Organic silicon heat-conducting gel with high heat conductivity and high temperature resistance and preparation method of organic silicon heat-conducting gel

Abstract

The invention relates to the technical field of gel, in particular to high-thermal-conductivity and high-temperature-resistant organosilicone thermal-conductive gel and a preparation method thereof. The invention discloses high-thermal-conductivity and high-temperature-resistant organosilicone heat-conducting gel, which is prepared from the following raw materials in percentage by weight: 4.5 to 5 percent of simethicone, 0.3 to 0.4 percent of dispersing agent, 70 to 80 percent of modified aluminum oxide and 15 to 25 percent of modified zinc oxide. According to the organic silicon heat-conducting gel, the modified aluminum oxide and the modified zinc oxide which are subjected to surface treatment modification can be better combined with the simethicone, so that the effect of reducing the viscosity is achieved, and meanwhile, the organic silicon heat-conducting gel cannot be pulverized in a high-temperature environment.

Description

Technical Field

[0001] The invention relates to the technical field of gel, and in particular to a high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel and a preparation method thereof. Background Art

[0002] Silicone thermal conductive gel is a gel-like thermal conductive material made by mixing, blending and encapsulating silicone oil composite thermal conductive filler. Silicone thermal conductive gel has the advantages of high stability, low stress, good affinity and good insulation. At the same time, it has strong plasticity and can fill uneven interfaces, which can meet the heat transfer requirements of various applications.

[0003] With the development of high-tech, the demand for high-end thermal conductive gels has gradually become a trend. However, the existing non-curing high thermal conductive gels on the market are prone to cracking at high temperatures, making it difficult to achieve both high thermal conductivity and high temperature resistance. They have poor aging performance and are difficult to adapt to various application scenarios and meet various application needs.

[0004] To this end, the present application provides a high thermal conductivity and high temperature resistant organic silicon thermal conductive gel and a preparation method thereof. Summary of the invention

[0005] The present application provides a high thermal conductivity and high temperature resistant organic silicone thermal conductive gel and a preparation method thereof. The organic silicone thermal conductive gel, after surface treatment and modification, the modified aluminum oxide and the modified zinc oxide can be better combined with dimethyl silicone oil, thereby achieving the effect of reducing viscosity. At the same time, the organic silicone thermal conductive gel will not powder in a high temperature environment.

[0006] The technical solution adopted by this application to solve its technical problem is:

[0007] In a first aspect, the present application provides a high thermal conductivity and high temperature resistant organic silicon thermal conductive gel, comprising the following raw materials in percentage by weight:

[0008]

[0009] Preferably, the dimethyl silicone oil is a dimethyl silicone oil with a volatile matter of less than 0.5%.

[0010] Preferably, the viscosity of the dimethyl silicone oil is 1000-1500 cps.

[0011] Preferably, the dispersant is modified acrylic silicone.

[0012] Preferably, the modified alumina is alumina surface-treated with polysiloxane.

[0013] Preferably, the modified zinc oxide is zinc oxide surface-treated with polysiloxane.

[0014] Preferably, the particle size of the aluminum oxide is 0.5-2 microns.

[0015] Preferably, the particle size of the zinc oxide is 0.5-2 microns.

[0016] Preferably, the chemical structural formula of the polysiloxane is:

[0017]

[0018] The second object of the present application is to provide a method for preparing the above-mentioned high thermal conductivity and high temperature resistant silicone thermally conductive gel, comprising the following steps:

[0019] According to the weight percentage composition of the high thermal conductivity and high temperature resistant silicone thermal conductive gel, the materials are prepared; dimethyl silicone oil, dispersant, and part of the modified alumina are fully mixed, and then the remaining modified alumina is added and fully mixed; finally, modified zinc oxide is added and fully mixed to obtain the silicone thermal conductive gel.

[0020] The beneficial effects of this application are:

[0021] 1. The modified aluminum oxide and modified zinc oxide of the organic silicone thermally conductive gel described in the present application can be better combined with dimethyl silicone oil after surface treatment, thereby achieving the effect of reducing viscosity. At the same time, the organic silicone thermally conductive gel will not powder in a high temperature environment.

[0022] 2. The thermal conductivity of the silicone thermally conductive gel prepared in this application is less than 0.35℃·cm 2 / W, thermal conductivity>6W / (m·K)), insulation voltage as high as 10mV / mm, and no powdering after aging at 150℃ for 1000h. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0024] Figure 1 This is a process flow chart of a method for preparing a high thermal conductivity and high temperature resistant organic silicone thermally conductive gel described in this application. DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0026] As used herein, "and / or" includes the term of any and all combinations of one or more associated listed items. The terms used herein are only used to describe specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It is further understood that "including", when used in this specification, specifies the stated features, integers, steps, operations, elements and / or compositions, but does not exclude the existence or addition of one or more other features, integers, steps, operations, elements, compositions and / or combinations thereof.

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. It is further understood that terms, such as defined in commonly used dictionaries, are interpreted in accordance with their meanings in the context of the relevant art and are not in an idealized or overly formal sense unless explicitly so defined herein.

[0028] The exemplary invention described herein may appropriately lack any one or more element limitations that are not specifically disclosed herein. Therefore, the terms "comprise", "include", "contain", etc. should be understood broadly and non-restrictively. In addition, the terminology used herein is used as a description, not a limitation, and it is unintentional to use these terminology expressions that do not include any equivalent characteristics, but only describe some of their characteristics, but various modifications are possible within the scope of the present invention according to the rights. Therefore, although the present invention has been specifically disclosed by preferred embodiments and optional features, the modifications disclosed herein to embody the changes of the present invention may be recorded by those skilled in the art, and such modifications and changes will be considered to be within the scope of the present invention.

[0029] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0030]

[0031] Wherein, the dimethyl silicone oil is a dimethyl silicone oil with a volatility of less than 0.5%, and the viscosity of the dimethyl silicone oil is 1000-1500cps. Therefore, in the present application, the use of low-volatile dimethyl silicone oil can reduce the volatilization of silicone oil and prevent the gel from powdering during long-term work. The weight percentage of dimethyl silicone oil in the organic silicone thermal conductive gel raw material is 4.5%-5%, for example, it can be any value of 4.5%, 4.6%, 4.7%, 5.0%, and it only needs to meet the requirement of 4.5%-5% (including the endpoint values ​​of 4.5% and 5%). In the present application, if the content of dimethyl silicone oil exceeds 5%, the thermal conductivity and mechanical strength of the gel may be reduced, causing the gel to be too soft, affecting its performance in practical applications; if the content of dimethyl silicone oil is lower than 4.5%, the fluidity and thermal conductivity of the gel may be reduced, affecting its filling and heat transfer effects.

[0032] Wherein, the dispersant is modified acrylic silicone. The weight percentage of the dispersant in the organic silicone thermal conductive gel raw material is 0.3%-0.4%, for example, it can be any value among 0.3%, 0.4%, 0.35%, and 0.38%, as long as the requirement of 0.3%-0.4% is met (including the endpoint values ​​of 0.3% and 0.4%). In this application, if the content of the dispersant exceeds 0.4%, too many impurities may be introduced, affecting the purity and performance of the gel; at the same time, too much dispersant may also have an adverse effect on the viscosity of the gel; if the content of the dispersant is less than 0.3%, it may not be able to effectively disperse other components, resulting in reduced uniformity and stability of the gel.

[0033] Wherein, the modified alumina is alumina surface-treated with polysiloxane. The weight percentage of modified alumina in the organic silicon thermal conductive gel raw material is 70%-80%, for example, it can be any value among 70%, 71%, 75%, 80%, and it only needs to meet the requirement of 70%-80% (including the endpoint values ​​of 70% and 80%). In the present application, if the content of modified alumina exceeds 80%, the gel may be too viscous, affecting its fluidity and filling capacity; if the content of modified alumina is less than 70%, the thermal conductivity of the gel may be reduced, and the expected thermal conduction effect cannot be achieved.

[0034] The specific process of preparing modified alumina is to select alumina with a particle size of 0.5-2 microns and dry it; immerse the dried alumina in polysiloxane, stir and mix at 100 rpm for 40 minutes, and then let it stand for 3 hours; take out the alumina, and solidify it at 80-90°C to obtain modified alumina.

[0035] Aluminum oxide itself has a high thermal conductivity. In this application, the thermal conductivity can be greatly improved by adding it to the silicone thermal conductive gel, reaching an ultra-high thermal conductivity of more than 6W / (m·K).

[0036] Wherein, the modified zinc oxide is zinc oxide that has been surface treated with polysiloxane. The weight percentage of modified zinc oxide in the organic silicone thermal conductive gel raw material is 15%-25%, for example, it can be any value among 15%, 20%, 21%, and 25%, as long as it meets the requirement of 15%-25% (including the endpoint values ​​15% and 25%). In this application, if the content of modified zinc oxide exceeds 25%, it may affect the overall thermal conductivity of the gel and increase the brittleness of the gel. If the content of modified zinc oxide is less than 15%, the thermal stability and electrical insulation of the gel may be reduced, affecting its application in high temperature environments.

[0037] The specific process of preparing the modified zinc oxide is to select zinc oxide with a particle size of 0.5-2 microns and dry it; immerse the dried zinc oxide in polysiloxane, stir and mix at 100 rpm for 40 minutes, and then let it stand for 3 hours; take out the zinc oxide, and solidify it at 80-90°C to obtain the modified zinc oxide.

[0038] Zinc oxide has a high melting point and can maintain stable chemical and photoelectric properties at high temperatures, and is not easily changed or damaged. In this application, by adding modified zinc oxide, ultraviolet rays can be absorbed and converted into heat energy, so that the temperature rise rate of the coating becomes slower, thereby extending the service life of the coating.

[0039] Wherein, the chemical structural formula of the polysiloxane described above is:

[0040]

[0041] Therefore, the zinc oxide and aluminum oxide modified by the polysiloxane surface treatment have better binding (compatibility) with dimethyl silicone oil, thereby achieving the effect of reducing viscosity, making the modified zinc oxide and modified zinc oxide better dispersed in dimethyl silicone oil, and the silicone thermal conductive gel will not powder in a high temperature environment.

[0042] like Figure 1 As shown, the method for preparing the above-mentioned high thermal conductivity and high temperature resistant organic silicon thermal conductive gel comprises the following steps:

[0043] According to the weight percentage composition of the high thermal conductivity and high temperature resistant silicone thermal conductive gel, the materials are prepared; dimethyl silicone oil, dispersant, and part of the modified alumina are fully mixed, and then the remaining modified alumina is added and fully mixed; finally, modified zinc oxide is added and fully mixed to obtain the silicone thermal conductive gel.

[0044] In the embodiments or comparative examples, some raw materials are as follows:

[0045] The viscosity of dimethyl silicone oil is 1000cps, and the volatile matter is less than 0.5%.

[0046] The dispersant is modified acrylic silicone, from Shin-Etsu KP-578.

[0047] Example 1

[0048] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0049] Dimethyl silicone oil 4.8%, dispersant -0.4%, modified alumina 74.9%, modified zinc oxide 19.9%.

[0050] The preparation process of modified alumina is as follows: select alumina with a particle size of 0.5 microns, wash and dry it with clean water; immerse the dried alumina in polysiloxane, stir and mix at 100 rpm for 40 minutes, and then let it stand for 3 hours; take out the alumina, and solidify it at 80°C to obtain modified alumina.

[0051] The preparation process of modified zinc oxide is as follows: zinc oxide with a particle size of 0.5 microns is selected, washed with clean water and dried; the dried zinc oxide is immersed in polysiloxane, stirred and mixed at 100 rpm for 40 minutes, and then allowed to stand for 3 hours; the zinc oxide is taken out and solidified at 80°C to obtain modified zinc oxide.

[0052] The method for preparing the above-mentioned silicone thermally conductive gel comprises the following steps:

[0053] Prepare the materials according to the weight percentage composition of the high thermal conductivity and high temperature resistant silicone thermal conductive gel; stir and mix dimethyl silicone oil, dispersant and part of modified alumina at 800 rpm for 10 minutes; add the remaining modified alumina and stir and mix at the same speed for 10 minutes; add modified zinc oxide, increase the speed to 1000 rpm, and stir and mix for 30 minutes to obtain the finished product.

[0054] Example 2

[0055] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0056] Dimethyl silicone oil 4.8%, dispersant 0.3%, modified alumina 74.4%, modified zinc oxide 20.5%.

[0057] The preparation process of modified alumina is as follows: select alumina with a particle size of 2 microns, wash and dry it with clean water; immerse the dried alumina in polysiloxane, stir and mix at 100 rpm for 40 minutes, and then let it stand for 3 hours; take out the alumina, and solidify it at 90°C to obtain modified alumina.

[0058] The preparation process of modified zinc oxide is as follows: zinc oxide with a particle size of 2 microns is selected, washed with clean water and dried; the dried zinc oxide is immersed in polysiloxane, stirred and mixed at 100 rpm for 40 minutes, and then allowed to stand for 3 hours; the zinc oxide is taken out and cured at 90°C to obtain modified zinc oxide.

[0059] The method for preparing the above-mentioned silicone thermally conductive gel comprises the following steps:

[0060] Prepare the materials according to the weight percentage composition of the high thermal conductivity and high temperature resistant silicone thermal conductive gel; stir and mix dimethyl silicone oil, dispersant and part of modified alumina at 800 rpm for 10 minutes; add the remaining modified alumina and stir and mix at the same speed for 10 minutes; add modified zinc oxide, increase the speed to 1000 rpm, and stir and mix for 30 minutes to obtain the finished product.

[0061] Example 3

[0062] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0063] Dimethyl silicone oil 4.5%, dispersant 0.3%, modified alumina 70.2%, modified zinc oxide 25%.

[0064] The preparation process of modified alumina is as follows: select alumina with a particle size of 1 micron, wash and dry it with clean water; immerse the dried alumina in polysiloxane, stir and mix at 100 rpm for 40 minutes, and then let it stand for 3 hours; take out the alumina, and solidify it at 85°C to obtain modified alumina.

[0065] The preparation process of modified zinc oxide is as follows: zinc oxide with a particle size of 1 micron is selected, washed with clean water and dried; the dried zinc oxide is immersed in polysiloxane, stirred and mixed at 100 rpm for 40 minutes, and then allowed to stand for 3 hours; the zinc oxide is taken out and solidified at 85°C to obtain modified zinc oxide.

[0066] The method for preparing the above-mentioned silicone thermally conductive gel comprises the following steps:

[0067] Prepare the materials according to the weight percentage composition of the high thermal conductivity and high temperature resistant silicone thermal conductive gel; stir and mix dimethyl silicone oil, dispersant and part of modified alumina at 800 rpm for 10 minutes; add the remaining modified alumina and stir and mix at the same speed for 10 minutes; add modified zinc oxide, increase the speed to 1000 rpm, and stir and mix for 30 minutes to obtain the finished product.

[0068] Example 4

[0069] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0070] 4.6% dimethyl silicone oil, 0.4% dispersant, 80% modified alumina, 15% modified zinc oxide.

[0071] The preparation process of modified alumina is as follows: select alumina with a particle size of 1.5 microns, wash and dry it with clean water; immerse the dried alumina in polysiloxane, stir and mix at 100 rpm for 40 minutes, and then let it stand for 3 hours; take out the alumina, and solidify it at 85°C to obtain modified alumina.

[0072] The preparation process of modified zinc oxide is as follows: zinc oxide with a particle size of 1.5 microns is selected, washed with clean water and dried; the dried zinc oxide is immersed in polysiloxane, stirred and mixed at 100 rpm for 40 minutes, and then allowed to stand for 3 hours; the zinc oxide is taken out and solidified at 90°C to obtain modified zinc oxide.

[0073] The method for preparing the above-mentioned silicone thermally conductive gel comprises the following steps:

[0074] Prepare the materials according to the weight percentage composition of the high thermal conductivity and high temperature resistant silicone thermal conductive gel; stir and mix dimethyl silicone oil, dispersant and part of modified alumina at 800 rpm for 10 minutes; add the remaining modified alumina and stir and mix at the same speed for 10 minutes; add modified zinc oxide, increase the speed to 1000 rpm, and stir and mix for 30 minutes to obtain the finished product.

[0075] Comparative Example 1

[0076] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0077] Dimethyl silicone oil 4.9%, dispersant 0.3%, aluminum oxide 74.9%, zinc oxide 19.9%.

[0078] Select aluminum oxide with a particle size of 0.5 microns, wash it with clean water, and dry it;

[0079] Select zinc oxide with a particle size of 0.5 microns, wash it with clean water, and dry it;

[0080] The remaining conditions are the same as those in Example 1.

[0081] Comparative Example 2

[0082] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0083] 3.7% dimethyl silicone oil, 0.3% dispersant, 70% modified alumina, 26% modified zinc oxide.

[0084] The remaining conditions are the same as those in Example 1.

[0085] Comparative Example 3

[0086] A high-thermal-conductivity and high-temperature-resistant organic silicon thermally conductive gel comprises the following raw materials in percentage by weight:

[0087] Dimethyl silicone oil 4.8%, dispersant 0.4%, modified alumina 94.8%.

[0088] The remaining conditions are the same as those in Example 1.

[0089] The performance of the silicone thermally conductive gel prepared in Examples 1-4 and Comparative Examples 1-3 was tested, and the test results are summarized in Table 1 below; the thermal impedance was tested by a Ruiling thermal analysis instrument under the condition of 40psi; the thermal conductivity was tested by a Xiangyi thermal conductivity tester. The thermal thickness was 5mm; the insulation voltage test condition was 1mm thick. The powdering condition was observed after the silicone thermally conductive gel was aged for 1000h at 150°C.

[0090] Table 1

[0091]

[0092] Therefore, it can be seen from Table 1 above that Comparative Example 1 shows that unmodified alumina and unmodified zinc oxide are difficult to fuse with dimethyl silicone oil. The reason is that high thermal conductivity alumina and zinc oxide have low oil absorption rates, and adding a high proportion of them to dimethyl silicone oil causes a rapid increase in viscosity and a low extrusion rate.

[0093] Comparative Example 2 shows that too much zinc oxide will reduce the life of the silicone thermal conductive gel and cause it to powderize quickly in a high temperature environment, posing a great safety hazard.

[0094] Comparative Example 3 shows that without adding zinc oxide, the life of the prepared gel is reduced and it quickly turns into powder under high temperature environment, which poses a great safety hazard.

[0095] The raw materials or reagents used in the examples and comparative examples of the present invention are all purchased from mainstream manufacturers in the market. Those without indicating the manufacturer or concentration are all analytically pure raw materials or reagents that can be routinely obtained. As long as they can play the expected role, there is no special limitation.

[0096] The instruments and equipment used in this embodiment are all purchased from major manufacturers in the market, and there is no particular limitation as long as they can play the expected role. In this embodiment, if no specific technology or conditions are specified, the technology or conditions described in the literature in this field or the product instructions are used. The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A high thermal conductivity and high temperature resistant silicone thermal conductive gel, It is characterized in that The raw materials include the following weight percentages:

2. The thermally conductive silicone gel according to claim 1, It is characterized in that The dimethyl silicone oil is dimethyl silicone oil with a volatile content of less than 0.5%.

3. The thermally conductive silicone gel according to claim 1 or 2, It is characterized in that The viscosity of the dimethyl silicone oil is 1000-1500 cps.

4. The thermally conductive silicone gel according to claim 1, It is characterized in that The dispersant is modified acrylic silicone.

5. The thermally conductive silicone gel according to claim 1, It is characterized in that The modified alumina is alumina surface-treated with polysiloxane.

6. The thermally conductive silicone gel according to claim 1, It is characterized in that The modified zinc oxide is zinc oxide surface-treated with polysiloxane.

7. The thermally conductive silicone gel according to claim 5, It is characterized in that The particle size of the aluminum oxide is 0.5-2 microns.

8. The thermally conductive silicone gel according to claim 6, It is characterized in that The particle size of the zinc oxide is 0.5-2 microns.

9. The thermally conductive silicone gel according to claim 5 or 6, It is characterized in that The chemical structural formula of the polysiloxane is:

10. A method for preparing the high thermal conductivity and high temperature resistant organic silicon thermally conductive gel according to any one of claims 1 to 9, It is characterized in that The following steps are involved: Prepare materials according to the weight percentage composition of high thermal conductivity and high temperature resistant organic silicon thermal conductive gel; Fully mix the dimethyl silicone oil, dispersant, and part of the modified alumina, and then add the remaining modified alumina and mix thoroughly; Finally, modified zinc oxide is added and mixed thoroughly to obtain the silicone thermal conductive gel.

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