Strengthened glass article

Abstract

A tempered glass article comprises a tempered glass substrate having a first main surface, a second main surface, and an end face orthogonal to the first and second main surfaces, and having undergone chemical strengthening treatment, and a protective layer disposed on the end face. The protective layer has a bottom edge extending from a first end face on the side of the first main surface to a second end face on the side of the second main surface along the end face in a cross-sectional view orthogonal to the first main surface, and an arc portion connecting the first end face and the second end face, satisfying the following formulas (1) to (3). C1 / C2≥1.1···(1) C1: potassium concentration at the first end face or the second end face C2: potassium concentration at the center of the tempered glass substrate in the thickness direction in the end face 0.18≤H / L≤1.21···(2) H: length from the vertex of the arc portion to the end face L: length of the bottom edge 40°≤θ1≤135°···(3) θ1: first contact angle at the first end face in the arc portion.

Description

Technical Field

[0001] This invention relates to a reinforced glass article. Background Technology

[0002] For example, in fields such as cover glass for electronic devices, high strength is sometimes required for the glass articles used. As a configuration that can be used in such cases, Patent Document 1 discloses a reinforced glass article that has undergone chemical strengthening treatment.

[0003] In addition, Patent Document 2 discloses a tempered glass article in which a protective layer is provided on the end face of a tempered glass substrate with a chamfered outer periphery.

[0004] Prior technology documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2017 / 038853

[0007] Patent Document 2: International Publication No. 2013 / 154034 Summary of the Invention

[0008] However, when the tempered glass articles described in Patent Documents 1 and 2 are used as cover glass, when an object collides with the end of the tempered glass article, the collision area may be damaged.

[0009] The purpose of this invention is to provide a reinforced glass article with improved end strength.

[0010] One aspect of the present invention comprises a tempered glass article comprising: a tempered glass substrate subjected to chemical strengthening treatment, having a first main surface as a visual identification surface, a second main surface opposite to the first main surface, and an end surface orthogonal to the first main surface and the second main surface; and a protective layer disposed on the end surface; wherein the protective layer, in a cross-sectional view orthogonal to the first main surface, has: a bottom edge portion extending along the end surface from a first end portion on the side of the first main surface to a second end portion on the side of the second main surface, and an arc portion connecting the first end portion and the second end portion, satisfying the following formulas (1), (2) and (3).

[0011] C1 / C2≥1.1 ··· (1)

[0012] C1: The potassium concentration at the first end or the second end of the aforementioned end face.

[0013] C2: Potassium concentration at the center of the reinforced glass substrate in the thickness direction on the aforementioned end face.

[0014] 0.18≤H / L≤1.21 ··· (2)

[0015] H: The length from the vertex of the aforementioned arc portion to the aforementioned end face.

[0016] L: Length of the aforementioned bottom edge

[0017] 40°≤θ1≤135° ··· (3)

[0018] θ1: The first contact angle on the first end side of the aforementioned arc portion.

[0019] According to the present invention, it is possible to provide a reinforced glass article with improved end strength. Attached Figure Description

[0020] Figure 1 These are top views of the tempered glass articles according to embodiments 1 to 4.

[0021] Figure 2 It is along Figure 1 A cross-sectional view of a reinforced glass article according to the first embodiment of the A-A line.

[0022] Figure 3 These are explanatory diagrams illustrating the manufacturing methods of the tempered glass articles according to embodiments 1 to 4.

[0023] Figure 4 It is along Figure 1 A cross-sectional view of a reinforced glass article according to the second embodiment of the A-A line.

[0024] Figure 5 It is along Figure 1 A cross-sectional view of a reinforced glass article according to the third embodiment of the A-A line.

[0025] Figure 6 It is along Figure 1 A cross-sectional view of a reinforced glass article according to the fourth embodiment of the A-A line.

[0026] Figure 7 This is a side view of the impact testing machine in the embodiment.

[0027] Figure 8 This is a top view of the impact testing machine in the embodiment.

[0028] Figure 9 This is a side view of the sharpness evaluation testing machine.

[0029] Figure 10 This is a frontal view of the sharpness evaluation testing machine.

[0030] Figure 11 This is a schematic diagram showing the positional relationship between the light source and the detector in the appearance evaluation test. Detailed Implementation

[0031] [First Embodiment]

[0032] The first embodiment of the present invention will now be described. It should be noted that, for ease of understanding of the present invention, the various configurations may be exaggerated in the figures described below.

[0033] <Composition of tempered glass items>

[0034] First, the composition of tempered glass items will be explained.

[0035] Figure 1 This is a top view of a tempered glass item. Figure 2 It is along Figure 1 A cross-sectional view of a reinforced glass item along line A-A.

[0036] Figure 1 The tempered glass article 1A shown includes: a tempered glass substrate 2, and a low-reflection film 3 and a protective layer 4A disposed on the tempered glass substrate 2.

[0037] The application of the tempered glass article 1A is not particularly limited, and examples include cover glass for vehicle-mounted or portable displays, and combinations of projected images in head-up displays. In this embodiment, as... Figure 2 As shown, the tempered glass article 1A is configured as a cover glass provided on the display surface 91 side of the display 9.

[0038] The reinforced glass substrate 2 is formed, for example, into a quadrilateral plate shape, having a first main surface 21, a second main surface 22 opposite to the first main surface 21, and an end surface 23 orthogonal to the first main surface 21 and the second main surface 22. Here, the end surface 23 being orthogonal to the first main surface 21 and the second main surface 22 means that the edge portion of the boundary between the end surface 23 and the first main surface 21 and the edge portion of the boundary between the end surface 23 and the second main surface 22 is not chamfered. This not only indicates the case where the angle formed by the end surface 23 and the first main surface 21 or the second main surface 22 is 90°, but also includes the case where the angle is within 90° ± 5°.

[0039] The second main surface 22 of the tempered glass article 1A, which includes the tempered glass substrate 2, is attached to the display surface 91. In this way, when the tempered glass article 1A is used, the first main surface 21 becomes the visual recognition surface for the user's visual perception. In addition, when there is no housing or the like of the display 9 at the position opposite to the end surface 23, the protective layer 4A is completely exposed.

[0040] The glass composition of the tempered glass substrate 2 is not particularly limited as long as it is a composition capable of chemical strengthening. For example, the tempered glass substrate 2 can be soda-lime glass, aluminosilicate glass, or alkali aluminosilicate glass.

[0041] The thickness of the tempered glass substrate 2 is not particularly limited, but for effective chemical strengthening, it is generally preferred to be 5 mm or less, and more preferably 3 mm or less. However, in the case of cover glass for automotive displays such as those used in car navigation systems, from a strength point of view, the thickness of the tempered glass substrate 2 is preferably 0.2 mm or more, more preferably 0.8 mm or more, and even more preferably 1 mm or more.

[0042] The arithmetic mean roughness Ra of the end face 23 is preferably 0.1 μm or more, more preferably 0.3 μm or more. Furthermore, the arithmetic mean roughness Ra of the end face 23 is preferably 2.0 μm or less, more preferably 1.0 μm or less. It should be noted that in this embodiment, the upper and lower limits can be appropriately combined.

[0043] The reinforced glass substrate 2 is manufactured using a chemical strengthening process with potassium nitrate molten salt.

[0044] Potassium ions are introduced into the entire end face 23 of the reinforced glass substrate 2 through a chemical strengthening process. The end face 23 is configured in a manner that satisfies the following formula (1).

[0045] C1 / C2≥1.1 ··· (1)

[0046] C1: Potassium concentration at the first end 231 on the first main surface 21 side or the second end 232 on the second main surface 22 side of end face 23.

[0047] C2: Potassium concentration at the center 233 of the reinforced glass substrate 2 in the thickness direction of the end face 23.

[0048] At all positions in the outer peripheral direction of the reinforced glass substrate 2 in the end face 23, the above equation (1) is satisfied.

[0049] The potassium concentrations represented by C1 and C2 in equation (1) do not include the potassium concentration contained in the matrix portion of the reinforced glass substrate 2 other than end face 23, i.e., the matrix concentration other than end face 23. The matrix concentration is almost the same as the arithmetic mean concentration of potassium ions relative to volume of the reinforced glass substrate 2 before chemical strengthening.

[0050] Potassium concentration can be calculated, for example, by the method described in Patent Document 1.

[0051] First, line scan analysis was performed on end face 23 using EDX (Energy Dispersive X-ray Spectrometry). Then, the concentration of potassium ions (atomic ratio) normalized to silicon ions was calculated as the potassium concentration expressed in terms of C1 and C2.

[0052] In end face 23, since ion exchange is more likely to occur at the first end face 231 or the second end face 232 than at the center portion 233 in the thickness direction, the C1 / C2 ratio in the above formula (1) is 1.1 or more, preferably 1.2 or more, more preferably 1.3 or more, and even more preferably 1.4 or more. It should be noted that in this embodiment, the upper limit and lower limit values ​​of C1 / C2 in the above formula (1) can be appropriately combined.

[0053] The potassium concentration C1 is preferably 0.25 or more, more preferably 0.27 or more, and even more preferably 0.29 or more. The potassium concentration C1 is preferably 0.40 or less, more preferably 0.35 or less, and even more preferably 0.32 or less. The potassium concentration C2 is preferably 0.15 or more, more preferably 0.17 or more, and even more preferably 0.19 or more. The potassium concentration C2 is preferably 0.25 or less, more preferably 0.23 or less, and even more preferably 0.21 or less. It should be noted that in this embodiment, the upper and lower limits of the potassium concentrations C1 and C2 can be appropriately combined.

[0054] In the first embodiment and the second to fourth embodiments described below, the tempered glass substrate 2 is a flat plate. However, the tempered glass substrate 2 may also have a curved portion, which is formed by bending the tempered glass substrate 2 into a concave or convex shape when mounted on the display surface 91 side of the display 9. The radius of curvature of the curved portion is preferably 50 mm or more, more preferably 100 mm or more, and even more preferably 200 mm or more. The radius of curvature of the curved portion is, for example, 10000 mm or less, preferably 5000 mm or less, and more preferably 3000 mm or less. It should be noted that in this embodiment, the upper and lower values ​​of the radius of curvature of the curved portion can be appropriately combined. It should be noted that in this application, "curved" refers to a radius of curvature of 10000 mm or less; when the radius of curvature is greater than 10000 mm, it is considered a flat plate. In addition, the shape of the curved portion of the tempered glass substrate 2 can be a curved shape that bends only in a single direction, a curved shape that bends in two orthogonal directions, or a curved shape that bends in three or more directions.

[0055] In addition, in the first to fourth embodiments, the tempered glass substrate 2 has an end face 23 that is orthogonal to the first main surface 21 and the second main surface 22. In the case where the tempered glass substrate 2 has a curved portion near the end face 23, it means that the tangent of the first main surface 21 in the first end 231 is orthogonal to the end face 23.

[0056] A low-reflection film 3 is disposed on the first main surface 21, which serves as the visual recognition surface. In embodiments 1 to 4, the low-reflection film 3 is disposed on the portion of the first main surface 21 excluding the peripheral portion, or it may be disposed on the entire surface. The composition of the low-reflection film 3 is not particularly limited as long as it can suppress light reflection; for example, it may be a composition formed by stacking a high refractive index layer with a refractive index of 1.9 or higher at a wavelength of 550 nm and a low refractive index layer with a refractive index of 1.6 or lower at a wavelength of 550 nm. Alternatively, it may be a composition formed by only one low refractive index layer. The low-reflection film 3 may be a composition comprising one high refractive index layer and one low refractive index layer, or it may be a composition comprising two or more low refractive index layers. When it comprises two or more high refractive index layers and low refractive index layers, it is preferable to alternately stack high refractive index layers and low refractive index layers.

[0057] It should be noted that the low-reflection film 3 may not be provided. In addition, at least one of the following layers may be provided on the first main surface 21: an anti-reflection layer, an anti-glare layer, and an anti-fouling layer; or at least one of the following layers may be provided on the second main surface 22: a decorative layer and a light-shielding layer.

[0058] The protective layer 4A is formed by curing an ultraviolet-curable resin. It should be noted that the protective layer 4A can be formed from a light-curable resin or a thermosetting resin that cures under light of wavelengths other than ultraviolet light. For example, the protective layer 4A can be a cured product of a curable resin composition selected from one or more curable resin compositions chosen from olefinic thiol resins, silicone resins, epoxy resins, polyester resins, acrylic resins, and polyurethane resins. It should be noted that a two-component curable resin composition consisting of the protective layer and a curing agent can be used as the curable resin composition. By using a two-component curable resin composition, curing can be achieved at room temperature without ultraviolet irradiation or heating. Examples of two-component curable resin compositions include, for example, curable resin compositions of epoxy resin, polyester resin, polyurethane resin, or silicone resin. Furthermore, from the perspective of the aesthetics of the tempered glass article 1A, the refractive index of the protective layer 4A is preferably designed to have a difference of 0.2 or less from the refractive index of the tempered glass substrate 2.

[0059] Although protective layer 4A is as Figure 1 The protective layer 4A is configured to cover the entire end faces 23 corresponding to the four sides of the tempered glass substrate 2 in a top view, but it can also be configured to cover only a portion of the outer periphery of the end faces 23. For example, when the tempered glass article 1A is mounted on the display 9, a protective layer 4A can be provided on the end faces 23 facing upwards and to the left and right sides, but not on the end face 23 facing downwards. Figure 2As shown, the protective layer 4A has, in a cross-sectional view orthogonal to the first main surface 21, a bottom edge portion 41A extending along the end surface 23 from the first end portion 231 in the end surface 23 to the second end portion 232, and an arc portion 42A connecting the first end portion 231 and the second end portion 232.

[0060] The protective layer 4A is composed of a bottom edge portion 41A and an arc portion 42A as described above, and is provided in a manner to avoid its presence on the first main surface 21 and the second main surface 22.

[0061] The protective layer 4A is formed in a shape that satisfies the following formula (2).

[0062] 0.18≤H / L≤1.21 ··· (2)

[0063] H: The length from the vertex 421A of the arc portion 42A to the end face 23 (bottom edge 41A).

[0064] L: Length of the bottom edge 41A

[0065] Vertex 421A refers to the position furthest from the bottom edge 41A of the arc portion 42A in the planar direction of the first main surface 21. In addition, the length from vertex 421A to end face 23 refers to the shortest length along the planar direction of the first main surface 21. It should be noted that H in the above formula (2) is sometimes referred to as the "maximum height of the protective layer".

[0066] The H / L ratio in formula (2) is 0.18 or more, preferably 0.22 or more, more preferably 0.26 or more, and even more preferably 0.30 or more. Additionally, the H / L ratio in formula (2) is 1.21 or less, preferably 1.00 or less, more preferably 0.80 or less, and even more preferably 0.60 or less. It should be noted that in this embodiment, the upper and lower limits of the H / L ratio in formula (2) can be appropriately combined.

[0067] Furthermore, the maximum height H of the protective layer is preferably 50 μm or more, more preferably 60 μm or more, and most preferably 72 μm or more. Additionally, the maximum height H of the protective layer is preferably 1500 μm or less, more preferably 1000 μm or less, and most preferably 600 μm or less. It should be noted that in this embodiment, the upper and lower limits of the maximum height H of the protective layer can be appropriately combined.

[0068] Furthermore, to further improve the strength of the end of the tempered glass article 1A, the length L of the bottom edge 41A is preferably 500 μm or more, more preferably 700 μm or more, and most preferably 1100 μm or more. Additionally, from the viewpoint of reducing weight when mounting vehicle-mounted displays such as car navigation systems in a vehicle, the length L of the bottom edge 41A is preferably 3000 μm or less, more preferably 2000 μm or less, and most preferably 1300 μm or less. It should be noted that in this embodiment, the upper and lower values ​​of the length L of the bottom edge 41A can be appropriately combined.

[0069] The vertex 421A of the protective layer 4A is formed on a central virtual line C that passes through the thickness direction center portion 233 of the end face 23 and is parallel to the first main face 21, that is, it is located at the thickness direction center of the tempered glass substrate 2. Hereinafter, the thickness direction center of the tempered glass substrate 2 is sometimes referred to as the "substrate thickness direction center". In addition, the direction in which the central virtual line C extends is sometimes referred to as the "height direction of the protective layer". It should be noted that the vertex 421A being located at the substrate thickness direction center means including the case where the vertex 421A is strictly located at the substrate thickness direction center and the case where it is located closer to the first main face 21 or the second main face 22 side by a length that is only 1 μm or less different from the substrate thickness direction center.

[0070] The protective layer 4A is formed in a shape that satisfies the following formula (3).

[0071] 40°≤θ1≤135° ··· (3)

[0072] θ1: The first contact angle on the side of the first end portion 231 in the arc portion 42A

[0073] The first contact angle θ1 and the second contact angle θ2 on the second end 232 side of the arc portion 42A are angles calculated according to the θ / 2 method.

[0074] The first contact angle θ1 is calculated based on the assumption that the arc from the first end 231 to the vertex 421A is part of a circle. The second contact angle θ2 is calculated based on the assumption that the arc from the second end 232 to the vertex 421A is part of a circle.

[0075] In the first embodiment, since the vertex 421A is located at the center of the substrate thickness direction, the first contact angle θ1 and the second contact angle θ2 are the same angle.

[0076] From the viewpoint of suppressing the sharpness of the first end 231, the first contact angle θ1 is 40° or more. The first contact angle θ1 is preferably 45° or more, more preferably 65° or more, and most preferably 75° or more. Furthermore, from the viewpoint of improving the appearance of the tempered glass article 1A, the first contact angle θ1 is 135° or less, preferably 90° or less, more preferably 77° or less, and most preferably 75° or less. It should be noted that in this embodiment, the upper and lower limits of the first contact angle θ1 can be appropriately combined.

[0077] The protective layer 4A may contain at least one bubble B, or it may not contain any bubbles. Bubble B is usually elliptical in shape. The size of bubble B is preferably between 10 μm and 8000 μm in length of its maximum diameter.

[0078] The protective layer 4A is preferably constructed in a manner that satisfies the following conditions.

[0079] 0≤L * ≤95 (CIE1976L) * a * b * Chromaticity coordinates)

[0080] L * This refers to the brightness of reflected light in the CIE-Lab color system when the illumination light uses a standard D65 illuminant. * The value of spectral reflectance, measured based on JIS R3106, was calculated according to JIS Z 8781-4. In this specification, the L of the protective layer... * L refers to the light reflected from the outer periphery of a tempered glass article containing a protective layer, as measured by the method described in the embodiments. * .

[0081] The above L of protective layer 4A * Preferably, it is 0 or higher, more preferably 5 or higher, even more preferably 10 or higher, and preferably 95 or lower, more preferably 80 or lower, even more preferably 50 or lower, and most preferably 25 or lower. The L of the protective layer 4A * Within the aforementioned range, the aesthetics of the tempered glass article 1A are improved.

[0082] <Manufacturing Method of Tempered Glass Items>

[0083] Next, the manufacturing method of the tempered glass article 1A will be explained.

[0084] Figure 3 This is an illustration of the manufacturing process for tempered glass items.

[0085] like Figure 3As shown, the manufacturing method of the tempered glass article 1A according to the first embodiment includes: a raw material preparation process, a laser irradiation process, a chemical strengthening process, a low-reflection film formation process, a separation process, and a protective layer formation process.

[0086] The original board preparation process prepares an original board 10 that can yield at least one reinforced glass substrate 2.

[0087] The laser irradiation process forms multiple void regions 11 by irradiating a main surface of the original plate 10 with a laser from a direction orthogonal to that main surface. It should be noted that the main surface irradiated by the laser can be either the main surface corresponding to the first main surface 21 of the tempered glass substrate 2 or the main surface corresponding to the second main surface 22. The void regions 11 include in-plane void regions and internal void rows.

[0088] The in-plane void region is formed on one of the main surfaces of the original plate 10 that has been irradiated by the laser. The in-plane void region is a linear region composed of multiple voids arranged at predetermined intervals along one direction.

[0089] The internal void row is formed on another main surface side, which is closer to the in-plane void region. The internal void row is a linear region composed of multiple voids arranged at a predetermined interval along the thickness direction of the original plate 10 on the other main surface side of each void that constitutes the in-plane void region.

[0090] Figure 3 This indicates the formation of three gap regions 11 extending along the long side of the rectangular original plate 10 and four gap regions 11 extending along the short side.

[0091] The chemical strengthening process involves chemically strengthening the original plate 10, which has formed the void region 11, using potassium nitrate molten salt. The chemical strengthening process is carried out on the end face 23 of the strengthened glass substrate 2 obtained from the original plate 10, which satisfies the above formula (1).

[0092] It can be inferred that the reason for introducing potassium ions into the end face 23, which is not exposed in the original plate 10 state, is that the molten salt is introduced into the interior of the original plate 10 through the voids constituting the void region 11, and a displacement reaction occurs between the introduced molten salt and the part corresponding to the end face 23.

[0093] The low-reflection film formation process involves forming a low-reflection film 3 on the main surface of the original plate 10 corresponding to the first main surface 21 of the tempered glass substrate 2 using a known method.

[0094] The separation process involves breaking the original plate 10 along the gap region 11 to separate the tempered glass substrate 2. During the separation process, since each gap constituting the gap region 11 functions similarly to a perforation formed on the main surface and inside of the original plate 10, the tempered glass substrate 2 can be easily separated.

[0095] The method for separating the reinforced glass substrate 2 is not particularly limited, and the method described in Patent Document 1 can be used. Figure 9 or Figure 10 The method.

[0096] Figure 3 This indicates that six reinforced glass substrates 2 can be separated from the original plate 10.

[0097] The arithmetic mean roughness Ra of the end face 23 of the reinforced glass substrate 2 obtained in this way is 0.1 μm to 2.0 μm as described above.

[0098] The protective layer forming process involves forming a protective layer 4A on the end face 23 of the reinforced glass substrate 2.

[0099] There is no particular limitation on the method for forming the protective layer 4A on the end face 23. A method including the following UV-curable resin preparation process, coating preparation process, coating process, curing preparation process and curing process can be used.

[0100] The preparation process for UV-curable resins includes, for example, stirring the UV-curable resin to introduce air bubbles into it.

[0101] The coating preparation step involves fixing the tempered glass substrate 2 so that one end face 23 faces upward, for example, so that this end face 23 is orthogonal to the vertical direction. It should be noted that the coating preparation step can be performed before or after the UV-curable resin preparation step, or it can be performed simultaneously.

[0102] The coating process involves applying UV-curable resin to the entire end face 23 while moving the coating nozzle above the upward-facing end face 23, following the coating preparation process. At this time, the UV-curable resin is applied in a manner that prevents it from adhering to the first main surface 21 and the second main surface 22.

[0103] In addition, the above-mentioned coating preparation and coating processes are also performed on the remaining three end faces 23, and the ultraviolet-curable resin is applied with the end faces 23 of the object to be coated facing upwards.

[0104] It should be noted that, in addition to avoiding the presence of air bubbles in the UV-curable resin during the UV-curable resin preparation process, air-bounced UV-curable resin can also be coated by adjusting the coating state during the coating process.

[0105] In addition, the coating process can be performed only on the part where the protective layer 4A needs to be applied. For example, it can be performed on one to three end faces 23 as a whole, or only on a part of the outer periphery of one end face 23.

[0106] The curing preparation process involves rotating the reinforced glass substrate 2 after applying UV-curable resin to all end faces 23 that need to be coated, so that the end faces 23 are parallel to the vertical direction, i.e., the first main face 21 or the second main face 22 faces upward and the end faces 23 face to the side.

[0107] The curing process involves irradiating the UV-curable resin with ultraviolet light after the curing preparation process to form a protective layer 4A with the aforementioned properties.

[0108] In the method for forming the protective layer 4A as described above, during the coating process, the UV-curable resin has an arcuate portion connecting the first end 231 and the second end 232 due to surface tension, and the coating is performed with the apex of this arcuate portion located at the center in the thickness direction of the substrate. Then, in the curing preparation process, the end face 23 coated with the UV-curable resin faces to the side. When the end face 23 faces to the side, the uncured UV-curable resin may deform due to gravity, causing the apex of the arcuate portion to shift to a lower position than the center in the thickness direction of the substrate.

[0109] In the first embodiment, with the end face 23 coated with the UV-curable resin facing to the side, at least one of the viscosity of the UV-curable resin and the time from the curing preparation step to the curing step is adjusted to prevent the UV-curable resin from deforming due to gravity.

[0110] The protective layer 4A is formed by the above method of forming the protective layer 4A, wherein the vertex 421A is located at the center in the thickness direction of the substrate and contains a bubble B inside.

[0111] It should be noted that a protective layer forming process can also be performed to form a protective layer 4A that does not contain bubble B.

[0112] <Effects of the first embodiment>

[0113] The tempered glass article 1A comprises: a tempered glass substrate 2 having a first main surface 21, a second main surface 22 serving as visual identification surfaces, and an end surface 23 orthogonal to the first main surface 21 and the second main surface 22, and having undergone chemical strengthening treatment; and a protective layer 4A disposed on the end surface 23. The protective layer 4A has a bottom edge portion 41A and an arc portion 42A. The potassium concentration in the end surface 23 satisfies the above formula (1). The protective layer 4A satisfies the above formulas (2) and (3).

[0114] By providing a protective layer 4A with such a configuration on the end face 23, such as Figure 2As shown, when the tempered glass article 1A is mounted on the display 9, when the object P approaches the first end 231, the object P will collide with the protective layer 4A before colliding with the first end 231. The impact on the first end 231 is reduced by the collision between the protective layer 4A and the object P. In addition, since the potassium concentration distribution of the end face 23 satisfies the above formula (1), the strength of the portions on the first end 231 side and the second end 232 side is improved compared to the case where the potassium concentration of the end face 23 is constant in the thickness direction of the tempered glass substrate 2, which does not satisfy the above formula (1).

[0115] Therefore, even for tempered glass articles 1A where the edge portions of the boundary between the end face 23 and the first main face 21 and the second main face 22 are not chamfered and these edge portions have a shape that is easily damaged, the strength of its end can be improved.

[0116] Furthermore, when a protective layer 4A with the above-described configuration is provided on the end face 23, when a person's finger Q (not shown) approaches the end face 23, the finger Q will not contact the end face 23, but will contact the protective layer 4A. If the edges of the first main surface 21, the second main surface 22, and the end face 23 of the tempered glass article 1A are sharp, a person's finger Q may come into contact with the end face 23 of the tempered glass article 1A when handling it, potentially causing injury. However, by providing a protective layer 4A with the above-described configuration on the end face 23, the sharpness of the edges of the edges of the first main surface 21, the second main surface 22, and the end face 23 of the tempered glass article 1A can be reduced, thereby preventing injury to the person's finger Q.

[0117] like Figure 2 As shown, when the tempered glass article 1A is used in a manner where the entire first main surface 21 is visually discernible without being obscured by the casing of the display 9, as described in Patent Document 2, the aesthetics of the tempered glass article 1A deteriorate when there is an extension portion extending a portion of the protective layer to the outer periphery of the first main surface 21. Since the protective layer 4A of the tempered glass article 1A is provided to not exist on the first main surface 21 and the second main surface 22, the deterioration of the aesthetics of the tempered glass article 1A can be suppressed.

[0118] Protective layer 4A contains bubble B.

[0119] Therefore, when the same amount of UV-curable resin is used to form the protective layer 4A, the volume of the protective layer 4A can be increased compared to when air bubbles B are not present, resulting in greater impact absorption capacity. This further improves the end strength of the tempered glass article 1A.

[0120] [Second Embodiment]

[0121] Next, the second embodiment of the present invention will be described.

[0122] Figure 4 It is along Figure 1 A cross-sectional view of the tempered glass article along line A-A. It should be noted that for configurations identical to those in the first embodiment, the same names and symbols are used, and descriptions are simplified or omitted.

[0123] <Composition of tempered glass items>

[0124] Figure 1 and Figure 4 The tempered glass article 1B shown includes a tempered glass substrate 2, a low-reflection film 3, and a protective layer 4B. The protective layer 4B is identical in structure to the protective layer 4A except for its shape. The shape of the protective layer 4B will be described below.

[0125] The protective layer 4B has a bottom edge portion 41B extending along the end face 23 from a first end face 231 to a second end face 232, and an arcuate portion 42B connecting the first end face 231 and the second end face 232. The protective layer 4B is configured not to exist on the first main surface 21 and the second main surface 22.

[0126] The protective layer 4B is formed to satisfy the above formulas (2) and (3).

[0127] The protective layer 4B is formed with its vertex 421B located closer to the second main surface 22 than the center in the thickness direction of the substrate. Therefore, the first contact angle θ1 is smaller than the second contact angle θ2.

[0128] The protective layer 4B may contain at least one bubble B, or it may not contain any bubbles.

[0129] The protective layer 4B is preferably constructed in a manner that satisfies the following conditions.

[0130] 0≤L * ≤95 (CIE1976L) * a * b * Chromaticity coordinates)

[0131] L of protective layer 4B * Preferably, it is 0 or higher, more preferably 5 or higher, even more preferably 10 or higher, and preferably 95 or lower, more preferably 80 or lower, even more preferably 50 or lower, and most preferably 25 or lower. If the L of the protective layer 4B... * Within the aforementioned range, the aesthetics of reinforced glass item 1B are improved.

[0132] <Manufacturing Method of Tempered Glass Items>

[0133] Next, according to Figure 3The manufacturing method of the tempered glass article 1B is described.

[0134] like Figure 3 As shown, the manufacturing method of the tempered glass article 1B according to the second embodiment includes the same steps as the manufacturing method of the tempered glass article 1A according to the first embodiment. Except for the protective layer forming step, the steps are the same as those in the first embodiment. Hereinafter, the protective layer forming step will be described in detail.

[0135] In the protective layer forming process, there is no particular limitation on the method of forming the protective layer 4B on the end face 23, and a method including the same process as in the first embodiment can be used.

[0136] In the method for forming the protective layer 4B, the UV-curable resin preparation step, coating preparation step, and coating step are performed in the same manner as in the first embodiment, so that the UV-curable resin is coated with the apex of the arc portion located at the center in the thickness direction of the substrate.

[0137] In the curing preparation process, the reinforced glass substrate 2 is rotated with the first main surface 21 facing upward and the end surface 23 facing to the side.

[0138] In the curing process, after the curing preparation process, the UV-curable resin is irradiated with UV light to form a protective layer 4B containing air bubbles B.

[0139] It should be noted that the protective layer forming process can also be carried out by forming a protective layer 4B that does not contain bubbles B inside.

[0140] In the second embodiment, at least one of the viscosity of the UV-curable resin and the time from the curing preparation step to the curing step is adjusted so that the uncured UV-curable resin deforms due to gravity, thereby causing the apex of the arc portion to be biased to a lower position than the center in the thickness direction of the substrate.

[0141] As the uncured UV-curable resin deforms when the first main surface 21 is facing upwards, a protective layer 4B is formed with its vertex 421B located on the side of the second main surface 22, which is closer to the center of the substrate in the thickness direction.

[0142] It should be noted that airflow can be applied to the uncured UV-curable resin, or the UV-curable resin can be heated to reduce its viscosity, causing the apex of the arc portion to be biased towards the lower side than the center in the thickness direction of the substrate. Alternatively, the reinforced glass substrate 2 can be moved upwards, utilizing the inertial force at this time to bias the apex of the arc portion towards the lower side than the center in the thickness direction of the substrate.

[0143] <Effects of the Second Embodiment>

[0144] According to the second embodiment, by providing a protective layer 4B having the above-described configuration on the tempered glass article 1B, the strength of the end of the tempered glass article 1B is further improved, similar to the first embodiment. Furthermore, it is possible to prevent the end face 23 from scratching a person's finger Q, similar to the first embodiment.

[0145] like Figure 4 As shown, when the tempered glass item 1B is installed on the display 9, the dividing line K of the range in which the user can visually distinguish the tempered glass item 1B is a straight line that includes the user's eye and the first end 231 of the tempered glass item 1B.

[0146] As shown by the double-dotted line, when the vertex 421A is located at the center of the protective layer 4A in the thickness direction of the substrate, when the user sees the tempered glass item 1A, the portion of the protective layer 4A that is closer to the first main surface 21 than the center in the thickness direction of the substrate is located closer to the user side than the dividing line K, and thus will not be obscured by the tempered glass substrate 2. Therefore, the aesthetics of the tempered glass item 1A are reduced.

[0147] On the other hand, as shown by the solid line, when the vertex 421B is located on the protective layer 4B further from the center of the substrate thickness direction on the second main surface 22, when the user sees the tempered glass article 1B, the portion of the protective layer 4B further from the center of the substrate thickness direction on the first main surface 21 is located on the side opposite to the user, further from the dividing line K, and is obscured by the tempered glass substrate 2. Furthermore, when the angle between the dividing line K and the first main surface 21 is less than a certain angle, the linear region along the outer edge of the first main surface 21 in the protective layer 4B appears black, making the protective layer 4B difficult to identify. Therefore, it is possible to suppress the reduction in the aesthetics of the tempered glass article 1B.

[0148] exist Figure 4 The diagram shows the protective layer 4B, where vertex 421B is located further along the second main surface 22 than the center in the thickness direction of the substrate. When the user sees the tempered glass article 1B, the protective layer 4B is completely obscured by the tempered glass substrate 2. However, depending on the size of the first contact angle θ1, sometimes the protective layer 4B is not completely obscured by the tempered glass substrate 2. Nevertheless, the size of this unobscured area is smaller than that of the protective layer 4A, and the aesthetics of the tempered glass article 1B are better than those of the tempered glass article 1A.

[0149] In particular, when the vertex 421B is located closer to the second main surface 22 than the center in the thickness direction of the substrate, the smaller the first contact angle θ1, the easier it is for the protective layer 4B to be obscured by the tempered glass substrate 2, thus suppressing the reduction in the aesthetics of the tempered glass article 1B. From this viewpoint, the first contact angle θ1 of the protective layer 4B is preferably 77° or less, more preferably 75° or less. Furthermore, the first contact angle θ1 of the protective layer 4B is preferably 40° or more, more preferably 65° or more. It should be noted that in this embodiment, the upper and lower values ​​of the first contact angle θ1 can be appropriately combined.

[0150] From the perspective that a smaller first contact angle θ1 can better suppress the reduction in aesthetics, it is possible to reduce the first contact angle θ1 by placing the vertex of the protective layer at the center of the substrate thickness direction and reducing the maximum height H. However, in this case, the volume of the protective layer becomes smaller, thus reducing the impact absorption force and consequently reducing the strength of the end of the tempered glass article. Therefore, it is impossible to simultaneously improve the end strength of the tempered glass article and suppress the reduction in aesthetics.

[0151] On the other hand, if the first contact angle θ1 is reduced by increasing the maximum height H to a certain extent, as in the case of protective layer 4B, and by positioning the vertex 421B further away from the second main surface 22 than the center in the thickness direction of the substrate, then the reduction in the volume of protective layer 4B can be suppressed, and the reduction in impact absorption force can be suppressed. Therefore, it is possible to both improve the strength of the end of the tempered glass article 1B and suppress the reduction in aesthetics.

[0152] [Third Embodiment]

[0153] Next, the third embodiment of the present invention will be described.

[0154] Figure 5 It is along Figure 1 A cross-sectional view of the tempered glass article along line A-A. It should be noted that for configurations identical to those in the second embodiment, the same names and symbols are used, and descriptions are simplified or omitted.

[0155] <Composition of tempered glass items>

[0156] Figure 1 and Figure 5 The tempered glass article 1C shown includes a tempered glass substrate 2, a low-reflection film 3, and a protective layer 4C. The protective layer 4C is identical in structure to the protective layer 4A except for its shape. The shape of the protective layer 4C will be described below.

[0157] The protective layer 4C has a bottom edge portion 41C extending along the end face 23 from a first end face 231 to a second end face 232, and an arc portion 42C connecting the first end face 231 and the second end face 232. The protective layer 4C is configured not to exist on the first main surface 21 and the second main surface 22.

[0158] The protective layer 4C is formed into a shape that satisfies the above formulas (2) and (3).

[0159] The protective layer 4C is formed with its vertex 421C located closer to the first main surface 21 than the center in the thickness direction of the substrate. Therefore, the first contact angle θ1 is greater than the second contact angle θ2.

[0160] The protective layer 4C may contain at least one bubble B, or it may not contain any bubbles.

[0161] The protective layer 4C is preferably constructed in a manner that satisfies the following conditions.

[0162] 0≤L * ≤95 (CIE1976L) * a * b * Chromaticity coordinates)

[0163] L of protective layer 4C * Preferably, it is 0 or higher, more preferably 5 or higher, even more preferably 10 or higher, and preferably 95 or lower, more preferably 80 or lower, even more preferably 50 or lower, and most preferably 25 or lower. The L of the protective layer 4C * When the above range is met, the aesthetics of tempered glass items 1C are improved.

[0164] <Manufacturing Method of Tempered Glass Items>

[0165] Next, according to Figure 3 The manufacturing method of tempered glass article 1C is described.

[0166] like Figure 3 As shown, the manufacturing method of the tempered glass article 1C according to the third embodiment includes the same steps as the manufacturing method of the tempered glass article 1A according to the first embodiment. Except for the protective layer forming step, the steps are the same as those in the first embodiment. Hereinafter, the protective layer forming step will be described in detail.

[0167] In the protective layer forming process, the method of forming the protective layer 4C on the end face 23 is not particularly limited, and a method including the same process as in the first embodiment can be used.

[0168] In the method for forming the protective layer 4C, the UV-curable resin preparation step, coating preparation step, and coating step are performed in the same manner as in the first embodiment, so that the UV-curable resin is coated with the apex of the arc portion located on the central virtual line C.

[0169] In the curing preparation process, the reinforced glass substrate 2 is rotated with the second main surface 22 facing upward and the end surface 23 facing to the side.

[0170] In the curing process, after the curing preparation process, the UV-curable resin is irradiated with ultraviolet light to form a protective layer 4C containing air bubbles B.

[0171] It should be noted that the protective layer forming process can also be carried out by forming a protective layer 4C that does not contain bubbles B inside.

[0172] In the third embodiment, at least one of the viscosity of the UV-curable resin and the time from the curing preparation step to the curing step is adjusted in the same way as in the second embodiment so that the uncured UV-curable resin is deformed by gravity.

[0173] Due to the deformation of the uncured UV-curable resin when the second main surface 22 is facing upward, a protective layer 4C with vertex 421C is formed on the side of the first main surface 21 that is closer to the center in the thickness direction of the substrate.

[0174] <Effects of the Third Embodiment>

[0175] According to the third embodiment, by providing a protective layer 4C having the above-described configuration on the tempered glass article 1C, the strength of the end of the tempered glass article 1C is further improved, similar to the first embodiment. Furthermore, as in the first embodiment, it is also possible to prevent the end face 23 from scratching a person's finger Q.

[0176] like Figure 5 As shown, when the tempered glass article 1C is mounted on the display 9, when the object P approaches the first end 231, before colliding with the first end 231, the object P collides with the portion of the protective layer 4C that is closer to the first main surface 21 than the center in the thickness direction of the substrate.

[0177] Since vertex 421C is located further from the first main surface 21 than the center in the thickness direction of the substrate, the portion of the protective layer 4C on the first main surface 21 side is farther from the center 233 in the thickness direction than the same portion of the protective layer 4A (shown by the double-dotted line) where vertex 421A is located at the center in the thickness direction of the substrate. Therefore, the position in the protective layer 4C that first impacts the object P will be farther from the tempered glass substrate 2 than the position in the protective layer 4A that first impacts the object P. Consequently, the impact absorption force in the protective layer 4C is greater than that in the protective layer 4A, further improving the strength of the end of the tempered glass article 1C.

[0178] [Fourth Implementation]

[0179] Next, the fourth embodiment of the present invention will be described.

[0180] Figure 6 It is along Figure 1 A cross-sectional view of the tempered glass article along line A-A. It should be noted that for configurations identical to those in the first embodiment, the same names and symbols are used, and descriptions are simplified or omitted.

[0181] <The Composition of Reinforced Glass Items>

[0182] Figure 1 and Figure 6 The tempered glass article 1D shown includes a tempered glass substrate 2, a low-reflection film 3, and a protective layer 4D. The protective layer 4D is identical in composition to the protective layer 4A, except for its shape, material, and properties. The shape, material, and properties of the protective layer 4D will be described below.

[0183] The protective layer 4D has a bottom edge portion 41D extending along the end face 23 from a first end 231 to a second end 232, and an arc portion 42D connecting the first end 231 and the second end 232. The protective layer 4D is configured not to exist on the first main surface 21 and the second main surface 22.

[0184] The protective layer 4D is formed into a shape that satisfies the above equations (2) and (3).

[0185] It should be noted that the protective layer 4D can be formed in the same manner as in the first embodiment, with the vertex 421D located at the center in the thickness direction of the substrate. On the other hand, the protective layer 4D can be formed in the same manner as in the second embodiment, with the vertex 421D located further away from the center in the thickness direction of the substrate than the second main surface 22, or it can be formed in the same manner as in the third embodiment, with the vertex 421D located further away from the center in the thickness direction of the substrate than the first main surface 21.

[0186] The protective layer 4D may contain at least one bubble B, or it may not contain any bubbles.

[0187] The protective layer 4D is constructed in a manner that meets the following conditions.

[0188] 0≤L * ≤80 (CIE1976L) * a * b * Chromaticity coordinates)

[0189] From the perspective of providing light-shielding properties to the end face 23 of the tempered glass article 1D and improving the aesthetics of the tempered glass article 1D, the L of the protective layer 4D... * The value is 0 or higher, preferably 5 or higher, and more preferably 10 or higher. Furthermore, from the viewpoint of enabling the end face 23 of the strengthened glass article 1D to possess light-shielding properties and improving the aesthetics of the strengthened glass article 1D, the L of the protective layer 4D... * The value is 80 or less, preferably 50 or less, more preferably 25 or less, and even more preferably 20 or less. It should be noted that in this embodiment, L... * The upper and lower limits can be combined appropriately.

[0190] Furthermore, considering the improvement of the appearance of the tempered glass article 1D, the difference between the refractive index of the protective layer 4D and the refractive index of the tempered glass substrate 2 is preferably 0.2 or less, more preferably 0.05 or less, and most preferably 0.02 or less. The difference between the refractive index of the protective layer 4D and the refractive index of the tempered glass substrate 2 is preferably 0.001 or more, more preferably 0 or more. It should be noted that in this embodiment, the upper and lower limits can be appropriately combined.

[0191] The protective layer 4D preferably contains a resin in which black, gold, silver, blue, or red pigments are dispersed. By dispersing these pigments in the resin, 0 ≤ L * With a value ≤80, the end face 23 of the tempered glass article 1D can be given light-shielding properties. As a result, the aesthetics of the tempered glass article 1D are improved. In particular, when black pigment is dispersed in the resin, the boundary between the tempered glass substrate 2 and the protective layer 4D becomes less distinguishable, and the tempered glass substrate 2 and the protective layer 4D appear to be integrated. Therefore, this is preferred from the viewpoint of improving the aesthetics of the tempered glass article 1D.

[0192] As the aforementioned pigments, organic pigments such as carbon black and inorganic pigments such as titanium black are preferred. In particular, inorganic pigments are preferred because they exhibit excellent durability, for example, even in environments exposed to ultraviolet light.

[0193] <Manufacturing Method of Tempered Glass Items>

[0194] Next, according to Figure 3 The manufacturing method of tempered glass article 1D is explained.

[0195] like Figure 3 As shown, the manufacturing method of the tempered glass article 1D according to the fourth embodiment includes the same steps as the manufacturing method of the tempered glass article 1A according to the first embodiment. Except for the protective layer forming step, the steps are the same as those in the first embodiment. Hereinafter, the protective layer forming step will be described in detail.

[0196] In the protective layer forming process, the method of forming the protective layer 4D on the end face 23 is not particularly limited, and a method including the same process as in the first embodiment can be used.

[0197] In the method for forming the protective layer 4D, the UV-curable resin preparation process, coating preparation process, and coating process are performed in the same manner as in the first embodiment, so that the UV-curable resin is coated with the apex of the arc portion located at the center in the thickness direction of the substrate.

[0198] In the curing preparation process, the reinforced glass substrate 2 is rotated with the first main surface 21 or the second main surface 22 facing upwards and the end surface 23 facing to the side.

[0199] In the curing process, after the curing preparation step, ultraviolet (UV) light is irradiated onto the UV-curable resin to form a protective layer 4D containing internal air bubbles B. Here, the protective layer 4D can be heated after irradiating the UV-curable resin. Heating the protective layer 4D improves the adhesion between the glass and the resin, promoting the curing of the UV-curable resin. The heating temperature is preferably 40°C or higher, more preferably 60°C or higher. Furthermore, the heating time is preferably 5 minutes or more, more preferably 10 minutes or more.

[0200] It should be noted that the protective layer forming process can also be performed by forming a protective layer 4D that does not contain air bubbles B. It should also be noted that the tempered glass article 1D can be manufactured by the same process as the manufacturing method of the tempered glass article 1B of the second embodiment or the tempered glass article 1C of the third embodiment.

[0201] <Effects of the Fourth Implementation>

[0202] According to the fourth embodiment, by providing a protective layer 4D having the above-described configuration on the tempered glass article 1D, the strength of the end of the tempered glass article 1D can be further improved, similar to the first embodiment. Furthermore, it is possible to prevent the end face 23 from scratching a person's finger Q, similar to the first embodiment.

[0203] In addition, due to the L of the 4D protective layer * The temperature range is 0 to 80, therefore the protective layer 4D has light-blocking properties. Thus, by providing the protective layer 4D with the above-described configuration on the tempered glass article 1D, the appearance of the tempered glass article 1D is improved.

[0204] In summary, this specification discloses the following structure.

[0205] [1] A reinforced glass article, comprising:

[0206] A chemically strengthened glass substrate has a first main surface serving as a visual recognition surface, a second main surface opposite to the first main surface, and an end surface orthogonal to the first and second main surfaces; and,

[0207] A protective layer is provided on the aforementioned end face;

[0208] In a cross-sectional view orthogonal to the first main surface, the protective layer has: a bottom edge extending along the end face from a first end on the first main surface side to a second end on the second main surface side, and an arcuate portion connecting the first end and the second end.

[0209] The following equations (1), (2), and (3) are satisfied.

[0210] C1 / C2≥1.1 ··· (1)

[0211] C1: The potassium concentration at the first end or the second end of the aforementioned end face.

[0212] C2: Potassium concentration at the center of the reinforced glass substrate in the thickness direction on the aforementioned end face.

[0213] 0.18≤H / L≤1.21 ··· (2)

[0214] H: The length from the vertex of the aforementioned arc portion to the aforementioned end face.

[0215] L: Length of the aforementioned bottom edge

[0216] 40°≤θ1≤135° ··· (3)

[0217] θ1: The first contact angle on the first end side of the aforementioned arc portion.

[0218] [2] The tempered glass article according to [1], wherein the protective layer contains air bubbles.

[0219] [3] The tempered glass article according to [1] or [2], wherein the vertex of the arc portion is located closer to the second main surface than the center of the tempered glass substrate in the thickness direction.

[0220] [4] The tempered glass article according to [3], wherein the first contact angle θ1 is 77° or less.

[0221] [5] The tempered glass article according to [1] or [2], wherein the vertex of the arc portion is located closer to the first main surface than the center of the tempered glass substrate in the thickness direction.

[0222] [6] The tempered glass article according to [1] or [2], wherein the brightness L of the above-mentioned protective layer * The range is 0 to 80.

[0223] Example

[0224] Next, embodiments of the present invention will be described. Examples 1-2 and 12-13 are comparative examples, and Examples 3-11 and 14-22 are exemplary examples. It should be noted that the present invention is not limited to the embodiments.

[0225] [Manufacturing methods and properties of protective layers for tempered glass items]

[0226] <Example 1>

[0227] Prepare a 1.1mm thick soda-lime glass as the base plate.

[0228] Perform on the original board Figure 2 The laser irradiation process is shown. In the void regions within each surface, the center-to-center distance between adjacent voids is 5 μm.

[0229] Next, a chemical fortification process is carried out using molten potassium nitrate salt.

[0230] In addition, the original board after the chemical strengthening process is separated to obtain multiple strengthened glass substrates. The strengthened glass substrates are rectangular plates with a long side of 80mm and a short side of 50mm.

[0231] A tempered glass article 1 with a protective layer, as described in Example 1, is obtained by performing a protective layer forming process on one end face of a tempered glass substrate, with the apex of the protective layer located at the center in the thickness direction of the substrate. In the protective layer forming process, "PHOTOBOND200" (hereinafter referred to as "transparent resin 1") manufactured by SUNRISE Co., Ltd. is used as the UV-curable resin. It should be noted that no treatment to introduce air bubbles into the UV-curable resin is performed. The UV-curable resin has a viscosity of 350 mPa·s, an elastic modulus of 6 MPa, and a hardness (Shore D) of 55. The intensity of the UV light during the curing process is 6000 mJ / cm². 2 .

[0232] As characteristics of the protective layer, the first contact angle θ1, the maximum height H, the length L in the thickness direction of the reinforced glass substrate at the bottom edge, and H / L are evaluated.

[0233] As shown in Table 1, the values ​​of θ1, H, L, and H / L are 15°, 72 μm, 1100 μm, and 0.07, respectively. Furthermore, the offset E of the vertex from the center of the substrate thickness direction was evaluated. A value of E less than 1 μm indicates that the vertex is located at the center of the substrate thickness direction.

[0234] Furthermore, the potassium concentration of the reinforced glass substrate was evaluated using the method illustrated in the first embodiment. The ratio of C1 to C2 was 1.2.

[0235] It should be noted that in Examples 2 to 22 below, the values ​​of C1 / C2 are the same as those in Example 1.

[0236] <Example 2>

[0237] The tempered glass article 1 of Example 2 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. In the protective layer formation conditions, the proportion of ultraviolet curable resin used was increased, the time from the curing preparation step to the curing step in the protective layer formation process was extended, and the vertex of the protective layer was located on the side opposite to the first main surface, which is the visual recognition surface, which is further away from the center in the thickness direction of the substrate. Otherwise, the conditions were the same as in Example 1.

[0238] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 20°, 98 μm, 1100 μm, and 0.09, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 3 μm.

[0239] <Example 3>

[0240] The tempered glass article 1 of Example 3 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The proportion of ultraviolet-curable resin used in the formation of the protective layer was higher than that in Example 2; otherwise, the conditions were the same as in Example 2.

[0241] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 40°, 202 μm, 1100 μm, and 0.18, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 5 μm.

[0242] <Example 4>

[0243] The tempered glass article 1 of Example 4 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The conditions for forming the protective layer were otherwise the same as in Example 3, except that the proportion of UV-curable resin used was greater than 3.

[0244] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 62°, 333 μm, 1100 μm, and 0.30, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 5 μm.

[0245] <Example 5>

[0246] The tempered glass article 1 of Example 5 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The conditions for forming the protective layer were otherwise the same as in Example 4, except that the proportion of ultraviolet-curable resin used was 4.

[0247] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 75°, 450 μm, 1100 μm, and 0.41, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 37 μm.

[0248] <Example 6>

[0249] The tempered glass article 1 of Example 6 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The protective layer formation conditions were otherwise the same as in Example 5, except that the proportion of ultraviolet-curable resin used was greater than 5.

[0250] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 77°, 476 μm, 1100 μm, and 0.43, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 48 μm.

[0251] <Example 7>

[0252] The tempered glass article 1 of Example 7 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The protective layer was formed under the same conditions as in Example 6, except that the vertex of the protective layer was located closer to the first main surface than the center in the thickness direction of the substrate.

[0253] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 83°, 446 μm, 1100 μm, and 0.41, respectively. Furthermore, the vertex is located further towards the first main surface than the center in the thickness direction of the substrate. The value of E is 46 μm.

[0254] <Example 8>

[0255] The tempered glass article 1 of Example 8 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The conditions for forming the protective layer were otherwise the same as in Example 1, except that the proportion of ultraviolet-curable resin used was greater than 1.

[0256] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 83°, 487 μm, 1100 μm, and 0.44, respectively. Furthermore, the value of E is less than 1 μm, and the vertex is located at the center of the substrate thickness direction.

[0257] <Example 9>

[0258] The tempered glass article 1 of Example 9 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The conditions for forming the protective layer were otherwise the same as in Example 6, except that the proportion of ultraviolet-curable resin used was greater than 6.

[0259] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 87°, 578 μm, 1100 μm, and 0.53, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 60 μm.

[0260] <Example 10>

[0261] The tempered glass article 1 of Example 10 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The conditions for forming the protective layer were otherwise the same as in Example 9, except that the proportion of UV-curable resin used was greater than 9.

[0262] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 110°, 943 μm, 1300 μm, and 0.73, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 10 μm.

[0263] <Example 11>

[0264] The tempered glass article 1 of Example 11 was obtained by forming a protective layer on multiple tempered glass substrates manufactured under the same conditions as in Example 1. The conditions for forming the protective layer were otherwise the same as in Example 8, except that the proportion of ultraviolet-curable resin used was greater than 8.

[0265] As shown in Table 1, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 135°, 1328 μm, 1100 μm, and 1.21, respectively. Additionally, the value of E is less than 1 μm, and the vertex is located at the center of the substrate thickness direction.

[0266] <Example 12>

[0267] In the protective layer forming process, a UV-curable resin containing black pigment (manufactured by Sekisui Medical Supplies Technology Co., Ltd., trade name: PHOTOLEC-A-785-60BK-T-300, hereinafter referred to as "black resin 1") was used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 12 was obtained under the same conditions as in Example 1.

[0268] As shown in Table 2, the values ​​of θ1, H, L, and H / L, which represent the characteristics of the protective layer, are the same as in Example 1. Additionally, the value of E is less than 1 μm, and the vertex is located at the center of the substrate thickness direction.

[0269] <Example 13>

[0270] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the tempered glass article 1 of Example 13 is obtained under the same conditions as in Example 2.

[0271] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 20°, 98 μm, 1100 μm, and 0.09, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 3 μm.

[0272] <Example 14>

[0273] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the tempered glass article 1 of Example 14 is obtained under the same conditions as in Example 3.

[0274] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 40°, 202 μm, 1100 μm, and 0.18, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 5 μm.

[0275] <Example 15>

[0276] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the tempered glass article 1 of Example 15 is obtained under the same conditions as in Example 4.

[0277] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 62°, 333 μm, 1100 μm, and 0.30, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 5 μm.

[0278] <Example 16>

[0279] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 16 is obtained under the same conditions as in Example 5.

[0280] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 75°, 450 μm, 1100 μm, and 0.41, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 37 μm.

[0281] <Example 17>

[0282] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 17 is obtained under the same conditions as in Example 6.

[0283] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 77°, 476 μm, 1100 μm, and 0.43, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 48 μm.

[0284] <Example 18>

[0285] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 18 is obtained under the same conditions as in Example 7.

[0286] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 83°, 446 μm, 1100 μm, and 0.41, respectively. Furthermore, the vertex is located further towards the first main surface than the center in the substrate thickness direction. The value of E is 46 μm.

[0287] <Example 19>

[0288] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the tempered glass article 1 of Example 19 is obtained under the same conditions as in Example 8.

[0289] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 83°, 487 μm, 1100 μm, and 0.44, respectively. Furthermore, the value of E is less than 1 μm, and the vertex is located at the center of the substrate thickness direction.

[0290] <Example 20>

[0291] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 20 is obtained under the same conditions as in Example 9.

[0292] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 87°, 578 μm, 1100 μm, and 0.53, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 60 μm.

[0293] <Example 21>

[0294] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 21 is obtained under the same conditions as in Example 10.

[0295] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 110°, 943 μm, 1300 μm, and 0.73, respectively. Furthermore, the vertex is located further along the second main surface than the center in the thickness direction of the substrate. The value of E is 10 μm.

[0296] <Example 22>

[0297] In the protective layer forming process, black resin 1 is used instead of transparent resin 1. Otherwise, the reinforced glass article 1 of Example 22 is obtained under the same conditions as in Example 11.

[0298] As shown in Table 2, the values ​​of θ1, H, L, and H / L, representing the characteristics of the protective layer, are 135°, 1328 μm, 1100 μm, and 1.21, respectively. Furthermore, the value of E is less than 1 μm, and the vertex is located at the center of the substrate thickness direction.

[0299]

[0300]

[0301] The impact resistance and sharpness of the end faces of tempered glass articles are evaluated using the following methods.

[0302] [Evaluation of the impact resistance of tempered glass items]

[0303] <Composition of Impact Testing Machine>

[0304] First, prepare Figure 7 , 8 The impact testing machine 8 shown. It should be noted that in the following description, sometimes... Figure 7 , 8 The XYZ coordinate axes shown are used as a reference to explain the directions of each component. The X-axis and Y-axis are mutually orthogonal and parallel to the horizontal plane. The Z-axis is orthogonal to the X-axis and Y-axis and parallel to the vertical direction. Here, Figure 8 Viewed from the Z-axis direction Figure 7 The top view obtained from the impact testing machine.

[0305] The impact testing machine 8 includes: a base 81, a sample holding part 82 for holding the reinforced glass article 1 to be evaluated, and an impact imparting part 83 for imparting impact to the reinforced glass article 1.

[0306] The base 81 is formed as a right-angled equilateral triangular prism with a base angle of 45°, and is placed on the mounting platform such that the face corresponding to one of the right-angled sides abuts against the mounting platform (not shown).

[0307] The sample holding part 82 includes a holding member 821 consisting of a metal plate fixed to a surface corresponding to the bottom edge of the base 81, and a clamping part (not shown). The tempered glass article 1 is placed on the holding member 821 with its first main surface 21 tilted at only 45° relative to the horizontal plane. The sample holding part 82 detachably holds the tempered glass article 1 placed on the holding member 821 via the clamping part, such that the downward-facing inclined surface 821A of the holding member 821 is on the same plane as the end face 23.

[0308] The impact-imposing part 83 includes: a cylindrical shaft 84 extending along the X-axis through which a bearing 831 is inserted; a connecting rod 832 extending in a rod shape from the outer circumference of the bearing; and an impactor 833 fixed to the front end of the connecting rod 832. The impactor 833 includes: a cuboid-shaped fixing body 834; and a triangular prism-shaped bevel pin 835 fixed to one face of the fixing body 834. The bevel pin 835 is made of superhard alloy and has a front end 835A with an angle of 100°. The impactor 833 weighs 152.8g.

[0309] like Figure 7 , 8 As shown by the solid line, when the impact-imposing part 83 is configured such that the connecting rod 832 is horizontal relative to the Z-axis direction, the front end 835A of the mountain-shaped pin 835 will first contact the protective layer 4 of the tempered glass article 1. It should be noted that, although... Figure 8 The symbol 4 is omitted, but the front end 835A of the impactor 833 contacts the protective layer 4, rather than the first end 231.

[0310] <Evaluation of impact resistance>

[0311] First, prepare 10 pieces of reinforced glass from Example 1. Next, as... Figure 7 , 8 The rotating link 832, indicated by the double-dotted line, brings the impactor 833 to a standstill when the impact energy reaches 0.5 mJ. Then, a piece of tempered glass 1 is held in the sample holder 82 with its end face 23 (with the protective layer 4) and inclined surface 821A on the same plane. Subsequently, by releasing the force that held the impactor 833 at rest, the impactor 833 is allowed to rotate freely, impacting the tempered glass 1 with an impact energy of 0.5 mJ.

[0312] Then, the impact-giving part 83 is moved in the X-axis direction and the collision position is shifted in the X-axis direction, and the impactor 833 is made to collide with the reinforced glass article 1 with a collision energy of 1.0 mJ.

[0313] The same test was performed on the remaining 9 pieces of reinforced glass 1, and the impactor 833 was colliding with two collision positions arranged in the X-axis direction with collision energies of 0.5 mJ and 1.0 mJ.

[0314] Prepare 10 pieces of each of the tempered glass articles 1 from Examples 2 to 22. At two collision positions arranged along the X-axis of each tempered glass article 1, the impactor 833 is made to collide with impact energies of 0.5 mJ and 1.0 mJ.

[0315] A microscope was used to examine each impact location in the 10 tempered glass articles 1 of Examples 1 to 22, and to determine whether a defect of a specified size or larger occurred under each impact energy. In this determination, damage with a length of 1.5 mm or more in the X-axis direction, or a length of 0.1 mm or more in the Y-axis direction, or a length of 0.1 mm or more in the substrate thickness direction was defined as a defect.

[0316] Next, for each of Examples 1 to 22, if the number of damaged tempered glass articles 1 is 3 or less under each collision energy, it is considered to meet the criteria; if it is 4 or more, it is considered not to meet the criteria. That is, if the defect rate is 30% or less under each collision energy, it is considered to meet the criteria; if the defect rate is greater than 30%, it is considered not to meet the criteria.

[0317] Furthermore, if the criteria are not met when the impact energy is either 0.5 mJ or 1.0 mJ or higher, the impact resistance rating is "C". If the criteria are met when the impact energy is 0.5 mJ, but not when it is 1.0 mJ, the impact resistance rating is "B". If the criteria are met when the impact energy is either 0.5 mJ or 1.0 mJ, the impact resistance rating is "A".

[0318] <Evaluation results of impact resistance>

[0319] The evaluation results of the impact resistance of Examples 1 to 11 are shown in Table 1.

[0320] Examples 1-2 where the protective layer 4 does not satisfy equations (2) and (3) are evaluated as "C". On the other hand, examples 3-11 where the protective layer 4 satisfies equations (2) and (3) are evaluated as either "B" or "A".

[0321] The evaluation results of the impact resistance of Examples 12 to 22 are shown in Table 2.

[0322] Examples 12-13 where the protective layer 4 does not satisfy equations (2) and (3) are evaluated as “C”. On the other hand, examples 14-22 where the protective layer 4 satisfies equations (2) and (3) are evaluated as either “B” or “A”.

[0323] In Examples 1-2 and 12-13, the first contact angle θ1 is less than the lower limit of the condition satisfying Equation (3). Compared with the same portion in Examples 3-11 and 14-22 where the first contact angle θ1 satisfies Equation (3), the portion of the first main surface 21 side of the protective layer 4 has a shorter distance from the center portion 233 in the thickness direction at the end face 23. Therefore, the position in the protective layer 4 of Example 1 that first impacts the impactor 833 is closer to the position of the tempered glass substrate than the position in the protective layer 4 of Examples 3-11 and 14-22. As a result, the impact absorption force of the protective layer 4 of Example 1 is considered to be less than that of the protective layer 4 of Examples 3-11 and 14-22. Examples 1-2 and 12-13 are rated as "C", while Examples 3-11 and 14-22 are rated as "B" or "A".

[0324] Furthermore, the evaluations of Examples 3 and 14, where the first contact angle θ1 is 40°, and Examples 4 and 15, where the first contact angle θ1 is 62°, are lower than those of Examples 5 to 11 and 16 to 22, where the first contact angle θ1 is 75° or higher.

[0325] For the same reasons explained for Examples 1-2 and 12-13, the portion of the protective layer 4 on the first main surface 21 side in Examples 3-4 and 14-15, like the same portion in Examples 5-11 and 16-22, has an insufficient distance from the center portion 233 in the thickness direction at the end face 23. As a result, the impact absorption capacity of the protective layer 4 in Examples 3-4 and 14-15 is considered insufficient, and Examples 3-4 and 14-15 are rated "B". On the other hand, Examples 5-11 and 16-22 are rated "A".

[0326] In summary, it can be confirmed that the strength of the end of the tempered glass article 1 can be improved by forming a protective layer 4 that satisfies equations (2) and (3). In particular, it can be confirmed that the strength of the end of the tempered glass article 1 can be further improved by forming a protective layer 4 that satisfies equations (2) and (3) and has a first contact angle θ1 of 75° or more.

[0327] [Evaluation of the sharpness of tempered glass items]

[0328] <Composition of the Sharpness Evaluation Test Machine>

[0329] First, prepare Figure 9 , 10 The sharpness evaluation testing machine 90 is shown. It should be noted that in the following description, sometimes "sharpness evaluation testing machine 90" is used. Figure 9 , 10 The XYZ coordinate axes shown are used as a reference to explain the directions of each component. The X-axis and Y-axis are mutually orthogonal and parallel to the horizontal plane. The Z-axis is orthogonal to the X-axis and Y-axis and parallel to the vertical direction. Here, Figure 10 From Figure 9 Point D in the middle is observed along the negative Y-axis. Figure 9The front view of the sharpness evaluation test machine.

[0330] The sharpness evaluation tester 90 includes: a measuring base 92, a sharpness sample holding part 93 for holding the tempered glass article 1 to be evaluated, and a sharpness evaluation part 94 for applying impact to the tempered glass article 1 by contact.

[0331] The base 92 is formed as a right-angled equilateral triangular prism with a base angle of 45°, and the face corresponding to one of the right-angled sides is placed on a mounting stage (not shown).

[0332] The sharpness sample holding part 93 includes: a base holding member 98 consisting of a metal plate fixed to the surface corresponding to the bottom edge of the measuring base 92, a clamping part (not shown), and a glass base 99 adjacent to the tempered glass article 1 and the measuring base 92. Figure 9 As shown, the tempered glass article 1 is placed on the base holding member 98 along one of the main surfaces of the glass base 99, with the first main surface 21 of the tempered glass article 1 tilted at only 45° relative to the horizontal plane. The sharpness sample holding part 93 detachably holds the tempered glass article 1 placed on the base holding member 98 by means of a clamping part.

[0333] The sharpness evaluation unit 94 includes a tester unit 96 extending in the Y-axis direction and an adhesive tape assembly unit 97 fixed to the front end of the tester unit 96. The adhesive tape assembly unit 97 has three layers of adhesive tape 971 to 973 with a softness that simulates the fingerprint surface of a human index finger. It should be noted that, starting from the outermost layer of the adhesive tape, they are sequentially defined as layer 1 973, layer 2 972, and layer 3 971.

[0334] As part of the testing equipment section 96, a sharp edge tester (manufactured by Excel Corporation, model: SET-50; hereinafter referred to as "SET-50") is used; as part of the tape assembly section 97, a tape assembly TC-3 (hereinafter referred to as "TC-3") manufactured by Excel Corporation is used. It should be noted that, as Figure 10 As shown, TC-3 is a tape assembly consisting of three flexible tapes 971-973, which are stacked on a pressure head 974 with a diameter of 12.7 mm, simulating the fingerprint surface of a human index finger. SET-50 has the function of pressing TC-3 onto the end face of the sample with a certain load.

[0335] <Sharpness rating>

[0336] First, prepare one piece of tempered glass 1 (Example 1). Next, fix the tempered glass 1 at a 45-degree angle relative to the horizontal plane of the ground. Apply a certain load to the TC-3 mounted on the SET-50. Figure 10Arrow F in the diagram (6.7 N) contacts protective layer 4. While maintaining the load, TC-3 is moved 100 mm (50 mm one way) reciprocating along protective layer 4D. This movement is repeated a total of 20 times within 20 seconds.

[0337] After confirming the state of TC-3 after movement, if the first layer of 973 tape of TC-3 is not cut, the sharpness rating is "A". If the first layer of 973 tape of the aforementioned tape assembly TC-3 is cut, the sharpness rating is "B".

[0338] Prepare one piece of each of the tempered glass items from Examples 2 to 22, and conduct the same evaluation as in Example 1.

[0339] <Sharpness Evaluation Results>

[0340] The sharpness evaluation results of Examples 1 to 11 are shown in Table 1.

[0341] Example 1 is rated "B". On the other hand, Examples 2-11 are rated "A".

[0342] The sharpness evaluation results of Examples 12-22 are shown in Table 2.

[0343] Example 12 is rated "B". On the other hand, Examples 13-22 are rated "A".

[0344] In Examples 1 and 12, the first contact angle θ1 is relatively small, at 15°. Compared to the first end portion 231 in Examples 2-11 and 13-22, the first contact angle θ1 in Examples 1 and 12 is smaller, indicating a sharper tip. As a result, the sharpness of Examples 1 and 12 is rated "B", while the sharpness of Examples 2-11 and 13-22 is rated "A".

[0345] In summary, it can be confirmed that by forming a protective layer 4 that satisfies equation (3), the first contact angle θ1 can be made large enough to suppress the sharpness of the end of the tempered glass article 1.

[0346] [Evaluation of the appearance of tempered glass items]

[0347] <Appearance Evaluation Methods>

[0348] use Figure 11 The device shown forms a protective layer 4 over the area of ​​the tempered glass article 1. The L value of the CIE-Lab color system is then determined. * Value, to evaluate the appearance of reinforced glass items.

[0349] First, a light source 701 is positioned above a workbench (not shown) with the direction of light illumination pointing downwards. A detector 702 is positioned above the workbench with the measurement range centered within the illumination range of the light source 701. The light source 701 uses illumination sensitive to the visible light region. Specifically, a white LED (OPTEX FA, OPF-S100X100W-DF) is used. It should be noted that since the intensity of each wavelength in the visible light region of a white LED is not constant, spectral data obtained using a white calibration plate is used to create a correction value, and the L value of the CIE-Lab colorimetric system is calculated using this correction value. * Value. A spectroradiometer (TOPCON TECHNOHOUSE SR-5000) is used as detector 702. Additionally, ASKUL Co., Ltd.'s "Multi Paper Super White (A4 size, whiteness approximately 92%)" photocopying paper is placed as a sheet component 703 within the measurement range on the worktable. Then, the tempered glass article 1 is placed on the sheet component 703 with the first main surface 21 facing upwards and the center of the outer periphery (length direction) of the protective layer 4 located at the center of the detection range of detector 702 when viewed from above. At this time, as... Figure 11 As shown, the configuration is adjusted such that the angle θ3 between the light 711 illuminating the protective layer 4 from the light source 701 and the light 712 reflected in the protective layer 4 and detected by the detector 702 is 45°. Additionally, as... Figure 11 The light source 701 is configured such that the distance d1 between the light source 701 and the protective layer 4 is 90 mm. Additionally, the detector 702 is configured such that the distance d2 between the detector 702 and the protective layer 4 is 280 mm.

[0350] Then, while illuminating the protective layer 4 with light 711 from the light source 701, the detector 702 detects and captures the light 712 reflected from the outer periphery of the tempered glass article 1 containing the protective layer 4. From the image data obtained by the detector 702, any point in the area of ​​the outer periphery of the tempered glass article 1 containing the protective layer 4, where the protective layer 4 is exposed, is taken as a measurement point P1. The brightness L of the CIE-Lab color system for a total of 9 pixels (348.9 μm square) in a 3×3 area surrounding the measurement point P1 is calculated. * The average value of this value is taken as the brightness L. *P1 In the area of ​​the outer periphery of the tempered glass article 1 containing the protective layer 4, select measurement points P2, P3, P4, and P5, which are different from measurement point P1, and measure the luminance L at P2 using the same procedure as described above. *P2 The brightness L at P3 *P3 The brightness L at P4 *P4 Brightness L at P5 *P5 Take the brightness L.*P1 ~ Luminance L *P5 the median value of is taken as L of the protective layer 4 * .

[0351] When a user visually identifies the tempered glass article 1, depending on the shape of the protective layer 4, the linear region along the outer edge of the first main surface 21 in the protective layer 4 sometimes looks black, making it difficult to identify the protective layer 4.

[0352] L obtained through measurement by the detector 702 * the smaller the value of is, the darker the protective layer 4 looks, which makes the boundary between the protective layer 4 and the tempered glass substrate 2 difficult to identify, and it is considered that the aesthetic appearance of the tempered glass article 1 is improved.

[0353] Based on this viewpoint, L of the protective layer 4 in each one tempered glass article 1 of Examples 1 to 22 was measured * . The above measurement was performed on each tempered glass article 1, and when L * has a value of 25 or less, the appearance is evaluated as "A". When L * has a value greater than 25 and 80 or less, the appearance is evaluated as "B". When L * has a value greater than 80, the appearance is evaluated as "C".

[0354] <Appearance Evaluation Results>

[0355] The appearance evaluation results of Examples 1 to 11 are shown in Table 1.

[0356] Examples 7 to 11 were evaluated as "C". In Example 7, the vertex of the protective layer 4 is located closer to the first main surface 21 than the center in the thickness direction of the substrate, and the first contact angle θ1 is 83°. In Examples 8 and 11, the vertex of the protective layer 4 is located at the center in the thickness direction of the substrate, and the first contact angle θ1 is 83° or more. In Examples 9 and 10, the vertex of the protective layer 4 is located closer to the second main surface 22 than the center in the thickness direction of the substrate, and the first contact angle θ1 is 87° or more. As described above, in Examples 7 to 11, the first contact angle θ1 of the protective layer 4 is 83° or more, so that the area that reflects irradiated light toward the detector 702 side is large. Therefore, it is considered that in Examples 7 to 11, the proportion of the width of the region that looks white in the protective layer 4 increases, and the proportion of the black region decreases. Hereinafter, the region in the protective layer 4 that reflects irradiated light toward the detector 702 side is sometimes referred to as a "retroreflection region".

[0357] Examples 2-6 are rated "A" or "B". In Examples 2-6, the vertex of the protective layer 4 is located further towards the second main surface 22 than the center in the thickness direction of the substrate, and the first contact angle θ1 is 77° or less. Thus, compared to the protective layer 4 in Examples 7-11, the protective layer 4 in Examples 2-6 has a smaller first contact angle θ1 and a smaller reflective area. Therefore, it is considered that the proportion of the white area in Examples 2-6 is smaller and the proportion of black area is larger compared to the protective layer 4 in Examples 7-11.

[0358] Furthermore, the evaluation of Example 6, where the first contact angle θ1 is 77°, is lower than that of Examples 2 to 5, where the first contact angle θ1 is 75° or less.

[0359] Furthermore, when comparing Example 6 and Example 7, although the maximum height H of the resin in Example 6 is larger, Example 6 is rated "B", which is higher than the rating "C" of Example 7. The reason for this is that the vertex of the protective layer 4 in Example 6 is biased towards the second main surface 22, and the first contact angle θ1 is smaller compared to Example 7, where the vertex is biased towards the first main surface 21.

[0360] Example 1 is rated "A". It is believed that although the vertex of the protective layer 4 in Example 1 is located at the center of the substrate thickness direction, the reflected area is small due to the first contact angle θ1 being 15°. Therefore, the proportion of the white area appears smaller and the proportion of black area appears larger.

[0361] Therefore, it can be confirmed that in Examples 1 to 11, by forming a protective layer 4 with a small first contact angle θ1, the reduction in the aesthetics of the tempered glass article 1 can be suppressed. In such a protective layer 4, from the viewpoint of aesthetics, it is confirmed that the first contact angle θ1 is preferably 77° or less, and more preferably 75° or less.

[0362] Next, the evaluation results of the appearance of Examples 12 to 22 are shown in Table 2.

[0363] Examples 12-22 are all rated "A". It can be confirmed that in Examples 12-22, by using black resin 1 to form the protective layer 4, L... * With a value of ≤25, the reflection of the incident light toward the detector 702 side is suppressed, making the reinforced glass item 1 and the protective layer 4 appear to be the same color, thus improving aesthetics.

[0364] Although the invention has been described in detail with reference to specific methods, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. It should be noted that this application is based on Japanese Patent Application No. 2024-015431, filed February 5, 2024, the contents of which are incorporated herein by reference.

[0365] Symbol Explanation

[0366] 1, 1A, 1B, 1C, 1D... tempered glass article, 2... tempered glass substrate, 4, 4A, 4B, 4C, 4D... protective layer, 21... first main surface, 22... second main surface, 23... end face, 41A, 41B, 41C, 41D... bottom edge, 42A, 42B, 42C, 42D... arc portion, 231... first end portion, 232... second end portion, 233... center portion in the thickness direction, 421A, 421B, 421C, 421D... vertex, B... bubble, θ1... first contact angle.

Claims

1. A reinforced glass article, comprising: A chemically strengthened glass substrate has a first main surface serving as a visual recognition surface, a second main surface opposite to the first main surface, and an end surface orthogonal to the first and second main surfaces; and, A protective layer disposed on the end face; The protective layer, in a cross-sectional view orthogonal to the first main surface, has: a bottom edge extending along the end face from a first end on the first main surface side of the end face to a second end on the second main surface side, and an arcuate portion connecting the first end and the second end. The following equations (1), (2) and (3) are satisfied. C1 / C2≥1.1 ··· (1) C1: The potassium concentration at the first end or the second end of the end face. C2: Potassium concentration at the center of the reinforced glass substrate in the thickness direction on the end face. H: The length from the vertex of the arc portion to the end face. L: The length of the bottom edge. 40°≤θ1≤135° ··· (3) θ1: The first contact angle on the first end side of the arc portion.

2. The tempered glass article according to claim 1, wherein, The protective layer contains air bubbles.

3. The tempered glass article according to claim 1, wherein, The vertex of the arc portion is located closer to the second main surface than the center of the thickness direction of the reinforced glass substrate.

4. The tempered glass article according to claim 3, wherein, The first contact angle θ1 is below 77°.

5. The tempered glass article according to claim 1, wherein, The vertex of the arc portion is located closer to the first main surface than the center of the thickness direction of the reinforced glass substrate.

6. The tempered glass article according to claim 1, wherein, The brightness L of the protective layer * The range is 0 to 80.

Images