Heat conductive silicone grease containing liquid metal heat conductive filler

Abstract

The invention creatively provides heat conductive silicone grease containing liquid metal heat conductive filler. The silicone grease includes, by weight, 40-60 parts of organic silicon basic resin, 40-100 parts of the liquid metal heat conductive filler, and 0-10 parts of other additives. The organic silicon basic resin is composed of, by mass, 30-70% of vinyl-terminated dimethyl polysiloxane, of which the dynamic viscosity is lower than 2000 cst at 25 DEG C, 25-40% of vinyl-terminated dimethyl polysiloxane, of which the dynamic viscosity is higher than 10000 cst at 25 DEG C, 5-10% of vinyl cyclopolysiloxane, 2-10% of hydrogen-containing silicone oil, of which the dynamic viscosity is 50-2000 cst at 25 DEG C, and 5-20% of polyether-modified polysiloxane. The heat conductive silicone grease has high heat conductivity and matrix stability.

Description

technical field [0001] The invention relates to the technical field of heat-conducting materials, in particular to a heat-conducting silicone grease containing liquid metal heat-conducting fillers. Background technique [0002] Thermally conductive silicone grease is a kind of high thermal conductivity insulating silicone material, which has excellent electrical insulation and thermal conductivity. It is widely used in heating elements and heat dissipation facilities of various electronics and electrical appliances, and plays the role of heat conduction and moisture-proof and explosion-proof. Thermally conductive silicone grease is usually made by adding a certain amount of thermally conductive filler to base silicone oil, and usually also adds a small amount of functional additives as needed to meet the needs of different occasions. The pursuit of higher thermal conductivity and the reduction of the oil separation degree of thermal conductive silicone grease are the two cor...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the thermal conductive fillers used in thermal grease are inorganic non-metallic materials, including aluminum oxide, magnesium oxide, zinc oxide and other metal oxides and silicon nitride, Boron nitride and other metal nitrides, these materials have stable performance, but their compatibility with base silicone oil is poor, and they are easy to separate, deposit, and delaminate with base silicone oil after a period of use

There are also some technologies that try to use precious metal particles such as gold and silver, or even nano-diamonds as thermally conductive fillers, but the cost of such materials is extremely high.

At present, the most researched is to use C materials such as graphite and carbon nanotubes as thermal conductive fillers. These materials also have many defects: (1) C materials are conductive, and they are easy to cause short circuits and other dangers when they are separated from the matrix or aggregated. ; (2) The compatibility between the C material and the basic silicone oil matrix is ​​also poor, and it needs surface treatment to improve the interfacial compatibility and dispersion effect; (3) Most of the C materials are anisotropic, and the conduction efficiency may decrease Affected by the direction of particle distribution, the conduction of heat in certain direction channels in the heat conduction network is not smooth

[0005] At present, for the application technology of liquid metal as a heat-conducting material, one is to directly disperse the liquid metal in the polymer matrix, but because the van der Waals force between the liquid metal is very large, The droplet particles dispersed in the polymer matrix are larger, and the size uniformity is poor. In addition, the bonding between the metal droplet and the polymer matrix is ​​poor, and the interface difference makes the thermal conductivity of the entire thermal conductive material not increase but decrease; There is a method to try to use solidified metal powder and coat it on the surface, and then disperse the coated metal powder in the polymer matrix as a heat-conducting material, but due to the low melting point of liquid metal, its metal particles and The coating operation needs to be carried out at low temperature, the operating conditions are harsh and the coating effect is not ideal

In addition, the existing technical means are to disperse the liquid metal in the whole polymer matrix, and exist as a specific heat-conducting material (heat-conducting patch), and cannot exist as an independent heat-conducting filler, which greatly limits the liquid metal as a Breadth and depth of applications for thermally conductive materials

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