JP2004160736A - Antireflection film, optical element and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film having an antireflection layer formed to have a good stain resistance (particularly dust wiping property). <P>SOLUTION: This antireflection film includes a hard coating layer provided directly on or via the other layer on one surface of a transparent substrate, the antireflection layer laminated on the front surface of the coating layer. The antireflection film is a dry cured film formed of at least two types of low refractive index materials each of which satisfies a refractive index:n<SB>d</SB><SP>20</SP>≤1.49 of a material (A) containing a polysiloxane structure as a main component and a material (B) containing a fluorine-containing material as a main component in such a manner that an amount of tribocharging (A) generated when the surface of the antireflection layer is rubbed with steep wool is -1 to +2 kV. <P>COPYRIGHT: (C)2004,JPO

Description

上記、結果に示すとおり実施例の反射防止機能付き偏光板は、コロナ処理をしなくても初期摩擦帯電量（Ａ）が、−１〜＋２ＫＶの範囲にあり、また摩擦帯電量（Ｂ）と初期摩擦帯電量（Ａ）との差（Ｂ−Ａ）が、±０．５ＫＶ以内であり使用環境が変わった場合にも良好な埃拭き取り性を有することが分かる。また良好な反射防止特性を有し、実用特性に優れるものであることが分かる。
【図面の簡単な説明】
【図１】本発明の反射防止フィルムの断面図の一例である。
【図２】本発明の反射防止フィルムの断面図の一例である。
【符号の説明】
１：透明基板
２：ハードコート層
３：反射防止層
４：微粒子[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an antireflection film used for suppressing a decrease in the visibility of a screen in an image display device such as a liquid crystal display (LCD), an organic EL display device, and a PDP, and a polarized light provided with the antireflection film. It relates to a plate, and furthermore to an optical element. The present invention also relates to an image display device provided with the antireflection film, the polarizing plate, or the optical element.
[0002]
[Prior art]
Liquid crystal panels are securing a solid position as displays through recent research and development. However, a monitor for a car navigation or a monitor for a video camera which is frequently used under bright illumination has a remarkable decrease in visibility due to surface reflection. For this reason, it is becoming indispensable to apply an antireflection treatment to a polarizing plate used for a liquid crystal panel, and most of the liquid crystal displays frequently used outdoors use a polarizing plate having an antireflection treatment.
[0003]
The anti-reflection treatment is generally performed by a dry treatment method such as a vacuum evaporation method, a sputtering method, and a CVD method to produce a multilayer laminate of a plurality of thin films made of materials having different refractive indices, thereby reducing reflection in a visible light region as much as possible. It is designed to make it work. However, vacuum equipment is required for forming a thin film by the above-mentioned dry processing, and the processing cost is extremely high. Therefore, recently, an antireflection film that has been subjected to an antireflection treatment by forming an antireflection film by wet coating has been manufactured. The structure of the antireflection film is usually composed of a transparent substrate serving as a substrate, a resin layer for imparting a hard coat property, and an antireflection layer having a low refractive index. In such an antireflection film, a high refractive index is required for the hard coat layer from the viewpoint of the reflectance, and a lower refractive index is required for the antireflection layer.
[0004]
As the low refractive index material for forming the anti-reflection layer, a fluorine-containing polymer or the like is used from the viewpoint of the refractive index and anti-staining property. Further, as a material satisfying a lower refractive index, a method of obtaining a low refractive index by a porous structure using a sol-gel reaction of alkoxysilane or organoalkoxysilane has been generally used. However, in the above-mentioned sol-gel reaction, if it is attempted to fire at a low temperature in order to control the reactivity to obtain a porous structure, it takes a long time to cure, and in a short time a sufficient scratch-resistant antireflection layer is required. Cannot be formed. In addition, the film surface obtained by the sol-gel reaction has a problem in terms of contamination.
[0005]
Further, it has been proposed to use a fluorine-containing compound having a polysiloxane structure for the antireflection layer (for example, see Patent Document 1). The formation of the anti-reflection layer by such a fluorine-containing compound is a uniform reaction, and is excellent in liquid stability and uniformity of the film after curing, and has a good degree of contamination. However, the above-mentioned fluorine-containing compound has a somewhat slow curing reaction rate, and it takes a long time to cure when firing at a low temperature. For example, when a triacetyl cellulose film, which is awarded as a protective film for a polarizing plate, is used as a transparent substrate and an antireflection layer of the fluorine-containing compound is formed thereon via a hard coat layer at a high temperature. If it is difficult to sinter at a temperature of about 100 ° C., a curing (aging) time of several days is required to obtain sufficient scratch resistance.
[0006]
Further, in order for the antireflection layer formed of the fluorine-containing compound to sufficiently exhibit contamination (particularly dust wiping properties), it was necessary to perform corona treatment or the like. Further, the antireflection layer formed by the fluorine-containing compound is easily affected by the use environment, and the contamination is reduced even when corona treatment or the like is performed. For example, it was difficult to wipe off dust during the dry season in winter.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-208898 (page 1-2)
[0008]
[Problems to be solved by the invention]
The present invention relates to an antireflection film in which a hard coat layer is provided and an antireflection layer having a low refractive index is laminated on the surface of the hard coat layer of a transparent substrate by coating, and has good stainability (particularly dust wiping properties). It is an object of the present invention to provide an antireflection film on which an antireflection layer is formed.
[0009]
Another object is to provide a polarizing plate provided with the antireflection film, and further to provide an optical element. Another object is to provide a display device on which the antireflection film, the polarizing plate, or the optical element is mounted.
[0010]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that the above object can be achieved by the following antireflection film, and have completed the present invention.
[0011]
That is, the present invention provides an anti-reflection film in which a hard coat layer is provided directly or via another layer on one surface of a transparent substrate, and an anti-reflection layer is further laminated on the surface of the hard coat layer.
The antireflection layer has a refractive index: n_d  ²⁰A dry cured film of (A) having a polysiloxane structure as a main component and (B) having a fluorine-containing material as a main component and formed of at least two kinds of low refractive index materials satisfying ≦ 1.49. ,
The present invention relates to an anti-reflection film, wherein a triboelectric charge (A) generated when the surface of the anti-reflection layer is rubbed with wool is -1 to +2 KV.
[0012]
The antireflection film of the present invention has an antifouling property improved by (B) containing the above-mentioned fluorine-containing material as a main component, and has an antireflection property and abrasion resistance obtained by (A) containing a polysiloxane structure as a main component. Can be compatible. As described above, the anti-reflection layer having good scratch resistance and stain resistance can be formed by the sol-gel coating material (coating liquid) of the type that controls the reactivity at the time of forming a thin film even when cured for a short time at a relatively low temperature. An antireflection film can be obtained with high productivity.
[0013]
Further, the adhesion between the low-refractive-index antireflection layer thus formed and the hard coat layer is improved as compared with an antireflection layer having (B) solely containing a fluorine-containing material as a main component. No peeling occurs at the interface between the hard coat layer and the antireflection layer in a reliability test or the like.
[0014]
Further, the triboelectric charge (A) generated when the surface of the antireflection layer is rubbed with wool is controlled to be -1 to +2 KV. If the triboelectric charge (A) is controlled within the above range, the antifouling property, particularly the dust wiping property, is good. It is preferable that the triboelectric charge (A) is controlled to be -0.8 to +1.8 KV. The measurement of the triboelectric charge (A) is described in detail in Examples.
[0015]
The antireflection film was left for 48 hours in an environment of 60 ° C. and 90% RH, dried at 80 ° C. for 10 minutes, and then rubbed on the surface with wool (B). The difference (BA) from the amount (A) is preferably within ± 0.5 KV.
[0016]
The antireflection film of the present invention has a small change in the triboelectric charge amount of within ± 0.5 KV even when placed in such a moist heat environment, and has little change in contamination over time. The difference (BA) is preferably as small as possible, and is preferably within ± 0.3 KV. The triboelectric charge (B) is measured by the same method as the triboelectric charge (A). Further, the triboelectric charge amount (B) is preferably in the range of -1 to +2 KV, more preferably -0.8 to +1.8 KV, similarly to the triboelectric charge amount (A).
[0017]
In order to control the antireflection layer so that the difference (BA) between the triboelectric charge amount (A) and the triboelectric charge amount (B) and the triboelectric charge amount (A) falls within the above range, it is necessary to use polysiloxane. A method of adjusting the content of (A) having a structure as a main component, and a method of adjusting the abundance ratio of fluorine groups on the outermost surface of the antireflection layer by performing a surface treatment such as corona treatment after forming the antireflection layer. It can be suitably adopted.
[0018]
In the antireflection film, (A) having the polysiloxane structure as a main component may have a solid content ratio of 10 to 80% by weight as a dry cured product in a dry cured film formed as an antireflection layer. preferable.
[0019]
The low-refractive-index material having the polysiloxane structure as a main component (A) has a high reactivity, and when used alone for forming an antireflection layer, it is easy to form a non-uniform film. Since it is formed densely, the value of the refractive index is also n_d  ²⁰(Refractive index at 20 ° C.) becomes about 1.45, and the reflectance (depending on the refractive index) increases. Therefore, in forming the anti-reflection layer, from the viewpoint of the balance between the reflectance, the adhesion to the hard coat layer, and the antifouling property (particularly, dust wiping property), the above-mentioned (A) having the polysiloxane structure as a main component is preferred. It is preferred that the solid content weight ratio be 10 to 80% by weight. The weight ratio of the solid content of (A) having the polysiloxane structure as a main component is more preferably 20% by weight or more from the viewpoint of adhesion to the hard coat layer. The denser the film is formed, and the higher the film strength is. On the other hand, considering the viewpoints of low reflection and antifouling properties (particularly dust wiping properties), the weight ratio of the solid content of (A) having the polysiloxane structure as a main component is preferably 80% by weight or less. It is more preferably at most 50% by weight, further preferably at most 40% by weight. The antireflection layer (low refractive index layer) preferably has a refractive index of generally 1.45 or less, more preferably 1.41 or less. Further, those having a reflectance of about 3% or less, more preferably 2.5% or less are suitable.
[0020]
In the antireflection film, the hard coat layer is formed of an ultraviolet curable resin, and n_d  ²⁰(Refractive index at 20 ° C.) is preferably 1.49 or more.
[0021]
The hard coat layer can be efficiently formed by a simple processing operation by a curing process using an ultraviolet curable resin. Further, the refractive index is n for a low refractive index antireflection layer._d  ²⁰(20 ° C. refractive index) is preferably 1.49 or more, more preferably 1.52 or more.
[0022]
In the antireflection film, the surface of the hard coat layer can have a smooth shape. Further, the antireflection film may have an antiglare property by making the surface of the hard coat layer uneven. By making the surface of the hard coat layer uneven, an antiglare film provided with light diffusing properties can be obtained.
[0023]
The present invention also relates to a polarizing plate, wherein the antireflection film is used as a protective film on one or both surfaces of a polarizer. The present invention also relates to a polarizing plate, wherein the polarizing plate and the antireflection film are laminated. The present invention also relates to an optical element, wherein the antireflection film or the polarizing plate is laminated on one or both sides of the optical element. The antireflection film of the present invention can be used for various applications, for example, used for optical elements. The polarizing plate laminated with the antireflection film of the present invention is excellent not only in the antireflection function but also in hard coat properties, scratch resistance, durability and the like.
[0024]
Furthermore, the present invention relates to an image display device using the antireflection film, the polarizing plate, or the optical element.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an antireflection film in which an antireflection layer 3 is laminated on a smooth surface of a hard coat layer 2 on a transparent substrate 1. FIG. 2 shows an antireflection film in which fine particles 4 are dispersed in the hard coat layer 2 and the surface of the hard coat layer 2 has an uneven shape. 1 and 2, the hard coat layer 2 is directly laminated on the transparent substrate 1. However, a plurality of hard coat layers 2 can be provided, and an easy adhesion layer, a conductive layer, Another layer such as a high refractive index layer provided from the viewpoint of reducing the reflectance can be formed.
[0026]
The transparent substrate 1 is not particularly limited as long as it has excellent visible light transmittance (light transmittance of 90% or more) and excellent transparency (haze value of 1% or less). Examples of the transparent substrate 1 include films made of transparent polymers such as polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, polycarbonate polymers, and acrylic polymers such as polymethyl methacrylate. Is raised. Styrene polymers such as polystyrene and acrylonitrile / styrene copolymer; polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure; olefin polymers such as ethylene / propylene copolymer; vinyl chloride polymers; nylon and aromatic polyamides And a film made of a transparent polymer such as an amide-based polymer. Furthermore, imide polymers, sulfone polymers, polyethersulfone polymers, polyetheretherketone polymers, polyphenylene sulfide polymers, vinyl alcohol polymers, vinylidene chloride polymers, vinyl butyral polymers, arylate polymers, polyoxymethylene polymers Films made of transparent polymers such as polymers, epoxy polymers and blends of the above polymers are also included. In particular, those having low optical birefringence are preferably used. From the viewpoint of a protective film for a polarizing plate, triacetyl cellulose, polycarbonate, an acrylic polymer, a cycloolefin resin, a polyolefin having a norbornene structure, and the like are preferable. The present invention is suitable for a transparent substrate, such as triacetyl cellulose, which is difficult to bake at a high temperature. At 130 ° C. or higher, the plasticizer in the film volatilizes at a temperature of 130 ° C. or more, and the properties of triacetyl cellulose are significantly reduced.
[0027]
Further, polymer films described in JP-A-2001-343529 (WO 01/37007), for example, (A) a thermoplastic resin having a substituted and / or unsubstituted imide group in the side chain, and (B) a thermoplastic resin having a side chain And / or an unsubstituted phenyl and a resin composition containing a thermoplastic resin having a nitrile group. A specific example is a film of a resin composition containing an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile / styrene copolymer. As the film, a film composed of a mixed extruded product of a resin composition or the like can be used.
[0028]
A transparent substrate that can be particularly preferably used in view of polarization characteristics and durability is a triacetyl cellulose film whose surface has been saponified with an alkali or the like. Although the thickness of the transparent substrate 1 can be determined as appropriate, it is generally about 10 to 500 μm in view of strength, workability such as handleability, and thin layer property. In particular, 20 to 300 μm is preferable, and 30 to 200 μm is more preferable.
[0029]
Further, it is preferable that the base film has as little coloring as possible. Therefore, Rth = [(nx + ny) / 2−nz] · d (where nx and ny are the main refractive indices in the film plane, nz is the refractive index in the film thickness direction, and d is the film thickness). A protective film having a retardation value in the film thickness direction of -90 nm to +75 nm is preferably used. By using a film having a retardation value (Rth) in the thickness direction of -90 nm to +75 nm, coloring (optical coloring) of the polarizing plate caused by the protective film can be substantially eliminated. The thickness direction retardation value (Rth) is more preferably -80 nm to +60 nm, and particularly preferably -70 nm to +45 nm.
[0030]
The hard coat layer 2 is not particularly limited as long as it has excellent hard coat properties, has sufficient strength after forming the film layer, and has excellent light transmittance. Examples of the resin forming the hard coat layer 2 include a thermosetting resin, a thermoplastic resin, an ultraviolet-curable resin, an electron beam-curable resin, and a two-component mixed resin. UV-curable resins that can efficiently form a hard coat layer with a simple processing operation in the curing treatment by the above method are preferred.
[0031]
Examples of the UV-curable resin include various resins such as polyester, acrylic, urethane, amide, silicone, and epoxy resins, and include UV-curable monomers, oligomers, and polymers. The UV-curable resin preferably used is, for example, a resin having a UV-polymerizable functional group, among which those containing a component of an acrylic monomer or oligomer having two or more, particularly 3 to 6 functional groups are mentioned. . Further, an ultraviolet ray polymerization initiator is blended with the ultraviolet ray curable resin.
[0032]
The surface of the hard coat layer 2 can have a fine uneven structure to provide antiglare properties. The method for forming the fine uneven structure on the surface is not particularly limited, and an appropriate method can be adopted. For example, the surface of the film used for forming the hard coat layer 2 is previously subjected to a roughening treatment by an appropriate method such as sandblasting, embossing roll, or chemical etching to give a fine uneven structure to the film surface. And a method of forming the surface of the material itself for forming the hard coat layer 2 into a fine uneven structure. Further, there is a method in which the hard coat layer 2 is separately applied on the hard coat layer 2 to give a fine uneven structure to the surface of the resin film layer by a transfer method using a mold or the like. Further, as shown in FIG. 2, there is a method in which fine particles 4 are dispersed and contained in the hard coat layer 2 to give a fine uneven structure. These fine uneven structures may be formed by combining two or more types of methods and forming a layer in which the surfaces of the fine uneven structures in different states are combined. Among the methods of forming the hard coat layer 2, a method of providing the hard coat layer 2 containing the fine particles 4 dispersed therein is preferable from the viewpoint of the formability of the surface of the fine uneven structure.
[0033]
Hereinafter, a method of providing the hard coat layer 2 by dispersing and containing the fine particles 4 will be described. As the fine particles 4, those having transparency, such as various metal oxides, glass, and plastic, can be used without particular limitation. For example, inorganic oxide fine particles such as silica, alumina, titania, zirconium oxide, calcium oxide, tin oxide, indium oxide, antimony oxide, polymethyl methacrylate, polystyrene, polyurethane, acrylic-styrene copolymer, benzoguanamine, melamine, polycarbonate, etc. And non-crosslinked organic fine particles and silicone fine particles composed of various polymers described above. The shape is not particularly limited and may be a bead-like sphere or an irregular shape such as a powder. One or more of these fine particles 4 can be appropriately selected and used. The average particle size of the fine particles is 1 to 10 μm, preferably 2 to 5 μm. Ultrafine particles of a metal oxide or the like may be dispersed and impregnated into the fine particles for the purpose of controlling the refractive index or imparting conductivity. The ratio of the fine particles 4 is appropriately determined in consideration of the average particle diameter of the fine particles 4, the thickness of the hard coat layer, and the like. In general, about 1 to 20 parts by weight with respect to 100 parts by weight of the resin. And more preferably 5 to 15 parts by weight.
[0034]
Additives such as a leveling agent, a thixotropic agent, and an antistatic agent can be used for the ultraviolet-curable resin (formation of the hard coat layer 2). The use of a thixotropic agent is advantageous for forming protruding particles on the surface of the fine uneven structure. Examples of the thixotropic agent include silica, mica, smectite and the like having a size of 0.1 μm or less.
[0035]
The method for forming the hard coat layer 2 is not particularly limited, and an appropriate method can be adopted. For example, a resin (containing fine particles 4 as appropriate) is applied on the transparent substrate 1, dried, and then cured. When fine particles 4 are contained, a hard coat layer 2 having an uneven shape on the surface is formed. The resin is applied by an appropriate method such as fountain, die coater, casting, spin coating, fountain metalling, and gravure. In the application, the resin may be diluted with a general solvent such as toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, isopropyl alcohol, and ethyl alcohol, or may be applied without dilution. You can also. The thickness of the hard coat layer 2 is not particularly limited, but is preferably about 0.5 to 20 μm, particularly preferably 1 to 10 μm.
[0036]
An antireflection layer 3 is laminated on the surface of the hard coat layer 2. The anti-reflection layer forming agent has a refractive index of n_d  ²⁰Contains at least two types of low refractive index materials satisfying ≦ 1.49. These antireflection layer forming agents form a dry cured film of (A) having a polysiloxane structure as a main component and (B) having a fluorine-containing material as a main component. The low-refractive-index material is mainly composed of a polysiloxane structure of a dry-cured product in a dry-cured film formed as an antireflection layer (A) and a fluorine-containing material (B). It is blended in such a ratio as to be the solid content weight ratio.
[0037]
Examples of the forming agent (A) having a polysiloxane structure as a main component include sol-gel materials using metal alkoxides such as alkoxysilane and alkoxytitanium. Of these, alkoxysilanes are preferred. Specific examples of the alkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetraalkoxysilanes such as tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyl Tributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3- Glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylto Ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane, trialkoxysilanes such as 3,4-epoxycyclohexylethyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, Examples include diethyldimethoxysilane and diethyldiethoxysilane. These alkoxysilanes can be used as a partial condensate thereof. Among these, tetraalkoxysilanes or partial condensates thereof are preferred. Particularly, tetramethoxysilane, tetraethoxysilane or a partial condensate thereof is preferable.
[0038]
Examples of the forming agent (B) mainly containing a fluorine-containing material include a fluorine-containing polymer. Examples of the monomer that forms the fluorine-containing polymer include fluoroolefins such as tetrafluoroethylene, hexafluoropropylene, and 3,3,3-trifluoropropylene; alkyl perfluorovinyl ethers or alkoxyalkyl perfluorovinyl ethers; Perfluoro (alkyl vinyl ethers) such as perfluoro (ethyl vinyl ether), perfluoro (ethyl vinyl ether), perfluoro (propyl vinyl ether), perfluoro (butyl vinyl ether) and perfluoro (isobutyl vinyl ether); perfluoro (alkoxyalkyl vinyl ether) such as perfluoro (propoxypropyl vinyl ether) And the like. One or more of these monomers can be used, and they can be copolymerized with other monomers.
[0039]
As the forming agent (B) mainly containing a fluorine-containing material, a fluorine-containing sol-gel-based material such as perfluoroalkylalkoxysilane can be used. As the perfluoroalkylalkoxysilane, for example, a compound represented by the general formula (1): CF₃  (CF₂  )_n  CH₂  CH₂  Si (OR)₃  (Wherein, R represents an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 0 to 12). Specifically, for example, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane Ethoxysilane and the like can be mentioned. Of these, compounds wherein n is 2 to 6 are preferred.
[0040]
When a fluorine-containing material (especially a fluorine-based polymer) and a polysiloxane forming agent are used as the low refractive index material, it is preferable to use a mixed solvent containing a ketone-based solvent and an alcohol-based solvent. Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone and the like. Examples of the alcohol solvent include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, i-butanol, t-butanol and the like. In particular, it is preferable to combine methyl ethyl ketone and methyl isobutyl ketone as ketone solvents and ethanol, n-butanol and t-butanol as alcohol solvents. The ratio of the ketone-based solvent to the alcohol-based solvent is not particularly limited, but is preferably ketone-based solvent: alcohol-based solvent (weight ratio) = 1: 20 to 20: 1, and more preferably 1: 5 to 5: 1. preferable.
[0041]
In addition, in addition to the low refractive index component, the coating liquid for forming the antireflection layer may further include a compatibilizer, a crosslinking agent, a coupling agent, an antioxidant, an ultraviolet absorber, and a refractive index, if necessary. Adjusters and the like can be added as appropriate.
[0042]
The ratio of the forming agent of (A) containing the polysiloxane structure as a main component and the forming agent of the antireflection layer containing the forming agent of (B) containing a fluorine-containing material as a main component is preferably in the above-mentioned ratio. However, it is desirable to mix these immediately before coating from the viewpoint of solution stability.
[0043]
In addition, a sol in which silica, alumina, titania, zirconia, magnesium fluoride, ceria, or the like is dispersed in an alcohol solvent may be added to the anti-reflection layer forming agent. In addition, additives such as metal salts and metal compounds can be appropriately compounded.
[0044]
An antireflection layer 3 is formed by applying an antireflection layer forming agent (solution) to the hard coat layer 2, drying and curing. The anti-reflection layer 3 is formed by evaporating the solvent and forming a coating by forming the (A) having a polysiloxane structure as a main component and the (B) forming agent having a fluorine-containing material as a main component. Is what you do. The method for applying the antireflection layer-forming agent is not particularly limited, and examples thereof include ordinary methods such as a dip method, a spin coating method, a brush coating method, a roll coating method, and a flexographic printing method.
[0045]
Although the drying and curing temperatures are not particularly limited, the drying and curing can be performed at a low temperature of 60 to 150 ° C, more preferably 70 to 120 ° C, in a short time of 100 hours or less, further preferably 0.5 to 10 hours. In addition, the temperature and the time are not limited to the above ranges, and can be appropriately adjusted. For heating, a method such as a hot plate, an oven, and a belt furnace is appropriately adopted.
[0046]
The thickness of the antireflection layer is not particularly limited, but is preferably about 50 to 300 nm, particularly preferably 70 to 120 nm. The condition for suppressing the light reflectance at the wavelength of 550 nm, which has the highest visibility most effectively, is usually set so that the thickness (nm) is about 550 (nm) / (4 × refractive index of the antireflection layer). Is preferred.
[0047]
Further, an optical element can be bonded to the transparent substrate 1 of the antireflection film shown in FIG. 1 or 2 (not shown). Further, the above-described antireflection film can also be produced by using the protective film used for the optical element (polarizer) as a transparent substrate.
[0048]
Examples of the optical element include a polarizer. The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, and a dichromatic dye such as iodine or a dichroic dye. And uniaxially stretched by adsorbing a hydrophilic substance, or a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol or a dehydrochlorinated product of polyvinyl chloride. Among these, a polarizer composed of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 μm.
[0049]
A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine, and stretching the film to 3 to 7 times its original length. If necessary, it can be immersed in an aqueous solution of boric acid or potassium iodide. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, dirt on the surface of the polyvinyl alcohol-based film and an anti-blocking agent can be washed, and by swelling the polyvinyl alcohol-based film, the effect of preventing unevenness such as uneven dyeing can be obtained. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. Stretching can be performed in an aqueous solution of boric acid or potassium iodide or in a water bath.
[0050]
The polarizer is usually provided with a transparent protective film on one or both sides and used as a polarizing plate. The transparent protective film preferably has excellent transparency, mechanical strength, thermal stability, moisture shielding property, isotropy and the like. As the transparent protective film, the same material as the transparent substrate described above is used. As the transparent protective film, a transparent protective film made of the same polymer material on both sides may be used, or a transparent protective film made of a different polymer material or the like may be used. When the antireflection film is provided on one side or both sides of a polarizer (polarizing plate), the transparent substrate of the antireflection film can also serve as a transparent protective film of the polarizer.
[0051]
In addition, the surface of the transparent protective film on which the polarizer is not bonded may be subjected to a hard coat layer or a treatment for preventing sticking. The hard coat treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate, for example, by applying a suitable ultraviolet-curable resin such as an acrylic resin or a silicone resin to a cured film having excellent hardness and sliding properties, etc., as a transparent protective film. It can be formed by a method of adding to the surface of. In addition, the anti-sticking treatment is performed for the purpose of preventing adhesion to an adjacent layer. The hard coat layer, the anti-sticking layer and the like can be provided on the transparent protective film itself, or can be separately provided as an optical layer separately from the transparent protective film.
[0052]
In practical use, an optical film in which another optical element (optical layer) is laminated on the polarizing plate can be used as the optical element. The optical layer is not particularly limited. For example, the optical layer is used for forming a liquid crystal display device such as a reflection plate, a semi-transmission plate, a retardation plate (including a wavelength plate such as 1/2 or 1/4), a viewing angle compensation film, and the like. One or more optical layers that may be used may be used. In particular, a reflective polarizing plate or a semi-transmissive polarizing plate in which a reflecting plate or a transflective reflecting plate is further laminated on a polarizing plate, an elliptically polarizing plate or a circular polarizing plate in which a retardation plate is further laminated on a polarizing plate, a polarized light A wide viewing angle polarizing plate obtained by further laminating a viewing angle compensation film on a plate, or a polarizing plate obtained by further laminating a brightness enhancement film on a polarizing plate is preferable.
[0053]
The reflection type polarizing plate is provided with a reflection layer on a polarizing plate, and is used to form a liquid crystal display device of a type that reflects incident light from a viewing side (display side) and displays the reflected light. There is an advantage that the built-in light source can be omitted, and the liquid crystal display device can be easily made thinner. The reflection type polarizing plate can be formed by an appropriate method such as a method in which a reflective layer made of metal or the like is provided on one surface of the polarizing plate via the transparent protective film or the like, if necessary.
[0054]
Specific examples of the reflective polarizing plate include those in which a reflective layer formed by attaching a foil or a vapor-deposited film made of a reflective metal such as aluminum to one surface of a transparent protective film that has been matted as necessary.
[0055]
The reflection plate can be used as a reflection sheet or the like in which a reflection layer is provided on an appropriate film conforming to the transparent film, instead of directly applying the reflection plate to the transparent protective film of the polarizing plate. Since the reflective layer is usually made of a metal, the use form in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like is intended to prevent a decrease in the reflectance due to oxidation and, as a result, a long-lasting initial reflectance. It is more preferable to avoid separately providing a protective layer.
[0056]
The transflective polarizing plate can be obtained by forming a transflective reflective layer such as a half mirror that reflects and transmits light with the reflective layer. A transflective polarizing plate is usually provided on the back side of a liquid crystal cell. When a liquid crystal display device or the like is used in a relatively bright atmosphere, an image is displayed by reflecting incident light from the viewing side (display side). In a relatively dark atmosphere, a liquid crystal display device of a type that displays an image using a built-in light source such as a backlight built in the back side of a transflective polarizing plate can be formed. That is, the transflective polarizing plate can save energy for use of a light source such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of a type that can be used with a built-in light source even in a relatively dark atmosphere. It is.
[0057]
An elliptically polarizing plate or a circularly polarizing plate in which a retardation plate is further laminated on a polarizing plate will be described. When changing linearly polarized light to elliptically or circularly polarized light, changing elliptically or circularly polarized light to linearly polarized light, or changing the polarization direction of linearly polarized light, a phase difference plate or the like is used. In particular, a so-called quarter-wave plate (also referred to as a λ / 4 plate) is used as a retardation plate that changes linearly polarized light into circularly polarized light or converts circularly polarized light into linearly polarized light. A half-wave plate (also referred to as a λ / 2 plate) is usually used to change the polarization direction of linearly polarized light.
[0058]
The elliptically polarizing plate compensates (prevents) coloring (blue or yellow) caused by the birefringence of the liquid crystal layer of a super twisted nematic (STN) type liquid crystal display device, and is effectively used for a black-and-white display without the coloring. Can be Further, the one in which the three-dimensional refractive index is controlled is preferable because coloring which occurs when the screen of the liquid crystal display device is viewed from an oblique direction can be compensated (prevented). The circularly polarizing plate is effectively used, for example, when adjusting the color tone of an image of a reflection type liquid crystal display device that displays an image in color, and also has an antireflection function. As specific examples of the above retardation plate, polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene and other polyolefins, polyarylate, birefringent film obtained by stretching a film made of a suitable polymer such as polyamide And an alignment film of a liquid crystal polymer, and an alignment layer of a liquid crystal polymer supported by a film. The retardation plate may have an appropriate retardation depending on the purpose of use, such as, for example, a color plate due to birefringence of various wave plates or a liquid crystal layer, or a target for compensation of a viewing angle or the like. A retardation plate may be laminated to control optical characteristics such as retardation.
[0059]
Further, the elliptically polarizing plate or the reflection type elliptically polarizing plate is obtained by laminating a polarizing plate or a reflection type polarizing plate and a retardation plate in an appropriate combination. Such an elliptically polarizing plate or the like may be formed by sequentially and separately laminating a (reflection type) polarizing plate and a retardation plate in the process of manufacturing a liquid crystal display device so as to form a combination. An optical film such as a polarizing plate has an advantage that the stability of quality and laminating workability are excellent and the production efficiency of a liquid crystal display device or the like can be improved.
[0060]
The viewing angle compensation film is a film for widening the viewing angle so that an image can be seen relatively clearly even when the screen of the liquid crystal display device is viewed not in a direction perpendicular to the screen but in a slightly oblique direction. Such a viewing angle compensating retardation plate includes, for example, a retardation film, an alignment film such as a liquid crystal polymer, and a transparent substrate on which an alignment layer such as a liquid crystal polymer is supported. The ordinary retardation plate is a polymer film having birefringence uniaxially stretched in the plane direction, whereas the retardation plate used as the viewing angle compensation film is biaxially stretched in the plane direction. A birefringent polymer film such as a polymer film having birefringence or a birefringent polymer such as a birefringent polymer and a birefringent polymer in which the refractive index in the thickness direction is stretched uniaxially in the plane direction and also stretched in the thickness direction and controlled in the thickness direction. Used. Examples of the obliquely oriented film include a film obtained by bonding a heat shrinkable film to a polymer film and subjecting the polymer film to a stretching treatment and / or shrinkage treatment under the action of the shrinkage force caused by heating, and a film obtained by obliquely aligning a liquid crystal polymer. No. As the raw material polymer of the retardation plate, the same polymer as described in the above retardation plate is used to prevent coloring or the like due to a change in the viewing angle based on the phase difference due to the liquid crystal cell and to enlarge the viewing angle for good visibility. Any appropriate one for the purpose can be used.
[0061]
In addition, because of achieving a wide viewing angle for viewing, an optically compensatory retardation plate that supports an optically anisotropic layer consisting of an alignment layer of liquid crystal polymer, especially a tilted alignment layer of discotic liquid crystal polymer, with a triacetyl cellulose film Can be preferably used.
[0062]
A polarizing plate obtained by laminating a polarizing plate and a brightness enhancement film is usually used by being provided on the back side of a liquid crystal cell. The brightness enhancement film reflects linearly polarized light of a predetermined polarization axis or circularly polarized light of a predetermined direction when natural light is incident due to reflection from a backlight or a back side of a liquid crystal display device, and has a property of transmitting other light. A polarizing plate obtained by laminating a brightness enhancement film and a polarizing plate, while transmitting light from a light source such as a backlight to obtain a transmission light in a predetermined polarization state, is reflected without transmitting light other than the predetermined polarization state. You. The light reflected on the surface of the brightness enhancement film is further inverted through a reflection layer or the like provided on the rear side thereof and re-incident on the brightness enhancement film, and a part or all of the light is transmitted as light of a predetermined polarization state to thereby obtain brightness. In addition to increasing the amount of light transmitted through the enhancement film, it is also possible to improve the luminance by supplying polarized light that is hardly absorbed by the polarizer to increase the amount of light that can be used for liquid crystal display image display and the like. In other words, when light is incident through the polarizer from the back side of the liquid crystal cell with a backlight or the like without using a brightness enhancement film, light having a polarization direction that does not match the polarization axis of the polarizer is almost completely polarized. Is absorbed by the polarizer and does not pass through the polarizer. That is, although it depends on the characteristics of the polarizer used, about 50% of the light is absorbed by the polarizer, and accordingly, the amount of light available for liquid crystal image display and the like decreases, and the image becomes darker. The brightness enhancement film is such that light having a polarization direction as absorbed by the polarizer is once reflected by the brightness enhancement film without being incident on the polarizer, and further inverted through a reflection layer or the like provided behind the same. The brightness enhancement film transmits only the polarized light whose polarization direction has been changed so that the polarization direction of the light reflected and inverted between the two can pass through the polarizer. Since light is supplied to the polarizer, light from a backlight or the like can be efficiently used for displaying an image on the liquid crystal display device, and the screen can be brightened.
[0063]
A diffusion plate may be provided between the brightness enhancement film and the above-mentioned reflection layer or the like. The light in the polarization state reflected by the brightness enhancement film goes to the reflection layer and the like, but the diffuser provided uniformly diffuses the light passing therethrough, and at the same time, eliminates the polarization state and becomes a non-polarization state. That is, the diffuser returns the polarized light to the original natural light state. The light in the non-polarized state, that is, the light in the natural light state is repeatedly directed to the reflection layer and the like, reflected through the reflection layer and the like, again passed through the diffusion plate and re-incident on the brightness enhancement film. Thus, while maintaining the brightness of the display screen by providing a diffusion plate that returns polarized light to the original natural light state between the brightness enhancement film and the reflective layer, etc., at the same time, reducing unevenness in the brightness of the display screen, A uniform and bright screen can be provided. It is considered that by providing such a diffusion plate, the number of repetitions of the reflection of the first incident light is moderately increased, and a uniform bright display screen can be provided in combination with the diffusion function of the diffusion plate.
[0064]
The brightness enhancement film has a property of transmitting linearly polarized light having a predetermined polarization axis and reflecting other light, such as a multilayer thin film of a dielectric or a multilayer laminate of thin films having different refractive index anisotropies. As shown in the figure, such as a cholesteric liquid crystal polymer oriented film or a film in which the oriented liquid crystal layer is supported on a film substrate, it exhibits a property of reflecting either left-handed or right-handed circularly polarized light and transmitting other light. Any suitable one such as one can be used.
[0065]
Therefore, in the brightness enhancement film of the type that transmits linearly polarized light having the predetermined polarization axis, the transmitted light is incident on the polarization plate as it is, with the polarization axis aligned, thereby efficiently transmitting the light while suppressing the absorption loss by the polarization plate. Can be done. On the other hand, in a brightness enhancement film of the type that emits circularly polarized light, such as a cholesteric liquid crystal layer, it can be directly incident on a polarizer, but from the viewpoint of suppressing absorption loss, the circularly polarized light is linearly polarized through a retardation plate. It is preferable that the light is incident on a polarizing plate. By using a quarter-wave plate as the retardation plate, circularly polarized light can be converted to linearly polarized light.
[0066]
A retardation plate that functions as a quarter-wave plate in a wide wavelength range such as a visible light region exhibits, for example, a retardation layer that functions as a quarter-wave plate for light-color light having a wavelength of 550 nm and other retardation characteristics. It can be obtained by a method of superimposing a retardation layer, for example, a retardation layer functioning as a half-wave plate. Therefore, the retardation plate disposed between the polarizing plate and the brightness enhancement film may be composed of one or more retardation layers.
[0067]
The cholesteric liquid crystal layer is also configured such that two or three or more cholesteric liquid crystal layers are superimposed on each other to reflect circularly polarized light in a wide wavelength range such as a visible light region. Based on this, it is possible to obtain circularly polarized light transmitted in a wide wavelength range.
[0068]
Further, the polarizing plate may be formed by laminating a polarizing plate and two or three or more optical layers as in the above-mentioned polarized light separating type polarizing plate. Therefore, a reflective elliptically polarizing plate or a transflective elliptically polarizing plate obtained by combining the above-mentioned reflective polarizing plate, semi-transmissive polarizing plate, and retardation plate may be used.
[0069]
The lamination of the antireflection film on the optical element and the lamination of various optical layers on the polarizing plate can also be performed by a method of sequentially laminating the layers in the process of manufacturing a liquid crystal display device or the like. The laminated structure has an advantage that it is excellent in quality stability, assembling work, and the like, and can improve a manufacturing process of a liquid crystal display device or the like. Appropriate bonding means such as an adhesive layer can be used for lamination. When bonding the polarizing plate and other optical films, their optical axes can be set at an appropriate angle depending on the intended retardation characteristics and the like.
[0070]
The above-described polarizing plate, at least one surface of an optical element such as an optical film in which at least one polarizing plate is laminated, the antireflection film is provided, but the surface where the antireflection film is not provided is provided. And an adhesive layer for bonding to another member such as a liquid crystal cell. The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is not particularly limited, and for example, an acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, and a polymer having a fluorine-based or rubber-based polymer as a base polymer are appropriately selected. Can be used. In particular, an acrylic adhesive having excellent optical transparency, exhibiting appropriate wettability, cohesiveness and adhesive adhesive properties and having excellent weather resistance and heat resistance can be preferably used.
[0071]
In addition to the above, prevention of foaming and peeling phenomena due to moisture absorption, reduction of optical characteristics due to thermal expansion difference and the like, prevention of warpage of the liquid crystal cell, and, in view of the formability of a liquid crystal display device having high quality and excellent durability, etc. An adhesive layer having low moisture absorption and excellent heat resistance is preferred.
[0072]
The adhesive layer is, for example, a natural or synthetic resin, in particular, a tackifier resin, or a filler, a pigment, a colorant, an antioxidant, or the like made of glass fiber, glass beads, metal powder, other inorganic powder, and the like. May be added to the pressure-sensitive adhesive layer. In addition, an adhesive layer containing fine particles and exhibiting light diffusibility may be used.
[0073]
The attachment of an adhesive layer to an optical element such as a polarizing plate or an optical film can be performed by an appropriate method. As an example thereof, for example, an adhesive solution of about 10 to 40% by weight is prepared by dissolving or dispersing a base polymer or a composition thereof in a solvent composed of a single solvent or a mixture of appropriate solvents such as toluene and ethyl acetate, A method of directly attaching it to the optical element by an appropriate development method such as a casting method or a coating method, or a method of forming an adhesive layer on a separator according to the above and transferring it to the optical element. can give. The adhesive layer may be provided as a superimposed layer of different compositions or types of layers. The thickness of the pressure-sensitive adhesive layer can be appropriately determined depending on the purpose of use, adhesive strength, and the like, and is generally 1 to 500 µm, preferably 5 to 200 µm, particularly preferably 10 to 100 µm.
[0074]
A separator is temporarily attached to the exposed surface of the adhesive layer for the purpose of preventing contamination and the like until the adhesive layer is put to practical use and covered. This can prevent the adhesive layer from coming into contact with the adhesive layer in a normal handling state. Except for the above thickness conditions, the separator may be, for example, a plastic film, a rubber sheet, paper, cloth, a nonwoven fabric, a net, a foamed sheet or a metal foil, a suitable thin sheet such as a laminate thereof, or a silicone-based material as necessary. Appropriate conventional ones, such as those coated with an appropriate release agent such as a long-chain alkyl-based, fluorine-based, or molybdenum sulfide, may be used.
[0075]
In the present invention, for example, a salicylic acid ester compound, a benzophenol compound, a benzotriazole compound, a cyanoacrylate, etc. A compound having ultraviolet absorbing ability by a method such as a method of treating with an ultraviolet absorbing agent such as a system compound or a nickel complex salt compound may be used.
[0076]
The optical element provided with the antireflection film of the present invention can be preferably used for forming various devices such as a liquid crystal display device. The formation of the liquid crystal display device can be performed according to a conventional method. That is, a liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell and an optical element and, if necessary, an illumination system and incorporating a drive circuit. There is no particular limitation except that an element is used, and it can be in accordance with the prior art. As for the liquid crystal cell, any type such as TN type, STN type and π type can be used.
[0077]
An appropriate liquid crystal display device such as a liquid crystal display device in which the optical element is arranged on one or both sides of a liquid crystal cell, or a lighting system using a backlight or a reflector can be formed. In that case, the optical element according to the present invention can be installed on one side or both sides of the liquid crystal cell. When optical elements are provided on both sides, they may be the same or different. Further, when forming the liquid crystal display device, for example, a suitable component such as a diffusion plate, an anti-glare layer, an antireflection film, a protection plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, etc. Two or more layers can be arranged.
[0078]
Next, an organic electroluminescence device (organic EL display device) will be described. In general, in an organic EL display device, a luminous body (organic electroluminescent luminous body) is formed by sequentially laminating a transparent electrode, an organic luminescent layer, and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like, and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a configuration having various combinations such as a stacked body of such a light emitting layer and an electron injection layer made of a perylene derivative, or a stacked body of a hole injection layer, a light emitting layer, and an electron injection layer thereof is known. Has been.
[0079]
In an organic EL display device, holes and electrons are injected into an organic light emitting layer by applying a voltage to a transparent electrode and a metal electrode, and energy generated by recombination of these holes and electrons excites a fluorescent substance. Then, light is emitted on the principle that the excited fluorescent substance emits light when returning to the ground state. The mechanism of recombination on the way is the same as that of a general diode, and as can be expected from this, the current and the emission intensity show strong nonlinearity accompanied by rectification with respect to the applied voltage.
[0080]
In an organic EL display device, at least one of the electrodes must be transparent in order to extract light emitted from the organic light emitting layer. Usually, a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used as an anode. Used as On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a material having a small work function for the cathode, and usually a metal electrode such as Mg-Ag or Al-Li is used.
[0081]
In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. Therefore, the organic light emitting layer transmits light almost completely, similarly to the transparent electrode. As a result, when light is incident from the surface of the transparent substrate during non-light emission, light transmitted through the transparent electrode and the organic light-emitting layer and reflected by the metal electrode again exits to the surface side of the transparent substrate, and when viewed from the outside, The display surface of the organic EL display device looks like a mirror surface.
[0082]
In an organic EL display device including an organic electroluminescent luminous body having a transparent electrode on the front side of an organic luminescent layer that emits light by applying a voltage and a metal electrode on the back side of the organic luminescent layer, the surface of the transparent electrode A polarizing plate can be provided on the side, and a retardation plate can be provided between the transparent electrode and the polarizing plate.
[0083]
Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarizing function. In particular, if the retardation plate is formed of a 1/4 wavelength plate and the angle between the polarization directions of the polarizing plate and the retardation plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. .
[0084]
That is, as for the external light incident on the organic EL display device, only the linearly polarized light component is transmitted by the polarizing plate. This linearly polarized light is generally converted into elliptically polarized light by the phase difference plate, but becomes circularly polarized light particularly when the phase difference plate is a １ wavelength plate and the angle between the polarization directions of the polarizing plate and the phase difference plate is π / 4. .
[0085]
This circularly polarized light transmits through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again by the phase difference plate. The linearly polarized light cannot pass through the polarizing plate because it is orthogonal to the polarizing direction of the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.
[0086]
【Example】
Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.
[0087]
Manufacturing example
(Creation of polarizer)
An 80 μm-thick polyvinyl alcohol film is dyed in a 0.3% aqueous iodine solution, stretched up to 5 times in a 4% boric acid, 2% aqueous potassium iodide solution, and then dried at 50 ° C. for 4 minutes. To obtain a polarizer.
[0088]
(Preparation of polarizing plate)
A polyvinyl alcohol-based adhesive was applied to both sides of the polarizer, and a 80 μm-thick triacetyl cellulose film was laminated as a protective film to form a polarizing plate.
[0089]
Example 1
(Preparation of antireflection layer forming agent)
100 parts of a polyfluoroolefin resin (tetrafluoroethylene / hexafluoropropylene / propylene copolymer) having a number average molecular weight (in terms of polystyrene) of 5,000 and a siloxane oligomer (part of tetraethoxysilane) having a relative molecular weight of 950 in terms of ethylene glycol determined by GPC. 30 parts of a (condensed polymer) was dissolved in a mixed solvent of methyl ethyl ketone: methyl isobutyl ketone: propyl alcohol (weight ratio: 10:70:20) to obtain a coating solution having a solid content of 2%. The respective materials were formed into a single film, and the refractive index values measured using an Abbe refractometer were 1.38 for the polyfluoroolefin-based resin and 1.45 for the polysiloxane obtained from the siloxane oligomer. Was.
[0090]
(Formation of hard coat layer)
A toluene solution was prepared by mixing and dispersing 12 g of polystyrene particles having an average particle diameter of 3.5 μm with 100 g of a commercially available urethane acrylate ultraviolet curing resin. This toluene solution is applied on one side (triacetylcellulose film) of the polarizing plate using a wire bar, dried with a solvent, and then irradiated with ultraviolet light from a low-pressure UV lamp to form a 5 μm-thick hard coat layer having an antiglare function. did. The refractive index of the resin on which the hard coat layer was formed was 1.52.
[0091]
(Formation of anti-reflection layer)
Subsequently, the coating solution prepared above is applied using a wire bar so that the thickness after curing becomes about 100 nm, and is heated and cured at 90 ° C. for 1 hour to form an anti-reflection layer. A polarizing plate was prepared. The refractive index of the antireflection layer was 1.40. Further, the antireflection layer had a solid content ratio of about 30% by weight as a cured product after drying (A) having a polysiloxane structure as a main component.
[0092]
Example 2
(Preparation of anti-reflection film)
A toluene solution of an ultraviolet-curable acrylic hard coat resin is applied onto a 80 μm-thick triacetyl cellulose film using a wire bar, dried with a solvent, and then irradiated with ultraviolet light by a low-pressure UV lamp to form a 5 μm-thick hard coat layer. did. The refractive index of the resin on which the hard coat layer was formed was 1.51. Next, an antireflection layer was formed using the same coating liquid as in Example 1 in the same manner as in Example 1 to prepare an antireflection film.
[0093]
(Preparation of polarizing plate with anti-reflection function)
An 80 μm-thick triacetyl cellulose film on one side of the polarizer, and a triacetyl cellulose film of the antireflection film on the other side, and a polarizing plate with an antireflection function by bonding with a polyvinyl alcohol-based adhesive. Created.
[0094]
Comparative Example 1
A polarizing plate with an antireflection function was prepared in the same manner as in Example 1 except that a fluorine-modified alkoxylan solution having a refractive index of 1.38 was used as a coating liquid in (Formation of an antireflection layer) of Example 1. did.
[0095]
Comparative Example 2
In Example 2 (preparation of antireflection film), reflection was performed in the same manner as in Example 2 except that a fluorine-modified alkoxylane solution having a refractive index of 1.38 was used as a coating liquid for forming an antireflection layer. A prevention film was made. Thereafter, in the same manner as in Example 2, a polarizing plate with an antireflection function was prepared.
[0096]
Comparative Example 3
The surface of the antireflection layer of the polarizing plate with antireflection function obtained in Comparative Example 1 was irradiated with corona treatment at an output of 1.5 KV for 10 seconds.
[0097]
Comparative Example 4
The surface of the antireflection layer of the polarizing plate with an antireflection function obtained in Comparative Example 2 was irradiated with a corona treatment at an output of 1.5 KV for 10 seconds.
[0098]
The following evaluations were performed on the polarizing plates with an antireflection function obtained in Examples and Comparative Examples. Table 1 shows the results.
[0099]
(Initial triboelectric charge (A))
The surface of the polarizing plate with an antireflection function (sample size: 40 mm x 40 mm) on which the antireflection layer was not applied was fixed on an evaluation stage. The antireflection layer was rubbed with a rotating body (70 mmφ) around which wool was wound (300 rpm, stage moving speed 8.3 mm / sec, 23 ± 1 ° C.), and triboelectric charging was generated. (KSD-0101), the charge amount (KV) was measured at room temperature (23 ° C.) with a width of 1 cm.
[0100]
(Amount of triboelectric charge after humidification (B))
The polarizing plate with an anti-reflection function (sample size: 40 mm × 40 mm) was left in an environment of 60 ° C. and 90% RH for 48 hours, and dried at 80 ° C. for 10 minutes. Thereafter, the triboelectric charge (B) was measured under the same conditions as in the measurement of the triboelectric charge (A).
[0101]
(Dust wiping properties)
After measuring the triboelectric charge amounts (A) and (B), a powder obtained by crushing a 100% pulp tissue on the anti-reflection layer of the sample is scattered, and whether or not it can be wiped off with cotton (MILLIKEN, ANTICON GOLD) Was visually determined according to the following criteria.
：: Can be wiped off.
×: Cannot be wiped off.
[0102]
(Reflectance)
After roughening the back of the polarizing plate with anti-reflection function (the surface on which the anti-reflection layer is not formed) with steel wool, spray a black acrylic lacquer to remove the reflection on the back of the sample. (Shimadzu Corporation, UV-2400) was used to measure the total reflectance (%). From the results, a Y value in a 2 ° C light source visual field was calculated.
[0103]
[Table 1]

As shown in the above results, the polarizing plate with an antireflection function of the example has an initial triboelectric charge (A) in the range of −1 to +2 KV without corona treatment, and has a triboelectric charge (B). The difference (BA) from the initial triboelectric charge amount (A) is within ± 0.5 KV, and it can be seen that the device has good dust wiping properties even when the use environment changes. Further, it can be seen that it has good antireflection characteristics and is excellent in practical characteristics.
[Brief description of the drawings]
FIG. 1 is an example of a cross-sectional view of an antireflection film of the present invention.
FIG. 2 is an example of a cross-sectional view of the antireflection film of the present invention.
[Explanation of symbols]
1: Transparent substrate
2: Hard coat layer
3: Anti-reflection layer
4: Fine particles

Claims (10)

An anti-reflection film in which a hard coat layer is provided directly or via another layer on one surface of the transparent substrate, and further an anti-reflection layer is laminated on the surface of the hard coat layer,
The antireflection layer, the refractive index: satisfying n _d ²⁰ ≦ 1.49, formed by at least two kinds of low refractive index material, a polysiloxane structure as the main component (A) and a fluorine-containing material mainly A dried and cured film of component (B),
An antireflection film, wherein a triboelectric charge (A) generated when the surface of the antireflection layer is rubbed with wool is -1 to +2 KV. The antireflection film was left in an environment of 60 ° C. and 90% RH for 48 hours, dried at 80 ° C. for 10 minutes, and then rubbed on the surface with wool (B). The anti-reflection film according to claim 1, wherein the difference (BA) from (A) is within ± 0.5 KV. 2. The composition according to claim 1, wherein (A) having the polysiloxane structure as a main component has a solid content ratio of 10 to 80% by weight as a dry cured product in a dry cured film formed as an antireflection layer. Or the antireflection film according to 2. The anti-reflection coating according to any one of claims 1 to 3, wherein the hard coat layer is formed of an ultraviolet curable resin, and has an _nd ²⁰ (refractive index at 20 ° C) of 1.49 or more. the film. The antireflection film according to any one of claims 1 to 4, wherein the surface of the hard coat layer has a smooth shape. The antireflection film according to any one of claims 1 to 4, wherein the surface of the hard coat layer has an uneven shape and has antiglare properties. A polarizing plate, wherein a transparent substrate of the antireflection film according to claim 1 is used as a protective film on one or both surfaces of a polarizer. A polarizing plate comprising: a polarizing plate; and the antireflection film according to claim 1. An optical element, wherein the antireflection film according to any one of claims 1 to 6 or the polarizing plate according to any one of claims 7 to 8 is laminated on one or both sides of the optical element. An image display device using the antireflection film according to claim 1, the polarizing plate according to claim 7, or the optical element according to claim 9.

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