A single-component highly thermally conductive gel resistant to transformer oil, its preparation method and application

Abstract

The present invention discloses a single-component highly thermally conductive gel resistant to transformer oil. By weight percentage, the raw materials for preparation include 2-10% of silicone oil, 80-96% of thermally conductive powder, and 1.32-18.3% of additives, and the sum of the weight percentages of the raw materials for preparation is 100%; the additives at least include 1-10% of reinforcing agent and 0.1-5% of tackifier. The present invention adopts a combination of spherical alumina and spherical aluminum nitride thermally conductive powders, which can improve the thermal conductivity of the thermally conductive gel. Especially in an ultra-thin interface, the spherical thermally conductive powders have a certain fluidity, which can improve the thermal conductivity effect. And introducing modified montmorillonite as a reinforcing agent can enhance the erosion resistance and thermal conductivity of the thermally conductive gel, effectively preventing the thermally conductive powder from entering the transformer oil with the dissolution of the silicone oil. The present invention can effectively improve the erosion loss caused by being impregnated in the transformer oil, so as to maintain a small loss and high thermal conductivity.

Description

Technical Field

[0001] The present invention relates to the field of processing of organic polymer compounds, and specifically relates to a single-component high thermal conductivity gel resistant to transformer oil, a preparation method thereof, and an application thereof. Background Art

[0002] With the rapid development of computer information technology, the increasing computing power makes the heat generation of chips more and more serious, and the requirements for the thermal conductivity of materials are getting higher and higher. At present, most of the thermal conductive materials on the market are thermal conductive greases, which have good heat dissipation effect and low thermal resistance. At present, some chips achieve high computing power by increasing the area, resulting in a large gap between the chip and the radiator. In order to improve the heat dissipation efficiency, the heat-generating components will be immersed in transformer oil, and part of the heat will be taken away by the transformer oil. However, the flowing contact between the transformer oil and the thermal conductive grease will cause erosion loss of the thermal conductive grease, resulting in the loss of the thermal conductive material and the reduction of the thermal conductivity. Therefore, it is crucial to develop a thermal conductive material with high thermal conductivity and resistance to transformer oil erosion.

[0003] Chinese Patent Application CN113817178A discloses a low oil-permeable and high thermal conductivity thermal conductive gel and a preparation method thereof. By using vinyl silicone oil that has undergone secondary removal of low-molecular substances and collocating with boron nitride with low density and high thermal conductivity, the oil yield of the product is low. While ensuring a thermal conductivity of 1.5 - 3.5 W, the density is below 2.0 g / cm 3 However, it is not resistant to transformer oil erosion. Chinese Patent CN115403933B discloses a high-extrusion and low oil-permeable single-component thermal conductive gel and a preparation method thereof. By using boron trifluoride ether complex to treat the surface of boron nitride to increase the porosity of boron nitride, thereby increasing the adsorption capacity of boron nitride for silicone oil molecules, the thermal conductive gel has a good extrusion rate and a low oil leakage rate, but it is also not resistant to transformer oil erosion. Summary of the Invention

[0004] In order to develop a thermal conductive material with high thermal conductivity and resistance to transformer oil erosion, the first aspect of the present invention provides a single-component high thermal conductivity gel resistant to transformer oil. Calculated by weight percentage, the raw materials for preparation include 2 - 10% of silicone oil, 80 - 96% of thermal conductive powder, and 1.32 - 18.3% of additives. The sum of the weight percentages of the raw materials for preparation is 100%; calculated by the total percentage of the thermal conductive gel, the additives at least include 1 - 10% of reinforcing agent and 0.1 - 5% of tackifier; the reinforcing agent includes modified montmorillonite.

[0005] As an implementation manner, the reinforcing agent includes at least one of carbon black, white carbon black, calcium carbonate, modified montmorillonite, or kaolin.

[0006] As an implementation manner, the thermal conductive powder is spherical, and the particle size of the thermal conductive powder is 1 - 120 μm.

[0007] As an implementation manner, the particle size of the heat-conducting powder is 1-90 μm.

[0008] As an implementation manner, the particle size of the heat-conducting powder is a combination of 1-10 μm, 40-70 μm, and 50-90 μm.

[0009] As an implementation manner, the heat-conducting powder includes at least one of alumina, aluminum hydroxide, zinc oxide, magnesium oxide, aluminum nitride, graphene, carbon fiber, carbon nanotube, or diamond.

[0010] As an implementation manner, the heat-conducting powder includes at least one of alumina and aluminum nitride.

[0011] During the experiment, the inventor found that using modified montmorillonite to modify silicone oil can improve the erosion resistance and heat conduction performance of the heat-conducting gel. The possible reason is speculated as follows: Modified montmorillonite powder has hydrophilicity and adsorption. By introducing modified montmorillonite, a hydrophilic structure can be added to the heat-conducting powder, effectively preventing the heat-conducting powder from entering the transformer oil as the silicone oil dissolves. Moreover, modified montmorillonite has a layered structure and can better form a heat conduction path at a thinner interface.

[0012] As an implementation manner, the tackifier includes at least one of borate tackifier, alkyl borate tackifier, ester group-containing siloxane tackifier, epoxy group-containing tackifier, vinyl siloxane tackifier, silicon hydride group-containing oligomer, β-diketonyl siloxane, or alkoxysilane tackifier.

[0013] As an implementation manner, the tackifier includes at least one of vinyltrimethoxysilane or 2,2'-diallylbisphenol A.

[0014] During the experiment, the inventor further found that introducing a vinyl group-containing tackifier or an epoxy group-containing tackifier into the heat-conducting gel can further improve the erosion resistance of the heat-conducting gel. The possible reason is speculated as follows: By using a vinyl group-containing or epoxy group-containing tackifier, the cross-linking reaction sites are increased, turning linear vinyl silicone oil into a three-dimensional network structure with branches connected to each other. This structure can wrap around the heat-conducting powder, increasing the steric hindrance between molecules and reducing the loss of the heat-conducting powder. Moreover, the heat-conducting gel with a three-dimensional network structure enhances the adhesion effect to the substrate, further improving the erosion resistance of the heat-conducting gel against transformer oil, thus ensuring less loss and higher heat conduction performance.

[0015] As an implementation manner, the additives further include a cross-linking agent, a coupling agent, an inhibitor, and a catalyst. The cross-linking agent includes at least one of terminal hydrogen-containing silicone oil and side-chain hydrogen-containing silicone oil; the hydrogen content of the terminal hydrogen-containing silicone oil and the side-chain hydrogen-containing silicone oil is 0.05-1.5 wt%.

[0016] As an implementation manner, based on the weight percentage of the one-component high thermal conductivity gel, the auxiliary agent further includes 0.01-1% of a cross-linking agent, 0.1-1.5% of a coupling agent, 0.01-0.3% of an inhibitor, and 0.1-0.5% of a catalyst.

[0017] As an implementation manner, the cross-linking agent includes hydrogen-containing silicone oil with side groups.

[0018] As an implementation manner, the silicone oil includes at least one of vinyl-terminated silicone oil, vinyl-side-terminated silicone oil, vinyl-dimethyl-terminated silicone oil, or hydroxy silicone oil.

[0019] As an implementation manner, the viscosity of the cross-linking agent at 25°C is 20-200 mm² / s, and the viscosity of the silicone oil at 25°C is 100-5000 mm² / s.

[0020] As an implementation manner, the coupling agent includes but is not limited to at least one of octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, glycidyl ether ethyltrimethoxysilane, or hexadecyltrimethoxysilane.

[0021] As an implementation manner, the coupling agent includes at least one of dodecyltrimethoxysilane or hexadecyltrimethoxysilane.

[0022] As an implementation manner, the inhibitor includes but is not limited to at least one of ethynylcyclohexanol, 3-methyl-1-pentyn-3-ol, 3-phenyl-1-butyn-3-ol butynol, or 11-trimethyldodecyn-3-ol.

[0023] As an implementation manner, the inhibitor includes ethynylcyclohexanol.

[0024] As an implementation manner, the catalyst is a Pt catalyst, and the Pt content is 1000-5000 ppm. (The Pt content refers to the content of Pt in the catalyst, which is 1000-5000 ppm)

[0025] As an implementation manner, the catalyst is a Karstedt catalyst.

[0026] The second aspect of the present invention provides a preparation method of a one-component high thermal conductivity gel resistant to transformer oil, including the following steps:

[0027] S1 Add silicone oil, thermal conductive powder, coupling agent, and tackifier to a planetary mixer and stir for 1-2 h at a stirring speed of 20-60 r / min;

[0028] Add a reinforcing agent in S2, heat up to 100 - 180 °C, stir under vacuum for 1 - 3 h, and the rotation speed is 20 - 60 r / min;

[0029] Cool to 25 °C in S3, add a cross-linking agent and an inhibitor, stir under vacuum for 0.5 - 2 h, and the rotation speed is 20 - 60 r / min;

[0030] Add a catalyst in S4, heat up to 120 - 180 °C, stir under vacuum for 1 - 2 h, and the rotation speed is 20 - 60 r / min;

[0031] Cool to 25 °C in S5 to obtain a one-component high thermal conductivity gel.

[0032] The third aspect of the present invention provides an application of a one-component high thermal conductivity gel resistant to transformer oil, which is applied to electronic heat-conducting components.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) For the one-component high thermal conductivity gel resistant to transformer oil of the present invention, the combination of spherical alumina and spherical aluminum nitride thermal conductive powders is adopted, which can improve the thermal conductivity of the thermal conductive gel. Especially in the ultra-thin interface, the spherical thermal conductive powders have a certain fluidity, which can improve the thermal conductivity effect.

[0035] (2) For the one-component high thermal conductivity gel resistant to transformer oil of the present invention, the thermal conductive powders adopt a combination of three particle sizes of 1 - 10 μm, 40 - 70 μm, and 50 - 90 μm (high, medium, and low), which can further increase the connection between the thermal conductive powders, reduce the voids between the thermal conductive powders, and further improve the thermal conductivity.

[0036] (3) For the one-component high thermal conductivity gel resistant to transformer oil of the present invention, introducing modified montmorillonite as a reinforcing agent can enhance the erosion resistance and thermal conductivity of the thermal conductive gel, and effectively prevent the thermal conductive powders from entering the transformer oil with the dissolution of silicone oil.

[0037] (4) For the one-component high thermal conductivity gel resistant to transformer oil of the present invention, introducing a vinyl-containing tackifier or an epoxy group-containing tackifier can further improve the erosion resistance of the thermal conductive gel, reduce the loss of the thermal conductive powders, and increase the bonding effect on the substrate.

[0038] (5) The one-component high thermal conductivity gel resistant to transformer oil of the present invention can effectively improve the erosion loss caused by immersion in transformer oil, so as to maintain a small loss and high thermal conductivity. Description of the Drawings

[0039] Figure 1 It is an example diagram of the one-component high thermal conductivity gel resistant to transformer oil prepared in the example in the working environment of transformer oil circulation.

[0040] In the figure: 1. Thermal conductive gel. Specific implementation manner

[0041] The raw material suppliers of the examples and comparative examples are as follows:

[0042] The 2μm spherical alumina was purchased from Bengbu Zhongheng New Material Technology Co., Ltd., model number CTE02;

[0043] The 40μm spherical alumina was purchased from Bengbu Zhongheng New Material Technology Co., Ltd., model number CTE40;

[0044] The 5μm spherical alumina was purchased from Bengbu Zhongheng New Material Technology Co., Ltd., model number CTE05;

[0045] The 50μm spherical alumina was purchased from Bengbu Zhongheng New Material Technology Co., Ltd., model number CTE50;

[0046] The 70μm spherical alumina was purchased from Bengbu Zhongheng New Material Technology Co., Ltd., model number CTE70;

[0047] The 90μm spherical alumina was purchased from Bengbu Zhongheng New Material Technology Co., Ltd., model number CTE90;

[0048] The 80μm spherical aluminum nitride was purchased from Ya'an Baitu High - tech Materials Co., Ltd., model number TA - S80.

[0049] The vinyl - terminated silicone oil with a viscosity of 1000mm² / s at 25°C was purchased from Dongguan Xinkang Organosilicon Materials Co., Ltd., model number LK - 3011;

[0050] The vinyl - terminated silicone oil with a viscosity of 500mm² / s at 25°C was purchased from Dongguan Xinkang Organosilicon Materials Co., Ltd., model number LK3030 - 500.

[0051] The Karstedt catalyst with a Pt content of 3000ppm was purchased from Guangzhou Xiyou New Materials Co., Ltd., model number PT - 3000SW;

[0052] The Karstedt catalyst with a Pt content of 5000ppm was purchased from Guangzhou Xiyou New Materials Co., Ltd., model number PT - 5000SW.

[0053] The side - chain hydrogen - containing silicone oil with a hydrogen content of 0.5wt% was purchased from Ningbo Runhe High - tech Materials Co., Ltd., model number RH - H503;

[0054] The side - chain hydrogen - containing silicone oil with a hydrogen content of 0.36wt% was purchased from Ningbo Runhe High - tech Materials Co., Ltd., model number RH - H536;

[0055] The side-chain hydrogen-containing silicone oil with a hydrogen content of 0.18 wt% was purchased from Ningbo Runhe High-Tech Materials Co., Ltd., and the model is RH-H33;

[0056] The side-chain hydrogen-containing silicone oil with a hydrogen content of 0.1 wt% was purchased from Ningbo Runhe High-Tech Materials Co., Ltd., and the model is RH-H86;

[0057] The side-chain hydrogen-containing silicone oil with a hydrogen content of 0.15 wt% was purchased from Ningbo Runhe High-Tech Materials Co., Ltd., and the model is RH-H57.

[0058] Example 1

[0059] A single-component highly thermally conductive gel resistant to transformer oil 1, the preparation raw materials include 500 g of silicone oil, 5000 g of thermally conductive powder, and 277.4 g of additives.

[0060] The thermally conductive powder includes 2500 g of spherical alumina with a particle size of 2 μm and 2500 g of spherical alumina with a particle size of 40 μm.

[0061] The silicone oil is vinyl-terminated silicone oil, and its viscosity at 25 °C is 1000 mm² / s.

[0062] The additives include 15 g of coupling agent which is dodecyltrimethoxysilane, 15 g of tackifier which is vinyltrimethoxysilane, 240 g of reinforcing agent which is modified montmorillonite, 0.8 g of crosslinking agent which is side-chain hydrogen-containing silicone oil, 0.6 g of inhibitor which is ethynylcyclohexanol, and 6 g of catalyst which is Karstedt catalyst, with a Pt content of 3000 ppm.

[0063] The hydrogen content of the side-chain hydrogen-containing silicone oil is 0.5 wt%.

[0064] The modified montmorillonite was purchased from Lingshou County Huarun Mineral Powder Processing Factory, and the model is dr-103.

[0065] A preparation method of a single-component highly thermally conductive gel resistant to transformer oil, comprising the following steps:

[0066] S1 Add the silicone oil, thermally conductive powder, coupling agent, and tackifier into a planetary mixer and stir for 1 h at a stirring speed of 40 r / min;

[0067] S2 Add the reinforcing agent, heat up to 120 °C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0068] S3 Cool to 25 °C, add the crosslinking agent and inhibitor, and stir under vacuum for 1 h at a rotation speed of 50 r / min;

[0069] S4 Add the catalyst, heat up to 150 °C, and stir under vacuum for 1.5 h at a rotation speed of 50 r / min;

[0070] The S5 is cooled to 25 °C to obtain a single-component high thermal conductivity gel.

[0071] Example 2

[0072] A single-component high thermal conductivity gel 1 resistant to transformer oil, the preparation raw materials include 500 g of silicone oil, 5800 g of thermal conductive powder and 349.2 g of additives.

[0073] The thermal conductive powder includes 2400 g of spherical alumina with a particle size of 5 μm and 3400 g of spherical alumina with a particle size of 50 μm.

[0074] The silicone oil is vinyl-terminated silicone oil, and its viscosity at 25 °C is 1000 mm² / s.

[0075] The additives include 20 g of coupling agent as cetyltrimethoxysilane, 20 g of tackifier as vinyltrimethoxysilane, 300 g of reinforcing agent as modified montmorillonite, 1.2 g of crosslinking agent as side-chain hydrogen-containing silicone oil, 1 g of inhibitor as ethynylcyclohexanol, and 7 g of catalyst as Karstedt catalyst with a Pt content of 3000 ppm.

[0076] The hydrogen content of the side-chain hydrogen-containing silicone oil is 0.36 wt%.

[0077] The modified montmorillonite is purchased from LingShou County HuaRun Mineral Powder Factory, and the model is dr-103.

[0078] A preparation method of a single-component high thermal conductivity gel 1 resistant to transformer oil, comprising the following steps:

[0079] S1 Add the silicone oil, thermal conductive powder, coupling agent, and tackifier into a planetary mixer and stir for 1 h at a stirring speed of 50 r / min;

[0080] S2 Add the reinforcing agent, heat up to 120 °C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0081] S3 Cool to 25 °C, add the crosslinking agent and inhibitor, and stir under vacuum for 1 h at a rotation speed of 50 r / min;

[0082] S4 Add the catalyst, heat up to 150 °C, and stir under vacuum for 1.5 h at a rotation speed of 50 r / min;

[0083] S5 Cool to 25 °C to obtain a single-component high thermal conductivity gel.

[0084] Example 3

[0085] A single-component high thermal conductivity gel 1 resistant to transformer oil, the preparation raw materials include 500 g of silicone oil, 7200 g of thermal conductive powder and 442.5 g of additives.

[0086] The heat-conducting powder includes 3000 g of spherical alumina with a particle size of 5 μm and 4200 g of spherical alumina with a particle size of 70 μm.

[0087] The silicone oil is vinyl-terminated silicone oil with a viscosity of 500 mm² / s at 25°C.

[0088] The additives include 30 g of coupling agent hexadecyltrimethoxysilane, 40 g of tackifier 2,2'-diallylbisphenol A, 360 g of reinforcing agent modified montmorillonite, 3 g of crosslinking agent side-chain hydrogen-containing silicone oil, 1.5 g of inhibitor ethynylcyclohexanol, and 9 g of catalyst Karstedt catalyst with a Pt content of 5000 ppm.

[0089] The hydrogen content of the side-chain hydrogen-containing silicone oil is 0.18 wt%.

[0090] The modified montmorillonite is purchased from LingShou County HuaRun Mineral Powder Processing Factory, with the model dr-103.

[0091] A preparation method of a single-component high heat-conducting gel resistant to transformer oil includes the following steps:

[0092] S1 Add the silicone oil, heat-conducting powder, coupling agent, and tackifier into a planetary mixer and stir for 1 h at a stirring speed of 50 r / min;

[0093] S2 Add the reinforcing agent, heat up to 120°C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0094] S3 Cool to 25°C, add the crosslinking agent and inhibitor, and stir under vacuum for 1 h at a rotation speed of 50 r / min;

[0095] S4 Add the catalyst, heat up to 150°C, and stir under vacuum for 1.5 h at a rotation speed of 50 r / min;

[0096] S5 Cool to 25°C to obtain the single-component high heat-conducting gel.

[0097] Example 4

[0098] A single-component high heat-conducting gel 1 resistant to transformer oil, the preparation raw materials include 500 g of silicone oil, 8500 g of heat-conducting powder, and 741.1 g of additives.

[0099] The heat-conducting powder includes 1500 g of spherical alumina with a particle size of 5 μm, 4500 g of spherical alumina with a particle size of 40 μm, and 2500 g of spherical alumina with a particle size of 90 μm.

[0100] The silicone oil is vinyl-terminated dimethyl silicone oil with a viscosity of 500 mm² / s at 25°C.

[0101] The auxiliary agent includes 45 g of coupling agent, dodecyltrimethoxysilane; 80 g of tackifier, 2,2'-diallylbisphenol A; 600 g of reinforcing agent, modified montmorillonite; 4.5 g of crosslinking agent, side-chain hydrogen-containing silicone oil; 1.6 g of inhibitor, ethynylcyclohexanol; 10 g of catalyst, Karstedt catalyst, with a Pt content of 5000 ppm.

[0102] The hydrogen content of the side-chain hydrogen-containing silicone oil is 0.1 wt%.

[0103] The modified montmorillonite is purchased from Huarun Mineral Powder Factory, Lingshou County, with the model of dr-103.

[0104] A preparation method of a single-component high thermal conductivity gel resistant to transformer oil includes the following steps:

[0105] S1 Add silicone oil, thermal conductive powder, coupling agent, and tackifier to a planetary mixer and stir for 1.5 h at a stirring speed of 50 r / min;

[0106] S2 Add the reinforcing agent, heat up to 150 °C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0107] S3 Cool to 25 °C, add the crosslinking agent and inhibitor, and stir under vacuum for 1 h at a rotation speed of 50 r / min;

[0108] S4 Add the catalyst, heat up to 150 °C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0109] S5 Cool to 25 °C to obtain the single-component high thermal conductivity gel.

[0110] Example 5

[0111] A single-component high thermal conductivity gel 1 resistant to transformer oil, the preparation raw materials include 500 g of silicone oil, 8100 g of thermal conductive powder, and 522.8 g of auxiliary agent.

[0112] The thermal conductive powder includes 120 g of spherical alumina with a particle size of 5 μm, 450 g of spherical alumina with a particle size of 50 μm, and 240 g of spherical aluminum nitride with a particle size of 80 μm.

[0113] The silicone oil is vinyl-terminated silicone oil with a viscosity of 500 mm² / s at 25 °C.

[0114] The auxiliary agent includes 36 g of coupling agent, dodecyltrimethoxysilane; 70 g of tackifier, 2,2'-diallylbisphenol A; 400 g of reinforcing agent, modified montmorillonite; 3 g of crosslinking agent, side-chain hydrogen-containing silicone oil; 1.8 g of inhibitor, ethynylcyclohexanol; 12 g of catalyst, Karstedt catalyst, with a Pt content of 3000 ppm.

[0115] The hydrogen content of the side-group hydrogen-containing silicone oil is 0.15 wt%.

[0116] The modified montmorillonite is purchased from LingShou County HuaRun Mineral Powder Processing Factory, and the model is dr-103.

[0117] A preparation method of a single-component high thermal conductivity gel resistant to transformer oil includes the following steps:

[0118] S1 Add silicone oil, thermal conductive powder, coupling agent, and tackifier to a planetary mixer and stir for 1.5 h at a stirring speed of 50 r / min;

[0119] S2 Add a reinforcing agent, heat up to 150 °C, and stir under vacuum for 2.5 h at a rotation speed of 50 r / min;

[0120] S3 Cool to 25 °C, add a crosslinking agent and an inhibitor, and stir under vacuum for 1.5 h at a rotation speed of 50 r / min;

[0121] S4 Add a catalyst, heat up to 150 °C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0122] S5 Cool to 25 °C to obtain a single-component high thermal conductivity gel.

[0123] The example diagram of the prepared single-component high thermal conductivity gel resistant to transformer oil in the transformer oil circulating working environment is shown in Figure 1 , and the prepared thermal conductivity gel is thermal conductivity gel 1 in the figure.

[0124] Comparative Example 1

[0125] A single-component high thermal conductivity gel resistant to transformer oil, the preparation raw materials include 500 g of silicone oil, 5000 g of thermal conductive powder and 22.4 g of additives.

[0126] The thermal conductive powder includes 2500 g of spherical alumina with a particle size of 2 μm and 2500 g of spherical alumina with a particle size of 40 μm.

[0127] The silicone oil is vinyl-terminated silicone oil, and the viscosity at 25 °C is 500 mm² / s.

[0128] The additives include 15 g of coupling agent as dodecyltrimethoxysilane, 0.8 g of crosslinking agent as side-group hydrogen-containing silicone oil, 0.6 g of inhibitor as ethynylcyclohexanol, and 6 g of catalyst as Karstedt catalyst, with a Pt content of 3000 ppm.

[0129] The hydrogen content of the side-group hydrogen-containing silicone oil is 0.5 wt%.

[0130] A preparation method of a single-component high thermal conductivity gel resistant to transformer oil includes the following steps:

[0131] S1 Add silicone oil, thermally conductive powder, coupling agent, crosslinking agent, and inhibitor into a planetary mixer and stir for 1.5 h at a stirring speed of 50 r / min;

[0132] S2 Add a catalyst, heat up to 150 °C, and stir under vacuum for 1.5 h at a rotation speed of 50 r / min;

[0133] S3 Cool to 25 °C to obtain a one-component highly thermally conductive gel.

[0134] Comparative Example 2

[0135] A one-component highly thermally conductive gel resistant to transformer oil, the preparation raw materials of which include 500 g of silicone oil, 7200 g of thermally conductive powder, and 42.5 g of additives.

[0136] The thermally conductive powder includes 3000 g of spherical alumina with a particle size of 5 μm and 4200 g of spherical alumina with a particle size of 70 μm.

[0137] The silicone oil is vinyl-terminated silicone oil with a viscosity of 500 mm² / s at 25 °C.

[0138] The additives include 30 g of coupling agent hexadecyltrimethoxysilane, 3 g of crosslinking agent hydrogen-containing silicone oil with side groups, 1.5 g of inhibitor ethynylcyclohexanol, and 8 g of catalyst Karstedt catalyst with a Pt content of 3000 ppm.

[0139] The hydrogen content of the hydrogen-containing silicone oil with side groups is 0.18 wt%.

[0140] A preparation method of a one-component highly thermally conductive gel resistant to transformer oil, comprising the following steps:

[0141] S1 Add silicone oil, thermally conductive powder, coupling agent, crosslinking agent, and inhibitor into a planetary mixer and stir for 2 h at a stirring speed of 50 r / min;

[0142] S2 Add a catalyst, heat up to 120 °C, and stir under vacuum for 1.5 h at a rotation speed of 50 r / min;

[0143] S3 Cool to 25 °C to obtain a one-component highly thermally conductive gel.

[0144] Comparative Example 3

[0145] A one-component highly thermally conductive gel resistant to transformer oil, the preparation raw materials of which include 500 g of silicone oil, 8200 g of thermally conductive powder, and 52.8 g of additives.

[0146] The thermally conductive powder includes 1200 g of spherical alumina with a particle size of 5 μm, 4500 g of spherical alumina with a particle size of 50 μm, and 2500 g of spherical aluminum nitride with a particle size of 80 μm.

[0147] The silicone oil is vinyl-terminated silicone oil with a viscosity of 500 mm² / s at 25°C.

[0148] The additives include 36 g of coupling agent which is dodecyltrimethoxysilane, 3 g of crosslinking agent which is hydrogen-containing silicone oil with side groups, 1.8 g of inhibitor which is ethynylcyclohexanol, and 12 g of catalyst which is Karstedt catalyst with a Pt content of 3000 ppm.

[0149] The hydrogen content of the hydrogen-containing silicone oil with side groups is 0.15 wt%.

[0150] A preparation method of a single-component highly thermally conductive gel resistant to transformer oil includes the following steps:

[0151] S1 Add the silicone oil, thermally conductive powder, coupling agent, crosslinking agent, and inhibitor into a planetary stirrer and stir for 2 h at a stirring speed of 50 r / min;

[0152] S2 Add the catalyst, heat up to 150°C, and stir under vacuum for 2 h at a rotation speed of 50 r / min;

[0153] S3 Cool to 25°C to obtain the single-component highly thermally conductive gel.

[0154] Performance testing

[0155] 1. Thermal conductivity: Refer to the standard of ASTM D5470 to test the thermal conductivity.

[0156] 2. Temperature rise test and weight loss ratio: Coat the thermally conductive gels of the examples and comparative examples on a copper plate of 150×150×2 mm, with the coating specification: Φ30×2 mm (diameter 30 mm, thickness 2 mm). At the same time, fix and limit with a heating element assembly, operate for 24 h, use a temperature rise tester to test the temperature rise on the surface of the copper plate, and weigh the weight of the thermally conductive gel as m0.

[0157] Immerse the above workpiece in a container filled with transformer oil for 1000 h, take it out and air-dry it naturally, operate for 24 h, use a temperature rise tester to test the temperature rise on the surface of the copper plate, weigh the weight of the thermally conductive gel after soaking and drying as m1, and calculate the weight loss ratio before and after soaking. Weight loss ratio = (m0 - m1) / m0 × 100%.

[0158] The test results are shown in Table 1 below.

[0159] Table 1

[0160]

[0161] The results show that the single-component highly thermally conductive gel of the present invention can effectively improve the erosion loss caused by immersion in transformer oil, thereby maintaining a small loss and high thermal conductivity.

Claims

1. A single-component highly thermally conductive gel resistant to transformer oil, characterized in that, By weight percentage, the preparation raw materials include 2-10% of silicone oil, 80-96% of thermally conductive powder, and 1.32-18.3% of additives. The sum of the weight percentages of the preparation raw materials is 100%; based on the total percentage of the thermally conductive gel, the additives at least include 1-10% of reinforcing agent and 0.1-5% of tackifier; the reinforcing agent includes modified montmorillonite. The thermally conductive powder is spherical, and the particle size of the thermally conductive powder is a combination of 1-10μm, 40-70μm, and 50-90μm. The thermally conductive powder includes at least one of alumina and aluminum nitride. The tackifier includes at least one of vinyltrimethoxysilane or 2,2'-diallylbisphenol A.

2. The single-component highly thermally conductive gel resistant to transformer oil according to claim 1, characterized in that, The additives also include a crosslinking agent, a coupling agent, an inhibitor, and a catalyst. The crosslinking agent includes at least one of terminal hydrogen-containing silicone oil and side-chain hydrogen-containing silicone oil.

3. The single-component highly thermally conductive gel resistant to transformer oil according to claim 2, wherein, The hydrogen content of both the terminal hydrogen-containing silicone oil and the side-chain hydrogen-containing silicone oil is 0.05-1.5wt%.

4. The single-component highly thermally conductive gel resistant to transformer oil according to claim 1, wherein The silicone oil includes at least one of terminal vinyl silicone oil, terminal and side vinyl silicone oil, dimethyl silicone oil, or hydroxyl silicone oil.

5. The single-component highly thermally conductive gel resistant to transformer oil according to claim 2, wherein The viscosity of the crosslinking agent at 25°C is 20-200mm² / s, and the viscosity of the silicone oil at 25°C is 100-5000mm² / s.

6. A method for preparing a single-component highly thermally conductive gel resistant to transformer oil according to any one of claims 2-5, characterized in that, It includes the following steps: S1 Add silicone oil, thermally conductive powder, coupling agent, and tackifier into a blender and stir for 1-2h at a stirring speed of 20-60r / min. S2 Add the reinforcing agent, heat up to 100-180°C, and stir under vacuum for 1-3h at a rotation speed of 20-60r / min. S3 Cool to 25°C, add the crosslinking agent and inhibitor, and stir under vacuum for 0.5-2h at a rotation speed of 20-60r / min. S4 Add the catalyst, heat up to 120-180°C, and stir under vacuum for 1-2h at a rotation speed of 20-60r / min. S5 Cool to 25°C to obtain a one-component highly thermally conductive gel.

7. Use of a single-component highly thermally conductive gel resistant to transformer oil according to any one of claims 1-5, characterized in that, It is applied to electronic thermally conductive components.

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