Glass, method for manufacturing same, and method for selecting glass

Abstract

The present invention pertains to glass having a first main surface and a second main surface opposite from the first main surface. At least a portion of the first main surface has a structure with recesses and protrusions. A visibility indicator value T of the outermost surface in a region on the first main surface side in which the structure with recesses and protrusions is provided is 0.85 or higher, and the average dynamic friction coefficient COF thereof is 0.70 or higher. The present invention also pertains to a method for manufacturing the glass, the method comprising: preparing glass having a first main surface and a second main surface opposite from the first main surface; and forming a structure with recesses and protrusions on at least a portion of the first main surface.

Description

Glass, its manufacturing method, and method for selecting glass

[0001] This invention relates to glass, a method for manufacturing the same, and a method for selecting glass.

[0002] Generally, a cover made of a transparent substrate such as a glass plate is placed on the display surface side of a display device such as an LCD (Liquid Crystal Display) device to protect the display device.

[0003] For example, cover glass in automotive display devices is required to possess predetermined levels of optical properties in terms of resolution or visibility, reflected image diffusion, and glare. Therefore, when selecting a transparent substrate such as a glass plate, it is insufficient to consider only one optical property, and it is often necessary to consider multiple optical properties simultaneously.

[0004] Therefore, Patent Document 1 discloses that when evaluated using three index values—resolution index value T, reflected image diffusion index value R, and glare index value S—a glass plate with resolution, reflected image diffusion, and glare prevention suitable for in-vehicle display devices can be obtained if these index values ​​meet a specific range.

[0005] Furthermore, Patent Document 2 discloses that, in addition to the visibility index value T, the reflected image diffusion index value R, and the glare index value S, a glass plate with excellent color reproducibility can be obtained if the transmitted haze satisfies a specific range.

[0006] Japanese Patent No. 5867649 Japanese Patent No. 7067077

[0007] In contrast to the above, cover glass and similar components in display devices, not limited to automotive applications, are not only used for viewing but also as touch panels, and these opportunities are expected to increase in the future. Examples of glass that users touch include, in addition to the touch panels mentioned above, cover glass on the casings (including the back casing) of electronic devices (personal computers, mobile computers, smartphones, etc.).

[0008] However, our research has shown that for glass used in applications that involve contact, such as touch panels, improving abrasion resistance is also important. This is because repeated wiping of fingerprints and other dirt from the glass can potentially alter its tactile feel.

[0009] Therefore, the present invention aims to provide glass with excellent wear resistance and a method for manufacturing the same. It also aims to provide a method for selecting the above-mentioned glass.

[0010] One aspect of the present invention relates to a glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a portion thereof, and the visibility index value T at the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or higher, and the average coefficient of dynamic friction COF is 0.70 or higher, and the visibility index value T and the average coefficient of dynamic friction COF are quantified by the method shown below. Visibility index value T: Using a DM&S SMS-1000, the glass is placed 30 mm away from a slit-shaped white light source with a length of 40 mm and a width of 0.1 mm, with the first main surface side facing the light source, and the brightness at the outermost surface of the region having the uneven structure is measured from the second main surface side of the glass. A camera lens with a focal length of 16 mm is used with an aperture of 5.6, and the distance from the outermost surface of the first main surface side of the glass to the camera lens is set to 550 mm. The angle θ = 0° is defined as the direction parallel to the thickness direction of the glass, and the average value of the brightness in the range of angle θ = 0° ± 0.1° is T １ Let T be the average value of the brightness in the range of angle θ = 0.7° ± 0.1°. ２ Let T be the average value of the brightness in the range of angle θ = -0.7° ± 0.1°. ３ In this case, the value calculated by the following formula (1) shall be defined as the visibility index value T. Visibility index value T = 1 - (T ２ +T ３ ) / (2×T １) Equation (1) Average dynamic friction coefficient COF: The dynamic friction coefficient is measured in a static friction measuring machine in an environment of 25°C and 70% humidity by sliding a simulated finger on the outermost surface of the region having the uneven structure on the first main surface side of the glass at a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency is 10 kHz. The simulated finger is made of urethane, and the contact portion with the outermost surface has linear protrusions formed at 0.5 mm intervals within an area of ​​10 mm × 15 mm, perpendicular to the sliding direction. Here, counting back from the time when the coefficient of dynamic friction is maximum, the start time is defined as the time when the relative velocity between the glass and the simulated finger first becomes 0 mm / second or less, and the end time is defined as the time when, after the time represented by {(start time) + (0.75 × scanning distance / scanning speed)}, the relative velocity between the glass and the simulated finger first becomes 5 mm / second or less. The average coefficient of dynamic friction COF is calculated by the following formula (2). Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time and the end time) ± 0.1 seconds. Formula (2)

[0011] Another aspect of the present invention relates to a glass having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface has an uneven structure in at least a portion thereof, and the kurtosis Sku at the outermost surface of the region having the uneven structure on the first main surface side is 5.0 or less, and the area ratio Smr1 of the protruding peaks is 7.5% or more.

[0012] Another aspect of the present invention relates to a glass having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface has an uneven structure in at least a portion thereof, and the Sk / Sz ratio, calculated from the level difference Sk (μm) of the core portion and the maximum height Sz (μm) of the uneven structure at the outermost surface of the region having the uneven structure on the first main surface side, is 0.25 or greater.

[0013] Another aspect of the present invention relates to a method for manufacturing glass, which includes preparing glass having a first main surface and a second main surface facing the first main surface, and forming an uneven structure on at least a portion of the first main surface.

[0014] Another aspect of the present invention relates to a method for selecting any of the above-mentioned glasses.

[0015] According to the present invention, it is possible to provide glass with excellent wear resistance and a method for manufacturing the same. Furthermore, a method for selecting the above-mentioned glass can also be provided.

[0016] Figure 1 is a schematic diagram showing an example of a measuring device used when measuring the visibility index value T. Figure 2 is a schematic cross-sectional view showing a method for manufacturing glass according to one embodiment of the present invention, using an example of a transfer mold.

[0017] The present invention will be described in detail below. In this specification, the "~" indicating a numerical range is used to mean that the values ​​before and after it are included as the lower and upper limits. The measurement of the average dynamic friction coefficient and the wear resistance test in this specification shall be carried out in a constant temperature and humidity chamber (Thermal Stream, manufactured by Orion Machinery Co., Ltd.) in an environment where the temperature and humidity are set.

[0018] 《Glass》 The glass according to this embodiment has a first main surface and a second main surface facing the first main surface, and the first main surface has an uneven structure in at least a part of it.

[0019] Through our investigations, we have come to realize that, as an example of the glass according to this embodiment, which has excellent wear resistance of the first main surface, the following first, second, and third embodiments can be cited.

[0020] <First Embodiment> In the first embodiment, the visibility index value T at the outermost surface of the region having an uneven structure on the first main surface side is 0.85 or higher. In addition, the mean dynamic friction coefficient COF at the outermost surface is 0.70 or higher. By satisfying these indicators, the glass of the first embodiment has excellent abrasion resistance on the first main surface and good visibility.

[0021] <Average Dynamic Friction Coefficient COF> The inventors have found that the average dynamic friction coefficient COF is an effective index for evaluating the abrasion resistance of a glass surface. The average dynamic friction coefficient COF is quantified by the following method. In this specification, it is preferable to use the average value measured at three arbitrary locations for the average dynamic friction coefficient COF. However, locations that take extreme outlier values ​​that are more than 50% away from the median value should be excluded from the arbitrary measurement locations.

[0022] (Measurement Method) Using a static friction measuring machine, the coefficient of dynamic friction is measured by sliding a simulated finger across the outermost surface of a region having an uneven structure on the first main surface side of a glass surface in an environment of 25°C and 70% humidity, with a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency is 10 kHz.

[0023] The artificial finger is made of urethane, and the contact area with the outermost surface of the glass has linear protrusions formed at 0.5 mm intervals within a 10 mm x 15 mm area, perpendicular to the sliding direction.

[0024] Here, working backward from the time when the coefficient of dynamic friction is maximum, the time when the relative velocity between the glass and the simulated finger first becomes 0 mm / second or less is defined as the start time of movement. The time when the relative velocity between the glass and the simulated finger first becomes 5 mm / second or less after the time represented by {(start time of movement) + (0.75 × scanning distance / scanning speed)} is defined as the end time of movement. The value calculated by the following formula (2) is defined as the average coefficient of dynamic friction COF. Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time of movement and the end time of movement) ± 0.1 seconds. Formula (2)

[0025] Furthermore, the scanning distance and scanning speed in the formula used to determine the end time of the above movement are 30 mm and 30 mm / second, respectively, as described in the conditions for the sliding of the simulated finger.

[0026] In the first embodiment, the average coefficient of dynamic friction COF is 0.70 or higher, preferably 0.70 to 1.80. Here, from the viewpoint of improving the wear resistance of the glass, the average coefficient of dynamic friction COF is 0.70 or higher, preferably 0.75 or higher, more preferably 0.80 or higher, and even more preferably 1.00 or higher. On the other hand, from the viewpoint of making finger sliding smooth when touching the glass, the average coefficient of dynamic friction COF is preferably 1.80 or lower, more preferably 1.50 or lower, even more preferably 1.40 or lower, and particularly preferably 1.32 or lower.

[0027] For the mean coefficient of kinetic friction COF to satisfy the above range, for example, the shape of the uneven structure on the first main surface side of the glass is set to a predetermined range. For example, if the tips of the protrusions in the uneven structure of the surface are rounded, the contact area with the user's fingers, etc., increases, and the surface of the glass becomes less prone to wear.

[0028] Glass satisfying the above-described uneven structure can be obtained, for example, by the glass manufacturing method according to this embodiment, as described later.

[0029] <Visibility Index Value T> As described above, the first main surface of the glass according to this embodiment has an uneven structure in at least a part of it. This uneven structure scatters the light reflected from the glass surface, reducing glare so that the user can view the glass surface without stress. In other words, by providing an uneven structure, it is possible to make glass with excellent anti-glare properties. The visibility index value T is effective as an index value for such anti-glare properties. For example, glass with a small visibility index value T (close to 0) has poor visibility, while glass with a large visibility index value T has good visibility. For this reason, the glass according to the first embodiment is useful, for example, as cover glass for a display device.

[0030] In this embodiment, the visibility index value T is quantified by the following method. In this specification, it is preferable to use the average value measured at any three points on the diagonal as the visibility index value T. However, points that take extreme outlier values, more than 50% away from the median, should be excluded from the arbitrary measurement points.

[0031] (Measurement method) Using an SMS-1000 manufactured by DM&S (Display-Messtechnik & Systeme), a glass is placed 30 mm above a slit-shaped white light source with a length of 40 mm and a width of 0.1 mm such that the first main surface side faces the light source side. Then, the luminance on the outermost surface of the region having the concavo-convex structure is measured from the second main surface side of the glass.

[0032] The camera lens uses a lens with a focal length of 16 mm at an aperture of 5.6, and the distance from the outermost surface on the first main surface side of the glass to the camera lens is set to 550 mm.

[0033] Taking the direction parallel to the thickness direction of the glass as the angle θ = 0°, the average value of the luminance in the range of the angle θ = 0° ± 0.1° is T １ And taking the average value of the luminance in the range of the angle θ = 0.7° ± 0.1° as T ２ And taking the average value of the luminance in the range of the angle θ = -0.7° ± 0.1° as T ３ When this is done, the value calculated by the following formula (1) is taken as the visibility index value T. Visibility index value T = 1 - (T ２ + T ３ ) / (2 × T １ ) Formula (1)

[0034] More specifically, referring to FIG. 1, one aspect of the method for measuring the visibility index value T of the glass 50 will be described.

[0035] The measuring device 70A has a light source 71 and a detector (analyzer) 75, and the glass 50 to be measured, that is, the sample to be measured, is disposed within the measuring device 70A. The glass 50 has a first main surface 52 having a concavo-convex structure and a second main surface 53.

[0036] The light source 71 emits first light in a direction parallel to the thickness direction of the glass 50 from the first main surface 52 side toward the glass 50, and the detector (analyzer) 75 located on the second main surface 53 side of the glass 50 detects and analyzes the luminance of the transmitted light that has passed through the glass 50.

[0037] Taking the direction parallel to the thickness direction of the glass 50 as the angle θ = 0°, the average value of the luminance detected in the range of the angle θ = 0° ± 0.1° (T １), the average value of the brightness detected in the range of angle θ = 0.7° ± 0.1° (T ２ ) and the average value of the brightness detected in the range of angle θ = -0.7° ± 0.1° (T ３ From this, the visibility index value T of the glass 50 is calculated using the above formula (1).

[0038] Note that a negative (-) sign in angle θ indicates a counterclockwise inclination relative to the first incident light beam, while a positive (+) sign indicates a clockwise inclination relative to the first incident light beam.

[0039] The analysis device used is the SMS-1000 manufactured by DM&S (Display-Mestechnik & System), but if a successor device compliant with JIS C1006:2019 is available from DM&S, that successor device may be used instead. Furthermore, a camera lens such as the C1614A lens (manufactured by Ricoh Co., Ltd.) can be used.

[0040] In the first embodiment, the visibility index value T at the outermost surface of the region having an uneven structure on the first main surface side of the glass is 0.85 or higher, preferably 0.86 or higher, more preferably 0.87 or higher, and the higher the value, the better. The upper limit of the visibility index value T is 1.0. The visibility index value T may be, for example, 0.85 to 1.0.

[0041] The visibility index value T can be set to a desired range, for example, by the shape and density of the uneven structure.

[0042] Furthermore, if a film such as an anti-reflective coating or an anti-fouling coating is formed to cover the uneven structure, the visibility index value T will satisfy the above range at the outermost surface after the film has been removed. Methods for removing the film include, for example, UV ozone cleaning. For example, UV ozone cleaning can be performed by irradiating the surface with a UV ozone cleaning machine (PL30-200, manufactured by Sen Special Light Source Co., Ltd.) at 200W for 30 minutes.

[0043] <Second Embodiment> In the second embodiment, the kurtosis Sku at the outermost surface of the region having an uneven structure on the first main surface side is 5.0 or less. Also, the area ratio Smr1 of the protruding peaks at the outermost surface is 7.5% or more. By satisfying these surface roughness indicators, the glass of the second embodiment has a surface shape on the first main surface that provides excellent wear resistance. Glass satisfying the above uneven structure can be obtained, for example, by the glass manufacturing method according to this embodiment described later.

[0044] <Kurtosis Sku> Kurtosis Sku is the fourth-power mean of Z(x,y) in the reference region, non-dimensionalized by raising the root mean square height (Sq) to the fourth power, and is a value measured in accordance with ISO 25178. Specifically, it can be measured using a laser microscope equipped with a white light interferometer (VK-X3000, manufactured by Keyence Corporation) with an acquired data count of 1024 × 768 pixels and a measurement area of ​​1449 μm × 1086 μm.

[0045] In the second embodiment, the kurtosis Sku at the outermost surface of the region having an uneven structure on the first main surface side is 5.0 or less. A kurtosis Sku of 5.0 or less reduces the number of sharp peaks and valleys in the uneven structure of the glass surface. This reduces localized stress concentration, improving wear resistance. From this viewpoint, the kurtosis Sku is 5.0 or less, preferably 3.5 or less, and more preferably 3.0 or less. Furthermore, from the viewpoint of improving anti-glare properties, the kurtosis Sku is preferably 1.0 or more, more preferably 1.5 or more, even more preferably 2.0 or more, and particularly preferably 2.5 or more. For example, the kurtosis Sku may be between 1.0 and 5.0, between 2.0 and 3.5, or between 2.5 and 3.0.

[0046] <Area ratio Smr1 of protruding peaks> The area ratio Smr1 (%) of the protruding peaks refers to the area ratio of the part of the uneven structure that is higher than the core, and is a value measured in accordance with ISO 25178. Specifically, it can be measured using a laser microscope equipped with a white light interferometer (VK-X3000, manufactured by Keyence Corporation) with an acquisition data count of 1024 × 768 pixels and a measurement area of ​​1449 μm × 1086 μm.

[0047] In the second embodiment, the area ratio Smr1 of the protruding peaks on the outermost surface of the region having an uneven structure on the first main surface side is 7.5% or more. By having an area ratio Smr1 of 7.5% or more of the protruding peaks, the contact area with the user's fingers, etc., is increased, making the glass surface less prone to wear, i.e., improving wear resistance. From this viewpoint, the area ratio Smr1 of the protruding peaks is 7.5% or more, and preferably 8.0% or more. The upper limit of the area ratio Smr1 of the protruding peaks is not particularly limited, but for example, it is usually 25.0% or less, and may be 15.0% or less, or 10.0% or less. The area ratio Smr1 of the protruding peaks may be, for example, 7.5 to 25.0%.

[0048] <Third Embodiment> In the third embodiment, the Sk / Sz ratio, calculated from the level difference Sk (μm) of the core portion at the outermost surface of the region having the uneven structure on the first main surface side and the maximum height Sz (μm) of the uneven structure, is 0.25 or greater. By satisfying this surface roughness index, the glass of the third embodiment provides excellent wear resistance to the surface shape of the first main surface. Glass satisfying the above uneven structure can be obtained, for example, by the glass manufacturing method according to this embodiment, which will be described later.

[0049] <Sk / Sz> Sk / Sz is calculated from the level difference Sk (μm) of the core portion at the outermost surface of the region having the uneven structure on the first main surface side of the glass according to this embodiment, and the maximum height Sz (μm) of the uneven structure, and represents the slope of the equivalent straight line in the load curve as a relative value that can be compared regardless of the size of the uneven structure.

[0050] The core level difference Sk (μm) refers to the height of the core portion, which is the part of the load curve obtained for the uneven structure that falls within the height range of the equivalent straight line's load area ratio from 0% to 100%, and is measured in accordance with ISO 25178. The maximum height Sz (μm) of the uneven structure refers to the maximum height from the top (peak) to the bottom (valley) of the uneven structure, and is measured in accordance with ISO 25178. Specifically, both can be measured using a laser microscope equipped with a white light interferometer (VK-X3000, manufactured by Keyence Corporation), with an acquisition data count of 1024 × 768 pixels and a measurement area of ​​1449 μm × 1086 μm.

[0051] By dividing the level difference Sk (μm) of the core by the maximum height Sz (μm) of the uneven structure, the slope of the equivalent straight line, Sk / Sz, is obtained as a relative value that can be compared regardless of the size of the uneven structure.

[0052] In the third embodiment, the Sk / Sz at the outermost surface of the region having an uneven structure on the first main surface side is 0.25 or higher. A Sk / Sz of 0.25 or higher results in a nearly constant change in area ratio and fewer steep inclines on the surface of the uneven structure, thus improving wear resistance. From this viewpoint, the Sk / Sz is 0.25 or higher, preferably 0.28 or higher, more preferably 0.30 or higher, and even more preferably 0.32 or higher. The upper limit of the Sk / Sz is not particularly limited, but for example, it is usually 0.65 or lower. The Sk / Sz may be, for example, 0.25 to 0.65.

[0053] The level difference Sk of the core portion described above is preferably 0.1 to 10.0 μm. From the viewpoint of anti-glare properties, the level difference Sk of the core portion is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1.0 μm or more. From the viewpoint of wear resistance, the level difference Sk of the core portion is preferably 10.0 μm or less, and more preferably 9.5 μm or less.

[0054] The maximum height Sz of the above-mentioned uneven structure is preferably 0.4 to 20.0 μm. From the viewpoint of anti-glare properties, the maximum height Sz of the uneven structure is preferably 0.4 μm or more, and more preferably 0.5 μm or more. From the viewpoint of wear resistance, the maximum height Sz of the uneven structure is preferably 20.0 μm or less, and more preferably 15.0 μm or less.

[0055] The glass according to this embodiment may be made by appropriately combining the constituent elements of the first to third embodiments described above. For example, the glass of the first embodiment may further satisfy at least one of the following requirements (A) to (C): (A) The kurtosis Sk is 5.0 or less. (B) The area ratio Smr1 of the protruding peaks is 7.5% or more. (C) The Sk / Sz is 0.25 or more. The glass of the second embodiment may further satisfy at least one of the following requirements (C) to (E): (C) The Sk / Sz is 0.25 or more. (D) The mean kinetic friction coefficient COF is 0.70 or more. (E) The visibility index value T is 0.85 or more. The glass of the third embodiment may further satisfy at least one of the following requirements (A) to (B) and (D) to (E). (A) The kurtosis Sku is 5.0 or less. (B) The area ratio Smr1 of the protruding peaks is 7.5% or more. (D) The mean coefficient of kinetic friction COF is 0.70 or more. (E) The visibility index value T is 0.85 or more. Furthermore, the glass according to this embodiment may be, for example, a form that satisfies requirement (D) and at least one of requirements (A) to (C). More specifically, the glass according to this embodiment may have, for example, a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a part of it, and satisfies any of the following (a) to (d). (a) On the first main surface, at the outermost surface of the region having the above-mentioned uneven structure, the visibility index value T is 0.85 or higher, the average coefficient of dynamic friction COF is 0.70 or higher, the crustosis Sk is 5.0 or lower, and the area ratio Smr1 of the protruding peaks is 7.5% or higher. (b) On the first main surface, at the outermost surface of the region having the above-mentioned uneven structure, the visibility index value T is 0.85 or higher, the average coefficient of dynamic friction COF is 0.70 or higher, and the Sk / Sz is 0.25 or higher. (c) On the first main surface, at the outermost surface of the region having the above-mentioned uneven structure, the crustosis Sk is 5.0 or lower, the area ratio Smr1 of the protruding peaks is 7.5% or higher, and the Sk / Sz is 0.25 or higher.(d) On the first main surface side, at the outermost surface of the region having the above-mentioned uneven structure, the visibility index value T is 0.85 or higher, the mean dynamic friction coefficient COF is 0.70 or higher, the kurtosis Sk is 5.0 or lower, the area ratio Smr1 of the protruding peaks is 7.5% or higher, and Sk / Sz is 0.25 or higher.

[0056] The following information can be applied to any of the first to third embodiments of the glass described above.

[0057] <Glass Composition> In this embodiment, various types of glass compositions can be used as the glass, but for example, alkali-free glass, soda-lime glass, soda-lime silicate glass, aluminosilicate glass, borate glass, lithium aluminosilicate glass, lead glass, alkali barium glass, aluminoborosilicate glass, borosilicate glass, etc. can be used. Among these, soda-lime glass and aluminosilicate glass are more preferred from the viewpoint of facilitating ion exchange in the chemical strengthening treatment described later.

[0058] Furthermore, the glass composition preferably contains sodium, and a composition that allows for strengthening by molding and chemical strengthening treatment is preferred.

[0059] More specifically, the glass composition can be expressed in mole percent based on oxides, for example, SiO ２ 50-80%, Al ２ O ３ 0.1 to 25%, Li ２ O + Na ２ O+K ２ O 3-30%, MgO 0-25%, CaO 0-25%, and ZrO ２ Examples of glass containing 0-5% of [the substance] include, but are not particularly limited to, glass containing [the substance].

[0060] More specifically, the following glass compositions (I) to (V) are listed. For example, "containing 0-25% MgO" means that MgO is not essential, but it may be included in up to 25%.

[0061] (I) The composition expressed in mol% based on oxides is SiO ２ 63-73%, Al ２ O ３0.1-5.2%, Na ２ O at 10-16%, K ２ 0 to 1.5% O, Li ２ A composition expressed in mole percent based on glass (II) oxide containing 0-5.0% O, 5-13% MgO, and 4-10% CaO is SiO ２ 50-74%, Al ２ O ３ 1-10% Na ２ O: 6-14%, K ２ 3-11% O, Li ２ 0-5.0% O, 2-15% MgO, 0-6% CaO, and ZrO ２ It contains 0-5% of SiO ２ and Al ２ O ３ The total content of Na is 75% or less. ２ O and K ２ A composition expressed in molar percentages based on glass (III) oxide, where the total content of O is 12-25% and the total content of MgO and CaO is 7-15%, is SiO ２ 68-80%, Al ２ O ３ 4-10%, Na ２ O 5-15%, K ２ O 0-1%, Li ２ 0-5.0% O, 4-15% MgO and ZrO ２ A composition expressed in molar percentage based on glass (IV) oxide containing 0-1% of SiO ２ 67-75%, Al ２ O ３ 0-4%, Na ２ O 7-15%, K ２ O 1-9%, Li ２ 0-5.0% O, 6-14% MgO and ZrO ２ It contains 0-1.5% of SiO ２ and Al ２ O ３ The total content is 71-75%, Na ２ O and K ２ The total O content is 12-20%, and if CaO is present, its content is less than 1%. The composition, expressed in molar percentage based on glass (V) oxide, is SiO ２56-73%, Al ２ O ３ 7-24%, B ２ O ３ 0-6%, P ２ O ５ 0-6%, Li ２ 2-12% O, Na ２ O 2-11%, K ２ O 0-5%, MgO 0-8%, CaO 0-2%, SrO 0-5%, BaO 0-5%, ZnO 0-5%, TiO ２ 0-2% and ZrO ２ A composition expressed in molar percentage based on glass (VI) oxide containing 0-4% of SiO ２ 58-80%, Al ２ O ３ 13-18%, B ２ O ３ 0-5%, P ２ O ５ 0.5-4%, Li ２ 3-10% O, Na ２ O 5-20%, K ２ O 0-2%, MgO 0-11%, CaO 0-20%, SrO 0-20%, BaO 0-15%, ZnO 0-10%, TiO ２ 0-1%, ZrO ２ Glass containing 0-2%

[0062] <Chemical Strengthening Treatment> In this embodiment, from the viewpoint of increasing strength and preventing breakage when external stress is applied, it is preferable to introduce a compressive stress layer on the outermost surface of the glass, and it is even more preferable to use chemically strengthened glass that has undergone chemical strengthening treatment by ion exchange treatment.

[0063] When chemically strengthening glass, in order to properly perform the chemical strengthening treatment, the Li in the glass composition ２ O and Na ２ The total O content is preferably 12 mol% or more.

[0064] Furthermore, in order to increase the surface compressive stress (CS) and the depth of the compressive stress layer (DOL), the composition of the glass is SiO ２Al 60 mol% or more, ２ O ３ It is preferable that it contains 8 mol% or more of [the substance].

[0065] <Size and Shape> The thickness of the glass according to this embodiment is not particularly limited, but when chemical strengthening treatment is performed, it is generally preferable to have a thickness of 3 mm or less from the viewpoint of effectively performing the treatment. In addition to the above viewpoint, when used as cover glass for the housing of electronic equipment, the thickness of the glass is more preferably 1.5 mm or less from the viewpoint of reducing the weight of the housing, and the thickness of the glass is preferably 0.05 mm or more, and more preferably 0.3 mm or more from the viewpoint of strength.

[0066] The size of the glass according to this embodiment is not particularly limited and can be determined as appropriate depending on the application.

[0067] The glass according to this embodiment may be flat glass or curved glass. Specifically, as curved glass, it may have a bent portion on at least one of the first main surface and the second main surface. A bent portion means a portion where the mean curvature is not zero. In this case, it is preferable to form a predetermined shape from flat glass.

[0068] <Abrasion Resistance: Water Droplet Contact Angle> The glass according to this embodiment exhibits excellent abrasion resistance of the first main surface. Abrasion resistance can be evaluated, for example, by the results of the abrasion resistance test described below.

[0069] Approximately 2 μL of distilled water is dropped onto the glass surface to be tested, and the water droplet contact angle is measured using a contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.). After measurement, the distilled water on the glass surface is wiped off. Next, a flannel cloth conforming to JIS L0803:2011 is placed on the glass with a load of 500 g and slid back and forth 1500 times at a speed of 40 back-and-forth movements per minute in an environment of 24°C and 44% humidity. After that, the water droplet contact angle is measured in the same manner as above for the abraded portion of the glass surface. The water droplet contact angle is measured at three different locations on the glass surface, and the average value is calculated. The smaller the absolute value of the difference in water droplet contact angle before and after sliding the flannel cloth, the smaller the change in the properties of the glass surface due to friction, indicating superior abrasion resistance. The absolute value of the difference in water droplet contact angle before and after sliding the flannel cloth is preferably 25° or less, more preferably 15° or less, even more preferably 10° or less, and the smaller the value, the better.

[0070] <Applications> The applications of the glass according to this embodiment are not particularly limited as long as they are touched by the user. For example, it can be used as cover glass for displays (notebook computers, monitors, LCDs, PDPs, ELDs, CRTs, PDAs, etc.), including when used as a touch panel, and as cover glass for the casing (including the rear casing) of electronic devices (personal computers, mobile computers, smartphones, etc.). The glass according to this embodiment is arranged so that the side touched by the user becomes the first main surface side.

[0071] <Selection Method> The present invention also relates to a method for selecting the glass according to the above embodiment in order to obtain glass with excellent wear resistance.

[0072] The glass according to the above embodiment is a glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a part of it. In the first embodiment, the visibility index value T at the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or more, and the mean dynamic friction coefficient COF is 0.70 or more. In the second embodiment, the crustosis Sk at the outermost surface of the region having the uneven structure on the first main surface side is 5.0 or less, and the area ratio Smr1 of the protruding peaks is 7.5% or more. In the third embodiment, the Sk / Sz calculated from the level difference Sk (μm) of the core portion and the maximum height Sz (μm) of the uneven structure at the outermost surface of the region having the uneven structure on the first main surface side is 0.25 or more.

[0073] The preferred embodiment of the glass in the selection method according to this embodiment is the same as the preferred embodiment of the glass described above.

[0074] 《Glass with Functional Layer》 The glass according to this embodiment may be made into glass with a functional layer by providing a functional layer on at least one of the first main surface and the second main surface. Note that the constituent requirements (A) to (E) described above for the first, second, and third embodiments are satisfied by the outermost surface of the glass body that does not include the functional layer. To check whether the glass according to this embodiment and the glass with a functional layer including the functional layer satisfy the constituent requirements of the first to third embodiments, the functional layer is removed from the glass with a functional layer, and then the glass body is measured. UV ozone cleaning as described above can be used to remove the functional layer.

[0075] Examples of the functional layers mentioned above include anti-reflective coatings, anti-fouling coatings, and printing layers, with anti-fouling coatings being more preferred. Only one type of functional layer may be provided, or two or more types may be provided.

[0076] <Anti-reflective coating> If the glass according to this embodiment has an anti-reflective coating, it is sufficient for the anti-reflective coating to cover at least a part of the uneven structure formed on the first main surface, and it is preferable that it covers the area of ​​the first main surface of the glass that the user touches. If the uneven structure is formed in all of the areas that are touched, it is preferable that the anti-reflective coating is formed in all of those areas.

[0077] Generally, applying an anti-reflective coating to glass reduces its reflectivity, thereby reducing glare caused by reflected light. Furthermore, using glass with an anti-reflective coating in a display device improves the light transmittance from the device, thereby enhancing the visibility of the image display device.

[0078] As the anti-reflective coating, conventionally widely used anti-reflective coatings can be employed. For example, such an anti-reflective coating may have a laminated structure in which two or more layers of low refractive index layers and high refractive index layers are alternately laminated.

[0079] The above-described laminated structure allows for optical design with a layer configuration that exhibits lower reflectivity over a wider wavelength range as the number of layers increases. For example, the number of layers in the above-described anti-reflective laminated structure is preferably 2 to 8 in total, and 2 to 6 layers is more preferable from the viewpoint of reflectivity reduction effect and mass productionability.

[0080] The materials for the high refractive index layer and the low refractive index layer are not particularly limited and can be appropriately selected considering the required degree of anti-reflective properties and productivity, but the main component of the high refractive index layer is preferably at least one selected from the group consisting of silicon nitride, titanium oxide, niobium oxide, tantalum oxide, and zirconium oxide, and more preferably at least one selected from the group consisting of silicon nitride, niobium oxide, and tantalum oxide from the viewpoint of productivity and refractive index.

[0081] The material constituting the low refractive index layer is preferably at least one selected from the group consisting of silicon dioxide, a material containing a mixed oxide of Si and Sn, a material containing a mixed oxide of Si and Zr, and a material containing a mixed oxide of Si and Al. From the viewpoint of productivity and refractive index, a layer made of silicon dioxide is more preferable.

[0082] <Anti-fouling film> The glass according to this embodiment may have an anti-fouling (AFP: Anti-Finger Print) film covering the uneven structure formed on the first main surface, or, if the anti-reflective film is present, on top of it.

[0083] An anti-fouling film is a film that suppresses the adhesion of organic and inorganic substances to a surface, or, even if organic or inorganic substances do adhere to the surface, it is a film that allows the adhered substances to be easily removed by cleaning, such as by wiping.

[0084] The antifouling film is not particularly limited as long as it can impart antifouling properties, but compounds containing fluorine are preferred. For example, a fluorine-containing organosilicon compound coating obtained by curing a fluorine-containing organosilicon compound by hydrolysis condensation reaction is an example.

[0085] The fluorine-containing organosilicon compound is not particularly limited as long as it can impart antifouling, water-repellent, and oil-repellent properties. For example, a fluorine-containing organosilicon compound having one or more groups selected from the group consisting of polyfluoropolyether groups, polyfluoroalkylene groups, and polyfluoroalkyl groups can be mentioned. Note that a polyfluoropolyether group refers to a divalent group having a structure in which polyfluoroalkylene groups and etheric oxygen atoms are alternately bonded.

[0086] Examples of commercially available fluorine-containing organosilicon compounds 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).

[0087] The thickness of the antifouling film is not particularly limited, but when the antifouling film consists of a fluorine-containing organosilicon compound coating, the thickness is preferably 2 to 20 nm. From the viewpoint of uniformly covering the surface with the antifouling film and obtaining good abrasion resistance, the above thickness is preferably 2 nm or more. Furthermore, from the viewpoint of maintaining good optical properties, the above thickness is preferably 20 nm or less, more preferably 15 nm or less, and even more preferably 10 nm or less.

[0088] <Printed Layer> The glass according to this embodiment may have a printed layer on at least a portion of the second main surface. When the glass is used as a cover glass for a display device, providing a printed layer has the effect of clearly indicating the button positions to the user and improving operability, and also the effect of improving the design by concealing the wiring for the touch panel.

[0089] The printed layer is preferably provided on at least a portion of the second main surface, and is provided using known methods and conditions.

[0090] In addition to the above, the glass according to this embodiment may have other functional layers provided on at least one of the first main surface and the second main surface, to the extent that it does not impair the effects of the present invention. Examples of other functional layers include infrared-cutting layers, ultraviolet-cutting layers, water-repellent layers, antistatic layers, undercoat layers, adhesion-improving layers, protective layers, and the like. These other functional layers can be conventionally known or used in known methods.

[0091] 《Method for Manufacturing Glass》 The method for manufacturing glass according to this embodiment includes the following steps (i) and (ii): (i) A step of preparing glass having a first main surface and a second main surface facing the first main surface; (ii) A step of forming an uneven structure on at least a part of the first main surface.

[0092] Between steps (i) and (ii) above, or after step (ii), a step (iii) of strengthening the glass may be further included, and it is preferable that the strengthening step be performed after step (ii).

[0093] Furthermore, when manufacturing the glass with the functional layer described above, step (iv) may further include a step of forming the functional layer on at least one of the first main surface and the second main surface. Step (iv) may be performed after step (ii), but if the strengthening treatment in step (iii) is performed, it is preferable to perform step (iv) after step (iii).

[0094] <Step (i): Process of preparing glass> The glass used in step (i) may be commercially available or manufactured.

[0095] When manufacturing glass, conventionally known methods can be employed. For example, raw materials for each component are mixed to achieve the desired composition and heated and melted in a glass melting furnace. The glass is homogenized by bubbling, stirring, adding fining agents, etc., and then molded into a predetermined shape using a known molding method and slowly cooled.

[0096] Glass molding methods include, for example, the float method, press method, fusion method, down-draw method, and roll-out method. Among these, the float method is preferred for mass production. In addition to the float method, the fusion method and down-draw method are also preferred as continuous molding methods.

[0097] After the glass component, formed by any molding method, is slowly cooled, it is cut to the desired size. If more precise dimensional accuracy is required, the cut glass component may be subjected to polishing or edge finishing as described later. This reduces cracking and chipping of the glass during handling in the molding process, thereby improving yield.

[0098] If the glass has a bent portion on at least one of the first main surface and the second main surface, it may be formed into a predetermined shape from a flat sheet of glass. This forming may be carried out while heating the glass, and the forming method can be, for example, self-weight forming, vacuum forming, or press forming.

[0099] The bending of the glass portion may be performed before or simultaneously with step (ii). In particular, when a heat molding method using a transfer mold is performed in step (ii), it is preferable to perform the bending of the glass portion simultaneously with step (ii) from the viewpoint of simplifying the manufacturing method.

[0100] When polishing at least one main surface of glass, for example, polishing can be performed by moving a rotary polishing tool at a constant speed while applying constant pressure to the polishing part. By polishing under constant pressure and constant speed conditions, the polished surface can be uniformly polished at a constant polishing rate.

[0101] The edges of the glass may be chamfered or otherwise processed. Chamfering is preferably done by mechanical grinding, commonly known as R-chamfering or C-chamfering, but it can also be done by etching or other methods, and is not particularly limited.

[0102] <Step (ii): Step for forming an uneven structure> In step (ii), an area having an uneven structure is formed on at least a part of the first main surface. Methods for forming the uneven structure include a heat molding method using a transfer mold, a frosting method, a two-fluid spray method or an electrostatic spray method to form an area having an uneven structure on the first main surface, a wet blasting method followed by etching, and a wet blasting method.

[0103] In this embodiment, a heat molding method using a transfer mold is particularly preferred.

[0104] - A heat molding method using a heat molding transfer mold is a method in which glass is placed on a transfer mold having a transfer-oriented uneven structure on at least a part of its surface, with the first main surface in contact with the transfer-oriented uneven structure, the glass is heated to a heat molding temperature, and the transfer-oriented uneven structure is transferred to the first main surface.

[0105] The above-described transfer mold has a transfer-oriented uneven structure on at least a portion of its surface. This transfer-oriented uneven structure corresponds to an uneven structure formed on at least a portion of the first main surface of the glass. By transferring the transfer-oriented uneven structure to at least a portion of the first main surface of the glass, it is possible to manufacture glass in which the first main surface has an uneven structure on at least a portion of it.

[0106] The transfer of the transfer-type uneven structure to the first main surface of the glass is preferably carried out by sealing the glass and the transfer mold inside the apparatus and reducing the pressure inside the apparatus at the thermoforming temperature, thereby causing the first main surface to adhere closely to the transfer-type uneven structure.

[0107] The transfer mold more preferably includes a first mold having the transfer-oriented uneven structure and a second mold having through holes. The first mold and the second mold may each consist of a single member or multiple members. When the transfer mold includes a first mold and a second mold, it is more preferable that the pressure reduction within the apparatus is performed through the through holes of the second mold. The second mold may have only one through hole or multiple through holes.

[0108] More specifically, with reference to Figure 2, one embodiment of a method for manufacturing glass 50 by a heat molding method using a transfer mold 100 will be described.

[0109] A first mold 80 having a transfer-oriented uneven structure 81 on its surface and a second mold 90 having through holes 91 are prepared. In this embodiment, one through hole 91 is provided approximately in the center of the second mold 90. The first mold 80 is placed in the center of the second mold 90 to form a transfer mold 100.

[0110] The glass 50 is placed near the center of the area of ​​the first mold 80 having the transfer surface 81, such that the first main surface 52 is in contact with the transfer surface 81. The second mold 90 is fixed to the lower shaft of a molding apparatus (not shown) (manufactured by Shibaura Machine (formerly Toshiba Machine) Co., Ltd., glass element molding apparatus: GMP-315V). The through hole 91 is connected to an external vacuum pump.

[0111] Next, nitrogen gas is blown in through a through hole provided at the top of the molding apparatus to fill the inside of the molding apparatus with nitrogen gas. In addition to nitrogen gas, an inert gas such as argon gas may also be used. After that, the molding apparatus is heated to the thermoforming temperature. After heating, the pressure inside the molding apparatus is reduced by an external vacuum pump through the through hole 91 of the second mold 90. Since there is a gap 92 between the first mold 80 and the second mold 90, the glass 50 is vacuumed through this gap 92 during the reduction of pressure. The gap 92 can be formed, for example, by irregularities or grooves provided on at least one of the surfaces of the second mold 90 that are in contact with the first mold 80 and the surface of the first mold 80 that are in contact with the second mold 90. As a result, the first main surface 52 adheres closely to the transfer irregularity structure 81, and the transfer irregularity structure 81 is transferred to at least a part of the first main surface 52 of the glass 50. Next, the molding apparatus is slowly cooled, the transfer mold 100 is lowered and retracted, and the glass is allowed to cool to room temperature to obtain glass 50 with an uneven structure formed on the first main surface 52.

[0112] Examples of transfer material types include quartz, carbon, stainless steel, alumina, and zirconia. Among these, from the viewpoint of creating a glass surface shape with excellent wear resistance, it is preferable that at least the portion of the transfer type having a transfer-oriented uneven structure be made of quartz or carbon, and more preferably quartz.

[0113] In the above transfer type, the arithmetic mean roughness Sa in the transfer surface structure is preferably 0.5 to 3.0 μm. From the viewpoint of controlling the surface structure of the resulting glass and obtaining glass with excellent wear resistance, the arithmetic mean roughness Sa is preferably 0.5 μm or more, more preferably 0.7 μm or more, even more preferably 0.8 μm or more, particularly preferably 0.9 μm or more, and also preferably 3.0 μm or less, more preferably 2.6 μm or less, even more preferably 2.2 μm or less, and particularly preferably 1.8 μm or less.

[0114] The method for forming the above-mentioned transfer-oriented uneven structure is not particularly limited, and known methods such as sandblasting, hydrofluoric acid etching, machining, and laser processing can be used.

[0115] A functional film, such as a release film, may be provided on the surface of the above-mentioned transfer mold. If the functional film is a release film, examples of its materials include DLC, BN, Ni, Cr, CrN, Ti, Al, C, etc. If the functional film is provided so as to cover at least a part of the transfer surface irregularities on the surface of the transfer mold, the functional film will be formed to conform to the irregularities, and therefore the transfer surface irregularities and the irregularities on the outermost surface on which the functional film is provided will be substantially the same.

[0116] In the heat molding method, the attainable viscosity of the glass is preferably 7.0 to 13.5 dPa·s. From the viewpoint of transfer characteristics to the glass surface, the attainable viscosity is preferably 13.5 dPa·s or less, more preferably 13.0 dPa·s or less, even more preferably 12.5 dPa·s or less, and particularly preferably 12.0 dPa·s or less. Furthermore, from the viewpoint of preventing adhesion between the glass and the transfer mold, the attainable viscosity is preferably 7.0 dPa·s or more, more preferably 7.5 dPa·s or more, even more preferably 8.0 dPa·s or more, and particularly preferably 8.5 dPa·s or more.

[0117] The target pressure during the above-mentioned depressurization is preferably -100 to -40 kPa. From the viewpoint of preventing damage to the transfer type, the target pressure is preferably -100 kPa or higher, more preferably -95 kPa or higher, even more preferably -90 kPa or higher, and particularly preferably -85 kPa or higher. Furthermore, from the viewpoint of transfer characteristics to the glass surface, the target pressure is preferably -40 kPa or lower, more preferably -45 kPa or lower, even more preferably -50 kPa or lower, and particularly preferably -55 kPa or lower.

[0118] By employing the heat molding method described above, it is possible to suitably obtain a glass with excellent wear resistance that satisfies at least one of the following conditions at the outermost surface of the region having an uneven structure: visibility index value T of 0.85 or higher and mean dynamic friction coefficient COF of 0.70 or higher; kurtosis Sk of 5.0 or lower and area ratio Smr1 of protruding peaks of 7.5% or higher; and Sk / Sz of 0.25 or higher. Furthermore, since the above heat molding method does not use harmful chemicals (e.g., hydrofluoric acid, hydrochloric acid, sulfuric acid, nitric acid, sodium hydroxide, potassium hydroxide, ethyl acetate, etc.), it is excellent in terms of reducing environmental impact.

[0119] • Frost Method: When forming an uneven structure using the frost method, the following steps are generally performed in order: pre-washing, washing, chemical immersion, and washing. Conventionally known methods can be used for each of these steps.

[0120] • Wet blasting method: When forming an uneven structure using the wet blasting method, generally, wet blasting is performed on glass, preferably polished glass, followed by processes such as cleaning, etching, and cleaning. Conventional known methods can be used for each of these processes.

[0121] <Process (iii): Strengthening process> When performing process (iii) to strengthen the glass, process (iii) may be performed between process (i) and process (ii) above, but it is preferable to perform it after process (ii).

[0122] By applying a strengthening treatment to at least one of the first main surface and the second main surface of the glass, a compressive stress layer is formed on the surface, thereby increasing its strength and scratch resistance.

[0123] Both physical and chemical strengthening treatments are applicable, but chemical strengthening is preferred because it allows for the introduction of greater compressive stress even in thin glass.

[0124] Chemical strengthening involves immersing glass in molten alkali metal salt at a temperature below the glass transition temperature, thereby replacing alkali metal ions with smaller ionic radii on the glass surface with alkali metal ions with larger ionic radii. Specifically, Li ions on the glass surface are exchanged for Na ions, or Na ions on the glass surface are exchanged for K ions. This allows for the formation of a compressive stress layer on the glass surface.

[0125] The molten salts and treatment conditions used in the chemical strengthening process can be those that are already known.

[0126] <Process (iv): Process for forming a functional layer> In process (iv), a functional layer is optionally formed on glass with an uneven surface structure, or on glass with an uneven surface structure that has been further chemically strengthened, to create glass with a functional layer.

[0127] When forming a functional layer, it is sufficient to form it on at least one of the first main surface and the second main surface, depending on the type of functional layer. For example, when forming an anti-reflective film or an anti-fouling film as a functional layer, it is sufficient to form it so as to cover at least a part of the uneven structure of the first main surface, and it is preferable to form it so as to cover the area of ​​the glass that the user touches. For example, when forming both an anti-reflective film and an anti-fouling film as a functional layer, it is preferable to further form the anti-fouling film on top of the anti-reflective film.

[0128] Anti-reflective coatings can be formed by conventionally known methods. For example, an anti-reflective coating can be obtained by sequentially forming and laminating dielectric layers on the surface of a first main surface of glass using known film formation methods such as sputtering, vacuum deposition, coating, chemical vapor deposition (CVD), and physical vapor deposition (PVD) methods such as PLD. An anti-reflective coating may also be formed on the surface of a second main surface of glass.

[0129] Antifouling films can also be formed by conventionally known methods. For example, a silane coupling agent composition having a fluoroalkyl group, such as a perfluoroalkyl group containing a perfluoro(polyoxyalkylene) chain, can be applied by a spin coating method, dip coating method, casting method, slit coating method, spray coating method, etc., followed by heat treatment as necessary. Alternatively, a vacuum deposition method can be used in which a fluorine-containing organosilicon compound is vapor-deposited onto the surface of the adhesion layer, followed by heat treatment as necessary.

[0130] As described above, the following configuration is disclosed in this specification. [1] Glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure at least in part, and the visibility index value T at the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or more, and the average coefficient of kinetic friction COF is 0.70 or more. The visibility index value T and the average coefficient of kinetic friction COF are quantified by the methods shown below, respectively. Visibility index value T: Using SMS-1000 manufactured by DMS&S Co., Ltd., place the glass at a position 30 mm above a slit-shaped white light source with a length of 40 mm and a width of 0.1 mm so that the first main surface side is the light source side. Measure the luminance at the outermost surface of the region having the uneven structure from the second main surface side of the glass. The camera lens uses a lens with a focal length of 16 mm and a diaphragm of 5.6, and the distance from the outermost surface on the first main surface side of the glass to the camera lens is set to 550 mm. Set the direction parallel to the thickness direction of the glass as the angle θ = 0°, and take the average value of the luminance in the range of the angle θ = 0° ± 0.1° as T １ and take the average value of the luminance in the range of the angle θ = 0.7° ± 0.1° as T ２ and take the average value of the luminance in the range of the angle θ = -0.7° ± 0.1° as T ３ When this is done, the value calculated by the following formula (1) is taken as the visibility index value T. Visibility index value T = 1 - (T ２ + T ３ ) / (2 × T １) Equation (1) Average dynamic friction coefficient COF: The dynamic friction coefficient is measured in a static friction measuring machine in an environment of 25°C and 70% humidity by sliding a simulated finger on the outermost surface of the region having the uneven structure on the first main surface side of the glass at a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency is 10 kHz. The simulated finger is made of urethane, and the contact portion with the outermost surface has linear protrusions formed at 0.5 mm intervals within an area of ​​10 mm × 15 mm, perpendicular to the sliding direction. Here, counting back from the time when the coefficient of dynamic friction is at its maximum, the time at which the relative speed between the glass and the simulated finger first becomes 0 mm / second or less is defined as the start time of movement, and the time at which the relative speed between the glass and the simulated finger first becomes 5 mm / second or less after the time represented by {(start time of movement) + (0.75 × scanning distance / scanning speed)} is defined as the end time of movement, the value calculated by the following formula (2) is defined as the average coefficient of dynamic friction COF. Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time of movement and the end time of movement) ± 0.1 seconds Formula (2) [2] Glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a part thereof, the kurtosis Sku at the outermost surface of the region having the uneven structure on the first main surface side is 5.0 or less, and the area ratio Smr1 of the protruding peaks is 7.5% or more. [3] Glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a part thereof, and the Sk / Sz calculated from the level difference Sk (μm) of the core portion and the maximum height Sz (μm) of the uneven structure at the outermost surface of the region having the uneven structure on the first main surface side is 0.25 or more. [4] Glass according to [2] or [3], wherein the visibility index value T at the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or more, the average coefficient of dynamic friction COF is 0.70 or more, and the visibility index value T and the average coefficient of dynamic friction COF are quantified by the method shown below, respectively.Visibility index value T: Using an SMS-1000 manufactured by DMS&S Co., place the glass 30 mm above a slit-shaped white light source with a length of 40 mm and a width of 0.1 mm such that the first main surface side faces the light source side, and measure the luminance on the outermost surface of the region having the concavo-convex structure from the second main surface side of the glass. The camera lens uses a lens with a focal length of 16 mm at an aperture of 5.6, and the distance from the outermost surface on the first main surface side of the glass to the camera lens is set to 550 mm. Set the direction parallel to the thickness direction of the glass as the angle θ = 0°, and take the average value of the luminance in the range of the angle θ = 0° ± 0.1° as T. １ and take the average value of the luminance in the range of the angle θ = 0.7° ± 0.1° as T ２ and take the average value of the luminance in the range of the angle θ = -0.7° ± 0.1° as T ３ When this is done, the value calculated by the following formula (1) is taken as the visibility index value T. Visibility index value T = 1 - (T ２ + T ３ ) / (2 × T １) Equation (1) Average dynamic friction coefficient COF: The dynamic friction coefficient is measured in a static friction measuring machine in an environment of 25°C and 70% humidity by sliding a simulated finger on the outermost surface of the region having the uneven structure on the first main surface side of the glass at a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency is 10 kHz. The simulated finger is made of urethane, and the contact portion with the outermost surface has linear protrusions formed at 0.5 mm intervals within an area of ​​10 mm × 15 mm, perpendicular to the sliding direction. Here, counting back from the time when the coefficient of dynamic friction is at its maximum, the time at which the relative speed between the glass and the simulated finger first becomes 0 mm / second or less is defined as the start time of movement, and the time at which the relative speed between the glass and the simulated finger first becomes 5 mm / second or less after the time represented by {(start time of movement) + (0.75 × scanning distance / scanning speed)} is defined as the end time of movement, the value calculated by the following formula (2) is defined as the average coefficient of dynamic friction COF. Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time of movement and the end time of movement) ± 0.1 seconds Formula (2) [5] The glass according to [1] or [3], wherein the kurtosis Sku at the outermost surface of the region having the uneven structure on the first main surface side is 5.0 or less, and the area ratio Smr1 of the protruding peaks is 7.5% or more. [6] The glass according to [1] or [2], wherein the Sk / Sz calculated from the level difference Sk (μm) of the core portion and the maximum height Sz (μm) of the uneven structure at the outermost surface of the region having the uneven structure on the first main surface side is 0.25 or more. [7] The glass according to any one of [1] to [6], wherein the glass is a bendable glass. [8] A method for manufacturing glass according to any one of [1] to [7], comprising preparing a glass having a first main surface and a second main surface facing the first main surface, and forming an uneven structure on at least a part of the first main surface. [9] The method for manufacturing glass according to [8], wherein the formation of the uneven structure is comprising placing the glass on a transfer mold having a transfer uneven structure on at least a part of its surface such that the first main surface is in contact with the transfer uneven structure, heating the glass to a thermoforming temperature, and transferring the transfer uneven structure to the first main surface.

[10] The method for manufacturing glass according to [9], wherein the transfer is performed by sealing the glass and the transfer mold inside the apparatus and reducing the pressure inside the apparatus at the thermoforming temperature to bring the first main surface into close contact with the transfer surface.

[11] A method for selecting glass according to any one of [1] to [7].

[12] The glass according to [1] or [4], wherein the visibility index value T is 0.86 to 1.0 and the mean dynamic friction coefficient COF is 0.70 to 1.80.

[13] The glass according to [2] or [5], wherein the kurtosis Sk is 1.0 to 3.5 and the area ratio Smr1 of the protruding peaks is 8.0% to 25.0%.

[14] The glass according to [3] or [6], wherein the Sk / Sz is 0.28 to 0.65.

[0131] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following description. Examples 1 to 3 are examples, and Example 4 is a comparative example.

[0132] 《Evaluation Method》 The following evaluations and measurements were performed for each example. For each physical property, measurements were taken at three arbitrary points on the glass, and the average value was used.

[0133] <Visibility Index Value T> A piece of glass was placed 30 mm away from a slit-shaped white light source measuring 40 mm in length and 0.1 mm in width, with the first main surface facing the light source. Then, using an SMS-1000 (analytical device) manufactured by DM&S (Display-Mestechnik & System), the light transmitted through the glass and the angle θ were detected from the second main surface side of the glass, and the brightness at the outermost surface of each region with an uneven structure was measured.

[0134] A Ricoh C1614A lens with a focal length of 16mm was used as the camera lens, set to an aperture of f / 5.6. The distance from the outermost surface of the first main surface of the glass to the camera lens was set to 550mm.

[0135] When the angle θ = 0° is defined as the direction parallel to the thickness of the glass, the average value of the brightness in the range of angle θ = 0° ± 0.1° is T. １ Let T be the average value of the brightness in the range of angle θ = 0.7° ± 0.1°. ２Let T be the average value of the brightness in the range of angle θ = -0.7° ± 0.1°. ３ In this case, the value calculated by the following formula (1) was defined as the visibility index value T. Visibility index value T = 1 - (T ２ +T ３ ) / (2×T １ ) Formula (1)

[0136] <Average Dynamic Friction Coefficient (COF)> The dynamic friction coefficient was measured using a static-dynamic friction measuring instrument (Trinity Labs, multi-functional static-dynamic friction measuring instrument TL201) in an environment of 25°C and 70% humidity. A simulated finger was slid across the outermost surface of a region with an uneven structure on the first main surface side of glass at a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency was 10 kHz, and the number of samples taken was 5.

[0137] The artificial finger was made of urethane (manufactured by Trinity Labs, urethane artificial finger), and the contact area with the outermost surface of the glass had linear protrusions formed at 0.5 mm intervals within a 10 mm x 15 mm area, perpendicular to the sliding direction.

[0138] Here, working backward from the time when the coefficient of dynamic friction is maximum, the start time is defined as the time when the relative velocity between the glass and the simulated finger first falls below 0 mm / second. The end time is defined as the time after the time expressed as {(start time) + (0.75 × scanning distance / scanning speed)} when the relative velocity between the glass and the simulated finger first falls below 5 mm / second. The value calculated by the following equation (2) is defined as the average coefficient of dynamic friction COF. Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time and the end time) ± 0.1 seconds Equation (2)

[0139] <Surface Roughness> On the outermost surface of the region of the glass having an uneven surface structure, the surface roughness indices, kurtosis Sku, area ratio Smr1 of the protruding peaks, level difference Sk of the core, and maximum height Sz of the uneven surface structure were measured using a laser microscope equipped with a white light interferometer (VK-X3000, manufactured by Keyence Corporation). The number of acquired data points was 1024 × 768 pixels, and the measurement area was 1449 μm × 1086 μm.

[0140] <Abrasion resistance: Water droplet contact angle> The following tests were conducted to evaluate the abrasion resistance of the glass.

[0141] Approximately 2 μL of distilled water was dropped onto the glass surface, and the water droplet contact angle was measured using a contact angle meter (DM-701, Kyowa Interface Science Co., Ltd.). After measurement, the distilled water on the glass surface was wiped off. Next, a flannel cloth conforming to JIS L0803:2011 was placed on the glass with a load of 500 g and slid back and forth 1500 times at a speed of 40 back-and-forth cycles per minute in an environment of 24°C and 44% humidity. Subsequently, the water droplet contact angle was measured in the same manner as above for the abraded portion of the glass surface. The water droplet contact angle was measured at three different locations on the glass surface, and the average value was calculated. The abrasion resistance was evaluated from the absolute value of the difference in water droplet contact angle before and after sliding the flannel cloth according to the following criteria: 25° or less: A (Good) 25° or more: B (Poor)

[0142] <Test Examples> <Example 1> A first type consisting of a quartz transfer member having a transfer-oriented uneven structure on its surface and a carbon inset mold, and a second type (concave type) made of carbon having through holes were prepared. The arithmetic mean roughness Sa of the region of the transfer member having the transfer-oriented uneven structure was 1.22 μm, determined by the following method.

[0143] Using a laser microscope equipped with a white light interferometer (VK-X3000, manufactured by Keyence Corporation), the surface of the transfer material was measured in laser confocal mode with a standard 10x objective lens. The arithmetic mean roughness Sa within the measurement range (1060 μm × 1413 μm) was measured at five random locations on the surface of the transfer material, and the average value was calculated.

[0144] The above transfer member was fitted inside the above-mentioned insert mold to form the first mold, and then the first mold was placed in the central position of the second mold to form the transfer mold.

[0145] The edges of a 80 mm x 80 mm, 1.0 mm thick soda-lime glass were chamfered. This glass was placed near the center of the area of ​​the transfer member having a transfer-oriented uneven structure. With the glass placed on the transfer mold, the second mold was fixed to the lower shaft of a molding machine (manufactured by Shibaura Machine (formerly Toshiba Machine) Co., Ltd., glass element molding machine: GMP-315V). The through hole in the center of the second mold was connected to an external vacuum pump.

[0146] Nitrogen gas was injected at a rate of 10 L / min through a through-hole located at the top of the molding apparatus to fill the inside of the apparatus with nitrogen gas. Then, heating of the molding apparatus was started. The temperature was raised from a starting temperature of 25°C to a thermoforming temperature of 700°C in 20 minutes. Heating was stopped when the second mold reached the thermoforming temperature. The heating rate was controlled to be within a range of 0.5°C / min or less. The viscosity of the glass reached at the thermoforming temperature was 8.4 dPa·s.

[0147] Next, depressurization was initiated using an external vacuum pump through the second type of through-hole. Depressurization was terminated 120 seconds after the pressure inside the molding apparatus reached the set value (-70 kPa).

[0148] The molding apparatus was slowly cooled to 100°C over 30 minutes. Next, the transfer mold was lowered and retracted, and the thermoformed glass was allowed to cool to room temperature to obtain the glass of Example 1.

[0149] <Example 2> The glass of Example 2 was obtained in the same manner as in Example 1, except that a transfer member with an arithmetic mean roughness Sa of 1.59 μm was used and aluminosilicate glass was used as the glass. The viscosity of the glass at the thermoforming temperature was 8.3 dPa·s.

[0150] <Example 3> The glass of Example 3 was obtained in the same manner as in Example 1, except that aluminosilicate glass was used as the glass. The viscosity of the glass at the thermoforming temperature was 8.3 dPa·s.

[0151] <Example 4> A piece of glass measuring 100 mm x 100 mm and 0.55 mm thick (manufactured by AGC Inc., product name: DragonTrail®) was prepared. The glass of Example 4 was produced by applying wet blasting and wet etching treatments to the first main surface of the glass in the following order.

[0152] In the wet blasting process, a slurry containing 12% by volume of ceramic particles was used. The slurry injection pressure (gas pressure) was 0.3 MPa, the projection distance (distance between nozzle and glass WD) was 30 mm, the nozzle scanning speed was 400 mm / sec, and the number of nozzle scans was 2. The slurry was injected together with compressed air. Gas pressure refers to the pressure of the compressed air.

[0153] In the subsequent wet etching process, the first main surface of the glass was etched to a thickness of 90 μm using an etching solution containing hydrogen fluoride.

[0154] The evaluation results for each glass obtained are shown in Table 1.

[0155]

[0156] Based on the results above, the glass in Examples 1 to 3 exhibited excellent abrasion resistance because the average coefficient of dynamic friction COF, kurtosis Sk, and the area ratio of the protruding peaks Smr1 or Sk / Sz were within an appropriate range. Furthermore, the visibility index value T for each glass was 0.85 or higher, indicating excellent visibility.

[0157] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications are possible without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2024-170919, filed on 30 September 2024, which is incorporated herein by reference in its entirety.

[0158] Because the glass according to the present invention has excellent abrasion resistance, it can be suitably used in applications that involve contact, such as touch panels.

[0159] 50 Glass 52 First main surface 53 Second main surface 70A Measuring device 71 Light source 75 Detector (analysis device) 80 Type 1 81 Transfer surface structure 90 Type 2 91 Through hole 92 Void 100 Transfer type

Claims

1. A glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a portion thereof, the visibility index value T at the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or higher, and the average coefficient of dynamic friction COF is 0.70 or higher, and the visibility index value T and the average coefficient of dynamic friction COF are quantified by the methods shown below. Visibility index value T: Using a DM&S SMS-1000, the glass is placed 30 mm away from a slit-shaped white light source with a length of 40 mm and a width of 0.1 mm, with the first main surface side facing the light source, and the brightness at the outermost surface of the region having the uneven structure is measured from the second main surface side of the glass. A camera lens with a focal length of 16 mm is used with an aperture of 5.6, and the distance from the outermost surface of the first main surface side of the glass to the camera lens is set to 550 mm. The angle θ = 0° is defined as the direction parallel to the thickness direction of the glass, and the average value of the brightness in the range of angle θ = 0° ± 0.1° is T １ Let T be the average value of the brightness in the range of angle θ = 0.7° ± 0.1°. ２ Let T be the average value of the brightness in the range of angle θ = -0.7° ± 0.1°. ３ In this case, the value calculated by the following formula (1) shall be defined as the visibility index value T. Visibility index value T = 1 - (T ２ +T ３ ) / (2×T １ ) Equation (1) Average dynamic friction coefficient COF: The dynamic friction coefficient is measured in a static friction measuring machine in an environment of 25°C and 70% humidity by sliding a simulated finger on the outermost surface of the region having the uneven structure on the first main surface side of the glass at a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency is 10 kHz. The simulated finger is made of urethane, and the contact portion with the outermost surface has linear protrusions formed at 0.5 mm intervals within an area of ​​10 mm × 15 mm, perpendicular to the sliding direction. Here, counting back from the time when the coefficient of dynamic friction is maximum, the start time is defined as the time when the relative velocity between the glass and the simulated finger first becomes 0 mm / second or less, and the end time is defined as the time when, after the time represented by {(start time) + (0.75 × scanning distance / scanning speed)}, the relative velocity between the glass and the simulated finger first becomes 5 mm / second or less. The average coefficient of dynamic friction COF is calculated by the following formula (2). Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time and the end time) ± 0.1 seconds. Formula (2) 2. Glass having a first main surface and a second main surface opposite to the first main surface, wherein the first main surface has an uneven structure in at least a portion thereof, the kurtosis Sku at the outermost surface of the region having the uneven structure on the first main surface side is 5.0 or less, and the area ratio Smr1 of the protruding peaks is 7.5% or more.

3. Glass having a first main surface and a second main surface facing the first main surface, wherein the first main surface has an uneven structure in at least a portion thereof, and the Sk / Sz ratio calculated from the level difference Sk (μm) of the core portion and the maximum height Sz (μm) of the uneven structure at the outermost surface of the region having the uneven structure on the first main surface side is 0.25 or greater.

4. The glass according to claim 2 or 3, wherein the visibility index value T at the outermost surface of the region having the uneven structure on the first main surface side is 0.85 or greater, the average coefficient of dynamic friction COF is 0.70 or greater, and the visibility index value T and the average coefficient of dynamic friction COF are quantified by the methods shown below. Visibility index value T: Using the SMS-1000 manufactured by DM&S, place the glass at a position 30 mm above a slit-shaped white light source with a length of 40 mm and a width of 0.1 mm such that the first main surface side faces the light source side, and measure the luminance on the outermost surface of the region having the concavo-convex structure from the second main surface side of the glass. The camera lens uses a lens with a focal length of 16 mm with an aperture of 5.6, and the distance from the outermost surface on the first main surface side of the glass to the camera lens is set to 550 mm. Set the direction parallel to the thickness direction of the glass as the angle θ = 0°, and the average value of the luminance in the range of the angle θ = 0° ± 0.1° is defined as T １ and the average value of the luminance in the range of the angle θ = 0.7° ± 0.1° is defined as T ２ and the average value of the luminance in the range of the angle θ = -0.7° ± 0.1° is defined as T ３ When this is done, the value calculated by the following formula (1) is defined as the visibility index value T. Visibility index value T = 1 - (T ２ + T ３ ) / (2 × T １ ) Formula (1) Average coefficient of kinetic friction COF: In a static and kinetic friction measuring machine, in an environment with a temperature of 25°C and a humidity of 70%, on the outermost surface of the region having the concavo-convex structure on the first main surface side of the glass, the coefficient of kinetic friction is measured by sliding a pseudo finger with a scanning distance of 30 mm, a load of 100 g, and a scanning speed of 30 mm / second. The data acquisition frequency is set to 10 kHz The aforementioned artificial finger is made of urethane, and the contact portion with the outermost surface has linear protrusions formed at 0.5 mm intervals within an area of ​​10 mm × 15 mm, perpendicular to the sliding direction. Here, counting back from the time when the coefficient of dynamic friction is maximum, the time when the relative speed between the glass and the artificial finger first becomes 0 mm / second or less is defined as the start time of movement, and the time when the relative speed between the glass and the artificial finger first becomes 5 mm / second or less after the time represented by {(start time of movement) + (0.75 × scanning distance / scanning speed)} is defined as the end time of movement, the value calculated by the following formula (2) is defined as the average coefficient of dynamic friction COF. Average coefficient of dynamic friction COF = (average value of the coefficient of dynamic friction at the midpoint between the start time of movement and the end time of movement) ± 0.1 seconds Formula (2) 5. The glass according to claim 1 or 3, wherein the kurtosis Sku at the outermost surface of the region having the uneven structure on the first main surface side is 5.0 or less, and the area ratio Smr1 of the protruding peaks is 7.5% or more.

6. The glass according to claim 1 or 2, wherein the Sk / Sz, calculated from the level difference Sk (μm) of the core portion and the maximum height Sz (μm) of the uneven structure at the outermost surface of the region having the uneven structure on the first main surface side, is 0.25 or greater.

7. The glass according to any one of claims 1 to 3, wherein the glass is curved glass.

8. A method for manufacturing glass according to any one of claims 1 to 3, comprising: preparing glass having a first main surface and a second main surface facing the first main surface; and forming an uneven structure on at least a portion of the first main surface.

9. The method for manufacturing glass according to claim 8, wherein the formation of the uneven structure includes placing the glass on a transfer mold having a transfer uneven structure on at least a portion of its surface such that the first main surface is in contact with the transfer uneven structure, heating the glass to a thermoforming temperature, and transferring the transfer uneven structure to the first main surface.

10. The method for manufacturing glass according to claim 9, wherein the transfer includes sealing the glass and the transfer mold inside the apparatus and reducing the pressure inside the apparatus at the thermoforming temperature to bring the first main surface into close contact with the transfer surface.

11. A method for selecting the glass according to any one of claims 1 to 3.

12. The glass according to claim 1, wherein the visibility index value T is 0.86 to 1.0, and the mean kinetic friction coefficient COF is 0.70 to 1.

80.

13. The glass according to claim 2, wherein the kurtosis Sku is 1.0 to 3.5, and the area ratio Smr1 of the protruding peaks is 8.0% to 25.0%.

14. The glass according to claim 3, wherein the Sk / Sz is 0.28 to 0.65.

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