An ultra-thin flexible glass and its preparation method

Abstract

An ultra-thin flexible glass and its preparation method belong to the technical field of glass manufacturing. The raw materials of the ultra-thin flexible glass are composed of silicon dioxide, aluminum oxide, sodium oxide, boron trioxide, calcium oxide, lithium oxide, a composite toughening agent, a composite flux, and a composite fining agent. The ultra-thin flexible glass prepared by the present invention has an ultimate bending radius of 2-3 mm, a maximum number of bending times of 350,000-360,000 times, a surface compressive stress of 916-937 MPa, a Vickers hardness of 610-623 MPa, and an elastic modulus of 79-82 GPa.

Description

Technical Field

[0001] The present invention relates to an ultra-thin flexible glass and a preparation method thereof, belonging to the technical field of glass manufacturing. Background Art

[0002] Ultra-Thin Glass (UTG) refers to flexible glass with a thickness ≤ 0.1 mm, which is a new material combining the advantages of glass and plastic. Because it can not only be bent, but also has excellent hardness, transparency, heat resistance, relatively stable mechanical and chemical properties, it plays a key role not only in the field of flexible displays such as foldable mobile phones, flexible e-books, and curved TVs, but also has broad application prospects in the fields of flexible printing, space environment, etc.

[0003] The preparation process of ultra-thin flexible glass is mainly divided into one-step forming and two-step forming. The one-step forming process mainly includes the float method, the overflow down-draw method, and the slot down-draw method. Its basic principle is to directly heat and draw the molten glass liquid to form an ultra-thin glass with a thickness ≤ 0.1 mm at one time. The one-step forming technology is extremely difficult, the raw material melting is difficult, and it is not easy to draw thin, so that the glass material cannot simultaneously have high strength, high bending resistance, and high hardness. The two-step forming process is to thin the relatively thick glass product, mainly including physical thinning method, chemical thinning method, and secondary down-draw method, etc. Although the two-step forming process is simple, it has the disadvantages of high cost and environmental unfriendliness. Therefore, how to coordinate the strength, hardness, and bending resistance of ultra-thin flexible glass from the perspectives of glass composition, glass melting process, and post-strengthening has become the focus of research, and make it suitable for forming flexible glass by the overflow down-draw method.

[0004] Chinese Patent CN115745416A discloses a production process of ultra-thin flexible glass and the glass thereof, which successively includes glass surface grooving, chemical thinning, glass cutting, edge polishing, chemical tempering, pickling, and cleaning according to the process flow. When grooving the surface, grooves with a width of 0.02 - 1 mm are cut on both sides of the same surface of the glass, and the depth of the groove is 30 - 60% of the glass thickness. When cutting the glass, the waste edges and groove parts are removed. This patent uses the chemical thinning method to obtain ultra-thin flexible glass, and also involves process steps such as pickling and cleaning that generate a large amount of waste liquid. This preparation method is very environmentally unfriendly and it is difficult to fundamentally improve the mechanical properties of ultra-thin flexible glass.

[0005] Chinese Patent CN116621469A discloses an ultra-thin flexible glass and its preparation method and application. The method includes: (1) etching a glass sheet in the presence of an etchant to obtain a glass substrate; (2) stacking at least two of the glass substrates, with an adhesive layer disposed between adjacent glass substrates to obtain a laminated glass, and protective layers are disposed on both the upper surface and the lower surface of the laminated glass to obtain a glass to be processed; (3) sequentially subjecting the glass to be processed to ultraviolet curing treatment and profile machining treatment to obtain a formed glass; (4) performing ion exchange strengthening treatment on the formed glass with potassium nitrate in the presence of an additive. This patent also uses an etching method, i.e., a chemical thinning method, to obtain the ultra-thin flexible glass. The inherent toughness of the glass substrate has not been effectively improved, and the environmental friendliness of the etching process is very poor. In addition, this patent also designs a relatively complex adhesive layer, which will also affect the production efficiency to a certain extent.

[0006] As can be seen from the above, there is currently a problem in the preparation of ultra-thin flexible glass that its mechanical properties cannot be essentially improved from the perspective of glass body preparation. Therefore, it is a method and approach with great research significance and practical value to improve the strength, hardness and bend resistance of ultra-thin flexible glass from the aspects of glass composition, glass melting process and subsequent strengthening. Summary of the Invention

[0007] Aiming at the deficiencies of the above-mentioned existing technologies, the present invention provides an ultra-thin flexible glass and its preparation method, achieving the following invention objectives: preparing an ultra-thin flexible glass with high strength, high bend resistance and high hardness from the perspectives of adjusting glass composition, glass melting process and subsequent strengthening.

[0008] To achieve the above invention objectives, the present invention adopts the following technical solutions:

[0009] An ultra-thin flexible glass and its preparation method, the raw material composition of the ultra-thin flexible glass is, in parts by weight:

[0010] Silica 150 - 280 parts,

[0011] Aluminum oxide 10 - 50 parts,

[0012] Sodium oxide 5 - 10 parts,

[0013] Boron trioxide 1 - 5 parts,

[0014] Calcium oxide 2 - 9 parts,

[0015] Lithium oxide 1 - 10 parts,

[0016] Composite toughening agent 5 - 20 parts,

[0017] Composite flux 3 - 10 parts,

[0018] 2 - 8 parts of composite fining agent;

[0019] The composite toughening agent is a mixture of magnesium boride and magnesium nitride;

[0020] The mass ratio of magnesium boride to magnesium nitride is 10 - 60:39;

[0021] The composite flux is a mixture of calcium molybdate, potassium fluozirconate and zirconate;

[0022] The zirconate is one of lithium zirconate and sodium zirconate;

[0023] The mass ratio of calcium molybdate, potassium fluozirconate and zirconate is 10 - 80:3 - 9:10 - 50;

[0024] The composite fining agent is a mixture of strontium molybdate, molybdenum trioxide and potassium fluotitanate;

[0025] The mass ratio of strontium molybdate, molybdenum trioxide and potassium fluotitanate is 20 - 90:5 - 20:15 - 40;

[0026] The following is a further improvement of the above technical solution:

[0027] Step 1, melting

[0028] According to the raw material composition of the ultra - thin flexible glass by weight, mix silicon dioxide, aluminum oxide, sodium oxide, boron trioxide, calcium oxide, lithium oxide, composite toughening agent, composite flux and composite fining agent evenly preliminary, then put them into a glass melting furnace. After the heating and constant - temperature process, they are melted into a high - temperature glass melt;

[0029] The heating and constant - temperature process is specifically operated as follows: heat at a rate of 2 - 5 °C / min to 1000 - 1200 °C and keep warm for 30 - 50 minutes, then heat at a rate of 1 - 3 °C / min to 1500 - 1680 °C and keep warm for 1 - 4 hours, and then cool down to 1400 - 1480 °C and keep warm for 20 - 40 minutes.

[0030] Step 2, overflow and drawdown

[0031] Inject the high - temperature glass melt from the glass melting furnace into the trough. The glass melt liquid enters the overflow trough through the trough, and under the action of its own gravity, flows downward along the two overflow surfaces of the overflow brick to form two planar melt flows, and the two melt flows merge into a glass ribbon at the tip of the overflow brick, and an ultra - thin flexible glass semi - finished product is obtained after cooling.

[0032] Step 3, ion - exchange strengthening

[0033] First, preheat the ultra-thin flexible glass semi-finished product to the constant temperature of the molten salt, then place the ultra-thin flexible glass semi-finished product into the molten salt that has been preheated to the constant temperature for ion exchange strengthening. After the strengthening is completed, quickly cool it to room temperature, and then soak it in warm water. After cleaning and drying, the strengthened ultra-thin flexible glass is obtained;

[0034] The molten salt is a mixture of potassium nitrate, potassium vanadate, and potassium stannate;

[0035] The mass ratio of potassium nitrate, potassium vanadate, and potassium stannate is 50 - 110:3 - 8:10 - 30;

[0036] The constant temperature of the molten salt is 390 - 440 °C;

[0037] For the ion exchange strengthening, the strengthening time is 10 - 30 min;

[0038] For the rapid cooling, the cooling rate is 2 - 6 °C / min.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The composite toughening agent composed of magnesium boride and magnesium nitride in the present invention can effectively improve the toughness of the ultra-thin flexible glass, enhance the bending resistance performance and increase the elastic modulus. The general toughening principle is as follows: both magnesium boride and magnesium nitride are ionic compounds with regular crystal structures. During the glass melting process, the ions released after the melting of magnesium boride and magnesium nitride can quickly enter the network structure of the glass melt, and during the cooling process of the glass melt, it promotes the precipitation of nano-crystals that enhance and toughen the glass matrix, thereby achieving the effect of enhancing and toughening the ultra-thin flexible glass;

[0041] 2. In the composite flux added in the present invention, calcium molybdate, potassium fluorozirconate, and zirconate are contained. The melting points of these three substances are all below 900 °C and their fluidity after melting is very good, and their compatibility with the glass melt is particularly good. The relevant metal ions ionized after melting can lubricate the network structure of the glass melt, promote the fluidity of the glass melt, so it can promote the uniform rheological properties of the glass melt during the overflow down-draw forming process, and further promote the improvement of various properties of the glass after forming;

[0042] 3. The composite fining agent composed of strontium molybdate, molybdenum trioxide, and potassium fluorotitanate added in the present invention has a fining effect mainly relying on the high-temperature thermal decomposition of strontium molybdate and potassium fluorotitanate and the high-temperature boiling of molybdenum trioxide. The decomposition or high-temperature boiling temperatures of these three are all above 1000 °C, and it has an obvious effect on removing the tiny bubbles in the viscous glass melt with a high silica content. Therefore, in the present invention, a very good fining effect can be achieved on the basis of maintaining a high silica content, and finally, an ultra-thin flexible glass with very excellent mechanical properties is obtained;

[0043] 4. In the ion exchange strengthening step of the present invention, in the molten salt formulation used, in addition to conventional potassium nitrate, potassium vanadate and potassium stannate are added. The main functions of these two substances are to enhance the ionic activity of potassium ions in the low-temperature molten salt. Since the ionic charge interaction forces of the two negative ions, vanadate and stannate, are significantly smaller than that of nitrate, in the molten salt involving these two negative ions, the overall charge attraction force on potassium ions will be correspondingly reduced. Therefore, the potassium ions in the molten salt liquid are more likely to rapidly exchange with the sodium ions in the glass, and the sodium ions are more easily captured by the oxygen-containing acid root negative ions, thereby promoting the rate and depth of ion strengthening.

[0044] 5. The ultra-thin flexible glass prepared by the present invention has an ultimate bending radius of 2 - 3 mm, a maximum number of bending times of 350,000 - 360,000 times, a surface compressive stress of 916 - 937 MPa, a Vickers hardness of 610 - 623 MPa, and an elastic modulus of 79 - 82 GPa. Specific Embodiments

[0045] The following describes the preferred embodiments of the present invention. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention.

[0046] Example 1: A method for preparing ultra-thin flexible glass

[0047] Step 1. Melting

[0048] The raw material composition of the ultra-thin flexible glass is as follows, by weight:

[0049] Silicon dioxide 200 parts,

[0050] Aluminum oxide 40 parts,

[0051] Sodium oxide 6 parts,

[0052] Boron trioxide 4 parts,

[0053] Calcium oxide 6 parts,

[0054] Lithium oxide 8 parts,

[0055] Composite toughening agent 13 parts,

[0056] Composite flux 8 parts,

[0057] Composite fining agent 5 parts;

[0058] The composite toughening agent is a mixture of magnesium boride and magnesium nitride;

[0059] The mass ratio of magnesium boride to magnesium nitride is 40:39;

[0060] The composite flux is a mixture of calcium molybdate, potassium hexafluorozirconate, and zirconate;

[0061] The zirconate is lithium zirconate;

[0062] The mass ratio of calcium molybdate, potassium hexafluorozirconate, and zirconate is 50:7:40;

[0063] The composite fining agent is a mixture of strontium molybdate, molybdenum trioxide, and potassium hexafluorotitanate;

[0064] The mass ratio of strontium molybdate, molybdenum trioxide, and potassium hexafluorotitanate is 60:15:30;

[0065] According to the raw material composition of the ultra-thin flexible glass by weight, silica, alumina, sodium oxide, boron trioxide, calcium oxide, lithium oxide, composite toughening agent, composite flux, and composite fining agent are preliminarily mixed evenly and then put into a glass melting furnace. After a heating and constant temperature process, it is melted into a high-temperature glass melt;

[0066] For the heating and constant temperature process, the specific operation is: heating at a rate of 3°C / min to 1100°C and holding for 45 minutes, then heating at a rate of 2°C / min to 1580°C and holding for 2 hours, and then cooling to 1450°C and holding for 35 minutes.

[0067] Step 2, overflow and draw down

[0068] Inject the high-temperature glass melt from the glass melting furnace into the trough. The glass melt liquid enters the overflow trough through the trough and, under its own gravity, flows downward along the two overflow surfaces of the overflow brick to form two planar melt flows, and the two melt flows merge into a glass ribbon at the tip of the overflow brick. After cooling, an ultra-thin flexible glass semi-finished product is obtained.

[0069] Step 3, ion exchange strengthening

[0070] First, preheat the ultra-thin flexible glass semi-finished product to the constant temperature of the molten salt, then put the ultra-thin flexible glass semi-finished product into the molten salt that has been heated to the constant temperature in advance for ion exchange strengthening. After the strengthening is completed, quickly cool it to room temperature, then soak it in warm water, and after cleaning and drying, an enhanced ultra-thin flexible glass is obtained;

[0071] The molten salt is a mixture of potassium nitrate, potassium metavanadate, and potassium stannate;

[0072] The mass ratio of potassium nitrate, potassium metavanadate, and potassium stannate is 90:5:20;

[0073] The constant temperature of the molten salt is 410°C;

[0074] For the ion exchange strengthening, the strengthening time is 20 min;

[0075] For the rapid cooling, the cooling rate is 5 °C / min.

[0076] Example 2: A method for preparing ultra-thin flexible glass

[0077] Step 1, melting

[0078] The raw material composition of the ultra-thin flexible glass is as follows, by weight:

[0079] 150 parts of silicon dioxide,

[0080] 10 parts of aluminum oxide,

[0081] 5 parts of sodium oxide,

[0082] 1 part of boron trioxide,

[0083] 2 parts of calcium oxide,

[0084] 1 part of lithium oxide,

[0085] 5 parts of composite toughening agent,

[0086] 3 parts of composite flux,

[0087] 2 parts of composite fining agent;

[0088] The composite toughening agent is a mixture of magnesium boride and magnesium nitride;

[0089] The mass ratio of magnesium boride to magnesium nitride is 10:39;

[0090] The composite flux is a mixture of calcium molybdate, potassium fluorozirconate, and zirconate;

[0091] The zirconate is sodium zirconate;

[0092] The mass ratio of calcium molybdate, potassium fluorozirconate, and zirconate is 10:3:10;

[0093] The composite fining agent is a mixture of strontium molybdate, molybdenum trioxide, and potassium fluotitanate;

[0094] The mass ratio of strontium molybdate, molybdenum trioxide, and potassium fluotitanate is 20:5:15;

[0095] According to the raw material composition of the ultra-thin flexible glass by weight, silicon dioxide, aluminum oxide, sodium oxide, boron trioxide, calcium oxide, lithium oxide, composite toughening agent, composite flux, and composite fining agent are preliminarily mixed evenly and then put into a glass melting furnace. After a heating and constant temperature process, it is melted into a high-temperature glass melt;

[0096] The temperature-raising and constant-temperature process is specifically operated as follows: raise the temperature to 1000°C at a rate of 2°C / min and keep it warm for 30 minutes, then raise the temperature to 1500°C at a rate of 1°C / min and keep it warm for 1 hour, and then cool it down to 1400°C and keep it warm for 20 minutes.

[0097] Step 2, overflow and draw down

[0098] Inject the high-temperature glass melt from the glass furnace into the trough. The glass melt liquid enters the overflow trough through the trough, and under the action of its own gravity, it flows downward along the two overflow surfaces of the overflow brick to form two planar melt flows, and the two melt flows merge into a glass ribbon at the tip of the overflow brick, and an ultra-thin flexible glass semi-finished product is obtained after cooling.

[0099] Step 3, ion exchange strengthening

[0100] First, preheat the ultra-thin flexible glass semi-finished product to the constant temperature of the molten salt, and then put the ultra-thin flexible glass semi-finished product into the molten salt that has been preheated to the constant temperature for ion exchange strengthening. After the strengthening is completed, quickly cool it to room temperature, and then soak it in warm water, and obtain the strengthened ultra-thin flexible glass after cleaning and drying;

[0101] The molten salt is a mixture of potassium nitrate, potassium metavanadate, and potassium stannate;

[0102] The mass ratio of potassium nitrate, potassium metavanadate, and potassium stannate is 50:3:10;

[0103] The constant temperature of the molten salt is 390°C;

[0104] For the ion exchange strengthening, the strengthening time is 10 min;

[0105] For the rapid cooling, the cooling rate is 2°C / min.

[0106] Example 3: A method for preparing ultra-thin flexible glass

[0107] Step 1, melting

[0108] The raw material composition of the ultra-thin flexible glass is as follows, in parts by weight:

[0109] Silica 280 parts,

[0110] Aluminum oxide 50 parts,

[0111] Sodium oxide 10 parts,

[0112] Boron trioxide 5 parts,

[0113] Calcium oxide 9 parts,

[0114] Lithium oxide 10 parts,

[0115] 20 parts of composite toughening agent,

[0116] 10 parts of composite flux,

[0117] 8 parts of composite fining agent;

[0118] The composite toughening agent is a mixture of magnesium boride and magnesium nitride;

[0119] The mass ratio of magnesium boride to magnesium nitride is 60:39;

[0120] The composite flux is a mixture of calcium molybdate, potassium fluozirconate, and zirconate;

[0121] The zirconate is lithium zirconate;

[0122] The mass ratio of calcium molybdate, potassium fluozirconate, and zirconate is 80:9:50;

[0123] The composite fining agent is a mixture of strontium molybdate, molybdenum trioxide, and potassium fluotitanate;

[0124] The mass ratio of strontium molybdate, molybdenum trioxide, and potassium fluotitanate is 90:20:40;

[0125] According to the raw material composition of the ultra-thin flexible glass in parts by weight, silica, alumina, sodium oxide, boron trioxide, calcium oxide, lithium oxide, composite toughening agent, composite flux, and composite fining agent are preliminarily mixed evenly and then put into a glass melting furnace. After a heating and constant temperature process, it is melted into a high-temperature glass melt;

[0126] The specific operation of the heating and constant temperature process is: heating at a rate of 5°C / min to 1200°C and holding for 50 minutes, then heating at a rate of 3°C / min to 1680°C and holding for 4 hours, and then cooling to 1480°C and holding for 40 minutes.

[0127] Step 2, overflow and draw down

[0128] Inject the high-temperature glass melt from the glass melting furnace into the trough. The glass melt liquid enters the overflow trough through the trough and, under its own gravity, flows downward along the two overflow surfaces of the overflow brick to form two planar melt flows, and the two melt flows merge into a glass ribbon at the tip of the overflow brick. After cooling, an ultra-thin flexible glass semi-finished product is obtained.

[0129] Step 3, ion exchange strengthening

[0130] First, preheat the ultra-thin flexible glass semi-finished product to the constant temperature of the molten salt, and then put the ultra-thin flexible glass semi-finished product into the molten salt that has been preheated to the constant temperature for ion exchange strengthening. After the strengthening is completed, quickly cool it to room temperature, then soak it in warm water, and after cleaning and drying, an enhanced ultra-thin flexible glass is obtained;

[0131] The molten salt is a mixture of potassium nitrate, potassium vanadate, and potassium stannate;

[0132] The mass ratio of potassium nitrate, potassium vanadate, and potassium stannate is 110:8:30;

[0133] The constant temperature of the molten salt is 440 °C;

[0134] For the ion exchange strengthening, the strengthening time is 30 min;

[0135] For the rapid cooling, the cooling rate is 6 °C / min.

[0136] Comparative Example 1: Based on Example 1, in Step 1, during melting, no composite toughening agent is added, and 13 parts of the composite toughening agent are replaced with 13 parts of silicon dioxide in equal amounts. The specific operation is as follows:

[0137] Step 1, Melting

[0138] Replace 13 parts of the composite toughening agent with 13 parts of silicon dioxide in equal amounts, and other operations are the same as in Example 1;

[0139] Steps 2 and 3 are operated in the same way as in Example 1.

[0140] Comparative Example 2: Based on Example 1, in Step 1, during melting, no composite flux is added, and 8 parts of the composite flux are replaced with 8 parts of silicon dioxide in equal amounts. The specific operation is as follows:

[0141] Step 1, Melting

[0142] Replace 8 parts of the composite flux with 8 parts of silicon dioxide in equal amounts, and other operations are the same as in Example 1;

[0143] Steps 2 and 3 are operated in the same way as in Example 1.

[0144] Comparative Example 3: Based on Example 1, in Step 1, during melting, no composite fining agent is added, and 5 parts of the composite fining agent are replaced with 5 parts of silicon dioxide in equal amounts. The specific operation is as follows:

[0145] Step 1, Melting

[0146] Replace 5 parts of the composite fining agent with 5 parts of silicon dioxide in equal amounts, and other operations are the same as in Example 1;

[0147] Steps 2 and 3 are operated in the same way as in Example 1.

[0148] Comparative Example 4: Based on Example 1, in Step 3, during ion exchange strengthening, potassium vanadate and potassium stannate are not added to the molten salt, and 5 parts of potassium vanadate and 20 parts of potassium stannate are replaced with 25 parts of potassium nitrate in equal amounts. The specific operation is as follows:

[0149] Steps 1 and 2 are operated in the same way as in Example 1;

[0150] Step 3: Ion exchange strengthening

[0151] Replace 5 parts of potassium vanadate and 20 parts of potassium stannate with 25 parts of potassium nitrate in equal amounts, and other operations are the same as in Example 1.

[0152] Performance test:

[0153] Test the obtained ultra-thin flexible glass of Example 1, 2, 3 and Comparative Example 1, 2, 3, 4 for indicators such as the ultimate bending radius, the maximum number of bending times, the surface compressive stress, the Vickers hardness, and the elastic modulus:

[0154] 1. Ultimate bending radius: Test the ultimate bending radius R according to GB / T38686-2020 "Test method for flexibility of ultra-thin glass - Two-point bending method".

[0155] 2. Maximum number of bending times: Fix the two ends of the long side of the sample on the bending fatigue testing machine respectively, set the reciprocating frequency of the testing machine to 30 times / min. After the sample reaches the bending radius, the moving plate retreats to the starting position to complete 1 bending fatigue test, and then cycle the sample back and forth;

[0156] 3. Surface compressive stress: Test according to Chapter 9 of ASTM C1422 / C1422M-20 "Standard specification for chemically strengthened flat glass" using an SLP-2000 scattered light stress meter;

[0157] 4. Vickers hardness: Test according to GB / T 4340.1-2009 "Vickers hardness test for metallic materials" using a micro Vickers hardness tester with a loading force of 200g and a loading time of 10s;

[0158] 5. Elastic modulus: Test according to GB / T 37780-2019 "Test method for elastic modulus, shear modulus and Poisson's ratio of glass materials";

[0159] The results are shown in Table 1:

[0160] Table 1

[0161] As can be seen from the data in Table 1, the ultimate bending radii of Examples 1-3 are very small, the maximum number of bending times are all 350,000 times and above, the surface compressive stress is greater than 900 MPa, the Vickers hardness is above 600 MPa, and the elastic modulus is 79 GPa and above. This shows that the ultra-thin flexible glass obtained by the present invention has excellent properties such as high strength, high bending resistance, and high hardness; in Comparative Example 1, no composite toughening agent is added, the ultimate bending radius of Comparative Example 1 increases to 8 mm, the maximum number of bending times decreases to 160,000 times, the surface compressive stress also decreases slightly, the Vickers hardness decreases slightly, and the elastic modulus decreases to 48 GPa. This shows that the composite toughening agent has a great influence on the toughness of the ultra-thin flexible glass and also has a certain influence on the surface strength and hardness; in Comparative Example 2, no composite flux is added, the ultimate bending radius of Comparative Example 2 increases to 6 mm, the maximum number of bending times decreases to 260,000 times, the surface compressive stress decreases significantly, the Vickers hardness decreases to 549 MPa, and the elastic modulus also decreases to 59 GPa accordingly. This shows that the composite flux has a very significant influence on the surface hardness, mechanical strength, and toughness of the ultra-thin flexible glass. This may be because the composite flux can improve the fluidity of the glass melt, and then affect the crystallization process of the glass components during the cooling process and ultimately affect the relevant mechanical properties of the ultra-thin flexible glass; in Comparative Example 3, no composite clarifying agent is added, and the indexes such as the ultimate bending radius, the maximum number of bending times, the surface compressive stress, the Vickers hardness, and the elastic modulus of Comparative Example 3 are all reduced to the lowest values of all examples and comparative examples. It can be seen that the composite clarifying agent plays a very crucial role in removing the tiny bubbles in the ultra-thin flexible glass melt. If the ultra-thin flexible glass melt is not effectively clarified, the tiny bubbles will have a fatal impact on the various properties of the glass; in the ion exchange strengthening step of Comparative Example 4, potassium vanadate and potassium stannate are not added to the molten salt. The ultimate bending radius of Comparative Example 4 increases to 8 mm, the maximum number of bending times decreases to 310,000 times, and the surface compressive stress, the Vickers hardness, and the elastic modulus all decrease very significantly. It can be seen that the addition of potassium vanadate and potassium stannate can effectively promote the ion strengthening process of the ultra-thin flexible glass and promote the significant improvement of the overall performance of the ultra-thin flexible glass.

[0162] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent replacements or changes should be covered within the protection scope of the present invention.

Claims

1. An ultra-thin flexible glass, characterized in that: The raw materials of the ultra-thin flexible glass are composed of silica, alumina, sodium oxide, boron trioxide, calcium oxide, lithium oxide, a composite toughening agent, a composite flux, and a composite fining agent; The composite toughening agent is a mixture of magnesium boride and magnesium nitride; The composite flux is a mixture of calcium molybdate, potassium fluozirconate, and zirconate; The composite fining agent is a mixture of strontium molybdate, molybdenum trioxide, and potassium fluotitanate; The raw material composition of the ultra-thin flexible glass is as follows by weight: 150 - 280 parts of silica, 10 - 50 parts of alumina, 5 - 10 parts of sodium oxide, 1 - 5 parts of boron trioxide, 2 - 9 parts of calcium oxide, 1 - 10 parts of lithium oxide, 5 - 20 parts of the composite toughening agent, 3 - 10 parts of the composite flux, and 2 - 8 parts of the composite fining agent; The mass ratio of magnesium boride to magnesium nitride is 10 - 60:39; The zirconate is one of lithium zirconate and sodium zirconate; The mass ratio of calcium molybdate, potassium fluozirconate, and zirconate is 10 - 80:3 - 9:10 - 50; The mass ratio of strontium molybdate, molybdenum trioxide, and potassium fluotitanate is 20 - 90:5 - 20:15 - 40.

2. The preparation method of the ultra-thin flexible glass according to claim 1, characterized in that: The preparation method includes three steps: melting, overflow down-drawing, and ion exchange strengthening; For the ion exchange strengthening, first preheat the semi-finished ultra-thin flexible glass to the constant temperature of the molten salt, then put the semi-finished ultra-thin flexible glass into the molten salt that has been preheated to the constant temperature for ion exchange strengthening. After the strengthening is completed, quickly cool it to room temperature, then soak it in warm water, and obtain the strengthened ultra-thin flexible glass after cleaning and drying; The molten salt is a mixture of potassium nitrate, potassium vanadate, and potassium stannate; The mass ratio of potassium nitrate, potassium vanadate, and potassium stannate is 50 - 110:3 - 8:10 - 30.

3. The preparation method of the ultra-thin flexible glass according to claim 2, characterized in that: For the melting, according to the raw material composition of the ultra-thin flexible glass by weight, after preliminarily mixing silica, alumina, sodium oxide, boron trioxide, calcium oxide, lithium oxide, the composite toughening agent, the composite flux, and the composite fining agent evenly, put them into a glass furnace, and after a heating and constant temperature process, melt them into a high-temperature glass melt; For the overflow down-drawing, inject the high-temperature glass melt from the glass furnace into the trough. The glass melt liquid enters the overflow trough through the trough, and under the action of its own gravity, flows downward along the two overflow surfaces of the overflow brick to form two planar melt flows, and merges into a glass ribbon at the tip of the overflow brick, and the semi-finished ultra-thin flexible glass is obtained after cooling.

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