WO2022024744A1 - Cover glass - Google Patents

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Publication number
WO2022024744A1
WO2022024744A1 PCT/JP2021/026257 JP2021026257W WO2022024744A1 WO 2022024744 A1 WO2022024744 A1 WO 2022024744A1 JP 2021026257 W JP2021026257 W JP 2021026257W WO 2022024744 A1 WO2022024744 A1 WO 2022024744A1
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WO
WIPO (PCT)
Prior art keywords
refractive index
layer
glass substrate
cover glass
antireflection film
Prior art date
Application number
PCT/JP2021/026257
Other languages
French (fr)
Japanese (ja)
Inventor
隆義 齊藤
Original Assignee
日本電気硝子株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 日本電気硝子株式会社 filed Critical 日本電気硝子株式会社
Priority to CN202180027502.1A priority Critical patent/CN115380012A/en
Publication of WO2022024744A1 publication Critical patent/WO2022024744A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/11—Anti-reflection coatings
    • G02B1/113—Anti-reflection coatings using inorganic layer materials only
    • G02B1/115—Multilayers
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/02—Diffusing elements; Afocal elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements

Definitions

  • the present invention relates to a cover glass having an anti-glare function.
  • Cover glass is widely used for displays such as mobile phones, tablet terminals, and televisions.
  • the legibility of such a display may be deteriorated due to reflection of external light or the like.
  • a method of reducing the reflection on the display and improving the visibility a method of providing an anti-glare layer having an uneven structure on the surface is known. Further, as a method of improving the antiglare effect and the contrast, a method of providing an antireflection film is known.
  • Patent Document 1 discloses a method of applying antiglare processing by forming an uneven shape on the surface of a transparent substrate and a method of providing a low-reflection film.
  • the low-refractive-index film a laminated body in which a high-refractive index layer and a low-refractive index layer are laminated is described.
  • An object of the present invention is to provide a cover glass that can effectively improve visibility.
  • the cover glass according to the first invention of the present application includes a glass substrate, an anti-glare layer having a concavo-convex structure provided on the glass substrate, and an antireflection film provided on the anti-glare layer. It is characterized in that, when light is incident from the antireflection film side, the visual reflectance of the positively reflected light is smaller than the visual reflectance of the reflected scattered light.
  • the cover glass according to the second invention of the present application includes a glass substrate, an antiglare layer provided on the glass substrate, and an antireflection film provided on the antiglare layer, and the glass. It is characterized in that the composition of the substrate and the antiglare layer are different.
  • the first invention and the second invention may be collectively referred to as the present invention.
  • the absolute value of the difference between the refractive index of the glass substrate and the refractive index of the antiglare layer is preferably 0.02 or more.
  • the anti-glare layer has a flat portion and a non-flat portion.
  • the thickness of the flat portion is preferably 5 nm or more and 500 nm or less.
  • the visual reflectance of the reflected light due to the structure of the first laminated body in which the flat portion of the antiglare layer and the antireflection film are provided in this order on the glass substrate is not the same as that of the antiglare layer. It is preferably smaller than the visual reflectance due to the structure of the second laminated body in which the antireflection film is provided on the flat portion.
  • an optical adjustment layer having a refractive index different from that of the glass substrate is provided between the glass substrate and the antiglare layer.
  • the absolute value of the difference between the refractive index of the optical adjustment layer and the refractive index of the antiglare layer is preferably 0.2 or more.
  • FIG. 1 is a schematic cross-sectional view showing a cover glass according to a first embodiment of the present invention.
  • 2 (a) and 2 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of specularly reflected light.
  • 3 (a) and 3 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of reflected scattered light.
  • FIG. 4 is a schematic cross-sectional view for explaining a first laminated body in which a flat portion of an antiglare layer and an antireflection film are laminated in this order on a glass substrate.
  • FIG. 5 is a schematic cross-sectional view for explaining a second laminated body in which an antireflection film is laminated on a non-flat portion on an antiglare layer.
  • FIG. 6 is a schematic cross-sectional view showing a cover glass according to a second embodiment of the present invention.
  • FIG. 7 is a schematic cross-sectional view for explaining a third laminated body in which an optical adjustment layer, an antiglare layer, and an antireflection film are laminated in this order on a glass substrate.
  • FIG. 1 is a schematic cross-sectional view showing a cover glass according to a first embodiment of the present invention.
  • the cover glass 1 includes a glass substrate 2, an antiglare layer 3, and an antireflection film 4.
  • the anti-glare layer 3 is provided on the glass substrate 2. Further, an antireflection film 4 is provided on the antiglare layer 3.
  • the glass substrate 2 has a substantially rectangular plate-like shape.
  • the glass substrate 2 may have a shape such as a substantially disk shape, and the shape is not particularly limited.
  • the thickness of the glass substrate 2 is not particularly limited and can be appropriately set according to the light transmittance and the like.
  • the thickness of the glass substrate 2 can be, for example, about 0.1 mm to 3 mm.
  • the glass used for the glass substrate 2 is not particularly limited, and for example, borosilicate glass, non-alkali glass, aluminosilicate glass, chemically tempered glass and the like can be used.
  • the glass substrate 2 has a first main surface 2a and a second main surface 2b.
  • the first main surface 2a and the second main surface 2b face each other.
  • the anti-glare layer 3 is provided on the first main surface 2a of the glass substrate 2. Further, the anti-glare layer 3 has an uneven structure.
  • the anti-glare layer 3 is provided to impart a so-called anti-glare effect that suppresses reflection of external light and the like.
  • the anti-glare layer 3 is an inorganic film.
  • Such an anti-glare layer 3 can be formed by applying an inorganic paint on a glass substrate 2 and drying it.
  • the anti-glare layer 3 is formed by applying an inorganic paint by a spray coating method and drying it.
  • the method of applying the inorganic paint is not limited to the spray coating method, and other coating methods may be used.
  • the inorganic paint is composed of a silica precursor.
  • the inorganic paint may be composed of, for example, an alumina precursor, a zirconia precursor, a titania precursor, or the like. These precursors may be used alone or in combination of two or more.
  • the solvent of the inorganic paint for example, water, alcohol or the like can be used.
  • silica precursor examples include alkoxysilanes such as tetraethoxysilane and tetramethoxysilane, hydrolyzed condensates of alkoxysilane (sol-gel silica), and silazane. From the viewpoint of further enhancing the antiglare effect, an alkoxysilane such as tetraethoxysilane or tetramethoxysilane, or a hydrolyzed condensate thereof is preferable, and a hydrolyzed condensate of tetraethoxysilane is more preferable.
  • alumina precursor examples include aluminum alkoxide, a hydrolyzed condensate of aluminum alkoxide, a water-soluble aluminum salt, and an aluminum chelate.
  • zirconia precursor examples include zirconium alkoxide and a hydrolyzed condensate of zirconium alkoxide.
  • titania precursor examples include titanium alkoxide and a hydrolyzed condensate of titanium alkoxide.
  • the inorganic paint may contain inorganic particles.
  • the inorganic particles include silica particles, alumina particles, zirconia particles, titania particles, hafnia particles, yttria particles and the like.
  • the average thickness of the anti-glare layer 3 is not particularly limited. However, from the viewpoint of further enhancing the antiglare effect, the average thickness of the antiglare layer 3 is preferably 0.1 ⁇ m or more and 2 ⁇ m or less, and more preferably 0.15 ⁇ m or more and 1.75 ⁇ m or less. It is more preferably 0.2 ⁇ m or more and 1 ⁇ m or less.
  • the antireflection film 4 is preferably a dielectric multilayer film. In this case, the image sharpness on a display or the like can be further improved.
  • the antireflection film 4 is a dielectric multilayer layer in which a high refractive index film 5 having a relatively high refractive index and a low refractive index film 6 having a relatively low refractive index are alternately laminated in this order. It is a membrane.
  • the antireflection film 4 is a dielectric multilayer film in which a low refractive index film 6 having a relatively low refractive index and a high refractive index film 5 having a relatively high refractive index are alternately laminated in this order. May be.
  • Examples of the material of the high refractive index film 5 include niobium oxide, titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silicon nitride, aluminum oxide, and aluminum nitride as in the present embodiment.
  • Examples of the material of the low refractive index film 6 include silicon oxide and aluminum oxide.
  • each layer constituting the antireflection film 4 is preferably 1 nm or more and 500 nm or less, more preferably 2 nm or more and 300 nm or less, and further preferably 5 nm or more and 200 nm or less.
  • the total number of layers constituting the antireflection film 4 is preferably 2 or more and 7 or less. By setting it within such a range, an effective and easily formable film can be obtained.
  • the overall thickness of the antireflection film 4 is preferably 50 nm or more and 1000 nm or less, more preferably 75 nm or more and 750 nm or less, and further preferably 100 nm or more and 500 nm or less.
  • the antireflection film 4 can be formed by, for example, a sputtering method, a CVD method, a vacuum vapor deposition method, or the like.
  • the visual reflectance of the normal reflected light B is smaller than the visual reflectance of the reflected scattered light C. Therefore, in the cover glass 1, the reflection of external light can be effectively suppressed, and the visibility in a display or the like can be effectively improved.
  • a method for measuring the visual reflectance of the specular reflected light B and the visual reflectance of the reflected scattered light C in the cover glass 1 will be described with reference to FIGS. 2 and 3.
  • FIG. 2 (a) and 2 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of specularly reflected light.
  • the reflected light intensity X1 of the specularly reflected light B in the cover glass 1 shown in FIG. 2A is measured.
  • a process of suppressing the back surface reflection is performed so that the back surface reflection of the cover glass 1 does not affect the measurement.
  • the reflected light intensity Y1 of the specular reflected light B is measured with the aluminum film 8 (thickness about 300 nm) formed on the upper surface of the antireflection film 4 of the cover glass 1. do.
  • the reflection spectrum of the specular reflected light B can be measured from the ratio X1 / Y1 of these reflected light intensities.
  • the reflected light intensities X1 and Y1 of the normal reflected light B are, for example, measured by a spectrophotometer, the incident angle of the incident light is 8 °, the angle of the reflected reflected light received is 8 °, the measurement wavelength is 380 nm to 800 nm, and the measurement wavelength.
  • the interval can be measured at 1 nm.
  • the specular reflectance of the specular reflected light B with respect to the D65 light source can be obtained in accordance with JIS Z8722: 2009.
  • 3 (a) and 3 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of reflected scattered light.
  • the reflected light intensity X2 of the reflected scattered light C in the cover glass 1 shown in FIG. 3A is measured.
  • a process of suppressing the back surface reflection is performed so that the back surface reflection of the cover glass 1 does not affect the measurement.
  • the reflected light intensity Y2 of the reflected scattered light C is measured with the aluminum film 8 formed on the upper surface of the antireflection film 4 of the cover glass 1.
  • the reflection spectrum of the reflected scattered light C can be measured from the ratio X2 / Y2 of these reflected light intensities.
  • the reflected light intensities X2 and Y2 of the reflected scattered light C are, for example, measured by a spectrophotometer, the incident angle of the incident light is 8 °, the angle of the received reflected light is 11 °, the measurement wavelength is 380 nm to 800 nm, and the measurement wavelength.
  • the interval can be measured at 1 nm.
  • the visual reflectance of the reflected scattered light C with respect to the D65 light source can be obtained in accordance with JIS Z8722: 2009.
  • the present inventor has the first laminated body 10 whose specular reflected light B has a reflection spectrum shown in FIG. 4, that is, the flat portion of the antiglare layer 3 and the antireflection film 4 are laminated in this order on the glass substrate 2. We have found that it is caused by the structure of the laminate. It was also found that the reflection spectrum of the reflected scattered light C is generated by the structure of the second laminated body 11 shown in FIG. 5, that is, the laminated body in which the antireflection film 4 is laminated on the non-flat portion of the antiglare layer 3. ..
  • the specular reflectance of the specular reflected light B is the visual reflectance of the reflected light due to the structure of the first laminated body 10 in which the flat portion of the antiglare layer 3 and the antireflection film 4 are laminated in this order on the glass substrate 2. It can be obtained by the reflectance. Further, the visual reflectance of the reflected scattered light C can be obtained from the visual reflectance due to the structure of the second laminated body 11 in which the antireflection film 4 is laminated on the non-flat portion of the antiglare layer 3.
  • the visual reflectance of the specular reflected light B can be adjusted by designing the first laminated body 10 in which the flat portion of the antiglare layer 3 and the antireflection film 4 are laminated in this order on the glass substrate 2. ..
  • the visual reflectance of the specularly reflected light B can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
  • the visual reflectance of the reflected scattered light C can be adjusted by designing the second laminated body 11 in which the antireflection film 4 is laminated on the non-flat portion of the antiglare layer 3.
  • the visual reflectance of the reflected scattered light C can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
  • Normal reflection is achieved by designing the thickness of the antireflection film 4, particularly the thickness and material of the high refractive index film 5 and the low refractive index film 6 so that the visual reflectance of the first laminated body 10 is as low as possible.
  • the visual reflectance of the light B can be made smaller than the visual reflectance of the reflected scattered light C.
  • the difference between the visual reflectance of the reflected scattered light C and the visual reflectance of the specular reflected light B is preferably 0.01% or more, more preferably 0.05%. That is all. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively.
  • the upper limit of the difference between the visual reflectance of the reflected scattered light C and the visual reflectance of the specular reflected light B can be, for example, 1%.
  • the compositions of the glass substrate 2 and the anti-glare layer 3 are different. Even in this case, the reflection of external light can be effectively suppressed, and the visibility can be effectively improved.
  • the absolute value of the difference between the refractive index of the glass substrate 2 and the refractive index of the antiglare layer 3 is preferably 0.02 or more, more preferably 0.05 or more. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively. Further, from the viewpoint of more effectively improving visibility, the refractive index of the antiglare layer 3 is preferably smaller than that of the glass substrate 2.
  • the thickness of the antireflection film 4 particularly the thickness and material of the high refractive index film 5 and the low refractive index film 6, it is possible to more effectively suppress the reflection of external light, and the visibility can be improved. Can be improved more effectively.
  • the anti-glare layer 3 preferably has a flat portion.
  • the flat portion refers to a portion where the frequency distribution of the uneven height of the surface of the anti-glare layer 3 is obtained and the height is within ⁇ 20 nm, which is the most frequent. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively.
  • the thickness of the flat portion can be preferably 5 nm or more, more preferably 10 nm or more, preferably 500 nm or less, and more preferably 200 nm or less.
  • the area of the flat portion with respect to the area of the entire anti-glare layer 3 can be, for example, 15% or more and 60% or less.
  • the non-flat portion means a portion other than the flat portion. Further, in the frequency distribution of the uneven height on the surface of the anti-glare layer 3, the load area ratio at the height 50 nm lower than the most frequent height is 0.9 or less, and the height is 50 nm higher than the most frequent height. When the load area ratio is 0.1 or more, it is assumed that the anti-glare layer 3 does not have a flat portion.
  • FIG. 6 is a schematic cross-sectional view showing a cover glass according to a second embodiment of the present invention.
  • an optical adjustment layer 7 is provided between the glass substrate 2 and the anti-glare layer 3.
  • the optical adjustment layer 7 is a high refractive index layer having a relatively high refractive index.
  • the optical adjustment layer 7 may be a low refractive index layer having a relatively low refractive index, and may be a layer having a different refractive index from the glass substrate 2.
  • Other points are the same as those of the first embodiment.
  • the visual reflectance of the specular reflected light B is smaller than the visual reflectance of the reflected scattered light C, so that the reflection of external light can be effectively suppressed and the display or the like can be visually recognized. Sex can be effectively improved.
  • the design of the third laminated body 30 in which the optical adjustment layer 7, the antiglare layer 3, and the antireflection film 4 are laminated in this order on the glass substrate 2 is positive.
  • the specular reflectance of the reflected light B can be adjusted.
  • the visual reflectance of the specularly reflected light B can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
  • the visual reflectance of the reflected scattered light C can be adjusted by designing the second laminated body 11 in which the antireflection film 4 is laminated on the antiglare layer 3.
  • the visual reflectance of the reflected scattered light C can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
  • the absolute value of the difference between the refractive index of the antiglare layer 3 and the refractive index of the optical adjustment layer 7 is preferably 0.2 or more, and more preferably 1.0 or more. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively. Further, from the viewpoint of more effectively improving the visibility, the refractive index of the antiglare layer 3 is preferably smaller than the refractive index of the optical adjustment layer 7.
  • the present invention is not limited to the configurations of the first embodiment and the second embodiment.
  • another layer may be provided on the antireflection film 4.
  • the other layer include an antifouling layer.
  • the antifouling layer preferably contains an organosilicon compound. By containing the organosilicon compound, the adhesion to the antireflection film 4 can be further enhanced. This makes it difficult for the antifouling layer to peel off even after long-term use.
  • organosilicon compound examples include one or more compounds selected from a silane coupling agent, a silicone oil, a silicone resin, a silicone rubber, a hydrophobic silica, and a fluorine-containing organosilicon compound.
  • the thickness of the antifouling layer is preferably 0.5 nm or more and 20 nm or less, more preferably 0.75 nm or more and 15 nm or less, and further preferably 1 nm or more and 10 nm or less.
  • the method for forming the antifouling layer is not particularly limited, and can be formed by, for example, applying a diluted solution of an organosilicon compound or the like by a spray coating method or the like.
  • Example 1 First, a glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50) was prepared. Next, a coating agent containing a silica precursor was applied onto a glass substrate by a spray coating method to form an anti-glare layer (refractive index: 1.44) having a thickness of 20 nm. The amount of the coating agent applied was 35 ml / m 2 . The difference between the refractive index of the glass substrate and the refractive index of the antiglare layer was 0.06. The area ratio of the flat portion was 47%.
  • a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 12.73 nm was formed on the antiglare layer by a sputtering method.
  • a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 34.84 nm was formed by a sputtering method.
  • a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 113.44 nm was formed by a sputtering method.
  • a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 85.45 nm was formed by a sputtering method.
  • a dielectric multilayer film in which a high-refractive index film and a low-refractive index film were alternately laminated in a total of four layers was produced, and a cover glass was obtained.
  • Example 2 First, a glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50) was prepared. Next, an optical adjustment layer (refractive index: 2.35) made of niobium oxide (Nb 2 O 5 ) having a thickness of 2.36 nm was formed on the anti-glare layer by a sputtering method.
  • an optical adjustment layer reffractive index: 2.35 made of niobium oxide (Nb 2 O 5 ) having a thickness of 2.36 nm was formed on the anti-glare layer by a sputtering method.
  • a coating agent containing a silica precursor was applied onto a glass substrate by a spray coating method to form an antiglare layer (refractive index: 1.44) having a thickness of 54 nm.
  • the amount of the inorganic paint applied was 70 ml / m 2 .
  • the difference between the refractive index of the optical adjustment layer and the refractive index of the antiglare layer was 0.85.
  • the area ratio of the flat portion was 21%.
  • a high-refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 16.13 nm was formed on the anti-glare layer by a sputtering method.
  • a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 36.77 nm was formed by a sputtering method.
  • a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 114.61 nm was formed by a sputtering method.
  • a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 86.09 nm was formed by a sputtering method.
  • SiO 2 silicon oxide
  • a total of four layers of high-refractive-index films and low-refractive-index films were alternately laminated to prepare an antireflection film, and a cover glass was obtained.
  • Example 1 An anti-glare layer was formed on the glass substrate in the same manner as in Example 1. Next, on the anti-glare layer, a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 45 nm, a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 10.37 nm, and a thickness 36 by a sputtering method.
  • SiO 2 silicon oxide
  • Nb 2 O 5 niobium oxide
  • It is composed of a low refractive index film made of .21 nm silicon oxide (SiO 2 ), a high refractive index film made of niobide oxide (Nb 2 O 5 ) having a thickness of 109.45 nm, and silicon oxide (SiO 2 ) having a thickness of 81.44 nm.
  • a low refractive index film made of .21 nm silicon oxide (SiO 2 )
  • a high refractive index film made of niobide oxide (Nb 2 O 5 ) having a thickness of 109.45 nm
  • silicon oxide (SiO 2 ) having a thickness of 81.44 nm.
  • a total of four layers are alternately laminated in this order: a rate film, a high refractive index film made of niobide oxide (Nb 2 O 5 ) having a thickness of 109.45 nm, and a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 81.44 nm.
  • An antireflection film was prepared, and a cover glass was obtained.
  • Visual reflectance The visual reflectance of the specular reflected light and the reflected scattered light was measured using a spectrophotometer (manufactured by Hitachi High-Tech Science Co., Ltd., product number "U-4000"). Specifically, in the visual reflectance measurement of the positively reflected light, the incident angle of the light is 8 °, the light receiving angle is 8 °, the measurement wavelength is 380 nm to 800 nm, the measurement interval is 1 nm, and the measured reflection. From the spectrum, the visual reflectance of the positively reflected light with respect to the D65 light source was determined according to JIS Z8722: 2009.
  • the incident angle is 8 °
  • the light receiving angle is 11 °
  • the measurement wavelength is 380 nm to 800 nm
  • the measurement interval is 1 nm
  • the visual reflectance of the reflected scattered light with respect to the D65 light source was determined in accordance with the above. The results are shown in Table 1 below. In Table 1 below, the specular reflectance based on the bare glass is also shown.
  • the standard normal reflectance reflectance of the raw glass was obtained by obtaining the average value (average reflectance) of the reflectance in the measurement wavelength range from the reflection spectrum of the normal reflected light and from the ratio to the average reflectance of the plain glass (Comparative Example 5). ..
  • the reflection index value C Clarity was measured by a reflection distribution measurement mode using SMS-1000 (manufactured by Display-Messtechnik & System). Using a lens with a focal length of 16 mm, the incident angle of the incident light is set to 3 °, the distance from the irradiation position on the cover glass of the examples and the comparative examples to the lens is set to 410 mm, and the cover glasses of the examples and the comparative examples are set. It was measured by sticking it on a blackboard glass with a liquid having a refractive index of 1.53 attached to the back surface of the lens.
  • an arbitrary photographic image is displayed on a display device with a resolution of 264 ppi, an evaluation sample is placed so as to cover half of the image, and the photographic image and the photographic image through the evaluation sample are compared and the difference cannot be discriminated.
  • "A” is the one that can be confirmed slightly
  • "B” is the one that can confirm the difference slightly
  • "C” is the one that feels a little deterioration of the photographic image through the evaluation sample
  • “C” is the one that feels the deterioration of the photographic image through the evaluation sample.
  • D The one that felt the deterioration of the photographic image through the evaluation sample was evaluated as "D"
  • the one that felt the deterioration of the photographic image through the evaluation sample was evaluated as "E".

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Abstract

Provided is a cover glass whereby visibility can be effectively enhanced.　A cover glass 1 comprising a glass substrate 2, an antiglare layer 3 provided on the glass substrate 2, and an antireflective film 4 provided on the antiglare layer 3, the luminous reflectance of regularly reflected light when light impinges on the cover glass 1 from the antireflective-film 4 side being less than the luminous reflectance of reflected scattered light.

Description

カバーガラスcover glass
　本発明は、アンチグレア機能を有するカバーガラスに関する。 The present invention relates to a cover glass having an anti-glare function.
　カバーガラスは、携帯電話機、タブレット端末、テレビ等のディスプレイに広く用いられている。このようなディスプレイの視認性は、外光の映り込みなどにより低下することがある。ディスプレイの映り込みを低減し、視認性を向上させる方法として、表面に凹凸構造を有するアンチグレア層を設ける方法が知られている。さらに、防眩効果とコントラストを向上させる方法として、反射防止膜を設ける方法が知られている。 Cover glass is widely used for displays such as mobile phones, tablet terminals, and televisions. The legibility of such a display may be deteriorated due to reflection of external light or the like. As a method of reducing the reflection on the display and improving the visibility, a method of providing an anti-glare layer having an uneven structure on the surface is known. Further, as a method of improving the antiglare effect and the contrast, a method of providing an antireflection film is known.
　例えば、下記の特許文献１には、透明基体の表面に凹凸形状を形成することにより、防眩加工を施す方法や、低反射膜を設ける方法が開示されている。低反射膜としては、高屈折率層と低屈折率層とを積層した積層体が記載されている。 For example, Patent Document 1 below discloses a method of applying antiglare processing by forming an uneven shape on the surface of a transparent substrate and a method of providing a low-reflection film. As the low-refractive-index film, a laminated body in which a high-refractive index layer and a low-refractive index layer are laminated is described.
特許第５８３９１３４号公報Japanese Patent No. 5839134
　近年、スマートフォンやデジタルサイネージ等のディスプレイにおいては、外光の映り込みをさらに一層低減させ、視認性をさらに一層向上させることが求められている。しかしながら、特許文献１のカバーガラスにおいても、外光の映り込みを十分には低減することはできず、視認性をなお十分に向上させることができないという問題がある。 In recent years, in displays such as smartphones and digital signage, it is required to further reduce the reflection of external light and further improve the visibility. However, even with the cover glass of Patent Document 1, there is a problem that the reflection of external light cannot be sufficiently reduced and the visibility cannot be sufficiently improved.
　本発明の目的は、視認性を効果的に向上させることができる、カバーガラスを提供することにある。 An object of the present invention is to provide a cover glass that can effectively improve visibility.
　本願の第１の発明に係るカバーガラスは、ガラス基板と、前記ガラス基板上に設けられている、凹凸構造を有するアンチグレア層と、前記アンチグレア層上に設けられている、反射防止膜と、を備え、前記反射防止膜側から光を入射させたときに、正反射光の視感反射率が、反射散乱光の視感反射率よりも小さいことを特徴とする。 The cover glass according to the first invention of the present application includes a glass substrate, an anti-glare layer having a concavo-convex structure provided on the glass substrate, and an antireflection film provided on the anti-glare layer. It is characterized in that, when light is incident from the antireflection film side, the visual reflectance of the positively reflected light is smaller than the visual reflectance of the reflected scattered light.
　本願の第２の発明に係るカバーガラスは、ガラス基板と、前記ガラス基板上に設けられている、アンチグレア層と、前記アンチグレア層上に設けられている、反射防止膜と、を備え、前記ガラス基板と前記アンチグレア層との組成が異なっていることを特徴とする。 The cover glass according to the second invention of the present application includes a glass substrate, an antiglare layer provided on the glass substrate, and an antireflection film provided on the antiglare layer, and the glass. It is characterized in that the composition of the substrate and the antiglare layer are different.
　以下、第１の発明と第２の発明を総称して、本発明と称する場合があるものとする。 Hereinafter, the first invention and the second invention may be collectively referred to as the present invention.
　本発明においては、前記ガラス基板の屈折率と前記アンチグレア層の屈折率との差の絶対値が、０．０２以上であることが好ましい。 In the present invention, the absolute value of the difference between the refractive index of the glass substrate and the refractive index of the antiglare layer is preferably 0.02 or more.
　本発明においては、前記アンチグレア層が、平坦部及び非平坦部を有することが好ましい。 In the present invention, it is preferable that the anti-glare layer has a flat portion and a non-flat portion.
　本発明においては、前記平坦部の厚みが、５ｎｍ以上、５００ｎｍ以下であることが好ましい。 In the present invention, the thickness of the flat portion is preferably 5 nm or more and 500 nm or less.
　本発明においては、前記ガラス基板上に前記アンチグレア層の平坦部及び前記反射防止膜がこの順に設けられてなる第１の積層体の構造による反射光の視感反射率が、前記アンチグレア層の非平坦部上に前記反射防止膜が設けられてなる第２の積層体の構造による視感反射率よりも小さいことが好ましい。 In the present invention, the visual reflectance of the reflected light due to the structure of the first laminated body in which the flat portion of the antiglare layer and the antireflection film are provided in this order on the glass substrate is not the same as that of the antiglare layer. It is preferably smaller than the visual reflectance due to the structure of the second laminated body in which the antireflection film is provided on the flat portion.
　本発明においては、前記ガラス基板と前記アンチグレア層との間に、前記ガラス基板とは屈折率が異なっている、光学調整層が設けられていることが好ましい。 In the present invention, it is preferable that an optical adjustment layer having a refractive index different from that of the glass substrate is provided between the glass substrate and the antiglare layer.
　本発明においては、前記光学調整層の屈折率と前記アンチグレア層の屈折率との差の絶対値が、０．２以上であることが好ましい。 In the present invention, the absolute value of the difference between the refractive index of the optical adjustment layer and the refractive index of the antiglare layer is preferably 0.2 or more.
　本発明によれば、視認性を効果的に向上させることができる、カバーガラスを提供することができる。 According to the present invention, it is possible to provide a cover glass that can effectively improve visibility.
図１は、本発明の第１の実施形態に係るカバーガラスを示す模式的断面図である。FIG. 1 is a schematic cross-sectional view showing a cover glass according to a first embodiment of the present invention. 図２（ａ）及び（ｂ）は、正反射光の視感反射率の測定方法を説明するための模式的断面図である。2 (a) and 2 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of specularly reflected light. 図３（ａ）及び（ｂ）は、反射散乱光の視感反射率の測定方法を説明するための模式的断面図である。3 (a) and 3 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of reflected scattered light. 図４は、ガラス基板上にアンチグレア層の平坦部及び反射防止膜がこの順に積層されてなる第１の積層体を説明するための模式的断面図である。FIG. 4 is a schematic cross-sectional view for explaining a first laminated body in which a flat portion of an antiglare layer and an antireflection film are laminated in this order on a glass substrate. 図５は、アンチグレア層上の非平坦部に反射防止膜が積層されてなる第２の積層体を説明するための模式的断面図である。FIG. 5 is a schematic cross-sectional view for explaining a second laminated body in which an antireflection film is laminated on a non-flat portion on an antiglare layer. 図６は、本発明の第２の実施形態に係るカバーガラスを示す模式的断面図である。FIG. 6 is a schematic cross-sectional view showing a cover glass according to a second embodiment of the present invention. 図７は、ガラス基板上に、光学調整層、アンチグレア層、及び反射防止膜がこの順に積層されてなる第３の積層体を説明するための模式的断面図である。FIG. 7 is a schematic cross-sectional view for explaining a third laminated body in which an optical adjustment layer, an antiglare layer, and an antireflection film are laminated in this order on a glass substrate.
　以下、好ましい実施形態について説明する。但し、以下の実施形態は単なる例示であり、本発明は以下の実施形態に限定されるものではない。また、各図面において、実質的に同一の機能を有する部材は同一の符号で参照する場合がある。なお、以下の図面において、Ａは入射光であり、Ｂは正反射光であり、Ｃは反射散乱光である。 Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Further, in each drawing, members having substantially the same function may be referred to by the same reference numeral. In the following drawings, A is incident light, B is specular reflected light, and C is reflected scattered light.
　（第１の実施形態）
　図１は、本発明の第１の実施形態に係るカバーガラスを示す模式的断面図である。図１に示すように、カバーガラス１は、ガラス基板２と、アンチグレア層３と、反射防止膜４とを備える。ガラス基板２の上に、アンチグレア層３が設けられている。また、アンチグレア層３の上に、反射防止膜４が設けられている。 (First Embodiment)
FIG. 1 is a schematic cross-sectional view showing a cover glass according to a first embodiment of the present invention. As shown in FIG. 1, the cover glass 1 includes a glass substrate 2, an antiglare layer 3, and an antireflection film 4. The anti-glare layer 3 is provided on the glass substrate 2. Further, an antireflection film 4 is provided on the antiglare layer 3.
　本実施形態において、ガラス基板２は、略矩形板状の形状を有する。もっとも、ガラス基板２は、例えば、略円板状等の形状を有していてもよく、その形状は特に限定されない。 In the present embodiment, the glass substrate 2 has a substantially rectangular plate-like shape. However, the glass substrate 2 may have a shape such as a substantially disk shape, and the shape is not particularly limited.
　ガラス基板２の厚みは、特に限定されず、光透過率などに応じて適宜設定することができる。ガラス基板２の厚みは、例えば、０．１ｍｍ～３ｍｍ程度とすることができる。 The thickness of the glass substrate 2 is not particularly limited and can be appropriately set according to the light transmittance and the like. The thickness of the glass substrate 2 can be, for example, about 0.1 mm to 3 mm.
　ガラス基板２に用いられるガラスとしては、特に限定されず、例えば、ホウケイ酸ガラス、無アルカリガラス、アルミノシリケートガラス、化学強化ガラス等を用いることができる。 The glass used for the glass substrate 2 is not particularly limited, and for example, borosilicate glass, non-alkali glass, aluminosilicate glass, chemically tempered glass and the like can be used.
　また、ガラス基板２は、第１の主面２ａ及び第２の主面２ｂを有する。第１の主面２ａ及び第２の主面２ｂは、対向し合っている。ガラス基板２の第１の主面２ａ上に、アンチグレア層３が設けられている。また、アンチグレア層３は、凹凸構造を有する。アンチグレア層３は、外光の映り込み等を抑制する、いわゆる防眩効果を付与するために設けられている。 Further, the glass substrate 2 has a first main surface 2a and a second main surface 2b. The first main surface 2a and the second main surface 2b face each other. The anti-glare layer 3 is provided on the first main surface 2a of the glass substrate 2. Further, the anti-glare layer 3 has an uneven structure. The anti-glare layer 3 is provided to impart a so-called anti-glare effect that suppresses reflection of external light and the like.
　本実施形態において、アンチグレア層３は、無機膜である。このようなアンチグレア層３は、ガラス基板２上に、無機塗料を塗布し、乾燥させることにより形成することができる。本実施形態において、アンチグレア層３は、無機塗料をスプレーコート法によって塗布し、乾燥させることにより形成されている。なお、無機塗料の塗布方法は、スプレーコート法に限定されず、他の塗布方法により塗布してもよい。 In this embodiment, the anti-glare layer 3 is an inorganic film. Such an anti-glare layer 3 can be formed by applying an inorganic paint on a glass substrate 2 and drying it. In the present embodiment, the anti-glare layer 3 is formed by applying an inorganic paint by a spray coating method and drying it. The method of applying the inorganic paint is not limited to the spray coating method, and other coating methods may be used.
　本実施形態において、無機塗料は、シリカ前駆体により構成されている。もっとも、無機塗料は、例えば、アルミナ前駆体、ジルコニア前駆体、チタニア前駆体等により構成されていてもよい。これらの前駆体は、１種を単独で用いてもよく、複数種を併用してもよい。また、無機塗料の溶媒としては、例えば、水、アルコール等を用いることができる。 In this embodiment, the inorganic paint is composed of a silica precursor. However, the inorganic paint may be composed of, for example, an alumina precursor, a zirconia precursor, a titania precursor, or the like. These precursors may be used alone or in combination of two or more. Further, as the solvent of the inorganic paint, for example, water, alcohol or the like can be used.
　シリカ前駆体としては、テトラエトキシシラン、テトラメトキシシラン等のアルコキシシラン、アルコキシシランの加水分解縮合物（ゾルゲルシリカ）、シラザン等が挙げられる。防眩効果をより一層高める観点からは、テトラエトキシシラン、テトラメトキシシラン等のアルコキシシラン、それらの加水分解縮合物であることが好ましく、テトラエトキシシランの加水分解縮合物であることがより好ましい。 Examples of the silica precursor include alkoxysilanes such as tetraethoxysilane and tetramethoxysilane, hydrolyzed condensates of alkoxysilane (sol-gel silica), and silazane. From the viewpoint of further enhancing the antiglare effect, an alkoxysilane such as tetraethoxysilane or tetramethoxysilane, or a hydrolyzed condensate thereof is preferable, and a hydrolyzed condensate of tetraethoxysilane is more preferable.
　アルミナ前駆体としては、アルミニウムアルコキシド、アルミニウムアルコキシドの加水分解縮合物、水溶性アルミニウム塩、アルミニウムキレート等が挙げられる。 Examples of the alumina precursor include aluminum alkoxide, a hydrolyzed condensate of aluminum alkoxide, a water-soluble aluminum salt, and an aluminum chelate.
　ジルコニア前駆体としては、ジルコニウムアルコキシド、ジルコニウムアルコキシドの加水分解縮合物等が挙げられる。 Examples of the zirconia precursor include zirconium alkoxide and a hydrolyzed condensate of zirconium alkoxide.
　チタニア前駆体としては、チタンアルコキシド、チタンアルコキシドの加水分解縮合物等が挙げられる。 Examples of the titania precursor include titanium alkoxide and a hydrolyzed condensate of titanium alkoxide.
　また、無機塗料は、無機粒子を含んでいてもよい。無機粒子としては、例えば、シリカ粒子、アルミナ粒子、ジルコニア粒子、チタニア粒子、ハフニア粒子、イットリア粒子等が挙げられる。 Further, the inorganic paint may contain inorganic particles. Examples of the inorganic particles include silica particles, alumina particles, zirconia particles, titania particles, hafnia particles, yttria particles and the like.
　アンチグレア層３の平均厚みは、特に限定されない。もっとも、防眩効果をより一層高める観点からは、アンチグレア層３の平均厚みは、０．１μｍ以上、２μｍ以下であることが好ましく、０．１５μｍ以上、１．７５μｍ以下であることがより好ましく、０．２μｍ以上、１μｍ以下であることがさらに好ましい。 The average thickness of the anti-glare layer 3 is not particularly limited. However, from the viewpoint of further enhancing the antiglare effect, the average thickness of the antiglare layer 3 is preferably 0.1 μm or more and 2 μm or less, and more preferably 0.15 μm or more and 1.75 μm or less. It is more preferably 0.2 μm or more and 1 μm or less.
　反射防止膜４は、誘電体多層膜であることが好ましい。この場合、ディスプレイ等における画像鮮明度をより一層向上させることができる。本実施形態において、反射防止膜４は、相対的に屈折率が高い高屈折率膜５と、相対的に屈折率が低い低屈折率膜６とが、この順に交互に積層された誘電体多層膜である。なお、反射防止膜４は、相対的に屈折率が低い低屈折率膜６と、相対的に屈折率が高い高屈折率膜５とが、この順に交互に積層された誘電体多層膜であってもよい。 The antireflection film 4 is preferably a dielectric multilayer film. In this case, the image sharpness on a display or the like can be further improved. In the present embodiment, the antireflection film 4 is a dielectric multilayer layer in which a high refractive index film 5 having a relatively high refractive index and a low refractive index film 6 having a relatively low refractive index are alternately laminated in this order. It is a membrane. The antireflection film 4 is a dielectric multilayer film in which a low refractive index film 6 having a relatively low refractive index and a high refractive index film 5 having a relatively high refractive index are alternately laminated in this order. May be.
　高屈折率膜５の材料としては、例えば、本実施形態のような酸化ニオブ、酸化チタン、酸化ジルコニウム、酸化ハフニウム、酸化タンタル、窒化ケイ素、酸化アルミニウム、窒化アルミニウムが挙げられる。 Examples of the material of the high refractive index film 5 include niobium oxide, titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silicon nitride, aluminum oxide, and aluminum nitride as in the present embodiment.
　低屈折率膜６の材料としては、例えば、酸化ケイ素や、酸化アルミニウム等が挙げられる。 Examples of the material of the low refractive index film 6 include silicon oxide and aluminum oxide.
　反射防止膜４を構成する各層の厚みは、１ｎｍ以上、５００ｎｍ以下であることが好ましく、２ｎｍ以上、３００ｎｍ以下であることがより好ましく、５ｎｍ以上、２００ｎｍ以下であることがさらに好ましい。 The thickness of each layer constituting the antireflection film 4 is preferably 1 nm or more and 500 nm or less, more preferably 2 nm or more and 300 nm or less, and further preferably 5 nm or more and 200 nm or less.
　反射防止膜４を構成する層の総数は、２層以上、７層以下であることが好ましい。このような範囲内にすることにより、効果的で、かつ簡易に形成可能な膜にすることができる。 The total number of layers constituting the antireflection film 4 is preferably 2 or more and 7 or less. By setting it within such a range, an effective and easily formable film can be obtained.
　反射防止膜４の全体の厚みは、５０ｎｍ以上、１０００ｎｍ以下であることが好ましく、７５ｎｍ以上、７５０ｎｍ以下であることがより好ましく、１００ｎｍ以上、５００ｎｍ以下であることがさらに好ましい。 The overall thickness of the antireflection film 4 is preferably 50 nm or more and 1000 nm or less, more preferably 75 nm or more and 750 nm or less, and further preferably 100 nm or more and 500 nm or less.
　反射防止膜４は、例えば、スパッタリング法、ＣＶＤ法、又は真空蒸着法等により形成することができる。 The antireflection film 4 can be formed by, for example, a sputtering method, a CVD method, a vacuum vapor deposition method, or the like.
　本実施形態のカバーガラス１では、反射防止膜４側から入射光Ａを入射させたときに、正反射光Ｂの視感反射率が、反射散乱光Ｃの視感反射率よりも小さい。このため、カバーガラス１では、外光の映り込みを効果的に抑制することができ、ディスプレイ等における視認性を効果的に向上させることができる。以下、図２及び図３を参照しつつ、カバーガラス１における正反射光Ｂの視感反射率及び反射散乱光Ｃの視感反射率の測定方法を説明する。 In the cover glass 1 of the present embodiment, when the incident light A is incident from the antireflection film 4 side, the visual reflectance of the normal reflected light B is smaller than the visual reflectance of the reflected scattered light C. Therefore, in the cover glass 1, the reflection of external light can be effectively suppressed, and the visibility in a display or the like can be effectively improved. Hereinafter, a method for measuring the visual reflectance of the specular reflected light B and the visual reflectance of the reflected scattered light C in the cover glass 1 will be described with reference to FIGS. 2 and 3.
　図２（ａ）及び（ｂ）は、正反射光の視感反射率の測定方法を説明するための模式的断面図である。まず、図２（ａ）に示すカバーガラス１における正反射光Ｂの反射光強度Ｘ１を測定する。なお、正反射光Ｂの反射光強度Ｘ１を測定する際には、カバーガラス１の裏面反射が測定に影響しないように裏面反射を抑制する処理を行う。次に、図２（ｂ）に示すように、カバーガラス１の反射防止膜４の上面にアルミニウム膜８（膜厚約３００ｎｍ）を形成した状態で、正反射光Ｂの反射光強度Ｙ１を測定する。そして、これらの反射光強度の比Ｘ１／Ｙ１から正反射光Ｂの反射スペクトルを測定することができる。なお、正反射光Ｂの反射光強度Ｘ１，Ｙ１は、例えば、分光光度計により、入射光の入射角は８°、受光する反射光の角度は８°、測定波長は３８０ｎｍ～８００ｎｍ、測定波長間隔は１ｎｍとして、測定することができる。そして、測定された反射スペクトルから、ＪＩＳ　Ｚ８７２２：２００９に準拠し、Ｄ６５光源に対する正反射光Ｂの視感反射率を求めることができる。 2 (a) and 2 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of specularly reflected light. First, the reflected light intensity X1 of the specularly reflected light B in the cover glass 1 shown in FIG. 2A is measured. When measuring the reflected light intensity X1 of the specular reflected light B, a process of suppressing the back surface reflection is performed so that the back surface reflection of the cover glass 1 does not affect the measurement. Next, as shown in FIG. 2B, the reflected light intensity Y1 of the specular reflected light B is measured with the aluminum film 8 (thickness about 300 nm) formed on the upper surface of the antireflection film 4 of the cover glass 1. do. Then, the reflection spectrum of the specular reflected light B can be measured from the ratio X1 / Y1 of these reflected light intensities. The reflected light intensities X1 and Y1 of the normal reflected light B are, for example, measured by a spectrophotometer, the incident angle of the incident light is 8 °, the angle of the reflected reflected light received is 8 °, the measurement wavelength is 380 nm to 800 nm, and the measurement wavelength. The interval can be measured at 1 nm. Then, from the measured reflection spectrum, the specular reflectance of the specular reflected light B with respect to the D65 light source can be obtained in accordance with JIS Z8722: 2009.
　図３（ａ）及び（ｂ）は、反射散乱光の視感反射率の測定方法を説明するための模式的断面図である。まず、図３（ａ）に示すカバーガラス１における反射散乱光Ｃの反射光強度Ｘ２を測定する。なお、反射散乱光Ｃの反射光強度Ｘ２を測定する際には、カバーガラス１の裏面反射が測定に影響しないように裏面反射を抑制する処理を行う。次に、図３（ｂ）に示すように、カバーガラス１の反射防止膜４の上面にアルミニウム膜８を形成した状態で、反射散乱光Ｃの反射光強度Ｙ２を測定する。そして、これらの反射光強度の比Ｘ２／Ｙ２から反射散乱光Ｃの反射スペクトルを測定することができる。なお、反射散乱光Ｃの反射光強度Ｘ２，Ｙ２は、例えば、分光光度計により、入射光の入射角は８°、受光する反射光の角度は１１°、測定波長は３８０ｎｍ～８００ｎｍ、測定波長間隔は１ｎｍとして、測定することができる。そして、測定された反射スペクトルから、ＪＩＳ　Ｚ８７２２：２００９に準拠し、Ｄ６５光源に対する反射散乱光Ｃの視感反射率を求めることができる。 3 (a) and 3 (b) are schematic cross-sectional views for explaining a method of measuring the visual reflectance of reflected scattered light. First, the reflected light intensity X2 of the reflected scattered light C in the cover glass 1 shown in FIG. 3A is measured. When measuring the reflected light intensity X2 of the reflected scattered light C, a process of suppressing the back surface reflection is performed so that the back surface reflection of the cover glass 1 does not affect the measurement. Next, as shown in FIG. 3B, the reflected light intensity Y2 of the reflected scattered light C is measured with the aluminum film 8 formed on the upper surface of the antireflection film 4 of the cover glass 1. Then, the reflection spectrum of the reflected scattered light C can be measured from the ratio X2 / Y2 of these reflected light intensities. The reflected light intensities X2 and Y2 of the reflected scattered light C are, for example, measured by a spectrophotometer, the incident angle of the incident light is 8 °, the angle of the received reflected light is 11 °, the measurement wavelength is 380 nm to 800 nm, and the measurement wavelength. The interval can be measured at 1 nm. Then, from the measured reflection spectrum, the visual reflectance of the reflected scattered light C with respect to the D65 light source can be obtained in accordance with JIS Z8722: 2009.
　従来、ガラス基板上に、アンチグレア層や、反射防止膜を設けた場合、各界面で反射が生じ、その反射特性は複雑なものとなっていた。これに対して、本発明者は、正反射光Ｂ及び反射散乱光Ｃの反射スペクトルに着目し、正反射光Ｂの視感反射率を反射散乱光Ｃの視感反射率よりも小さくすることにより、外光の映り込みを効果的に抑制することができ、視認性を効果的に向上できることを見出した。 Conventionally, when an anti-glare layer or an antireflection film is provided on a glass substrate, reflection occurs at each interface, and its reflection characteristics are complicated. On the other hand, the present inventor pays attention to the reflection spectra of the forward reflected light B and the reflected scattered light C, and makes the visual reflectance of the positive reflected light B smaller than the visual reflectance of the reflected scattered light C. As a result, it was found that the reflection of external light can be effectively suppressed and the visibility can be effectively improved.
　また、本発明者は、正反射光Ｂの反射スペクトルが図４に示す第１の積層体１０、すなわちガラス基板２上にアンチグレア層３の平坦部及び反射防止膜４がこの順に積層されてなる積層体の構造によって生じることを見出した。また、反射散乱光Ｃの反射スペクトルが図５に示す第２の積層体１１、すなわちアンチグレア層３の非平坦部上に反射防止膜４が積層されてなる積層体の構造によって生じることを見出した。 Further, the present inventor has the first laminated body 10 whose specular reflected light B has a reflection spectrum shown in FIG. 4, that is, the flat portion of the antiglare layer 3 and the antireflection film 4 are laminated in this order on the glass substrate 2. We have found that it is caused by the structure of the laminate. It was also found that the reflection spectrum of the reflected scattered light C is generated by the structure of the second laminated body 11 shown in FIG. 5, that is, the laminated body in which the antireflection film 4 is laminated on the non-flat portion of the antiglare layer 3. ..
　従って、正反射光Ｂの視感反射率は、ガラス基板２上にアンチグレア層３の平坦部及び反射防止膜４がこの順に積層されてなる第１の積層体１０の構造による反射光の視感反射率により求めることができる。また、反射散乱光Ｃの視感反射率は、アンチグレア層３の非平坦部上に反射防止膜４が積層されてなる第２の積層体１１の構造による視感反射率により求めることができる。 Therefore, the specular reflectance of the specular reflected light B is the visual reflectance of the reflected light due to the structure of the first laminated body 10 in which the flat portion of the antiglare layer 3 and the antireflection film 4 are laminated in this order on the glass substrate 2. It can be obtained by the reflectance. Further, the visual reflectance of the reflected scattered light C can be obtained from the visual reflectance due to the structure of the second laminated body 11 in which the antireflection film 4 is laminated on the non-flat portion of the antiglare layer 3.
　よって、ガラス基板２上にアンチグレア層３の平坦部及び反射防止膜４がこの順に積層されてなる第１の積層体１０の設計により、正反射光Ｂの視感反射率を調整することができる。正反射光Ｂの視感反射率は、各層の屈折率、特に各層を構成する材料、各層の厚み等により調整することができる。 Therefore, the visual reflectance of the specular reflected light B can be adjusted by designing the first laminated body 10 in which the flat portion of the antiglare layer 3 and the antireflection film 4 are laminated in this order on the glass substrate 2. .. The visual reflectance of the specularly reflected light B can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
　また、アンチグレア層３の非平坦部上に反射防止膜４が積層されてなる第２の積層体１１の設計により、反射散乱光Ｃの視感反射率を調整することができる。反射散乱光Ｃの視感反射率は、各層の屈折率、特に各層を構成する材料、各層の厚み等により調整することができる。 Further, the visual reflectance of the reflected scattered light C can be adjusted by designing the second laminated body 11 in which the antireflection film 4 is laminated on the non-flat portion of the antiglare layer 3. The visual reflectance of the reflected scattered light C can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
　第１の積層体１０における視感反射率ができる限り低くなるように、反射防止膜４の厚み、特に高屈折率膜５及び低屈折率膜６の厚みや材料を設計することにより、正反射光Ｂの視感反射率を反射散乱光Ｃの視感反射率よりも小さくすることができる。 Normal reflection is achieved by designing the thickness of the antireflection film 4, particularly the thickness and material of the high refractive index film 5 and the low refractive index film 6 so that the visual reflectance of the first laminated body 10 is as low as possible. The visual reflectance of the light B can be made smaller than the visual reflectance of the reflected scattered light C.
　本実施形態のカバーガラス１では、反射散乱光Ｃの視感反射率と正反射光Ｂの視感反射率との差は、好ましくは０．０１％以上であり、より好ましくは０．０５％以上である。この場合、外光の映り込みをより効果的に抑制することができ、視認性をより効果的に向上することができる。なお、反射散乱光Ｃの視感反射率と正反射光Ｂの視感反射率との差の上限値は、例えば、１％とすることができる。 In the cover glass 1 of the present embodiment, the difference between the visual reflectance of the reflected scattered light C and the visual reflectance of the specular reflected light B is preferably 0.01% or more, more preferably 0.05%. That is all. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively. The upper limit of the difference between the visual reflectance of the reflected scattered light C and the visual reflectance of the specular reflected light B can be, for example, 1%.
　本実施形態のカバーガラス１の別の局面では、ガラス基板２とアンチグレア層３の組成が異なっている。この場合においても、外光の映り込みを効果的に抑制することができ、視認性を効果的に向上することができる。 In another aspect of the cover glass 1 of the present embodiment, the compositions of the glass substrate 2 and the anti-glare layer 3 are different. Even in this case, the reflection of external light can be effectively suppressed, and the visibility can be effectively improved.
　本発明において、ガラス基板２の屈折率とアンチグレア層３の屈折率との差の絶対値は、好ましくは０．０２以上であり、より好ましくは０．０５以上である。この場合、外光の映り込みをより効果的に抑制することができ、視認性をより効果的に向上することができる。また、視認性をより効果的に向上する観点から、アンチグレア層３の屈折率は、ガラス基板２の屈折率より小さいことが好ましい。 In the present invention, the absolute value of the difference between the refractive index of the glass substrate 2 and the refractive index of the antiglare layer 3 is preferably 0.02 or more, more preferably 0.05 or more. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively. Further, from the viewpoint of more effectively improving visibility, the refractive index of the antiglare layer 3 is preferably smaller than that of the glass substrate 2.
　また、反射防止膜４の厚み、特に高屈折率膜５及び低屈折率膜６の厚みや材料を調整することによっても、外光の映り込みをより効果的に抑制することができ、視認性をより効果的に向上することができる。 Further, by adjusting the thickness of the antireflection film 4, particularly the thickness and material of the high refractive index film 5 and the low refractive index film 6, it is possible to more effectively suppress the reflection of external light, and the visibility can be improved. Can be improved more effectively.
　アンチグレア層３は、平坦部を有していることが好ましい。ここで、平坦部とは、アンチグレア層３の表面の凹凸高さの頻度分布を求め、最も頻度が高い高さ±２０ｎｍ以内となる箇所のことをいう。この場合、外光の映り込みをより効果的に抑制することができ、視認性をより効果的に向上することができる。この場合、平坦部の厚みは、好ましくは５ｎｍ以上、より好ましくは１０ｎｍ以上、好ましくは５００ｎｍ以下、より好ましくは２００ｎｍ以下とすることができる。また、平面視において、アンチグレア層３全体の面積に対する平坦部の面積は、例えば、１５％以上、６０％以下とすることができる。なお、非平坦部とは、平坦部以外の箇所のことをいう。また、アンチグレア層３の表面の凹凸高さの頻度分布において、最も頻度が高い高さから５０ｎｍ低い高さでの負荷面積率が０．９以下、かつ、最も頻度が高い高さから５０ｎｍ高い高さでの負荷面積率が０．１以上である場合、アンチグレア層３は、平坦部を有していないものとする。 The anti-glare layer 3 preferably has a flat portion. Here, the flat portion refers to a portion where the frequency distribution of the uneven height of the surface of the anti-glare layer 3 is obtained and the height is within ± 20 nm, which is the most frequent. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively. In this case, the thickness of the flat portion can be preferably 5 nm or more, more preferably 10 nm or more, preferably 500 nm or less, and more preferably 200 nm or less. Further, in a plan view, the area of the flat portion with respect to the area of the entire anti-glare layer 3 can be, for example, 15% or more and 60% or less. The non-flat portion means a portion other than the flat portion. Further, in the frequency distribution of the uneven height on the surface of the anti-glare layer 3, the load area ratio at the height 50 nm lower than the most frequent height is 0.9 or less, and the height is 50 nm higher than the most frequent height. When the load area ratio is 0.1 or more, it is assumed that the anti-glare layer 3 does not have a flat portion.
　（第２の実施形態）
　図６は、本発明の第２の実施形態に係るカバーガラスを示す模式的断面図である。図６に示すように、カバーガラス２１では、ガラス基板２とアンチグレア層３との間に、光学調整層７が設けられている。本実施形態では、光学調整層７が、相対的に屈折率が高い高屈折率層である。もっとも、光学調整層７は、相対的に屈折率が低い低屈折率層であってもよく、ガラス基板２と屈折率の異なる層であればよい。その他の点は、第１の実施形態と同様である。 (Second embodiment)
FIG. 6 is a schematic cross-sectional view showing a cover glass according to a second embodiment of the present invention. As shown in FIG. 6, in the cover glass 21, an optical adjustment layer 7 is provided between the glass substrate 2 and the anti-glare layer 3. In the present embodiment, the optical adjustment layer 7 is a high refractive index layer having a relatively high refractive index. However, the optical adjustment layer 7 may be a low refractive index layer having a relatively low refractive index, and may be a layer having a different refractive index from the glass substrate 2. Other points are the same as those of the first embodiment.
　カバーガラス２１においても、正反射光Ｂの視感反射率が、反射散乱光Ｃの視感反射率よりも小さいので、外光の映り込みを効果的に抑制することができ、ディスプレイ等の視認性を効果的に向上させることができる。 Even in the cover glass 21, the visual reflectance of the specular reflected light B is smaller than the visual reflectance of the reflected scattered light C, so that the reflection of external light can be effectively suppressed and the display or the like can be visually recognized. Sex can be effectively improved.
　なお、この場合、図７に示すように、ガラス基板２上に、光学調整層７、アンチグレア層３、及び反射防止膜４がこの順に積層されてなる第３の積層体３０の設計により、正反射光Ｂの視感反射率を調整することができる。正反射光Ｂの視感反射率は、各層の屈折率、特に各層を構成する材料、各層の厚み等により調整することができる。 In this case, as shown in FIG. 7, the design of the third laminated body 30 in which the optical adjustment layer 7, the antiglare layer 3, and the antireflection film 4 are laminated in this order on the glass substrate 2 is positive. The specular reflectance of the reflected light B can be adjusted. The visual reflectance of the specularly reflected light B can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
　また、アンチグレア層３上に反射防止膜４が積層されてなる第２の積層体１１の設計により、反射散乱光Ｃの視感反射率を調整することができる。反射散乱光Ｃの視感反射率は、各層の屈折率、特に各層を構成する材料、各層の厚み等により調整することができる。 Further, the visual reflectance of the reflected scattered light C can be adjusted by designing the second laminated body 11 in which the antireflection film 4 is laminated on the antiglare layer 3. The visual reflectance of the reflected scattered light C can be adjusted by adjusting the refractive index of each layer, particularly the material constituting each layer, the thickness of each layer, and the like.
　アンチグレア層３の屈折率と光学調整層７の屈折率との差の絶対値は、好ましくは０．２以上であり、より好ましくは１．０以上である。この場合、外光の映り込みをより効果的に抑制することができ、視認性をより効果的に向上することができる。また、視認性をより効果的に向上する観点から、アンチグレア層３の屈折率は、光学調整層７の屈折率より小さいことが好ましい。 The absolute value of the difference between the refractive index of the antiglare layer 3 and the refractive index of the optical adjustment layer 7 is preferably 0.2 or more, and more preferably 1.0 or more. In this case, the reflection of external light can be suppressed more effectively, and the visibility can be improved more effectively. Further, from the viewpoint of more effectively improving the visibility, the refractive index of the antiglare layer 3 is preferably smaller than the refractive index of the optical adjustment layer 7.
　なお、本発明は、第１の実施形態及び第２の実施形態の構成に限定されない。例えば、反射防止膜４の上に他の層が設けられていてもよい。他の層としては、例えば、防汚層が挙げられる。防汚層は、有機ケイ素化合物を含むことが好ましい。有機ケイ素化合物を含むことにより、反射防止膜４との密着性をより一層高めることができる。これにより、長期間の使用によっても、防汚層が剥離し難い。 The present invention is not limited to the configurations of the first embodiment and the second embodiment. For example, another layer may be provided on the antireflection film 4. Examples of the other layer include an antifouling layer. The antifouling layer preferably contains an organosilicon compound. By containing the organosilicon compound, the adhesion to the antireflection film 4 can be further enhanced. This makes it difficult for the antifouling layer to peel off even after long-term use.
　有機ケイ素化合物としては、例えば、シランカップリング剤、シリコーンオイル、シリコーンレジン、シリコーンゴム、疎水性シリカ、及びフッ素含有有機ケイ素化合物から選択される１つ以上の化合物を挙げることができる。 Examples of the organosilicon compound include one or more compounds selected from a silane coupling agent, a silicone oil, a silicone resin, a silicone rubber, a hydrophobic silica, and a fluorine-containing organosilicon compound.
　防汚層の厚みは、０．５ｎｍ以上、２０ｎｍ以下であることが好ましく、０．７５ｎｍ以上、１５ｎｍ以下であることがより好ましく、１ｎｍ以上、１０ｎｍ以下であることがさらに好ましい。 The thickness of the antifouling layer is preferably 0.5 nm or more and 20 nm or less, more preferably 0.75 nm or more and 15 nm or less, and further preferably 1 nm or more and 10 nm or less.
　防汚層の形成方法は、特に限定されるものではなく、例えば、有機ケイ素化合物等の希釈液をスプレーコート法などにより塗布することにより形成することができる。 The method for forming the antifouling layer is not particularly limited, and can be formed by, for example, applying a diluted solution of an organosilicon compound or the like by a spray coating method or the like.
　以下、本発明について、具体的な実施例に基づいて、さらに詳細に説明する。本発明は、以下の実施例に何ら限定されるものではなく、その要旨を変更しない範囲において適宜変更して実施することが可能である。 Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples, and can be appropriately modified and implemented without changing the gist thereof.
　（実施例１）
　まず、ガラス基板（日本電気硝子株式会社製、品番「Ｔ２Ｘ－１」、屈折率：１．５０）を用意した。次に、ガラス基板上に、シリカ前駆体を含むコーティング剤を、スプレーコート法により塗布し、厚み２０ｎｍのアンチグレア層（屈折率：１．４４）を形成した。なお、コーティング剤の塗布量は、３５ｍｌ／ｍ２とした。また、ガラス基板の屈折率とアンチグレア層の屈折率との差は、０．０６であった。平坦部の面積割合は４７％であった。 (Example 1)
First, a glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50) was prepared. Next, a coating agent containing a silica precursor was applied onto a glass substrate by a spray coating method to form an anti-glare layer (refractive index: 1.44) having a thickness of 20 nm. The amount of the coating agent applied was 35 ml / m 2 . The difference between the refractive index of the glass substrate and the refractive index of the antiglare layer was 0.06. The area ratio of the flat portion was 47%.
　次に、アンチグレア層上に、スパッタリング法により、厚み１２．７３ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜を形成した。次に、スパッタリング法により、厚み３４．８４ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜を形成した。次に、スパッタリング法により、厚み１１３．４４ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜を形成した。次に、スパッタリング法により、厚み８５．４５ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜を形成した。これにより、高屈折率膜と低屈折率膜とが交互に合計４層積層されてなる誘電体多層膜を作製し、カバーガラスを得た。 Next, a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 12.73 nm was formed on the antiglare layer by a sputtering method. Next, a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 34.84 nm was formed by a sputtering method. Next, a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 113.44 nm was formed by a sputtering method. Next, a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 85.45 nm was formed by a sputtering method. As a result, a dielectric multilayer film in which a high-refractive index film and a low-refractive index film were alternately laminated in a total of four layers was produced, and a cover glass was obtained.
　（実施例２）
　まず、ガラス基板（日本電気硝子株式会社製、品番「Ｔ２Ｘ－１」、屈折率：１．５０）を用意した。次に、アンチグレア層上に、スパッタリング法により、厚み２．３６ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる光学調整層（屈折率：２．３５）を形成した。 (Example 2)
First, a glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50) was prepared. Next, an optical adjustment layer (refractive index: 2.35) made of niobium oxide (Nb 2 O 5 ) having a thickness of 2.36 nm was formed on the anti-glare layer by a sputtering method.
　次に、ガラス基板上に、シリカ前駆体を含むコーティング剤を、スプレーコート法により塗布し、厚み５４ｎｍのアンチグレア層（屈折率：１．４４）を成膜した。なお、無機塗料の塗布量は、７０ｍｌ／ｍ２とした。また、光学調整層の屈折率とアンチグレア層の屈折率との差は、０．８５であった。平坦部の面積割合は２１％であった。 Next, a coating agent containing a silica precursor was applied onto a glass substrate by a spray coating method to form an antiglare layer (refractive index: 1.44) having a thickness of 54 nm. The amount of the inorganic paint applied was 70 ml / m 2 . The difference between the refractive index of the optical adjustment layer and the refractive index of the antiglare layer was 0.85. The area ratio of the flat portion was 21%.
　次に、アンチグレア層上に、スパッタリング法により、厚み１６．１３ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜を形成した。次に、スパッタリング法により、厚み３６．７７ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜を形成した。次に、スパッタリング法により、厚み１１４．６１ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜を形成した。次に、スパッタリング法により、厚み８６．０９ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜を形成した。これにより、高屈折率膜と低屈折率膜とが交互に合計４層積層されてなる反射防止膜を作製し、カバーガラスを得た。 Next, a high-refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 16.13 nm was formed on the anti-glare layer by a sputtering method. Next, a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 36.77 nm was formed by a sputtering method. Next, a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 114.61 nm was formed by a sputtering method. Next, a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 86.09 nm was formed by a sputtering method. As a result, a total of four layers of high-refractive-index films and low-refractive-index films were alternately laminated to prepare an antireflection film, and a cover glass was obtained.
　（比較例１）
　実施例１と同様にしてガラス基板上にアンチグレア層を形成した。次に、アンチグレア層上に、スパッタリング法により、厚み４５ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜、厚み１０．３７ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜、厚み３６．２１ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜、厚み１０９．４５ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜、及び厚み８１．４４ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜がこの順に交互に合計５層積層されてなる反射防止膜を作製し、カバーガラスを得た。 (Comparative Example 1)
An anti-glare layer was formed on the glass substrate in the same manner as in Example 1. Next, on the anti-glare layer, a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 45 nm, a high refractive index film made of niobium oxide (Nb 2 O 5 ) having a thickness of 10.37 nm, and a thickness 36 by a sputtering method. It is composed of a low refractive index film made of .21 nm silicon oxide (SiO 2 ), a high refractive index film made of niobide oxide (Nb 2 O 5 ) having a thickness of 109.45 nm, and silicon oxide (SiO 2 ) having a thickness of 81.44 nm. A total of five layers of low-refractive index films were alternately laminated in this order to prepare an antireflection film, and a cover glass was obtained.
　（比較例２）
　反射防止膜を設けなかったこと以外は、実施例１と同様にしてカバーガラスを得た。 (Comparative Example 2)
A cover glass was obtained in the same manner as in Example 1 except that the antireflection film was not provided.
　（比較例３）
　ガラス基板（日本電気硝子株式会社製、品番「Ｔ２Ｘ－１」、屈折率：１．５０）をエッチングすることにより、アンチグレア処理を施した。次に、アンチグレア処理したガラス基板上に、スパッタリング法により、厚み１０．３ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜、厚み３６．２１ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜、厚み１０９．４５ｎｍの酸化ニオブ（Ｎｂ２Ｏ５）からなる高屈折率膜、及び厚み８１．４４ｎｍの酸化ケイ素（ＳｉＯ２）からなる低屈折率膜がこの順に交互に合計４層積層されてなる反射防止膜を作製し、カバーガラスを得た。 (Comparative Example 3)
An anti-glare treatment was applied by etching a glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50). Next, on an anti-glare treated glass substrate, a high refractive index film made of niobide (Nb 2 O 5 ) having a thickness of 10.3 nm and a low refractive index made of silicon oxide (SiO 2 ) having a thickness of 36.21 nm were subjected to a sputtering method. A total of four layers are alternately laminated in this order: a rate film, a high refractive index film made of niobide oxide (Nb 2 O 5 ) having a thickness of 109.45 nm, and a low refractive index film made of silicon oxide (SiO 2 ) having a thickness of 81.44 nm. An antireflection film was prepared, and a cover glass was obtained.
　（比較例４）
　ガラス基板（日本電気硝子株式会社製、品番「Ｔ２Ｘ－１」、屈折率：１．５０）をエッチングすることにより、アンチグレア処理を施し、カバーガラスを得た。 (Comparative Example 4)
By etching a glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50), antiglare treatment was performed to obtain a cover glass.
　（比較例５）
　ガラス基板（日本電気硝子株式会社製、品番「Ｔ２Ｘ－１」、屈折率：１．５０）をそのまま素ガラスとして使用した。 (Comparative Example 5)
A glass substrate (manufactured by Nippon Electric Glass Co., Ltd., product number "T2X-1", refractive index: 1.50) was used as it was as raw glass.
　＜評価＞
　（視感反射率）
　分光光度計（日立ハイテクサイエンス社製、品番「Ｕ－４０００」）を用いて、正反射光及び反射散乱光の視感反射率を測定した。具体的には、正反射光の視感反射率測定は、光の入射角度は８°とし、受光角度は８°とし、測定波長は３８０ｎｍ～８００ｎｍとし、測定間隔は１ｎｍとし、測定された反射スペクトルから、ＪＩＳ　Ｚ８７２２：２００９に準拠し、Ｄ６５光源に対する正反射光の視感反射率を求めた。反射散乱光の視感反射率測定は、入射角度は８°とし、受光角度は１１°とし、測定波長は３８０ｎｍ～８００ｎｍとし、測定間隔は１ｎｍとし、測定された反射スペクトルから、ＪＩＳ　Ｚ８７２２：２００９に準拠し、Ｄ６５光源に対する反射散乱光の視感反射率を求めた。結果を下記の表１に示す。なお、下記の表１では、素ガラス基準正反射反射率も併せて示した。素ガラス基準正反射反射率は、正反射光の反射スペクトルから、測定波長域の反射率の平均値（平均反射率）を求め、素ガラス（比較例５）の平均反射率に対する比から求めた。 <Evaluation>
(Visual reflectance)
The visual reflectance of the specular reflected light and the reflected scattered light was measured using a spectrophotometer (manufactured by Hitachi High-Tech Science Co., Ltd., product number "U-4000"). Specifically, in the visual reflectance measurement of the positively reflected light, the incident angle of the light is 8 °, the light receiving angle is 8 °, the measurement wavelength is 380 nm to 800 nm, the measurement interval is 1 nm, and the measured reflection. From the spectrum, the visual reflectance of the positively reflected light with respect to the D65 light source was determined according to JIS Z8722: 2009. In the visual reflectance measurement of the reflected scattered light, the incident angle is 8 °, the light receiving angle is 11 °, the measurement wavelength is 380 nm to 800 nm, the measurement interval is 1 nm, and from the measured reflection spectrum, JIS Z8722: 2009. The visual reflectance of the reflected scattered light with respect to the D65 light source was determined in accordance with the above. The results are shown in Table 1 below. In Table 1 below, the specular reflectance based on the bare glass is also shown. The standard normal reflectance reflectance of the raw glass was obtained by obtaining the average value (average reflectance) of the reflectance in the measurement wavelength range from the reflection spectrum of the normal reflected light and from the ratio to the average reflectance of the plain glass (Comparative Example 5). ..
　（平坦部の面積割合）
　ＫＥＹＥＮＣＥ社製、レーザー顕微鏡ＶＫ-Ｘ２６０を用い、１５０倍対物レンズにて、アンチグレア層の凹凸高さを９５μｍ×７１μｍの測定範囲で測定した。次に、測定した高さデータの頻度分布を求め、最も頻度が大きい高さが０となるようにシフト補正した。補正した高さが－２０ｎｍ以上＋２０ｎｍ以下である領域の面積を求め、これを平坦部の面積とした。得られた平坦部の面積をレーザー顕微鏡の測定範囲の面積で割ることで平坦部の面積割合とした。 (Area ratio of flat part)
Using a laser microscope VK-X260 manufactured by KEYENCE, the height of the unevenness of the antiglare layer was measured in a measurement range of 95 μm × 71 μm with a 150x objective lens. Next, the frequency distribution of the measured height data was obtained, and shift correction was performed so that the height with the highest frequency was 0. The area of the region where the corrected height was −20 nm or more and + 20 nm or less was obtained, and this was defined as the area of the flat portion. The area of the flat portion obtained was divided by the area of the measurement range of the laser microscope to obtain the area ratio of the flat portion.
　（映り込み指標値）
　映り込み指標値Ｃ：Ｃｌａｒｉｔｙは、ＳＭＳ－１０００（Ｄｉｓｐｌａｙ－Ｍｅｓｓｔｅｃｈｎｉｋ＆Ｓｙｓｔｅｍｅ社製）を用いて、反射分布測定モードにより測定した。なお、焦点距離１６ｍｍのレンズを用い、入射光の入射角を３°、実施例及び比較例のカバーガラス上の照射位置からレンズまでの距離を４１０ｍｍに設定し、実施例及び比較例のカバーガラスの裏面に屈折率１．５３の浸液を付けた状態で黒板ガラスと貼り付けて測定した。 (Reflection index value)
The reflection index value C: Clarity was measured by a reflection distribution measurement mode using SMS-1000 (manufactured by Display-Messtechnik & System). Using a lens with a focal length of 16 mm, the incident angle of the incident light is set to 3 °, the distance from the irradiation position on the cover glass of the examples and the comparative examples to the lens is set to 410 mm, and the cover glasses of the examples and the comparative examples are set. It was measured by sticking it on a blackboard glass with a liquid having a refractive index of 1.53 attached to the back surface of the lens.
　（官能試験）
　防眩性については、ライン光源を映り込ませた状態で、映り込んだライン光源の輪郭が認識できないものを「Ａ」、輪郭をかろうじて認識できるものを「Ｂ」、輪郭をある程度認識できるものを「Ｃ」、輪郭がはっきり認識できるものを「Ｄ」として評価した。 (Sensory test)
Regarding the anti-glare property, when the line light source is reflected, the one that cannot recognize the outline of the reflected line light source is "A", the one that can barely recognize the outline is "B", and the one that can recognize the outline to some extent. "C" and those with clearly recognizable contours were evaluated as "D".
　画像鮮明度については、解像度２６４ｐｐｉの表示装置上に任意の写真画像を表示させ、その半分を覆うように評価サンプルを置き、写真画像と評価サンプル越しの写真画像を比較しその差が判別できなかったものを「Ａ」、その差がわずかながらに確認できたものを「Ｂ」、評価サンプル越しの写真画像の劣化を少し感じたものを「Ｃ」、評価サンプル越しの写真画像の劣化を感じたものを「Ｄ」、評価サンプル越しの写真画像の劣化を大きく感じたものを「Ｅ」として評価した。 Regarding image sharpness, an arbitrary photographic image is displayed on a display device with a resolution of 264 ppi, an evaluation sample is placed so as to cover half of the image, and the photographic image and the photographic image through the evaluation sample are compared and the difference cannot be discriminated. "A" is the one that can be confirmed slightly, "B" is the one that can confirm the difference slightly, "C" is the one that feels a little deterioration of the photographic image through the evaluation sample, and "C" is the one that feels the deterioration of the photographic image through the evaluation sample. The one that felt the deterioration of the photographic image through the evaluation sample was evaluated as "D", and the one that felt the deterioration of the photographic image through the evaluation sample was evaluated as "E".
　結果を下記の表１に示す。 The results are shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１より、実施例１～２では、官能試験の評価がいずれも「Ａ」又は「Ｂ」であり、視認性が向上されていることが確認できた。一方、比較例１～５では、官能試験の評価のうちいずれかが、「Ｃ」、「Ｄ」、又は「Ｅ」であり、視認性を十分に向上させることができなかった。 From Table 1, it was confirmed that in Examples 1 and 2, the evaluation of the sensory test was "A" or "B", and the visibility was improved. On the other hand, in Comparative Examples 1 to 5, any one of the evaluations of the sensory test was "C", "D", or "E", and the visibility could not be sufficiently improved.
１，２１…カバーガラス
２…ガラス基板
２ａ…第１の主面
２ｂ…第２の主面
３…アンチグレア層
４…反射防止膜
５…高屈折率膜
６…低屈折率膜
７…光学調整層
８…アルミニウム膜
１０…第１の積層体
１１…第２の積層体
３０…第３の積層体 1,21 ... Cover glass 2 ... Glass substrate 2a ... First main surface 2b ... Second main surface 3 ... Anti-glare layer 4 ... Antireflection film 5 ... High refractive index film 6 ... Low refractive index film 7 ... Optical adjustment layer 8 ... Aluminum film 10 ... First laminated body 11 ... Second laminated body 30 ... Third laminated body

Claims (8)

  1. 　ガラス基板と、
    　前記ガラス基板上に設けられている、凹凸構造を有するアンチグレア層と、
    　前記アンチグレア層上に設けられている、反射防止膜と、
    を備え、
    　前記反射防止膜側から光を入射させたときに、正反射光の視感反射率が、反射散乱光の視感反射率よりも小さい、カバーガラス。     With a glass substrate
    An anti-glare layer having an uneven structure provided on the glass substrate,
    An antireflection film provided on the antiglare layer,
    Equipped with
    A cover glass in which the visual reflectance of positively reflected light is smaller than the visual reflectance of reflected scattered light when light is incident from the antireflection film side.
  2. 　ガラス基板と、
    　前記ガラス基板上に設けられている、アンチグレア層と、
    　前記アンチグレア層上に設けられている、反射防止膜と、
    を備え、
    　前記ガラス基板と前記アンチグレア層との組成が異なっている、カバーガラス。     With a glass substrate
    The anti-glare layer provided on the glass substrate and
    An antireflection film provided on the antiglare layer,
    Equipped with
    A cover glass having a different composition between the glass substrate and the antiglare layer.
  3. 　前記ガラス基板の屈折率と前記アンチグレア層の屈折率との差の絶対値が、０．０２以上である、請求項１または請求項２に記載のカバーガラス。 The cover glass according to claim 1 or 2, wherein the absolute value of the difference between the refractive index of the glass substrate and the refractive index of the antiglare layer is 0.02 or more.
  4. 　前記アンチグレア層が、平坦部及び非平坦部を有する、請求項１～請求項３のいずれか１項に記載のカバーガラス。 The cover glass according to any one of claims 1 to 3, wherein the anti-glare layer has a flat portion and a non-flat portion.
  5. 　前記平坦部の厚みが、５ｎｍ以上、５００ｎｍ以下である、請求項４に記載のカバーガラス。 The cover glass according to claim 4, wherein the flat portion has a thickness of 5 nm or more and 500 nm or less.
  6. 　前記ガラス基板上に前記アンチグレア層の平坦部及び前記反射防止膜がこの順に設けられてなる第１の積層体の構造による反射光の視感反射率が、前記アンチグレア層の非平坦部上に前記反射防止膜が設けられてなる第２の積層体の構造による視感反射率よりも小さい、請求項４または請求項５に記載のカバーガラス。 The visual reflectance of the reflected light due to the structure of the first laminated body in which the flat portion of the antiglare layer and the antireflection film are provided in this order on the glass substrate is the same on the non-flat portion of the antiglare layer. The cover glass according to claim 4 or 5, which is smaller than the visual reflectance due to the structure of the second laminated body provided with the antireflection film.
  7. 　前記ガラス基板と前記アンチグレア層との間に、前記ガラス基板とは屈折率が異なっている、光学調整層が設けられている、請求項１～請求項６のいずれか１項に記載のカバーガラス。 The cover glass according to any one of claims 1 to 6, wherein an optical adjustment layer having a refractive index different from that of the glass substrate is provided between the glass substrate and the antiglare layer. ..
  8. 　前記光学調整層の屈折率と前記アンチグレア層の屈折率との差の絶対値が、０．２以上である、請求項７に記載のカバーガラス。 The cover glass according to claim 7, wherein the absolute value of the difference between the refractive index of the optical adjustment layer and the refractive index of the antiglare layer is 0.2 or more.
PCT/JP2021/026257 2020-07-27 2021-07-13 Cover glass WO2022024744A1 (en)

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WO2017038868A1 (en) * 2015-08-31 2017-03-09 旭硝子株式会社 Translucent structure, method for manufacturing same, and article
JP2018158879A (en) * 2017-03-23 2018-10-11 Ａｇｃ株式会社 Antiglare glass substrate
JP2019123652A (en) * 2018-01-18 2019-07-25 Ａｇｃ株式会社 Glass plate and display device
JP2019144475A (en) * 2018-02-22 2019-08-29 Ａｇｃ株式会社 Light transmissive structure
JP2019184709A (en) * 2018-04-04 2019-10-24 日本電気硝子株式会社 Article

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Publication number Priority date Publication date Assignee Title
JP2016043694A (en) * 2014-08-21 2016-04-04 ティーピーケイ タッチ ソリューションズ（シアメン）インコーポレーテッド Composite substrate structure and touch sensing device
WO2017038868A1 (en) * 2015-08-31 2017-03-09 旭硝子株式会社 Translucent structure, method for manufacturing same, and article
JP2018158879A (en) * 2017-03-23 2018-10-11 Ａｇｃ株式会社 Antiglare glass substrate
JP2019123652A (en) * 2018-01-18 2019-07-25 Ａｇｃ株式会社 Glass plate and display device
JP2019144475A (en) * 2018-02-22 2019-08-29 Ａｇｃ株式会社 Light transmissive structure
JP2019184709A (en) * 2018-04-04 2019-10-24 日本電気硝子株式会社 Article

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