CN-121975325-A - Nanometer coated one-dimensional orientation synergistic enhanced high-heat-conductivity silica gel material and preparation process thereof

CN121975325ACN 121975325 ACN121975325 ACN 121975325ACN-121975325-A

Abstract

The invention provides a nano-coated one-dimensional orientation synergistic enhanced high-heat-conductivity silica gel material and a preparation process thereof, and relates to the field of heat-conductivity silica gel. The nano-coated one-dimensional orientation synergistic enhanced high-heat-conductivity silica gel material comprises a silica gel matrix, wherein nano-coated microparticles uniformly dispersed in the silica gel matrix are formed by uniformly coating high-heat-conductivity nanoparticles on the surfaces of micron-sized heat-conductivity particles. According to the nano-coating one-dimensional orientation synergistic reinforced high-heat-conductivity silica gel material and the preparation process thereof, a multistage process of 'three-dimensional node construction by nano-coating, regular channel formation by one-dimensional orientation and cooperative network construction' is adopted, and firstly, high-heat-conductivity nano-particles (such as graphene nano-sheets, carbon nano-tubes and boron nitride nano-sheets) are uniformly coated on the surfaces of micron-sized heat-conductivity particles (such as alumina, aluminum nitride and boron nitride micron powder with the particle size of 1-100 mu m) by adopting a liquid phase reduction-in-situ growth or chemical vapor deposition technology.

Inventors

MENG HONG
RAO QIUSHI
HE YAOWU
WANG MENG
LIU ZHIJUN
LIU ZHENGUO
LIU JIFENG
YANG HUI

Assignees

广东乐普泰新材料科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251219

Claims (9)

1. The nano-coated one-dimensional orientation synergistic reinforced high-heat-conductivity silica gel material comprises a silica gel matrix and is characterized in that nano-coated microparticles uniformly dispersed in the silica gel matrix are formed by uniformly coating high-heat-conductivity nanoparticles on the surfaces of micron-sized heat-conductivity particles, wherein the micron-sized heat-conductivity particles are at least one of alumina, aluminum nitride and boron nitride micron powder, the particle size is 1-100 mu m, the high-heat-conductivity nanoparticles are at least one of graphene nano sheets, carbon nano tubes and boron nitride nano sheets, the high-heat-conductivity nanoparticles form a coating layer, and the coating layer is tightly connected with the micron-sized heat-conductivity particles through Van der Waals force or chemical bonds to construct a three-dimensional heat-conductivity network node; The one-dimensional heat conducting material is at least one of a carbon nano tube array, a silver nano wire and a boron nitride nano rod, the length-diameter ratio of the one-dimensional heat conducting material is more than or equal to 50:1, and the one-dimensional heat conducting material forms a regular one-dimensional heat conducting channel; The one-dimensional heat conduction channel and the three-dimensional heat conduction network node mutually penetrate to construct a three-dimensional heat conduction path with the cooperation of the three-dimensional node and the one-dimensional channel.
2. The nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material according to claim 1, wherein the mass of the nano-coated micron particles is 1% -20% of the mass of the micron-sized thermal conductivity particles.
3. The nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material according to claim 1, wherein the mass fraction of the one-dimensional thermal conductivity material in the silica gel matrix is 1% -10%, the mass fraction of the nano-coated microparticles in the silica gel matrix is 5% -25%, and the total mass fraction of the one-dimensional thermal conductivity material and the nano-coated microparticles is less than or equal to 25%.
4. The nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material according to claim 1, wherein the silica gel matrix is at least one of methyl vinyl silicone rubber and vinyl silicone oil.
5. The nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material according to claim 1, wherein the thermal conductivity coefficient of the three-dimensional high thermal conductivity silica gel composite material is more than or equal to 5.0W/(m.K), the Shore hardness is 20-40A, the volume resistivity is more than or equal to 1.0X104 Ω.cm, and the shear strength is more than or equal to 2.0MPa.
6. The preparation process of the nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material is characterized by comprising the following steps: preparing nano-coated microparticles, namely uniformly coating the high-heat-conductivity nanoparticles on the surfaces of the micron-sized heat-conducting particles by adopting a liquid-phase in-situ reaction or chemical vapor deposition technology to form the nano-coated microparticles; orientation arrangement of one-dimensional heat conducting materials, namely, orientation arrangement of the one-dimensional heat conducting materials along a specific direction through an external magnetic field orientation induction, mechanical stretching or orientation freezing casting process; And (3) composite dispersion, namely mixing the nano-coated micron particles, the one-dimensional heat conducting material and a silica gel matrix, and uniformly dispersing the nano-coated micron particles and the one-dimensional heat conducting material in the silica gel matrix through mechanical stirring and ultrasonic dispersion to form the three-dimensional high heat conducting silica gel composite material.
7. The preparation process of the nano-coated one-dimensional orientation synergistic enhanced high heat conduction silica gel material of claim 6, wherein in the preparation step of the nano-coated micron particles, when a liquid phase in-situ reaction is adopted, a precursor of the high heat conduction nano particles is added into a solution containing the micron-sized heat conduction particles, the high heat conduction nano particles are deposited on the surfaces of the micron-sized heat conduction particles through a reduction reaction, and when a chemical vapor deposition technology is adopted, carbon-containing or nitrogen-containing gas is used as a reaction source, and the high heat conduction nano particles are deposited on the surfaces of the micron-sized heat conduction particles.
8. The preparation process of the nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material is characterized in that when the one-dimensional thermal conductive material is a magnetic one-dimensional material, an external magnetic field is adopted for orientation induction, and when the one-dimensional thermal conductive material is a non-magnetic one-dimensional material, a mechanical stretching or orientation freezing casting process is adopted.
9. The preparation process of the nano-coated one-dimensional orientation synergistic enhanced high thermal conductivity silica gel material is characterized in that the rotation speed of mechanical stirring is 500-2000rpm, the time is 30-120min, the power of ultrasonic dispersion is 100-500W, and the time is 10-60min.

Description

Nanometer coated one-dimensional orientation synergistic enhanced high-heat-conductivity silica gel material and preparation process thereof Technical Field The invention relates to the technical field of heat-conducting silica gel, in particular to a nano-coated one-dimensional orientation synergistic enhanced high heat-conducting silica gel material and a preparation process thereof. Background With the rapid development of the emerging technologies such as 5G communication, artificial intelligence, new energy automobiles and the like, electronic devices are advancing toward high power and high integration. Taking a smart phone as an example, the operation speed of the chip is continuously improved, the number of transistors integrated in the smart phone is exponentially increased, so that the heat generated by the chip in the working process is rapidly increased, and a power module (such as an IGBT module) of the new energy automobile can release a large amount of heat energy in the electric energy conversion process. If the heat cannot be effectively dissipated in time, the temperature of the electronic device is increased sharply, the performance and the operation efficiency of the device are reduced, the service life of the device is shortened, and even potential safety hazards such as chip thermal failure, battery thermal runaway and the like are caused. Therefore, an efficient thermal management technology becomes a key for guaranteeing stable and reliable operation of electronic devices, and the heat-conducting silica gel plays a vital role in the heat transfer process as a common thermal interface material in the field of electronic packaging. The heat-conducting silica gel is generally based on a silica gel matrix (such as methyl vinyl silicone rubber and vinyl silicone oil), and the heat-conducting property of the heat-conducting silica gel is improved by adding high heat-conducting filler. The conventional heat conductive filler is mainly micron-sized particles (such as alumina, aluminum nitride and the like), however, the intrinsic heat conductivity coefficient of the micron-sized filler is relatively limited, and under the condition of high filling amount (more than 50vol% of filling is usually needed to obtain better heat conductive effect), the viscosity of the silica gel composite material is greatly increased, the processability is poor, and the requirements of electronic devices on the flexibility and operability of the packaging material are difficult to meet. Meanwhile, excessive filling of the filler can obviously influence the insulating property and mechanical properties (such as flexibility and cohesiveness) of the composite material, and the balance of high heat conduction and other comprehensive properties cannot be considered. In order to solve the above problems, researchers have been exploring the use of nanoscale thermal conductive fillers (e.g., graphene nanoplatelets, carbon nanotubes, boron nitride nanoplatelets/nanorods, etc.) to enhance the performance of thermal conductive silica gels. The nano filler has extremely high intrinsic heat conduction coefficient (for example, the intrinsic heat conduction coefficient of graphene can reach 5300W/(m.K), the carbon nano tube can reach 3000-6000W/(m.K), and the boron nitride nano sheet can reach 400-2000W/(m.K)), so that the heat conduction property of the heat conduction silica gel can be obviously improved theoretically. However, the nano filler has extremely high specific surface area and surface energy, is extremely easy to generate agglomeration phenomenon in a silica gel matrix, and is difficult to uniformly disperse. The agglomeration can lead to the failure of forming an effective heat conduction path between the fillers, and a large amount of interfacial thermal resistance exists in the heat transfer process, so that the high heat conduction performance of the nano-filler can not be fully exerted, and the actual heat conduction effect is far lower than theoretical expectation. In addition, the interface compatibility between the nano filler and the silica gel matrix is poor, so that the interface thermal resistance is further increased, and the improvement of the heat conduction performance of the heat conduction silica gel is limited. In order to improve the dispersibility of the heat conducting filler in the silica gel matrix and construct an effective heat conducting path, the prior art mainly adopts two strategies, namely, the surface energy of the nano filler is reduced through surface modification (such as using a silane coupling agent, a titanate coupling agent and the like), the compatibility of the nano filler with the silica gel matrix is improved, the dispersion of the filler is promoted, and the contact probability between the fillers is increased through optimizing the grading of the fillers (such as compounding micron-sized and nano-sized fillers with different particle sizes), so as to construct a heat co