JP2015203752A - Antireflection film, polarizing plate with antireflection film, and transmissive liquid crystal display comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film that gives no hue to reflected light of external light from a front face thereof, that can decrease a hue in reflected light of external light incident at various angles, and that has a good state of film thickness uniformity and excellent adhesiveness.SOLUTION: The antireflection film comprises a transparent support body. On the transparent support body, a hard coat layer, a high refractive index layer, and a low refractive index layer are stacked in this order from the transparent support body side, where refractive indices of the films of these layers satisfy (high refractive index layer)>(hard coat layer) and (transparent support body)>(low refractive index layer). The high refractive index layer contains a binder resin and an additive, in which an organic compound having an aromatic ring in the molecule is used for the binder resin, an organic compound having at least either of fluorine and silicon and having an aromatic ring in the molecule is used for the additive, and the additive is incorporated by 0.01 to 0.2 pt.wt. with respect to 100 pts.wt of the binder resin. The resulting film decreases a hue in reflected light of external light incident at various angles and has excellent adhesiveness.

Description

  The present invention provides an antireflection film, an antireflection film-attached polarizing plate, and an antireflection film provided for the purpose of preventing external light from being reflected on the surface of a display or the like and an air gap layer existing between polarizing plates of a touch panel. The present invention relates to a transmissive liquid crystal display.

  In general, a display is used in an environment where external light or the like enters regardless of whether the display is used indoors or outdoors. Incident light such as external light is specularly reflected on the display surface and the like, and the reflected image thereby mixes with the display image, thereby degrading the screen display quality. Therefore, it is essential to provide an antireflection function on the display surface or the like, and there is a demand for higher performance of the antireflection function.

  In general, the antireflection function can be obtained by forming a multi-layered antireflection layer having a repeating structure of a high refractive index layer and a low refractive index layer made of a transparent material such as a metal oxide on a transparent support. These antireflection layers having a multilayer structure can be formed by a dry film forming method such as a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. In the case of forming an antireflection layer using a dry film formation method, there is an advantage that the film thickness of the low refractive index layer and the high refractive index layer can be precisely controlled, but the film formation is performed in a vacuum. There is a problem that productivity is low and it is not suitable for mass production. On the other hand, as a method for forming an antireflection layer, attention has been focused on production of an antireflection film by a wet film formation method using a coating liquid capable of increasing the area, continuously producing, and reducing the cost.

  In recent years, with the spread of mobile terminals, the number of cases where the image display device itself is operated at hand has increased. Further, since it is exposed to strong external light outdoors during the daytime than when used indoors, there is a need for an antireflection film having a low reflectance that does not impair visibility even outdoors.

  Further, when an antireflection film is applied to a stationary installation type image display device, most of them are premised on reducing reflected light from a fixed light source. This means that the incident angle of external light does not change. On the other hand, in the case of a mobile terminal, since it is used outdoors or operated at hand, external light is incident from various angles, and viewers often observe the display from various angles. . Therefore, when trying to apply an antireflection film to a mobile terminal, it is necessary to consider not only the reflected light from the front but also the reflected light, especially the color of the reflected light, for the light source of all incident angles. . At present, most anti-reflection films are designed for stationary image display devices, so the film design does not assume that the incident angle and reflection angle of external light will change. There are many.

  One of the methods for realizing an antireflection film that reduces the coloring of external light incident from various angles is a method using an optical multilayer film. It is composed of a plurality of layers having different refractive indexes. Usually, in the case of two optical layers, a high refractive index layer having a higher refractive index than that of the transparent support, and a low refractive index lower than that of the transparent support. In this case, it is a structure in which an intermediate refractive index layer is provided between a transparent support and a high refractive index layer in the optical two-layer product. is there. It is also possible in principle to use a multilayer optical film layer structure in which the number of high refractive index layers and low refractive index layers is increased by an arbitrary number. However, when increasing the number of layers, deterioration of surface properties (film thickness unevenness) becomes a problem. Even if the film thickness unevenness of each layer is small, as they are laminated, the film thickness unevenness of each layer overlaps and the film thickness unevenness as a whole increases. Further, as the number of layers is increased, the influence on the hue of reflected light in the laminate due to the change in the film thickness of each layer increases, so that it is important to suppress film thickness unevenness. As the reflectance is further reduced, when the reflectance is high, the film thickness unevenness that has been difficult to see due to the reflected light becomes clear. In order to suppress the film thickness unevenness, an additive is usually used for imparting leveling properties. However, in the intermediate layer in the laminate, the additive that can be used is limited due to the problem of recoatability. Further, since the cost is increased by increasing the number of layers, it can be said that the optical two-layer product or the three-layer product described above is preferable. In any case, it is essential to stack a high refractive index layer having a higher refractive index than that of the transparent support. Further, in most cases, inorganic fine particles are used as the material used for the high refractive index layer. (Patent Document 1) (Patent Document 2)

Japanese Patent Laying-Open No. 2005-238772 JP-A-2005-316350

  However, in the case where the refractive index is improved by using inorganic fine particles in the high refractive index layer, a binder resin for fixing the inorganic fine particles as a film is used. To increase the refractive index of the high refractive index layer, it can be dealt with by increasing the proportion of inorganic fine particles used, but since the film strength and film uniformity of the high refractive index layer are deteriorated, the stability of the coating liquid is adversely affected, In consideration of the quality as an antireflection film, there is a problem that the upper limit of the use ratio of the inorganic fine particles is determined and the degree of freedom in optical design of the antireflection film is impaired.

  An object of the present invention is to have an excellent antireflection function, reduce the reflectance and hue of reflected light from the front, and reduce the color of reflected light of external light incident from various angles. An antireflection film having excellent film thickness unevenness and excellent adhesion, an image display device or a liquid crystal display device including the antireflection film, a polarizing plate including the antireflection film, and a transmissive liquid crystal display are provided. There is to do.

The invention according to claim 1 of the present invention is an antireflection film obtained by sequentially laminating a hard coat layer, a high refractive index layer, and a low refractive index layer on one surface of a transparent support,
The high refractive index layer contains at least a binder resin having an aromatic ring in the molecule, an additive selected from one or more of fluorine-containing aromatic compounds and silicon-containing aromatic compounds,
And the said additive is mix | blended in the range of 0.01-0.2 mass part with respect to 100 mass parts of the said binder resin, It is an antireflection film characterized by the above-mentioned.

  The invention according to claim 2 is the antireflection film according to claim 1, wherein the binder resin contains a bisphenol A skeleton.

  The invention according to claim 3 is a polarizing plate with an antireflection film, characterized in that the antireflection film according to claim 1 or 2 is used and a polarizing plate is provided on the other surface side of the transparent support. is there.

  The invention according to claim 4 is a transmissive liquid crystal display comprising the polarizing plate with an antireflection film according to claim 3.

According to claim 1 of the present invention, on one surface of the transparent support, a hard coat layer, a high refractive index layer,
The antireflective film is formed by sequentially laminating a low refractive index layer, and the high refractive index layer is at least one of a binder resin having an aromatic ring in a molecule, a fluorine-containing aromatic compound, and a silicon-containing aromatic compound. And a high refractive index layer by blending the additive in a range of 0.01 to 0.2 parts by mass with respect to 100 parts by mass of the binder resin. Both strength and uniformity can be improved.

  Conventionally used acrylic additives have a problem that recoatability is good, but leveling properties are bad, and as a solution to this problem, it is necessary to increase the amount of additive added. There is a problem that the ratio of the additive increases and the refractive index decreases.

  However, the high refractive index layer according to the present invention provides recoatability by using a fluorine-containing aromatic compound or silicon-containing aromatic compound as an additive, and has high compatibility with these additives. By selecting a binder resin having an aromatic ring in the molecule, the blending ratio of the additive can be suppressed to a low level. As a result, the strength and uniformity of the film can be maintained without reducing the refractive index of the high refractive index layer.

  According to claim 2, an additive selected from the fluorine-containing aromatic compound and the silicon-containing aromatic compound by selecting a resin having a bisphenol A skeleton as the binder resin having an aromatic ring in the molecule. In contrast, higher compatibility can be provided.

  Moreover, according to claim 3, by using the antireflection film according to claim 1 or 2, a polarizing plate having an excellent antireflection function by providing a polarizing plate on the other surface side of the transparent support. Can be provided.

  As described above, by providing the transmissive liquid crystal display with the antireflection film of the present invention and the polarizing plate with the antireflection film provided with the antireflection film, the hue of the reflected light from the front in addition to the antireflection function In addition, it is possible to provide a transmissive liquid crystal display that reduces the coloring of reflected light of external light incident from various angles.

It is a schematic cross section of one embodiment of the antireflection film of the present invention. 1 is a schematic cross-sectional view showing an embodiment of a polarizing plate with a hard coat film according to the present invention. The schematic sectional drawing which shows the transmissive liquid crystal display which comprised the polarizing plate with a hard coat film which concerns on this invention. The schematic sectional drawing which shows the transmissive liquid crystal display which comprised the polarizing plate with a hard coat film which concerns on this invention.

  Hereinafter, the antireflection film of the present invention will be described in detail.

  As shown in FIG. 1, the antireflection film of the present invention comprises an antireflection film 1 in which a hard coat layer 12, a high refractive index layer 13, and a low refractive index layer 13 are sequentially laminated on one surface of a transparent support 11. The high refractive index layer 13 contains at least a binder resin having an aromatic ring in the molecule, an additive selected from one or more of a fluorine-containing aromatic compound and a silicon-containing aromatic compound, And the said additive is mix | blended in the range of 0.01-0.2 mass part with respect to 100 mass parts of the said binder resin, It is characterized by the above-mentioned.

  The luminous average reflectance of the antireflection film of the present invention is preferably in the range of 0.05% or more and 1.00% or less. When the luminous average reflectance is less than 0.05%, the refractive index of the high refractive index layer must be adjusted higher, and the refractive index of the low refractive index layer must be adjusted lower.

However, in general, in order to adjust the refractive index, it is necessary to increase the amount of addition of a refractive index adjusting material such as metal oxide fine particles or silica fine particles. The problem of causing a decrease in hardness arises. In addition, when the luminous average reflectance is higher than 1.00%, a reduction in contrast occurs when mounted on a display or the like due to deterioration of the antireflection function.

The antireflection film of the present invention can reduce the hue of reflected light from the front, and can reduce the coloring of external reflected light incident from various angles. More specifically, it is desirable to satisfy the following conditions. The hue of the reflected light under the reflection condition in which the incident angle is in the range of 5 ° to 45 ° and the incident angle is equal to the reflection angle in the wavelength range of 380 nm to 780 nm of the C light source which is the CIE standard light source is CIE1976L ^* a ^* b ^*. By satisfying −3 ≦ a ^* ≦ 3 and −5 ≦ b ^* ≦ 5 in the color space, even when the incident angle of the external light changes, the hue of the reflected light of the antireflection film becomes a neutral color. It is good to meet. Since the hue of the reflected light is better when a ^* = 0 and b ^* = 0 at any angle, it is more preferable that −1 ≦ a ^* ≦ 1 and −1 ≦ b ^* ≦ 1.

  Hereinafter, the layer configuration of the antireflection film according to the present invention will be described in detail.

  As shown in FIG. 1 as an embodiment, the antireflection film 1 of the present invention has a three-layer structure in which a hard coat layer 12, a high refractive index layer 13, and a low refractive index layer 14 are sequentially laminated on a transparent support 11. It is. At this time, it is possible to have a multilayer structure in which the number of layers of the high refractive index layer 13 and the low refractive index layer 14 is increased by an arbitrary number.

Specifically, by adjusting the film thickness and refractive index of each of the above layers, the a ^* value and b ^* value, which are hue parameters of the reflected light, can be adjusted to the intended ones. In the antireflection film of the present invention, the transparent support 11, the hard coat layer 12, the high refractive index layer 13, and the low refractive index layer 14 constituting the antireflective film have a refractive index relationship of the respective layers. > Hard coat layer, transparent support> Low refractive index layer. At this time, the refractive index of the hard coat layer 12 is in the range of 1.45 to 1.55, the refractive index n ₁ of the high refractive index layer 13 is in the range of 1.55 to 1.75, and the refractive index of the low refractive index layer 14 is. it is desirable rate _{n 2} is in the range of 1.25 to 1.35.

Further, the film thickness of each layer at this time is such that the film thickness of the hard coat layer is 3.0 to 10 μm, the film thickness d ₁ of the high refractive index layer and the film thickness d ₂ of the low refractive index layer are respectively represented by the following formulas: The range (unit: nm) of (1) and (2) is desirable.
Formula (1) (2 × λ / 4) × 0.8 <n ₁ d ₁ <(2 × λ / 4) × 1.2
Formula (2) (1 × λ / 4) × 0.9 <n ₂ d ₂ <(1 × λ / 4) × 1.1
Here, λ is an antireflection design center wavelength in the antireflection film of the present invention. This wavelength is usually selected in the green wavelength band (for example, 550 nm) that is most easily perceived by humans.

  Examples of the coating method of the hard coat layer, the high refractive index layer and the low refractive index layer in the present invention include existing coating methods such as a spray method, a screen printing method, a doctor blade method, a gravure printing method, a die coating method, and an inkjet method. However, it is not particularly limited.

  As the transparent support 11 according to the present invention, in consideration of optical properties such as transparency and refractive index of light, and various physical properties such as impact resistance, heat resistance and durability, polyolefins such as polyethylene and polypropylene are used. Polyesters such as polyethylene terephthalate and polyethylene naphthalate, celluloses such as triacetyl cellulose, diacetyl cellulose and cellophane, polyamides such as 6-nylon and 6,6-nylon, acrylics such as polymethyl methacrylate, polystyrene, poly Those made of an organic polymer such as vinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, ethylene vinyl alcohol are used. In particular, polyethylene terephthalate, triacetyl cellulose, polycarbonate, and polymethyl methacrylate are preferable. Among these, triacetyl cellulose can be suitably used for various displays because of its low birefringence and good transparency.

  Furthermore, these organic polymers may be added with known additives such as ultraviolet absorbers, infrared absorbers, plasticizers, lubricants, colorants, antioxidants, flame retardants, etc. Can be used. The transparent support may be composed of one or a mixture of two or more selected from the above organic polymers, or a polymer, or may be a laminate of a plurality of layers.

  In addition, it is preferable that the thickness of a transparent support body is the range of 20-200 micrometers, and also it is preferable that it is the range of 20-80 micrometers.

  An acrylic material can be used as the hard coat layer 12 according to the present invention. Acrylic materials include monofunctional, bifunctional or trifunctional or higher (meth) acrylate compounds such as acrylic acid or methacrylic acid ester of polyhydric alcohol, diisocyanate and polyhydric alcohol, and hydroxyester of acrylic acid or methacrylic acid, etc. A polyfunctional urethane (meth) acrylate compound as synthesized from the above can be used. Besides these, as ionizing radiation type materials, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can be used. .

  In the present invention, “(meth) acrylate” refers to both “acrylate” and “methacrylate”. For example, “urethane (meth) acrylate” indicates both “urethane acrylate” and “urethane methacrylate”.

  Examples of the monofunctional (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl ( (Meth) acrylate, t-butyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) ) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, benzyl (Meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethyl carbitol (meth) acrylate, phosphoric acid (meth) acrylate, ethylene oxide modified phosphoric acid (meth) acrylate, phenoxy (meta) ) Acrylate, ethylene oxide modified phenoxy (meth) acrylate, propylene oxide modified phenoxy (meth) acrylate, nonylphenol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) Acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl hydrogen phthalate, 2- (meth) acryloyloxypropyl hydrogen Phthalate, 2- (meth) acryloyloxypropyl hexahydrohydrogen phthalate, 2- (meth) acryloyloxypropyl tetrahydrohydrogen phthalate, dimethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate , Hexafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, 2 -Adamantane derivatives mono (meth) acrylates such as adamantyl acrylate having a monovalent mono (meth) acrylate derived from adamantane and adamantanediol.

  Examples of the bifunctional (meth) acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate, and nonanediol di (meth). ) Acrylate, ethoxylated hexanediol di (meth) acrylate, propoxylated hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (Meth) acrylate, neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol Ruji (meth) acrylate, di (meth) acrylate, such as hydroxypivalic acid neopentyl glycol di (meth) acrylate.

  Examples of the trifunctional or higher functional (meth) acrylate compound include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, and tris 2-hydroxy. Ethyl isocyanurate tri (meth) acrylate, tri (meth) acrylate such as glycerin tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, etc. Trifunctional (meth) acrylate compounds, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol te Trifunctional or higher polyfunctionality such as la (meth) acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane hexa (meth) acrylate ( Examples thereof include a (meth) acrylate compound and a polyfunctional (meth) acrylate compound obtained by substituting a part of these (meth) acrylates with an alkyl group or ε-caprolactone.

  Among acrylic materials, polyfunctional urethane acrylates can be suitably 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. . The urethane acrylate is obtained by reacting a polyhydric alcohol, a polyvalent isocyanate, and a hydroxyl group-containing acrylate. Specifically, Kyoeisha Chemical Co., Ltd., UA-306H, UA-306T, UA-306l, etc., Nippon Synthetic Chemical Co., Ltd., UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV -7650B, etc., manufactured by Shin-Nakamura Chemical Co., Ltd., U-4HA, U-6HA, UA-100H, U-6LPA, U-15HA, UA-32P, U-324A, etc., manufactured by Daicel UCB, Ebecryl-1290, Ebecryl -1290K, Ebecryl-5129, etc., manufactured by Negami Kogyo Co., Ltd., UN-3220HA, UN-3220HB, UN-3220HC, UN-3220HS, etc. can be mentioned, but not limited thereto.

  Besides these, as ionizing radiation type materials, polyether resins, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, etc. having acrylate functional groups can be used. The material is not particularly limited.

  In addition, since the ionizing radiation curable material is cured by ultraviolet rays, a photopolymerization initiator is added to the hard coat layer forming coating solution. Any photopolymerization initiator may be used as long as it generates radicals when irradiated with ultraviolet rays. For example, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones are used. Can do. The addition amount of the photopolymerization initiator is 0.1 to 10 parts by weight, preferably 1 to 7 parts by weight, more preferably 1 to 5 parts by weight with respect to 100 parts by weight of the ionizing radiation curable material. Parts by weight.

  Furthermore, a solvent and various additives can be added to the coating liquid for forming a hard coat layer as necessary. Solvents include aromatic hydrocarbons such as toluene, xylene, cyclohexane and cyclohexylbenzene, hydrocarbons such as n-hexane, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, dioxane, dioxolane, and trioxane. , Ethers such as tetrahydrofuran, anisole and phenetole, and ketones such as methyl isobutyl ketone, methyl butyl ketone, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, and methylcyclohexanone , Ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate Suitable for coating among esters such as n-pentyl acetate and γ-ptyrolactone, cellosolves such as methyl cellosolve, cellosolve, butyl cellosolve and cellosolve acetate, and alcohols such as methanol, ethanol, isopropyl alcohol and butanol Etc. are selected as appropriate. In addition, a surface adjusting agent, a refractive index adjusting agent, an adhesion improver, a curing agent, and the like can be added to the coating liquid as additives.

  Moreover, you may add another additive to the coating liquid for hard-coat layer formation. Examples of the additive include a defoaming agent, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, and a polymerization inhibitor.

  The high refractive index layer 13 according to the present invention contains at least a binder resin having an aromatic ring in the molecule, and an additive selected from one or more of a fluorine-containing aromatic compound and a silicon-containing aromatic compound. In addition, a material to which metal fine particles, a silane coupling agent or organic fine particles are added can be used. These components are appropriately selected depending on the required refractive index, and the refractive index is adjusted by a combination of materials, a mixing ratio, and the like.

  The binder resin is preferably a resin having a refractive index of 1.50 or more, and examples thereof include phenol resins (bisphenol A, bisphenol F, bisphenol S, etc.), oxetane resins, and the like.

  Among the resins containing the aromatic ring, bisphenol A-containing acrylate is preferably used. Specifically, EO-modified bisphenol A diacrylate, PO-modified bisphenol A diacrylate, or the like can be used.

  In addition to this, an acrylic material exemplified as the ionizing radiation curable material contained in the hard coat layer forming coating liquid can be mixed and used in combination. Acrylic materials are synthesized from polyfunctional or polyfunctional (meth) acrylate compounds such as polyhydric alcohol acrylic acid or methacrylic acid ester, diisocyanate and polyhydric alcohol, and acrylic acid or methacrylic acid hydroxy ester. Such a polyfunctional urethane (meth) acrylate compound can be used. Besides these, as ionizing radiation type materials, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can be used. .

  When the metal fine particles or organic fine particles are added, metal alkoxides such as Ti, Ta, Zr, In, and Zn, and metal fine particles such as titanium oxide, zirconium oxide, zinc oxide, indium oxide, and antimony oxide can be used. In particular, antimony oxide is preferably used.

  Although what is used as a dilution solvent is not specifically limited, Alcohols, such as methanol, ethanol, isopropanol, butanol, 2-methoxyethanol, are considered in consideration of the stability of a composition, the wettability with respect to a hard-coat layer, volatility, etc. , Ketones such as acetone, methyl ethyl ketone and methyl isobutyl, esters such as methyl acetate, ethyl acetate and butyl acetate, ethers such as diisopropyl ether, glycols such as ethylene glycol, propylene glycol and hexylene glycol, ethyl cellosolve and butyl cellosolve Glycol ethers such as ethyl carbitol and butyl carbitol, aliphatic hydrocarbons such as hexane, heptane and octane, halogenated hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene, N-mes Rupiroridon, dimethylformamide and the like. Further, the solvent can be used not only as one type but also as a mixture of two or more types.

  Moreover, it is desirable to add an additive in order to prevent film thickness unevenness of the coating film. As the additive used for the intermediate layer, an additive such as acrylic which has a relatively low surface energy reducing ability and is difficult to be unevenly distributed on the coating film surface is used. However, acrylic additives have good recoating properties but weak leveling properties, and the amount added must be increased in order to suppress film thickness unevenness. Therefore, the ratio of the additive becomes high and the refractive index becomes low. The additive used in the present invention is characterized by containing at least one of fluorine and silicon and an aromatic ring in the molecule.

  In general, fluorine and silicon have a high surface energy reducing ability and excellent leveling properties. However, when an additive containing fluorine or silicon is usually used for the intermediate layer, the recoatability is poor, and the upper layer repels and is difficult to apply. By containing an aromatic ring in the molecule of the additive, the compatibility with the binder containing the aromatic ring in the molecule is improved as in the present invention. Therefore, since the solvent ratio is high in the coating liquid, the additive is unevenly distributed on the coating film surface, exhibits leveling properties, and the solvent volatilizes during the drying process, so the binder ratio becomes higher than the solvent ratio, and the additive Incorporated into the binder and less unevenly distributed on the surface, the repelling when the upper layer is applied is suppressed. Even if fluorine with a low refractive index is contained in the additive molecule, the refractive index of the additive itself is increased by containing an aromatic ring with a high refractive index, and the refractive index of the high refractive index layer by the additive is increased. The decrease can also be suppressed.

  The amount of the additive containing at least one of fluorine or silicon and an aromatic ring in the molecule is preferably 0.05 to 0.2 parts by weight with respect to 100 parts by weight of the binder resin. When the addition amount is less than 0.05 parts by weight, the leveling property is weak and the film thickness unevenness cannot be suppressed. On the other hand, when the addition amount is more than 0.2 parts by weight, the recoatability is poor and repelling occurs when the low refractive index layer is laminated on the high refractive index layer.

As the low refractive index layer 14 according to the present invention, as the low refractive particles, LiF, MgF, 3NaF.AlF or AlF (all having a refractive index of 1.4), or Na ₃ AlF ₆ (cryolite, refraction) Low refractive index particles made of a low refractive material having a refractive index of 1.33) can be used. Moreover, the particle | grains which have a space | gap inside a particle | grain can be used suitably. In the case of particles having voids inside the particles, the voids can be made to have a refractive index of air (≈1), so that they can be low refractive index particles having a very low refractive index. Specifically, low refractive index silica particles having voids inside can be used.

  The low refractive index particles preferably have a particle size of 1 nm to 100 nm. When the particle diameter exceeds 100 nm, light is remarkably reflected by Rayleigh scattering, and the low refractive index layer tends to be whitened and the transparency of the antireflection film tends to be lowered. On the other hand, when the particle size is less than 1 nm, problems such as non-uniformity of particles in the low refractive index layer due to aggregation of particles occur.

  The binder matrix forming material for forming the low refractive index layer 14 includes an ionizing radiation curable material. As the ionizing radiation curable material, acrylic materials exemplified as the ionizing radiation curable material contained in the hard coat layer forming coating liquid can be used. Acrylic materials are synthesized from polyfunctional or polyfunctional (meth) acrylate compounds such as polyhydric alcohol acrylic acid or methacrylic acid ester, diisocyanate and polyhydric alcohol, and acrylic acid or methacrylic acid hydroxy ester. Such a polyfunctional urethane (meth) acrylate compound can be used. Besides these, as ionizing radiation type materials, polyether resins having an acrylate functional group, polyester resins, epoxy resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and the like can be used. .

  The antireflection film 1 according to the present invention can be suitably used as a part of a display member or an image device. Hereinafter, as an application example thereof, an embodiment of a polarizing plate with an antireflection film will be described with reference to FIG.

  As illustrated in FIG. 2, the polarizing plate 200 with an antireflection film includes an antireflection film 1 and a polarizing plate 2. Specifically, the polarizing plate 2 composed of the polarizing layer 23 and the transparent substrate 21 is disposed on the side of the transparent substrate 11 constituting the antireflection film 1 where the hard coat layer 12 is not formed. That is, the hard coat layer 12, the high refractive index layer 13, and the low refractive index layer 14 are laminated on one surface (the upper surface in FIG. 2) of the transparent substrate 11, and the other surface ( In FIG. 2, a polarizing layer 23 and a transparent substrate 21 are laminated in this order from the transparent substrate 11 side on the lower surface.

  Next, an embodiment of a transmissive liquid crystal display including the polarizing plate with an antireflection film will be described below.

  As shown in FIG. 3, the transmissive liquid crystal display 300 includes a polarizing plate 200a with an antireflection film, a liquid crystal cell 3, a polarizing plate 4, and a backlight unit 5. The liquid crystal cell 3, the polarizing plate 4, and the backlight unit 5 are held in this order on the surface opposite to the surface on which the antireflection film 1 is formed.

  The liquid crystal cell 3 is held on the side opposite to the side on which the hard coat layer 12 is formed with respect to the transparent substrate 11 in the polarizing plate 200a with an antireflection film. The antireflection film-attached polarizing plate 200 a includes an antireflection film 1 and a polarizing plate 2 a on the transparent base material 11 side of the antireflection film 1. The polarizing plate 2a is formed by laminating a transparent substrate 22, a polarizing layer 23, and a transparent substrate 21 in order from the transparent substrate 11 side. The liquid crystal cell 3 is held on the surface side opposite to the surface on which the hard coat layer 12 of the polarizing plate 200a with antireflection film is formed, that is, on the transparent substrate 21 side. At this time, in the transmissive liquid crystal display 300, the antireflection film 1 side is the observation side, that is, the display surface.

  The transmissive liquid crystal display 300 includes the transparent base material 11 of the antireflection film 1 and the transparent base material 22 of the polarizing plate 2a separately.

  The backlight unit 5 includes a light source and a light diffusion plate (not shown). Although not shown, the liquid crystal cell 3 has a structure in which an electrode is provided on one transparent base material, an electrode and a color filter are provided on the other transparent base material, and liquid crystal is sealed between both electrodes. . In the polarizing plate 2 a provided so as to sandwich the liquid crystal cell 3, the polarizing layer 23 is sandwiched between the transparent substrate 21 and the transparent substrate 22, and in the polarizing plate 4, the transparent substrate 41 and the transparent substrate The polarizing layer 43 is sandwiched between the material 42.

  Further, the transmissive liquid crystal display according to the present invention may have a configuration including a polarizing plate 200 with an antireflection film as shown in FIG. 4 (different from FIG. 3).

  A transmissive liquid crystal display 400 shown in FIG. 4 includes a polarizing plate 200 with an antireflection film, a liquid crystal cell 3, a polarizing plate 4, and a backlight unit 5. The liquid crystal cell 3, the polarizing plate 4, and the backlight unit 5 are held in this order on the surface opposite to the surface on which the film is formed. The polarizing plate with antireflection film 200 includes an antireflection film 1 and a polarizing plate 2 on the transparent base material 11 side of the antireflection film 1. In the polarizing plate 2, a polarizing layer 23 and a transparent substrate 21 are laminated in order from the transparent substrate 11 side. The liquid crystal cell 3 is held on the surface side opposite to the surface on which the low refractive index layer 14 of the polarizing plate 200 with an antireflection film is formed, that is, on the transparent substrate 21 side. At this time, in the transmissive liquid crystal display 400, the hard coat film 1 side is the observation side, that is, the display surface.

  In the transmissive liquid crystal display 400, a polarizing layer 23 and a transparent substrate 22 are provided in this order as the polarizing plate 2 on the surface of the antireflection film 1 on which the hard coat layer 12 is not formed, that is, the surface of the transparent substrate 11. It has been.

  Similar to the transmissive liquid crystal display 300, the backlight unit 5 includes a light source and a light diffusion plate (not shown). Although not shown, the liquid crystal cell 3 has a structure in which an electrode is provided on one transparent base material, an electrode and a color filter are provided on the other transparent base material, and liquid crystal is sealed between both electrodes. . In the polarizing plate 2 (a part of the polarizing plate 200 with an antireflection film) provided so as to sandwich the liquid crystal cell 3, a polarizing layer 23 is sandwiched between the transparent substrate 21 and the transparent substrate 11, and the polarizing plate 4. , The polarizing layer 43 is sandwiched between the transparent base material 41 and the transparent base material 42.

  Note that the transmissive liquid crystal displays 300 and 400 of the present invention may include other functional members. Other functional members include, for example, a diffusion film, a prism sheet, a brightness enhancement film for effectively using light emitted from a backlight, and a phase difference film for compensating for a phase difference between a liquid crystal cell and a polarizing plate. However, it is not limited to these.

  Hereinafter, the present invention will be described more specifically based on examples.

<Example 1>
"Formation of hard coat layer"
As the transparent support, a triacetyl cellulose film having a thickness of 80 μm was used, and a composition for forming a hard coat layer having the following composition was applied and dried by a bar coating method so that the film thickness after drying was 5 μm. Thereafter, a hard coat layer was formed by irradiating an ultraviolet ray of 300 mJ / cm ² with a high pressure mercury lamp in an atmosphere with an oxygen concentration of 1000 ppm.

<Composition for forming hard coat layer>
Pentaerythritol triacrylate (PE3A) 15.00 parts by weight Pentaerythritol tetraacrylate (PE4A) 15.00 parts by weight Urethane acrylate (UA) 25.00 parts by weight Photopolymerization initiator 2.00 parts by weight (Ciba Specialty Chemicals) Manufactured by Irgacure 184)
0.10 parts by weight of additive (BIC Chemie Japan Co., Ltd .: BYK-350)
Methyl ethyl ketone (MEK) 42.90 parts by weight

"Formation of a high refractive index layer"
Next, on the said hard-coat layer, it applied by the bar coating method using the coating liquid for high refractive index layer which consists of the following composition, and was dried so that the film thickness after drying might be set to 150 nm. Then, 300 mJ / cm < ² > of ultraviolet rays were irradiated with the high pressure mercury lamp in the atmosphere with an oxygen concentration of 1000 ppm, and the high refractive index layer was formed.

<Composition for forming high refractive index layer>
Bisphenol AEO adduct dimethacrylate 6.00 parts by weight (Osaka Organic Chemical Co., Ltd .: Biscoat # 700)
Antimony oxide fine particle dispersion 14.00 parts by weight (average particle size 10 nm, solid content 25%, solvent methyl isobutyl ketone)
0.10 parts by weight of photopolymerization initiator (Ciba Specialty Chemicals: Irgacure 184)
Additive 0.010 parts by weight (fluorine, silicon-containing aromatic oligomer)
Methyl isobutyl ketone (MIBK) 80.00 parts by weight

"Formation of a low refractive index layer"
Next, on the high refractive index layer, a coating solution for forming a low refractive index layer having the following composition was applied and dried by a bar coating method so that the film thickness after drying was 100 nm. Then, 300 mJ / cm < ² > ultraviolet-ray was irradiated with the high pressure mercury lamp in the oxygen concentration 1000ppm atmosphere, the low-refractive-index layer was formed, and the antireflection film was produced.

<Composition for forming low refractive index layer>
Porous silica fine particle dispersion 32.08 parts by weight (average particle size 50 nm, solid content 20%, solvent methyl isobutyl ketone)
Dipentaerythritol hexaacrylate 1.68 parts by weight Photopolymerization initiator 0.07 parts by weight (manufactured by Ciba Specialty Chemicals: Irg. 184)
Leveling agent 0.18 parts by weight (BYK-UV3500, manufactured by Big Chemie Japan, solid content> 97%)
Methyl isobutyl ketone (MIBK) 66.00 parts by weight

<Example 2>
Regarding the formation of the high refractive index layer, the antimony oxide fine particle dispersion was 15.00 parts by weight, the additive contained fluorine, 0.011 part by weight of bisphenol AEO adduct dimethacrylate, 79.00 parts by weight of MIBK, An antireflection film was produced in the same manner as in Example 1 except that the thickness was 140 nm.

<Example 3>
Regarding the formation of the high refractive index layer, bisphenol AEO adduct dimethacrylate was converted to 2-hydroxy-3-phenoxypropyl acrylate (Kyoeisha Chemical: Epoxy ester M-6).
00A) 5.00 parts by weight, antimony oxide fine particle dispersion liquid 13.00 parts by weight, additives containing fluorine and silicon, 0.007 parts by weight aromatic oligomer, MIBK 82.00 parts by weight, and film thickness 160 nm An antireflection film was produced in the same manner as in Example 1 except that.

<Example 4>
Regarding formation of a high refractive index layer, bisphenol AEO adduct dimethacrylate is 6.00 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate, antimony oxide fine particle dispersion is 12.00 parts by weight, and the additive contains silicon, aromatic An antireflection film was produced in the same manner as in Example 1 except that 0.005 part by weight of oligomer, 82.00 parts by weight of MIBK, and the film thickness was 160 nm.

<Comparative Example 1>
Regarding the formation of the high refractive index layer, 7.00 parts by weight of bisphenol AEO adduct dimethacrylate, 17.00 parts by weight of antimony oxide fine particle dispersion, 0.013 parts by weight of acrylic oligomer, and 76.00 parts by weight of MIBK An antireflection film was produced in the same manner as in Example 1 except that the part was used.

<Comparative Example 2>
Regarding the formation of the high refractive index layer, 5.00 parts by weight of bisphenol AEO adduct dimethacrylate, 16.00 parts by weight of antimony oxide fine particle dispersion, 0.008 parts by weight of fluorine, silicon-containing oligomer, 79 parts of MIBK An antireflection film was produced in the same manner as in Example 1 except that the amount was 0.000 part by weight.

<Comparative Example 3>
Regarding the formation of the high refractive index layer, 4.00 parts by weight of bisphenol AEO adduct dimethacrylate, pentaerythritol triacrylate (PE3A), 15.00 parts by weight of antimony oxide fine particle dispersion, fluorine, silicon-containing additive, aromatic An antireflection film was produced in the same manner as in Example 1 except that 0.007 part by weight of oligomer and 81.00 part by weight of MIBK were used.

<Comparative Example 4>
Regarding formation of the high refractive index layer, 7.00 parts by weight of bisphenol AEO adduct dimethacrylate, 28.00 parts by weight of antimony oxide fine particle dispersion, fluorine, silicon-containing additive, 0.0005 parts by weight of aromatic oligomer, An antireflection film was produced in the same manner as in Example 1 except that MIBK was changed to 65.00 parts by weight.

<Comparative Example 5>
Regarding the formation of the high refractive index layer, 5.00 parts by weight of bisphenol AEO adduct dimethacrylate, 22.00 parts by weight of antimony oxide fine particle dispersion, fluorine, silicon-containing additive, 0.012 parts by weight of aromatic oligomer, An antireflection film was produced in the same manner as in Example 1 except that MIBK was changed to 73.00 parts by weight.

<Comparative Example 6>
Regarding formation of the high refractive index layer, 4.00 parts by weight of bisphenol AEO adduct dimethacrylate, 17.00 parts by weight of antimony oxide fine particle dispersion, 0.007 parts by weight of aromatic oligomer, and 79.00 of MIBK. An antireflection film was produced in the same manner as in Example 1 except that the amount was changed to parts by weight.

The high refractive index layer forming compositions used in Examples 1 to 4 and Comparative Examples 1 to 6 are shown in Table 1 below.

<Evaluation>
The antireflection films obtained in Examples 1 to 4 and Comparative Examples 1 to 6 were evaluated by the following methods. The results are shown in Table 2 below.

(Hue of reflected light)
About the surface of the low-refractive-index layer of the obtained antireflection film, an automatic spectrophotometer (manufactured by Hitachi, U-4100) was used to measure the spectral reflectance at an incident angle of 5 °. From the obtained spectral reflectance curve The hue of the reflected light was determined, and it was determined whether this hue satisfies −3 ≦ a ^* ≦ 3 and −5 ≦ b ^* ≦ 5 in the CIE1976L ^* a ^* b ^* color space. In the measurement, a matte black paint was applied to the surface of the triacetyl cellulose film, which is a transparent support, on which the low refractive index layer was not formed, and antireflection treatment was performed. Judgment criteria are shown below.
○: The target reflection hue is satisfied ×: The target reflection hue is not satisfied

(Thickness unevenness)
A matte black paint was applied to the surface of the antireflection film where the low refractive index layer was not formed, and the unevenness of the antireflection film was visually evaluated. Judgment criteria are shown below.
○: Unevenness ×: Unevenness

(Low refractive index layer repellent)
A matte black paint was applied to the surface of the antireflection film where the low refractive index layer was not formed, and the repellency of the low refractive index layer was visually evaluated. Judgment criteria are shown below.
○: No low refractive index layer repelling ×: Low refractive index layer repelling

(Adhesion)
The surface of the low-refractive index layer of the obtained antireflection film is cut in a grid pattern so that 1 square is 10 squares × 10 squares = 100 squares, and an adhesive tape (manufactured by Nichiban Co., Ltd.) is used. A peel test was performed, and the residual ratio of 100 parts by mass was evaluated. Judgment criteria are shown below.
○: All squares are not peeled × 1: More than one square is peeled off

(Abrasion resistance)
Using steel wool (Bonster # 0000, manufactured by Nippon Steel Wool Co., Ltd.) on the surface of the low-refractive index layer of the obtained antireflection film, rubbing 10 times with a load of 250 g / cm ² and visually observing the presence or absence of scratches. And evaluated. Judgment criteria are shown below.
○: No scratch was confirmed Δ: Slight scratch was confirmed ×: Scratch was confirmed

In the antireflection film as the product of the present invention obtained in Examples 1 to 4, Examples 3 and 4 were slightly inferior to Examples 1 and 2 in scratch resistance, but in all evaluation tests, both It showed good performance. On the other hand, in the comparative example products obtained in Comparative Examples 1 to 6, some defects were confirmed for all the evaluation tests. Specifically, the film of the comparative example obtained in Comparative Example 1 was uneven in film thickness, and in Comparative Example 2, repellency was generated in the low refractive index layer, and good adhesion could not be obtained. In Comparative Example 3, repellency occurred in the low refractive index layer, good adhesion could not be obtained, and scratches were generated due to scratch resistance. In Comparative Example 4, film thickness unevenness occurred. Further, in Comparative Example 5, cissing occurred in the low refractive index layer, and good adhesion could not be obtained, and scratches were generated due to scratch resistance. In Comparative Example 6, film thickness unevenness occurred and good adhesion could not be obtained.

  From the examples, according to the present invention, it has an excellent antireflection function, reduces the reflectance and hue of the reflected light from the front, and also reflects the color of the reflected light of external light incident from various angles. It was proved that an antireflection film that can reduce the taste and has excellent film thickness unevenness and excellent adhesion can be obtained.

DESCRIPTION OF SYMBOLS 1 Antireflection film 11, 21, 22, 41, 42 Transparent support 12 Hard coat layer 13 High refractive index layer 14 Low refractive index layer 2, 2a Polarizing plate 23, 43 Polarizing layer 200, 200a Polarizing plate with antireflection film 3 Liquid crystal cell 300, 400 Transmission type liquid crystal display 4 Polarizing plate 5 Backlight unit

Claims (4)

An antireflection film formed by sequentially laminating a hard coat layer, a high refractive index layer, and a low refractive index layer on one surface of a transparent support,
The high refractive index layer contains at least a binder resin having an aromatic ring in the molecule, an additive selected from one or more of fluorine-containing aromatic compounds and silicon-containing aromatic compounds,
And the said additive is mix | blended in the range of 0.01-0.2 mass part with respect to 100 mass parts of the said binder resin, The antireflection film characterized by the above-mentioned.   The antireflection film according to claim 1, wherein the binder resin contains a bisphenol A skeleton.   A polarizing plate with an antireflection film, comprising a polarizing plate on the other surface side of the transparent support using the antireflection film according to claim 1.   A transmissive liquid crystal display comprising the polarizing plate with an antireflection film according to claim 3.