High-thermal-conductivity silicone grease interface material composition, silicone grease interface material and preparation method therefor

Abstract

The present invention relates to the field of silicone grease interface materials. Provided are a high-thermal-conductivity silicone grease interface material composition, a silicone grease interface material and a preparation method therefor. On the basis of the composition of the present invention, by using a non-reactive silicone oil as a main silicone oil together with a thermal conductive powder and a special treating agent, a silicone grease interface material having both high thermal conductivity and a relatively low thermal resistance and also having relatively good aging resistance can be prepared. The composition comprises the following components in parts by weight: 1-20 parts, preferably 3-15 parts, of a non-reactive silicone oil; 60-98 parts, preferably 80-95 parts, of a thermal-conductive filler; 0.1-6 parts, preferably 1-4 parts, of a treating agent; and 0.01-1 parts, preferably 0.01-0.5 parts, of an auxiliary agent, wherein the treating agent at least comprises an asymmetric silicone oil, and optionally comprises an alkyl trimethoxy silane.

Description

High thermal conductivity silicone grease interface material composition, silicone grease interface material and preparation method thereof Technical Field

[0001] The present invention relates to the field of silicone grease interface materials, and in particular to a high thermal conductivity silicone grease interface material composition, a silicone grease interface material and a preparation method thereof. Background Art

[0002] With the development of science and technology and the improvement of people's living standards, electrical equipment continues to tend to be high-power and electronic components tend to be intensive, which puts higher requirements on heat dissipation.

[0003] Silicone-based thermal grease is a highly thermally conductive silicone material that does not undergo a curing reaction and can maintain its paste-like state for long periods of time at temperatures between -50°C and +230°C. It is widely used in electrical equipment at the interface between heating elements (power tubes, thyristors, electric heating piles, etc.) and heat sinks (heat sinks, heat strips, housings, etc.), effectively reducing interfacial contact thermal resistance, facilitating heat conduction and heat dissipation from the heating elements, and thus ensuring stable electrical performance in electronic instruments and meters. However, the thermal conductivity, stability, oil separation rate, and thermal resistance of thermal grease directly impact the efficient operation of the equipment.

[0004] Chinese patent CN112608480B provides a silicone thermal conductive material composition, which is a silicone thermal conductive material composition developed based on reactive silicone oil as the main silicone oil and a single alumina filler. In this solution, the silicone thermal conductive material composition includes alumina filler, decyltrimethoxysilane, vinyl-terminated silicone oil, hydrogen-containing silicone oil, inhibitor, catalyst and asymmetric silicone oil, wherein the alumina filler is a combination of spherical alumina powder, ellipsoidal alumina powder and random alumina powder, and the mass ratio of the three is 4.5-5.5:2.5-3.5:0.5-1.5. The patent proposes a solution to improve the thermal conductive material composition composed of a reactive silicone oil system and a single alumina filler. By combining specific alumina fillers and adding asymmetric silicone oil, the alumina filler and other components can be well dispersed in the reactive silicone oil system, obtaining a thermal conductive material with good thermal conductivity. For reactive silicone oil systems and single alumina thermal powder systems, because reactive silicone oil systems are inherently reactive, surface treatment of thermal fillers, especially single thermal fillers, is relatively easy, making it easy to obtain a product with good stability through the reaction system. However, for non-reactive silicone oil systems, and for thermal powder systems with more complex compositions, because neither the product preparation process nor subsequent applications involve reactions, obtaining a silicone grease interface material with good stability and overall performance for these systems will face more technical challenges. Due to these differences, the thermal material improvement solution of a reactive silicone oil system + a single thermal powder cannot be directly applied to a non-reactive silicone oil system + a system with multiple thermal powders.

[0005] For non-reactive silicone oil systems, especially for thermal grease interface material systems consisting of non-reactive silicone oil + more complex thermally conductive powders, how to provide a silicone grease interface material with excellent performance in terms of high thermal conductivity, high reliability, low thermal resistance and / or low volatility is one of the technical difficulties in this field that urgently needs to be broken through.

[0006] Summary of the Invention

[0007] The present invention provides a high thermal conductivity silicone grease interface material composition, a silicone grease interface material and a preparation method thereof. Based on the composition of the present invention, non-reactive silicone oil is used as the main component, and the silicone oil is combined with thermal conductive powder and a special treatment agent to prepare a silicone grease interface material that has both high thermal conductivity and low thermal resistance and has excellent aging resistance.

[0008] To achieve its purpose, the present invention provides the following technical solutions:

[0009] In one aspect, the present invention provides a high thermal conductivity silicone grease interface material composition, comprising the following components in parts by weight:

[0010] 1-20 parts of non-reactive silicone oil, such as 1, 3, 5, 10, 15, 20 parts, preferably 3-15 parts;

[0011] 60-98 parts of thermally conductive filler, for example 60, 65, 70, 75, 80, 85, 90, 95, 98 parts, preferably 80-95 parts;

[0012] 0.1-6 parts of the treatment agent, such as 0.1, 0.5, 1, 1.5, 2, 3, 4, 6 parts, preferably 1-4 parts;

[0013] 0.01-1 part of auxiliary agent; for example, 0.01, 0.03, 0.05, 0.1, 0.3, 0.5, 0.7, 1 part, preferably 0.01-0.5 part;

[0014] Wherein, the treating agent at least includes asymmetric silicone oil, and optionally includes alkyltrimethoxysilane.

[0015] Herein, "optionally including" means including or not including.

[0016] Furthermore, in the composition of the present invention, the asymmetric silicone oil has the following structural formula (I):

[0017] Wherein, each B independently has the following structural formula (II):

[0018] Y has the following structural formula (III):

[0019] Z in the structural formula (II) and the structural formula (III) is independently a hydrocarbylene group having 10 or less carbon atoms, such as ethylene or ethylenephenyl;

[0020] Each A is independently an aliphatic hydrocarbon group having 20 or less carbon atoms, such as methyl, ethyl, propyl, butyl or vinyl;

[0021] Each R 1 Each is independently an aliphatic hydrocarbon group or an aromatic hydrocarbon group having 4 or less carbon atoms, such as methyl, ethyl, propyl, butyl or phenyl;

[0022] R 2 is ethyl, vinyl, phenyl or trifluoropropyl;

[0023] Each R 3 are independently an aliphatic hydrocarbon group having 4 or less carbon atoms, such as methyl, ethyl, propyl or isopropyl;

[0024] Each R 4 are independently methyl, ethyl or phenyl;

[0025] In formula (II) or formula (III), r=0-2, such as 0, 1, 2, etc.; in formula (III), k=1-100, such as 5-10, 40-50, 70-80, etc.; t=1-10, such as 1-2, 6-7, etc.;

[0026] In structural formula (I), m=50-1000, for example, 50, 60, 80, 94, 95, 100, 130, 150, 160, 164, 165, 200, 400, 600, 800, 1000, etc., for example, 50-260, for example, 56-254, for example, 60-70, for example, 100-120, for example, 95-165, etc.; n=0-100, for example, 0, 5-10, 25-30, etc., p=0-100, for example, 0, 5-10, 60-70, etc., q=0-10, for example, 0, 3-5, 7-8, etc.

[0027] The inventors have discovered that by introducing the above-mentioned asymmetric silicone oil (especially the asymmetric silicone oil of structural formula (I)) as a treating agent into a thermally conductive silicone grease interface material formulation system with non-reactive silicone oil as the main silicone oil, and in a preferred embodiment, further introducing alkyltrimethoxysilane as a treating agent, and combining the non-reactive silicone oil, thermally conductive filler, treating agent and auxiliary agent according to the above-mentioned weight parts, a high thermal conductive silicone grease interface material having both high thermal conductivity and low thermal resistance and better aging resistance can be obtained.

[0028] Regarding the asymmetric silicone oil of structural formula (I) described herein, its preparation method is described in detail in Chinese patent CN112608480B. The asymmetric silicone oil of structural formula (I) used in the present invention can be prepared with reference to the preparation method disclosed in Chinese patent CN112608480B, or can also be prepared with reference to other known preparation methods.

[0029] In the composition of the present invention, the treatment agent may be solely the asymmetric silicone oil, or may be a combination of an asymmetric silicone oil and an alkyltrimethoxysilane. Preferably, the treatment agent comprises an asymmetric silicone oil and the alkyltrimethoxysilane; the number of carbon atoms of the alkyl group in the alkyltrimethoxysilane is 1-16, such as 1, 2, 4, 6, 8, 10, 12, 14, 16, etc., preferably 6-16; preferably, the mass ratio of the asymmetric silicone oil to the alkyltrimethoxysilane is 0.5:1-20:1, such as 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, 3:1, 5:1, 10:1, 15:1, 20:1, etc. The inventors have found that in the formulation system of the present invention, the use of a treatment agent composed of asymmetric silicone oil and alkyltrimethoxysilane is conducive to further obtaining a thermally conductive silicone grease with lower thermal resistance and better aging resistance, while also taking into account high thermal conductivity and relatively low viscosity.

[0030] The high-thermal-conductivity silicone grease interface material composition of the present invention is based on a non-reactive silicone oil formulation. Furthermore, the non-reactive silicone oil is preferably selected from a combination of one or more of methyl silicone oil, octyl silicone oil, phenyl silicone oil, polyether-modified silicone oil, and polydimethylsiloxane. Preferably, the polydimethylsiloxane is a cross-linked polydimethylsiloxane formed by the reaction of vinyl silicone oil and hydrogen-containing silicone oil in the presence of a catalyst. Preferably, the volatility index of the non-reactive silicone oil is ≤0.1wt% at a high temperature of 150°C. Using this preferred non-reactive silicone oil improves the low volatility of the silicone grease interface material, further enhancing its high reliability during application. In the formulation system of the present invention, the non-reactive silicone oil of the preferred structure described above is combined with a treatment agent (including at least an asymmetric silicone oil of structural formula (I), preferably also including alkyltrimethoxysilane) and other components such as a thermally conductive filler in a specific ratio. The components form a special molecular interaction force in the system, which can obtain a highly reliable high-thermal conductive silicone grease interface material with good aging resistance.

[0031] Furthermore, the thermally conductive filler is selected from one or more of a thermally conductive metal filler and a thermally conductive non-metallic filler. Preferably, the thermally conductive filler is a combination of a thermally conductive metal filler and a thermally conductive non-metallic filler. Preferably, the mass ratio of the thermally conductive metal filler to the thermally conductive non-metallic filler is 0.1:1-5:1, such as 0.1:1, 0.15:1, 0.2:1, 0.5:1, 1:1, 3:1, 5:1, etc. Based on the formulation system of the present invention, in a system where non-reactive silicone oil is the main silicone oil, by introducing a variety of different thermally conductive fillers (especially thermally conductive metal fillers + thermally conductive non-metallic fillers), it is also possible to obtain a silicone grease interface material that has both high thermal conductivity and low thermal resistance, and at the same time has better aging resistance.

[0032] In some embodiments, the thermally conductive metal filler is selected from one or more of aluminum powder, silver powder, and copper powder; the thermally conductive non-metallic filler is selected from one or more of silicon powder, zinc oxide, aluminum oxide, and aluminum nitride.

[0033] In a preferred embodiment, the thermally conductive metal filler has a particle size of 0.1-2 μm, or 10-12 μm, or is a combination of thermally conductive metal fillers having a particle size of 0.1-2 μm and a particle size of 10-12 μm. The thermally conductive non-metallic filler is a combination of one or more fillers having the following particle sizes a)-d): a) 0.1-2 μm; b) 10-20 μm; c) 40-50 μm; d) 70-80 μm. Those skilled in the art can select and use the thermally conductive metal fillers and thermally conductive non-metallic fillers of various particle sizes described above according to actual product requirements. As an example, for example, the thermal conductive filler is composed of a 0.1-2um thermal conductive metal filler and a 0.1-2um thermal conductive non-metal filler; for example, the thermal conductive filler is composed of a 0.1-2um thermal conductive metal filler, a 10-12um thermal conductive metal filler, and a 0.1-2um thermal conductive non-metal filler; for example, the thermal conductive filler is composed of a 0.1-2um thermal conductive metal filler, a 10-20um thermal conductive non-metal filler and a 0.1-2um thermal conductive non-metal filler, and the mass ratio of the three is, for example, 5-2 5:40-75:5-35; for example, the thermal conductive filler is composed of 0.1-2um thermal conductive metal filler, 0.1-2um thermal conductive non-metal filler, and 40-50um thermal conductive non-metal filler; for example, the thermal conductive filler is composed of 0.1-2um thermal conductive metal filler, 10-20um thermal conductive non-metal filler, and 40-50um thermal conductive non-metal filler; for example, the thermal conductive filler is composed of 0.1-2um thermal conductive metal filler, 10-12um thermal conductive metal filler, 0.1-2um thermal conductive non-metal filler, 10-20um thermal conductive non-metal filler, and 70-80um thermal conductive non-metal filler, etc. The above are only examples and will not be repeated one by one.

[0034] Furthermore, the additive is a high-temperature resistant additive, preferably selected from one or more of cerium oxide and phenolic substances. Preferably, the cerium oxide is nanoscale or submicron-sized, where nanoscale refers to a particle size of 10-500 nm and submicron refers to a particle size of 0.5-0.9 μm. Preferably, the phenolic substance includes one or more of di-tert-butyl-p-cresol, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, β-(4-hydroxy-3,5-di-tert-butylphenyl) propionate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. Using the preferred additive further improves the durability and weather resistance of the product in practical applications.

[0035] The present invention also provides a method for preparing a high thermal conductivity silicone grease interface material, wherein the high thermal conductivity silicone grease interface material is prepared using the composition described above, and the preparation method comprises the following steps:

[0036] (1) uniformly mixing the non-reactive silicone oil, the treatment agent and the thermally conductive filler;

[0037] (2) heating and mixing the mixture obtained in step (1) at 50-80° C. (e.g., 50° C., 60° C., 70° C., 75° C., 80° C., etc.) for the first stage, then heating and mixing at 90-130° C. (e.g., 90° C., 100° C., 110° C., 120° C., 130° C., etc.) for the second stage, and then heating and mixing at 140-180° C. (e.g., 140° C., 150° C., 160° C., 170° C., 180° C., etc.) for the third stage;

[0038] (3) Cooling the mixed material obtained in step (2), and then adding the auxiliary agent to mix, for example, mixing for 10-30 minutes, and then continuing the vacuum degassing operation after mixing.

[0039] The inventors have discovered that when preparing a high thermal conductivity silicone grease interface material based on the high thermal conductivity silicone grease interface material composition provided by the present invention (based on a non-reactive silicone oil system, especially based on a non-reactive silicone oil system + a plurality of different types of thermal conductive fillers), the other components in the composition of the present invention are combined and prepared according to the above steps, and the first stage of heating and mixing, the second stage of heating and mixing, and the third stage of heating and mixing are carried out in sequence at a specific temperature, which is conducive to the full interaction between the components. Although there is no reaction process like the reactive silicone oil system, the thermal conductive filler, especially a plurality of different types of thermal conductive fillers, can be uniformly dispersed and mixed with the components in the non-reactive silicone oil system, thereby obtaining a product with excellent stability, and a product with low thermal resistance, high thermal conductivity and excellent aging resistance.

[0040] Preferably, the temperature of the first stage heating and mixing is 70-80°C, the temperature of the second stage heating and mixing is 110-130°C, and the temperature of the third stage heating and mixing is 160-180°C; using the preferred temperature for three-stage heating and mixing is beneficial to further improve the comprehensive performance of the prepared silicone grease interface material, not only to further reduce the viscosity and thermal resistance, but also to further improve the aging resistance.

[0041] In some embodiments, in step (2), the mixing time of the first stage of heating and mixing is 20-60 minutes, the mixing time of the second stage of heating and mixing is 30-60 minutes, and the mixing time of the third stage of heating and mixing is 10-30 minutes.

[0042] Preferably, in step (2), the second stage of heating and mixing and the third stage of heating and mixing are performed under a vacuum environment.

[0043] In some embodiments, in step (3), the temperature is lowered to 20-30°C.

[0044] Preferably, in step (1), the non-reactive silicone oil and the treating agent are first mixed evenly, and then mixed evenly with the thermally conductive filler, so as to facilitate good and uniform dispersion of the components.

[0045] The present invention also provides a high thermal conductivity silicone grease interface material prepared by the preparation method described above.

[0046] The technical solution provided by the present invention has the following beneficial effects:

[0047] By adopting the solution of the present invention, a silicone grease interface material system based on non-reactive silicone oil, especially non-reactive silicone oil + multiple thermally conductive fillers, can be obtained, which has both high thermal conductivity and low thermal resistance and has better aging resistance.

[0048] The preparation method provided by the present invention is used to prepare a high thermal conductivity silicone grease interface material based on the high thermal conductivity silicone grease interface material composition provided by the present invention, and the first stage of heating mixing, the second stage of heating mixing and the third stage of heating mixing are carried out in sequence at a specific temperature, which is conducive to obtaining a product with low thermal resistance, high thermal conductivity and excellent aging resistance.

[0049] The high-thermal-conductivity silicone grease interface material provided by the present invention, through the interaction of its components and, in particular, in conjunction with the present invention's preparation process, produces a material with low volatility and high reliability. After undergoing long-term reliability testing at high temperatures, high humidity, and other conditions, no oil separation was observed. The high-thermal-conductivity silicone grease interface material provided by the present invention is particularly suitable for high-end heat dissipation applications and can meet the heat dissipation requirements of high-power devices.

[0050] The high thermal conductivity silicone grease interface material composition of the present invention can produce a silicone grease interface material with excellent reliability by rationally matching the various components. After long-term aging tests under conditions of high temperature and high humidity, hot and cold shock, and high temperature, it does not show problems such as oil separation, cracking, and falling off, and the basic physical properties change less than the initial values. DETAILED DESCRIPTION

[0051] In order to facilitate the understanding of the present invention, the present invention will be further described below in conjunction with examples. It should be understood that the following examples are only for a better understanding of the present invention and do not mean that the present invention is limited to the following examples.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The term "and / or" as may be used herein includes any and all combinations of one or more of the associated listed items. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0053] Where specific experimental steps or conditions are not specified in the examples, the corresponding conventional experimental steps or conditions in the art can be used. Reagents or instruments used without specifying the manufacturer are all commercially available conventional products.

[0054] The information of some of the testing equipment and equipment used in the following examples and comparative examples is as follows:

[0055] Stirred tank, model DPD2 / DS2, Ross (Wuxi) Equipment Co., Ltd.;

[0056] Oven, model PHH-102M, Espec Testing Instrument Co., Ltd.;

[0057] Constant temperature and humidity chamber, model GPL-2, Espec Testing Instrument Co., Ltd.

[0058] The evaluation method of aging test results is as follows:

[0059] Surface oil separation test: This refers to placing the product at a high temperature of 125°C for 72 hours and observing the oil separation on the surface;

[0060] The sag test involves evenly coating the product on a copper plate with a coating size requirement of 30 mm in diameter and 0.2 mm in thickness. The copper plate is then placed vertically and placed under different test conditions for 1000 hours. The changes in the adhesive's shape and original dimensions are observed to obtain the corresponding post-aging sag test results. Specifically, the test environment is 150°C high temperature, obtaining sag results after aging at 150°C; the test environment is a hot and cold shock aging test conducted 500 times at -40°C / 30 minutes and 125°C / 30 minutes, obtaining sag results after hot and cold shock aging; the test environment is 85°C / 85% RH for 500 hours, obtaining sag results after high temperature and high humidity aging.

[0061] Cracking after aging: This involves evenly coating the product on a copper plate with a coating size of 30 mm in diameter and 0.2 mm in thickness. The product is then placed in different test environments for 1,000 hours to observe whether the adhesive hardens or cracks. Specifically, the test environment is 150°C, resulting in cracking after aging at 150°C. The test environment involves performing a thermal shock aging test at -40°C for 30 minutes and then 125°C for 30 minutes, for a total of 1,000 cycles, to obtain cracking after thermal shock aging. The test environment is 85°C / 85% RH for 500 hours, to obtain cracking after high-temperature and high-humidity aging.

[0062] Thermal conductive filler particle size test: using a laser particle size analyzer, model 2000B, Dandong Better Instrument Co., Ltd.

[0063] Viscosity test: using a lamina viscometer, model DV2TRVCP, Brookfield, rotor 52, at 0.1 rpm, at a temperature of 25°C;

[0064] Thermal resistance test: tested using a thermal resistance meter, model LW-9389, produced by Taiwan Ruiling Technology Co., Ltd.

[0065] Thermal conductivity test: tested using a thermal conductivity meter, model TPS 2500S, HotDisk Ltd., Sweden;

[0066] Some raw material description:

[0067] Dimethyl silicone oil: Wanhua Chemical Group Co., Ltd., volatile matter at 150°C is 0.1 wt%;

[0068] Phenyl silicone oil: Wanhua Chemical Group Co., Ltd., volatile matter at 150°C is 0.1 wt%;

[0069] Hexadecyltrimethoxysilane: Hubei New Blue Sky New Materials Co., Ltd.

[0070] Hexamethyldisilazane: Hubei New Blue Sky New Materials Co., Ltd.

[0071] Methyltrimethoxysilane: Hubei New Blue Sky New Materials Co., Ltd.

[0072] The asymmetric silicone oil 1 used in Example 1 was prepared by referring to Example 6 in Chinese patent CN112608480B; the structural formula is

[0073] Asymmetric silicone oil 2 used in Example 2: The preparation process was prepared according to Example 7 in Chinese patent CN112608480B; the structural formula is

[0074] Example 1

[0075] Prepare high thermal conductivity silicone grease interface material as follows:

[0076] Step (1), 5 parts by weight of dimethyl silicone oil and 2 parts by weight of asymmetric silicone oil 1 are mixed uniformly to obtain a mixture 1;

[0077] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 15 parts by weight of aluminum powder (particle size 1 μm), 58 parts by weight of aluminum oxide (particle size 10 μm), and 20 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0078] Step (2), stirring the mixture 2 for 30 minutes under the condition that the temperature of the reactor is set to 50°C; then setting the temperature of the reactor to 90°C and setting it to a vacuum state, and continuing to stir for 30 minutes under the vacuum environment; finally setting the temperature of the reactor to 150°C and continuing to mix under the vacuum environment for 15 minutes.

[0079] Step (3), cooling the reactor of step (2) to 30° C., adding 0.05 parts of cerium oxide (particle size of 0.5 μm), stirring for 15 minutes, and then vacuum stirring for 10 minutes, and discharging to obtain a high thermal conductivity silicone grease interface material;

[0080] The product prepared in the reactor is placed in a constant temperature and humidity room (temperature between 23-25°C, humidity between 40%-60% RH), and after the product temperature stabilizes, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging are performed.

[0081] Example 2

[0082] Prepare high thermal conductivity silicone grease interface material as follows:

[0083] Step (1), 10 parts by weight of phenyl silicone oil and 1.2 parts by weight of asymmetric silicone oil 2 are first mixed uniformly to obtain a mixture 1;

[0084] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 13 parts by weight of aluminum powder (particle size 1 μm), 55 parts by weight of aluminum oxide (particle size 10 μm), and 22 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0085] Step (2), stirring the mixture 2 for 30 minutes under the condition that the temperature of the reactor is set to 50°C; then setting the temperature of the reactor to 90°C and setting it to a vacuum state, and continuing to stir for 30 minutes under the vacuum environment; finally setting the temperature of the reactor to 150°C and continuing to mix for 15 minutes under the vacuum environment.

[0086] Step (3), cooling the reactor of step (2) to 30° C., adding 0.05 parts of di-tert-butyl-p-cresol, stirring for 15 minutes, and then vacuum stirring for 10 minutes, and discharging to obtain a high thermal conductivity silicone grease interface material;

[0087] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0088] Example 3 (compared with Example 1, mixture 1 is different)

[0089] Prepare high thermal conductivity silicone grease interface material as follows:

[0090] Step (1) is carried out with reference to step (1) of Example 1, except that the preparation process of mixture 1 is as follows: 5 parts by weight of dimethyl silicone oil, 1 part by weight of asymmetric silicone oil 1 and 1 part by weight of hexadecyltrimethoxysilane are uniformly mixed to obtain mixture 1; the remaining operations of step (1) are the same as step (1) of Example 1.

[0091] Step (2) is carried out with reference to step (2) of Example 1.

[0092] Step (3) is carried out with reference to step (3) of Example 1.

[0093] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0094] Example 4 (compared with Example 2, mixture 1 is different)

[0095] Prepare high thermal conductivity silicone grease interface material as follows:

[0096] Step (1) is carried out with reference to step (1) of Example 2, except that the preparation process of mixture 1 is as follows: 10 parts by weight of phenyl silicone oil, 0.6 parts by weight of asymmetric silicone oil 2 and 0.6 parts by weight of hexadecyltrimethoxysilane are mixed uniformly to obtain mixture 1; the remaining operations of step (1) are the same as step (1) of Example 2.

[0097] Step (2) is carried out with reference to step (2) of Example 2.

[0098] Step (3) is carried out with reference to step (3) of Example 2.

[0099] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0100] Example 5 (Compared with Example 1, the mixing temperature of step (2) is different)

[0101] Prepare high thermal conductivity silicone grease interface material as follows:

[0102] Step (1) is carried out with reference to step (1) of Example 1 to obtain mixture 2.

[0103] Step (2), stirring the mixture 2 obtained in step (1) for 30 minutes under the condition that the temperature of the reactor is set to 80°C; then setting the temperature of the reactor to 120°C, setting a vacuum state, and continuing to stir for 30 minutes under the vacuum environment; finally setting the temperature of the reactor to 180°C, and continuing to mix for 15 minutes under the vacuum environment.

[0104] Step (3), cooling the reactor of step (2) to 30° C., adding 0.05 parts of cerium oxide (particle size of 0.5 μm), stirring for 15 minutes, and then vacuum stirring for 10 minutes, and discharging to obtain a high thermal conductivity silicone grease interface material;

[0105] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0106] Example 6 (Compared with Example 2, the mixing temperature in step (2) is different)

[0107] Prepare high thermal conductivity silicone grease interface material as follows:

[0108] Step (1): proceed as per step (1) of Example 2 to obtain mixture 2;

[0109] Step (2): The mixture 2 obtained in step (1) was stirred for 30 minutes under the condition that the reactor temperature was set to 80°C; then the reactor temperature was set to 120°C and set to a vacuum state, and stirring was continued for 30 minutes under the vacuum environment; finally, the reactor temperature was set to 180°C and mixing was continued for 15 minutes under the vacuum environment.

[0110] Step (3): Cool the reactor to 30° C., add 0.05 parts of di-tert-butyl-p-cresol, stir for 15 minutes, and then vacuum stir for 10 minutes to obtain a high thermal conductivity silicone grease interface material;

[0111] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0112] Example 7 (Compared with Example 3, the mixing temperature of step (2) is different)

[0113] Prepare high thermal conductivity silicone grease interface material as follows:

[0114] Step (1): proceed with reference to step (1) of Example 3 to obtain mixture 2.

[0115] Step (2): Stir the mixture 2 for 30 minutes under the condition that the temperature of the reactor is set to 80°C; then set the temperature of the reactor to 120°C and set it to a vacuum state, and continue stirring for 30 minutes under the vacuum environment; finally, set the temperature of the reactor to 180°C and continue mixing for 15 minutes under the vacuum environment.

[0116] Step (3): Cool the reactor of step (2) to 30° C., add 0.05 parts of cerium oxide (particle size 300 nm), stir for 15 minutes, and then vacuum stir for 10 minutes to obtain a high thermal conductivity silicone grease interface material;

[0117] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0118] Example 8 (Compared with Example 4, the mixing temperature of step (2) is different)

[0119] Prepare high thermal conductivity silicone grease interface material as follows:

[0120] Step (1) is carried out with reference to step (1) of Example 4 to obtain mixture 2.

[0121] Step (2), stirring the mixture 2 for 30 minutes under the condition that the reactor temperature is set to 80°C; then setting the reactor temperature to 120°C and setting it to a vacuum state, and continuing to stir for 30 minutes under the vacuum environment; finally setting the reactor temperature to 180°C and continuing to mix under the vacuum environment for 15 minutes.

[0122] Step (3), cooling the reactor to 30° C., adding 0.05 parts of di-tert-butyl-p-cresol, stirring for 15 minutes, and then vacuum stirring for 10 minutes, and discharging to obtain a high thermal conductivity silicone grease interface material.

[0123] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0124] Comparative Example 1 (compared with Example 1)

[0125] Prepare the thermal conductive silicone grease interface material as follows:

[0126] Step (1), 5 parts by weight of dimethyl silicone oil and 2 parts by weight of hexamethyldisilazane are uniformly mixed to obtain a mixture 1;

[0127] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 15 parts by weight of aluminum powder (particle size 1 μm), 58 parts by weight of aluminum oxide (particle size 10 μm), and 20 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0128] Step (2), stirring the mixture 2 for 60 minutes under the condition that the temperature of the reactor is set to 120° C.; then setting the reactor to a vacuum state and stirring for 30 minutes.

[0129] Step (3), cooling the reactor to 30°C, adding 0.05 parts of cerium oxide (particle size 0.5 μm), stirring for 15 minutes, and then vacuum stirring for 10 minutes, discharging to obtain the product;

[0130] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and the viscosity, thermal conductivity, thermal resistance, thermal aging and other tests were performed after the temperature of the product stabilized.

[0131] Comparative Example 2 (compared with Example 1)

[0132] Prepare the thermal conductive silicone grease interface material as follows:

[0133] Step (1), 5 parts by weight of dimethyl silicone oil and 2 parts by weight of methyltrimethoxysilane are mixed uniformly to obtain a mixture 1;

[0134] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 15 parts by weight of aluminum powder (particle size 1 μm), 58 parts by weight of aluminum oxide (particle size 10 μm), and 20 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0135] Step (2), stirring the mixture 2 for 60 minutes under the condition that the temperature of the reactor is set to 120° C.; then setting the reactor to a vacuum state and stirring for 30 minutes.

[0136] Step (3), cooling the reactor to 30° C., adding 0.05 parts of di-tert-butyl-p-cresol, stirring for 15 minutes, and then vacuum stirring for 10 minutes to obtain the product;

[0137] The product prepared in the reactor was placed in a constant temperature and humidity room with reference to Example 1, and after the temperature of the product stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0138] Comparative Example 3 (compared with Example 2)

[0139] Prepare the thermal conductive silicone grease interface material as follows:

[0140] Step (1), 10 parts by weight of phenyl silicone oil and 1.2 parts by weight of hexamethyldisilazane are mixed uniformly to obtain a mixture 1;

[0141] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 13 parts by weight of aluminum powder (particle size 1 μm), 55 parts by weight of aluminum oxide (particle size 10 μm), and 22 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0142] Step (2), stirring the mixture 2 for 60 minutes under the condition that the reactor temperature is set to 120° C., and then setting the reactor to a vacuum state and stirring for 30 minutes.

[0143] Step (3), cooling the reactor to 30°C, adding 0.05 parts of cerium oxide (particle size 0.5 μm), stirring for 15 minutes, and then vacuum stirring for 10 minutes, discharging to obtain the product;

[0144] The product prepared in the reactor is placed in a constant temperature and humidity room, and after the temperature of the product stabilizes, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging are performed.

[0145] Comparative Example 4 (compared with Example 2)

[0146] Prepare the thermal conductive silicone grease interface material as follows:

[0147] Step (1), 10 parts by weight of phenyl silicone oil and 1.2 parts by weight of methyltrimethoxysilane are uniformly mixed to obtain a mixture 1;

[0148] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 13 parts by weight of aluminum powder (particle size 1 μm), 55 parts by weight of aluminum oxide (particle size 10 μm), and 22 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0149] Step (2), stirring the mixture 2 for 60 minutes under the condition that the reactor temperature is set to 120° C., and then setting the reactor to a vacuum state and stirring for 30 minutes.

[0150] Step (3), cooling the reactor to 30° C., adding 0.05 parts of di-tert-butyl-p-cresol, stirring for 15 minutes, and then vacuum stirring for 10 minutes to obtain the product;

[0151] The product prepared in the reactor is placed in a constant temperature and humidity room, and after the temperature of the product stabilizes, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging are performed.

[0152] Comparative Example 5 (compared with Example 2)

[0153] Prepare high thermal conductivity silicone grease interface material as follows:

[0154] Step (1), 10 parts by weight of phenyl silicone oil and 1.2 parts by weight of asymmetric silicone oil 2 are first mixed uniformly to obtain a mixture 1;

[0155] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 13 parts by weight of aluminum powder (particle size 1 μm), 55 parts by weight of aluminum oxide (particle size 10 μm), and 22 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0156] Step (2), stirring the mixture 2 for 30 minutes under the condition that the reactor temperature is set to 110° C.; then setting the reactor temperature to 150° C. and setting it to a vacuum state, and continuing stirring under the vacuum environment for 30 minutes;

[0157] Step (3), cooling the reactor of step (2) to 30° C., adding 0.05 parts of di-tert-butyl-p-cresol, stirring for 15 minutes, and then vacuum stirring for 10 minutes, and discharging to obtain a high thermal conductivity silicone grease interface material;

[0158] The product prepared in the reactor is placed in a constant temperature and humidity room, and after the temperature of the product stabilizes, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging are performed.

[0159] Comparative Example 6 (compared with Example 1)

[0160] Prepare high thermal conductivity silicone grease interface material as follows:

[0161] Step (1), 5 parts by weight of dimethyl silicone oil, 4 parts by weight of asymmetric silicone oil and 3 parts of hexadecyltrimethoxysilane are mixed uniformly to obtain a mixture 1;

[0162] Then, a pre-mixed thermally conductive filler was added to the mixture 1 in three portions, wherein the thermally conductive filler included 15 parts by weight of aluminum powder (particle size 1 μm), 58 parts by weight of aluminum oxide (particle size 10 μm), and 20 parts by weight of zinc oxide (particle size 0.5 μm). After the thermally conductive filler was added, the mixture was mixed to obtain a mixture 2.

[0163] Step (2), stirring the mixture 2 for 30 minutes under the condition that the temperature of the reactor is set to 50°C; then setting the temperature of the reactor to 90°C and setting it to a vacuum state, and continuing to stir for 30 minutes under the vacuum environment; finally setting the temperature of the reactor to 150°C and continuing to mix under the vacuum environment for 15 minutes.

[0164] Step (3), cooling the reactor of step (2) to 30° C., adding 1 part of cerium oxide (particle size of 0.5 μm), stirring for 15 minutes, and then vacuum stirring for 10 minutes, and discharging to obtain a high thermal conductivity silicone grease interface material;

[0165] Referring to Example 1, the product prepared in the reactor was placed in a constant temperature and humidity room (temperature between 23-25°C, humidity between 40%-60% RH), and after the product temperature stabilized, performance tests such as viscosity, thermal conductivity, thermal resistance, and thermal aging were performed.

[0166] Table 1 Summary of experimental results of embodiments and comparative examples

[0167] Note: 1. The criteria for determining surface oil separation are: when the oil and powder are clearly separated on the surface of the product and the thickness of the oil layer is greater than 1mm, it is considered severe oil separation; when a slight oil layer can be slightly felt on the surface of the product but the surface oil cannot be absorbed, it is considered slight oil separation; when it is difficult to determine whether there is oil separation on the surface, but there is a difference from the initial state of the product, it is considered very slight oil separation.

[0168] 2. In Table 1, the values ​​of each vertical flow test are the dimensional changes of the tested product in the vertical direction during the vertical flow test on the copper plate surface.

[0169] From the above experimental results, it can be seen that the silicone grease interface material obtained in the embodiment of the present invention can not only obtain high thermal conductivity (≥4.0 W / m·K), but also can take into account low thermal resistance and better aging resistance.

[0170] The main difference between Example 3 and Example 1, and between Example 4 and Example 2, is that the treating agent is composed of asymmetric silicone oil and alkyltrimethoxysilane, and the resulting product has relatively lower viscosity and thermal resistance, and further improved aging resistance.

[0171] Compared with Example 1, Example 6 with Example 2, Example 7 with Example 3, and Example 8 with Example 4, the main difference lies in the different temperature conditions for the three-stage heating and mixing during the preparation process. It can be seen that Examples 5, 6, 7, and 8 use more preferred temperature conditions for the three-stage heating and mixing, which can further improve the performance of the product, have relatively lower viscosity and thermal resistance, and have more excellent aging resistance. Compared with Example 1, and Example 8 with Example 2, the treatment agent is composed of asymmetric silicone oil and alkyltrimethoxysilane, and the three-stage heating and mixing is carried out under preferred temperature conditions, which can more significantly improve product performance, more significantly reduce viscosity and thermal resistance, and more significantly improve surface oil separation and sag after aging in the aging test, and have more excellent aging resistance.

[0172] It will be readily understood that the above embodiments are merely examples for clarity of description and are not intended to limit the present invention to these examples. Those skilled in the art will readily appreciate that other variations or modifications based on the above description are possible. It is not necessary and impossible to provide an exhaustive list of all possible implementations. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A high thermal conductivity silicone grease interface material composition, It is characterized in that The composition comprises the following components in parts by weight: 1-20 parts of non-reactive silicone oil, preferably 3-15 parts; 60-98 parts of thermal conductive filler, preferably 80-95 parts; 0.1-6 parts of treatment agent, preferably 1-4 parts; 0.01-1 part of auxiliary agent, preferably 0.01-0.5 part; Wherein, the treating agent at least includes asymmetric silicone oil, and optionally includes alkyltrimethoxysilane.

2. The high thermal conductivity silicone grease interface material composition according to claim 1, It is characterized in that The asymmetric silicone oil has the following structural formula (I): Wherein, each B independently has the following structural formula (II): Y has the following structural formula (III): Z in the structural formula (II) and the structural formula (III) is independently an alkylene group having 10 or less carbon atoms, such as ethylene or ethylenephenyl; Each A is independently an aliphatic hydrocarbon group having 20 or less carbon atoms, such as methyl, ethyl, propyl, butyl or vinyl; Each R 1 Each is independently an aliphatic hydrocarbon group or an aromatic hydrocarbon group having 4 or less carbon atoms, such as methyl, ethyl, propyl, butyl or phenyl; R 2 is ethyl, vinyl, phenyl or trifluoropropyl; Each R 3 are independently an aliphatic hydrocarbon group having 4 or less carbon atoms, such as methyl, ethyl, propyl or isopropyl; Each R 4 are independently methyl, ethyl or phenyl; In the structural formula (II) or the structural formula (III), r=0-2; in the structural formula (III), k=1-100, t=1-10; In the structural formula (I), m=50-1000, n=0-100, p=0-100, q=0-10.

3. The high thermal conductivity silicone grease interface material composition according to claim 2, It is characterized in that The treating agent comprises the asymmetric silicone oil and the alkyltrimethoxysilane; The carbon number of the alkyl group in the alkyltrimethoxysilane is 1-16, preferably 6-16; Preferably, the mass ratio of the asymmetric silicone oil to the alkyltrimethoxysilane is 0.5:1-20:

1.

4. The high thermal conductivity silicone grease interface material composition according to any one of claims 1 to 3, It is characterized in that The non-reactive silicone oil is selected from a combination of one or more of methyl silicone oil, octyl silicone oil, phenyl silicone oil, polyether-modified silicone oil, and polydimethylsiloxane; preferably, the polydimethylsiloxane is prepared by reacting vinyl silicone oil and hydrogen-containing silicone oil; Preferably, the volatility index of the non-reactive silicone oil is volatile matter ≤ 0.1 wt % at a high temperature of 150°C.

5. The high thermal conductivity silicone grease interface material composition according to claim 4, It is characterized in that The thermally conductive filler is selected from one or more of a thermally conductive metal filler and a thermally conductive non-metal filler; Preferably, the thermally conductive filler is a combination of a thermally conductive metal filler and a thermally conductive non-metallic filler. Preferably, the mass ratio of the thermally conductive metal filler to the thermally conductive non-metallic filler is 0.1:1-5:

1.

6. The high thermal conductivity silicone grease interface material composition according to claim 5, It is characterized in that The thermally conductive metal filler is selected from one or more of aluminum powder, silver powder, and copper powder; The thermally conductive non-metallic filler is selected from one or more of silicon powder, zinc oxide, aluminum oxide, and aluminum nitride.

7. The high thermal conductivity silicone grease interface material composition according to claim 5 or 6, It is characterized in that The particle size of the thermally conductive metal filler is 0.1-2um, or 10-12um, or the thermally conductive metal filler is a combination of thermally conductive metal fillers with a particle size of 0.1-2um and a particle size of 10-12um; The thermally conductive non-metallic filler is composed of one or more fillers having the following particle sizes a)-d): a) Particle size is 0.1-2um; b) Particle size is 10-20um; c) Particle size is 40-50um; d) Particle size is 70-80um.

8. The high thermal conductivity silicone grease interface material composition according to any one of claims 1 to 7, It is characterized in that The auxiliary agent is selected from one or more of cerium oxide and phenolic substances. Preferably, the cerium oxide is nano-scale or submicron-scale cerium oxide; Preferably, the phenolic substance includes one or more of di-tert-butyl-p-cresol, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, β-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

9. A method for preparing a high thermal conductivity silicone grease interface material. It is characterized in that The high thermal conductivity silicone grease interface material is prepared by using the composition according to any one of claims 1 to 8, and the preparation method comprises the following steps: (1) uniformly mixing the non-reactive silicone oil, the treatment agent and the thermally conductive filler; (2) heating and mixing the mixture obtained in step (1) at 50-80° C. for the first stage, then heating and mixing at 90-130° C. for the second stage, and then heating and mixing at 140-180° C. for the third stage; (3) cooling the mixed material obtained in step (2), and then adding the auxiliary agent to mix; Preferably, the temperature of the first stage of heating and mixing is 70-80°C, the temperature of the second stage of heating and mixing is 110-130°C, and the temperature of the third stage of heating and mixing is 160-180°C; Preferably, in step (2), the mixing time of the first stage of heating and mixing is 20-60 minutes. The mixing time of the second stage of heating and mixing is 30-60 minutes, and the mixing time of the third stage of heating and mixing is 10-30 minutes; Preferably, in step (2), the second stage of heating and mixing and the third stage of heating and mixing are performed under a vacuum environment; Preferably, in step (3), the temperature is lowered to 20-30°C; Preferably, in step (1), the non-reactive silicone oil and the treating agent are first mixed evenly, and then mixed evenly with the thermally conductive filler.

10. A high thermal conductivity silicone grease interface material prepared by the preparation method according to claim 9.

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