Preparation method of novel ultrathin glass chemical tempering fused salt

Abstract

The invention discloses a preparation method of novel ultrathin glass chemical toughening molten salt, and belongs to the technical field of ultrathin glass chemical toughening, in the invention, by adding silver nitrate, lithium nitrate and other components, the melting point of the molten salt is reduced, the toughening temperature is reduced to below 380 DEG C, and the occurrence of deformation of ultrathin glass is effectively reduced. Meanwhile, by optimizing the components of the fused salt, the ion exchange rate is increased, the tempering time is shortened, and the production efficiency is improved. By optimizing the molten salt components, the tempering temperature is reduced, and the energy consumption during tempering is effectively reduced. Meanwhile, components such as silver nitrate, strontium nitrate and barium nitrate are added, so that a more compact pressure stress layer is formed on the surface of the glass, and the mechanical strength of the ultra-thin glass is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical strengthening of ultra-thin glass, and specifically relates to a method for preparing a novel chemical strengthening molten salt for ultra-thin glass. Background Art

[0002] With the rapid development of the electronic display industry, ultra-thin glass is increasingly widely used in electronic products such as smart phones and tablet computers; in order to improve the mechanical strength of ultra-thin glass, a chemical strengthening method is usually adopted, that is, the ultra-thin glass is immersed in a high-temperature molten salt, and a compressive stress layer is formed on the glass surface through ion exchange, thereby improving the strength of the ultra-thin glass.

[0003] However, traditional glass chemical strengthening molten salts mainly use potassium nitrate (KNO3) as the main component, but it has the following disadvantages: the tempering temperature of traditional potassium nitrate molten salts is usually above 400°C, which easily causes deformation of ultra-thin glass; in order to achieve a sufficient ion exchange depth, a long tempering time is required, reducing production efficiency; traditional potassium nitrate molten salts have limited improvement in the strength of ultra-thin glass and are difficult to meet the increasingly high product requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a novel chemical strengthening molten salt for ultra-thin glass in order to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows: A method for preparing a novel chemical strengthening molten salt for ultra-thin glass, the method comprising the following steps:

[0006] The method comprises the following steps:

[0007] S1: Determine the composition and proportion range of the molten salt raw materials: potassium nitrate KNO3 60% - 80%, silver nitrate AgNO3 5% - 20%, lithium nitrate LiNO3 5% - 10%, calcium nitrate Ca(NO3)2 2% - 5%, strontium nitrate Sr(NO3)2 1% - 3%, barium nitrate Ba(NO3)2 0.5% - 2%;

[0008] S2: Accurately weigh the weight percentages of the respective raw materials according to the target ratio;

[0009] S3: Add the weighed raw materials to a mixer in sequence;

[0010] S4: Start the mixer and mix the raw materials at a set speed until the mixing uniformity reaches over 95%;

[0011] S5: Collect the uniformly mixed molten salt and conduct a uniformity test;

[0012] S6: Transfer the mixed salt to a chemical tempering furnace and spread it flat on the bottom of the furnace chamber;

[0013] S7: Start the heating program of the toughening furnace, raise the temperature to 300°C - 380°C to completely melt the mixed salt into a liquid state;

[0014] S8: Maintain the molten state for 10 - 20 minutes to ensure uniform distribution of the molten salt components;

[0015] S9: Turn off the heating program, store it after the molten salt cools naturally, and use it for the chemical toughening treatment of ultra-thin glass.

[0016] In a preferred embodiment, in step S1, each component is weighed one by one using a high-precision electronic balance, and the error needs to be controlled within ±0.1%.

[0017] In a preferred embodiment, in step S2, raw materials such as potassium nitrate and silver nitrate need to be pre-dried to remove moisture to avoid generating bubbles or uneven composition during the melting process. The weighing order is preferably carried out in descending order of proportion. For example, first weigh potassium nitrate, and then weigh silver nitrate, lithium nitrate, etc. in sequence to reduce the risk of cross-contamination.

[0018] In a preferred embodiment, in step S3, the weighed raw materials are put into a double-screw conical mixer and mixed at a speed of 20 - 40 revolutions per minute for 30 - 60 minutes. During the mixing process, samples need to be taken regularly for detection to ensure that the mixing uniformity reaches more than 95%. For raw materials with large particle size differences (such as barium nitrate particles being finer), the mixing time can be extended or a segmented mixing process can be adopted, first rough mixing and then fine mixing, to avoid local agglomeration affecting the final molten salt performance.

[0019] In a preferred embodiment, in step S4, a laser particle size analyzer and X-ray fluorescence spectrometry are used to detect the particle size distribution and composition consistency of the mixed salt. If stratification of light components such as silver nitrate or lithium nitrate is detected, it needs to be put back into the mixer for supplementary mixing for 10 - 15 minutes. The qualified mixed salt needs to be sealed and stored in a dry environment to prevent moisture absorption and caking, and the storage time should not exceed 48 hours.

[0020] In a preferred embodiment, in step S5, the mixed salt is evenly laid on the bottom of the high-temperature resistant alloy crucible of the chemical toughening furnace, and the laying thickness is controlled at 5 - 8 cm. Too thick is likely to cause too large a temperature difference between the bottom and the surface layer, and too thin will reduce the utilization rate of the molten salt. Before loading the furnace, the furnace chamber needs to be cleaned and nitrogen is introduced for protection to prevent the oxidation and decomposition of nitrates during the melting process.

[0021] In a preferred embodiment, in step S6, after starting the toughening furnace, the temperature is gradually increased to 300 - 380°C at a rate of 5 - 8°C per minute, and the specific temperature is adjusted according to the ratio. For example, the molten salt containing 20% silver nitrate can be set at 340°C. During the melting stage, the temperature distribution inside the crucible needs to be monitored in real time, and the temperature difference is controlled within ±5°C through a multi-zone heating system to avoid local overheating causing component volatilization or decomposition.

[0022] In a preferred embodiment, in step S7, after the molten salt is completely liquefied, the target temperature is maintained and mechanical stirring is continued for 10 - 20 minutes. The stirring speed is set at 50 - 80 revolutions per minute to promote the uniform dispersion of heavy components such as strontium nitrate and barium nitrate. During this stage, the ion concentration of the molten salt needs to be monitored through an on-line conductivity meter. If the fluctuation exceeds 3%, the stirring time is extended to ensure the consistent chemical activity of the molten salt.

[0023] In a preferred embodiment, in step S8, after shutting down the heating system, the temperature of the molten salt is cooled to below 80°C by natural cooling, and then transferred to a sealed stainless steel container. During the cooling process, vibration or rapid temperature drop needs to be avoided to prevent stress cracks caused by the crystallization of the molten salt. The storage environment temperature needs to be below 25°C and the relative humidity is below 30% to ensure that the molten salt can be quickly remelted and has stable performance in subsequent toughening processes.

[0024] In a preferred embodiment, in step S9, after the molten salt is homogenized, the heating system of the toughening furnace is shut down and the stirring is stopped, and it is naturally cooled in the furnace to below 80°C. The cooling rate needs to be controlled at 3 - 5°C per minute to avoid stress accumulation or crack generation inside the molten salt due to excessive temperature difference. After the cooled solid molten salt is crushed and screened to remove lumps or impurities, it is filled into a sealed moisture-proof stainless steel container and labeled with the composition ratio and production batch. The storage environment needs to be kept at a constant temperature and humidity, the temperature is not higher than 25°C, and the relative humidity is below 30%, to avoid the molten salt from absorbing moisture or undergoing a deliquescence reaction, and to ensure the chemical activity stability after remelting in subsequent toughening processes.

[0025] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0026] 1. In the present invention, by adding components such as silver nitrate and lithium nitrate, the melting point of the molten salt is reduced, the toughening temperature is lowered to below 380°C, effectively reducing the occurrence of deformation of ultra-thin glass. At the same time, by optimizing the molten salt composition, the ion exchange rate is increased, the toughening time is shortened, and the production efficiency is improved.

[0027] 2. In the present invention, by optimizing the molten salt composition, the toughening temperature is lowered, effectively reducing the energy consumption during toughening. At the same time, by adding components such as silver nitrate, strontium nitrate, and barium nitrate, a denser compressive stress layer is formed on the glass surface, significantly improving the mechanical strength of ultra-thin glass. Brief Description of the Drawings

[0028] Figure 1 This is a schematic diagram of the process principle of the present invention. Detailed Description of the Preferred Embodiments

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Embodiment 1:

[0031] Referring to Figure 1 ,

[0032] A method for preparing a novel ultra-thin glass chemically strengthened molten salt, comprising the following steps:

[0033] The method comprises the following steps:

[0034] S1: Determine the composition and proportion range of the molten salt raw materials: potassium nitrate KNO3 75%, silver nitrate AgNO3 15%, lithium nitrate LiNO3 5%, calcium nitrate Ca(NO3)2 3%, strontium nitrate Sr(NO3)2 1.5%, barium nitrate Ba(NO3)2 0.5%;

[0035] S2: Accurately weigh the weight percentages of the raw materials according to the target ratio;

[0036] S3: Add the weighed raw materials to a mixer in sequence;

[0037] S4: Start the mixer and mix the raw materials at a set speed until the mixing uniformity reaches over 95%;

[0038] S5: Collect the uniformly mixed molten salt and conduct a uniformity test;

[0039] S6: Transfer the molten salt to a chemical toughening furnace and spread it flat on the bottom of the furnace chamber;

[0040] S7: Start the heating program of the toughening furnace and raise the temperature to 360°C to completely melt the molten salt into a liquid state;

[0041] S8: Maintain the molten state for 10 to 20 minutes to ensure uniform distribution of the molten salt components;

[0042] S9: Turn off the heating program, store the molten salt after natural cooling, and use it for the chemical toughening treatment of ultra-thin glass.

[0043] In step S1, a high-precision electronic balance is used to weigh each component one by one, and the error needs to be controlled within ±0.1%.

[0044] In step S2, raw materials such as potassium nitrate and silver nitrate need to be pre-dried to remove moisture to avoid generating bubbles or uneven composition during the melting process. It is recommended to carry out the weighing sequence in descending order of proportion. For example, first weigh potassium nitrate, and then successively weigh silver nitrate, lithium nitrate, etc., to reduce the risk of cross-contamination.

[0045] In step S3, the weighed raw materials are put into a double-helix conical mixer and mixed at a rotation speed of 20 - 40 revolutions per minute for 30 - 60 minutes. During the mixing process, samples need to be taken regularly for detection to ensure that the mixing uniformity reaches more than 95%. For raw materials with large particle size differences (such as barium nitrate particles being finer), the mixing time can be extended or a segmented mixing process can be adopted, first rough mixing and then fine mixing, to avoid local agglomeration affecting the final molten salt performance.

[0046] In step S4, a laser particle size analyzer and X-ray fluorescence spectrometry are used to detect the particle size distribution and composition consistency of the mixed salt. If stratification of light components such as silver nitrate or lithium nitrate is detected, it is necessary to put it back into the mixer for supplementary mixing for 10 - 15 minutes. The qualified mixed salt needs to be sealed and stored in a dry environment to prevent moisture absorption and caking, and the storage time should not exceed 48 hours.

[0047] In step S5, the mixed salt is evenly laid at the bottom of a high-temperature resistant alloy crucible in a chemical tempering furnace, and the laying thickness is controlled at 5 - 8 cm. If it is too thick, it is easy to cause too large a temperature difference between the bottom and the surface layer; if it is too thin, it will reduce the utilization rate of the molten salt. Before loading the furnace, the furnace chamber needs to be cleaned and nitrogen is introduced for protection to prevent the oxidation and decomposition of nitrates during the melting process.

[0048] In step S6, after starting the tempering furnace, the temperature is gradually increased to 300 - 380°C at a rate of 5 - 8°C per minute, and the specific temperature is adjusted according to the ratio. For example, the molten salt containing 20% silver nitrate can be set at 340°C. During the melting stage, the temperature distribution in the crucible needs to be monitored in real time, and the temperature difference is controlled within ±5°C through a multi-zone heating system to avoid local overheating causing component volatilization or decomposition.

[0049] In step S7, after the molten salt is completely liquefied, maintain the target temperature and continuously mechanically stir for 10 - 20 minutes. The stirring speed is set at 50 - 80 revolutions per minute to promote the uniform dispersion of heavy components such as strontium nitrate and barium nitrate. During this stage, the ion concentration of the molten salt needs to be monitored through an on-line conductivity meter. If the fluctuation exceeds 3%, the stirring time is extended to ensure the consistent chemical activity of the molten salt.

[0050] In step S8, after turning off the heating system, the temperature of the molten salt is cooled to below 80°C by natural cooling, and then transferred to a sealed stainless steel container. During the cooling process, vibration or rapid temperature drop needs to be avoided to prevent stress cracks caused by the crystallization of the molten salt. The storage environment temperature needs to be lower than 25°C and the relative humidity is lower than 30% to ensure that the molten salt can be quickly remelted and its performance is stable in the subsequent tempering process.

[0051] In step S9, after the molten salt is homogenized, the heating system of the toughening furnace is turned off and the stirring is stopped, allowing it to cool naturally in the furnace to below 80 °C. The cooling rate needs to be controlled at 3 - 5 °C per minute to avoid stress accumulation or crack formation inside the molten salt due to excessive temperature difference. After cooling, the solidified molten salt is crushed and screened. After removing lumps or impurities, it is filled into a sealed and moisture-proof stainless steel container, and the composition ratio and production batch are marked. The storage environment needs to maintain constant temperature and humidity, with the temperature not exceeding 25 °C and the relative humidity below 30%, to avoid the molten salt from absorbing moisture or undergoing deliquescence reactions, ensuring the chemical activity stability after remelting in subsequent toughening processes.

[0052] Example Two:

[0053] Refer to Figure 1 ,

[0054] A preparation method for a novel ultra-thin glass chemically toughened molten salt includes the following steps:

[0055] The method includes the following steps:

[0056] S1: Determine the composition and ratio range of the molten salt raw materials: potassium nitrate KNO3 70%, silver nitrate AgNO3 18%, lithium nitrate LiNO3 6%, calcium nitrate Ca(NO3)2 3%, strontium nitrate Sr(NO3)2 2%, barium nitrate Ba(NO3)2 1%;

[0057] S2: Accurately weigh the weight percentages of each raw material according to the target ratio;

[0058] S3: Add the weighed raw materials to the mixer in sequence;

[0059] S4: Start the mixer and mix the raw materials at a set speed until the mixing uniformity reaches over 95%;

[0060] S5: Collect the uniformly mixed molten salt and conduct uniformity detection;

[0061] S6: Transfer the mixed salt to the chemical toughening furnace and spread it flat on the bottom of the furnace chamber;

[0062] S7: Start the heating program of the toughening furnace and raise the temperature to 350 °C to completely melt the mixed salt into a liquid state;

[0063] S8: Maintain the molten state for 10 - 20 minutes to ensure uniform distribution of the molten salt components;

[0064] S9: Turn off the heating program, store the molten salt after natural cooling, and use it for the chemical toughening treatment of ultra-thin glass.

[0065] In step S1, use a high-precision electronic balance to weigh each component one by one, and the error needs to be controlled within ±0.1%.

[0066] In step S2, raw materials such as potassium nitrate and silver nitrate need to be pre-dried to remove moisture to avoid generating bubbles or uneven composition during the melting process. The weighing order is recommended to be carried out in descending order of proportion. For example, first weigh potassium nitrate, and then sequentially weigh silver nitrate, lithium nitrate, etc., to reduce the risk of cross-contamination.

[0067] In step S3, the weighed raw materials are put into a double-helix conical mixer and mixed at a speed of 20 - 40 revolutions per minute for 30 - 60 minutes. During the mixing process, samples need to be taken regularly for detection to ensure that the mixing uniformity reaches more than 95%. For raw materials with large particle size differences (such as barium nitrate particles being finer), the mixing time can be extended or a segmented mixing process can be adopted, first rough mixing and then fine mixing, to avoid local agglomeration affecting the final molten salt performance.

[0068] In step S4, a laser particle size analyzer and X-ray fluorescence spectrometry are used to detect the particle size distribution and composition consistency of the mixed salt. If stratification of light components such as silver nitrate or lithium nitrate is detected, it is necessary to put it back into the mixer for supplementary mixing for 10 - 15 minutes. The qualified mixed salt needs to be sealed and stored in a dry environment to prevent moisture absorption and caking, and the storage time should not exceed 48 hours.

[0069] In step S5, the mixed salt is evenly laid at the bottom of a high-temperature resistant alloy crucible in a chemical toughening furnace, and the laying thickness is controlled at 5 - 8 cm. Too thick is likely to cause too large a temperature difference between the bottom and the surface layer, and too thin will reduce the utilization rate of the molten salt. Before loading the furnace, the furnace chamber needs to be cleaned and nitrogen is introduced for protection to prevent the oxidation and decomposition of nitrates during the melting process.

[0070] In step S6, after starting the toughening furnace, the temperature is gradually increased to 300 - 380 °C at a rate of 5 - 8 °C per minute, and the specific temperature is adjusted according to the ratio. For example, the molten salt containing 20% silver nitrate can be set at 340 °C. During the melting stage, the temperature distribution in the crucible needs to be monitored in real time, and the temperature difference is controlled within ±5 °C through a multi-zone heating system to avoid local overheating causing component volatilization or decomposition.

[0071] In step S7, after the molten salt is completely liquefied, the target temperature is maintained and mechanical stirring is continued for 10 - 20 minutes. The stirring speed is set at 50 - 80 revolutions per minute to promote the uniform dispersion of heavy components such as strontium nitrate and barium nitrate. During this stage, the ion concentration of the molten salt needs to be monitored through an on-line conductivity meter. If the fluctuation exceeds 3%, the stirring time is extended to ensure the consistent chemical activity of the molten salt.

[0072] In step S8, after closing the heating system, the temperature of the molten salt is cooled to below 80 °C by natural cooling, and then transferred to a sealed stainless steel container. During the cooling process, vibration or rapid temperature drop needs to be avoided to prevent stress cracks caused by the crystallization of the molten salt. The storage environment temperature needs to be below 25 °C and the relative humidity is below 30% to ensure that the molten salt can be quickly remelted and has stable performance in the subsequent toughening process.

[0073] In step S9, after the molten salt is homogenized, turn off the heating system of the toughening furnace and stop stirring, allowing it to cool naturally in the furnace to below 80°C. The cooling rate needs to be controlled at 3 - 5°C per minute to avoid stress accumulation or crack formation inside the molten salt due to excessive temperature difference. After cooling, the solidified molten salt is crushed and screened. After removing lumps or impurities, it is filled into a sealed and moisture-proof stainless steel container, and the ingredient ratio and production batch are marked. The storage environment needs to maintain constant temperature and humidity, with the temperature not exceeding 25°C and the relative humidity below 30%, to avoid the molten salt from absorbing moisture or undergoing deliquescence reactions, ensuring the chemical activity stability after remelting in subsequent toughening processes.

[0074] Example 3:

[0075] Refer to Figure 1 ,

[0076] A preparation method for a novel chemically toughened molten salt for ultra-thin glass includes the following steps:

[0077] The method includes the following steps:

[0078] S1: Determine the composition and ratio range of the molten salt raw materials: potassium nitrate KNO3 65%, silver nitrate AgNO3 20%, lithium nitrate LiNO3 8%, calcium nitrate Ca(NO3)2 5%, strontium nitrate Sr(NO3)2 1.2%, barium nitrate Ba(NO3)2 0.8%;

[0079] S2: Accurately weigh the weight percentages of each raw material according to the target ratio;

[0080] S3: Add the weighed raw materials to the mixer in sequence;

[0081] S4: Start the mixer and mix the raw materials at a set speed until the mixing uniformity reaches over 95%;

[0082] S5: Collect the uniformly mixed salt and conduct a uniformity test;

[0083] S6: Transfer the mixed salt to the chemical toughening furnace and spread it flat on the bottom of the furnace;

[0084] S7: Start the heating program of the toughening furnace and raise the temperature to 340°C to completely melt the mixed salt into a liquid state;

[0085] S8: Maintain the molten state for 10 - 20 minutes to ensure uniform distribution of the molten salt components;

[0086] S9: Turn off the heating program, store the molten salt after natural cooling, and use it for the chemical toughening treatment of ultra-thin glass.

[0087] In step S1, each component is weighed one by one using a high-precision electronic balance, and the error needs to be controlled within ±0.1%.

[0088] In step S2, raw materials such as potassium nitrate and silver nitrate need to be pre-dried to remove moisture to avoid generating bubbles or uneven composition during the melting process. The weighing order is recommended to be carried out in descending order of proportion. For example, first weigh potassium nitrate, and then successively weigh silver nitrate, lithium nitrate, etc., to reduce the risk of cross-contamination.

[0089] In step S3, the weighed raw materials are put into a double-helix conical mixer and mixed at a speed of 20 - 40 revolutions per minute for 30 - 60 minutes. During the mixing process, samples need to be taken regularly for detection to ensure that the mixing uniformity reaches more than 95%. For raw materials with large particle size differences (such as barium nitrate particles being finer), the mixing time can be extended or a segmented mixing process can be adopted, first rough mixing and then fine mixing, to avoid local agglomeration affecting the final molten salt performance.

[0090] In step S4, a laser particle size analyzer and X-ray fluorescence spectrometry are used to detect the particle size distribution and composition consistency of the mixed salt. If light components such as silver nitrate or lithium nitrate are detected to be stratified, they need to be put back into the mixer for supplementary mixing for 10 - 15 minutes. The qualified mixed salt needs to be sealed and stored in a dry environment to prevent moisture absorption and caking, and the storage time should not exceed 48 hours.

[0091] In step S5, the mixed salt is evenly spread at the bottom of a high-temperature resistant alloy crucible in a chemical tempering furnace, and the paving thickness is controlled at 5 - 8 cm. Being too thick is likely to cause too large a temperature difference between the bottom and the surface layer, while being too thin will reduce the utilization rate of the molten salt. Before loading the furnace, the furnace chamber needs to be cleaned and nitrogen is introduced for protection to prevent the oxidation and decomposition of nitrates during the melting process.

[0092] In step S6, after starting the tempering furnace, the temperature is gradually increased to 300 - 380°C at a rate of 5 - 8°C per minute, and the specific temperature is adjusted according to the ratio. For example, the molten salt containing 20% silver nitrate can be set at 340°C. During the melting stage, the temperature distribution inside the crucible needs to be monitored in real time, and the temperature difference is controlled within ±5°C through a multi-zone heating system to avoid local overheating causing component volatilization or decomposition.

[0093] In step S7, after the molten salt is completely liquefied, the target temperature is maintained and mechanical stirring is continued for 10 - 20 minutes. The stirring speed is set at 50 - 80 revolutions per minute to promote the uniform dispersion of heavy components such as strontium nitrate and barium nitrate. During this stage, the ion concentration of the molten salt needs to be monitored through an on-line conductivity meter. If the fluctuation exceeds 3%, the stirring time is extended to ensure the consistent chemical activity of the molten salt.

[0094] In step S8, after turning off the heating system, the temperature of the molten salt is reduced to below 80°C by natural cooling, and then it is transferred to a sealed stainless-steel container. During the cooling process, vibration or rapid temperature reduction should be avoided to prevent stress cracks caused by the crystallization of the molten salt. The storage environment temperature should be below 25°C and the relative humidity should be below 30% to ensure that the molten salt can be quickly remelted and its performance is stable during the subsequent toughening process.

[0095] In step S9, after the molten salt is homogenized, turn off the heating system of the toughening furnace and stop stirring, and let it cool naturally in the furnace to below 80°C. The cooling rate should be controlled at 3 - 5°C per minute to avoid stress accumulation or crack generation inside the molten salt due to excessive temperature difference. After the cooled solid molten salt is crushed and screened to remove lumps or impurities, it is loaded into a sealed moisture-proof stainless-steel container and marked with the formulation ratio and production batch. The storage environment should be kept at a constant temperature and humidity, with the temperature not higher than 25°C and the relative humidity below 30%, to avoid the molten salt from absorbing moisture or undergoing a deliquescence reaction and ensure the chemical activity stability after remelting during the subsequent toughening process.

[0096] Comparative example: The performance of ultra-thin glass tempered with traditional toughening molten salt (100% potassium nitrate) is compared with that of the glass tempered with the molten salt of the present invention as follows:

[0097] Item Tempering Temperature (°C) Tempering Time (min) Surface Compressive Stress (MPa) Glass Strength (MPa) Traditional Molten Salt 400 60 703 556 Example 1 360 45 762 584 Example 2 350 42 807 603 Example 3 340 38 818 619

[0098] It can be seen from the above that: The toughening molten salts prepared in Examples 1 - 3 of the present invention have significantly reduced toughening temperature, significantly shortened toughening time, and both the surface compressive stress and strength of the glass are higher than those of the comparative example; it shows that the toughening molten salt provided by the present invention has the advantages of low toughening temperature, short toughening time, and good toughening effect, and can effectively improve the strength of ultra-thin glass.

[0099] In the present invention, by adding components such as silver nitrate and lithium nitrate, the melting point of the molten salt is reduced, and the toughening temperature is reduced to below 380°C, effectively reducing the occurrence of deformation of ultra-thin glass. At the same time, by optimizing the composition of the molten salt, the ion exchange rate is increased, the toughening time is shortened, and the production efficiency is improved.

[0100] In the present invention, by optimizing the composition of the molten salt, the toughening temperature is reduced, effectively reducing the energy consumption during toughening. At the same time, by adding components such as silver nitrate, strontium nitrate, and barium nitrate, a denser compressive stress layer is formed on the glass surface, significantly improving the mechanical strength of ultra-thin glass.

[0101] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the said element.

[0102] The above description enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A novel method for preparing ultra-thin glass chemically tempered molten salt, characterized in that: The method comprises the following steps: The method comprises the following steps: S1: Determine the composition and ratio range of the molten salt raw materials: potassium nitrate KNO3 60% ~ 80%, silver nitrate AgNO3 5% ~ 20%, lithium nitrate LiNO3 5% ~ 10%, calcium nitrate Ca(NO3) 22% ~ 5%, strontium nitrate Sr(NO3) 21% ~ 3%, barium nitrate Ba(NO3) 20.5% ~ 2%; S2: According to the target ratio, accurately weigh the weight percentage of each raw material; S3: Add the weighed raw materials into the mixer in sequence; S4: Start the mixer to mix the raw materials at a set speed until the mixing uniformity reaches more than 95%; S5: Collect the uniformly mixed salt and perform uniformity detection; S6: transferring the mixed salt into the chemical tempering furnace and spreading it on the bottom of the furnace; S7: starting the tempering furnace heating program, raising the temperature to 300°C-380°C, so that the mixed salt is completely melted into a liquid state; S8: Maintain the molten state for 10 to 20 minutes to ensure that the molten salt composition is evenly distributed; S9: Turn off the heating program and store the molten salt after it cools naturally for chemical tempering of ultra-thin glass.

2. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In step S1, each component is weighed one by one using a high-precision electronic balance, and the error must be controlled within ±0.1%.

3. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In step S2, the potassium nitrate and silver nitrate raw materials need to be dried in advance to remove moisture to avoid bubbles or uneven composition during the melting process; the weighing order is recommended to be from high to low in terms of proportion.

4. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In the step S3, the weighed raw materials are put into a double-screw cone mixer and mixed at a speed of 20-40 rpm for 30 to 60 minutes. During the mixing process, sampling and testing are required to ensure that the mixing uniformity reaches more than 95%. For raw materials with large differences in particle size, the mixing time can be extended or a segmented mixing process can be adopted, first coarse mixing and then fine mixing, to avoid local agglomeration affecting the final molten salt performance.

5. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In step S4, a laser particle size analyzer and an X-ray fluorescence spectrometer are used to detect the particle distribution and component consistency of the mixed salt; if stratification of light components of silver nitrate or lithium nitrate is detected, the mixed salt needs to be re-added to the mixer for additional mixing for 10 to 15 minutes; the qualified mixed salt needs to be sealed and stored in a dry environment to prevent moisture absorption and agglomeration, and the storage time should not exceed 48 hours.

6. The method for preparing a novel ultra-thin glass chemically tempered molten salt according to claim 1, characterized in that: In step S5, the mixed salt is evenly spread on the bottom of the high-temperature resistant alloy crucible of the chemical tempering furnace, and the thickness of the spread is controlled to be 5-8 cm; too thick a spread may easily lead to a large temperature difference between the bottom and the surface, while too thin a spread may reduce the utilization rate of the molten salt; before loading the furnace, the furnace chamber needs to be cleaned and nitrogen protection is introduced to prevent nitrate oxidation and decomposition during the melting process.

7. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In step S6, after the tempering furnace is started, the temperature is gradually increased to 300-380° C. at a rate of 5-8° C. / min, and the specific temperature is adjusted according to the ratio.

8. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In the step S7, after the molten salt is completely liquefied, the target temperature is maintained and mechanical stirring is continued for 10 to 20 minutes; the stirring speed is set to 50 to 80 rpm to promote uniform dispersion of the heavy components of strontium nitrate and barium nitrate; During this stage, the molten salt ion concentration needs to be monitored by an online conductivity meter. If the fluctuation exceeds 3%, the stirring time is extended to ensure consistent chemical activity of the molten salt.

9. The method for preparing a novel ultra-thin glass chemically tempered molten salt as claimed in claim 1, characterized in that: In step S8, after the heating system is turned off, the molten salt temperature is reduced to below 80° C. by natural cooling, and then transferred to a sealed stainless steel container; vibration or rapid cooling should be avoided during the cooling process to prevent stress cracks caused by crystallization of the molten salt; the storage environment temperature should be lower than 25° C. and the relative humidity should be lower than 30% to ensure that the molten salt can be quickly re-melted and the performance is stable in the subsequent tempering process.

10. The method for preparing a novel ultra-thin glass chemically tempered molten salt according to claim 1, characterized in that: In the step S9, after the molten salt is homogenized, the heating system of the tempering furnace is turned off and the stirring is stopped, so that the molten salt is naturally cooled to below 80°C in the furnace; the cooling rate needs to be controlled at 3-5°C / minute to avoid stress accumulation or cracks in the molten salt due to excessive temperature difference; the cooled solid molten salt is crushed and screened to remove lumps or impurities, and then loaded into a sealed moisture-proof stainless steel container, and the composition ratio and production batch are marked; the storage environment needs to maintain a constant temperature and humidity, with a temperature not higher than 25°C and a relative humidity lower than 30%, to avoid moisture absorption or deliquescence reaction of the molten salt, and to ensure the chemical activity stability after remelting in the subsequent tempering process.

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