High-reliability high-thermal-conductivity silicone grease as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of heat-conducting interface materials, and particularly relates to high-reliability high-heat-conducting silicone grease as well as a preparation method and application thereof. The high-reliability and high-thermal-conductivity silicone grease contains alkoxy silicone oil, methyl phenyl silicone oil and a thermal conductive filler in a mass ratio of 1: (0.08-0.375): (10-25), the alkoxy silicone oil has a structure as shown in a formula (1). The key point of the invention is to design and synthesize alkoxy silicone oil with a specific structure, and on this basis, the alkoxy silicone oil cooperates with the methyl phenyl silicone oil and the heat-conducting filler, so that the wettability of the high-heat-conductivity silicone grease is remarkably improved, and the reliability of the high-heat-conductivity silicone grease when the high-heat-conductivity silicone grease is applied to heat dissipation operation of electronic components is improved. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of thermal conductive interface materials, and in particular relates to a high-reliability and high-thermal conductive silicone grease and a preparation method and application thereof. Background Art

[0002] In the heat conduction of insulated gate bipolar transistors (IGBTs), heat is mainly transferred by the metal contact between the IGBT heat dissipation surface and the heat sink surface, and copper or aluminum is often used as the base material. However, due to the unevenness between the contact surfaces, there is a certain amount of air in the gap, and the thermal conductivity of air is only 0.025W / (m·K), which seriously reduces the heat conduction efficiency. If the thermal conductive material is first applied to the surface of the IGBT heat dissipation surface, under the action of assembly and screw tightening force, the air between the contact surfaces is squeezed out and the gap is filled. At this time, since the thermal conductivity of the thermal conductive material (generally between 0.8 and 4W / (m·K)) is 32 to 160 times that of air, although the main heat conduction is still completed by heat conduction between metals, it can better improve the heat transfer between the contact surfaces, reduce thermal resistance, and improve heat dissipation efficiency.

[0003] As IGBT develops towards high power and high integration, higher requirements are placed on thermal interface materials (TIM), such as low thermal resistance and long-term reliability. Thermal grease (also known as heat dissipation paste) is a paste-like thermal interface material with organic silicone as the main raw material. It can maintain a grease state at temperatures of -50 to 200°C. Because of its good surface wettability and low contact thermal resistance, it was first used as TIM in IGBT modules. However, existing thermal greases generally have problems with decreased wettability and poor reliability after 1 to 2 years of use. Therefore, the demand for high-reliability high-thermal grease is increasing rapidly. Summary of the invention

[0004] The purpose of the present invention is to provide a high-reliability and high-thermal-conductivity silicone grease and a preparation method and application thereof to address the problem that the existing thermally conductive silicone grease materials have decreased wettability and poor reliability after long-term use, so as to meet the demand for high-performance thermal interface materials (TIM).

[0005] In a first aspect, the present invention provides a high-reliability and high-thermal-conductivity silicone grease, characterized in that the high-reliability and high-thermal-conductivity silicone grease contains alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler in a mass ratio of 1:(0.08-0.375):(10-25); the alkoxy silicone oil has a structure as shown in formula (1);

[0006]

[0007] In formula (1), m is an integer of 1 to 50, n is an integer of 1 to 100, and R1, R2, R3 and R1' to R9' are each independently a C1 to C3 alkyl group.

[0008] In a preferred embodiment, the content of the alkoxy silicone oil is 40 to 60 parts by weight, the content of the methylphenyl silicone oil is 5 to 15 parts by weight, and the content of the thermal conductive filler is 600 to 1000 parts by weight.

[0009] In a preferred embodiment, the preparation method of the alkoxy silicone oil comprises: subjecting vinyl alkoxy silicone oil and pendant hydrogen-containing silicone oil to an addition reaction in the presence of a platinum catalyst to obtain the alkoxy silicone oil.

[0010] In a preferred embodiment, the amount of the vinyl alkoxy silicone oil is 5 to 20 parts by weight, the amount of the side hydrogen silicone oil is 20 to 40 parts by weight, and the amount of the platinum catalyst is 0.5 to 1 part by weight.

[0011] In a preferred embodiment, the conditions of the addition reaction include: temperature of 80-120° C. and time of 2-6 h.

[0012] In a preferred embodiment, the structural formula of the vinyl alkoxy silicone oil is CH2=CH-Si(OR1)(OR2)(OR3), wherein R1, R2, and R3 are each independently a C1-C3 alkyl group.

[0013] In a preferred embodiment, the structural formula of the side hydrogenated silicone oil is (R1'R2'R3')Si-O-[(R4'R5')Si-O] m -[(R6')(H)Si-O] n -Si(R7'R8'R9'), wherein m is an integer of 1 to 50, n is an integer of 1 to 100, and R1' to R9' are each independently a C1 to C3 alkyl group.

[0014] In a preferred embodiment, the mass proportion of hydrogen in the hydrogen-containing silicone oil is 0.05-1.5 wt %.

[0015] In a preferred embodiment, the viscosity of the side hydrogenated silicone oil at 25° C. is 50 to 500 mPa·s.

[0016] In a preferred embodiment, the viscosity of the alkoxy silicone oil at 25° C. is 50 to 500 mPa·s.

[0017] In a preferred embodiment, the methylphenyl silicone oil has a phenyl content of 4.2 to 11 mole%.

[0018] In a preferred embodiment, the thermally conductive filler is selected from at least one of metal fillers, carbon materials and inorganic thermally conductive particles.

[0019] In a preferred embodiment, the thermally conductive filler comprises spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm.

[0020] In a preferred embodiment, based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm in the thermally conductive filler account for 1 to 40 wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm in the thermally conductive filler account for 10 to 40 wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm in the thermally conductive filler account for 20 to 60 wt% of the total mass.

[0021] In a second aspect, the present invention provides a method for preparing the above-mentioned high-reliability and high-thermal-conductivity silicone grease, the preparation method comprising: mixing alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler to obtain high-reliability and high-thermal-conductivity silicone grease.

[0022] In a preferred embodiment, the mixing treatment is carried out at a temperature of 120 to 170° C. and for a time of 0.5 to 1.5 h.

[0023] In a preferred embodiment, the mixing process includes stirring under a vacuum state.

[0024] In a third aspect, the present invention also provides the application of the above-mentioned high-reliability and high-thermal-conductivity silicone grease in products with heat dissipation requirements.

[0025] The key to the present invention is to design and synthesize an alkoxy silicone oil with a specific structure, and on this basis, prepare a high thermal conductivity silicone grease with high reliability in a certain proportion with methylphenyl silicone oil and a thermal conductive filler. Due to the synergistic effect between the alkoxy silicone oil with a specific structure, the methylphenyl silicone oil and the thermal conductive filler, it is ensured that the silicone grease provided by the present invention does not overflow with small molecule silicone oil during long-term use, thereby avoiding the situation that the silicone grease is easy to dry out after working for a long time at high temperature, significantly improving the wettability of the high thermal conductivity silicone grease, thereby improving its reliability when used in the heat dissipation operation of electronic components. DETAILED DESCRIPTION

[0026] The high reliability and high thermal conductivity silicone grease provided by the present invention contains alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler. The mass ratio of the alkoxy silicone oil to the methylphenyl silicone oil is 1:(0.08-0.375), such as 1:0.08, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.375 or any value therebetween. The mass ratio of the alkoxy silicone oil to the thermal conductive filler is 1:(10-25), such as 1:10, 1:12, 1:15, 1:18, 1:20, 1:22, 1:25 or any value therebetween. The alkoxy silicone oil preferably has a structure as shown in formula (1). In formula (1), m is an integer of 1 to 50, such as 1, 5, 10, 20, 30, 40, 50 or any integer therebetween, n is an integer of 1 to 100, such as 1, 5, 10, 20, 50, 80, 100 or any integer therebetween, and R1, R2, R3, R1' to R9' are each independently a C1 to C3 alkyl group. The C1 to C3 alkyl group may be any one of a methyl group, an ethyl group, a n-propyl group, and an isopropyl group.

[0027]

[0028] In the present invention, the content of the alkoxy silicone oil is preferably 40 to 60 parts by weight, such as 40, 45, 50, 55, 60 parts by weight or any value therebetween. The content of the methylphenyl silicone oil is preferably 5 to 15 parts by weight, such as 5, 8, 10, 12, 15 parts by weight or any value therebetween. The content of the thermal conductive filler is preferably 600 to 1000 parts by weight, such as 600, 700, 800, 900, 1000 parts by weight or any value therebetween.

[0029] In the present invention, the preparation method of the alkoxy silicone oil preferably comprises: vinyl alkoxy silicone oil and side hydrogen silicone oil are subjected to addition reaction in the presence of a platinum catalyst to obtain. The amount of the vinyl alkoxy silicone oil is preferably 5 to 20 parts by weight, such as 5, 8, 10, 12, 15, 18, 20 parts by weight or any value therebetween. The amount of the side hydrogen silicone oil is preferably 20 to 40 parts by weight, such as 20, 22, 25, 28, 30, 32, 35, 38, 40 parts by weight or any value therebetween. The amount of the platinum catalyst is preferably 0.5 to 1 part by weight, such as 0.5, 0.6, 0.7, 0.8, 0.9, 1 part by weight or any value therebetween. The conditions of the addition reaction may include: the temperature is preferably 80-120°C, such as 80°C, 90°C, 100°C, 110°C, 120°C or any value therebetween; the time is preferably 2-6h, such as 2h, 3h, 4h, 5h, 6h or any value therebetween. In a specific embodiment, the preparation method of the alkoxy silicone oil is as follows: 5-20 parts by weight of vinyl alkoxy silicone oil, 20-40 parts by weight of side hydrogen silicone oil and 0.5-1 parts by weight of platinum catalyst are mixed and stirred evenly, heated to 80-120°C while stirring, reacted for 2-6h, and then cooled to room temperature to obtain an alkoxy silicone oil having a structure shown in formula (1). The platinum catalyst is preferably at least one of a platinum-vinylsiloxane catalyst, a chloroplatinic acid catalyst and a platinum-alkyne-based catalyst, and more preferably a platinum-vinylsiloxane catalyst.

[0030] In the present invention, the structural formula of the vinyl alkoxy silicone oil is CH2=CH-Si(OR1)(OR2)(OR3), wherein R1, R2, and R3 are each independently preferably a C1-C3 alkyl group. The C1-C3 alkyl group may be any one of a methyl group, an ethyl group, a n-propyl group, and an isopropyl group. Specific examples of the vinyl alkoxy silicone oil include, but are not limited to, at least one of vinyl trimethoxy silicone oil, vinyl triethoxy silicone oil, vinyl tri-n-propoxy silicone oil, and vinyl tri-isopropoxy silicone oil.

[0031] In the present invention, the structural formula of the side hydrogen silicone oil is (R1'R2'R3')Si-O-[(R4'R5')Si-O] m -[(R6')(H)Si-O] n-Si(R7'R8'R9'), wherein m is an integer of 1 to 50, n is an integer of 1 to 100, and R1' to R9' are each independently a C1 to C3 alkyl group. The mass proportion of hydrogen in the side hydrogen-containing silicone oil is preferably 0.05 to 1.5wt%, such as 0.05wt%, 0.1wt%, 0.5wt%, 1wt%, 1.2wt%, 1.5wt% or any value therebetween. The viscosity of the side hydrogen-containing silicone oil at 25°C is preferably 50 to 500mPa·s, such as 50mPa·s, 100mPa·s, 200mPa·s, 300mPa·s, 400mPa·s, 500mPa·s or any value therebetween.

[0032] In the present invention, the viscosity of the alkoxy silicone oil at 25° C. is preferably 50 to 500 mPa·s, such as 50 mPa·s, 100 mPa·s, 200 mPa·s, 300 mPa·s, 400 mPa·s, 500 mPa·s or any value therebetween. Controlling the viscosity of the alkoxy silicone oil within the above preferred range is more conducive to the application of silicone grease.

[0033] In the present invention, the phenyl content of the methylphenyl silicone oil is preferably 4.2-11 mole%, such as 4.2 mole%, 5 mole%, 6 mole%, 7 mole%, 8 mole%, 9 mole%, 10 mole%, 11 mole% or any value therebetween. Controlling the phenyl content of the methylphenyl silicone oil within the above preferred range is more conducive to controlling the thixotropy of the silicone grease, improving the stability of the system, allowing the high thermal conductivity silicone grease to maintain a high wettability, and improving its reliability when used in the heat dissipation operation of electronic components.

[0034] In the present invention, the thermally conductive filler can be a conventional choice in the art, preferably at least one of metal fillers, carbon materials and inorganic thermally conductive particles, and specific examples include but are not limited to: at least one of diamond, graphite, carbon black, aluminum oxide, aluminum nitride, zinc oxide, aluminum hydroxide, copper powder, aluminum powder, iron powder, boron nitride and silicon powder. The thermally conductive filler preferably includes spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm, and the particle size can be 0.3 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 7 μm, 10 μm, 15 μm, 20 μm or any value therebetween or any range of values ​​therebetween. More preferably, based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm in the thermally conductive filler account for 1 to 40 wt% of the total mass, and the mass proportion can be 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt% or any value therebetween; the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm in the thermally conductive filler account for 10 to 40 wt% of the total mass, The mass proportion can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt% or any value therebetween; the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm in the thermally conductive filler account for 20 to 60wt% of the total mass, and the mass proportion can be 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt% or any value therebetween.

[0035] In the present invention, the preparation method of the high-reliability high-thermal-conductivity silicone grease comprises: mixing alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler to obtain high-reliability high-thermal-conductivity silicone grease. The temperature of the mixing treatment is preferably 120-170°C, such as 120°C, 130°C, 140°C, 150°C, 160°C, 170°C or any value therebetween; the time is preferably 0.5-1.5h, such as 0.5h, 0.8h, 1h, 1.2h, 1.5h or any value therebetween. The mixing treatment preferably includes stirring under vacuum. The preparation method of the high-reliability high-thermal-conductivity silicone grease is as follows: adding alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler to a planetary mixer, stirring at room temperature for 0.5-1.5h; heating to 120-170°C, evacuating at a pressure of -0.1MPa and continuing to stir for 0.5-1.5h, and cooling to room temperature to obtain high-reliability high-thermal-conductivity silicone grease.

[0036] The present invention will be described in detail below through specific embodiments.

[0037] The parts in the following preparation examples, embodiments and comparative examples are all parts by weight.

[0038] Preparation Example 1 Alkoxy silicone oil SOM-1

[0039] 15 parts of vinyl trimethoxy silicone oil, 40 parts of hydrogenated silicone oil (purchased from Runhe, brand RH-H503, structural formula (CH3)3-Si-O-[(CH3)2Si-O] m -[(CH3)(H)Si-O] n -Si(CH3)3, with a hydrogen content of 0.05wt% and a viscosity of 50mPa·s at 25°C) and 0.7 parts of platinum (0)-1,3-diethene-1,1,3,3-tetramethyldisiloxane complex are added to a glass reactor and stirred evenly. The temperature is raised to 100°C while stirring, and the reaction is stirred for 4 hours. The temperature is then cooled to room temperature to obtain alkoxy silicone oil, named SOM-1, with a viscosity of 50mPa·s at 25°C.

[0040] Preparation Example 2 Alkoxy silicone oil SOM-2

[0041] 15 parts of vinyl trimethoxy silicone oil and 40 parts of hydrogenated silicone oil (purchased from Runhe Company, brand RH-H86, structural formula (CH3)3-Si-O-[(CH3)2Si-O] m -[(CH3)(H)Si-O] n -Si(CH3)3, with a hydrogen content of 0.09wt% and a viscosity of 100mPa·s at 25°C) and 0.7 parts of platinum (0)-1,3-diethene-1,1,3,3-tetramethyldisiloxane complex were added to a glass reactor and stirred evenly. The temperature was raised to 100°C while stirring, and the reaction was stirred for 4 hours. The temperature was then cooled to room temperature to obtain alkoxy silicone oil, named SOM-1, with a viscosity of 100mPa·s at 25°C.

[0042] Preparation Example 3 Alkoxy silicone oil SOM-3

[0043] 15 parts of vinyl trimethoxy silicone oil, 40 parts of side hydrogen silicone oil (purchased from Runhe Company, brand RH-H35, structural formula (CH3)3-Si-O-[(CH3)2Si-O] m -[(CH3)(H)Si-O] n-Si(CH3)3, with a hydrogen content of 0.13wt% and a viscosity of 130mPa·s at 25°C) and 0.7 parts of platinum (0)-1,3-diethene-1,1,3,3-tetramethyldisiloxane complex are added to a glass reactor and stirred evenly. The temperature is raised to 100°C while stirring, and the reaction is stirred for 4 hours. The temperature is then cooled to room temperature to obtain alkoxy silicone oil, named SOM-1, with a viscosity of 130mPa·s at 25°C.

[0044] Preparation Example 4 Alkoxy silicone oil SOM-4

[0045] 15 parts of vinyl trimethoxy silicone oil and 40 parts of side hydrogen silicone oil (purchased from Anbia Company, brand name AndisilXL-12, structural formula (CH3)3-Si-O-[(CH3)2Si-O] m -[(CH3)(H)Si-O] n -Si(CH3)3, with a hydrogen content of 0.11wt% and a viscosity of 500mPa·s at 25°C) and 0.7 parts of platinum (0)-1,3-diethene-1,1,3,3-tetramethyldisiloxane complex are added to a glass reactor and stirred evenly. The temperature is raised to 100°C while stirring, and the reaction is stirred for 4 hours. The temperature is then cooled to room temperature to obtain alkoxy silicone oil, named SOM-1, with a viscosity of 500mPa·s at 25°C.

[0046] Preparation Example 5 Alkoxy silicone oil SOM-5

[0047] 8 parts of vinyl triethoxy silicone oil, 20 parts of side hydrogen silicone oil (purchased from Runhe Company, brand RH-H86, structural formula (CH3)3-Si-O-[(CH3)2Si-O] m -[(CH3)(H)Si-O] n -Si(CH3)3, with a hydrogen content of 0.09wt% and a viscosity of 100mPa·s at 25°C) and 0.7 parts of chloroplatinic acid are added to a glass reactor and stirred evenly. The temperature is raised to 100°C while stirring, and the reaction is stirred for 4 hours. The temperature is then cooled to room temperature to obtain alkoxy silicone oil, named SOM-5, with a viscosity of 100mPa·s at 25°C.

[0048] Preparation Example 6 Alkoxy silicone oil SOM-6

[0049] 20 parts of vinyl triisopropoxy silicone oil and 30 parts of side hydrogen silicone oil (purchased from Runhe Company, brand RH-H86, structural formula (CH3)3-Si-O-[(CH3)2Si-O] m -[(CH3)(H)Si-O] n-Si(CH3)3, with a hydrogen content of 0.09wt% and a viscosity of 100mPa·s at 25°C) and 0.7 parts of chloroplatinic acid are added to a glass reactor and stirred evenly. The temperature is raised to 100°C while stirring, and the reaction is stirred for 4 hours. The temperature is then cooled to room temperature to obtain alkoxy silicone oil, named SOM-6, with a viscosity of 100mPa·s at 25°C.

[0050] Example 1

[0051] Add 50 parts of alkoxy silicone oil SOM-1, 10 parts of methylphenyl silicone oil (purchased from Anbia, brand AndisilSF 1208, phenyl content of 4.2 mole%), and 800 parts of thermal conductive filler into a planetary mixer and stir at room temperature for 1 hour; heat to 150°C, evacuate at -0.1 MPa pressure and continue stirring for 0.5 hours. After cooling to room temperature, thermal conductive silicone grease is obtained and divided into 1L jars.

[0052] Among them, the thermally conductive filler is aluminum oxide, including spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm; based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm account for 20wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm account for 25wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm account for 55wt% of the total mass.

[0053] Example 2

[0054] 50 parts of alkoxy silicone oil SOM-2, 10 parts of methylphenyl silicone oil (purchased from Anbia, brand AndisilSF 1208, phenyl content of 4.2 mole%), and 800 parts of thermal conductive filler are added to a planetary mixer and stirred at room temperature for 1 hour; the temperature is raised to 150°C, and after vacuuming at a pressure of -0.1 MPa, stirring is continued for 0.5 hours. After cooling to room temperature, thermal conductive silicone grease is obtained and divided into 1L jars.

[0055] Among them, the thermally conductive filler is aluminum oxide, including spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm; based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm account for 20wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm account for 25wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm account for 55wt% of the total mass.

[0056] Example 3

[0057] 50 parts of alkoxy silicone oil SOM-3, 10 parts of methylphenyl silicone oil (purchased from Anbia, brand AndisilSF 1208, phenyl content of 4.2 mole%), and 800 parts of thermal conductive filler were added to a planetary mixer and stirred at room temperature for 1 hour; the temperature was raised to 150°C, and after vacuuming at a pressure of -0.1 MPa, stirring was continued for 0.5 hours. After cooling to room temperature, thermal conductive silicone grease was obtained and divided into 1L jars.

[0058] Among them, the thermally conductive filler is aluminum oxide, including spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm; based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm account for 20wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm account for 25wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm account for 55wt% of the total mass.

[0059] Example 4

[0060] Add 50 parts of alkoxy silicone oil SOM-4, 10 parts of methylphenyl silicone oil (purchased from Anbia, brand name AndisilSF 1208, phenyl content of 4.2 mole%), and 800 parts of thermal conductive filler into a planetary mixer and stir at room temperature for 1 hour; heat to 150°C, evacuate at -0.1 MPa pressure and continue stirring for 0.5 hours. After cooling to room temperature, thermal conductive silicone grease is obtained and divided into 1L jars.

[0061] Among them, the thermally conductive filler is aluminum oxide, including spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm; based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm account for 20wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm account for 25wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm account for 55wt% of the total mass.

[0062] Example 5

[0063] 60 parts of alkoxy silicone oil SOM-5, 15 parts of methylphenyl silicone oil (purchased from Anbia, brand AndisilSF 1208, phenyl content of 4.2 mole%), and 1000 parts of thermal conductive filler were added to a planetary mixer and stirred at room temperature for 1 hour; the temperature was raised to 150°C, and after vacuuming at a pressure of -0.1 MPa, stirring was continued for 0.5 hours. After cooling to room temperature, thermal conductive silicone grease was obtained and divided into 1L jars.

[0064] Among them, the thermally conductive filler is aluminum oxide, including spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm; based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm account for 20wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm account for 25wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm account for 55wt% of the total mass.

[0065] Example 6

[0066] Add 40 parts of alkoxy silicone oil SOM-6, 5 parts of methylphenyl silicone oil (purchased from Anbia, brand Andisil SF1208, phenyl content of 4.2 mole%), and 600 parts of thermal conductive filler into a planetary mixer and stir at room temperature for 1 hour; heat to 150°C, evacuate at -0.1MPa pressure and continue stirring for 0.5h. After cooling to room temperature, thermal conductive silicone grease is obtained and divided into 1L jars.

[0067] Among them, the thermally conductive filler is aluminum oxide, including spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 20 μm; based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm account for 20wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm account for 25wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm account for 55wt% of the total mass.

[0068] Example 7

[0069] Thermally conductive silicone grease was prepared according to the method of Example 1, except that the same amount of methylphenyl silicone oil (purchased from Anbia Company, brand No. SF 1223, phenyl content of 11 mole%), and other conditions were the same as those in Example 1, thereby preparing a thermal conductive silicone grease.

[0070] Example 8

[0071] Thermally conductive silicone grease was prepared according to the method of Example 1, except that the same amount of methylphenyl silicone oil (purchased from Anbia Company, brand No. SF 1243, phenyl content of 23 mole%), and other conditions were the same as those in Example 1, thereby preparing a thermal conductive silicone grease.

[0072] Comparative Example 1

[0073] A reference thermal grease was prepared according to the method of Example 1, except that the same amount of dimethyl silicone oil (purchased from Shanghai Suoke Industrial Co., Ltd., brand PMX-200 dimethyl silicone oil 50#, viscosity at 25°C is 50 mPa·s) was used instead of alkoxy silicone oil SOM-1, and the other conditions were the same as in Example 1, thereby preparing a reference thermal grease.

[0074] Comparative Example 2

[0075] A reference thermal grease was prepared according to the method of Example 1, except that the same amount of dimethyl silicone oil (purchased from Shanghai Suokai Industrial Co., Ltd., brand PMX-200 dimethyl silicone oil 100#, viscosity at 25°C is 100 mPa·s) was used instead of alkoxy silicone oil SOM-1, and the other conditions were the same as in Example 1, thereby preparing a reference thermal grease.

[0076] Comparative Example 3

[0077] A reference thermal grease was prepared according to the method of Example 1, except that the same amount of dimethyl silicone oil (purchased from Guangzhou Laibao Silicon Materials Co., Ltd., with a brand name of 200 cst and a viscosity of 200 mPa·s at 25°C) was used instead of the alkoxy silicone oil SOM-1, and the other conditions were the same as those in Example 1, thereby preparing a reference thermal grease.

[0078] Comparative Example 4

[0079] A reference thermal grease was prepared according to the method of Example 1, except that the same amount of dimethyl silicone oil (purchased from Guangzhou Laibao Silicon Materials Co., Ltd., with a brand name of 500cst and a viscosity of 500mPa·s at 25°C) was used instead of the alkoxy silicone oil SOM-1, and the other conditions were the same as those in Example 1, thereby preparing a reference thermal grease.

[0080] Comparative Example 5

[0081] A reference thermal grease was prepared according to the method of Example 1, except that the same amount of dimethyl silicone oil (purchased from Shanghai Suoke Industrial Co., Ltd., brand PMX-200 dimethyl silicone oil 50#, viscosity at 25°C of 50 mPa·s) was used instead of methylphenyl silicone oil (purchased from Anbia, brand Andisil SF 1208, phenyl content of 4.2 mole%), and the other conditions were the same as in Example 1, thereby preparing a reference thermal grease.

[0082] Test Case

[0083] The thermally conductive silicone grease prepared in the above examples and comparative examples was tested for viscosity, thermal conductivity, oil separation performance, volatility, and wetting performance according to the following method. The results are shown in Table 1.

[0084] (1) Viscosity test: The viscosity test was carried out according to the method in GB / T2794-1995.

[0085] (2) Thermal conductivity: The thermally conductive silicone grease prepared in the above examples and comparative examples was added to a polytetrafluoroethylene mold, baked at 120° C. for 20 min, cooled to room temperature, and cut into samples with a size of 25×25×2 mm. The thermal conductivity was then tested according to ASTM-D5470.

[0086] (3) Oil-release performance: Weigh 0.2 g of silicone grease and place it on a piece of A4 paper with a thickness of 1 mm. Press it into a small circle and bake it in an oven at 150°C for 24 hours. Measure and record the distance the silicone oil diffuses.

[0087] (4) Volatilization test: Weigh 1.0g of silicone grease and apply it on an aluminum sheet. The weight is recorded as m1. Then, it is placed in an oven and baked at 150°C for 24 hours. Then, it is taken out and weighed and recorded as m2. The volatility (%) = (m1-m2) / m1*100.

[0088] (5) Wettability of silicone grease: Weigh 2.0g of silicone grease and apply it on an aluminum sheet, then bake it in an oven at 200℃ for 7 days. Then touch the silicone grease with your hand to see if it is as wet as before being placed in the oven, or if it has become dry or powdery.

[0089] Table 1

[0090]

[0091] From the results in Table 1, it can be seen that compared with Comparative Examples 1 to 5, the high thermal conductive silicone grease provided by Examples 1 to 8 of the present invention has lower oil separation performance and smaller volatility, and has good wettability. It can be seen that the high thermal conductive silicone grease provided by the present invention can maintain good wettability and has high reliability.

[0092] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A high reliability and high thermal conductivity silicone grease, characterized in that: The high-reliability and high-thermal-conductivity silicone grease contains alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler in a mass ratio of 1:(0.08-0.375):(10-25); the alkoxy silicone oil has a structure as shown in formula (1); In formula (1), m is an integer of 1 to 50, n is an integer of 1 to 100, and R1, R2, R3 and R1' to R9' are each independently a C1 to C3 alkyl group.

2. The high-reliability and high-thermal-conductivity silicone grease according to claim 1, characterized in that: The content of the alkoxy silicone oil is 40 to 60 parts by weight, the content of the methylphenyl silicone oil is 5 to 15 parts by weight, and the content of the thermal conductive filler is 600 to 1000 parts by weight.

3. The high reliability and high thermal conductivity silicone grease according to claim 1, characterized in that: The preparation method of the alkoxy silicone oil comprises: subjecting vinyl alkoxy silicone oil and side hydrogen-containing silicone oil to an addition reaction in the presence of a platinum catalyst to obtain the alkoxy silicone oil; Preferably, the amount of the vinyl alkoxy silicone oil is 5 to 20 parts by weight, the amount of the side hydrogen silicone oil is 20 to 40 parts by weight, and the amount of the platinum catalyst is 0.5 to 1 part by weight.

4. The high reliability and high thermal conductivity silicone grease according to claim 1, characterized in that: The conditions of the addition reaction include: temperature of 80 to 120° C. and time of 2 to 6 hours.

5. The high-reliability and high-thermal-conductivity silicone grease according to claim 1, characterized in that: The structural formula of the vinyl alkoxy silicone oil is CH2=CH-Si(OR1)(OR2)(OR3), wherein R1, R2, and R3 are each independently a C1-C3 alkyl group; Preferably, the structural formula of the side hydrogenated silicone oil is (R1'R2'R3')Si-O-[(R4'R5')Si-O] m -[(R6')(H)Si-O] n -Si(R7'R8'R9'), wherein m is an integer of 1 to 50, n is an integer of 1 to 100, and R1' to R9' are each independently a C1 to C3 alkyl group; Preferably, the mass proportion of hydrogen in the hydrogen-containing silicone oil is 0.05 to 1.5 wt %; Preferably, the viscosity of the hydrogenated silicone oil at 25° C. is 50 to 500 mPa·s.

6. The high-reliability and high-thermal-conductivity silicone grease according to claim 1, characterized in that: The viscosity of the alkoxy silicone oil at 25° C. is 50 to 500 mPa·s; Preferably, the methylphenyl silicone oil has a phenyl content of 4.2 to 11 mole%.

7. The high-reliability and high-thermal-conductivity silicone grease according to claim 1, characterized in that: The thermally conductive filler is selected from at least one of metal fillers, carbon materials and inorganic thermally conductive particles; Preferably, the thermally conductive filler comprises spherical and / or quasi-spherical thermally conductive particles having a particle size of 0.3 to 20 μm; Preferably, based on the total mass of the thermally conductive filler, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 0.3 to 2 μm in the thermally conductive filler account for 1 to 40 wt% of the total mass, the spherical and / or quasi-spherical thermally conductive particles with a particle size of 3 to 5 μm in the thermally conductive filler account for 10 to 40 wt% of the total mass, and the spherical and / or quasi-spherical thermally conductive particles with a particle size of 7 to 20 μm in the thermally conductive filler account for 20 to 60 wt% of the total mass.

8. The method for preparing the high-reliability and high-thermal-conductivity silicone grease according to any one of claims 1 to 7, characterized in that: The preparation method comprises: mixing alkoxy silicone oil, methylphenyl silicone oil and thermal conductive filler to obtain high-reliability and high-thermal conductive silicone grease.

9. The method for preparing high-reliability and high-thermal-conductivity silicone grease according to claim 8, characterized in that: The mixing treatment temperature is 120-170°C and the time is 0.5-1.5h; Preferably, the mixing process includes stirring under a vacuum state.

10. Use of the high-reliability and high-thermal-conductivity silicone grease according to any one of claims 1 to 7 in products with heat dissipation requirements.

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