Glass product and display device including the same

Abstract

The present disclosure provides a glass product and a display device including the same. The glass product includes: a first surface; a second surface, opposite to the first surface; a first compression area, extending from the first surface to a first compression depth; a second compression area, extending from the second surface to a second compression depth; and a tensile area, arranged between the first compression depth and the second compression depth, wherein the stress distribution of the first compression area includes a first trend line between the first surface and a first transition point, a second trend line between the first transition point and the second transition point, and a third trend line between the second transition point and the first compression depth, the depth from the first surface to the first transition point is less than 10um, the stress at the first transition point is more than 200MPa, the depth from the first surface to the second transition point is less than 50um to 80um, and the stress at the second transition point is 40MPa to 100MPa.

Description

Technical Field

[0001] The present disclosure relates to a glass product and a display device including the same. Background Art

[0002] Glass products are often used in electronic devices including display devices or building materials, etc. For example, glass products are suitable for substrates of flat panel display devices such as liquid crystal display devices, OLED, and electrophoretic display devices, or window covers for protecting the same.

[0003] As the number of portable electronic devices such as smartphones and tablets increases, glass products used for them are often exposed to external impact. For portability, it is required to develop glass products that are thin and can withstand external impact. Although attempts have been made to improve the strength of glass products through thermal or chemical strengthening, in order to meet customer needs, more precise stress distribution management is required. Summary of the invention

[0004] An object of the present disclosure is to provide a glass product having good strength at a specific depth.

[0005] Another problem to be solved by the present disclosure is to provide a display device including a glass product having good strength at a specific depth.

[0006] The problems of the present disclosure are not limited to the problems mentioned above, and those skilled in the art can clearly understand other technical problems not mentioned from the following description.

[0007] A glass product according to one embodiment for solving the above-mentioned problem includes: a first surface; a second surface opposite to the first surface; a first compression region extending from the first surface to a first compression depth; a second compression region extending from the second surface to a second compression depth; and a tensile region arranged between the first compression depth and the second compression depth, wherein the stress distribution of the first compression region includes a first trend line between the first surface and a first transition point, a second trend line between the first transition point and the second transition point, and a third trend line between the second transition point and the first compression depth, the depth from the first surface to the first transition point is less than 10 um, and the stress at the first transition point is greater than 200 MPa, the depth from the first surface to the second transition point is less than 50 um to 80 um, and the stress at the second transition point is 40 MPa to 100 MPa.

[0008] It may be that the first trend line has a first average slope, the second trend line has a second average slope, the third trend line has a third average slope, and the first average slope, the second average slope and the third average slope each have a negative value.

[0009] It may be that the first average slope is greater than the second average slope and the third average slope.

[0010] It may be that the second average slope is greater than the third average slope.

[0011] It may be that the tangent line at the first transition point has a first transition point slope, and the first transition point slope has a negative value.

[0012] It may be that the magnitude of the first transition point slope has a value between the magnitude of the first average slope and the magnitude of the second average slope.

[0013] It may be that the tangent line at the second transition point has a second transition point slope, and the second transition point slope has a negative value.

[0014] It may be that the magnitude of the second transition point slope has a value between the magnitude of the second average slope and the magnitude of the third average slope.

[0015] It may be that the first trend line has a first tangent slope, the second trend line has a second tangent slope, the third trend line has a third tangent slope, and the first tangent slope, the second tangent slope, and the third tangent slope all have negative values.

[0016] It may be that all the first tangent slopes of the first trend line have negative values, all the second tangent slopes of the second trend line have negative values, and all the third tangent slopes of the third trend line have negative values.

[0017] It may be that the compressive stress of the first surface is 700 MPa to 950 MPa, and the first compression depth is 125 um to 135 um.

[0018] It may be that the glass article comprises lithium aluminosilicate.

[0019] It may be that the stress distribution in the second compression region has a symmetrical relationship with the stress distribution in the first compression region.

[0020] A glass product according to another embodiment for solving the above-mentioned problem comprises: a first surface; a second surface opposite to the first surface; a first compression region extending from the first surface to a first compression depth; a second compression region extending from the second surface to a second compression depth; and a tensile region arranged between the first compression depth and the second compression depth, wherein the stress distribution of the first compression region comprises a first trend line between the first surface and a first transition point, a second trend line between the first transition point and the second transition point, and a third trend line between the second transition point and the first compression depth, wherein the first trend line has a first function, the second trend line has a second function, and the third trend line has a third function, wherein the first function, the second function, and the third function are respectively y=a 1 (xp 1 ) 2 +q 1 , y=a 2 (xp 2 ) 2 +q 2 , y=a 3 (xp 3 ) 2 +q 3 , where a 1 、a 2 、a 3 are the quadratic coefficients of the first function, the second function and the third function, respectively, 1 、p 2 、p 3 are the x-axis coordinates of the vertices of the first function, the second function, and the third function, respectively, 1 ,q 2 ,q 3 are the y-axis coordinates of the vertices of the first function, the second function, and the third function, respectively. 1 、a 2 、a 3 are positive values ​​respectively.

[0021] It can be that a of the first function 1 is greater than the a of the second function 2 and a of the third function 3 , the second function a 2 is greater than a of the third function 3 .

[0022] It can be that the p of the first function 1 The range of the second function is 5um to 50um. 2The range is 50um to 150um, the third function p 3 The range of the first function is 160um to 250um. 1 The range of the second function is 100MPa to 300MPa. 2 The range of the third function is 5MPa to 80MPa. 3 The range is -60MPa to 0MPa.

[0023] It may be that the depth from the first surface to the first transition point is less than 10um, the stress at the first transition point is more than 200MPa, the depth from the first surface to the second transition point is 50um to less than 80um, and the stress at the second transition point is 40MPa to 100MPa.

[0024] It may be that the stress distribution in the second compression region has a symmetrical relationship with the stress distribution in the first compression region.

[0025] A display device according to one embodiment for solving the other problem includes: a display panel including a plurality of pixels; a window cover plate arranged above the display panel; and an optically transparent bonding layer arranged between the display panel and the window cover plate, the window cover plate including: a first surface; a second surface opposite to the first surface; a first compression area extending from the first surface to a first compression depth; a second compression area extending from the second surface to a second compression depth; and a stretching area arranged between the first compression depth and the second compression depth, the stress distribution of the first compression area includes a first trend line between the first surface and a first transition point, a second trend line between the first transition point and the second transition point, and a third trend line between the second transition point and the first compression depth, the depth from the first surface to the first transition point is less than 10um, the stress at the first transition point is greater than 200MPa, the depth from the first surface to the second transition point is less than 50um to 80um, the stress at the second transition point is 40MPa to 100MPa, and the stress is greater than 100MPa at 30um from the first surface.

[0026] It may be that the first trend line has a first average slope, the second trend line has a second average slope, the third trend line has a third average slope, the first average slope, the second average slope and the third average slope respectively have negative values, and the magnitude of the first average slope is respectively greater than the magnitude of the second average slope and the magnitude of the third average slope.

[0027] Details of other embodiments are included in the detailed description and drawings.

[0028] (Effect of Publicity)

[0029] According to the glass product and the display device according to one embodiment, the stress in the range corresponding to the depth of the common crack is increased, so that the crack resistance can be improved.

[0030] The effects according to the embodiments are not limited to the above-exemplified contents, and more effects are included in this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a perspective view of a glass article according to various embodiments.

[0032] Figure 2 4 is a cross-sectional view showing an example in which a glass product according to an embodiment is suitable for use as a window cover of a display device.

[0033] Figure 3 is a cross-sectional view of a flat plate-shaped glass article according to an embodiment.

[0034] Figure 4 is a schematic diagram showing an ion exchange process according to an embodiment.

[0035] Figure 5 is a graph showing stress distribution of a glass product according to an embodiment.

[0036] Figure 6 Is magnification Figure 5 Graph near the first compression region.

[0037] Figure 7 It is a schematic diagram showing a first average slope of a first trend line, a second average slope of a second trend line, a third average slope of a third trend line, a first tangent slope at a first transition point, and a second tangent slope at a second transition point.

[0038] Figure 8 1 is a schematic diagram showing crack resistance of a glass product according to an embodiment.

[0039] Fig. 9 is a graph showing stress distribution of a glass article according to another embodiment.

[0040] Fig.10 is a cross-sectional view showing a glass product further incorporating a spatter layer.

[0041] (Explanation of Reference Numerals)

[0042] 100, 101, 102, 103: Glass products

[0043] CSR1, CSR2: Compression Region

[0044] CTR: Stretch Area

[0045] CS1, CS2: Maximum compressive stress

[0046] TP1, TP2: Transition points

[0047] DOC1, DOC2: Compression depth DETAILED DESCRIPTION

[0048] Reference and attachment Figure 1 The advantages and features of the present disclosure and the methods for realizing them will become clear from the embodiments described in detail below. However, the present disclosure is not limited to the embodiments disclosed below, and can be implemented in various forms different from each other. The embodiments are provided only to make the disclosure of the present disclosure complete and to fully convey the scope of the disclosure to people with common knowledge in the technical field to which the present disclosure belongs. The present disclosure is limited only by the scope of the claims.

[0049] Reference to an element or layer being "on" another element or layer includes all cases where the element is directly on the other element or has other layers or other elements interposed therebetween. Throughout the specification, the same reference numerals refer to the same constituent elements.

[0050] Although the terms first, second, etc. are used to describe various constituent elements, it is clear that these constituent elements are not limited to these terms. These terms are used only to distinguish one constituent element from other constituent elements. Therefore, the first constituent element mentioned below can obviously also be the second constituent element within the technical concept of the present disclosure.

[0051] In this specification, a "glass product" refers to an object that is entirely composed of glass or partially contains glass.

[0052] Hereinafter, embodiments will be described with reference to the accompanying drawings.

[0053] Figure 1 is a perspective view of a glass article according to various embodiments.

[0054] Glass is used not only in tablet computers, laptops, smartphones, e-books, televisions, and computer monitors, but also in electronic devices including displays such as refrigerators and washing machines that include displays as window covers for protecting displays, display panel substrates, touch panel substrates, optical components such as light guides, etc. Glass can also be used in glass covers for car dashboards, glass covers for solar cells, built-in materials for building materials, windows for buildings or houses, etc.

[0055] Some glasses are required to have strong strength. For example, in the case of window glass, in order to meet the necessary conditions of high transmittance and light weight, it is preferred to have a thin thickness and a strength that is not easily broken by external impact. Glass with strengthened strength can be manufactured by methods such as chemical strengthening or thermal strengthening. Examples of various shapes of strengthened glass are shown in Figure 1 middle.

[0056] Reference Figure 1 In one embodiment, the glass product 100 may be in the shape of a flat sheet or a flat plate. In another embodiment, the glass products 101, 102, and 103 may be in a three-dimensional shape including a curved portion. For example, the edge of the flat portion may be bent (see "101"), or the entire portion may be bent (see "102"), or folded (see "103").

[0057] The planar shape of the glass products 100-103 may be a rectangle, but is not limited thereto, and may have various shapes such as a rectangle with rounded corners, a square, a circle, an ellipse, etc. In the following embodiments, as the glass products 100-103, a planar plate with a planar shape of a rectangle is used as an example for explanation, but it is obvious that it is not limited thereto.

[0058] Figure 2 4 is a cross-sectional view showing an example in which a glass product according to an embodiment is suitable for use as a window cover of a display device.

[0059] Reference Figure 2 The display device 500 may include a display panel 200 , a window cover plate 100 disposed on the display panel 200 , and an optically transparent bonding layer 300 disposed between the display panel 200 and the window cover plate 100 to bond the display panel 200 and the window cover plate 100 .

[0060] The display panel 200 includes not only self-luminous display panels such as an organic light-emitting display panel (OLED), an inorganic light-emitting display panel (inorganic EL), a quantum dot light-emitting display panel (QED), a micro-LED display panel (micro-LED), a nano-LED display panel (nano-LED), a plasma display panel (PDP), a field emission display panel (FED), a cathode ray display panel (CRT), etc., but also light-receiving display panels such as a liquid crystal display panel (LCD) and an electrophoretic display panel (EPD).

[0061] The display panel 200 includes a plurality of pixels PX, and an image can be displayed using light emitted from each pixel PX. The display device 500 may further include a touch component (not shown). In one embodiment, the touch component may be built into the display panel 200. For example, by directly forming a touch component on the display component of the display panel 200, the display panel 200 itself can perform a touch function. In another embodiment, the touch component may be separately manufactured relative to the display panel 200 and attached to the upper surface of the display panel 200 through an optically transparent bonding layer.

[0062] The window cover 100 is disposed above the display panel 200. The window cover 100 serves to protect the display panel 200. As the main body of the window cover 100, a tempered glass product 100 may be applicable. The window cover 100 may be larger than the display panel 200 and its side protrudes outward than the side of the display panel 200, but is not limited thereto. The window cover 100 may further include a printed layer disposed on at least one surface of the glass product 100 at an edge portion of the glass product 100. The printed layer of the window cover 100 makes it impossible to visually identify the frame area of ​​the display device 500 from the outside, and may perform a decorative function according to circumstances.

[0063] An optically transparent bonding layer 300 is disposed between the display panel 200 and the window cover 100. The optically transparent bonding layer 300 serves to fix the window cover 100 on the display panel 200. The optically transparent bonding layer 300 may include an optically clear adhesive (OCA) or an optically clear resin (OCR).

[0064] Hereinafter, the above-mentioned tempered glass product 100 will be described in more detail.

[0065] Figure 3 is a cross-sectional view of a flat plate-shaped glass article according to an embodiment.

[0066] Reference Figure 3 The glass article 100 may include a first surface US, a second surface RS, and a side surface. In the flat plate-shaped glass article 100, the first surface US and the second surface RS are main surfaces having a wide area, and the side surface becomes an outer side surface connecting the first surface US and the second surface RS.

[0067] The first surface US and the second surface RS are opposite to each other in the thickness direction. When the glass article 100 functions to transmit light like the window cover 100 of a display, light may mainly enter toward any one of the first surface US and the second surface RS and transmit toward the other.

[0068] The thickness t of the glass article 100 is defined by the distance between the first surface US and the second surface RS. Although the thickness t of the glass article 100 is not limited thereto, it can be in the range of 0.1 mm to 2 mm. In one embodiment, the thickness t of the glass article 100 can be about 0.8 mm or less. In another embodiment, the thickness t of the glass article 100 can be about 0.75 mm or less. In another embodiment, the thickness t of the glass article 100 can be about 0.7 mm or less. In another embodiment, the thickness t of the glass article 100 can be about 0.6 mm or less. In another embodiment, the thickness t of the glass article 100 can be about 0.65 mm or less. In another embodiment, the thickness t of the glass article 100 can be about 0.5 mm or less. In another embodiment, the thickness t of the glass article 100 can be about 0.3 mm or less. In certain embodiments, the thickness t of the glass article 100 can be in the range of 0.45 mm to 0.8 mm or in the range of 0.5 mm to 0.75 mm. The glass article 100 may have a uniform thickness t, but is not limited thereto, and may have thicknesses t that are different from each other according to regions.

[0069] The glass product 100 can be strengthened to have a predetermined stress distribution inside. The strengthened glass product 100 can better prevent the occurrence of cracks, the propagation of cracks, breakage, etc. caused by external impact than the glass product 100 before strengthening. The glass product 100 strengthened by the strengthening process can have various stresses according to the region. For example, it can be that the compression regions CSR1 and CSR2 with compressive stress are configured near the surface of the glass product 100, that is, near the first surface US and the second surface RS, and the tensile region CTR with tensile stress is configured inside the glass product 100. The boundary between the compression regions CSR1, CSR2 and the tensile region CTR can have a stress value of 0. The compressive stress in a compression region CSR1, CSR2 will have different stress values ​​depending on the position (that is, the depth from the surface). In addition, the tensile region CTR will also have different stress values ​​depending on the depth from the surface US, RS.

[0070] In the glass product 100, the positions of the compression regions CSR1 and CSR2, the stress distribution in the compression regions CSR1 and CSR2, the compression energy of the compression regions CSR1 and CSR2 or the tension energy of the tension region CTR, etc. have a great influence on the mechanical properties of the glass product 100 such as the surface strength. The details of this will be described later.

[0071] The glass article 100 includes a glass composition. The glass composition of the glass article 100 may include various components known in the art. In one embodiment, the glass composition may include LAS glass ceramics containing lithium aluminosilicate. For example, the glass composition may contain SiO in an amount of 50 mol% to 80 mol%. 2 , containing Al in an amount of 1 mol% to 30 mol% 2 O 3 , 0 mol% to 5 mol% of the content contains B 2 O 3 , containing P in an amount of 0 mol% to 4 mol% 2 O 5 , containing Li in an amount of 3 mol% to 20 mol% 2 O, containing Na in an amount of 0 mol% to 20 mol% 2 O, containing K in an amount of 0 mol% to 10 mol% 2 O, MgO at a content of 3 mol% to 20 mol%, CaO at a content of 0 mol% to 20 mol%, SrO at a content of 0 mol% to 20 mol%, BaO at a content of 0 mol% to 15 mol%, ZnO at a content of 0 mol% to 10 mol%, TiO at a content of 0 mol% to 1 mol% 2 , containing ZrO in an amount of 0 mol% to 8 mol% 2 .

[0072] Here, "content is 0 mol %" means that the corresponding component is not substantially contained. The composition "substantially containing" a specific component means that the specific component is intentionally not contained in the raw materials, etc., including the case where a trace amount of impurities of 0.1 mol % or less is inevitably contained, for example.

[0073] If we explain each component of the glass composition in more detail, SiO 2 It can play the role of forming the skeleton of glass, improving chemical durability, and reducing cracks when flaws (indentations) are generated on the glass surface. In order to fully perform the above-mentioned functions, SiO can be included in an amount of 50 mol% or more. 2 In order to exhibit sufficient melting properties, SiO 2 The content may be 80 mol% or less.

[0074] Al 2 O 3 It plays a role in improving the breakability of glass. 2 O 3 It can help to produce a smaller number of fragments when the glass breaks.2 O 3 It can act as an effective component to improve the ion exchange performance during chemical strengthening and increase the surface compressive stress after strengthening. 2 O 3 When the content of Al is 1 mol% or more, the above-mentioned functions can be effectively performed. On the other hand, in order to maintain the acid resistance and melting property of the glass, Al 2 O 3 The content is 30 mol% or less.

[0075] B 2 O 3 Improves the glass's resistance to chipping and improves its melting properties. 2 O 3 It can be omitted (0 mol%), but when it is contained in 0.5 mol% or more, the solubility of the glass can be further improved. 2 O 3 A content of 5 mol% or less is advantageous in suppressing the occurrence of streaks during melting.

[0076] P 2 O 5 Improve ion exchange performance and crack resistance. 2 O 5 It can be omitted (0 mol%), but can meaningfully perform the above function when it is contained in 0.5 mol% or more. 2 O 5 A content of 4 mol% or less helps prevent a significant decrease in crushability and acid resistance.

[0077] Li 2 O plays a role in forming surface compressive stress through ion exchange. Li ions arranged near the glass surface can be exchanged for Na ions etc. through the ion exchange process. 2 O can further improve the crushability of the glass. Li for efficient ion exchange 2 The content of O is 3 mol % or more, and preferably 20 mol % or less in view of acid resistance.

[0078] Na 2 O plays a role in forming surface compressive stress through ion exchange and improving the solubility of the glass. The Na ions arranged near the glass surface can be exchanged for K ions etc. through the ion exchange process. 2 O may be omitted, but when contained, it is preferably contained in an amount of 1 mol% or more in order to effectively perform the above-mentioned functions. When there is only a Li ion and Na ion exchange process without a K ion exchange process, Na may be preferably used for smooth Li ion and Na ion exchange. 2The content of O is less than 8 mol%. When accompanied by K ion exchange process, a larger amount of Na 2 O, but in this case, the content may preferably be 20 mol% or less from the viewpoint of acid resistance.

[0079] K 2 O improves ion exchange performance and is related to fragmentation. K 2 O can be omitted, but in order to improve the ion exchange performance, it can be contained in an amount of 0.5 mol% or more. K is used to prevent excessive decrease in crushing properties. 2 The content of O may be 10 mol% or less.

[0080] MgO increases the surface compressive stress of chemically strengthened glass and improves crushability. When the content is 3 mol% or more, the above-mentioned effects can be effectively performed. When the content of MgO is 20 mol% or less, it is beneficial to reduce the possibility of devitrification when the glass is melted.

[0081] CaO plays a role in improving the melting property of glass and improving crushability. CaO can be omitted, but in order to effectively perform the above-mentioned functions, it is preferably present in an amount of 0.5 mol% or more. If the content of CaO is too large, the ion exchange performance may decrease, so it is preferred that the content of CaO has a value of 20 mol% or less.

[0082] Like CaO, SrO plays a role in improving the melting property of glass and improving crushability. SrO can be omitted, but in order to effectively perform the above-mentioned functions, it is preferably present in an amount of 0.5 mol% or more. If the SrO content is too high, the ion exchange performance may decrease, so it is preferred that the SrO content has a value of 20 mol% or less.

[0083] BaO plays a role in improving the melting property of glass and improving its crushability. BaO can be omitted. In order to effectively perform the above-mentioned functions, it is preferably contained in an amount of 0.5 mol% or more. A BaO content of 15 mol% or less can be beneficial in preventing the ion exchange performance from decreasing.

[0084] ZnO plays a role in improving the meltability of glass. ZnO can be omitted, but when the content is 0.25 mol% or more, a significant effect of improving meltability can be achieved. In order to prevent the weather resistance from decreasing, the content of ZnO is preferably kept below 10 mol%.

[0085] TiO 2 Improve the breakability of chemically strengthened glass. TiO 2It can be omitted. When the content is 0.1 mol% or more, a significant effect of improving crushability can be achieved by including it. From the perspective of preventing devitrification during melting, TiO is preferably 2 The content is 1 mol% or less.

[0086] ZrO 2 It can increase the surface compressive stress based on ion exchange and improve the crushability of glass. ZrO 2 It can be omitted, but when it is contained in an amount of 0.5 mol% or more, it can effectively perform the above-mentioned functions. ZrO 2 A content of 8 mol% or less can be advantageous in suppressing devitrification during melting.

[0087] In addition to the above-listed components, the glass composition may also include Y 2 O 3 ,La 2 O 3 , Nb 2 O 5 、 2 O 5 , Gd 2 O 3 The composition of the glass product 100 can be changed by a molding process or an ion exchange process described later.

[0088] The glass composition can be formed into a plate glass shape by various methods known in the art, such as float process, fusion draw process, slot draw process, etc.

[0089] The chemical strengthening of the strengthened glass article 100 according to one embodiment can be performed by an ion exchange process. The ion exchange process is a process of exchanging ions inside the glass for other ions. Through the ion exchange process, ions on the surface of the glass or near it can be replaced or exchanged with larger ions with the same atomic valence or oxidation state. For example, when the glass includes Li + 、Na + , K + , Rb + When the monovalent alkali metal is present, the monovalent cation on the surface can be exchanged for Na with a larger ionic radius than that of + , K + , Rb + , Cs + ions. For a detailed description of the ion exchange process, refer to Figure 4 .

[0090] Figure 4is a schematic diagram showing an ion exchange process according to an embodiment.

[0091] Figure 4 The case where the sodium ions in the glass are exchanged for potassium ions is exemplified in FIG.

[0092] Reference Figure 4 , if the glass containing sodium ions is exposed to potassium ions by immersing it in a molten salt bath (bath) including potassium nitrate, the sodium ions inside the glass may be discharged to the outside and their positions may be replaced by potassium ions. The exchanged potassium ions have a larger ionic radius than sodium ions, so compressive stress is generated. The more potassium ions are exchanged, the greater the compressive stress becomes. Since the ion exchange is completed through the surface of the glass, the amount of potassium ions on the surface of the glass may be the largest. While a part of the exchanged potassium ions diffuses into the interior of the glass, the depth of the compression region, that is, the compression depth, can be increased, but the amount can be generally reduced the farther away from the surface. Therefore, the glass can have a stress distribution in which the compressive stress on the surface is the largest and the more it decreases towards the inside. However, the embodiments are not limited to the examples, and the stress distribution can be changed according to the temperature, time, number of times, presence or absence of heat treatment, etc. of the ion exchange process.

[0093] The ion exchange process may be performed more than three times. For example, the ion exchange process may include a primary ion exchange process, a secondary ion exchange process, and a tertiary ion exchange process. The primary ion exchange process to the tertiary ion exchange process may be performed in different baths. Each ion exchange process may be performed simultaneously on a plurality of glasses. That is, a plurality of glasses may be immersed in a bath, and ion exchange may be performed simultaneously in the plurality of glasses. A detailed description of the ion exchange process will be described later.

[0094] Hereinafter, stress distribution of the tempered glass product 100 will be described in detail.

[0095] Figure 5 is a graph showing stress distribution of a glass product according to an embodiment. Figure 5 In the graph of , the x-axis represents the thickness direction of the glass product. Figure 5 In the present specification, the magnitude of compressive / tensile stress refers to the magnitude of the absolute value regardless of the positive or negative value of the value.

[0096] Reference Figure 5The glass product 100 includes a first compression region CSR1 extending (or expanding) from the first surface US to a first compression depth DOC1 and a second compression region CSR2 extending (or expanding) from the second surface RS to a second compression depth DOC2. A tensile region CTR is disposed between the first compression depth DOC1 and the second compression depth DOC2. The overall stress distribution in the glass product 100 may have a symmetrical relationship between the two surface US and RS side regions with respect to the center in the thickness t direction. Although Figure 5 Although not shown in the figure, compression regions and tension regions may also be configured in a similar manner between the facing sides of the glass article 100 .

[0097] The first compression region CSR1 and the second compression region CSR2 play a role in resisting external impacts and preventing cracks from occurring in the glass product 100 or damage to the glass product 100. The greater the maximum compression stresses CS1 and CS2 of the first compression region CSR1 and the second compression region CSR2, the greater the strength of the glass product 100. External impacts are usually transmitted through the surface of the glass product 100, so having the maximum compression stresses CS1 and CS2 on the surface of the glass product 100 is advantageous in terms of durability. From this point of view, the compression stresses of the first compression region CSR1 and the second compression region CSR2 tend to be the largest on the surface and generally decrease as they go inward.

[0098] The first compression depth DOC1 and the second compression depth DOC2 prevent cracks or grooves formed on the first surface US and the second surface RS from propagating to the tensile region CTR inside the glass product 100. The larger the first compression depth DOC1 and the second compression depth DOC2, the better the cracks can be prevented from propagating. The location corresponding to the first compression depth DOC1 and the second compression depth DOC2 corresponds to the boundary between the compression regions CSR1 and CSR2 and the tensile region CTR, and the stress value thereof becomes 0.

[0099] Across the entire glass article 100, the tensile stress of the tensile region CTR may be balanced with the compressive stress of the compressive regions CSR1 and CSR2. That is, the sum of the compressive stress (i.e., the compressive energy) and the sum of the tensile stress (i.e., the tensile energy) in the glass article 100 may be the same. In the glass article 100, the stress energy accumulated in a region having a certain width in the thickness t direction may be calculated by integrating the stress distribution. When the stress distribution in the glass article 100 having a thickness of t is represented by a function f(x), the following relationship may hold.

[0100] [Formula 1]

[0101]

[0102] The greater the tensile stress inside the glass product 100, the greater the risk that the fragments will violently explode and break from the inside of the glass product 100 when the glass product 100 breaks. The maximum tensile stress that satisfies the fragility criterion of the glass product 100 is not limited thereto, but may satisfy the following relationship.

[0103] [Formula 2]

[0104] CT 1 ≤-38.7×ln(t)+48.2

[0105] In some embodiments, the maximum tensile stress CT1 may be 100 MPa or less or 85 MPa or less. On the other hand, a maximum tensile stress CT1 of 75 MPa or more may be preferred in terms of improving mechanical properties such as strength. In one embodiment, the maximum tensile stress CT1 may be 75 MPa or more and 85 MPa or less, but is not limited thereto.

[0106] The maximum tensile stress CT1 of the glass article 100 may be substantially located at the center of the thickness t direction of the glass article 100. For example, the maximum tensile stress CT1 of the glass article 100 may be located at a depth ranging from 0.4t to 0.6t or ranging from 0.45t to 0.55t, or at a depth of about 0.5t.

[0107] On the other hand, in order to improve the strength of the glass product 100, the compressive stress and the compression depth DOC1, DOC2 are preferably large, but if the compression energy increases, the tensile energy also increases, and the maximum tensile stress CT1 can also increase. In order to have high strength while meeting the fragility benchmark, it is preferred to adjust the stress distribution so that the maximum compressive stress CS1, CS2 and the compression depth DOC1, DOC2 are large and the compression energy becomes small. To this end, the first compression region CSR1 and the second compression region CSR2 may respectively include transition points where the slope of the stress distribution changes sharply. However, when cracks occur on the surface US, RS of the glass product 100 due to external impact, the cracks may penetrate to a depth of about 30um to 50um from the surface US, RS of the glass product 100. In order to improve the resistance to the cracks, the glass product 100 according to one embodiment can increase the stress at a depth of about 30um to 50um from the surface US, RS of the glass product 100.

[0108] In order to satisfy the above-mentioned high strength and brittleness standards, primary ion exchange and tertiary ion exchange are performed, but in order to improve crack resistance, secondary ion exchange may be performed between the primary ion exchange and the tertiary ion exchange.

[0109] That is, the glass product 100 according to one embodiment can include two transition points TP1, TP2 and two transition points TP3, PT4 in the compression regions CSR1, CSR2 by performing one to three ion exchanges. The shape of such stress distribution (especially the shape of the stress distribution of the compressive stress) can be precisely adjusted by adjusting the process conditions of the first ion exchange process, the second ion exchange process, and the third ion exchange process.

[0110] For a detailed description of the stress distribution in the compression region, refer to Figure 6 and Figure 7 The following description will focus on the stress distribution of the first compression region CSR1. The first compression region CSR1 and the second compression region CSR2 have a symmetrical relationship in stress distribution, so the description of the repetitive stress distribution of the second compression region CSR2 will be omitted or simplified.

[0111] Figure 6 Is magnification Figure 5 Graph near the first compression region. Figure 7 is a schematic diagram showing the first average slope of the first trend line, the second average slope of the second trend line, the third average slope of the third trend line, the first tangent slope at the first transition point, and the second tangent slope at the second transition point. Figure 6 In the figure, sample #1 represents the glass product 100 according to an embodiment in which three-stage strengthening is achieved, and sample #2 represents the glass product according to a comparative example in which two-stage strengthening is achieved.

[0112] Reference Figure 6 and Figure 7 , the stress distribution in the first compression region CSR1 may include a first trend line, a second trend line, and a third trend line.

[0113] The first trend line to the third trend line each have a negative slope, and the slope decreases as a whole from the first trend line to the third trend line.

[0114] In the first compression region CSR1 , the stress distribution includes at least two first transition points TP1 (or inflection points) and a second transition point TP2 (or inflection point) where the slope changes sharply.

[0115] The first transition point TP1 is located between the first surface US and the first compression depth DOC1. The stress distribution may be divided into a first trend line and a second trend line based on the first transition point TP1. That is, the stress distribution may include a first trend line extending from the first surface US to the first transition point TP1.

[0116] The second transition point TP2 is located between the first transition point TP1 and the first compression depth DOC1. The stress distribution can be divided into a second trend line and a third trend line based on the second transition point TP2. That is, the stress distribution can include a second trend line extending from the first transition point TP1 to the second transition point TP2, and a third trend line extending from the second transition point TP2 to the first compression depth DOC1.

[0117] The first trend line, the second trend line, and the third trend line can be divided by the ion types that invade respectively. For example, potassium ions generally invade the depth interval of the first trend line located relatively to the first surface US side in the first compression region CSR1, and potassium ions substantially less than the potassium ions that invade the depth interval of the first trend line can invade the depth interval of the second trend line. On the contrary, potassium ions may not substantially invade the third trend line. On the contrary, sodium ions having an ion size smaller than potassium ions not only invade the depth interval of the second trend line, but also invade the depth of the third trend line.

[0118] In the first compression region CSR1, the stress of the first trend line relative to the first surface US side can be mainly determined by the density of potassium ions. As described above, the interval of the first trend line may also include sodium ions, but the stress of the corresponding interval may mainly depend on the density of potassium ions with larger ion size. In the depth interval of the first trend line, the greater the density of potassium ions, the higher the stress is, and the stress distribution can be roughly similar to the density distribution of potassium ions. The first transition point TP1 can correspond to the maximum penetration depth of multiple potassium ions.

[0119] The stress of the second trend line located relatively inside the first compression region CSR1 can be determined by the density of potassium ions and sodium ions which are much less than the potassium ions invading the first trend line. That is, in the depth interval of the second trend line, the greater the density of the minority potassium ions and sodium ions, the higher the stress is, and the stress distribution can be roughly similar to the density distribution of the minority potassium ions and sodium ions.

[0120] The stress of the third trend line located innermost in the first compression region CSR1 is mainly determined by the density of sodium ions. That is, in the depth range of the third trend line, the greater the density of sodium ions, the higher the stress, and the stress distribution is roughly similar to the density distribution of sodium ions.

[0121] The first trend line can be expressed as a first function which is a quadratic function as shown in the following equation 3 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0122] [Formula 3]

[0123] y=a 1 (xp 1 )2 +q 1

[0124] In the first function, the coefficient of the quadratic term is a 1 The coefficients representing the shape and slope of the first function, p 1 is the x-axis coordinate (depth) of the vertex of the first function, q 1 is the y-axis coordinate of the vertex of the first function (stress).

[0125] The second trend line can be expressed by a second function that is a quadratic function as shown in the following equation 4 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0126] [Formula 4]

[0127] y=a 2 (xp 2 ) 2 +q 2

[0128] In the second function, the coefficient of the quadratic term is a 2 The coefficients representing the shape and slope of the second function, p 2 is the x-axis coordinate (depth) of the vertex of the second function, q 2 is the y-axis coordinate of the vertex of the second function (stress).

[0129] The third trend line can be expressed by a third function that is a quadratic function as shown in the following Expression 5 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0130] [Formula 5]

[0131] y=a 3 (xp 3 ) 2 +q 3

[0132] In the third function, the coefficient of the quadratic term, i.e., a 3 becomes the coefficient representing the shape and slope of the third function, p 3 is the x-axis coordinate (depth) of the vertex of the third function, q 3 is the y-axis coordinate of the vertex of the third function (stress).

[0133] In the function, the coefficient of the quadratic term, i.e., a 1 、a 2 and a 3That is, all the first tangent slopes of the first trend line may have negative values, all the second tangent slopes of the second trend line may have negative values, and all the third tangent slopes of the third trend line may have negative values.

[0134] It can be that a of the first function 1 is greater than the a of the second function 2 and a of the third function 3 , the second function a 2 is greater than a of the third function 3 That is, the slope of the first function may be greater than the slope of the second function and the slope of the third function, that is, the function width gradually increases as the first function, the second function, and the third function are approached.

[0135] It may be that the compressive stress CS of the first surface US is 700 MPa to 950 MPa, and the first compression depth DOC1 is 125 um to 135 um.

[0136] It can be that the x-axis coordinate of the vertex of the first function is p 1 The range is 5um to 50um, and the x-axis coordinate of the vertex of the second function is p 2 The range is 50um to 150um, and the x-axis coordinate of the vertex of the third function is p 3 The range is 160um to 250um, and the y-axis coordinate of the vertex of the first function is q 1 The range is 100MPa to 300MPa, and the y-axis coordinate of the vertex of the second function is q 2 The range is 5MPa to 80MPa, and the y-axis coordinate of the vertex of the third function is q 3 The range is -60MPa to 0MPa.

[0137] The slope (or inclination) of the stress distribution changes sharply with the first transition point TP1 and the second transition point TP2 as references.

[0138] The x-axis coordinate DOL_TP1 (depth from the first surface US to the first transition point TP1 ) at the first transition point TP1 may be approximately 20 um or less or approximately 10 um or less.

[0139] The y-axis coordinate CS_TP1 (stress) at the first transition point TP1 may be about 200 MPa or more.

[0140] The x-axis coordinate DOL_TP2 (depth from the first surface US to the second transition point TP2 ) at the second transition point TP2 may be about 50 um to about 80 um.

[0141] The y-axis coordinate CS_TP2 (stress) at the second transition point TP2 may be about 40 MPa to about 100 MPa.

[0142] According to one embodiment, the glass product 100 has a y-axis coordinate CS_TP1 (stress) at the first transition point TP1 of about 20 um or less or about 10 um when the x-axis coordinate DOL_TP1 (depth from the first surface US to the first transition point TP1) is about 20 um or less, and a y-axis coordinate CS_TP1 (stress) at the first transition point TP1 is about 200 MPa or more, and has a y-axis coordinate CS_TP2 (stress) at the second transition point TP2 of about 40 MPa to about 100 MPa when the x-axis coordinate DOL_TP2 (depth from the first surface US to the second transition point TP2) is about 50 um to about 80 um. Therefore, when cracks occur on the surfaces US and RS of the glass product 100 due to external impact, it is possible to ensure resistance to cracks that penetrate to a depth of about 30 um to 50 um from the surfaces US and RS of the glass product 100. That is, at a location where the x-axis coordinate of the stress distribution of the glass product 100 is 30 um to 50 um, the y-axis coordinate has a stress of about 100 MPa or more, thereby accommodating the crack depth and improving the crack resistance of the glass product 100 .

[0143] That is, in order to improve the resistance to the cracks, the glass article 100 according to an embodiment can increase stress at a depth of about 30 um to 50 um from the surface US, RS of the glass article 100 .

[0144] Reference Figure 7 , a line segment l1 of the first trend line connecting the first surface US to the first transition point TP1 can be expressed by a fourth function which is a linear function as shown in the following equation 6 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0145] [Formula 6]

[0146] y=a 4 x+b 1

[0147] In the fourth function, the coefficient of the first-order term, i.e., a 4 represents the slope of the fourth function, b 1 represents the stress at the first surface US of the fourth function.

[0148] A line segment l2 of the second trend line connecting the first transition point TP1 to the second transition point TP2 can be expressed by a fifth function that is a linear function as shown in the following Expression 7 in a coordinate plane where depth is the x-axis and stress is the y-axis.

[0149] [Formula 7]

[0150] y=a5 x+b 2

[0151] In the fifth function, the coefficient of the first-order term, i.e., a 5 represents the slope of the fifth function, b 2 represents the stress at the first surface US of the fifth function.

[0152] A line segment l3 of the third trend line connecting the second transition point TP2 to the first compression depth DOC1 can be expressed by a sixth function that is a linear function as shown in the following Expression 8 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0153] [Formula 8]

[0154] y=a 6 x+b 3

[0155] In the sixth function, the coefficient of the first-order term is a 6 represents the slope of the sixth function, b 3 represents the stress at the first surface US of the sixth function.

[0156] Refer to formula 6 to formula 8 and Figure 7 , a 4 to a 6 can have negative slopes, a 4 The absolute value of can be greater than a 5 The absolute value of a 6 The absolute value of a 5 The absolute value of can be greater than a 6 The absolute value of .

[0157] The tangent line l4 at the first transition point TP1 can be expressed by a seventh function that is a linear function as shown in the following Expression 9 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0158] [Formula 9]

[0159] y=a 7 x+b 4

[0160] In the seventh function, the coefficient of the first-order term, i.e., a 7 represents the slope of the seventh function, b 4 represents the stress at the first surface US of the seventh function.

[0161] The tangent line l5 at the second transition point TP2 can be expressed by an eighth function that is a linear function as shown in the following equation 10 in a coordinate plane where the depth is the x-axis and the stress is the y-axis.

[0162] [Formula 10]

[0163] y=a 8 x+b 5

[0164] In the eighth function, the coefficient of the first-order term is a 8 represents the slope of the eighth function, b 5 represents the stress at the first surface US of the eighth function.

[0165] Refer to equations 6 to 10 and Figure 7 , a 7 and a 8 can have negative values. It can be, a 7 The absolute value of has a 4 The absolute value of a 5 The absolute value of a 8 The absolute value of can have a 5 The absolute value of a 6 The absolute value of the value is between .

[0166] Refer again Figure 6 and Figure 7 The first trend line, the second trend line and the third trend line having different slopes may be generated by multiple ion exchange processes. The third trend line may be generated by a single ion exchange process, the second trend line may be generated by a secondary ion exchange process, and the first trend line may be generated by a tertiary ion exchange process.

[0167] To be more specific, the primary ion exchange process is a process of imparting compression depths DOC1 and DOC2 to the glass, which is usually carried out by exposing the glass to a single molten salt containing sodium ions or a mixed molten salt containing potassium ions and sodium ions. For example, for the primary ion exchange process, the glass is immersed in a first bath comprising a single molten salt containing sodium nitrate or a mixed molten salt mixed with potassium nitrate and sodium nitrate. When a mixed molten salt is used, the contents of potassium nitrate and sodium nitrate in the first bath are similar, but the content of sodium nitrate may be greater than the content of potassium nitrate. For example, the salt ratio of potassium nitrate and sodium nitrate may be adjusted in the range of 40:60 to less than 50:50. In one embodiment, in the mixed molten salt of the primary ion exchange process, the salt ratio of potassium nitrate and sodium nitrate may be 40:60, but is not limited thereto.

[0168] The primary ion exchange process may be performed at a temperature range of ±20° C. relative to a temperature 50° C. lower than the glass transition temperature. For example, when the glass transition temperature is about 580° C., the primary ion exchange process may be performed at a temperature above about 500° C. The primary ion exchange process time may be 3 to 8 hours, but is not limited thereto.

[0169] Through the primary ion exchange process, the lithium ions / sodium ions in the glass are exchanged for the sodium ions / potassium ions in the molten salt, which are larger ions than the lithium ions / sodium ions, and the concentration of the sodium ions and / or potassium ions in the glass increases. On the other hand, the molten salt provides and receives lithium ions from the glass, so the molten salt in the first bath after the primary ion exchange process may also include lithium ions in addition to the sodium ions and potassium ions.

[0170] After the primary ion exchange process and before the secondary ion exchange process, a stress relief process (or annealing process) may be performed. The stress relief process may be performed at a temperature above about 500°C for 1 to 3 hours. Through the stress relief process, the maximum compressive stress is reduced, and the sodium ions (and / or potassium ions) diffuse into the interior of the glass, and the compression depth can be increased. The stress relief process may be performed in air or in liquid. The stress relief process may also be omitted.

[0171] If the primary ion exchange process is completed (when the stress relief process is added, if the stress relief process is completed), a stress distribution corresponding to the third trend line is generated. That is, after the sodium ions and / or potassium ions of the mixed molten salt are exchanged and penetrated into the interior of the glass, they diffuse in the depth direction. The sodium ions generally diffuse to the first compression depth DOC1 to form a first compression region CSR1 having a compressive stress from the first surface US to the first compression depth DOC1. That is, the first compression depth DOC1 is determined by the primary ion exchange process and / or the stress relief process.

[0172] On the other hand, the density of the diffused ions is generally inversely proportional to the diffusion distance. Sodium ions and potassium ions diffuse from the surface of the glass into the interior of the glass through ion exchange and diffuse in the depth direction, so the concentration of sodium ions and potassium ions tends to decrease linearly as they are farther from the first surface US of the glass.

[0173] In addition, the diffusion degree of ions is inversely proportional to the size of the ions. That is, the smaller the size of the ions, the more they can diffuse. Therefore, when sodium ions and potassium ions completely penetrate into the interior of the glass through a single ion exchange process, sodium ions with a relatively smaller size diffuse more and can penetrate deeper. Although sodium ions diffuse to the first compression depth DOC1, potassium ions can diffuse to a depth below the second transition point TP2 at most.

[0174] Thus, the first compression depth DOC1 has a close correlation with the maximum diffusion depth of sodium ions as smaller ions to be ion-exchanged. The first compression depth DOC1 may be the same as the maximum diffusion depth of sodium ions, or even if there is a slight difference, it is located around and has a relationship substantially proportional to the maximum diffusion depth of sodium ions. Thus, the primary ion exchange process and / or stress relief process is a process for forming a predetermined first compression depth DOC1 through sufficient diffusion, and is performed for a sufficiently long time to allow the ions to diffuse sufficiently.

[0175] The stress distribution due to the sodium ions intruding through the primary ion exchange shows a shape like the third trend line.

[0176] Depending on the size of the diffused ions, the stress at the corresponding diffused portion is different. As described above, when cracks occur on the surface US, RS of the glass product 100 due to external impact, the cracks may penetrate to a depth of about 30um to 50um from the surface US, RS of the glass product 100. However, due to the small size of the sodium ions, it is difficult to ensure sufficient stress for crack resistance at the crack penetration depth. That is, the primary ion exchange process has limitations in forming sufficient stress for crack resistance at a depth of about 30um to 50um from the surface US, RS of the glass product 100. Therefore, in order to form a greater stress at the corresponding depth, a secondary ion exchange process is performed after the primary ion exchange process.

[0177] The secondary ion exchange process is a process for increasing the stress in the depth between the first transition point TP1 and the second transition point TP2 of the stress distribution of the glass product 100, for example, in the depth of about 30um to 50um, and is usually carried out in a manner of exposing to a mixed molten salt containing potassium ions and sodium ions. For example, for the secondary ion exchange process, the glass subjected to the primary ion exchange process is immersed in a second bath comprising a mixed molten salt mixed with potassium nitrate and sodium nitrate. The content of potassium nitrate in the second bath may be greater than that in the primary ion exchange process. For example, the salt ratio of sodium nitrate to potassium nitrate in the second bath may be adjusted in a range of more than 40:60 and less than 60:40. In one embodiment, the salt ratio of sodium nitrate to potassium nitrate in the second bath may be 50:50.

[0178] The secondary ion exchange process may be performed at a lower temperature and for a shorter time than the primary ion exchange process. For example, the secondary ion exchange process may be performed at a temperature range of 380° C. to 460° C. for 1 to 3 hours or 1.3 to 2 hours.

[0179] Through the secondary ion exchange, the stress in the depth between the first transition point TP1 and the second transition point TP2, for example, about 30um to 50um, can be increased. Specifically, the amount of potassium ions intruding into the corresponding depth through the secondary ion exchange can be greater than the amount of potassium ions intruding into the second transition point TP2 and the first compression depth DOC1 through the primary ion exchange. That is, the potassium ions intrude into the depth between the first transition point TP1 and the second transition point TP2, for example, about 30um to 50um, so that the compressive stress of the corresponding part is changed to be larger by the potassium ions of large size.

[0180] The stress distribution formed by the potassium ions that additionally intrude into the depth between the first transition point TP1 and the second transition point TP2 by the secondary ion exchange process takes a shape like the second trend line.

[0181] However, in the secondary ion exchange process, there is a limitation in increasing the maximum compressive stress CS1 of the first surface US because the potassium ion content does not differ greatly from the sodium ion content. Therefore, in order to form a larger surface compressive stress CS1, a tertiary ion exchange process is performed after the secondary ion exchange process.

[0182] As a process for increasing the maximum compressive stress CS1, the tertiary ion exchange process is usually carried out in a manner of exposing to a molten single salt containing potassium ions or a mixed molten salt containing potassium ions and sodium ions. For example, for the tertiary ion exchange process, the glass subjected to the secondary ion exchange process is immersed in a third bath comprising a single molten salt containing potassium nitrate or a mixed molten salt mixed with potassium nitrate and sodium nitrate. When using a mixed molten salt, the salt ratio is also adjusted so that potassium ions become the main ions invading the interior of the glass. That is, the content of potassium nitrate in the third bath is greater than that in the secondary ion exchange process, and further, the concentration of potassium nitrate can be greater than that of sodium nitrate. For example, the salt ratio of potassium nitrate and sodium nitrate in the third bath can be adjusted in the range of 80:20 to 98:2. In one embodiment, in the mixed molten salt of the tertiary ion exchange process, the salt ratio of potassium nitrate and sodium nitrate can be 92:8, but is not limited thereto.

[0183] The tertiary ion exchange process may be performed at a lower temperature and for a shorter time than the primary ion exchange process. For example, the tertiary ion exchange process may be performed at a temperature range of 380° C. to 460° C. for 1 to 3 hours or 1.3 to 2 hours.

[0184] The compressive stress in the shallow depth region of the glass surface US can be significantly increased by the tertiary ion exchange process. The stress distribution formed by the potassium ions additionally intruded by the tertiary ion exchange process shows a shape like the first trend line.

[0185] Figure 81 is a schematic diagram showing crack resistance of a glass product according to an embodiment.

[0186] Reference Figure 8 , the penetration depth d1 of the crack can be about 30um to 50um.

[0187] According to one embodiment, the glass product 100 is further subjected to a secondary ion exchange between the primary ion exchange and the tertiary ion exchange in a bath having a higher potassium content than the primary ion exchange, so that the stress in the depth range from the depth DOL_TP1 of the first transition point TP1 to the depth DOL_TP2 of the second transition point TP2 of the glass product 100 can be increased, thereby improving the resistance to the cracks.

[0188] Fig. 9 is a graph showing stress distribution of a glass product according to another embodiment, Fig.10 is a cross-sectional view showing a glass product further incorporating a spatter layer.

[0189] Reference Fig. 9 and Fig.10 The stress distribution of the glass product according to this embodiment is different from the stress distribution of the glass product 100 according to an embodiment in that the stress distribution of the glass product completes a total of 4 ion exchange processes and the first compression region includes three transition points (or inflection points).

[0190] To be more specific, the stress distribution of the glass article according to this embodiment completes a total of four ion exchange processes and the first compression region includes three transition points (or inflection points).

[0191] The x-axis coordinate DOL_TP1_1 (depth from the first surface US to the first transition point TP1_1 ) at the first transition point TP1_1 may be approximately 10 um or less.

[0192] The y-axis coordinate CS_TP1_1 (stress) at the first transition point TP1_1 may be about 700 MPa to more than 800 MPa.

[0193] The x-axis coordinate DOL_TP2_1 (depth from the first surface US to the second transition point TP2_1 ) at the second transition point TP2_1 may be about 15 um to about 30 um.

[0194] The y-axis coordinate CS_TP2_1 (stress) at the second transition point TP2_1 may be about 500 MPa to about 600 MPa.

[0195] The x-axis coordinate DOL_TP3_1 (depth from the first surface US to the third transition point TP3_1 ) at the third transition point TP3_1 may be about 80 um to about 100 um.

[0196] The y-axis coordinate CS_TP3_1 (stress) at the third transition point TP3_1 may be about 100 MPa to about 200 MPa.

[0197] The stress distribution of the glass article according to the present embodiment may include a first trend line from the first surface US to the first transition point TP1_1, a second trend line from the first transition point TP1_1 to the second transition point TP2_1, a third trend line from the second transition point TP2_1 to the third transition point TP3_1, and a fourth trend line from the third transition point TP3_1 to the first compression depth DOC1.

[0198] The average slopes of the first trend line, the second trend line, the third trend line, and the fourth trend line may all have negative values. The first trend line, the second trend line, the third trend line, and the fourth trend line may have average slopes whose absolute values ​​decrease in sequence.

[0199] The fourth trend line may be generated by performing a primary ion exchange in a bath of potassium nitrate and sodium nitrate in a ratio of 50:50 at a temperature of about 500° C. for about 2 hours to 5 hours, but the conditions are not limited thereto.

[0200] The third trend line may be generated by performing secondary ion exchange in a bath of potassium nitrate and sodium nitrate at a ratio of 70:30 at a temperature of about 380° C. to 460° C. for about 1 hour to 3 hours, but the conditions are not limited thereto.

[0201] The second trend line may be generated by performing three ion exchanges in a bath of potassium nitrate and sodium nitrate at a ratio of 95:2 at a temperature of about 380° C. to 460° C. for about 1 to 2 hours, but the conditions are not limited thereto.

[0202] The first trend line may be generated by performing four ion exchanges in a bath of potassium nitrate and sodium nitrate at a ratio of 98:2 at a temperature of about 300° C. for about 30 minutes to 1 hour, but the conditions are not limited thereto.

[0203] On the other hand, when the ion exchange process is performed four times as in this embodiment, the area of ​​the first compression region CSR1 can be increased. Therefore, the area of ​​the tension region CTR can also be increased at the same time. If the glass product is damaged due to the crack reaching the tension region CTR, the destructive force may be increased. Fig.10 Thus, by further disposing the scattering layer FM on the glass product 100, it is possible to prevent the scattering of broken pieces due to the breakage of the glass product. The scattering layer FM may include a film widely known in the technical field.

[0204] The embodiments of the present disclosure are described above with reference to the attached drawings, but it should be understood by those with common knowledge in the technical field to which the present disclosure belongs that the present disclosure can be implemented in other specific ways without changing the technical concept or essential features of the present disclosure. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and not restrictive.

Claims

1. A glass product, wherein: include: a first surface; a second surface, opposite to the first surface; a first compression region extending from the first surface to a first compression depth; a second compression region extending from the second surface to a second compression depth; as well as a stretching region disposed between the first compression depth and the second compression depth, The stress distribution of the first compression area includes a first trend line between the first surface and a first transition point, a second trend line between the first transition point and a second transition point, and a third trend line between the second transition point and the first compression depth, the first transition point and the second transition point being inflection points. The depth from the first surface to the first transition point is less than 10 um, The stress at the first transition point is above 200 MPa, The depth from the first surface to the second transition point is 50um to less than 80um, The stress at the second transition point is 40 MPa to 100 MPa.

2. The glass product according to claim 1, wherein: The first trend line has a first average slope, the second trend line has a second average slope, and the third trend line has a third average slope. The first average slope, the second average slope, and the third average slope each have a negative value.

3. The glass product according to claim 2, wherein: The first average slope is greater than the second average slope and the third average slope.

4. The glass product according to claim 3, wherein: The second average slope is greater than the third average slope.

5. The glass product according to claim 4, wherein: The tangent line at the first transition point has a first transition point slope, and the first transition point slope has a negative value.

6. The glass product according to claim 5, wherein: The magnitude of the first transition point slope has a value between the magnitude of the first average slope and the magnitude of the second average slope.

7. The glass product according to claim 6, wherein: The tangent line at the second transition point has a second transition point slope, and the second transition point slope has a negative value.

8. The glass product according to claim 7, wherein: The magnitude of the second transition point slope has a value between the magnitude of the second average slope and the magnitude of the third average slope.

9. The glass product according to claim 1, wherein: The first trend line has a first tangent slope, The second trend line has a second tangent slope, The third trend line has a third tangent slope, The first tangent slope, the second tangent slope, and the third tangent slope all have negative values.

10. The glass product according to claim 9, wherein: All the first tangent slopes of the first trend line have negative values, All the second tangent slopes of the second trend line have negative values, All of the third tangent slopes of the third trend line have negative values.

11. The glass product according to claim 1, wherein: The compressive stress of the first surface is 700 MPa to 950 MPa, and the first compression depth is 125 um to 135 um.

12. The glass product according to claim 1, wherein: The glass article includes lithium aluminosilicate.

13. The glass product according to claim 1, wherein: The stress distribution of the second compression region has a symmetrical relationship with the stress distribution of the first compression region.

14. A glass product, wherein: include: a first surface; a second surface, opposite to the first surface; a first compression region extending from the first surface to a first compression depth; a second compression region extending from the second surface to a second compression depth; as well as a stretching region disposed between the first compression depth and the second compression depth, The stress distribution of the first compression area includes a first trend line between the first surface and a first transition point, a second trend line between the first transition point and a second transition point, and a third trend line between the second transition point and the first compression depth, the first transition point and the second transition point being inflection points. The first trend line has a first function, The second trend line has a second function, The third trend line has a third function, The first function, the second function and the third function are respectively y=a1(x-p1) 2 +q1、 <h2 style=";text-align:left;direction:ltr">y = a2(x-p2)<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +q2、 <h2 style=";text-align:left;direction:ltr">y = a3(x-p3)<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +q3, Wherein, a1, a2, a3 are the quadratic coefficients of the first function, the second function and the third function, respectively; p1, p2, p3 are the x-axis coordinates of the vertices of the first function, the second function and the third function, respectively; q1, q2, q3 are the y-axis coordinates of the vertices of the first function, the second function and the third function, respectively; a1, a2, and a3 of the first function to the third function are positive values ​​respectively.

15. The glass product according to claim 14, wherein: a1 of the first function is greater than a2 of the second function and a3 of the third function, a2 of the second function is greater than a3 of the third function.

16. The glass article according to claim 15, wherein: The range of p1 of the first function is 5um to 50um, The range of p2 of the second function is 50um to 150um, The range of p3 of the third function is 160um to 250um, The range of q1 of the first function is 100MPa to 300MPa, The range of q2 of the second function is 5MPa to 80MPa, The range of q3 of the third function is -60 MPa to 0 MPa.

17. The glass article according to claim 14, wherein: The depth from the first surface to the first transition point is less than 10 um, The stress at the first transition point is above 200 MPa, The depth from the first surface to the second transition point is 50um to less than 80um, The stress at the second transition point is 40 MPa to 100 MPa.

18. The glass article according to claim 14, wherein: The stress distribution of the second compression region has a symmetrical relationship with the stress distribution of the first compression region.

19. A display device, wherein: include: A display panel including a plurality of pixels; A window cover plate, arranged above the display panel; as well as An optically transparent bonding layer is disposed between the display panel and the window cover. The window cover comprises: a first surface; a second surface, opposite to the first surface; a first compression region extending from the first surface to a first compression depth; a second compression region extending from the second surface to a second compression depth; and a stretching region disposed between the first compression depth and the second compression depth, The stress distribution of the first compression area includes a first trend line between the first surface and a first transition point, a second trend line between the first transition point and a second transition point, and a third trend line between the second transition point and the first compression depth, the first transition point and the second transition point being inflection points. The depth from the first surface to the first transition point is less than 10 um, The stress at the first transition point is above 200 MPa, The depth from the first surface to the second transition point is 50um to less than 80um, The stress at the second transition point is 40 MPa to 100 MPa, At a distance of 30 um from the first surface, the stress is above 100 MPa.

20. The display device according to claim 19, wherein: The first trend line has a first average slope, The second trend line has a second average slope, The third trend line has a third average slope, The first average slope, the second average slope, and the third average slope each have a negative value, The first average slope is greater than the second average slope and the third average slope.

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