High-thermal-conductivity low-viscosity heat-conducting pouring sealant and preparation method thereof

Abstract

The invention relates to the field of pouring sealant materials, and particularly discloses a high-thermal-conductivity low-viscosity heat-conducting pouring sealant and a preparation method thereof. The invention relates to a heat-conducting pouring sealant with high heat conductivity and low viscosity. Comprising the following raw materials in parts by weight: 40 to 50 parts of bilateral vinyl silicone oil, 5 to 8 parts of terminated hydrogen-containing silicone oil, 300 to 400 parts of aluminum nitride, 400 to 500 parts of diamond, 100 to 300 parts of nano aluminum oxide, 10 to 20 parts of cerium hydroxide, 5 to 10 parts of diethylaminoethyl methacrylate, 5 to 8 parts of allyl glycidyl ether, 0.5 to 1 part of an inhibitor and 0.5 to 1 part of a catalyst. The vinyl silicone oil molecular chains on the two sides are compounded with the diethylaminoethyl methacrylate and the allyl glycidyl ether, so that the viscosity of the pouring sealant is reduced, and the flowability of the pouring sealant is improved.

Description

Technical Field

[0001] This application relates to the field of potting compound materials, and in particular to a high thermal conductivity, low viscosity thermally conductive potting compound and its preparation method. Background Technology

[0002] Good heat dissipation ensures stable operation of electronic components, extends their lifespan, reduces the probability of failure, and thus improves the reliability and stability of the entire device. Thermally conductive potting compounds, as commonly used heat dissipation filling materials, are crucial for meeting the needs of various fields through performance optimization. In recent years, in-depth research in this area has driven continuous technological advancements.

[0003] Currently, to improve the thermal conductivity of potting compounds, people often add thermally conductive media. Common thermally conductive media include metal oxides and carbon materials, which have a certain thermal conductivity and can improve the thermal conductivity of potting compounds to some extent.

[0004] For some complex equipment, the thermally conductive material needs to have good fluidity to facilitate construction and operation. Therefore, the thermally conductive potting compound needs to have low viscosity. However, while traditional technology adds thermally conductive media to improve thermal conductivity, it often significantly increases the viscosity of the potting compound, resulting in poor fluidity and making it difficult to achieve good filling effect in practical applications. Summary of the Invention

[0005] To improve the flowability of existing thermally conductive potting compounds, this application provides a high thermal conductivity, low viscosity thermally conductive potting compound and its preparation method.

[0006] In a first aspect, this application provides a high thermal conductivity, low viscosity thermally conductive potting compound, employing the following technical solution: A high thermal conductivity, low viscosity thermally conductive potting compound comprising the following raw materials in parts by weight: 40-50 parts of double-sided vinyl silicone oil, 5-8 parts of end-hydrogen silicone oil, 300-400 parts of aluminum nitride, 400-500 parts of diamond, 100-300 parts of nano-alumina, 10-20 parts of cerium hydroxide, 5-10 parts of diethylaminoethyl methacrylate, 5-8 parts of allyl glycidyl ether, 0.5-1 part of inhibitor, and 0.5-1 part of catalyst.

[0007] By adopting the above technical solution, the double-sided vinyl silicone oil can react with the hydroxyl groups on the surfaces of aluminum nitride, diamond, nano-alumina, and cerium hydroxide, thereby reducing the hydroxyl content on the filler surface, lowering the viscosity of the potting compound system, and improving the fluidity of the potting compound.

[0008] Linking diethylaminoethyl methacrylate and allyl glycidyl ether to the bilateral vinyl silicone oil molecular chains introduces hydrophilic and lipophilic groups. On one hand, this promotes better bonding between the bilateral vinyl silicone oil and aluminum nitride, diamond, nano-alumina, and cerium hydroxide, reducing the interfacial energy between these materials and mitigating particle agglomeration. This further reduces the viscosity and improves the flowability of the potting compound. On the other hand, introducing epoxy groups into the potting compound system enhances the reaction between the potting compound and the polar groups on the substrate surface, strengthening interfacial bonding and improving the adhesion and flexibility of the potting compound to the substrate.

[0009] Preferably, the catalyst is a platinum catalyst and the inhibitor is ethynylcyclohexanol.

[0010] Preferably, the aluminum nitride has a particle size of 5-20 μm, the nano-alumina has a particle size of 100-300 nm, the diamond has a particle size of 80-120 μm, and the cerium hydroxide has a particle size of 80-120 μm.

[0011] By adopting the above technical solution, and mixing thermally conductive fillers of different sizes in a certain proportion, the densest packing state can be achieved, which enables the matrix in the potting compound system to tightly wrap around the particle surface, thereby improving the density and thermal conductivity of the potting compound.

[0012] Preferably, the aluminum nitride, diamond, nano-alumina, and cerium hydroxide are pre-treated with surface treatment, including the following specific steps: mixing aluminum nitride, diamond, nano-alumina, and cerium hydroxide, stirring evenly to obtain a mixed filler, heating the mixed filler, adding 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and long-chain fatty acids, stirring to react, removing the mixed filler and drying it, thus completing the surface treatment of aluminum nitride, diamond, nano-alumina, and cerium hydroxide.

[0013] By adopting the above technical solution, the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and long-chain fatty acids can adsorb and hydrogen bond with the mixed filler, which can firmly anchor it on the surface of the filler particles. Utilizing the outward arrangement of the hydrophobic bis(trifluoromethanesulfonyl)imide anions and the outward extension of the long alkyl chains, the compatibility between the filler and the organosilicon matrix is ​​enhanced on the one hand, and a strong steric hindrance effect is provided on the other hand, reducing the surface polarity of the filler. This dual effect reduces the direct contact and agglomeration of filler particles, further reducing the viscosity of the potting compound and improving its flowability.

[0014] Preferably, the mass ratio of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to mixed filler and long-chain fatty acid in the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution is (0.1-0.3):10:(0.3-0.5).

[0015] Preferably, the mixed filler is heated to 100-110°C before adding 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and long-chain fatty acids.

[0016] Preferably, the long-chain fatty acid is a mixture of oleic acid and stearic acid.

[0017] Secondly, this application provides a method for preparing a high thermal conductivity, low viscosity thermally conductive potting compound, using the following technical solution: A method for preparing a high thermal conductivity, low viscosity thermally conductive potting compound includes the following specific steps: Bilateral vinyl silicone oil, hydrogen-terminated silicone oil, allyl glycidyl ether, aluminum nitride, diamond, nano alumina, and cerium hydroxide are mixed and stirred evenly. Under the protection of nitrogen, the mixture is heated to a higher temperature, and then a catalyst and inhibitor are added and mixed evenly to obtain a high thermal conductivity, low viscosity thermally conductive potting compound.

[0018] By adopting the above technical solution, a dense network structure can be formed under the synergistic effect of various components, while maintaining a low viscosity. This results in the prepared potting compound having good flowability, strength, and toughness, and reduces the phenomenon of potting compound cracking.

[0019] Preferably, the heating temperature is 90-120℃.

[0020] In summary, this application has the following beneficial effects: 1. Because this application uses a compounding process between the double-sided vinyl silicone oil molecular chains and diethylaminoethyl methacrylate and allyl glycidyl ether, it promotes a better binding effect between the double-sided vinyl silicone oil and aluminum nitride, diamond, nano alumina, and cerium hydroxide, thereby improving the phenomenon of agglomeration of aluminum nitride, diamond, nano alumina, and cerium hydroxide particles, reducing the viscosity of the potting compound, and improving the flowability of the potting compound.

[0021] 2. In this application, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and long-chain fatty acids are used to treat the surface of aluminum nitride, diamond, nano alumina and cerium hydroxide, which are adsorbed on the surface of the filler particles, enhancing the compatibility of the filler with the organosilicon matrix. At the same time, it can also provide a strong steric hindrance effect and reduce the surface polarity of the filler. The dual effect reduces the direct contact and agglomeration of filler particles, further reducing the viscosity of the potting compound and improving the flowability of the potting compound. Detailed Implementation

[0022] The present application will be further described in detail below with reference to the embodiments.

[0023] All raw materials used in the examples are commercially available. Example Example 1

[0024] This embodiment provides a high thermal conductivity, low viscosity thermally conductive potting compound, comprising the following raw materials in parts by weight: 45g of double-sided vinyl silicone oil, 7g of end-hydrogen silicone oil, 350g of aluminum nitride, 450g of diamond, 200g of nano-alumina, 15g of cerium hydroxide, 8g of diethylaminoethyl methacrylate, 7g of allyl glycidyl ether, 0.8g of inhibitor, and 0.8g of catalyst. The catalyst is chloroplatinic acid, the inhibitor is ethynylcyclohexanol, the viscosity of the double-sided vinyl silicone oil is 20 cps, the viscosity of the end-hydrogen silicone oil is 50 cps, the average particle size of the aluminum nitride is 10 μm, the average particle size of the nano-alumina is 200 nm, the average particle size of the diamond is 90 μm, and the average particle size of the cerium hydroxide is 100 μm.

[0025] The preparation method of high thermal conductivity and low viscosity thermally conductive potting compound includes the following specific steps: Bilateral vinyl silicone oil, end-hydrogen silicone oil, allyl glycidyl ether, aluminum nitride, diamond, nano alumina, and cerium hydroxide are mixed and stirred evenly. Under the protection of nitrogen, the mixture is heated to 95°C, and then a catalyst and inhibitor are added and mixed evenly. After reacting for 1 hour, the temperature is further increased to 120°C and cured for 30 minutes to obtain a high thermal conductivity, low viscosity thermally conductive potting compound.

[0026] Example 2

[0027] The difference between Example 2 and Example 1 is that the high thermal conductivity and low viscosity thermally conductive potting compound includes the following raw materials in parts by weight: 40g of double-sided vinyl silicone oil, 5g of hydrogen-terminated silicone oil, 300g of aluminum nitride, 500g of diamond, 100g of nano-alumina, 20g of cerium hydroxide, 5g of diethylaminoethyl methacrylate, 8g of allyl glycidyl ether, 0.5g of inhibitor, and 1g of catalyst.

[0028] Example 3 The difference between Example 3 and Example 1 is that the high thermal conductivity and low viscosity thermally conductive potting compound includes the following raw materials in parts by weight: 50g of double-sided vinyl silicone oil, 8g of hydrogen-terminated silicone oil, 400g of aluminum nitride, 400g of diamond, 300g of nano-alumina, 10g of cerium hydroxide, 10g of diethylaminoethyl methacrylate, 5g of allyl glycidyl ether, 1g of inhibitor, and 0.5g of catalyst.

[0029] Example 4 The difference between Example 4 and Example 1 is that aluminum nitride, diamond, nano aluminum oxide, and cerium hydroxide were pre-treated with a surface.

[0030] The preparation method of high thermal conductivity and low viscosity thermally conductive potting compound includes the following specific steps: S1: Aluminum nitride, diamond, nano-alumina, and cerium hydroxide are mixed and stirred until homogeneous to obtain a mixed filler. The mixed filler is heated to 105℃, and then a 20% (w / w) solution of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in anhydrous ethanol and long-chain fatty acids are added and mixed. The mixture is stirred and reacted for 30 minutes. The mixed filler is then removed and dried, thus completing the surface treatment of aluminum nitride, diamond, nano-alumina, and cerium hydroxide. The long-chain fatty acid is oleic acid, and the mass ratio of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to the mixed filler and long-chain fatty acids in the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution is 0.2:10:0.4.

[0031] S2: Mix double-sided vinyl silicone oil, hydrogen-terminated silicone oil, allyl glycidyl ether, and surface-treated aluminum nitride, diamond, nano-alumina, and cerium hydroxide. Stir until homogeneous. Under the protection of nitrogen, heat to 95°C, then add catalyst and inhibitor and mix until homogeneous. After reacting for 1 hour, continue heating to 120°C and mature for 30 minutes to obtain a high thermal conductivity, low viscosity thermally conductive potting compound.

[0032] Example 5 The difference between Example 5 and Example 4 is that, in the surface treatment of aluminum nitride, diamond, nano alumina, and cerium hydroxide, the mass ratio of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to mixed filler and long-chain fatty acid in the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution is 0.1:10:0.5.

[0033] Example 6 The difference between Example 6 and Example 4 is that, in the surface treatment of aluminum nitride, diamond, nano alumina, and cerium hydroxide, the mass ratio of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to mixed filler and long-chain fatty acid in the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution is 0.3:10:0.3.

[0034] Example 7 The difference between Example 7 and Example 4 is that, in the surface treatment of aluminum nitride, diamond, nano alumina, and cerium hydroxide, the long-chain fatty acid is a mixture of oleic acid and stearic acid, with a mass ratio of oleic acid to stearic acid of 1:1.

[0035] Example 8 The difference between Example 8 and Example 4 is that long-chain fatty acids are not used in the surface treatment of aluminum nitride, diamond, nano-alumina, and cerium hydroxide.

[0036] The preparation method of high thermal conductivity and low viscosity thermally conductive potting compound includes the following specific steps: S1: Aluminum nitride, diamond, nano-alumina, and cerium hydroxide are mixed and stirred until homogeneous to obtain a mixed filler. The mixed filler is heated to 105℃, and then a 20% (w / w) solution of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in anhydrous ethanol is added and mixed. The mixture is stirred and reacted for 30 minutes. The mixed filler is then removed and dried, thus completing the surface treatment of aluminum nitride, diamond, nano-alumina, and cerium hydroxide. The mass ratio of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to the mixed filler in the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution is 0.2:10.

[0037] S2: Mix double-sided vinyl silicone oil, hydrogen-terminated silicone oil, allyl glycidyl ether, and surface-treated aluminum nitride, diamond, nano-alumina, and cerium hydroxide. Stir until homogeneous. Under the protection of nitrogen, heat to 95°C, then add catalyst and inhibitor and mix until homogeneous. After reacting for 1 hour, continue heating to 120°C and mature for 30 minutes to obtain a high thermal conductivity, low viscosity thermally conductive potting compound.

[0038] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that diethylaminoethyl methacrylate is not used in the high thermal conductivity, low viscosity thermally conductive potting compound raw material.

[0039] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the high thermal conductivity, low viscosity thermally conductive potting compound does not use diethylaminoethyl methacrylate and allyl glycidyl ether.

[0040] Performance testing The high thermal conductivity and low viscosity thermally conductive potting compounds provided in Examples 1-8 and Comparative Examples 1-2 of this application were subjected to the following performance tests, and the specific test results are shown in Table 1.

[0041] Detection methods I. Viscosity Test The viscosity of the high thermal conductivity, low viscosity thermally conductive potting compound prepared in this application was tested at 25°C using a Brookfield viscometer.

[0042] II. Thermal conductivity The thermal conductivity of the high thermal conductivity and low viscosity thermally conductive potting compound prepared in this application was tested according to the method of GB / T 10297-2015 "Determination of thermal conductivity of non-metallic solid materials".

[0043] III. Liquidity The time required for 3 ml of the high thermal conductivity, low viscosity thermally conductive potting compound prepared in this application to reach a leveling diameter of 50 mm was measured.

[0044] Table 1: Performance Test Results Data Table

[0045] The performance test results show that the potting compound prepared in this application has good flowability and thermal conductivity. Through the synergistic effect of each component, the viscosity of the potting compound is reduced and its flowability is improved. A comparison between Comparative Examples 1-2 and Example 1 shows that Comparative Example 1 does not use diethylaminoethyl methacrylate, and Comparative Example 2 does not use diethylaminoethyl methacrylate and allyl glycidyl ether. The performance test results show that the overall performance of the prepared potting compounds decreases in both cases. This further demonstrates that diethylaminoethyl methacrylate and allyl glycidyl ether can introduce hydrophilic and lipophilic groups into the potting compound system, improving the dispersibility and compatibility of the system, reducing viscosity, and thus improving flowability.

[0046] The performance test results of Examples 4-7 show that surface treatment of aluminum nitride, diamond, nano-alumina, and cerium hydroxide, using 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt-anhydrous ethanol solution and long-chain fatty acids, can enhance the compatibility of the filler with the organosilicon matrix, reduce the surface polarity of the filler, and reduce the direct contact and agglomeration of filler particles through a dual effect, further reducing the viscosity of the potting compound and improving its flowability. A comparison between Examples 8 and 4 shows that Example 4 has a better surface treatment effect on aluminum nitride, diamond, nano-alumina, and cerium hydroxide.

[0047] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A high thermal conductivity, low viscosity thermally conductive potting compound, characterized in that, The raw materials include the following parts by weight: 40-50 parts of double-sided vinyl silicone oil, 5-8 parts of end-hydrogen silicone oil, 300-400 parts of aluminum nitride, 400-500 parts of diamond, 100-300 parts of nano-alumina, 10-20 parts of cerium hydroxide, 5-10 parts of diethylaminoethyl methacrylate, 5-8 parts of allyl glycidyl ether, 0.5-1 part of inhibitor, and 0.5-1 part of catalyst.

2. The high thermal conductivity, low viscosity thermally conductive potting compound according to claim 1, characterized in that, The catalyst is a platinum catalyst, and the inhibitor is ethynylcyclohexanol.

3. The high thermal conductivity, low viscosity thermally conductive potting compound according to claim 1, characterized in that, The aluminum nitride has a particle size of 5-20 μm, the nano-alumina has a particle size of 100-300 nm, the diamond has a particle size of 80-120 μm, and the cerium hydroxide has a particle size of 80-120 μm.

4. The high thermal conductivity, low viscosity thermally conductive potting compound according to claim 3, characterized in that, The aluminum nitride, diamond, nano alumina, and cerium hydroxide are pre-treated with the following specific steps: aluminum nitride, diamond, nano alumina, and cerium hydroxide are mixed and stirred evenly to obtain a mixed filler. The mixed filler is heated and then 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and long-chain fatty acids are added and mixed. The mixture is stirred and reacted. The mixed filler is then removed and dried to complete the surface treatment of aluminum nitride, diamond, nano alumina, and cerium hydroxide.

5. The high thermal conductivity, low viscosity thermally conductive potting compound according to claim 4, characterized in that, The mass ratio of 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt to mixed filler and long-chain fatty acid in the 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution is (0.1-0.3):10:(0.3-0.5).

6. The high thermal conductivity, low viscosity thermally conductive potting compound according to claim 4, characterized in that, The mixed filler is heated to 100-110℃ and then 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and long-chain fatty acids are added.

7. The high thermal conductivity, low viscosity thermally conductive potting compound according to claim 4, characterized in that, The long-chain fatty acid is a mixture of oleic acid and stearic acid.

8. A method for preparing a high thermal conductivity, low viscosity thermally conductive potting compound as described in any one of claims 1-7, characterized in that, The specific steps include the following: Bilateral vinyl silicone oil, hydrogen-terminated silicone oil, allyl glycidyl ether, aluminum nitride, diamond, nano alumina, and cerium hydroxide are mixed and stirred evenly. Under the protection of nitrogen, the mixture is heated to a higher temperature, and then a catalyst and inhibitor are added and mixed evenly to obtain a high thermal conductivity, low viscosity thermally conductive potting compound.

9. The method for preparing the high thermal conductivity, low viscosity thermally conductive potting compound according to claim 8, characterized in that, The heating temperature is 90-120℃.

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