High-performance foldable flexible glass and method of making the same

Abstract

The application discloses high-performance foldable flexible glass and a preparation method thereof, and belongs to the technical field of novel display materials. The high-performance foldable flexible glass comprises the following raw materials in percentage by mass: SiO2: 58-62%, Al2O3: 15-20%, Na2O: 11-15%, K2O: 3-6%, CaO: 2-4%, MgO: 2-6%, ZrO2: 0.6-1.2%, Sc2O3: 0.3-1.0%, Nb2O5: 0.5-1.5%, and SrO: 0.8-2.2%. The total amount of SiO2 and Al2O3 is limited to guarantee the network base strength, Sc2O3 is used to fill oxygen vacancy defects and enhance the network structure, Nb2O5 is used to form an octahedral crosslink to improve the bending strength and hardness, and SrO is used to moderately weaken the network aggregation degree to improve the flexibility. In the preparation process, stage temperature control melting and micro-negative pressure clarification processes are adopted to ensure that the components are uniformly distributed and bubbles are effectively removed, and sectional annealing is combined to eliminate internal stress. The application significantly improves the bending strength, hardness and bending life while guaranteeing the high elastic modulus, and meets the application requirements of the foldable display field for high-performance flexible glass.

Description

Technical Field

[0001] This invention belongs to the field of novel display materials technology, specifically relating to a high-performance foldable flexible glass and its preparation method. Background Technology

[0002] Flexible foldable display technology is one of the most revolutionary developments in the consumer electronics field in recent years. New display products, represented by foldable screen phones, rollable screens, wraparound screens, and flexible wearable devices, are gradually moving from concept to large-scale commercialization. As the core carrier and protective material for flexible display panels, ultra-thin flexible glass (UTG) has become the preferred cover material for high-end foldable screen terminals due to its excellent surface hardness, high light transmittance, good thermal stability, and superior touch feel compared to polymer films.

[0003] As foldable screen products evolve towards smaller bending radii, higher bending frequencies, thinner thicknesses, and higher reliability, unprecedentedly stringent requirements are being placed on the comprehensive performance of UTG materials. However, existing flexible glass technologies face significant bottlenecks in achieving the synergistic optimization of these performance characteristics. Mainstream technologies often employ sodium aluminosilicate glass systems, improving the mechanical properties and formability of the glass by introducing conventional modifying elements such as Li₂O, B₂O₃, and Y₂O₃. Practice has shown that these systems generally suffer from imbalances in elastic modulus and flexibility, insufficient flexural strength, low strain point, and short bending life, making it difficult to meet the stringent requirements of high-end end products for comprehensive material performance.

[0004] Furthermore, existing technologies largely rely on single-element or simple binary modification systems, lacking systematic research on the synergistic mechanisms between the defect repair effects of rare earth elements, the network cross-linking enhancement effects of transition metal oxides, and the regulation of flexibility by differences in the ionic radii of alkaline earth metals. Moreover, conventional forming processes struggle to precisely control the internal stress and microstructure of glass, limiting improvements in key performance indicators.

[0005] Therefore, there is an urgent need to develop a high-performance foldable flexible glass and its preparation method that can solve the above problems, in order to meet the higher application requirements in the field of new display materials technology. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-performance foldable flexible glass and its preparation method.

[0007] The objective of this invention can be achieved through the following technical solutions: A high-performance foldable flexible glass comprises the following raw materials in weight percentages: The composition is as follows: SiO2: 58-62%, Al2O3: 15-20%, Na2O: 11-15%, K2O: 3-6%, CaO: 2-4%, MgO: 2-6%, ZrO2: 0.6-1.2%, Sc2O3: 0.3-1.0%, Nb2O5: 0.5-1.5%, SrO: 0.8-2.2%; among which, 72%≤SiO2+Al2O3≤76%; 15%≤Na2O+K2O≤16%; 4%≤MgO+CaO≤6%.

[0008] As a preferred embodiment of the present invention, the components are: Sc2O3: 0.6-0.9%, Nb2O5: 1.0-1.4%, SrO: 1.4-1.8% by mass percentage.

[0009] Compared with existing technologies, the high-performance foldable flexible glass composition provided by this invention has the following advantages: 1. Introduce Sc2O3 and utilize Sc 3+ With Si 4+ Al 3+ Matched ionic radii are embedded in the gaps of the glass network to fill oxygen vacancies, promote the formation of bridging oxygen bonds, significantly improve the integrity and stability of the network structure, and ensure high elastic modulus and strain point filling of oxygen vacancies to enhance the network structure; 2. Introducing Nb2O5 forms a stable octahedral structure, enhances the cross-linking degree of the glass network, and significantly improves the flexural strength and Vickers hardness. At the same time, its content is controlled within a reasonable range to avoid affecting the light transmittance. 3. By introducing SrO, its larger ionic radius is used to moderately weaken the network polymerization degree and reduce the elastic modulus to improve flexibility, while taking into account chemical stability, thus significantly extending the bending life. 4. By synergistically constraining multiple components, a performance-balanced system is constructed. For example, limiting SiO2+Al2O3 (72-76%) ensures the basic strength of the network; Na2O+K2O (15-16%) balances melting performance and chemical stability; CaO+MgO (4-6%) regulates the coefficient of thermal expansion and strain point to avoid thermal stress cracking; and ZrO2 (0.6-1.2%) refines grains to improve hardness and wear resistance, forming a complete component synergistic design system.

[0010] This invention also provides a method for preparing high-performance foldable flexible glass, comprising the following steps: A1. After crushing quartz sand with a purity ≥ 99.9%, alumina, sodium carbonate, potassium carbonate, calcium carbonate, magnesium oxide, zirconium oxide, scandium oxide, niobium pentoxide and strontium carbonate, weigh them according to the proportion, add them to a mixer under inert gas protection and stir to obtain a uniform mixture. A2. Place the mixture in a glass furnace for melting and clarification. After melting and clarification, shape the molten glass through a forming process to obtain ultra-thin glass. A3. The ultra-thin glass is placed in an annealing furnace for annealing. After annealing, it is chemically thinned and chemically strengthened to obtain high-performance foldable flexible glass.

[0011] As a preferred embodiment of the present invention, the particle size after pulverization is ≤80μm.

[0012] In a preferred embodiment of the present invention, the inert gas is argon.

[0013] As a preferred embodiment of the present invention, the mixing machine has a rotation speed of 400-600 r / min and a mixing time of 45-75 min.

[0014] As a preferred embodiment of the present invention, the molding process is one of the float glass method, slit-pull method, and overflow-pull method.

[0015] As a preferred embodiment of the present invention, the melting and clarification processes employ a segmented temperature control method: first, the temperature is increased to 750-850°C at a heating rate of 4°C / min, and held at this temperature for 3 hours under normal pressure to allow the raw materials to fully decompose and initially melt; then, the temperature is increased to 1450-1550°C at a heating rate of 2°C / min, and held at this temperature for 4 hours under normal pressure to promote the homogenization of the glass melt; finally, the temperature is increased to 1620-1680°C at a heating rate of 1°C / min, while the furnace pressure is adjusted to 0.7 atmospheres, and the temperature is held for clarification for 8-10 hours under these conditions to effectively remove air bubbles from the glass melt.

[0016] As a preferred embodiment of the present invention, the annealing adopts a segmented annealing method: first, the temperature is raised to 520-560℃ at a heating rate of 1.5℃ / min and held for 4-5 hours; then, the temperature is cooled to 250℃ at a cooling rate of 0.8℃ / min and held for 2 hours; finally, the temperature is naturally cooled to room temperature.

[0017] In the preparation process of this invention, a stepped heating system is adopted in the melting and clarification stages, which can reduce component segregation and ensure uniform distribution of modified elements. Secondly, the negative pressure clarification is conducive to defoaming of the glass melt, improving glass quality and yield. Finally, in the annealing stage, a segmented annealing process is adopted, which can more thoroughly eliminate residual stress inside the glass and further improve flexural strength and bending life.

[0018] The beneficial effects of this invention are: 1. This invention introduces Sc2O3, Nb2O5 and SrO to fill oxygen vacancy defects and enhance network crosslinking. While ensuring high elastic modulus, it significantly improves flexural strength, Vickers hardness and flexibility, and effectively extends bending life. 2. By limiting the total amount range of key components, the glass network strength, melt forming performance, chemical stability and coefficient of thermal expansion are synergistically optimized to avoid thermal stress cracking during bending. 3. The staged temperature-controlled melting and micro-negative pressure clarification process is adopted to reduce component segregation, ensure uniform distribution of modified elements, and effectively promote the defoaming of glass melt, thereby improving glass quality and yield. 4. Through segmented annealing process, residual stress inside the glass is eliminated more thoroughly, further improving flexural strength and bending life; In summary, this invention provides a foldable flexible glass that combines high strength, high flexibility, long bending life, high light transmittance, and good process adaptability. It is suitable for high-end scenarios such as foldable screen terminals and flexible wearable devices, and has significant application value. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example A method for preparing high-performance foldable flexible glass includes the following steps: A1. After pulverizing quartz sand, alumina, sodium carbonate, potassium carbonate, calcium carbonate, magnesium oxide, zirconium oxide, scandium oxide, niobium pentoxide and strontium carbonate with a purity ≥99.9% to a particle size ≤80μm, weigh the raw materials according to the raw material ratio in Table 1, add them to a mixer (speed 400-600r / min) under argon protection (argon gas replaced to oxygen content ≤0.1%) and stir for 45-75min to obtain a uniform mixture; A2. Place the mixture in a glass furnace and heat it to 750-850℃ at a rate of 4℃ / min, then hold it at that temperature for 3 hours under normal pressure. Next, heat it to 1450-1550℃ at a rate of 2℃ / min, and hold it at that temperature for 4 hours under normal pressure. Finally, heat it to 1620-1680℃ at a rate of 1℃ / min, while adjusting the pressure inside the furnace to 0.7 atmospheres. Hold it at this temperature for 8-10 hours to clarify. After melting and clarification, shape the molten glass using the float glass process to obtain ultrathin glass. A3. The ultra-thin glass is placed in an annealing furnace and heated to 520-560°C at a heating rate of 1.5°C / min and held for 4-5 hours. Then it is cooled to 250°C at a cooling rate of 0.8°C / min and held for 2 hours. Finally, it is allowed to cool naturally to room temperature. After annealing, chemical thinning and chemical strengthening are performed to obtain high-performance foldable flexible glass, namely Examples 1-6.

[0021] Table 1 Comparative Example The difference between the comparative example and the embodiment is that the raw materials are weighed according to the raw material ratio in Table 2, and the glass is prepared by mass percentage.

[0022] Table 2 The performance of Examples 1-6 and Comparative Examples 1-4 was measured. The results of Examples 1-6 are shown in Table 3. Table 3 The results of the measurements for Comparative Examples 1-4 are shown in Table 4: Table 4 By comparing the data from the six sets of examples and the four sets of comparative examples in Tables 3 and 4, the following conclusions can be drawn: 1. Examples 1-5 strictly adhered to the proportion constraints of 72%≤SiO2+Al2O3≤76%; 15%≤Na2O+K2O≤16%; 4%≤MgO+CaO≤6%. Therefore, all core performance indicators met the standards (original sheet elastic modulus ≥90GPa, average transmittance of 380-780nm ≥91%, bending life after thinning and strengthening ≥200,000 cycles@R1.5mm), verifying that the constraints can balance the strength, formability and flexibility of the glass network. 2. In Example 6, because Na2O+K2O=18%, which exceeds the constraint range of 15-16%, the elastic modulus of the original sheet dropped to 73.5GPa, the flexural strength was only 265MPa, and the bending life dropped significantly to 160,000 cycles. This proves that excessive alkali metal content will destroy the network stability and lead to overall performance degradation. 3. In Comparative Example 1, no composite modification components were added. The original glass had an elastic modulus of only 78 GPa and a bending life of only 80,000 cycles. All performance characteristics were far lower than those of Examples 1-5. Furthermore, as shown in Comparative Examples 2-4, the absence of any single component would lead to a significant deterioration in the glass's bending life, elastic modulus, and flexural strength. The performance of all three components coexisting was far superior to any combination of two components. This confirms that the synergistic effect of Sc2O3, Nb2O5, and SrO is the core of the performance breakthrough, and all three are indispensable. 4. The formulation of Example 1 has the best performance, with an elastic modulus of 91.2 GPa, an average transmittance of 91.5% in the 380-780 nm range, and a bending life of 240,000 cycles. This indicates that the synergistic effect of the three modifying elements is optimal under this ratio, making it the most suitable for production. In summary, this invention significantly improves the flexibility and bending life of glass while maintaining its high strength, solving the problem of insufficient bending life of traditional flexible glass. It provides a high-performance, high-reliability glass material solution for high-end display applications such as foldable screen terminals and flexible wearable devices, and has significant application value.

[0023] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A high-performance foldable flexible glass, characterized in that, Including the following percentages by weight of raw materials: SiO2: 58-62%, Al2O3: 15-20%, Na2O: 11-15%, K2O: 3-6%, CaO: 2-4%, MgO: 2-6%, ZrO2: 0.6-1.2%, Sc2O3: 0.3-1.0%, Nb2O5: 0.5-1.5%, SrO: 0.8-2.2%.

2. The high-performance foldable flexible glass according to claim 1, characterized in that, By mass percentage: 72%≤SiO2+Al2O3≤76%; 15%≤Na2O+K2O≤16%; 4%≤MgO+CaO≤6%.

3. The high-performance foldable flexible glass according to claim 1, characterized in that, The contents of Sc2O3, Nb2O5 and SrO by mass percentage are as follows: Sc2O3: 0.6-0.9%, Nb2O5: 1.0-1.4%, SrO: 1.4-1.8%.

4. A method for preparing high-performance foldable flexible glass, used to prepare the high-performance foldable flexible glass according to any one of claims 1-3, characterized in that, Includes the following steps: A1. Weigh the raw materials according to the proportions and add them to the mixer to mix and obtain a uniform mixture; A2. Place the mixture in a glass furnace for melting and clarification. After melting and clarification, shape the molten glass through a forming process to obtain ultra-thin glass. A3. The ultra-thin glass is placed in an annealing furnace for annealing. After treatment, high-performance foldable flexible glass is obtained.

5. The method for preparing high-performance foldable flexible glass according to claim 4, characterized in that, The mixer operates at a speed of 400-600 r / min and a mixing time of 45-75 min.

6. The method for preparing high-performance foldable flexible glass according to claim 4, characterized in that, The molding process is one of the following: float glass, slot-down drawing, and overflow drawing.

7. The method for preparing high-performance foldable flexible glass according to claim 4, characterized in that, The melting and clarification processes employ a segmented temperature control method: first, the temperature is increased to 750-850℃ at a rate of 4℃ / min and held at this temperature for 3 hours under normal pressure; then, the temperature is increased to 1450-1550℃ at a rate of 2℃ / min and held at this temperature for 4 hours under normal pressure; finally, the temperature is increased to 1620-1680℃ at a rate of 1℃ / min, while the pressure is adjusted to 0.7 atmospheres, and the temperature is held for clarification for 8-10 hours.

8. The method for preparing high-performance foldable flexible glass according to claim 4, characterized in that, The annealing process is carried out in stages: first, the temperature is increased to 520-560℃ at a heating rate of 1.5℃ / min and held for 4-5 hours; then, the temperature is cooled to 250℃ at a cooling rate of 0.8℃ / min and held for 2 hours; finally, the temperature is allowed to cool naturally to room temperature.

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