Preparation method of heat-conducting powder for eliminating thixotropy of anhydride component of epoxy adhesive

Abstract

The present invention provides a method for preparing a heat-conducting powder for eliminating the thixotropy of the anhydride component of an epoxy adhesive, which is carried out through the following steps: 1) Using an alkyl acrylate as a reaction monomer and a polyphosphate ester as a functional unit, and reacting with a capping agent and a free radical initiator under certain conditions to obtain a novel powder surface treatment agent; 2) Coating the surface of the heat-conducting powder with the above-mentioned powder surface treatment agent by means of a high-speed disperser or a continuous powder modifier to obtain a heat-conducting powder that can eliminate the thixotropy of the anhydride component of the epoxy adhesive. The heat-conducting powder of the present invention has good dispersibility in the anhydride component of the epoxy adhesive, has little influence on the viscosity of the system, does not generate thixotropy under both normal temperature and high temperature conditions, and at the same time has good balanced thermal properties, chemical properties and mechanical properties. The prepared heat-conducting epoxy adhesive composition can be used in coatings, structural composite materials and encapsulation systems for electronic and electrical components, and has a wide range of applications.

Description

Technical Field

[0001] The present invention relates to a method for surface treatment of thermally conductive powder, and specifically to a method for preparing a thermally conductive powder and a surface treatment agent that eliminate the thixotropy of the anhydride component of epoxy adhesives. The thermally conductive powder prepared by this method has good dispersibility in anhydrides, has little influence on the viscosity of the system, does not generate thixotropy under both normal and high temperature conditions, and has advantages such as good balanced thermal, chemical, and mechanical properties. Background Art

[0002] Epoxy resin-based thermally conductive adhesives (hereinafter referred to as epoxy thermally conductive adhesives) are a commonly used type of chip adhesive in the field of electronic packaging. They are composed of a matrix epoxy resin, a thermally conductive filler, a curing agent, additives, etc. Through the bonding action of the matrix resin, the thermally conductive particles are combined together to form a thermally conductive path, realizing the heat transfer function of the bonded materials. In practical applications, in order to achieve a higher thermal conductivity, a large amount of thermally conductive powder is often filled. After a large amount of powder is filled, the intrinsic properties of the epoxy system will be damaged. At present, the requirements for extrudability and viscosity of epoxy thermally conductive adhesives are becoming increasingly strict. It is difficult to meet the above performance requirements by only adding thermally conductive fillers to epoxy resins. Therefore, thermally conductive fillers are often added to the curing agent component as well to share the influence of the fillers on the resin matrix.

[0003] Epoxy resins belong to thermoplastic resins and must be combined with a curing agent to be used as adhesives. Anhydrides have become one of the curing agents with the largest consumption in epoxy resins due to their low volatility, low physiological toxicity, and low skin irritation. The epoxy system using anhydrides as curing agents has advantages such as a long operation cycle, a small shrinkage rate of the cured product, a high heat distortion temperature, good heat resistance, and excellent mechanical and electrical properties. Therefore, realizing high filling of thermally conductive fillers in epoxy resins and anhydride components and reducing their influence on the intrinsic properties of the system are the key problems that need to be solved urgently at present. For conventional thermally conductive powders, if no surface treatment is carried out, the thermal conductivity is difficult to meet the actual use requirements with a small addition amount. Secondly, the thickening is serious in epoxy resins and anhydride components, thus affecting the physical properties and operating properties of the materials. At present, most of the thermally conductive powders applied to epoxy resins in the market are surface-treated with conventional small-molecular-weight silane coupling agents and dispersants, etc. This treatment method can effectively reduce the oil absorption value of the powder, increase the addition amount of the powder, and has good compatibility in epoxy resins. However, obvious thixotropy will occur when applied in anhydride components, or even if there is no thixotropy at room temperature, thixotropy will reappear and be more serious during heating and defoaming, affecting the comprehensive performance of the epoxy two-component system, such as the extrudability of epoxy adhesive bonds, the leveling property of epoxy potting adhesives, the imbalance of the mixing ratio caused by thixotropy during the mixing of epoxy adhesive two components, difficulty in defoaming, and large performance fluctuations. Summary of the Invention

[0004] The present invention aims to solve the problem that in the prior art, when using small-molecular-weight silane coupling agents and dispersants to surface-treat heat-conducting powders, thixotropy often occurs at room temperature during their application in the anhydride component of epoxy adhesives, or there is no thixotropy at room temperature, but thixotropy reappears and becomes more serious after heating to remove bubbles. A powder surface treatment agent is provided and used for the surface treatment of heat-conducting powders. The prepared heat-conducting powders do not show thixotropy at room temperature during their application in the anhydride component of epoxy adhesives, do not show thixotropy when heated to 100 °C, and still do not show thixotropy after cooling to standard temperature and humidity.

[0005] In order to achieve the above object of the invention, the specific technical solution is as follows:

[0006] A method for preparing heat-conducting powders for eliminating thixotropy of the anhydride component of epoxy adhesives, comprising the following steps:

[0007] (1) Preparation of the powder surface treatment agent: Pass dry nitrogen into a dry reaction kettle. After the air is exhausted, add a certain amount of solvent, stir and heat to 40 - 60 °C; mix a certain amount of reaction monomers, functional units, capping agents, and free radical initiators evenly and continuously drop them into the reaction kettle, and react at 70 - 90 °C for 1 - 5 h to obtain a novel powder surface treatment agent;

[0008] (2) Surface modification of heat-conducting powders: Add heat-conducting powders heated to 60 - 80 °C by hot air into a high-speed mixer or a continuous powder modifier; dilute the above surface treatment agent by a certain proportion and continuously spray it into the high-speed moving heat-conducting powders in a high-pressure atomization manner, and continuously stir for 3 - 60 min to obtain heat-conducting powders that can eliminate thixotropy of the anhydride component of epoxy adhesives;

[0009] The mass parts ratio of each reactant component in (1) is as follows: 85% - 92% reaction monomers, 0.5% - 10% functional units, 0.1% - 5% capping agents, 0.01% - 0.2% free radical initiators, wherein the solvent ratio is 10% - 50% of the total reactants; the mass parts ratio of each component in (2) is as follows: 90 - 99.9% heat-conducting powders, 0.1 - 10% surface treatment agent.

[0010] The reaction monomer is an alkyl acrylate, wherein the alkyl group can be linear or branched, and the number of carbon atoms is 1 - 18.

[0011] The functional unit is a polyphosphate ester, and its chain segment structural formula is:

[0012]

[0013] where n is 3 - 20, and R is a straight-chain or branched-chain alkyl group with 1 - 5 carbon atoms.

[0014] The capping agent is 3-mercaptopropionate.

[0015] The radical initiator described above is a peroxide initiator and a redox initiator. Among them, the peroxide initiator is preferably tert-hexyl peroxy-2-ethylhexanoate, benzoyl peroxide, tert-butyl peroxy maleate; the redox initiator is preferably an organic peroxide / vanadium compound, a naphthenic acid metal salt / butyraldehyde. Selecting the radical initiator can avoid the adverse effects of the residual substances after the initiator fails on the stability of the treatment agent and the stability of the modified anhydride system.

[0016] The solvent is one or more of ethyl acetate, butyl acetate, and methyl ethyl ketone. As the reaction medium, the solvent can avoid excessive local temperature during the reaction, and at the same time can adjust the viscosity of the powder surface treatment agent, which is beneficial to its dispersion during modification and more uniformly coats the powder surface.

[0017] The heat-conducting powder is one or more of powders such as alumina, magnesia, boron nitride, aluminum nitride, zinc oxide, silicon oxide, silicon carbide, and graphite.

[0018] The prepared heat-conducting powder for eliminating the thixotropy of the anhydride component of the epoxy adhesive is used for the anhydride component, and the anhydride component is one or more of liquid anhydrides such as methyltetrahydrophthalic anhydride, methyl nadic anhydride, dodecenyl succinic anhydride, methylhexahydrophthalic anhydride, and terpene-based anhydride.

[0019] To test the modification effect of the prepared auxiliary agent on the powder, the following method can be used for verification: According to the specific thermal conductivity requirements, the surface-treated heat-conducting powder is added to the liquid anhydride. The mass ratio of the heat-conducting powder to the liquid anhydride is 1-10:1. Use a disperser or kneader with an inner wall specially treated with acid and corrosion resistance to disperse the powder evenly. The evenly dispersed components are filled into a test container and placed in a vacuum chamber to evacuate and defoam. The vacuum degree is 0.092-0.099, and it is kept at a constant temperature for 24 h under standard temperature and humidity conditions. The thixotropy and flowability at the standard temperature are measured; for the high-temperature condition test, the material kneaded at room temperature is heated to 100 °C and kept at a constant temperature for 2-8 h to make the internal and external temperatures of the material balanced, and the thixotropy and flowability under the high-temperature condition after constant temperature are measured. The test after cooling to the standard temperature condition after high temperature means that the material is cooled to room temperature after high temperature and kept at a constant temperature for 24 h under standard temperature and humidity conditions, and the thixotropy and flowability of the material after high temperature are measured again.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The novel powder surface treatment agent prepared by the present invention is a macromolecular polymer with "functional segments" and "soft segments". Among them, (1) the "functional units" are composed of polyphosphate esters. The strong polarity of the phosphate ester groups is conducive to adsorption and combination with the powder, enhancing the compatibility between the powder and the anhydride, and effectively eliminating the room temperature thixotropy, high temperature thixotropy and thixotropy after high temperature cooling caused by the addition of the heat-conducting powder; (2) the "soft segments" are composed of alkyl flexible molecular chains as the main chain. Without affecting the heat distortion temperature of the material, it can effectively eliminate the stress at the compatible interface between the epoxy resin and the heat-conducting powder, improve the performance of the system and ensure the thermal conductivity; (3) Compared with conventional coupling agents and dispersants, the surface treatment agent with a larger molecular weight in the present invention can not only play a good plasticizing role between molecular chains while ensuring the viscosity of the system in the anhydride component of the epoxy adhesive, which is beneficial to eliminating thixotropy. Detailed Description of the Invention

[0022] To introduce the present invention in more detail, the following examples are used to further elaborate and explain the present invention.

[0023] Example 1

[0024] Preparation of the powder surface treatment agent: Dry nitrogen is introduced into a dry reaction kettle with a volume of 1 L to discharge air. After the air is exhausted, 300 ml of ethyl acetate is added and stirred and heated to 50 °C; under a dry nitrogen atmosphere, 120 g of isooctyl methacrylate, 12 g of polyphosphate ester (n = 5, carbon atom number is 2), 1.5 g of methyl 3-mercaptopropionate, and 0.07 g of tert-hexyl peroxy-2-ethylhexanoate are mixed evenly and then continuously added dropwise to the reaction kettle for reaction. The reaction temperature is 75 °C and the reaction time is 3.5 h, thus obtaining the novel powder surface treatment agent.

[0025] Surface modification of the heat-conducting powder: 3 Kg of alumina heated to 70 °C by hot air is added to a high-speed mixer with a barrel volume of 10 liters, and the constant rotation speed is 1500 r / min. 30 g of the surface treatment agent prepared above is continuously sprayed into the high-speed moving powder by high-pressure atomization, and continuously stirred for 30 min, thus obtaining the heat-conducting powder that needs to be surface-treated.

[0026] Method for judging the performance of the finished product: Add 150 g of the above-mentioned surface-treated powder and 30 g of methyltetrahydrophthalic anhydride in a ratio of 5:1 into a disperser with an inner wall specially treated with acid and corrosion resistance and a volume of 200 ml, stir evenly, put the evenly stirred material into a vacuum box and evacuate it to a vacuum degree of 0.098 for vacuum defoaming, keep it at a constant temperature for 24 h under standard temperature and humidity conditions, and test thixotropy and leveling property; for the high-temperature condition test, heat the above-kneaded material to 100 °C and keep it at a constant temperature for 2 h to make the internal and external temperatures of the material balanced, and measure the thixotropy and leveling property under high-temperature conditions after constant temperature; after the material is cooled to room temperature after high temperature, keep it at a constant temperature for 24 h under standard temperature and humidity conditions, and measure the thixotropy and leveling property of the material after high temperature again.

[0027] Example 2

[0028] Preparation of the powder surface treatment agent: Introduce dry nitrogen into a dry reaction kettle with a volume of 1 L to discharge air. After the air is exhausted, add 300 ml of butyl acetate, stir and heat to 65 °C; under a dry nitrogen atmosphere, mix 150 g of lauryl methacrylate, 15 g of polyphosphate ester (n = 3, number of carbon atoms is 2), 1.0 g of methyl 3-mercaptopropionate, and 0.25 g of tert-butyl permaleate evenly and continuously drop them into the reaction kettle for reaction. The reaction temperature is 90 °C and the reaction time is 1.5 h.

[0029] Modification of the heat-conducting powder: Add 3 Kg of magnesium oxide heated to 75 °C by hot air into a high-speed mixer with a barrel volume of 10 L, with a constant rotation speed of 1500 r / min. Dilute 90 g of the above-prepared surface treatment agent and continuously spray it into the high-speed moving powder by high-pressure atomization, and continuously stir for 30 min to obtain the heat-conducting powder that needs to be surface-treated.

[0030] Method for judging the performance of the finished product: Add 120 g of the above-mentioned surface-treated powder and 30 g of methyltetrahydrophthalic anhydride in a ratio of 4:1 into a disperser with an inner wall specially treated with acid and corrosion resistance and a volume of 200 ml, stir evenly, put the evenly stirred material into a vacuum box and evacuate it to a vacuum degree of 0.098 for vacuum defoaming, keep it at a constant temperature for 24 h under standard temperature and humidity conditions, and test thixotropy and leveling property. For the high-temperature condition test, heat the above-kneaded material to 100 °C and keep it at a constant temperature for 2 h to make the internal and external temperatures of the material balanced, and measure the thixotropy and leveling property under high-temperature conditions after constant temperature. After the material is cooled to room temperature after high temperature, keep it at a constant temperature for 24 h under standard temperature and humidity conditions, and measure the thixotropy and leveling property of the material after high temperature again.

[0031] Example 3

[0032] Preparation of powder surface treatment agent: Dry nitrogen is introduced into a 1L dry reaction kettle to expel air. After the air is completely expelled, 250 ml of butyl acetate is added, stirred, and heated to 65 °C. Under a dry nitrogen atmosphere, 180 g of butyl methacrylate, 12 g of polyphosphate ester (n = 10, with 2 carbon atoms), 3.0 g of ethyl 3-mercaptopropionate, and 0.8 g of tert-butyl permaleate are mixed evenly and continuously added dropwise to the reaction kettle for reaction. The reaction temperature is 90 °C, and the reaction lasts for 2 h.

[0033] Modification of thermally conductive powder: 30 Kg of alumina heated to 75 °C by hot air is continuously sucked into a powder modification machine by negative pressure. The constant rotation speed of the modification machine is 1250 r / min. 450 g of the surface treatment agent prepared above is diluted and continuously sprayed into the high-speed moving powder by high-pressure atomization, and continuously stirred for 30 min to obtain the thermally conductive powder that requires surface treatment.

[0034] Method for judging the performance of the finished product: 480 g of the powder after surface treatment above and 60 g of methyl nadic anhydride are added in a ratio of 8:1 to a disperser with a volume of 1 liter and an inner wall specially treated with acid and corrosion resistance, and stirred evenly. The evenly stirred material is put into a vacuum box and evacuated to a vacuum degree of 0.095 for vacuum degassing, and kept at a constant temperature for 24 h under standard temperature and humidity conditions to test thixotropy and leveling property. For the high-temperature condition test, the kneaded material above is heated to 100 °C and kept at a constant temperature for 2 h to make the internal and external temperatures of the material balanced, and the thixotropy and leveling property under high-temperature conditions after constant temperature are measured. After the material is cooled to room temperature after high temperature, it is kept at a constant temperature for 24 h under standard temperature and humidity conditions, and the thixotropy and leveling property of the material after high temperature are measured again.

[0035] Example 4

[0036] Preparation of powder surface treatment agent: Dry nitrogen is introduced into a 1L dry reaction kettle to expel air. After the air is completely expelled, 300 ml of butyl acetate is added, stirred, and heated to 65 °C. Under a dry nitrogen atmosphere, 185 g of stearyl methacrylate, 18 g of polyphosphate ester (n = 10, with 5 carbon atoms), 1.5 g of ethyl 3-mercaptopropionate, and 0.5 g of metal naphthenate / butyraldehyde are mixed evenly and continuously added dropwise to the reaction kettle for reaction. The reaction temperature is 80 °C, and the reaction lasts for 4 h.

[0037] Surface modification of thermally conductive powder: 3 Kg of boron nitride heated to 75 °C by hot air is added to a high-speed mixer with a barrel volume of 10 liters. The constant rotation speed is 1350 r / min. 30 g of isopropyl alcohol and 90 g of the above surface treatment agent are diluted and continuously sprayed into the high-speed moving powder by high-pressure atomization, and continuously stirred for 15 min to obtain the thermally conductive powder that requires surface treatment.

[0038] Finished product performance judgment method: 100 g of the above-mentioned surface-treated powder and 100 g of methyltetrahydrophthalic anhydride are added in a ratio of 1:1 to a disperser with an inner wall made of special acid-resistant and corrosion-resistant material and a volume of 500 ml, and stirred evenly. The evenly stirred material is put into a vacuum box and evacuated to a vacuum degree of 0.096 for vacuum degassing, and kept at a constant temperature for 24 h under standard temperature and humidity conditions, and the thixotropy and leveling property are tested; for the high-temperature condition test, the above-kneaded material is heated to 100 °C and kept at a constant temperature for 4 h to make the internal and external temperatures of the material balanced, and the thixotropy and leveling property under high-temperature conditions after constant temperature are measured. After the material is cooled to room temperature after high temperature, it is kept at a constant temperature for 24 h under standard temperature and humidity conditions, and the thixotropy and leveling property of the material after high temperature are measured again.

[0039] Comparative example 1

[0040] Comparative example 1 is the thermal conductive powder used in Example 1, which is directly added to the acid anhydride as a finished product without surface modification, and its finished product performance judgment method is the same as that of Example 1.

[0041] Comparative example 2

[0042] Comparative example 2 is the thermal conductive powder used in Example 2, which is directly added to the acid anhydride as a finished product without surface modification, and its finished product performance judgment method is the same as that of Example 2.

[0043] Comparative example 3

[0044] Comparative example 3 is the thermal conductive powder used in Example 3, which is directly added to the acid anhydride as a finished product without surface modification, and its finished product performance judgment method is the same as that of Example 3.

[0045] Comparative example 4

[0046] Comparative example 4 is the thermal conductive powder used in Example 4, which is directly added to the acid anhydride as a finished product without surface modification, and its finished product performance judgment method is the same as that of Example 4.

[0047] Comparative example 5

[0048] Comparative example 5 is the thermal conductive powder used in Example 1. The surface modifier prepared in Example 1 is replaced with n-octyltriethoxysilane, and its powder surface modification and finished product performance judgment method are the same as those of Example 1.

[0049] Testing methods for various performances:

[0050] Thermal conductivity: Using a heat flow method thermal conductivity meter, the thermal conductivity of the material is tested according to the standard of ASTM-D5470. The well-dispersed test sample in the vacuum disperser is evenly scraped and coated in a polytetrafluoroethylene mold ring with an inner diameter of 30 mm, the material thickness is 2 mm, and it is evenly coated. The ambient temperature is 23 ± 2 °C, the test pressure is 10 psi, the upper thermal column temperature is 65 °C, and the lower thermal column temperature is 30 °C;

[0051] Thixotropy test: The viscosity test was carried out using a Brookfield rotational viscometer. When the speed ratio of the same rotor was 10:1, two viscosity ratios were measured as the judgment standard of the thixotropy ratio. When the ratio was greater than 1.5, the leveling property of the material became poor, and with the increase of the ratio, obvious thixotropy occurred in the material and it was difficult to return to its original state after stirring.

[0052] Leveling property test: After wiping a glass plate of 200mm * 200 * 5mm clean, place it on a horizontal tabletop. Place a stainless steel metal cylinder with an inner diameter of 28mm, an outer diameter of 32mm, and a height of 32mm in the middle of the glass plate. Slowly add the sample to be tested into the cylinder until the liquid level of the sample is flush with the cylinder nozzle. Start timing after lifting the cylinder. The sample starts to spread in a circular shape on the glass sheet, and then scrape the material inside the cylinder to the center of the colloid. Measure the diameter of the material spread from different angles every 5 minutes from the start of timing and take the average value. Stop until the diameter of the material has no obvious change. The same sample is tested three times.

[0053] Test under standard temperature conditions: After the sample is kept at a constant temperature of 25 °C for 24h, observe the state and test the thixotropy and leveling property;

[0054] Test under high temperature conditions: Place the sample in a constant temperature oil bath set at a temperature of 100 °C, place it for the required time, and ensure that the temperature of the material does not fluctuate during the test. Observe the state and conduct thixotropy and leveling property tests.

[0055] Test after cooling to standard temperature after high temperature: After the material is cooled to room temperature after high temperature, keep it at a constant temperature of 24h under standard temperature conditions, and observe and measure the thixotropy and leveling property of the material after high temperature again.

[0056] Test the finished product performance of Examples 1 - 4 and Comparative Examples 1 - 5, and the results are shown in Table 1.

[0057] Table 1

[0058]

[0059]

[0060] It can be seen from Table 1 that compared with the conventional small - molecular - weight silane coupling agent, the treatment agent prepared by the present invention for the surface treatment of heat - conducting powder can effectively eliminate the thixotropy of the powder in the anhydride component of the epoxy adhesive, the thixotropy ratio is significantly reduced, while improving the leveling property of the material, and the modified powder still has excellent thermal conductivity, effectively avoiding problems such as differences in the mixing ratio of the two components of the epoxy adhesive, uneven mixing, and large performance deviations caused by thixotropy.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a heat-conducting powder for eliminating the thixotropy of the anhydride component of an epoxy adhesive, characterized in that, The heat-conducting powder is prepared by modifying with a surface treatment agent of a macromolecular polymer having a functional segment and a soft segment, wherein the functional segment is composed of polyphosphate ester, and the soft segment is composed of an alkyl flexible molecular chain; specifically, the following steps are included: (1) Preparation of the powder surface treatment agent: Introduce dry nitrogen into a dry reaction kettle. After the air is exhausted, add a certain amount of solvent, stir and heat to 40-60°C; Mix a certain amount of reaction monomers, functional units, capping agents, and free radical initiators evenly and continuously drop them into the reaction kettle, and react at 70-90°C for 1-5 hours to obtain a novel powder surface treatment agent; (2) Surface modification of the heat-conducting powder: Add the heat-conducting powder heated to 60-80°C by hot air into a high-speed mixer or a powder continuous modifier; Dilute the above surface treatment agent by a certain proportion and continuously spray it into the high-speed moving heat-conducting powder in a high-pressure atomization manner, and continuously stir for 3-60 minutes to obtain a heat-conducting powder that can eliminate the thixotropy of the anhydride component of the epoxy adhesive; Among them, the mass parts ratio of each reactant component in the above (1) is as follows: 85%-92% reaction monomer, 0.5%-10% functional unit, 0.1%-5% capping agent, 0.01%-0.2% free radical initiator, wherein the solvent ratio is 10%-50% of the total reactants; The mass parts ratio of each component in the above (2) is as follows: 90-99.9% heat-conducting powder, 0.1-10% surface treatment agent; The reaction monomer is an alkyl acrylate, wherein the alkyl group can be linear or branched, and the number of carbon atoms is 1-18; The functional unit is polyphosphate ester, and its chain segment structure is: Among them, n is 3-20, and R is a straight-chain or branched-chain alkyl group of C1-C5.

2. The method for preparing the heat-conducting powder for eliminating the thixotropy of the anhydride component of the epoxy adhesive according to claim 1, characterized in that, The capping agent is methyl 3-mercaptopropionate or ethyl 3-mercaptopropionate.

3. The method for preparing the heat-conducting powder for eliminating the thixotropy of the anhydride component of the epoxy adhesive according to claim 1, wherein The free radical initiator is a peroxide initiator and a redox initiator, wherein the peroxide initiator is one or more of tert-hexyl peroxy-2-ethylhexanoate, benzoyl peroxide, and tert-butyl peroxy maleate; The redox initiator is one or more of organic peroxide / vanadium compound and naphthenic acid metal salt / butyraldehyde.

4. The method for preparing a heat-conducting powder for eliminating the thixotropy of the anhydride component of an epoxy adhesive according to claim 1, characterized in that, The solvent is one or more of ethyl acetate, butyl acetate, and methyl ethyl ketone.

5. The method for preparing a heat-conducting powder for eliminating the thixotropy of the anhydride component of an epoxy adhesive according to claim 1, wherein The heat-conducting powder is one or more of alumina, magnesia, boron nitride, aluminum nitride, zinc oxide, silicon oxide, silicon carbide, and graphite.

6. The heat-conducting powder for eliminating the thixotropy of the anhydride component of the epoxy adhesive prepared according to any one of claims 1-5, characterized in that For the anhydride component, the anhydride component is one or more of methyltetrahydrophthalic anhydride, methylnadic anhydride, dodecenyl succinic anhydride, methylhexahydrophthalic anhydride, and terpene-based anhydride.

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