Anti-aging organic silicon gel prepared from high-thermal-conductivity filler and preparation method of anti-aging organic silicon gel

Abstract

The invention discloses a preparation method of anti-aging organic silicon gel prepared from high-thermal-conductivity filler, which comprises the following steps: carrying out surface activation on boron nitride and silicon nitride by adopting surface plasma treatment; by adopting a nano coating technology, a thin organic coating layer is formed on the surface of the filler, and the uniform dispersity of the filler in a silicon matrix is optimized; the preparation method comprises the following steps: pre-mixing part of filler with vinyl silicone oil, primarily dispersing by using a high-speed shear mixer, and then adding hydrogen-containing silicone oil for secondary mixing; carrying out mixing and dispersing treatment under a vacuum condition, thoroughly dispersing the filler in a vacuum environment by utilizing ultrasonic waves, and carrying out degassing treatment at the same time; adding an anti-aging agent, an ultraviolet light absorber and a wetting agent, then adding a platinum catalyst and a curing accelerator, and adjusting the crosslinking speed; and injecting the mixed organic silicon gel material into a mold, and carrying out pre-curing treatment. By adopting the high-thermal-conductivity filler and optimizing the surface treatment and dispersion process of the filler, the heat dissipation capability and the aging resistance are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of organic silicon gel, in particular to an anti-aging organic silicon gel prepared by high thermal conductive filler and a preparation method thereof. Background Art

[0002] The heat generated by the semiconductor must be discharged to the surrounding environment to keep the temperature of the semiconductor element junction within the safe operating range. Usually, this heat dissipation process requires the use of a heat sink to diffuse the heat; if the heat sink is fixed to the surface of the semiconductor package, the two surfaces need to be in close contact. When the two surfaces mentioned above are connected together, only the high point will be in contact, and an air gap will be formed at the low point. Generally, there will be more than 90% of air gaps in the contact area, which will cause a significant increase in thermal resistance. In order to eliminate these air gaps on the contact interface, it is necessary to introduce a thermal interface material with a thermal conductivity much greater than that of air, such as thermal conductive gel, so that the two rough and uneven mating surfaces are closely connected together, significantly reducing the interface thermal resistance, improving the heat flow transfer efficiency, and thus reducing the temperature of the junction. Conventional thermal conductive gels will have problems such as hardness climbing, silicone oil precipitation, and decreased flexibility during high-temperature aging, which will seriously affect its thermal conductivity and heat dissipation performance and cannot meet the application requirements of precision electronic components.

[0003] High thermal conductivity fillers such as boron nitride and silicon nitride have poor dispersion in the silicone matrix and are prone to agglomeration, resulting in uneven thermal conductivity and decreased mechanical properties of the material. Uneven dispersion of fillers will cause local differences in the thermal conductivity of the material and affect the overall mechanical properties and electrical insulation properties. The compatibility between inorganic fillers (such as boron nitride and silicon nitride) and the silicone matrix is ​​poor, resulting in weak interfacial bonding and affecting the overall performance of the material. Poor compatibility can cause delamination and cracking of the material during use, affecting its service life and reliability. Silicone gel materials will age under long-term high temperature, ultraviolet light or chemical media, resulting in performance degradation. The surface treatment, dispersion, mixing and gel curing processes of high thermal conductivity fillers are relatively complex and require precise control of various process parameters. Some silicone materials may release volatile organic compounds (VOCs) or produce other harmful byproducts during the preparation and curing process, posing certain environmental and safety risks. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above and / or existing problems in the aging-resistant silicone gel prepared with high thermal conductive fillers and the preparation method thereof, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is how to provide an aging-resistant silicone gel prepared with a high thermal conductive filler and a preparation method thereof.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] An embodiment of the present invention provides an aging-resistant silicone gel prepared with a high thermal conductive filler, which includes the following raw materials in parts by weight: 40-60 parts of vinyl silicone oil, 5-15 parts of hydrogenated silicone oil, 15-25 parts of boron nitride, 5-10 parts of silicon nitride, 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of antioxidant, 0.1-0.3 parts of ultraviolet absorber, and 0.05-0.2 parts of wetting agent.

[0009] As a preferred solution of the aging-resistant silicone gel prepared by the high thermal conductive filler of the present invention, the antioxidant is butylated hydroxytoluene, the ultraviolet absorber is a benzophenone compound, and the wetting agent is a polyether wetting agent.

[0010] As a preferred solution of the method for preparing aging-resistant organic silicone gel prepared with high thermal conductive filler described in the present invention, the method comprises the following steps: surface plasma treatment is used to activate the surface of boron nitride and silicon nitride to enhance their compatibility with the organic silicone substrate; nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix; part of the filler is pre-mixed with vinyl silicone oil, and initially dispersed by a high-speed shear mixer, and then hydrogen-containing silicone oil is added for secondary mixing to enhance the cross-linking property of the material; mixing and dispersing treatment is carried out under vacuum conditions, and ultrasonic waves are used to thoroughly disperse the filler in a vacuum environment, and degassing treatment is carried out at the same time to eliminate bubbles in the mixture; anti-aging agent, ultraviolet absorber and wetting agent are added to enhance the environmental stability and service life of the material, and then a platinum catalyst and a curing accelerator are added to adjust the cross-linking speed to ensure rapid curing at room temperature or low temperature; the mixed organic silicone gel material is injected into a mold for pre-curing treatment, and the temperature and time are controlled to gradually solidify the material.

[0011] As a preferred scheme for the method for preparing aging-resistant silicone gel with high thermal conductive filler described in the present invention, the surface activation of boron nitride and silicon nitride by surface plasma treatment to enhance their compatibility with the silicone substrate includes: the vacuum degree during treatment is 100-300mTorr, the plasma treatment power is set at 50-200W, the surface activation time is 5-20min, and the gas flow rate is controlled at 10-50sccm.

[0012] As a preferred solution of the method for preparing aging-resistant organic silicone gel with high thermal conductive filler according to the present invention, the nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix, including: controlling the concentration of the filler at 10-30wt% to ensure that the filler is evenly dispersed in the solution and can fully contact with the coating material; controlling the concentration of the coating material at 2-10wt%; using high-speed stirring and ultrasonic treatment, with the power set at 100-500W and the time at 5-15min, to ensure the uniform dispersion of the filler in the solution and promote the formation of the coating layer; controlling the temperature during the coating process at 25-60°C and controlling the thickness of the coating layer at 5-50nm.

[0013] As a preferred solution of the method for preparing aging-resistant organic silicone gel prepared by high thermal conductive filler of the present invention, wherein: part of the filler is pre-mixed with vinyl silicone oil and initially dispersed by high-speed shear mixer. Then, hydrogen-containing silicone oil is added for secondary mixing, and the cross-linking property of the enhanced material includes: vinyl silicone oil ion content <10ppm, monomer content <50ppm; the ratio of filler to vinyl silicone oil is controlled at 1:(2-3), the initial shear speed is set to 3000-5000RPM, gradually increased to 7000-10000RPM, the mixing time is 15-30min, and the temperature during the mixing process is controlled at 25-40℃; during the secondary mixing, the shear speed is reduced, the initial speed is 2000-4000RPM, gradually increased to 5000-8000RPM, the mixing time is 10-20min, and the temperature is maintained at 30-50℃.

[0014] As a preferred solution of the method for preparing aging-resistant silicone gel with high thermal conductive filler described in the present invention, the mixing and dispersing treatment is carried out under vacuum conditions, the filler is thoroughly dispersed in a vacuum environment by using ultrasound, and a degassing treatment is carried out at the same time to eliminate bubbles in the mixture, including: starting the agitator at a vacuum degree of <10Pa, stirring at a speed of 2000-5000RPM for 15-30min, and during the stirring process, using an ultrasonic dispersing device at the same time, setting the frequency to 25-30kHz, the power to 400-800W, and the dispersion time to 10-15min; the degassing time is 20-30min, and the temperature should be controlled at 25-40°C.

[0015] As a preferred solution of the method for preparing aging-resistant silicone gel with high thermal conductive filler described in the present invention, the method comprises: adding an anti-aging agent, an ultraviolet absorber and a wetting agent to enhance the environmental stability and service life of the material, and then adding a platinum catalyst and a curing promoter to adjust the crosslinking speed to ensure rapid curing at room temperature or low temperature, comprising: stirring at a speed of 2000-5000RPM for 10-20min during the mixing process; and curing at 15-25°C during the curing process, achieving preliminary curing in 2-4h, and completely curing within 24h.

[0016] As a preferred scheme of the method for preparing aging-resistant silicone gel with high thermal conductivity filler described in the present invention, the mixed silicone gel material is injected into the mold, pre-cured, and the temperature and time are controlled to gradually solidify the material, including: the pre-curing treatment is maintained at 25°C, and after the initial pre-curing for 2-4 hours, the temperature is gradually increased to 50-60°C and maintained for 4-6 hours.

[0017] The beneficial effects of the present invention are as follows: by using high thermal conductivity fillers such as boron nitride and silicon nitride, and optimizing the surface treatment and dispersion process of the fillers, the thermal conductivity of the material reaches or exceeds 3.5W / m·K, which significantly improves the heat dissipation capacity and meets the heat dissipation requirements of high-performance electronic equipment and power devices. The material has excellent high temperature resistance, UV resistance and chemical corrosion resistance after special formula design and the addition of anti-aging additives. It can maintain elasticity and electrical insulation properties for a long time in a wide temperature range of -60°C to 250°C, and is suitable for use in harsh environments. Silicone gel materials have excellent waterproof and moisture-proof properties. Even in long-term humid or submerged environments, they can still maintain stable insulation properties. They are particularly suitable for applications in outdoor equipment and high humidity environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0019] Figure 1 Process flow chart of the method for preparing aging-resistant silicone gel for high thermal conductivity filler. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0023] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] Example 1

[0025] Reference Figure 1 , which is an embodiment of the present invention.

[0026] A method for preparing an aging-resistant silicone gel prepared with a high thermal conductive filler:

[0027] Prepare 44 parts of vinyl silicone oil, 7 parts of hydrogenated silicone oil, 17 parts of boron nitride, 6 parts of silicon nitride, 0.01 parts of platinum catalyst, 0.1 parts of antioxidant, 0.1 parts of ultraviolet absorber, and 0.05 parts of wetting agent;

[0028] Surface plasma treatment was used to activate the surfaces of boron nitride and silicon nitride. The vacuum degree during treatment was 100 mTorr, the plasma treatment power was set at 50 W, the surface activation time was 5 min, and the gas flow rate was controlled at 10 sccm.

[0029] Nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix. The concentration of the filler is controlled at 10wt%, and the concentration of the coating material is controlled at 2wt%. High-speed stirring and ultrasonic treatment are used, the power is set at 100W, the time is 5min, the temperature during the coating process is controlled at 25℃, and the thickness of the coating layer is controlled at 5nm.

[0030] Premix part of the filler with vinyl silicone oil, use a high-speed shear mixer for preliminary dispersion, then add hydrogenated silicone oil for secondary mixing to enhance the crosslinking of the material. The ion content of the vinyl silicone oil is 10ppm and the monomer content is 50ppm. The ratio of filler to vinyl silicone oil is controlled at 1:2, the initial shear speed is set at 3000RPM, gradually increased to 7000RPM, the mixing time is 15min, and the temperature during the mixing process is controlled at 25°C. During the secondary mixing, the shear speed is reduced, the initial speed is 2000RPM, gradually increased to 5000RPM, the mixing time is 10min, and the temperature is maintained at 30°C.

[0031] Mix and disperse under vacuum conditions, use ultrasound to thoroughly disperse the filler in a vacuum environment, and degas to eliminate bubbles in the mixture. Start the agitator at a vacuum of 10Pa and stir at a speed of 2000RPM for 15 minutes. During the stirring process, use ultrasonic dispersion equipment at the same time, set the frequency to 25kHz, the power to 400W, and the dispersion time to 10 minutes; the degassing time is 20 minutes, and the temperature should be controlled at 25℃;

[0032] Add anti-aging agent, UV absorber and wetting agent to enhance the environmental stability and service life of the material, then add platinum catalyst and curing agent to adjust the cross-linking speed to ensure rapid curing at room temperature or low temperature. Stir at 200RPM for 10 minutes during the mixing process; place at 15°C for curing, and achieve preliminary curing in 2-4 hours, and fully cure within 24 hours;

[0033] The mixed silicone gel material is injected into the mold for pre-curing treatment. The temperature and time are controlled to allow the material to solidify gradually. The pre-curing treatment is maintained at 25°C. After the initial pre-curing for 2 hours, the temperature is gradually increased to 50°C and maintained for 4 hours.

[0034] Example 2

[0035] A method for preparing an aging-resistant silicone gel prepared with a high thermal conductive filler:

[0036] Prepare 48 parts of vinyl silicone oil, 9 parts of hydrogenated silicone oil, 19 parts of boron nitride, 7 parts of silicon nitride, 0.02 parts of platinum catalyst, 0.2 parts of antioxidant, 0.14 parts of ultraviolet absorber, and 0.08 parts of wetting agent;

[0037] Surface plasma treatment was used to activate the surfaces of boron nitride and silicon nitride. The vacuum degree during treatment was 150 mTorr, the plasma treatment power was set at 80 W, the surface activation time was 8 min, and the gas flow rate was controlled at 20 sccm.

[0038] Nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix. The concentration of the filler is controlled at 15wt%, and the concentration of the coating material is controlled at 4wt%. High-speed stirring and ultrasonic treatment are used, the power is set at 200W, the time is 7min, the temperature during the coating process is controlled at 30℃, and the thickness of the coating layer is controlled at 15nm.

[0039] Premix part of the filler with vinyl silicone oil, use a high-speed shear mixer for preliminary dispersion, then add hydrogenated silicone oil for secondary mixing to enhance the crosslinking of the material. The ion content of the vinyl silicone oil is 9ppm and the monomer content is 40ppm. The ratio of filler to vinyl silicone oil is controlled at 1:2.2, the initial shear speed is set at 3500RPM, gradually increased to 7500RPM, the mixing time is 18min, and the temperature during the mixing process is controlled at 28°C. During the secondary mixing, the shear speed is reduced, the initial speed is 2500RPM, gradually increased to 5500RPM, the mixing time is 12min, and the temperature is maintained at 35°C.

[0040] Mix and disperse under vacuum conditions, use ultrasound to thoroughly disperse the filler in a vacuum environment, and degas to eliminate bubbles in the mixture. Start the agitator at a vacuum of 9 Pa and stir at a speed of 2500RPM for 18 minutes. During the stirring process, use ultrasonic dispersion equipment at the same time, set the frequency to 26kHz, the power to 500W, and the dispersion time to 11 minutes; the degassing time is 22 minutes, and the temperature should be controlled at 28°C;

[0041] Add anti-aging agent, UV absorber and wetting agent to enhance the environmental stability and service life of the material, then add platinum catalyst and curing agent to adjust the cross-linking speed to ensure rapid curing at room temperature or low temperature. Stir at 2500RPM for 12 minutes during the mixing process; place at 17°C for curing, and achieve preliminary curing in 2-4 hours, and fully cure within 24 hours;

[0042] The mixed silicone gel material is injected into the mold for pre-curing treatment. The temperature and time are controlled to allow the material to solidify gradually. The pre-curing treatment is maintained at 25°C. After the initial pre-curing for 2.5 hours, the temperature is gradually increased to 52°C and maintained for 4.5 hours.

[0043] Example 3

[0044] A method for preparing an aging-resistant silicone gel prepared with a high thermal conductive filler:

[0045] Prepare 52 parts of vinyl silicone oil, 11 parts of hydrogenated silicone oil, 21 parts of boron nitride, 7 parts of silicon nitride, 0.03 parts of platinum catalyst, 0.3 parts of antioxidant, 0.18 parts of ultraviolet absorber, and 0.11 parts of wetting agent;

[0046] Surface plasma treatment was used to activate the surfaces of boron nitride and silicon nitride. The vacuum degree during treatment was 200 mTorr, the plasma treatment power was set at 110 W, the surface activation time was 11 min, and the gas flow rate was controlled at 30 sccm.

[0047] Nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix. The concentration of the filler is controlled at 20wt%, and the concentration of the coating material is controlled at 6wt%. High-speed stirring and ultrasonic treatment are used, the power is set at 300W, the time is 9min, the temperature during the coating process is controlled at 35℃, and the thickness of the coating layer is controlled at 25nm.

[0048] Premix part of the filler with vinyl silicone oil, use a high-speed shear mixer for preliminary dispersion, then add hydrogenated silicone oil for secondary mixing to enhance the crosslinking of the material. The ion content of the vinyl silicone oil is 8ppm and the monomer content is 30ppm. The ratio of filler to vinyl silicone oil is controlled at 1:2.4, the initial shear speed is set at 4000RPM, gradually increased to 8000RPM, the mixing time is 21min, and the temperature during the mixing process is controlled at 32°C. During the secondary mixing, the shear speed is reduced, the initial speed is 3000RPM, gradually increased to 6500RPM, the mixing time is 16min, and the temperature is maintained at 40°C.

[0049] Mix and disperse under vacuum conditions, use ultrasound to thoroughly disperse the filler in a vacuum environment, and degas to eliminate bubbles in the mixture. Start the agitator at a vacuum of 8 Pa and stir at a speed of 3000 RPM for 21 minutes. During the stirring process, use ultrasonic dispersion equipment at the same time, set the frequency to 27 kHz, the power to 600 W, and the dispersion time to 12 minutes; the degassing time is 24 minutes, and the temperature should be controlled at 31°C;

[0050] Anti-aging agent, UV absorber and wetting agent are added to enhance the environmental stability and service life of the material, and then platinum catalyst and curing agent are added to adjust the cross-linking speed to ensure rapid curing at room temperature or low temperature. The mixing process is stirred at a speed of 3000RPM for 14 minutes; the curing process is placed at 19°C for curing, and preliminary curing is achieved within 3 hours, and complete curing is achieved within 24 hours;

[0051] The mixed silicone gel material is injected into the mold for pre-curing treatment. The temperature and time are controlled to allow the material to gradually solidify. The pre-curing treatment is maintained at 25°C. After the initial pre-curing for 3 hours, the temperature is gradually increased to 54°C and maintained for 5 hours.

[0052] Example 4

[0053] A method for preparing an aging-resistant silicone gel prepared with a high thermal conductive filler:

[0054] Prepare 56 parts of vinyl silicone oil, 13 parts of hydrogenated silicone oil, 23 parts of boron nitride, 8 parts of silicon nitride, 0.04 parts of platinum catalyst, 0.4 parts of antioxidant, 0.25 parts of ultraviolet absorber, and 0.15 parts of wetting agent;

[0055] Surface plasma treatment was used to activate the surfaces of boron nitride and silicon nitride. The vacuum degree during treatment was 250 mTorr, the plasma treatment power was set at 150 W, the surface activation time was 15 min, and the gas flow rate was controlled at 40 sccm.

[0056] Nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix. The concentration of the filler is controlled at 25wt%, and the concentration of the coating material is controlled at 8wt%. High-speed stirring and ultrasonic treatment are used, the power is set at 400W, the time is 13min, the temperature during the coating process is controlled at 50℃, and the thickness of the coating layer is controlled at 45nm.

[0057] Premix part of the filler with vinyl silicone oil, use a high-speed shear mixer for preliminary dispersion, then add hydrogenated silicone oil for secondary mixing to enhance the crosslinking of the material. The ion content of the vinyl silicone oil is 7ppm and the monomer content is 20ppm. The ratio of filler to vinyl silicone oil is controlled at 1:2.8, the initial shear speed is set at 4500RPM, gradually increased to 9000RPM, the mixing time is 25min, and the temperature during the mixing process is controlled at 35°C. During the secondary mixing, the shear speed is reduced, the initial speed is 3500RPM, gradually increased to 7500RPM, the mixing time is 15min, and the temperature is maintained at 45°C.

[0058] Mix and disperse under vacuum conditions, use ultrasound to thoroughly disperse the filler in a vacuum environment, and degas to eliminate bubbles in the mixture. Start the agitator at a vacuum of 7Pa and stir at a speed of 4000RPM for 25 minutes. During the stirring process, use ultrasonic dispersion equipment at the same time, set the frequency to 28kHz, the power to 700W, and the dispersion time to 14 minutes; the degassing time is 28 minutes, and the temperature should be controlled at 38°C;

[0059] Anti-aging agent, UV absorber and wetting agent are added to enhance the environmental stability and service life of the material, and then platinum catalyst and curing agent are added to adjust the cross-linking speed to ensure rapid curing at room temperature or low temperature. The mixing process is stirred at a speed of 4000RPM for 18 minutes; the curing process is placed at 20°C for curing, and the initial curing is achieved in 3.5 hours, and the complete curing is achieved within 24 hours;

[0060] The mixed silicone gel material is injected into the mold for pre-curing treatment. The temperature and time are controlled to gradually solidify the material. The pre-curing treatment is maintained at 25°C. After the initial pre-curing for 3.5 hours, the temperature is gradually increased to 58°C and maintained for 5 hours.

[0061] Example 5

[0062] A method for preparing an aging-resistant silicone gel prepared with a high thermal conductive filler:

[0063] Prepare 60 parts of vinyl silicone oil, 15 parts of hydrogenated silicone oil, 25 parts of boron nitride, 10 parts of silicon nitride, 0.05 parts of platinum catalyst, 0.5 parts of antioxidant, 0.3 parts of ultraviolet absorber, and 0.2 parts of wetting agent;

[0064] Surface plasma treatment was used to activate the surfaces of boron nitride and silicon nitride. The vacuum degree during treatment was 300 mTorr, the plasma treatment power was set at 200 W, the surface activation time was 20 min, and the gas flow rate was controlled at 50 sccm.

[0065] Nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix. The concentration of the filler is controlled at 30wt%, and the concentration of the coating material is controlled at 10wt%. High-speed stirring and ultrasonic treatment are used, the power is set at 500W, the time is 15min, the temperature during the coating process is controlled at 60℃, and the thickness of the coating layer is controlled at 50nm.

[0066] Premix part of the filler with vinyl silicone oil, use a high-speed shear mixer for preliminary dispersion, then add hydrogenated silicone oil for secondary mixing to enhance the crosslinking of the material. The ion content of the vinyl silicone oil is 6ppm and the monomer content is 10ppm. The ratio of filler to vinyl silicone oil is controlled at 1:3, the initial shear speed is set at 5000RPM, gradually increased to 10000RPM, the mixing time is 30min, and the temperature during the mixing process is controlled at 40°C. During the secondary mixing, the shear speed is reduced, the initial speed is 4000RPM, gradually increased to 8000RPM, the mixing time is 20min, and the temperature is maintained at 50°C.

[0067] Mix and disperse under vacuum conditions, use ultrasound to thoroughly disperse the filler in a vacuum environment, and degas to eliminate bubbles in the mixture. Start the agitator at a vacuum of 6Pa and stir at a speed of 5000RPM for 30min. During the stirring process, use ultrasonic dispersion equipment at the same time, set the frequency to 30kHz, the power to 800W, and the dispersion time to 15min; the degassing time is 30min, and the temperature should be controlled at 40℃;

[0068] Add anti-aging agent, UV absorber and wetting agent to enhance the environmental stability and service life of the material, then add platinum catalyst and curing agent to adjust the cross-linking speed to ensure rapid curing at room temperature or low temperature. Stir at 5000RPM for 20 minutes during the mixing process; place at 25°C for curing, achieve preliminary curing in 4 hours, and fully cure within 24 hours;

[0069] The mixed silicone gel material is injected into the mold for pre-curing treatment. The temperature and time are controlled to allow the material to solidify gradually. The pre-curing treatment is maintained at 25°C. After the initial pre-curing for 4 hours, the temperature is gradually increased to 60°C and maintained for 6 hours.

[0070] Comparison Example

[0071]

[0072] Table 1

[0073] It can be seen from Table 1 that the aging-resistant silicone gel prepared by the high thermal conductive filler of the present invention exhibits excellent physical, chemical and electrical properties before and after curing. The material has high thermal conductivity, good mechanical and electrical insulation, excellent aging resistance and environmental stability.

[0074] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An aging-resistant silicone gel prepared from a high thermal conductive filler, characterized in that: The invention is prepared from the following raw materials in parts by weight: 40-60 parts of vinyl silicone oil, 5-15 parts of hydrogen-containing silicone oil, 15-25 parts of boron nitride, 5-10 parts of silicon nitride, 0.01-0.05 parts of platinum catalyst, 0.1-0.5 parts of antioxidant, 0.1-0.3 parts of ultraviolet absorber and 0.05-0.2 parts of wetting agent.

2. The aging-resistant organic silicon gel prepared by the high thermal conductive filler according to claim 1, characterized in that: The antioxidant is butylated hydroxytoluene, the ultraviolet absorber is a benzophenone compound, and the wetting agent is a polyether wetting agent.

3. A method for preparing an aging-resistant silicone gel prepared with a high thermal conductive filler, characterized in that: include: S1: Surface activation of boron nitride and silicon nitride by surface plasma treatment to enhance their compatibility with silicone substrates; S2: Nano-coating technology is used to form a thin organic coating layer on the surface of the filler to prevent agglomeration and optimize the uniform dispersion of the filler in the silicon matrix; S3: Premix part of the filler with vinyl silicone oil, use a high-speed shear mixer for preliminary dispersion, and then add hydrogenated silicone oil for secondary mixing to enhance the crosslinking of the material; S4: Mixing and dispersing under vacuum conditions, using ultrasound to thoroughly disperse the filler in a vacuum environment, and degassing to eliminate bubbles in the mixture; S5: adding an anti-aging agent, a UV absorber and a wetting agent to enhance the environmental stability and service life of the material, and then adding a platinum catalyst and a curing agent to adjust the crosslinking speed to ensure rapid curing at room temperature or low temperature; S6: Inject the mixed silicone gel material into the mold for pre-curing treatment, control the temperature and time, and allow the material to solidify gradually.

4. The method for preparing an aging-resistant silicone gel prepared by a high thermal conductive filler according to claim 3, characterized in that: The S1 includes: The vacuum degree during treatment is 100-300 mTorr, the plasma treatment power is set at 50-200 W, the surface activation time is 5-20 min, and the gas flow rate is controlled at 10-50 sccm.

5. The method for preparing the aging-resistant silicone gel prepared by the high thermal conductive filler according to claim 3, characterized in that: The S2 includes: The concentration of the filler is controlled at 10-30 wt% to ensure that the filler is evenly dispersed in the solution and can fully contact with the coating material; the concentration of the coating material is controlled at 2-10wt%; high-speed stirring and ultrasonic treatment are used, the power is set at 100-500W, and the time is 5-15min to ensure that the filler is evenly dispersed in the solution and promote the formation of the coating layer; the temperature during the coating process is controlled at 25-60°C, and the thickness of the coating layer is controlled at 5-50 nm.

6. The method for preparing the aging-resistant silicone gel prepared by the high thermal conductive filler according to claim 3, characterized in that: The S3 includes: The ion content of vinyl silicone oil is less than 10ppm, and the monomer content is less than 50ppm; the ratio of filler to vinyl silicone oil is controlled at 1:(2-3), the initial shear speed is set to 3000-5000 RPM, gradually increased to 7000-10000 RPM, the mixing time is 15-30min, and the temperature during the mixing process is controlled at 25-40°C; during the secondary mixing, the shear speed is reduced, the initial speed is 2000-4000 RPM, gradually increased to 5000-8000 RPM, the mixing time is 10-20min, and the temperature is maintained at 30-50°C.

7. The method for preparing the aging-resistant silicone gel prepared by the high thermal conductive filler according to claim 3, characterized in that: The S4 includes: Under a vacuum degree of <10 Pa, start the agitator and stir at a speed of 2000-5000 RPM for 15-30 minutes. During the stirring process, use ultrasonic dispersion equipment at the same time, set the frequency to 25-30 kHz, the power to 400-800W, the dispersion time to 10-15 minutes; the degassing time is 20-30 minutes, and the temperature should be controlled at 25-40°C.

8. The method for preparing the aging-resistant silicone gel prepared by the high thermal conductive filler according to claim 3, characterized in that: The S5 includes: During the mixing process, stir at a speed of 2000-5000 RPM for 10-20 minutes; during the curing process, place it at 15-25°C for curing, and achieve preliminary curing in 2-4 hours, and fully cure within 24 hours.

9. The method for preparing an aging-resistant silicone gel prepared by a high thermal conductive filler according to claim 3, characterized in that: The S6 includes: The pre-curing treatment is maintained at 25°C. After the initial pre-curing for 2-4 hours, the temperature is gradually increased to 50-60°C and maintained for 4-6 hours.

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