Transparent substrate with antireflection coating and image display device

Abstract

To provide a transparent substrate with antireflection coating with which a reflected glare of external light is sufficiently suppressed, and an image display device that includes this substrate.SOLUTION: The present invention relates to a transparent substrate with antireflection coating comprising a transparent substrate having two principal planes and having a diffusion layer and an antireflection coating on one principal plane of the transparent substrate in the order stated. (A) The luminous reflectance (SCI Y) on the outermost surface of the transparent substrate with antireflection coating is 1% or less; (B) the antireflection coating is of a laminate structure in which at least two dielectric layers mutually differing in refractive index are laminated; (C) the ratio SCE Y / SCI Y of the diffuse reflectance (SCI Y) on the outermost surface of the transparent substrate with antireflection coating to the luminous reflectance (SCI Y) on the outermost surface of the transparent substrate with antireflection coating is 0.15 or greater.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a transparent substrate with an antireflection film and an image display device including the same.

Background Art

[0002] In recent years, from the viewpoint of aesthetics, a method of installing a transparent substrate such as a cover glass on the front surface of an image display device such as a liquid crystal display (LCD) has been used. However, in such a transparent substrate, one of the problems is the reflection caused by the reflection of external light.

[0003] Conventionally, in order to prevent the reflection of external light, a transparent substrate provided with an antireflection film (hereinafter, also referred to as a transparent substrate with an antireflection film) is known. For example, Patent Document 1 discloses a transparent substrate with an antireflection film having a light absorption ability and being insulating. Patent Document 2 discloses a transparent conductive laminate in which a silicon oxide layer and a copper layer are laminated in this order. Patent Document 3 discloses an antireflection film having a film made of a high refractive index material and a film made of a low refractive index material on the surface of a glass plate, and the film made of the low refractive index material is disposed on the outermost surface.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional transparent substrate with an antireflection film, the reflection of external light cannot be sufficiently suppressed, and there is room for further preventing the reflection of external light. Therefore, an object of the present invention is to provide a transparent substrate with an antireflection film in which external light reflection is sufficiently suppressed, and an image display device including the same.

Means for Solving the Problems

[0006] The present invention is as follows. (1) A transparent substrate with an antireflection film having two main surfaces and having a diffusion layer and an antireflection film in this order on one of the main surfaces of the transparent substrate, wherein (A) the visual reflectance (SCI Y) of the outermost surface of the transparent substrate with the antireflection film is 1% or less, (B) the antireflection film has a laminated structure in which at least two dielectric layers having different refractive indexes are laminated, and (C) SCE Y / SCI Y, which is the ratio of the diffuse reflectance (SCE Y) of the outermost surface of the transparent substrate with the antireflection film to the visual reflectance (SCI Y) of the outermost surface of the transparent substrate with the antireflection film, is 0.15 or more. Transparent substrate with an antireflection film. (2) The transparent substrate with an antireflection film according to (1) above, wherein the haze value of the laminate of the transparent substrate and the diffusion layer is 10% or more. (3) The transparent substrate with an antireflection film according to (1) or (2) above, wherein the visual transmittance (Y) is 20 to 90%. (4) The transparent substrate with an antireflection film according to any one of (1) to (3) above, wherein the sheet resistance of the antireflection film is 10 4 Ω / □ or more. (5) The transparent substrate with an antireflection film according to any one of (1) to (4) above, wherein the b * value in the transmitted color under a D65 light source is 5 or less. (6) The transparent substrate with an anti-reflective film according to any one of (1) to (5) above, wherein at least one of the dielectric layers is mainly composed of an oxide of Si, and at least one other layer of the layered structure is mainly composed of a mixed oxide of at least one oxide selected from group A consisting of Mo and W and at least one oxide selected from group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn and In, and the content of the elements of group B in the mixed oxide relative to the total of the elements of group A and the elements of group B in the mixed oxide is 65% by mass or less. (7) The transparent substrate with an anti-reflective coating according to any one of (1) to (6), further comprising an anti-fouling coating on the anti-reflective coating. (8) The transparent substrate with an anti-reflective coating according to any one of (1) to (7), wherein the transparent substrate includes glass. (9) The transparent substrate with an anti-reflective coating according to any one of (1) to (8), wherein the transparent substrate comprises at least one resin selected from polyethylene terephthalate, polycarbonate, acrylic, silicone, or triacetylcellulose. (10) The transparent substrate with an anti-reflective coating according to any one of (1) to (9), wherein the transparent substrate is a laminate of glass and at least one resin selected from polyethylene terephthalate, polycarbonate, acrylic, silicone, or triacetylcellulose. (11) The transparent substrate with an anti-reflective coating according to (8) or (10), wherein the glass is chemically strengthened. (12) The transparent substrate with an anti-reflective coating according to any one of (1) to (11), wherein the main surface of the transparent substrate having the anti-reflective coating is treated with an anti-glare coating. (13) An image display device comprising a transparent substrate with an anti-reflective coating as described in any one of (1) to (12) above. [Effects of the Invention]

[0007] According to one aspect of the present invention, a transparent substrate with an anti-reflective coating that sufficiently suppresses reflection of external light is provided. The transparent substrate with an anti-reflective coating according to one aspect of the present invention is suitable as a cover glass for an image display device due to the above-mentioned features. Furthermore, according to one aspect of the present invention, an image display device is provided that includes the above-mentioned transparent substrate with an anti-reflective coating. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic cross-sectional view showing one example of the configuration of a transparent substrate with an anti-reflective coating according to one embodiment of the present invention. [Figure 2] Figures 2(a) to (d) are laser microscope images of the surface shape of anti-glare PET films used in some of the examples. [Figure 3] Figures 3(a) to (d) are laser microscope images of the surface shape of anti-glare PET film or anti-glare TAC film used in some of the examples. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below. In this specification, having another layer or film on the main surface of a substrate such as a transparent substrate, on a layer such as a diffusion layer, or on a film such as an anti-reflective film is not limited to the other layer or film being provided in contact with the main surface, layer, or film, but is sufficient if the layer or film is provided in an upward direction. For example, having a diffusion layer on the main surface of a transparent substrate means that the diffusion layer is provided in contact with the main surface of the transparent substrate, or any other arbitrary layer or film is provided between the transparent substrate and the diffusion layer.

[0010] A transparent substrate with an anti-reflective coating according to one aspect of the present invention is a transparent substrate having two main surfaces and a transparent substrate with an anti-reflective coating having a diffuse layer and an anti-reflective coating in that order on one of the main surfaces of the transparent substrate, wherein (A) the luminous reflectance (SCI Y) of the outermost surface of the transparent substrate with the anti-reflective coating is 1% or less, (B) the anti-reflective coating has a laminated structure in which at least two dielectric layers with different refractive indices are laminated, and (C) the ratio of the diffuse reflectance (SCE Y) of the outermost surface of the transparent substrate with the anti-reflective coating to the luminous reflectance (SCI Y), SCE Y / SCI Y, is 0.15 or more.

[0011] Figure 1 is a schematic cross-sectional view showing one example of the configuration of a transparent substrate with an anti-reflective coating according to one aspect of the present invention. A diffusion layer 31 is formed on the transparent substrate 10, and an anti-reflective coating (multilayer film) 30 is formed on the diffusion layer 31.

[0012] <Transparent base> In this embodiment, the transparent substrate having two main surfaces (hereinafter also simply referred to as the transparent substrate) preferably has a refractive index of 1.4 to 1.7. If the refractive index of the transparent substrate is within the above range, reflection at the bonding surface can be sufficiently suppressed when optically bonding a display, touch panel, etc. The refractive index is more preferably 1.45 or higher, even more preferably 1.47 or higher, and even more preferably 1.65 or lower, and even more preferably 1.6 or lower.

[0013] The transparent substrate preferably contains at least one of glass and resin. More preferably, the transparent substrate contains both glass and resin. When the transparent substrate includes glass, the high surface flatness of the glass allows for the creation of clear, high-quality images when placed on the display surface. When the transparent substrate contains resin, it is less prone to cracking from external impacts, making it safer than glass. Furthermore, if transparent films such as PET or TAC are selected as the resin, continuous processing using rolls becomes possible as a method for forming a diffusion layer as an anti-glare treatment, thus reducing costs. Additionally, applying fine particles of various materials as a diffusion layer offers greater design flexibility compared to etching the glass surface. When a transparent substrate includes both glass and resin, for example, by laminating a resin film with a diffusion layer onto the glass, the transparent substrate can be configured to include both glass and resin, offering advantages such as the flatness of glass and the shatterproof function and design flexibility of the diffusion layer provided by the resin.

[0014] When the transparent substrate contains glass, the type of glass is not particularly limited, and glass with various compositions can be used. In particular, the glass preferably contains sodium, and a composition that allows for strengthening by molding and chemical strengthening treatment is preferred. Specifically, examples include aluminosilicate glass, soda-lime glass, borosilicate glass, lead glass, alkali barium glass, and aluminoborsilicate glass. In this specification, if the transparent substrate includes glass, the transparent substrate is also referred to as a glass substrate.

[0015] There are no particular restrictions on the thickness of the glass substrate, but if the glass is subjected to chemical strengthening treatment, it is usually preferable to have a thickness of 5 mm or less, more preferably 3 mm or less, and even more preferably 1.5 mm or less, in order to effectively perform chemical strengthening. It is also usually 0.2 mm or more.

[0016] Chemically strengthened glass is preferred for the glass substrate. This increases the strength of the transparent substrate with an anti-reflective coating. If the glass substrate is subjected to the anti-glare treatment described later, the chemical strengthening should be performed after the anti-glare treatment and before forming the anti-reflective coating (multilayer film).

[0017] Preferably, the glass substrate has an anti-glare treatment applied to the main surface on the side with the anti-reflective coating. This enhances the anti-glare properties of the transparent substrate, resulting in a clearer image observed through the transparent substrate.

[0018] When the transparent substrate contains a resin, the type of resin is not particularly limited, and resins with various compositions can be used. Among these, thermoplastic resins or thermosetting resins are preferred, and examples include polyvinyl chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, polyester resin, polyurethane resin, cellulose resin, acrylic resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, fluororesin, thermoplastic elastomer, polyamide resin, polyimide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polylactic acid resin, cyclic polyolefin resin, polyphenylene sulfide resin, etc. Among these, cellulose resins are preferred, and examples include triacetylcellulose resin, polycarbonate resin, polyethylene terephthalate resin, etc. These resins may be used individually or in combination of two or more. The above resin is particularly preferably composed of at least one resin selected from polyethylene terephthalate, polycarbonate, acrylic, silicone, and triacetylcellulose. These resins are preferred because they are colorless, transparent, highly permeable, and low scattering, are readily available and therefore relatively inexpensive, and can be used to impart functionality as the main component of hard coats and adhesives. In this specification, if the transparent substrate contains a resin, the transparent substrate is also referred to as the resin substrate.

[0019] The resin substrate is preferably in the form of a film. When the resin substrate is in the form of a film, i.e., a resin film, its thickness is not particularly limited, but is preferably 20 to 150 μm, and more preferably 40 to 80 μm.

[0020] If the transparent substrate includes both glass and resin, for example, the resin substrate may be provided on top of the glass substrate.

[0021] Furthermore, while the transparent substrate has a diffusion layer on one of its main surfaces, as described later, examples of laminates having a transparent substrate (or part thereof) and a diffusion layer (hereinafter also simply referred to as a laminate) include resin substrate-anti-glare layer, glass substrate-anti-glare layer, and so on. Examples of resin substrate-anti-glare layer materials include anti-glare PET film and anti-glare TAC film. Examples of anti-glare PET film include those manufactured by Higashiyama Film Co., Ltd. (product names: BHC-III and EHC-30a) and those manufactured by Reiko Co., Ltd. Examples of anti-glare TAC film include anti-glare TAC film (manufactured by Toppan TOMOEGAWA Optical Film Co., Ltd., product name VZ50) and anti-glare TAC film (manufactured by Toppan TOMOEGAWA Optical Film Co., Ltd., product name VH66H). As described later, the glass substrate-anti-glare layer is obtained by applying an anti-glare treatment to the main surface of the glass substrate that has an anti-reflective coating, thereby providing the anti-glare layer.

[0022] The above laminate preferably has a haze value of 10% or more, more preferably 15% or more, even more preferably 20% or more, even more preferably 25% or more, and particularly preferably 50% or more. Having the haze value of the above laminate within this range allows for more effective suppression of reflections of ambient light. Furthermore, the haze value is preferably 90% or less, more preferably 85% or less, and even more preferably 82% or less. Having the haze value of the above laminate within this range suppresses a decrease in display resolution and also suppresses image whitening when ambient light enters the display. The above haze values ​​are measured using a haze meter (HR-100 model, manufactured by Murakami Color Research Institute Co., Ltd.) in accordance with JIS K 7136:2000.

[0023] The above laminate preferably has an arithmetic mean surface roughness (Sa) of 0.05 to 0.6 μm, and more preferably 0.05 to 0.55 μm. Sa is defined in ISO 25178 and can be measured, for example, using a laser microscope VK-X3000 manufactured by Keyence Corporation. A small Sa means that the surface roughness of the transparent substrate is small, resulting in low diffuse reflectance (SCE Y) due to low diffuseness of reflected light, making it difficult to obtain a reflection suppression effect. A large Sa means that the surface roughness is large, resulting in high diffuse reflectance, but surface dirt is difficult to remove, which is undesirable for display surface materials. Sa can be adjusted by appropriately changing parameters such as the type of fine particles used as a diffuser, the average particle size, and the amount of mixing, appropriately controlling the etching conditions of the surface treatment, or appropriately curing and forming an unbalanced diffusion layer such as a sol-gel silica system.

[0024] The above laminate has a surface area ratio Sdr (hereinafter also simply referred to as "Sdr") calculated from the surface area obtained by measurement using a laser microscope VK-X3000 manufactured by Keyence Corporation, which is preferably 0.001 to 0.12, and more preferably 0.0025 to 0.11. Sdr is defined in ISO 25178 and is expressed by the following formula. Developed area ratio Sdr={(AB) / B} A: Surface area (unfolded area) that reflects the actual irregularities in the measurement area. B: Area of ​​a flat surface without irregularities in the measurement area A small Sdr means that the surface area of ​​the transparent substrate is small. When the surface area decreases relatively, the diffuseness of reflected light decreases, the diffuse reflectance (SCE Y) decreases, and the reflection suppression effect is difficult to obtain. A large Sdr means that the surface area of ​​the transparent substrate is large, and the area of ​​the anti-reflective layer exposed to the outside air increases relatively, raising concerns about a decrease in the reliability of the anti-reflective film. Sdr can be adjusted by appropriately changing parameters such as the type of fine particles used as the diffusion material, the average particle size, and the amount of mixing, by appropriately controlling the etching conditions of the surface treatment, or by appropriately curing and forming an unbalanced diffusion layer such as a sol-gel silica system.

[0025] The above laminate preferably has an Sdq (root mean square slope) of 0.03 to 0.50, and more preferably 0.07 to 0.49. Sdq is defined in ISO 25178 and can be measured, for example, with a laser microscope VK-X3000 manufactured by Keyence Corporation. A small Sdq means a small root mean square slope, resulting in lower diffuseness of reflected light, a smaller diffuse reflectance (SCE Y), and difficulty in achieving reflection suppression. A large Sdq increases the root mean square slope and increases the sharpness of the outermost surface of the transparent substrate, resulting in a rough, snagging feel when touched with fingers or cloth, thus degrading the tactile sensation. Sdq can be adjusted by appropriately changing parameters such as the type of fine particles used as a diffusion material, the average particle size, and the amount of mixing, by appropriately controlling the etching conditions of the surface treatment, or by appropriately curing and forming an unbalanced diffusion layer such as a sol-gel silica system.

[0026] The above laminate preferably has an Spc (average of the principal curvature of the peaks on the surface) of 150 to 2500 (1 / mm). Spc is specified in ISO 25178 and can be measured, for example, using a Keyence VK-X3000 laser microscope. If Spc is small, the arithmetic mean curvature of the peaks becomes small, the diffuse reflectance (SCE Y) of the outermost surface of the transparent substrate becomes small, and the reflection suppression effect cannot be obtained. If Spc is large, the arithmetic mean curvature of the peaks becomes large, resulting in a rough feeling when touched with fingers or cloth, and the tactile sensation deteriorates. Spc can be adjusted by appropriately changing parameters such as the type of fine particles used as a diffusion material, the average particle size, and the amount of mixing, appropriately controlling the etching conditions of the surface treatment, or appropriately curing and forming an unbalanced diffusion layer such as a sol-gel silica system.

[0027] <Diffusion layer> In this embodiment, the diffusion layer is provided on one of the main surfaces of the transparent substrate described above. The diffusion layer refers to a layer that diffuses specularly reflected light and reduces glare and reflections, and examples include an anti-glare layer in which the hard coat layer is given the function of diffusing specularly reflected light (anti-glare properties).

[0028] The anti-glare layer has an uneven surface on one side, which causes light scattering, increases the haze value, and provides anti-glare properties. The anti-glare layer consists of an anti-glare layer composition in which at least particulate matter having anti-glare properties itself is dispersed in a solution of a polymer resin as a binder. The anti-glare layer can be formed, for example, by applying the above anti-glare layer composition to one main surface of a transparent substrate.

[0029] Examples of particulate materials having anti-glare properties include inorganic fine particles such as silica, clay, talc, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, titanium dioxide, synthetic zeolite, alumina, and smectite, as well as organic fine particles including styrene resin, urethane resin, benzoguanamine resin, silicone resin, and acrylic resin.

[0030] Furthermore, the polymer resin used as a binder for the hard coat layer or the anti-glare layer can include, for example, polyester resins, acrylic resins, acrylic urethane resins, polyester acrylate resins, polyurethane acrylate resins, epoxy acrylate resins, urethane resins, and the like.

[0031] Furthermore, if the transparent substrate is a glass substrate, the glass substrate may have a diffusion layer on one of its main surfaces by applying an anti-glare treatment to the main surface on the side having the anti-reflective coating. This can enhance the anti-glare properties of the transparent substrate, resulting in a clearer image observed through the transparent substrate. The method of anti-glare treatment is not particularly limited; for example, a method of applying a surface treatment to the main surface of a glass substrate to form desired irregularities can be used. Specifically, one method involves chemically treating the main surface of the glass substrate, such as applying a frost treatment. Frosting can be performed, for example, by immersing the glass substrate to be treated in a mixed solution of hydrogen fluoride and ammonium fluoride, thereby chemically surface-treating the immersed surface. In addition to chemical treatments such as frosting, other methods can also be used, such as sandblasting, which involves blasting the surface of a glass substrate with crystalline silicon dioxide powder, silicon carbide powder, etc., using pressurized air, or physical treatments, such as polishing with a brush coated with crystalline silicon dioxide powder, silicon carbide powder, etc., and moistened with water.

[0032] <Anti-reflective film> The anti-reflective film in this embodiment has a laminated structure in which at least two dielectric layers with different refractive indices are stacked, and has the function of suppressing light reflection. The anti-reflective film (multilayer film) 30 shown in Figure 1 has a laminated structure in which a first dielectric layer 32 and a second dielectric layer 34 with different refractive indices are stacked. By stacking the first dielectric layer 32 and the second dielectric layer 34, which have different refractive indices, light reflection is suppressed. The first dielectric layer 32 is a high refractive index layer, and the second dielectric layer 34 is a low refractive index layer.

[0033] In the anti-reflective film (multilayer film) 30 shown in Figure 1, the first dielectric layer 32 is preferably composed of a mixed oxide mainly of at least one oxide selected from group A consisting of Mo and W, and at least one oxide selected from group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In. However, it is preferable that the content of group B elements in the mixed oxide (hereinafter referred to as the group B content) relative to the total of group A elements and group B elements in the mixed oxide is 65% by mass or less. Here, "mainly" means the component with the highest content (by mass) in the first dielectric layer 32, for example, that the layer is composed of 70% by mass or more of the relevant component.

[0034] The yellowish tint of transmitted light can be suppressed if the content of group B in the first dielectric layer (ABO) 32, which is composed of a mixed oxide of at least one oxide selected from group A consisting of Mo and W, and at least one oxide selected from group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, is 65% by mass or less.

[0035] The second dielectric layer 34 is mainly composed of Si oxide (SiO₂). x Preferably, it is composed of the following. Here, "mainly" means the component that is present in the second dielectric layer 34 in the largest amount (by mass), for example, that the layer contains 70% by mass or more of the relevant component.

[0036] The first dielectric layer 32 is preferably composed of a mixed oxide of at least one oxide selected from group A consisting of Mo and W, and at least one oxide selected from group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In. Among these, Mo is preferred as group A and Nb as group B.

[0037] By using Mo and Nb for the second dielectric layer 34, which is an oxygen-deficient silicon oxide layer, and for the first dielectric layer 32, it is preferable that the silicon oxide layer does not take on a yellowish tint in visible light, even though it is oxygen-deficient, whereas conventional oxygen-deficient silicon oxide layers take on a yellowish tint in visible light.

[0038] From the viewpoint of transmittance with the transparent substrate 10, the refractive index of the first dielectric layer 32 at a wavelength of 550 nm is preferably 1.8 to 2.3.

[0039] The extinction coefficient of the first dielectric layer 32 is preferably 0.005 to 3, and more preferably 0.04 to 0.38. If the extinction coefficient is 0.005 or higher, the desired absorption rate can be achieved with an appropriate number of layers. If the extinction coefficient is 3 or lower, it is relatively easy to achieve a balance between reflective color and transmittance.

[0040] The anti-reflective film (multilayer film) 30 shown in Figure 1 is a two-layer laminated structure consisting of a first dielectric layer 32 and a second dielectric layer 34. However, the anti-reflective film (multilayer film) in this embodiment is not limited to this, and may also be a laminated structure in which three or more dielectric layers with different refractive indices are laminated. In this case, it is not necessary for all dielectric layers to have different refractive indices. For example, in the case of a three-layer laminated structure, it can be a three-layer laminated structure of low refractive index layer, high refractive index layer, and low refractive index layer, or a three-layer laminated structure of high refractive index layer, low refractive index layer, and high refractive index layer. In the former case, the two low refractive index layers, and in the latter case, the two high refractive index layers, may have the same refractive index. Also, for example, in the case of a four-layer laminated structure, it can be a four-layer laminated structure of low refractive index layer, high refractive index layer, low refractive index layer, and high refractive index layer, or a four-layer laminated structure of high refractive index layer, low refractive index layer, high refractive index layer, and low refractive index layer. In this case, the two low refractive index layers and two high refractive index layers, respectively, may have the same refractive index.

[0041] In the case of a laminated structure in which three or more layers with different refractive indices are stacked, the first dielectric layer (ABO) 32 and the second dielectric layer (SiO x )34 may also include dielectric layers other than 34. In this case, the first dielectric layer (ABO)32 and the second dielectric layer (SiO x Each layer is selected to form a three-layer laminated structure of low refractive index layer, high refractive index layer, and low refractive index layer, or a three-layer laminated structure of high refractive index layer, low refractive index layer, and high refractive index layer, or a four-layer laminated structure of low refractive index layer, high refractive index layer, low refractive index layer, and high refractive index layer, or a four-layer laminated structure of high refractive index layer, low refractive index layer, high refractive index layer, and low refractive index layer. However, the outermost layer is the second dielectric layer (SiO x )34 is preferable. In order to obtain low reflectivity, the outermost layer is the second dielectric layer (SiO x )34 can be manufactured relatively easily. Also, when forming an antifouling film on the anti-reflective film 30, as described later, the antifouling film is made of the second dielectric layer (SiO2) from the viewpoint of bonding properties related to the durability of the antifouling film. x It is preferable to form it on 34.

[0042] The first dielectric layer (A-B-O) 32 is preferably amorphous. If it is amorphous, it can be formed at a relatively low temperature, and when the transparent substrate 10 contains resin, the resin is not damaged by heat and can be suitably applied.

[0043] Note that, as an insulating light-transmitting film having light absorption ability, a halftone mask used in the semiconductor manufacturing field is known. As the halftone mask, an oxygen-deficient film such as a Mo-SiO film containing a small amount of Mo is used. Also, as an insulating light-transmitting film having light absorption ability, a narrow bandgap film used in the semiconductor manufacturing field is known. x However, since these light-transmitting films have a high light absorption ability on the short wavelength side of visible light, the transmitted light has a yellowish tint. Therefore, they are not suitable for the cover glass of an image display device.

[0044] In a preferred embodiment of the present invention, by having a first dielectric layer 32 with an increased content of Mo or W and a second dielectric layer 34 composed of SiO or the like, a transparent substrate with an antireflection film having light absorption ability, insulating properties, and excellent adhesion and strength can be obtained. x

[0045]

[0046] The antireflection film 30 in this embodiment can be formed on the main surface of the transparent substrate 10 using a known film formation method such as a sputtering method, a vacuum evaporation method, or a coating method. That is, the dielectric layers constituting the antireflection film 30 are formed on the main surface of the diffusion layer 31 using a known film formation method such as a sputtering method, a vacuum evaporation method, or a coating method according to their stacking order. Also, the antireflection film 30 may be formed on the main surface of the transparent substrate by combining a plurality of film formation methods. For example, the antireflection film 30 is formed by a sputtering method, and only the outermost antifouling film is formed by an evaporation method or a coating method, or the antireflection film 30 except for the outermost layer is formed by a sputtering method, and only the outermost layer is formed by an organic film having antifouling properties.

[0047] The anti-reflective coating 30 is preferably formed by a method of laminating thin films in a vacuum, such as sputtering or vacuum deposition, from the viewpoint of reducing reflectivity, increasing durability, and increasing hardness. Furthermore, this lamination method in a vacuum results in superior surface hardness and a higher effect of reducing reflectivity compared to forming the anti-reflective coating by wet coating, which involves curing and drying the coating liquid. It also allows for a stable SCI Y value of 1% or less and provides an appropriate in-plane reflectivity distribution.

[0047] Sputtering methods include magnetron sputtering, pulse sputtering, AC sputtering, and digital sputtering.

[0048] For example, the magnetron sputtering method involves placing a magnet on the back surface of a dielectric material to generate a magnetic field, causing gas ions to collide with the surface of the dielectric material and be knocked out, thereby sputtering to form a film with a thickness of several nanometers. This method can form a continuous film of dielectric material, which is an oxide or nitride of the dielectric material.

[0049] Furthermore, unlike conventional magnetron sputtering, digital sputtering, for example, involves first forming an ultrathin metal film by sputtering, and then oxidizing it by irradiating it with oxygen plasma, oxygen ions, or oxygen radicals. This process is repeated within the same chamber to form a thin film of metal oxide. In this case, since the film-forming molecules are metallic when they adhere to the substrate, it is presumed to be more ductile than when metal oxides are used for film deposition. Therefore, rearrangement of the film-forming molecules is more likely to occur even with the same energy, resulting in a denser and smoother film.

[0050] <Anti-fouling coating> The transparent substrate with the anti-reflective coating of this embodiment may further have an anti-fouling coating (also called an "Anti Finger Print (AFP) coating") on the anti-reflective coating, from the viewpoint of protecting the outermost surface of the anti-reflective coating. The anti-fouling coating can be composed of, for example, a fluorine-containing organosilicon compound. The fluorine-containing organosilicon compound is not particularly limited as long as it can impart anti-fouling, water-repellent, and oil-repellent properties, and examples include fluorine-containing organosilicon compounds having one or more groups selected from the group consisting of polyfluoropolyether groups, polyfluoroalkylene groups, and polyfluoroalkyl groups. A polyfluoropolyether group is a divalent group having a structure in which polyfluoroalkylene groups and etheric oxygen atoms are alternately bonded.

[0051] Furthermore, commercially available fluorine-containing organosilicon compounds having one or more groups selected from the group consisting of polyfluoropolyether groups, polyfluoroalkylene groups, and polyfluoroalkyl groups include KP-801 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY178 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-130 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-185 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Optool® DSX and Optool AES (both trade names, manufactured by Daikin Corporation), and others, which can be preferably used.

[0052] In this embodiment, if the transparent substrate with an anti-reflective coating also has an anti-fouling coating, the anti-fouling coating will be provided on top of the anti-reflective coating. When the anti-reflective coating is provided on both sides of the two main surfaces of the transparent substrate, the anti-fouling coating can be formed on both anti-reflective coatings, but it is also possible to laminate the anti-fouling coating on only one of the main surfaces. This is because the anti-fouling coating only needs to be provided in areas that may come into contact with human hands, etc., and the configuration can be selected according to the application, etc.

[0053] (Luminous reflectance: SCI Y) The transparent substrate with the anti-reflective coating of this embodiment has a surface luminous reflectance (SCI Y) of 1% or less. If the luminous reflectance (SCI Y) is within the above range, it is highly effective in preventing external light from reflecting onto the screen when used as a cover glass for an image display device. The luminous reflectance (SCI Y) is preferably 0.9% or less, more preferably 0.8% or less, and even more preferably 0.75% or less. The luminous reflectance (SCI Y) can be measured using the method specified in JIS Z 8722 (2009), as described in the examples below. Specifically, the luminous reflectance (SCI Y) can be measured after removing back surface reflection by applying black tape to the other main surface of the transparent substrate (hereinafter also referred to as the back surface of the transparent substrate, or simply the back surface), which is not the main surface on which the anti-reflective coating is applied. The calculation of SCI Y requires the specification of a light source, but since the present invention is intended to suppress reflections in bright daylight, it is preferable to use a D65 light source for the calculation.

[0054] In the transparent substrate with anti-reflective coating according to this embodiment, in order to make the luminous reflectance (SCI Y) 1% or less, for example, the luminous transmittance (Y) of the transparent substrate with anti-reflective coating should be made 90% or less. To achieve this, it is preferable to use a mixed oxide as the first dielectric layer, mainly consisting of at least one oxide selected from group A, which consists of Mo and W, and at least one oxide selected from group B, which consists of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, and to adjust the oxidation amount of the film. By adjusting the oxidation amount and giving absorption to the anti-reflective coating, diffuse reflection from the diffuse layer formed on the transparent substrate can be suppressed.

[0055] (Diffuse reflectance: SCE Y) The transparent substrate with the anti-reflective coating in this embodiment preferably has a diffuse reflectance (SCE Y) of 0.05% or more on its outermost surface, more preferably 0.1% or more, and even more preferably 0.2% or more. When the diffuse reflectance (SCE Y) is within the above range, it is preferable that the effect of preventing external light from reflecting onto the screen is further enhanced when used as cover glass for an image display device.

[0056] The above diffuse reflectance (SCE Y) is measured using a spectrophotometer (Konica Minolta, product name: CM-26d) according to the method specified in JIS Z 8722 (2009), as described in the examples below. Specifically, the diffuse reflectance (SCE Y) of the outermost surface of the transparent substrate with the anti-reflective coating is measured by attaching black tape to the other main surface of the transparent substrate (hereinafter also referred to as the back surface of the transparent substrate, or simply the back surface) that does not have the anti-reflective coating, thereby removing back surface reflection. The black tape used must be one that substantially does not contain a diffuse reflectance component. The presence or absence of a diffuse reflectance component can be evaluated by attaching the black tape whose diffuse reflectance component to be evaluated to a transparent material with almost zero diffuse reflectance component, such as float glass, and measuring the SCE Y, which is the diffuse reflectance component, from the glass surface. Here, a black tape that substantially does not contain a diffuse reflectance component means that the SCE Y is 0.02% or less using the measurement method described above. Note that the calculation of SCE Y requires the specification of a light source, but since the present invention is intended to suppress reflections in bright daylight, it is preferable to use a D65 light source for the calculation.

[0057] In other words, in the transparent substrate with an anti-reflective coating according to this embodiment, the diffuse reflectance (SCE Y) of the outermost surface is measured using a spectrophotometer by attaching a black tape that substantially does not contain a diffuse reflectance component to the other of the two main surfaces of the transparent substrate, which is not the main surface on which the anti-reflective coating is attached, and using the method specified in JIS Z 8722 (2009).

[0058] When evaluating the reflectance of the outermost surface of a transparent substrate with an anti-reflective coating, a black material is a crucial element for eliminating back-surface reflection. The black material needs to adhere closely to the main surface to eliminate the interface between air and the main surface, and black tape or black paint is commonly used. Furthermore, in order to accurately evaluate the diffuse reflectance of the outermost surface, it is necessary to use a black material that has almost no diffuse reflectance component. For example, when using black tape, 3M's black vinyl tape (product name: 117) has a diffuse reflectance component that corresponds to approximately 0.7% SCE Y under a D65 light source, making it unsuitable for this evaluation. On the other hand, Tomoegawa Paper Co., Ltd.'s black tape (product name: Kukkiri Mieru) contains virtually no diffuse reflectance component (diffuse reflectance corresponds to approximately 0.01% SCE Y under a D65 light source), and is preferably used for measurements in a state where back-surface reflection has been eliminated, as in this case.

[0059] Regarding black paint, it is common practice to print a black light-shielding film on the back of the display's front cover for purposes such as concealing wiring around the screen's perimeter from the viewer. Examples include black paints manufactured by Teikoku Ink Manufacturing Co., Ltd. and Jujo Chemical Co., Ltd. Such black light-shielding films for displays are often polyester-based inks mixed with black pigment for lightfastness, but they have a diffuse reflectance of 0.2-0.3% due to the pigment, making them unsuitable for evaluations where the ratio of diffuse reflectance on the outermost surface of a transparent substrate with an anti-reflective coating is important, as in this case.

[0060] In the transparent substrate with anti-reflective coating according to this embodiment, in order to make the diffuse reflectance (SCE Y) 0.05% or more, it is preferable to make the haze value of the diffuse layer, such as an anti-glare layer, or the laminate of the transparent substrate and the diffuse layer 10% or more, more preferably 25% or more, and even more preferably 50% or more.

[0061] (Diffuse reflectance: SCE Y / Luminous reflectance: SCI Y) In the transparent substrate with an anti-reflective coating according to this embodiment, it is important that the ratio of the diffuse reflectance (SCE Y) of the outermost surface of the transparent substrate with the anti-reflective coating to the luminous reflectance (SCI Y) of the outermost surface of the transparent substrate with the anti-reflective coating, SCE Y / SCI Y, is 0.15 or greater.

[0062] The above luminous reflectance (SCI Y) is calculated by measuring total reflected light, including specular and diffuse reflected light, and therefore evaluates the color of the material itself, regardless of the surface condition of the transparent substrate with the anti-reflective coating. On the other hand, the above diffuse reflectance (SCE Y) is calculated by removing specular reflected light from the total reflected light and measuring only the diffuse reflected light, and therefore provides a color evaluation that is closer to what the human eye perceives. Therefore, a higher diffuse reflectance (SCE Y) relative to the luminous reflectance (SCI Y) means that the ratio of diffuse reflected light to total reflected light (specular reflected light + diffuse reflected light) is large, which is desirable because it reduces the reflection of ambient light onto the screen.

[0063] The SCE Y / SCI Y ratio is preferably 0.2 or higher, more preferably 0.25 or higher, even more preferably 0.3 or higher, even more preferably 0.35 or higher, even more preferably 0.4 or higher, even more preferably 0.45 or higher, even more preferably 0.5 or higher, and particularly preferably 0.6 or higher. Furthermore, the SCE Y / SCI Y ratio may be, for example, 1 or less, or 0.75 or less.

[0064] In the transparent substrate with anti-reflective coating of this embodiment, in order to make the SCE Y / SCI Y ratio 0.15 or higher, it is preferable to use a laminate of a transparent substrate and a diffusion layer with a haze value of 10% or higher, more preferably a laminate of a transparent substrate and a diffusion layer with a haze value of 25% or higher, and even more preferably a laminate of a transparent substrate and a diffusion layer with a haze value of 50% or higher.

[0065] (Luminous transmittance: Y) The transparent substrate with the anti-reflective coating in this embodiment preferably has a luminous transmittance (Y) of 20 to 90%. If the luminous transmittance (Y) is within this range, it has appropriate light absorption capabilities, and therefore, when used as a cover glass for an image display device, it can suppress light reflection. This improves the bright-field contrast of the image display device. A luminous transmittance (Y) of 50 to 90% is more preferable, and 60 to 90% is even more preferable. Furthermore, the luminous transmittance (Y) may be 88% or less, 80% or less, 75% or less, 70% or less, 30% or more, or 40% or more. Furthermore, the luminous transmittance (Y) can be measured using the method specified in JIS Z 8701 (1999), as described in the examples below.

[0066] In the transparent substrate with an anti-reflective film according to this embodiment, in order to make the luminous transmittance (Y) 20 to 90%, it is preferable to use a mixed oxide as the first dielectric, for example, which mainly consists of at least one oxide selected from group A consisting of Mo and W, and at least one oxide selected from group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, and adjust the oxidation amount of the film.

[0067] The luminous transmittance (Y) in the transparent substrate with the anti-reflective coating of this embodiment can be adjusted, for example, by controlling the irradiation time of the oxidation source, the irradiation output, the distance from the substrate, and the amount of oxidation gas when forming the first dielectric layer, which is a high refractive index layer in the anti-reflective coating described above.

[0068] (Sheet resistance) In this embodiment, the transparent substrate with an anti-reflective coating has a sheet resistance of 10 4 A value of Ω / □ or greater is preferable. Since the anti-reflective coating is insulating, when the sheet resistance of the anti-reflective coating is within the above range, and when used as a cover glass for an image display device, even if a touch panel is added, the change in capacitance due to finger contact necessary for a capacitive touch sensor is maintained, allowing the touch panel to function. The above sheet resistance is 10 6 Ω / □ or greater is more preferable, 10 8A ratio of Ω / □ or higher is even more preferable. The sheet resistance can be measured using the method specified in JIS K 6911 (2006), as described in the examples below.

[0069] In the transparent substrate with an anti-reflective coating according to this embodiment, the sheet resistance of the anti-reflective coating is set to 10 4 To achieve a value greater than Ω / □, for example, the metal content in the anti-reflective coating can be adjusted.

[0070] (b in transmitted color under D65 light source) * value) The transparent substrate with the anti-reflective coating in this embodiment has a transmitted color of b under a D65 light source. * The value is preferably 5 or less. (See b above) * When the value is within the above range, the transmitted light does not have a yellowish tint, making it suitable for use as cover glass for image display devices. * The value is more preferably 3 or less, and even more preferably 2 or less. Also, the above b * The lower limit of the value is preferably -6 or higher, and more preferably -4 or higher. * When the value is within the above range, the transmitted light becomes colorless and does not obstruct the transmitted light, which is preferable. Note that the transmitted color under a D65 light source is b * The value can be measured using the method specified in JIS Z 8729 (2004), as described in the examples below.

[0071] In the transparent substrate with an anti-reflective coating of this embodiment, the transmitted color under a D65 light source is b * To make the value 5 or less, for example, adjust the material composition of the first dielectric. Specifically, increasing the proportion of group A as described above will increase the transmittance of short wavelengths, and b * A decrease in the value can be expected.

[0072] (Brightness of diffuse reflected light: SCE L) * ) The transparent substrate with the anti-reflective coating in this embodiment has a lightness (SCE L) of diffusely reflected light. * It is preferable that the brightness of the diffuse reflected light (SCE L) is 7 or less. *When the above range is used as cover glass for an image display device, the effect of preventing external light from reflecting onto the screen is further enhanced, which is preferable. The brightness of the above diffuse reflected light (SCE L * ) is more preferably 6 or less, and even more preferably 5 or less. The brightness of the diffusely reflected light (SCE L) is as follows: * The lightness (SCE L) of the diffusely reflected light can be measured using a spectrophotometer (manufactured by Konica Minolta, product name: CM-26d) by the method specified in JIS Z 8722 (2009), as described in the examples below. Specifically, the lightness (SCE L) of the diffusely reflected light can be measured using the method specified in JIS Z 8722 (2009). * ) can be measured with back surface reflection removed by applying black tape to the other main surface of the transparent substrate (hereinafter also referred to as the back surface of the transparent substrate, or simply the back surface), which is not the main surface on which the anti-reflective coating is applied.

[0073] In the transparent substrate with an anti-reflective coating according to this embodiment, the brightness of diffusely reflected light (SCE L * To reduce the value to 7 or less, for example, by reducing the haze value of a diffusion layer such as an anti-glare layer, or a laminate of a transparent substrate and a diffusion layer.

[0074] (Brightness of total internal reflection: SCI L) * ) The transparent substrate with the anti-reflective coating in this embodiment has a total reflected light brightness (SCI L * ) is preferably 9 or less. The brightness of the above total reflected light (SCI L * When used as cover glass for an image display device, the effect of preventing external light from reflecting onto the screen is further enhanced, which is preferable. The brightness of the total reflected light (SCI L) * ) is more preferably 8 or less, and even more preferably 6 or less. The brightness of the total reflected light (SCI L) is as described above. * The lightness (SCI L) of the total reflected light can be measured using a spectrophotometer (manufactured by Konica Minolta, product name: CM-26d) by the method specified in JIS Z 8722 (2009), as described in the examples below. Specifically, the lightness (SCI L) of the total reflected light is measured. *) can be measured with back surface reflection removed by applying black tape to the other main surface of the transparent substrate (hereinafter also referred to as the back surface of the transparent substrate, or simply the back surface), which is not the main surface on which the anti-reflective coating is applied.

[0075] In the transparent substrate with an anti-reflective coating according to this embodiment, the brightness of the total reflected light (SCI L * To reduce the haze value to 9 or less, for example, by reducing the haze value of a diffusion layer such as an anti-glare layer, or the laminate of a transparent substrate and a diffusion layer, or by reducing the luminous transmittance (Y) of a transparent substrate with an anti-reflective coating to 90% or less.

[0076] (Application) The transparent substrate with an anti-reflective coating according to this embodiment is suitable as a cover glass for image display devices, particularly as a cover glass for image display devices mounted in vehicles, such as navigation systems mounted in vehicles. The transparent substrate with an anti-reflective coating according to this embodiment makes it difficult for structures and people inside the vehicle that are illuminated by external light such as sunlight to be reflected on the screen, and especially when the transparent substrate includes both glass and resin, it is expected to improve both the quality of the display and shatterproof performance. Image display devices for navigation systems mounted in vehicles, etc., employ liquid crystal displays (LCDs) that are highly heat resistant and durable. Furthermore, due to its characteristic of making it difficult for surrounding objects to be reflected on the display, it is also suitable as a surface material for large-screen image display devices. In addition to liquid crystal displays, high-brightness LED displays and organic EL displays with high contrast in bright light are also used as such image display devices.

[0077] (Image display device) One embodiment of the present invention provides an image display device comprising the transparent substrate with the anti-reflective coating described above. Examples of image display devices include those in which the transparent substrate with the anti-reflective coating is provided on top of a liquid crystal display (LCD), an LED display, or an organic EL display. [Examples]

[0078] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Examples 1 to 10 are examples, and Examples 11 to 15 are comparative examples.

[0079] (Example 1) A transparent substrate with an anti-reflective coating was fabricated by forming a diffusion layer and an anti-reflective coating in that order on one of the main surfaces of a transparent substrate using the following method. The transparent substrate was configured to consist of a resin substrate on a glass substrate, as will be described later.

[0080] A diffusion layer was created on a transparent substrate by laminating an anti-glare PET film (manufactured by Reiko Co., Ltd., Sa: 0.274 μm, Sdr: 0.1083, Sdq: 0.48, Spc: 1931 (1 / mm), haze value: 79%) as a laminate (resin film + anti-glare layer) onto one main surface of a chemically strengthened glass substrate (DragonTrail: registered trademark, manufactured by AGC Inc.) measuring 50 mm in length, 50 mm in width, and 1.1 mm in thickness, using a transparent acrylic adhesive. The surface shape of the anti-glare PET film is shown in Figure 2(a) as a photograph taken with a Keyence VK-X3000 laser microscope.

[0081] Next, using a target prepared by digital sputtering, where niobium and molybdenum were mixed and sintered in a weight ratio of 50:50 as the dielectric layer (1) (high refractive index layer), a pressure of 0.2 Pa was maintained with argon gas, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2 A microscopic metal film was deposited by pulse sputtering under conditions of a reverse pulse width of 3 μsec, and immediately afterward, the film was oxidized with oxygen gas. This process was repeated at high speed to deposit an oxide film, and a 20 nm Mo-Nb-O layer was deposited on the main surface of a transparent substrate to which a diffusion layer had been bonded.

[0082] Next, for the dielectric layer (2) (low refractive index layer), the same digital sputtering method was used with a silicon target, maintaining a pressure of 0.2 Pa with argon gas, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2A silicon oxide film is formed by rapidly repeating pulse sputtering with a reverse pulse width of 3 μsec to deposit a silicon film of minute thickness, and then immediately oxidizing it with oxygen gas. A silicon oxide film is then layered on top of the above Mo-Nb-O layer with a silicon oxide film of 30 nm thickness [silica (SiO₂)]. x A layer consisting of ) was formed. Here, the oxygen flow rate when oxidizing with oxygen gas was 500 sccm, and the power input to the oxidation source was 1000 W.

[0083] Next, using a target prepared by sintering a mixture of niobium and molybdenum in a weight ratio of 50:50 using the same digital sputtering method as the dielectric layer (3) (high refractive index layer), a frequency of 100 kHz and a power density of 10.0 W / cm² were applied while maintaining a pressure of 0.2 Pa with argon gas. 2 Pulse sputtering was performed under conditions of a reverse pulse width of 3 μsec to deposit a metal film of minute thickness, and immediately afterward, oxidation with oxygen gas was repeated at high speed to deposit an oxide film, which was then layered on top of the silicon oxide layer to form a Mo-Nb-O layer with a thickness of 120 nm.

[0084] Next, for the dielectric layer (4) (low refractive index layer), the same digital sputtering method was used with a silicon target, maintaining a pressure of 0.2 Pa with argon gas, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2 By performing pulse sputtering under conditions of a reverse pulse width of 3 μsec to deposit a silicon film of minute thickness, and then immediately oxidizing it with oxygen gas, this process is repeated at high speed to deposit a silicon oxide film, which is then layered on top of the Mo-Nb-O layer to form a silicon oxide film with a thickness of 88 nm [silica (SiO2)]. x A layer consisting of ) was formed. Here, the oxygen flow rate when oxidizing with oxygen gas was 500 sccm, and the power input to the oxidation source was 1000 W. Based on the above, an anti-reflective coating was applied to the diffusion layer, and KY-185 manufactured by Shin-Etsu Chemical Co., Ltd. was vacuum-deposited to a thickness of 4 nm as an anti-fouling coating on the top layer to obtain a transparent substrate with an anti-reflective coating.

[0085] The following evaluations were performed on the fabricated transparent substrate with anti-reflective coating.

[0086] (Luminous transmittance: Y) The luminous transmittance (Y) of the fabricated transparent substrate with anti-reflective coating was measured using the method specified in JIS Z 8701 (1999). Spectral transmittance was measured using a spectrophotometer (Shimadzu Corporation, product name: SolidSpec-3700), and the luminous transmittance (stimulus value Y as specified in JIS Z 8701 (1999)) was calculated. A D65 light source was used to calculate the stimulus value Y.

[0087] (Luminous reflectance: SCI Y) In the fabricated transparent substrate with an anti-reflective coating, the luminous reflectance (SCI Y) of the outermost surface of the transparent substrate with the anti-reflective coating was measured using the method specified in JIS Z 8722 (2009). Specifically, black tape was applied to the other main surface of the transparent substrate (not the main surface on which the anti-reflective coating was applied) to remove back-surface reflection, and the luminous reflectance (SCI Y) of the total reflected light was measured using a spectrophotometer (Konica Minolta, product name: CM-26d). A D65 light source was used. The black tape used was Kukkiri Miel manufactured by Tomoegawa Paper Co., Ltd.

[0088] (Brightness of total internal reflection: SCI L) * ) In the fabricated transparent substrate with anti-reflective coating, the brightness of the total reflected light (SCI L) * The total reflected light intensity (SCI L) was measured using the method specified in JIS Z 8722 (2009). Specifically, black tape was applied to the other main surface of the transparent substrate, which was not the main surface on which the anti-reflective coating was applied, thereby removing back surface reflection. The light intensity (SCI L) of the total reflected light was then measured using a spectrophotometer (Konica Minolta, product name: CM-26d). * The following measurements were taken. A D65 light source was used. For the black tape, we used Kukkiri Miel manufactured by Tomoegawa Paper Co., Ltd.

[0089] (Diffuse reflectance: SCE Y) In the fabricated transparent substrate with anti-reflective coating, the diffuse reflectance (SCE Y) of the outermost surface of the transparent substrate with anti-reflective coating was measured using the method specified in JIS Z 8722 (2009). Specifically, black tape was applied to the other main surface of the transparent substrate (not the main surface on which the anti-reflective coating was applied) to remove back surface reflection, and the diffuse reflectance (SCE Y) was measured using a spectrophotometer (Konica Minolta, product name: CM-26d). A D65 light source was used. Kukkiri Miel, manufactured by Tomoegawa Paper Co., Ltd., was used as the black tape. Note that Kukkiri Miel has a diffuse reflectance of approximately 0.01% in SCE Y value under a D65 light source, and substantially contains no diffuse reflection component.

[0090] (Brightness of diffuse reflected light: SCE L) * ) In the fabricated transparent substrate with anti-reflective coating, the brightness of diffuse reflected light (SCE L * The lightness (SCE L) of the diffuse reflected light was measured using the method specified in JIS Z 8722 (2009). Specifically, black tape was applied to the other main surface of the transparent substrate, not the main surface on which the anti-reflective coating was applied, thereby removing back surface reflection. The lightness (SCE L) of the diffuse reflected light was then measured using a spectrophotometer (Konica Minolta, product name: CM-26d). * The following measurements were taken. A D65 light source was used. For the black tape, we used Kukkiri Miel manufactured by Tomoegawa Paper Co., Ltd.

[0091] (Transmitted color under D65 light source of transparent substrate with anti-reflective coating (b * value)) From the transmission spectrum obtained by measuring the spectral transmittance described above, the color index (b) specified in JIS Z 8729 (2004) can be used. * The value was calculated. A D65 light source was used.

[0092] (Sheet resistance of anti-reflective coating) The sheet resistance was measured in accordance with JIS K 6911 (2006) using a measuring device (manufactured by Mitsubishi Chemical Analytec Co., Ltd., device name: Highresta UP (MCP-HT450 model)). The probe was placed in the center of a transparent substrate with an anti-reflective coating, and the measurement was taken by applying 10V for 10 seconds.

[0093] (Scratch resistance test) A scratch resistance test was conducted to evaluate scratch resistance. A cloth with a thickness of 3, impregnated with ethanol, was used on a transparent substrate with an anti-reflective coating, applying a rubbing test at 1 kg / cm². 2 A friction test was conducted with a load applied, consisting of 1,000 back-and-forth abrasions. Afterward, the surface of the transparent substrate with the anti-reflective coating was visually inspected for scratches. As a control, the same test was also performed on a sample without the anti-reflective coating, where the anti-glare layer was the outermost surface.

[0094] (Example 2) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Reiko Co., Ltd.) having the physical properties shown in Table 1, the film was formed in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 2. The evaluation results are shown in Table 2 below.

[0095] (Example 3) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: BHC-III) having the physical properties shown in Table 1, the film was formed in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 3. The evaluation results are shown in Table 2 below.

[0096] (Example 4) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: EHC-30a) having the physical properties shown in Table 1, and changing the oxygen flow rate when oxidizing the first dielectric layer with oxygen gas from 500 sccm to 800 sccm, the film was formed in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 4. The evaluation results are shown in Table 2 below.

[0097] (Example 5) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: EHC-30a) having the physical properties shown in Table 1, the film was formed in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 5. The evaluation results are shown in Table 2 below.

[0098] (Example 6) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: EHC-30a) having the physical properties shown in Table 1, and changing the power input to the oxidation source of the first dielectric layer to 700W, the film was deposited in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 6. The evaluation results are shown in Table 2 below.

[0099] (Example 7) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Reiko Co., Ltd.) having the physical properties shown in Table 1, and changing the oxygen flow rate when oxidizing the first dielectric layer with oxygen gas to 800 sccm, the film was formed in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 7. The evaluation results are shown in Table 2 below.

[0100] (Example 8) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Reiko Co., Ltd.) having the physical properties shown in Table 1, the film was formed in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 8. The evaluation results are shown in Table 2 below.

[0101] (Example 9) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Reiko Co., Ltd.) having the physical properties shown in Table 1, and changing the power input to the oxidation source of the first dielectric layer to 700W, the film was deposited in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 9. The evaluation results are shown in Table 2 below.

[0102] (Example 10) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare TAC film (manufactured by Toppan TOMOEGAWA Optical Film Co., Ltd., product name VZ50) having the physical properties shown in Table 1, the film was formed in the same manner as in Example 1, and the transparent substrate with anti-reflective coating of Example 10 was obtained. The evaluation results are shown in Table 2 below.

[0103] (Example 11) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare TAC film (manufactured by Toppan TOMOEGAWA Optical Film Co., Ltd., product name CHC) having the physical properties shown in Table 1, the film was formed in the same manner as in Example 1, and the transparent substrate with anti-reflective coating of Example 11 was obtained. The evaluation results are shown in Table 2 below.

[0104] (Example 12) The laminate (resin film + anti-glare layer) was changed to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: EHC-10a) having the physical properties shown in Table 1, and the power input to the oxidation source of the first dielectric layer was set to 700W. Except for these changes, the film was deposited in the same manner as in Example 1, to obtain the transparent substrate with anti-reflective coating of Example 12. The evaluation results are shown in Table 2 below.

[0105] (Example 13) Except for changing the laminate (resin film + anti-glare layer) to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: EHC-05a) having the physical properties shown in Table 1, and changing the power input to the oxidation source of the first dielectric layer to 700W, the film was deposited in the same manner as in Example 1 to obtain the transparent substrate with anti-reflective coating of Example 13. The evaluation results are shown in Table 2 below.

[0106] (Example 14) The laminate (resin film + anti-glare layer) was changed to an anti-glare PET film (manufactured by Higashiyama Film Co., Ltd., product name: EHC-30a) having the physical properties shown in Table 1, and the anti-reflective coating was changed to a transparent AR film deposited by the method described below. The film was deposited in the same manner as in Example 1, and the transparent substrate with anti-reflective coating of Example 14 was obtained.

[0107] (Method for forming transparent AR films) First, as the dielectric layer (1) (high refractive index layer), a titanium target was subjected to digital sputtering using argon gas while maintaining a pressure of 0.2 Pa, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2 A microscopic metal film was deposited by pulse sputtering under conditions of a reverse pulse width of 3 μsec, and then immediately afterwards, the film was oxidized with oxygen gas. This process was repeated at high speed to deposit an oxide film, and an 11 nm Ti-O layer was deposited on the main surface of a transparent substrate to which a diffusion layer had been bonded.

[0108] Next, for the dielectric layer (2) (low refractive index layer), the same digital sputtering method was used with a silicon target, maintaining a pressure of 0.2 Pa with argon gas, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2 By performing pulse sputtering under conditions of a reverse pulse width of 3 μsec to deposit a silicon film of minute thickness, and then immediately oxidizing it with oxygen gas, this process is repeated at high speed to deposit a silicon oxide film, which is then layered on top of the Ti-O layer to form a silicon oxide film with a thickness of 35 nm [silica (SiO2)]. x A layer consisting of ) was formed. Here, the oxygen flow rate when oxidizing with oxygen gas was 500 sccm, and the power input to the oxidation source was 1000 W.

[0109] Next, as the dielectric layer (3) (high refractive index layer), the same digital sputtering method was used with a titanium target, maintaining the pressure at 0.2 Pa with argon gas, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2 By performing pulse sputtering under conditions of a reverse pulse width of 3 μsec, a metal film of minute thickness was deposited, and immediately afterward, oxidation with oxygen gas was repeated at high speed to deposit an oxide film, which was then layered on top of the silicon oxide layer to form a Ti-O layer with a thickness of 104 nm.

[0110] Next, for the dielectric layer (4) (low refractive index layer), the same digital sputtering method was used with a silicon target, maintaining a pressure of 0.2 Pa with argon gas, at a frequency of 100 kHz and a power density of 10.0 W / cm². 2 By performing pulse sputtering under conditions of a reverse pulse width of 3 μsec to deposit a silicon film of minute thickness, and then immediately oxidizing it with oxygen gas, this process is repeated at high speed to deposit a silicon oxide film, which is then layered on top of the Ti-O layer to form a silicon oxide film with a thickness of 86 nm [silica (SiO2)]. x A layer consisting of ) was formed. Here, the oxygen flow rate when oxidizing with oxygen gas was 500 sccm, and the power input to the oxidation source was 1000 W. The evaluation results are shown in Table 2 below.

[0111] (Example 15) The laminate (resin film + anti-glare layer) was changed to one having the physical properties shown in Table 1 (manufactured by Reiko Co., Ltd.), and the anti-reflective coating was changed to the same transparent AR as in Example 14. The film was formed in the same manner as in Example 1, and the transparent substrate with anti-reflective coating of Example 15 was obtained. The evaluation results are shown in Table 2 below.

[0112] [Table 1]

[0113] [Table 2]

[0114] As shown in Table 2, the transparent substrates with anti-reflective coatings in Examples 1 to 10 have a luminous reflectance (SCI Y) of 1% or less and an SCE Y / SCI Y ratio of 0.15 or more. Therefore, when used as cover glass for image display devices, they have a high effect in preventing reflection of ambient light, and when the reflected images of structures, etc., are visually inspected, the outlines of the images are blurred and the reflections are not noticeable. On the other hand, the transparent substrates with anti-reflective coatings in Examples 11 to 13 had an SCE Y / SCI Y ratio of less than 0.15, and the transparent substrates with anti-reflective coatings in Examples 14 to 15 had a luminous reflectance (SCI Y) of more than 1%. When used as cover glass for image display devices, these materials had a low effect in preventing reflections from ambient light. When the reflected images of structures and other objects were visually inspected, the outlines of the images were sharp, and the reflections were noticeable. Furthermore, in Examples 1 to 15, anti-reflective coatings were formed using sputtering and vacuum deposition methods. In scratch resistance tests, no scratches were found in any of Examples 1 to 15, whereas scratches were visually confirmed in the control example where no anti-reflective coating was applied and the anti-glare layer was the outermost surface. This confirmed that surface abrasion resistance is improved by forming the anti-reflective coating in a vacuum. [Explanation of Symbols]

[0115] 10 Transparent substrate 30 Anti-reflection coating 31 Diffusion layer 32 First Dielectric Layer 34 Second Dielectric Layer

Claims

1. A transparent substrate with an anti-reflection film, comprising a transparent substrate having two main surfaces and a diffusion layer and an anti-reflection film in this order on one of the main surfaces of the transparent substrate, wherein (A) the luminous reflectance (SC1 Y) of the outermost surface of the transparent substrate with an anti-reflection film is 1% or less, (B) the anti-reflection film has a laminated structure in which at least two dielectric layers having refractive indices different from each other are laminated, and (C) the ratio of the diffuse reflectance (SC1 Y) of the outermost surface of the transparent substrate with an anti-reflection film to the luminous reflectance (SC1 Y) of the outermost surface of the transparent substrate with an anti-reflection film, SCE Y / SCI Y, is 0.15 or more. Transparent substrate with anti-reflection coating.

2. 2. The transparent substrate with an antireflection film according to claim 1, wherein a haze value of a laminate of the transparent substrate and the diffusing layer is 10% or more.

3. 2. The anti-reflection coated transparent substrate according to claim 1, wherein the luminous transmittance (Y) is 20 to 90%.

4. The sheet resistance of the anti-reflection film is 10 ４ 2. The transparent substrate with an antireflection film according to claim 1, wherein the resistance is Ω / □ or more.

5. b in transmitted color under D65 light source ＊ 2. The transparent substrate with an antireflection film according to claim 1, wherein the value is 5 or less.

6. 2. The transparent substrate with an anti-reflection film according to claim 1, wherein at least one of the dielectric layers is composed mainly of an oxide of Si, and at least one other layer of the layers of the laminate structure is composed mainly of a mixed oxide of at least one oxide selected from Group A consisting of Mo and W and at least one oxide selected from Group B consisting of Si, Nb, Ti, Zr, Ta, Al, Sn, and In, and the content of the elements of Group B contained in the mixed oxide relative to the total of the elements of Group A contained in the mixed oxide and the elements of Group B contained in the mixed oxide is 65 mass% or less.

7. The transparent substrate with an antireflection film according to claim 1 , further comprising an antifouling film on the antireflection film.

8. 2. The transparent substrate with an anti-reflection film according to claim 1, wherein the transparent substrate comprises glass.

9. 2. The transparent substrate with an antireflection film according to claim 1, wherein the transparent substrate comprises at least one resin selected from polyethylene terephthalate, polycarbonate, acrylic, silicone, and triacetyl cellulose.

10. 2. The transparent substrate with an anti-reflection film according to claim 1, wherein the transparent substrate is a laminate of glass and at least one resin selected from polyethylene terephthalate, polycarbonate, acrylic, silicone, and triacetyl cellulose.

11. The transparent substrate with an antireflection film according to claim 8 , wherein the glass is chemically strengthened.

12. 2. The transparent substrate with an antireflection film according to claim 1, wherein the transparent substrate has a main surface on which the antireflection film is provided that is subjected to an antiglare treatment.

13. A transparent substrate with an anti-reflection film as described in claim 1, wherein the haze value of the laminate of the transparent substrate and the diffusion layer is 50% or more.

14. An image display device comprising the anti-reflection coated transparent substrate according to any one of claims 1 to 13.

Images