Flexible ultra-thin glass with high contact resistance

Abstract

The invention relates to an ultrathin chemically tempered glass article having a thickness of less than or equal to 0.4 mm. In order to improve sharp object contact resistance, the glass article has a rupture force (given in N) greater than 30 times the thickness (t) of the glass article (t given in mm). Further, the glass article has a fracture bending radius (given in mm) less than 100,000 multiplied by the thickness (t) of the glass article (t given in mm) divided by the value of surface compressive stress (in MPa) at the first surface.

Description

[0001] This application is a divisional application of Chinese patent application 201780091517.8, filed on June 2, 2017. Technical Field

[0002] This invention relates to an ultrathin glass article possessing high resistance to sharp object contact and high flexibility. The invention also relates to the use of high-strength flexible glass as a flexible general-purpose planar surface in: flexible and printed electronics, sensors for touch panels, fingerprint sensors, thin-film battery substrates, mobile electronic devices, semiconductor interlayers, flexible displays, solar cells, or other applications requiring high chemical stability, temperature stability, low permeability, flexibility, and low thickness. In addition to consumer and industrial electronics, this invention can also be used for protective applications in industrial production or metrology. Background Technology

[0003] Thin glasses with different compositions are suitable substrate materials for many applications where transparency, high chemical and heat resistance, and defined chemical and physical properties are important. For example, alkali-free glass can be used in display panels and as a material for chip-format electronic packaging. Alkali-containing silicate glasses are used as substrates for filter coatings, touch sensor substrates, and fingerprint sensor module covers.

[0004] Aluminosilicate (AS), lithium aluminosilicate (LAS), borosilicate, and soda-lime glass are widely used in applications such as cover plates for fingerprint sensors (FPS), protective covers, and display covers. In these applications, specific tests such as 3-point bending (3PB), drop ball testing, and scratch resistance confirm that chemical tempering can typically improve the mechanical strength of the glass.

[0005] Chemical tempering is a well-known method for increasing the strength of glass, such as that used as cover glass for display applications, including soda-lime glass, aluminosilicate (AS) glass, lithium aluminosilicate (LAS) glass, or borosilicate glass. In this process, the surface compressive stress (CS) is typically between 500 MPa and 1,000 MPa, and the depth of the ion exchange layer is typically greater than 30 μm, preferably greater than 40 μm. For safety protection applications in transportation or aviation, the depth of the exchange layer in AS glass can be greater than 100 μm. Generally, all these applications require glass with high CS and high DoL, and the glass thickness is typically in the range of about 0.5 mm to 10 mm.

[0006] Currently, the ongoing demand for new product features and broader applications necessitates thinner, lighter glass substrates with high strength and flexibility. Ultra-thin glass (UTG) is commonly used as protective covers for delicate electronic products. The increasing demand for new product features and the development of new and broader applications requires glass substrates that are thinner, lighter, stronger, and more flexible. Due to its flexibility, UTG has been researched and developed for covers and displays in devices such as smartphones, tablets, watches, and other wearable devices. This glass can also be used as a cover for fingerprint sensor modules and camera lens covers.

[0007] However, processing becomes increasingly difficult when the glass sheet thickness is less than 0.5 mm, primarily due to defects such as cracks and debris at the glass edges leading to breakage. Furthermore, the overall mechanical strength, reflected in bending or impact strength, is significantly reduced. While CNC (computer-controlled numerical control) grinding can typically remove defects from the edges of thicker glass, mechanical grinding is rarely suitable for ultrathin glass less than 0.3 mm thick. Edge etching can be a solution for removing defects in ultrathin glass, but the flexibility of thin glass sheets is still limited by the glass's inherently low bending strength. Therefore, strengthening is particularly important for thin glass. However, for ultrathin glass, the strengthening process always carries the risk of spontaneous breakage due to the high tensile stress at its center.

[0008] Typically, ultrathin flat glass with a thickness <0.5 mm can be produced using direct thermoforming methods, such as down-drawing, overflow melting, or special float glass. Re-drawing is also feasible. Because the surface of directly thermoformed thin glass is cooled from a high-temperature molten state to room temperature, it exhibits better surface uniformity and surface roughness compared to thin glass post-processed through chemical or physical methods (e.g., via grinding and polishing). Down-drawing can be used to produce glass thinner than 0.3 mm or even 0.1 mm, such as aluminosilicate glass, lithium aluminosilicate glass, alkali metal borosilicate glass, soda-lime glass, or alkali-free aluminosilicate glass.

[0009] Several inventions have described the chemical tempering of UTG. US2015183680 describes the tempering of glass <0.4 mm with a limited range of central tension and a DoL > 30 μm. However, a DoL > 30 μm leads to problems such as fragility and spontaneous breakage in ultrathin tempered glass. Furthermore, the patent application does not describe how to prepare glass <0.4 mm thick. WO 2014 / 139147 A1 discloses the tempering of glass <0.5 mm thick with a compressive stress <700 MPa and a DoL <30 μm. However, ultrathin tempered aluminosilicate glass tends to have low mechanical resistance and is prone to breakage upon contact with sharp and hard objects. Typically, to obtain flexible glass with an optimal bending radius, it is assumed that the value of DoL (depth of the ion exchange layer) (given in μm) should be as high as approximately 0.1 to 0.2 times the corresponding glass thickness. Conversely, known tempered ultrathin glasses have been found to have rather low resistance to sharp object contact (i.e., resistance to sharp object pressure). Therefore, this type of tempered glass is prone to breakage when scratched by hard objects such as sand or metal edges. Resistance to sharp object pressure is a characteristic of UTG that withstands pressure, where a sharp object is pressed against the glass surface.

[0010] There are many factors related to UTG (Ultra-Thin Glass), including glass thickness, tempering processes, and results (different CS, DoL, CT), making it difficult to accurately predict whether a glass product can be used in a specific application. However, in practice, testing finished products (e.g., pressing a fingerprint sensor with a sand finger until it breaks) is not only inefficient but also wasteful of the product itself. To reduce the risk of damage to customers, glass manufacturers and processors have developed numerous tests to demonstrate the contact resistance and flexibility of tempered ultra-thin glass, such as 3-point bending (3PB), drop ball, scratch resistance, etc. However, these tests are complex and often fail. Summary of the Invention

[0011] The purpose of this invention is to overcome the problems of the prior art and to provide an ultrathin glass that can achieve high flexibility and high resistance to sharp objects. Another purpose of this invention is to set evaluation criteria for UTG with reliable properties for electronic applications.

[0012] Explanation of technical terms Glassware: Glassware can be any size. For example, it can be a long, thin strip of glass (glass roll), a large glass sheet, a smaller section of glass cut from a glass roll or sheet, or a single small glass item (such as an FPS or monitor cover).

[0013] Thickness (t): The thickness of the glass product is the arithmetic mean of the thicknesses of the samples to be measured.

[0014] Compressive stress (CS): Compression generated in the glass network after ion exchange on the surface layer of the glass. This compression may not be released by glass deformation but instead acts as a persistent stress. CS decreases from its maximum value at the surface of the glass (surface CS) toward the interior of the glass. Commercially available testing machines, such as the FSM6000 (Luceo Co., Ltd., Tokyo, Japan), can measure CS using waveguide mechanisms.

[0015] Layer depth (DoL): The thickness of the region where the ion exchange layer (CS) exists. Commercially available testing equipment, such as the FSM6000 (Luceo Co., Ltd., Tokyo, Japan), can measure DoL using a waveguide mechanism.

[0016] Central Tension (CT): When CS is induced on one or both sides of a single glass plate, tensile stress must be induced in the central region of the glass in order to balance the stress according to Newton's third principle. This is called central tension. CT can be calculated from the measured CS and DoL.

[0017] Average roughness (R) a R is a measure of surface texture. It is quantified by the perpendicular deviation of the real surface from its ideal form. Typically, the magnitude parameter characterizes the surface based on the perpendicular deviation of the roughness curve from the mean line. a It is the arithmetic mean of the absolute values ​​of these vertical deviations.

[0018] Rupture force: Rupture force is the force (given in N) that can be applied to an object until a chemically tempered ultrathin glass product breaks (i.e., cracks appear). Rupture force is determined by a steel rod and sandpaper pressure test, which is described in more detail below.

[0019] Bending radius of breakage (BBR): The bending radius of breakage (given in mm) is the smallest radius (r) of the arc at which a glass article reaches its maximum deflection before twisting, breaking, or fracturing. It is measured at the internal curvature of the glass material at the point of bending. A smaller radius means greater flexibility and deflection of the glass. The bending radius is a parameter that depends on the glass thickness, Young's modulus, and glass strength. Chemically tempered ultrathin glass has a very small thickness, a low Young's modulus, and high strength. All three factors contribute to a smaller bending radius and better flexibility. The tests used to determine the BBR are described in more detail below.

[0020] This invention provides a chemically tempered glass article having a thickness (t) of less than 0.4 mm, a first surface and a second surface, and a compressive stress region extending from the first surface to a first depth (DoL) in the glass article, the region being defined by compressive stress (CS), wherein the surface CS at the first surface is at least 100 MPa. The first surface and the second surface are located on opposite sides of the glass article. The breaking force of the glass article (given in N) is at least 30 times the thickness (t, in mm) of the glass article. The breaking force is determined in a sandpaper pressure test. In this test, the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm at a flat front surface is loaded onto the first surface of the glass article until it breaks, wherein P180 type sandpaper is placed between the front surface of the steel rod and the first surface of the glass article, wherein the abrasive side of the sandpaper is in contact with the first surface. Furthermore, the glass article according to the invention has a fracture bending radius (given in mm) that is less than the result of multiplying the thickness of the glass article (t, in mm) by 100,000 and then dividing by the value of the surface compressive stress (in MPa) measured at the first surface.

[0021] The glass article according to the invention has an optimized stress distribution. It achieves a balance between a small bending radius and high resistance to contact with sharp objects (especially pressure resistance). Surprisingly, it has been found that the glass article is reasonably strong and tough enough to be suitable for applications involving ultra-thin glass products, especially in everyday use, if the following conditions are met: a) In the above sandpaper test, the breaking force of the glass product (given in N) ≥ 30*t (t is the value of the corresponding thickness of the glass product, in "mm"), and b) Its fracture bending radius (given in mm) < 100000 * t / CS, where t is the thickness of the glass article (given in mm) and CS is the measured surface compressive stress (given in MPa). This means that in the latter calculation, the product is divided by a value corresponding to the measured surface compressive strength (given in MPa) on the first surface of the glass article.

[0022] These standards allow for the determination of whether reinforced, ultra-thin glass articles possess sufficient strength and flexibility for their intended applications before they become part of a product. Surprisingly, it was found that the breaking force is closely related to the glass thickness. Therefore, thinner glass is particularly sensitive to breakage from contact with hard and sharp objects.

[0023] Surprisingly, the inventors discovered that the breaking force standard of ultrathin glass can be described by the factor 30 of this invention and the thickness of the glass article. The factor of this invention will be valid if the breaking force of the glass article is determined using a universal testing machine (UTM) in the sandpaper pressure test record of this invention. In this test, the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm at a flat front surface is loaded onto the first surface of the glass article (which is chemically tempered), and pressed until the first surface breaks. P180 type sandpaper is placed between the front surface of the steel rod and the first surface of the glass article, with the abrasive side of the sandpaper in contact with the first surface. The longitudinal axis of the steel rod is perpendicular to the first surface of the glass article. The steel rod is moved in the direction corresponding to its longitudinal axis at a continuous loading speed of 1 mm / min until the glass article breaks. Small samples (11 mm × 11 mm) are tested using P180 sandpaper according to ISO 6344 (e.g., #180 sandpaper manufactured by "Buehler") at a room temperature of approximately 20°C and a relative humidity of approximately 50%. To test larger glass items, a diamond cutting wheel is used to cut them into smaller samples. These smaller samples are not further edge-treated. The samples are then pressed with a rod until they break (a crack is created). The breaking force (also known as "sandpaper pressure") is the maximum force applied when a glass item breaks. Breaking means that a crack appears on the surface of the glass item or it breaks into two or more pieces. The breakage is determined using signals from UTM software.

[0024] This test is tailored for ultra-thin glass products and is particularly suitable for them. The test reproduces the aforementioned problem in a very simple way: the pressure contact between a glass product (such as an FPS or touchscreen display) and a sharp, hard object.

[0025] Surprisingly, the inventors have found that the breaking bending radius criterion for ultra-thin glass can be described by a factor of 100000 of the present invention, the thickness of the glass article, and the measured surface CS. The factor of the present invention will be valid if the breaking bending radius of the glass article is determined in the two-point bending test as described herein. The breaking bending radius is determined using a UTM (Universal Testing Machine) on small samples (20 mm × 70 mm) at a room temperature of about 20 °C and a relative humidity of about 50%. If a larger glass article is to be tested, it is cut into small samples using a diamond cutting wheel. No further edge treatment is performed on these samples. The glass article is placed in the bending position with its opposite ends between two parallel plates (steel plates). Then, the distance between the plates is continuously decreased such that the bending radius of the glass article is reduced until it breaks, with a loading speed of 60 mm / min. When the ultra-thin glass article kinks or is damaged or breaks into two or several parts determined by the signal of the UTM software, the distance between the plates is recorded. From this distance, the corresponding bending radius of the glass article at the time of breakage is calculated. - If the tested glass article has a treated edge (where the glass article can be edge-treated, for example, by CNC grinding, etched by an acid (such as HCl, HNO3, H2SO4, NH4HF2 or a mixture thereof), and then tempered), its bending radius is smaller compared to the corresponding glass article without a treated edge because the edge treatment increases the strength and thus reduces the bending radius.

[0026] The two-point bending test is adjusted and is particularly suitable for ultra-thin glass articles. In the test, the above problems are reproduced in a very simple manner, that is, when loading the glass article (such as an FPS or a touch display), it is bent. In the context of the present invention, it has been found that the two-point bending method is more meaningful than other known bending strength tests such as three-point and four-point bending tests.

[0027] In an advantageous embodiment of the present invention, the breaking bending radius (in mm) of the chemically tempered glass article is less than the result obtained by multiplying the thickness of the glass article (t, in mm) by 80000 and dividing by the value of the surface compressive stress measured at the first surface (in MPa) (<t * 80000 / CS). Preferably, the breaking bending radius (in mm) can be less than the result obtained by multiplying the thickness of the glass article (t, in mm) by 70000 and dividing by the value of the surface compressive stress measured at the first surface (in MPa) (<t * 70000 / CS). In some variants, the breaking bending radius (in mm) can be less than the result obtained by multiplying the thickness of the glass article (t, in mm) by 60000 and dividing by the value of the surface compressive stress measured at the first surface (in MPa) (<t * 60000 / CS).

[0028] As mentioned above, ultrathin glass articles are used in many areas of everyday applications, such as as cover plates for fingerprint sensors, especially in smartphones and tablets. To improve the strength of the cover plate, chemical tempering is preferred. In this case, in the prior art, it is generally considered necessary to have high compressive strength and high DoL to ensure the flexibility and strength of the ultrathin glass. Therefore, such known tempered glass articles typically have high compressive stress (CS) and DoL >20 μm, which results in high central tension (CT) within the glass. However, the inventors surprisingly discovered that without additional protection for the surface in contact with sharp objects, the resistance to sharp object contact of such known tempered glass decreases rapidly with increasing DoL, and reaches a minimum when the ratio between DoL (given in μm) and thickness (given in μm) is approximately between 0.1 and 0.2. Therefore, if such a known tempered glass article is subjected to pressure or impact from an object with high hardness (e.g., sand particles sticking to a finger when pressing the cover of an FPS), a crack will extend through the reinforcing layer of the cover (limited by compressive stress (CS)). Even with very low contact force, the crack will reach the tensile portion of the glass. Due to the high central tensile stress present in this region of the glass, the known glass article will spontaneously shatter, damaging the cover.

[0029] Surprisingly, the inventors discovered that the glass articles according to the invention are more reliable in terms of flexibility and contact resistance during further processing and everyday use. This is because the stress distribution of the glass articles according to the invention has been improved and optimized. In other words, if the ultra-thin glass articles meet the required breaking force and the required breaking bending radius (referring to their corresponding thickness and measured surface CS), then the glass articles of the invention have a low risk of breakage during use (e.g., as cover glass for fingerprint sensors).

[0030] As described above, chemically tempered glass articles according to the present invention can have completely different sizes. Therefore, the following issues must be considered in determining the breaking force and the breaking bending radius: When the glass products are large (e.g., glass rolls or large sheets), the breaking force of multiple samples is measured using a sandpaper pressure test. For this, a random sample of N values ​​is used. N should be large enough to obtain a statistically assured average. Preferably, at least 20 samples are tested, more preferably at least 30. The number of samples depends on the corresponding size of the glass product being tested. The measurements are statistically evaluated using the Weibull distribution method. The B10 value of the Weibull distribution (i.e., the calculated force (in N) from which 10% of the samples break) is determined and used to represent the required breaking force.

[0031] However, when the glass product is small (such as individual small covers), a single measurement of the breaking force is sufficient to represent the required breaking force.

[0032] When the number of measurements is between 2 and 19, the average measured fracture force is used to represent the required fracture force.

[0033] For the fracture bending radius, an average value can be calculated. For this, a random sample of N values ​​is used. The number of samples depends on the corresponding size of the glass article to be evaluated. Preferably, N should be large enough to obtain a statistically assured average value. It is preferable to test at least 20, more preferably at least 30 samples. Therefore, for the fracture bending radius R1...R n Take N random samples of values, and calculate the average value for these random samples. and variance .

[0034] The average fracture bend radius is used to represent the required fracture bend radius. However, when glass products are small (e.g., individual small cover glass), a single measurement of the fracture bend radius is sufficient to represent the required fracture bend radius.

[0035] The mean and variance of the fracture force are calculated accordingly.

[0036] In one embodiment, the glass is an alkali-containing glass, such as alkali metal aluminosilicate glass, alkali metal silicate glass, alkali metal borosilicate glass, alkali metal aluminoborosilicate glass, alkali metal borosilicate glass, alkali metal germanate glass, alkali metal borosilicate glass, alkali metal soda-lime glass, and combinations thereof.

[0037] The thickness of the ultrathin glass article according to the invention is less than or equal to 400 μm, preferably less than or equal to 330 μm, even more preferably less than or equal to 250 μm, further preferably less than or equal to 210 μm, preferably less than or equal to 180 μm, even more preferably less than or equal to 150 μm, more preferably less than or equal to 130 μm, more preferably less than or equal to 100 μm, more preferably less than or equal to 80 μm, more preferably less than or equal to 70 μm, further preferably less than or equal to 50 μm, further preferably less than or equal to 30 μm, and even more preferably less than or equal to 10 μm. The thickness can be at least 5 μm. Such particularly thin glass articles are desirable for the various applications described above. In particular, the thin thickness imparts flexibility to the glass.

[0038] According to advantageous embodiments, the glass articles can be flat articles and / or flexible articles and / or deformable articles. A “flat” article can be, for example, a substantially planar or flat glass article. However, in the sense of this invention, “flat” also includes articles that are deformable or deformed in two or three dimensions.

[0039] These and other aspects, advantages and features will be described in more detail in the following paragraphs, figures and appended claims.

[0040] To achieve good chemical tempering properties, the glass should contain a certain amount of alkali metal ions, preferably Na₂O. Furthermore, adding a small amount of K₂O to the glass composition can also improve the chemical tempering rate. In addition, it has been found that adding Al₂O₃ to the glass composition can significantly improve the tempering properties of the glass.

[0041] SiO2 is the primary glass network forming agent in the glass of this invention. Additionally, Al2O3, B2O3, and P2O5 can also be used as glass network forming agents. In conventional production methods, the total content of SiO2, B2O3, and P2O5 should not be less than 40%. Otherwise, the glass sheet may be difficult to form, may become brittle, and may lose transparency. A high SiO2 content will require high melting points and operating temperatures in glass production; typically, the SiO2 content should be less than 90%. In a preferred embodiment, the SiO2 content in the glass is between 40 and 75 wt%, more preferably between 50 and 70 wt%, and even more preferably between 55 and 68 wt%. In other preferred embodiments, the SiO2 content in the glass is between 55 and 69 wt%, more preferably between 57 and 66 wt%, and even more preferably between 57 and 63 wt%. In another preferred embodiment, the SiO2 content in the glass is between 60 and 85 wt%, more preferably between 63 and 84 wt%, and even more preferably between 63 and 83 wt%. In another preferred embodiment, the SiO2 content in the glass is between 40 and 81 wt%, more preferably between 50 and 81 wt%, and even more preferably between 55 and 76 wt%. Adding B2O3 and P2O5 to SiO2 can alter the network properties and lower the melting point and operating temperature of the glass. Furthermore, the glass network forming agent has a significant impact on the CTE of the glass.

[0042] Furthermore, B2O3 in the glass network forms two different polyhedral structures, which are more suitable for external loading forces. Adding B2O3 typically results in lower thermal expansion and Young's modulus, leading to good thermal shock resistance, slowing down chemical tempering, and thus facilitating the acquisition of low CS and low DoL. Therefore, adding B2O3 to ultrathin glass can significantly improve the performance of chemically tempered processing windows and ultrathin glass, and broaden the practical applications of chemically tempered ultrathin glass. In a preferred embodiment, the amount of B2O3 in the glass of the present invention is between 0 and 20 wt%, more preferably between 0 and 18 wt%, and even more preferably between 0 and 15 wt%. In some embodiments, the amount of B2O3 can be between 0 and 5 wt%, preferably between 0 and 2 wt%. In another embodiment, the amount of B2O3 can be between 5 and 20 wt%, preferably between 5 and 18 wt%. If the amount of B2O3 is too high, the melting point of the glass may be too high. Furthermore, when the amount of B2O3 is too high, the chemical tempering performance decreases. Variants without B2O3 may be preferred.

[0043] Al2O3 can be used as a glass network forming agent and a glass network modifier. Depending on the amount of Al2O3, [AlO4] tetrahedra and [AlO6] hexahedrons are formed in the glass network, and the ion exchange rate can be adjusted by changing the size of the ion exchange space within the glass network. Typically, the content of this component varies depending on the corresponding glass type. Therefore, some glasses of the present invention preferably include Al2O3 in an amount of at least 2 wt%, more preferably at least 10 wt%, or even at least 15 wt%. However, if the Al2O3 content is too high, the melting point and operating temperature of the glass will also be very high, and crystallization will easily form, causing the glass to lose its transparency and flexibility. Therefore, some glasses of the present invention preferably contain Al2O3 in an amount of up to 30 wt%, more preferably up to 27 wt%, and even more preferably up to 25 wt%. Advantageous embodiments may contain up to 20 wt% Al2O3, preferably up to 15 wt% or up to 10 wt%, or even more preferably up to 8 wt%, preferably up to 7 wt%, preferably up to 6 wt%, preferably up to 5 wt%. Some glass variants may be free of Al2O3. Other advantageous glass variants may contain at least 15 wt%, preferably at least 18 wt% Al2O3 and / or up to 25 wt%, preferably up to 23 wt%, more preferably up to 22 wt% Al2O3.

[0044] Alkali metal oxides such as K₂O, Na₂O, and Li₂O are used as glass modifiers. They can disrupt the glass network and form non-bridging oxides within it. Adding alkali metals may lower the operating temperature of the glass and increase its CTE. The content of sodium and lithium is important for chemically temperable ultrathin flexible glass because sodium...+ / Li + Na + / K + Li + / K + Ion exchange is a necessary step for tempering; if the glass itself does not contain alkali, it will not be tempered. However, sodium is preferred over lithium because lithium can significantly reduce the diffusivity of the glass. Therefore, some glasses of the present invention preferably include Li₂O in an amount of up to 5 wt%, more preferably up to 4 wt%, more preferably up to 2 wt%, more preferably up to 1 wt%, and more preferably up to 0.1 wt%. Some preferred embodiments do not even contain Li₂O. Depending on the glass type, the lower limit for Li₂O can be 3 wt%, preferably 3.5 wt%.

[0045] The glass of the present invention preferably comprises Na₂O in an amount of at least 4 wt%, more preferably at least 5 wt%, more preferably at least 6 wt%, more preferably at least 8 wt%, and more preferably at least 10 wt%. Sodium is very important for chemical tempering performance because chemical tempering preferably involves ion exchange between sodium in the glass and potassium in the chemical tempering medium. However, the sodium content should not be too high, as excessive sodium content may severely degrade the glass network and may make glass formation extremely difficult. Another important factor is that the ultrathin glass should have a low CTE to meet the requirement that the glass should not contain too much Na₂O. Therefore, the glass preferably comprises Na₂O in an amount of at most 30 wt%, more preferably at most 28 wt%, more preferably at most 27 wt%, more preferably at most 25 wt%, and more preferably at most 20 wt%.

[0046] The glass of the present invention may include K2O. However, since the glass is preferably chemically tempered by exchanging sodium ions in the glass with potassium ions in a chemical tempering medium, an excessive K2O content in the glass will impair the chemical tempering performance. Therefore, the glass of the present invention preferably includes up to 10 wt%, more preferably up to 8 wt% K2O. Some preferred embodiments include up to 7 wt%, other preferred embodiments include up to 4 wt%, more preferably up to 2 wt%, more preferably up to 1 wt%, and more preferably up to 0.1 wt% K2O. Some preferred embodiments do not even contain K2O.

[0047] However, the total amount of alkali metals should preferably not exceed 35 wt%, more preferably not exceed 30 wt%, more preferably not exceed 28 wt%, more preferably not exceed 27 wt%, and even more preferably not exceed 25 wt%, because excessive alkali content may severely degrade the glass network and make the glass extremely difficult to form. Some glass variants include up to 16 wt%, preferably up to 14 wt% alkali metals. Another important factor is that the ultrathin glass should have a low CTE to meet the requirement that the glass should not contain excessive amounts of alkali metal elements. However, as mentioned above, the glass should contain alkali metal elements to promote chemical tempering. Therefore, the glass of the present invention preferably includes at least 2 wt%, more preferably at least 3 wt%, more preferably at least 4 wt%, more preferably at least 5 wt%, and more preferably at least 6 wt% alkali metal oxides.

[0048] Alkaline earth metal oxides, such as MgO, CaO, SrO, and BaO, can be used as network modifiers and can lower the glass-forming temperature. These oxides can be added to adjust the CTE and Young's modulus of the glass. Alkaline earth metal oxides have a very important function: they can change the refractive index of the glass to meet specific requirements. For example, MgO can lower the refractive index of the glass, while BaO can increase it. The weight content of alkaline earth metal oxides should preferably not exceed 40 wt%, preferably not exceed 30 wt%, preferably not exceed 25 wt%, even more preferably not exceed 20 wt%, more preferably not exceed 15 wt%, more preferably not exceed 13 wt%, and even more preferably not exceed 12 wt%. Some glass variants may include up to 10 wt%, preferably up to 5 wt%, more preferably up to 4 wt% of alkaline earth metal oxides. If the amount of alkaline earth metal oxides is too high, it may degrade the chemical tempering properties of the glass. The lower limit for alkaline earth metal oxides can be 1 wt% or 5 wt%. Furthermore, if the amount of alkaline earth metal oxides is too high, it may increase the tendency for crystallization. Some advantageous glass variants may be free of alkaline earth metal oxides.

[0049] Some transition metal oxides in glass, such as ZnO and ZrO2, have similar functions to alkaline earth metal oxides and may be included in some embodiments. Other transition metal oxides, such as Nd2O3, Fe2O3, CoO, NiO, V2O5, MnO2, TiO2, CuO, CeO2, and Cr2O3, are used as colorants to manufacture glasses with specific optical or photonic functions, such as color filters or light converters. As2O3, Sb2O3, SnO2, SO3, Cl, and / or F may also be added as clarifying agents in amounts of 0 to 2 wt%. Rare earth oxides may also be added in amounts of 0 to 5 wt% to impart magnetic or photonic or optical functions to the glass plate.

[0050] The following advantageous compositions refer to different types of glass before tempering.

[0051] In one embodiment, the ultrathin flexible glass is an alkali metal aluminosilicate glass comprising a specified amount of the following components (in wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents in amounts of 0 to 2 wt%. Rare earth oxides can also be added in amounts of 0 to 5 wt% to impart magnetic, photonic, or optical properties to the glass plate.

[0052] The alkali metal aluminosilicate glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0053] Most preferably, the alkali metal aluminosilicate glass of the present invention comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0054] In one embodiment, the ultrathin flexible glass is soda-lime glass, which comprises specified amounts of the following components (in wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0055] The soda-lime glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0056] The soda-lime glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0057] The soda-lime glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0058] Most preferably, the soda-lime glass of the present invention comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0059] Most preferably, the soda-lime glass of the present invention comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0060] In one embodiment, the ultrathin flexible glass is a lithium aluminosilicate glass comprising specified amounts of the following components (in wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents in amounts of 0 to 2 wt%. Rare earth oxides can also be added in amounts of 0 to 5 wt% to impart magnetic, photonic, or optical properties to the glass plate.

[0061] The lithium aluminum silicate glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0062] Most preferably, the lithium aluminosilicate glass of the present invention comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0063] In one embodiment, the ultrathin flexible glass is a borosilicate glass comprising specified amounts of the following components (in wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0064] The borosilicate glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0065] The borosilicate glass of the present invention preferably comprises the following components in specified amounts (wt%): Optionally, coloring oxides such as Nd₂O₃, Fe₂O₃, CoO, NiO, V₂O₅, MnO₂, CuO, CeO₂, and Cr₂O₃ can be added. 0-2 wt% of As₂O₃, Sb₂O₃, SnO₂, SO₃, Cl, and / or F can also be added as clarifying agents. 0-5 wt% of rare earth oxides can also be added to impart magnetic, photonic, or optical properties to the glass plate.

[0066] Typically, the ultrathin glass according to the present invention can be produced by polishing or etching downwards from a thicker glass. However, both methods are uneconomical and produce glass with poor surface quality. For example, by R... a Roughness measures the surface quality of the glass.

[0067] For large-scale production, direct thermoforming is preferred, such as the draw-out and overflow melting methods. Redrawing is also advantageous. These methods are cost-effective, produce high-quality glass surfaces, and can produce ultra-thin glass with thicknesses ranging from 5 μm (or even smaller) to 500 μm. For example, the draw-out / overflow melting method can reduce the surface roughness R of the original or flame-polished surface. aThe thickness is less than 5 nm, preferably less than 2 nm, and even more preferably less than 1 nm. The thickness can also be precisely controlled between 5 μm and 500 μm. Thinness imparts flexibility to the glass. A special float glass process can produce ultra-thin glass with a pristine surface, which is both economical and suitable for mass production. However, float glass has a tin-like side, unlike the other side. This difference between the two sides can cause warping after chemical tempering, and the different surface energies on both sides can affect the printing or coating process. Another variant of UTG can be produced by sawing ultra-thin glass products from thick glass ingots, rods, blocks, etc.

[0068] Strengthening, also known as tempering, is achieved by immersing glass in a molten salt bath containing potassium ions or by covering the glass with a paste containing potassium ions or other alkali metal ions, and then heating it at a high temperature for a certain period of time. The larger alkali metal ions in the salt bath or paste exchange with the smaller alkali metal ions in the glass, resulting in surface compressive stress due to this ion exchange.

[0069] The chemically tempered glass articles of this invention are obtained by chemically tempering chemically temperable glass articles. The tempering process is accomplished by immersing the ultrathin glass article in a salt bath containing monovalent ions to exchange with alkali ions within the glass. The radius of the monovalent ions in the salt bath is larger than the radius of the alkali ions within the glass. Due to the larger ion compression within the glass network, compressive stress is generated in the glass after ion exchange. After ion exchange, the strength and flexibility of the ultrathin glass are remarkably and significantly improved. Furthermore, the CS induced by chemical tempering improves the bending properties of the tempered glass articles and increases the scratch resistance of the glass.

[0070] The most commonly used salts for chemical tempering are those containing Na. + or contains K + Molten salts or mixtures thereof. Commonly used salts are NaNO3, KNO3, NaCl, KCl, K2SO4, Na2SO4, Na2CO3, and K2CO3. Additives such as NaOH, KOH, and other sodium or potassium salts can also be used to better control ion exchange rates, CS, and DoL during chemical tempering. Contains Ag + or contains Cu 2+ Salt baths can be used to give ultra-thin glass antimicrobial properties.

[0071] Chemical tempering is not limited to a single step. It can comprise multiple steps using alkali metal ions of varying concentrations in a salt bath to achieve better tempering properties. Therefore, glass articles chemically tempered according to the present invention can be tempered in one step or in several steps, such as in two steps.

[0072] The chemically tempered glass article according to the invention may have only one surface (first surface), wherein a compressive stress region extending from the first surface to a first depth exists in the glass article, wherein this region is defined by compressive stress. In this case, the glass article includes only one tempered side. Preferably, the glass article according to the invention further includes a second compressive stress region extending from a second surface to a second depth (DoL) in the glass article, wherein this region is defined by compressive stress, wherein the surface compressive stress (CS) at the second surface is at least 100 MPa. The second surface is located on the opposite side of the first surface. Therefore, this preferred glass article is tempered on both sides.

[0073] Compressive stress (CS) depends primarily on the glass composition. Higher Al₂O₃ content can contribute to achieving higher compressive stress. To achieve a balance between the glass's thermoforming capability and chemical tempering performance, the surface compressive stress is preferably below 1200 MPa. After tempering, ultrathin glass should possess sufficiently high compressive stress to obtain high strength. Therefore, the surface compressive stress at the first and / or second surfaces is preferably equal to or greater than 100 MPa, preferably equal to or greater than 200 MPa, more preferably equal to or greater than 300 MPa, still preferably equal to or greater than 400 MPa, and even more preferably equal to or greater than 500 MPa. In a particularly preferred embodiment, the surface compressive stress is equal to or greater than 600 MPa, more preferably equal to or greater than 700 MPa, and even more preferably equal to or greater than 800 MPa. Of course, the CS at the first surface and the CS at the second surface can be substantially the same or different.

[0074] Typically, DoL depends on the glass composition, but it can increase almost indefinitely with increasing tempering time and temperature. A defined DoL is necessary to ensure the stable strength of tempered glass, but when ultra-thin glass products are under compressive stress, an excessively high DoL can increase the self-breakage rate and strength.

[0075] Therefore, according to a first preferred variant of the invention, it is preferable to control the DoL to be very low (a glass variant with low DoL). To achieve the defined low DoL, the tempering temperature is reduced and / or the tempering time is shortened. According to the invention, a lower tempering temperature may be preferred because DoL is more sensitive to temperature and longer tempering times are easier to set during mass production. However, reducing the tempering time is also feasible to reduce the DoL of the glass article.

[0076] The inventors have discovered that a DoL (in μm) in the range of 0.5 μm to 120 * t / CS μm (t is given in μm, CS = surface compressive stress measured at the first surface (in MPa)) is advantageous for the stress distribution of the ultrathin glass article according to the invention. Preferably, the glass article has a DoL (in μm) in the range of 0.5 μm to 90 * t / CS μm, more preferably 1 μm to 90 * t / CS μm (t is given in μm, CS = surface compressive stress measured at the first surface (in MPa)), and even more preferably in the range of 0.5 μm to 60 * t / CS μm, more preferably 1 μm to 60 * t / CS μm (t is given in μm, CS = surface compressive stress measured at the first surface (in MPa)). Some advantageous embodiments may have a DoL (in μm) in the range of 0.5 μm to 45 * t / CS μm, preferably 1 μm to 45 * t / CS μm (t is given in μm, CS = surface compressive stress measured at the first surface (given in MPa)). Other advantageous embodiments may have a DoL (in μm) in the range of 0.5 μm to 27 * t / CS μm, preferably 1 μm to 27 * t / CS μm (t is given in μm, CS = surface compressive stress measured at the first surface (given in MPa)). In the calculations given above, “x * t / CS” means x multiplied by the thickness of the glass article and divided by the CS value of the measured surface, where x can be 120, 90, 60, 45, or 27.

[0077] In each case, the favorable value of DoL depends on the glass composition, thickness, and applied pressure (CS) of the corresponding glass article. Typically, glass articles according to the advantageous embodiments described above have a very low DoL. By reducing DoL, CT also decreases. If high pressure is applied to the glass articles of these embodiments by a sharp object, the resulting defects will only appear on the glass surface. Due to the significant reduction in CT, the resulting defects cannot overcome the internal strength of the glass article, thus preventing the glass article from breaking into two or more pieces. The resistance to sharp object pressure is thus improved in glass articles with such low DoL.

[0078] According to a second preferred variant of the invention, the DoL of the glass article can be very high (a glass variant with high DoL). It may be advantageous if the glass article has a DoL (in μm) in the range of 27*t / CS μm to 0.5*t μm (t given in μm, CS = surface compressive stress measured at the first surface (in MPa)), preferably in the range of 45*t / CS μm to 0.45*t μm (t given in μm, CS = surface compressive stress measured at the first surface (in MPa)), more preferably in the range of 60*t / CS μm to 0.4*t μm (t given in μm, CS = surface compressive stress measured at the first surface (in MPa)), and even more preferably in the range of 90*t / CS μm to 0.35*t μm (t given in μm, CS = surface compressive stress measured at the first surface (in MPa)). In the calculations given above, "y*t / CS" represents y multiplied by the thickness of the glass article and divided by the measured surface CS, where y can be 27, 45, 60, or 90. "z*t" refers to z multiplied by the thickness of the glass article, where z can be 0.5, 0.45, 0.4, or 0.35. To obtain a balanced stress distribution, such glass articles preferably include coatings and / or laminates. Even if the DoL of the glass article is very high, the coatings and / or laminates can resist scratch defects caused by sharp objects on the glass surface. Therefore, the inventors have discovered that alternatives with low DoL can be applied by depositing coatings and / or laminated polymer layers on one or both surfaces of the glass article to improve resistance to sharp object contact. Of course, glass articles with low DoL can also include coatings and / or laminates. The laminated polymer layers and / or coatings can completely or partially cover the surface of the glass article.

[0079] According to an advantageous embodiment, the tempered glass article comprises a laminated polymer layer, wherein the thickness of the polymer layer is at least 1 μm, preferably at least 5 μm, more preferably at least 10 μm, more preferably at least 20 μm, and most preferably at least 40 μm, to improve resistance to contact with sharp objects. The maximum thickness of the polymer layer can be 200 μm. Lamination can be performed using various known methods.

[0080] In the case of lamination, the polymer material can be selected from, for example, the group consisting of: silicone polymers, sol-gel polymers, polycarbonate (PC), polyethersulfone, polyacrylate, polyimide (PI), inorganic silica / polymer hybrids, cyclic olefin copolymers, polyolefins, and silicone resins. Polyethylene (PE), polypropylene, polyvinyl chloride, polystyrene, styrene-acrylonitrile copolymer, thermoplastic polyurethane resin (TPU), polymethyl methacrylate (PMMA), ethylene-vinyl acetate copolymer, polyethylene terephthalate (PET), polybutylene terephthalate, polyamide (PA), polyacetal, polyphenylene ether, polyphenylene sulfide, fluoropolymers, chlorinated polymers, ethylene-tetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), polyethylene naphthalate (PEN), terpolymers made of tetrafluoroethylene, terpolymers made of hexafluoropropylene, and terpolymers made of vinylidene fluoride (THV) or polyurethane, or mixtures thereof. The polymer layer can be applied to ultrathin chemically tempered glass articles by any known method.

[0081] According to another advantageous embodiment, the tempered glass article includes a coating layer on at least one surface, the coating layer comprising a coating material. The coating of the protective layer can be applied by any known coating method, such as chemical vapor deposition (CVD), dip coating, spin coating, inkjet printing, casting, screen printing, painting, and spraying. However, the invention is not limited to those procedures. Suitable coating materials are also known in the art. For example, it may include rigid plastic reactive resins, which are polymers selected from the group consisting of: phenolic plastics, phenol-formaldehyde resins, amino plastics, urea-formaldehyde resins, melamine-formaldehyde resins, epoxy resins, unsaturated polyester resins, vinyl ester resins, styrene acrylate resins, diallyl phthalate resins, silicone resins, crosslinked polyurethane resins, polymethyl methacrylate reactive resins, and polyacrylate reactive resins.

[0082] According to advantageous embodiments of the invention, the CT of the tempered glass article is less than or equal to 200 MPa, more preferably less than or equal to 150 MPa, more preferably less than or equal to 120 MPa, and even more preferably less than or equal to 100 MPa. Some advantageous embodiments may have a CT of less than or equal to 65 MPa. Other advantageous embodiments may have a CT of less than or equal to 45 MPa. Some glass variants may even have a CT of less than or equal to 25 MPa. These CT values ​​are particularly advantageous for glass article variants with low DoL.

[0083] Due to their low DoL (Dosage-to-Limit), the internal CT (Collateral Pressure) of these glass products is reduced. This reduction in CT significantly impacts the pressure resistance of tempered glass products. Even if the tempered surface of a glass product with a small CT is damaged by a sharp, hard object, the product will not break because the internal strength of the glass structure can overcome the small CT.

[0084] Alternatively, for variations of glass articles with high DoL, it may be advantageous if they have a central tensile stress (CT) greater than or equal to 27 MPa, more preferably greater than or equal to 45 MPa, more preferably greater than or equal to 65 MPa, more preferably greater than or equal to 100 MPa.

[0085] Glass products can be additionally coated to achieve, for example, anti-reflective, scratch-resistant, fingerprint-resistant, antimicrobial, anti-glare, and combinations of these functions.

[0086] As mentioned above, CS, DoL, and CT depend on the glass composition (glass type), glass thickness, and tempering conditions.

[0087] The inventors have discovered that, in the case of UTG aluminosilicate glass, the following features are advantageous: Chemically tempered glass article has a thickness (t) of less than 0.4 mm, a first surface and a second surface, and a compressive stress region extending from the first surface to a first depth (DoL) in the glass article, the region being defined by compressive stress (CS), wherein the surface CS at the first surface is at least 450 MPa. - The breaking force (given in N) of the glass article is at least the thickness of the glass article (t (mm)) multiplied by 30, wherein the breaking force is determined in a sandpaper pressure test. In the test, the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm is loaded onto the first surface of the glass article at the flat front surface until it breaks, wherein P180 type sandpaper is placed between the flat front surface of the steel rod and the first surface of the glass article, with the abrasive side of the sandpaper in contact with the first surface, and - The fracture bending radius of the glass article (given in mm) is <100000*t / CS, preferably <80000*t / CS, more preferably <70000*t / CS, and even more preferably <60000*T / CS, where the thickness t is given in mm and CS is the surface compressive stress (given in MPa) measured at the first surface.

[0088] Preferably, the chemically tempered glass article has a DoL (in μm) in the range of 0.5 μm to 120 * t / CS μm, more preferably in the range of 1 μm to 90 * t / CS μm, more preferably in the range of 1 μm to 60 * t / CS μm, even more preferably in the range of 1 μm to 45 * t / CS μm, and even more preferably in the range of 1 μm to 27 * t / CS μm, where t is given in μm and CS is the surface compressive stress (in MPa) measured at the first surface. A preferred CT may be less than or equal to 200 MPa, preferably less than or equal to 150 MPa, more preferably less than or equal to 120 MPa, more preferably less than or equal to 100 MPa, even more preferably less than or equal to 65 MPa, and even more preferably less than or equal to 45 MPa.

[0089] Alternatively, chemically tempered glass articles may have a DoL (in μm) in the range of 27*t / CS μm to 0.5*t μm, preferably in the range of 45*t / CS μm to 0.45*t μm, more preferably in the range of 60*t / CS μm to 0.4*t μm, and even more preferably in the range of 90*t / CS μm to 0.35*t μm, where t is in μm and CS is the surface compressive stress (given in MPa) measured at the first surface. In these embodiments, CT is preferably greater than or equal to 27 MPa, more preferably greater than or equal to 45 MPa, and even more preferably greater than or equal to 65 MPa.

[0090] Preferably, in aluminosilicate glass, the surface pressure (CS) at the first and / or second surfaces of the glass article can be equal to or greater than 450 MPa, preferably equal to or greater than 500 MPa, more preferably equal to or greater than 550 MPa, and more preferably equal to or greater than 600 MPa. In some advantageous embodiments, the surface pressure (CS) can be equal to or greater than 700 MPa, more preferably equal to or greater than 800 MPa.

[0091] In the case of UTG lithium aluminosilicate glass, the following characteristics are advantageous: Chemically tempered glass articles have a thickness (t) of less than 0.4 mm, a first surface and a second surface, and a compressive stress region extending from the first surface to a first depth (DoL) in the glass articles, said region being defined by compressive stress (CS), wherein the surface CS at the first surface is at least 350 MPa, wherein - The breaking force (given in N) of the glass article is at least the thickness of the glass article (t (mm)) multiplied by 30, wherein the breaking force is determined in a sandpaper pressure test. In the test, the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm is applied to the first surface of the glass article at a flat front surface until it breaks. P180 type sandpaper is placed between the flat front surface of the steel rod and the first surface of the glass article, with the abrasive side of the sandpaper in contact with the first surface. - The fracture bending radius of the glass article (given in mm) is <100000*t / CS, preferably <80000*t / CS, more preferably <70000*t / CS, and even more preferably <60000*T / CS, where the thickness t is given in mm and CS is the surface compressive stress (given in MPa) measured at the first surface.

[0092] Preferably, the chemically tempered glass article has a DoL (in μm) in the range of 0.5 μm to 120 * t / CS μm, more preferably in the range of 1 μm to 90 * t / CS μm, more preferably in the range of 1 μm to 60 * t / CS μm, more preferably in the range of 1 μm to 45 * t / CS μm, and even more preferably in the range of 1 μm to 27 * t / CS μm, where t is given in μm and CS is the surface compressive stress (in MPa) measured at the first surface. Preferably, CT can be less than or equal to 150 MPa, more preferably less than or equal to 100 MPa, even more preferably less than or equal to 65 MPa, and even more preferably less than or equal to 45 MPa.

[0093] Alternatively, chemically tempered glass articles may have a DoL (in μm) in the range of 27*t / CS μm to 0.5*t μm, preferably in the range of 45*t / CS μm to 0.45*t μm, more preferably in the range of 60*t / CS μm to 0.4*t μm, and even more preferably in the range of 90*t / CS μm to 0.35*t μm, where t is in μm and CS is the surface compressive stress (given in MPa) measured at the first surface. The CT of these embodiments may be greater than or equal to 27 MPa, more preferably greater than or equal to 45 MPa, more preferably greater than or equal to 65 MPa, and more preferably greater than or equal to 100 MPa.

[0094] Preferably, the surface pressure (CS) of the lithium aluminum silicate glass at the first and / or second surfaces of the glass article can be equal to or greater than 350 MPa, equal to or greater than 500 MPa, equal to or greater than 600 MPa, preferably equal to or greater than 700 MPa, and more preferably equal to or greater than 800 MPa.

[0095] In the case of UTG borosilicate glass, the following characteristics are advantageous: Chemically tempered glass articles have a thickness (t) of less than 0.4 mm, a first surface and a second surface, and a compressive stress region extending from the first surface to a first depth (DoL) within the glass articles, said region being defined by compressive stress (CS), wherein the surface CS at the first surface is at least 100 MPa, wherein - The breaking force (given in N) of the glass article is at least the thickness of the glass article (t (mm)) multiplied by 30, wherein the breaking force is determined in a sandpaper pressure test. In the test, the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm is applied to the first surface of the glass article at a flat front surface until it breaks. P180 type sandpaper is placed between the flat front surface of the steel rod and the first surface of the glass article, wherein the abrasive side of the sandpaper is in contact with the first surface, and... - The fracture bending radius of the glass article (given in mm) is <100000*t / CS, preferably <80000*t / CS, more preferably <70000*t / CS, and even more preferably <60000*T / CS, where the thickness t is given in mm and CS is the surface compressive stress (given in MPa) measured at the first surface.

[0096] Preferably, the chemically tempered glass article has a DoL (given in μm) in the range of 0.5 μm to 60 * t / CS μm, more preferably in the range of 1 μm to 45 * t / CS μm, and even more preferably in the range of 1 μm to 27 * t / CS μm, where t is given in μm and CS is the surface compressive stress (given in MPa) measured at the first surface. Preferably, CT can be less than or equal to 150 MPa, more preferably less than or equal to 120 MPa, more preferably less than or equal to 100 MPa, even more preferably less than or equal to 65 MPa, even more preferably less than or equal to 45 MPa, and even more preferably less than or equal to 25 MPa.

[0097] Alternatively, chemically tempered glass articles may have a DoL (in μm) in the range of 27*t / CS μm to 0.5*t μm, preferably in the range of 45*t / CS μm to 0.45*t μm, where t is given in μm and CS is the surface compressive stress (given in MPa) measured at the first surface. In this alternative, CT may be greater than or equal to 27 MPa, more preferably greater than or equal to 45 MPa, and even more preferably greater than or equal to 65 MPa.

[0098] Preferably, the surface pressure (CS) at the first and / or second surfaces of the borosilicate glass can be equal to or greater than 100 MPa, more preferably equal to or greater than 200 MPa, and even more preferably equal to or greater than 300 MPa.

[0099] In the case of UTG soda-lime glass, the following characteristics are advantageous: Chemically tempered glass articles have a thickness (t) of less than 0.4 mm, a first surface and a second surface, and a compressive stress region extending from the first surface to a first depth (DoL) in the glass articles, said region being defined by compressive stress (CS), wherein the surface CS at the first surface is at least 200 MPa, wherein - The average breaking force (given in N) of the glass article is at least 30 times the thickness of the glass article (t (mm)), wherein the breaking force is determined in a sandpaper pressure test. In the test, the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm is loaded onto the first surface of the glass article at a flat front surface until it breaks. P180 type sandpaper is placed between the flat front surface of the steel rod and the first surface of the glass article, with the abrasive side of the sandpaper in contact with the first surface. - The fracture bending radius of the glass article (given in mm) is <100000*t / CS, preferably <80000*t / CS, more preferably <70000*t / CS, and even more preferably <60000*T / CS, where the thickness t is given in mm and CS is the surface compressive stress (given in MPa) measured at the first surface.

[0100] Preferably, the chemically tempered glass article has a DoL (in μm) in the range of 0.5 μm to 90 * t / CS μm, more preferably in the range of 0.5 μm to 60 * t / CS μm, even more preferably in the range of 1 μm to 45 * t / CS μm, and even more preferably in the range of 1 μm to 27 * t / CS μm, where t is given in μm and CS is the surface compressive stress (in MPa) measured at the first surface. Preferably, CT can be less than or equal to 150 MPa, less than or equal to 100 MPa, more preferably less than or equal to 65 MPa, and even more preferably less than or equal to 45 MPa.

[0101] Alternatively, chemically tempered glass articles may have a DoL (in μm) in the range of 27*t / CS μm to 0.5*t μm, preferably in the range of 45*t / CS μm to 0.45*t μm, and more preferably in the range of 60*t / CS μm to 0.4*t μm, where t is given in μm and CS is the surface compressive stress (given in MPa) measured at the first surface. The CT of these embodiments may be greater than or equal to 27 MPa, more preferably greater than or equal to 45 MPa, more preferably greater than or equal to 65 MPa, and more preferably greater than or equal to 100 MPa.

[0102] Preferably, the surface pressure (CS) at the first and / or second surfaces of the soda-lime glass can be equal to or greater than 200 MPa, and more preferably equal to or greater than 300 MPa.

[0103] Glass articles can be used in applications such as display substrates or protective covers, fingerprint sensor covers, general sensor substrates or covers, cover glass for consumer electronics, protective covers for displays, and other surfaces, especially curved surfaces. Furthermore, glass articles can also be used in applications such as display substrates and covers, fragile sensors, fingerprint sensor module substrates or covers, semiconductor packaging, thin-film battery pack substrates and covers, foldable displays, and camera lens covers. In certain embodiments, glass articles can be used as cover films for resistive touchscreens, and as consumable protective films for displays, mobile phones, cameras, gaming gadgets, tablets, laptops, televisions, mirrors, windows, aviation windows, furniture, and white goods.

[0104] This invention is particularly applicable to flexible electronic devices (e.g., curved displays, wearable devices) that are lightweight, thin, and flexible. Such flexible devices also require flexible substrates, for example, for holding or mounting the components. Furthermore, flexible displays with high contact resistance and small bending radii are possible.

[0105] Furthermore, the present invention is particularly suitable for forming laminated structures comprising at least two ultrathin glass layers and an organic layer therebetween, wherein at least one glass layer is a chemically tempered glass article according to the present invention, and wherein the organic layer is preferably selected from the group consisting of: optically clear adhesive (OCA), optically clear resin (OCR), polyvinyl butyral (PVB), polycarbonate (PC), polyvinyl chloride (PVC), and thermoplastic polyurethane (TPU). Glass articles of the above-described laminated structure form are also an object of the present invention.

[0106] According to a preferred variant of the invention, ultrathin chemically tempered glass articles are used to form laminated layered structures (also known as “glass laminates”). The laminated layered structure comprises, for example, two ultrathin glass layers and an organic layer therebetween. At least one of these UTG layers is a glass article according to the invention. In one case, the glass laminate comprises a tempered glass layer and an untempered glass layer, wherein the tempered glass layer has at least one tempered surface located on the outside of the glass laminate. Of course, both UTG layers can be glass articles according to the invention (meaning the glass laminate comprises two tempered glass layers). In the latter case, it is preferred that each glass layer has at least one tempered surface that can be located on the outside of the glass laminate. Of course, the glass laminate can consist of more than two ultrathin glass layers. Glass laminates having three, four, five, or more UTG layers (tempered and / or untempered in any combination) may also have an organic layer between the UTG layers. The organic layer is preferably selected from optically clear adhesives (OCA), optically clear resins (OCR), polyvinyl butyral (PVB), polycarbonate (PC), polyvinyl chloride (PVC), and thermoplastic polyurethane (TPU). Methods for manufacturing such glass laminates are known.

[0107] The glass laminate may include at least one tempered glass layer with a high DoL or a low DoL. It may be advantageous for the glass laminate to include a laminated polymer layer and / or a coating layer on at least one side, wherein the polymer layer has a thickness of at least 1 μm, preferably at least 5 μm, more preferably at least 10 μm, more preferably at least 20 μm, and most preferably at least 40 μm, to improve resistance to sharp object contact. The laminated polymer layer may completely or partially cover the surface of the glass laminate.

[0108] Glass laminates may comprise glass layers with the same thickness and / or DoL. Alternatively, glass laminates may comprise ultrathin glass layers with different thicknesses and / or different DoLs. For example, a glass laminate may have a structure of “0.05 mm glass layer + OCA / OCR + 0.07 mm glass layer”, wherein the glass layers have the same DoL (e.g., 6 μm). Another structure may be “0.05 mm glass layer (DoL 11 μm) + OCA / OCR + 0.07 mm glass layer (DoL 4 μm)”.

[0109] Advantageously, laminated structures can exhibit higher strength or stability compared to monolithic glass products of the same thickness. Furthermore, the layers in a laminated structure can be made of thin or very thin glass, making the structure thin and flexible without compromising overall strength or stability. Therefore, the bending performance of glass laminates can even surpass that of monolithic glass products. For example, a glass laminate comprising two 0.05 mm tempered glass layers with an interlayer of OCA can have a smaller bending radius than a 0.1 mm thick glass product.

[0110] If a single pane of glass breaks, it can damage, for example, the display of an electronic device. Glass laminates offer more protection. Even if the ultra-thin outer layer of glass breaks, another layer of glass on the back provides further protection.

[0111] According to the present invention, a method for preparing the glass article of the present invention is also provided, the method comprising the following steps: a) Provide a composition of raw materials for the desired glass, b) Melt the composition. c) Producing glass products using flat glass manufacturing processes. d) Chemically tempering the glass article, and e) Optionally, at least one surface of the glass article is coated with a coating. f) Optionally, at least one surface of the glass article is laminated to a polymer layer. The tempering temperature ranges from 340℃ to 480℃, and the tempering time ranges from 30 seconds to 48 hours.

[0112] According to the method of the present invention, the tempering temperature is reduced and / or the tempering time is shortened to achieve innovative glass articles with optimized stress distribution.

[0113] Preferably, the flat glass process is a down-drawing process or a re-drawing process.

[0114] Advantageously, the chemical tempering process includes an ion exchange process. For large-scale production, it is advantageous if the ion exchange process involves immersing the glass article or a portion thereof in a salt bath containing monovalent cations. Preferably, the monovalent cations are potassium ions and / or sodium ions.

[0115] For some glass types, chemical tempering may preferably include two consecutive tempering steps, wherein the first step includes tempering with a first tempering agent, and the second step includes tempering with a second tempering agent. Preferably, the first and second tempering agents comprise KNO3 and / or NaNO3 and / or mixtures thereof, or consist of these.

[0116] More details about the manufacturing and tempering process have been described above. Attached Figure Description

[0117] The figures in the accompanying drawings show: Figure 1 This is a simplified illustration of a sandpaper pressure test.

[0118] Figure 2 The average breaking force is given in the comparative and example cases of glass type 1.

[0119] Figure 3 The B10 fracture force is shown in the comparative and example cases of glass type 1.

[0120] Figure 4 The average fracture force in the example (Example 2).

[0121] Figure 5 The B10 fracture force is shown in Example 2. Detailed Implementation

[0122] Table 1 shows compositions of several typical examples (types 1-5) of chemically temperable direct thermoforming ultrathin glass.

[0123] Table 1: Examples of the composition of direct thermoforming UTG for different glass types Glass articles 1 of different glass types are produced using a pull-down process. These glass articles are then chemically tempered to form ultra-thin chemically tempered glass articles. Each ultra-thin glass article has a first surface 2 and a second surface 3. In the illustrated embodiment, both sides of each sample of the glass article are tempered. Therefore, a compressive stress region of a certain depth (DoL) exists on each side of the glass article. All samples are cut from a larger glass article using a diamond cutting wheel. The samples are tested without any further edge treatment (e.g., polishing, etching).

[0124] Comparative Example - Glass Type 1 Numerous Type 1 glass samples with lengths of 11 mm, widths of 11 mm, and thicknesses of 0.05 mm, 0.07 mm, and 0.1 mm were prepared and chemically tempered. Different tempering conditions (shown in Table 2) were used to obtain different CS values ​​with DoL > 10 μm. After ion exchange, the tempered samples were cleaned and measured using an FSM 6000.

[0125] The sandpaper pressure test, described in detail above, was used to test the resistance to contact with sharp, hard objects. A simplified illustration of the test is shown below. Figure 1As shown in the diagram, the second surface 3 of the glass article 1 is placed on a steel plate 4. A steel rod with a diameter of 3 mm is loaded onto the first surface 2 of the glass article 1 at the flat front surface 8, and the first surface is pressed until it breaks, wherein P180 type sandpaper 5 is placed between the front surface 8 of the steel rod 7 and the first surface 2 of the glass article 1. The abrasive side of the sandpaper 5 is in contact with the first surface 2. Twenty tempered samples with each thickness and DoL were tested and evaluated. The average breaking force was calculated as described above, and the B10 force was calculated using the Weibull method.

[0126] Furthermore, to determine the fracture bending radius, the aforementioned two-point bending method was used, and 20 tempered samples with each thickness and DoL were tested using samples measuring 20 mm × 70 mm. The average fracture bending radius was calculated as described above.

[0127] Table 2 shows the test results (mean and B10 value calculated using the Weibull method) for the contact resistance and bending radius of comparative examples A to H. Figure 2 In the table, the results of sandpaper pressure tests (mean breaking force) are given for comparative examples A to C and E to H. The vertical lines indicate the distribution of the measured values ​​around the corresponding average value in each case. Figure 3 The calculated B10 forces for comparative examples A to C and E to H are given in the figure.

[0128] Table 2: Glass Type 1, Tempering Conditions and Results (Comparative Example) Example 1 - Glass Type 1: Numerous Type 1 glass samples with lengths of 11 mm, widths of 11 mm, and thicknesses of 0.05 mm, 0.07 mm, 0.1 mm, 0.145 mm, 0.25 mm, and 0.33 mm were prepared and chemically tempered. Different tempering conditions (shown in Table 3) were used to obtain different CS and DoL values. After ion exchange, the tempered samples were cleaned and measured using an FSM 6000.

[0129] The sandpaper pressure test, described in detail above, was used to test the resistance to contact with sharp, hard objects. A simplified illustration of the test is shown below. Figure 1 As shown in Table 3, 20 tempered samples with each thickness and DoL were tested and evaluated as described above. Table 3 shows the average sandpaper pressure (= average breaking force, in "N") that could be applied until the glass sample was damaged, corresponding to different DoL and thicknesses. The calculated B10 force (in N) is further given. Figure 2The average breaking force (results of sandpaper pressure tests) of samples with thicknesses of 0.05 mm, 0.07 mm, and 0.1 mm, and different DoL, are shown in Examples 1 to 6. The vertical lines indicate the distribution of the measurements around the corresponding average value in each case. Figure 3 The calculated B10 force (sandpaper pressure test) for Examples 1 to 6 is given in the table.

[0130] Furthermore, to determine the average fracture bending radius, the aforementioned two-point bending method was used. Twenty tempered samples with each thickness and DoL were tested using samples measuring 20 mm × 70 mm, and evaluated as described above. Since the measurements were taken directly after the samples were cut (meaning no edge treatment was performed), the bending radius of edge-treated glass products will be smaller.

[0131] Table 3: Glass Type 1, Tempering Conditions and Results from Figure 2 and Figure 3 It is clear that, for example, glass type 1 samples with a DoL of less than 10 μm and a thickness of 0.1 mm (Examples 4 to 6) exhibit greater average breaking force and B10 force than samples of the same thickness but with a higher DoL (Comparative Examples E to H). Therefore, these examples are more resistant to contact with highly sharp objects (pressure contact) compared to the comparative examples. The same results can be observed when comparing other examples of corresponding thicknesses (e.g., 0.05 mm, 0.07 mm). Furthermore, the accompanying figures show that as the DoL decreases, both the average breaking force and B10 force increase, referring to examples of the same thickness (e.g., Examples 4 to 6 or Examples 2 and 3). Different DoL values ​​are achieved by varying the tempering conditions (in this case, varying the tempering time at extremely low tempering temperatures), as shown in Tables 2 and 3.

[0132] In a preferred embodiment, an ultrathin glass of 0.1 mm thickness is tempered to obtain a surface CS of 828 MPa and a DoL of 9 μm, and the resulting CT is only 91 MPa (Example 6). The glass article has a sandpaper pressure B10 force of 9.9 N. Therefore, its breaking force (in N) > 3 (calculated by ≥30*0.1). Furthermore, the average breaking bending radius of this embodiment is <7 mm. Therefore, its breaking bending radius is within the standard "<12" (calculated by <100000*0.1 / 828), and even within the standard "<7.2" (calculated by <60000*0.1 / 828). Thus, this glass article has an optimized stress distribution, achieving a balance between high flexibility (small bending radius) and high resistance to sharp object contact.

[0133] Conversely, Comparative Example E is an ultrathin glass with a thickness of 0.1 mm, tempered to achieve a surface CS of 793 MPa and a DoL of 15 μm, with a resulting CT of only 170 MPa. This glass article has a sandpaper pressure B10 force of 0.7 N. Therefore, its breaking force (in N) is <3 (calculated by: ≥30*0.1). The average breaking bending radius of this embodiment is <6 mm. Therefore, its breaking bending radius is within the standard "<13" (calculated by <100000*0.1 / 793), even within the standard "<7.6" (calculated by <60000*0.1 / 793). Although the bending radius of this comparative example is acceptable, such a glass article is not suitable for use in a product because it does not achieve an optimized stress distribution that balances high flexibility (small bending radius) with high resistance to sharp object contact. The breaking force of this glass article is too low.

[0134] Example 2 - Laminated Glass Type 1 with High DoL Numerous glass type 1 samples, each 11 mm in length, 11 mm in width, and 0.1 mm in thickness, were prepared and chemically tempered. Tempering conditions were applied with a CS of 717 MPa and a DoL of 28 μm. After ion exchange, the tempered samples were cleaned and measured using an FSM 6000. PE or PET films of varying thicknesses (10 μm or 50 μm in this case) were laminated onto the glass samples (Examples 13 to 16). The samples' resistance to contact with sharp, hard objects was then tested using a sharp object pressing test (sandpaper pressure test) as described above. In each experiment, 20 samples for each lamination treatment were tested and evaluated in conjunction with Example 1. Table 4 shows the sample conditions and experimental results. Related Figure 4 The sandpaper pressure test results (average breaking force) for the corresponding example are shown. Figure 5 The calculated B10 force for the corresponding instance is shown.

[0135] from Figure 4 and Figure 5 As can be seen, despite the very high DoL of the samples, the resistance to sharp object pressure in Examples 15 and 16 is improved. This is achieved by laminating polymer layers onto the glass, where a thicker 50 μm polymer layer provides better protection against sharp object contact forces than a thinner polymer layer. Example 13 is a glass sample without lamination. Due to the properties of the laminating materials, the 50 μm PET layer appears to be more effective than the 50 μm PE layer.

[0136] Table 4: Laminated glass type 1 (0.1 mm, high DoL) (tempering conditions and results) Example 3 - Glass Type 2 Samples of glass type 2 with a length of 11 mm, a width of 11 mm, and thicknesses of 0.1 mm, 0.25 mm, and 0.33 mm were prepared and chemically tempered. Different tempering conditions were used to obtain different CS and DoL. Example 17 was tempered in one step, while Examples 18 to 20 were tempered in two steps. After ion exchange, the tempered samples were cleaned and measured using an FSM 6000. The resistance of the samples to contact with sharp, hard objects was then tested by a sharp object pressure test (sandpaper pressure test) as described above. In addition, the fracture bending radius was measured using a sample with a length of 70 mm and a width of 20 mm using a two-point bending method. In each test / experiment, multiple (20) samples with each thickness and DoL were tested and evaluated in conjunction with Example 1. Table 5 shows the sample conditions and experimental results (Examples 17 to 20).

[0137] Table 5: Glass Type 2 (0.1 mm, 0.25 mm, 0.33 mm), Tempering Conditions and Results Example 4 - Glass Type 3 Samples of glass type 3 with a length of 11 mm, a width of 11 mm, and thicknesses of 0.1 mm and 0.21 mm were prepared and chemically tempered. Different tempering conditions were used to obtain different CS and DoL values. After ion exchange, the tempered samples were cleaned and measured using an FSM 6000. The resistance of the samples to contact with sharp, hard objects was then tested by a sharp object pressure test (sandpaper pressure test) as described above. In addition, the fracture bending radius was measured using samples of each thickness with a length of 70 mm and a width of 20 mm using the two-point bending method described above. In each test / experiment, multiple (20) samples with each thickness and DoL were tested and evaluated in conjunction with Example 1. Table 6 shows the sample conditions and experimental results (Examples 21 to 23).

[0138] Table 6: Glass Type 3 (0.1 mm and 0.21 mm), Tempering Conditions and Results Example 5 - Glass Type 4 Samples of glass type 4 with a length of 11 mm, a width of 11 mm, and thicknesses of 0.145 mm, 0.33 mm, and 0.4 mm were prepared and chemically tempered. Different tempering conditions were used to obtain different CS and DoL values. After ion exchange, the tempered samples were cleaned and measured using an FSM 6000. The samples' resistance to contact with sharp, hard objects was then tested using a sharp object pressure test (sandpaper pressure test) as described above. Furthermore, the fracture bending radius was measured using the two-point bending method described above, with samples of each thickness having a length of 70 mm and a width of 20 mm. In each test / experiment, multiple (20) samples of each thickness were tested and evaluated in conjunction with Example 1. Table 7 shows the sample conditions and experimental results (Examples 24 to 26).

[0139] Table 7: Glass Type 4 (0.1 mm, 0.33 mm, 0.4 mm), Tempering Conditions and Results This type of glass has a very low CS (Critical Strain). However, even with a low CS, it resists sharp and hard objects very well.

[0140] Example 6 - Glass Type 5 Glass type 5 samples with a length of 11 mm, a width of 11 mm, and a thickness of 0.1 mm were prepared and chemically tempered. Different tempering conditions were used to obtain different CS and DoL. After ion exchange, the tempered samples were cleaned and measured using an FSM6000. The resistance of the samples to contact with sharp objects was then tested by a sharp object pressure test (sandpaper pressure test) as described above. In addition, the fracture bending radius was measured using a sample with a length of 70 mm and a width of 20 mm using the two-point bending method described above. In each test / experiment, multiple (20) samples with each DoL were tested and evaluated in conjunction with Example 1. Table 8 shows the sample conditions and experimental results (Examples 27 to 29).

[0141] Table 8: Glass Type 5 (0.1 mm), Tempering Conditions and Results Typically, the strength of ultrathin chemically tempered glass articles according to the present invention, determined by sandpaper pressure testing, follows a Weibull distribution. Tables 2 to 7 give the B10 values ​​that define the force required to break when 10% of the samples break.

Claims

1. A chemically tempered glass article (1) having a thickness (t) equal to or less than 0.1 mm, a first surface (2) and a second surface (3) and a compressive stress region extending from the first surface to a first depth (DoL) in the glass article, the region being defined by compressive stress (CS), wherein the surface compressive stress (CS) at the first surface (2) is at least 600 MPa, wherein - The breaking force (given in N) of the glass article is at least a value equal to the thickness (t, in mm) of the glass article multiplied by 30, wherein the breaking force is determined in a sandpaper pressure test in which the second surface of the glass article is placed on a steel plate, and a steel rod with a diameter of 3 mm at a flat front surface is applied to the first surface of the glass article until it breaks, wherein P180 type sandpaper is placed between the flat front surface of the steel rod and the first surface of the glass article, wherein the abrasive side of the sandpaper is in contact with the first surface, and - The fracture radius of the glass article (given in mm) is less than the result obtained by multiplying the thickness of the article (t, in mm) by 100,000 and then dividing by the surface compressive stress (in MPa) measured at the first surface, preferably less than the result obtained by multiplying the thickness of the glass article (t, in mm) by 80,000 and then dividing by the surface compressive stress (in MPa) measured at the first surface, particularly preferably less than the result obtained by multiplying the thickness of the glass article (t, in mm) by 70,000 and then dividing by the surface compressive stress (in MPa) measured at the first surface, and even more preferably less than the result obtained by multiplying the thickness of the glass article (t, in mm) by 60,000 and then dividing by the surface compressive stress (in MPa) measured at the first surface. The glass comprises, in specified amounts (wt%) of the following components: The glass contains at most 2 wt% Li2O. The central tensile stress of the glass article is in the range of >120 MPa to 456 MPa.

2. The chemically tempered glass article according to claim 1, wherein the glass article comprises a coating layer and / or a laminated polymer layer on its surface as a protective layer to protect the glass article and improve its resistance to pressure from sharp objects.

3. The chemically tempered glass article according to claim 1 or 2, wherein the glass does not contain Li2O and / or wherein the glass does not contain B2O3.

4. The chemically tempered glass article according to claim 1 or 2, wherein the glass comprises ZrO2 and / or the glass comprises 0 to 5 wt% B2O3.

5. The chemically tempered glass article according to any one of the preceding claims, wherein the thickness of the glass article is ≤0.07 mm, preferably ≤0.05 mm, even more preferably ≤0.03 mm, even more preferably ≤0.01 mm and / or ≥0.005 mm.

6. The chemically tempered glass article according to any one of the preceding claims, wherein the DoL (in μm) of the article is in the range of 60*t / CS μm to 0.4*t μm, and even more preferably in the range of 90*t / CS μm to 0.35*t μm, where t is given in μm and CS is the value of the surface compressive stress (given in MPa) measured at the first surface.

7. The chemically tempered glass article according to any one of claims 2 to 6, wherein the thickness of the polymer layer is ≥1 μm, preferably ≥5 μm, more preferably ≥10 μm, even more preferably ≥20 μm, even more preferably ≥40 μm and / or <200 μm.

8. A chemically tempered glass article according to any one of the preceding claims, wherein the glass article has a second compressive stress region extending from the second surface (3) of the glass article to a second depth (DoL) therein, the region being defined by compressive stress (CS), wherein the surface compressive stress at the second surface (3) is at least 600 MPa.

9. A chemically tempered glass article according to any one of the preceding claims, wherein the surface compressive stress (CS) of the glass article (1) at the first surface (2) and / or the second surface (3) is equal to or greater than 700 MPa, and more preferably equal to or greater than 800 MPa.

10. The chemically tempered glass article according to claim 1, wherein the glass article (1) has a thickness (t) equal to or less than 0.07 mm, and wherein the surface compressive stress (CS) of the glass article (1) at the first surface (2) and / or the second surface (3) is equal to or greater than 700 MPa.

11. A chemically tempered glass article according to any one of the preceding claims, wherein the glass article is a flat article and / or a flexible article and / or a deformable article.

12. Use of a chemically tempered glass article according to any one of the preceding claims, as a cover film for a resistive screen, and as a consumable protective film for displays, mobile phones, cameras, game consoles, tablets, laptops, televisions, mirrors, windows, aviation windows, furniture, and white goods.

13. Use of a chemically tempered glass article according to any one of claims 1 to 11, for use in: display substrates and covers, fragile sensors, fingerprint sensor module substrates or covers, semiconductor packaging, thin-film battery pack substrates and covers, foldable displays, and camera lens covers.

14. Use of a chemically tempered glass article according to any one of claims 1 to 11 for forming a laminated structure, wherein the laminated structure comprises at least two ultrathin glass layers and an organic layer therebetween, wherein at least one glass layer is a chemically tempered glass article according to the invention, and wherein the organic layer is preferably selected from the group consisting of: optically clear adhesives (OCA), optically clear resins (OCR), polyvinyl butyral (PVB), polycarbonate (PC), polyvinyl chloride (PVC), and thermoplastic polyurethane (TPU).

15. A method for producing chemically tempered glass articles according to any one of claims 1 to 11, comprising the following steps: a) Provide a composition of raw materials for the desired glass, b) Melt the composition. c) Producing glass products using flat glass manufacturing processes. d) Chemically tempering the glass article, and e) Optionally, at least one surface of the glass article is coated with a coating. f) Optionally, at least one surface of the glass article is laminated to a polymer layer. The tempering temperature ranges from 340℃ to 480℃, and the tempering time ranges from 30 seconds to 48 hours.

16. The method of claim 15, wherein the flat glass process is a down-drawing process or a re-drawing process.

17. The method of claim 15 or 16, wherein the chemical tempering step comprises an ion exchange process.

18. The method of claim 17, wherein the ion exchange process comprises immersing the glass article or a portion thereof in a salt bath containing monovalent cations.

19. The method of claim 18, wherein the monovalent cation is a potassium ion and / or a sodium ion.

20. The method according to any one of claims 15 to 19, wherein chemical tempering comprises two consecutive tempering steps, wherein the first step comprises tempering with a first tempering agent and the second step comprises tempering with a second tempering agent.

21. The method of claim 20, wherein the first tempering agent and the second tempering agent comprise KNO3, NaNO3 and / or mixtures thereof, or are composed of them.

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