TW201339628A - Antireflective film - Google Patents

Abstract

Provided is an antireflective film, which does not give reflected light of a natural light coming from front side color, and is able to decrease the color thereof regarding to reflected light of a natural light reflecting from various angles in an anti reflective film. Specifically, provided is an antireflective film, which is characterized in that as any incident light in the range whose incident angle is from 5 DEG to 50 DEG in the region of the wavelength 380nm to 780nm of a C light source belonging to CIE standard light source, a hue of reflected light on condition that an incident angle and a reflected angle are equal all satisfies -3 ≤ a* ≤ 3, -5 ≤ b* ≤ 5 in the CIE1976L*a*b* color space.

Description

Antireflection film

The content disclosed in the present specification relates to an antireflection film provided for the purpose of preventing external light from being reflected by a display screen of a display device or the like, a display device including the antireflection film, a polarizing plate having the antireflection film, and Touch panel. Such an anti-reflection panel is suitable for use in a display screen provided on a display device.

In general, the display is used in an environment where incident light or the like is incident, whether it is used indoors or outdoors. In addition, incident light such as light is periodically reflected on the surface of the display or the like, and the resulting reflected image is mixed with the display image to cause deterioration in display quality of the screen. Therefore, it is necessary to impart an anti-reflection function to the surface of the display, and the performance of the anti-reflection function is required.

In general, the antireflection function can be obtained by forming an antireflection layer of a multilayer structure derived from a repetitive structure of a high refractive index layer and a low refractive index layer of a transparent material such as a metal oxide on a transparent support. The antireflection layer comprising the multilayer structure may be a chemical deposition (CVD) method, or a substance It is formed by a dry film formation method such as a deposition (PVD) method. When the antireflection layer is formed by a dry film formation method, although the film thickness of the low refractive index layer and the high refractive index layer can be precisely controlled, on the other hand, since film formation is performed in a vacuum, productivity is produced. Low, not suitable for mass production. Further, as a method of forming an antireflection layer, it has been attracting attention to produce an antireflection film by a wet film formation method using a coating liquid which can be used in a large area, continuous production, and low cost.

Prior technical literature Patent literature

Patent Document 1 JP-A-2007-256346

In recent years, with the popularization of mobile terminals, there has been an increasing demand for operating the image display device body on the hand. In addition, the use of the outside of the house in the daylight is exposed to strong external light. Therefore, an antireflection film having a low reflectivity which is also non-destructive to the outside of the house is required.

Furthermore, when an anti-reflection film is applied to a fixed-type image display device, most of it is based on the assumption that the reflected light from the fixed light source is reduced; this means that "the incident angle of the external light does not change". On the other hand, in the case of a mobile terminal, since it is used outdoors or on the hand, the incidence of external light is incident from various angles, and even the viewer often views at various angles. monitor. Therefore, if an anti-reflection film is to be applied to a mobile terminal, it is necessary to investigate the reflected light of the light source of various incident angles, especially the color of the reflected light, not just the reflected light from the front side. In fact, most of the anti-reflection films are designed for a fixed-type image display device, and the problem is that the film design does not assume that the incident angle and the reflection angle of the external light may change.

One of the objects disclosed in the present specification is to provide an antireflection film which can reduce the hue of reflected light from the front surface and which can reduce the hue of the reflected light of the external light incident from various angles, and the antireflection film A display device, a polarizing plate including the antireflection film, and a touch panel.

This object is achieved by providing an antireflection film, an image display device or a liquid crystal display device including the antireflection film, and a polarizing plate including the antireflection film, which will be described later.

That is, in one form, the anti-reflection film is characterized in that any incident light having an incident angle of 5° to 50° in a region of a wavelength of 380 nm to 780 nm of a C light source belonging to a CIE standard light source is incident. The hue of the reflected light at the angle of reflection equal to the angle of reflection satisfies -3≦a*≦3, -5≦b*≦5 in the CIE1976L* a* b* color space.

In one embodiment, an antireflection film is provided which is characterized in that the visual average reflectance of the surface of the antireflection film is in the range of 0.05% or more and 1.0% or less.

In another aspect, a display device including the antireflection film described above can be provided.

As used herein, the term "display device" refers to a terminal device for visually outputting to a user, for example, a display screen is mapped to an image. As such a display device, particularly, a liquid crystal display (LCD), a CRT display, an organic electroluminescence display (ELD), a plasma display (PDP), a surface electric field display (SED), a field emission display (FED), etc. It is not limited to this.

In still another aspect, a polarizing plate including the antireflection film may be provided.

In still another aspect, a touch panel having the anti-reflection film described above can also be provided.

By providing the antireflection film as described above in an image display device or a liquid crystal display device, the visual average reflectance of the surface of the antireflection film can be in the range of 0.05% or more and 1.0% or less, so that the reflected light from the front surface is provided. The situation of the color is reduced, and at the same time, the color of the reflected light of the incident light incident from various angles is reduced. Further, the same effect can be obtained by providing the polarizing plate using the antireflection film on the surface of the liquid crystal display device and using the antireflection film on the touch panel.

10‧‧‧Anti-reflective film

11‧‧‧Transparent support

12‧‧‧hard coating

13‧‧‧High refractive index layer

14‧‧‧Low refractive index layer

21‧‧‧ is a range of hue that does not cause the reflected light of the anti-reflective film to have a color and a color

Fig. 1 is a schematic cross-sectional view showing an antireflection film of an embodiment.

Fig. 2 is a graph showing the angular correlation of the hue of the reflected light of the antireflection film produced in the examples and the comparative examples.

Hereinafter, the exemplary anti-reflection film disclosed in the present specification will be described in detail.

The antireflection film disclosed in the present specification is equal to any incident light having an incident angle of 5° to 50° in a region of a wavelength of 380 nm to 780 nm of a C light source belonging to a CIE standard light source, at an incident angle and a reflection angle. The hue of the reflected light under reflective conditions satisfies -3≦a*≦3, -5≦b*≦5 in the CIE1976L* a* b* color space. Therefore, even if the incident angle of the external light changes, the hue of the reflected light of the antireflection film is still a neutral color.

Furthermore, for incident light with an incident angle of 5°, the hue of the reflected light in the range of the reflection angle of -5° to -80° satisfies -3≦a*≦3 in the CIE1976L* a* b* color space. And -5 ≦ b* ≦ 5, whereby the hue of the reflected light when only changing the viewing angle of the antireflection film is changed to a neutral color, and it is preferable to satisfy the condition.

If the incident angle in the region of the wavelength of 380 nm to 780 nm of the C light source belonging to the CIE standard light source is any range of 5° to 50° Light, the hue of the reflected light under the reflection condition of the incident angle and the reflection angle satisfies -Δ≦a*≦3, -△b*≦3 (where △a*) in the CIE1976L* a* b* color space =a*max-a*min, △b*=b*max-b*min, a*max and a*min represent the maximum and minimum values of the a* value, respectively, and b*max and b*min represent respectively The maximum and minimum values of the b* value), the hue change at the angle of incidence or reflection angle is reduced, so it is preferable to satisfy this condition. The smaller the variation of the hue is, the better, so △a*≦1, Δb*≦1 is more preferable.

In one embodiment, the visual average reflectance of the antireflection film is preferably in the range of 0.05% or more and 1.0% or less.

(layer structure of anti-reflection film)

The layer structure of the antireflection film will be described in detail with reference to Fig. 1 . The antireflection film of this example is provided by applying a hard coat layer on a transparent support and sequentially laminating a multilayer structure of a high refractive index layer and a low refractive index layer thereon. At this time, the number of layers of the high refractive index layer and the low refractive index layer is not limited. However, when considering the cost and the productivity, etc., as shown in Fig. 1, the antireflection film (10) of this example is coated with a hard coat layer (12) on a transparent support (11), and is coated thereon. The refractive index layer (13), which is further laminated with the low refractive index layer (14), can be suitably used as an antireflection film.

At this time, by continuously adjusting the film thickness and the refractive index of each layer, the a* value and the b* value which are the hue parameters of the reflected light can be made to conform to the target value. E.g, It is preferable that the film thickness of the hard coat layer is in the range of 3.0 μm or more and 10 μm or less, the refractive index of the hard coat layer is in the range of 1.48 or more and 1.53 or less, and the film thickness of the high refractive index layer is in the range of 230 nm or more and 260 nm or less. The refractive index of the high refractive index layer is in the range of 1.58 or more and 1.64 or less, the film thickness of the low refractive index layer is in the range of 115 nm or more and 135 nm or less, and the visual average reflectance of the refractive index of the low refractive index layer is 0.05% or more. A refractive index in the range of 1.0% or less (for example, a refractive index of 1.30).

Examples of the coating method of the hard coat layer, the high refractive index layer, and the low refractive index layer as described above include a spray method, a screen printing method, a doctor blade forming method, a gravure printing method, a die coating method, and an ink jet method. The coating method is not particularly limited.

The transparent support system in the antireflection film of the present example is prepared from various organic polymers 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. The organic polymer may, for example, be not limited thereto: a polyolefin such as polyethylene or polypropylene, a polyester such as polyethylene terephthalate or polyethylene naphthalate, or a triethyl group. Cellulose based on mercapto cellulose, diethyl acetyl cellulose, celorophan, polyacrylamide such as 6-nylon, 6,6-nylon, polyacrylamide, polystyrene, poly Vinyl chloride, polyimine, polyvinyl alcohol, polycarbonate, ethylene vinyl alcohol, and the like. Preferably, the organic polymer is polyethylene terephthalate, triethyl fluorenyl cellulose, polycarbonate, or polymethyl methacrylate. More preferably, the organic polymer is triethylenesulfonyl cellulose, which is suitable for various displays because of its small complex refractive index and good transparency.

Further, by adding a well-known additive such as an ultraviolet absorber, an infrared absorbing agent, a plasticizer, a slip agent, a colorant, an antioxidant, a flame retardant, or the like to the organic polymer, various kinds of transparent supports can be added. Features. Further, the transparent support may be prepared by using one or a mixture of two or more kinds of the above organic polymers or a polymer, or may be a laminate of a plurality of layers.

Further, the thickness of the transparent support is preferably in the range of 20 μm or more and 200 μm or less, and more preferably in the range of 20 μm or more and 80 μm or less.

In one embodiment, an acrylic material may be used as the hard coat layer in the antireflection film. As the acrylic material, a monofunctional, difunctional or trifunctional or higher (meth) acrylate compound such as acrylic acid or methacrylate of a polyhydric alcohol, synthesized from a diisocyanate and a polyhydric alcohol, and an acrylic acid or a methyl group can be used. A polyfunctional urethane (meth) acrylate compound such as a hydroxy ester of acrylic acid or the like. Further, in addition to the above, as the free radiation type material, a polyether resin having an acrylate functional group, a polyester resin, an epoxy resin, an alkyd resin, a acetal resin, a polybutadiene resin, or the like may be used. A polythiol polyene resin or the like.

Moreover, when used in this specification, the term "(meth)acrylate" means both "acrylate" and "methacrylate". For example, "urethane (meth) acrylate" means both "urethane acrylate" and "urethane methacrylate".

Examples of the monofunctional (meth) acrylate compound include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. Base) n-butyl acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, glycidyl (meth)acrylate, propylene oxime Porphyrin, N-vinylpyrrolidone, tetrahydrofuran acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isodecyl (meth)acrylate, Lauryl (meth)acrylate, tridecyl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, 2-(meth)acrylate Ethoxyethyl ester, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth) acrylate, (meth) acrylate phosphate, ethylene oxide modified (meth) acrylate phosphate , (meth) acrylate phenoxylate, ethylene oxide modified phenoxy (meth) acrylate, propylene oxide modified phenoxy (meth) acrylate, nonyl phenol (meth) acrylate, ring Oxygen ethane modified nonylphenol (meth) acrylate, propylene oxide modified nonyl phenol (meth) acrylate, methoxy diethylene glycol (meth) acrylate, methoxy polyethylene Alcohol (meth) acrylate, methoxy propylene glycol (meth) acrylate, 2-(methyl) propylene oxirane ethyl 2-hydroxypropyl phthalate, 2-hydroxy group (meth) acrylate 3-phenoxypropyl ester, hydrogen phthalate 2-(Methyl) propylene oxime ethyl ester, 2-(methyl) propylene oxypropyl phthalate, 2-(methyl) propylene oxypropyl hexahydrophthalate, tetrahydrogen 2-(Methyl)propenyl isopropyl phthalate, dimethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, (A) Hexyl hexafluoropropyl acrylate, octafluoropropyl (meth) acrylate, octafluoropropyl (meth) acrylate, monovalent (meth) acrylate derived from 2-adamantane and adamantane diol The adamantane derivative mono(meth)acrylate such as an adamantyl acrylate is not limited thereto.

Examples of the difunctional (meth) acrylate compound include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, and butanediol di(meth)acrylate. Hexanediol di(meth)acrylate, decanediol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylic acid Ester, 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 di(meth)acrylate, hydroxytrimethylacetic acid neopentyl glycol di(meth)acrylate The bis(meth)acrylate or the like is not limited thereto.

Examples of the trifunctional or higher (meth) acrylate compound include trimethylolpropane tri(meth) acrylate, ethoxylated trimethylolpropane tri(meth) acrylate, and propoxy group. Tris(meth)acrylate such as trimethylolpropane tri(meth)acrylate, 2-hydroxyethyl tris(meth)acrylate, tris(meth)acrylate, or the like a trifunctional (meth) acrylate compound such as pentaerythritol tri(meth) acrylate, dipentaerythritol tri(meth) acrylate or ditrimethylolpropane tri (meth) acrylate, Or pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylic acid Ester, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane hexa a trifunctional or higher polyfunctional (meth) acrylate compound such as a methyl acrylate or a polyfunctional (meth) acrylate compound in which a part of such (meth) acrylate is substituted with an alkyl group or ε-caprolactone Etc., but not limited to this.

Among the acrylic materials, polyfunctional urethane acrylates can be used for the reason that the desired molecular weight and molecular structure can be designed, and the physical properties of the formed hard coat layer can be easily obtained. The urethane acrylate can be obtained by reacting a polyol, a polyvalent isocyanate, and a hydroxyl group-containing acrylate. Specifically, UA-306H, UA-306T, UA-3061, etc., manufactured by Kyoeisha Chemical Co., Ltd., UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV-7650B, manufactured by Nippon Synthetic Chemical Co., Ltd. Etc. U-4HA, U-6HA, UA-100H, U-6LPA, U-15HA, UA-32P, U-324A, etc., Ebecryl-1290, Ebecryl-1290K, Ebecryl, manufactured by DAICEL-UCB -5129, etc., under the Industrial Company, UN-3220HA, UN-3220HB, UN-3220HC, UN-3220HS, etc., except this.

In addition, as the free radiation type material, a polyether resin having an acrylate functional group, a polyester resin, an epoxy resin, an alkyd resin, a acetal resin, a polybutadiene resin, and a polysulfide may be used. The alcohol polyene resin or the like is not particularly limited.

Further, since the free radiation curing material is cured by ultraviolet rays, a photopolymerization initiator is added to the coating liquid for forming a hard coat layer. The photopolymerization initiator may be any one which generates a radical when irradiated with ultraviolet rays, and examples thereof include acetophenones, benzoin, benzophenones, phosphine oxides, ketals, anthracenes, and the like. Thioxanthone. Further, the photopolymerization initiator is added in an amount of from 0.1 part by weight to 10 parts by weight, preferably from 1 part by weight to 7 parts by weight, more preferably 1 part by weight, per 100 parts by weight of the radical radiation-curable material. ~5 parts by weight.

Further, a solvent or various additives may be added as needed in the coating liquid for forming a hard coat layer. The solvent may be an aromatic hydrocarbon such as toluene, xylene, cyclohexane or cyclohexylbenzene, a hydrocarbon such as n-hexane, dibutyl ether, dimethoxymethane, dimethoxyethane or diethoxyethane. , propylene oxide, two Alkane, dioxolane, three Ethers such as alkane, tetrahydrofuran, anisole and ethyl phenyl ether, methyl isobutyl ketone, methyl butyl ketone, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diiso Ketones such as butyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, and methylcyclohexanone, and ethyl formate, propyl formate, n-amyl formate, methyl acetate, ethyl acetate, Methyl propionate, ethyl propionate, n-amyl acetate, and esters such as γ-butyrolactone, even methyl cerulelus, 赛路苏, butyl 赛路苏, 赛路苏 acetate, etc. Among the alcohols such as Susu, methanol, ethanol, isopropanol, and butanol, the suitability of the coating is considered to be appropriately selected. Further, a surface conditioning agent, a refractive index adjusting agent, an adhesion improving agent, a curing agent, or the like may be added as an additive to the coating liquid.

Further, other additives may be added to the coating liquid for forming a hard coat layer. Examples of such an additive include a foaming agent, a leveling agent, an antioxidant, an ultraviolet absorber, a photostabilizer, and a polymerization inhibitor.

In one embodiment, as the high refractive index layer in the antireflection film, a binder containing any one or more of a metal alkoxide, a decane coupling agent, and an organic resin may be used, and further added to the binder. Metal particles or organic particles. These components are appropriately selected depending on the refractive index of the organic coating layer required, and the refractive index is adjusted depending on the combination of materials, the mixing ratio, and the like. For example, as the high refractive index material, a metal alkoxide such as Ti, Ta, Zr, In, or Zn, or metal fine particles such as titanium oxide, zirconium oxide, zinc oxide, or indium oxide are used.

The use as a diluent solvent is not particularly limited. However, the stability of the composition, the wettability to the hard coat layer, the volatility, and the like are considered, and examples of the diluent solvent to be used include alcohols such as methanol, ethanol, isopropanol, butanol, and 2-methoxyethanol. Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate and butyl acetate, ethers such as diisopropyl ether, ethylene glycol, propylene glycol, 2 - glycols such as methyl-2,4-pentanediol, glycolic ethers such as ethyl celecoxib, butyl sage, ethyl carbitol, butyl carbitol, hexane, heptane, An aliphatic hydrocarbon such as octane, a halogenated hydrocarbon, an aromatic hydrocarbon such as benzene, toluene or xylene, N-methylpyrrolidone or dimethylformamide. Further, the solvent is not limited to one type, and may be used as a mixture of two or more types.

As a binder matrix forming material for forming a high refractive index layer, an epitaxial radiation hardening type material is contained. As the free radiation curable material, an acrylic material exemplified as an epitaxial radiation-curable material contained in a coating liquid for forming a hard coat layer can be used. As the acrylic material, a monofunctional or polyfunctional (meth) acrylate compound such as acrylic acid or methacrylic acid ester of a polyhydric alcohol, a hydroxy ester synthesized from a diisocyanate and a polyhydric alcohol, and acrylic acid or methacrylic acid can be used. A class of polyfunctional urethane (meth) acrylate compounds. Further, in addition to the above, as the free radiation type material, a polyether resin having an acrylate functional group, a polyester resin, an epoxy resin, an alkyd resin, a acetal resin, a polybutadiene resin, or the like may be used. A polythiol polyene resin or the like.

In one embodiment, as the low refractive index layer in the antireflection film, for the low refractive particles, LiF, MgF, and 3NaF may be used. A low refractive index particle of a low refractive material such as AlF or AlF (having a refractive index of 1.4) or Na ₃ AlF ₆ (cryolite, refractive index of 1.33). Further, particles having voids inside the particles can also be applied. In the particles containing voids in the particles, since the void portion is made to have a refractive index (≒1) of air, a low refractive index particle having an extremely low refractive index can be obtained. Specifically, low refractive index ceria particles containing voids inside can be used.

The low refractive index particles used in the low refractive index layer preferably have a particle diameter of from 1 nm to 100 nm. When the particle diameter is larger than 100 nm, the light is significantly reflected by Rayleigh scattering, so that the low refractive index layer is whitened. There is a tendency that the transparency of the antireflection film is lowered. On the other hand, when the particle diameter is less than 1 nm, problems such as aggregation of particles cause unevenness of particles in the low refractive index layer occur.

As the binder matrix forming material for forming the low refractive index layer, it contains an epitaxial radiation hardening type material. As the free radiation curable material, an acrylic material exemplified as an epitaxial radiation-curable material contained in a coating liquid for forming a hard coat layer can be used. As the acrylic material, a monofunctional or polyfunctional (meth) acrylate compound such as acrylic acid or methacrylic acid ester of a polyhydric alcohol, a hydroxy ester synthesized from a diisocyanate and a polyhydric alcohol, and acrylic acid or methacrylic acid can be used. A class of polyfunctional urethane (meth) acrylate compounds. Further, in addition to the above, as the free radiation type material, a polyether resin having an acrylate functional group, a polyester resin, an epoxy resin, an alkyd resin, a acetal resin, a polybutadiene resin, or the like may be used. A polythiol polyene resin or the like. Further, these resins may be suitably fluorinated.

[Examples]

Hereinafter, the examples and comparative examples will be further described, but the examples are shown for illustrative purposes only, and the present invention is not limited to the following examples. Each of Preparation Example 1 to Modification Example 3 which will be described later is a preparation example of the coating liquid for forming a hard coat layer, the coating liquid for forming a high refractive index layer, and the coating liquid for forming a low refractive index layer used in Example 1. Using these, the antireflection film of Example 1 was produced following the procedures shown in the formation examples 1 to 3. Further, the films of Comparative Examples 1 to 7 were produced by changing the production conditions described later.

[Example 1] <Modulation Example 1> (coating solution for forming a hard coat layer)

25 parts by mass of dipentaerythritol triacrylate, 25 parts by mass of neopentyl alcohol tetraacrylate, 50 parts by mass of urethane acrylate, and 5 parts by mass of IRGACURE 184 (manufactured by BASF Corporation) The initiator ()) was dissolved in 118 parts by mass of methyl ethyl ketone to prepare a coating layer for forming a hard coat layer.

<Modulation Example 2> (coating liquid for forming a high refractive index layer)

3 parts by mass of urethane acrylate, 18 parts by mass of zirconia fine particle dispersion (solid content: 25%, solvent: methyl isobutyl ketone), and 0.1 part by mass of IRGACURE 184 (manufactured by BASF Corporation) The initiator ()) was diluted with 79 parts by weight of methyl isobutyl ketone to prepare a coating liquid for forming a high refractive index layer.

<Modulation Example 3> (coating liquid for forming a low refractive index layer)

18 parts by mass of the porous ceria fine particle dispersion (solid content 20%, solvent: methyl isobutyl ketone), 1.99 parts by mass of EO-modified dipentaerythritol hexaacrylate (trade name: DPEA- 12, manufactured by Nippon Kasaku Co., Ltd., 0.07 parts by mass of a polymerization initiator (manufactured by BASF Corporation, trade name: IRGACURE 184), and 0.20 parts by mass of TSF 4460 (trade name, Momentive Performance Materials (manufactured by Momentive Performance Materials: alkyl polyether modified ketone oil), which was diluted with 80 parts by weight of methyl isobutyl ketone as a solvent to prepare a coating liquid for forming a low refractive index layer.

[Formation of Layer Structure of Antireflection Film] <Formation Example 1> (formation of hard coating)

The coating liquid for forming a hard coat layer was applied to one side of a triethylenesulfonated cellulose film (manufactured by FUJIFILM: film thickness: 60 μm), dried in an oven at 80 ° C for 60 seconds, and dried, and then irradiated with an ultraviolet irradiation device (Fusion UV Systems, Japan). The light source H Bulb was irradiated with ultraviolet rays at an irradiation line amount of 300 mJ/m ² to form a transparent hard coat layer having a dry film thickness of 5 μm. The hard coat has a refractive index of 1.52.

<Formation Example 2> (Formation of high refractive index layer)

The coating liquid for forming a high refractive index layer was applied onto the hard coat layer formed by the above method, and the film thickness after drying was 250 nm. This was irradiated with ultraviolet rays by an ultraviolet irradiation device (Fusion UV Systems, Japan, light source H Bulb) at an irradiation dose of 192 mJ/m ² to form a high refractive index layer. The refractive index of the high refractive index layer was 1.60.

<Formation Example 3> (Formation of low refractive index layer)

The coating liquid for forming a low refractive index layer was applied onto the high refractive index layer formed by the above method, and the film thickness after drying was 120 nm. The ultraviolet ray irradiation apparatus (Fusion UV Systems, Japan, light source H Bulb) was irradiated with ultraviolet rays at an irradiation dose of 192 mJ/m ² to be cured to form a low refractive index layer, thereby producing an antireflection film. The refractive index of the low refractive index layer was 1.30.

[About the comparative example]

3 parts by mass of urethane acrylate of Example 2, 18 parts by mass of zirconia fine particle dispersion (solid content 20%, solvent: methyl isobutyl ketone), and 0.1 part by mass of IRGACURE 184 (BASF Corporation) The antireflection film of Comparative Example 2 to Comparative Example 3 was prepared by mainly changing the amount of methyl isobutyl ketone based on 79 parts by weight of methyl isobutyl ketone based on methyl isobutyl ketone (manufactured by photopolymerization initiator). The antireflection film of Comparative Example 4 to Comparative Example 5 was produced by changing the amounts of the urethane acrylate and the zirconia fine particle dispersion.

18 parts by mass of the porous cerium oxide microparticle dispersion (solid content 20%, solvent: methyl isobutyl ketone), and 1.99 parts by mass of EO-modified dipentaerythritol hexaacrylate (product) Name: DPEA-12, manufactured by Nippon Chemical Co., Ltd., 0.07 parts by mass of a polymerization initiator (manufactured by BASF Corporation, trade name: IRGACURE 184), and 0.20 parts by mass of TSF 4460 (trade name, manufactured by Momentive Performance Materials) The antireflection film of Comparative Example 6 to Comparative Example 7 was prepared by mainly changing the amount of methyl isobutyl ketone based on 80 parts by weight of methyl isobutyl ketone based on polyether modified fluorenone oil.

The more specific contents of Comparative Examples 1 to 7 will be described below.

<Comparative Example 1>

This is an example in which the high refractive index layer shown in the formation example 2 is not applied to the hard coat layer, and the low refractive index layer is applied on the hard coat layer instead.

<Comparative Example 2>

This is an example in which the film thickness after drying of the high refractive index layer formed in Formation Example 2 was 290 nm. Here, 74 parts by weight of methyl isobutyl ketone as a solvent was prepared to prepare a coating liquid for forming a high refractive index layer.

<Comparative Example 3>

This is an example in which the film thickness after drying of the high refractive index layer formed in Formation Example 2 was 190 nm. Here, 84 parts by weight of methyl isobutyl ketone as a solvent was prepared to prepare a coating liquid for forming a high refractive index layer.

<Comparative Example 4>

This is an example in which 1.5 parts by weight of the urethane acrylate of the high refractive index layer of Example 2 and 24 parts by weight of the zirconia fine particle dispersion were applied, and the refractive index of the formed film after drying was 1.66.

<Comparative Example 5>

This is an example in which 6 parts by weight of the urethane acrylate of the high refractive index layer of Example 2 and 6 parts by weight of the zirconia fine particle dispersion were applied to form a film having a refractive index of 1.56 after drying.

<Comparative Example 6>

This is an example in which the film thickness after drying of the low refractive index layer formed in Formation Example 3 was 140 nm. Here, 75 parts by weight of methyl isobutyl ketone as a solvent is prepared to prepare a coating liquid for forming a low refractive index layer.

<Comparative Example 7>

This is an example in which the film thickness after drying of the low refractive index layer formed in Formation Example 3 was 110 nm. Here, 85 parts by weight of methyl isobutyl ketone as a solvent was prepared to prepare a coating liquid for forming a low refractive index layer.

The modulation method of the above comparative example is based on the operation in the first embodiment unless otherwise specified.

[Evaluation of anti-reflection film]

The antireflection films obtained in Example 1 and Comparative Examples 1 to 7 were evaluated by the following methods.

(visual average reflectivity)

The surface reflectance of the low refractive index layer of the obtained antireflection film was measured by an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.) at an incident angle of 5°. Further, from the scored light reflectance curve, the visual average reflectance is obtained based on JIS R3106. Further, at the time of measurement, a matte black paint was applied to a surface of the triethylenesulfide-based cellulose film which is a transparent support, and a low-refractive-index layer was not formed, and an anti-reflection treatment was performed.

(the hue of reflected light)

The surface of the low refractive index layer of the obtained antireflection film was measured for the light reflectance at an incident angle of 5° by an automatic spectrophotometer (U-4100 manufactured by Hitachi, Ltd.), and the hue of the reflected light was obtained from the scored light reflectance curve. Further, at the time of measurement, a matte black paint was applied to a surface of the triethylenesulfide-based cellulose film which is a transparent support, and a low-refractive-index layer was not formed, and an anti-reflection treatment was performed.

(Angle dependence of the hue of reflected light)

The surface of the low refractive index layer of the obtained antireflection film was measured by an automatic spectrophotometer (U-4100 manufactured by Hitachi, Ltd.) at an incident angle of 5 to 50 (5°, 10°) under the same incident angle and reflection angle. The splitting reflectance of 20°, 30°, 40°, and 50°, and then the hue of the reflected light is obtained from the scored light reflectance curve. Further, at the time of measurement, a matte black paint was applied to a surface of the triethylenesulfide-based cellulose film which is a transparent support, and a low-refractive-index layer was not formed, and an anti-reflection treatment was performed.

(Evaluation Results)

The evaluation results are shown in Table 1 and Figure 2. In addition, in Fig. 2, the end point of the arrow is the result of the hue corresponding to the end point of the range of the incident angle of 5° to 50°, that is, the starting point of the arrow is the result of the incident angle of 5°, and the arrow The end point is the result of an incident angle of 50°.

From the results of Table 1, Example 1 showed good performance. Further, in the first embodiment, as a result of the second drawing, the angular dependence of the hue of the reflected light also shows good performance. Further, in Fig. 2, the range indicated by reference numeral 21 means a range of hue which does not cause the reflected light of the antireflection film to have a color and a color. Further, in Comparative Example 4, since a uniform film was not formed, it was impossible to measure. In the above embodiments, the antireflection film can have a visual average reflectance of 0.05% or more and 1.0% or less on the surface of the antireflection film, and can reduce the hue of the reflected light from the front side, and at the same time, the foreign object incident from various angles. The reflected light of light can also reduce its hue.

21‧‧‧ is a range of hue that does not cause the reflected light of the anti-reflective film to have a color and a color

Claims (5)

An antireflection film characterized in that any incident light having an incident angle of 5° to 50° in a region of a wavelength of 380 nm to 780 nm of a C light source belonging to a CIE standard light source is equal in incident angle and reflection angle thereof. The hue of the reflected light under reflective conditions satisfies -3≦a*≦3, -5≦b*≦5 in the CIE1976L* a* b* color space. The antireflection film of claim 1, wherein the visual average reflectance on the surface of the antireflection film is in the range of 0.05% or more and 1.0% or less. A display device comprising the antireflection film of claim 1 or 2. A polarizing plate comprising the antireflection film of claim 1 or 2. A touch panel comprising the antireflection film of claim 1 or 2.