JP2013073069A - Antireflection film, polarizing plate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film capable of preventing a polarizing layer from fading when used as a polarizing plate.SOLUTION: An antireflection film 10 can suppress an influence caused by an amide compound in a side direction of a transparent base material 11 by providing a shielding layer 14 containing silicon oxide between the transparent base material 11 and a hard coat layer 12 containing an amide compound. Thus, a polarizing layer is prevented from fading by providing the polarizing layer on the transparent base material 11 on the side opposite to a formation surface of the shielding layer 14 of the antireflection film 11.

Description

  The present invention relates to an antireflection film, a polarizing plate using the antireflection film, and a display device incorporating the antireflection film.

  In general, the image display apparatus has a problem that it becomes difficult to recognize an image when external light is reflected on a display screen. In recent years, opportunities to be taken not only indoors but also outdoors have increased, and reflection of external light on the display screen and high durability have become more important issues.

  Therefore, it has been proposed to use a laminate in which layers having different refractive indexes are laminated as an antireflection film, and to provide the antireflection film on the display device surface.

  For example, an antireflection film in which a layer containing an amide compound is laminated has been proposed (see Patent Document 1).

  Further, it has been proposed to provide a polarizing layer on an antireflection film and use it as a polarizing plate for use in a display device or the like.

  For example, as a polarizing plate used for a liquid crystal display panel (LCD panel), a polarizing plate having a configuration in which a polarizing layer is provided on an antireflection film has been proposed (see Patent Document 2).

Japanese Patent Laid-Open No. 2005-148861 JP 2000-32428 A

  However, the polarizing plate having the polarizing layer provided on the antireflection film has a problem that the polarizing layer fades.

  Then, this invention is made | formed in order to solve the above-mentioned problem, and when using it as a polarizing plate, it aims at providing the antireflection film by which a polarizing layer is suppressed from fading.

  As a result of intensive studies, the present inventor has found that the amide compound present in the antireflection film promotes fading of the polarizing plate, and silicon oxide that shields the amide compound between the layer containing the amide compound and the polarizing layer. It came to the idea of suppressing the fading of a polarizing plate by providing the shielding layer containing.

  One embodiment of the present invention includes a transparent substrate, a hard coat layer laminated above the transparent substrate, an antireflection layer laminated above the hard coat layer, the transparent substrate and the hard substrate. An antireflection film comprising a shielding layer between the coating layer, the hard coating layer being a hard coating layer containing an amide compound, and the shielding layer being a shielding layer containing silicon oxide Is an antireflection film characterized by

  The silicon oxide is preferably made from a particulate silicon oxide having a particle size in the range of 45 μm or more and less than 85 μm.

  Further, the thickness of the shielding layer may be in the range of 200 nm to 350 nm.

Moreover, it is preferable that the above-mentioned antireflection film has a water vapor barrier property in a range of 7.0 g / m ² / day or less.

  One embodiment of the present invention is a polarizing plate comprising: the antireflection film described above; and a polarizing layer on a transparent substrate opposite to the surface on which the shielding layer of the antireflection film is formed. It is.

  One embodiment of the present invention is a display device using the polarizing plate described above.

  The antireflection film of the present invention suppresses the influence of the amide compound in the direction toward the transparent substrate by providing a shielding layer containing silicon oxide between the transparent substrate and the hard coat layer containing the amide compound. I can do it. For this reason, the polarizing plate by which the fading of the polarizing layer was suppressed can be provided by providing the polarizing layer on the transparent substrate opposite to the surface on which the shielding layer of the antireflection film is formed.

It is the schematic which shows an example of the antireflection film of this invention. It is the schematic which shows the process of shape | molding the vapor deposition material containing the silicon oxide for forming the shielding layer of the antireflection film of this invention. It is the schematic which shows an example of the polarizing plate of this invention. It is the schematic which shows an example of the display apparatus of this invention.

Hereinafter, the antireflection film of the present invention will be described.
The antireflection film of the present invention comprises a transparent substrate, a hard coat layer laminated above the transparent substrate, an antireflection layer laminated above the hard coat layer, the transparent substrate and the hard substrate. A shielding layer between the coating layer, the hard coating layer is a hard coating layer containing an amide compound, and the shielding layer is a shielding layer containing silicon oxide.

  The antireflection film of the present invention suppresses the influence of the amide compound in the direction toward the transparent substrate by providing a shielding layer containing silicon oxide between the transparent substrate and the hard coat layer containing the amide compound. I can do it. For this reason, the polarizing plate by which the fading of the polarizing layer was suppressed can be provided by providing the polarizing layer on the transparent substrate opposite to the surface on which the shielding layer of the antireflection film is formed.

FIG. 1 shows an example of the antireflection film of the present invention.
FIG. 1 shows an antireflection film 10 in which an antireflection layer 13 / hard coat layer 12 / shielding layer 14 / transparent substrate 11 are laminated in this order as viewed from the outermost surface.

As the transparent substrate, a material having excellent mechanical strength and dimensional stability and having translucency may be appropriately selected from known materials and used. For example, a plastic film may be used. Specific examples of the plastic film include polyethylene terephthalate (PET), polyethersulfone (PES), polystyrene (PS), polyethylene naphthalate (PEN), polyarylate (PAR), and polyetheretherketone (PEEK). , Polycarbonate (PC), Polyethylene (PE), Polypropylene (PP), Polyamide (PA) such as nylon 6, Cellulose resin film such as Polyimide (PI), Triacetylcellulose (TAC), Polyurethane (PUR), Polytetra Fluorine resins such as fluoroethylene, vinyl compounds such as polyvinyl chloride (PVC), polyacrylic acid (PMMA), polyacrylic acid esters, polyacrylonitrile, addition polymers of vinyl compounds, polymethacrylic acid, polymers Vinylidene compounds such as chloric acid esters, polyvinylidene chloride, vinylidene fluoride / trifluoroethylene copolymers, vinyl compounds such as ethylene / vinyl acetate copolymers or copolymers of fluorine-based compounds, polyethers such as polyethylene oxide, Epoxy resin, polyvinyl alcohol (PVA), polyvinyl butyral, and the like may be used.
In particular, a triacetyl cellulose (TAC) film is preferable as a material used for the antireflection film of the present invention because it has little birefringence and good transparency.

  Further, the transparent substrate may be subjected to a surface treatment such as a corona treatment or a low temperature plasma treatment. By performing the surface treatment, it is possible to improve adhesion in stacking other layers.

  The hard coat layer is provided in order to improve the mechanical strength of the antireflection film. By providing the hard coat layer, advantages such as high surface hardness, scratch resistance against scratching with a load such as a pencil, and suppression of cracks in the upper layer can be obtained.

  Further, the film thickness of the hard coat layer may be appropriately designed according to desired specifications. Specifically, for example, it is preferably in the range of about 5 μm to 12 μm. However, the film thickness of the hard coat layer in the antireflection film of the present invention is not limited to the above range.

  The hard coat layer is made of a material containing an amide compound. By including an amide compound in the hard coat layer, both improvement in hardness and warpage resistance of the antireflection film can be achieved. The amide compound contained in the hard coat layer of the antireflection film of the present invention is an amide having a carbon-carbon unsaturated double bond, which is a monomer having one or more amide groups and one or more polymerizable groups in one molecule. Compounds are preferred. Examples of the amide compound having a carbon-carbon unsaturated double bond include (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dibutyl (meth) acrylamide, Acrylic compounds such as N, N-dioctyl (meth) acrylamide, N-monobutyl (meth) acrylamide, N- (2-hydroxyethyl) acrylamide, N- (2-hydroxyethyl) methacrylamide (meth) acryloylmorpholine, N Examples thereof include vinyl compounds such as -vinylformamide, 2-propenylformamide, N-vinylpyrrolidone, and N-vinyl-ε-caprolactam.

Moreover, as a formation method of a hard-coat layer, you may use a well-known layer formation method suitably according to the material selected for the hard-coat layer.
Hereinafter, as an example, a method for preparing a hard coat layer forming coating liquid, applying a hard coat layer forming coating liquid, drying, curing by ionizing radiation, and forming a hard coat layer will be specifically described. I do.

  First, a coating liquid for forming a hard coat layer is prepared. A material for forming the hard coat layer is appropriately selected, and the material is diffused in a solvent. For example, the hard coat layer forming coating liquid may be a liquid in which a quaternary ammonium salt material, an amide compound, a photopolymerizable monomer, a photopolymerization initiator, and the like are diffused in a solvent.

The quaternary ammonium salt material has a structure of (—N ⁺ X ⁻ ), and by providing the quaternary ammonium cation (N ⁺ ) and an anion (X ⁻ ), the hard coat layer is made conductive. At this time, as X ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , F ⁻ , HSO ₄ ⁻ , SO ₄ ²⁻ , NO ₃ ⁻ , PO ₄ ³⁻ , HPO ₄ ²⁻ , H ₂ PO ₄ ⁻ , SO ₃ ^-, OH ^-, and the like.

As the quaternary ammonium salt material, an acrylic material containing a quaternary ammonium salt as a functional group in the molecule can be suitably used. Examples of the acrylic material containing a quaternary ammonium salt in the molecule as a functional group include, for example, acrylic acid or methacrylic acid ester of a polyhydric alcohol containing a quaternary ammonium salt (—N ⁺ X ⁻ ) in the molecule as a functional group. Such polyfunctional or polyfunctional (meth) acrylate compounds, polyfunctional urethane (meth) acrylate compounds synthesized from diisocyanate and polyhydric alcohol, acrylic acid or methacrylic acid hydroxy ester, etc. can be used. . In addition to these, examples of the ionizing radiation type material include polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like.

The photopolymerizable monomer may be appropriately selected from known materials in consideration of mechanical strength and the like. For example, an acrylic material may be used. Examples of acrylic materials include polymethylolpropane tri (meth) acrylate hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol. Hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, “polyfunctional (meth) acrylate compound such as acrylic acid or methacrylic acid ester of polyhydric alcohol”, “A polyfunctional urethane (meth) acrylate compound synthesized from a polyhydric alcohol, a polyvalent isocyanate and a hydroxyl group-containing acrylate”.
In particular, an acrylic material having three or more functional groups is preferable as a material used for the hard coat layer because of its excellent hardness and curing rate. Examples of the material having three or more functional groups include pentaerythritol hexa (meth) acrylate.
In addition, a polyfunctional urethane acrylate can be preferably used because the desired molecular weight and molecular structure can be designed and the physical properties of the formed hard coat layer can be easily balanced.
“(Meth) acrylate” refers to both “acrylate” and “methacrylate”. For example, “urethane (meth) acrylate” refers to both “urethane acrylate” and “urethane methacrylate”.

  A suitable one may be selected according to the photopolymerization initiator and the selected photopolymerizable monomer. For example, photopolymerization initiators such as acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, and thioxanthones may be used.

  The solvent may be appropriately selected in consideration of the stability of the composition, wettability with respect to the coating surface, volatility, and the like. Specifically, for example, alcohols such as methanol, ethanol, isopropanol, butanol and 2-methoxyethanol, ketones such as acetone and methyl ethyl ketone methyl isobutyl, esters such as methyl acetate, ethyl acetate and butyl acetate, diisopropyl ether and the like Ethers, glycols such as ethylene glycol, propylene glycol and hexylene glycol, glycol ethers such as ethyl cellosolve, butyl cellosolve, ethyl carbitol and butyl carbitol, aliphatic hydrocarbons such as hexane, heptane and octane, halogens Hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene, N-methylpyrrolidone, dimethylformamide, and the like may be used. Further, the solvent may be a mixed solvent obtained by mixing not only one type but also two or more types of solvents.

  Next, the hard coat layer forming coating solution is applied and dried.

  As a coating method, a coating method using a roll coater, a reverse roll coater, a gravure coater, a micro gravure coater, a knife coater, a bar coater, a wire bar coater, a die coater, or a dip coater may be used.

  Next, the hard coat layer-forming coating liquid is irradiated with ionizing radiation to form a hard coat layer.

  As the ionizing radiation, ionizing radiation to be used as appropriate may be selected according to the selected photopolymerization initiator. As the ionizing radiation, for example, ultraviolet rays or electron beams may be used. Moreover, when irradiating ionizing radiation, you may irradiate in various atmospheres, such as air | atmosphere and inert gas, such as nitrogen and argon. In the case of using ultraviolet rays for irradiating ionizing radiation, irradiation may be performed using a low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, electrodeless discharge tube, or the like.

  The antireflection layer is a layer having a refractive index different from that of the hard coat layer. By providing the antireflection layer, reflection of external light or the like on the display screen as an observation surface can be prevented.

  Further, the film thickness of the antireflection layer may be appropriately designed according to desired specifications. Specifically, for example, it is preferably in the range of about 95 nm to 110 nm. However, the film thickness of the antireflection layer in the antireflection film of the present invention is not limited to the above range.

Moreover, as a formation method of an antireflection layer, you may use a well-known layer formation method suitably according to the material selected for the antireflection layer.
Hereinafter, as an example, a method for adjusting the coating solution for forming an antireflection layer, applying the coating solution for forming an antireflection layer, drying, curing by ionizing radiation, and forming the antireflection layer will be specifically described. I do.

  First, the antireflection layer-forming coating solution is adjusted. A material for forming the antireflection layer is appropriately selected, and the material is diffused in a solvent. For example, the antireflection layer-forming coating liquid may be a liquid in which low refractive index particles, a material having water repellency, a photopolymerizable monomer, a photopolymerization initiator, and the like are diffused in a solvent.

The low refractive index particles are selected to control the refractive index of the antireflection layer. As the low refractive index particles, for example, {LiF, MgF, 3NaF · AlF ₃ , AlF ₃ (each having a refractive index of 1.4)}, Na ₃ AlF ₆ (cryolite refractive index 1.33), low refractive index Silica particles may be used. In particular, it is preferable to use low refractive index silica particles as the low refractive index particles. The low refractive index silica particles are low refractive index particles having voids inside the particles, and in the particles having voids inside the particles, the voids can have the refractive index of air (≈1). , Low refractive index particles with a very low refractive index. Examples of the low refractive index silica particles include porous silica particles and shell structure silica particles.

  When low refractive index silica particles are used for the low refractive index particles, the particle size of the low refractive index silica particles is preferably in the range of about 1 nm to 100 nm, and more preferably in the range of about 50 nm to 80 nm. . When the particle diameter of the low refractive index silica particles exceeds 100 nm, light is remarkably reflected by Rayleigh scattering, the antireflection layer 13 is whitened, and the transparency of the antireflection film 10 tends to be lowered. On the other hand, when the particle size of the low refractive index silica particles is less than 1 nm, problems such as non-uniformity of particles in the antireflection layer due to aggregation of particles occur.

  The material having water repellency may be appropriately selected from materials showing water repellency. For example, (1) silicone-based materials such as alkyl aralkyl-modified silicone oil, alkyl-modified silicone oil, polyether-modified silicone oil, alkyl polyether-modified silicone oil, (2) alkyl alkoxysilane compounds, silane siloxane compounds, polyester groups An organic silicon compound such as a silane compound, a silane compound having a polyether group, or a siloxane compound may be used.

The photopolymerizable monomer may be appropriately selected from known materials in consideration of mechanical strength and the like. For example, an acrylic material may be used. Examples of acrylic materials include polymethylolpropane tri (meth) acrylate hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol. Hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, “polyfunctional (meth) acrylate compound such as acrylic acid or methacrylic acid ester of polyhydric alcohol”, “A polyfunctional urethane (meth) acrylate compound synthesized from a polyhydric alcohol, a polyvalent isocyanate and a hydroxyl group-containing acrylate”.
In particular, an acrylic material having three or more functional groups is preferable as a material used for the antireflection layer because of its excellent hardness and curing rate. Examples of the material having three or more functional groups include pentaerythritol hexa (meth) acrylate.
In addition, a polyfunctional urethane acrylate can be suitably used because the desired molecular weight and molecular structure can be designed and the physical properties of the formed antireflection layer can be easily balanced.
“(Meth) acrylate” refers to both “acrylate” and “methacrylate”. For example, “urethane (meth) acrylate” refers to both “urethane acrylate” and “urethane methacrylate”.

  A suitable photopolymerization initiator may be selected according to the selected photopolymerizable monomer. For example, photopolymerization initiators such as acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, and thioxanthones may be used.

  The solvent may be appropriately selected in consideration of the stability of the composition, wettability with respect to the coating surface, volatility, and the like. Specifically, for example, alcohols such as methanol, ethanol, isopropanol, butanol and 2-methoxyethanol, ketones such as acetone and methyl ethyl ketone methyl isobutyl, esters such as methyl acetate, ethyl acetate and butyl acetate, diisopropyl ether and the like Ethers, glycols such as ethylene glycol, propylene glycol and hexylene glycol, glycol ethers such as ethyl cellosolve, butyl cellosolve, ethyl carbitol and butyl carbitol, aliphatic hydrocarbons such as hexane, heptane and octane, halogens Hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene, N-methylpyrrolidone, dimethylformamide, and the like may be used. Further, the solvent may be a mixed solvent obtained by mixing not only one type but also two or more types of solvents.

  Next, a coating liquid for forming an antireflection layer is applied and dried.

  As a coating method, a coating method using a roll coater, a reverse roll coater, a gravure coater, a micro gravure coater, a knife coater, a bar coater, a wire bar coater, a die coater, or a dip coater may be used.

  Next, the coated coating liquid for forming the antireflection layer is irradiated with ionizing radiation to form a hard coat layer.

  As the ionizing radiation, ionizing radiation to be used as appropriate may be selected according to the selected photopolymerization initiator. As the ionizing radiation, for example, ultraviolet rays or electron beams may be used. Moreover, when irradiating ionizing radiation, you may irradiate in various atmospheres, such as air | atmosphere and inert gas, such as nitrogen and argon. In the case of using ultraviolet rays for irradiating ionizing radiation, irradiation may be performed using a low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, electrodeless discharge tube, or the like.

  The shielding layer is a layer containing silicon oxide, and is provided to prevent the amide compound contained in the hard coat layer from penetrating and diffusing into other layers.

  The thickness of the shielding layer is preferably in the range of about 200 nm to 350 nm. When the film thickness of the formed shielding layer is less than 200 μm, the barrier layer has a barrier effect on the amide compound, and the effect of suppressing fading of the polarizing plate cannot be made sufficient. Further, when the thickness of the formed shielding layer exceeds 350 nm, it is not preferable because it takes time to form the shielding layer and the manufacturing cost increases.

In addition, as a method for forming the shielding layer, a method capable of suitably forming a layer containing silicon oxide may be appropriately selected from known methods. For example, you may form using dry coating methods, such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and vacuum deposition.
Hereinafter, as an example, a method of forming a shielding layer by EB deposition, which is vacuum deposition, by forming a deposition material containing silicon oxide will be described.

  First, a vapor deposition material containing silicon oxide is formed. (A) Silicon powder is put into a mold, (b) Pressurized from above the mold using a press plate, (c) Pressurized and molded silicon is peeled from the mold, (d) Molded By depositing silicon in a heating furnace while injecting oxygen, a vapor deposition material containing silicon oxide in which granular silicon oxide is aggregated can be formed. At this time, the oxidation degree of the outermost surface of the vapor deposition material is higher than that inside. In this case, the degree of oxidation refers to the oxygen / silicon ratio.

  The vapor deposition material containing silicon oxide is preferably made of particulate silicon oxide having a particle size in the range of 45 μm or more and less than 85 μm. When the particle size of silicon oxide is 85 μm or more, the density on the outermost surface of the vapor deposition material becomes rough, and therefore, EB irradiation is not uniformly performed, and a uniform shielding layer cannot be formed. In addition, when the particle size of silicon oxide is 45 μm or less, the density of the vapor deposition material itself increases, so that the vapor deposition material itself is damaged at the time of EB irradiation, and fragments may collide with the vapor deposition target, which may damage the vapor deposition target. .

  Next, the obtained deposition material containing silicon oxide can be irradiated with an electron beam (EB) under vacuum to perform EB deposition, thereby forming a shielding layer.

In FIG. 2, the process of shape | molding the vapor deposition material containing a silicon oxide is shown.
FIG.
(A) a step of charging powder silicon A into a mold B;
(B) A step of pressurizing J using a press plate C from the upper part of the mold B,
(C) a step of peeling the pressed and molded silicon plate E from the mold,
(D) A step of obtaining a silicon oxide plate I by firing the peeled silicon plate E while injecting oxygen G in a heating furnace F.
FIG. 2 also shows a silicon pillar E formed into a columnar shape and a silicon oxide pillar H fired into a columnar shape by using a columnar mold B.
At this time, the pressure J may be a pressure in a range of about 100 kN to 200 kN. Moreover, the firing conditions of the heating furnace F may be a temperature range of 1000 ° C. and a heating time of about 30 minutes to 60 minutes.

  The antireflection film of the present invention preferably has an average luminous reflectance in the range of 0.5% to 1.5%. When the average luminous reflectance exceeds 1.5%, the antireflection performance is lowered, and reflection of external light is likely to occur. On the other hand, when the average luminous reflectance is less than 0.4%, it is necessary to laminate a high refractive index layer and a low refractive index in order to realize high antireflection performance, resulting in high cost.

  The antireflection film of the present invention preferably has a total light transmittance of 95% or more. If the total light transmittance is less than 95%, it becomes unsuitable to be provided on the surface of an image device such as a transmissive liquid crystal display.

In the antireflection film of the present invention, the surface resistance value of the surface of the antireflection layer is preferably 1.0 × 10 ⁵ (Ω / cm ² ) or more and 1.0 × 10 ¹¹ (Ω / cm ² ) or less. . In order to impart high antistatic properties such as a surface resistance value of 1.0 × 10 ¹¹ (Ω / cm ² ) or less to the hard coat layer, conductive particles such as metal particles and metal oxide particles are used. In the case of forming a hard coat layer having antistatic properties, it is necessary to add a considerable amount of conductive particles, and at this time, the total light transmittance is lowered. However, when a quaternary ammonium salt material is used to form a hard coat layer having antistatic properties, good antistatic performance can be exhibited and a decrease in the total light transmittance can be prevented.

  The antireflection film of the present invention preferably has a haze in the range of 0.05% or more and 0.3% or less. By setting the haze to 0.3% or less, an antireflection film with high bright place contrast can be obtained. When the haze exceeds 0.3%, it is possible to apparently suppress light leakage when black is displayed in a dark place due to transmission loss due to scattering, but when displaying black in a bright place. The black display is blurred by scattering and the contrast is lowered. The haze of the antireflection film is preferably small, but it is difficult to make it less than 0.01%.

In addition, the antireflection film of the present invention preferably has a water vapor barrier property in a range of about 5.0 g / m ² / day to 7.0 g / m ² / day. When the water vapor barrier property exceeds 7.0 g / m ² / day or less, the antireflection film may not have a sufficient effect of suppressing fading of the polarizing plate. Moreover, in the antireflection film of the present invention, the water vapor barrier property is preferably 5.0 g / m ² / day or more. In the case where the water vapor barrier property of the antireflection film is less than 5.0 g / m ² / day, it becomes difficult for moisture in the polarizing layer to pass through the antireflection film when it is converted into a polarizing plate. May occur.

Hereinafter, the polarizing plate of the present invention will be described.
The polarizing plate of this invention is equipped with a polarizing layer on the transparent base material on the opposite side to the formation surface of the shielding layer of the above-mentioned antireflection film.

  The polarizing layer may be formed by appropriately selecting a material that exhibits physical properties to be polarized when transmitted from known materials. For example, you may use the PVA polarizing film etc. which show polarization | polarized-light performance by orientating and adsorb | sucking iodine to the polyvinyl alcohol film and its derivative which were mainly stretch-oriented.

FIG. 3 shows an example of the polarizing plate 210 of the present invention.
FIG. 3 shows the antireflection film 10 in which the antireflection layer 13 / hard coat layer 12 / shielding layer 14 / transparent substrate 11 / are laminated in this order, as viewed from the surface layer, on the side opposite to the surface on which the shielding layer 14 is formed. It is the schematic which shows the polarizing plate 210 which laminated | stacked the polarizing layer 23 and the polarizing plate transparent base material 22 on the transparent base material 11 of this.

The display device of the present invention will be described below.
The display device of the present invention is a display device using the above polarizing plate.

  The display device of the present invention may include other functional members in addition to the above polarizing plate. Other functional members include, for example, a diffusion film, a prism sheet, a brightness enhancement film, a retardation film for compensating for a retardation of a liquid crystal cell and a polarizing plate, for effectively using light emitted from a backlight, Etc.

FIG. 4 shows an example of the display device of the present invention.
FIG. 4 shows the polarization in which the antireflection layer 13 / hard coat layer 12 / shielding layer 14 / transparent substrate 11 / polarizing layer 23 / polarizing plate transparent substrate 22 / are laminated in this order as viewed from the outermost layer as the observation surface. A plate 210, a liquid crystal cell 30 disposed below the polarizing plate 210, and a first polarizing plate transparent base material upper layer 41 / second polarizing plate polarizing layer 43 / second polarizing plate disposed below the liquid crystal cell 30. The outline which shows the display apparatus which has the liquid crystal cell 30 provided with the 2nd polarizing plate 40 on which the board transparent base material lower layer 42 was laminated | stacked in this order, and the backlight unit 50 arrange | positioned under this 2nd polarizing plate. FIG.

<Example 1>
First, the vapor deposition material was vacuum-deposited on the transparent substrate to form a shielding layer.
At this time, a tri-acetyl cellulose (TAC) film was used as the transparent substrate. The vapor deposition material was a vapor deposition material obtained by molding and baking silicon oxide having a particle size of 45 μm. The thickness of the shielding layer was 250 nm.

Next, a coating liquid for forming a hard coat layer was applied on the shielding layer, dried, and irradiated with ultraviolet rays to form a transparent hard cord layer.
At this time, the dry film thickness of the shielding layer was 10 μm. Moreover, ultraviolet irradiation was performed on the conditions of irradiation dose of 250 mJ / m < ² > using the ultraviolet irradiation device (Fusion UV Systems Japan, light source H bulb). The composition of the hard coat layer forming coating solution used is shown below.

(Hardcoat layer forming coating solution: Example 1)
Quaternary ammonium salt material / methacryloyloxyethyltrimethylammonium chloride (manufactured by Kyoeisha, Light Ester DQ-100): 20 parts by weight.
Amide compound / N-vinylformamide (Arakawa Chemicals, beam set 770): 10 parts by weight.
Photopolymerizable monomer / pentaerythritol tetraacrylate: 25 parts by weight.
Photopolymerization initiator / Irgacure 184 (manufactured by BASF): 5 parts by weight.
Other / urethane acrylate: 75 parts by weight
Methyl acetate: 50 parts by weight
2-butanone: 50 parts by weight.

Next, an antireflection layer-forming coating solution was applied onto the hard coat layer, dried, and irradiated with ultraviolet rays to form a transparent antireflection layer.
At this time, the dry film thickness of the antireflection layer was 100 nm. Moreover, ultraviolet irradiation was performed on the conditions of the irradiation dose of 200 mJ / m < ² > using the ultraviolet irradiation device (Fusion UV Systems Japan, light source H bulb). The composition of the antireflection layer forming coating solution used is shown below.

(Antireflection layer-forming coating solution: Example 1)
Low refractive index particles / silica particles (average particle size 50 nm): 36 parts by weight.
Photopolymerizable monomer / dipentaerythritol hexaacrylate: 1.6 parts by weight.
Water repellent material / Momentive Performance Materials TSF44: 0.2 parts by weight.
Photopolymerization initiator / Irgacure 184 (manufactured by BASF): 0.2 parts by weight.
Other / Isopropyl alcohol: 72.2 parts by weight.
Methyl isobutyl ketone: 13.8 parts by weight.

  From the above, the antireflection film of the present invention in which the transparent base material / shielding layer / hard coat layer / antireflection layer was laminated in this order was obtained.

Next, a PVA polarizing film and a tri-acetyl cellulose (TAC) film were attached to the obtained antireflection film.
From the above, the polarizing plate of the present invention in which the antireflection film / PVA polarizing film / TAC film of the present invention was laminated in this order was obtained.

<Example 2>
A polarizing plate was prepared in the same manner as in Example 1. However, the particle size of the silicon oxide used for the vapor deposition material was 60 μm.

<Example 3>
A polarizing plate was prepared in the same manner as in Example 1. However, the particle size of silicon oxide used for the vapor deposition material was 30 μm.

<Example 4>
A polarizing plate was prepared in the same manner as in Example 1. However, the particle size of silicon oxide used for the vapor deposition material was 85 μm.

<Example 5>
A polarizing plate was prepared in the same manner as in Example 1. However, the film thickness of the shielding layer was 50 nm.

<Comparative Example 1>
A polarizing plate was prepared in the same manner as in Example 1. However, in the preparation of the antireflection film, a hard coat layer was formed directly on the transparent substrate, and no shielding layer was provided.

<Evaluation>
About the polarizing plate obtained in Examples 1-5 and Comparative Example 1, (1) haze, (2) visual average reflectance, (3) surface resistance value, (4) water vapor barrier property, (5) polarized light Evaluation of fading of the board was performed. Each inspection condition is shown below. The evaluation results are summarized in Table 1.

(Haze)
About the obtained anti-reflective film, haze was measured with the haze meter (Nippon Denshoku Industries Co., Ltd. make, NDH2000).

(Visibility average reflectance)
About the surface of the antireflection layer of the obtained antireflection film, the spectral reflectance at an incident angle of 5 ° was measured using an automatic spectrophotometer (manufactured by Hitachi, U-4100, measurement wavelength 360 to 800 nm). Further, the average luminous reflectance was obtained from the obtained spectral reflectance curve. In the measurement, a matte black paint was applied to the surface of the transparent substrate on which the antireflection layer was not formed, and antireflection treatment was performed. The average luminous reflectance is a reflectance value obtained by calibrating the reflectance of each wavelength of visible light with the relative luminous sensitivity and averaging it. At this time, the photopic standard relative luminous sensitivity is used as the specific luminous efficiency.

(Surface resistance value)
About the surface of the antireflection layer of the obtained antireflection film, the surface resistance value based on JIS K6911 was measured.

(Water vapor barrier property)
About the obtained anti-reflective film, based on JISZ0208, water vapor | steam barrier property was measured by the cup method on 40 degreeC and 90% conditions.

(Evaluation of fading of polarizing plate)
First, the polarizing plate to be evaluated was accelerated and deteriorated under the conditions of 65 ° C. to 95% and 200 hours.
Next, a TAC / PVA polarizing film / TAC polarizing plate prepared in advance and an acceleratedly deteriorated polarizing plate were set in a crossed Nicol state at the upper part of the lamp in a dark room.
Next, it was evaluated from the upper part of the lamp whether there was light leakage visually.

  As shown in Table 1, in Examples 1 to 5 in which the shielding layer was formed, it was confirmed that fading of the polarizing plate was suppressed as compared with Comparative Example 1 in which the shielding layer was not formed.

Moreover, it was confirmed that Example 3 in which the particle diameter of silicon oxide is smaller than 45 μm is slightly faded compared with Examples 1 and 2 in which the particle diameter is in the range of 45 μm or more and less than 85 μm.
Further, although Example 4 in which the particle size of silicon oxide is 85 μm or more was compared with Examples 1 and 2 in which the particle size was in the range of 45 μm or more and less than 85 μm, the color fading of the polarizing plate was not confirmed equally, It was confirmed that the shielding layer was partially colored and was not very suitable for an antireflection film. This is thought to be because the amount of material consumed by EB irradiation is not uniform due to the large particle size.
Further, in Example 5 in which the shielding layer was less than 200 nm, it was confirmed that the polarizing plate was slightly faded as compared with Examples 1 and 2 in which the shielding layer was in the range of 200 nm to 350 nm. This is presumably because the water vapor barrier property was in the range of 7.0 g / m ² / day or less due to the thin thickness of the shielding layer.

  From the above, it was confirmed that fading of the polarizing plate is suppressed by forming a shielding layer containing silicon oxide. In addition, it was confirmed that it is more preferable to use particulate silicon oxide in the range of 45 μm or more and less than 85 μm as the vapor deposition material. Moreover, it was confirmed that the thickness of the shielding layer is more preferably in the range of 200 nm to 350 nm.

  The present invention can be expected to be widely used for all apparatuses using polarizing plates. For example, (1) image display devices such as CRT displays, liquid crystal displays, plasma displays, EL displays, (2) windows made of glass, plastic films, etc., (3) polarizing plates used on the surfaces of optical lenses, glasses, etc. .

10 ......... Antireflection film 11 ......... Transparent substrate 12 ......... Hard coat layer 13 ......... Antireflection layer 14 ...... Shielding layer 210 ... Polarizing plate 22 ......... Polarizing substrate transparent substrate 23 ... ...... Polarizing layer 30 ......... Liquid crystal cell 40 ......... Second polarizing plate 41 ......... Second polarizing plate transparent substrate upper layer 42 ......... Second polarizing plate transparent substrate lower layer 43 ......... Second polarizing plate Polarizing layer 50 ......... Backlight unit

Claims (6)

A transparent substrate;
A hard coat layer laminated above the transparent substrate;
An antireflection layer laminated above the hard coat layer;
A shielding layer between the transparent substrate and the hard coat layer,
The hard coat layer is a hard coat layer containing an amide compound,
The antireflection film, wherein the shielding layer is a shielding layer containing silicon oxide. 2. The antireflection film according to claim 1, wherein the silicon oxide is made from particulate silicon oxide having a particle size in a range of 45 μm or more and less than 85 μm. The thickness of the said shielding layer exists in the range of 200 nm or more and 350 nm or less, The antireflection film in any one of Claim 1 or Claim 2 characterized by the above-mentioned. The antireflection film according to any one of claims 1 to 3, further comprising a water vapor barrier property in a range of 7.0 g / m ² / day or less. An antireflection film according to any one of claims 1 to 4,
A polarizing layer on the transparent substrate opposite to the surface on which the shielding layer of the antireflection film is formed;
A polarizing plate comprising:   A display device using the polarizing plate according to claim 5.