Preparation method of 10W insulating heat-conducting silicone grease

Abstract

The invention relates to the technical field of preparation of insulating heat-conducting silicone grease, in particular to a preparation method of 10W insulating heat-conducting silicone grease. The preparation method comprises the following steps: mixing 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane serving as a filling base material with a heat-conducting filler to form a mixture; the preparation method comprises the following steps: mixing 2-phenyl-6-ethyltrimethoxymethylsilyl-hexamethylcyclotetrasiloxane, kneading at high temperature for 30 minutes, heating the mixture until trimethoxy in the 2-phenyl-6-ethyltrimethoxymethylsilyl-hexamethylcyclotetrasiloxane on the surface of the powder is hydrolyzed to generate methanol, and volatilizing at high temperature to remove the methanol so as to reduce the viscosity of the mixture and increase the loading capacity of the heat-conducting filler. According to the invention, 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is used as a filling base material, and diamond, single crystal aluminum nitride, nano-zinc oxide and single crystal aluminum oxide are used as heat-conducting fillers for compounding, so that the heat-conducting material is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of insulating thermally conductive silicone grease preparation, and in particular to a method for preparing 10W insulating thermally conductive silicone grease. Background Art

[0002] Thermal grease is an interface thermal conductive material with good thermal conductivity. It is widely used in automotive electronics, new energy, energy storage, LED, PC, power supply and other industries to fill interface gaps and reduce thermal resistance. Thermal grease in the prior art usually uses metal aluminum powder as a thermal conductive filler to improve thermal conductivity.

[0003] However, this high thermal conductivity silicone grease has the following disadvantages: (1) The thermal conductivity coefficient cannot exceed 10W / mK: The thermal conductivity coefficient of traditional thermal conductive silicone grease is usually difficult to exceed 10W / mK, which limits its application in areas with high thermal conductivity requirements. (2) The product is conductive but not insulating: Since metal aluminum powder is used as a thermal conductive filler, the thermal conductive silicone grease is conductive and cannot meet the insulation performance requirements of the end product. (3) Aluminum powder is easily oxidized during long-term use, and its overall performance is reduced: Metal aluminum powder is easily oxidized during long-term use, resulting in a decrease in its thermal conductivity and mechanical properties, affecting the life and reliability of the product. Summary of the invention

[0004] The invention provides a preparation method of 10W insulating thermally conductive silicone grease, which is prepared by using 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane as a filling substrate, and using diamond, single crystal aluminum nitride, nano zinc oxide and single crystal aluminum oxide as thermally conductive fillers for compounding.

[0005] The technical scheme adopted by the present invention is: a preparation method of a 10W insulating thermally conductive silicone grease, wherein 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is used as a filling base material and mixed with a thermally conductive filler to form a mixture, and then the mixture is heated to a temperature sufficient to hydrolyze the trimethoxy group in the 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane on the surface of the powder to generate methanol, and the methanol is volatilized and removed at a high temperature to reduce the viscosity of the mixture and increase the loading amount of the thermally conductive filler.

[0006] As a further improvement of the present invention, the thermal conductive filler includes nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide and diamond.

[0007] As a further improvement of the present invention, the particle size of the nano zinc oxide is less than 1 micron, the particle size of the single crystal aluminum nitride is 10 microns, the particle size of the single crystal aluminum oxide is 5 microns, and the particle size of the diamond is 20 microns.

[0008] As a further improvement of the present invention, the viscosity of the 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is 50 cps.

[0009] As a further improvement of the present invention, the 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane, nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide, and diamond are counted in parts by weight: 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane accounts for 80-100 parts; nano zinc oxide accounts for 400-600 parts, single crystal aluminum nitride accounts for 200-800 parts, single crystal aluminum oxide accounts for 200-600 parts, and diamond accounts for 200-800 parts.

[0010] The beneficial effects of the present invention are as follows: (1) Significantly improving thermal conductivity: The present invention uses phenylsiloxane as a filling substrate and compounds it with high thermal conductivity fillers such as nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide and diamond to achieve a significant improvement in thermal conductivity, reaching or exceeding 10W / mK, meeting the needs of industry applications with high thermal conductivity requirements.

[0011] (2) Ensuring insulation performance: The formula of the present invention does not use metal aluminum powder, but uses materials with good insulation properties as thermal conductive fillers, ensuring that the thermal grease is non-conductive and has a breakdown voltage of up to 6KV / mm, which greatly improves the safety of the product and is suitable for application scenarios with strict requirements on electrical insulation.

[0012] (3) Enhanced long-term reliability: After fully removing the hydroxyl group, the formula material of the present invention can effectively reduce the aging and performance degradation of the material. After aging reliability testing, the thermal conductivity of the thermal grease does not change by more than 10%, ensuring the stability and reliability of the product in long-term use and extending the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural diagram of 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane of a method for preparing a 10W insulating thermally conductive silicone grease of the present invention;

[0014] Figure 2 It is a reaction principle diagram of a method for preparing 10W insulating thermal conductive silicone grease of the present invention. DETAILED DESCRIPTION

[0015] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0016] The invention provides a preparation method of 10W insulating thermally conductive silicone grease. 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is used as a filling base material and mixed with a thermally conductive filler to form a mixture. The mixture is then kneaded at high temperature for 30 minutes and then heated to a temperature sufficient to hydrolyze trimethoxy groups in the 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane on the surface of the powder to generate methanol, which is volatilized and removed at high temperature to reduce the viscosity of the mixture and increase the loading amount of the thermally conductive filler.

[0017] The thermal conductive filler in the present invention comprises nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide and diamond. The particle size of nano zinc oxide is less than 1 micron, the particle size of single crystal aluminum nitride is 10 microns, the particle size of single crystal aluminum oxide is 5 microns, and the particle size of diamond is 20 microns. The viscosity of 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is 50cps.

[0018] In the present invention, the weight proportions of 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane, nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide and diamond are as follows: 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane accounts for 80-100 parts; nano zinc oxide accounts for 400-600 parts, single crystal aluminum nitride accounts for 200-800 parts, single crystal aluminum oxide accounts for 200-600 parts and diamond accounts for 200-800 parts.

[0019] The preparation test was carried out according to the above method, and the test cases included Example 1, Example 2, Example 3, Example 4, and Example 5, as shown in the following table. (Phenylsiloxane is the abbreviation of 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane)

[0020]

[0021] The finished thermal grease products obtained in Example 1, Example 2, Example 3, Example 4, and Example 5 were subjected to performance tests, and the specific performance data are shown in the following table.

[0022]

[0023] As can be seen from the table above, Example 4 has the best overall effect, and its thermal conductivity, thermal resistance and viscosity all meet the product performance requirements of 10W insulating thermal grease. The thermal conductivity reaches 10.17W / mK, and the thermal resistance is 0.09℃*cm 2 / W, and the viscosity is 382.8Pa.s, both of which are at a relatively good level. The performance changes little after the reliability test, and the thermal conductivity coefficient does not decrease but increases to 10.38W / mK, which shows that the thermal conductive silicone grease prepared by the present invention can still maintain good performance in long-term use.

[0024] In summary, the preparation method of a 10W insulating thermal conductive silicone grease of the present invention, by adopting the above-mentioned formula and process, not only solves the problems of conductivity and long-term performance degradation of high thermal conductive silicone grease in the prior art, but also greatly improves the thermal conductivity of the material, meets the application fields with high thermal conductivity requirements, and shows excellent technical effects and application prospects.

[0025] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing 10W insulating thermally conductive silicone grease, characterized in that: 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is used as a filling base material and mixed with a thermally conductive filler to form a mixture. The mixture is then kneaded at high temperature for 30 minutes and then heated to a temperature sufficient to hydrolyze the trimethoxy group in the 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane on the surface of the powder to generate methanol, which is volatilized and removed at high temperature to reduce the viscosity of the mixture and increase the loading amount of the thermally conductive filler.

2. The method for preparing a 10W insulating thermally conductive silicone grease according to claim 1, characterized in that: The thermal conductive filler includes nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide and diamond.

3. The method for preparing a 10W insulating thermally conductive silicone grease according to claim 2, characterized in that: The particle size of the nano zinc oxide is less than 1 micron, the particle size of the single crystal aluminum nitride is 10 microns, the particle size of the single crystal aluminum oxide is 5 microns, and the particle size of the diamond is 20 microns.

4. The method for preparing a 10W insulating thermally conductive silicone grease according to claim 1, characterized in that: The viscosity of the 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane is 50 cps.

5. The method for preparing a 10W insulating thermally conductive silicone grease according to claim 3, characterized in that: The 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane, nano zinc oxide, single crystal aluminum nitride, single crystal aluminum oxide, and diamond are counted in parts by weight: 2-phenyl-6-ethyltrimethoxysilyl-hexamethylcyclotetrasiloxane accounts for 80-100 parts; nano zinc oxide accounts for 400-600 parts, single crystal aluminum nitride accounts for 200-800 parts, single crystal aluminum oxide accounts for 200-600 parts, and diamond accounts for 200-800 parts.

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