A method of chemically strengthening a glass container

Abstract

The application belongs to the technical field of glass and relates to a chemical strengthening method of a glass container. + The application relates to a chemical strengthening method of a glass container, the material of the glass container is silicate glass containing exchangeable Na, and the method comprises the following steps: adding potassium nitrate and kaolin into deionized water, heating and fully stirring to dissolve and disperse to form a coating solution, spraying the coating solution to the surface of the glass container, and performing high-temperature heat treatment to form an ion exchange strengthening layer and chemically strengthen the glass container; the temperature of the high-temperature heat treatment is 430-450 DEG C; in the coating solution, the mass fraction of the potassium nitrate is 19.5%-29.3%, and the mass fraction of the kaolin is 22%-31.7%. The method adopts the synergistic strengthening mechanism of the kaolin-KNO3 composite system, and the anti-falling performance of the glass container subjected to the chemical strengthening treatment is obviously improved compared with that of common glass containers.

Description

Technical Field

[0001] This invention belongs to the field of glass technology and relates to a chemical strengthening method for glass containers. Background Technology

[0002] Glass containers, with their excellent optical transparency, aesthetics, and chemical stability, occupy an important position in the packaging of food and beverages, pharmaceuticals, and cosmetics. However, traditional glass containers suffer from insufficient surface strength and poor abrasion resistance, making them prone to surface scratches and even breakage during practical use. Especially in applications requiring high mechanical strength, such as transportation and machining, the impact resistance of ordinary glass containers often falls short of the demands.

[0003] Chemical strengthening of glass containers, particularly through ion exchange technology, can significantly improve various surface properties, such as surface strength and abrasion resistance. However, traditional ion exchange processes are limited by the hollow structure of the glass container, making it prone to buoyancy in the molten salt bath. This results in some areas not being fully submerged, affecting the uniformity of ion exchange. To prevent the glass container from floating, additional fixing devices must be used to ensure its submersion in the molten salt. Moreover, these fixing devices apply localized stress to the glass surface, which can introduce internal defects into the glass and reduce the mechanical strength of the glass container.

[0004] The literature (Strengthening of a soda-lime-silica glass by ion exchange using an adherent potassium salt coating, Glass Technology: European Journal of Glass Science and Technology Part A 57 (2016) 6-14.) proposes a novel method for ion exchange strengthening of soda-lime-silica glass based on an adherent potassium salt coating. The key to this method is that during heat treatment, the pre-coated potassium salt layer firmly adheres to the glass surface, thus forming a stable potassium-sodium ion exchange source. To achieve this, the literature employs a special suspension system containing a thermally stable and chemically inert binder. This system not only precisely controls the coating viscosity but also effectively prevents liquid potassium nitrate from flowing during high-temperature treatment. Currently, the application of this spraying technology in room-temperature processing environments has not been studied.

[0005] Therefore, it is of great significance to study a chemical strengthening method for glass containers in order to solve the problems existing in the prior art. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art and provide a chemical strengthening method for glass containers.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A chemical strengthening method for a glass container, wherein the glass container is made of exchangeable Na. + For silicate glass, potassium nitrate (KNO3) and kaolin (Al2Si2O5(OH)4) are added to deionized water, heated and stirred to fully dissolve and disperse to form a coating solution. The coating solution is then sprayed onto the surface (including the bottom) of the glass container. After high-temperature heat treatment, an ion exchange strengthening layer is formed, which chemically strengthens the glass container.

[0009] The high-temperature heat treatment temperature is 430~450℃;

[0010] In the coating solution, the mass fraction of potassium nitrate is 19.5%~29.3%, and the mass fraction of kaolin is 22%~31.7%.

[0011] Since the spraying process is carried out at room temperature (25±2℃), the solubility characteristics of potassium nitrate (KNO3) become a key limiting factor: the solubility of potassium nitrate at room temperature is approximately 38 g / 100 mL H2O, and its dissolution process is endothermic, resulting in the actual amount dissolved being significantly affected by ambient temperature. Low potassium nitrate content leads to incomplete ion exchange reactions, insufficient surface compressive stress layer thickness, and a lack of significant improvement in the impact resistance of the glass container. Excessive concentration causes undissolved KNO3 particles exceeding the solubility limit to easily deposit, potentially clogging the spray nozzle and affecting spray uniformity. Kaolin, as the carrier of potassium nitrate, requires strict content control. Too low a content results in an excessively thin coating that is prone to peeling, and potassium nitrate is easily melted and lost at high temperatures, reducing ion exchange efficiency. Too high a content significantly increases solution viscosity, leading to poor atomization and deterioration of spray quality.

[0012] As a preferred technical solution:

[0013] A chemical strengthening method for a glass container as described above, containing exchangeable Na + The silicate glass is either soda-lime glass or borosilicate glass.

[0014] The chemical strengthening method for a glass container as described above includes the following specific steps:

[0015] Step 1: Add potassium nitrate and kaolin to deionized water, heat and stir to fully dissolve and disperse to form a coating solution;

[0016] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container;

[0017] Step 3: Transfer the coated glass container to an oven and dry the moisture in the coating at 60~80℃. The drying temperature and time should be adjusted according to the characteristics of the coating and the material of the glass container to ensure that the moisture in the coating evaporates completely and to avoid damage to the coating on the surface of the glass container.

[0018] Step 4: Place the dried glass container in a box furnace and heat it to 430~450℃ at a heating rate of 10℃ / min, and keep it at that temperature for 4~8 hours. Then remove the glass container and let it cool to room temperature in the air.

[0019] Glass containers treated with a spray coating process require a high-temperature heat treatment stage for chemical strengthening. High-temperature heat treatment is a crucial step in the chemical strengthening process of glass containers. At room temperature, the Na in the glass network structure... + It has extremely low ion migration activity, but high-temperature heat treatment can significantly enhance the ion migration of Na. + Its diffusion ability promotes its migration from the interior of the glass to the surface, interacting with K in the molten salt coating. + A displacement reaction occurs. When the K ion has a larger radius... + (0.138nm) Replaces Na + When the crystal is at a lattice position of 0.102 nm, local lattice expansion is induced on the glass surface. This expansion effect is strongly constrained by the underlying glass substrate, which has not undergone ion exchange, thus forming a compressive stress layer on the surface. This unique "external pressure and internal tension" stress structure not only effectively resists impact but also inhibits the initiation and propagation of cracks, significantly reducing the risk of breakage during use.

[0020] Step 5: Use deionized water to ultrasonically clean the surface of the glass container to remove the coating material (mainly kaolin and potassium nitrate) that did not participate in the reaction to form the ion exchange strengthening layer. Then, dry the ultrasonically cleaned glass container.

[0021] In the chemical strengthening method for a glass container as described above, the heating temperature in step 1 is 40~50℃ and the stirring speed is 200~300r / min.

[0022] In the chemical strengthening method for glass containers described above, in step 2, the air spray gun pressure is 0.4~0.5MPa, the spraying distance is 20~30cm, and the spraying flow rate is 100~200mL / min. During the spraying process, the spray gun pressure, spraying distance, and spraying flow rate are controlled to ensure that the uniformity and thickness of the coating meet the requirements.

[0023] In the chemical strengthening method for glass containers described above, the thickness of the coating formed on the glass surface after spraying is 100~300μm.

[0024] In the chemical strengthening method for a glass container as described above, the drying time in step 3 is 20-30 minutes.

[0025] In the chemical strengthening method for a glass container described above, the ultrasonic cleaning in step 5 has a power of 480W and a time of 10~20min.

[0026] In the chemical strengthening method for a glass container as described above, the drying temperature in step 5 is 60~80℃ and the time is 20~30min.

[0027] Invention principle:

[0028] This invention relates to a glass surface strengthening method based on a potassium nitrate-kaolin composite system. The core of this technology lies in the synergistic strengthening mechanism generated by the composite system: First, the layered silicate structure of kaolin effectively coats potassium nitrate, and its unique interlayer channels not only provide K... + The directional diffusion provides a transport path and can also suppress the flow and loss of potassium nitrate melt at high temperatures (430~450℃), ensuring the stability of the ion exchange process; secondly, the porous structure of kaolinite has excellent K... + The sustained-release function can continuously release Na from the glass surface. + -K + Ion exchange reaction provides a potassium ion source, thereby forming a reinforcing layer with excellent mechanical properties on the glass surface. Experimental data show that glass containers treated using the method of this invention exhibit significantly improved drop resistance compared to untreated samples. This composite system successfully solves the technical problems of molten salt loss and uneven strengthening inherent in single KNO3 systems by organically combining the physical confinement effect of kaolinite with the chemical strengthening function of potassium nitrate.

[0029] However, coating systems prepared using materials such as corundum powder, potassium silicate, and diatomaceous earth have significant technical limitations, leading to the following key defects in their application:

[0030] First, during the coating solution preparation stage, because these materials lack stable interlayer fixation, the prepared suspension is prone to stratification upon standing. This physical instability directly causes uneven distribution of components in the coating solution, severely affecting the stability of subsequent high-temperature heat treatment.

[0031] Secondly, the resulting coatings often exhibit significant structural defects, including: excessively high microporosity, leading to insufficient coating density; poor thickness uniformity, affecting the overall consistency of the coating; and low interfacial bonding strength, easily causing coating peeling. These structural defects ultimately hinder the K+ process during ion exchange. + The effective utilization rate is significantly reduced, and the surface strength of the glass container cannot be effectively enhanced.

[0032] Beneficial effects:

[0033] (1) A chemical strengthening method for a glass container according to the present invention employs a synergistic strengthening mechanism of a kaolin-KNO3 composite system. The interlayer structure of kaolin can effectively coat and fix the KNO3 melt, inhibiting the loss of KNO3 during high-temperature treatment; KNO3 dissociates at high temperature to generate K + It can diffuse directionally along the interlayer channels of kaolinite and react with Na on the surface of the glass matrix. + A displacement reaction occurs, forming an ion exchange strengthening layer that strengthens the glass container.

[0034] (2) A chemical strengthening method for glass containers according to the present invention, the spraying method directly sprays the coating solution onto the surface of the glass container, avoiding the problem of the glass container floating in molten salt, without the need for additional fixing devices, simplifying the process flow, and making the operation more efficient and convenient.

[0035] (3) A chemical strengthening method for glass containers according to the present invention, wherein the glass containers subjected to chemical strengthening treatment have significantly improved drop resistance compared with ordinary glass containers.

[0036] (4) The present invention provides a chemical strengthening method for glass containers. By systematically optimizing the potassium nitrate concentration and kaolin content parameters, a highly efficient spray coating process suitable for room temperature environments has been successfully developed. Experiments show that the composite coating prepared by this process exhibits a significant performance enhancement effect after high-temperature heat treatment. Specifically, the present invention has achieved the following breakthroughs: a room temperature spray coating process window based on the solubility characteristics of potassium nitrate has been established; a kaolin-potassium nitrate composite formulation suitable for coating the surface of glass containers has been developed; and the structural strengthening effect of subsequent heat treatment on the room temperature spray coating has been confirmed, providing an energy-saving and efficient room temperature spray coating solution for the surface modification of glass containers. Detailed Implementation

[0037] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] The glass container in this embodiment of the invention is a common glass baby bottle made of borosilicate glass. Its specific chemical composition and mass percentage are as follows: silicon dioxide (SiO2): 75%, boron trioxide (B2O3): 10.5%, aluminum oxide (Al2O3): 5%, sodium oxide (Na2O): 7%, calcium oxide (CaO): 1.5%, and other trace components: 1%. The bottle height is 135±1mm, empty bottle weight is 180±2g, capacity is 240mL, bottle mouth inner diameter is 42±1mm, bottle body diameter is 60±2mm, bottle body wall thickness is 2.2±0.1mm, and bottle bottom wall thickness is 3.5±0.2mm.

[0039] It should be noted that the embodiments of the present invention use borosilicate glass with the above-mentioned composition as an example for illustration, but this should not be construed as a limitation on the scope of protection of the present invention. Theoretically, all materials containing exchangeable Na... + Containers made of silicate glass, when treated with the chemical strengthening method of this invention, can achieve the claimed effects and are all within the protection scope of this invention.

[0040] The testing methods involved in the performance indicators of this invention are as follows:

[0041] Overall Drop Performance Test: To verify the overall drop performance of ordinary glass baby bottles and the chemically strengthened glass baby bottles of this invention, an overall drop performance test was conducted according to the national standard GB 38995-2020. Under normal temperature and pressure, the sample was filled with room temperature water of the nominal volume. The sample was then dropped freely onto the impact surface of the test platform from a specified height above the impact surface, following the test sequence. The height test for ordinary glass baby bottles started at a height of (30±2cm), while the test for chemically strengthened glass baby bottles started at a height of (70±2cm). The impact surface consisted of a 5mm thick vinyl polymer sheet, which was fixed on a floor tile with an area of ​​at least 0.25m². 2 .

[0042] The first step is the vertical drop test: Place the assembled glass bottle sample on the clamp of the drop tester, ensuring the sample is stable. Adjust the drop tester to bring the glass bottle sample to the set drop height. Release the glass bottle, allowing it to fall freely vertically onto the drop surface.

[0043] The second step is the parallel drop test: Adjust the glass bottle sample to a horizontal position, ensuring that the sample's center of gravity is parallel to the drop surface. Release the sample and allow it to fall freely onto the drop surface.

[0044] Finally, the 45° drop test is performed: the glass bottle sample is adjusted to a 45° angle with the drop surface, ensuring that the sample's center of gravity passes through the drop point at that angle. The sample is then released to fall freely onto the drop surface.

[0045] Check the integrity of the glass baby bottle after the drop, record the damage, and determine whether the glass baby bottle meets the national standard requirements based on the degree of damage.

[0046] The kaolin used in this invention has a purity of not less than 99.7% (analytical grade, AR grade) and a powder particle fineness of 1250 mesh.

[0047] The potassium nitrate used in this invention is of the following type and specification: AR (Shanghai Test), with a purity of ≥99.0%, and manufactured by Sinopharm Chemical Reagent Co., Ltd.

[0048] Example 1

[0049] A chemical strengthening method for a glass container made of borosilicate glass, comprising the following steps:

[0050] Step 1: Add potassium nitrate and kaolin to deionized water, heat at 40°C and stir to fully dissolve and disperse to form a coating solution;

[0051] The stirring speed was 250 r / min; the coating solution contained 22% potassium nitrate and 29.2% kaolin.

[0052] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container. After spraying, the thickness of the coating formed on the glass surface is 233μm.

[0053] The air spray gun has a pressure of 0.4 MPa, a spraying distance of 22 cm, and a spraying flow rate of 125 mL / min.

[0054] Step 3: Transfer the coated glass container to an oven and dry at 70°C for 24 minutes;

[0055] Step 4: Place the dried glass container in a box furnace and heat it to 450°C at a heating rate of 10°C / min, and keep it at that temperature for 4 hours. Then remove the glass container and let it cool to room temperature in the air.

[0056] Step 5: Ultrasonically clean the surface of the glass container with deionized water at a power of 480W for 14 minutes, and then dry the ultrasonically cleaned glass container at a temperature of 65°C for 20 minutes.

[0057] The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1.

[0058] Comparative Example 1

[0059] A method for strengthening a glass container is basically the same as in Example 1, except that the glass container is a regular glass baby bottle, i.e., it has not undergone chemical strengthening treatment. The overall drop performance test results of the glass container are shown in Table 1.

[0060] Comparing Comparative Example 1 and Example 1, it can be found that the drop resistance of the untreated glass baby bottle in Comparative Example 1 does not exceed 60cm. This is because the chemical strengthening process forms a protective compressive stress layer on the glass surface through ion exchange. This structure effectively improves the mechanical strength of the glass, inhibits crack propagation, and enhances impact resistance, thereby preventing brittle fracture. In contrast, the untreated glass in Comparative Example 1 lacks this crucial protective structure, resulting in significantly inferior overall performance.

[0061] Comparative Example 2

[0062] A chemical strengthening method for glass containers is basically the same as in Example 1, except that: kaolin is not added in step 1, and the mass fraction of potassium nitrate in the coating solution is 51.2%.

[0063] Comparative Example 3

[0064] A chemical strengthening method for glass containers is basically the same as in Example 1, except that potassium nitrate is not added in step 1, and the mass fraction of kaolin in the coating solution is 51.2%.

[0065] The overall drop performance test results of the chemically strengthened glass containers of Comparative Example 2 and Comparative Example 3 are shown in Table 1.

[0066] Comparative Examples 2, 3, and 1 were compared. Comparative Example 2 investigated the effects of heat treatment on the performance of glass containers using potassium nitrate alone, and Comparative Example 3 investigated the effects of heat treatment on the coating changes during the heat treatment process using kaolin alone. When a single potassium nitrate solution (Comparative Example 2) was used for spraying, the significant fluidity of molten potassium nitrate during high-temperature treatment made it difficult for the effective components to adhere stably to the glass substrate surface, resulting in reduced ion exchange efficiency and failure to achieve the expected strengthening effect. If kaolin alone (Comparative Example 3) was used as the coating material, it was prone to structural stress cracks under high-temperature conditions. This structural defect not only damaged the integrity of the coating but also significantly reduced the interfacial bonding strength between the coating and the glass substrate. Therefore, it was concluded that a single modification method failed to overcome the existing performance bottlenecks, and a composite treatment process was necessary.

[0067] Comparative Example 4

[0068] A chemical strengthening method for glass containers is basically the same as in Example 1, except that in step 1, 29.2% of kaolin is replaced by 8.8% corundum powder, 8.8% potassium silicate and 11.6% diatomaceous earth (refer to patent CN103896498A).

[0069] Comparative Example 5

[0070] A chemical strengthening method for glass containers is basically the same as in Example 1, except that in step 1, 7.3% corundum powder, 7.3% potassium silicate and 14.6% diatomaceous earth are used to replace 29.2% kaolin (refer to patent CN103896498A).

[0071] The overall drop performance test results of the chemically strengthened glass containers of Comparative Example 4 and Comparative Example 5 are shown in Table 1.

[0072] Comparing Comparative Examples 4, 5 and 1, it can be found that Comparative Examples 4 and 5 modified the spraying system with diatomaceous earth and corundum powder, but the performance indicators of the glass baby bottle were not significantly improved. Through experimental verification and theoretical analysis, the technical defects mainly stem from the following two aspects: (1) The coating solution doped with diatomaceous earth and corundum powder exhibits stratification when left to stand, affecting the uniformity of the coating composition and seriously affecting the uniformity of ion exchange; (2) The interfacial bonding strength between the modified coating and the glass substrate is insufficient, resulting in poor coating adhesion performance and significantly reducing ion exchange efficiency.

[0073] Comparative Example 6

[0074] A chemical strengthening method for glass containers is basically the same as in Example 1, except that the mass fraction of potassium nitrate in the coating solution in step 1 is 14.6% and the mass fraction of kaolin is 36.6%.

[0075] The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1.

[0076] Comparing Comparative Example 6 with Example 1, it can be found that Comparative Example 6 has poor drop resistance. This is because the potassium nitrate content in the coating directly affects the ion exchange efficiency. The amount of potassium nitrate added in Comparative Example 6 is insufficient. When the potassium ion concentration reaches the optimized value, the compressive stress level of the glass surface can be significantly improved, thereby improving its mechanical properties.

[0077] Comparative Example 7

[0078] A chemical strengthening method for glass containers is basically the same as in Example 1, except that the mass fraction of potassium nitrate in the coating solution in step 1 is 31.7% and the mass fraction of kaolin is 19.5%.

[0079] The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1.

[0080] Comparing Comparative Example 7 with Example 1, it can be found that Comparative Example 7 has poor drop resistance. This is because the kaolin content in the coating is significantly correlated with the coating performance. When the amount of kaolin added is insufficient, the resulting coating thickness is too thin (only 80 μm), which makes it difficult to effectively block the flow of molten potassium nitrate during high-temperature treatment, resulting in a decrease in the uniformity of coating coverage and thus affecting the stability of ion exchange.

[0081] Example 2

[0082] A chemical strengthening method for a glass container made of borosilicate glass, comprising the following steps:

[0083] Step 1: Add potassium nitrate and kaolin to deionized water, heat at 50°C and stir to fully dissolve and disperse to form a coating solution;

[0084] The stirring speed was 300 r / min; the coating solution contained 22% potassium nitrate and 29.2% kaolin.

[0085] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container. After spraying, the coating thickness on the glass surface is 252μm.

[0086] The air spray gun has a pressure of 0.45 MPa, a spraying distance of 24 cm, and a spraying flow rate of 175 mL / min.

[0087] Step 3: Transfer the coated glass container to an oven and dry at 70°C for 28 minutes;

[0088] Step 4: Place the dried glass container in a box furnace and heat it to 430°C at a heating rate of 10°C / min, and keep it at that temperature for 4 hours. Then remove the glass container and let it cool to room temperature in the air.

[0089] Step 5: Ultrasonically clean the surface of the glass container with deionized water at a power of 480W for 18 minutes, and then dry the ultrasonically cleaned glass container at a temperature of 75°C for 28 minutes.

[0090] Example 3

[0091] A chemical strengthening method for a glass container made of borosilicate glass, comprising the following steps:

[0092] Step 1: Add potassium nitrate and kaolin to deionized water, heat at 45°C and stir to fully dissolve and disperse to form a coating solution;

[0093] The stirring speed was 250 r / min; the coating solution contained 22% potassium nitrate and 29.2% kaolin.

[0094] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container. After spraying, the thickness of the coating formed on the glass surface is 246μm.

[0095] The air spray gun has a pressure of 0.45 MPa, a spraying distance of 26 cm, and a spraying flow rate of 150 mL / min.

[0096] Step 3: Transfer the coated glass container to an oven and dry at 75°C for 26 minutes;

[0097] Step 4: Place the dried glass container in a box furnace and heat it to 450°C at a heating rate of 10°C / min, and keep it at that temperature for 8 hours. Then remove the glass container and let it cool to room temperature in the air.

[0098] Step 5: Ultrasonically clean the surface of the glass container with deionized water at a power of 480W for 16 minutes, and then dry the ultrasonically cleaned glass container at a temperature of 70°C for 24 minutes.

[0099] Examples 2 and 3 investigated the control of heat treatment temperature and time parameters on the ion exchange effect. The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1. The experimental results show that: (1) When the heat treatment temperature is appropriately reduced, although the ion exchange kinetic rate slows down, it is conducive to forming a more gradual stress distribution. This optimized stress field structure can significantly improve the mechanical strength characteristics of glass products; (2) Extending the heat treatment time will cause the compressive stress on the glass surface to relax, resulting in a synchronous decrease in the stress layer depth and surface stress value, thereby weakening the drop resistance of the sample.

[0100] Example 4

[0101] A chemical strengthening method for a glass container made of borosilicate glass, comprising the following steps:

[0102] Step 1: Add potassium nitrate and kaolin to deionized water, heat at 40°C and stir to fully dissolve and disperse to form a coating solution;

[0103] The stirring speed was 200 r / min; the coating solution contained 19.5% potassium nitrate and 22% kaolin.

[0104] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container. After spraying, the thickness of the coating formed on the glass surface is 178μm.

[0105] The air spray gun has a pressure of 0.4 MPa, a spraying distance of 20 cm, and a spraying flow rate of 100 mL / min.

[0106] Step 3: Transfer the coated glass container to an oven and dry it at 60°C for 20 minutes;

[0107] Step 4: Place the dried glass container in a box furnace and heat it to 450°C at a heating rate of 10°C / min, and keep it at that temperature for 4 hours. Then remove the glass container and let it cool to room temperature in the air.

[0108] Step 5: Ultrasonically clean the surface of the glass container with deionized water at a power of 480W for 10 minutes, and then dry the ultrasonically cleaned glass container at a temperature of 60°C for 22 minutes.

[0109] The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1.

[0110] Example 5

[0111] A chemical strengthening method for a glass container made of borosilicate glass, comprising the following steps:

[0112] Step 1: Add potassium nitrate and kaolin to deionized water, heat at 50°C and stir to fully dissolve and disperse to form a coating solution;

[0113] The stirring speed was 250 r / min; the coating solution contained 29.3% potassium nitrate and 24% kaolin.

[0114] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container. After spraying, the thickness of the coating formed on the glass surface is 213μm.

[0115] The air spray gun has a pressure of 0.45 MPa, a spraying distance of 26 cm, and a spraying flow rate of 150 mL / min.

[0116] Step 3: Transfer the coated glass container to an oven and dry at 70°C for 24 minutes;

[0117] Step 4: Place the dried glass container in a box furnace and heat it to 450°C at a heating rate of 10°C / min, and keep it at that temperature for 4 hours. Then remove the glass container and let it cool to room temperature in the air.

[0118] Step 5: Ultrasonically clean the surface of the glass container with deionized water at a power of 480W for 15 minutes, and then dry the ultrasonically cleaned glass container at a temperature of 70°C for 25 minutes.

[0119] The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1.

[0120] Example 6

[0121] A chemical strengthening method for a glass container made of borosilicate glass, comprising the following steps:

[0122] Step 1: Add potassium nitrate and kaolin to deionized water, heat at 45°C and stir to fully dissolve and disperse to form a coating solution;

[0123] The stirring speed was 300 r / min; the coating solution contained 19.5% potassium nitrate and 31.7% kaolin by mass.

[0124] Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container. After spraying, the thickness of the coating formed on the glass surface is 276μm.

[0125] The air spray gun has a pressure of 0.5 MPa, a spraying distance of 30 cm, and a spraying flow rate of 200 mL / min.

[0126] Step 3: Transfer the coated glass container to an oven and dry it at 80°C for 30 minutes;

[0127] Step 4: Place the dried glass container in a box furnace and heat it to 450°C at a heating rate of 10°C / min, and keep it at that temperature for 4 hours. Then remove the glass container and let it cool to room temperature in the air.

[0128] Step 5: Ultrasonically clean the surface of the glass container with deionized water at a power of 480W for 20 minutes, and then dry the ultrasonically cleaned glass container at a temperature of 80℃ for 30 minutes.

[0129] The overall drop performance test results of the chemically strengthened glass containers are shown in Table 1.

[0130] Table 1. Drop performance test results of Examples 1-6 and Comparative Examples 1-7

[0131]

Claims

1. A chemical strengthening method for a glass container, wherein the glass container is made of a material containing exchangeable Na. + The silicate glass is characterized by: Potassium nitrate and kaolin are added to deionized water, heated and stirred to fully dissolve and disperse to form a coating solution. The coating solution is then sprayed onto the surface of the glass container. After high-temperature heat treatment, an ion exchange strengthening layer is formed, thus chemically strengthening the glass container. The high-temperature heat treatment temperature is 430~450℃; In the coating solution, the mass fraction of potassium nitrate is 19.5%~29.3%, and the mass fraction of kaolin is 22%~31.7%.

2. The chemical strengthening method for a glass container according to claim 1, characterized in that, Contains exchangeable Na + The silicate glass is either soda-lime glass or borosilicate glass.

3. A chemical strengthening method for a glass container according to claim 1 or 2, characterized in that, The specific steps are as follows: Step 1: Add potassium nitrate and kaolin to deionized water, heat and stir to fully dissolve and disperse to form a coating solution; Step 2: Use an air spray gun to evenly spray the coating solution onto the surface of the glass container; Step 3: Transfer the coated glass container to an oven and dry the moisture in the coating at 60~80℃; Step 4: Place the dried glass container in a box furnace and heat it to 430~450℃ at a heating rate of 10℃ / min, and keep it at that temperature for 4~8 hours. Then remove the glass container and let it cool to room temperature in the air. Step 5: Use deionized water to ultrasonically clean the surface of the glass container, and then dry the ultrasonically cleaned glass container.

4. The chemical strengthening method for a glass container according to claim 3, characterized in that, In step 1, the heating temperature is 40~50℃ and the stirring speed is 200~300r / min.

5. The chemical strengthening method for a glass container according to claim 3, characterized in that, In step 2, the air spray gun pressure is 0.4~0.5MPa, the spraying distance is 20~30cm, and the spraying flow rate is 100~200mL / min.

6. The chemical strengthening method for a glass container according to claim 5, characterized in that, The thickness of the coating formed on the glass surface after spraying is 100~300μm.

7. The chemical strengthening method for a glass container according to claim 3, characterized in that, The drying time in step 3 is 20~30 minutes.

8. The chemical strengthening method for a glass container according to claim 3, characterized in that, In step 5, the ultrasonic cleaning power is 480W and the time is 10~20min.

9. The chemical strengthening method for a glass container according to claim 3, characterized in that, In step 5, the drying temperature is 60~80℃ and the time is 20~30min.

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