A two-component heat-conducting silica gel for heat dissipation of new energy devices and a preparation method thereof

Abstract

This invention relates to the field of thermally conductive silicone gel technology, specifically a two-component thermally conductive silicone gel for heat dissipation in new energy devices and its preparation method. The invention comprises the following steps: Step 1: Mixing maleimide compound, epoxy-containing double-bonded organosilicon, toluene, and 2-methylimidazole uniformly, reacting at 30-40℃ for 5-7 hours, and then rotary evaporating to obtain a thickener; Step 2: Mixing vinyl silicone oil, thickener, modified diamond, modified aluminum nitride, modified alumina, modified boron nitride, and hydrogen-containing silicone oil uniformly to obtain component A; mixing vinyl silicone oil, modified diamond, modified aluminum nitride, modified alumina, modified boron nitride, modified MQ resin, inhibitor, and platinum catalyst uniformly to obtain component B; Step 3: Mixing components A and B uniformly, and then degassing under vacuum to obtain a two-component thermally conductive silicone gel with excellent thermal conductivity and high-temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of thermally conductive silicone gel technology, specifically a two-component thermally conductive silicone gel for heat dissipation of new energy devices and its preparation method. Background Technology

[0002] With the rapid development of new energy technologies, such as the widespread application of new energy vehicles, energy storage systems, and photovoltaic inverters, the power density and integration of new energy devices are constantly increasing, and the heat generated during operation is also increasing significantly. If this heat cannot be dissipated in a timely and effective manner, it will cause the device temperature to rise, thereby affecting its performance, reliability, and service life, and may even cause safety problems.

[0003] Thermally conductive silicone gel, as an important thermal interface material, possesses excellent filling properties, thermal conductivity, and flexibility, enabling it to closely adhere to the surface of components, thereby effectively reducing contact thermal resistance and achieving efficient heat dissipation. Therefore, it has been widely used in the heat dissipation field of new energy equipment.

[0004] However, existing thermally conductive silicone gels suffer from problems such as insufficient thermal conductivity, poor mechanical properties, complex preparation processes, or excessively high costs, making it difficult to meet the heat dissipation requirements of some high-power-density new energy devices. For example, some thermally conductive gels use a single powder filler, resulting in insufficient construction of thermal conductivity pathways and low heat transfer efficiency; some formulations have poor powder dispersibility and are prone to agglomeration, leading to unstable thermal conductivity; at the same time, existing modification processes often suffer from insufficient modification and poor compatibility between powder and matrix, affecting the overall performance of the gel.

[0005] Therefore, we propose a two-component thermally conductive silicon gel for heat dissipation of new energy devices and its preparation method. Summary of the Invention

[0006] The purpose of this invention is to provide a two-component thermally conductive silicone gel for heat dissipation of new energy devices and its preparation method, so as to solve the problems raised in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a two-component thermally conductive silicone gel for heat dissipation in new energy devices includes the following steps: Step 1: Mix maleimide compound, organosilicon containing epoxy double bond, toluene and 2-methylimidazole evenly, react at 30-40℃ for 5-7 hours, and obtain thickener by rotary evaporation; Step 2: Mix vinyl silicone oil, tackifier, modified diamond, modified aluminum nitride, modified alumina, modified boron nitride, and hydrogen-containing silicone oil evenly to obtain material A; mix vinyl silicone oil, modified diamond, modified aluminum nitride, modified alumina, modified boron nitride, modified MQ resin, inhibitor, and platinum catalyst evenly to obtain material B. Step 3: Mix component A and component B evenly, and then degas under vacuum to obtain a two-component thermally conductive silicone gel.

[0008] Further, the preparation method of the modified diamond is as follows: diamond is stirred in sodium hydroxide solution at 80-90℃ for 2-4 hours, washed until neutral, and dried to obtain pretreated diamond; n-decyltrimethoxysilane, anhydrous ethanol and deionized water are mixed evenly to obtain mixture A; take the pretreated diamond, spray 2 / 3 of the mass of mixture A at a speed of 300-400 r / min, stir at a speed of 750-850 r / min for 3-5 minutes, spray the remaining mass of mixture A a second time, continue stirring at a speed of 750-850 r / min for 3-5 minutes, bake and solidify, and cool to room temperature to obtain modified diamond.

[0009] Furthermore, in the mixture A, the mass ratio of n-decyltrimethoxysilane, anhydrous ethanol and deionized water is 1:(10-15):(2-5).

[0010] Furthermore, the mass ratio of the pretreated diamond to the mixture A is 1:(12-18).

[0011] Further, the preparation methods of the modified aluminum nitride, modified alumina, and modified boron nitride are as follows: Aluminum nitride, alumina, and boron nitride are respectively subjected to baking pretreatment, followed by cooling to obtain pretreated aluminum nitride, pretreated alumina, and pretreated boron nitride; n-octyltriethoxysilane, anhydrous ethanol, and deionized water are mixed evenly to obtain mixture B; 2 / 3 of the mass of the pretreated aluminum nitride, pretreated alumina, and pretreated boron nitride are initially sprayed onto each mixture at a speed of 300-400 r / min, and stirred for 3-5 min at a speed of 750-850 r / min; the remaining mass of mixture B is then sprayed onto each mixture a second time, and stirred for another 3-5 min at a speed of 750-850 r / min; the mixture is then baked and cured, and cooled to room temperature to obtain modified aluminum nitride, modified alumina, and modified boron nitride.

[0012] Furthermore, in the mixture B, the mass ratio of n-octyltriethoxysilane, anhydrous ethanol and deionized water is 1:(10-15):(2-5).

[0013] Furthermore, the mass ratio of the pretreated aluminum nitride, pretreated alumina, and pretreated boron nitride to the mixed solution B is 1:(12-18).

[0014] Further, the A material is composed of the following components in parts by weight: 1-5 parts vinyl silicone oil, 0.5-1.5 parts tackifier, 40-80 parts modified aluminum nitride, 20-50 parts modified alumina, 1-10 parts modified diamond, 10-30 parts modified boron nitride, and 0.1-5.0 parts hydrogen-containing silicone oil.

[0015] Further, the B material is composed of the following components in parts by weight: 1-5 parts vinyl silicone oil, 40-80 parts modified aluminum nitride, 20-50 parts modified alumina, 1-10 parts modified diamond, 10-30 parts modified boron nitride, 1-3 parts modified MQ resin, 0.005-0.010 parts inhibitor, and 0.003-0.008 parts platinum catalyst.

[0016] Further, the mass ratio of the maleimide compound, the epoxy-containing organosilicon, toluene, and 2-methylimidazole is 1:(2-4):(15-25):(0.005-0.01).

[0017] Furthermore, the preparation method of the maleimide compound is as follows: Maleic anhydride and N,N'-dimethylformamide were mixed evenly and heated to 60-70℃. A mixed solution of 2-(4-aminophenyl)-5-aminobenzimidazole and N,N'-dimethylformamide was added dropwise over 30-50 minutes. The reaction was carried out under nitrogen protection for 2-4 hours. After cooling to room temperature, the intermediate was obtained by filtration, washing, and vacuum drying. Under nitrogen protection, the intermediate was mixed evenly with xylene, and p-toluenesulfonic acid and p-hydroxyanisole were added. The mixture was heated to 100-110℃ and subjected to reflux for water separation and cyclization dehydration for 5-7 hours. After rotary evaporation, filtration, washing, purification, and vacuum drying, the maleimide compound was obtained.

[0018] Further, the mass ratio of maleic anhydride to N,N'-dimethylformamide is 1:(10-12), and the mass ratio of 2-(4-aminophenyl)-5-aminobenzimidazole to N,N'-dimethylformamide is 1:(10-12).

[0019] Furthermore, the molar ratio of maleic anhydride to 2-(4-aminophenyl)-5-aminobenzimidazole is 1:1.

[0020] Further, the mass ratio of the intermediate, xylene, p-toluenesulfonic acid and p-hydroxyanisole is 1:(4-6):(0.1-0.3):(0.01-0.02).

[0021] Furthermore, the preparation method of the epoxy-containing double-bonded organosilicon is as follows: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, diphenylsilanediol and acetone were stirred evenly, and then tetrabutyl titanate was added. The reaction was carried out at 40-50℃ for 12-15 h, and finally the temperature was raised to 100-110℃ and the reaction was continued under reduced pressure for 3-5 h to obtain organosilicon containing epoxy double bonds.

[0022] Further, the molar ratio of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane and diphenylsilanediol is 1:(1.0-1.2):(2.0-2.2).

[0023] Furthermore, the amount of tetrabutyl titanate used is 1-3% of the total weight of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane and diphenylsilanediol.

[0024] Furthermore, the modified MQ resin is prepared as follows: After stirring methyl MQ resin, methyl methacrylate and hydroquinone until completely dissolved, the mixture is heated to 80-90℃ and refluxed. 3-aminopropyltriethoxysilane and a catalyst are added, and the mixture is stirred for 1-2 hours. Then, acryloyloxytrimethoxysilane is added, and the mixture is stirred for 1-2 hours. The mixture is then cooled to room temperature to obtain the modified MQ resin.

[0025] Further, the mass ratio of the methyl MQ resin, methyl methacrylate and hydroquinone is 1:(1-2):(0.002-0.004).

[0026] Furthermore, the amount of 3-aminopropyltriethoxysilane used is 0.3-0.5 times the mass of methyl MQ resin; the mass ratio of 3-aminopropyltriethoxysilane to catalyst is 1:(0.005-0.010), and the catalyst is cyclohexanone oxime.

[0027] Furthermore, the amount of acryloyloxytrimethoxysilane used is 0.2-0.4 times the mass of methyl MQ resin.

[0028] Furthermore, the mass ratio of material A to material B is 1:1.

[0029] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention constructs a highly efficient, dense, and stable thermally conductive network through multi-particle-size synergistic filling and refined surface modification and process control. Firstly, it innovatively employs a combination of micron-sized powders, following a stacking logic of "large particle skeleton, medium particle filling, and small particle gap filling." Larger-sized alumina and diamond are used to construct the large-particle skeleton, aluminum nitride / boron nitride fills the gaps in the skeleton, and smaller-sized alumina further fills the tiny voids, effectively eliminating "air gaps" in the thermally conductive pathways and forming a continuous, uninterrupted thermally conductive network. In the adhesive preparation process, a "three-stage powder addition and step-by-step stirring" method (components A and B are each thoroughly stirred with a single powder before adding the next) avoids the breakage of the thermally conductive pathways caused by powder agglomeration, ensuring the uniform distribution of high thermal conductivity powder in the silicone oil matrix, allowing heat to be rapidly transferred along the powder particles. Secondly, a specific surface modification strategy was designed to address the differences in surface polarity and particle size of different powders: for diamond with strong surface inertness, n-decyltrimethoxysilane was selected as a modifier to improve compatibility with silicone oil by utilizing its long-chain alkyl groups; for polar powders such as aluminum nitride, aluminum oxide, and boron nitride, n-octyltriethoxysilane with active groups was selected as a modifier to react with the hydroxyl groups on the powder surface to reduce surface energy, effectively avoiding the problems of "insufficient modification leading to agglomeration" or "excessive modification affecting thermal conductivity"; Finally, this invention employs a two-stage spraying and segmented stirring process in the modification process to ensure uniform distribution of the modifier. Combined with two 125°C baking cycles (pretreatment and curing), this removes the original moisture in the powder, avoids interference from hydrolysis on the modification, and completely evaporates the ethanol. This promotes the formation of stable chemical bonds between the modifier and the powder surface, rather than physical adsorption, thereby maintaining the excellent dispersion of the powder in the system over the long term. The synergistic effect of these measures significantly improves the thermal conductivity and long-term reliability of the composite material.

[0030] 2. This invention uses diphenylsilanediol, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and 3-methacryloyloxypropylmethyldimethoxysilane as raw materials to synthesize phenyl silicone resin containing epoxy groups and double bonds, i.e., organosilicon containing epoxy groups and double bonds, via a non-hydrolyzed sol-gel method. Then, by precisely controlling the molar ratio of maleic anhydride and 2-(4-aminophenyl)-5-aminobenzimidazole to 1:1, maleic anhydride undergoes an amidation reaction only with the amino group at one end of 2-(4-aminophenyl)-5-aminobenzimidazole, introducing a rigid benzimidazole ring structure. The amino group at the other end is retained and can be further grafted onto organosilicon containing epoxy groups and double bonds through an epoxy ring-opening reaction to obtain a tackifier. The introduced rigid aromatic heterocyclic structure can effectively improve the thermal stability of the entire cured network, thereby significantly enhancing the heat resistance of the thermally conductive silicone gel. In this scheme, methyl MQ resin was modified with acryloyloxytrimethoxysilane and aminopropyltriethoxysilane to synthesize a modified MQ resin containing alkoxy, acryloyloxy and aminopropyl groups. By compounding the modified MQ resin with a tackifier, a synergistic effect was achieved. The rigid benzimidazole ring in the tackifier could effectively inhibit the excessive cross-linking of the polymer network at high temperatures. At the same time, the modified MQ resin could optimize the interface and stabilize the filler dispersion. The synergistic effect of the two is the key to maintaining the long-term softness (low hardness) and high-temperature resistance of the material. Detailed Implementation

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Unless otherwise specified, all parts below are by weight. It should be noted that there are no special restrictions on the purchasers of any of the raw materials involved in this invention. Exemplary examples include (in this embodiment) diamond: particle size 70 μm; aluminum nitride: particle sizes 25 μm and 40 μm (mass ratio of the two is 1:1); alumina: particle sizes 1 μm and 80 μm (mass ratio of the two is 1:1); boron nitride: particle size 40 μm; hydrogen-containing silicone oil: active hydrogen mass fraction 0.12%; vinyl silicone oil: grade V909621, viscosity 90 mPa·S (25℃); inhibitor: 1-acetylenecyclohexanol; methyl MQ resin: model JFC-808.

[0033] Example 1: A method for preparing a two-component thermally conductive silicone gel for heat dissipation of new energy devices, comprising the following processes: Step 1: Mix 0.5 parts of maleimide compound, 1 part of organosilicon containing epoxy double bond, 7.5 parts of toluene and 0.0025 parts of 2-methylimidazole evenly, react at 30°C for 5 hours, and obtain the thickener by rotary evaporation; Step 2: Stir 2 parts of diamond in 20 parts of 1 mol / L sodium hydroxide solution at 80℃ for 2 hours, wash until neutral, and dry to obtain pretreated diamond; mix 2 parts of n-decyltrimethoxysilane, 20 parts of anhydrous ethanol and 4 parts of deionized water evenly to obtain mixture A; take 2 parts of pretreated diamond, spray 16 parts of mixture A at 300 r / min, stir at 750 r / min for 3 minutes, spray 8 parts of mixture A a second time, continue stirring at 750 r / min for 3 minutes, bake and cure at 125℃ for 3 hours, cool to room temperature to obtain modified diamond; Pretreated aluminum nitride, alumina, and boron nitride were pretreated by baking at 125°C for 3 hours, followed by cooling to obtain pretreated aluminum nitride, alumina, and boron nitride. Octyltriethoxysilane, anhydrous ethanol, and deionized water were mixed at a mass ratio of 1:10:2 to obtain mixture B. 80 parts of pretreated aluminum nitride were sprayed with 640 parts of mixture B at 300 r / min, stirred at 750 r / min for 3 minutes, and then a second spray of 320 parts of mixture B was performed, stirred at 750 r / min for another 3 minutes. The mixture was then baked and cured at 125°C for 3 hours, and cooled to room temperature to obtain modified aluminum nitride. 40 parts of pretreated aluminum nitride were then... Modified alumina was prepared by spraying 320 parts of mixed solution B at 300 r / min, stirring at 750 r / min for 3 min, spraying 160 parts of mixed solution B a second time, stirring at 750 r / min for another 3 min, baking and curing at 125℃ for 3 h, and cooling to room temperature. Modified boron nitride was also prepared by spraying 20 parts of pretreated boron nitride at 300 r / min, spraying 160 parts of mixed solution B a second time, stirring at 750 r / min for 3 min, spraying 80 parts of mixed solution B a second time, stirring at 750 r / min for another 3 min, baking and curing at 125℃ for 3 h, and cooling to room temperature. Mix 1 part vinyl silicone oil, 0.5 part tackifier, 1 part modified diamond, 40 parts modified aluminum nitride, 20 parts modified alumina, 10 parts modified boron nitride, and 0.1 part hydrogen-containing silicone oil evenly to obtain material A; mix 1 part vinyl silicone oil, 1 part modified diamond, 40 parts modified aluminum nitride, 20 parts modified alumina, 10 parts modified boron nitride, 1 part modified MQ resin, 0.005 part inhibitor, and 0.003 part platinum catalyst evenly to obtain material B; Step 3: Mix component A and component B at a mass ratio of 1:1 until homogeneous, and then degas under vacuum to obtain a two-component thermally conductive silicone gel. The preparation method of maleimide compounds is as follows: Maleic anhydride and N,N'-dimethylformamide were mixed evenly at a mass ratio of 1:10, heated to 60°C, and a mixed solution of 2-(4-aminophenyl)-5-aminobenzimidazole and N,N'-dimethylformamide at a mass ratio of 1:10 was added dropwise over 30 minutes. The reaction was carried out under nitrogen protection for 2 hours, cooled to room temperature, and obtained by filtration, washing, and vacuum drying to yield an intermediate with a molar ratio of maleic anhydride to 2-(4-aminophenyl)-5-aminobenzimidazole of 1:1. Under nitrogen protection, 0.5 parts of the intermediate and 2 parts of xylene were mixed evenly, and 0.05 parts of p-toluenesulfonic acid and 0.005 parts of p-hydroxyanisole were added. The mixture was heated to 100°C and subjected to reflux for water separation and cyclization dehydration for 5 hours. After rotary evaporation, filtration, washing, purification, and vacuum drying, maleimide compound was obtained. The preparation method of organosilicon containing epoxy double bonds is as follows: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane and diphenylsilanediol were mixed in a molar ratio of 1:1:2, dissolved completely in acetone, and then tetrabutyl titanate was added at 1% of the total mass of the reactants. The mixture was reacted at 40°C for 12 h, and then the temperature was raised to 100°C and the reaction was continued at -0.09 MPa for 3 h to obtain an organosilicon containing epoxy double bonds. The preparation method of modified MQ resin is as follows: One part of methyl MQ resin, one part of methyl methacrylate, and 0.002 parts of hydroquinone were stirred until completely dissolved. The mixture was then heated to 80°C and refluxed. 0.3 parts of 3-aminopropyltriethoxysilane and 0.015 parts of cyclohexanone oxime were added, and the mixture was stirred for 1 hour. Then, 0.2 parts of acryloyloxytrimethoxysilane were added, and the mixture was stirred for 1 hour. The mixture was then cooled to room temperature to obtain the modified MQ resin.

[0034] Example 2: A method for preparing a two-component thermally conductive silicone gel for heat dissipation of new energy devices, comprising the following processes: Step 1: Mix 1 part maleimide compound, 3 parts organosilicon containing epoxy double bonds, 20 parts toluene and 0.015 parts 2-methylimidazole evenly, react at 35°C for 6 hours, and obtain the thickener by rotary evaporation; Step 2: 10 parts of diamond were stirred in 30 parts of 1 mol / L sodium hydroxide solution at 85℃ for 4 hours, washed until neutral, and dried to obtain pretreated diamond; 10 parts of n-decyltrimethoxysilane, 140 parts of anhydrous ethanol and 40 parts of deionized water were mixed evenly to obtain mixture A; 100 parts of mixture A were sprayed onto the pretreated diamond at 350 r / min, stirred at 800 r / min for 4 minutes, and then 50 parts of mixture A were sprayed onto the diamond, stirred at 800 r / min for another 4 minutes. The mixture was then baked and cured at 125℃ for 3 hours and cooled to room temperature to obtain modified diamond; 120 parts of aluminum nitride, 60 parts of alumina, and 40 parts of boron nitride were pretreated by baking at 125℃ for 3 hours, followed by cooling to obtain pretreated aluminum nitride, pretreated alumina, and pretreated boron nitride. Octyltriethoxysilane, anhydrous ethanol, and deionized water were mixed uniformly at a mass ratio of 1:12:4 to obtain mixture B. 120 parts of pretreated aluminum nitride were sprayed with 1200 parts of mixture B at 350 r / min, stirred at 800 r / min for 4 minutes, and then sprayed with 600 parts of mixture B again, stirred at 800 r / min for another 4 minutes. The mixture was then baked and cured at 125℃ for 3 hours, and cooled to room temperature to obtain modified aluminum nitride. 60 parts of pretreated aluminum nitride were then... Modified alumina was prepared by spraying 600 parts of mixed solution B at 350 r / min, stirring at 750 r / min for 4 min, spraying 300 parts of mixed solution B a second time, stirring at 800 r / min for another 4 min, baking and curing at 125℃ for 3 h, and cooling to room temperature. Modified boron nitride was also prepared by spraying 40 parts of pretreated boron nitride at 350 r / min, stirring at 800 r / min for 4 min, spraying 200 parts of mixed solution B a second time, stirring at 750 r / min for another 4 min, baking and curing at 125℃ for 3 h, and cooling to room temperature. Mix 3 parts vinyl silicone oil, 1 part tackifier, 5 parts modified diamond, 60 parts modified aluminum nitride, 30 parts modified alumina, 20 parts modified boron nitride, and 3 parts hydrogen-containing silicone oil evenly to obtain material A; mix 3 parts vinyl silicone oil, 5 parts modified diamond, 60 parts modified aluminum nitride, 30 parts modified alumina, 20 parts modified boron nitride, 2 parts modified MQ resin, 0.008 parts inhibitor, and 0.005 parts platinum catalyst evenly to obtain material B; Step 3: Mix component A and component B at a mass ratio of 1:1 until homogeneous, and then degas under vacuum to obtain a two-component thermally conductive silicone gel. The preparation method of maleimide compounds is as follows: Maleic anhydride and N,N'-dimethylformamide were mixed evenly at a mass ratio of 1:11, heated to 65°C, and a mixed solution of 2-(4-aminophenyl)-5-aminobenzimidazole and N,N'-dimethylformamide at a mass ratio of 1:11 was added dropwise over 40 minutes. The reaction was carried out under nitrogen protection for 3 hours, cooled to room temperature, and obtained by filtration, washing, and vacuum drying to yield an intermediate with a molar ratio of maleic anhydride to 2-(4-aminophenyl)-5-aminobenzimidazole of 1:1. Under nitrogen protection, 1 part of the intermediate and 5 parts of xylene were mixed evenly, and 0.2 parts of p-toluenesulfonic acid and 0.015 parts of p-hydroxyanisole were added. The mixture was heated to 105°C and subjected to reflux for water separation and cyclization dehydration for 6 hours. After rotary evaporation, filtration, washing, purification, and vacuum drying, maleimide compound was obtained. The preparation method of organosilicon containing epoxy double bonds is as follows: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxy, and diphenylsilanediol were mixed in a molar ratio of 1:1.1:2.1, dissolved completely in acetone, and then 2% tetrabutyl titanate (by mass of the total reactants) was added. The mixture was reacted at 45°C for 14 hours, and then the temperature was raised to 105°C and the reaction was continued at -0.09 MPa for 4 hours to obtain an organosilicon containing epoxy double bonds. The preparation method of modified MQ resin is as follows: Two parts of methyl MQ resin, three parts of methyl methacrylate, and 0.006 parts of hydroquinone were stirred until completely dissolved. The mixture was then heated to 85°C and refluxed. 0.8 parts of 3-aminopropyltriethoxysilane and 0.0064 parts of cyclohexanone oxime were added, and the mixture was stirred for 1.5 hours. Then, 0.6 parts of acryloyloxytrimethoxysilane were added, and the mixture was stirred for 1.5 hours. The mixture was then cooled to room temperature to obtain the modified MQ resin.

[0035] Example 3: A method for preparing a two-component thermally conductive silicone gel for heat dissipation of new energy devices, comprising the following processes: Step 1: Mix 1 part maleimide compound, 4 parts organosilicon containing epoxy double bonds, 25 parts toluene and 0.01 parts 2-methylimidazole evenly, react at 40°C for 7 hours, and obtain the thickener by rotary evaporation; Step 2: 20 parts of diamond were stirred in 80 parts of 1 mol / L sodium hydroxide solution at 90℃ for 5 hours, washed until neutral, and dried to obtain pretreated diamond; 24 parts of n-decyltrimethoxysilane, 360 parts of anhydrous ethanol and 120 parts of deionized water were mixed evenly to obtain mixture A; 20 parts of pretreated diamond were taken, and 240 parts by weight of mixture A were sprayed on at 400 r / min for the first time, and stirred at 850 r / min for 5 minutes; 120 parts of mixture A were sprayed on a second time, and stirred at 850 r / min for another 5 minutes; after baking and curing, the modified diamond was obtained. Pretreated aluminum nitride, alumina, and boron nitride were prepared by baking at 125°C for 3 hours, followed by cooling. 160 parts of aluminum nitride, 100 parts of alumina, and 60 parts of boron nitride were then pretreated by baking at 125°C for 3 hours, followed by cooling to obtain pretreated aluminum nitride, alumina, and boron nitride. Octyltriethoxysilane, anhydrous ethanol, and deionized water were mixed at a mass ratio of 1:15:4 to obtain mixture B. 160 parts of pretreated aluminum nitride were sprayed with 1920 parts of mixture B at 400 r / min, stirred at 850 r / min for 4 minutes, and then sprayed with 960 parts of mixture B again at 800 r / min for another 4 minutes. The mixture was then baked and cured at 125°C for 3 hours and cooled to room temperature to obtain modified aluminum nitride. 100 parts of pretreated aluminum nitride were then... Modified alumina was prepared by first spraying 1200 parts of mixture B at 400 r / min, stirring at 850 r / min for 4 min, then spraying 600 parts of mixture B again, stirring at 800 r / min for another 4 min, baking and curing at 125℃ for 3 h, and cooling to room temperature. Modified boron nitride was also prepared by first spraying 720 parts of mixture B at 850 r / min, stirring at 850 r / min for 4 min, then spraying 360 parts of mixture B again, stirring at 850 r / min for another 4 min, baking and curing at 125℃ for 3 h, and cooling to room temperature. Mix 5 parts vinyl silicone oil, 1.50 parts tackifier, 10 parts modified diamond, 80 parts modified aluminum nitride, 50 parts modified alumina, 30 parts modified boron nitride, and 5.0 parts hydrogen-containing silicone oil evenly to obtain component A; mix 5 parts vinyl silicone oil, 10 parts modified diamond, 80 parts modified aluminum nitride, 50 parts modified alumina, 30 parts modified boron nitride, 3 parts modified MQ resin, 0.010 parts inhibitor, and 0.008 parts platinum catalyst evenly to obtain component B. Step 3: Mix component A and component B at a mass ratio of 1:1 until homogeneous, and then degas under vacuum to obtain a two-component thermally conductive silicone gel. The preparation method of maleimide compounds is as follows: Maleic anhydride and N,N'-dimethylformamide were mixed evenly at a mass ratio of 1:12, heated to 70°C, and a mixed solution of 2-(4-aminophenyl)-5-aminobenzimidazole and N,N'-dimethylformamide at a mass ratio of 1:12 was added dropwise over 50 minutes. The reaction was carried out under nitrogen protection for 4 hours, cooled to room temperature, and obtained by filtration, washing, and vacuum drying to yield an intermediate with a molar ratio of maleic anhydride to 2-(4-aminophenyl)-5-aminobenzimidazole of 1:1. Under nitrogen protection, 1 part of the intermediate and 6 parts of xylene were mixed evenly, and 0.3 parts of p-toluenesulfonic acid and 0.02 parts of p-hydroxyanisole were added. The mixture was heated to 110°C and subjected to reflux for water separation and cyclization dehydration for 7 hours. After rotary evaporation, filtration, washing, purification, and vacuum drying, maleimide compound was obtained. The preparation method of organosilicon containing epoxy double bonds is as follows: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane and diphenylsilanediol were mixed in a molar ratio of 1:1.2:2.2, dissolved completely in acetone, and then tetrabutyl titanate (3% by mass of the total reactants) was added. The mixture was reacted at 50°C for 15 h, and then the temperature was raised to 110°C and the reaction was continued at -0.09 MPa for 5 h to obtain an organosilicon containing epoxy double bonds. The preparation method of modified MQ resin is as follows: Three parts of methyl MQ resin, six parts of methyl methacrylate, and 0.012 parts of hydroquinone were stirred until completely dissolved. The mixture was then heated to 90°C and refluxed. 1.5 parts of 3-aminopropyltriethoxysilane and 0.015 parts of cyclohexanone oxime were added, and the mixture was stirred for 2 hours. Then, 1.2 parts of acryloyloxytrimethoxysilane were added, and the mixture was stirred for 2 hours. The mixture was then cooled to room temperature to obtain the modified MQ resin.

[0036] Comparative Example 1: Comparative Example 1 is based on Example 2. No thickener was introduced in Comparative Example 1, and the remaining process steps and reaction parameters were the same as in Example 2.

[0037] Comparative Example 2: Comparative Example 2 is based on Example 2, except that the modified MQ resin is replaced with the same mass of methyl MQ resin, and the remaining process steps and reaction parameters are the same as in Example 2.

[0038] Comparative Example 3: Comparative Example 3 is based on Example 2. The tackifier in the comparative example is replaced with the same mass of epoxy-containing double-bonded organosilicon. The remaining process steps and reaction parameters are the same as in Example 2.

[0039] Experiment: The two-component thermally conductive silicone gels obtained in Examples 1-3 and Comparative Examples 1-3 were injected into molds and cured at room temperature for 24 hours to obtain test pieces. The thermal conductivity was tested according to ASTM D5470 standard; the Shore 00 hardness was tested according to GB / T 531.1-2008 standard; high temperature aging test method: the samples were placed in an oven and heated at 150℃ for 1000 hours to test the Shore 00 hardness and record the data.

[0040] The test results are shown in Table 1.

[0041] Table 1. Test results of relevant properties of two-component thermally conductive silicone gel

[0042] Based on the data in the table above, the following conclusions can be clearly drawn: Combining Examples 1-3 and Comparative Examples 1-3, it can be seen that the two-component thermally conductive silicone gel prepared by the present invention has excellent thermal conductivity and high-temperature resistance. Compared with Examples 1-3, the thermal conductivity and high-temperature resistance of the products obtained in Comparative Examples 1 and 2 both decreased, indicating that the present invention effectively enhances the interaction between the filler and the matrix by introducing a tackifier, thereby effectively improving the overall performance of the material. Compared with methyl MQ resin, the modified MQ resin prepared by the present invention has a better modification effect. The high-temperature resistance of Comparative Example 3 decreased because no maleimide compound was introduced.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a two-component thermally conductive silicone gel for heat dissipation in new energy devices, characterized in that: Includes the following steps: Step 1: Mix maleimide compound, organosilicon containing epoxy double bond, toluene and 2-methylimidazole evenly, react at 30-40℃ for 5-7 hours, and obtain thickener by rotary evaporation; Step 2: Mix vinyl silicone oil, tackifier, modified diamond, modified aluminum nitride, modified alumina, modified boron nitride, and hydrogen-containing silicone oil evenly to obtain material A; mix vinyl silicone oil, modified diamond, modified aluminum nitride, modified alumina, modified boron nitride, modified MQ resin, inhibitor, and platinum catalyst evenly to obtain material B. Step 3: Mix component A and component B evenly, and then degas under vacuum to obtain a two-component thermally conductive silicone gel.

2. The method for preparing a two-component thermally conductive silica gel for heat dissipation of new energy devices according to claim 1, characterized in that: The preparation method of the maleimide compound is as follows: Maleic anhydride and N,N'-dimethylformamide were mixed evenly and heated to 60-70℃. A mixed solution of 2-(4-aminophenyl)-5-aminobenzimidazole and N,N'-dimethylformamide was added dropwise over 30-50 minutes. The reaction was carried out under nitrogen protection for 2-4 hours. After cooling to room temperature, the intermediate was obtained by filtration, washing, and vacuum drying. Under nitrogen protection, the intermediate was mixed evenly with xylene, and p-toluenesulfonic acid and p-hydroxyanisole were added. The mixture was heated to 100-110℃ and subjected to reflux for water separation and cyclization dehydration for 5-7 hours. After rotary evaporation, filtration, washing, purification, and vacuum drying, the maleimide compound was obtained.

3. The method for preparing a two-component thermally conductive silica gel for heat dissipation of new energy devices according to claim 1, characterized in that: The preparation method of the epoxy-containing double-bonded organosilicon is as follows: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, diphenylsilanediol and acetone were stirred evenly, and then tetrabutyl titanate was added. The reaction was carried out at 40-50℃ for 12-15 h, and finally the temperature was raised to 100-110℃ and the reaction was continued under reduced pressure for 3-5 h to obtain organosilicon containing epoxy double bonds.

4. The method for preparing a two-component thermally conductive silica gel for heat dissipation of new energy devices according to claim 1, characterized in that: Material A is composed of the following components in parts by weight: 1-5 parts vinyl silicone oil, 0.5-1.5 parts tackifier, 40-80 parts modified aluminum nitride, 20-50 parts modified alumina, 1-10 parts modified diamond, 10-30 parts modified boron nitride, and 0.1-5.0 parts hydrogen-containing silicone oil.

5. The method for preparing a two-component thermally conductive silicone gel for heat dissipation of new energy devices according to claim 4, characterized in that: Material B is composed of the following components in parts by weight: 1-5 parts vinyl silicone oil, 40-80 parts modified aluminum nitride, 20-50 parts modified alumina, 1-10 parts modified diamond, 10-30 parts modified boron nitride, 1-3 parts modified MQ resin, 0.005-0.010 parts inhibitor, and 0.003-0.008 parts platinum catalyst.

6. The method for preparing a two-component thermally conductive silica gel for heat dissipation of new energy devices according to claim 1, characterized in that: The modified diamond is prepared as follows: Pretreated diamond is prepared by stirring diamond in sodium hydroxide solution at 80-90℃ for 2-4 hours, washing until neutral, and drying. Mix n-decyltrimethoxysilane, anhydrous ethanol, and deionized water to obtain mixture A. Take the pretreated diamond and spray 2 / 3 of the mass of mixture A at 300-400 r / min. Stir at 750-850 r / min for 3-5 minutes. Spray the remaining mass of mixture A a second time and continue stirring at 750-850 r / min for 3-5 minutes. After baking and curing, cool to room temperature to obtain modified diamond.

7. The method for preparing a two-component thermally conductive silica gel for heat dissipation of new energy devices according to claim 1, characterized in that: The preparation methods of the modified aluminum nitride, modified aluminum oxide, and modified boron nitride are as follows: Aluminum nitride, alumina, and boron nitride were pretreated by baking and then cooled to obtain pretreated aluminum nitride, pretreated alumina, and pretreated boron nitride. Octyltriethoxysilane, anhydrous ethanol, and deionized water were mixed evenly to obtain mixture B. Two-thirds of the mass of each of the pretreated aluminum nitride, pretreated alumina, and pretreated boron nitride were initially sprayed onto each mixture at 300-400 rpm. The mixture was then stirred at 750-850 rpm for 3-5 minutes. The remaining mass of mixture B was then sprayed onto each mixture a second time, and the mixture was stirred at 750-850 rpm for another 3-5 minutes. After baking and curing, the mixture was cooled to room temperature to obtain modified aluminum nitride, modified alumina, and modified boron nitride.

8. The method for preparing a two-component thermally conductive silicone gel for heat dissipation of new energy devices according to claim 1, characterized in that: The modified MQ resin is prepared as follows: After stirring methyl MQ resin, methyl methacrylate and hydroquinone until completely dissolved, the mixture is heated to 80-90℃ and refluxed. 3-aminopropyltriethoxysilane and a catalyst are added, and the mixture is stirred for 1-2 hours. Then, acryloyloxytrimethoxysilane is added, and the mixture is stirred for 1-2 hours. The mixture is then cooled to room temperature to obtain the modified MQ resin.

9. The method for preparing a two-component thermally conductive silica gel for heat dissipation of new energy devices according to claim 1, characterized in that: The mass ratio of material A to material B is 1:

1.

10. A two-component thermally conductive silicone gel for heat dissipation of new energy devices prepared by the preparation method according to any one of claims 1-9.

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