High-adhesion epoxy adhesive and preparation method thereof

Abstract

The invention relates to the field of adhesives, in particular to a high-adhesion epoxy adhesive and a preparation method thereof. The adhesive is prepared from the following components in parts by weight: 40 to 100 parts of hydrogenated epoxy resin, 40 to 100 parts of secondary thiol curing agent, 0.5 to 5 parts of latent accelerator, 0.1 to 5 parts of stabilizer and 0.1 to 1 part of coupling agent. According to the epoxy adhesive prepared by the invention, the compatibility of all components is good, the preparation method is simple and convenient, complex reaction or harsh conditions are not needed, the production process is simple, the controllability is high, the product quality is stable, and the epoxy adhesive is very suitable for large-scale industrial production and application.

Description

Technical Field

[0001] This invention relates to the field of adhesives, and more specifically to a high-adhesion epoxy adhesive and its preparation method. Background Technology

[0002] With the upgrading of consumer electronics products, more and more electronic products are equipped with electronic display screens or transparent viewing windows. For the bonding and fixing of these components, adhesive materials with good curing transparency and resistance to yellowing due to moisture and heat are often required to ensure the transparency and aesthetics of the product during use. Furthermore, many of these bonded components have low temperature resistance, and the thermal stress generated at the curing temperature may lead to poor dimensional stability of the bonded components. Therefore, adhesive materials need to be able to cure at lower curing temperatures. In terms of application methods, single-component adhesives have advantages, such as no mixing required, convenient and quick operation, and better avoidance of air bubble formation. Therefore, the demand for adhesives meeting the above requirements is becoming increasingly prominent.

[0003] Chinese invention patent CN202311290097.X discloses a colorless, transparent epoxy composition with high UV resistance to yellowing and its preparation method. This invention uses alicyclic epoxy resin and alicyclic acid anhydride curing agent as the main components of the formulation, and prepares A and B components of adhesive separately. The color of the cured product is <1.0. After UV aging for 400 hours, the yellowing color increases by 1.45, achieving low color and good yellowing resistance. However, it requires mixing and then bonding and fixing by heat curing at 100℃-180℃ for 1-10 hours. The two-component mixing process is cumbersome and the curing temperature is high, which may cause irreversible damage to temperature-sensitive devices. Chinese invention patent CN201911256647.X discloses a low-temperature curing single-component transparent epoxy adhesive, its preparation method, and its application. It uses an aliphatic epoxy resin and a polythiol curing agent, combined with a polyurethane-modified epoxy resin, which can cure at 80 degrees Celsius for 10 minutes. It is colorless and transparent, and can maintain high transparency and low yellowing after damp heat aging and thermal shock aging. However, it has poor room temperature stability and low bonding strength.

[0004] Based on the above technical background, the market demand for single-component, low-temperature curing, yellowing and aging resistant, and colorless transparent adhesives with good adhesion is increasing. The existing adhesive technology solutions for aging and yellowing resistance have the following problems: (1) The formulation of alicyclic anhydride curing agent has a high curing temperature and requires two-component mixing, which is complicated; (2) The solution of alicyclic epoxy resin and thiol curing agent has low bonding strength and poor room temperature stability; (3) Aromatic epoxy resin adhesives are prone to yellowing and decreased transparency under humid heat aging conditions. Summary of the Invention

[0005] In view of the problems existing in the prior art, the purpose of this invention is to provide a high-adhesion epoxy adhesive and its preparation method.

[0006] The objective of this invention is achieved through the following technical solution: In a first aspect, the present invention provides a high-adhesion epoxy adhesive, comprising, by weight parts: Hydrogenated epoxy resin: 40-100 parts, secondary thiol curing agent: 40-100 parts, latent accelerator: 0.5-5 parts, stabilizer: 0.1-5 parts, coupling agent: 0.1-1 parts.

[0007] Preferably, the hydrogenated epoxy resin comprises at least one selected from tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin, 1,2-cyclohexanediol diglycidyl ether, and 1,4-cyclohexanediol diglycidyl ether.

[0008] Preferably, the secondary thiol curing agent is at least one selected from pentaerythritol tetra(3-mercaptobutyric acid), pentahexanetriol tris(3-mercaptobutyric acid), di(3-mercaptobutyric acid)-1,4-butanediol ester, and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

[0009] Preferably, the latent accelerator is prepared by using 5-amino-2-mercaptobenzimidazole and 4-hydroxybutylvinyl ether to prepare an intermediate product through a click chemical reaction, and then performing a condensation reaction with glycidyl furfuryl ether to obtain the final product.

[0010] Preferably, the stabilizer is at least one selected from salicylic acid, barbituric acid, stearic acid, lauric acid, and fumaric acid.

[0011] Preferably, the coupling agent is a silane coupling agent, including at least one of 2-(3,4-epoxycyclohexyl)ethoxysilane, 3-glycidylpropyltrimethoxysilane, 3-glycidylpropylmethyldiethoxysilane, 3-glycidylpropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane.

[0012] Preferably, the preparation method of the latent promoter includes the following steps: a. Add 5-amino-2-mercaptobenzimidazole to ethanol, stir under nitrogen protection, add 4-hydroxybutylvinyl ether and photoinitiator, continue stirring to mix the system evenly, irradiate the reaction mixture with ultraviolet light at room temperature, and continue to react for 4-8 hours. Concentrate the reaction solution under reduced pressure to remove most of the solvent, and purify the crude product by recrystallization to obtain the intermediate product. b. Under nitrogen protection, the intermediate product is dissolved in tetrahydrofuran, glycidyl furfuryl ether and catalyst are added, and dehydrating agent is added. The reaction system is heated to 60-80℃ and stirred for 12-24 hours. After the reaction is completed, solid impurities are removed by filtration, and the filtrate is concentrated under reduced pressure. The crude product is purified by recrystallization to obtain a latent promoter.

[0013] Preferably, in step a, the ratio of 5-amino-2-mercaptobenzimidazole, 4-hydroxybutylvinyl ether and ethanol is 1.65 g:(1.28-1.51) g:(10-20) mL.

[0014] Preferably, in step a, the photoinitiator is benzoin dimethyl ether, and the amount added is 1%-6% of the mass of 5-amino-2-mercaptobenzimidazole.

[0015] Preferably, in step b, the ratio of intermediate product, glycidyl furfural ether, and tetrahydrofuran is 2.8 g:(1.54-1.62) g:(20-30) mL.

[0016] Preferably, in step b, the catalyst is triethylamine, and the amount added is 2%-5% of the mass of glycidyl furfuryl ether.

[0017] Secondly, the present invention provides a method for preparing a high-adhesion epoxy adhesive, comprising: Step 1: Add hydrogenated epoxy resin, secondary mercaptan curing agent, stabilizer and coupling agent into the reactor in the specified proportions, control the temperature between 25-30℃ with circulating water, and stir thoroughly. Step 2: Add a latent accelerator, stir thoroughly again, vacuum degas, discharge and package.

[0018] The beneficial effects of this invention are as follows: 1. This invention prepares an epoxy adhesive with good compatibility among its components, a simple preparation method that does not require complex reactions or harsh conditions, a simple and controllable production process, and stable product quality, making it very suitable for large-scale industrial production and application.

[0019] 2. The resin component selected is hydrogenated epoxy resin. Compared with commonly used bisphenol A epoxy resin, hydrogenated epoxy resin has low viscosity, high reactivity, and excellent weather resistance. The curing agent selected is a secondary thiol curing agent. Secondary thiol curing agents have high functionality and can form a curing network with high crosslinking density and low internal stress with epoxy resin. In addition, the latent accelerator prepared in this invention has a better promoting effect on the thiol-epoxy curing system than traditional amine curing systems, resulting in cured products with lower water absorption and better hydrolysis resistance.

[0020] 3. This invention prepares a novel latent accelerator, DHC. The accelerator is prepared by first using 5-amino-2-mercaptobenzimidazole and 4-hydroxybutylvinyl ether through a click chemical reaction, followed by a condensation reaction with glycidyl furfuryl ether, resulting in a multifunctional, heat-sensitive, structured accelerator integrating benzimidazole, thioether, flexible chain, furfuryl group, and hydroxyl group. Compared to traditional tertiary amine and imidazole accelerators, its active center is blocked by its molecular structure, exhibiting higher chemical inertness at room temperature. When curing is required, DHC can be rapidly activated at relatively low temperatures (e.g., 80°C), efficiently catalyzing the thiol-epoxy ring-opening addition reaction to achieve rapid curing. This not only reduces the energy consumption of the curing process but also avoids potential thermal damage and internal thermal stress caused by high-temperature curing to heat-sensitive substrates, broadening the application range of adhesives.

[0021] 4. The adhesive prepared by this invention exhibits stable viscosity and good flowability after mixing at room temperature, making it suitable for various application processes such as dispensing, potting, and impregnation. Its latent properties ensure that the viscosity will not increase sharply or flow due to exothermic reactions during application, making it particularly suitable for applications requiring precise control of adhesive quantity or complex filling. Its rapid curing upon heating further improves production efficiency. Detailed Implementation

[0022] To better understand the above technical solutions, exemplary embodiments of the present invention are described in more detail below. While exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0023] The present invention will be further described below with reference to the following embodiments.

[0024] Raw material information is shown in Table 1 below: Table 1. Raw material information used in the examples and comparative examples Example 1 A high-adhesion epoxy adhesive, comprising, by weight parts: Hydrogenated epoxy resin: 42 parts, secondary thiol curing agent: 54 parts, latent accelerator: 3 parts, stabilizer: 0.5 parts, coupling agent: 0.5 parts.

[0025] The hydrogenated epoxy resin is diglycidyl tetrahydrophthalate; the secondary thiol curing agent is pentaerythritol tetra(3-mercaptobutyric acid) ester; the stabilizer is salicylic acid; and the coupling agent is 2-(3,4-epoxycyclohexyl)ethoxysilane.

[0026] The preparation method of the latent promoter DHC includes the following steps: a. In a dry reaction flask, 1.65 g of 5-amino-2-mercaptobenzimidazole was added to 15 mL of anhydrous ethanol and stirred under nitrogen protection. 1.41 g of 4-hydroxybutylvinyl ether and 0.05 g of photoinitiator benzoin dimethyl ether were added, and stirring was continued until the system was homogeneous. The reaction mixture was irradiated with ultraviolet light (wavelength 365 nm) at room temperature (25 °C) for 4-8 h. The reaction solution was concentrated under reduced pressure to remove most of the solvent. The crude product was purified by recrystallization to obtain the intermediate product. b. Under nitrogen protection, 2.8 g of intermediate product was dissolved in 25 mL of tetrahydrofuran, 1.58 g of glycidyl furfural ether and 0.05 g of triethylamine catalyst were added, and an appropriate amount of molecular sieve was added to absorb the water generated in the reaction. The reaction system was heated to 70 °C and stirred for 18 h. After the reaction was completed, the molecular sieve and possible solid impurities were removed by filtration. The filtrate was concentrated under reduced pressure, and the crude product was purified by recrystallization to obtain the latent promoter DHC.

[0027] The method for preparing the above-mentioned high-adhesion epoxy adhesive includes: Step 1: Add hydrogenated epoxy resin, secondary mercaptan curing agent, stabilizer and coupling agent into the reactor in the specified proportions, control the temperature between 25-30℃ with circulating water, and stir thoroughly. Step 2: Add a latent accelerator, stir thoroughly again, vacuum degas, discharge and package.

[0028] Example 2 A high-adhesion epoxy adhesive, comprising, by weight parts: Hydrogenated epoxy resin: 44 parts, secondary thiol curing agent: 52 parts, latent accelerator: 3 parts, stabilizer: 0.5 parts, coupling agent: 0.5 parts.

[0029] The hydrogenated epoxy resin is diglycidyl hexahydrophthalic acid; the secondary thiol curing agent is pentahexanetriol tris(3-mercaptobutyric acid); the stabilizer is salicylic acid; the coupling agent is 3-glycidylpropyltrimethoxysilane; and the preparation method of the latent accelerator is the same as in Example 1.

[0030] The method for preparing the above-mentioned high-adhesion epoxy adhesive includes: Step 1: Add hydrogenated epoxy resin, secondary mercaptan curing agent, stabilizer and coupling agent into the reactor in the specified proportions, control the temperature between 25-30℃ with circulating water, and stir thoroughly. Step 2: Add a latent accelerator, stir thoroughly again, vacuum degas, discharge and package.

[0031] Example 3 A high-adhesion epoxy adhesive, comprising, by weight parts: Hydrogenated epoxy resin: 48 parts, secondary thiol curing agent: 48 parts, latent accelerator: 3 parts, stabilizer: 0.5 parts, coupling agent: 0.5 parts.

[0032] Wherein, the hydrogenated epoxy resin is hydrogenated bisphenol A epoxy resin; the secondary thiol curing agent is bis(3-mercaptobutyric acid)-1,4-butanediol ester; the stabilizer is salicylic acid; the coupling agent is 2-(3,4-epoxycyclohexyl)ethalkyltrimethoxysilane; and the preparation method of the latent accelerator is the same as in Example 1.

[0033] The method for preparing the above-mentioned high-adhesion epoxy adhesive includes: Step 1: Add hydrogenated epoxy resin, secondary mercaptan curing agent, stabilizer and coupling agent into the reactor in the specified proportions, control the temperature between 25-30℃ with circulating water, and stir thoroughly. Step 2: Add a latent accelerator, stir thoroughly again, vacuum degas, discharge and package.

[0034] Example 4 A high-adhesion epoxy adhesive, comprising, by weight parts: Hydrogenated epoxy resin: 40-100 parts, secondary thiol curing agent: 40-100 parts, latent accelerator: 3 parts, stabilizer: 0.5 parts, coupling agent: 0.5 parts.

[0035] Wherein, the hydrogenated epoxy resin is diglycidyl tetrahydrophthalate; the secondary thiol curing agent is pentaerythritol tetrakis(3-mercaptobutyric acid) ester; the stabilizer is fumaric acid; the coupling agent is 3-glycidylpropyltrimethoxysilane; and the preparation method of the latent accelerator is the same as in Example 1.

[0036] The method for preparing the above-mentioned high-adhesion epoxy adhesive includes: Step 1: Add hydrogenated epoxy resin, secondary mercaptan curing agent, stabilizer and coupling agent into the reactor in the specified proportions, control the temperature between 25-30℃ with circulating water, and stir thoroughly. Step 2: Add a latent accelerator, stir thoroughly again, vacuum degas, discharge and package.

[0037] Example 5 A high-adhesion epoxy adhesive differs from Example 1 in that the preparation method parameters of the latent accelerator are different.

[0038] The preparation method of the latent promoter includes the following steps: a. In a dry reaction flask, 1.65 g of 5-amino-2-mercaptobenzimidazole was added to 10 mL of anhydrous ethanol. The mixture was stirred under nitrogen protection, and then 1.28 g of 4-hydroxybutylvinyl ether and 0.02 g of photoinitiator benzoin dimethyl ether were added. The mixture was stirred until homogeneous. The reaction mixture was irradiated with ultraviolet light (wavelength 365 nm) at room temperature (25 °C) for 4-8 h. The reaction solution was concentrated under reduced pressure to remove most of the solvent. The crude product was purified by recrystallization to obtain the intermediate product. b. Under nitrogen protection, 2.8 g of intermediate product was dissolved in 20 mL of tetrahydrofuran, 1.54 g of glycidyl furfural ether and 0.03 g of triethylamine catalyst were added, and an appropriate amount of molecular sieve was added to absorb the water generated in the reaction. The reaction system was heated to 60 °C and stirred for 12 h. After the reaction was completed, the molecular sieve and possible solid impurities were removed by filtration. The filtrate was concentrated under reduced pressure, and the crude product was purified by recrystallization to obtain the latent promoter.

[0039] Example 6 A high-adhesion epoxy adhesive differs from Example 1 in that the preparation method parameters of the latent accelerator are different.

[0040] The preparation method of the latent promoter includes the following steps: a. In a dry reaction flask, 1.65 g of 5-amino-2-mercaptobenzimidazole was added to 20 mL of anhydrous ethanol. The mixture was stirred under nitrogen protection, and then 1.51 g of 4-hydroxybutylvinyl ether and 0.1 g of photoinitiator benzoin dimethyl ether were added. The mixture was stirred until homogeneous. The reaction mixture was irradiated with ultraviolet light (wavelength 365 nm) at room temperature (25 °C) for 8 h. The reaction solution was concentrated under reduced pressure to remove most of the solvent. The crude product was purified by recrystallization to obtain the intermediate product. b. Under nitrogen protection, 2.8 g of intermediate product was dissolved in 30 mL of tetrahydrofuran, 1.62 g of glycidyl furfural ether and 0.08 g of triethylamine catalyst were added, and an appropriate amount of molecular sieve was added to absorb the water generated in the reaction. The reaction system was heated to 80 °C and stirred for 24 h. After the reaction was completed, the molecular sieve and possible solid impurities were removed by filtration. The filtrate was concentrated under reduced pressure, and the crude product was purified by recrystallization to obtain the latent promoter.

[0041] Comparative Example 1 An epoxy adhesive, differing from Example 1 in that the latent accelerator DHC is replaced with the latent accelerator DF.

[0042] The preparation method of the latent promoter DF includes the following steps: 1.65 g of 5-amino-2-mercaptobenzimidazole was added to 15 mL of anhydrous ethanol and stirred under nitrogen protection. 1.41 g of 4-hydroxybutylvinyl ether and 0.05 g of photoinitiator benzoin dimethyl ether were added, and stirring was continued until the system was homogeneous. The reaction mixture was irradiated with ultraviolet light (wavelength 365 nm) at room temperature (25 °C) for 4-8 h. The reaction solution was concentrated under reduced pressure to remove most of the solvent. The crude product was purified by recrystallization to obtain the latent promoter DF.

[0043] Comparative Example 2 An epoxy adhesive differs from Example 1 in that the secondary thiol curing agent is replaced with a primary thiol curing agent, and the primary thiol curing agent is pentaerythritol tetramercaptoacetate.

[0044] The specific components of the epoxy adhesives prepared in Examples 1-4 and Comparative Examples 1-2 are shown in Table 2: Table 2. Comparison of the components of the epoxy adhesives prepared in the examples and comparative examples. Experimental Example The epoxy adhesives prepared in Examples 1-4 and Comparative Examples 1-2 were tested respectively: 1. The test items and methods are shown in Table 3: Table 3 Test Items and Methods 2. The test data are shown in Tables 4 and 5: Table 4 Test data after curing Table 5 Data after damp heat aging and thermal shock aging Comparing the test data after curing in Table 4, the basic properties of Examples 1-4 all meet the conditions of curing within 20 minutes at 80℃, initial yellowness <1.0, bond strength >10MPa, and operability at room temperature >10 days. In Comparative Example 1, the latent accelerator DHC was replaced with the latent accelerator DF, resulting in a higher curing temperature and a decrease in bond strength, which is below 10MPa. In Comparative Example 2, the secondary thiol was replaced with the primary thiol, resulting in decreased stability and an operability at 25℃ of less than 10 days.

[0045] Comparing the damp heat aging and thermal shock test data in Table 5, the bonding strength of Comparative Example 1 decreased again, falling below 5 MPa; the yellowing of the adhesive in Comparative Example 2 increased significantly after aging compared to other cases, and the bonding strength and light transmittance also decreased significantly, indicating that its aging resistance was worse than other cases.

[0046] In summary, this demonstrates that although the amount of latent accelerator added is small, it has a significant impact on the performance of epoxy resin. The latent accelerator prepared in the embodiments of this invention... The curing efficiency, mechanical properties, thermal stability, environmental resistance, and storage stability of epoxy resins are determined by these factors. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0047] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-adhesion epoxy adhesive, characterized in that, Calculated by weight, including: Hydrogenated epoxy resin: 40-100 parts, secondary thiol curing agent: 40-100 parts, latent accelerator: 0.5-5 parts, stabilizer: 0.1-5 parts, coupling agent: 0.1-1 parts; The latent promoter is prepared by using 5-amino-2-mercaptobenzimidazole and 4-hydroxybutylvinyl ether to prepare an intermediate product through a click chemical reaction, and then reacting it with glycidyl furfuryl ether to obtain the final product.

2. The high-adhesion epoxy adhesive according to claim 1, characterized in that, The hydrogenated epoxy resin includes at least one selected from tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, hydrogenated bisphenol A epoxy resin, hydrogenated bisphenol F epoxy resin, 1,2-cyclohexanediol diglycidyl ether, and 1,4-cyclohexanediol diglycidyl ether.

3. The high-adhesion epoxy adhesive according to claim 1, characterized in that, The secondary thiol curing agent is at least one of pentaerythritol tetra(3-mercaptobutyric acid), pentahexanetriol tris(3-mercaptobutyric acid), di(3-mercaptobutyric acid)-1,4-butanediol ester, and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

4. The high-adhesion epoxy adhesive according to claim 1, characterized in that, The stabilizer is at least one of salicylic acid, barbituric acid, stearic acid, lauric acid, and fumaric acid.

5. The high-adhesion epoxy adhesive according to claim 1, characterized in that, The coupling agent is a silane coupling agent, including at least one of 2-(3,4-epoxycyclohexyl)ethoxysilane, 3-glycidylpropyltrimethoxysilane, 3-glycidylpropylmethyldiethoxysilane, 3-glycidylpropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropylmethyldiethoxysilane.

6. The high-adhesion epoxy adhesive according to claim 1, characterized in that, The preparation method of the latent promoter includes the following steps: a. Add 5-amino-2-mercaptobenzimidazole to ethanol, stir under nitrogen protection, add 4-hydroxybutylvinyl ether and photoinitiator, continue stirring to mix the system evenly, irradiate the reaction mixture with ultraviolet light at room temperature, and continue to react for 4-8 hours. Concentrate the reaction solution under reduced pressure to remove most of the solvent, and purify the crude product by recrystallization to obtain the intermediate product. b. Under nitrogen protection, the intermediate product is dissolved in tetrahydrofuran, glycidyl furfuryl ether and catalyst are added, and dehydrating agent is added. The reaction system is heated to 60-80℃ and stirred for 12-24 hours. After the reaction is completed, solid impurities are removed by filtration, and the filtrate is concentrated under reduced pressure. The crude product is purified by recrystallization to obtain a latent promoter.

7. The high-adhesion epoxy adhesive according to claim 6, characterized in that, In step a, the ratio of 5-amino-2-mercaptobenzimidazole, 4-hydroxybutyl vinyl ether and ethanol is 1.65 g:(1.28-1.51) g:(10-20) mL; the photoinitiator is benzoin dimethyl ether, and the amount added is 1%-6% of the mass of 5-amino-2-mercaptobenzimidazole.

8. The high-adhesion epoxy adhesive according to claim 6, characterized in that, In step b, the ratio of intermediate product, glycidyl furfur ether, and tetrahydrofuran is 2.8 g:(1.54-1.62) g:(20-30) mL; the catalyst is triethylamine, and the amount added is 2%-5% of the mass of glycidyl furfur ether.

9. The high-adhesion epoxy adhesive according to claim 6, characterized in that, The curing conditions for the epoxy adhesive are: curing at 80℃ for 10-20 minutes.

10. A method for preparing the high-adhesion epoxy adhesive according to claim 1, characterized in that, include: Step 1: Add hydrogenated epoxy resin, secondary mercaptan curing agent, stabilizer and coupling agent into the reactor in the specified proportions, control the temperature between 25-30℃ with circulating water, and stir thoroughly. Step 2: Add a latent accelerator, stir thoroughly again, vacuum degas, discharge and package.

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