Heat-conducting gel with high heat conductivity and high extrusion rate and preparation method of heat-conducting gel

Abstract

The invention relates to the technical field of thermal interface materials, in particular to heat-conducting gel with high heat conductivity and high extrusion rate and a preparation method of the heat-conducting gel. The heat-conducting gel with high heat conductivity and high extrusion rate is prepared from the following preparation raw materials in parts by mass: 2 to 10 parts of vinyl silicone oil, 0.1 to 1 part of cross-linking agent, 0.1 to 1 part of inhibitor, 100 to 300 parts of heat-conducting filler, 2 to 10 parts of performance additive and 0.1 to 1 part of catalyst. The heat-conducting gel with high heat conductivity and high extrusion rate, provided by the invention, not only has excellent performance in the aspects of heat-conducting property, extrusion rate and heat stability, but also is remarkably improved in the aspects of dispersity and compatibility, and has important industrial application value and market competitiveness.

Description

Technical Field

[0001] The present application relates to the technical field of thermal interface materials, and in particular to a thermally conductive gel with high thermal conductivity and high extrusion rate and a preparation method thereof. Background Art

[0002] Existing thermally conductive gels generally have problems with low thermal conductivity (≤12W / m·K) and insufficient extrusion rate, making it difficult to meet the heat dissipation requirements of high-power electronic devices. For example, traditional thermally conductive gels have limited thermal conductivity due to poor filler dispersion and high interface thermal resistance. In addition, high filler content will reduce gel fluidity and make the extrusion rate lower than 20g / min, affecting production efficiency. Therefore, there is an urgent need for a thermally conductive gel with both high thermal conductivity and high extrusion rate. Summary of the invention

[0003] In response to the shortcomings of current technology, the present application provides a thermally conductive gel with high thermal conductivity and high extrusion rate and a preparation method thereof. The thermally conductive gel with high thermal conductivity and high extrusion rate prepared in the present application has excellent thermal conductivity, high extrusion rate and thermal stability, and meets the heat dissipation requirements of high-power devices such as 5G chips and GPUs.

[0004] In the first aspect, the present application provides a thermally conductive gel with high thermal conductivity and high extrusion rate, adopting the following technical scheme: a thermally conductive gel with high thermal conductivity and high extrusion rate, comprising the following preparation raw materials, calculated by weight: 2-10 parts of vinyl silicone oil, 0.1-1 parts of cross-linking agent, 0.1-1 parts of inhibitor, 100-300 parts of thermally conductive filler, 2-10 parts of modification aid, and 0.1-1 parts of catalyst.

[0005] By adopting the above technical solutions, vinyl silicone oil is used as the base polymer to provide the main structure of the gel. Vinyl silicone oil has a low viscosity and good fluidity, which helps to improve the extrusion rate of the gel. At the same time, the cross-linking reaction between vinyl silicone oil and the cross-linking agent can form a stable three-dimensional network structure, ensuring the thermal stability of the gel. The cross-linking agent (such as hydrogen-containing silicone oil) is used to react with vinyl silicone oil to form a stable three-dimensional network structure. This not only enhances the mechanical strength and thermal stability of the gel, but also balances the fluidity and cross-linking efficiency of the gel. The inhibitor is used to control the curing rate and cross-linking degree of the gel to ensure the stable performance of the gel. The thermal conductive filler is composed of modified diamond, modified alumina and nano-zinc oxide. These fillers improve the interfacial compatibility through modification, significantly enhancing the thermal conductivity. At the same time, by controlling the particle size distribution, an efficient thermal conductive network is formed to further enhance the thermal conductivity. The modification aid is used to improve the fluidity of the gel, increase the extrusion rate and thermal stability. At the same time, the modification aid can also improve the thermal conductivity. The catalyst is used to accelerate the cross-linking reaction to ensure that the gel can be cured and formed within an appropriate time. In summary, through the interaction and synergy of each component, the thermal conductivity, extrusion rate and thermal stability of the thermal conductive gel are jointly improved, enabling it to meet the heat dissipation requirements of high-power devices.

[0006] Preferably, the vinyl silicone oil is divinyl polydimethylsiloxane, and the viscosity of the divinyl polydimethylsiloxane is 20 - 500 mPa·s.

[0007] Preferably, the cross-linking agent is side hydrogen-containing silicone oil, the viscosity of the side hydrogen-containing silicone oil is 100 mPa·s, and the active hydrogen content fraction is 0.2 - 0.3%.

[0008] Preferably, the thermal conductive filler is prepared by mixing modified diamond, modified alumina and nano-zinc oxide in a mass ratio of 30 - 40:40 - 50:10 - 15. Among them, the particle size of the modified diamond is 1 - 50 μm; the particle size of the modified alumina is 0.5 - 10 μm; the particle size of the nano-zinc oxide is 30 - 80 nm.

[0009] By adopting the above technical solutions, the functions of the modified diamond are as follows: Through ozonation treatment and reaction with organosilicon compounds, the hydrophobicity and compatibility of the modified diamond with organosilicon compounds are improved, thereby enhancing its dispersibility and uniformity in the thermal conductive gel. The modified diamond interacts with other components to form a percolation network structure in the thermal conductive gel, effectively improving the thermal conductivity and heat conduction efficiency. The functions of the modified alumina are as follows: Through surface modification and secondary cross-linking modification, the interfacial bonding force between the modified alumina and the silicone oil matrix is enhanced. The modified alumina can improve the thermal conductive network structure inside the gel, reduce the thermal resistance and increase the thermal conductivity efficiency. Alumina powders with different particle sizes and shapes can form a multi-level and multi-dimensional thermal conductive filler network, enhancing the thermal stability and toughness of the gel. Nano zinc oxide has a high specific surface area and thermal conductivity coefficient, which can effectively improve the overall thermal conductivity of the thermal conductive gel. By reasonably proportioning and compounding thermal conductive fillers with different particle sizes and shapes, an efficient thermal conductive network structure can be formed in the thermal conductive gel. By controlling the particle size distribution and species ratio of the thermal conductive fillers, the thermal conductivity can be balanced with the fluidity, thermal stability and other properties of the gel. The interaction between the modified diamond, the modified alumina and the nano zinc oxide can improve the comprehensive properties of the thermal conductive gel, including thermal conductivity, extrusion rate and thermal stability. In summary, through reasonable proportioning and modification treatment, these thermal conductive fillers can form an efficient thermal conductive network structure in the thermal conductive gel, while enhancing the dispersibility, uniformity, thermal stability and extrusion rate of the gel, meeting the heat dissipation requirements of high-power devices.

[0010] Preferably, the preparation method of the modified diamond includes the following steps: S51. According to mass parts, 100 parts of diamond are placed in 300 parts of sodium hydroxide solution with a mass concentration of 50 g / L, pretreated at 85 °C for 4 - 5 h to wash off the surface oil, filtered, and then the deoiled diamond is put into an ozonation treatment device for ozonation treatment at an ozone concentration of 150 mg / L for 3 - 4 hours, followed by solid-liquid separation to obtain ozonated modified diamond; S52. According to mass parts, 100 parts of ozonated modified diamond are added to a reactor containing 150 parts of 3-methacryloxypropyltrimethoxysilane and 400 parts of toluene, heated in an oil bath and stirred at 90 °C, with the condensate refluxed for 4 - 5 h. Then, the diamond treated with 3-methacryloxypropyltrimethoxysilane is rinsed 3 times with ethanol and then washed 2 times with distilled water, filtered by suction, dried, and sieved to obtain the modified diamond.

[0011] By adopting the above technical solution, for pretreatment and ozonation modification (step S51), the diamond is treated with a NaOH solution (50 g / L, 85 °C) for 4 - 5 hours to remove surface impurities and oil stains, and improve the active sites for subsequent reactions. It is then treated at an ozone concentration of 150 mg / L for 3 - 4 hours, and oxygen-containing functional groups such as hydroxyl (-OH) and carboxyl (-COOH) are generated on the diamond surface, enhancing the chemical bonding ability with the silicone matrix. For silane coupling agent grafting (step S52), the ozonated diamond and 3-methacryloxypropyltrimethoxysilane (KH570) are refluxed in toluene for 4 - 5 hours. The methoxy group (-OCH3) of KH570 hydrolyzes into silanol (-Si-OH), which condenses with the hydroxyl groups on the diamond surface to form Si-O-Si covalent bonds. The methacryloxy group (CH2=C(CH3)COO-) of KH570 provides an unsaturated double bond, which undergoes a cross-linking reaction with the vinyl group in vinyl silicone oil under the action of a catalyst (such as platinum), enhancing the interfacial bonding. The role of the modified diamond in the thermal conductive gel: 1) Improve dispersibility and compatibility. The organic long chain of KH570 makes the diamond surface change from hydrophilic to hydrophobic, improving the compatibility with the silicone oil matrix and reducing filler agglomeration. The silane coupling agent forms a "bridge" between the diamond and the matrix, reducing the interfacial thermal resistance and improving the thermal conductivity. 2) Construct a percolation thermal conductive network. The modified diamond with a size of 1 - 50 μm serves as the main thermal conduction channel to form a continuous three-dimensional network. Nano-zinc oxide (30 - 80 nm) fills the gaps between the diamond and alumina, reducing phonon scattering and increasing the thermal conductivity. 3) Enhance the extrusion rate, surface lubrication effect: The surface of the modified diamond is smooth, reducing the frictional resistance between the fillers. Combined with low-viscosity vinyl silicone oil, high extrudability can still be maintained under high filler loading.

[0012] Preferably, the preparation method of the modified alumina includes the following steps: S61. According to the mass parts, in 1000 parts of deionized water solution with a pH of 4 - 5, add 20 parts of ethyltrimethoxysilane, stir for 10 min, then add 500 parts of alumina, carry out surface modification for 3 - 4 h, then filter, and wash with water until neutral to obtain pre-modified alumina; S62. By mass parts, 500 parts of pre-modified alumina are added to 3000 parts of an aqueous solution of fatty alcohol polyoxyethylene (7) ether with a mass concentration of 8%, and stirred for 30 - 40 min; then, 2000 parts of hydroxyethyl methacrylate and 200 parts of an aqueous solution of potassium persulfate with a mass concentration of 10% are added dropwise under stirring conditions, and the mixture is kept at a constant temperature of 85 °C for reaction for 5 - 6 h; then, under stirring and at a temperature of 85 °C, 800 parts of 3-methacryloxypropyltrimethoxysilane and 100 parts of an aqueous solution of potassium persulfate with a mass concentration of 10% are added dropwise, and after reacting at a constant temperature of 85 °C for 5 - 6 h, filtration, washing, drying, and sieving are carried out to obtain modified alumina. The alumina is prepared by mixing single-crystal alumina and spherical alumina in a mass ratio of 3:1, wherein the particle size of the single-crystal alumina is 0.5 - 10 μm, and the particle size of the spherical alumina is 1 - 5 μm.

[0013] By adopting the above technical solution, the alumina is pre-modified by ethyltrimethoxysilane and secondly cross-linked and modified by hydroxyethyl methacrylate / silane, and an organic-inorganic hybrid layer is constructed on the surface of the alumina. This modified layer forms a chemical bond (such as Si-O-Si bond) with the vinyl silicone oil matrix, reducing the interfacial thermal resistance. When single-crystal alumina (flake structure) and spherical alumina are compounded at a ratio of 3:1: the flake structure provides a surface contact heat conduction path, improving the thermal conductivity; the spherical particles fill the gaps between the flakes, increasing the packing density of the filler, and the 0.5 - 10 μm particle size gradient distribution forms a "large particle skeleton + small particle filling" structure, enhancing the thermal conductivity coefficient. The hydroxyl content on the surface of the modified alumina is reduced, and it can significantly improve the extrusion rate in synergy with the low-viscosity silicone oil. The three-dimensional network formed by the secondary cross-linking makes the gel have higher thermal stability, meeting the heat dissipation requirements of high-power devices such as 5G chips and GPUs. In short, after the alumina is first surface-modified by ethyltrimethoxysilane and then secondly cross-linked and modified by hydroxyethyl methacrylate and 3-methacryloxypropyltrimethoxysilane in sequence, it can enhance the interfacial binding force between the alumina and the silicone oil matrix, improve the thermal conduction network structure inside the gel, and improve the thermal conduction efficiency on the basis of reducing the thermal resistance; secondly, by introducing alumina powders with different particle sizes and shapes, a multi-level and multi-dimensional thermal conduction filler network can be formed, which can improve the thermal stability and toughness of the gel and further enhance the extrusion rate of the gel.

[0014] Preferably, the modifying agent is composed of octyltrimethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1.

[0015] By adopting the above technical solution, octyltrimethoxysilane and vinyltrimethoxysilane may have different rheological properties. By adjusting their ratios, the rheological properties of the thermal conductive gel can be optimized, enabling it to exhibit better fluidity during the extrusion process. Octyltrimethoxysilane and vinyltrimethoxysilane may enhance the interfacial interaction between the filler and the matrix by reacting with specific functional groups on the surface of the thermal conductive filler. This enhanced interfacial interaction contributes to improving the overall performance of the thermal conductive gel. Octyltrimethoxysilane and vinyltrimethoxysilane may help form a stable three-dimensional network structure, which helps improve the thermal stability of the thermal conductive gel. The two substances may interact at the molecular level to form a synergistic effect. This synergistic effect may improve the overall performance of the thermal conductive gel, such as increasing the thermal conductivity and extrusion rate.

[0016] Preferably, the catalyst is a platinum catalyst, and the content of the platinum catalyst is 8-12 ppm in terms of the mass of platinum; the inhibitor is ethynylcyclohexanol.

[0017] In a second aspect, the present application provides a method for preparing a thermal conductive gel with high thermal conductivity and high extrusion rate, adopting the following technical solution: As a general technical concept, the present application also provides the method for preparing the above-mentioned thermal conductive gel with high thermal conductivity and high extrusion rate, including the following steps: S101. According to the mass parts, put vinyl silicone oil and a modifying agent into a blender and stir and mix them evenly; S102. Add a thermal conductive filler to the product of step S101 and stir and disperse it at 1000-1500 rpm for 30-60 minutes; then add a crosslinking agent, an inhibitor and a catalyst and stir until uniform at 300 rpm; S103. After evacuating the product of step S102 for 30-40 min, with the relative vacuum pressure being -0.02 MPa to -0.05 MPa, let it stand for 60 min to obtain a thermal conductive gel with high thermal conductivity and high extrusion rate.

[0018] In summary, the beneficial technical effects of the present application are as follows: 1. Improvement in thermal conductivity: By using modified diamond, modified alumina and nano-zinc oxide as thermal conductive fillers and finely controlling the particle size distribution, an efficient thermal conductive network is formed. This structure can effectively improve the thermal conductivity of the thermal conductive gel and meet the heat dissipation requirements of high-power devices.

[0019] 2. Increase in extrusion rate: Through the crosslinking system of low-viscosity vinyl silicone oil and a crosslinking agent, as well as the use of a modifying agent, the fluidity and crosslinking efficiency are balanced, thereby increasing the extrusion rate of the thermal conductive gel. This is of great significance for the continuous processing process in industrial production.

[0020] 3. Enhanced thermal stability: By using modified alumina, not only the thermal conductivity is improved, but also the thermal conductivity network structure inside the gel is enhanced due to the optimized interfacial bonding force, reducing the thermal resistance and thus increasing the thermal conductivity efficiency. At the same time, alumina powders with different particle sizes and shapes can form a multi-level and multi-dimensional thermal conductive filler network, enhancing the thermal stability and toughness of the gel.

[0021] 4. Improved dispersibility and compatibility: After surface treatment, the modified diamond has improved dispersibility and uniformity in the thermal conductive gel, forming a "percolation network" structure, further enhancing the thermal conductivity. At the same time, the surface modification and secondary cross-linking modification of the modified alumina enhance the interfacial bonding force between the alumina and the silicone oil matrix.

[0022] 5. Further improvement of the extrusion rate: The interaction between the functional groups on the surface of the modified thermal conductive filler and the silicone oil matrix further enhances the extrusion rate of the gel, which is of great significance for improving production efficiency and reducing production costs. Detailed implementation manners

[0023] The implementation manners of the present application will be described in detail below in combination with the embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For those reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0024] In the following preparation examples and embodiments, 1 part represents 100 g.

[0025] Preparation Example 1 Preparation of modified diamond The preparation method of the modified diamond includes the following steps: S51. According to the mass fraction, 100 parts of diamond are placed in 300 parts of sodium hydroxide solution with a mass concentration of 50 g / L, pretreated at 85 °C for 4.5 h to wash off the surface oil, filtered, and then the degreased diamond is put into an ozonation treatment device for ozonation treatment at an ozone concentration of 150 mg / L for 3.5 hours, and solid-liquid separation is carried out to obtain ozonation-modified diamond; S52. According to the mass fraction, 100 parts of ozonation-modified diamond are added to a reactor containing 150 parts of 3-methacryloxypropyltrimethoxysilane and 400 parts of toluene, heated in an oil bath at 90 °C and stirred, and the condensate is refluxed for 4.5 h. Then the diamond treated with 3-methacryloxypropyltrimethoxysilane is rinsed 3 times with ethanol, then washed 2 times with distilled water, filtered, dried, and sieved to obtain modified diamond with a particle size of 1 - 50 μm.

[0026] Preparation Example 2 Preparation of modified alumina Preparation method of modified alumina, comprising the following steps: S61. By mass, add 20 parts of ethyltrimethoxysilane to 1000 parts of deionized aqueous solution with a pH of 4.5, stir for 10 min, then add 500 parts of alumina, carry out surface modification for 3.5 h, filter, wash with water until neutral to obtain pre-modified alumina; the alumina is prepared by mixing single-crystal alumina and spherical alumina in a mass ratio of 3:1, wherein the particle size of the single-crystal alumina is 0.5 - 10 μm, and the particle size of the spherical alumina is 1 - 5 μm; S62. By mass, add 500 parts of pre-modified alumina to 3000 parts of an aqueous solution of fatty alcohol polyoxyethylene (7) ether with a mass concentration of 8%, stir for 35 min; then dropwise add 2000 parts of hydroxyethyl methacrylate and 200 parts of an aqueous solution of potassium persulfate with a mass concentration of 10% under stirring conditions, and carry out a constant-temperature reaction at 85 °C for 5.6 h; then continue to dropwise add 800 parts of 3-methacryloxypropyltrimethoxysilane and 100 parts of an aqueous solution of potassium persulfate with a mass concentration of 10% under stirring and at a temperature of 85 °C, carry out a constant-temperature reaction at 85 °C for 6 h, then filter, wash, dry, and sieve to obtain modified alumina with a particle size of 0.5 - 10 μm.

[0027] Example 1 A thermal conductive gel with high thermal conductivity and high extrusion rate, by mass, comprising the following preparation raw materials: 2 parts of divinyl polydimethylsiloxane, 0.1 part of side hydrogen-containing silicone oil, 0.1 part of ethynylcyclohexanol, 100 parts of thermal conductive filler, 4 parts of modification assistant, 0.1 part of platinum catalyst, the viscosity of the divinyl polydimethylsiloxane is 100 mPa·s, the viscosity of the side hydrogen-containing silicone oil is 100 mPa·s, the active hydrogen content fraction is 0.2%, the thermal conductive filler is prepared by mixing modified diamond, modified alumina and nano-zinc oxide in a mass ratio of 30:40:10, wherein the particle size of the nano-zinc oxide is 30 - 80 nm; the modification assistant is composed of octyltrimethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1, and the content of the platinum catalyst is 8 ppm in terms of the mass of platinum; Preparation method of the above thermal conductive gel with high thermal conductivity and high extrusion rate, comprising the following steps: S101. By mass, put divinyl polydimethylsiloxane and the modification assistant into a blender, stir and mix evenly; S102. Add the thermal conductive filler to the product in step S101 and stir and disperse at 1000 rpm for 30 minutes; then add the side hydrogen-containing silicone oil, ethynylcyclohexanol and the platinum catalyst and stir evenly at 300 rpm; S103. After evacuating the product of step S102 for 30 min, the relative vacuum pressure is -0.02 MPa, and it is allowed to stand for 60 min to obtain a thermal conductive gel with high thermal conductivity and high extrusion rate.

[0028] Example 2 A thermal conductive gel with high thermal conductivity and high extrusion rate, by mass, includes the following preparation raw materials: 10 parts of divinyl polydimethylsiloxane, 1 part of side hydrogen-containing silicone oil, 1 part of ethynylcyclohexanol, 300 parts of thermal conductive filler, 10 parts of modification aid, 1 part of platinum catalyst. The viscosity of the divinyl polydimethylsiloxane is 20 mPa·s, the viscosity of the side hydrogen-containing silicone oil is 100 mPa·s, and the active hydrogen content fraction is 0.3%. The thermal conductive filler is prepared by mixing modified diamond, modified alumina and nano-zinc oxide in a mass ratio of 40:50:15. Among them, the particle size of the nano-zinc oxide is 30 - 80 nm. The modification aid consists of octyltrimethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1. The content of the platinum catalyst is 12 ppm in terms of the mass of platinum. The preparation method of the above thermal conductive gel with high thermal conductivity and high extrusion rate includes the following steps: S101. According to the mass, put divinyl polydimethylsiloxane and the modification aid into a blender and stir and mix evenly. S102. Add the thermal conductive filler to the product of step S101 and stir and disperse at 1500 rpm for 60 minutes; then add the side hydrogen-containing silicone oil, ethynylcyclohexanol and platinum catalyst and stir at 300 rpm until uniform. S103. After evacuating the product of step S102 for 40 min, the relative vacuum pressure is -0.05 MPa, and it is allowed to stand for 60 min to obtain a thermal conductive gel with high thermal conductivity and high extrusion rate.

[0029] Example 3 A thermal conductive gel with high thermal conductivity and high extrusion rate, by mass, includes the following preparation raw materials: 6 parts of divinyl polydimethylsiloxane, 0.6 part of side hydrogen-containing silicone oil, 0.5 part of ethynylcyclohexanol, 200 parts of thermal conductive filler, 7 parts of modification aid, 0.4 part of platinum catalyst. The viscosity of the divinyl polydimethylsiloxane is 200 mPa·s, the viscosity of the side hydrogen-containing silicone oil is 100 mPa·s, and the active hydrogen content fraction is 0.2%. The thermal conductive filler is prepared by mixing modified diamond, modified alumina and nano-zinc oxide in a mass ratio of 35:45:12. Among them, the particle size of the nano-zinc oxide is 30 - 80 nm. The modification aid consists of octyltrimethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1. The content of the platinum catalyst is 10 ppm in terms of the mass of platinum. The preparation method of the above thermal conductive gel with high thermal conductivity and high extrusion rate includes the following steps: S101. According to the mass parts, put divinyl polydimethylsiloxane and a modifying assistant into a blender, and stir and mix them evenly; S102. Add a heat-conducting filler to the product of step S101 and stir and disperse it at 1300 rpm for 50 minutes; then add side hydrogen-containing silicone oil, ethynylcyclohexanol and a platinum catalyst and stir until uniform at 300 rpm; S103. After evacuating the product of step S102 for 35 min, with a relative vacuum pressure of -0.03 MPa, let it stand for 60 min to obtain a heat-conducting gel with a high heat conductivity and a high extrusion rate.

[0030] Comparative Example 1 Same as Example 3, except that unmodified diamond with a particle size of 1 - 50 μm in equal mass parts is used instead of modified diamond.

[0031] Comparative Example 2 Same as Example 3, except that the equal mass parts of the mixture (the mixture is prepared by mixing unmodified single-crystal alumina (particle size of 0.5 - 10 μm) and unmodified spherical alumina (particle size of 1 - 5 μm) in a mass ratio of 3:1) are used instead of modified alumina.

[0032] Comparative Example 3 Same as Example 3, except that the modifying assistant is octyltrimethoxysilane.

[0033] Comparative Example 4 Same as Example 3, except that the modifying assistant is vinyltrimethoxysilane.

[0034] Performance Test Take samples of the heat-conducting gels with high heat conductivity and high extrusion rate prepared in Examples 1 - 3 and Comparative Examples 1 - 4 for the following performance tests. Take 3 parallel samples for each group, and the results are averaged. The test results are shown in Table 1; Thermal Conductivity: Test according to ASTM D5470; Extrusion Rate: At 25 °C and under a pressure of 60 psi, through a syringe with a diameter of 5 mm, test the weight of the glue flowing out within 1 minute; Thermal Stability: Refer to GB / T 7124 for high and low temperature cycling ( 100 cycles), test the thermal conductivity, and calculate the thermal conductivity retention rate to evaluate the thermal stability.

[0035] Table 1 Performance Test Analyzing the data in Table 1, it can be seen that: 1) The thermal conductive gels prepared in Examples 1 - 3 with high thermal conductivity and high extrusion rate have excellent thermal conductivity, high extrusion rate and thermal stability, meeting the heat dissipation requirements of high - power devices such as 5G chips and GPUs.

[0036] 2) Through the performance comparison and analysis of the thermal conductive gels with high thermal conductivity and high extrusion rate prepared by combining Example 3 and Comparative Example 1, it is shown that the modified diamond prepared in this application, after being ozonized and modified with 3 - methacryloxypropyltrimethoxysilane, undergoes ozonation treatment on the surface of diamond particles and reacts with organosilicon compounds, improving the hydrophobicity of diamond and its compatibility with organosilicon compounds. Specifically: 1) The organic long chain of 3 - methacryloxypropyltrimethoxysilane turns the diamond surface from hydrophilic to hydrophobic, improving the compatibility with the silicone oil matrix and reducing filler agglomeration. 3 - methacryloxypropyltrimethoxysilane forms a "bridge" between the diamond and the matrix, reducing the interfacial thermal resistance and enhancing the thermal conductivity efficiency. 2) Construct a percolation thermal network, where the modified diamond with a size of 1 - 50μm serves as the main heat - conducting channel to form a continuous three - dimensional network. Nano - zinc oxide fills the voids between diamond and alumina, reducing phonon scattering and enhancing the thermal conductivity. 3) Enhance the extrusion rate. The surface of the modified diamond is smooth, reducing the frictional resistance between fillers. Combined with low - viscosity vinyl silicone oil, it still maintains high extrudability under high filler loading.

[0037] 3) Through the performance comparison and analysis of the thermal conductive gels with high thermal conductivity and high extrusion rate prepared by combining Example 3 and Comparative Example 2, it is shown that the modified alumina prepared in this application, after being surface - modified with ethyltrimethoxysilane alumina first and then undergoing secondary cross - linking modification with 2 - hydroxyethyl methacrylate and 3 - methacryloxypropyltrimethoxysilane in sequence, can enhance the interfacial binding force between alumina and the silicone oil matrix, improve the thermal conductive network structure inside the gel, and increase the thermal conductivity efficiency on the basis of reducing thermal resistance; secondly, by introducing alumina powders with different particle sizes and shapes, a multi - level and multi - dimensional thermal conductive filler network can be formed, which can improve the thermal stability and toughness of the gel and further enhance the extrusion rate of the gel.

[0038] 4) Through the performance comparison and analysis of the thermal conductive gels with high thermal conductivity and high extrusion rate prepared by combining Example 3 and Comparative Examples 3 - 4, it is shown that the modifying agent is composed of octyltrimethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:1. By utilizing the combined action between octyltrimethoxysilane and vinyltrimethoxysilane, the overall performance of the thermal conductive gel with high thermal conductivity and high extrusion rate can be further improved.

[0039] The above embodiments are only used to explain the technical solutions of the present application rather than limit them. Although the above embodiments have specifically described the present application, those skilled in the art should understand that they can still modify the specific implementation manners of the present invention or make equivalent replacements. Any modification and equivalent replacement that do not depart from the spirit and scope of the present application shall be covered by the protection scope of the present application.

Claims

1. A thermal conductive gel with high thermal conductivity and high extrusion rate, characterized in that, By mass parts, it includes the following preparation raw materials: 2-10 parts of vinyl silicone oil, 0.1-1 part of crosslinking agent, 0.1-1 part of inhibitor, 100-300 parts of heat-conducting filler, 2-10 parts of modifying assistant, and 0.1-1 part of catalyst.

2. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 1, characterized in that, The vinyl silicone oil is divinyl polydimethylsiloxane, and the viscosity of the divinyl polydimethylsiloxane is 20-500 mPa·s.

3. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 1, wherein The crosslinking agent is side hydrogen-containing silicone oil, the viscosity of the side hydrogen-containing silicone oil is 100 mPa·s, and the active hydrogen content fraction is 0.2-0.3%.

4. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 1, wherein, The heat-conducting filler is prepared by mixing modified diamond, modified alumina and nano zinc oxide in a mass parts ratio of 30-40:40-50:10-15. Among them, the particle size of the modified diamond is 1-50 μm; the particle size of the modified alumina is 0.5-10 μm; the particle size of the nano zinc oxide is 30-80 nm.

5. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 4, wherein The preparation method of the modified diamond includes the following steps: S51. According to mass parts, put 100 parts of diamond into 300 parts of sodium hydroxide solution with a mass concentration of 50 g / L, pretreat at 85 °C for 4-5 h, wash off the surface oil, filter, and then put the degreased diamond into an ozonation treatment device, and carry out ozonation treatment at an ozone concentration of 150 mg / L for 3-4 hours, carry out solid-liquid separation to obtain ozonation-modified diamond; S52. According to mass parts, add 100 parts of ozonation-modified diamond to a reactor containing 150 parts of 3-methacryloxypropyltrimethoxysilane and 400 parts of toluene, carry out oil bath and stir at 90 °C, condense and reflux the gel for 4-5 h, and then rinse the diamond treated with 3-methacryloxypropyltrimethoxysilane 3 times with ethanol, then wash 2 times with distilled water, carry out suction filtration, drying, and sieving to obtain modified diamond.

6. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 4, wherein The preparation method of the modified alumina includes the following steps: S61. According to mass parts, add 20 parts of ethyltrimethoxysilane to 1000 parts of deionized water solution with a pH of 4-5, stir for 10 min, then add 500 parts of alumina, carry out surface modification for 3-4 h, filter, and wash with water until neutral to obtain pre-modified alumina; S62. According to mass parts, add 500 parts of pre-modified alumina to 3000 parts of an aqueous solution of fatty alcohol polyoxyethylene (7) ether with a mass concentration of 8%, stir for 30-40 min; then dropwise add 2000 parts of hydroxyethyl methacrylate and 200 parts of an aqueous solution of potassium persulfate with a mass concentration of 10% under stirring conditions, carry out constant temperature reaction at 85 °C for 5-6 h; then continue to dropwise add 800 parts of 3-methacryloxypropyltrimethoxysilane and 100 parts of an aqueous solution of potassium persulfate with a mass concentration of 10% under stirring and at a temperature of 85 °C, carry out constant temperature reaction at 85 °C for 5-6 h, then carry out filtration, washing, drying, and sieving to obtain modified alumina.

7. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 6, characterized in that, The alumina is prepared by mixing single crystal alumina and spherical alumina in a mass parts ratio of 3:

1. Among them, the particle size of the single crystal alumina is 0.5-10 μm, and the particle size of the spherical alumina is 1-5 μm.

8. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 1, wherein The modified auxiliary agent is composed of octyltrimethoxysilane and vinyltrimethoxysilane in a mass ratio of 1:

1.

9. The thermal conductive gel with high thermal conductivity and high extrusion rate according to claim 1, characterized in that, The catalyst is a platinum catalyst, and the content of the platinum catalyst is 8 - 12 ppm in terms of the mass of platinum; the inhibitor is ethynylcyclohexanol.

10. A method for preparing a thermal conductive gel with high thermal conductivity and high extrusion rate according to any one of claims 1-9, characterized in that, It includes the following steps: S101. Put vinyl silicone oil and the modified auxiliary agent into a blender according to the mass parts, and stir and mix evenly. S102. Add a heat-conducting filler to the product in step S101 and stir and disperse it at 1000 - 1500 rpm for 30 - 60 minutes; then add a cross-linking agent, an inhibitor and a catalyst and stir at 300 rpm until uniform. S103. After evacuating the product in step S102 for 30 - 40 minutes, with a relative vacuum pressure of -0.02 MPa to -0.05 MPa, let it stand for 60 minutes to obtain a heat-conducting gel with a high heat conductivity and a high extrusion rate.

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