Preparation method of phase change heat-conducting silica gel and product thereof

Abstract

The application discloses a preparation method of phase change heat-conducting silica gel and a product, and relates to the technical field of silica gel, in particular to the preparation method of the phase change heat-conducting silica gel. The preparation method comprises the following steps: a, stirring and mixing vinyl silicone oil and ethylene-propylene-diene rubber powder to obtain a basic pre-preparation mixed oil; b, stirring and mixing nano-zinc oxide, aluminum hydroxide, spherical aluminum oxide, methoxy-silicon azane and the basic pre-preparation mixed oil to obtain base material A; c, stirring and mixing the basic pre-preparation mixed oil, base material, acetylenic alcohol inhibitor and hydrogen-containing silicone oil to obtain base material B; and d, performing casting forming on the base material B after vacuum stirring and mixing with platinum water to obtain the phase change heat-conducting silica gel product. The phase change heat-conducting silica gel product prepared by the preparation method has the advantages of good heat-conducting performance and good high-temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of thermally conductive silicone materials, and in particular to a method for preparing phase change thermally conductive silicone and a product thereof. Background Technology

[0002] Thermally conductive silicone is a composite material used for thermal management of electronic devices. It is mainly used in fields such as CPU chip heat dissipation, heat conduction of high-power components, LED lighting, and heat dissipation systems for new energy vehicle battery packs.

[0003] It should be noted that existing thermally conductive silicone products have internal gaps, which means there is internal interfacial thermal resistance during heat conduction. This internal interfacial thermal resistance reduces the thermal conductivity of the silicone, meaning that existing thermally conductive silicone products have the defect of poor thermal conductivity.

[0004] Furthermore, existing thermal conductive silicone products lack an internal network support structure, resulting in poor overall integrity under high-temperature conditions. In other words, existing thermal conductive silicone products have the defect of poor high-temperature resistance. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing phase change thermally conductive silicone to address the shortcomings of existing technologies. The phase change thermally conductive silicone product prepared by this method has the advantages of good thermal conductivity and good high-temperature resistance.

[0006] Another objective of this invention is to provide a phase change thermally conductive silicone product that addresses the shortcomings of existing technologies. This phase change thermally conductive silicone has the advantages of good thermal conductivity and good high-temperature resistance.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0008] A method for preparing phase change thermally conductive silicone includes the following steps: Step a: Take vinyl silicone oil and EPDM rubber powder in a mass ratio of 4:1 and mix them in a double planetary disperser to obtain a basic premixed oil with a viscosity of 3000CS-7000CS. The basic premixed oil is then cooled and set aside for later use. Step b: Take 9 kg of nano zinc oxide, 43 kg of aluminum hydroxide with a particle size D50 of 20 μm, and 48 kg of spherical alumina with a particle size D50 of 40 μm and carry out the first stage of stirring and mixing in a double planetary disperser. The temperature of the first stage of stirring and mixing is 95℃ and the time is 2 h. During the first stage of stirring and mixing, 0.3 kg of methoxysilazane is sprayed and added simultaneously to carry out surface activation treatment. After the first stage of mixing in the double planetary disperser is completed, 10 kg of the pre-mixed base oil prepared in step a is added to the double planetary disperser, and the second stage of mixing is carried out to obtain base material A, which is then cooled for later use. The temperature of the second stage of mixing is 80℃-90℃ and the time is 1 hour. Step c: Take 10 kg of the basic premixed oil prepared in step a and all the base material A prepared in step b and perform the first stage of mixing in a double planetary disperser. The temperature of the first stage mixing is room temperature and the time is 30 min. After the first stage of mixing in the dual planetary disperser is completed, 3g of alkynol inhibitor is added to the dual planetary disperser and the second stage of mixing is carried out. The temperature of the second stage of mixing is room temperature and the time is 30min. After the second stage of mixing in the double planetary disperser is completed, 600g of hydrogen-containing silicone oil with a hydrogen content of 0.18% is added to the double planetary disperser, and the third stage of mixing is carried out to obtain base material B. Base material B is placed for 2 hours and then set aside. The temperature of the third stage of mixing is room temperature and the time is 1 hour. The third stage of mixing is carried out in a vacuum environment. Step d: Take 0.3g of 3000PPM platinum water and 1kg of base material B prepared in step c and vacuum stir for 30min using a vacuum stirring device. A phase change thermally conductive silicone product was prepared by using a casting molding method with platinum water after vacuum stirring and base material B.

[0009] In step a, the mixing temperature is 80°C, the mixing rate is 60-80 r / min, the time is 30 min, and the mixing process is carried out in a vacuum environment.

[0010] In step a, the viscosity of the vinyl silicone oil is 500 CS, and the vinyl content in the vinyl silicone oil is 1.2% by mass.

[0011] In step a, the ethylene content in the EPDM rubber powder is greater than 70%.

[0012] In step c, the alkynyl alcohol inhibitor is acetylenol.

[0013] In step d, the phase change thermally conductive silicone product is cast to a thickness of 2.0 mm, a casting temperature of 120°C, and a casting time of 20 min.

[0014] A phase change thermally conductive silicone product is prepared by the above-described phase change thermally conductive silicone preparation method.

[0015] Compared with existing technologies, the present invention has the following beneficial effects: Specifically, the phase change thermally conductive silicone product prepared by the phase change thermally conductive silicone preparation method of the present invention, when the ambient temperature is above 60°C, the EPDM rubber absorbs heat and enters a slightly molten state. At this slightly molten state, the EPDM rubber can effectively fill the gaps between materials, thereby reducing the internal interfacial thermal resistance and exhibiting excellent thermal conductivity. Furthermore, simultaneously in the high-temperature range (above 60°C), vinyl silicone oil and H-containing silicone oil form a network support structure through platinum catalysis, which better maintains the integrity of the material and indirectly improves the material's high-temperature resistance. Therefore, the phase change thermally conductive silicone product prepared by the phase change thermally conductive silicone preparation method of the present invention has the advantages of good thermal conductivity and good high-temperature resistance. Detailed Implementation

[0016] The present invention will now be described in conjunction with specific embodiments.

[0017] Example 1: A method for preparing phase change thermally conductive silicone, comprising the following steps: Step a: Take vinyl silicone oil and EPDM rubber powder in a mass ratio of 4:1 and mix them in a double planetary disperser to obtain a basic premixed oil with a viscosity of 3000CS-7000CS. The basic premixed oil is then cooled and set aside for later use. Step b: Take 9 kg of nano zinc oxide, 43 kg of aluminum hydroxide with a particle size D50 of 20 μm, and 48 kg of spherical alumina with a particle size D50 of 40 μm and carry out the first stage of stirring and mixing in a double planetary disperser. The temperature of the first stage of stirring and mixing is 95℃ and the time is 2 h. During the first stage of stirring and mixing, 0.3 kg of methoxysilazane is sprayed and added simultaneously to carry out surface activation treatment. After the first stage of mixing in the double planetary disperser is completed, 10 kg of the pre-mixed base oil prepared in step a is added to the double planetary disperser, and the second stage of mixing is carried out to obtain base material A, which is then cooled for later use. The temperature of the second stage of mixing is 80℃-90℃ and the time is 1 hour. Step c: Take 10 kg of the basic premixed oil prepared in step a and all the base material A prepared in step b and perform the first stage of mixing in a double planetary disperser. The temperature of the first stage mixing is room temperature and the time is 30 min. After the first stage of mixing in the dual planetary disperser is completed, 3g of alkynyl alcohol inhibitor is added to the dual planetary disperser and the second stage of mixing is carried out. The temperature of the second stage of mixing is room temperature and the time is 30 minutes. It should be noted that the alkynyl alcohol inhibitor can be acetylenol. After the second stage of mixing in the double planetary disperser is completed, 600g of hydrogen-containing silicone oil with a hydrogen content of 0.18% is added to the double planetary disperser, and the third stage of mixing is carried out to obtain base material B. Base material B is placed for 2 hours and then set aside. The temperature of the third stage of mixing is room temperature and the time is 1 hour. The third stage of mixing is carried out in a vacuum environment. Step d: Take 0.3g of 3000PPM platinum water and 1kg of base material B prepared in step c and vacuum stir for 30min using a vacuum stirring device. A phase change thermally conductive silicone product was prepared by using a casting molding method with platinum water after vacuum stirring and base material B.

[0018] For the phase change thermally conductive silicone product prepared by the method described in Example 1, when the ambient temperature is above 60°C, the EPDM rubber absorbs heat and enters a slightly molten state. At this slightly molten state, the EPDM rubber effectively fills the gaps between materials, thereby reducing the interfacial thermal resistance and exhibiting excellent thermal conductivity. Furthermore, in the high-temperature range (above 60°C), vinyl silicone oil and H-containing silicone oil form a network support structure through platinum catalysis. This better maintains the integrity of the material, indirectly improving its high-temperature resistance.

[0019] In summary, the phase change thermally conductive silicone prepared by the method described in Example 1 has the advantages of good thermal conductivity and high temperature resistance.

[0020] Example 2 differs from Example 1 in that: in step a, the stirring and mixing process is carried out at a temperature of 80°C, a stirring rate of 60-80 r / min, and a time of 30 min, and the stirring and mixing process is carried out in a vacuum environment.

[0021] Example 3 differs from Example 1 in that: in step a, the viscosity of the vinyl silicone oil is 500 CS, and the vinyl content in the vinyl silicone oil is 1.2% by mass.

[0022] Example 4 differs from Example 1 in that, in step a, the ethylene content in the EPDM rubber powder is >70%.

[0023] Example 5 differs from Example 1 in that, in step d, the phase change thermally conductive silicone product has a casting thickness of 2.0 mm, a casting temperature of 120°C, and a casting time of 20 min.

[0024] Example 6: A phase change thermally conductive silicone product, prepared by the above-described phase change thermally conductive silicone preparation method.

[0025] For the phase change thermally conductive silicone product in this embodiment, the thermal conductivity of the material itself at room temperature can reach 2.87 W / mk.

[0026] For the phase change thermally conductive silicone product of Example 6, when the ambient temperature is above 60°C, the EPDM rubber absorbs heat and enters a slightly molten state. At this slightly molten state, the EPDM rubber effectively fills the gaps between materials, thereby reducing the interfacial thermal resistance and exhibiting excellent thermal conductivity. Furthermore, in the high-temperature range (above 60°C), vinyl silicone oil and H-containing silicone oil form a network support structure through platinum catalysis. This better maintains the integrity of the material, indirectly improving its high-temperature resistance.

[0027] In summary, the phase change thermally conductive silicone of this embodiment six has the advantages of good thermal conductivity and good high temperature resistance.

[0028] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for preparing phase change thermally conductive silicone, characterized in that, It includes the following steps, specifically: Step a: Take vinyl silicone oil and EPDM rubber powder in a mass ratio of 4:1 and mix them in a double planetary disperser to obtain a basic premixed oil with a viscosity of 3000CS-7000CS. The basic premixed oil is then cooled and set aside for later use. Step b: Take 9 kg of nano zinc oxide, 43 kg of aluminum hydroxide with a particle size D50 of 20 μm, and 48 kg of spherical alumina with a particle size D50 of 40 μm and carry out the first stage of stirring and mixing in a double planetary disperser. The temperature of the first stage of stirring and mixing is 95℃ and the time is 2 h. During the first stage of stirring and mixing, 0.3 kg of methoxysilazane is sprayed and added simultaneously to carry out surface activation treatment. After the first stage of mixing in the double planetary disperser is completed, 10 kg of the pre-mixed base oil prepared in step a is added to the double planetary disperser, and the second stage of mixing is carried out to obtain base material A, which is then cooled for later use. The temperature of the second stage of mixing is 80℃-90℃ and the time is 1 hour. Step c: Take 10 kg of the basic premixed oil prepared in step a and all the base material A prepared in step b and perform the first stage of mixing in a double planetary disperser. The temperature of the first stage mixing is room temperature and the time is 30 min. After the first stage of mixing in the dual planetary disperser is completed, 3g of alkynol inhibitor is added to the dual planetary disperser and the second stage of mixing is carried out. The temperature of the second stage of mixing is room temperature and the time is 30min. After the second stage of mixing in the double planetary disperser is completed, 600g of hydrogen-containing silicone oil with a hydrogen content of 0.18% is added to the double planetary disperser, and the third stage of mixing is carried out to obtain base material B. Base material B is placed for 2 hours and then set aside. The temperature of the third stage of mixing is room temperature and the time is 1 hour. The third stage of mixing is carried out in a vacuum environment. Step d: Take 0.3g of 3000PPM platinum water and 1kg of base material B prepared in step c and vacuum stir for 30min using a vacuum stirring device. A phase change thermally conductive silicone product was prepared by using a casting molding method with platinum water after vacuum stirring and base material B.

2. The method for preparing phase change thermally conductive silicone according to claim 1, characterized in that: In step a, the stirring and mixing process is carried out at a temperature of 80°C, a stirring rate of 60-80 r / min, and a time of 30 min, and is conducted in a vacuum environment.

3. The method for preparing phase change thermally conductive silicone according to claim 1, characterized in that: In step a, the viscosity of the vinyl silicone oil is 500 CS, and the vinyl content in the vinyl silicone oil is 1.2% by mass.

4. The method for preparing phase change thermally conductive silicone according to claim 1, characterized in that: In step a, the ethylene content in the EPDM rubber powder is >70%.

5. The method for preparing phase change thermally conductive silicone according to claim 1, characterized in that: In step c, the alkynyl alcohol inhibitor is acetylenol.

6. The method for preparing phase change thermally conductive silicone according to claim 1, characterized in that: In step d, the phase change thermally conductive silicone product is cast to a thickness of 2.0 mm, a casting temperature of 120°C, and a casting time of 20 min.

7. A phase change thermally conductive silicone product, characterized in that: It is prepared by the phase change thermally conductive silicone preparation method according to any one of claims 1 to 6.