A high-temperature resistant and stable tempered glass modification and strengthening process

Abstract

This invention relates to the field of glass surface treatment technology and discloses a high-temperature resistant and stable tempered glass modification and strengthening process. The process includes: cleaning and drying the substrate and immersing it in a treatment solution, followed by baking and curing to form a solid inorganic precursor layer; preheating the initial processed glass; molten potassium nitrate in a bath and adding solid strontium phosphate premixed particles for dispersion, then adding potassium tetraborate and sodium metasilicate to obtain a modified and strengthened molten salt bath; immersing the glass to be strengthened in the salt bath for low-temperature treatment to wet the precursor layer, followed by high-temperature strengthening treatment to allow potassium and sodium ion exchange and enable the precursor layer to participate in surface structure adjustment; after cooling the treatment bath, the glass is pulled out, cooled, cleaned, and dried to obtain the finished product. This invention relies on the precursor layer and modified molten salt to reconstruct the surface network, restricting the thermal migration of modified ions to alleviate compressive stress relaxation, thereby improving the overall quality of the high-temperature resistant and stable tempered glass modification and strengthening process.

Description

Technical Field

[0001] This invention relates to the field of glass surface treatment technology, specifically to a high-temperature resistant and stable tempered glass modification and strengthening process. Background Technology

[0002] Tempered glass is a type of safety glass with a compressive stress layer on its surface. Its overall mechanical properties are primarily improved through modification and strengthening of the substrate. In the manufacturing process of specialty tempered glass for vehicles and ships, as well as laminated glass, deep surface strengthening of the substrate is typically required to meet practical application demands. Furthermore, related strengthening processes are also frequently applied to the surface modification of microcrystalline glass and foam glass.

[0003] In industrial applications, high-alumina silicate glass substrates are typically used as the base material for this type of treatment. These industrial-grade glass substrates contain ion-exchangeable components such as sodium oxide. Traditional modification and strengthening processes primarily involve immersing the glass substrate in a high-temperature molten alkali metal salt bath, utilizing the volume expansion induced by ion exchange to generate surface compressive stress. To obtain high-temperature stable glass products, current processes often directly add multiple active salt components to the salt bath, attempting to reconstruct the shallow surface network of the glass through the simultaneous penetration of multiple ions, thereby maintaining the stress state of the material under heated conditions.

[0004] However, directly mixing multiple active salts in a formulation can easily trigger complex side reactions and precipitate insoluble substances under high-temperature molten conditions. Once these precipitates adhere to the glass substrate surface, they increase light scattering and reduce product transmittance. Simultaneously, the surface network constructed by traditional ion exchange processes has limited binding force on the internal network-modifying ions. In prolonged high-temperature environments, ion thermal migration can easily lead to attenuation and relaxation of surface compressive stress. Furthermore, existing conventional processes typically involve lifting and transferring the substrate across different temperature ranges during transfer; sudden changes in local temperature can easily cause internal thermal stress imbalances, thereby increasing the risk of substrate cracking.

[0005] Therefore, this invention proposes a high-temperature resistant and stable tempered glass modification and strengthening process to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high-temperature resistant and stable tempered glass modification and strengthening process. The technical problem solved by this invention is that when tempered glass is exposed to high-temperature environments for extended periods, the surface compressive stress is prone to attenuation and relaxation, making it difficult to maintain a stable stress state. Furthermore, during the modification and strengthening process, the multi-element molten salt bath easily generates insoluble precipitates that adhere to the glass substrate surface. This typically leads to increased light scattering and decreased light transmittance, severely affecting the optical quality of the final product.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a high-temperature resistant and stable tempered glass modification and strengthening process, which adopts the following technical solution: Clean glass substrate is obtained by cleaning and drying the glass substrate; the clean glass substrate is immersed in an aqueous interface treatment solution, and then lifted, allowed to stand for leveling, and heated and baked to solidify on the surface of the clean glass substrate to form a solid inorganic precursor layer, thus obtaining pre-processed glass; the pre-processed glass is preheated to obtain glass to be strengthened; potassium nitrate is melted into liquid potassium nitrate in a treatment tank, and solid strontium phosphorus premixed particles are added and dispersed in a circulation to obtain a basic molten salt bath; potassium tetraborate and sodium metasilicate are added to the basic molten salt bath to obtain a modified strengthening molten salt bath; the glass to be strengthened is immersed in the modified strengthening molten salt bath, and low-temperature treatment is performed to wet the solid inorganic precursor layer with the modified strengthening molten salt bath, followed by high-temperature strengthening treatment, which allows potassium ions in the modified strengthening molten salt bath to exchange with sodium ions in the glass to be strengthened, and allows the solid inorganic precursor layer to participate in the surface structure adjustment to obtain strengthened glass; the treatment tank containing the strengthened glass is cooled, the strengthened glass is lifted out of the treatment tank, and after cooling, cleaning, and drying, the finished tempered glass is obtained.

[0008] By adopting the above technical solution, an aqueous interface treatment liquid can be dried and cured on the surface of a glass substrate to pre-introduce inorganic components with a specific network structure and form a solid inorganic precursor layer, which usually serves as a transition medium for subsequent ion exchange and interface modification.

[0009] When preparing the molten salt bath, a stepwise feeding method is adopted, in which solid strontium phosphorus premixed particles are dispersed in liquid potassium nitrate and then potassium tetraborate and sodium metasilicate are added. This method can, to a certain extent, slow down the intense contact of various active substances in a short period of time, which helps to inhibit the nucleation and growth of insoluble precipitates, maintain a relatively uniform macroscopic phase of the molten liquid, and thus reduce the light-scattering particles attached to the glass surface during subsequent processing.

[0010] During the strengthening stage, the liquid phase molten salt is used to wet the solid inorganic precursor layer to form a continuous solid-liquid interface by relying on low-temperature treatment. On this basis, the temperature is directly raised to a high temperature for strengthening. The volume displacement between potassium ions and sodium ions can not only generate surface compressive stress, but the components in the precursor layer will also participate in the reconstruction of the glass surface network structure together with the modified ions in the molten salt bath.

[0011] This composite network structure, constructed in situ on the shallow surface of the glass, can limit the migration rate of network-modified ions when exposed to high temperatures, thereby slowing down the relaxation rate of surface compressive stress. Therefore, the method provided in this application helps to obtain finished tempered glass with better surface condition and improved high-temperature stress decay resistance.

[0012] Preferably, the aqueous interface treatment solution is made from raw materials comprising the following parts by weight: deionized water: 100.0 parts, potassium pyrophosphate: 0.5-1.2 parts, potassium aluminate: 0.5-1.5 parts, potassium tetraborate: 1.0-2.5 parts, and alkaline nano silica sol with a silica solid content of 0.5-1.5 parts; and the pH value of the aqueous interface treatment solution is between 10.5 and 11.5.

[0013] By employing the above technical solution, deionized water is used as the dispersion medium, potassium pyrophosphate, potassium aluminate, and potassium tetraborate provide phosphorus-oxygen, aluminum-oxygen, and boron-oxygen structural units, and alkaline nano-silica sol provides the silicon-oxygen framework. Maintaining the pH value between 10.5 and 11.5 primarily aims to maintain the charge balance on the surface of the silica sol particles, thereby reducing the probability of collisional aggregation between colloidal particles and promoting good dispersion of each component in the liquid phase. After baking and curing, this facilitates the formation of an inorganic precursor layer with a certain density and uniform thickness on the glass surface.

[0014] Preferably, the solid strontium phosphate premix granules are made from raw materials comprising the following parts by weight: potassium nitrate: 5.0-15.0 parts, strontium nitrate: 3.0-5.0 parts, and potassium pyrophosphate: 1.5-2.5 parts.

[0015] By employing the above technical solution, potassium nitrate serves as a solid-phase support, physically isolating strontium nitrate and potassium pyrophosphate beforehand. Upon introduction into the main molten salt bath, as the potassium nitrate support melts, strontium nitrate and potassium pyrophosphate are released relatively slowly into the liquid phase. This carrier-like slow-release effect helps reduce the concentration of reactants in localized areas, thereby inhibiting the precipitation of complex phosphate deposits at high temperatures to some extent.

[0016] Preferably, in the step of immersing the clean glass substrate in an aqueous interface treatment solution, the temperature of the aqueous interface treatment solution is 15-25°C, and the immersion time is 5-15 minutes; the step of obtaining the pre-processed glass by lifting, standing, and baking to solidify on the surface of the clean glass substrate to form a solid-phase inorganic precursor layer includes: vertically lifting the clean glass substrate out of the aqueous interface treatment solution and suspending it in the air, then preheating and baking it at 100-120°C for 10-20 minutes, and then heating it to 220-260°C at a heating rate of 1-5°C / min and maintaining the baking for 30-50 minutes, so that the surface of the clean glass substrate is dehydrated and solidified to form the solid-phase inorganic precursor layer, thereby obtaining the pre-processed glass.

[0017] By adopting the above technical solutions, controlling the immersion temperature and time can promote better wetting of the glass surface and adsorption of a certain amount of treatment liquid; after lifting and static leveling, a liquid film with a relatively uniform thickness can usually be formed by relying on the surface tension of the liquid; through gradient heating preheating and high-temperature baking, while removing free water and some structural water, the inorganic components can undergo condensation reaction, so that the precursor layer can achieve a better adhesion effect on the glass surface.

[0018] Preferably, the step of preheating the pre-processed glass to obtain the glass to be strengthened includes: heating the pre-processed glass to 300-330°C at a heating rate of 2-5°C / min and maintaining the temperature for 20-40 minutes to perform deep dehydration and preheating the substrate of the pre-processed glass to obtain the glass to be strengthened.

[0019] By employing the above technical solution, deep dehydration and increased substrate temperature help alleviate residual thermal stress within the glass, while simultaneously enabling a tighter bond between the solid-phase inorganic precursor layer and the glass substrate. The heated glass is then directly immersed in a high-temperature molten salt bath, reducing the temperature gradient at the moment of solid-liquid contact and lowering the risk of thermal cracking of the glass substrate.

[0020] Preferably, the step of melting potassium nitrate into liquid potassium nitrate in the treatment tank and then adding solid strontium phosphorus premixed granules for circulation dispersion to obtain a basic molten salt bath includes: adding 85.0–95.0 parts by weight of potassium nitrate to the treatment tank, heating it to 340–360°C at a heating rate of 1–5°C / min and holding it at that temperature to completely melt the potassium nitrate into liquid potassium nitrate; starting circulation to make the flow rate of the liquid potassium nitrate 0.05–0.30 m / s; and then adding the solid strontium phosphorus premixed granules in batches. The basic molten salt bath is prepared by maintaining a circulating flow and dispersion in liquid potassium nitrate. The step of adding potassium tetraborate and sodium metasilicate to the basic molten salt bath to obtain a modified and strengthened molten salt bath includes: adding 3.0 to 7.0 parts by weight of potassium tetraborate to the basic molten salt bath in batches while maintaining the liquid temperature at 350 to 370°C, circulating the flow, and simultaneously adding 0.5 to 1.2 parts by weight of sodium metasilicate at the same time as the last batch of potassium tetraborate is added, and the circulation continues to obtain the modified and strengthened molten salt bath.

[0021] By adopting the above technical solution, a constant circulating flow rate is set to promote uniform heat and mass transfer in the liquid phase; solid strontium phosphorus premixed particles are added in batches and dispersed in a circulating manner so that the released active ions can obtain better diffusion effect in the liquid phase; potassium tetraborate is added in batches while sodium metasilicate is added simultaneously at a constant liquid temperature. The fluxing and network modification effects of sodium metasilicate can improve the dissolution and dispersion ability of multi-components in potassium nitrate, which is conducive to obtaining a molten liquid phase with better light transmittance and less precipitation.

[0022] Preferably, the step of immersing the glass to be strengthened in the modified strengthening molten salt bath and performing low-temperature treatment to wet the solid-phase inorganic precursor layer includes: treating the glass to be strengthened immersed in the modified strengthening molten salt bath for 1.5 to 2.5 hours at a temperature of 360–380°C and a flow rate of 0.05–0.30 m / s, so that the modified strengthening molten salt bath wets the solid-phase inorganic precursor layer; the subsequent high-temperature strengthening treatment to wet the modified strengthening molten salt bath... The steps for obtaining strengthened glass by exchanging potassium ions in a salt bath with sodium ions in the glass to be strengthened and by having the solid-phase inorganic precursor layer participate in the surface structure adjustment include: after the low-temperature treatment, without lifting the glass to be strengthened, directly heating the treatment tank to 460-480°C at a heating rate of 1-2°C / min and maintaining the treatment for 4.0-6.0 hours, so that potassium ions in the modified strengthening molten salt bath exchange with sodium ions in the glass to be strengthened, and the solid-phase inorganic precursor layer participates in the surface structure adjustment, thereby obtaining the strengthened glass.

[0023] By employing the above technical solution, low-temperature treatment allows the molten salt bath to gradually penetrate into the solid-phase inorganic precursor layer, which helps to remove interfacial microbubbles. Long-term strengthening through a gradual, direct heating rate without pulling not only deepens the ion exchange depth to increase the surface compressive stress and stress layer depth, but also facilitates further cross-linking and fusion of the aluminum oxide, boron oxide, silicon oxide, and phosphorus oxide structural units within the precursor layer with the glass surface network. This in-situ constructed dense layer enhances the glass's resistance to bending fracture and, to some extent, restricts the outward release of internal stress under high-temperature conditions.

[0024] Preferably, the preparation steps of the aqueous interface treatment solution include: adjusting the temperature of the deionized water to 10-20°C, starting stirring, sequentially adding the corresponding weight parts of potassium pyrophosphate, potassium aluminate, and potassium tetraborate, and after the solids are completely dissolved or uniformly mixed, adding the alkaline nano silica sol dropwise and continuing stirring, and finally adjusting the pH value to 10.5-11.5 using potassium hydroxide aqueous solution or dilute phosphoric acid solution, and obtaining the aqueous interface treatment solution by filtration.

[0025] By employing the above technical solution, the initial temperature of deionized water is controlled within a lower range, which helps to mitigate thermal fluctuations and the initial hydrolysis rate during the dissolution of inorganic salts. The sequential addition of solids ensures that each component gradually dissolves and mixes in the liquid phase, reducing the risk of precipitation caused by excessively high local concentrations.

[0026] Adding nano-silica sol dropwise after solid dispersion, along with stirring and targeted pH adjustment, effectively maintains the stability of the colloidal system and prevents early aggregation of silica sol particles. The final filtration process removes any undissolved large particles or impurities, which improves the uniformity and appearance quality of the precursor layer finally coated on the glass surface.

[0027] Preferably, the preparation steps of the solid strontium phosphate premix granules include: heating the potassium nitrate to 400-430°C at a heating rate of 1-5°C / min to melt the potassium nitrate and obtain a liquid potassium nitrate matrix; starting a stirrer at a stirring speed of 100-200 r / min, adding the mixed powder of strontium nitrate and potassium pyrophosphate in batches to the liquid potassium nitrate matrix, and continuing to stir at 400-430°C for 30-45 min after the total amount has been added, to obtain a primary dispersion melt in a solid-liquid mixed state; pouring the primary dispersion melt onto a cooling metal plate to cool and solidify, and then crushing and sieving through an 80-200 mesh standard sieve to obtain the solid strontium phosphate premix granules.

[0028] By employing the above technical solution, using molten potassium nitrate as the fluid matrix and adding the mixed powder in batches with mechanical stirring at an appropriate speed, strontium nitrate and potassium pyrophosphate can be sufficiently dispersed in the liquid phase, while mitigating the agglomeration phenomenon caused by direct contact between the powder and the high-temperature liquid surface. Maintaining stirring at a constant temperature for a prolonged period promotes the formation of a relatively uniform solid-liquid mixture. Subsequently, rapid cooling using a cooling metal plate solidifies and locks in this uniformly dispersed phase structure. After crushing and sieving to a specific mesh size, the particle size distribution range of the premixed particles is standardized. This allows the premixed particles to melt and release their internal active components at a relatively gentle and consistent rate when subsequently added to the main salt bath, further reducing the possibility of drastic fluctuations in local ion concentrations within the main salt bath.

[0029] Preferably, the step of cooling the processing tank containing the tempered glass includes: cooling the processing tank containing the tempered glass to 370-390°C at a cooling rate of 1-3°C / min; the step of lifting the tempered glass out of the processing tank and obtaining finished tempered glass after cooling, cleaning and drying includes: lifting the tempered glass vertically out of the processing tank at a speed of 20-100 mm / min, and naturally cooling it in air until the surface temperature of the tempered glass does not exceed 100°C; immersing the tempered glass in hot deionized water at 80-90°C for 5-15 minutes, ultrasonically cleaning it in a deionized water bath at 20-35°C for 3-10 minutes, and rinsing it with deionized water spray for 1-5 minutes; finally, baking it with hot air at 100-120°C for 10-30 minutes to obtain the finished tempered glass.

[0030] By adopting the above technical solutions, the stepped cooling and low-speed uniform lifting allow the high-temperature salt liquid adhering to the glass surface to flow and drip naturally, thereby reducing the thickness of residual salt on the surface. Natural cooling in the air can reduce the probability of surface micro-cracks caused by rapid cooling. After soaking in hot deionized water, ultrasonic cleaning, and spray rinsing, the residual inorganic salt is removed by using the acoustic cavitation effect and water flow to wash away the residue. Then, the moisture is dried by hot air baking, and finally, a finished tempered glass with good surface smoothness and stable mechanical properties is obtained.

[0031] This invention provides a high-temperature resistant and stable tempered glass modification and strengthening process. It has the following beneficial effects: 1. This invention constructs a solid-phase inorganic precursor layer on the surface of a glass substrate using a curing treatment liquid. This solid-phase inorganic precursor layer participates in the adjustment of the glass surface structure during subsequent strengthening treatments. This composite network helps reduce the thermal migration of modifying ions, thereby mitigating surface compressive stress relaxation. Through this mechanism, the resulting tempered glass exhibits good high-temperature resistance in heated environments, and its internal stress is maintained in a relatively stable state.

[0032] 2. This invention disperses solid strontium phosphate premixed particles in liquid potassium nitrate and adds a co-solvent in stages. The slow-release effect of the solid support in the melt regulates the ion release rate. This staged formulation modification method alleviates the intense contact between components and reduces the probability of insoluble precipitates forming. This helps maintain the uniformity of the salt bath phase and reduces light-scattering particles adhering to the substrate, allowing the finished product to retain good light transmittance and appearance quality.

[0033] 3. This invention employs a method of first wetting at low temperature and then directly heating to perform ion exchange. This allows the liquid-phase molten salt to penetrate the precursor layer and expel interfacial bubbles. In-situ heating without pulling helps maintain a continuous ion exchange process, contributing to increased stress layer depth and bending resistance. This continuous process mitigates sudden temperature changes that may occur during process transitions, reduces the risk of thermal shock breakage, and promotes better deep cross-linking between inorganic components and the substrate network. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the macroscopic physicochemical stability test results of each test object in Test Example 1 of the present invention; wherein, (a) is the initial turbidity test result diagram of each test object; (b) is the kinematic viscosity change rate test result diagram of each test object after standing for 24 hours; Figure 2 This is a graph showing the test results of the mass percentage of molten salt insoluble precipitate for each test object in Test Example 2 of the present invention. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0036] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0037] High-alumina silicate glass substrates are industrial-grade glass substrates containing sodium oxide (Na2O) components that can undergo ion exchange.

[0038] Fatty alcohol polyoxyethylene ether (CAS No.: 68131-39-5) is a non-ionic, commercially available industrial-grade product.

[0039] Potassium pyrophosphate (K4P2O7, CAS No.: 7320-34-5), potassium aluminate (KAlO2), potassium tetraborate (K2B4O7, CAS No.: 1332-77-0), potassium nitrate (KNO3, CAS No.: 7757-79-1), strontium nitrate (Sr(NO3)2, CAS No.: 10042-76-9), and sodium metasilicate (Na2SiO3, CAS No.: 6834-92-0) are all of anhydrous or low water of crystallization grade, industrial or analytical grade.

[0040] The alkaline nano-silica sol used has water as the dispersion medium and amorphous silica (SiO2, CAS No.: 7631-86-9) as the effective solid phase. The initial colloidal particle size of the silica sol is controlled between 10 nm and 20 nm, the initial pH value is between 9.0 and 10.0, the silica solid content is between 25% and 30% (mass fraction), and the water content is between 70% and 75% (mass fraction). The amount of alkaline nano-silica sol added in each preparation example is calculated based on the effective silica solid content.

[0041] Preparation Example 1: This preparation example provides a method for preparing an aqueous phase interface treatment solution, including the following steps: S1. Open the reactor with the circulating cooling jacket, add 100.0 parts by weight of deionized water into the reactor, adjust the liquid temperature in the reactor to 15℃, turn on the stirrer, set the stirring speed to 300r / min, add 0.85 parts by weight of potassium pyrophosphate, and continue stirring for 10min until the solid is completely dissolved to obtain the first clear solution. S2. Maintain the liquid temperature in the reactor at 15℃ and the stirring speed at 300r / min. Add 1.0 part by weight of potassium aluminate to the first clear solution at a uniform rate within 12min. After the addition is completed, continue stirring for 15min to obtain the second mixture. S3. Maintain the liquid temperature in the reactor at 15℃ and the stirring speed at 300r / min. Add 1.75 parts by weight of potassium tetraborate to the second mixture and continue stirring for 15min to obtain the third mixture. S4. Maintain the liquid temperature in the reactor at 15℃ and the stirring speed at 300r / min. Add 1.0 part by weight of alkaline nano silica sol based on the silica solid content to the third mixture over a period of 20min. After the addition is complete, continue stirring for 40min to obtain the fourth mixture. S5. Maintain the liquid temperature in the reactor at 15℃ and the stirring speed at 300r / min. Adjust the pH value of the fourth mixture to 11.0 using potassium hydroxide aqueous solution or dilute phosphoric acid solution. Finally, filter through a 10μm pore size filter to obtain an aqueous interface treatment solution without visible flocculation and sedimentation.

[0042] Preparation Example 2: This preparation example provides a method for preparing an aqueous phase interface treatment solution, the method comprising the following steps: S1. Open the reactor with the circulating cooling jacket, add 100.0 parts by weight of deionized water into the reactor, adjust the liquid temperature in the reactor to 10℃, turn on the stirrer, set the stirring speed to 200r / min, add 0.5 parts by weight of potassium pyrophosphate, and continue stirring for 5min until the solid is completely dissolved to obtain the first clear solution. S2. Maintain the liquid temperature in the reactor at 10℃ and the stirring speed at 200r / min. Add 0.5 parts by weight of potassium aluminate to the first clear solution at a uniform rate within 5 minutes. After the addition is completed, continue stirring for 10 minutes to obtain the second mixture. S3. Maintain the liquid temperature in the reactor at 10℃ and the stirring speed at 200r / min. Add 1.0 part by weight of potassium tetraborate to the second mixture and continue stirring for 10min to obtain the third mixture. S4. Maintain the liquid temperature in the reactor at 10℃ and the stirring speed at 200r / min. Add 0.5 parts by weight of alkaline nano silica sol based on the silica solid content to the third mixture over a period of 10min. After the addition is complete, continue stirring for 20min to obtain the fourth mixture. S5. Maintain the liquid temperature in the reactor at 10℃ and the stirring speed at 200r / min. Adjust the pH of the fourth mixture to 10.5 using potassium hydroxide aqueous solution or dilute phosphoric acid solution. Finally, filter through a 5μm pore size filter to obtain an aqueous interface treatment solution without visible flocculation and sedimentation.

[0043] Preparation Example 3: This preparation example provides a method for preparing an aqueous phase interface treatment solution, the method comprising the following steps: S1. Open the reactor with the circulating cooling jacket, add 100.0 parts by weight of deionized water into the reactor, adjust the liquid temperature in the reactor to 20°C, turn on the stirrer, set the stirring speed to 400 r / min, add 1.2 parts by weight of potassium pyrophosphate, and continue stirring for 15 min until the solid is completely dissolved to obtain the first clear solution. S2. Maintain the liquid temperature in the reactor at 20℃ and the stirring speed at 400r / min. Add 1.5 parts by weight of potassium aluminate to the first clear solution at a uniform rate within 20 minutes. After the addition is completed, continue stirring for 20 minutes to obtain the second mixture. S3. Maintain the liquid temperature in the reactor at 20℃ and the stirring speed at 400r / min. Add 2.5 parts by weight of potassium tetraborate to the second mixture and continue stirring for 20min to obtain the third mixture. S4. Maintain the liquid temperature in the reactor at 20℃ and the stirring speed at 400r / min. Add 1.5 parts by weight of alkaline nano silica sol based on the silica solid content to the third mixture over a period of 30min. After the addition is complete, continue stirring for 60min to obtain the fourth mixture. S5. Maintain the liquid temperature in the reactor at 20℃ and the stirring speed at 400r / min. Adjust the pH value of the fourth mixture to 11.5 using potassium hydroxide aqueous solution or dilute phosphoric acid solution. Finally, filter through a 20μm pore size filter to obtain an aqueous interface treatment solution without visible flocculation and sedimentation.

[0044] Preparation Example 4: This preparation example provides a method for preparing strontium phosphorus premixed granules, the method comprising the following steps: S1. Add 10.0 parts by weight of potassium nitrate carrier to a corrosion-resistant crucible with stirring function, heat to 415°C at a heating rate of 3°C / min, so that the potassium nitrate carrier melts into a liquid state, and maintain the temperature at 415°C for 20 min to obtain liquid potassium nitrate matrix. S2. Start the stirring of the corrosion-resistant crucible and set the stirring speed to 150 r / min. Add the mixed powder of 4.0 parts by weight of strontium nitrate and 2.0 parts by weight of potassium pyrophosphate in 3 batches to the liquid potassium nitrate matrix. Stir for 10 min after each batch is added. After the total amount is added, continue stirring at 415℃ for 38 min to obtain a primary dispersion melt in a solid-liquid mixed state. S3. Pour the primary dispersed melt onto a clean, dry cooling metal plate at 20°C to cool and solidify. Use an oil-free, oxidizing salt-resistant pulverizer to crush the solidified material and pass it through a 150-mesh standard sieve to obtain solid strontium phosphate premixed granules.

[0045] Preparation Example 5: This preparation example provides a method for preparing strontium phosphorus premixed granules, the method comprising the following steps: S1. Add 5.0 parts by weight of potassium nitrate carrier to a corrosion-resistant crucible with stirring function, heat to 400°C at a heating rate of 1°C / min, so that the potassium nitrate carrier melts into a liquid state, and maintain the temperature at 400°C for 10 min to obtain liquid potassium nitrate matrix. S2. Start the stirring of the corrosion-resistant crucible and set the stirring speed to 100 r / min. Add the mixed powder of 3.0 parts by weight of strontium nitrate and 1.5 parts by weight of potassium pyrophosphate in two batches to the liquid potassium nitrate matrix. Stir for 5 min after each batch is added. After the full amount is added, continue stirring at 400℃ for 30 min to obtain a primary dispersion melt in a solid-liquid mixed state. S3. Pour the primary dispersed melt onto a cooling metal plate at 20°C to cool and solidify. Use a pulverizer to crush the solidified material and pass it through an 80-mesh standard sieve to obtain solid strontium phosphate premixed granules.

[0046] Preparation Example 6: This preparation example provides a method for preparing strontium phosphorus premixed granules, the method comprising the following steps: S1. Add 15.0 parts by weight of potassium nitrate carrier to a corrosion-resistant crucible with stirring function, heat to 430°C at a heating rate of 5°C / min, so that the potassium nitrate carrier melts into a liquid state, and maintain the temperature at 430°C for 30 min to obtain liquid potassium nitrate matrix. S2. Start stirring the corrosion-resistant crucible and set the stirring speed to 200 r / min. Add 5.0 parts by weight of strontium nitrate and 2.5 parts by weight of potassium pyrophosphate mixed powder into the liquid potassium nitrate matrix in 5 batches. Stir for 15 min after each batch is added. After the total amount is added, continue stirring at 430℃ for 45 min to obtain a primary dispersion melt in a solid-liquid mixed state. S3. Pour the primary dispersed melt onto a cooling metal plate at 20°C to cool and solidify. Use a pulverizer to crush the solidified material and pass it through a 200-mesh standard sieve to obtain solid strontium phosphate premixed granules. Example 1

[0047] This embodiment provides a high-temperature resistant and stable tempered glass modification and strengthening process, which includes the following steps: S1. Cleaning and drying of glass substrate: A high-aluminosilicate glass substrate measuring 150mm × 75mm × 2.0mm (length × width × thickness) was placed in an ultrasonic cleaning tank. 100.0 parts by weight of deionized water and 0.3 parts by weight of nonionic fatty alcohol polyoxyethylene ether were added to the ultrasonic cleaning tank as a surfactant. The mixture was circulated and stirred evenly to prepare a water-based cleaning solution. The ultrasonic cleaning tank was turned on, the ultrasonic frequency was set to 35kHz, and the temperature of the water-based cleaning solution was maintained at 50℃. The ultrasonic cleaning was performed for 15 minutes. Subsequently, deionized water was used for spray rinsing, with the spray pressure set to 0.25MPa and the spray duration set to 3 minutes. The rinsed glass was then transferred to a hot air circulating oven and baked at 115℃ for 20 minutes to obtain a dry and oil-free clean glass substrate.

[0048] S2. Impregnation with aqueous interface treatment solution and formation of solid-phase inorganic precursor layer: A clean glass substrate was immersed in the aqueous interface treatment solution obtained in Preparation Example 1 at a temperature of 20°C and allowed to stand for 10 minutes. Then, the glass was vertically pulled out of the aqueous interface treatment solution at a uniform lifting speed of 125 mm / min and suspended in an environment at a temperature of 22°C for 3 minutes to allow the liquid film to level. The glass was then transferred to a hot air circulating oven and preheated at 110°C for 15 minutes. It was then transferred to a high-temperature curing oven and heated to 240°C at a heating rate of 3°C / min. The temperature was maintained at 240°C for 40 minutes to remove free water and some structural water, resulting in a pre-processed glass carrying a solid inorganic precursor layer.

[0049] S3. Secondary preheating of glass substrate: The pre-processed glass is transferred into a high-temperature preheating furnace and heated to 315°C at a heating rate of 3°C / min. It is then baked at 315°C for 30 minutes to perform deep dehydration and preheat the substrate, resulting in glass to be strengthened after high-temperature preheating.

[0050] S4. Preparation of basic molten salt bath: Add 90.0 parts by weight of solid potassium nitrate to the molten salt main treatment tank of the chemical tempering furnace, heat to 350°C at a heating rate of 3°C / min, and maintain the temperature at 350°C for 45 min to completely melt it into a liquid state, thus obtaining a liquid potassium nitrate main tank; turn on the circulation pump of the molten salt main treatment tank of the chemical tempering furnace, and set the flow rate of liquid potassium nitrate to 0.15 m / s; divide the solid strontium phosphorus premixed particles obtained in Preparation Example 4 into 4 batches and add them to the liquid potassium nitrate main tank. After each batch is added, maintain the circulation flow for 15 min, and after the entire batch is added, maintain the temperature at 350°C and continue to circulate for 45 min to obtain a basic molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits.

[0051] S5. Final modified and strengthened molten salt bath preparation and two-stage strengthening treatment: The temperature of the molten salt main treatment tank in the chemical tempering furnace was maintained at 360℃. 5.0 parts by weight of potassium tetraborate solid powder sieved through a 150-mesh sieve was added to the basic molten salt bath in three batches. After each batch was added, the bath was kept circulating for 15 minutes. At the same time as the last batch of potassium tetraborate solid was added, 1.0 parts by weight of sodium metasilicate solid was added simultaneously. After the addition, the bath was kept at 360℃ and continued to circulate for 45 minutes to obtain the final modified and strengthened molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits. The glass to be strengthened obtained in S3 was immersed in the final modified strengthening molten salt bath, and the temperature of the main molten salt treatment tank was maintained at 370℃, the salt bath flow rate was 0.15m / s, and the treatment was carried out for 2.0h to wet the precursor layer with salt bath, thus obtaining glass after the first stage of low temperature interface treatment; then, without lifting the glass, the main molten salt treatment tank was directly heated to 470℃ at a heating rate of 1.5℃ / min, and the treatment was carried out at 470℃ for 5.0h to obtain glass that has completed high temperature synergistic strengthening.

[0052] S6. Stepped cooling, unloading, cleaning and drying: The molten salt main treatment tank containing the glass that has undergone high-temperature synergistic strengthening is cooled to 380°C at a cooling rate of 2°C / min. Then, the glass is lifted vertically out of the molten salt main treatment tank at a uniform speed of 60mm / min and suspended in room temperature air to cool naturally until the glass surface temperature does not exceed 100°C. The glass is then immersed in hot deionized water at 85°C for 10 minutes. It is then transferred to an ultrasonic cleaning tank containing deionized water at 27°C and cleaned at an ultrasonic frequency of 35kHz for 6 minutes. Deionized water is then sprayed at a pressure of 0.25MPa for 3 minutes. Finally, it is purged and baked with a hot air knife at 110°C for 20 minutes to obtain high-temperature resistant and stable finished tempered glass. Example 2

[0053] This embodiment provides a high-temperature resistant and stable tempered glass modification and strengthening process, which includes the following steps: S1. Place a high-aluminosilicate glass sheet with dimensions of 150mm × 75mm × 2.0mm (length × width × thickness) into an ultrasonic cleaning tank. Add 100.0 parts by weight of deionized water and 0.1 parts by weight of nonionic fatty alcohol polyoxyethylene ether as a surfactant to the ultrasonic cleaning tank. Circulate and stir evenly to prepare a water-based cleaning solution. Turn on the ultrasonic cleaning tank, set the ultrasonic frequency to 25kHz, maintain the water-based cleaning solution temperature at 40℃, and ultrasonically clean for 10 minutes. Then, use deionized water for spray rinsing, setting the spray pressure to 0.1MPa and the spray duration to 1 minute. Transfer the rinsed glass to a hot air circulating oven and bake at 100℃ for 15 minutes to obtain a dry, oil-free, and clean glass substrate.

[0054] S2. Immerse a clean glass substrate in the aqueous interface treatment solution obtained in Preparation Example 2 at a temperature of 15°C and let it stand for 5 minutes. Then, lift the glass vertically out of the aqueous interface treatment solution at a uniform lifting speed of 50 mm / min and hang it in an environment at a temperature of 15°C for 1 minute to allow the liquid film to level. Transfer the glass to a hot air circulating oven and preheat it at 100°C for 10 minutes. Then transfer it to a high temperature curing oven and heat it to 220°C at a heating rate of 1°C / min. Maintain the temperature at 220°C for 30 minutes to obtain a pre-processed glass carrying a solid inorganic precursor layer.

[0055] S3. Transfer the pre-processed glass into a high-temperature preheating furnace and heat it to 300°C at a heating rate of 2°C / min. Maintain the temperature at 300°C for 20 minutes to obtain the glass to be strengthened after high-temperature preheating.

[0056] S4. Add 95.0 parts by weight of solid potassium nitrate to the molten salt main treatment tank of the chemical tempering furnace, heat to 340°C at a heating rate of 1°C / min, and maintain the temperature at 340°C for 30 min to completely melt it into a liquid state, thus obtaining a liquid potassium nitrate main tank; turn on the circulation pump of the molten salt main treatment tank of the chemical tempering furnace, and set the flow rate of liquid potassium nitrate to 0.05 m / s; divide the solid strontium phosphorus premixed particles obtained in Preparation Example 5 into 3 batches and add them to the liquid potassium nitrate main tank. After each batch is added, maintain the circulation flow for 10 min. After the entire batch is added, maintain the temperature at 340°C and continue to circulate for 30 min to obtain a basic molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits.

[0057] S5. Maintain the temperature of the molten salt main treatment tank of the chemical tempering furnace at 350℃. Add 3.0 parts by weight of potassium tetraborate solid powder sieved through an 80-mesh sieve in two batches to the basic molten salt bath. After each batch is added, keep the bath circulating for 10 minutes. At the same time as the last batch of potassium tetraborate solid is added, add 0.5 parts by weight of sodium metasilicate solid. After adding, keep the bath circulating at 350℃ for 30 minutes to obtain the final modified and strengthened molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits. The glass to be strengthened obtained from S3 was immersed in a final modified strengthening molten salt bath with macroscopically uniform dispersion and no visible coarse hard deposits. The temperature of the main molten salt treatment tank was maintained at 360℃, the salt bath flow rate was 0.05m / s, and the treatment was carried out for 1.5h to obtain glass that had undergone the first stage of low-temperature interface treatment. Subsequently, without lifting the glass, the main molten salt treatment tank was directly heated to 460℃ at a heating rate of 1℃ / min and maintained at 460℃ for 4.0h to obtain glass that had completed high-temperature synergistic strengthening.

[0058] S6. Cool the molten salt main treatment tank containing the glass that has undergone high-temperature synergistic strengthening to 370°C at a cooling rate of 1°C / min; then lift the glass vertically out of the molten salt main treatment tank at a uniform speed of 20mm / min, and suspend it in room temperature air to cool naturally until the glass surface temperature does not exceed 100°C; immerse the glass in hot deionized water at 80°C for 5 minutes; transfer it to an ultrasonic cleaning tank containing deionized water at 20°C and clean it for 3 minutes at an ultrasonic frequency of 25kHz; spray it with deionized water at a spray pressure of 0.1MPa for 1 minute; finally, bake it in a hot air circulating oven at 100°C for 10 minutes to obtain high-temperature resistant and stable finished tempered glass. Example 3

[0059] This embodiment provides a high-temperature resistant and stable tempered glass modification and strengthening process, which includes the following steps: S1. Place a high-aluminosilicate glass sheet with dimensions of 150mm × 75mm × 2.0mm (length × width × thickness) into an ultrasonic cleaning tank. Add 100.0 parts by weight of deionized water and 0.5 parts by weight of nonionic fatty alcohol polyoxyethylene ether as a surfactant to the ultrasonic cleaning tank. Circulate and stir evenly to prepare a water-based cleaning solution. Turn on the ultrasonic cleaning tank, set the ultrasonic frequency to 45kHz, maintain the water-based cleaning solution temperature at 60℃, and ultrasonically clean for 20 minutes. Then, use deionized water for spray rinsing, setting the spray pressure to 0.4MPa and the spray duration to 5 minutes. Transfer the rinsed glass to a hot air circulating oven and bake at 130℃ for 30 minutes to obtain a dry, oil-free, and clean glass substrate.

[0060] S2. Immerse a clean glass substrate in the aqueous interface treatment solution obtained in Preparation Example 3 at a temperature of 25°C and let it stand for 15 minutes. Then, lift the glass vertically out of the aqueous interface treatment solution at a uniform lifting speed of 200 mm / min and hang it in an environment at a temperature of 30°C for 5 minutes to allow the liquid film to level. Transfer the glass to a hot air circulating oven and preheat it at 120°C for 20 minutes. Then transfer it to a high temperature curing oven and heat it to 260°C at a heating rate of 5°C / min. Maintain the temperature at 260°C for 50 minutes to obtain a pre-processed glass carrying a solid inorganic precursor layer.

[0061] S3. Transfer the pre-processed glass into a high-temperature preheating furnace and heat it to 330°C at a heating rate of 5°C / min. Maintain the temperature at 330°C for 40 minutes to obtain the glass to be strengthened after high-temperature preheating.

[0062] S4. Add 85.0 parts by weight of solid potassium nitrate to the molten salt main treatment tank of the chemical tempering furnace, heat it to 360°C at a heating rate of 5°C / min, and maintain the temperature at 360°C for 60 min to completely melt it into a liquid state, thus obtaining a liquid potassium nitrate main tank; turn on the circulation pump of the molten salt main treatment tank of the chemical tempering furnace, and set the flow rate of liquid potassium nitrate to 0.30 m / s; divide the solid strontium phosphorus premixed particles obtained in Preparation Example 6 into 5 batches and add them to the liquid potassium nitrate main tank. After each batch is added, maintain the circulation flow for 20 min, and after the entire batch is added, maintain the temperature at 360°C and continue to circulate for 60 min to obtain a basic molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits.

[0063] S5. Maintain the temperature of the molten salt main treatment tank of the chemical tempering furnace at 370℃. Add 7.0 parts by weight of potassium tetraborate solid powder sieved through a 200-mesh sieve into the basic molten salt bath in 4 batches. After each batch is added, keep the bath circulating for 20 minutes. At the same time as the last batch of potassium tetraborate solid is added, add 1.2 parts by weight of sodium metasilicate solid. After adding, keep the bath at 370℃ and continue to circulate for 60 minutes to obtain the final modified and strengthened molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits. The glass to be strengthened obtained from S3 was immersed in a final modified strengthening molten salt bath with uniform macroscopic dispersion and no visible coarse hard deposits. The temperature of the main molten salt treatment tank was maintained at 380℃ and the salt bath flow rate was 0.30m / s for 2.5h to obtain glass that had undergone the first stage of low-temperature interface treatment. Subsequently, without lifting the glass, the main molten salt treatment tank was directly heated to 480℃ at a heating rate of 2℃ / min and maintained at 480℃ for 6.0h to obtain glass that had completed high-temperature synergistic strengthening.

[0064] S6. Cool the molten salt main treatment tank containing the glass that has undergone high-temperature synergistic strengthening to 390°C at a cooling rate of 3°C / min; then lift the glass vertically out of the molten salt main treatment tank at a uniform speed of 100mm / min, and suspend it in room temperature air to cool naturally until the glass surface temperature does not exceed 100°C; immerse the glass in hot deionized water at 90°C for 15 minutes; transfer it to an ultrasonic cleaning tank containing deionized water at 35°C, and clean it for 10 minutes at an ultrasonic frequency of 45kHz; spray it with deionized water at a spray pressure of 0.4MPa for 5 minutes; finally, blow and bake it with a hot air knife at 120°C for 30 minutes to obtain high-temperature resistant and stable finished tempered glass.

[0065] Comparative Example 1: Compared with Example 1, the difference lies in the change of the inorganic salt feeding method in steps 4 and 5: Instead of adding solid strontium phosphate premixed granules in four batches in step 4, and adding potassium tetraborate solid powder and sodium metasilicate solid in three batches in step 5, 100.0 parts by weight of potassium nitrate solid is added to the molten salt main treatment tank in step 4. After the potassium nitrate is completely melted into a liquid state at 350°C, 4.0 parts by weight of strontium nitrate, 2.0 parts by weight of potassium pyrophosphate, 5.0 parts by weight of potassium tetraborate solid powder, and 1.0 parts by weight of sodium metasilicate solid, equivalent to the total amount used in Example 1, are all added at once to the liquid potassium nitrate main tank. No solid materials are added in step 5; the rest are the same.

[0066] Comparative Example 2: The difference compared to Example 1 is that step 2 in Example 1 has been completely removed: Furthermore, the action "moving the pre-processed glass into the high-temperature preheating furnace" in step 3 is replaced with "directly moving the clean glass substrate obtained in step 1 into the high-temperature preheating furnace"; the rest are the same.

[0067] Comparative Example 3: Compared to Example 1, the difference lies in the change of the temperature control parameters after glass immersion in step 5: Replace the following in step 5: “Maintain the temperature of the molten salt main treatment tank at 370℃, the salt bath flow rate at 0.15m / s, and treat for 2.0h…then, without lifting the glass, directly heat the molten salt main treatment tank to 470℃ at a heating rate of 1.5℃ / min, and maintain the temperature at 470℃ for 5.0h” with: “After immersing the glass to be strengthened obtained in step 3 into the final modified and strengthened molten salt bath, instead of performing the first stage low-temperature interface treatment at 370℃, directly heat the molten salt main treatment tank to 470℃ at a heating rate of 1.5℃ / min, and maintain the temperature at 470℃ for 7.0h”; the rest remains the same.

[0068] Comparative Example 4: The difference compared to Example 1 is that the stability control conditions of the aqueous phase interface treatment solution used in step 2 were changed: Replace the action in step 2, "immerse the clean glass substrate in the aqueous interface treatment solution obtained in Preparation Example 1 at a temperature of 20°C", with "immerse the clean glass substrate in the comparative mixed colloidal treatment solution at a temperature of 25°C without pH adjustment"; the rest are the same.

[0069] In the comparative mixed colloidal treatment solution, the component amounts were exactly the same as in preparation example 1. However, the liquid phase temperature was maintained at room temperature of 25°C throughout the preparation process, and no potassium hydroxide aqueous solution or dilute phosphoric acid solution was used for pH adjustment in the final stage of preparation. This allowed the treatment solution to maintain the natural pH state of the mixed components (the pH value under this natural mixed state is below 10.5).

[0070] Test Example 1: Experimental steps: 1. Extract the aqueous phase interface treatment solutions obtained from Preparation Example 1, Preparation Example 2, and Preparation Example 3, as well as the comparative mixed colloidal treatment solution obtained from Comparative Example 4, as test objects. Measure 500 mL of each of the above test objects and transfer them into clean, dry stoppered glass reagent bottles.

[0071] 2. Take 10 mL of the newly prepared test sample from each glass reagent bottle and inject it into a cuvette. Use a turbidity meter to measure the turbidity of the liquid phase at 25°C. Test each sample in parallel three times and take the arithmetic mean as the initial turbidity test value of the test object. Record the unit as NTU.

[0072] 3. Take 15 mL of each of the newly prepared test samples from each glass reagent bottle and place them in a 20℃ constant temperature water bath. Use an Ubbelohde capillary viscometer to test the fluid viscosity. Record the time it takes for the liquid to flow through the capillary and convert the result to obtain the initial kinematic viscosity of the test sample. The unit is recorded as mm. 2 / s.

[0073] 4. Seal the glass reagent bottle containing the remaining test sample with the original stopper and place it in a constant temperature and light-proof test chamber at 25℃ for 24 hours. After the standing time, extract each group of samples without shaking the reagent bottle and place them again in a constant temperature water bath at 20℃. Measure the kinematic viscosity of the test sample after 24 hours of standing using an Ubbelohde capillary viscometer. Record the unit as mm. 2 / s.

[0074] 5. According to the formula: kinematic viscosity change rate = (kinematic viscosity after standing for 24 hours - initial kinematic viscosity) / initial kinematic viscosity × 100%, the kinematic viscosity change rate of each test object is calculated respectively.

[0075] Experimental results (see Table 1): Table 1: Macroscopic Physicochemical Stability Test Data

[0076] Test conclusion: According to Table 1 and Figure 1 As shown, the initial turbidity values ​​of the aqueous interface treatment solutions obtained in Preparation Examples 1 to 3 were in the range of 2.62 NTU to 4.87 NTU, and the kinematic viscosity change rate after standing for 24 hours was less than 4.0%. The initial turbidity value of the comparative mixed colloidal treatment solution obtained in Comparative Example 4 reached 86.73 NTU, and the kinematic viscosity change rate after standing for 24 hours reached 72.32%, both of which were higher than those of Preparation Examples 1 to 3.

[0077] The treatment solution involved in this invention contains a multi-element inorganic salt and silica sol, and the system has a high ionic strength. In Preparation Examples 1 to 3, the preparation temperature was controlled within the range of 10°C to 20°C, which helps to reduce the collision frequency between colloidal particles; at the same time, an alkaline solution was used to adjust the pH value to the range of 10.5 to 11.5, which helps to maintain the charge stability of the silica sol particle surface.

[0078] Comparative Example 4, prepared at 25°C without pH adjustment, exhibited higher initial turbidity and a larger rate of change in kinematic viscosity under these test conditions. This indicates that the system is more prone to particle aggregation, flocculation, or viscosity increase during settling. The test results demonstrate that the temperature control and pH adjustment techniques used in the preparation example are beneficial for improving the dispersion stability of the blend system, thereby facilitating uniform coating and stable use of the treated solution in subsequent glass substrate impregnation processes.

[0079] Test Example 2: Experimental steps: 1. The final modified and strengthened molten salt baths obtained in Examples 1, 2, and 3, as well as the molten salt bath obtained in Comparative Example 1, were extracted as test objects.

[0080] 2. Maintain the working temperature of the molten salt main treatment tank where each test object is located. Use a stainless steel sampler to take samples from different depths of the molten salt main treatment tank corresponding to each test object and mix them. Use an analytical balance to accurately weigh the mixed high-temperature liquid salt bath and record the weighing value as the initial high-temperature liquid salt bath sample mass of each test object.

[0081] 3. Transfer the weighed initial high-temperature liquid salt bath samples into a heat-preheated filtration device at 380°C. This device contains a high-temperature porous ceramic filter element with a known initial mass and a pore size of 0.5 μm. Turn on the filtration device to allow the high-temperature liquid salt bath to pass through the porous ceramic filter element, trapping insoluble solids in the liquid salt bath.

[0082] 4. After filtration, cool the porous ceramic filter element with the adhering solid residue to room temperature. Rinse the porous ceramic filter element and the surface residue with 80℃ hot deionized water until the conductivity of the collected eluent is below 5μS / cm. Transfer the porous ceramic filter element to a drying oven at 150℃ and dry it at a constant temperature for 24 hours. Then, remove it and cool it to room temperature in a desiccator.

[0083] 5. Using an analytical balance, the dried porous ceramic filter element and the surface insoluble solids were weighed separately. The total mass obtained was subtracted from the initial mass of the corresponding porous ceramic filter element to obtain the mass of the insoluble precipitate of the test object. According to the formula: Mass percentage of molten salt insoluble precipitate = (Mass of insoluble precipitate / Initial high-temperature liquid salt bath sample mass) × 100%, the mass percentage of molten salt insoluble precipitate in Examples 1, 2, 3, and Comparative Example 1 was calculated respectively.

[0084] Experimental results (see Table 2): Table 2: Test data on macroscopic phase stability and precipitation amount

[0085] Test conclusion: According to Table 2 and Figure 2 As shown, the final modified and strengthened molten salt baths prepared in Examples 1, 2, and 3 had a molten salt insoluble precipitate mass ratio ranging from 0.086% to 0.154%; the molten salt bath prepared in Comparative Example 1 had a molten salt insoluble precipitate mass ratio of 2.856%. Under the test conditions, the insoluble precipitate mass ratio of Comparative Example 1 was higher than that of Examples 1 to 3.

[0086] In Comparative Example 1, strontium nitrate, potassium pyrophosphate, potassium tetraborate, and sodium metasilicate were added to the main tank of liquid potassium nitrate in a one-time centralized feeding method. This may cause the concentration of relevant ions in a local area to increase in a short period of time, thereby making it easier for insoluble substances to form and precipitate.

[0087] In Examples 1, 2, and 3, strontium nitrate and potassium pyrophosphate were first premixed using a potassium nitrate carrier to form solid strontium phosphate premixed particles, which were then added in batches to the liquid potassium nitrate main tank in subsequent processes. Simultaneously, potassium tetraborate and sodium metasilicate were added to the molten salt bath in a later stage. This operation method helps reduce the probability of multiple active components coming into contact with large quantities simultaneously in a localized area.

[0088] Under the test conditions, the batch feeding and delayed feeding processes showed a lower mass ratio of insoluble precipitates, indicating that these process conditions are beneficial to reducing the formation of insoluble precipitates in the molten salt bath and to maintaining the phase stability of the molten salt bath during the treatment process.

[0089] Test Example 3: Experimental steps: 1. The final tempered glass products obtained in Examples 1, 2, 3, and Comparative Example 1 were extracted as test objects. Five samples were taken from each example and comparative example, and this number was recorded as the number of single test samples for each test object. The surface of each sample in each test object was wiped with a lint-free cloth soaked in anhydrous ethanol and placed at 25°C to air dry for later use.

[0090] 2. The visible light transmittance of each test object was tested using a transmittance meter in the wavelength range of 380nm to 780nm. For each sample, five different locations were selected at the center and four corners of its surface to measure and record the transmittance values. The arithmetic mean of these five values ​​was calculated as the single-piece transmittance of the sample. Subsequently, the arithmetic mean of the single-piece transmittance of the five samples in each group was calculated, and the result was recorded as the average visible light transmittance of the corresponding test object, with the unit recorded as .

[0091] 3. The surface light scattering degree of each test object is measured using a haze meter. For each sample, five different locations are selected at the center and four corners of the surface to measure and record the haze values. The arithmetic mean of these five values ​​is calculated as the haze value of a single sample. Subsequently, the arithmetic mean of the haze values ​​of the five samples in each group is calculated, and the result is recorded as the average haze value of the corresponding test object, with the unit recorded as .

[0092] Experimental results (see Table 3): Table 3: Optical and surface quality test data of the strengthened glass

[0093] Test conclusion: According to the data in Table 3, the final tempered glass products obtained in Examples 1, 2, and 3 have an average visible light transmittance ranging from 91.25% to 91.68% and an average haze value ranging from 0.12% to 0.21%. The tempered glass obtained in Comparative Example 1 has an average visible light transmittance of 87.32% and an average haze value of 2.45%. Under the test conditions, the average visible light transmittance of the glass obtained in Examples 1 to 3 is higher than that of Comparative Example 1, and the average haze value is lower than that of Comparative Example 1.

[0094] Comparative Example 1 used a one-time centralized feeding method during the molten salt bath preparation process, resulting in a relatively high content of insoluble precipitates inside the molten salt bath. During the glass immersion strengthening stage, these insoluble precipitates may adhere to the surface of the glass substrate, potentially affecting the smoothness and optical uniformity of the glass surface. Incident light undergoes diffuse reflection and scattering in areas with surface particle adhesion or localized roughness, which may lead to a decrease in visible light transmittance and an increase in haze.

[0095] Examples 1, 2, and 3 involve pre-applying a solid-phase inorganic precursor layer to the glass surface via aqueous immersion. This precursor layer, after subsequent fixation and molten salt treatment, did not significantly affect the glass's light transmittance. Furthermore, the batch-feeding and delayed-time feeding operations during the molten salt bath preparation stage helped reduce the formation of insoluble precipitates in the molten salt bath. Test results show that this combined process helps reduce the adhesion of solid particles to the glass surface and helps maintain the optical transmittance and surface condition of the strengthened finished glass.

[0096] Test Example 4: Experimental steps: 1. The final tempered glass products obtained from Examples 1, 2, and 3, as well as Comparative Examples 2 and 3, were extracted as test objects. Ten samples were randomly selected from each test object, and this number was recorded as the sample quantity for each test object. Each sample from each test object was ultrasonically cleaned for 5 minutes using anhydrous ethanol, and then placed in a drying oven at 60°C for later use.

[0097] 2. The surface compressive stress and stress layer depth of each test object were tested using a surface stress tester based on the photoelastic principle. For each sample, the tester prism was attached to the sample surface using a refractive index matching liquid. Five test points were selected in the center and four corners of the sample surface. The interference fringe spacing and critical angle detected by the instrument were read. The surface compressive stress value and stress layer depth value of each test point were obtained by conversion. The arithmetic mean of the values ​​at these 5 test points is calculated and used as the single-piece surface compressive stress and single-piece stress layer depth of the sample. Subsequently, the arithmetic mean of the single-piece surface compressive stress and the arithmetic mean of the single-piece stress layer depth are calculated for the corresponding 10 samples in each test object. The results are recorded as the surface compressive stress of the test object in MPa and the stress layer depth in μm, respectively.

[0098] 3. Use a material testing machine to perform four-point bending strength tests on each test object. For each sample, place it flat on the support span of the test fixture, set the lower support roller distance to 60mm and the upper loading roller distance to 20mm; control the loading head to apply the load downward at a constant displacement rate of 2mm / min, and record the maximum load value at the moment the sample breaks.

[0099] According to the formula: Four-point bending strength = (3 × maximum load × (lower support roller distance - upper loading roller distance)) / (2 × sample width × sample thickness squared), the single-piece four-point bending strength of the sample is calculated. Then, the arithmetic mean of the single-piece four-point bending strength of the corresponding 10 samples in each test object is calculated, and the result is recorded as the four-point bending strength of the corresponding test object, and the unit is recorded as MPa.

[0100] Experimental results (see Table 4): Table 4: Test data of basic mechanical properties and surface stress at room temperature

[0101] Test conclusion: According to the data in Table 4, the surface compressive stress of the tempered glass obtained in Examples 1, 2 and 3 was measured to be in the range of 843.7 MPa to 884.1 MPa, the stress layer depth was in the range of 46.9 μm to 51.3 μm, and the four-point bending strength was in the range of 718.9 MPa to 752.3 MPa.

[0102] The tempered glass obtained in Comparative Example 2 had a surface compressive stress of 635.8 MPa and a four-point bending strength of 524.1 MPa; the tempered glass obtained in Comparative Example 3 had a surface compressive stress of 712.5 MPa and a four-point bending strength of 611.8 MPa. Under the test conditions, the surface compressive stress, stress layer depth, and four-point bending strength of the tempered glass obtained in Examples 1 to 3 were all higher than those in Comparative Example 2 and Comparative Example 3.

[0103] Comparative Example 2 did not undergo aqueous precursor layer impregnation treatment, and a solid-phase inorganic precursor layer containing aluminum oxide, boron oxide, silicon oxide, and phosphorus oxide structural units was not pre-formed on the glass surface. This is detrimental to the formation of the shallow surface composite interface structure during subsequent molten salt treatment, resulting in lower surface compressive stress and four-point bending strength values. Comparative Example 3 omitted the first-stage low-temperature wetting process, leaving the glass with the pre-formed precursor layer without a process of smooth contact and interface bonding with the molten salt components at a lower temperature. This may affect the continuity of the shallow surface structure and the stress formation effect during the subsequent high-temperature strengthening process.

[0104] Examples 1, 2, and 3 involve pre-depositing a solid-phase inorganic precursor layer on the glass substrate surface through immersion in an aqueous treatment solution. Combined with the low-temperature wetting transition in the first stage of the strengthening process, this facilitates a more continuous interfacial contact between the glass surface and the molten salt components. In the second stage of high-temperature strengthening, K... + / Na +Ion exchange and shallow surface composite interface structure adjustment were carried out simultaneously. Test results show that the combination of precursor layer pretreatment and two-stage temperature-controlled strengthening is beneficial to increasing the stress layer depth of the glass surface and improving the bending fracture resistance of the finished glass.

[0105] Test Example 5: Experimental steps: 1. Ten finished tempered glass samples from Examples 1, 2, and 3, and Comparative Examples 2 and 3, were extracted as test objects for this test example, and the number was recorded as the sample quantity for each test object. The surface compressive stress values ​​measured for each test object in Test Example 4 were recorded as the initial surface compressive stress of each test object, with the unit recorded as MPa.

[0106] 2. Place each sample from each test subject in a high-temperature environment chamber, set the ambient temperature to 400℃, and keep it at that temperature for 50 hours. After the temperature is maintained, remove all samples from each test subject and allow them to cool naturally at room temperature.

[0107] 3. Surface compressive stress tests were performed on each cooled test object using a surface stress tester based on the photoelastic principle. For each sample, a refractive index matching liquid was used to attach the tester prism to the sample surface. Five test points were selected in the center and four corner areas of the sample surface, and the interference fringe spacing and critical angle were read. The surface compressive stress values ​​of each test point after 50 hours of high-temperature storage were obtained after conversion. The arithmetic mean of the values ​​of these five test points was calculated as the single-piece surface compressive stress of the sample after 50 hours of high-temperature storage.

[0108] Subsequently, the arithmetic mean of the surface compressive stress of each of the 10 samples in each test object after 50 hours of high-temperature storage was calculated, and the result was recorded as the surface compressive stress of the test object after 50 hours of high-temperature storage, with the unit recorded as MPa.

[0109] 4. Based on the formula: High temperature stress retention rate = (Surface compressive stress after 50 hours of high temperature storage / Initial surface compressive stress) × 100%, the high temperature stress retention rates of Examples 1, 2, and 3, as well as Comparative Examples 2 and 3, were calculated respectively.

[0110] Experimental results (see Table 5): Table 5: Test data on stress relaxation performance under high temperature storage

[0111] Test conclusion: According to the data in Table 5, the high-temperature stress retention rates of the tempered glass obtained in Examples 1, 2, and 3, after being kept at 400℃ for 50 hours, ranged from 92.70% to 94.10%. The high-temperature stress retention rate of the tempered glass obtained in Comparative Example 2 was 61.69%, and that of the tempered glass obtained in Comparative Example 3 was 71.80%. Under these test conditions, the high-temperature stress retention rates of the tempered glass obtained in Examples 1 to 3 were higher than those in Comparative Examples 2 and 3.

[0112] Comparative Example 2 lacked an aqueous precursor layer, and the glass surface layer did not pre-introduce aluminum oxide, boron oxide, silicon oxide, and phosphorus oxide structural units, which was detrimental to the formation of a composite shallow interface structure. As a result, the surface compressive stress value decreased relatively significantly after high-temperature storage. Comparative Example 3 lacked a first-stage low-temperature transition wetting process. The glass with a pre-placed precursor layer lacked a process of gradual contact and interface bonding with the molten salt components at lower temperatures, which was detrimental to the continuous formation of the shallow composite structure. Its high-temperature stress retention rate was lower than that of Examples 1 to 3.

[0113] Examples 1, 2, and 3 combine aqueous phase treatment with a two-stage temperature control process to create a composite interface structure involving multiple inorganic structural units on the shallow surface of the glass during molten salt treatment. This composite interface structure may help improve the stability of the glass surface structure under high-temperature environments and reduce the attenuation trend of surface compressive stress during high-temperature storage. Test results show that this combined process condition is beneficial for improving the stress relaxation performance of the finished glass in high-temperature environments and for maintaining the stability of surface compressive stress under high-temperature conditions.

[0114] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-temperature resistant and stable tempered glass modification and strengthening process, characterized in that, include: Cleaning and drying the glass substrate yields a clean glass substrate; The clean glass substrate is immersed in an aqueous interface treatment solution, and after being lifted, allowed to stand and leveled and heated and baked, a solid inorganic precursor layer is formed on the surface of the clean glass substrate to obtain the initial processed glass. The pre-processed glass is preheated to obtain the glass to be strengthened; Potassium nitrate is melted into liquid potassium nitrate in a treatment tank, and then solid strontium phosphorus premixed particles are added and dispersed in a circulating manner to obtain a basic molten salt bath; Potassium tetraborate and sodium metasilicate are added to the basic molten salt bath to obtain a modified and enhanced molten salt bath; The glass to be strengthened is immersed in the modified strengthening molten salt bath, and the modified strengthening molten salt bath is used to wet the solid inorganic precursor layer. Then, the glass is strengthened at high temperature, so that the potassium ions in the modified strengthening molten salt bath exchange with the sodium ions in the glass to be strengthened, and the solid inorganic precursor layer participates in the surface structure adjustment to obtain strengthened glass. The processing tank containing the tempered glass is cooled down, the tempered glass is lifted out of the processing tank, and the finished tempered glass is obtained after cooling, cleaning and drying.

2. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, The aqueous interface treatment solution is made from the following raw materials in parts by weight: deionized water: 100.0 parts, potassium pyrophosphate: 0.5-1.2 parts, potassium aluminate: 0.5-1.5 parts, potassium tetraborate: 1.0-2.5 parts, and alkaline nano silica sol in parts by weight based on silica solid content; and the pH value of the aqueous interface treatment solution is between 10.5 and 11.

5.

3. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, The solid strontium phosphate premix granules are made from raw materials comprising the following parts by weight: potassium nitrate: 5.0-15.0 parts, strontium nitrate: 3.0-5.0 parts, and potassium pyrophosphate: 1.5-2.5 parts.

4. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, In the step of immersing the clean glass substrate in an aqueous interface treatment solution, the temperature of the aqueous interface treatment solution is 15-25°C and the immersion time is 5-15 minutes. The steps of obtaining pre-processed glass by lifting, standing, and baking to solidify a solid-phase inorganic precursor layer on the surface of the clean glass substrate include: vertically lifting the clean glass substrate out of the aqueous interface treatment liquid and suspending it in the air for standing; then preheating and baking it at 100-120°C for 10-20 minutes; then heating it to 220-260°C at a heating rate of 1-5°C / min and maintaining the baking temperature for 30-50 minutes, so that the surface of the clean glass substrate is dehydrated and solidified to form the solid-phase inorganic precursor layer, thereby obtaining the pre-processed glass.

5. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, The step of preheating the pre-processed glass to obtain the glass to be strengthened includes: heating the pre-processed glass to 300-330°C at a heating rate of 2-5°C / min and maintaining the temperature for 20-40 minutes to perform deep dehydration and preheating the substrate of the pre-processed glass to obtain the glass to be strengthened.

6. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, The step of melting potassium nitrate into liquid potassium nitrate in a treatment tank and then adding solid strontium phosphorus premixed particles for circulation dispersion to obtain a basic molten salt bath includes: adding 85.0 to 95.0 parts by weight of potassium nitrate to the treatment tank, heating it to 340 to 360°C at a heating rate of 1 to 5°C / min and holding it at that temperature to completely melt the potassium nitrate into liquid potassium nitrate; starting circulation to make the flow rate of the liquid potassium nitrate 0.05 to 0.30 m / s; and then adding the solid strontium phosphorus premixed particles in batches to the liquid potassium nitrate to maintain circulation and dispersion, thereby obtaining the basic molten salt bath. The step of adding potassium tetraborate and sodium metasilicate to the basic molten salt bath to obtain a modified and strengthened molten salt bath includes: under the condition of maintaining the liquid temperature at 350-370°C, adding 3.0-7.0 parts by weight of potassium tetraborate in batches to the basic molten salt bath and circulating it, and simultaneously adding 0.5-1.2 parts by weight of sodium metasilicate at the same time as the last batch of potassium tetraborate is added, and continuing to circulate to obtain the modified and strengthened molten salt bath.

7. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, The step of immersing the glass to be strengthened in the modified strengthening molten salt bath and treating it at low temperature to wet the solid inorganic precursor layer includes: treating the glass to be strengthened immersed in the modified strengthening molten salt bath for 1.5 to 2.5 hours under the conditions of a temperature of 360 to 380°C and a flow rate of 0.05 to 0.30 m / s in the modified strengthening molten salt bath, so that the modified strengthening molten salt bath wets the solid inorganic precursor layer; The subsequent high-temperature strengthening treatment, which involves the exchange of potassium ions in the modified strengthening molten salt bath with sodium ions in the glass to be strengthened, and the participation of the solid-phase inorganic precursor layer in surface structure adjustment to obtain strengthened glass, includes the following steps: after the low-temperature treatment, without lifting the glass to be strengthened, directly heating the treatment tank to 460-480°C at a heating rate of 1-2°C / min and maintaining the temperature for 4.0-6.0 hours, so that the potassium ions in the modified strengthening molten salt bath exchange with the sodium ions in the glass to be strengthened, and the participation of the solid-phase inorganic precursor layer in surface structure adjustment to obtain the strengthened glass.

8. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 2, characterized in that, The preparation steps of the aqueous interface treatment solution include: adjusting the temperature of the deionized water to 10-20°C, starting the stirring, adding the corresponding weight parts of potassium pyrophosphate, potassium aluminate and potassium tetraborate in sequence, and after the solids are completely dissolved or uniformly mixed, adding the alkaline nano silica sol dropwise and continuing to stir, finally adjusting the pH value to 10.5-11.5 with potassium hydroxide aqueous solution or dilute phosphoric acid solution, and obtaining the aqueous interface treatment solution by filtration.

9. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 3, characterized in that, The preparation steps of the solid strontium phosphate premix granules include: heating the potassium nitrate to 400-430°C at a heating rate of 1-5°C / min to melt the potassium nitrate and obtain a liquid potassium nitrate matrix; starting a stirrer at a stirring speed of 100-200 r / min, adding the mixed powder of strontium nitrate and potassium pyrophosphate in batches to the liquid potassium nitrate matrix, and continuing to stir at 400-430°C for 30-45 min after the total amount has been added to obtain a primary dispersion melt in a solid-liquid mixed state; pouring the primary dispersion melt onto a cooling metal plate to cool and solidify, and then crushing and sieving through an 80-200 mesh standard sieve to obtain the solid strontium phosphate premix granules.

10. The high-temperature resistant and stable tempered glass modification and strengthening process according to claim 1, characterized in that, The step of cooling the processing tank containing the tempered glass includes: cooling the processing tank containing the tempered glass to 370-390°C at a cooling rate of 1-3°C / min. The steps of lifting the tempered glass out of the processing tank, cooling, cleaning, and drying to obtain the finished tempered glass include: lifting the tempered glass vertically out of the processing tank at a speed of 20-100 mm / min, and naturally cooling it in air until the surface temperature of the tempered glass does not exceed 100°C; immersing the tempered glass in hot deionized water at 80-90°C for 5-15 minutes, ultrasonically cleaning it in a deionized water bath at 20-35°C for 3-10 minutes, and rinsing it with deionized water spray for 1-5 minutes; and finally baking it with hot air at 100-120°C for 10-30 minutes to obtain the finished tempered glass.

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