Low-temperature-resistant and waterproof epoxy potting adhesive and its preparation process

Abstract

The present invention relates to the field of potting adhesive technology, particularly to the field of IPC C09J163. Furthermore, it relates to a low-temperature-resistant, waterproof epoxy potting adhesive and its preparation process. It is prepared by mixing component A and component B in a weight ratio of (4-6):1; the component A comprises the following raw materials in parts by weight: 80-90 parts of epoxy resin, 80-110 parts of inorganic filler, 10-20 parts of diluent, 10-20 parts of toughening agent, and 3-7 parts of auxiliary agent; the component B is a composite curing agent. The epoxy potting adhesive prepared by the present invention can be used in extremely low-temperature environments and has excellent waterproof properties. It is suitable for sealing electronic components in extremely low-temperature, high-humidity, or underwater environments.

Description

Technical Field

[0001] The present invention relates to the technical field of potting adhesives, in particular to the field of IPC C09J163, and further to a low-temperature-resistant and waterproof epoxy potting adhesive and a preparation process thereof. Background Art

[0002] As an insulating material that prevents direct exposure of components and circuits, potting compound is indispensable in the electronics industry. Currently, commercially available potting compounds include epoxy, polyurethane, and silicone. Epoxy potting compounds are widely used due to their superior overall performance. However, commercially available epoxy potting compounds are highly hygroscopic. When used on electronic components in high-humidity or underwater environments, this can degrade the dielectric properties of these components, leading to equipment failures and other problems. Furthermore, thermal shrinkage at low temperatures can produce significant internal stress, resulting in poor toughness and a tendency for the compound to crack or peel.

[0003] Chinese patent CN 201910742669 discloses a highly heat-resistant and low-temperature resistant epoxy resin potting compound and its preparation method. The epoxy resin potting compound is prepared by mixing component A and component B in a mass ratio of 100:30-50 and curing at 120°C for 2 hours, 150°C for 2 hours, and 180°C for 4 hours to produce the epoxy potting compound. This invention utilizes a special epoxy resin (nitrile rubber core-shell modified epoxy) and a unique modification process to ensure both excellent low-temperature and heat resistance. The use of methyl nadic anhydride or its modified form as a curing agent imparts a high glass transition temperature to the product, resulting in excellent high-temperature resistance. A flame-retardant system of brominated epoxy resin and antimony trioxide imparts excellent flame retardancy. However, this technical solution suffers from high curing temperatures, prolonged curing times, and demanding curing conditions. Summary of the Invention

[0004] The first aspect of the present invention provides a low-temperature resistant and waterproof epoxy potting adhesive, which is mixed by component A and component B in a weight ratio of (4-6):1; the component A includes the following raw materials in parts by weight: 80-90 parts of epoxy resin, 80-110 parts of inorganic filler, 10-20 parts of diluent, 10-20 parts of toughening agent, and 3-7 parts of auxiliary agent; the component B is a composite curing agent.

[0005] Preferably, the epoxy resin is selected from one or a combination of the epoxy resin of formula (1) and the epoxy resin of formula (2); the epoxy resin of formula (1):

[0006]

[0007] Formula (2) epoxy resin:

[0008]

[0009] Among them, R1 is a weakly polar binding group, R2 is a flexible skeleton, and n is a natural number.

[0010] Preferably, the epoxy resin is selected from a combination of the epoxy resin of formula (1) and the epoxy resin of formula (2).

[0011] Preferably, the weight ratio of the epoxy resin of formula (1) to the epoxy resin of formula (2) is (60-75):(10-20).

[0012] Preferably, the epoxy resin of formula (1) has a viscosity of 11,000 to 15,000 cps / 25° C. and an epoxy equivalent weight of 180 to 190 g / eq.

[0013] Preferably, the epoxy resin of formula (2) has a viscosity of 13,000 to 17,000 cps / 25° C. and an epoxy equivalent weight of 430 to 450 g / eq.

[0014] Preferably, the epoxy resin of formula (2) has a viscosity of 15000 cps / 25° C. and an epoxy equivalent weight of 450 g / eq.

[0015] Through extensive creative research, the applicant discovered that when the present application system selects the epoxy resin of formula (1) with a viscosity of 11,000 to 15,000 cps / 25°C and an epoxy equivalent of 180 to 190 g / eq and the epoxy resin of formula (2) with a viscosity of 13,000 to 17,000 cps / 25°C and an epoxy equivalent of 430 to 450 g / eq in a weight ratio of (60 to 75): (10 to 20), while improving the shear strength of the epoxy potting adhesive, it can also further reduce its curing shrinkage and improve its flexibility. The applicant speculates that this is because: on the one hand, it can reduce the surface tension of the system, thereby improving the wettability to the substrate, thereby improving the bonding strength while reducing the generation of internal stress, reducing its curing shrinkage, and improving its flexibility; on the other hand, the addition of the epoxy resin of formula (2) further improves its flexibility due to its unique soft skeleton.

[0016] Preferably, the inorganic filler is selected from one or more combinations of alumina, silicon powder, aluminum hydroxide, and calcium carbonate.

[0017] Preferably, the inorganic filler is selected from a combination of alumina and silica powder.

[0018] Preferably, the mass ratio of the aluminum oxide to the silicon powder is 1:(2-4).

[0019] Preferably, the silicon micropowder is flaky silicon micropowder.

[0020] Preferably, the particle size of the flaky silicon powder is 500-800 mesh.

[0021] Preferably, the alumina is spherical alumina.

[0022] Preferably, the average particle size D50 of the spherical alumina is 0.5 to 3 μm.

[0023] Preferably, the average particle size D50 of the spherical flaky aluminum oxide is 1 to 3 μm.

[0024] During the experiment, the applicant discovered that when the present application used flaky silicon micropowder with a particle size of 500-800 mesh alone, the compatibility of the flaky silicon micropowder with epoxy resin was poor, resulting in a large shrinkage rate after the potting compound was cured and poor waterproofing effect. However, when a certain amount of spherical alumina was added to the flaky silicon micropowder, the shrinkage rate of the potting compound after curing could be reduced to a certain extent, and the shear strength could be increased; at the same time, the waterproof performance of the potting compound could also be improved. The applicant speculates that this is because: on the one hand, the flaky silicon micropowder and spherical alumina can increase the filling amount of the powder and reduce the curing shrinkage rate. When the potting compound layer is subjected to force, the flaky silicon micropowder and spherical alumina can absorb part of the stress and thus increase the shear strength; on the other hand, the addition of flaky silicon micropowder and spherical alumina increases the surface roughness of the potting compound layer, improves the hydrophobicity of the potting compound layer, and further improves the waterproofness of the potting compound.

[0025] Preferably, the diluent is selected from at least one of 1,4-butanediol diglycidyl ether, n-butyl glycidyl ether, and neopentyl glycol diglycidyl ether.

[0026] Preferably, the toughening agent is selected from at least one of nano core-shell rubber epoxy resin toughening agent, polyurethane toughening agent, and liquid carboxyl-terminated nitrile rubber.

[0027] Preferably, the toughening agent is a nano core-shell rubber epoxy resin toughening agent.

[0028] Preferably, the nano core-shell rubber epoxy resin toughening agent comprises the following raw materials: liquid bisphenol A epoxy resin and nano core-shell rubber; the content of the nano core-shell rubber component is 30 to 50 wt%.

[0029] Preferably, the nano core-shell rubber is selected from at least one of styrene-butadiene rubber and polybutadiene rubber.

[0030] Preferably, the nano core-shell rubber is polybutadiene rubber.

[0031] Preferably, the epoxy equivalent of the nano core-shell rubber epoxy resin toughening agent is 270 to 310 g / eq.

[0032] Preferably, the auxiliary agent is selected from at least one of a defoaming agent, a dispersant, and a black paste.

[0033] Preferably, the auxiliary agent is a combination of a defoaming agent and a black paste.

[0034] Preferably, the mass ratio of the defoaming agent to the color paste is (1-3): (2-4).

[0035] Preferably, the defoaming agent is selected from at least one of an organosilicon defoaming agent, a polymer defoaming agent, an organosilicon and a polymer defoaming agent.

[0036] Preferably, the composite curing agent comprises the following raw materials in parts by weight: 45 to 55 parts of curing agent and 1 to 3 parts of accelerator.

[0037] Preferably, the curing agent is selected from one or a combination of polyamide curing agent and alicyclic amine curing agent.

[0038] Preferably, the curing agent is a polyamide curing agent.

[0039] Preferably, the polyamide curing agent has an amine value of 350 to 420 mgKOH / g and a viscosity of 700 to 1200 mPa.s / 25°C.

[0040] Preferably, the polyamide curing agent has an amine value of 390 mgKOH / g and a viscosity of 900 mPa.s / 25°C.

[0041] Preferably, the accelerator is at least one selected from 2,4,6-tris(dimethylaminomethyl)phenol and dimethylaminomethylphenol.

[0042] Preferably, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0043] The present applicant has found through a large number of creative experiments that when the epoxy resin of formula (1) with a viscosity of 11000-15000 cps / 25°C and an epoxy equivalent of 180-190 g / eq and the epoxy resin of formula (2) with a viscosity of 13000-17000 cps / 25°C and an epoxy equivalent of 430-450 g / eq and the nano core-shell rubber epoxy resin toughening agent with an epoxy equivalent of 270-310 g / eq are selected in the present application system, the bonding performance and flexibility of the epoxy potting compound can be improved, but it still cannot be used in an extreme low temperature environment (such as -45°C); in order to solve the above technical problems, the present applicant has found through a large number of creative experiments that when the present application adopts polyamide as a curing agent and 2,4,6-tris(dimethylaminomethyl)phenol as an accelerator, the flexibility of the epoxy potting compound can be further improved, and the epoxy potting compound can have good flexibility in an extreme low temperature environment while further improving the waterproofness of the epoxy potting compound. The applicant speculates that this is because the longer fatty acid carbon chain contained in the polyamide structure can further isolate the rigid internal benzene ring in the epoxy resin molecule in the system of the present application, further improving the flexibility of the epoxy potting compound; at the same time, its unique -CO-NH- can further improve the waterproof performance of the epoxy potting compound while also reducing the polar groups in the molecular structure of the epoxy potting compound after curing, thereby achieving excellent waterproof effect while achieving extreme low temperature resistance.

[0044] During the experiment, the applicant further found that when the amine value of the polyamide curing agent is 350-420 mgKOH / g and the viscosity is 700-1200 mPa.s / 25°C, especially when the amine value of the polyamide curing agent is 390 mgKOH / g and the viscosity is 900 mPa.s / 25°C, it can not only improve the curing reaction of polyamide with epoxy resin and toughening agent to a certain extent, but also avoid incomplete internal curing caused by excessive reaction. At the same time, it can also avoid affecting the permeability of the epoxy potting adhesive and its bonding performance.

[0045] A second aspect of the present invention provides a preparation process for a low-temperature resistant and waterproof epoxy potting adhesive, comprising the following steps:

[0046] (1) Weigh each raw material by weight;

[0047] (2) mixing the epoxy resin, filler, diluent, toughening agent and additives and stirring them uniformly, and then vacuum degassing to obtain component A;

[0048] (3) mixing the curing agent and the accelerator and stirring them uniformly, and then vacuum degassing to obtain component B;

[0049] (4) Mix the A component and the B component evenly according to the weight ratio.

[0050] Beneficial effects:

[0051] 1. The present application selects an epoxy resin of formula (1) with a viscosity of 11,000 to 15,000 cps / 25°C and an epoxy equivalent of 180 to 190 g / eq in a weight ratio of (60 to 75): (10 to 20) and an epoxy resin of formula (2) with a viscosity of 13,000 to 17,000 cps / 25°C and an epoxy equivalent of 430 to 450 g / eq. While improving the shear strength of the epoxy potting compound, it can also further reduce its curing shrinkage and improve its flexibility.

[0052] 2. When using 500-800 mesh flaky silicon powder alone in this application, its compatibility with epoxy resin is poor, resulting in large shrinkage of the potting compound after curing and poor waterproofing. However, adding a certain amount of spherical alumina to the flaky silicon powder can reduce the shrinkage of the potting compound after curing to a certain extent, improve shear strength, and also enhance the waterproofing performance of the potting compound.

[0053] 3. The present application selects a nano core-shell rubber epoxy resin toughening agent, especially when the nano core-shell rubber epoxy resin toughening agent includes liquid bisphenol A epoxy resin and nano core-shell rubber; the content of the nano core-shell rubber component is 30 to 50 wt%; the nano core-shell rubber is polybutadiene rubber, and the epoxy equivalent of the nano core-shell rubber epoxy resin toughening agent is 270 to 310 g / eq. While improving the flexibility of the epoxy potting compound, it can also maintain its good hardness; at the same time, it can further improve its low temperature resistance, so that it can be used in extreme low temperature environments.

[0054] 4. When this application uses polyamide as a curing agent and 2,4,6-tris(dimethylaminomethyl)phenol as an accelerator, it can further improve the flexibility of the epoxy potting adhesive, ensure that the epoxy potting adhesive has good flexibility in extreme low temperature environments, and further improve the waterproofness of the epoxy potting adhesive.

[0055] 5. In this application, when the amine value of the polyamide curing agent is 350-420 mgKOH / g and the viscosity is 700-1200 mPa.s / 25°C, especially when the amine value of the polyamide curing agent is 390 mgKOH / g and the viscosity is 900 mPa.s / 25°C, it can not only improve the curing reaction of polyamide with epoxy resin and toughening agent to a certain extent, but also avoid incomplete internal curing caused by excessive reaction. At the same time, it can also avoid affecting the permeability of the epoxy potting adhesive and its bonding performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a photograph of the appearance of the epoxy potting adhesive prepared in Example 1 of the present invention before being immersed in water.

[0057] Figure 2 This is a photograph of the appearance of the epoxy potting adhesive prepared in Example 1 of the present invention when immersed in water. DETAILED DESCRIPTION

[0058] Example 1

[0059] Example 1 provides a low-temperature resistant, waterproof epoxy potting compound, which is mixed by component A and component B in a weight ratio of 5:1; the component A includes the following raw materials in parts by weight: 85 parts of epoxy resin, 90 parts of inorganic filler, 10 parts of diluent, 12 parts of toughening agent, and 5 parts of auxiliary agent; the component B is a composite curing agent.

[0060] The epoxy resin is selected from a combination of the epoxy resin of formula (1) and the epoxy resin of formula (2); the epoxy resin of formula (1):

[0061]

[0062] Formula (2) epoxy resin:

[0063]

[0064] Among them, R1 is a weakly polar binding group, R2 is a flexible skeleton, and n is a natural number.

[0065] The weight ratio of the epoxy resin of formula (1) to the epoxy resin of formula (2) is 70:15.

[0066] The epoxy resin of formula (1) has a viscosity of 11,000 to 15,000 cps / 25° C. and an epoxy equivalent weight of 180 to 190 g / eq. It was purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd., model: NPEL-128.

[0067] The epoxy resin of formula (2) has a viscosity of 15,000 cps / 25° C. and an epoxy equivalent weight of 450 g / eq. It was purchased from Qingdao DIC Fine Chemical Co., Ltd., model number: EXA-4850-150.

[0068] The inorganic filler is selected from a combination of alumina and silica powder.

[0069] The mass ratio of the aluminum oxide to the silicon powder is 1:3.

[0070] The silicon micropowder is flaky silicon micropowder.

[0071] The particle size of the flaky silicon powder is 800 mesh and was purchased from Shandong Jialin Energy Technology Co., Ltd.

[0072] The aluminum oxide is spherical aluminum oxide.

[0073] The spherical alumina has an average particle size D50 of 2 μm and is purchased from Qinhuangdao Yinuo High-tech Materials Development Co., Ltd., model: S02.

[0074] The diluent is 1,4-butanediol diglycidyl ether.

[0075] The toughening agent is a nano core-shell rubber epoxy resin toughening agent.

[0076] The nano core-shell rubber epoxy resin toughening agent comprises liquid bisphenol A epoxy resin and nano core-shell rubber; the content of the nano core-shell rubber component is 40 wt%.

[0077] The nano core-shell rubber is polybutadiene rubber.

[0078] The epoxy equivalent of the nano core-shell rubber epoxy resin toughening agent is 301 g / eq, and the model is: Zhongyuan Chemical MX154.

[0079] The auxiliary agent is a combination of a defoamer and a black color paste.

[0080] The mass ratio of the defoamer to the color paste is 2:2.

[0081] The defoamer is a silicone and polymer defoamer, model: BYK530.

[0082] The composite curing agent includes the following raw materials in parts by weight: 45 parts of curing agent and 1.5 parts of accelerator.

[0083] The curing agent is a polyamide curing agent.

[0084] The polyamide curing agent has an amine value of 390 mgKOH / g and a viscosity of 900 mPa.s / 25° C., and its model is Evonik Ancamide 2784.

[0085] The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0086] A preparation process of a low-temperature resistant and waterproof epoxy potting adhesive comprises the following steps:

[0087] (1) Weigh each raw material by weight;

[0088] (2) mixing epoxy resin, filler, diluent, toughening agent and additives and stirring them uniformly, and then vacuum degassing to obtain component A;

[0089] (3) mixing the curing agent and the accelerator and stirring them uniformly, and then vacuum degassing to obtain component B;

[0090] (4) Mix the A component and the B component evenly according to the weight ratio.

[0091] Example 2

[0092] Example 2 Example 1 provides a low-temperature resistant, waterproof epoxy potting glue, which is mixed by component A and component B in a weight ratio of 5:1; the component A includes the following raw materials in parts by weight: 90 parts of epoxy resin, 95 parts of inorganic filler, 15 parts of diluent, 15 parts of toughening agent, and 5 parts of auxiliary agent; the component B is a composite curing agent.

[0093] The epoxy resin is selected from a combination of the epoxy resin of formula (1) and the epoxy resin of formula (2); the epoxy resin of formula (1):

[0094]

[0095] Formula (2) epoxy resin:

[0096]

[0097] Among them, R1 is a weakly polar binding group, R2 is a flexible skeleton, and n is a natural number.

[0098] The weight ratio of the epoxy resin of formula (1) to the epoxy resin of formula (2) is 72:18.

[0099] The epoxy resin of formula (1) has a viscosity of 11,000 to 15,000 cps / 25° C. and an epoxy equivalent weight of 180 to 190 g / eq. It was purchased from Nan Ya Epoxy Resin (Kunshan) Co., Ltd., model: NPEL-128.

[0100] The epoxy resin of formula (2) has a viscosity of 15,000 cps / 25° C. and an epoxy equivalent weight of 450 g / eq. It was purchased from Qingdao DIC Fine Chemical Co., Ltd., model number: EXA-4850-150.

[0101] The inorganic filler is selected from a combination of alumina and silica powder.

[0102] The mass ratio of the aluminum oxide to the silicon powder is 1:3.

[0103] The silicon micropowder is flaky silicon micropowder.

[0104] The particle size of the flaky silicon powder is 800 mesh and was purchased from Shandong Jialin Energy Technology Co., Ltd.

[0105] The aluminum oxide is spherical aluminum oxide.

[0106] The spherical alumina has an average particle size D50 of 2 μm and is purchased from Qinhuangdao Yinuo High-tech Materials Development Co., Ltd., model: S02.

[0107] The diluent is 1,4-butanediol diglycidyl ether.

[0108] The toughening agent is a nano core-shell rubber epoxy resin toughening agent.

[0109] The nano core-shell rubber epoxy resin toughening agent comprises liquid bisphenol A epoxy resin and nano core-shell rubber; the content of the nano core-shell rubber component is 40 wt%.

[0110] The nano core-shell rubber is polybutadiene rubber.

[0111] The epoxy equivalent of the nano core-shell rubber epoxy resin toughening agent is 301 g / eq, and the model is: Zhongyuan Chemical MX154.

[0112] The auxiliary agent is a combination of a defoamer and a black color paste.

[0113] The mass ratio of the defoamer to the color paste is 2:3.

[0114] The defoamer is a silicone and polymer defoamer, model: BYK530.

[0115] The composite curing agent includes the following raw materials in parts by weight: 48 parts of curing agent and 1.6 parts of accelerator.

[0116] The curing agent is a polyamide curing agent.

[0117] The polyamide curing agent has an amine value of 390 mgKOH / g and a viscosity of 900 mPa.s / 25° C., and its model is Evonik Ancamide 2784.

[0118] The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0119] A preparation process of a low-temperature resistant and waterproof epoxy potting adhesive comprises the following steps:

[0120] (1) Weigh each raw material by weight;

[0121] (2) mixing epoxy resin, filler, diluent, toughening agent and additives and stirring them uniformly, and then vacuum degassing to obtain component A;

[0122] (3) mixing the curing agent and the accelerator and stirring them uniformly, and then vacuum degassing to obtain component B;

[0123] (4) Mix the A component and the B component evenly according to the weight ratio.

[0124] Comparative Example 1

[0125] Comparative Example 1 provides a low-temperature resistant and waterproof epoxy potting compound, the specific implementation of which is the same as that of Example 1, except that the epoxy resin of formula (2) is replaced by flexible epoxy resin EP-4000, which is purchased from Wuxi Huilong Electronic Materials Co., Ltd.

[0126] A preparation process of a low-temperature resistant and waterproof epoxy potting adhesive, the specific implementation method of which is the same as that of Example 1.

[0127] Comparative Example 2

[0128] Comparative Example 2 provides a low-temperature resistant, waterproof epoxy potting compound, the specific implementation of which is the same as that of Example 1, except that the nano core-shell rubber epoxy resin toughening agent with model number MX154 of Kaneka Chemical is replaced with model number MX113 of Kaneka Chemical; the nano core-shell rubber epoxy resin toughening agent includes liquid bisphenol A epoxy resin and nano core-shell rubber; the content of the nano core-shell rubber component is 33wt%.

[0129] The nano core-shell rubber is styrene-butadiene rubber.

[0130] The epoxy equivalent of the nano core-shell rubber epoxy resin toughening agent is 260 g / eq.

[0131] A preparation process of a low-temperature resistant and waterproof epoxy potting adhesive, the specific implementation method of which is the same as that of Example 1.

[0132] Comparative Example 3

[0133] Comparative Example 3 provides a low-temperature resistant and waterproof epoxy potting compound, the specific implementation of which is the same as that of Example 1, except that the curing agent is an alicyclic amine curing agent purchased from Guangzhou Libaoshi Trading Development Co., Ltd., model: EPIKURE3370.

[0134] A preparation process of a low-temperature resistant and waterproof epoxy potting adhesive, the specific implementation method of which is the same as that of Example 1.

[0135] Performance testing:

[0136] 1. The test items and test methods of the epoxy potting adhesive prepared in Example 1 before curing are shown in Table 1.

[0137] 2. Test items and test methods after curing of Examples 1-2 and Comparative Examples 1-3 are shown in Table 2: Curing conditions are 80°C and time is 30 min; the appearance of the epoxy potting glue prepared in Example 1 before immersion in water during the water absorption test is shown in Table 2. Figure 1 As shown; the appearance photo when immersed in water is as follows Figure 2 shown.

[0138] Test results:

[0139] Table 1

[0140]

[0141] Table 2

[0142]

Claims

1. A low temperature resistant and waterproof epoxy potting adhesive, characterized in that: The invention is prepared by mixing component A and component B in a weight ratio of (4-6):1; the component A comprises the following raw materials in parts by weight: 80-90 parts of epoxy resin, 80-110 parts of inorganic filler, 10-20 parts of diluent, 10-20 parts of toughening agent, and 3-7 parts of auxiliary agent; the component B is a composite curing agent; the epoxy resin is a combination of the epoxy resin of formula (1) and the epoxy resin of formula (2), and the weight ratio of the epoxy resin of formula (1) to the epoxy resin of formula (2) is (60-75):(10-20); the epoxy resin of formula (1): ； Formula (2) epoxy resin: ； Wherein, R1 is a weak polar binding group, R2 is a flexible skeleton, and n is a natural number; the viscosity of the epoxy resin of formula (1) is 11000~15000 cps, and the epoxy equivalent is 180~190 g / eq; the viscosity of the epoxy resin of formula (2) is 13000~17000 cps / 25℃, and the epoxy equivalent is 430~450 g / eq, model EXA-4850-150; the inorganic filler is selected from a combination of alumina and silicon powder, the mass ratio of the alumina to the silicon powder is 1: (2~4), the silicon powder is flaky silicon powder, and the particle size of the flaky silicon powder is 500~800 mesh; the alumina is spherical alumina, and the average particle size D50 of the spherical alumina is 0.5~3µm; the toughening agent is a nano core-shell rubber epoxy resin toughening agent, and the nano core-shell rubber epoxy resin toughening agent includes the following raw materials: liquid bisphenol A epoxy resin and nano core-shell rubber; the content of the nano core-shell rubber component is 30~50wt%; the nano core-shell rubber is polybutadiene rubber, and the epoxy equivalent of the nano core-shell rubber epoxy resin toughening agent is 270~310 g / eq; the composite curing agent includes the following raw materials in parts by weight: 45-55 parts of a curing agent and 1-3 parts of an accelerator, the curing agent is a polyamide curing agent, the amine value of the polyamide curing agent is 350-420 mgKOH / g, the viscosity at 25°C is 700-1200 mPa.s, and the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

2. A preparation process of the low-temperature resistant and waterproof epoxy potting adhesive according to claim 1, characterized in that: The following steps are involved: (1) Weigh each raw material by weight; (2) The epoxy resin, inorganic filler, diluent, toughening agent and additive are mixed and stirred evenly, and then vacuum degassed to obtain component A; (3) Mix the curing agent and accelerator and stir them evenly, then vacuum degas to obtain component B; (4) Mix component A and component B evenly according to the weight ratio.

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