Epoxy potting adhesive, preparation method and application thereof

Abstract

The application provides an epoxy pouring sealant and a preparation method and application thereof. The epoxy pouring sealant comprises component A and component B; the component A comprises an epoxy resin, carboxyl-terminated butyl nitrile rubber and an epoxy diluent, the epoxy resin comprises bisphenol F type epoxy resin, phosphorus-containing epoxy resin and tetraglycidyl amine type epoxy resin; and the component B comprises a curing agent, an accelerator, a dispersant and a filler. The epoxy pouring sealant has the advantages of low viscosity of a bisphenol F type epoxy resin (YDF-170) and methylhexahydrophthalic anhydride system, stable curing exothermicity and shrinkage rate, so that the pouring sealant can realize low bubble rate after pouring, strong adhesion and difficulty in causing glass to break during the curing process. Meanwhile, the formula has strong basic CTI capacity and excellent comprehensive performance.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to an epoxy potting compound, its preparation method, and its application. Background Technology

[0002] Encapsulating adhesives are used in complex applications such as the connection between water and glass, and between electrodes and wires. Generally, the following methods are used to seal water sections: First, rubber ring sealing; however, creepage and ozone can easily cause rubber rings to catch fire or age and fail. Second, silicone ring sealing; however, the high and low temperature cycles during discharge can reduce the elasticity of silicone rings, leading to leaks and shortening the product's lifespan. Third, silicone sealant sealing; however, it does not meet electrical performance requirements, and the adhesion between the sealant and the glass interface is weak, making it prone to leakage after high and low temperature cycles. Fourth, epoxy sealant sealing; however, some epoxy sealants fail to meet electrical aging performance standards, harden after curing, and due to the difference in expansion coefficients between epoxy and glass, high and low temperature cycles can cause internal stress in the glass, potentially leading to breakage.

[0003] Meanwhile, the high-voltage electrode and its wire connections also require potting protection. If exposed to air, corrosion, aging, and even electric arcing may occur. The heat generated during the discharge process causes the high-voltage electrode to heat up, with the temperature in the discharge area reaching over 200°C. This temperature change also affects the potting area. If the potting compound is not chosen appropriately, it can easily loosen from the high-voltage electrode, leading to water and air leaks.

[0004] Therefore, among the aforementioned sealing solutions, epoxy potting compound is still the optimal choice. However, conventional potting compounds cannot meet the application requirements. For example, the two-component epoxy potting compound resistant to high and low temperature cracking in Chinese patent CN115926703A utilizes the low viscosity of bisphenol F epoxy resin to enhance the potting compound's permeability and uses polyurethane-modified epoxy resin for toughening, achieving the effect of resisting high and low temperature cracking. However, this potting compound cures at room temperature and does not significantly improve flame retardancy, electrical properties, or heat resistance. Another example is the nitrogen- and phosphorus-containing high-temperature halogen-free flame-retardant resin composition in Chinese patent CN116444950A. This composition improves epoxy vinyl resin by blending two types of epoxy resins, one containing nitrogen and the other phosphorus, so that the final cured molecular chains contain nitrogen and phosphorus. This achieves intrinsic flame retardancy while ensuring high high-temperature resistance of the resin; the maximum heat resistance temperature is 220℃, but it cannot be used as a potting compound.

[0005] Therefore, there is an urgent need for an epoxy potting compound that is resistant to high and low temperature cracking, tracking, halogen-free flame retardancy, and thermal aging. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention proposes an epoxy potting compound, its preparation method, and its application.

[0007] In a first aspect, the present invention provides an epoxy potting compound comprising component A and component B; wherein component A comprises epoxy resin, carboxyl-terminated nitrile rubber, and epoxy diluent, and wherein the epoxy resin comprises bisphenol F type epoxy resin, phosphorus-containing epoxy resin, and tetraglycidylamine type epoxy resin.

[0008] Component B includes a curing agent, an accelerator, a dispersant, and a filler.

[0009] As a specific embodiment of the present invention, component A further includes defoamer, dispersant, flame retardant and colorant.

[0010] In a specific embodiment of the present invention, the amount of carboxyl-terminated nitrile rubber added is 2 to 5% of the total mass of epoxy resin, preferably 4%.

[0011] As a specific embodiment of the present invention, the epoxy diluent is trimethylolpropane glycidyl ether, and the amount added is 5-8% of the total mass of the epoxy resin.

[0012] As a specific embodiment of the present invention, the defoamer includes BYK900, and the amount added is 0.1-0.5% of the total mass of epoxy resin.

[0013] As a specific embodiment of the present invention, the dispersant includes BYK108, and the amount added is 0.1-0.5% of the total mass of epoxy resin.

[0014] As a specific embodiment of the present invention, the flame retardant includes melamine urate, and the amount added is 40% to 50% of the total mass of epoxy resin.

[0015] As a specific embodiment of the present invention, the colorant includes titanium dioxide, and the amount added is 1-2% of the total mass of epoxy resin.

[0016] As a specific embodiment of the present invention, the mass ratio of the bisphenol F type epoxy resin, the phosphorus-containing epoxy resin, and the tetraglycidylamine type epoxy resin is (5-7):(2-4):1; preferably 6:3:1.

[0017] As a specific embodiment of the present invention, the curing agent in component B includes methylhexahydrophthalic anhydride.

[0018] As a specific embodiment of the present invention, the accelerator includes DMP-30, and the amount added is 1-3% of the mass of the curing agent, preferably 2%.

[0019] As a specific embodiment of the present invention, the dispersant includes BYK108, and the amount added is 1-3% of the mass of the curing agent, preferably 2%.

[0020] In a specific embodiment of the present invention, the filler includes aluminum hydroxide, and the amount added is 70-100% of the mass of the curing agent, preferably 75-85%, and most preferably 80%; the particle size of the aluminum hydroxide is less than 2000 mesh.

[0021] The preferred filler in the epoxy potting compound of the present invention is aluminum hydroxide, as the conductivity of carbon black is not conducive to its application in the high alternating electric field and creepage environment of the plasma activated water device.

[0022] Secondly, the present invention provides a method for preparing the epoxy potting compound described in the first aspect, comprising the following steps:

[0023] S1: Mix the epoxy resin, carboxyl-terminated nitrile rubber, epoxy diluent, defoamer, dispersant, flame retardant and colorant evenly to obtain component A;

[0024] S2: Component B is obtained by uniformly mixing the curing agent, accelerator, dispersant and filler;

[0025] S3: Mix component A and component B evenly, degas, pot and cure to obtain the epoxy potting compound.

[0026] As a specific embodiment of the present invention, step S1 includes the following steps:

[0027] S11: Mix the epoxy resin and carboxyl-terminated butadiene-acrylonitrile rubber to obtain a first mixture;

[0028] S12: Add epoxy diluent, defoamer, dispersant, flame retardant and colorant to the first mixture obtained in step S11, and mix evenly to obtain component A.

[0029] According to the present invention, the three epoxy resins are premixed. After the addition of carboxyl-terminated nitrile butadiene rubber (CTBN), the mixture undergoes partial molecular polymerization, which reduces the internal stress caused by asynchronous curing due to different types of epoxy resins. At the same time, the pre-reaction of CTBN with epoxy resins also improves the dispersibility of CTBN, further reducing the risk of internal stress; it can also improve the final quality of epoxy potting compound.

[0030] In a specific embodiment of the present invention, in step S1, the epoxy resin includes bisphenol F type epoxy resin, phosphorus-containing epoxy resin, and tetraglycidylamine type epoxy resin; the mass ratio of the bisphenol F type epoxy resin, phosphorus-containing epoxy resin, and tetraglycidylamine type epoxy resin is (5-7):(2-4):1; preferably 6:3:1.

[0031] As a specific embodiment of the present invention, step S1 is further described as follows:

[0032] (1) Add bisphenol F type epoxy resin to the reactor and stir to raise the temperature to 80°C;

[0033] (2) Add phosphorus-containing epoxy resin to the reactor and stir until it melts and is evenly mixed;

[0034] (3) Add tetraglycidylamine type epoxy resin to the reactor and stir until melted and mixed evenly;

[0035] (4) Add CTBN to the reactor and stir at 75-85℃ for 1-2 hours;

[0036] (5) Cool down to 45-55℃, add epoxy diluent to the reactor, and stir evenly;

[0037] (6) Add defoamer and dispersant to the reactor and stir until homogeneous;

[0038] (7) Add flame retardant to the reactor and stir until homogeneous;

[0039] (8) Add colorant to the reactor; stir and mix evenly to obtain component A.

[0040] In a specific embodiment of the present invention, in step S3, the mass ratio of component A to component B is (0.5-2):1, preferably 1:1;

[0041] As a specific embodiment of the present invention, in step S3, the curing conditions include: first curing at a temperature of 80°C for 0.5-2 hours, then curing at a temperature of 110°C for 1-2 hours, and finally curing at a temperature of 120°C for 3-5 hours.

[0042] Thirdly, the present invention provides the application of the epoxy potting compound described in the first aspect or the epoxy potting compound prepared by the preparation method described in the second aspect in the field of sealing.

[0043] As a specific embodiment of the present invention, the sealing field is particularly used in areas where water and electricity meet.

[0044] All of the above-mentioned raw materials used in this invention can be prepared in-house or purchased commercially; this invention does not impose any particular limitations on them.

[0045] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0046] 1. The epoxy potting compound of this invention utilizes the low viscosity, stable curing exothermic response, and low shrinkage of the bisphenol F type epoxy resin (YDF-170) and methylhexahydrophthalic anhydride system, resulting in a low bubble rate, strong adhesion, and reduced risk of glass breakage during curing. Furthermore, this formulation exhibits strong basic CTI (Cryogenic Tolerance) capability and excellent overall performance.

[0047] 2. The epoxy potting compound formulation system of the present invention introduces CTBN (carboxyl-terminated nitrile butadiene rubber) to increase the elasticity of the potting compound. The amount added is controlled at 3-5%. The increased elasticity can ensure that the glass tube does not crack during high and low temperature cycling, and at the same time, it will not reduce the temperature resistance of the resin system too much.

[0048] 3. The epoxy potting compound of this invention introduces a mixed epoxy system to improve the temperature resistance and halogen-free flame retardant properties of the potting compound. The epoxy system incorporates phosphorus-containing epoxy EP-1033 and AG-80 epoxy. The former increases the phosphorus content of the resin system, while the latter increases the crosslinking density of the resin. Since both EP-1033 and AG-80 have relatively high viscosity, to achieve better results and further improve the epoxy dispersibility of CTBN, a stepwise addition method is used: first, the epoxy resin and carboxyl-terminated nitrile rubber are mixed, and then other components are added to ensure uniform mixing and a certain degree of prepolymerization of the epoxy resin. This method can reduce internal stress caused by asynchronous curing due to different epoxy types. Simultaneously, the pre-reaction between CTBN and epoxy also improves the dispersibility of CTBN, further reducing the risk of internal stress.

[0049] 4. In the epoxy potting compound of this invention, halogen-free MCA flame retardant filler is used as an external nitrogen source to achieve a synergistic flame retardant effect of phosphorus and nitrogen. MCA has a high nitrogen content and a high decomposition temperature, resulting in good flame retardant effect while having minimal impact on the temperature resistance rating of the system. The epoxy potting compound of this invention is resistant to high and low temperature cracking, tracking, halogen-free flame retardancy, and heat aging, and in particular meets the practical application requirements of plasma-activated water devices.

[0050] 5. In the epoxy potting compound of the present invention, aluminum hydroxide with a particle size passing through a 2000-mesh sieve is used as an auxiliary filler, auxiliary flame retardant, and auxiliary agent to enhance electrical tracking resistance. Controlling the addition ratio of MCA to aluminum hydroxide to achieve a 1:1 mass ratio of epoxy to curing agent is more beneficial for practical applications.

[0051] 6. In the epoxy potting compound of the present invention, the preferred colorant is titanium dioxide. The conductivity of carbon black is not conducive to its application in the high alternating electric field and creepage environment of the plasma activated water device. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of a plasma-activated water reaction device in an application example of the present invention. Detailed Implementation

[0053] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0054] Example 1

[0055] This embodiment provides an epoxy potting compound and its preparation method, with specific details as follows:

[0056] S1: Preparation of component A:

[0057] (1) Add 60 parts of bisphenol F type epoxy resin YDF-170 to the reactor, stir and heat to 80℃;

[0058] (2) Add 30 parts of phosphorus-containing epoxy resin EP-1033 to the reactor and stir until melted and mixed evenly;

[0059] (3) Add 10 parts of tetraglycidylamine type epoxy resin AG-80 to the reactor, stir until melted and mixed evenly to obtain the total amount of epoxy resin.

[0060] (4) Add 4 parts of carboxyl-terminated butadiene-acrylonitrile rubber (CTBN) to the reactor and stir for 1.5 hours at 80°C.

[0061] (5) Cool down to 50°C, add 6 parts of epoxy diluent trimethylolpropane glycidyl ether (636 diluent) to the reactor, and stir evenly;

[0062] (6) Add 0.5 parts of defoamer BYK900 and 0.5 parts of dispersant BYK108 to the reactor and stir until homogeneous;

[0063] (7) Add 50 parts of flame retardant melamine urate (MCA) to the reactor and stir until homogeneous;

[0064] (8) Add 2 parts of titanium dioxide colorant to the reactor to make it white; stir and mix evenly, then cool to room temperature to obtain component A. The proportions are shown in Table 1:

[0065] Table 1

[0066] Bisphenol F type epoxy resin YDF-170 60 Phosphorus-containing epoxy EP-1033 30 Tetraglycidylamine type epoxy resin AG-80 10 Carboxyl-terminated butadiene nitrile rubber (CTBN) 4 636 diluent 6 Defoamer BYK900 0.5 Dispersant BYK108 0.5 Melamine urate (MCA) 50 Titanium dioxide 2

[0067] S2: Preparation of component B:

[0068] 100 parts of curing agent methylhexahydrophthalic anhydride, 2 parts of accelerator DMP-30, 2 parts of dispersant BYK108 and 80 parts of aluminum hydroxide (particle size passed through a 2000-mesh sieve) were added to the reactor and stirred until homogeneous to obtain component B.

[0069] S3: Mix component A obtained in step S1 and component B obtained in step S2 at a mass ratio of 1:1. After mixing evenly, perform degassing treatment. After potting, first cure at 80℃ for 1 hour, then cure at 110℃ for 1.5 hours, and finally cure at 120℃ for 4 hours to obtain epoxy potting compound.

[0070] The epoxy potting compound obtained in Example 1 was tested, and the results are shown in Table 2:

[0071] Table 2

[0072]

[0073]

[0074] Example 2

[0075] This embodiment provides an epoxy potting compound and its preparation method, with specific details as follows:

[0076] S1: Preparation of component A:

[0077] The preparation method is the same as in Example 1, and the formulation of component A is shown in Table 3:

[0078] Table 3

[0079] Bisphenol F type epoxy resin YDF-170 50 Phosphorus-containing epoxy EP-1033 40 Tetraglycidylamine type epoxy resin AG-80 10 Carboxyl-terminated butadiene nitrile rubber (CTBN) 4 636 diluent 8 Defoamer BYK900 0.5 Dispersant BYK108 0.5 melamine urate MCA 50 Titanium dioxide 2

[0080] S2: Same as Example 1.

[0081] S3: Same as Example 1.

[0082] The epoxy potting compound obtained in Example 2 was tested, and the results are shown in Table 4:

[0083] Table 4

[0084]

[0085] Example 3

[0086] This embodiment provides an epoxy potting compound and its preparation method, with specific details as follows:

[0087] S1: Preparation of component A:

[0088] The preparation method is the same as in Example 1, and the formulation of component A is shown in Table 5:

[0089] Table 5

[0090] Bisphenol F type epoxy resin YDF-170 70 Phosphorus-containing epoxy EP-1033 20 Tetraglycidylamine type epoxy resin AG-80 10 Carboxyl-terminated butadiene nitrile rubber (CTBN) 4 636 diluent 6 Defoamer BYK900 0.5 Dispersant BYK108 0.5 melamine urate MCA 50 Titanium dioxide 2

[0091] S2: Same as Example 1.

[0092] S3: Same as Example 1.

[0093] The epoxy potting compound obtained in Example 3 was tested, and the results are shown in Table 6:

[0094] Table 6

[0095]

[0096] Comparative Example 1

[0097] This comparative example provides an epoxy potting compound and its preparation method, with specific details as follows:

[0098] S1: Preparation of component A:

[0099] The preparation method is the same as in Example 1, and the formulation of component A is shown in Table 7:

[0100] Table 7

[0101] Bisphenol A epoxy resin E51 90 Phosphorus-containing epoxy EP-1033 30 AG-80 10 Carboxyl-terminated butadiene nitrile rubber (CTBN) 4 636 diluent 16 Defoamer BYK900 0.5 Dispersant BYK108 0.5 melamine urate MCA 50 Titanium dioxide 2

[0102] S2: Same as Example 1.

[0103] S3: Same as Example 1.

[0104] The epoxy potting compound obtained in Example 1 was tested, and the results are shown in Table 8:

[0105] Table 8

[0106]

[0107] Application examples

[0108] The epoxy potting compound obtained in Example 1 was applied to a plasma-activated water device, such as... Figure 1 As shown, a quartz glass tube is partially submerged in water, with the water grounded. The electrodes inside the quartz tube are connected to a high-voltage circuit. When an alternating current is applied between the high-voltage electrode and the grounding electrode, a dielectric barrier discharge occurs between the high-voltage electrode and the quartz glass medium. Gas blown in through the air inlet carries the generated active substances into the water. When commercializing this prototype, two issues need to be addressed: 1. The entire system must be airtight. In a high-voltage, water-based environment, leaks pose a risk of electric shock to users. 2. The high-voltage electrode connectors must be sealed. High voltage combined with a humid environment can easily lead to problems such as point discharge, accelerated corrosion of metal electrodes, and accelerated electro-aging of exposed parts.

[0109] In underwater plasma discharge devices, the main reaction area is dielectric barrier discharge, where water serves as one electrode. Although water is considered a conductor, its conductivity is actually weak. In this device, the water exhibits a different potential difference from the grounding electrode depending on its distance from the grounding electrode. Simultaneously, due to issues such as bubble disturbance, water evaporation as a coolant, and other factors, creepage can occur at points of contact with the outside environment, such as the junction of the glass tube and the water tank cover, and the vent (generally considered grounded and at zero potential). These creepages are difficult to eliminate or avoid.

[0110] Due to the unique environment at the connection between the glass tube and the water tank cover, many sealed water sections cannot be used. Furthermore, the high-voltage electrode and its wire connections require potting protection; exposure to air can easily lead to corrosion, aging, and even electric arcing. The heat generated during the discharge process causes the high-voltage electrode to heat up, with temperatures in the discharge area reaching over 200°C. This heat transfer to the potting area also causes temperature changes. If the potting compound is not chosen appropriately, it can easily loosen from the high-voltage electrode, leading to water and air leaks.

[0111] The epoxy potting compound obtained in Example 1 was applied to the connection between the glass tube and the water tank cover. The actual application performance was excellent. It was able to run continuously for 72 hours without leakage or tracking, and it was resistant to high temperature, halogen-free flame retardant, and resistant to high and low temperature cycles.

[0112] In summary, the epoxy potting compound of this invention, using a low-viscosity bisphenol F epoxy resin and methylhexahydrophthalic anhydride base system, exhibits excellent tracking resistance and insulation properties, considering both impregnation and low curing speed. The three-component epoxy compound, with the introduction of CTBN pre-curing, and the separate addition of phosphorus-containing epoxy and AG-80, along with the pre-curing step, ensures uniform molecular mixing and the pre-crosslinking of CTBN, all contributing to its effectiveness. The phosphorus-nitrogen synergistic flame retardancy is achieved through the introduction of phosphorus from the phosphorus-containing epoxy and nitrogen from the filler. The MCA contains a large amount of nitrogen, which can alleviate tracking issues in this application, while the MCA does not affect the product's temperature resistance. The synergistic effect of aluminum hydroxide enhances tracking resistance and halogen-free flame retardancy, and also allows adjustment of the mass ratio between component A and component B to achieve a precise 1:1 ratio, facilitating subsequent application formulation.

[0113] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 50-90, in this specification it means specifically listing values ​​such as 51-89, 52-88… and 69-71 and 70-71, etc. For non-integer values, it may be appropriately considered that a unit is 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0114] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. An epoxy potting compound, characterized in that, This epoxy potting compound comprises component A and component B; component A comprises epoxy resin, carboxyl-terminated nitrile butadiene rubber, and epoxy diluent, and also includes defoamer, dispersant, flame retardant, and colorant; the epoxy resin comprises bisphenol F type epoxy resin, phosphorus-containing epoxy resin, and tetraglycidylamine type epoxy resin, and the mass ratio of the bisphenol F type epoxy resin, phosphorus-containing epoxy resin, and tetraglycidylamine type epoxy resin is (5-7):(2-4):1; the amount of carboxyl-terminated nitrile butadiene rubber added is 2-5% of the total mass of epoxy resin; Component B includes a curing agent, an accelerator, a dispersant, and a filler; The preparation method of the epoxy potting compound includes the following steps: S1: Mix the epoxy resin, carboxyl-terminated nitrile rubber, epoxy diluent, defoamer, dispersant, flame retardant and colorant evenly to obtain component A; S2: Component B is obtained by uniformly mixing the curing agent, accelerator, dispersant and filler; S3: Mix component A and component B evenly, degas, pot, and cure to obtain the epoxy potting compound; Step S1 includes the following steps: S11: Mix the epoxy resin and carboxyl-terminated butadiene-acrylonitrile rubber to obtain a first mixture; S12: Add epoxy diluent, defoamer, dispersant, flame retardant and colorant to the first mixture obtained in step S11, and mix evenly to obtain component A.

2. The epoxy potting compound according to claim 1, characterized in that, The epoxy diluent is trimethylolpropane glycidyl ether, and the amount of trimethylolpropane glycidyl ether added is 5-8% of the total mass of the epoxy resin.

3. The epoxy potting compound according to claim 2, characterized in that, The amount of carboxyl-terminated butadiene-acrylonitrile rubber added is 4% of the total mass of the epoxy resin.

4. The epoxy potting compound according to any one of claims 1-3, characterized in that, The defoamer includes BYK900, and the amount of BYK900 added is 0.1-0.5% of the total mass of the epoxy resin; and / or The dispersant includes BYK108, and the amount of BYK108 added is 0.1-0.5% of the total mass of the epoxy resin; and / or The flame retardant includes melamine urate, and the amount of melamine urate added is 40% to 50% of the total mass of the epoxy resin; and / or The colorant includes titanium dioxide, and the amount of titanium dioxide added is 1-5% of the total mass of epoxy resin.

5. The epoxy potting compound according to claim 4, characterized in that, The amount of titanium dioxide added is 2% of the total mass of epoxy resin.

6. The epoxy potting compound according to any one of claims 1-3, characterized in that, The curing agent in component B includes methylhexahydrophthalic anhydride; and / or The accelerator includes DMP-30, and the amount of DMP-30 added is 1-3% of the mass of the curing agent; and / or The dispersant includes BYK108, and the amount of BYK108 added is 1-3% of the mass of the curing agent; and / or The filler includes aluminum hydroxide, and the amount of aluminum hydroxide added is 70-100% of the mass of the curing agent; the particle size of the aluminum hydroxide is less than 2000 mesh.

7. The epoxy potting compound according to claim 6, characterized in that, The amount of DMP-30 added is 2% of the mass of the curing agent; and / or The amount of BYK108 added is 2% of the mass of the curing agent; and / or The amount of aluminum hydroxide added is 75-85% of the mass of the curing agent.

8. The epoxy potting compound according to claim 7, characterized in that, The amount of aluminum hydroxide added is 80% of the mass of the curing agent.

9. A method for preparing the epoxy potting compound according to any one of claims 1-8, characterized in that, Includes the following steps: S1: Mix the epoxy resin, carboxyl-terminated nitrile rubber, epoxy diluent, defoamer, dispersant, flame retardant and colorant evenly to obtain component A; S2: Component B is obtained by uniformly mixing the curing agent, accelerator, dispersant and filler; S3: Mix component A and component B evenly, degas, pot, and cure to obtain the epoxy potting compound; Step S1 includes the following steps: S11: Mix the epoxy resin and carboxyl-terminated butadiene-acrylonitrile rubber to obtain a first mixture; S12: Add epoxy diluent, defoamer, dispersant, flame retardant and colorant to the first mixture obtained in step S11, and mix evenly to obtain component A.

10. The preparation method according to claim 9, characterized in that, The mass ratio of the bisphenol F type epoxy resin, the phosphorus-containing epoxy resin, and the tetraglycidylamine type epoxy resin is 6:3:

1.

11. The preparation method according to claim 9 or 10, characterized in that, In step S3, the mass ratio of component A to component B is (0.5-2):1; The curing conditions include: first curing at 80℃ for 0.5-2 hours, then curing at 110℃ for 1-2 hours, and finally curing at 120℃ for 3-5 hours.

12. The preparation method according to claim 11, characterized in that, In step S3, the mass ratio of component A to component B is 1:

1.

13. The application of the epoxy potting compound according to any one of claims 1-8 or the epoxy potting compound prepared by the preparation method according to any one of claims 9-12 in the field of sealing.

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