Stripping solution for removing microcrystalline glass alon film layer and method for removing microcrystalline glass alon film layer

Abstract

This invention relates to the field of PVD film stripping technology, and discloses a stripping solution and method for removing AlON films from glass-ceramic substrates. The stripping solution comprises a primary stripping agent, a corrosion inhibitor, a chelating agent, a penetration accelerator, and a dispersing and cleaning agent. The primary stripping agent includes alkali metal hydroxides; the corrosion inhibitor includes gluconate and metasilicate; the penetration accelerator includes formate and alkanolamine compounds; and the chelating agent includes compounds with six coordination sites containing amino and carboxyl groups. The stripping solution provided by this invention can rapidly remove AlON films in a short time and is friendly to the appearance and optical properties of products with glass-ceramic substrates.

Description

Technical Field

[0001] This invention relates to the field of PVD stripping technology, specifically to a stripping solution for removing AlON film from glass-ceramic and a method for removing AlON film from glass-ceramic. Background Technology

[0002] With the rapid development of technology, the existing strength specifications of 3D mobile phone cover glass are no longer sufficient to meet customers' higher requirements for product durability and reliability. To improve the mechanical strength of the cover glass, microcrystalline glass is selected as the substrate, and its surface structure needs to be reinforced on both sides.

[0003] For example, an aluminum oxide nitride (AlON) film is deposited on the concave side using physical vapor deposition (PVD), with the film thickness controlled at 250-350 nm. Then, ion exchange is performed on the convex side to enhance its strength. Afterward, the PVD film on the concave side is completely removed, ensuring that the product's appearance (e.g., no scratches, surface roughness meets requirements) and related optical properties (e.g., transmittance) are not affected. Next, a PVD barrier layer is deposited on the convex side, and ion exchange is performed on the concave side again. Finally, the PVD film on the convex side is completely removed, again without damaging the appearance and optical properties.

[0004] Existing PVD stripping solutions generally use 85wt% phosphoric acid solution or at least 50wt% NaOH solution.

[0005] The AlON film needs to be removed from the 85wt% phosphoric acid solution by heating it to 90°C and taking at least 60 minutes to ensure that the film is completely removed. Heating it to 90°C will cause it to decompose and produce toxic phosphorus oxide fumes, resulting in a strong irritating odor in the room, which poses a serious threat to the eyes and health of the operators and also harms the surrounding environment. In addition, scratches are inevitable on the product after the removal of the film.

[0006] Using a 50wt% NaOH solution to strip the AlON film inevitably results in scratches on the product after stripping (the main reason being that glass-ceramics are composed of crystalline and glassy phases; the crystalline structure of glass-ceramics causes selective corrosion in alkaline solutions, with the crystalline phase being alkali-resistant and the alkali preferentially corroding the glassy phase, causing the crystalline phase to protrude, thus scratches are usually visible in the gaps between the crystalline phases and are quite obvious; in addition, the higher the concentration, the faster the corrosion rate of glass-ceramics, and the easier it is to cause scratches on the glass substrate, seriously affecting product quality); and existing stripping operations often use single-tank manual operation, which is laborious for operators and poses safety hazards.

[0007] To address the appearance, safety, and process issues associated with the removal of AlON coatings from microcrystalline glass, there is an urgent need to develop a removal solution that can effectively remove AlON coatings in a short time while being friendly to the appearance and optical properties of products with microcrystalline glass as the substrate. Summary of the Invention

[0008] The purpose of this invention is to provide a stripping solution and method that can effectively strip AlON coatings from glass-ceramic substrates in a short time, meet cleanliness requirements, and is friendly to the appearance and optical performance of products with glass-ceramic substrates.

[0009] To achieve the above objectives, a first aspect of the present invention provides a stripping solution for removing AlON films from microcrystalline glass. The stripping solution comprises a primary stripping agent, a corrosion inhibitor, a chelating agent, a penetration accelerator, and a dispersing and cleaning agent. The primary stripping agent comprises an alkali metal hydroxide; the corrosion inhibitor comprises soluble gluconate or metasilicate; the penetration accelerator comprises soluble formate or alkanolamine compounds; and the chelating agent comprises a soluble compound with six coordination sites having amino and carboxyl groups. The stripping solution contains 1.43-2.14 mol / L hydroxide ions, 0.15-0.30 mol / L formate ions, 0.18-0.30 mol / L metasilicate ions, and 0.27-0.46 mol / L gluconate ions. The chelating agent has a concentration of 0.10-0.37 mol / L, and the alkanolamine compound has a concentration of 0.65-1.00 mol / L. Based on the total mass of the stripping solution, the dispersing cleaning agent has a mass fraction of 3.5-6.0 wt%.

[0010] A second aspect of the present invention provides a method for stripping AlON film from microcrystalline glass, comprising the following steps: S1, In the presence of a diluted stripping solution, the microcrystalline glass AlON film is pretreated to obtain the pretreated material; S2, in the presence of stripping solution I, the pretreated material is stripped to obtain microcrystalline glass with the AlON film removed; The diluted stripping solution is obtained by diluting stripping solution II, and the conditions are controlled such that the concentration of stripping solution II in the diluted stripping solution is 3-8 vol%. Both the stripping solution I and the stripping solution II are the stripping solutions described in the first aspect above.

[0011] Compared with the prior art, the stripping solution provided by the present invention has the following beneficial effects: The stripping solution provided by this invention utilizes the synergistic effect of its various components to significantly improve the corrosion and peeling rate of the AlON film under specific conditions of penetration accelerator, chelating agent, and low alkalinity, thereby shortening the processing time. By increasing the stripping speed, the time the substrate is exposed to the corrosive solution is shortened, thus significantly reducing the risk of corrosion to the substrate. Furthermore, through the synergistic effect of corrosion inhibitors, the corrosion rate of the glass-ceramic is significantly reduced, thereby reducing the corrosion of the glass-ceramic substrate and achieving a highly efficient, mild, and environmentally friendly stripping effect.

[0012] The stripping solution provided by this invention can not only effectively remove the AlON film layer of microcrystalline glass, but also avoid the problems of product scratches and safety hazards that occur when using existing PVD stripping solutions with 85wt% phosphoric acid solution or at least 50wt% NaOH solution. The appearance and optical properties (such as transmittance and surface roughness) of the microcrystalline glass substrate treated with the stripping solution provided by this invention are not significantly affected, the surface is free of scratches, and the mechanical strength and durability of the substrate are preserved.

[0013] Meanwhile, the stripping solution provided by this invention can complete the stripping of AlON film on microcrystalline glass within 3-10 minutes, and reduces corrosion of the microcrystalline glass substrate. It solves the key technical problems in the stripping process of AlON film on microcrystalline glass, and improves production efficiency while reducing equipment occupation time and energy consumption. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the plating removal process according to a specific embodiment of the present invention; Figure 2 This is a SEM image of the white glass slide provided by the present invention; Figure 3 This is a SEM image of the coated sheet provided by the present invention; Figure 4 This is a SEM image of the product after plating removal in Embodiment 1 of the present invention; Figure 5 This is a SEM image of the product after plating removal in Embodiment 2 of the present invention; Figure 6 This is a SEM image of the product after plating removal in Embodiment 3 of the present invention; Figure 7 This is a SEM image of the product after plating removal in Example 4 of the present invention; Figure 8 This is a SEM image of the product after plating removal in Embodiment 5 of the present invention; Figure 9 This is a SEM image of the product after plating removal in Embodiment 6 of the present invention; Figure 10 This is a SEM image of the product after plating removal in Comparative Example 1 of the present invention; Figure 11 This is a SEM image of the product after plating removal in Comparative Example 2 of the present invention; Figure 12 This is a SEM image of the product after plating removal in Comparative Example 3 of the present invention; Figure 13 This is a SEM image of the product after plating removal in Comparative Example 4 of this invention; Figure 14 This is a SEM image of the product after plating removal in Comparative Example 5 of the present invention; Figure 15 This is a SEM image of the product after plating removal in Comparative Example 6 of the present invention; Figure 16 This is a SEM image of the product after plating removal in Comparative Example 7 of the present invention; Figure 17 This is a SEM image of the product after plating removal in Comparative Example 8 of the present invention. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] It should be noted that, in this invention, hydroxide ions in the stripping solution are measured by titration after dilution of the stripping solution; metasilicate ions are measured by molybdenum blue spectrophotometry; and the concentration of alkanolamine compounds is measured by salicylaldehyde spectrophotometry. Those skilled in the art should understand that, in the specific measurement process, the concentration of alkanolamine compounds can be measured first, then the total alkali concentration can be measured by titration, and finally, the concentration of hydroxide ions in the stripping solution can be obtained by subtracting the corresponding concentration of alkanolamine compounds from the total alkali concentration.

[0017] It should be noted that in this invention, the stripping solution is strongly alkaline, and the alkanolamine compounds mainly exist in molecular form under this hydroxide ion concentration environment, with hydrolysis being negligible.

[0018] As previously described, a first aspect of the present invention provides a stripping solution for removing AlON films from microcrystalline glass. The raw materials of the stripping solution include a primary stripping agent, a corrosion inhibitor, a chelating agent, a penetration accelerator, and a dispersing and cleaning agent. The primary stripping agent comprises an alkali metal hydroxide; the corrosion inhibitor comprises soluble gluconate or metasilicate; the penetration accelerator comprises soluble formate or alkanolamine compounds; and the chelating agent comprises a soluble compound with six coordination sites having amino and carboxyl groups. The stripping solution contains 1.43-2.14 mol / L hydroxide ions, 0.15-0.30 mol / L formate ions, 0.20-0.30 mol / L metasilicate ions, and 0.27-0.46 mol / L gluconate ions. The chelating agent contains 0.12-0.37 mol / L, and the alkanolamine compound contains 0.65-1.00 mol / L. Based on the total mass of the stripping solution, the dispersing cleaning agent has a mass fraction of 3.5-6.0 wt%.

[0019] This invention addresses the chemical composition of AlON films while fully considering the sensitivity of glass-ceramic substrates. The innovative stripping solution utilizes synergistic interactions between specific concentrations of chemical components to significantly improve the corrosion and peeling rates of AlON films, shortening processing time. By increasing the stripping speed, the time the substrate is exposed to the corrosive solution is reduced, thereby significantly lowering the risk of corrosion. Furthermore, through the synergistic effect of corrosion inhibitors, the corrosion rate of the glass-ceramic is significantly reduced, minimizing corrosion of the glass-ceramic substrate and achieving a highly efficient, gentle, and environmentally friendly stripping effect.

[0020] This invention controls the pH of the stripping solution to a range that effectively corrodes the AlON film without excessively corroding the microcrystalline glass substrate by adjusting the hydroxide ion concentration (1.43-2.14 mol / L) and utilizing the synergistic effect of each component.

[0021] By selecting a penetration accelerator containing formate and alkanolamine compounds and controlling its concentration at specific levels (formate ion concentration of 0.15-0.30 mol / L and alkanolamine compound concentration of 0.65-1.00 mol / L), and through synergistic effects with other components in the stripping solution, the stripping process of the AlON film can be accelerated. The main reasons are as follows: alkanolamine compounds react with OH-... - In combination with aluminum-containing films such as aluminum nitride, it can directly corrode the aluminum-containing film, forming a loose, basic aluminum salt-containing modified layer on its surface, effectively accelerating film removal; the amino and hydroxyl groups in the amine compounds can react with the corroded aluminum ions (Al2O3). 3+ The formation of soluble and stable complexes can "pull" corrosion products from the surface into the solution, preventing their redeposition and thus continuously exposing new film layers for corrosion, significantly accelerating the overall stripping rate. Formate ions can reduce the passivation film (such as Al2O3) produced on the substrate surface, eliminating the barrier layer that hinders the penetration of the stripping solution, allowing strong alkali and chelating agents to quickly contact the AlON film, avoiding localized penetration obstruction and uneven stripping. Formate ions can reduce the surface tension of the stripping solution, improve the wettability of the film layer, reduce droplet shrinkage, and allow the stripping solution to spread and penetrate the film layer quickly, accelerating the film layer disintegration and peeling.

[0022] The stripping solution provided by this invention uses a soluble compound with six coordination sites containing amino and carboxyl groups as a chelating agent. This compound can form a stable hexadecanthal chelate with aluminum ions in the AlON film, effectively complexing aluminum ions, thereby accelerating film removal and preventing corrosion products from depositing on the substrate surface, further improving stripping efficiency.

[0023] The stripping solution provided by this invention uses metasilicate ions and gluconate ions as the main components of the corrosion inhibitor, which can effectively prevent the microcrystalline glass from being corroded and scratched during the stripping process. It is also suitable for alkaline stripping environments, significantly reducing the corrosion rate of the microcrystalline glass without sacrificing stripping efficiency, thus reducing the corrosion rate on the microcrystalline glass substrate. The combination of metasilicate and gluconate ions has a corrosion inhibition mechanism that matches the selective corrosion characteristics of microcrystalline glass in alkaline solutions. The grain boundaries of microcrystalline glass are weak points for alkali attack, and metasilicate ions can rapidly form an extremely thin, negatively charged protective layer on the substrate surface through chemical adsorption, inhibiting OH-. - The protective layer, formed on a smooth crystal surface, easily leaves voids at grain boundaries. Gluconate ions, as high-energy sites preferentially adsorbed at these grain boundaries, provide a film-forming framework for metasilicate ions, resulting in a co-adsorption of the two to form an inorganic-organic hybrid film. Furthermore, gluconate ions significantly reduce the corrosion rate of the glass substrate through a combination of effects including deactivating metal catalytic centers, complexing leaching ions, and buffering and dispersing. In addition, an appropriate amount of metasilicate ions provides excellent alkalinity buffering capacity, helping to stabilize the system pH within a window favorable for glass protection.

[0024] The addition of 3.5-6.0 wt% dispersant in the stripping solution of this invention can effectively block aluminum ions, preventing them from precipitating into scale on the substrate surface, and further improve the wettability and dispersibility of the stripping solution. This not only improves the cleaning effect of the stripping solution but also enhances the disintegration rate of the film layer, thereby shortening the processing time.

[0025] In some embodiments, the chelating agent comprises glutamate diacetate. The inventors of this invention have discovered that, in this preferred embodiment, glutamate diacetate forms a more saturated and structurally stable hexadecanoid chelate with aluminum ions through six coordination sites of two nitrogen atoms from the amino group and four negatively charged carboxylate oxygen atoms, thereby enabling the chelation of Al... 3+ It is firmly fixed at the molecular center, which makes it superior to traditional EDTA and NTA in terms of wide pH range (especially alkaline), high stability and environmental friendliness.

[0026] In a preferred embodiment, the chelating agent comprises glutamate diacetate and triacetate, and the molar ratio of the glutamate diacetate to the triacetate in the chelating agent is 1:1.00-1.15. The inventors of this invention have discovered that, in this preferred embodiment, the triacetate forms a stable water-soluble complex with the ions dissolved during the stripping process, preventing the accumulation of impurity ions on the film surface or substrate surface. Simultaneously, in alkaline stripping solutions, it can help maintain pH stability, ensuring the reaction efficiency of the main solvent in the stripping agent; furthermore, it can work in conjunction with corrosion inhibitors to complex free metal ions, reducing the corrosion rate of the substrate and maintaining the surface smoothness of the substrate. Experiments have shown that when combined with tetrasaturated glutamic acid diacetate, it can chelate and complement each other, covering a wider range of impurity metal ion types. It controls impurities from multiple dimensions, such as complexing ions and synergistic corrosion inhibition, to avoid impurity deposition or adverse effects, resulting in more comprehensive impurity control. It also buffers pH fluctuations and balances environmental protection and economy. In combination, it reduces the concentration of metal ions, promotes the positive progress of the stripping reaction, increases the stripping rate, and makes the rate easier to control.

[0027] Preferably, in the raw materials of the stripping solution, the molar ratio of the alkali metal hydroxide to the alkanolamine compound is 1:0.40-0.50. In this preferred embodiment, the alkanolamine compound can play a better role in buffering and stabilizing pH, making the alkaline environment of the working solution more durable and stable, and improving the synergistic effect of the various components in the stripping solution.

[0028] In a preferred embodiment, the molar ratio of the formate to the alkanolamine compound in the penetration accelerator is 1:3.00-4.50. This preferred embodiment allows for a more effective synergistic effect among the components in the stripping solution, ensuring that the AlON film is rapidly removed without damaging the appearance and optical properties of the glass-ceramic substrate.

[0029] Preferably, in the stripping solution, the molar ratio of metasilicate ions to gluconate ions is 1:1.40-1.70. Experiments have verified that, under this preferred condition, the two have a good synergistic effect, which can significantly reduce the corrosion rate of the glass-ceramic and reduce the corrosion of the glass-ceramic substrate.

[0030] In some embodiments, the alkali metal hydroxide includes potassium hydroxide and / or sodium hydroxide.

[0031] In some embodiments, the alkanolamine compound includes at least one of monoethanolamine and triethanolamine.

[0032] In some embodiments, the formate includes sodium formate and / or potassium formate.

[0033] In some embodiments, the gluconate includes sodium gluconate and / or potassium gluconate.

[0034] In some embodiments, the metasilicate includes sodium metasilicate pentahydrate and / or potassium metasilicate and / or lithium metasilicate.

[0035] According to a preferred embodiment, the dispersing cleaning agent comprises an alkali metal salt of polyacrylate and an alkyl glycoside. The inventors of this invention have discovered that, in this preferred embodiment, the alkali metal salt of polyacrylate, through the dispersing and adsorption effects of multiple carboxyl groups, can effectively block aluminum ions, preventing them from precipitating and forming scale, thus exhibiting primarily a dispersing and scale-inhibiting effect. Furthermore, the alkyl glycoside, when combined with the alkali metal salt of polyacrylate, can further enhance its dispersing, anti-deposition, and wetting effects.

[0036] Based on the total mass of the stripping solution, the mass fraction of the alkali metal salt of polyacrylate is 3-5 wt%, and the mass fraction of the alkyl glycoside is 0.5-1 wt%. Under these conditions, the stripping effect is better, the efficiency is higher, and the economy is better.

[0037] In some embodiments, the alkali metal polyacrylate salt comprises sodium polyacrylate, wherein the sodium polyacrylate has a solid content of 40-50 wt% and an average molecular weight of 3000-6000.

[0038] This invention does not impose any particular requirements on the preparation method of the stripping solution for removing the AlON film layer from microcrystalline glass; those skilled in the art can select appropriate methods based on known techniques. Exemplarily, this invention provides a method for preparing the stripping solution for removing the AlON film layer from microcrystalline glass, comprising: In a stainless steel mixing tank, the components of the stripping solution described in the first aspect are stirred and mixed for 2-4 hours, and then cooled to room temperature to obtain the stripping solution for removing the AlON film layer of microcrystalline glass.

[0039] As previously described, a second aspect of the present invention provides a method for removing an AlON film layer from a glass-ceramic substrate, comprising the following steps: S1, In the presence of a diluted stripping solution, the microcrystalline glass AlON film is pretreated to obtain the pretreated material; S2, in the presence of stripping solution I, the pretreated material is stripped to obtain microcrystalline glass with the AlON film removed; The diluted stripping solution is obtained by diluting stripping solution II, and the conditions are controlled such that the concentration of stripping solution II in the diluted stripping solution is 3-8 vol%. Both the stripping solution I and the stripping solution II are the stripping solutions described in the first aspect above.

[0040] It should be noted that the compositions of the stripping solution I and the stripping solution II may be the same or different.

[0041] In some implementations, the pretreatment conditions in step S1 include: a temperature of 40-60°C and a time of 2-4 minutes.

[0042] According to a preferred embodiment, in step S2, the conditions for the stripping process include: a temperature of 90-100°C and a time of 3-10 minutes. Under this preferred condition, the stripping can be completed quickly without causing significant corrosion to the microcrystalline glass, and without affecting its appearance and optical performance.

[0043] In some embodiments, the method further includes: in step S1, washing the pretreated material with water to obtain the pretreated material.

[0044] In some embodiments, the method further includes: in step S2, the material after the stripping treatment is sequentially washed with water and dried to obtain the microcrystalline glass with the AlON film removed.

[0045] The present invention exemplarily in Figure 1 The document provides a schematic diagram of a specific implementation of the stripping process: Specifically, the sample to be stripped is first loaded onto the platform and then conveyed to the pretreatment tank for pretreatment of the AlON film layer on the glass-ceramic (dilute stripping solution / pump circulation / 50℃ / 3min); then it passes through water washing tank 1 (pure water / bubbling / 50℃ / 3min) to obtain pretreated material; the pretreated material is then conveyed to the stripping tank for stripping treatment, and then the stripped material is sequentially passed through water washing tank 2 (pure water / bubbling / 50℃ / 3min), water washing tank 3 (pure water / bubbling / 50℃ / 3min), water washing tank 4 (pure water / bubbling / 50℃ / 3min), and water washing tank 5 (pure water / 55℃ / 3min) for washing; finally, the washed material is conveyed to the drying tank for drying treatment (80℃ / 5min), and then conveyed to the platform for unloading.

[0046] It should be noted that the present invention does not have any particular requirements regarding the type of water, and those skilled in the art can select it based on known techniques. For example, the water can be deionized water or ultrapure water.

[0047] In this invention, room temperature refers to a temperature of 25±2℃.

[0048] The present invention will be described in detail below through examples. Unless otherwise specified, the instruments, reagents, and materials involved in the following examples are all conventional instruments, reagents, and materials, which can be obtained through legitimate commercial channels. Unless otherwise stated, all reagents used are commercially available analytical grade products.

[0049] Alkali metal hydroxides: potassium hydroxide.

[0050] Corrosion inhibitor: Gluconate: Sodium gluconate.

[0051] Metasilicate: Sodium metasilicate.

[0052] Penetration accelerator: Formate: Sodium formate.

[0053] Alkylamine compounds: monoethanolamine.

[0054] Chelating agents: Tetrasodium glutamate diacetate (abbreviated as GLDA), trisodium nitrilotriacetate.

[0055] Dispersed cleaning agent: Alkyl glycoside: purchased from Shanghai Fakai Chemical Co., Ltd., brand name APG06.

[0056] Sodium polyacrylate: solid content approximately 45 wt%, average molecular weight approximately 4500, Dow Acusol 445N.

[0057] Sample to be stripped: A microcrystalline glass coated with an AlON film, the thickness of which is 300 nm.

[0058] Example 1 See Figure 1 In this embodiment, the AlON film layer on the microcrystalline glass is stripped according to a method including the following steps: S1. First, the sample to be stripped is loaded onto the platform and then transferred to the pretreatment tank to pretreat the AlON film layer of the microcrystalline glass (dilute stripping solution / pump circulation / 50℃ / 3min); then after passing through the water washing tank 1 (pure water / bubbling / 50℃ / 3min), the pretreated material is obtained. S2. The pretreated material is then transferred to the stripping tank for stripping treatment. After stripping, the material is sequentially washed in water washing tank 2 (pure water / bubbling / 50℃ / 3min), water washing tank 3 (pure water / bubbling / 50℃ / 3min), water washing tank 4 (pure water / bubbling / 50℃ / 3min), and water washing tank 5 (pure water / 55℃ / 3min). Finally, the washed material is transferred to the drying tank for drying treatment (80℃ / 5min) to obtain microcrystalline glass with the AlON film layer removed, and then transferred to the platform for unloading.

[0059] In this embodiment, the diluted stripping solution is obtained by diluting the stripping solution, and the control conditions are such that the concentration of the stripping solution in the diluted stripping solution is 5 vol; the formula of the stripping solution and the stripping process are shown in Table 1.

[0060] Examples 2 to 6 Unless otherwise specified, Examples 2 through 6 were carried out using methods similar to those in Example 1, except for the formulation of the stripping solution and the stripping process, as detailed in Table 1. Any parts not listed are the same as in Example 1.

[0061] Table 1

[0062] Note: All "wt%" values ​​in the table are based on the total mass of the stripping solution; Mole ratio 1 This refers to the molar ratio of potassium hydroxide to monoethanolamine in the raw materials of the stripping solution. Mole ratio 2 This refers to the molar ratio of sodium formate to monoethanolamine in a penetration accelerator. Mole ratio 3 : Refers to the molar ratio of sodium metasilicate pentahydrate and sodium gluconate in the stripping solution.

[0063] Mole ratio 4 : refers to the molar ratio of tetrasodium glutamate diacetate and trisodium nitrotriacetate in the stripping solution.

[0064] Comparative Example 1 This comparative example was conducted using a method similar to that of Example 3, except that: The formulation of the stripping solution in this comparative example is as follows: based on the total mass of the stripping solution, the stripping solution contains 85 wt% phosphoric acid and the balance is water; and the stripping treatment temperature is 90℃ and the time is 60 min. The parts not listed are the same as in Example 3.

[0065] Comparative Example 2 This comparative example was conducted using a method similar to that of Example 3, except that: The formulation of the stripping solution in this comparative example is as follows: based on the total mass of the stripping solution, the stripping solution contains 70 wt% potassium hydroxide and the balance is water; and the stripping treatment temperature is 120℃ and the time is 5 min. The parts not listed are the same as in Example 3.

[0066] Comparative Example 3 This comparative example was conducted using a method similar to that of Example 3, except that: The formulation of the stripping solution in this comparative example is as follows: based on the total mass of the stripping solution, the stripping solution contains 50 wt% sodium hydroxide, 5 wt% sodium gluconate, and the balance is water; and the stripping treatment temperature is 120℃ and the time is 5 min. The parts not listed are the same as in Example 3.

[0067] Comparative Example 4 This comparative example was conducted using a method similar to that of Example 3, except that: The formulation of the stripping solution in this comparative example is as follows: based on the total mass of the stripping solution, the stripping solution contains 20 wt% potassium hydroxide, 3 wt% trisodium triacetate, 3 wt% monoethanolamine, and the balance is water; and the stripping treatment temperature is 100℃ and the time is 10 min. The parts not listed are the same as in Example 3.

[0068] Comparative Example 5 This comparative example was conducted using a method similar to that of Example 3, except that: The formulation of the stripping solution in this comparative example is as follows: based on the total mass of the stripping solution, the stripping solution contains 5 wt% potassium hydroxide, 3 wt% tetrasodium glutamate diacetate, 3 wt% monoethanolamine, and the balance is water; and the stripping treatment temperature is 100℃ and the time is 10 min. The parts not listed are the same as in Example 3.

[0069] Comparative Example 6 This comparative example was conducted using a method similar to that of Example 3, except that: In this comparative example, sodium formate in Example 3 was replaced with sodium citrate of equal molar concentration; The parts not listed are the same as in Example 3.

[0070] Comparative Example 7 This comparative example was conducted using a method similar to that of Example 3, except that: In Example 3, sodium gluconate was replaced with sodium metasilicate pentahydrate, so that the concentration of metasilicate ions was the sum of the concentrations of metasilicate ions and gluconate ions in Example 3; all other parts not listed are the same as in Example 3.

[0071] Comparative Example 8 This comparative example was conducted using a method similar to that of Example 3, except that: In Example 3, monoethanolamine was replaced with sodium formate, so that the concentration of formate ions was the sum of the concentrations of formate ions and monoethanolamine in Example 3; all other parts not listed are the same as in Example 3.

[0072] Test case 1. Performance tests were conducted on the blank products after stripping of the aforementioned embodiments and comparative examples: (1) Appearance of the submitted item (visual inspection); (2) The surface roughness was tested according to the standard methods of ISO 25178-2 (surface characteristic parameters) and ISO 25178-6 (measurement methods). The average value of three tests were taken at three random points. Sa is the average surface roughness of the glass surface, which is the average value of the sum of the absolute values ​​of the deviations of the height of all points from the average surface height in the measurement area, representing the overall level of surface undulation. Sz is the limit roughness of the glass surface, which is the vertical distance between the highest peak and the lowest valley in the measurement area, representing the extreme range of surface undulation. (3) Test transmittance according to the ISO 15368:2021 standard method (the average value of 3 tests conducted at 3 random points). The test results are shown in Table 2: Table 2

[0073] Note: "Clear glass sheet" refers to a glass product made of microcrystalline glass that has been polished on both sides without coating or pressure cleaning; "coated sheet" refers to a glass product made of microcrystalline glass that has been polished on both sides with coating but without pressure; the examples and comparative examples all use clear glass sheets as the control group. The closer the transmittance is to clear glass, the better the effect, and the same applies to roughness. " / " indicates that surface scratches cannot be inspected because the plating has not been completely removed.

[0074] 2. The microstructure of the white glass slide, the coated slide, and the products after decoction removal in Examples 1-6 and Comparative Examples 1-8 were tested using electron microscopy, and EDS data were output simultaneously. The results are as follows: Figures 2-17 As shown in Table 3: Figure 2 and Figure 3 SEM images of a white glass slide and a coated slide, respectively. Figures 4-9 The images shown are SEM images of the products after plating removal in Examples 1 to 6. Figures 10-17 SEM images of the products after plating removal from Comparative Examples 1 to 8; Table 3

[0075] Continued from Table 3

[0076] SEM images, EDS composition analysis, transmittance, and surface roughness tests of the product surface show that Examples 1 to 6 all achieved complete AlON film removal, and the microcrystalline glass surface was free of scratches after removal, with no significant impact on optical properties (such as transmittance and surface roughness). Furthermore, in Example 1, even with a hydroxide ion concentration of 2.14 mol / L and a removal treatment at 100°C for 10 minutes, the microcrystalline glass surface remained scratch-free; in Example 3, a removal treatment at 90°C for 3 minutes with a hydroxide ion concentration of 1.78 mol / L was sufficient to complete the removal, leaving the microcrystalline glass surface free of scratches; and in Example 5, even with a hydroxide ion concentration of 1.43 mol / L and a relatively low overall formulation content, a removal treatment at 100°C for 3 minutes was also sufficient to complete the removal.

[0077] The stripping solutions provided in Comparative Examples 1-4 all successfully stripped the AlON film, but the surface was scratched after stripping, and the transmittance and surface roughness did not meet the requirements. In Comparative Example 5, the alkali concentration was reduced, and even though the stripping time was increased to some extent, the stripping effect still failed to meet the requirements, indicating that low alkalinity cannot completely strip the film within 10 minutes. Comparative Example 6 did not completely complete the stripping within 3 minutes, indicating that sodium formate and monoethanolamine can accelerate the stripping of the AlON film in the system. Comparative Example 7 was able to complete the stripping under the same stripping conditions, but the surface was obviously scratched, indicating that using only sodium metasilicate pentahydrate was not effective. Comparative Example 8 also did not completely complete the stripping within 3 minutes.

[0078] The results above show that the stripping solution provided by this invention for removing AlON film from microcrystalline glass can remove the AlON film cleanly in a short time; at the same time, the overall appearance (scratches), roughness, and transmittance all meet the requirements.

[0079] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A stripping solution for removing a microcrystalline glass AlON film layer, characterized by, The raw materials of the stripping solution include a main stripping agent, a corrosion inhibitor, a chelating agent, a penetration accelerator, and a dispersing and cleaning agent; the main stripping agent includes alkali metal hydroxides; the corrosion inhibitor includes soluble gluconates and metasilicates; the penetration accelerator includes soluble formates and alkanolamine compounds; and the chelating agent includes soluble compounds with six coordination sites containing amino and carboxyl groups. The stripping solution contains 1.43-2.14 mol / L hydroxide ions, 0.15-0.30 mol / L formate ions, 0.18-0.30 mol / L metasilicate ions, and 0.27-0.46 mol / L gluconate ions. The chelating agent has a concentration of 0.10-0.37 mol / L, and the alkanolamine compound has a concentration of 0.65-1.00 mol / L. Based on the total mass of the stripping solution, the dispersing cleaning agent has a mass fraction of 3.5-6.0 wt%.

2. The stripping solution for removing the microcrystalline glass AlON film layer according to claim 1, characterized in that, The chelating agent includes glutamate diacetate; And / or, the chelating agent comprises glutamate diacetate and nitric acid triacetate, and in the chelating agent, the molar ratio of the glutamate diacetate to the nitric acid triacetate is 1:1.00-1.

15.

3. The stripping solution for removing the microcrystalline glass AlON film layer according to claim 1, characterized in that, In the raw materials of the stripping solution, the molar ratio of the alkali metal hydroxide and the alkanolamine compound is 1:0.40-0.

50.

4. The stripping solution for removing the microcrystalline glass AlON film layer according to any one of claims 1 to 3, characterized in that, In the permeation accelerator, the molar ratio of the formate to the alcohol amine compound is 1:3.00-4.

50.

5. The stripping solution for removing AlON film from microcrystalline glass according to any one of claims 1-3, characterized in that, In the stripping solution, the molar ratio of metasilicate ions to gluconate ions is 1:1.40-1.

70.

6. The stripping solution for removing AlON film from microcrystalline glass according to any one of claims 1-3, characterized in that, The alkali metal hydroxides include potassium hydroxide and / or sodium hydroxide; And / or, the alkanolamine compound includes at least one of monoethanolamine and triethanolamine; And / or, the formate includes sodium formate and / or potassium formate; And / or, the gluconate includes sodium gluconate and / or potassium gluconate; And / or, the metasilicate includes sodium metasilicate pentahydrate and / or potassium metasilicate and / or lithium metasilicate.

7. The stripping solution for removing AlON film from microcrystalline glass according to any one of claims 1-3, characterized in that, The dispersing cleaning agent comprises an alkali metal salt of polyacrylate and an alkyl glycoside.

8. The stripping solution for removing AlON film from microcrystalline glass according to claim 7, characterized in that, Based on the total mass of the stripping solution, the mass fraction of the alkali metal salt of polyacrylate is 3-5 wt%, and the mass fraction of the alkyl glycoside is 0.5-1 wt%. And / or, the alkali metal salt of polyacrylate includes sodium polyacrylate, wherein the sodium polyacrylate has a solid content of 40-50 wt% and an average molecular weight of 3000-6000.

9. A method for stripping AlON film from microcrystalline glass, characterized in that, Includes the following steps: S1, In the presence of a diluted stripping solution, the microcrystalline glass AlON film is pretreated to obtain the pretreated material; S2, in the presence of stripping solution I, the pretreated material is stripped to obtain microcrystalline glass with the AlON film removed; The diluted stripping solution is obtained by diluting stripping solution II, and the conditions are controlled such that the concentration of stripping solution II in the diluted stripping solution is 3-8 vol%. Both the stripping solution I and the stripping solution II are stripping solutions according to any one of claims 1-8.

10. The method for stripping the AlON film layer from microcrystalline glass according to claim 9, characterized in that, In step S1, the pretreatment conditions include: a temperature of 40-60℃ and a time of 2-4 minutes; And / or, in step S2, the conditions for the stripping process include: a temperature of 90-100°C and a time of 3-10 min.

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