Low modulus ion exchangeable glass for improved manufacturability

Abstract

The provided glass compositions have low Young's modulus and slot draw technology compatibility due at least in part to the liquidus viscosity and liquidus temperature. When ion exchanged, the resulting glass articles can exhibit a ratio of the compressive stress peak value (in MPa) to the Young's modulus value (in GPa) of 13.0 or greater. The glass articles can have a compressive stress peak value in the range from 850 MPa to 1400 MPa. The glass articles are suitable for various high strength applications, including cover glass applications that are subjected to significant bending stresses during use, for example, cover glass for flexible displays.

Description

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 145,655, filed February 4, 2021, which is the subject of this application and whose full text is incorporated herein by reference. Technical Field

[0002] This disclosure relates to ion-exchangeable glass compositions. Specifically, the embodiments described herein relate to ion-exchangeable glass compositions for use in various industries (e.g., consumer electronics, transportation, construction, defense, medical, and packaging). Even more specifically, this disclosure relates to glass compositions for cover glass applications (e.g., cover glass for flexible displays). Background Technology

[0003] Many consumer products, such as smartphones, tablets, portable media players, personal computers, and cameras, incorporate a cover glass that can be used as a display cover and may also include touch functionality. Users often drop these devices onto hard surfaces, which can damage the cover glass and negatively impact the device's usability; for example, touch functionality may be affected.

[0004] Foldable or flexible displays for consumer electronics applications may benefit from flexible, thin ion-exchange glass. The ion-exchange process makes glass more resistant to flexure failure by introducing compressive stress onto the glass surface. This compressive stress, introduced through ion exchange, can, among other things, help prevent defects that could cause the glass to fail.

[0005] Therefore, there is a continued demand for ion-exchangeable glass compositions with desired mechanical properties for a variety of applications, including flexible and / or foldable cover glass applications. Summary of the Invention

[0006] This disclosure relates to ion-exchangeable glass compositions having strength and flexibility suitable for a variety of applications (e.g., for cover glass applications in flexible and / or foldable displays) and having liquidus properties that enhance manufacturability.

[0007] According to aspect (1), a glass is provided. The glass comprises: 68.5 mol% and 69.5 mol% of SiO2; 10.0 mol% and 10.5 mol% of Al2O3; 4.05 mol% and 5.25 mol% of MgO; 0.04 mol% and 1.1 mol% of CaO; 14.5 mol% and 15.8 mol% of Na2O; and 0.1 mol% and 0.2 mol% of SnO2.

[0008] According to aspect (2), the glass of aspect (1) is provided, wherein the glass is substantially free of Li2O.

[0009] According to aspect (3), glass is provided from aspect (1) to the preceding aspect, wherein the glass is substantially free of K2O.

[0010] According to aspect (4), glass is provided from aspect (1) to the preceding aspect, wherein the glass is substantially free of ZnO.

[0011] According to aspect (5), glass is provided from aspect (1) to the preceding aspect, wherein the glass is substantially free of SrO.

[0012] According to aspect (6), glass is provided for any of aspects (1) to the preceding aspect, wherein the glass is substantially free of BaO.

[0013] According to aspect (7), glass is provided from aspect (1) to the preceding aspect, wherein the glass is substantially free of B2O3.

[0014] According to aspect (8), glass is provided from aspect (1) to the preceding aspect, wherein the glass is substantially free of P2O5.

[0015] According to aspect (9), glass is provided from aspect (1) to the preceding aspect, wherein the glass is substantially free of Fe2O3.

[0016] According to aspect (10), a glass is provided from aspect (1) to the preceding aspect, wherein the glass comprises: 68.80 mol% and 69.23 mol% of SiO2; 10.01 mol% and 10.32 mol% of Al2O3; 4.35 mol% and 5.17 mol% of MgO; 0.04 mol% and 1.03 mol% of CaO; 14.91 mol% and 15.56 mol% of Na2O; and 0.18 mol% and 0.19 mol% of SnO2.

[0017] According to aspect (11), glass is provided from aspect (1) to any of the preceding aspects, wherein: Al2O3+MgO+CaO≥15 mol%.

[0018] According to aspect (12), glass is provided from aspect (1) to the preceding aspect, wherein the glass has a liquidus viscosity greater than or equal to 1200 kP.

[0019] According to aspect (13), glass is provided from aspect (1) to the preceding aspect, wherein the glass has a liquidus viscosity greater than or equal to 1200 kP and less than or equal to 4000 kP.

[0020] According to aspect (14), glass is provided from aspect (1) to the preceding aspect, wherein the glass has a liquidus temperature of less than or equal to 1000°C.

[0021] According to aspect (15), glass is provided from aspect (1) to the preceding aspect, wherein the glass has a liquidus temperature greater than or equal to 800°C and less than or equal to 1000°C.

[0022] According to aspect (16), glass is provided from aspect (1) to the preceding aspect, wherein the glass has a Young's modulus of less than or equal to 72 GPa.

[0023] According to aspect (17), glass is provided from aspect (1) to the preceding aspect, wherein the glass has a Young's modulus greater than or equal to 70 GPa and less than or equal to 72 GPa.

[0024] According to aspect (18), a glass article is provided. The glass article comprises the glass of any one of aspects (1) to the preceding aspect, wherein the glass article has a thickness of less than or equal to 4 mm.

[0025] According to aspect (19), a glass article of aspect (18) is provided, wherein the thickness is greater than or equal to 15 μm and less than or equal to 200 μm.

[0026] According to aspect (20), a glass article is provided. The glass article includes: a compressive stress layer extending from the surface of the glass article to a compression depth, the compressive stress layer including a compressive stress peak (measured in MPa), wherein the glass article is formed by ion exchange of a glass substrate comprising glass as described in any of aspects (1) to (17).

[0027] According to aspect (21), a glass article of aspect (20) is provided, wherein the ratio of the peak compressive stress of the glass substrate to the Young's modulus (measured in GPa) before ion exchange is greater than or equal to 13.0.

[0028] According to aspect (22), a glass article is provided. The glass article comprises: a compressive stress layer extending from the surface of the glass article to a compression depth, the compressive stress layer comprising a peak compressive stress (measured in MPa), and the composition at the center of the glass article comprising: greater than or equal to 68.5 mol% and less than or equal to 69.5 mol% of SiO2; greater than or equal to 10.0 mol% and less than or equal to 10.5 mol% of Al2O3; greater than or equal to 4.05 mol% and less than or equal to 5.25 mol% of MgO; greater than or equal to 0.04 mol% and less than or equal to 1.1 mol% of CaO; greater than or equal to 14.5 mol% and less than or equal to 15.8 mol% of Na2O; and greater than or equal to 0.1 mol% and less than or equal to 0.2 mol% of SnO2.

[0029] According to aspect (23), a glass article of aspect (22) is provided, wherein the ratio of the peak compressive stress to the Young's modulus value (measured in GPa) is greater than or equal to 13.0, and the Young's modulus value is the Young's modulus of glass having the same composition as the center of the glass article.

[0030] According to aspect (24), glass articles of aspect (21) or (23) are provided, wherein the ratio of the peak compressive stress to the Young's modulus is less than or equal to 18.0.

[0031] According to aspect (25), a glass article is provided from aspect (20) to the preceding aspect, wherein the compression depth is greater than or equal to 5 μm.

[0032] According to aspect (26), a glass article is provided from aspect (20) to the preceding aspect, wherein the compression depth is greater than or equal to 5 μm and less than or equal to 40 μm.

[0033] According to aspect (27), a glass article is provided from aspect (20) to the preceding aspect, wherein the compression depth is greater than or equal to 20 μm.

[0034] According to aspect (28), a glass article is provided from aspect (20) to the preceding aspect, wherein the compression depth is greater than or equal to 20 μm and less than or equal to 40 μm.

[0035] According to aspect (29), a glass article is provided from aspect (20) to the preceding aspect, wherein the compression depth is in the range of 5% to 20% of the thickness of the glass article.

[0036] According to aspect (30), a glass article is provided from aspect (20) to the preceding aspect, wherein the peak compressive stress is greater than or equal to 850 MPa and less than or equal to 1400 MPa.

[0037] According to aspect (31), a glass article is provided from aspect (20) to the preceding aspect, wherein the peak compressive stress is greater than or equal to 900 MPa.

[0038] According to aspect (32), glass articles are provided in any of aspects (20) to the preceding aspect, wherein the glass articles have a thickness of less than or equal to 4 mm.

[0039] According to aspect (33), a glass article is provided from aspect (20) to the preceding aspect, wherein the glass article has a thickness greater than or equal to 15 μm and less than or equal to 200 μm.

[0040] According to aspect (34), a method is provided. The method comprises the step of contacting a glass substrate with an ion exchange medium to form a glass article, the glass article comprising a compressive stress layer extending from the surface of the glass article to a compression depth, wherein the glass substrate comprises glass as claimed in any one of claims 1 to 17, and the compressive stress layer comprises a compressive stress peak measured in MPa.

[0041] According to aspect (35), the method of aspect (34) is provided, wherein the ratio of the peak compressive stress of the glass substrate to the Young's modulus (measured in GPa) before ion exchange is greater than or equal to 13.0.

[0042] According to aspect (36), the method of aspect (35) is provided, wherein the ratio of the peak compressive stress to the Young's modulus is less than or equal to 18.0.

[0043] According to aspect (37), a method of aspect (34) to any of the preceding aspects is provided, wherein the ion exchange medium contains greater than or equal to 50% by weight of potassium salt.

[0044] According to aspect (38), a method is provided for aspect (34) to any of the preceding aspects, wherein the ion exchange medium comprises KNO3.

[0045] According to aspect (39), a method is provided for any one of aspect (34) to the preceding aspect, wherein the contact lasts for a period of time greater than or equal to 1 hour and less than or equal to 24 hours.

[0046] According to aspect (40), a method is provided for any one of aspect (34) to the preceding aspect, wherein the contact lasts for a time greater than or equal to 1 hour and less than or equal to 8 hours.

[0047] According to aspect (41), a method of aspect (34) to any of the preceding aspects is provided, wherein the ion exchange medium is at a temperature greater than or equal to 350°C and less than or equal to 480°C.

[0048] According to aspect (42), the method of providing aspect (34) to any of the preceding aspects further includes: etching glass articles.

[0049] According to aspect (43), a method is provided for aspect (34) to any of the preceding aspects, wherein the compression depth is greater than or equal to 5 μm.

[0050] According to aspect (44), a method is provided for any one of aspect (34) to the preceding aspect, wherein the compression depth is greater than or equal to 5 μm and less than or equal to 40 μm.

[0051] According to aspect (45), a method is provided for aspect (34) to any of the preceding aspects, wherein the compression depth is greater than or equal to 20 μm.

[0052] According to aspect (46), a method is provided for aspect (34) to any of the preceding aspects, wherein the compression depth is greater than or equal to 20 μm and less than or equal to 40 μm.

[0053] According to aspect (47), the method of aspect (34) to any of the preceding aspects is provided, wherein the compression depth is in the range of 5% to 20% of the thickness of the glass article.

[0054] According to aspect (48), a method is provided for aspect (34) to any of the preceding aspects, wherein the peak compressive stress is greater than or equal to 850 MPa and less than or equal to 1400 MPa.

[0055] According to aspect (49), a method is provided for aspect (34) to any of the preceding aspects, wherein the peak compressive stress is greater than or equal to 900 MPa.

[0056] According to aspect (50), a method is provided for aspect (34) to any of the preceding aspects, wherein the glass article has a thickness of less than or equal to 4 mm.

[0057] According to aspect (51), a method of aspect (34) to any of the preceding aspects is provided, wherein the glass article has a thickness greater than or equal to 15 μm and less than or equal to 200 μm.

[0058] According to aspect (52), an electronic device is provided. The electronic device includes: an electronic display; and a glass article of any one of aspects (18) to (33), the glass article being disposed above the electronic display.

[0059] According to aspect (53), the electronic device of aspect (52) further includes: a housing including a front surface, a rear surface and a side surface; and an electrical component at least partially disposed within the housing, the electrical component including a controller, memory and an electronic display, wherein the electronic display is disposed at or adjacent to the front surface of the housing, and a glass article forms at least a portion of the housing. Attached Figure Description

[0060] The accompanying drawings, which are incorporated herein by reference and form part of this specification, illustrate embodiments of the present disclosure. Together with the detailed description, the drawings further serve to explain the principles and enable those skilled in the art to make and use the disclosed embodiments. These drawings are illustrative and not restrictive. Although the present disclosure is generally described in the context of these embodiments, it should be understood that the scope of the present disclosure is not intended to be limited to these specific embodiments. In the drawings, the same reference numerals denote the same or functionally similar components.

[0061] Figure 1 A cross-sectional view of a glass article having a compressive stress region according to some embodiments is shown.

[0062] Figure 2 A cross-sectional view of a glass article when it is bent, according to some embodiments.

[0063] Figure 3A A plan view of an exemplary electronic device incorporating any glass article disclosed herein.

[0064] Figure 3B for Figure 3A A perspective view of an exemplary electronic device. Detailed Implementation

[0065] The following implementation methods and examples are illustrative and not intended to limit the scope of this disclosure. Other suitable modifications and adjustments to various conditions and parameters that are commonly encountered in the technical field to which this application pertains and are obvious to those skilled in the art fall within the spirit and scope of this disclosure.

[0066] The glass described herein is a type of ion-exchangeable alkali metal aluminosilicate glass that can achieve high peak compressive stress through ion exchange. As used herein, "ion-exchangeable" means a glass composition, or a glass article containing such composition, capable of exchanging a first cation located at or near the surface of a substrate with a second cation of the same valence. The first ion may be a sodium ion. The second ion may be an ion of one of potassium, rubidium, or cesium, provided that the ionic radius of the second ion is greater than that of the first ion. The first ion is present in the glass substrate as its oxide (e.g., Na₂O). As used herein, "ion-exchanged glass" or "chemically strengthened glass" means that the glass has undergone at least one ion exchange process, in which cations located at or near the surface of the glass are exchanged with cations of the same valence.

[0067] The glass compositions described herein can be ion-exchanged to achieve high peak compressive stress. In some embodiments, the glass described herein can be ion-exchanged to achieve peak compressive stresses of about 900 MPa or greater, and up to about 1400 MPa. The high peak compressive stress imparted during the ion-exchange process provides high strength to glass with a shallow defect size distribution, thereby preventing failure during bending. The high peak compressive stress allows the glass to maintain net compression, thus allowing surface defects to be contained when the glass is subjected to close-radius bending. The glass according to the embodiments disclosed herein has a low Young's modulus, which results in lower bending stress values ​​during bending and thus prevents failure during bending events.

[0068] Furthermore, the glass composition described herein exhibits a peak compressive stress to Young's modulus ratio (peak compressive stress / Young's modulus, CS / E, where CS is in MPa and E is in GPa) of 13.0 or greater over a wide range of compression depths in the compression zone produced by the ion exchange process. Increasing this ratio is difficult because a higher Young's modulus is a common way to increase compressive stress; therefore, the surface compressive stress imparted during the ion exchange process is strongly influenced by the Young's modulus. In other words, the Young's modulus is a measure of the stiffness of the network. For example: [The text abruptly ends here, likely due to an incomplete translation or missing information.] + Ion exchange to Na +Sites provide compressive stress, but as the network becomes stiffer (as Young's modulus increases), expansion stress becomes even higher. Therefore, a common approach to achieving higher CS is to increase the Young's modulus of the ion-exchanged glass. In contrast, the glass compositions described herein achieve high CS while maintaining a low Young's modulus. A high CS / E ratio allows glass articles formed from the glass compositions to retain flexibility even after ion exchange. The glass compositions described herein have a sufficiently low Young's modulus before ion exchange and impart sufficiently high compressive stress values ​​during the ion exchange process to achieve a high CS / E ratio over a wide range of compression depths. This results in glass compositions that are flexible while also exhibiting high peak compressive stress. The glass compositions are able to withstand high surface compressive stresses at large compression depths (e.g., up to 50 μm), at least in part because the compositions resist stress relaxation that can occur during the ion exchange process. Stress relaxation, which becomes more pronounced with increasing temperature and time, is prone to occur in ion exchange processes where high compression depths are desired. These properties of the glass compositions described herein make them suitable for a variety of industrial applications, including high-strength cover glass applications that withstand significant bending stresses during use, such as cover glass in flexible foldable displays.

[0069] As used herein, “peak compressive stress” refers to the highest compressive stress (CS) value measured within the compressive stress region. In some embodiments, the peak compressive stress is located at the surface of the glass. In other embodiments, the peak compressive stress may occur at a depth below the surface, resulting in a “buried peak” distribution of compressive stress. Unless otherwise stated, compressive stress (including surface CS) is measured using a commercially available instrument, such as the FSM-6000 manufactured by Orihara Industrial Co., Ltd. (Japan). Surface stress measurement relies on the accurate measurement of the stress optical coefficient (SOC) related to the birefringence of the glass. SOC can be measured using Procedure C (glass disk method) as described in ASTM Standard C770-16, entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient.”

[0070] As used herein, “depth of compression (DOC)” refers to the depth at which stress within a glass article changes from compression to tension. At DOC, stress transitions from compressive stress to tensile stress and therefore exhibits a zero stress value. Depth of compression and layer depth can be measured using a surface stress meter (e.g., an FSM-6000 surface stress meter). As used herein, “depth of layer (DOL)” refers to the depth to which ions of a metal oxide diffuse into the glass article, where the ion concentration reaches its minimum. In embodiments where only potassium enters the glass article via ion exchange, DOC may be equal to DOL. Unless otherwise stated herein, DOC and DOL are considered equivalent.

[0071] The glass compositions described herein can also be manufactured at a reasonable cost. The glass compositions exhibit liquidus temperatures and liquidus viscosities suitable for certain manufacturing techniques (e.g., slot forming). These thermal properties increase the ease of manufacturing glass articles made from the compositions, which can reduce costs. Among other things, the glass compositions described in this disclosure particularly have alumina and magnesium oxide contents that contribute to achieving ideal liquidus viscosities and temperatures. In embodiments, the glass compositions may have a liquidus viscosity greater than or equal to 1200 kP (kiloposite).

[0072] The glass compositions described herein offer one or more of the following benefits: (1) Even without lithium, the compositions achieve high compressive stress values ​​at small depths of layer (DOL) during ion exchange. (2) The compositions have a low modulus, which contributes to a higher CS / E ratio and improves flexibility for thin, foldable applications. (3) The raw materials used to manufacture these glasses are inexpensive and readily available. (4) The compositions have a high per-modifier content, which facilitates melting. The “per-modifier” content of a glass composition means that the value of (R2O mol% + RO mol% - Al2O3 mol%) is greater than 0 mol%, where R2O mol% is the total mol% of all alkali metal oxides in the composition, and RO mol% is the total mol% of all alkaline earth metal oxides in the composition. (5) The compositions have liquidus temperatures and liquidus viscosities that are favorable for slot formation.

[0073] The glass compositions described herein exhibit properties comparable to existing glasses used in chemically strengthened applications (such as flexible and / or foldable applications) that withstand significant bending stresses, while also being formable using slot drawing techniques. Compatibility with slot drawing techniques, when compared to glass compositions used in similar applications, depends at least on the relatively high liquidus viscosity of the glass composition (greater than about 1200 kP). In other words, the glass compositions described herein offer the desired properties of existing flexible chemically strengthened glass articles while providing improved manufacturability. The glass compositions described herein are alkali metal aluminosilicates with a limited MgO content and containing CaO.

[0074] As used herein, the term "glass articles" is intended to include any material that is at least partially formed of glass.

[0075] For the glass compositions described herein, unless otherwise specified, the concentration of constituent components (e.g., SiO2, Al2O3, Na2O, etc.) is specified as a mole percentage (mol%) of oxides. The components of the glass compositions according to embodiments are discussed separately below. It should be understood that any range within the various reference ranges of a component can be independently combined with any range within the various reference ranges of any other component. As used herein, a trailing 0 in a number is intended to indicate the number of significant digits. For example, the number "1.0" includes two significant digits, and the number "1.00" includes three significant digits.

[0076] SiO2 can be the largest component in a glass composition, and therefore, it is the main component of the glass network formed by the glass composition. Pure SiO2 has a relatively low coefficient of thermal expansion (CTE – this property is measured at temperatures from 0°C to 300°C, as used herein) and is alkali-free. However, pure SiO2 has a high melting point. Therefore, if the concentration of SiO2 in the glass composition is too high, the formability of the glass composition can be reduced, because a higher concentration of SiO2 increases the difficulty of melting the glass, thus adversely affecting the formability of the glass.

[0077] In embodiments, the glass composition may include SiO2 in amounts greater than or equal to 68.5 mol% and less than or equal to 69.5 mol%, such as greater than or equal to 68.6 mol% and less than or equal to 69.4 mol%, greater than or equal to 68.7 mol% and less than or equal to 69.3 mol%, greater than or equal to 68.8 mol% and less than or equal to 69.2 mol%, greater than or equal to 68.9 mol% and less than or equal to 69.1 mol%, greater than or equal to 69.0 mol% and less than or equal to 69.5 mol%, and any and all ranges formed by any of the foregoing values. In embodiments, the glass composition may include SiO2 in amounts greater than or equal to 68.80 mol% and less than or equal to 69.23 mol%.

[0078] The glass composition disclosed herein includes Al2O3. The added Al2O3 can act as a glass network forming agent. Furthermore, when the concentration of Al2O3 in the composition is in equilibrium with the concentration of SiO2 and the concentration of alkali metal oxides, Al2O3 can lower the liquidus temperature of the glass melt.

[0079] In embodiments, the glass composition may include Al2O3 in amounts greater than or equal to 10.0 mol% and less than or equal to 10.5 mol%, such as greater than or equal to 10.1 mol% and less than or equal to 10.4 mol%, greater than or equal to 10.2 mol% and less than or equal to 10.3 mol%, and any and all ranges formed by any of the foregoing values. In embodiments, the glass composition may include Al2O3 in amounts greater than or equal to 10.01 mol% and less than or equal to 10.32 mol%.

[0080] In embodiments, the total amount of Al2O3, MgO, and CaO in the glass composition may be greater than or equal to 15 mol%, such as greater than or equal to 15.0 mol%, greater than or equal to 15.1 mol%, greater than or equal to 15.2 mol%, greater than or equal to 15.3 mol%, greater than or equal to 15.4 mol%, greater than or equal to 15.5 mol%, greater than or equal to 15.6 mol%, or greater than or equal to 15.7 mol%. In embodiments, the total amount of Al2O3, MgO, and CaO in the glass composition may be greater than or equal to 15.0 mol% and less than or equal to 15.8 mol%, such as greater than or equal to 15.1 mol% and less than or equal to 15.7 mol%, greater than or equal to 15.2 mol% and less than or equal to 15.6 mol%, greater than or equal to 15.3 mol% and less than or equal to 15.5 mol%, greater than or equal to 15.0 mol% and less than or equal to 15.4 mol%, and any and all ranges formed by any of the foregoing values.

[0081] The aforementioned Al₂O₃+MgO+CaO values ​​are advantageous for the glass compositions disclosed herein. These Al₂O₃+MgO+CaO values ​​contribute to the glass compositions' ability to achieve peak compressive stress over a wide range of compression depths.

[0082] The glass compositions described herein include Na₂O. Na₂O can contribute to the ion exchangeability of the glass composition and improve its formability, thereby improving the manufacturability of the glass composition. However, if excessive Na₂O is added to the glass composition, the CTE may be too low and the melting point may be too high.

[0083] In embodiments, the glass composition may include Na₂O in amounts greater than or equal to 14.5 mol% and less than or equal to 15.8 mol%, such as greater than or equal to 14.6 mol% and less than or equal to 15.7 mol%, greater than or equal to 14.7 mol% and less than or equal to 15.6 mol%, greater than or equal to 14.8 mol% and less than or equal to 15.5 mol%, greater than or equal to 14.9 mol% and less than or equal to 15.4 mol%, greater than or equal to 15.0 mol% and less than or equal to 15.3 mol%, greater than or equal to 15.1 mol% and less than or equal to 15.2 mol%, and any and all ranges formed by any of the foregoing values. In embodiments, the glass composition may include Na₂O in amounts of 15 mol% or more, 15.5 mol% or more, 16 mol% or more, 16.5 mol% or more, 17 mol% or more, 17.5 mol% or more, or 18 mol%. In this embodiment, the glass composition comprises Na2O in amounts greater than or equal to 14.91 mol% and less than or equal to 15.56 mol%.

[0084] The glass compositions described herein include MgO. MgO reduces the viscosity of the glass, which improves its formability and manufacturability. The inclusion of MgO in the glass composition also improves the strain point and Young's modulus, as well as the ion exchangeability of the glass. However, if too much MgO is added to the glass composition, the liquidus viscosity may be too low to be compatible with slot forming techniques. The glass compositions described herein have a magnesium-containing liquidus phase, forsterite; therefore, reducing the amount of MgO in the composition lowers the liquidus temperature, thereby increasing the liquidus viscosity. Adding too much MgO may also increase the density, and the CTE of the glass composition may increase to undesirable levels.

[0085] In embodiments, the glass composition may include MgO in amounts of: greater than or equal to 4.05 mol% and less than or equal to 5.25 mol%, such as: greater than or equal to 4.10 mol% and less than or equal to 5.20 mol%, greater than or equal to 4.15 mol% and less than or equal to 5.15 mol%, greater than or equal to 4.20 mol% and less than or equal to 5.10 mol%, greater than or equal to 4.25 mol% and less than or equal to 5.05 mol%, greater than or equal to 4.30 mol% and less than or equal to 5.00 mol%, greater than or equal to 4.35 mol%. The amounts are mol% and less than or equal to 4.95 mol%, greater than or equal to 4.40 mol% and less than or equal to 4.90 mol%, greater than or equal to 4.45 mol% and less than or equal to 4.85 mol%, greater than or equal to 4.50 mol% and less than or equal to 4.80 mol%, greater than or equal to 4.55 mol% and less than or equal to 4.75 mol%, greater than or equal to 4.60 mol% and less than or equal to 4.70 mol%, greater than or equal to 4.65 mol% and less than or equal to 4.95 mol%, and any and all ranges formed by any of the foregoing values. In embodiments, the glass composition may include MgO in amounts greater than or equal to 4.35 mol% and less than or equal to 5.17 mol%.

[0086] The glass compositions described herein include CaO. CaO can reduce the viscosity of the glass, which improves formability, strain point, and Young's modulus, and also enhances the ion exchangeability of the glass. However, if excessive CaO is added to the glass composition, the density and CTE of the glass composition can increase to undesirable levels.

[0087] In embodiments, the glass composition may include CaO in amounts greater than or equal to 0.04 mol% and less than or equal to 1.1 mol%, such as greater than or equal to 0.05 mol% and less than or equal to 1.1 mol%, greater than or equal to 0.1 mol% and less than or equal to 1.0 mol%, greater than or equal to 0.2 mol% and less than or equal to 0.9 mol%, greater than or equal to 0.3 mol% and less than or equal to 0.8 mol%, greater than or equal to 0.4 mol% and less than or equal to 0.7 mol%, greater than or equal to 0.5 mol% and less than or equal to 0.6 mol%, and any and all ranges formed by any of the foregoing values. In embodiments, the glass composition includes CaO in amounts greater than or equal to 0.04 mol% and less than or equal to 1.03 mol%.

[0088] The glass composition includes one or more clarifying agents. In embodiments, the clarifying agent may include, for example, SnO2. In embodiments, the glass composition includes SnO2 in amounts greater than or equal to 0.1 mol% and less than or equal to 0.2 mol%, such as greater than or equal to 0.10 mol% and less than or equal to 0.20 mol%, greater than or equal to 0.11 mol% and less than or equal to 0.19 mol%, greater than or equal to 0.12 mol% and less than or equal to 0.18 mol%, greater than or equal to 0.13 mol% and less than or equal to 0.17 mol%, greater than or equal to 0.14 mol% and less than or equal to 0.16 mol%, greater than or equal to 0.11 mol% and less than or equal to 0.15 mol%, and any and all ranges formed by any of the foregoing values. In embodiments, the glass composition includes SnO2 in amounts greater than or equal to 0.18 mol% and less than or equal to 0.19 mol%.

[0089] The glass compositions described herein may be free of or substantially free of one or more of the following: ZnO, SrO, BaO, B2O3, P2O5, Li2O, K2O, and Fe2O3. In embodiments, the glass compositions may be free of or substantially free of all of the following: ZnO, SrO, BaO, B2O3, P2O5, Li2O, K2O, and Fe2O3. Some of these oxides may be expensive and / or have limited availability. Alkaline earth metal oxides may undesirably increase Young's modulus and may slow down the ion exchange process. B2O3, P2O5, and K2O can reduce the compressive stress applied during the ion exchange process. The glass articles described herein achieve advantageous properties without the need for these oxides. Therefore, the compositions may exclude these oxides. As used herein, the term "substantially free" means that the component is not added as a component of the batch, even if the component may be present in very small amounts as a contaminant in the final glass. The raw materials and / or equipment used to produce the glass compositions of this disclosure may result in the presence of certain unintentionally added impurities or components in the final glass composition. Such materials, present in small amounts in the glass composition, are referred to as “tramp material.” A composition “substantially free” of a component means that the component was not intentionally added to the composition, but the composition may still contain trace amounts of the component. A composition “substantially free” of an oxide means that the oxide is present in an amount less than or equal to 0.1 mol% (e.g., from 0 mol% to 0.1 mol%). As used herein, a glass composition “free” of a component is defined as meaning that the component (e.g., an oxide) is not present in the composition, even if it is a trace or impurity.

[0090] The physical properties of the glass compositions disclosed herein and glass articles made from the glass compositions are discussed below.

[0091] In embodiments, the Young's modulus (E) of the glass composition may be less than or equal to 72 GPa, such as less than or equal to 72.0 GPa, less than or equal to 71.5 GPa, less than or equal to 71.0 GPa, less than or equal to 71 GPa, less than or equal to 70.5 GPa, or less. In embodiments, the glass composition may have a Young's modulus within the following ranges: greater than or equal to 70 GPa and less than or equal to 72 GPa, such as greater than or equal to 70.0 GPa and less than or equal to 72.0 GPa, greater than or equal to 70.5 GPa and less than or equal to 71.5 GPa, greater than or equal to 70.5 GPa and less than or equal to 71.0 GPa, and any and all ranges formed by any of the foregoing values.

[0092] Unless otherwise specified, the Young's modulus and Poisson's ratio values ​​disclosed in this disclosure refer to values ​​measured using the general type of resonant ultrasound spectrometry technique as described in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts". Furthermore, unless otherwise specified, the Young's modulus and Poisson's ratio of the glass composition or article are measured prior to any ion exchange process or any other strengthening process. Specifically, the Young's modulus and Poisson's ratio of the glass composition or article are measured before exposure to an ion exchange medium, for example, before immersion in an ion exchange bath.

[0093] In embodiments, the liquidus viscosity of the glass composition may be greater than or equal to 1200 kP, such as greater than or equal to 1300 kP, greater than or equal to 1400 kP, greater than or equal to 1500 kP, greater than or equal to 1600 kP, greater than or equal to 1700 kP, greater than or equal to 1800 kP, greater than or equal to 1900 kP, greater than or equal to 2000 kP, greater than or equal to 2100 kP, greater than or equal to 2200 kP, greater than or equal to 2300 kP, greater than or equal to 2400 kP, greater than... Or equal to 2500kP, greater than or equal to 2600kP, greater than or equal to 2700kP, greater than or equal to 2800kP, greater than or equal to 2900kP, greater than or equal to 3000kP, greater than or equal to 3100kP, greater than or equal to 3200kP, greater than or equal to 3300kP, greater than or equal to 3400kP, greater than or equal to 3500kP, greater than or equal to 3600kP, greater than or equal to 3700kP, greater than or equal to 3800kP, greater than or equal to 3900kP or greater. In embodiments, the liquidus viscosity of the glass composition can be within the following ranges: greater than or equal to 1200 kP and less than or equal to 4000 kP, such as greater than or equal to 1300 kP and less than or equal to 3900 kP, greater than or equal to 1400 kP and less than or equal to 3800 kP, greater than or equal to 1500 kP and less than or equal to 3700 kP, greater than or equal to 1600 kP and less than or equal to 3600 kP, greater than or equal to 1700 kP and less than or equal to 3500 kP, greater than or equal to 1800 kP and less than or equal to 3400 kP, greater than or equal to 1900 kP and less than or equal to 3300 kP. 00kP, greater than or equal to 2000kP and less than or equal to 3200kP, greater than or equal to 2100kP and less than or equal to 3100kP, greater than or equal to 2000kP and less than or equal to 3000kP, greater than or equal to 2100kP and less than or equal to 2900kP, greater than or equal to 2200kP and less than or equal to 2800kP, greater than or equal to 2300kP and less than or equal to 2700kP, greater than or equal to 2400kP and less than or equal to 2600kP, greater than or equal to 2500kP and less than or equal to 4000kP, and any and all ranges formed by any of the foregoing values.

[0094] As used herein, the term "liquidus viscosity" refers to the viscosity of molten glass at its liquidus temperature, where the liquidus temperature is the temperature at which the molten glass first crystallizes as it cools down from its melting temperature, or the temperature at which the last crystal melts as the temperature rises from room temperature. Unless otherwise specified, the liquidus viscosity disclosed in this application is determined by the following methods: First, the liquidus temperature of the glass is measured according to ASTM C829-81 (2015), entitled "Standard Practice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method." Next, the viscosity of the glass at its liquidus temperature is measured according to ASTM C965-96 (2012), entitled "Standard Practice for Measuring Viscosity of Glass Above the Softening Point." Unless otherwise specified, the liquidus viscosity and temperature of the glass composition or article are measured before the composition or article undergoes any ion exchange process or any other strengthening process. Specifically, the liquidus viscosity and temperature of the glass composition or article are measured before it is exposed to an ion-exchange solution, for example, before it is immersed in an ion-exchange solution.

[0095] In embodiments, the liquidus temperature of the glass composition may be less than or equal to 1000°C, such as less than or equal to 975°C, less than or equal to 950°C, less than or equal to 925°C, less than or equal to 900°C, less than or equal to 875°C, less than or equal to 850°C, less than or equal to 825°C, or lower. In embodiments, the liquidus temperature of the glass composition may be within the following ranges: greater than or equal to 800°C and less than or equal to 1000°C, such as greater than or equal to 825°C and less than or equal to 975°C, greater than or equal to 850°C and less than or equal to 950°C, greater than or equal to 875°C and less than or equal to 925°C, greater than or equal to 800°C and less than or equal to 900°C, and any and all ranges formed by any of the aforementioned endpoints. Unless otherwise specified, the liquidus temperature of glass shall be measured in accordance with ASTM C829-81 (2015), entitled “Standard Practice for Measurement of Liquidus Temperature of Glass by the Gradient Furnace Method.” Unless otherwise specified, the liquidus temperature referred to herein is the internal liquidus temperature.

[0096] Using the above composition, glass articles according to the embodiments can be formed by any suitable method, such as slot forming, float forming, rolling processes, etc. The glass composition and articles made therefrom may be characterized by their formation method. For example, the glass composition may be characterized by being float-formable (i.e., formed by the float process), draw-formable, and specifically, slot-drawn.

[0097] In this embodiment, the glass article described herein can be formed by a pull-down process. The pull-down process produces a glass article with a uniform thickness and a relatively pristine surface. Because the average flexural strength of the glass article is controlled by the amount and size of surface defects, the pristine surface with minimal contact has high initial strength. Furthermore, the pull-down glass article has a very flat, smooth surface, which can be used in the final application to the substrate without requiring costly grinding and polishing.

[0098] The glass articles described herein can be formed by a slot drawing process. In the slot drawing process, molten raw glass is supplied to a drawing groove. The bottom of the drawing groove has an open slot with nozzles extending along the length of the slot. The molten glass flows through the slot and / or the nozzles and is drawn downwards as a continuous glass article into the annealing zone.

[0099] Drawing processes are ideal for forming glass articles (e.g., glass sheets) because they allow for the formation of thin glass articles with very few defects. The liquidus viscosity of the glass compositions described herein (e.g., a liquidus viscosity greater than or equal to 1200 kPa) is compatible with drawing processes, especially slot drawing processes. The liquidus temperature of the glass compositions described herein also enhances the compatibility of the glass compositions with existing forming methods (such as slot drawing). Therefore, the glass compositions described herein are compatible with existing forming methods, thereby improving the manufacturability of glass articles formed from said glass compositions.

[0100] In one or more embodiments, the glass articles described herein may exhibit an amorphous microstructure and may be substantially free of crystals or microcrystals. In other words, in some embodiments, the glass articles exclude glass-ceramic materials. In some embodiments, the glass articles described herein may include glass-ceramic materials.

[0101] As described above, glass compositions and articles made from glass compositions can be strengthened by ion exchange processes. See also... Figure 1The glass article 100 may have one or more regions under compressive stress. For example, the glass article 100 may have a first compressive stress region 120 and / or a second compressive stress region 122 extending from the outer surface (e.g., surfaces 110, 112) of the glass article 100 to the depth of compression (DOC, d1, d2), and a second region (e.g., central region 130) extending from the DOC into the central or internal region of the glass article 100 under tensile stress or CT. The ion-exchanged compressive stress regions 120, 122 have different metal oxide concentrations at two or more points through the thickness (t) of the glass article 100. The compressive stresses of the two regions 120 and 122 are balanced by the tension stored in the central region 130 of the glass article 100.

[0102] According to the conventions commonly used in the art to which this application pertains, compressive force or compressive stress (CS) is expressed as a negative (<0) stress and tensile force or tensile stress is expressed as a positive (>0) stress. However, in this specification, CS is expressed as a positive or absolute value—that is, as described herein, CS = |CS|. CS may have a maximum value at the glass surface, and CS may vary as a function with respect to the distance d from the surface. Please see again Figure 1 The first compressive stress region 120 extends from the first surface 110 to a depth d1, while the second compressive stress region 122 extends from the second surface 112 to a depth d2. These compressive stress regions 120 and 122 together define the compression region or CS region of the glass article 100.

[0103] In an embodiment, the peak compressive stress in one or more compressive stress regions of the glass article may be in the range of greater than or equal to 850 MPa and less than or equal to 1400 MPa, such as greater than or equal to 900 MPa and less than or equal to 1350 MPa, greater than or equal to 950 MPa and less than or equal to 1300 MPa, greater than or equal to 1000 MPa and less than or equal to 1250 MPa, greater than or equal to 1050 MPa and less than or equal to 1200 MPa, greater than or equal to 1100 MPa and less than or equal to 1150 MPa, and any and all ranges formed between the aforementioned values. In an embodiment, the peak compressive stress in one or more compressive stress regions of the glass article may be greater than or equal to 900 MPa, such as greater than or equal to 950 MPa, greater than or equal to 1000 MPa, greater than or equal to 1050 MPa, greater than or equal to 1100 MPa, greater than or equal to 1150 MPa, greater than or equal to 1200 MPa, greater than or equal to 1250 MPa, greater than or equal to 1300 MPa, greater than or equal to 1350 MPa or greater.

[0104] In embodiments, the ratio of peak compressive stress to Young's modulus (peak compressive stress / Young's modulus, CS / E, where the unit of Young's modulus is GPa and the unit of CS is MPa) of a glass article made from the glass composition described herein may be 13.0, such as greater than or equal to 13.1, greater than or equal to 13.2, greater than or equal to 13.3, greater than or equal to 13.4, greater than or equal to 13.5, greater than or equal to 13.6, greater than or equal to 13.7, greater than or equal to 13.8, greater than or equal to 13.9, greater than or equal to 14.0, greater than or equal to 14.1 or greater. In embodiments, the glass article may have a CS / E ratio of the type described herein within the following ranges: greater than or equal to 13.0 and less than or equal to 18.0, such as greater than or equal to 13.1 and less than or equal to 17.5, greater than or equal to 13.2 and less than or equal to 17.0, greater than or equal to 13.3 and less than or equal to 16.5, greater than or equal to 13.4 and less than or equal to 16.0, greater than or equal to 13.5 and less than or equal to 15.5, greater than or equal to 13.6 and less than or equal to 15.0, greater than or equal to 13.7 and less than or equal to 14.5, greater than or equal to 13.8 and less than or equal to 14.1, greater than or equal to 13.9 and less than or equal to 14.0, and any and all ranges formed by any of the foregoing values. For the purposes of calculating the CS / E ratio described herein, Young's modulus (E) is the Young's modulus of the glass substrate used to form the glass article, or the Young's modulus of glass having the same composition as the center of the glass article.

[0105] These CS / E ratios and CS / E ratio ranges can be achieved at the peak compressive stress and / or compression depth described herein. For example, in one embodiment, the glass article can have the aforementioned CS / E ratio or CS / E ratio range at a peak compressive stress greater than or equal to 850 MPa and less than or equal to 1400 MPa. In another embodiment, the glass article can have the aforementioned CS / E ratio or CS / E ratio range at a compression depth in the range of 5 micrometers to 40 micrometers. In yet another embodiment, the glass article can have the aforementioned CS / E ratio or CS / E ratio range at a compression depth in the range of 5 micrometers to 40 micrometers. In yet another embodiment, the glass article can have the aforementioned CS / E ratio or CS / E ratio range at a compression depth in the range of 5% to 20% of the glass article thickness. In an embodiment, the glass article may have the above-mentioned CS / E ratio or CS / E ratio range under a peak compressive stress in the range of greater than or equal to 850 MPa and less than or equal to 1400 MPa and a compression depth in the range of greater than or equal to 5 μm and less than or equal to 40 μm.

[0106] For a given glass thickness, the high peak compressive stress achievable via ion exchange provides the ability to bend the glass to a tighter (i.e., smaller) bend radius. This high peak compressive stress allows the glass to maintain net compression, thus allowing surface defects to be contained when the glass is subjected to bending along a tighter radius. If near-surface defects are contained under this net compression, or within an effective surface compression layer, they will not propagate to failure.

[0107] Figure 2 The illustration depicts a two-point bend of a glass article 100 between two plates 200 using a bending force 202. The bending force 202 is applied using a two-point bend testing apparatus, wherein during the bend test, the two plates 200 press against the glass article 100 with a constant force (bending force 202). If necessary, fasteners associated with the testing apparatus ensure that the glass article 100 bends symmetrically relative to the fold line 210 when the bending force 202 is applied to the glass article 100 through the plates 200. The plates 200 may move together until a specific plate distance D is reached. As used herein, the term "failure" under bending force refers to cracking, breakage, delamination, crack propagation, permanent deformation, or other mechanisms that render the article unsuitable for its intended purpose.

[0108] exist Figure 2 In the process, the surface 110 of the glass article 100 is subjected to tensile stress due to bending, which causes the effective DOC from the surface 110 to decrease compared to the DOC from the surface 110 when the article is not bent, while the surface 112 is subjected to additional compressive stress due to bending. The effective DOC from the surface 110 increases with increasing plate distance and decreases with decreasing plate distance (when the surface 112 of the article 100 bends towards itself, such as...). Figure 2 (As shown). In other words, the effective depth of charge (DOC) is the DOC under unbent conditions minus the effective depth of charge resulting from the tensile stress caused by bending.

[0109] In an embodiment, when the glass article 100 is held between two plates 200 at 60°C and 93% relative humidity with a plate distance (D) of 10 mm or less for 240 hours, it can avoid failure during a static two-point bend test. For example, in an embodiment, when the glass article 100 is held between two plates at 60°C and 93% relative humidity with a plate distance (D) of 10 mm to 1 mm for 240 hours, it can avoid failure during a static two-point bend test. The plate distance (D) can be, for example, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, or any distance falling within any range formed by these values.

[0110] Depending on the ion exchange treatment and the thickness of the workpiece being measured, the depth of compression (DOC) can be measured using a surface stress meter or a scattered light polariscope (SCALP). When stress is generated in the substrate by exchanging potassium ions into it, a surface stress meter such as the FSM-6000 (Orihara Kogyo Co., Ltd., Japan) is used to measure the depth of compression. When stress is generated by exchanging sodium ions into it and the workpiece thickness exceeds approximately 400 micrometers, SCALP is used to measure the depth of compression and maximum center tension (CT). When stress is generated in the substrate by exchanging both potassium and sodium ions into it and the workpiece thickness exceeds approximately 400 micrometers, SCALP is used to measure the depth of compression and CT. Not wishing to be limited by theory, the sodium exchange depth can represent the depth of compression, while the potassium ion exchange depth can represent the change in compressive stress (but not necessarily the change from compression to tension). As used herein, "depth of layer" refers to the depth to which ions (e.g., sodium, potassium) have been exchanged into the substrate. Throughout this disclosure, when the maximum center tension cannot be directly measured by SCALP (e.g., when the test article is thinner than about 400 micrometers), the maximum center tension can be approximated by dividing the product of the maximum compressive stress and the compression depth by the difference between the substrate thickness and twice the compression depth, wherein the compressive stress and compression depth are measured by FSM.

[0111] When the substrate thickness is greater than approximately 400 micrometers, a graphical representation of the stress distribution can also be derived using the refracted near-field (RNF) method. When using the RNF method to derive a graphical representation of the stress distribution, the maximum CT value provided by SCALP is applied to the RNF method. Specifically, the stress distribution measured by the RNF is force-balanced and calibrated according to the maximum CT value provided by the SCALP measurement. The RNF method is described in U.S. Patent No. 8,854,623, entitled "Systems and methods for measuring a profile characteristic of a glass sample," which is incorporated herein by reference in its entirety. Specifically, the RNF method includes the following steps: placing a glass article in the vicinity of a reference block; generating a polarization-switched beam (which switches between orthogonal polarizations at a rate between 1 Hz and 50 Hz); measuring the power in the polarization-switched beam and generating a polarization-switched reference signal, wherein the power measured in each orthogonal polarization is within 50% of each other. The method further includes the following steps: transmitting a polarization-switched beam through a glass sample and a reference block to different depths within the glass sample, and then using a relay optical system to relay the transmitted polarization-switched beam to a signal photodetector, which generates a polarization-switched detector signal. The method also includes the following steps: dividing the detector signal by the reference signal to form a normalized detector signal, and determining the distribution characteristics of the glass sample from the normalized detector signal.

[0112] When performing SCALP measurements, a SCALP polarizer (e.g., SCALP-04 or SCALP-05) available from GlassStress Ltd. (Tallinn, Estonia) is used. Precise sample velocity (SS) and exposure time (t) are crucial when measuring samples to characterize at least one stress-related property. E To reduce measurement noise in a polarimeter to an acceptable level, many factors are involved. These factors include the characteristics of the image sensing device (e.g., gain, image capture rate (frames / second), pixel size, internal pixel averaging techniques, etc.), as well as the nature of the no-stress-related (NSR) correlated scattering characteristics, the intensity of the input beam, and the number of polarization states used. Other factors include the measurement wavelength of the beam from the laser source and the intensity of the scattered beam. Exemplary measurement wavelengths may include 640 nm, 518 nm, and 405 nm. Exemplary exposure times may range from 0.05 ms to 100 ms. Exemplary frame rates may range from 10 to 200 frames per second. Exemplary calculations of optical delay may be performed over measurement times t ranging from 0.1 s to 10 s.M It utilizes 2 to 200 frames.

[0113] In an embodiment, the glass article may have a maximum CT in the range of greater than or equal to 20 MPa and less than or equal to 400 MPa, such as greater than or equal to 50 MPa and less than or equal to 350 MPa, greater than or equal to 75 MPa and less than or equal to 300 MPa, greater than or equal to 100 MPa and less than or equal to 250 MPa, greater than or equal to 150 MPa and less than or equal to 200 MPa, and any and all ranges formed by any of the foregoing values.

[0114] In one embodiment, the DOC of regions 120 and 122 may be equal, resulting in a symmetrical stress distribution in the glass article. In other embodiments, the DOC of regions 120 and 122 may be different. In one embodiment, the DOC of the glass article may be in the range of greater than or equal to 5 μm and less than or equal to 40 μm, such as greater than or equal to 10 μm and less than or equal to 35 μm, greater than or equal to 15 μm and less than or equal to 30 μm, greater than or equal to 20 μm and less than or equal to 25 μm, greater than or equal to 20 μm and less than or equal to 40 μm, and any and all ranges formed by any of the foregoing values. In one embodiment, the DOC of the glass article may be greater than or equal to 5 μm, such as greater than or equal to 10 μm, greater than or equal to 15 μm, greater than or equal to 20 μm, greater than or equal to 25 μm, greater than or equal to 30 μm, greater than or equal to 35 μm, or greater.

[0115] The Depth of Compression (DOC) may also be reported as part of the thickness (t) of the glass article 100. In embodiments, the glass article may also have a Depth of Compression (DOC) in the range of greater than or equal to 5% (0.05t) of the thickness of the glass article and less than or equal to 20% (0.20t) of the thickness of the glass article, such as greater than or equal to 10% (0.10t) of the thickness of the glass article and less than or equal to 15% (0.15t) of the thickness of the glass article, and any and all ranges formed by any of the foregoing values.

[0116] The thickness (t) of the glass article 100 is measured between surface 110 and surface 112. In this embodiment, the thickness of the glass article 100 is less than or equal to 4 mm, such as less than or equal to 3.5 mm, less than or equal to 3 mm, less than or equal to 2.5 mm, less than or equal to 2 mm, less than or equal to 1.5 mm, less than or equal to 1 mm, less than or equal to 1000 μm, less than or equal to 975 μm, less than or equal to 950 μm, less than or equal to 925 μm, less than or equal to 900 μm, less than or equal to 875 μm, less than or equal to 850 μm, less than or equal to 825 μm, less than or equal to 800 μm, less than or equal to 775 μm, less than or equal to 750 μm, less than or equal to 725 μm, less than or equal to 700 μm, less than or equal to 675 μm, less than or equal to 650 μm, less than or equal to 625 μm. Less than or equal to 600 μm, less than or equal to 575 μm, less than or equal to 550 μm, less than or equal to 525 μm, less than or equal to 500 μm, less than or equal to 475 μm, less than or equal to 450 μm, less than or equal to 425 μm, less than or equal to 400 μm, less than or equal to 375 μm, less than or equal to 350 μm, less than or equal to 325 μm, less than or equal to 300 μm, less than or equal to 275 μm, less than or equal to 250 μm, less than or equal to 225 μm, less than or equal to 200 μm, less than or equal to 175 μm, less than or equal to 150 μm, less than or equal to 125 μm, less than or equal to 100 μm, less than or equal to 75 μm, less than or equal to 50 μm, less than or equal to 25 μm, or smaller.In embodiments, the thickness of the glass article 100 can be within the range of greater than or equal to 15 μm and less than or equal to 4 mm, such as greater than or equal to 25 μm and less than or equal to 3.5 mm, greater than or equal to 50 μm and less than or equal to 3 mm, greater than or equal to 75 μm and less than or equal to 2.5 mm, greater than or equal to 100 μm and less than or equal to 2 mm, greater than or equal to 125 μm and less than or equal to 2.5 mm, greater than or equal to 150 μm and less than or equal to 2 mm, greater than or equal to 175 μm and less than or equal to 1.5 mm, greater than or equal to 200 μm and less than or equal to 1 mm, greater than or equal to 225 μm and less than or equal to 1000 μm, greater than or equal to 250 μm and less than or equal to 975 μm, greater than or equal to 275 μm and less than or equal to 950 μm, greater than or equal to 300 μm and less than or equal to 925 μm, greater than or equal to 4 mm, and so on. The range is equal to 325 μm and less than or equal to 900 μm, greater than or equal to 350 μm and less than or equal to 875 μm, greater than or equal to 375 μm and less than or equal to 850 μm, greater than or equal to 400 μm and less than or equal to 825 μm, greater than or equal to 425 μm and less than or equal to 800 μm, greater than or equal to 450 μm and less than or equal to 775 μm, greater than or equal to 475 μm and less than or equal to 750 μm, greater than or equal to 500 μm and less than or equal to 725 μm, greater than or equal to 525 μm and less than or equal to 700 μm, greater than or equal to 550 μm and less than or equal to 675 μm, greater than or equal to 575 μm and less than or equal to 650 μm, greater than or equal to 600 μm and less than or equal to 625 μm, greater than or equal to 15 μm and less than or equal to 200 μm, and any and all ranges formed by any of the aforementioned endpoints. In one embodiment, the glass substrate used to form the glass article may have the same thickness as the required thickness of the glass article.

[0117] A compressive stress layer extending from the surface of the glass article to the compression depth can be formed in a glass article by exposing the glass substrate to an ion exchange medium. In an embodiment, the ion exchange medium may be a molten salt bath, such as a molten salt bath comprising molten potassium salt. In an embodiment, the ion exchange medium may comprise potassium salt in amounts greater than or equal to 50% by weight, such as greater than or equal to 60% by weight, greater than or equal to 70% by weight, greater than or equal to 80% by weight, greater than or equal to 90% by weight, or 100% by weight. In an embodiment, the ion exchange medium comprises potassium salt in the ranges of greater than or equal to 50% by weight and less than or equal to 100% by weight, such as greater than or equal to 60% by weight and less than or equal to 95% by weight, greater than or equal to 70% by weight and less than or equal to 90% by weight, greater than or equal to 80% by weight and less than or equal to 100% by weight, and any and all ranges formed by any of the foregoing values. In an embodiment, the potassium salt may be KNO3. In an embodiment, all or part of the remaining weight percentage in the ion exchange medium may be molten nitrate, such as NaNO3.

[0118] Glass substrates can be exposed to ion exchange media by immersing them in an ion exchange medium bath, spraying the ion exchange medium onto the glass substrate, or physically applying the ion exchange medium to the glass substrate. Glass substrates can be formed from any of the glass compositions described herein. After the ion exchange process, it should be understood that the composition of the glass article surface may differ from that of the glass substrate at the time of formation (e.g., the glass substrate before the ion exchange process). This is due to a type of alkali metal ion (such as Na+) in the glass at the time of formation. + ) is affected by larger alkali metal ions (such as K) + (This is replaced by...) However, in some embodiments, the glass composition at the center of the glass article will still have the same or substantially the same composition as the glass substrate at the time of formation. Unless otherwise specified, the glass composition disclosed in this application refers to the composition of the glass article at its center, wherein the composition is unaffected (or minimally affected) by the ion exchange process, i.e., the composition of the glass substrate at the time of formation. For this reason, it is contemplated that glass having the same composition as the composition at the center of the glass article will have the same properties as the glass substrate. As used herein, the center of the glass article refers to any location within the glass article at a distance of at least 0.5t from all its surfaces, where t is the thickness of the glass article.

[0119] According to the embodiment, when in contact with the glass substrate, the ion exchange medium can be at a temperature greater than or equal to 350°C and less than or equal to 480°C, such as greater than or equal to 360°C and less than or equal to 470°C, greater than or equal to 370°C and less than or equal to 460°C, greater than or equal to 380°C and less than or equal to 450°C, greater than or equal to 390°C and less than or equal to 440°C, greater than or equal to 400°C and less than or equal to 430°C, greater than or equal to 410°C and less than or equal to 420°C, and all ranges formed between the aforementioned values.

[0120] In an embodiment, the glass substrate may be exposed to the ion exchange medium for a time greater than or equal to 1 hour and less than or equal to 24 hours, such as greater than or equal to 2 hours and less than or equal to 20 hours, greater than or equal to 4 hours and less than or equal to 16 hours, greater than or equal to 6 hours and less than or equal to 12 hours, greater than or equal to 8 hours and less than or equal to 12 hours, greater than or equal to 1 hour and less than or equal to 8 hours, and all ranges formed by any of the foregoing values.

[0121] The glass article may also undergo additional processing. In one embodiment, the glass article may be etched after ion exchange. Etching can be used to reduce the thickness of the glass article and / or achieve a desired shape. In another embodiment, the glass article may have the same or substantially the same thickness as the glass substrate used to form the glass article.

[0122] The glass articles disclosed herein can be incorporated into another article (e.g., articles having a display (or display article) (e.g., consumer electronics, including mobile phones, watches, tablet computers, computers, navigation systems, and the like), building articles, transport articles (e.g., vehicles, trains, aircraft, ships, etc.), appliance articles, or any article that may benefit from some transparency, scratch resistance, abrasion resistance, or a combination thereof). Figure 3A and Figure 3B Exemplary articles incorporating any glass article disclosed herein are illustrated. Specifically, Figure 3A and 3B The consumer electronics product 300 includes a housing 302 having a front surface 304, a back surface 306, and a side surface 308. Electrical components at least partially or entirely located within the housing may include at least a controller 320, memory 322, and a display 310 located on or near the front surface 306 of the housing 302. The display 310 may be, for example, a light-emitting diode (LED) display or an organic light-emitting diode (OLED) display.

[0123] A cover substrate 312 may be disposed on or above the front surface 304 of the housing 302, such that it is positioned above the display 310. The cover substrate 312 may include any glasswork disclosed herein and may be referred to as "cover glass". The cover substrate 312 may be used to protect the display 310 and other components of the consumer electronics product 300 (e.g., controller 320 and memory 322) from damage. In some embodiments, the cover substrate 312 may be bonded to the display 310 using an adhesive. In some embodiments, the cover substrate 312 may define all or part of the front surface 304 of the housing 302. In some embodiments, the cover substrate 312 may define the front surface 304 of the housing 302 and all or part of the side surfaces 308 of the housing 302. In some embodiments, the consumer electronics product 300 may include a cover substrate defining all or part of the back surface 306 of the housing 302.

[0124] Example

[0125] The following examples will further clarify the implementation methods. It should be understood that these implementation methods are not limited to the methods described above.

[0126] Glass compositions were prepared using conventional glass forming methods, and the analyzed compositions are listed in Table 1 below. Compositions 1 to 13 in Table 1 are glass compositions according to embodiments of this application. Composition A in Table 1 is a control composition made from a similar oxide. In Table 1, all components are expressed in mol% and no unreported components were detected. Generally, amounts of 0.01 mol% or less in Table 1 are considered impurities, and these components were not intentionally added to the composition.

[0127] Table 2 lists the material properties of the compositions in Table 1. The Young's modulus (E) values ​​reported in Table 2 were measured according to the methods disclosed in this specification. The shear modulus values ​​were measured using the general type of resonant ultrasonic spectroscopy technique presented in ASTM E2001-13, entitled "Standard Guide for Resonant Ultrasound Spectroscopy for Defect Detection in Both Metallic and Non-metallic Parts".

[0128] The additional material properties listed in Table 2 include: density, where the density value is determined using the buoyancy method of ASTM C693-93 (2013); CTE (in the range of 0°C to 300°C), measured using the fiber relongation technique in parts per million (ppm / °C); strain point, annealing point, and softening point, where the strain point and annealing point are determined using the fiber relongation method of ASTM C336-71 (2015), and the softening point is determined using the fiber relongation method of ASTM C338-93 (2013); liquidus temperature and liquidus viscosity, where the liquidus temperature is determined as discussed herein, and the liquidus viscosity is determined as discussed herein; and the stress optical coefficient (SOC), which is related to the birefringence of the glass. Unless otherwise specified, SOC shall be measured according to Procedure C (Glass Disc Method) of ASTM Standard C770-16, entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety. Unless otherwise specified, the properties listed in Table 2 shall be measured before the composition or article undergoes any ion exchange process or any other strengthening process. The dilatometer shall be set up according to ASTM E228 (“Standard Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer”). For fiber extension testing, a fiber sample of the specific composition mounted in the dilatometer is inserted into a 0°C ice bath, followed by a 300°C isothermal furnace, to determine the average linear coefficient of thermal expansion over this temperature range. Fiber samples are prepared by flameworking. In Table 2, composition 5 did not reach the liquidus temperature and is therefore reported as below 950°C with a liquidus viscosity reported as greater than 3823 kPa. Of all the compositions in Table 2 that reached the liquidus temperature, the phase at the liquidus was forsterite.

[0129] Table 3 includes the ion exchange times and properties of compositions 1 to 13 and composition A from Table 1. For the ion exchange process reported in Table 3, samples of each composition were immersed in a molten salt bath consisting of 100% by weight KNO3 at a temperature of 410°C. Each sample had a thickness of 0.8 mm. Compressive stress and layer depth were measured using FSM.

[0130] Table 1

[0131] Composition A 1 2 3 4 5 6 7 <![CDATA[SiO2]]> 68.95 69.03 69.10 69.17 69.23 69.04 68.98 69.13 <![CDATA[Al2O3]]> 10.27 10.32 10.32 10.05 10.01 10.30 10.07 10.32 MgO 5.36 4.88 4.86 5.08 5.17 4.88 5.14 4.66 CaO 0.05 0.52 0.27 0.27 0.10 0.04 0.04 0.77 <![CDATA[Na2O]]> 15.20 15.06 15.25 15.23 15.29 15.53 15.56 14.91 <![CDATA[K2O]]> Mixed 0.01 0.00 0.00 0.00 0.01 0.00 0.01 <![CDATA[SnO2]]> 0.17 0.18 0.19 0.18 0.19 0.18 0.18 0.19 <![CDATA[TiO2]]> <![CDATA[Fe2O3]]> Mixed 0.01 0.01 0.01 0.01 0.01 0.01 0.01 <![CDATA[Al2O3+MgO+CaO]]> 15.68 15.72 15.45 15.40 15.28 15.22 15.25 15.75

[0132] Table 1 (continued)

[0133]

[0134]

[0135] Table 2

[0136]

[0137] Table 2 (continued)

[0138]

[0139] Table 2 (continued)

[0140]

[0141]

[0142] Table 3

[0143]

[0144]

[0145] Table 3 (continued)

[0146]

[0147] Table 3 (continued)

[0148]

[0149] Table 3 (continued)

[0150]

[0151] Table 3 (continued)

[0152]

[0153] Table 3 (continued)

[0154]

[0155] Table 3 (continued)

[0156]

[0157] Table 3 (continued)

[0158]

[0159]

[0160] As demonstrated by the reported results listed in the tables above, the compositions of this application achieve similar properties to existing compositions used in bendable applications upon chemical strengthening, while exhibiting improved liquidus viscosity and reduced liquidus temperature compatible with drawing techniques such as slot drawing. Furthermore, the results in Table 3 demonstrate that the glass compositions described herein can achieve a CS / E ratio of 13.0 or greater by incorporating DOLs of 20 μm or larger, and at least some compositions can achieve a CS / E ratio of 13.0 by incorporating DOLs of 40 μm or larger.

[0161] Although various embodiments have been described herein, they are presented as examples and not as limitations. It is obvious that adjustments and modifications based on the teachings and guidance presented herein fall within the meaning and scope of equivalents of the disclosed embodiments. Therefore, it will be apparent to those skilled in the art that various changes in form and detail can be made to the embodiments disclosed herein without departing from the spirit and scope of this disclosure. As will be understood by those skilled in the art, the elements of the embodiments presented herein are not necessarily mutually exclusive, but can be interchanged to satisfy various situations.

[0162] Detailed descriptions of embodiments of this disclosure are provided with reference to the embodiments illustrated in the accompanying drawings, wherein similar reference numerals are used to denote the same or functionally similar components. References to "one embodiment," "an embodiment," "some embodiments," "in some embodiments," etc., indicate that the embodiment may include specific features, structures, or characteristics, but each embodiment may not necessarily include specific features, structures, or characteristics. Furthermore, these phrases do not necessarily refer to the same embodiment. Moreover, whether explicitly described or not, when a specific feature, structure, or characteristic is described in connection with an embodiment, it is believed that such feature, structure, or characteristic will affect its combination with other embodiments to the knowledge of those skilled in the art.

[0163] The embodiments are illustrative and not intended to limit the scope of this disclosure. Other suitable modifications and adjustments to various conditions and parameters that are common in the art to which this application pertains and are obvious to those skilled in the art fall within the spirit and scope of this disclosure.

[0164] The indefinite articles “a” and “one” used to describe elements or components indicate the presence of one or more of these elements or components. Although these articles are generally used to indicate that the noun being modified is singular, unless otherwise specified in specific contexts, the articles “a” and “one” used herein also include plural nouns. Similarly, unless otherwise specified in specific contexts, the definite article “the” used herein also indicates that the noun being modified can be either singular or plural.

[0165] The directional terms used in this article—such as up, down, right, left, front, back, top, bottom, inward, outward—are used only with reference to the illustrated figures and are not intended to imply absolute orientation.

[0166] As used herein, the terms "substantially," "substantially," and their variations are intended to indicate that the described feature is equal to or approximately equal to a value or description. For example, a "substantially flat" surface is used to indicate a flat or nearly flat surface. Furthermore, "substantially" is intended to indicate that two values ​​are equal or approximately equal. In some embodiments, "substantially" may indicate values ​​that differ from each other by about 10%, for example, by about 5%, or by about 2%.

[0167] It should be understood that the wording or terminology used herein is descriptive and not limiting. The breadth and scope of this disclosure should not be limited to any of the exemplary embodiments described above, but should be defined in accordance with the appended claims and their equivalents.

Claims

1. A type of glass comprising: SiO2 with a content greater than or equal to 69.0 mol% and less than or equal to 69.5 mol%; Al2O3 with a content greater than or equal to 10.0 mol% and less than or equal to 10.5 mol%; MgO with a content greater than or equal to 4.05 mol% and less than or equal to 5.25 mol%; CaO with a content greater than or equal to 0.1 mol% and less than or equal to 1.1 mol%; Na₂O with a content greater than or equal to 14.5 mol% and less than or equal to 15.8 mol%; and SnO2 with a content greater than or equal to 0.1 mol% and less than or equal to 0.2 mol%, The glass has a liquidus viscosity greater than or equal to 1200 kP and less than or equal to 4000 kP. The glass has a Young's modulus greater than or equal to 71.1 GPa and less than or equal to 72 GPa, and The glass contains a magnesium olivine liquidus phase.

2. The glass of claim 1, wherein the glass is substantially free of Li2O.

3. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of K2O.

4. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of ZnO.

5. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of SrO.

6. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of BaO.

7. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of B2O3.

8. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of P2O5.

9. The glass as claimed in claim 1 or 2, wherein the glass is substantially free of Fe2O3.

10. The glass of claim 1 or 2, wherein the glass comprises: SiO2 with a content greater than or equal to 69.0 mol% and less than or equal to 69.23 mol%; Al₂O₃ with a content greater than or equal to 10.01 mol% and less than or equal to 10.32 mol%; MgO with a content greater than or equal to 4.35 mol% and less than or equal to 5.17 mol%; CaO with a content greater than or equal to 0.1 mol% and less than or equal to 1.03 mol%; Na₂O with a content greater than or equal to 14.91 mol% and less than or equal to 15.56 mol%; and SnO2 with a content greater than or equal to 0.18 mol% and less than or equal to 0.19 mol%.

11. The glass as claimed in claim 1 or 2, wherein: Al2O3 + MgO + CaO ≥ 15 moles.

12. The glass of claim 1 or 2, wherein the glass has a liquidus viscosity greater than or equal to 1200 kP and less than or equal to 3800 kP.

13. The glass of claim 1 or 2, wherein the glass has a liquidus temperature of less than or equal to 1000 °C.

14. The glass of claim 1 or 2, wherein the glass has a liquidus temperature greater than or equal to 800 °C and less than or equal to 1000 °C.

15. The glass of claim 1 or 2, wherein the glass has a Young's modulus greater than or equal to 71.1 GPa and less than or equal to 71.5 GPa.

16. A glass article comprising the glass of claim 1 or 2, wherein the glass article has a thickness of less than or equal to 4 mm.

17. The glass article of claim 16, wherein the thickness is greater than or equal to 15 μm and less than or equal to 200 μm.

18. A glass article comprising: The compressive stress layer extends from the surface of the glass product to the compression depth, and contains peak compressive stress measured in MPa. The glass article is formed by ion exchange of a glass substrate, the glass substrate comprising the glass of claim 1.

19. The glass article of claim 18, wherein, prior to ion exchange, the ratio of the peak compressive stress of the glass substrate to the Young's modulus measured in GPa is greater than or equal to 13.

0.

20. A glass article comprising: The compressive stress layer extends from the surface of the glass product to the compression depth, and contains peak compressive stress measured in MPa. The central components of a glass article include: SiO2 with a content greater than or equal to 69.0 mol% and less than or equal to 69.5 mol%; Al2O3 with a content greater than or equal to 10.0 mol% and less than or equal to 10.5 mol%; MgO with a content greater than or equal to 4.05 mol% and less than or equal to 5.25 mol%; CaO with a content greater than or equal to 0.1 mol% and less than or equal to 1.1 mol%; Na₂O with a content greater than or equal to 14.5 mol% and less than or equal to 15.8 mol%; and SnO2 with a content greater than or equal to 0.1 mol% and less than or equal to 0.2 mol%, The glass has a liquidus viscosity greater than or equal to 1200 kP and less than or equal to 4000 kP. The glass has a Young's modulus greater than or equal to 71.1 GPa and less than or equal to 72 GPa, and The glass contains a magnesium olivine liquidus phase.

21. The glass article of claim 20, wherein the ratio of the peak compressive stress to the Young's modulus measured in GPa is greater than or equal to 13.0, and the Young's modulus is the Young's modulus of glass having the same composition as the center of the glass article.

22. The glass article of claim 21, wherein the ratio of the peak compressive stress to the Young's modulus is less than or equal to 18.

0.

23. The glass article according to any one of claims 20 to 22, wherein the compression depth is greater than or equal to 5 μm.

24. The glass article according to any one of claims 20 to 22, wherein the compression depth is greater than or equal to 5 μm and less than or equal to 40 μm.

25. The glass article according to any one of claims 20 to 22, wherein the compression depth is greater than or equal to 20 μm.

26. The glass article according to any one of claims 20 to 22, wherein the compression depth is greater than or equal to 20 μm and less than or equal to 40 μm.

27. The glass article as claimed in any one of claims 20 to 22, wherein the compression depth is in the range of 5% to 20% of the thickness of the glass article.

28. The glass article according to any one of claims 20 to 22, wherein the peak compressive stress is greater than or equal to 850 MPa and less than or equal to 1400 MPa.

29. The glass article according to any one of claims 20 to 22, wherein the peak compressive stress is greater than or equal to 900 MPa.

30. The glass article as claimed in any one of claims 20 to 22, wherein the glass article has a thickness of less than or equal to 4 mm.

31. The glass article according to any one of claims 20 to 22, wherein the glass article has a thickness greater than or equal to 15 μm and less than or equal to 200 μm.

32. A method for forming a glass article, comprising: A glass substrate is brought into contact with an ion exchange medium to form a glass article, the glass article comprising a compressive stress layer extending from the surface of the glass article to a compression depth. The glass substrate comprises the glass of claim 1, and the compressive stress layer comprises a peak compressive stress measured in MPa.

33. The method of claim 32, wherein, prior to ion exchange, the ratio of the peak compressive stress of the glass substrate to the Young's modulus measured in GPa is greater than or equal to 13.

0.

34. The method of claim 33, wherein the ratio of the peak compressive stress to the Young's modulus is less than or equal to 18.

0.

35. The method of any one of claims 32 to 34, wherein the ion exchange medium comprises greater than or equal to 50% by weight of potassium salt.

36. The method of any one of claims 32 to 34, wherein the ion exchange medium comprises KNO3.

37. The method of any one of claims 32 to 34, wherein the contact lasts for a period of time greater than or equal to 1 hour and less than or equal to 24 hours.

38. The method of any one of claims 32 to 34, wherein the contact lasts for a period of time greater than or equal to 1 hour and less than or equal to 8 hours.

39. The method according to any one of claims 32 to 34, wherein the ion exchange medium is at a temperature greater than or equal to 350°C and less than or equal to 480°C.

40. The method of any one of claims 32 to 34, further comprising: etching the glass article.

41. The method of any one of claims 32 to 34, wherein the compression depth is greater than or equal to 5 μm.

42. The method of any one of claims 32 to 34, wherein the compression depth is greater than or equal to 5 μm and less than or equal to 40 μm.

43. The method of any one of claims 32 to 34, wherein the compression depth is greater than or equal to 20 μm.

44. The method of any one of claims 32 to 34, wherein the compression depth is greater than or equal to 20 μm and less than or equal to 40 μm.

45. The method of any one of claims 32 to 34, wherein the compression depth is in the range of 5% to 20% of the thickness of the glass article.

46. ​​The method of any one of claims 32 to 34, wherein the peak compressive stress is greater than or equal to 850 MPa and less than or equal to 1400 MPa.

47. The method according to any one of claims 32 to 34, wherein the peak compressive stress is greater than or equal to 900 MPa.

48. The method of any one of claims 32 to 34, wherein the glass article has a thickness of less than or equal to 4 mm.

49. The method of any one of claims 32 to 34, wherein the glass article has a thickness greater than or equal to 15 μm and less than or equal to 200 μm.

50. An electronic device comprising: Electronic displays; and The glass article according to any one of claims 20 to 31, wherein the glass article is disposed above an electronic display.

51. The electronic device of claim 50, further comprising: The housing includes a front surface, a rear surface, and side surfaces; and An electrical component, at least partially housed within a housing, includes a controller, memory, and an electronic display. The electronic display is disposed on or adjacent to the front surface of the housing, and the glass article forms at least a portion of the housing.

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