Bi-component heat-conducting epoxy pouring sealant with cold and hot impact resistance and preparation method of bi-component heat-conducting epoxy pouring sealant

Abstract

The invention discloses a two-component heat-conducting epoxy pouring sealant resistant to cold and hot impact and a preparation method of the two-component heat-conducting epoxy pouring sealant resistant to cold and hot impact, and the two-component heat-conducting epoxy pouring sealant resistant to cold and hot impact comprises a component A and a component B, the component A is prepared from the following raw materials in parts by weight: 5 to 10 parts of epoxy resin, 1 to 5 parts of epoxy-terminated polybutadiene rubber, 1 to 5 parts of axle housing flexibilizer, 60 to 90 parts of filler, 0.1 to 0.5 part of dispersing agent, 0.1 to 0.5 part of anti-settling agent and 0.1 to 0.5 part of toner; the component B is prepared from the following raw materials in parts by weight: 10 to 20 parts of anhydride curing agent, 1 to 5 parts of accelerant, 60 to 90 parts of filler, 0.1 to 0.5 part of dispersing agent and 0.1 to 0.5 part of anti-settling agent. The axle housing toughening agent is mixed and matched with the epoxy-terminated polybutadiene rubber, and a special island structure is formed, so that the cold and hot impact resistance of the epoxy pouring sealant is greatly improved. The heat conductivity of the epoxy resin pouring sealant is improved, the heat dissipation performance is excellent, the hot and cold impact resistance can meet the pouring requirements of electronic product components, the loss is reduced, the energy is saved, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of potting adhesives, and more specifically to a two-component thermally conductive epoxy potting adhesive resistant to cold and heat shocks and a preparation method thereof. Background Art

[0002] As a thermosetting polymer insulating material with excellent performance that can be cured at room temperature or under heating conditions, potting glue can be used for bonding, sealing, potting and coating protection of electronic components. It is an important and indispensable insulating material in the electronics industry. Potting glue is in liquid state before curing and has fluidity. The viscosity of potting glue varies according to the material, performance and production process of the product. At present, common types of potting glue include: epoxy potting glue, polyurethane potting glue, silicone potting glue, epoxy-anhydride system potting glue and other categories.

[0003] Epoxy potting glue is widely used for potting and protection of important parts or integrated components of electronic and electrical equipment due to its excellent sealing, electrical insulation, chemical corrosion resistance and weather resistance, as well as high mechanical strength and thermal conductivity. There are many varieties of epoxy potting glue on the market, which can basically meet the needs of most applications. The thermal conductivity of ordinary epoxy resin potting glue is relatively small, generally between 0.8-1.0W / m·K, which cannot meet the high thermal conductivity requirements of electronic components. By increasing the amount of thermal conductive agent, the thermal conductivity may be improved to a certain extent, but it may affect the mechanical properties of the potting glue, and it is easy to cause a sharp increase in viscosity, affecting the construction performance, and it is also easy for the filler to settle.

[0004] In recent years, with the development of new energy vehicles, magnetic levitation, electromagnetic catapults, aerospace and navigation technologies, existing epoxy potting adhesives still have some shortcomings for some special occasions, especially those with harsh operating conditions, large workpiece sizes, and complex internal insert geometries. One of the more prominent shortcomings is that the potted workpieces are prone to cracking. Some of them crack immediately after the curing is completed and the temperature drops to room temperature; some of them accumulate internal stress and cracks after repeated impacts of high and low temperatures or mechanical stress, which eventually leads to cracking and failure of the potting adhesive.

[0005] Therefore, there is an urgent need for a new type of potting compound that can improve the thermal shock resistance of epoxy potting compounds while improving the thermal conductivity of the epoxy system. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the present invention provides a two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks and a preparation method thereof.

[0007] In order to achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: a two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks, comprising component A and component B, wherein component A comprises the following raw materials in parts by weight: 5-10 parts of epoxy resin, 1-5 parts of terminal epoxy polybutadiene rubber, 1-5 parts of bridge shell toughening agent, 60-90 parts of filler, 0.1-0.5 parts of dispersant, 0.1-0.5 parts of anti-settling agent, and 0.1-0.5 parts of color powder;

[0008] The B component comprises the following raw materials in parts by weight: 10-20 parts of anhydride curing agent, 1-5 parts of accelerator, 60-90 parts of filler, 0.1-0.5 parts of dispersant, and 0.1-0.5 parts of anti-settling agent.

[0009] In the two-component thermal shock-resistant thermally conductive epoxy potting adhesive of the present invention, the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin or alicyclic epoxy resin, and the viscosity of the epoxy resin is less than 1000 cps.

[0010] In the two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks of the present invention, the bridge shell toughening agent is a bridge shell nanoparticle toughening agent.

[0011] In the two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks of the present invention, the filler is spherical alumina, and the filler particle size is one or a mixture of a median particle size of 40-50 microns, a median particle size of 5-8 microns, and a median particle size of 0.5-1 micron.

[0012] In the two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks of the present invention, the dispersant is at least one of BYK9076 dispersant or EFKA-FA 4611 dispersant, the color powder is carbon black, and the anti-settling agent is preferably BYK P104 or ANTI-TERRA-204.

[0013] In the two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock of the present invention, the acid anhydride curing agent is a mixture of one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methylnadic anhydride MNA.

[0014] In the two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks of the present invention, the accelerator comprises a phenolic accelerator, a modified imidazole accelerator and an amine accelerator.

[0015] In order to achieve the purpose of the present invention, the present invention is implemented by another technical solution: a preparation method of a two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks, based on the above-mentioned two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks, comprising the following steps:

[0016] Step 1: Weigh epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, filler, dispersant, anti-settling agent and color powder according to the above weight parts, use a stirrer to mix the epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, dispersant and anti-settling agent, and then add filler and color powder in sequence and stir to obtain component A;

[0017] Step 2: Weigh the anhydride curing agent, accelerator, filler, dispersant and anti-settling agent according to the above weight parts, use a stirrer to mix the anhydride curing agent, accelerator, dispersant and anti-settling agent, and then add the filler and stir to obtain component B;

[0018] Step 3: Mix the prepared component A and component B in a mass ratio of 1:1 to prepare a two-component thermally conductive epoxy potting adhesive that is resistant to cold and heat shock.

[0019] In the preparation method of the two-component fast-curing thermally conductive epoxy structural adhesive of the present invention, in step 1, the mixer is a vacuum degassing mixer, and step 1 is specifically as follows:

[0020] The epoxy resin, the epoxy-terminated polybutadiene rubber, the crosslinking shell toughening agent, the dispersant and the anti-settling agent are first stirred at a speed of 900 rpm for 30 seconds, and then stirred at a speed of 1200 rpm for 120 seconds;

[0021] After adding the filler and color powder, stir at 900 rpm for 30 seconds, and then stir at 1200 rpm for 120 seconds;

[0022] The vacuum degree was set to be maintained at 0.07-0.1 MPa, the speed was 1200 rpm, and the mixture was stirred for 150 s. The mixture was cooled to room temperature to obtain component A.

[0023] In the preparation method of the two-component fast-curing thermally conductive epoxy structural adhesive of the present invention, in step 2, the mixer is a vacuum degassing mixer, and step 2 is specifically as follows:

[0024] The anhydride curing agent, accelerator, dispersant and anti-settling agent were first stirred at 900 rpm for 30 s, and then at 1200 rpm for 120 s;

[0025] After adding the filler, stir at 900 rpm for 30 s, then at 1200 rpm for 120 s;

[0026] The vacuum degree was set to be maintained at 0.07-0.1 MPa, the speed was 1200 rpm, and the mixture was stirred for 150 s. The mixture was cooled to room temperature to obtain component B.

[0027] The implementation of the two-component thermally conductive epoxy potting glue resistant to cold and heat shock and the preparation method thereof of the present invention has the following beneficial effects: the bridge shell toughening agent of the present invention is mixed with the end-epoxy polybutadiene rubber to form a special island structure, which greatly improves the resistance of the epoxy potting glue to cold and heat shock. At the same time, the addition of vapor-phase alumina by the present invention greatly improves the sedimentation and hardening problem that exists during the long-term storage of the formula. By adjusting the formula, the thermal conductivity of the epoxy resin potting glue is improved, the heat dissipation performance is excellent, and the resistance to cold and heat shock can meet the potting requirements of electronic product components, reduce losses, save energy, and extend service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0029] Figure 1 The present invention is a schematic flow chart of a method for preparing a two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock. DETAILED DESCRIPTION

[0030] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] In the present application, a two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks comprises a component A and a component B, wherein the component A comprises the following raw materials in parts by weight: 5-10 parts of epoxy resin, 1-5 parts of epoxy-terminated polybutadiene rubber, 1-5 parts of bridge shell toughening agent, 60-90 parts of filler, 0.1-0.5 parts of dispersant, 0.1-0.5 parts of anti-settling agent, and 0.1-0.5 parts of color powder;

[0032] The B component comprises the following raw materials in parts by weight: 10-20 parts of anhydride curing agent, 1-5 parts of accelerator, 60-90 parts of filler, 0.1-0.5 parts of dispersant, and 0.1-0.5 parts of anti-settling agent.

[0033] Preferably, the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin or alicyclic epoxy resin, and the viscosity of the epoxy resin is less than 1000 cps.

[0034] Preferably, the crosslinking shell toughening agent is a crosslinking shell nanoparticle toughening agent.

[0035] Preferably, the filler is spherical alumina, and the filler particle size is one of a median particle size of 40-50 microns, a median particle size of 5-8 microns, a median particle size of 0.5-1 micron, or a mixture of several thereof.

[0036] Preferably, the dispersant is at least one of BYK9076 dispersant and EFKA-FA 4611 dispersant, the toner is carbon black, and the anti-settling agent is BYK P104 or ANTI-TERRA-204.

[0037] Preferably, the anhydride curing agent is a mixture of one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methylnadic anhydride MNA.

[0038] Preferably, the accelerator comprises a phenolic accelerator, a modified imidazole accelerator and an amine accelerator.

[0039] like Figure 1 As shown, the present application also discloses a method for preparing a two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks, based on the above-mentioned two-component thermally conductive epoxy potting adhesive resistant to cold and hot shocks, comprising the following steps:

[0040] Step 1: Weigh epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, filler, dispersant, anti-settling agent and color powder according to the above weight parts, use a stirrer to mix the epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, dispersant and anti-settling agent, and then add filler and color powder in sequence and stir to obtain component A;

[0041] Step 2: Weigh the anhydride curing agent, accelerator, filler, dispersant and anti-settling agent according to the above weight parts, use a stirrer to mix the anhydride curing agent, accelerator, dispersant and anti-settling agent, and then add the filler and stir to obtain component B;

[0042] Step 3: Mix the prepared component A and component B in a mass ratio of 1:1 to prepare a two-component thermally conductive epoxy potting adhesive that is resistant to cold and heat shock.

[0043] Specifically, in step 1, the mixer is a vacuum degassing mixer, and step 1 is specifically as follows:

[0044] The epoxy resin, the epoxy-terminated polybutadiene rubber, the crosslinking shell toughening agent, the dispersant and the anti-settling agent are first stirred at a speed of 900 rpm for 30 seconds, and then stirred at a speed of 1200 rpm for 120 seconds;

[0045] After adding the filler and color powder, stir at 900 rpm for 30 seconds, and then stir at 1200 rpm for 120 seconds;

[0046] The vacuum degree was set to be maintained at 0.07-0.1 MPa, the speed was 1200 rpm, and the mixture was stirred for 150 s. The mixture was cooled to room temperature to obtain component A.

[0047] Specifically, in step 2, the mixer is a vacuum degassing mixer, and step 2 is specifically as follows:

[0048] The anhydride curing agent, accelerator, dispersant and anti-settling agent were first stirred at 900 rpm for 30 s, and then at 1200 rpm for 120 s;

[0049] After adding the filler, stir at 900 rpm for 30 s, then at 1200 rpm for 120 s;

[0050] The vacuum degree was set to be maintained at 0.07-0.1 MPa, the speed was 1200 rpm, and the mixture was stirred for 150 s. The mixture was cooled to room temperature to obtain component B.

[0051] Embodiment 1

[0052] The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock and the preparation method thereof in this embodiment are as follows:

[0053] The following preparation process was carried out using a vacuum degassing mixer purchased from DAC 600.2VAC vacuum type Hauschild Speed ​​Mixer.

[0054] Preparation of main agent A component: First, 9 parts of low viscosity epoxy resin S-06E (epoxy resin), 5 parts of MX150 (bridge shell toughening agent) and 4 parts of EPOLEAD PB3600 (terminated epoxy polybutadiene rubber), 0.2 parts of BYK 9076 (dispersant), 0.1 parts of P104S (anti-settling agent) were added to the material cup, and the speed was set to 900rpm for 30s+1200rmp for 120s. After stirring, fillers and color powder were added. The fillers were specifically 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Al u C, set the speed to 900rpm30s+1200rmp 120s. After stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp 150s, and cool to room temperature to obtain the main agent component A.

[0055] Preparation of curing agent component B: First, 17.5 parts of MNA (anhydride curing agent) and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole (curing agent) were added to the material cup, and the speed was set to 900rpm for 30s + 1200rmp for 120s. After stirring, 48 parts of filler were added. The filler was specifically aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Alu C, set the speed to 900rpm for 30s+1200rmp for 120s. After the stirring is completed, set the vacuum degree to maintain at 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0056] Embodiment 2

[0057] The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock and the preparation method thereof in this embodiment are as follows:

[0058] The following preparation process was carried out using a vacuum degassing mixer purchased from DAC 600.2VAC vacuum type Hauschild Speed ​​Mixer.

[0059] Preparation of main agent A: First, add 9 parts of low viscosity epoxy resin S-06E, 5 parts of MX150 and 4 parts of EPOLEADPB4700 (terminated epoxy polybutadiene rubber), 0.2 parts of BYK9076 and 0.1 parts of P104S into the material cup, set the speed to 900 rpm for 30s + 1200 rpm for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of aluminum oxide. Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component A.

[0060] Preparation of curing agent component B: First, add 17.5 parts of MNA and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole to the material cup, set the speed to 900rpm for 30s + 1200rpm for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After the stirring is completed, set the vacuum degree to maintain at 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0061] Embodiment 3

[0062] Preparation of main agent A: First, 9 parts of low viscosity epoxy resin S-06E, 5 parts of MX150 and 4 parts of Polybd 700S (terminated epoxy polybutadiene rubber), 0.2 parts of BYK9076 and 0.1 parts of P104S were added to the material cup, and the speed was set to 900rpm for 30s + 1200rpm for 120s. After stirring, 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of aluminum oxide were added. Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component A.

[0063] Preparation of curing agent component B: First, add 17.5 parts of MNA and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole to the material cup, set the speed to 900rpm for 30s + 1200rpm for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After the stirring is completed, set the vacuum degree to maintain at 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0064] Comparative Example 1

[0065] Preparation of main agent A: First, add 9 parts of low viscosity epoxy resin S-06E, 5 parts of MX150 and 4 parts of JDD861340 (terminated epoxy CTBN), 0.2 parts of BYK 9076 and 0.1 parts of P104S into the material cup, set the speed to 900rpm for 30s + 1200rmp for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component A.

[0066] Preparation of curing agent component B: First, add 17.5 parts of MNA and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole to the material cup, set the speed to 900rpm for 30s + 1200rpm for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After the stirring is completed, set the vacuum degree to maintain at 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0067] Comparative Example 2

[0068] Preparation of main agent A: First, add 9 parts of low viscosity epoxy resin S-06E, 2 parts of MX150 and 7 parts of EPOLEADPB3600, 0.2 parts of BYK 9076 and 0.1 parts of P104S into the material cup, set the speed to 900rpm for 30s + 1200rmp for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of aluminum oxide. Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component A.

[0069] Preparation of curing agent component B: First, add 17.5 parts of MNA and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole to the material cup, set the speed to 900rpm for 30s + 1200rpm for 120s. After stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of Al u C, set the speed to 900rpm for 30s+1200rmp for 120s. After the stirring is completed, set the vacuum degree to maintain at 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0070] Comparative Example 3

[0071] Preparation of main agent component A: First, 9 parts of low-viscosity epoxy resin S-06E, 5 parts of MX150 and 4 parts of EPOLEADPB3600, 0.2 parts of byk 9076 and 0.1 parts of P104S are added to the material cup, and the speed is set to 900rpm for 30s+1200rmp for 120s. After stirring, 48 parts of aluminum oxide A, 19 parts of aluminum oxide B and 15.5 parts of aluminum oxide C are added, and the speed is set to 900rpm for 30s+1200rmp for 120s. After stirring, the vacuum degree is set to 0.07-0.1MPa, stirred at 1200rmp for 150s, and cooled to room temperature to obtain the main agent component A;

[0072] Preparation of curing agent component B: First, add 17.5 parts of MNA and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole into the material cup respectively, set the speed to 900rpm for 30s+1200rmp for 120s, after stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, and 15.5 parts of aluminum oxide C, set the speed to 900rpm for 30s+1200rmp for 120s, after stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0073] Comparative Example 4

[0074] Preparation of main agent component A: First, 9 parts of low-viscosity epoxy resin S-06E, 5 parts of MX150 and 4 parts of EPOLEADPB3600, 0.2 parts of byk 9076 and 0.1 parts of P104S are added to the material cup, and the speed is set to 900rpm for 30s+1200rmp for 120s. After stirring, 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C and 0.5 parts of fumed silica are added, and the speed is set to 900rpm for 30s+1200rmp for 120s. After stirring, the vacuum degree is set to 0.07-0.1MPa, stirred at 1200rmp for 150s, and cooled to room temperature to obtain the main agent component A;

[0075] Preparation of curing agent component B: First, add 17.5 parts of MNA and 0.5 parts of 1-cyanoethyl-2-ethyl-4-methylimidazole into the material cup respectively, set the speed to 900rpm for 30s+1200rmp for 120s, after stirring, add 48 parts of aluminum oxide A, 19 parts of aluminum oxide B, 15 parts of aluminum oxide C, and 0.5 parts of fumed silica, set the speed to 900rpm for 30s+1200rmp for 120s, after stirring, set the vacuum degree to 0.07-0.1MPa, stir at 1200rmp for 150s, and cool to room temperature to obtain the main agent component B.

[0076] Performance Testing

[0077] The properties of the rubber before curing, and after curing at 110℃ for 12h, 150℃ for 2h and 180℃ for 5h.

[0078] Table 1 Test results of main properties of the rubber obtained in the embodiment

[0079] The samples prepared in the examples were subjected to the following tests:

[0080] Anti-sedimentation test: Each component was placed in a 100 ml transparent PC can and heat aged at 50°C to test the sedimentation performance of the filler-containing component.

[0081] Comparing Example 1 with Comparative Examples 3 and 4, during the preparation process, when 0.5 parts of fumed silica was added, the colloid in Comparative Example 3 appeared to be in a paste state and lost its fluidity at room temperature.

[0082] After one week at 50°C, the upper layer of Comparative Example 2 was relatively clear, while the bottom was compacted.

[0083] In Example 1, the bottom shows soft sedimentation, which has good anti-settling performance.

[0084] The test results of the thermal shock resistance of the thermally conductive epoxy potting adhesive prepared in Examples 1 to 3 and Example 1 are shown in Table 1.

[0085] (1) Thermal conductivity:

[0086] Sample preparation: Mix component A and component B in a volume ratio of 2:1, pour the mixed glue into the silicone mold, and cure at room temperature for 24 hours to obtain the test sample. Sample requirements: diameter 30mm, thickness ≤5mm, and smooth surface.

[0087] Coat a layer of thermal conductive silicone grease on the surface of the prepared sample, then put it into the equipment to start the test. Each test process is carried out according to the standard ASTM D5470. The equipment used for the test is Xiangtan Instrument DRL-V thermal conductivity tester, with a cold pole temperature of 20℃, a hot pole temperature of 60℃, and a test pressure of 200N.

[0088] The results are shown in Table 1. The test results are shown in Table 1 below.

[0089] Table 1 Test results of various embodiments

[0090] Thermal conductivity W / mk 250 times (-40℃-150℃) 500 times (-40℃-150℃) Embodiment 1 2.05 Uncracked Uncracked Embodiment 2 2.05 Uncracked Uncracked Embodiment 3 2.02 Uncracked Uncracked Comparative Example 1 2.03 Uncracked Cracking Comparative Example 2 2.01 Cracking -

[0091] It can be seen from the experiment in Table 1 that the thermally conductive epoxy potting glue suitable for the heat dissipation copper tube burying process prepared in Examples 1-3 did not crack after 500 hot and cold shocks at -40°C to 125°C. However, Comparative Examples 1 and 2 cracked after 250 and 500 hot and cold shocks. For Comparative Example 1, since ETBN contains polar groups, the toughening effect is relatively poor relative to the polybutadiene main chain. For Comparative Example 2, when the amount of epoxy polybutadiene added is high, the bulk strength of the material decreases, and there is a lack of sufficient nano-bridge shell particles to form an island structure, which cannot effectively improve the toughness of the material itself, resulting in bulk cracking after hot and cold shocks.

[0092] In addition, in the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", "stacked" and the like should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0093] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock, characterized in that: The method comprises component A and component B, wherein component A comprises the following raw materials in parts by weight: 5-10 parts of epoxy resin, 1-5 parts of terminal epoxy polybutadiene rubber, 1-5 parts of bridge shell toughening agent, 60-90 parts of filler, 0.1-0.5 parts of dispersant, 0.1-0.5 parts of anti-settling agent, and 0.1-0.5 parts of color powder; The B component comprises the following raw materials in parts by weight: 10-20 parts of anhydride curing agent, 1-5 parts of accelerator, 60-90 parts of filler, 0.1-0.5 parts of dispersant, and 0.1-0.5 parts of anti-settling agent.

2. The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 1, characterized in that: The epoxy resin is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin or alicyclic epoxy resin, and the epoxy resin has a viscosity of less than 1000 cps.

3. The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 1, characterized in that: The crosslinking shell toughening agent is a crosslinking shell nanoparticle toughening agent.

4. The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 1, characterized in that: The filler is spherical alumina, and the filler particle size is one of a median particle size of 40-50 microns, a median particle size of 5-8 microns, a median particle size of 0.5-1 micron, or a mixture of several of them.

5. The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 1, characterized in that: The dispersant is at least one of BYK9076 dispersant and EFKA-FA 4611 dispersant, the toner is carbon black, and the anti-settling agent is preferably BYK P104 or ANTI-TERRA-204.

6. The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 1, characterized in that: The acid anhydride curing agent is a mixture of one or more of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and methylnadic anhydride MNA.

7. The two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 1, characterized in that: The accelerators include phenolic accelerators, modified imidazole accelerators and amine accelerators.

8. A method for preparing a two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock, based on the two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Weigh epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, filler, dispersant, anti-settling agent and color powder according to the above weight parts, use a stirrer to mix the epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, dispersant and anti-settling agent, and then add filler and color powder in sequence and stir to obtain component A; Step 2: Weigh the anhydride curing agent, accelerator, filler, dispersant and anti-settling agent according to the above weight parts, use a stirrer to mix the anhydride curing agent, accelerator, dispersant and anti-settling agent, and then add the filler and stir to obtain component B; Step 3: Mix the prepared component A and component B in a mass ratio of 1:1 to prepare a two-component thermally conductive epoxy potting adhesive that is resistant to cold and heat shock.

9. The method for preparing the two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 8, characterized in that: In the step 1, the mixer is a vacuum degassing mixer, and the step 1 is specifically as follows: The epoxy resin, epoxy-terminated polybutadiene rubber, bridge shell toughening agent, dispersant and anti-settling agent are first stirred at 900 rpm for 30 seconds, and then at 1200 rpm for 120 seconds; After adding the filler and color powder, stir at 900 rpm for 30 seconds, and then stir at 1200 rpm for 120 seconds; The vacuum degree was set to be maintained at 0.07-0.1 MPa, the speed was 1200 rpm, and the mixture was stirred for 150 s. The mixture was cooled to room temperature to obtain component A.

10. The method for preparing the two-component thermally conductive epoxy potting adhesive resistant to cold and heat shock according to claim 8, characterized in that: In the step 2, the mixer is a vacuum degassing mixer, and the step 2 is specifically as follows: The anhydride curing agent, accelerator, dispersant and anti-settling agent were first stirred at 900 rpm for 30 s, and then at 1200 rpm for 120 s; After adding the filler, stir at 900 rpm for 30 s, and then stir at 1200 rpm for 120 s; The vacuum degree was set to be maintained at 0.07-0.1 MPa, the speed was 1200 rpm, and the mixture was stirred for 150 s. The mixture was cooled to room temperature to obtain component B.

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