Heat-conducting epoxy adhesive composition and preparation method thereof

Abstract

The invention provides a two-component heat-conducting epoxy adhesive composition and a preparation method thereof, the two-component heat-conducting epoxy adhesive composition comprises a component A and a component B, the component A comprises epoxy resin and a nano heat-conducting filler pre-dispersion liquid, and the component B comprises an anhydride curing agent, an imidazole accelerant and nano heat-conducting filler powder; wherein the nano heat-conducting filler pre-dispersion liquid comprises nano heat-conducting filler powder, an epoxy diluent and an antioxidant; the weight ratio of the epoxy diluent to the nano heat-conducting filler powder is (20-25): 100; in the component A, the weight ratio of the nano heat-conducting filler pre-dispersion liquid is 50%-80%; and in the component B, the weight ratio of the nano heat-conducting filler powder is 40-70%. Compared with the prior art, the two-component heat-conducting epoxy adhesive composition and the preparation method thereof have good dispersion processing uniformity, storage anti-settling property and extrudability.

Description

Technical Field

[0001] The invention belongs to the technical field of thermally conductive epoxy adhesive materials, and relates to a thermally conductive epoxy adhesive composition prepared from a thermally conductive filler pre-dispersion liquid and a preparation method thereof. Background Art

[0002] Epoxy materials have a highly cross-linked structure and low thermal conductivity, making them poor conductors of heat. They often need to be filled with thermally conductive fillers with a high filling rate to be widely used in the thermal conductivity field. However, epoxy adhesives with high thermal conductivity obtained by increasing the filling rate generally have problems such as easy sedimentation, poor processability, weak bonding strength, and high brittleness.

[0003] By adding nano-sized thermal conductive fillers, a higher thermal conductivity effect can be achieved at a lower filling rate. However, the nano-sized thermal conductive fillers are prone to agglomeration and sedimentation during use. The invention patent with patent number CN200710189891.X provides a high thermal conductivity epoxy resin nanocomposite material preparation process. Through high-speed stirring and ultrasonic oscillation, nano-ceramic particles are evenly dispersed in epoxy resin, solving the sedimentation problem of nano-ceramic particles in resin. The thermal conductive epoxy glue obtained by ultrasonic oscillation of nano-thermal conductive fillers can indeed meet the needs of products with low sedimentation requirements. However, for products that need to be stored for a long time, it is still difficult to avoid the problem of sedimentation.

[0004] Improving the filler agglomeration problem through dispersion is also a common method. For example, patent CN202011319740.3 uses dispersion to solve the problem that graphene is easy to agglomerate and difficult to disperse in anti-corrosion coatings. However, in the field of thermal conductive epoxy adhesives, the use of nano-sized thermal conductive filler dispersions to solve the storage anti-sedimentation, thermal conductivity and extrusion properties of epoxy adhesives is still a problem that needs to be overcome urgently.

[0005] Therefore, there is an urgent need for a thermally conductive epoxy adhesive composition and a preparation method thereof, so that the epoxy adhesive composition has good anti-settling, thermal conductivity, and extrusion properties under the condition of long-term storage. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides:

[0007] A two-component thermally conductive epoxy adhesive composition, component A includes epoxy resin and nano thermally conductive filler pre-dispersion liquid, and component B includes an anhydride curing agent, an imidazole accelerator, and nano thermally conductive filler powder; wherein:

[0008] The nano thermally conductive filler pre-dispersion liquid comprises nano thermally conductive filler powder, epoxy diluent, and antioxidant; the weight ratio of the epoxy diluent to the nano thermally conductive filler powder is 20-25:100;

[0009] In the component A, the weight proportion of the nano thermal conductive filler pre-dispersion liquid is 50%-80%;

[0010] In the B component, the weight proportion of nano thermal conductive filler powder is 40-70%.

[0011] Furthermore, the weight ratio of the component A to the component B is 2-6:1; the weight proportion of the epoxy resin in the component A is 10-20%; and the weight proportion of the anhydride curing agent in the component B is 10-20%.

[0012] Furthermore, the epoxy resin in the component A is composed of bisphenol A epoxy resin and dimer acid modified epoxy resin, and the weight proportion of the dimer acid modified epoxy resin in the epoxy resin is 5%-25%.

[0013] Furthermore, the bisphenol A epoxy resin is composed of bisphenol A epoxy resin E-51 and bisphenol A epoxy resin E-44, and the weight proportion of bisphenol A epoxy resin E-44 in the A-type epoxy resin is 10%-20%.

[0014] Furthermore, the weight proportion of the imidazole accelerator in the component B is 0.5-1.5%; the imidazole accelerator is composed of 2-ethylimidazole and 2-ethyl-4-methylimidazole, and the weight proportion of 2-ethylimidazole in the accelerator is 25-35%.

[0015] A method for preparing the above-mentioned thermally conductive epoxy adhesive, S1. preparing a pre-dispersion liquid of a nano-thermal conductive filler, S2. preparing component A, S3. preparing component B, S4. preparing an epoxy adhesive composition; wherein:

[0016] The S1. preparing the nano thermally conductive filler pre-dispersion liquid comprises: S11. sequentially mixing the nano thermally conductive filler, the epoxy diluent, and the antioxidant, S12. intermittent ultrasonic dispersion, continuous ultrasonic dispersion;

[0017] The S2 preparation of the composition A component comprises: S21 sequentially mixing epoxy resin, nano-thermal conductive filler pre-dispersion, S22. stirring at room temperature, S23. degassing;

[0018] The step S3. preparing component B of the composition comprises: S31. sequentially mixing anhydride curing agent and nano thermal conductive filler powder, S32. intermittent ultrasonic dispersion and continuous ultrasonic dispersion, S33. heating and stirring, and S34. degassing.

[0019] The S4. preparing epoxy adhesive comprises: S41. mixing component A and component B, wherein the weight ratio of component A to component B is 2-6:1.

[0020] Furthermore, the S32. ultrasonic dispersion includes two dispersions: intermittent ultrasonic dispersion and continuous ultrasonic dispersion, the interval time of the intermittent ultrasonic dispersion is 5-10s, the time of each dispersion is 20-40s, and the total dispersion time is ≤1.0h.

[0021] Furthermore, in the step of sequentially mixing the anhydride curing agent and the nano thermal conductive filler powder in step S31, the anhydride curing agent is a partial anhydride curing agent; and between steps S32 and S33, a step of adding the remaining part of the anhydride curing agent is also included.

[0022] Furthermore, in the step S31. sequentially mixing a portion of the acid anhydride curing agent and the nano thermally conductive filler powder, a weight ratio of the portion of the acid anhydride curing agent and the nano thermally conductive filler powder is ≥20:100.

[0023] Compared with the prior art, the thermally conductive epoxy adhesive composition provided by the present invention has good processing dispersion uniformity, long-term storage anti-settling, extrudability and formula adaptability:

[0024] Common thermally conductive adhesive compositions extend the storage time by dividing the composition into two components, usually with the two components in a ratio of 1:1. Although the nano-thermal conductive filler dispersion can further improve the dispersion effect of the composition and extend the storage time, the introduction of a diluent to ensure the dispersion effect will have an adverse effect on the extrusion performance. Based on the aforementioned dispersion, the present invention improves the dispersion, the composition and ratio of the AB components, the two-component ratio of the composition and the preparation method, so that it not only meets the dispersion effect in the processing process and the anti-sedimentation performance in long-term storage, but also obtains good extrusion and formulation adaptability. DETAILED DESCRIPTION

[0025] A two-component thermally conductive epoxy adhesive composition, component A includes epoxy resin and nano thermally conductive filler pre-dispersion liquid, and component B includes an anhydride curing agent, an imidazole accelerator, and nano thermally conductive filler powder; wherein:

[0026] The nano thermally conductive filler pre-dispersion liquid comprises nano thermally conductive filler powder, epoxy diluent, and antioxidant; the weight ratio of the epoxy diluent to the nano thermally conductive filler powder is 20-25:100;

[0027] In the component A, the weight proportion of the nano thermal conductive filler pre-dispersion liquid is 50%-80%;

[0028] In the B component, the weight proportion of nano thermal conductive filler powder is 40-70%.

[0029] Furthermore, the weight ratio of the component A to the component B is 2-6:1; the weight proportion of the epoxy resin in the component A is 10-20%; and the weight proportion of the anhydride curing agent in the component B is 10-20%.

[0030] Furthermore, the epoxy resin in the component A is composed of bisphenol A epoxy resin and dimer acid modified epoxy resin, and the weight proportion of the dimer acid modified epoxy resin in the epoxy resin is 5%-25%.

[0031] Furthermore, the bisphenol A epoxy resin is composed of bisphenol A epoxy resin E-51 and bisphenol A epoxy resin E-44, and the weight proportion of bisphenol A epoxy resin E-44 in the A-type epoxy resin is 10%-20%.

[0032] Furthermore, the weight proportion of the imidazole accelerator in the component B is 0.5-1.5%; the imidazole accelerator is composed of 2-ethylimidazole and 2-ethyl-4-methylimidazole, and the weight proportion of 2-ethylimidazole in the accelerator is 25-35%.

[0033] Furthermore, the nano thermally conductive filler pre-dispersion liquid also includes an antioxidant, and the weight proportion of the antioxidant in the nano thermally conductive filler pre-dispersion liquid is ≤0.1%.

[0034] Specifically, the nano thermally conductive filler powder is selected from insulating nano thermally conductive fillers commonly used in the art, including but not limited to any one or a combination of nano alumina, silicon dioxide, silicon carbide, aluminum nitride, and boron nitride.

[0035] Specifically, the nano thermal conductive filler powder is preferably spherical or nearly spherical in shape.

[0036] Specifically, the nano thermal conductive filler powder has a particle size range of 50-200 nm. Preferably, the powder has a particle size of 150 nm.

[0037] Specifically, the epoxy diluent is an active diluent, selected from epoxy active diluents commonly used in the art, including but not limited to 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, C12-14 fatty glycidyl ether, any one or a combination of several thereof; preferably, the epoxy diluent is C12-14 fatty glycidyl ether.

[0038] Specifically, the weight proportion of the antioxidant in the nano thermal conductive filler pre-dispersion liquid is ≤1%; preferably, the antioxidant is pentaerythritol ester.

[0039] Specifically, the epoxy resin is selected from common epoxy resin materials in the art, including but not limited to any one or a combination of epoxy resin E-44, epoxy resin E-51, epoxy resin NPER-133L and epoxy resin NPEF-170.

[0040] Specifically, the dimer acid-modified epoxy resin is an addition product of bisphenol A resin and dibasic fatty acid.

[0041] Specifically, the epoxy curing agent is selected from any one or a combination of polyamide curing agents, fatty amine curing agents, phenolic amine curing agents, alicyclic amine curing agents, etc. commonly used in the art; preferably, the epoxy curing agent is an anhydride modified curing agent, which is used to chemically react with the epoxy resin and form a three-dimensional network structure, including but not limited to any one or a combination of phthalic anhydride, tetrahydrophthalic anhydride, etc.

[0042] Specifically, the component A also contains toughening agents and other commonly used additives in the art, and the amount and process of addition can be adjusted according to product requirements, including but not limited to any one or a combination of polyurethane modified epoxy resin, nano core-shell modified resin, carboxyl-terminated liquid nitrile rubber, amino-terminated liquid nitrile rubber, and paste resin.

[0043] Specifically, the component B also contains plasticizers, auxiliary agents and other additives commonly used in the art, and the amount and process of adding the plasticizers and auxiliary agents can be adjusted according to product requirements.

[0044] In the two-component epoxy adhesive composition of the present invention, the epoxy adhesive composition is prepared by using an improved nano-thermal conductive filler dispersion, which not only ensures the uniform dispersion effect of the nano-thermal conductive filler dispersion during the processing process and thus prolongs the storage time of the composition, but also solves the defects in extrusion and obtains a good extrusion effect; in addition, by improving the two-component ratio and the ratio of the components, the adaptability of the composition formula is further optimized. In the field of fine chemical products, small quantities and diverse needs are often the main demand, which puts higher requirements on the flexibility of the formula, especially the stability of the curing effect. The improved two-component epoxy adhesive formula of the present invention has good curing adjustment adaptability.

[0045] A method for preparing the above-mentioned thermally conductive epoxy adhesive, S1. preparing a pre-dispersion liquid of a nano-thermal conductive filler, S2. preparing component A, S3. preparing component B, S4. preparing an epoxy adhesive composition; wherein:

[0046] The S1. preparing the nano thermally conductive filler pre-dispersion liquid comprises: S11. sequentially mixing the nano thermally conductive filler, the epoxy diluent, and the antioxidant, S12. intermittent ultrasonic dispersion, continuous ultrasonic dispersion;

[0047] The S2 preparation of the composition A component comprises: S21 sequentially mixing epoxy resin, nano-thermal conductive filler pre-dispersion, S22. stirring at room temperature, S23. degassing;

[0048] The step S3. preparing component B of the composition comprises: S31. sequentially mixing anhydride curing agent and nano thermal conductive filler powder, S32. intermittent ultrasonic dispersion and continuous ultrasonic dispersion, S33. heating and stirring, and S34. degassing.

[0049] The S4. preparing epoxy adhesive comprises: S41. mixing component A and component B, wherein the weight ratio of component A to component B is 2-6:1.

[0050] Furthermore, the S32. ultrasonic dispersion includes two dispersions: intermittent ultrasonic dispersion and continuous ultrasonic dispersion, the interval time of the intermittent ultrasonic dispersion is 5-10s, the time of each dispersion is 20-40s, and the total dispersion time is ≤1.0h.

[0051] Furthermore, in the step of sequentially mixing the anhydride curing agent and the nano thermal conductive filler powder in step S31, the anhydride curing agent is a partial anhydride curing agent; and between steps S32 and S33, a step of adding the remaining part of the anhydride curing agent is also included.

[0052] Furthermore, in the step S31. sequentially mixing a portion of the acid anhydride curing agent and the nano thermally conductive filler powder, a weight ratio of the portion of the acid anhydride curing agent and the nano thermally conductive filler powder is ≥20:100.

[0053] Specifically, in the step S12., the interval time of intermittent ultrasonic pre-dispersion is 5-10s, the dispersion time each time is 20-30s, and the total dispersion time is 0.5-1.0h. Preferably, the intermittent ultrasonic dispersion time is 0.5h, the ultrasonic oscillation is once every 5s, each time is 20s, and the power is 500W; the total time for continuous ultrasonic uniform dispersion is 1.5-3.0h. Preferably, the continuous ultrasonic dispersion time is 1.5h, and the power is 800W.

[0054] Specifically, in the steps S23. degassing and S35. degassing, the vacuum degree is ≥80pa.

[0055] Specifically, in the step S32., the interval time of intermittent ultrasonic pre-dispersion is 5-10s, the dispersion time each time is 20-30s, and the total dispersion time is 0.5-1.0h. Preferably, the intermittent ultrasonic dispersion time is 0.75h, the ultrasonic oscillation is once every 10s, each time is 20s, and the power is 500W; the total time for continuous ultrasonic uniform dispersion is 1.5-3.0h. Preferably, the continuous ultrasonic dispersion time is 3.0h, and the power is 800W.

[0056] Specifically, in the step S34., the heating and stirring is a stirring kettle stirring and dispersing commonly used in the art, and the heating temperature is ≥80°C.

[0057] Specifically, after the step S42., the method further includes heating and curing the composition, wherein the curing heating temperature is 80-120°C, and preferably, the heating temperature is 100°C.

[0058] In the preparation method of the two-component epoxy adhesive composition of the present invention, intermittent ultrasonic pre-dispersion and the addition of an acid anhydride curing agent in appropriate proportions in batches can improve the dispersion uniformity of the nano thermal conductive filler powder during the mixing and dispersion process, thereby delaying the sedimentation phenomenon during the storage of the composition and extending the storage time of the composition.

[0059] Example 1

[0060] Raw materials:

[0061] The nano thermal conductive filler powder is alumina (commercial model DK410-1), the epoxy diluent is fatty glycidyl ether (commercial model C12-14), and the antioxidant is pentaerythritol ester (commercial model 1010);

[0062] The epoxy resin is bisphenol A epoxy resin E-51, bisphenol A epoxy resin E-44, dimer acid modified epoxy resin EPD-172, and the toughening agent is polyurethane (commercial model JEF-0211);

[0063] The anhydride curing agent is commercially available QS-820, and the accelerator is 2-ethylimidazole and 2-ethyl-4-methylimidazole.

[0064] Preparation method:

[0065] S1. 100 parts by weight of thermally conductive filler powder, 100 parts by weight of epoxy diluent, and 0.5 parts by weight of antioxidant were mixed; then, the mixture was transferred to an ultrasonic stirring mixer for intermittent ultrasonic pre-dispersion, the ultrasonic power was 500W, the total number of ultrasonic oscillations was 70 times, oscillation was once every 5S, each oscillation time was 20S, and the total dispersion time was 0.5h; finally, the ultrasonic power was turned to 800W for continuous ultrasonic uniform dispersion, the total ultrasonic oscillation stirring time was 2h, and a nano-thermal conductive filler pre-dispersion liquid was obtained;

[0066] S2. 140 parts by weight of E-51 bisphenol A epoxy resin, 0 parts by weight of E-44 bisphenol A epoxy resin, 0 parts by weight of EPD-172 dimer acid-modified epoxy resin, and 18 parts by weight of toughening agent were mixed and stirred until uniform; then, 420 parts by weight of the pre-dispersion of the nano-thermal conductive filler was added to the mixture, and stirring was continued until the mixture was uniform; finally, vacuum degassing was performed to obtain component A;

[0067] S3. 0 parts by weight of 2-ethylimidazole, 1.0 parts by weight of 2-ethyl-4-methylimidazole, 420 parts by weight of thermally conductive filler powder, and 90 parts by weight of epoxy curing agent were added to an ultrasonic stirring mixer for intermittent ultrasonic pre-dispersion, with an ultrasonic power of 500 W, a total number of ultrasonic oscillations of 70 times, oscillations every 5 seconds, each oscillation time of 20 seconds, and a total dispersion time of 0.75 hours; then, the ultrasonic power was turned to 800 W for continuous ultrasonic uniform dispersion, and ultrasonic oscillations were stirred for 3 hours; then, the vacuum was turned on, the temperature was raised to 80°C, and 90 parts by weight of epoxy curing agent were added again, mixed and stirred until uniform; finally, vacuum degassing was performed to obtain component B;

[0068] S4. Component A and component B are mixed in a weight ratio of 4:1, and the anti-settling and extrusion properties are tested; then, the mixture is heated to 100° C. for curing, and the thermal conductivity is tested.

[0069] Comparative Example 1

[0070] The difference between Comparative Example 1 and Example 1 is the weight ratio of the diluent to the nano thermally conductive filler powder in the nano thermally conductive filler pre-dispersion liquid.

[0071] Example 2

[0072] The difference between Example 2 and Example 1 is the weight ratio of the diluent to the nano thermally conductive filler powder in the nano thermally conductive filler pre-dispersion liquid.

[0073] Examples 21-23

[0074] The difference between Examples 21-23 and Example 2 is: the weight proportion of the nano thermal conductive filler in component B.

[0075] Examples 31-33

[0076] The difference between Examples 31-33 and Example 2 is that the weight proportion of the dimer acid-modified epoxy resin in component A in the epoxy resin.

[0077] Examples 34-36

[0078] The difference between Examples 34-36 and Examples 31-33 is that in component A, the weight proportion of bisphenol A epoxy resin E-44 in the bisphenol A epoxy resin.

[0079] Examples 37-39

[0080] The difference between Examples 37-39 and Examples 34-36 is that the weight proportion of 2-ethylimidazole in component B in the imidazole accelerator.

[0081] The materials and processes used in the embodiments and comparative examples of the present invention are shown in Table 1 below:

[0082] Table 1

[0083]

[0084] Test Method

[0085] Delamination and compaction: Store components A and B at 40°C for 7 days respectively, and observe whether delamination occurs and whether plate-like lumps appear on the bottom layer after delamination. If delamination or even compaction occurs, the anti-settling property is poor.

[0086] Thermal conductivity: Using the ASTM D 5470 heat flow steady-state method, the components A and B of the composition were mixed and injected into the mold, and then cured at 130°C for 30 minutes to obtain test samples of 26mm×26mm and thicknesses of 1, 2, and 3mm. Then, the thermal conductivity of the samples was tested at room temperature to see if it met the basic thermal conductivity requirement of ≥1W / m·k.

[0087] Extrusion: Use an EFD American 50cc needle to test the extrusion volume after 60s at 90psi.

[0088] The test results of the embodiments of the present invention and the comparative examples are shown in Table 2:

[0089] Table 2

[0090]

[0091]

[0092] It can be seen from the above embodiments, comparative examples and test results that the thermal conductivity of the thermally conductive epoxy adhesive prepared by the present invention is ≥1W / (m·K), meeting the common requirements of thermal conductivity, and also has the following features:

[0093] (1) Comparative Example 1 and Examples 1-2 show that the nano thermal conductive filler pre-dispersion has a significant effect on the extrudability of the epoxy adhesive product. This is because a diluent is added to the dispersion. A high content of diluent ensures the dispersion effect of the filler in the dispersion, but reduces the extrusion performance of the composition.

[0094] (2) Example 2 and Examples 21-23 show that the stratification phenomenon will not occur until the proportion of nano-thermal conductive filler powder in component B reaches more than 70%. This is because an improved dispersion process is used in the preparation process of component B, which improves the uniformity of the dispersion of the composition and delays the sedimentation of the powder during the storage of the composition;

[0095] (3) Example 2 and Examples 31-39 show that after the epoxy resin and accelerator in component A are replaced with common types and a small proportion, the thermal conductivity and extrusion performance of the product are less affected, and the composition formula has good stability. When the curing temperature, depth, etc. change, it is only necessary to appropriately change the type or proportion of the epoxy resin and accelerator, which is more flexible and convenient.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Those skilled in the art should understand that the technical solution of the present invention can be deduced or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A two-component thermally conductive epoxy adhesive composition, wherein component A comprises epoxy resin and nano thermally conductive filler pre-dispersion liquid, and component B comprises anhydride curing agent, imidazole accelerator, and nano thermally conductive filler powder; characterized in that: The nano thermally conductive filler pre-dispersion liquid comprises nano thermally conductive filler powder, epoxy diluent, and antioxidant; the weight ratio of the epoxy diluent to the nano thermally conductive filler powder is 20-25:100; In the component A, the weight proportion of the nano thermal conductive filler pre-dispersion liquid is 50%-80%; In the B component, the weight proportion of nano thermal conductive filler powder is 40-70%.

2. The two-component thermally conductive epoxy adhesive composition according to claim 1, wherein: The weight ratio of the component A to the component B is 2-6:1; the weight proportion of the epoxy resin in the component A is 10-20%; the weight proportion of the anhydride curing agent in the component B is 10-20%.

3. The two-component thermally conductive epoxy adhesive composition according to claim 2, wherein: The epoxy resin in the component A is composed of bisphenol A epoxy resin and dimer acid modified epoxy resin, and the weight proportion of the dimer acid modified epoxy resin in the epoxy resin is 5%-25%.

4. The two-component thermally conductive epoxy adhesive composition according to claim 3, characterized in that: The bisphenol A type epoxy resin is composed of bisphenol A type epoxy resin E-51 and bisphenol A type epoxy resin E-44, and the weight proportion of bisphenol A type epoxy resin E-44 in the A type epoxy resin is 10%-20%.

5. The two-component thermally conductive epoxy adhesive composition according to claim 4, characterized in that: The weight proportion of the imidazole accelerator in the component B is 0.5-1.5%; the imidazole accelerator is composed of 2-ethylimidazole and 2-ethyl-4-methylimidazole, and the weight proportion of 2-ethylimidazole in the imidazole accelerator is 25-35%.

6. A method for preparing a two-component thermally conductive epoxy adhesive composition as claimed in claim 1, comprising S1. preparing a pre-dispersion liquid of a nano-thermal conductive filler, S2. preparing component A, S3. preparing component B, and S4. preparing an epoxy adhesive composition; characterized in that: The S1. preparing the nano thermally conductive filler pre-dispersion liquid comprises: S11. sequentially mixing the nano thermally conductive filler, the epoxy diluent, and the antioxidant, S12. intermittent ultrasonic dispersion, continuous ultrasonic dispersion; The S2 preparation of the composition A component comprises: S21 sequentially mixing epoxy resin, nano-thermal conductive filler pre-dispersion, S22. stirring at room temperature, S23. degassing; The preparation of the composition B component comprises: S31. sequentially mixing anhydride curing agent and nano-thermal conductive filler powder, S32. intermittent ultrasonic dispersion, continuous ultrasonic dispersion, S33. heating and stirring, S34. degassing; The S4. preparing epoxy adhesive comprises: S41. mixing component A and component B, wherein the weight ratio of component A to component B is 2-6:

1.

7. The method for preparing the two-component thermally conductive epoxy adhesive composition according to claim 6, characterized in that: The S32. ultrasonic dispersion includes two dispersions: intermittent ultrasonic dispersion and continuous ultrasonic dispersion. The interval of the intermittent ultrasonic dispersion is 5-10s, the dispersion time of each dispersion is 20-40s, and the total dispersion time is ≤1.0h.

8. The method for preparing the two-component thermally conductive epoxy adhesive composition according to claim 7, characterized in that: In the step S31. of sequentially mixing the anhydride curing agent and the nano thermal conductive filler powder, the anhydride curing agent is a partial anhydride curing agent; and between the steps S32. and S33., a step of adding the remaining part of the anhydride curing agent is also included.

9. The method for preparing the two-component thermally conductive epoxy adhesive composition according to claim 8, characterized in that: The S31. sequentially mixes a portion of the acid anhydride curing agent and the nano thermally conductive filler powder, wherein the weight ratio of the portion of the acid anhydride curing agent to the nano thermally conductive filler powder is ≥20:100.

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