High-strength bendable ultra-thin flexible glass, and preparation method and application thereof

Abstract

This invention discloses a high-strength, bend-resistant, ultra-thin flexible glass, its preparation method, and its applications, belonging to the field of flexible glass technology. The glass composition, by mass percentage, comprises: SiO2 55-68%, Al2O3 10-22%, and Na2O 6.5-17%, satisfying 2.6 ≤ SiO2 / Al2O3 ≤ 5.0. The preparation method includes: thinning a glass substrate with the above composition; forming an opening structure with a depth of 30-50% of the thickness in its flexible region using laser etching; forming a circular arc edge groove with a depth of 40-50 μm in the flexible region by wet etching; performing segmented and zoned chemical strengthening on the substrate, such that the strengthening temperature of the flexible region is 5-10°C higher than that of the non-flexible region, and the strengthening time is 20-30 minutes longer; filling the grooves with resin and curing it. This invention achieves a balance between strength and flexibility in ultra-thin glass through the synergy of specific components, dual microstructure design, and differentiated strengthening processes. The product's bending radius can be as low as 1.3-1.5mm, and it can pass 300,000 bending tests. It also possesses high hardness and excellent impact resistance, making it suitable for high-end foldable display devices.

Description

Technical Field

[0001] This application relates to the field of glass manufacturing, and more specifically, to a high-strength, bend-resistant, ultra-thin flexible glass, its preparation method, and its application. Background Technology

[0002] With the evolution of flexible electronics technology, flexible displays and wearable devices are placing more stringent demands on the comprehensive performance of their core packaging and carrier material—ultra-thin flexible glass. An ideal material needs to possess high flexibility while also exhibiting high strength, impact resistance, and excellent chemical stability to meet the reliability requirements of repeated bending and daily use.

[0003] However, current ultrathin flexible glass still faces multiple technological constraints. At the materials level, improving flexibility often comes at the expense of strength, resulting in insufficient impact resistance and limited bending life; most products can only withstand tens of thousands of bends, and the critical radius of curvature is typically greater than 2mm. In terms of composition design, there is an over-reliance on single oxides, affecting melting processability, material stability, and the balance of surface stress and hardness after chemical strengthening. Regarding manufacturing processes, the commonly used uniform chemical strengthening parameters can easily lead to uneven surface stress distribution, causing localized stress concentration during bending and accelerating fatigue failure. In terms of structural design, traditional flat panel configurations concentrate bending stress in the hinge area, easily resulting in permanent creases or cracks; simultaneously, the lack of microstructure design in flexible sections not only limits further improvements in flexibility but also easily causes optical interference (Moiré effect) during bending, restricting its application in high-end display fields.

[0004] Meanwhile, at the level of process synergy, optimizing a single technology is no longer sufficient to achieve substantial breakthroughs. Current technological approaches often focus on improvements in a single aspect of materials, structure, or process, such as optimizing only the glass composition, designing only new grooves, or attempting only zoned strengthening. These "single-point breakthroughs" cannot systematically address the demanding multi-objective and cross-scale requirements faced by ultra-thin flexible glass. Materials are the foundation, structure is the carrier, and process is the guarantee of realization; the three are interdependent and mutually restrictive. Without synergistic design and integrated control from the material origin to the microstructure and then to the macroscopic strengthening process, the manufactured products inevitably suffer from shortcomings, such as significant defects in bending radius, fatigue life, optical performance, or impact resistance.

[0005] Current product performance still falls short of the aforementioned ideal goals. For example, the bending radius is mostly between 2 and 3 mm, the bending life is about 100,000 cycles, and the impact height from pen drops is generally less than 80 mm. Therefore, developing an ultrathin flexible glass with a small bending radius, long life, and high strength through synergistic innovation in composition, structure, and process has become an urgent technical challenge in this field. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a high-strength, bend-resistant, ultra-thin flexible glass, its preparation method, and its applications. It is particularly suitable for fields with stringent requirements regarding the flexibility, strength, and ultra-thinness of glass, such as flexible display panels, wearable devices, and flexible sensors.

[0007] The technical solution adopted in this application is as follows: In a first aspect, this application provides a method for preparing high-strength, bend-resistant, ultra-thin, flexible glass, comprising: S1. Provide a glass substrate, the composition of which, by mass percentage, comprises: 55-68% SiO2, 10-22% Al2O3, and 6.5-17% Na2O, and satisfies: 2.6 ≤ SiO2 / Al2O3 ≤ 5.0, wherein the thickness of the glass substrate is processed to ≤100μm; S2. On the glass substrate, corresponding to the pre-defined flexible bending area, a plurality of periodically oriented folded opening structures are formed by laser etching, wherein the depth of the opening structure in the thickness direction of the glass substrate is 30-50% of the thickness of the glass substrate; S3. On one main surface of the glass substrate, corresponding to the position of the flexible area, at least one arc-shaped edge groove with a depth of 40~50μm is formed by wet etching. S4. The glass substrate having the opening structure and groove is subjected to chemical strengthening treatment, the chemical strengthening treatment including a first strengthening step and a second strengthening step performed sequentially, and the strengthening temperature applied to the flexible area is 5-10°C higher than that to the non-flexible area, and the strengthening time is 20-30 minutes longer, so that the ratio of the compressive stress depth of the flexible area to the substrate thickness is higher than that of the non-flexible area. S5. Fill the groove with transparent polymer resin and then cure it. The thickness of the cured polymer resin layer is 18-25 μm.

[0008] Furthermore, the composition of the glass substrate also includes: K2O 0%~7%, MgO 2%~9%, Li2O 0%~5%, ZrO2 0%~3%, TiO2 0~2%, CaO 0~2%, and 0.1%~0.5% clarifying agent.

[0009] Furthermore, the composition of the aforementioned glass substrate also satisfies the following relationship: 1.2≤(Na2O+K2O) / MgO≤5; 0.3≤(MgO+CaO) / Al2O3≤1.0; And 0.8≤(R2O) / Al2O3≤2.5, where R2O is one or more of the alkali metals Na2O, K2O, and Li2O.

[0010] Furthermore, in step S2 above, the opening structure is a V-shaped opening or an arc-shaped opening, and adjacent opening structures are connected by unetched interconnects, wherein the interconnects form protrusions on the surface of the glass substrate.

[0011] Furthermore, in step S4 above, the temperature of the first strengthening is 380-430°C and the time is 30-240 minutes; the temperature of the second strengthening is 400-430°C and the time is 40-180 minutes.

[0012] Furthermore, in step S4 above, the flexible region is reinforced by masking the non-flexible region.

[0013] Furthermore, in step S1 above, the glass substrate with a thickness ≤100μm is obtained by a composite thinning process of physical grinding and chemical etching of the base glass after molding and annealing.

[0014] Secondly, this application also provides a high-strength, bend-resistant, ultra-thin flexible glass, which is prepared by the above-described method.

[0015] Furthermore, the above-mentioned glass has a bending radius of 1.3~1.5mm, a pen impact resistance height of 90~100mm, no crack failure after 300,000 bending tests, a surface stress ≥680Mpa, and a Vickers hardness ≥670MPa.

[0016] Thirdly, this application also provides a display device, including a flexible display module and a glass cover plate covering the flexible display module, wherein the glass cover plate is the high-strength, bend-resistant, ultra-thin flexible glass as described in claim 9.

[0017] In summary, this application has the following beneficial effects: This invention achieves technical results far exceeding conventional expectations in the field through deep synergistic innovation of "specific components - microstructure design - composite process". First, the designed specific glass composition provides a fundamental guarantee for achieving high performance, and its unique oxide ratio and constraint relationship lay the optimal foundation for subsequent ion exchange. Based on this material, the innovative use of a dual microstructure design of laser-etched openings and wet-etched grooves achieves synergistic improvement in mechanics and optics. Among them, the oriented folded opening structure not only increases the flexibility of the bending area by 3-4 times and reduces the critical bending radius to 1.3-1.5mm, but also cleverly disrupts the periodicity of light, increasing the moiré effect suppression rate to over 80%, thereby achieving extreme flexibility while completely solving the problem of crease optical interference that has plagued the industry. At the same time, the grooves with rounded edges, filled with a specific thickness of polyurethane resin, provide excellent elastic buffering, further reducing the critical bending radius by 20%-30%, ensuring a 100% pass rate in 300,000 bending tests, and fundamentally eliminating creases and breakage.

[0018] Crucially, the segmented and zoned chemical strengthening process implemented after the fabrication of structures such as grooves produced a significant synergistic enhancement effect with the aforementioned structures and materials. Through precise temperature and time control, this process achieved differentiated ion exchange depths and stress distributions in the bending and non-bending regions, resulting in a stable surface compressive stress (CS) of over 680 MPa and a Vickers hardness (Hv) of ≥670 MPa. Simultaneously, it increased the ratio of compressive stress depth to substrate thickness in the flexible region, effectively reducing stress concentration and buckling risk during bending.

[0019] This synergy of materials, structure, and process ultimately enables glass with a thickness not exceeding 100μm to achieve both excellent impact resistance (90-100mm pen impact height) and extreme bending reliability. The ultrathin flexible glass prepared by this invention breaks through the bottleneck of the mutual constraint between strength and flexibility in existing technologies, providing an unprecedented high-performance core material solution for flexible electronic devices, foldable screens, and wearable display devices. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the preparation method of the high-strength, bend-resistant, ultra-thin flexible glass provided in this application. Detailed Implementation

[0021] The embodiments of the present invention will be described in detail below with reference to the examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Specific conditions not specified in the examples shall be carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0022] The technical solution of this invention is as follows: A method for preparing high-strength, bend-resistant, ultra-thin flexible glass, comprising: S1. Provide a glass substrate, the composition of which, by mass percentage, comprises: 55-68% SiO2, 10-22% Al2O3, and 6.5-17% Na2O, and satisfies: 2.6 ≤ SiO2 / Al2O3 ≤ 5.0, wherein the thickness of the glass substrate is processed to ≤100μm; Furthermore, the glass substrate also comprises: K2O 0%~7%, MgO 2%~9%, Li2O 0%~5%, ZrO2 0%~3%, TiO2 0~2%, CaO 0~2%, and 0.1%~0.5% clarifying agent.

[0023] The clarifying agent is an SO4-containing agent. 2- Compounds (such as sodium sulfate), containing NO3 - Compounds (such as sodium nitrate), containing F - Compounds (such as calcium fluoride), containing Cl - One or more of the following compounds: (e.g., sodium chloride) and SnO2.

[0024] As a preferred embodiment of the present invention, the components satisfy one or more of the following relationships to further optimize the network structure, ion mobility and mechanical properties of the glass: 2.6 ≤ SiO2 / Al2O3 ≤ 5.0. This ratio controls the connectivity and rigidity of the glass network. If the ratio is too low, brittleness increases; if it is too high, the melting temperature is too high and the ion exchange capacity decreases.

[0025] 1.2≤(Na2O+K2O) / MgO≤5. This ratio regulates the balance between the "mixed alkali effect" of alkali metal oxides and the network breaking and accumulation of MgO, thus affecting the ion exchange rate and the toughness of the glass.

[0026] 0.8 ≤ (R2O) / Al2O3 ≤ 2.5. This ratio balances the relationship between alkali metal oxides and Al2O3, which helps to form a moderately relaxed and stable glass network structure, optimizing glass melt formability and chemical strengthening responsiveness while balancing flexibility and structural strength.

[0027] 0.3 ≤ (MgO+CaO) / Al2O3 ≤ 1.0. This ratio balances the relationship between divalent metal oxides and Al2O3, which helps to form a moderate non-bridging oxygen structure and improves the intrinsic strength and melt homogenization of the glass.

[0028] Step S1, which provides the glass substrate, specifically includes: (1) Batching and Melting: Weigh the corresponding raw materials such as quartz sand, alumina, sodium carbonate, potassium carbonate, magnesium oxide, lithium carbonate, zircon, titanium dioxide, and calcium carbonate according to the designed oxide mass percentage, and add the specified amount of clarifying agent, and mix evenly. Place the mixture in a continuous float melting furnace and melt, clarify and homogenize at a high temperature of 1520℃~1650℃ to obtain a uniform, bubble-free glass melt.

[0029] (2) Molding and annealing: The molten glass is poured into the tin bath, spread and polished to form a glass strip of uniform thickness, and then annealed to eliminate internal stress, resulting in a base glass with a thickness of 0.33 mm.

[0030] (3) Thinning: The above-mentioned base glass adopts a composite process of "physical grinding pre-thinning + chemical etching fine thinning". First, surface defects are removed by precision grinding, and then the thinning rate (0.5~1μm / min) is precisely controlled by hydrofluoric acid solution, with a final thickness ≤100 μm.

[0031] S2. On the glass substrate, corresponding to the pre-defined flexible bending area, a plurality of periodically oriented folded opening structures are formed by laser etching, wherein the depth of the opening structure in the thickness direction of the glass substrate is 30-50% of the thickness of the glass substrate; Furthermore, the opening includes one or more of V-shape and arc shape, and adjacent opening structures are connected by unetched interconnects. The interconnects form protruding structures on the surface of the glass substrate, and the triangular regions corresponding to adjacent openings can overlap to disperse bending stress and avoid optical interference.

[0032] S3. On one main surface of the glass substrate, corresponding to the position of the flexible area, at least one arc-shaped edge groove with a depth of 40~50μm is formed by wet etching. Further, specifically including: covering the non-bending area of ​​the glass with a UV anti-adhesion mask to protect the non-target area; etching the preset bending area with a hydrofluoric acid solution to form an arc-shaped edge groove with a depth of 40~50 μm; removing the UV mask and cleaning the residual etching solution and impurities on the surface of the glass sheet.

[0033] S4. The glass substrate having the opening structure and groove is subjected to chemical strengthening treatment, which includes a first strengthening step and a second strengthening step performed sequentially. The strengthening temperature applied to the flexible area is 5-10°C higher than that to the non-flexible area, and the strengthening time is 20-30 minutes longer, so that the ratio of compressive stress depth to substrate thickness in the flexible area is higher than that in the non-flexible area. After strengthening, the glass is removed and cooled to room temperature, and then washed with pure water to remove residual molten salt from the surface.

[0034] The segmented strengthening process includes: a primary strengthening at a temperature of 380-430°C for 30-240 minutes; and a secondary strengthening at a temperature of 400-430°C for 40-180 minutes, to achieve Na... + -K + Precise exchange; The zoned strengthening process includes: using a high-temperature resistant mask to block the rigid area (i.e., the non-flexible area) at the edge of the glass, adjusting the strengthening temperature of the central flexible area to be 5-10°C higher than that of the edge area, and extending the strengthening time by 20-30 minutes, so that the ratio of compressive stress depth to substrate thickness in the central flexible area is higher than that in the edge area, thereby reducing the risk of buckling.

[0035] S5. Fill the groove with transparent polymer resin and then cure it. The thickness of the cured polymer resin layer is 18-25 μm.

[0036] Preferably, the polymer resin is polyurethane resin. Specifically: high-temperature molten polyurethane resin is filled into the groove, the resin filling thickness is controlled to be 18~25 μm, and then cured at a low temperature of 110~130℃ for 20~40 min to obtain high-strength, bend-resistant, ultra-thin flexible glass.

[0037] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0038] Examples 1-10 This set of embodiments provides a group of high-strength, bend-resistant, ultra-thin flexible glass, the preparation method of which includes: (1) Preparation of ultrathin glass substrate: Using the component ratios in Examples 1-10 of Table 1 below, the raw materials corresponding to each component were calculated and weighed. The mixture was placed in a continuous float glass furnace and melted, clarified, and homogenized at a high temperature of 1560℃ to obtain a uniform, bubble-free molten glass. The molten glass was then poured into a tin bath, spread, and polished to form a glass ribbon of uniform thickness. Subsequently, annealing was performed to eliminate internal stress, resulting in a base glass with a thickness of 0.33 mm.

[0039] Subsequently, a combined physical grinding and chemical etching thinning process was adopted: first, the surface was pre-thinned by a precision double-sided grinding device to remove surface defects, and then finely thinned by a hydrofluoric acid etching solution to finally obtain an original glass substrate with a thickness of ≤100μm.

[0040] Table 1. Glass composition of each embodiment

[0041] (2) Structured processing: In the flexible region corresponding to the future bending shaft, V-shaped openings with a width of 0.1 mm and a depth of 30 μm are formed by laser etching, and the interconnect protrusion height is 20 μm. Adjacent openings are connected by unetched interconnects.

[0042] (3) Groove etching: Subsequently, on the same side with the opening structure, a UV mask was used to cover the non-bending area, and hydrofluoric acid solution was used to etch for 10 minutes to create a groove depth of 50 μm. Then, the UV mask was removed, and the surface residue was cleaned with pure water. A groove with a depth of 50 μm and a circular arc cross-section was etched in the center of the flexible area.

[0043] (4) Chemical fortification: The substrate was immersed in pure KNO3 molten salt. First, a high-temperature resistant mask was used to shield the rigid areas (i.e., non-flexible areas) at the glass edge. Then, segmented and zoned strengthening was performed using the following process parameters: Central flexible area: Strengthened at 425℃ for 240 minutes (first strengthening), followed by strengthening at 420℃ for 90 minutes (second strengthening). Non-flexible edge areas: Strengthened at 420°C for 220 minutes (first strengthening), followed by strengthening at 420°C for 60 minutes (second strengthening).

[0044] (5) Resin filling: Molten polyurethane resin is filled into the groove, with the filling thickness controlled at 22 μm, and then cured at 120°C for 30 minutes to obtain the final product.

[0045] The difference between this set of embodiments and Embodiment 3 lies in the process parameters of the segmented and zoned strengthening processes in the chemical strengthening process, as shown in Table 2: Table 2.

[0046] Example 21 The difference between this embodiment and Embodiment 3 lies in the structured processing and groove etching steps, specifically: (2) Structured processing: In the flexible region corresponding to the future bending shaft, laser etching is used to process oriented arc-shaped openings with a width of 0.15 mm, a depth of 50 μm, and an interconnect protrusion height of 20 μm. Adjacent openings are connected by unetched interconnects.

[0047] (3) Groove etching: Subsequently, on the same side with the opening structure, a UV mask was used to cover the non-bending area, and hydrofluoric acid solution was used to etch for 8 minutes to create a groove depth of 30 μm. Then, the UV mask was removed, and the surface residue was cleaned with pure water. A groove with a depth of 30 μm and a circular arc cross-section was etched in the center of the flexible area. Example

[0048] The difference between this embodiment and Embodiment 3 lies in the resin filling step, specifically: (5) Resin filling: Molten polyurethane resin is filled into the groove, with the filling thickness controlled at 25 μm, and then cured at 110°C for 40 minutes to obtain the final product.

[0049] Comparative Example 1 The glass in this comparative example has the following composition by mass percentage (based on oxides): SiO2 62.00%, Al2O3 20.50%, Na2O 8.00%, K2O 5.00%, MgO 2.00%, Li2O 0.50%, ZrO2 1.00%, CaO 1.00%, and 0.3% SO42-. 2- The oxides (SiO2 / Al2O3=3.02, (R2O) / Al2O3=0.66) were calculated and weighed. After mixing, the raw materials were melted, shaped, and annealed using the same process as in Example 3 to obtain a 0.33mm base glass. Subsequently, the glass was processed strictly according to the complete set of processes in Example 3 to obtain the sample.

[0050] Comparative Example 2 This comparative example uses the exact same glass composition (see Table 1, Example 3) and basic glass preparation process as Example 3. After obtaining a 100 μm glass sheet, no structuring processing (no laser etching openings) or groove etching and resin filling is performed. The flat glass sheet is directly subjected to the same segmented and zoned chemical strengthening process as in Example 3. After strengthening, only cooling and cleaning are performed to obtain the sample.

[0051] Comparative Example 3 Using the exact same glass composition and base glass preparation process as in Example 3, a 100 μm glass sheet was obtained. Flexible segment structuring (laser etching) and groove etching were then performed strictly according to the steps of Example 3. However, in the chemical strengthening step, a traditional global uniform parameter secondary strengthening process was employed, specifically: The glass sheet was immersed entirely in pure KNO3 molten salt. The first strengthening temperature was 420°C for 220 min. After removal, cooling, and cleaning, a second strengthening was performed at 420°C for 60 min. After strengthening, the same resin filling and curing steps as in Example 3 were performed to obtain the sample.

[0052] Comparative Example 4 This comparative example uses the exact same glass composition and preparation process as Example 3. The difference is that after the segmented chemical strengthening, the sample groove does not involve a resin filling step, and the sample is obtained after cleaning.

[0053] Comparative Example 5 This comparative example uses the exact same glass composition and preparation process as Example 3, except that the flexible segment structuring (laser etching) is performed strictly according to the steps of Example 3, but without groove etching, followed by segmental chemical strengthening. Because no grooves are processed, no resin filling step is involved subsequently.

[0054] Performance testing I. Testing Methods The methods for testing the physical properties and performance of the glass samples obtained in the examples and comparative examples are as follows: (1) Vickers hardness was measured by using a micro Vickers hardness tester in accordance with standard GB / T16534-2009, with a loading force of 200g and a loading time of 10s. (2) The elastic modulus was measured using JC / T687-1997(2007) "Test Methods for Elastic Modulus, Shear Modulus and Poisson's Ratio of Glass Materials"; (3) The surface compressive stress value (CS) and compressive stress layer depth (DOL) were measured using a surface stress meter (FSM-6000LE) in accordance with standard GB / T18144-2008; (4) Static ultimate bending radius of curvature: The ultimate bending radius R was tested according to GB / T38686-2020 "Test Method for Flexibility of Ultra-thin Glass - Two-point Bending Method"; (5) Pen impact height: The pen impact tester was used to test the pen penetration ability by dropping a 12g pen (0.5mm ballpoint diameter) onto the glass.

[0055] (6) Reduction of critical radius of curvature: Compare the reduction of the critical radius of curvature before and after the structuring process; (7) Moiré effect suppression rate: The suppression rate is calculated by detecting the interference fringes on the glass surface under bending conditions using an optical interferometer.

[0056] II. Test Results The test results of Examples 1-20 are shown in Tables 3 and 4: Table 3. Performance test results of the glass in Examples 1-10

[0057] Table 4. Performance test results of the glass in Examples 11-20

[0058] The test results of comparative examples 1 to 5 are shown in Table 5: Table 5. Performance test results of comparative glass

[0059] Combining the data from Example 3 and Comparative Example 1, it can be seen that, under the premise of using the exact same preparation process, the surface compressive stress and compressive stress layer depth of Example 1 are significantly lower than those of Example 3 simply because of the different glass composition (the (R2O) / Al2O3 ratio in Comparative Example 1 is too low). This directly leads to a sharp deterioration in its static bending performance and fatigue resistance. This is because the unreasonable glass network structure severely weakens the ion exchange capacity, making it impossible to effectively improve the intrinsic strength of the glass. Therefore, the specific glass composition range defined in this invention is the fundamental prerequisite for all subsequent strengthening and structural designs to be effective, and it plays a decisive role in achieving high mechanical properties.

[0060] Combining the data from Example 3 and Comparative Example 2, it can be seen that, while Comparative Example 2 maintains higher surface strength but without any microstructure processing, it fails the 300,000-cycle bending test because, despite having the same excellent composition and strengthening process, it fails to pass the test. This is because the stress on the flat glass sheet has nowhere to disperse during bending and is highly concentrated on the surface. This demonstrates that the microstructure design of laser-etched openings and grooves is key to achieving an ultra-small bending radius. The stress guidance and dispersion effect generated by this design is the core of the "flexibility" achieved in this solution; millimeter-level bending cannot be achieved solely through material strengthening.

[0061] Combining the data from Example 3 and Comparative Example 3, it can be seen that both have the same composition and microstructure, but the chemical strengthening processes are different (Comparative Example 3 uses traditional whole-area strengthening). Although Comparative Example 3 achieved acceptable bending performance, its 300,000-cycle bending life and Mohr effect suppression rate were significantly lower than those of Example 3. This is because the uniform strengthening process cannot form a gradient and deeper compressive stress layer in the preset bending area, resulting in insufficient crack propagation resistance in this area under repeated bending, and the uneven stress distribution exacerbates optical interference. This demonstrates that the "segmented + zoned" strengthening process of the present invention is not a simple parameter adjustment; it can specifically optimize the stress distribution in the bending area, thereby producing unexpected technical effects in improving fatigue life and optical uniformity.

[0062] Combining the data from Example 3 and Comparative Example 4, it can be seen that the only difference between the two is that the groove is not filled with resin. The bending performance of Comparative Example 4 is significantly worse than that of Example 3, and the impact height is also reduced. This clearly demonstrates that the groove and the polymer resin are a functional whole. Resin filling is not simply physical leveling; its core function is to buffer stress, dissipate energy, and prevent crack initiation at the tip of the groove. Without the buffering effect of resin, the groove may instead become a weak point for stress concentration and crack initiation.

[0063] Combining the data from Example 3 and Comparative Example 5, it can be seen that while the bending performance of the laser-engaged structure without the "groove + resin" structure is better than that of Comparative Examples 2 and 4, it is still far from reaching the level of Example 3. This indicates that the laser-engaged structure (whose main function is to disperse planar stress and suppress moiré fringes) and the "groove + resin" structure (whose main function is to provide stress buffering and energy absorption in the vertical direction) each solve mechanical problems in different dimensions. Their functions are complementary and indispensable. Their synergistic effect is key to achieving an extreme bending radius of 1.4 mm and an ultra-long fatigue life of 300,000 cycles.

[0064] As can be seen from all the comparative examples, the absence or degradation of any technical feature will lead to a significant shortcoming in the final performance. Only by fully combining specific components, dual microstructure design, and segmented and zoned strengthening processes, as shown in Example 3, can the performance bottleneck be overcome, and the seemingly contradictory goals of "high strength, ultra-toughness, long lifespan, and high optical quality" be achieved simultaneously. This fully demonstrates the strong synergistic effect among the features in the technical solution of this invention, and its final technical effect far exceeds the simple summation of the effects of various known methods, possessing outstanding substantive characteristics and significant progress, and exhibiting non-obviousness.

[0065] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing high-strength, bend-resistant, ultra-thin flexible glass, characterized in that, It includes: S1. Provide a glass substrate, the composition of which, by mass percentage, comprises: 55-68% SiO2, 10-22% Al2O3, and 6.5-17% Na2O, and satisfies: 2.6 ≤ SiO2 / Al2O3 ≤ 5.0, wherein the thickness of the glass substrate is processed to ≤100μm; S2. On the glass substrate, corresponding to the pre-defined flexible area of ​​the bend, a plurality of periodically oriented folded opening structures are formed by laser etching, wherein the depth of the opening structure in the thickness direction of the glass substrate is 40-50% of the thickness of the glass substrate; S3. On one main surface of the glass substrate, corresponding to the position of the flexible area, at least one arc-shaped edge groove with a depth of 30~50μm is formed by wet etching; S4. The glass substrate having the opening structure and groove is subjected to chemical strengthening treatment, the chemical strengthening treatment including a first strengthening step and a second strengthening step performed sequentially, and the strengthening temperature applied to the flexible area is 5-10°C higher than that to the non-flexible area, and the strengthening time is 20-30 minutes longer, so that the ratio of the compressive stress depth of the flexible area to the substrate thickness is higher than that of the non-flexible area. S5. Fill the groove with transparent polymer resin and then cure it. The thickness of the cured polymer resin layer is 18-25 μm.

2. The method for preparing high-strength, bend-resistant, ultra-thin flexible glass according to claim 1, characterized in that, The glass substrate also comprises: K2O 0%~7%, MgO 2%~9%, Li2O 0%~5%, ZrO2 0%~3%, TiO2 0~2%, CaO 0~2%, and 0.1%~0.5% clarifying agent.

3. The method for preparing high-strength, bend-resistant, ultra-thin flexible glass according to claim 2, characterized in that, The composition of the glass substrate also satisfies the following relationship: 1.2≤(Na2O+K2O) / MgO≤5; 0.3≤(MgO+CaO) / Al2O3≤1.0; And 0.8≤(R2O) / Al2O3≤2.5, where R2O is one or more of the alkali metals Na2O, K2O, and Li2O.

4. The method for preparing high-strength, bend-resistant, ultra-thin flexible glass according to claim 1, characterized in that, In step S2, the opening structure is a V-shaped opening or an arc-shaped opening, and adjacent opening structures are connected by unetched interconnects, wherein the interconnects form protrusions on the surface of the glass substrate.

5. The method for preparing high-strength, bend-resistant, ultra-thin flexible glass according to claim 1, characterized in that, In step S4, the temperature for the first strengthening is 380-430°C and the time is 30-240 minutes; the temperature for the second strengthening is 400-430°C and the time is 40-180 minutes.

6. The method for preparing high-strength, bend-resistant, ultra-thin flexible glass according to claim 1, characterized in that, In step S4, the flexible region is reinforced by masking the non-flexible region.

7. The method for preparing high-strength, bend-resistant, ultra-thin flexible glass according to claim 1, characterized in that, In step S1, the glass substrate with a thickness ≤100μm is obtained by a composite thinning process of physical grinding and chemical etching of the base glass after molding and annealing.

8. A high-strength, bend-resistant, ultra-thin flexible glass, characterized in that, It is prepared by any one of claims 1 to 7.

9. The high-strength, bend-resistant, ultra-thin flexible glass according to claim 8, characterized in that, The glass has a bending radius of 1.3~1.5mm, a pen impact resistance height of 90~100mm, no crack failure after 300,000 bending tests, a surface stress ≥680Mpa, and a Vickers hardness ≥670MPa.

10. A display device comprising a flexible display module and a glass cover plate covering the flexible display module, characterized in that, The glass cover is the high-strength, bend-resistant, ultra-thin, flexible glass as described in claim 9.

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