Preparation, application and removal method and system of high-bonding-strength epoxy-based adhesive capable of removing acid liquor

Abstract

The invention belongs to the technical field of adhesives, and discloses preparation, application and removal methods of an acid-removable high-bonding-strength epoxy-based adhesive, the process is simple, only simple weighing, stirring, heating and other operations are needed, complex equipment and complex processes are not needed, the operation is easy to control, the cost is low, and the method is suitable for industrial production. The operation time and difficulty and the equipment investment are greatly reduced; the production cost is low, the used raw materials are easy to obtain, expensive auxiliaries or solvents are not needed, the heating curing process is matched, the cost is comprehensively reduced, and the economical efficiency is extremely high; and thirdly, the adhesive can be removed by boiling with acid liquor, so that subsequent process treatment is facilitated. And fourthly, environmental protection is realized, no organic solvent is used in the whole process, VOC emission is avoided, the environmental protection standard is met, and the environmental protection concept is embodied.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, and particularly relates to the preparation, application, and removal method and system of an acid-removable high-adhesion epoxy adhesive. Background Technology

[0002] In the field of materials processing, adhesives are mainly used to bond and fix objects, ensuring their stability and integrity during processing. With the rapid development of modern industry, the quality and efficiency of material cutting and processing have become crucial, and adhesives play an indispensable role. As material cutting and processing technology continues to advance, the requirements are becoming increasingly stringent and complex, with ever-increasing demands for high precision, high reliability, and high performance. This places increasingly higher demands on adhesives used for fixing materials during the cutting and processing process, and existing epoxy adhesives can no longer meet the growing high-tech needs. Simultaneously, to reduce construction risks, minimize debonding time, and improve bond strength, the demand for high-performance adhesive materials and technologies that break through the limits of existing material performance is becoming increasingly urgent. There is a pressing need to address issues such as the workability, bond stability, and debonding properties of adhesives, and to develop adhesives with excellent bonding and debonding performance.

[0003] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0004] (1) Traditional adhesives have a long pre-curing and surface drying time, resulting in excessive bonding time and low production efficiency.

[0005] (2) The currently used adhesives use polythiol curing agents, which have uncontrollable curing and bonding time, limited operation time and space, and polythiol is expensive, resulting in extremely high costs.

[0006] (3) The bonding strength is low, which makes it difficult to meet the high strength requirements in the material cutting and processing process, resulting in problems such as high chipping rate and high edge breakage rate;

[0007] (4) Adhesives that meet the high-strength bonding requirements during the cutting process are difficult to remove after use, resulting in a high rate of contaminated sheets and making it difficult to meet the production requirements of high performance. Summary of the Invention

[0008] To address the problems existing in the prior art, this invention provides a method for preparing, applying, and removing an acid-removable epoxy-based adhesive with high bonding strength.

[0009] This invention is achieved by providing a method for preparing, applying, and removing an acid-removable high-adhesion epoxy-based adhesive, comprising:

[0010] Step 1: The adhesive is composed of E51 epoxy resin and polyetheramine;

[0011] Step 2: In a dry and clean environment, use a pre-calibrated high-precision electronic balance to accurately weigh a certain amount of E51 epoxy resin into a dry and clean 250mL beaker.

[0012] Step 3: Place the weighed E51 epoxy resin in a well-ventilated environment, use a high-precision calorimeter to determine its epoxy content, record the data and accurately calculate the required amount of active hydrogen; then use a high-precision electronic balance to accurately weigh an appropriate amount of polyetheramine. The polyetheramine used needs to be vacuum dried to remove moisture and impurities.

[0013] Step 4: When using, slowly add the weighed polyetheramine to E51 epoxy resin. During the addition process, it is necessary to keep stirring at a constant speed to prevent the polyetheramine from clumping. Keep the stirring speed within a certain range and stir for 3-5 minutes to ensure uniform mixing. After stirring, apply the mixture to the material parts to be bonded, and then transfer it to an 80℃ constant temperature oven for curing and bonding for 2 hours.

[0014] Step 5: After the cutting process is completed, soak the slices in a 35% acetic acid solution at 80°C for 30 to 50 minutes to thoroughly remove the residue.

[0015] Furthermore, the precise weighing of a certain amount is accurate to 0.001g.

[0016] Another object of the present invention is to provide a preparation, application, and removal system for an acid-removable high-adhesion epoxy adhesive, comprising:

[0017] The component module, used for adhesives, is composed of E51 epoxy resin and polyetheramine;

[0018] The weighing module is used to accurately weigh a certain amount of E51 epoxy resin in a dry and clean 250mL beaker using a pre-calibrated high-precision electronic balance in a dry and clean environment.

[0019] The calculation module is used to place the weighed E51 epoxy resin in a well-ventilated environment, use a high-precision calorimeter to determine its epoxy content, record the data and accurately calculate the required amount of active hydrogen; then, a high-precision electronic balance is used to accurately weigh an appropriate amount of polyetheramine, which must be vacuum dried to remove moisture and impurities.

[0020] The stirring module is used to slowly add the weighed polyetheramine to E51 epoxy resin during use. During the addition process, it is necessary to maintain a uniform stirring speed to prevent the polyetheramine from clumping. Keep the stirring speed within a certain range and stir for 3-5 minutes to ensure uniform mixing. After stirring, apply the mixture to the material parts to be bonded and then transfer it to an 80℃ constant temperature oven for curing and bonding for 2 hours.

[0021] The cutting module is used to thoroughly clean the slices by immersing them in a 35% acetic acid solution at 80°C for 30 to 50 minutes after the cutting process is completed.

[0022] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0023] First, the adhesive of this invention has the following significant advantages: Firstly, the process is simple, requiring only simple weighing, stirring, and heating operations, without complex equipment or cumbersome processes. Operation is easy to control, significantly reducing operation time, difficulty, and equipment investment. Secondly, the production cost is low; the raw materials are readily available and do not require expensive additives or solvents. Combined with the heating and curing process, costs are reduced comprehensively, making it highly economical. Thirdly, the adhesive can be removed by boiling in acid, facilitating subsequent processing. Fourthly, it is green and environmentally friendly, using no organic solvents throughout the process, eliminating VOC emissions, meeting environmental standards, and reflecting its environmental protection philosophy. Furthermore, this adhesive also possesses excellent adhesion, heat resistance, stability, high hardness, strong adhesion, and high bond shear strength. It exhibits excellent mechanical properties, low surface drying time, and high curing efficiency, effectively meeting cutting requirements and providing strong support for the high-quality development of related industries.

[0024] (1) Low cost: Only simple weighing and stirring are required, without complex equipment and cumbersome processes. The operation is easy to control, greatly reducing the difficulty of operation and equipment investment. The raw materials are readily available and do not require expensive additives or solvents. Combined with the low-temperature curing characteristics, energy consumption is significantly reduced, and costs are reduced in all aspects, making it extremely economical.

[0025] (2) Green and environmentally friendly with excellent performance: No organic solvents are used throughout the process, eliminating VOC emissions and meeting environmental standards. The resulting adhesive has high bonding strength, excellent heat resistance and chemical corrosion resistance, and is suitable for a variety of materials with a wide range of applications.

[0026] (3) It performs well during service and has a short cleaning and disposal time after service ends.

[0027] Secondly, after the technological transformation of this invention's minimalist two-component high-hardness removable epoxy adhesive, it is expected to first target four niche markets within 3-5 years: wind power, photovoltaics, semiconductor temporary bonding, and military maintenance, with cumulative sales potentially reaching 20-50 million yuan. The first round of patent licensing or technology investment can bring in 1-3 million yuan in cash revenue. Subsequently, as orders increase, the gross profit margin will be 10-15 percentage points higher than traditional formulas, with overall profits falling within a pragmatic range of less than 10 million yuan, providing a small but significant incremental demonstration for domestic high-end adhesives.

[0028] This invention, using only a two-component formulation of E51 epoxy resin and polyetheramine curing agent, achieves for the first time in the epoxy adhesive field three major properties simultaneously: "high hardness + heat curing + rapid removal by mild acid." It completely breaks the constraints of traditional high-hardness epoxy adhesives, which rely on complex curing systems, fillers, or additives for non-destructive removal. Through the molecular structure design of polyetheramine, its highly reactive amine groups are used to construct a high-density cross-linked network to ensure hardness. Furthermore, the acid-sensitive bonds of the polyether segments enable degradation under mild organic acid conditions, requiring no catalysts, toughening agents, or heavy metal additives. With a wide and controllable process window and low cost, it is suitable for temporary bonding of precision electronic components as well as repairable bonding of aerospace and military parts. It fills the gap in domestic and international "minimalist formulation, high hardness, and rapid removal" adhesive technology, providing a universal, compliant, and easily scalable new solution for high-end manufacturing such as semiconductors and aerospace composite materials.

[0029] The inability to quickly and gently remove high-hardness epoxy adhesives without damaging the substrate once cured has long been a core unresolved problem in the adhesive industry. For decades, the industry has struggled to strike a balance between "structural hardness" and "reversible removal on demand"—either sacrificing hardness by introducing hydrolyzable or photolytic groups, or maintaining high hardness but requiring removal only through high temperatures or mechanical destruction. This invention, using only two components, E51 resin and polyetheramine, is the first to design an integrated "high-density cross-linking / acid-sensitive bond breaking" network at the molecular level. Heating and curing achieves the hardness of structural adhesives while completely disintegrating them in mild acids, truly realizing the long-desired but unsuccessful technical goal of "high hardness with non-destructive, rapid, and environmentally friendly removal."

[0030] There has long been a technical prejudice in the industry that "high-hardness epoxy adhesives must rely on multi-component curing agents, fillers, or complex modification systems, and once cured, they cannot be quickly removed by gentle means." This invention uses only two components, E51 resin and polyetheramine. By precisely utilizing the dual characteristics of polyetheramine—"high cross-linking and acid-degradable"—it achieves both high hardness and gentle acid removal without adding any toughening, filler, or catalytic components. This directly breaks through the aforementioned prejudice and proves that "a minimalist formulation can also achieve both high hardness and controllable degradation." Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the preparation, application, and removal method of an acid-removable high-adhesion epoxy adhesive provided in this embodiment of the invention.

[0032] Figure 2 This is a block diagram of the preparation, application, and removal system of the acid-removable high-adhesion epoxy adhesive provided in the embodiments of the present invention.

[0033] Figure 3 This is a force-displacement curve of the adhesive provided in an embodiment of the present invention.

[0034] Figure 4 This is a stress-strain curve diagram of the adhesive provided in the embodiments of the present invention.

[0035] Figure 5 This is a bar chart showing the change in adhesive hardness provided in an embodiment of the present invention.

[0036] Figure 6 This is a bar chart showing the debonding time of the adhesive provided in the embodiments of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0038] like Figure 1 As shown in the figure, the preparation, application, and removal method of an acid-removable high-adhesion epoxy adhesive provided by an embodiment of the present invention includes the following steps:

[0039] S101, the adhesive is composed of E51 epoxy resin and polyetheramine;

[0040] S102. In a dry and clean environment, a certain amount of E51 epoxy resin is accurately weighed in a dry and clean 250mL beaker using a pre-calibrated high-precision electronic balance.

[0041] S103. Place the weighed E51 epoxy resin in a well-ventilated environment, use a high-precision calorimeter to determine its epoxy content, record the data and accurately calculate the required amount of active hydrogen; then use a high-precision electronic balance to accurately weigh an appropriate amount of polyetheramine. The polyetheramine used needs to be vacuum dried to remove moisture and impurities.

[0042] When using S104, slowly add the weighed polyetheramine to E51 epoxy resin while maintaining a constant stirring speed to prevent the polyetheramine from clumping. Keep the stirring speed within a certain range and stir for 3-5 minutes to ensure uniform mixing. After stirring, apply the mixture to the material parts to be bonded and then transfer it to an 80℃ constant temperature oven for curing and bonding for 2 hours.

[0043] S105, after the cutting process is completed, soak the slices in a 35% acetic acid solution at 80℃ for 30 to 50 minutes to completely remove the residue.

[0044] In the application of epoxy-based adhesives, existing technologies generally suffer from the difficulty of simultaneously achieving both bond strength and removability. Traditional epoxy adhesives, after curing, form a highly cross-linked three-dimensional network structure with strong chemical and solvent resistance. While providing excellent mechanical bonding, they often struggle to achieve non-destructive disassembly during equipment maintenance, component replacement, or rework, requiring mechanical damage or treatment with highly corrosive chemicals. This is not only time-consuming and labor-intensive but also prone to damaging the substrate and causing environmental pollution. Therefore, in industrial scenarios requiring temporary high-strength fixation followed by efficient and controllable removal, existing solutions fail to meet the requirements of process compatibility and maintainability.

[0045] This invention incorporates an acid-sensitive, removable mechanism in its material system design. Through precise stoichiometric proportioning of E51 epoxy resin and polyetheramine curing system, it ensures a high cross-linking density structure after curing to provide high adhesive strength, while also introducing chemical bond sites in the molecular chain structure that can be cleaved by weak acid media. During the curing stage, the epoxy groups undergo an addition reaction with the active hydrogen of the polyetheramine, generating stable β-hydroxy ether bonds and amine cross-linking structures. These cross-links exhibit excellent heat resistance and mechanical shock resistance under normal conditions.

[0046] In the post-treatment stage, by controlling the concentration, temperature, and soaking time of the acidic solution, the selective hydrolysis of amine bonds and their surrounding chemical environment by acetic acid breaks specific bonds in the cross-linked network. This process is not a complete degradation, but rather a localized chain breakage leading to a rapid loss of the material's mechanical integrity, causing the adhesive layer to peel off completely from the substrate surface. Due to the relatively weak acidity of the acid solution, the treatment process does not significantly corrode common metals, glass, ceramics, or some acid-resistant polymer substrates, significantly improving maintainability and environmental friendliness.

[0047] The core of this method lies in using precise epoxy equivalent measurement and active hydrogen stoichiometry to achieve a balance between high strength and controllable degradation in the cured system. High-precision calorimetry measurement of the epoxy value avoids proportioning deviations caused by batch variations in raw materials, ensuring the structural uniformity of the cross-linked network. This maximizes adhesion during use and guarantees the repeatability and thoroughness of the acid-based cleavage reaction during the cleaning phase.

[0048] In industrial applications, this technology can be widely used in scenarios such as electronic device packaging, precision mechanical assembly, and temporary positioning of optical components. For example, in the debugging of optical lens assemblies, the adhesive of this invention can withstand the stress and vibration during the assembly process during the fixing stage, ensuring the accuracy of the optical axis; after debugging is completed, the adhesive layer can be completely removed without damaging the lens mount and lens by weak acid treatment, providing a reversible solution for precision manufacturing and assembly processes.

[0049] This invention achieves a balance between high bonding strength and mild, removable properties through synergistic optimization of molecular design, proportion control, and acid-sensitive response mechanisms. It overcomes the industrial technical bottleneck of traditional epoxy adhesives, which struggle to balance high strength and maintainability, and provides a highly efficient, environmentally friendly, and controllable new adhesive material solution for engineering applications requiring temporary fixation and subsequent non-destructive disassembly.

[0050] The embodiment of the present invention provides a precise weighing of a certain amount: accurate to 0.001g.

[0051] like Figure 2 As shown in the figure, an acid-removable high-adhesion epoxy adhesive preparation, application, and removal system provided in this embodiment of the invention includes:

[0052] The component module, used for adhesives, is composed of E51 epoxy resin and polyetheramine;

[0053] The weighing module is used to accurately weigh a certain amount of E51 epoxy resin in a dry and clean 250mL beaker using a pre-calibrated high-precision electronic balance in a dry and clean environment.

[0054] The calculation module is used to place the weighed E51 epoxy resin in a well-ventilated environment, use a high-precision calorimeter to determine its epoxy content, record the data and accurately calculate the required amount of active hydrogen; then, a high-precision electronic balance is used to accurately weigh an appropriate amount of polyetheramine, which must be vacuum dried to remove moisture and impurities.

[0055] The stirring module is used to slowly add the weighed polyetheramine to E51 epoxy resin during use. During the addition process, it is necessary to maintain a uniform stirring speed to prevent the polyetheramine from clumping. Keep the stirring speed within a certain range and stir for 3-5 minutes to ensure uniform mixing. After stirring, apply the mixture to the material parts to be bonded and then transfer it to an 80℃ constant temperature oven for curing and bonding for 2 hours.

[0056] The cutting module is used to thoroughly clean the slices by immersing them in a 35% acetic acid solution at 80°C for 30 to 50 minutes after the cutting process is completed.

[0057] The core working principle of this system is based on the precise stoichiometric reaction of epoxy resin and polyetheramine, achieving a complete chain operation from ingredient preparation to curing and controlled removal through a modular process. The component modules provide the basic components for the chemical reaction, while the weighing and calculation modules ensure that the raw material ratios are strictly matched with the epoxy equivalent and the active hydrogen equivalent, thereby forming a uniform, high-crosslinking-density network structure during the curing reaction, providing the adhesive with excellent mechanical strength and heat resistance.

[0058] During the stirring and curing stage, the active hydrogen in the polyetheramine molecule undergoes a ring-opening addition reaction with the epoxy group in the E51 epoxy resin molecule, generating stable β-hydroxy ether bonds and amine cross-linking structures to construct a continuous three-dimensional network. This cross-linking structure exhibits good adhesion and chemical stability at both room temperature and high temperature, while reserving chemical bond sites in the molecular chain that can be selectively cleaved by weak acids, laying the foundation for subsequent reversible disassembly.

[0059] The removal process relies on the synergistic effect of the cutting module and the weak acid treatment. When the cured adhesive layer comes into contact with a 35% acetic acid solution at 80°C, the acetic acid causes directional hydrolysis of the amine bonds in the cross-linked network and their adjacent chemical environment, leading to the breakage of local chain segments and a rapid weakening of the overall mechanical support. As the network structure becomes unstable, the interface between the adhesive layer and the substrate loses its adhesion, achieving overall peeling and thus completing an efficient, gentle, and non-destructive removal process.

[0060] Figure 3 This is a force-displacement curve of the adhesive, showing its mechanical behavior under stress: In the initial stage (0-0.1 mm), the force change is small, and the curve is relatively flat, indicating that the adhesive mainly exhibits elastic deformation; in the middle stage (0.1-0.7 mm), the force increases significantly with increasing displacement, and the curve shows a steep upward trend, indicating that the adhesive gradually exhibits greater load-bearing capacity, possibly due to further deformation of the internal structure and stress transfer; in the peak stage (0.7 mm), the force reaches its maximum value, approximately 3800 N, indicating that the adhesive has withstood the maximum load, possibly due to the ultimate deformation or failure of the internal structure; in the failure stage (after 0.7 mm), the force drops rapidly, indicating that the adhesive has failed, possibly due to the fracture or peeling of the internal structure, leading to a sharp decrease in load-bearing capacity. Further analysis shows that the mechanical behavior of the adhesive is mainly due to its internal molecular structure and intermolecular interactions. During stress, the molecular chains of the adhesive undergo elastic and plastic deformation, thereby increasing the load-bearing capacity of the adhesive. When the internal structure of an adhesive reaches its limit of deformation or failure, the adhesive's load-bearing capacity will drop sharply, leading to the failure of the adhesive.

[0061] Figure 4This is a stress-strain curve of the adhesive, revealing its mechanical properties. In the initial stage, stress and strain show a linear relationship, indicating that the material primarily exhibits elastic behavior and can undergo reversible deformation under external force. As strain increases, the material enters the plastic deformation stage, where stress continues to increase but at a different rate, indicating that irreversible deformation begins. When the strain reaches approximately 8%, the stress reaches its maximum value of about 75 MPa, after which the curve rapidly declines, indicating material failure, possibly due to internal structural fracture or interfacial delamination.

[0062] In-depth analysis reveals that the mechanical behavior of adhesives is closely related to their molecular structure and cross-linking density. In the elastic stage, molecular chains undergo reversible conformational changes under external forces without permanent chemical bond breakage. In the plastic stage, irreversible conformational changes may occur, such as chain slippage or entanglement, leading to plastic deformation of the material. Good interfacial adhesion can improve the load-bearing capacity of adhesives, while weakening or disrupting the interface may cause the adhesive to fail under lower stress levels.

[0063] Figure 5 This is a bar chart showing the change in adhesive hardness. The chart reveals that the adhesive hardness value remains between 95 and 100, demonstrating good consistency and repeatability. This is because the epoxy resin forms a highly cross-linked three-dimensional network structure during curing. This structure tightly connects the molecular chains, significantly improving the material's hardness and strength. Simultaneously, polyetheramine, acting as a curing agent, not only promotes the curing reaction of the epoxy resin but also increases the cross-linking density of the adhesive through its reaction with epoxy groups, further enhancing hardness. Furthermore, the uniform mixing of epoxy resin and polyetheramine during preparation, along with suitable curing conditions, also contributes to the formation of a uniform structure, improving the overall hardness of the adhesive. These factors combined result in excellent mechanical properties and wear resistance in applications such as silicon ingot cutting.

[0064] Figure 6 This is a bar chart showing the degumming time of the adhesive. The chart shows that the degumming time of the adhesive in a 35% acetic acid solution heated to 80°C is approximately 35-50 minutes, with a relatively short average degumming time. This may be because the chemical structure of the adhesive is more prone to chemical reactions in acidic environments and under heating conditions, thus weakening the adhesion between the adhesive and the substrate. Secondly, heating accelerates the movement of adhesive molecules, reducing adhesion strength, while simultaneously enhancing the chemical activity of the degumming solution, thus promoting the degumming process.

[0065] Example 1:

[0066] Accurately weigh 4g of E51 epoxy resin into a disposable plastic cup. Then, calculate the required amount of active hydrogen (0.0204 mol) based on the epoxy group content of the epoxy resin, and weigh out 1.244g of polyetheramine accordingly. Slowly add the polyetheramine to the epoxy resin and stir thoroughly with a glass rod at 300-500 rpm for 3-5 minutes until the mixture is uniform in color. Place the well-stirred mixture in a constant temperature environment of 80℃ for 2 hours to cure. After curing, allow the adhesive to cool to room temperature. To remove the adhesive, soak it in a 35% acetic acid solution in a constant temperature environment of 80℃ for 30-50 minutes; it will then detach on its own.

[0067] Example 2:

[0068] Accurately weigh 5g of E51 epoxy resin into a disposable plastic cup. Then, calculate the required amount of active hydrogen (0.0255mol) based on the epoxy group content of the epoxy resin, and weigh out 1.556g of polyetheramine accordingly. Slowly add the polyetheramine to the epoxy resin and stir thoroughly with a glass rod at 300-500 rpm for 3-5 minutes until the mixture is uniform in color. Place the well-stirred mixture in a constant temperature environment of 80℃ for 2 hours to cure. After curing, allow the adhesive to cool to room temperature. To remove the adhesive, soak it in a 35% acetic acid solution at a constant temperature of 80℃ for 30-50 minutes; it will then detach on its own.

[0069] Example 3:

[0070] Accurately weigh 6g of E51 epoxy resin into a disposable plastic cup. Then, calculate the required amount of active hydrogen (0.0306 mol) based on the epoxy group content of the epoxy resin, and weigh out 1.867g of polyetheramine accordingly. Slowly add the polyetheramine to the epoxy resin and stir thoroughly with a glass rod at 300-500 rpm for 3-5 minutes until the mixture is uniform in color. Place the well-stirred mixture in a constant temperature environment of 80℃ for 2 hours to cure. After curing, allow the adhesive to cool to room temperature. To remove the adhesive, soak it in a 35% acetic acid solution in a constant temperature environment of 80℃ for 30-50 minutes; it will then detach on its own.

[0071] Example 4:

[0072] Accurately weigh 7g of E51 epoxy resin into a disposable plastic cup. Then, calculate the required amount of active hydrogen (0.0357 mol) based on the epoxy group content of the epoxy resin, and weigh out 2.178g of polyetheramine accordingly. Slowly add the polyetheramine to the epoxy resin and stir thoroughly with a glass rod at 300-500 rpm for 3-5 minutes until the mixture is uniform in color. Place the well-stirred mixture in a constant temperature environment of 80℃ for 2 hours to cure. After curing, allow the adhesive to cool to room temperature. To remove the adhesive, soak it in a 35% acetic acid solution at a constant temperature of 80℃ for 30-50 minutes; it will then detach on its own.

[0073] Example 5:

[0074] Accurately weigh 8g of E51 epoxy resin into a disposable plastic cup. Then, calculate the required amount of active hydrogen (0.0408 mol) based on the epoxy group content of the epoxy resin, and weigh out 2.489g of polyetheramine accordingly. Slowly add the polyetheramine to the epoxy resin and stir thoroughly with a glass rod at 300-500 rpm for 3-5 minutes until the mixture is uniform in color. Place the well-stirred mixture in a constant temperature environment of 80℃ for 2 hours to cure. After curing, allow the adhesive to cool to room temperature. To remove the adhesive, soak it in a 35% acetic acid solution at a constant temperature of 80℃ for 30-50 minutes; it will then detach on its own.

[0075] Example 1 (Temporary bonding of photovoltaic silicon wafers): E51 epoxy resin and polyetheramine D-230 were mixed in a certain proportion and then coated onto the back of a 156mm×156mm monocrystalline silicon wafer (80μm adhesive layer). The mixture was cured at 80℃ for 2 hours, and the shear strength was measured to be 12.16MPa and the Shore D hardness to be 97. The entire bonded part was immersed in an 80℃, 35% acetic acid solution. The adhesive layer completely detached within 30-50 minutes. There was no corrosion, no adhesive residue, and no contamination on the silicon wafer and glass, which met the dual requirements of high hardness positioning and non-destructive and rapid removal.

[0076] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing an acid-removable, high-strength epoxy-based adhesive, characterized in that, Includes the following steps: Step 1: Use E51 epoxy resin and polyetheramine as raw materials; Step 2: In a dry and clean environment, use a pre-calibrated high-precision electronic balance to weigh E51 epoxy resin in a dry and clean container. Step 3: Place the E51 epoxy resin in a ventilated environment, use a high-precision calorimeter to determine its epoxy content, calculate the required amount of active hydrogen based on the measured value, and weigh the polyetheramine that has been vacuum dried. Step 4: Slowly add the weighed polyetheramine to E51 epoxy resin, and stir at a constant speed until the mixture is homogeneous to obtain a mixture. Step 5: Apply the mixture to the surface of the material parts to be bonded and cure it under heating conditions to obtain a cured adhesive layer.

2. The preparation method according to claim 1, characterized in that, The polyetheramine is dried for more than 2 hours under a vacuum of not less than 0.09 MPa to remove moisture and impurities.

3. An acid-removable, high-strength epoxy-based adhesive, characterized in that, It is obtained by mixing and curing E51 epoxy resin and polyetheramine in a ratio matching epoxy equivalent to active hydrogen equivalent, and the cured structure contains chemical bond sites that can be cleaved by weak acid media.

4. The adhesive according to claim 3, characterized in that, The chemical bond sites are a combination of β-hydroxy ether bonds and amine cross-linking structures.

5. A method for removing acid, characterized in that, The cured adhesive layer formed by the adhesive according to claim 3 is immersed in a 35% acetic acid solution at 80°C for 30 to 50 minutes to separate the adhesive layer from the substrate.

6. The cleaning method according to claim 5, characterized in that, During the removal process, acetic acid selectively hydrolyzes the amine bonds in the adhesive layer and their surrounding chemical environment, resulting in local chain breakage of the crosslinked network.

7. A system for preparing and removing acid-removable high-adhesion-strength epoxy adhesives, characterized in that, include: Component modules for providing E51 epoxy resin and polyetheramine; The weighing module is used to accurately weigh E51 epoxy resin in a dry and clean environment. The calculation module is used to determine the epoxy content and calculate the required amount of active hydrogen; A stirring module is used to slowly add polyetheramine and stir until homogeneous; The curing module is used to cure the mixture at 80°C for 2 hours; The cleaning module is used to remove the cured adhesive layer by immersing it in a 35% acetic acid solution at 80°C for 30–50 minutes.

8. The system according to claim 7, characterized in that, The weighing module includes a high-precision electronic balance with an accuracy of not less than 0.001g.

9. A method for applying the adhesive of claim 3, characterized in that, This adhesive is used for electronic device packaging, precision mechanical assembly, or temporary positioning of optical components. It provides high bonding strength during use and allows for non-destructive separation using the removal method described in claim 5 when disassembly is required.

10. The method according to claim 9, characterized in that, In applications involving temporary positioning of optical components, the removal method can remove the adhesive layer without damaging the mount and lens.

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