JP4888593B2 - Anti-reflection material and electronic image display device using the same - Google Patents

Description

  The present invention relates to an antireflection material that is provided on the front surface of an electronic display and can improve antireflection performance and can suppress coloring, and an electronic image display device using the same.

  In recent years, electronic displays are widely used for televisions and monitors. In particular, displays are becoming thinner and larger, and plasma displays (PDP), liquid crystal displays (LEDs), and the like are attracting attention. These large displays require anti-reflection processing of the display in order to improve visibility, and anti-reflection processing is applied to most models.

  In general, the antireflection processing of the display is often set so as to reduce the reflectance near the human visual sensitivity center. For this reason, the thing of the structure which dropped the reflectance of 550-600 nm vicinity extremely is mainstream. However, with such a design, the reflection spectrum exhibits a so-called “V-shape”, and when the antireflection film is exposed to light, it is strongly colored from purple to blue. When such an antireflection film is set in front of an electronic display, the color of the antireflection film overlaps with the original color of the display, which hinders the color reproducibility of the display. In particular, when the background color is a dark color (black), there is a problem that coloring of the antireflection film is conspicuous and black is difficult to be reproduced as black.

  Further, in order to give the anti-reflection material sufficient surface hardness, a hard coat layer having a thickness of about 1 to 10 μm is often provided. In this case, the refractive indexes of the transparent resin film and the hard coat layer are usually different. If layers having different refractive indexes are laminated with a thickness of 1 to 10 μm, the surface is affected by the interference of light between the layers. There is a problem that a pattern like an oil film on water is generated (uneven interference), and the appearance is impaired and the quality of the electronic display is remarkably lowered. Furthermore, when the hard coat layer has a thickness of 1 to 3 μm, the hard coat layer is colored red and green due to the above-described interference action, which hinders the color reproducibility of the electronic display as well as the antireflection layer. There was a problem that.

  The following solutions have been proposed for these problems. That is, a multilayer structure comprising an outermost layer, a reduced reflection layer, a hard coat layer, and an interference layer is provided on the transparent resin film, and the maximum difference in reflectance amplitude in the wavelength region of 500 nm to 650 nm is 1.0% or less. Is proposed (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2003-177209 (second page)

  In the technique described in Patent Document 1, unevenness of light interference can be suppressed and deterioration in appearance can be suppressed by setting the maximum value of the difference in the amplitude of the reflectance in the visible light region to 1.0% or less. However, there is a problem that the antireflection performance cannot be sufficiently improved only by suppressing the difference in the amplitude of the reflectance, and coloring derived from the antireflection film itself cannot be sufficiently suppressed.

  Accordingly, an object of the present invention is to provide an antireflection material capable of improving antireflection performance and suppressing coloring, and an electronic image display device using the same.

In order to achieve the above object, the anti-reflection material of the first invention in the present invention forms an interference layer on a transparent resin film, a hard coat layer is provided on the interference layer, and the hard coat layer is formed on the hard coat layer. In addition to providing a low refractive index layer, the maximum difference in reflectance amplitude in the light wavelength region of 500 nm to 650 nm is 1% or less, the luminous reflectance Y for the CIE standard illuminant D65 is 2% or less, and the CIE standard In the anti-reflective material in which ab chroma Cab * = {(a *) ² + (b *) ² } ^1/2 for illuminant D65 is 10 or less, the refractive index of the transparent resin film is 1.55 to 1.70, interference The refractive index of the layer is within the range {(refractive index of the transparent resin film)} × (refractive index of the hard coat layer)} ^1/2 ± 0.03 and the optical film thickness is 125 to 165 nm. The rate is 1.45-1. 55, the film thickness is 1 to 10 μm, the refractive index of the low refractive index layer is 1.28 to 1.45, the refractive index is lower than the layer immediately below, and the optical film thickness n _L · d is 400. ≦ 4n _L · d (nm) ≦ 650 (where n _L is the refractive index of the low refractive index layer and d is the thickness of the layer).

The antireflection material of the second invention is characterized in that, in the first invention, the haze value defined in JIS K 7136 is 1% or less.
An electronic image display device according to a third aspect of the invention is characterized in that the antireflection material of the first or second aspect is provided on the front surface of the display.

According to the present invention, the following effects can be exhibited.
In the reduced reflection material according to the first aspect of the invention, since the visibility reflectance Y with respect to the CIE standard illuminant D65 is set to 2% or less, reflection on the surface of the reduced reflection material can be reduced, and the reduced reflection material It is possible to improve the antireflection performance. Furthermore, since the ab chroma Cab * = {(a *) ² + (b *) ² } ^1/2 for the CIE standard illuminant D65 is set to 10 or less, the reflection spectrum becomes flat, and in the visible light region. The difference in reflectance can be reduced, and coloring derived from the antireflection material itself can be suppressed.

Further, the refractive index of the transparent resin film is 1.55 to 1.70, and the refractive index of the interference layer is {(refractive index of transparent resin film)} × (refractive index of hard coat layer)} ^1/2 ± 0.03 The optical film thickness is 125 to 165 nm, the refractive index of the hard coat layer is 1.45 to 1.55, and the film thickness is 1 to 10 μm, thereby further reducing interference unevenness due to light interference. It is possible to suppress the coloring of the surface and improve the color reproducibility. Furthermore, the refractive index of the low refractive index layer is 1.28 to 1.45, the refractive index is lower than the layer immediately below, and the optical film thickness n _L · d is 400 ≦ 4 n _L · d (nm). ≦ 650 (where n _L is the refractive index of the low-refractive index layer and d is the thickness of the layer), a sufficient anti-reflection effect can be obtained, and in particular, the anti-reflection effect is expressed in visible light. be able to.

  In the anti-reflective material of the second invention, the haze value defined in JIS K 7136 is set to 1% or less, so that in addition to the effects of the first invention, a clear image without turbidity can be obtained. it can.

  In the electronic image display device according to the third aspect of the invention, since the anti-reflection material is provided on the front surface of the display, the effect of the anti-reflection material of the first or second invention can be exhibited.

The schematic sectional drawing which shows the structure of a reduced reflection material. 3 is a graph showing the relationship between the wavelength of light and the reflectance in Example 1. The graph which shows the relationship between the wavelength of light and the reflectance in the comparative example 1.

Hereinafter, embodiments of the present invention will be described in detail.
The anti-reflection material of this embodiment is configured by forming an interference layer on a transparent resin film, providing a hard coat layer on the interference layer, and providing a low refractive index layer on the hard coat layer. In this reduced reflection material, the maximum value of the difference in the amplitude of the reflectance in the light wavelength region of 500 nm to 650 nm is set to 1% or less. Furthermore, the luminous reflectance Y for the CIE standard illuminant D65 is 2% or less, and the ab chroma Cab * = {(a *) ² + (b *) ² } ^1/2 for the CIE standard illuminant D65 is set to 10 or less. Is done. In addition, the haze value specified in JIS K 7136 is preferably 1% or less.

  The transparent resin substrate forming the transparent resin film preferably has a refractive index (n) in the range of 1.45 to 1.70. As a transparent resin base material having a high refractive index (1.55 to 1.70), specifically, for example, polyethylene terephthalate (PET, n = 1.65), polycarbonate (PC, n = 1.59), Polyarylate (PAR, n = 1.60), polyether sulfone (PES, n = 1.65) and the like are preferable. Among these, as a transparent resin film having a high refractive index, a PET film is preferable in terms of ease of molding, availability, and cost.

  Moreover, the thickness of a transparent resin film becomes like this. Preferably it is 25-400 micrometers, More preferably, it is 50-200 micrometers. When the thickness is less than 25 μm or more than 400 μm, the handleability during the production and use of the anti-reflection material is lowered, which is not preferable.

  In the anti-reflective material, the maximum value of the difference in reflectance amplitude in the wavelength region of 500 nm to 650 nm is 1% or less. That is, the maximum value of the amplitude due to the interference light between the hard coat layer and the transparent resin film at a wavelength of 500 nm to 650 nm when the reflection spectrum of the transparent resin film surface is measured must be 1% or less. The maximum value of the difference in amplitude is more preferably 0.5% or less. When the maximum value of the difference in reflectance amplitude exceeds 1%, the unevenness of interference becomes conspicuous, lowering the quality of the appearance, and the color unevenness of red and green due to the unevenness of interference occurs, resulting in color reproduction of the electronic display. It will reduce the sex.

  The anti-reflection material has a visibility reflectance Y with respect to the CIE standard illuminant D65 of 2% or less, more preferably 1% or less. The CIE standard illuminant D65 is an illuminant whose relative spectral distribution is defined by the International Commission on Illumination (CIE) (radiation whose relative spectral distribution is defined over the entire wavelength range, which affects the color perception of the illuminated object). is there. The visibility reflectance Y is calculated as Y of the object color tristimulus value by reflection in the XYZ color system defined by JIS Z8701 using this relative spectral distribution. When the visibility reflectance Y exceeds 2%, the reflection reducing effect on the surface of the anti-reflective material is weakened, and the reflection of the background on the screen becomes strong, so that the color reproducibility of the electronic display is lowered. .

  Further, the effect of the present invention is further enhanced by setting the maximum reflectance in the wavelength range that human eyes perceive as light, that is, in the visible light region (380 nm to 780 nm), preferably 4% or less, more preferably 3% or less. be able to. The reason for this is that when the maximum reflectance in the visible light region exceeds 4%, an attempt to improve the antireflection performance tends to make the coloring of the anti-reflective material tight, and conversely the coloring of the anti-reflective material This is because the antireflection performance tends to deteriorate if the attempt is made to suppress the above.

In the anti-reflection material, ab chroma Cab * = {(a *) ² + (b *) ² } ^1/2 with respect to CIE standard illuminant D65 is 10 or less, preferably 5 or less. The ab chroma Cab represents an amount that approximately correlates with saturation in the color space CIE 1976 L * a * b * color system having a perceptually uniform rate recommended by the CIE in 1976. When the value of the ab chroma Cab exceeds 10, coloring of the surface of the anti-reflection material becomes conspicuous, and the color reproducibility of the electronic display is lowered.

  The anti-reflective material preferably has a haze value defined in JIS K 7136 of 1% or less, and more preferably 0.5% or less. When this haze value exceeds 1%, when the anti-reflective material is installed on the electronic display, the surface looks white and cloudy, and the color reproducibility of the electronic display is remarkably deteriorated. .

When a transparent resin film having a refractive index of 1.55 to 1.70 is used, it is desirable to reduce interference unevenness by laminating an interference layer and a hard coat layer from the substrate side on the transparent resin film. . For this purpose, the hard coat layer has a refractive index of 1.45 to 1.55 and a film thickness of 1 μm to 10 μm. The refractive index of the interference layer is within the range of {(refractive index of transparent resin film)} × (refractive index of hard coat layer)} ^1/2 ± 0.03 and the optical film thickness is 125 to 165 nm. The refractive index of the transparent resin film, the interference layer, and the hard coat layer satisfies the relationship of the refractive index of the transparent resin film> the refractive index of the interference layer> the refractive index of the hard coat layer. Laminate in order of coat layer. Here, the optical film thickness is the product of the refractive index (n) of the layer and the thickness (d) of the layer (n × d).

The refractive index of the interference layer is within the above range, preferably {(refractive index of transparent resin film) × (refractive index of hard coat layer)} ^1/2 ± 0.02. The interference unevenness can be most reduced when the refractive index of the interference layer is {(refractive index of the transparent resin film) × (refractive index of the hard coat layer)} ^1/2 .

  When the refractive index and the optical film thickness of the interference layer are outside the above ranges, the effect of reducing the light interference unevenness is reduced. Similarly, when the refractive index of the hard coat layer is less than 1.45 or more than 1.55, an appropriate light interference unevenness reduction effect cannot be obtained. When the thickness of the hard coat layer is less than 1 μm, sufficient surface strength cannot be obtained. On the other hand, when the film thickness exceeds 10 μm, problems such as a decrease in flex resistance occur.

  The interference layer may have a refractive index and a thickness within the above ranges, and the material and the method of forming the layer are not particularly limited. The material for forming the layer may be, for example, an organic substance or an inorganic substance alone or as a mixture. Examples of the organic substance include reactive monomers and polymers such as acrylate. Examples of the inorganic substance include silicon compounds, metals, and metal oxides. Is mentioned. Moreover, a conventionally known method can be used as a layer forming method, for example, a dry coating method such as a vapor deposition method, a sputtering method, a CVD method, an ion plating method, a dip coating method, a roll coating method, a gravure coating method, Examples include a wet coating method such as a die coating method. In particular, a method capable of accurately controlling the thickness is preferable.

  Other functions may be imparted to the interference layer as long as the effects of the present invention are not impaired. For example, the improvement of the adhesiveness of a transparent resin film and a hard-coat layer is mentioned. Moreover, when producing a transparent resin film from a resin material, that is, when stretching or casting, it is possible to simultaneously form an interference layer on the surface as a film. For example, when the transparent resin film is a PET film, an adhesive made of a polyester resin or the like is applied to the surface of the PET film in-line during the production of the PET film in order to improve the adhesion with the layer laminated thereon. To form an easy adhesion layer. By adjusting the refractive index and film thickness of the easy adhesion layer to the conditions of the interference layer, the easy adhesion layer can also serve as the interference layer.

  The hard coat layer formed on the interference layer has a refractive index and a film thickness within the above ranges, and the method for forming the layer is not particularly limited. Specifically, hardened | cured material, such as reactive silicon compounds, such as monofunctional (meth) acrylate, polyfunctional (meth) acrylate, and tetraethoxysilane, is mentioned, for example. Here, (meth) acrylate includes both methacrylic acid ester and acrylic acid ester. The same applies to the following compounds. Among these, from the viewpoint of achieving both productivity and hardness, a polymerization cured product of a composition containing an ultraviolet curable polyfunctional acrylate is particularly preferable.

  The composition containing an ultraviolet curable polyfunctional acrylate is not particularly limited. For example, a mixture of one or more known ultraviolet curable polyfunctional acrylates, a commercially available UV curable hard coat material, or other components as long as the effects of the present invention are not impaired. Further added ones can be used.

  The UV curable polyfunctional acrylate is not particularly limited. For example, dipentaerythritol hexaacrylate, tetramethylolmethane tetraacrylate, tetramethylolmethane triacrylate, trimethylolpropane triacrylate, 1,6-hexanediol Examples thereof include acrylic derivatives of polyfunctional alcohols such as diacrylate and 1,6-bis (3-acryloyloxy-2-hydroxypropyloxy) hexane, polyethylene glycol diacrylate, and polyurethane acrylate.

  It does not specifically limit with the other component contained in the composition containing a ultraviolet curable polyfunctional acrylate. For example, inorganic or organic fine particle filler, inorganic or organic fine particle pigment, and other inorganic or organic fine particles; polymer, polymerization initiator, polymerization inhibitor, antioxidant, dispersant, surfactant, Examples thereof include additives such as light stabilizers and leveling agents. Further, any amount of solvent can be added as long as it is dried after film formation in the wet coating method.

  The method for forming the hard coat layer is not particularly limited. When an organic material is used, the hard coat layer can be formed by a general wet coat method such as a roll coat method or a die coat method. The formed layer can be subjected to a curing reaction by heating, irradiation with active energy rays such as ultraviolet rays and electron beams, as necessary.

  Next, the anti-reflection layer can have a single layer structure. In the case of a single layer structure, one layer having a refractive index lower than that of the hard coat layer (low refractive index layer) is formed on the hard coat layer. As the number of layers increases, color unevenness is likely to occur due to slight film thickness unevenness of each layer, which tends to deteriorate the appearance and color reproducibility.

  The method for forming the antireflection layer is not particularly limited, and for example, a dry coating method, a wet coating method, or the like can be employed. In view of productivity and production cost, the wet coating method is particularly preferable. The wet coating method may be a known one, and representative examples thereof include a roll coating method, a spin coating method, and a dip coating method. In these, the method which can form continuously, such as a roll coat method, is preferable from the point of productivity.

  In order to exhibit the function of the anti-reflection layer, the refractive index of the low refractive index layer requires that the formed layer has a lower refractive index than the layer immediately below, and the refractive index is 1.28 to 1. .45 range. When it exceeds 1.45, it is difficult to obtain a sufficient anti-reflection effect by the wet coating method, and when the refractive index is less than 1.28, it tends to be difficult to form a sufficiently hard layer. .

The thickness of the anti-reflection layer varies depending on the type and shape of the transparent resin film and the structure of the anti-reflection layer, but a thickness equal to or less than the visible light wavelength per layer is preferable. For example, in order to exhibit the effect of reducing reflection in visible light, the optical film thickness n _L · d of the low refractive index layer is designed to satisfy 400 ≦ 4 n _L · d (nm) ≦ 650. Here, n _L is the refractive index of the low refractive index layer, and d is the thickness of the layer.

  As a material constituting the low refractive index layer, a composition containing an inorganic substance such as silicon oxide, lanthanum fluoride, magnesium fluoride, cerium fluoride, a single or mixture of fluorine-containing organic compounds, or a polymer of fluorine-containing organic compounds. Can be used. Further, a monomer containing no fluorine (abbreviated as a non-fluorine monomer) or a polymer can be used as a binder. Among these, silicon oxide-based fine particles, particularly hollow silicon oxide-based fine particles and fluorine-containing organic compounds are particularly preferable from the viewpoint of low refractive index.

  Examples of the hollow silicon oxide fine particles include those having cavities inside the outer shell and porous silica fine particles. The average particle diameter of the fine particles preferably does not greatly exceed the thickness of the layer, and is particularly preferably 0.1 μm or less. When the average particle size is increased, scattering occurs and the haze value increases, which is not suitable for the present invention. Further, the surface of the fine particles can be modified with various coupling agents as required. Examples of the various coupling agents include organically substituted silicon compounds, metal alkoxides such as aluminum, titanium, zirconium, and antimony, and organic acid salts. In particular, a film having high hardness can be formed by modifying the surface with a reactive group such as a (meth) acryloyl group.

  The fluorine-containing organic compound is not particularly limited. For example, fluorine-containing monofunctional (meth) acrylate, fluorine-containing polyfunctional (meth) acrylate, fluorine-containing itaconic acid ester, fluorine-containing maleic acid ester, fluorine-containing silicon Examples thereof include monomers such as compounds, and polymers thereof. Among these, fluorine-containing (meth) acrylate is preferable from the viewpoint of reactivity, and fluorine-containing polyfunctional (meth) acrylate is particularly preferable from the viewpoint of hardness and refractive index. By curing these fluorine-containing organic compounds, a layer having a low refractive index and a high hardness can be formed.

  Examples of the fluorine-containing monofunctional (meth) acrylate include 1- (meth) acryloyloxy-1-perfluoroalkylmethane, 1- (meth) acryloyloxy-2-perfluoroalkylethane, and the like. Examples of the perfluoroalkyl group include linear, branched and cyclic groups having 1 to 8 carbon atoms.

  As the fluorine-containing polyfunctional (meth) acrylate, fluorine-containing bifunctional (meth) acrylate, fluorine-containing trifunctional (meth) acrylate and fluorine-containing tetrafunctional (meth) acrylate are preferable. Examples of the fluorine-containing bifunctional (meth) acrylate include 1,2-di (meth) acryloyloxy-3-perfluoroalkylbutane, 2-hydroxy-1H, 1H, 2H, 3H, 3H-perfluoroalkyl-2. Examples include ', 2'-bis {(meth) acryloyloxymethyl} propionate and α, ω-di (meth) acryloyloxymethyl perfluoroalkane. The perfluoroalkyl group is preferably a linear, branched or cyclic group having 1 to 11 carbon atoms, and the perfluoroalkane group is preferably a linear one. These fluorine-containing bifunctional (meth) acrylates can be used alone or as a mixture when used.

  Examples of the fluorine-containing trifunctional (meth) acrylate include, for example, 2- (meth) acryloyloxy-1H, 1H, 2H, 3H, 3H-perfluoroalkyl-2 ′, 2′-bis {(meth) acryloyloxy Methyl} propionate. The perfluoroalkyl group is preferably a linear, branched or cyclic group having 1 to 11 carbon atoms.

  Examples of fluorine-containing tetrafunctional (meth) acrylates include α, β, ψ, ω-tetrakis {(meth) acryloyloxy} -αH, αH, βH, γH, γH, χH, χH, ψH, ωH, ωH- Perfluoroalkane and the like are preferable. The perfluoroalkane group is preferably a linear one having 1 to 14 carbon atoms. In use, the fluorine-containing tetrafunctional (meth) acrylate can be used alone or as a mixture.

  As a specific example of the fluorine-containing silicon compound, (1H, 1H, 2H, 2H-perfluoroalkyl) trimethoxysilane and the like are preferable. The perfluoroalkyl group is preferably a linear, branched or cyclic group having 1 to 10 carbon atoms. Examples of the polymer of the fluorinated organic compound or the polymer of the other fluorinated monomer include a homopolymer, a copolymer, or a copolymer with a non-fluorinated monomer of the fluorinated monomer. Linear polymers such as, polymers containing carbocycles or heterocycles in the chain, cyclic polymers, comb polymers, and the like. A conventionally well-known thing can be used as said non-fluorine-type monomer. Examples thereof include silicon compounds such as monofunctional or polyfunctional (meth) acrylates and tetraethoxysilane.

  The anti-reflective layer may contain other components in addition to the above compounds as long as the effects of the present invention are not impaired. Other components are not particularly limited, for example, inorganic or organic pigments, polymers, polymerization initiators, photopolymerization initiators, polymerization inhibitors, antioxidants, dispersants, surfactants, light stabilizers, Examples include additives such as leveling agents. Further, any amount of solvent can be added as long as it is dried after film formation in the wet coating method. The anti-reflection layer can be formed by wet coating, and if necessary, a layer can be formed by performing a curing reaction by irradiation with active energy rays such as ultraviolet rays and electron beams or heating. The curing reaction with active energy rays is preferably carried out in an inert gas atmosphere such as nitrogen or argon.

  The antireflection material can form an adhesive layer on the transparent resin film side. Although it does not specifically limit as a material used for a contact bonding layer, For example, an acrylic adhesive, a silicone adhesive, a ultraviolet curable adhesive, a thermosetting adhesive etc. can be mentioned. This adhesive layer can be provided with one or more types of functions such as blocking light in a specific wavelength region, improving contrast, and correcting color tone. For example, if the transmitted light color of the anti-reflective material is yellowish or the like, it is possible to correct the color tone by adding a pigment or the like.

  The antireflection material of the present embodiment can be used for applications that require an effect of improving color reproducibility, an effect of suppressing uneven light interference, and an effect of reducing reflection. In particular, it can be used on the surface of an electronic image display device. Examples of the electronic image display device include a cathode ray tube, a plasma display, a liquid crystal display device, and the like. It can be used directly on the screen surface or in close contact with a plate disposed on the front surface of the screen via an adhesive layer.

The effects exhibited by the above embodiment will be described collectively below.
-In the reduced reflection material of this embodiment, since the visibility reflectance Y with respect to CIE standard illuminant D65 is set to 2% or less, reflection on the surface of the reduced reflection material can be reduced, and the reduced reflection material It is possible to improve the antireflection performance. Furthermore, since the ab chroma Cab * = {(a *) ² + (b *) ² } ^1/2 for the CIE standard illuminant D65 is set to 10 or less, the reflection spectrum becomes flat, and in the visible light region. The difference in reflectance can be reduced, and coloring derived from the antireflection material itself can be suppressed.

Further, the refractive index of the transparent resin film is 1.55 to 1.70, and the refractive index of the interference layer is {(refractive index of transparent resin film)} × (refractive index of hard coat layer)} ^1/2 ± 0.03 The optical film thickness is 125 to 165 nm, the refractive index of the hard coat layer is 1.45 to 1.55, and the film thickness is 1 to 10 μm. For this reason, interference unevenness due to light interference can be further reduced, coloring of the surface can be suppressed, and color reproducibility can be improved. Furthermore, the refractive index of the low refractive index layer is 1.28 to 1.45, the refractive index is lower than the layer immediately below, and the optical film thickness n _L · d is 400 ≦ 4 n _L · d (nm). ≦ 650 (where n _L is the refractive index of the low-refractive index layer and d is the thickness of the layer), a sufficient anti-reflection effect can be obtained, and in particular, the anti-reflection effect is expressed in visible light. be able to.

In addition, when the haze value specified in JIS K 7136 is set to 1% or less, the anti-reflection material can obtain a clear image without turbidity.
Further, the anti-reflection layer constituting the anti-reflection material includes a low refractive index layer, and the refractive index of the low refractive index layer is set to a small range of 1.28 to 1.45. The rate Y can be lowered and the antireflection performance can be improved.

  In addition, since the electronic image display device is configured by providing the anti-reflective material on the front surface of the display, the above-described effects of the anti-reflective material can be exhibited.

Hereinafter, the embodiment will be described more specifically with reference to production examples, examples, and comparative examples. In addition, the refractive index of the hardened | cured material of the coating liquid for reduced reflection layers prepared by the manufacture example was measured as follows.
(1) On the acrylic plate (trade name: “Delagrass A”, manufactured by Asahi Kasei Kogyo Co., Ltd.) with a refractive index of 1.49, the coating solution for the anti-reflective layer is applied by a dip coater (manufactured by Sugiyama Motochemical Co., Ltd.) The layer thickness was adjusted so that the optical film thickness was about 550 nm with a dry film thickness.
(2) After drying the solvent, the coating solution for the anti-reflective layer was cured by irradiating with 400 mJ ultraviolet rays using a 120 W high-pressure mercury lamp in a nitrogen atmosphere with an ultraviolet irradiation device (Iwasaki Electric Co., Ltd.) as necessary. .
(3) The back surface of the acrylic plate is roughened with sandpaper and painted with a black paint, and a spectrophotometer ("U-Best V560", manufactured by JASCO Corporation) is used at 5 ° and -5 ° positive at 400 to 650 nm. The reflectance was measured, and the reflectance minimum value or maximum value was read.
(4) The refractive index was calculated from the extreme value of the reflectance using the following formula.

得られた減反射材の物性は以下の方法で評価した。
１）分光反射率： 減反射材の裏面（透明樹脂フィルム側）をサンドペーパーで粗し、黒色塗料で塗りつぶしたものを分光光度計（「Ｕ−Ｂｅｓｔ Ｖ５６０」、日本分光株式会社製）により、３８０〜７８０ｎｍの５°、−５°正反射スペクトルを測定した。これにより、減反射層の反射スペクトルが測定できる。
２）波長５００〜６５０ｎｍでの反射率の振幅の差の最大値： 分光反射率測定で得られた反射スペクトルより、波長５００〜６５０ｎｍでの反射率の振幅の差の最大値を読み取った。
３）視感度反射率Ｙ： 上記で測定した３８０〜７８０ｎｍの分光反射率と、ＣＩＥ標準イルミナントＤ６５の相対分光分布を用いて、ＪＩＳ Ｚ８７０１で規定されているＸＹＺ表色系における、反射による物体色の三刺激値Ｙを計算した。
４）abクロマ： １）で測定した３８０〜７８０ｎｍの分光反射率と、ＣＩＥ標準イルミナントＤ６５の相対分光分布を用いて、ＪＩＳ Ｚ８７２０に規定される色空間ＣＩＥ１９７６Ｌ*ａ*ｂ*表色系を計算し、求めたa*、b*値からCab*＝｛（ａ*）²＋（ｂ*）²｝^1/2を計算した。
５）ヘーズ値： ヘーズメーター（「ＮＤＨ２０００」、日本電色工業株式会社製）を用いてヘーズ値を測定した。
６）干渉むらの有無： 三波長蛍光灯管の下でフィルムの外観を観察し、干渉むらがはっきりと見える場合を×、殆ど観察されない場合と〇として評価した。
７）着色抑制（黒のしまり）： １０ｃｍ×１０ｃｍサイズのガラス板の片面にアクリル系粘着シートを使用して減反射フィルムを貼り合せ、もう片方の面に黒色フィルムを貼り合せたサンプルを作製した。このサンプルを、三波長蛍光灯管の下で観察し、裏面の黒色フィルムの黒色が、自然な黒色に見える場合を○、黒色が白茶けたり、減反射フィルムの着色がきつく、黒っぽく見えない場合を×として評価した。
〔製造例１−１、干渉層用塗液（ＩＦ−１）の調製〕
ジペンタエリスリトールヘキサアクリレート３０質量部、テトラメチロールメタントリアクリレート２０質量部、平均粒径０．０５μｍの酸化錫微粒子５０質量部、光重合開始剤（製品名：「ＩＲＧＡＣＵＲＥ９０７」、チバスペシャルティケミカル製）２質量部を２−ブタノール１０００質量部に溶解乃至分散して干渉層用塗液（ＩＦ−１）を調製した。硬化物の屈折率は１．５８であった。
〔製造例１−２、ハードコート層用塗液（ＨＣ−１）の調製〕
ジペンタエリスリトールヘキサアクリレート７０質量部、１，６−ビス（３−アクリロイルオキシ−２−ヒドロキシプロピルオキシ）ヘキサン３０質量部、光重合開始剤（商品名：「ＩＲＧＡＣＵＲＥ１８４」、チバスペシャルティケミカル製）４質量部、イソプロパノール１００質量部を混合してハードコート層用塗液（ＨＣ−１）を調製した。硬化物の屈折率は１．５２であった。
〔製造例１−７、低屈折率層用塗液（Ｌ−１）の調製〕
１，１０−ジアクリロイルオキシ−２，２，３，３，４，４，５，５，６，６，７，７，８，８，９，９−ヘキサデカフルオロデカン４０質量部、中空シリカゾル（固形分濃度２０質量％、平均粒径６０ｎｍ、触媒化成工業株式会社製）１２０質量部、光重合開始剤（商品名：「ＫＡＹＡＣＵＲＥ ＢＭＳ」、日本化薬株式会社製）５質量部を混合して、低屈折率層用塗液（Ｌ−１）を調製した。Ｌ−１の重合硬化物の屈折率は１．３２であった。
〔製造例１−８、低屈折率層用塗液（Ｌ−２）の調製〕
ジペンタエリスリトールヘキサアクリレート３０質量部、中空シリカゾル（固形分濃度２０質量％、平均粒径６０ｎｍ、触媒化成工業株式会社製）１４０質量部、光重合開始剤（商品名：「ＫＡＹＡＣＵＲＥ ＢＭＳ」、日本化薬株式会社製）５質量部を混合して、低屈折率層用塗液（Ｌ−２）を調製した。Ｌ−２の重合硬化物の屈折率は１．３５であった。
〔製造例１−９、低屈折率層用塗液（Ｌ−３）の調製〕
１，１０−ジアクリロイルオキシ−２，２，３，３，４，４，５，５，６，６，７，７，８，８，９，９−ヘキサデカフルオロデカン８０質量部、ジペンタエリスリトールヘキサアクリレート５質量部、シリカゲル微粒子分散液（商品名：「ＸＢＡ−ＳＴ」、日産化学株式会社製）６０質量部、光重合開始剤（商品名：「ＫＡＹＡＣＵＲＥ ＢＭＳ」、日本化薬株式会社製）５質量部を混合して低屈折率層用塗液（Ｌ−３）を調製した。Ｌ−３の重合硬化物の屈折率は１．４０であった。
（実施例１）
厚みが１００μｍのポリエチレンテレフタレート（ＰＥＴ）フィルム（商品名：「Ａ４３００」、東洋紡績株式会社製）上に干渉層として、干渉層用塗液ＩＦ−１をスピンコーターにより、光学膜厚が１４５〜１５５ｎｍになるように層の厚さを調整して塗布し、乾燥後、窒素雰囲気下で４００ｍＪ／ｃｍ²の紫外線により硬化した。

The physical properties of the obtained antireflection material were evaluated by the following methods.
1) Spectral reflectivity: The back surface (transparent resin film side) of the anti-reflective material was roughened with sandpaper, and the black paint was applied with a spectrophotometer ("U-Best V560", manufactured by JASCO Corporation). A 5 ° and −5 ° regular reflection spectrum of 380 to 780 nm was measured. Thereby, the reflection spectrum of the reduced reflection layer can be measured.
2) Maximum value of difference in amplitude of reflectance at wavelength of 500 to 650 nm: The maximum value of difference in amplitude of reflectance at wavelength of 500 to 650 nm was read from the reflection spectrum obtained by spectral reflectance measurement.
3) Visibility reflectance Y: Object color due to reflection in the XYZ color system defined by JIS Z8701, using the spectral reflectance of 380 to 780 nm measured above and the relative spectral distribution of CIE standard illuminant D65. The tristimulus value Y was calculated.
4) ab chroma: The color space CIE 1976 L * a * b * color system defined in JIS Z8720 is calculated using the spectral reflectance of 380 to 780 nm measured in 1) and the relative spectral distribution of CIE standard illuminant D65. Then, Cab * = {(a *) ² + (b *) ² } ^1/2 was calculated from the obtained a * and b * values.
5) Haze value: The haze value was measured using a haze meter ("NDH2000", manufactured by Nippon Denshoku Industries Co., Ltd.).
6) Presence / absence of interference unevenness: The appearance of the film was observed under a three-wavelength fluorescent lamp tube, and the case where the interference unevenness was clearly visible was evaluated as x, and the case where almost no interference was observed was evaluated as ◯.
7) Suppression of coloring (black margin): A sample was prepared by laminating a low reflection film using an acrylic adhesive sheet on one side of a 10 cm × 10 cm size glass plate and laminating a black film on the other side. . When this sample is observed under a three-wavelength fluorescent lamp tube, the black color of the black film on the back surface appears to be natural black, the black color is faint, the anti-reflection film is colored strongly, and it does not appear black Was evaluated as x.
[Production Example 1-1, Preparation of Interference Layer Coating Liquid (IF-1)]
30 parts by mass of dipentaerythritol hexaacrylate, 20 parts by mass of tetramethylolmethane triacrylate, 50 parts by mass of fine tin oxide particles having an average particle size of 0.05 μm, a photopolymerization initiator (product name: “IRGACURE907”, manufactured by Ciba Specialty Chemicals) 2 An interference layer coating solution (IF-1) was prepared by dissolving or dispersing mass parts in 1000 parts by mass of 2-butanol. The refractive index of the cured product was 1.58.
[Production Example 1-2, Preparation of Hard Coat Layer Coating Liquid (HC-1)]
Dipentaerythritol hexaacrylate 70 parts by mass, 1,6-bis (3-acryloyloxy-2-hydroxypropyloxy) hexane 30 parts by mass, photopolymerization initiator (trade name: “IRGACURE184”, manufactured by Ciba Specialty Chemicals) 4 parts by mass Part and 100 parts by mass of isopropanol were mixed to prepare a hard coat layer coating solution (HC-1). The refractive index of the cured product was 1.52.
[Production Example 1-7, Preparation of Coating Solution for Low Refractive Index Layer (L-1)]
1,10-Diacryloyloxy-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorodecane 40 parts by mass, hollow silica sol 120 parts by mass (solid content concentration 20% by mass, average particle size 60 nm, manufactured by Catalyst Kasei Kogyo Co., Ltd.), 5 parts by mass of photopolymerization initiator (trade name: “KAYACURE BMS”, manufactured by Nippon Kayaku Co., Ltd.) Thus, a coating liquid for low refractive index layer (L-1) was prepared. The refractive index of the polymerized cured product of L-1 was 1.32.
[Production Example 1-8, Preparation of Coating Solution for Low Refractive Index Layer (L-2)]
30 parts by mass of dipentaerythritol hexaacrylate, 140 parts by mass of hollow silica sol (solid content concentration 20% by mass, average particle size 60 nm, manufactured by Catalyst Kasei Kogyo Co., Ltd.), photopolymerization initiator (trade name: “KAYACURE BMS”, Nippon Kayaku (Made by Yakuhin Co., Ltd.) 5 parts by mass was mixed to prepare a coating solution for low refractive index layer (L-2). The refractive index of the polymerization cured product of L-2 was 1.35.
[Production Example 1-9, Preparation of coating solution for low refractive index layer (L-3)]
1,10-Diacryloyloxy-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorodecane, 80 parts by mass, dipenta Erythritol hexaacrylate 5 parts by mass, silica gel fine particle dispersion (trade name: “XBA-ST”, manufactured by Nissan Chemical Co., Ltd.), photopolymerization initiator (trade name: “KAYACURE BMS”, manufactured by Nippon Kayaku Co., Ltd. ) 5 parts by mass was mixed to prepare a coating solution for low refractive index layer (L-3). The refractive index of the polymerization cured product of L-3 was 1.40.
Example 1
As an interference layer on a polyethylene terephthalate (PET) film (trade name: “A4300”, manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm, an optical film thickness of 145 to 155 nm is applied to the interference layer coating liquid IF-1 using a spin coater. The thickness of the layer was adjusted so as to be applied, dried, and then cured with 400 mJ / cm ² ultraviolet light in a nitrogen atmosphere.

A hard coat layer coating solution HC-1 was applied thereon using a bar coater so as to have a dry film thickness of about 3 μm, and cured with ultraviolet rays of 400 mJ / cm ² . Next, using a spin coater, the low refractive index layer coating liquid L-1 is applied on the layer by adjusting the layer thickness so that the optical film thickness is 105 nm, and after drying, it is 400 mJ in a nitrogen atmosphere. Cured with / cm ² of ultraviolet light to produce a low reflection material. A schematic cross-sectional view of the obtained antireflection material is shown in FIG. As shown in FIG. 1, a hard coat layer 13 is provided on a transparent resin film 11 via an interference layer 12, and a low refractive index layer 14 is provided as a dereflection layer on the surface of the hard coat layer 13. ing.

The results of evaluating the spectral reflectance, the visibility reflectance, the maximum difference in the amplitude of the reflectance at a wavelength of 500 to 650 nm, the ab chroma Cab, the haze value, the presence or absence of interference unevenness, and the suppression of coloring are shown in FIG. 2 and Table 1. In FIG. 2, the maximum value of the difference in reflectance amplitude is indicated as X.
(Example 2)
A low reflection material was produced in the same manner as in Example 1 except that the low refractive index layer coating liquid was changed to L-2. Example 1 in which spectral reflectance, visibility reflectance, maximum value of difference in amplitude of reflectance at wavelength of 500 to 650 nm, ab chroma Cab, haze value, presence / absence of interference unevenness, and coloring suppression of the obtained anti-reflection material Measured and evaluated in the same manner. The results are shown in Table 1, respectively.
(Example 3)
A reflection reducing material was produced in the same manner as in Example 1 except that the low refractive index layer coating solution was changed to L-3. Example 1 in which spectral reflectance, visibility reflectance, maximum value of difference in amplitude of reflectance at wavelength of 500 to 650 nm, ab chroma Cab, haze value, presence / absence of interference unevenness, and coloring suppression of the obtained anti-reflection material Measured and evaluated in the same manner. The results are shown in Table 1, respectively.
(Comparative Example 1)
A reflection reducing material is produced in the same manner as in Example 1 except that the interference layer is not formed, and the spectral reflectance, the visibility reflectance, the maximum difference in the amplitude of the reflectance at a wavelength of 500 to 650 nm, the ab chroma Cab, The haze value, presence / absence of interference unevenness, and suppression of coloring were measured and evaluated in the same manner as in Example 1. The results are shown in FIG. 3 and Table 2, respectively. In FIG. 3, the maximum value of the difference in the amplitude of the reflectance is indicated as X.

以上の結果より、実施例１から３で作製した減反射材は、適切な屈折率の干渉層を形成することにより、波長５００から６５０ｎｍの反射率の振幅の差の最大値は０．５％以下となっており、干渉むらを低減させることができた。また、いずれの実施例においても、視感度反射率Ｙは２％以下、ａｂクロマＣａｂは１０以下、ヘーズ値は１％以下で、本発明における必要条件を全て満たしているため、優れた外観と低反射率を兼ね備えており、黒のしまり、色再現性共に申し分なかった。

From the above results, the anti-reflection material produced in Examples 1 to 3 has an interference layer with an appropriate refractive index, so that the maximum value of the difference in the amplitude of the reflectance at a wavelength of 500 to 650 nm is 0.5%. It was as follows, and interference unevenness could be reduced. In any of the examples, the luminous reflectance Y is 2% or less, the ab chroma Cab is 10 or less, and the haze value is 1% or less, which satisfies all the necessary conditions in the present invention. Combined with low reflectance, the black color and color reproducibility were satisfactory.

On the other hand, in Comparative Example 1, since there is no interference layer, the maximum value of the difference in reflectance amplitude at a wavelength of 500 to 650 nm exceeds 1.0%, and the interference unevenness of the hard coat layer is severe and reduced. A pattern as if oil floated on the surface of the reflective layer appeared, and both coloring suppression (black spots) and color reproducibility were poor.
Example 9
The acrylic pressure-sensitive adhesive sheet was uniformly bonded to the back surface (transparent resin film side) of the reduced reflection material produced in Examples 1 to 3 using a hand roller. Next, it was directly bonded to the surface of the plasma display via an adhesive sheet, and the appearance of interference unevenness when the display was turned off and the color reproducibility when the display was turned on were evaluated. As a result, when any of the films was used, the interference unevenness was not noticeable, and the primary color and black and white reproducibility was excellent. However, the interference unevenness was observed under a three-wavelength fluorescent lamp, and the degree of interference unevenness was evaluated. In addition, color reproducibility was evaluated by how red, blue, green, white, and black were displayed one after another using a computer connected to a display and image software, and how natural these colors looked.
(Comparative Example 6)
Using the anti-reflection material produced in Comparative Example 1, it was bonded to a plasma display in the same manner as in Example 9, and the appearance of uneven interference when the display was turned off and the color reproducibility when the display was turned on were evaluated. As a result, in the case of using the film of Comparative Example 1, interference unevenness is clearly observed, the appearance quality is remarkably deteriorated, and the hard coat layer derived from the interference unevenness is intensely colored in red and green. Color reproducibility was bad.

It should be noted that this embodiment can be implemented with the following modifications.
A hard coat layer and a low refractive index layer can be provided on both sides of the transparent resin film.
-It can also be configured to improve the antireflection performance by reducing the difference in haze value in the direction in which the light reflection direction is different.

It is preferable to ensure brightness by setting the light transmittance to 90% or higher, for example.
Further, the technical idea that can be grasped from the embodiment will be described below.
The refractive index of the transparent resin film is 1.55 to 1.70, and an interference layer, a hard coat layer, and a layer having a lower refractive index than at least the hard coat are provided on one side of the transparent resin film from the transparent resin film side. Provided on the outermost layer, the refractive index of the hard coat layer is 1.45 to 1.55, the film thickness is 1 to 10 μm, and the refractive index of the interference layer is {(refractive index of the transparent resin film) × (hard coat Refractive index of the layer)} In the range of ^1/2 ± 0.03, the optical film thickness is 125 to 165 nm, and the refractive index of each layer is the refractive index of the transparent resin film> the refractive index of the interference layer> the hard coat layer The anti-reflective material according to claim 1, wherein the refractive index has a refractive index relationship of 3. In this case, interference unevenness due to light interference can be further reduced, surface coloring can be suppressed, and color reproducibility can be improved.

  The transparent resin film is a polyethylene terephthalate film, the antireflection layer contains a low refractive index component, and the main component is hollow silicon oxide-based fine particles or a fluorine-containing organic compound. 2. The antireflection material according to 2. In this case, antireflection performance and color reproducibility can be improved.

  DESCRIPTION OF SYMBOLS 11 ... Transparent resin film, 12 ... Interference layer, 13 ... Hard-coat layer, 14 ... Low refractive index layer.

Claims (3)

An interference layer is formed on the transparent resin film, a hard coat layer is provided on the interference layer, a low refractive index layer is provided on the hard coat layer, and the amplitude of the reflectance in the light wavelength region of 500 nm to 650 nm is increased. maximum of 1% of the difference or less, with luminous reflectance Y for the CIE standard illuminant D65 is 2% or less, and ab chroma Cab for CIE standard illuminant D65 * = {(a *) 2 + (b *) 2} 1 ^{In the} anti-reflection material with ^{/ 2} of 10 or less,
The refractive index of the transparent resin film is 1.55-1.70, and the refractive index of the interference layer is {(the refractive index of the transparent resin film)} × (the refractive index of the hard coat layer)} ^1/2 ± 0.03 And the optical film thickness is 125 to 165 nm, the refractive index of the hard coat layer is 1.45 to 1.55, the film thickness is 1 to 10 μm, and the refractive index of the low refractive index layer is 1.28 to 1.45. And the optical film thickness n _L · d is 400 ≦ 4 n _L · d (nm) ≦ 650 (where n _L is the refractive index of the low refractive index layer, d is It is a thickness of the layer). The haze value prescribed | regulated to JISK7136 is 1% or less, The anti-reflective material of Claim 1 characterized by the above-mentioned. An electronic image display device comprising the display according to claim 1 or 2 on a front surface of a display.

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