, the amount of hollow silica fine particles, and the amount of binder so that the minimum reflectance at an incident angle of 5 degrees is 2% or less.

  In the present invention, the surface of silica fine particles or hollow silica fine particles is preferably treated with a reactive silane compound. A reactive silane compound is a compound having both a polymerizable functional group and a functional group capable of forming a covalent bond with a silica particle in the same molecule. By treating with this compound, silica fine particles and Since the surface of the hollow silica fine particles and the reactive silane compound are covalently bonded and a reaction with the binder occurs, the adhesion between the silica fine particles or the hollow silica fine particles and the binder can be improved. Moreover, since the surface slipperiness of silica fine particles or hollow silica fine particles can be improved, an antireflection film having high pencil hardness can be obtained. The polymerizable functional group is not particularly limited, and examples thereof include an unsaturated double bond such as a vinyl group, an acryl group, and a methacryl group, an epoxy group, and a hydroxyl group. .

As the reactive silane compound having both a polymerizable functional group and a functional group capable of forming a covalent bond in the same molecule, those described in (2) which can also be used as a binder for an antireflection layer, or these In which an alkyl group or a hydrogen group is substituted with fluorine. Specific examples include the following.
For example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3 -Methacryloxypropyltriethoxysilane, 3-acryloxypropyltriacetoxysilane, 3-acryloxypropyltris (trichloroacetoxy) silane, 3-acryloxypropyltris (trifluoroacetoxy) silane, 3-methacryloxypropyltriacetoxysilane 3-methacryloxypropyltris (trichloroacetoxy) silane, 3-methacryloxypropyltris (trifluoroacetoxy) silane, 3-glycidoxypropyltriacetoxy 3-glycidoxypropyltris (trichloroacetoxy) silane, 3-glycidoxypropyltris (trifluoroacetoxy) silane, 3-acryloxypropyltrichlorosilane, 3-acryloxypropyltribromosilane, 3-acryloxy Propyltrifluorosilane, 3-methacryloxypropyltrichlorosilane, 3-methacryloxypropyltribromosilane, 3-methacryloxypropyltrifluorosilane, 3-glycidoxypropyltrichlorosilane, 3-glycidoxypropyltribromosilane , Compounds such as 3-glycidoxypropyl trifluorosilane, those in which these alkyl groups and hydrogen groups are substituted with fluorine, and those obtained by reaction thereof.

As a method for treating the surface of silica fine particles or hollow silica fine particles with a reactive silane compound, it is preferable to use a functional group that forms a covalent bond with the silica particles of the reactive silane compound by partial hydrolysis and dehydration condensation. Partial hydrolysis and dehydration condensation reactions are carried out by reacting hydrolyzable silane with water, but as catalysts, acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, formic acid, acetic acid, ammonia, trialkylamine Alkalis such as sodium hydroxide, potassium hydroxide, choline and tetraalkylammonium hydroxide, and tin compounds such as dibutyltin dilaurate may be used.
The surface of silica fine particles or hollow silica fine particles often has 0.1 to 100 OH groups per 1 nm ² , and ^1/2 of the surface of silica fine particles or hollow silica fine particles in the treatment with a reactive silane compound. It is a preferred embodiment that 20 or more OH group-corresponding portions are reacted with the reactive silane compound, and further, a treatment in combination with fluoroalkyl (trialkoxy) silane is also a preferred embodiment. The treatment with fluoroalkyl (trialkoxy) silane may be performed in the presence of silica fine particles, hollow silica fine particles and a reactive silane compound, or may be performed separately.

As fluoroalkyl (trialkoxy) silane, for example,
_{CF 3 (CF 2) xCH 2} CH 2 Si (OR) 3
_{R: -CH 3, -C 2 H} 5, - alkyl group such as Iropuropiru group x: it is possible to use an integer of 1-10. In the treatment with the fluoroalkyl (trialkoxy) silane, it is preferable to react and bond more than 1/20 or more of the surface of the silica fine particles or hollow silica fine particles corresponding to the OH group. Thereby, the abrasion resistance of the antireflection layer can be further improved, the antifouling property of the surface can be improved, and the fingerprint wiping property can be improved.

From the viewpoint of reactivity of fluoroalkyl (trialkoxy) silane with silica fine particles and hollow silica fine particles, R: —CH ₃ is preferable, and x is preferably 3 to 7.
As a method of reacting a reactive silane compound and fluoroalkyl (trialkoxy) silane with silica fine particles or hollow silica fine particles, a reactive silane compound and fluoroalkyl (trialkoxy) silane are dispersed in a dispersion of silica fine particles or hollow silica fine particles. As a catalyst, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, formic acid, acetic acid and other acids, ammonia, trialkylamine, sodium hydroxide, potassium hydroxide, choline, tetraalkylammonium hydroxide, etc. The reaction can be carried out by adding a tin compound such as dibutyltin dilaurate and adjusting the appropriate temperature and time. In addition, by setting the total number of moles of the reactive silane compound and fluoroalkyl (trialkoxy) silane to be approximately equivalent to the total amount of surface OH groups, the silica particles of the reactive silane compound and fluoroalkyl (trialkoxy) silane It is possible to correspond to the quantity ratio on the surface of the hollow silica fine particles. The ratio of the reactive silane compound and the fluoroalkyl (trialkoxy) silane is preferably used in a weight ratio of 10: 1 to 1:10.

  The antireflection film of the present invention can have a configuration in which the antireflection layer comprises a hard coat layer, a high refractive index layer, and a low refractive index layer. As a configuration in this case, a configuration of transparent film / hard coat layer / high refractive index layer / low refractive index layer can be employed. The high refractive index layer is a layer having a refractive index higher than that of the low refractive index layer at 550 nm, and a layer having a refractive index difference of 0.10 or more, particularly 0.2 or more is preferably used. An antistatic function can be imparted to the high refractive index layer. As the high refractive index layer, for example, known inorganic fine particles such as oxides or composite oxides made of metals such as titanium, zirconium, zinc, antimony, indium, tin, cerium, tantalum, yttrium, hafnium, aluminum, and magnesium, Those dispersed in a binder are used. When a high refractive index layer is provided, it is preferably used to set the thickness to 50 nm to 250 nm. By providing a high refractive index layer, the minimum reflectance can be kept low.

As the layer structure of antireflection fill beam of the present invention, the structure of the transparent film / antistatic layer / hardcoat layer / low refractive index layer is one of the preferred embodiments. As the antistatic layer, a layer structure in which the function is imparted to the hard coat layer or an antistatic layer is provided between the transparent film and the hard coat layer is preferably used. As the antistatic layer, a known antistatic agent such as a surfactant or an ionic polymer or a conductive fine particle dispersed in a binder is used. Examples of the conductive fine particles include oxide or composite oxide fine particles such as indium, zinc, tin, molybdenum, antimony, and gallium, copper, silver, nickel, low melting point alloy (solder, etc.) metal fine particles, and a metal-coated polymer. Known materials such as fine particles, various kinds of carbon black, conductive polymer particles such as polypyrrole and polyaniline, metal fibers, and carbon fibers can be used. Among these, ITO (tin-containing indium oxide) particles, ATO (tin-containing antimony oxide) particles, and antimony pentoxide particles are particularly preferable because they can exhibit high transparency and conductivity.

The surface resistance of the antireflection film of the present invention is preferably 10 ⁶ Ω / □ to 10 ¹⁸ Ω / □. By reducing the surface resistivity, adhesion of dust and the like can be suppressed, and the yield when incorporated in a display or the like can be improved. Such surface resistance can be achieved by providing the layer constituting the antistatic function described so far.
The haze value of the antireflection film of the present invention is 0.5 to 5.0%. By setting the content to 0.5 to 5.0%, excellent transmission characteristics are exhibited. Of these, a haze value of 1.0 to 3.0% is preferably used. As described above, since the antireflection film has a very small haze value, a transmitted image can be clearly expressed. On the other hand, it is difficult to make the haze value less than 1%, and in order to obtain a haze value less than 0.5%, the reflection characteristics due to surface irregularities are sacrificed. Since the antireflection film of the present invention does not perform unevenness control due to aggregation of fine particles, etc., it is also possible to suppress internal scattering due to aggregation of fine particles, etc., and transmission characteristics as compared with a system using an aggregation structure of fine particles Is excellent.

The total light transmittance of the antireflection film of the present invention is preferably 88% or more. Of these, 90% or more is more preferably used. If it is less than 88%, the transmitted image tends to be blurred. Furthermore, it is not preferable because the luminance of the transmitted image is lowered.
The antireflection film of the present invention preferably has the following characteristics in image sharpness defined in JIS K-7105. Of the optical combs of the Suga Test Machine ICM-1T, it is preferable that the narrower the comb width is, the lower the sharpness is, and the wider the comb width is, the higher the sharpness is. Optical comb widths of 2 mm, 1 mm, 0.5 mm, 0.25 mm, and 0.125 mm are prepared. When the light is vertically transmitted through the antireflection film, the comb width is 0.5 mm. The degree is preferably 50% or less, and the sharpness at a comb width of 2 mm is preferably 50% or more. Particularly, those having a sharpness of 40% or less at a comb width of 0.5 mm are preferably used. In the PDP, the external light passes through the front filter, reflects on the back surface of the filter and the surface of the PDP module, and then passes through the filter again to be seen by human eyes. For this reason, it was found that the transmission characteristics also affect the reflection. Further, it is preferable to balance the clearness of the transmitted image and the prevention of the reflection, and it is most preferable to use the one having a sharpness of 10 to 40% at a comb width of 0.5 mm and a sharpness of 70 to 95% at a comb width of 2 mm. Can do. This characteristic can be controlled by controlling the uneven shape of the antireflection film. By controlling the period and height in an area where the surface irregularity period is large, it is possible to control an area where the optical comb width is narrow. On the other hand, a region having a wide comb width can be controlled by a region having a small uneven period. The sharpness can be controlled by controlling the period of each region and the height and frequency of the unevenness.

  In the present invention, the unevenness of the antireflection film side surface of the antireflection film is formed by transfer. The formation of irregularities by transfer refers to copying the shape from a mold having an irregular shape onto a film. As the mold having an uneven shape, various shapes such as a roll shape, a plate shape, and a continuous film shape can be used, and particularly a seamless roll shape and a film shape are preferably used. It is done. Various materials such as metal, glass, ceramic, and resin can be used as the material. These are variously selected depending on the transfer method. The formation of the concavo-convex shape on the mold can be performed by various methods such as precision machining, precision laser machining, electron beam machining (EB drawing), light exposure, and interference exposure. These may impart irregularities directly to the mold, or may be finally imparted to the mold by transferring irregularities several times after imparting irregularities to another material. The shape of the unevenness is maintained by one transfer, and the retention rate is preferably 65% or more, particularly 90% or more. Here, the retention rate means the reproduction rate of the height of the unevenness. The uneven shape of the mold is formed and adjusted so that the preferable unevenness of the antireflection film can be formed in consideration of the retention rate by transfer.

  In the present invention, the unevenness on the antireflection film side surface of the antireflection film preferably has an irregular arrangement, and in this case, the unevenness of the mold used for transfer also has an irregular arrangement. The irregular irregularities can be obtained by various methods, and those by interference exposure are most preferably used. Irregularities of irregularities due to interference exposure do not cause moiré when used as a display, and the film with irregularities controlled by interference exposure can realize clearness of transmitted light in a PDP with a wide viewing angle, and external light And a fluorescent lamp with little reflection, and a single color with little glare can be obtained. It is presumed that there is a difference in shape distribution that cannot be achieved by the control of unevenness using ordinary fine particles. Such a shape can be formed by precision machining or the like. However, in order to perform irregular shapes by precision machining, it is necessary to devise to input the machining program. In that case, a method of copying the shape by interference exposure, a method of processing a mixture of random particles of 30 μm to 300 μm, and the like can be used, and in particular, the uneven component having a long period exceeding 300 μm is reduced. It is preferable to form irregularities on the surface.

  Concavity and convexity formation by interference exposure means that irregular speckles are generated when coherent light diffused at each point on the surface of the diffuser that is exposed to light interferes with an irregular phase relationship. It means that irregularities are formed by exposing and developing a material. For example, Japanese Patent Application Publication No. 2004-508585 describes a method for producing a seamless master by interference exposure. The pitch and height of the unevenness can be adjusted by adjusting the type and distance of the light source, objective lens, diffuser, light shielding adjustment window, photosensitive material, and the like. The height of the unevenness can also be adjusted by adjusting conditions such as exposure time.

  As a method for forming irregularities by transfer, after coating a resin on a mold having an irregular shape, it is cured or semi-cured and then peeled off from the mold, and the shape is copied to the resin. After coating the resin on the transparent film Various methods can be used such as a method in which the shape is cured or semi-cured as it is together with the mold and then peeled off from the mold and the shape is copied to a resin, and a method in which a heated mold is pressed against the resin and the unevenness is copied by the pressure. As a curing method, depending on the resin used, curing by heat, curing means by electron beam or ultraviolet rays can be performed. In addition, when it peels from a type | mold in a semi-hardened state, it can be hardened further after peeling. In this case, the curing means may be a method different from the semi-curing means. When the resin with the uneven shape copied from the mold is peeled off, a mold release agent can be added to the resin to remove the resin from the mold without any defects, and a fluorine compound is applied to the mold surface. Thus, a method of facilitating release by forming a thin film can be performed. As a method for transferring the unevenness, for example, a method described in Japanese Patent Laid-Open Publication No. 2001-511725, Japanese Patent Application Laid-Open No. 2005-10231, Japanese Patent Application Laid-Open No. 2005-10230, or the like can be used.

  For example, when a hard coat layer is applied on a transparent film, a composition in which a release agent or an additive is added to the hard coat material as necessary is transparent as a coating solution using a solvent if necessary. Apply film to film. As the solvent, various solvents may be used to adjust the coating solution viscosity of the hard coat material, and water, methanol, ethanol, isopropanol, butanol, benzyl alcohol and other alcohols, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone. Ketones such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate, aliphatic hydrocarbons such as hexane, cyclohexane, methylene chloride, chloroform, Halogenated hydrocarbons such as carbon chloride, aromatic hydrocarbons such as benzene, toluene, xylene, amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, diethyl ether, dioxane, tetrahydrofuran Solvents of ethers such as ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, preferably toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol can be used. . After applying the hard coat material to the transparent film, if a solvent is used, remove the solvent by heating to 50 to 150 ° C. It can be semi-cured.

In the case of heating, a roll having a concavo-convex shape that has been heated in advance can be used. The cured state can be controlled by controlling the roll temperature and the contact time of the film. In the case of irradiating ultraviolet rays, the film can be cured or semi-cured by irradiating the ultraviolet rays from the transparent film side in a state where the film is wound around a roll having an uneven shape. The cured or semi-cured resin can be peeled from the mold to form a hard coat layer having an uneven shape. Here, in the case of semi-curing, it can be further cured by irradiation with heat or ultraviolet rays.
Application of the coating solution is a known method such as dipping, spin coater, knife coater, bar coater, blade coater, squeeze coater, reverse roll coater, gravure roll coater, slide coater, curtain coater, spray coater, die coater, cap coater, etc. Can be implemented. Of these, knife coaters, bar coaters, blade coaters, squeeze coaters, reverse roll coaters, gravure roll coaters, slide coaters, curtain coaters, spray coaters, die coaters and cap coaters that can be continuously applied are preferably used.

As a method for forming the low refractive index layer on the hard coat layer having an uneven shape, an evaporation method, a sputtering method, a plasma CVD method, a solution coating method, or the like can be used. As a method of coating the solution, for example, it can be obtained by applying and curing the hard coat layer in a state where silica fine particles, a binder, an additive and the like are dispersed in an appropriate dispersion medium. The dispersion medium to be used is not limited as long as silica fine particles, binders, additives and the like are substantially stably dispersed.
Specific examples of the dispersion medium include water, monohydric alcohols having 1 to 6 carbon atoms, dihydric alcohols having 1 to 6 carbon atoms, alcohols such as glycerin, formamide, N-methylformamide, N-ethylformamide, N , N-dimethylformamide, N, N-diethylformamide, N-methylacetamide, N-ethylacetamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methylpyrrolidone and other amides, tetrahydrofuran, diethyl ether , Ethers such as di (n-propyl) ether, diisopropyl ether, diglyme, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol dimethyl ether, ethylene glycol monomethyl ether Teranol, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monobutyl ether and other alkanol ethers, ethyl formate, acetic acid Methyl, ethyl acetate, ethyl lactate, ethylene glycol monomethyl ether acetate, ethylene glycol diacetate, propylene glycol monomethyl ether acetate, diethyl carbonate, ethylene carbonate, propylene carbonate, γ-butyrolactone, ethyl acetoacetate esters, acetone, methyl ethyl ketone, Methyl propyl ketone, methyl (n-butyl) ketone , Ketones such as methyl isobutyl ketone, methyl amyl ketone, acetylacetone, cyclopentanone and cyclohexanone, nitriles such as acetonitrile, propionitrile, n-butyronitrile and isobutyronitrile, dimethyl sulfoxide, dimethyl sulfone and sulfolane are suitable. Used for.

  More preferable dispersion media are monohydric alcohols having 1 to 6 carbon atoms, and ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monopropyl ether, propylene glycol monopropyl Ethers, alkanol ethers such as ethylene glycol monobutyl ether, propylene glycol monobutyl ether, acetone, methyl ethyl ketone, methyl propyl ketone, methyl (n-butyl) ketone, methyl isobutyl ketone, methyl amyl ketone, acetylacetone, cyclopentanone, cyclohexanone, etc. Ketones.

These dispersion media may be mixed or any other solvent or additive may be mixed as long as the object of the present invention is not impaired.
In applying the above dispersion to the hard coat layer, it is also effective to add a known leveling agent or a binding aid (coupling agent) in order to enhance the coating performance and the adhesion to the substrate.
The method for producing the low refractive index layer is, when applied using a coating composition, the content of inorganic particles such as silica fine particles, the concentration of the coating liquid, the types of binders and additives and their concentrations, the coating method, and the coating. It can be manufactured by controlling conditions and the like.

The concentration of the coating solution is, for example, 0.1 to 20 parts by weight as a reactive silane compound and 0.1 to 20 parts by weight of fluoroalkyl (trialkoxy) silane when the solid content of the hollow silica fine particles is 100 parts by weight. It is a preferable embodiment to adjust the content of the binder and the binder component in the range of 50 to 500 parts by weight.
Application of the coating composition is a known dipping, spin coater, knife coater, bar coater, blade coater, squeeze coater, reverse roll coater, gravure roll coater, slide coater, curtain coater, spray coater, die coater, cap coater, etc. It can be implemented using a method. Of these, knife coaters, bar coaters, blade coaters, squeeze coaters, reverse roll coaters, gravure roll coaters, slide coaters, curtain coaters, spray coaters, die coaters and cap coaters that can be continuously applied are preferably used.

After applying the above coating composition, it is effective to heat in order to volatilize the dispersion medium and to condense and crosslink the reactive silane compound and binder component. The heating temperature and time are determined by the heat resistance of the transparent film. For example, the heating temperature is selected from 50 ° C. to 200 ° C., and the time is selected from 1 second to 1 hour, preferably in the range of 80 ° C. to 150 ° C. and 5 seconds to 3 minutes. Moreover, when the said binder has radiation curability, an ultraviolet-ray, an electron beam, etc. are irradiated by a well-known method.
The antireflection film of the present invention can impart the antireflection function of the display device by sticking it to glass or the like on the surface of the display device using an adhesive. In the case of PDP, the pressure-sensitive adhesive can contain a neon-color-cutting dye, a near-infrared-cutting dye, an ultraviolet-cutting dye, a color-tone-adjusting dye, and the like.

The antireflection film of the present invention may be provided with a coating layer on the outermost surface in order to impart slipperiness or antifouling property to the surface. The coating layer is, for example, a fluororesin, a moisture curable silicone resin, a thermosetting silicone resin, silicon dioxide, a (meth) acrylic resin, a (meth) acrylic UV curable resin, an epoxy resin, a phenoxy resin, a novolac resin, It is made of any known material such as silicone acrylate resin, melamine resin, phenol resin, unsaturated polyester resin, polyimide resin, urethane resin, urea resin.
The film thickness of the coating layer is usually 50 nm or less, preferably 10 nm or less. The coating layer may be composed of a single layer or a plurality of layers. Among these, a fluororesin, a moisture curable silicone resin, and a thermosetting silicone resin are preferable in order to exhibit an antifouling effect.

The antireflection film of the present invention can be preferably used particularly on the outermost surface of the optical filter of the PDP. Other examples include an organic / inorganic EL display, a TV cathode ray tube, a notebook computer, an electronic notebook, a touch panel, a liquid crystal television, a liquid crystal display, In-vehicle TV, LCD video, projection TV, plasma addressed LCD, field emission display, LED display, optical fiber, optical information, etc .; household goods such as lighting glove, fluorescent lamp, mirror, watch; show Cases, forehead, semiconductor lithography, photocopying equipment, etc .; for use in a wide range of applications that require improved prevention of reflections in liquid crystal game equipment, pachinko machine glass, game machines, etc. Can do.
Hereinafter, examples will be described in order to further clarify the present invention.

[Various measurement methods]
Minimum reflectivity and minimum reflectivity wavelength at 5 ° firing angle;
In order to cut the reflected light on the back of the glass plate by attaching an antireflection film (transparent film side) to the glass plate (NA Techno Glass, NA35, 0.70 mmt, for TFT) using an acrylic optical adhesive. The back side was roughed with sandpaper and then painted with black ink. Then, using a spectrophotometer UV-2450 / MPC2200 type 5 ° absolute reflectance measuring device (manufactured by Shimadzu Corporation), the reflectance spectrum in the wavelength range of 300 nm to 800 nm is measured at 0.5 nm intervals, and the lowest The reflectance was defined as the minimum reflectance, and the wavelength at that time was defined as the minimum reflectance wavelength.

Transmission image sharpness; Suga Test Instruments Co., Ltd.'s image clarity measuring instrument ICM-1T was used to set light to be transmitted vertically to the antireflection film. Of the optical combs of ICM-1T, 2 mm, 1 mm, 0 The transmitted image clarity was measured for four types of optical combs of 0.5 mm and 0.25 mm.
Center plane average roughness (SRa), average wavelength (Sλa);
A film was pasted on an optical flat (made of glass) having a thickness of 5 mm or more, and an area of 1 mm × 1 mm to 3 mm × 3 mm was measured using a surface shape measuring instrument “Surfcoder ET4000” manufactured by Kosaka Laboratory. The selection of the measurement area was measured at 3 mm × 3 mm when Sλa exceeded 200 μm, and the evaluation was performed at an area of 1 mm × 1 mm otherwise. The feed rate of the X axis was 0.2 mm / s, the Y pitch was 10 μm, and the raw data was leveled by the least square method, and the surface shape parameters were calculated without using a cut-off. As the software used, SRa and Sλa were calculated using ET4000 standard software “3-dimensional surface roughness analysis program TDA-22”.

(4) Mountain Particle Analysis Using the data measured by the above (3) center plane average roughness (SRa), mountain particle analysis was performed using a standard “three-dimensional surface roughness analysis program TDA-22”. In the mountain particle analysis, the slice level was set to SRa μm, and the cut area was evaluated by a histogram obtained by classifying every 100 μm ² .
(5) Pencil hardness: Using a test pencil specified in JIS S6006, the pencil hardness at a load of 500 g was evaluated according to the pencil hardness evaluation method specified in JIS K5400.
(6) Measurement of total light transmittance and haze: Using a turbidimeter (haze meter) NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd., it was measured by the method defined in JIS K7361-1.
(7) Measurement of surface resistivity; Super insulation meter SM-8210 manufactured by Toa DKK Corporation was used as a measuring device, and a plate sample electrode SME-883 was used as an electrode, and the surface resistivity was measured by a method prescribed in JIS K6911. . (20 ° C, 65RH%)

(8) PDP transmission image evaluation: An antireflection film was attached to the outer surface of a front plate filter of a PDP display device having a front filter using an optical acrylic pressure-sensitive adhesive. Then, an image was displayed on the PDP display device, and the transmission image was observed obliquely from 55 °, and visually judged according to the following criteria.
◎ ・ ・ ・ Transparent image looks completely clear ○ ・ ・ ・ Transparent image is clear, but slightly blurred compared to when viewed from the front △ ・ ・ ・ Transparent image is blurred × ・ ・ ・ Transparent image Blurred and unclear (9) PDP glare evaluation: An antireflection film was installed in the same manner as in the transmission image evaluation, and glare caused by luminance spots in a single green color was visually determined by a signal generator.
◎ ・ ・ ・ Glitter is hardly seen.
○ ・ ・ ・ Slight glare can be confirmed.
Δ: Glare can be confirmed, but this is not an issue with normal video.
× ・ ・ ・ The level of glare is so bad that even normal images can be clearly seen.
(10) Evaluation of PDP reflection characteristics: An antireflection film was attached to the outer surface of the front plate filter of a PDP display device having a front filter using an optical acrylic adhesive. The light of the fluorescent lamp was directly reflected on the side where the antireflection film was formed, and the image of the reflected fluorescent lamp image was visually determined according to the following criteria.
◎ ・ ・ ・ The image of the fluorescent light is blurred.
○ ・ ・ ・ The image of the fluorescent lamp is slightly blurred. Or the image looks blurry but bright.
Δ: The image of the fluorescent lamp is slightly clear, but there is almost no reflection of the surrounding scenery.
X: The image of the fluorescent lamp can be clearly recognized.

[Adjustment of coating solution]
(Hard coat layer coating solution HC-A)
75 parts by weight of A-DPH (dipentaerythritol hexaacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.), 25 parts by weight of UV curable hard coat paint HIC-G (manufactured by Kyoeisha Chemical Co., Ltd., UV curable resin), 50 parts by weight of methyl ethyl ketone It melt | dissolved in the mixed solution of 50 weight part of methyl isobutyl ketone. 3 parts by weight of “Irgacure (registered trademark) 184” as an initiator was added to the solution and dissolved.

(Hard coat layer coating solution HC-B)
75 parts by weight of A-DPH (dipentaerythritol hexaacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.), 25 parts by weight of UV curable hard coat paint HIC-G (manufactured by Kyoeisha Chemical Co., Ltd., UV curable resin), 50 parts by weight of methyl ethyl ketone It melt | dissolved in the mixed solution of 50 weight part of methyl isobutyl ketone. 3 parts by weight of “Irgacure (registered trademark) 184” as an initiator was added to the solution and dissolved. 20 parts by weight of IPA-ST-ZL (manufactured by Nissan Chemical Industries, Ltd., SiO ₂ , particle size 70-100 nm, 30 wt% isopropanol (hereinafter referred to as IPA) dispersion) was mixed, and 0% of sodium methoxide was mixed therewith. A 28 mol% solution was added dropwise while stirring 22 parts by weight. Thereafter, the mixture was stirred for 1 hour to prepare a hard coat layer coating solution HC-B.

(Low refractive index layer coating liquid LA)
As the hollow silica fine particles, an isopropanol (hereinafter referred to as IPA) dispersion having an average particle diameter of 60 nm, a refractive index of 1.30, and a solid content of 20 wt% was used as the hollow silica fine particles. To 100 parts by weight of this hollow silica / IPA dispersion, 50 parts by weight of a fluorine-based low refractive material (manufactured by JSR Corporation, Opstar TU2085, solid content 10.5 wt%) was added. Diluted with 283 parts by weight of propylene glycol monomethyl ether acetate / t-butanol = 25/75 (weight ratio) to prepare a low refractive index layer coating solution LA with a solid content of 3 wt%.

(Antistatic layer coating solution HA)
1 part by weight of dipentaerythritol hexamethacrylate and 20% by weight of ITO dispersion assistant (phosphate ester) with respect to 20 parts by weight of ethanol dispersion of ITO fine particles (“ELECOM V-2506” manufactured by Catalytic Chemical Industry Co., Ltd. 20.5 wt%) System) 0.1 parts by weight, 0.1 part by weight of “Irgacure (registered trademark) 184” as an initiator, these were mixed and dispersed in an ethanol solvent, and antistatic layer coating having a solid content concentration of 4 wt% was applied. Liquid HA was prepared.

[Adjust mold]
Five types of types A to D were prepared in accordance with the description in JP-T-2004-508585. For simple evaluation, these were not made into a roll shape, but a square plate-like nickel metal having a side of about 10 cm was used as a mold. The molds A to F were manufactured by changing the type and distance of the laser light source, objective lens, and photosensitive material. In particular, A to C and F were prepared by shortening the exposure time to the photosensitive material by about 1/2 to 1/20 as compared with C and D, and having low unevenness. After applying a fluorine-based surface treatment agent (“Novec EGC-1720” fluorine-based treatment agent concentration of about 0.1 wt%, manufactured by Sumitomo 3M Co.) as mold release treatment to the uneven surfaces of the produced molds A to F, 120 ° C. And dried for 3 minutes. The coating thickness was adjusted so that the thickness after drying was about 5 nm.

[Example 1]
(Formation of antistatic layer)
As a transparent film, an optical PET film U46 (thickness: 100 μm) manufactured by Toray Industries, Inc. was used, and “antistatic layer coating solution HA” was applied thereto using a bar coater, and then at 60 ° C. for 2 minutes. After drying, using an UV exposure apparatus (H bulb) manufactured by Fusion UV Systems Japan Co., Ltd., it was cured at an illuminance of 2600 mW / cm ² and a light amount of 500 mJ / cm ² to obtain an antistatic layer. The thickness of the antistatic layer was about 150 nm.

(Preparation of hard coat layer)
The obtained film was coated with “Hard Coat Layer Coating Liquid HC-A” using a bar coater so that the thickness after drying was about 5 μm. The film after coating with a bar coater was dried at 80 ° C. for 3 minutes to obtain a state before forming irregularities.

(Transfer of irregularities to the hard coat layer)
The dried hard coat layer side and the mold A were pasted so that air did not enter, and the PET film surface was lightly smoothed with a roller. Thereafter, UV was irradiated from the PET side using a UV exposure apparatus (H bulb) manufactured by Fusion UV Systems Japan Co., Ltd. and irradiated with UV having an illuminance of 2600 mW / cm ² and a light amount of 750 mJ / cm ² . The hard coat layer and the mold A were slowly peeled off, and a hard coat layer with concavo-convex transferred onto the PET film and the antistatic layer could be obtained. This film was further irradiated with UV at 500 mJ / cm ² from the hard coat layer side using the same UV apparatus as described above to promote curing.

(Evaluation of antireflection film)
The obtained antireflection film (PET film / antistatic layer / hard coat layer with irregularities) was evaluated by the methods described in “Various measurement methods”, and the results are summarized in Table 1.
When the surface shape of the mold A used was measured in the same manner as the antireflection film, the transfer rate was 96%, and the unevenness of the antireflection film was slightly smaller, but the shape was almost the same as the mold. I found out.

[Example 2]
(Formation of a low refractive index layer)
The film obtained in Example 1 was coated with “low refractive index layer coating liquid LA” using a bar coater. Then, after drying at 120 ° C. for 1 minute, using a UV exposure apparatus (H bulb) manufactured by Fusion UV Systems Japan Co., Ltd., it is cured at an oxygen concentration of 100 ppm or less, an illuminance of 2600 mW / cm ² , and a light intensity of 1500 mJ / cm ^2. A low refractive index layer having a thickness of about 50 to 150 nm was formed to obtain an antireflection film composed of PET film / antistatic layer / hard coat layer with irregularities / low refractive index layer.

(Evaluation of antireflection film)
The obtained antireflection film was evaluated by the methods described in “Various measurement methods”. The results from this evaluation method are summarized in Table 1.
In the 1 mm × 1 mm shape measurement using ET4000, the surface shape showed no significant difference between Example 1 and Example 2.

[Examples 3-4, Comparative Examples 1-3]
After carrying out similarly to Example 1 until drying of an antistatic layer and a hard-coat layer, it transferred by changing the type | mold used for the transfer of the unevenness | corrugation to a hard-coat layer variously. The transfer method was the same as in Example 1. Thereafter, the low refractive index layer was formed in the same manner as in Example 2 to obtain various antireflection films.
The obtained antireflection film was evaluated in the same manner as in Example 2, and the results are summarized in Table 1.

[Comparative Example 4]
An antistatic layer was formed on the PET film in the same manner as in Example 1. Thereafter, the “hard coat layer coating solution HC-B” was applied using a bar coater so that the thickness after drying was about 5 μm. The film after coating with a bar coater is dried at 80 ° C. for 3 minutes, and the illuminance is 2600 mW / cm ² and the light intensity is 750 mJ / from the hard coat layer side using a UV exposure apparatus (H bulb) manufactured by Fusion UV Systems Japan. cm ² UV was irradiated. The obtained film had irregularities on the surface due to fine silica aggregation.
On this hard coat layer, a low refractive index layer was applied in the same manner as in Example 2 to obtain an antireflection film comprising PET film / antistatic layer / hard coat layer with unevenness / low refractive index.
The obtained antireflection film was evaluated in the same manner as in Example 2, and the results are summarized in Table 1.
Further, when a cross section of the obtained film was observed with an electron microscope, silica fine particles were aggregated, and formation of protrusions due to aggregation was observed. Moreover, when the surface distribution of Si by EDX on the surface of the antireflection layer side of the film obtained in Comparative Example 3 was measured, it was found that it corresponded well with the surface shape.

The antireflective film of the present invention has a wide viewing angle as a transmission characteristic, is hardly reflected, has an excellent balance with very little glare, and can be used as an antireflective film on the surface of various displays. Be expected. In particular, the properties of PDP as an antireflection film are also excellent and are expected to be used.

Claims (4)

An antireflection film comprising an antireflection layer formed on the transparent film and the transparent film, the antireflection layer side outermost surface of the antireflection film, the average wavelength (S [lambda]) 50 to 300 [mu] m, the center plane average roughness (SRa) is represented by the following formula (1), and has an unevenness with a cut area of 0 to 100 μm ² sliced by SRa having 50 or less protrusions in the range of 1 mm × 1 mm, and the unevenness is formed by transfer An antireflection film characterized by being made.
0.1 + 0.00065 × Sλa <SRa <0.003 × Sλa Formula (1)   2. The antireflection film according to claim 1, wherein the unevenness has an irregular arrangement.   The antireflection film according to claim 1, wherein the irregularities are transferred based on the irregularities formed by interference exposure.   2. The antireflection film according to claim 1, wherein the antireflection layer comprises a hard coat layer and a low refractive index layer.