Low-thermal-resistance heat-conducting gel and preparation method thereof

Abstract

The invention discloses low-thermal-resistance heat-conducting gel and a preparation method thereof, and belongs to the technical field of heat-conducting materials. The low-thermal-resistance heat-conducting gel is prepared from the following components in percentage by weight: 1 to 10 percent of vinyl silicone oil, 0.1 to 1 percent of methyl vinyl silicone rubber, 0.1 to 1 percent of hydrogen-containing silicone oil, 0.0001 to 0.01 percent of inhibitor, 0.01 to 0.1 percent of platinum catalyst, 25 to 60 percent of heat-conducting powder, 30 to 65 percent of liquid metal and 0.0001 to 0.5 percent of coupling agent. The vinyl silicone oil and the methyl vinyl silicone rubber are intertwined and cross-linked through the hydrogen-containing silicone oil to form a high-molecular-weight net-shaped structure, so that the compatibility with liquid metal can be enhanced while low-molecular-weight siloxane exudation is reduced, and the risk of leakage of the liquid metal is reduced; the powder is modified by adopting the combination of two coupling agents, so that the compatibility between the heat-conducting filler and the organic silicon polymer is improved, and meanwhile, the seepage of silicone oil is also reduced.

Description

Technical Field

[0001] The invention relates to the technical field of thermal conductive materials, and in particular to a low thermal resistance thermal conductive gel and a preparation method thereof. Background Art

[0002] With the continuous development and popularization of modern electronic equipment, the power density and integration of electronic components are constantly improving, and the heat generated by the equipment when working is also increasing. If the heat cannot be effectively dissipated, the performance and life of the equipment will be seriously affected. At present, the more commonly used thermal interface materials are mainly thermal conductive silicone grease, thermal conductive silicone gasket, thermal conductive gel, etc. Since there is no cross-linking between the internal materials of thermal conductive silicone grease, it is easy to cause oil and powder separation, and it may become dry and powdery after long-term use; thermal conductive gaskets are due to the increasing number of electronic components, the heat source of the circuit board is too concentrated, and the space between the heat sources is of different heights and shapes, the power of electronic products is getting larger and larger, and the contact surface between the gasket and the electronic component cannot completely eliminate bubbles, resulting in a large thermal resistance, which cannot meet the complex heat dissipation performance requirements; the amorphous state of thermal conductive gel can fill the heat conduction of any gap that cannot be met by the thermal conductive gasket; and the thermal conductive gel can be dispensed with automated equipment to meet the needs of automated production processes in the industrial field; but the thermal resistance is larger than that of silicone grease. As electronic components become more and more sophisticated, the thermal resistance of thermal interface materials must be as low as possible. However, silicone grease is easy to powder and dry, and a thermal interface material with high reliability and low thermal resistance is urgently needed. To this end, we propose a low thermal resistance thermal conductive gel and a preparation method to solve the above problem. Summary of the invention

[0003] Based on the problems existing in the background technology, the present invention provides a low thermal resistance thermal conductive gel and a preparation method thereof.

[0004] The present invention is implemented by the following technical solutions:

[0005] The first aspect of the present invention discloses a low thermal resistance thermal conductive gel with liquid gold enhanced thermal conductivity, which comprises the following components by weight percentage: 1-10% vinyl silicone oil, 0.1-1% methyl vinyl silicone rubber, 0.1-1% hydrogen-containing silicone oil, 0.0001-0.01% inhibitor, 0.01-0.1% platinum catalyst, 25-60% thermal conductive powder, 30-65% liquid metal, and 0.0001-0.5% coupling agent.

[0006] Furthermore, the vinyl silicone oil is a double-ended vinyl silicone oil with a viscosity of 100 to 5000 mPa.s.

[0007] Furthermore, the methyl vinyl silicone rubber is a side-end vinyl-encapsulated methyl vinyl silicone rubber with a molecular weight of 400,000 to 700,000.

[0008] Furthermore, the hydrogen-containing silicone oil is one or a combination of terminal hydrogen-containing silicone oil with a hydrogen content of 0.04 to 2% and side hydrogen-containing silicone oil with a hydrogen content of 0.04 to 2%.

[0009] Furthermore, the inhibitor contains at least one of phenylbutynol, methylbutynol, and ethynylcyclohexanol;

[0010] Furthermore, the platinum catalyst is a Custer platinum catalyst, and the platinum content is 1000-4000 ppm.

[0011] Furthermore, the thermally conductive powder comprises one or a combination of spherical aluminum powder, spherical aluminum nitride, and zinc oxide; the particle size of the spherical aluminum powder is 0.5 to 30 μm, the particle size of the spherical aluminum nitride is 0.5 to 30 μm, and the particle size of the zinc oxide is 0.1 to 1 μm.

[0012] Furthermore, the liquid metal is one or a combination of gallium-indium alloy, gallium-tin alloy, gallium-cesium alloy, tin-indium alloy, gallium-indium-tin alloy, gallium-indium-cesium alloy, and gallium-tin-cesium alloy.

[0013] Furthermore, the coupling agent is one or a combination of γ-methacryloxypropyltrimethoxysilane, dodecyltrimethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane.

[0014] The present invention also discloses a method for preparing a low thermal resistance thermal conductive gel, comprising the following steps:

[0015] Step 1, according to the raw material components, weigh the corresponding masses of vinyl silicone oil, methyl vinyl silicone rubber, hydrogen-containing silicone oil, and inhibitor, mix the above raw materials evenly, stir at a rate of 500-100 r / min, add the catalyst and continue to stir and mix evenly, continue to add liquid metal and stir, react at 125° C. to 150° C. for 2 to 5 hours, and cool to room temperature to obtain a prepolymer;

[0016] Step 2: Add the thermal conductive powder and the coupling agent into a planetary mixer according to the mass ratio, stir, place in an environment of 80-100° C., react for 2 hours, and then cool to obtain a modified thermal conductive filler;

[0017] Step 3: The prepolymer and the modified thermally conductive filler are put into a planetary mixer according to a mass ratio and stirred at room temperature to obtain a thermally conductive gel.

[0018] Beneficial effects of the present invention:

[0019] By introducing liquid metal into the gel, the liquid metal has many advantages such as high thermal conductivity, good fluidity, and easy solid-liquid phase conversion. When combined with thermally conductive fillers, the purpose of low thermal resistance can be achieved. However, due to the large surface tension of liquid metal and poor compatibility with silicone oil, it is very easy to polymerize and leak, which can easily lead to short circuits and burn hardware. The single-component uncured gel is in an amorphous state, and extrusion during use increases the risk of leakage. Therefore, how to prevent leakage is also a problem that must be solved.

[0020] Vinyl silicone oil and methyl vinyl silicone rubber are entangled with each other, and at the same time, the two are cross-linked through hydrogen-containing silicone oil to form a high molecular weight network structure, which can reduce the leakage of low molecular weight siloxanes while enhancing the compatibility with liquid metal and reducing the risk of liquid metal leakage; the powder is modified by a combination of two coupling agents, which increases the compatibility between the thermal conductive filler silicone polymer and reduces the leakage of silicone oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide further explanation of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the cross-sectional structure of the storage bin in the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the stirring paddle assembly in the present invention;

[0025] Figure 4 Schematic diagram of the structure of the variable diameter stirring blade in the present invention (cross-section of the stirring blade);

[0026] Figure 5 It is a structural schematic diagram of the blade support plate in the present invention;

[0027] Figure 6 It is a schematic diagram of the cross-sectional structure of the cleaning plate in the present invention.

[0028] In the figure: 11. stirring tank; 12. storage bin; 13. feeding pipe; 14. quantitative feeding valve; 15. outer gear ring; 16. planetary gear; 17. stirring shaft; 18. cleaning plate; 19. limit ring; 7. driving wheel; 8. driven wheel; 9. stirring motor; 21. upper fixed plate; 22. lower fixed plate; 23. fixed block; 24. blade support plate; 25. transmission shaft; 26. worm area; 27. first motor; 28. worm gear; 29. ​​first connecting rod; 31. second connecting rod; 32. stirring blade; 33. arc baffle; 34. ball; 35. elastic sleeve; 41. card plate; 42. card slot; 43. spring piece; 44. turntable; 45. dial block; 46. pressure block; 47. cam; 48. air bag; 49. pressure rod. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Example 1

[0031] 100 g of double-terminal vinyl silicone oil with a vinyl content of 0.45% and a molecular weight of 400,000, 15 g of methyl vinyl silicone rubber with a vinyl content of 0.17% and a molecular weight of 400,000, 10 g of terminal hydrogen-containing silicone oil with a hydrogen content of 0.08%, 5 g of side hydrogen-containing silicone oil with a hydrogen content of 0.08%, and 0.05 g of an inhibitor are put into a planetary mixer and stirred at a stirring speed of 800 r / min for 2 h. After stirring evenly, 0.8 g of a platinum catalyst and 1000 g of a gallium indium tin alloy are added, stirred evenly, heated to 150° C. and maintained for 2 h, and cooled to obtain a prepolymer 1;

[0032] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxy silane and dodecyl trimethoxy silane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h, and then cooled to obtain a thermal conductive filler 1;

[0033] The prepolymer 1 and the thermal conductive filler 1 were put into a planetary mixer, stirred at 100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 1.

[0034] Example 2

[0035] Put 100g of double-terminal vinyl silicone oil with a vinyl content of 400mpa.s and 0.45%, 15g of methyl vinyl silicone rubber with a molecular weight of 400,000 and a vinyl content of 0.17%, 10g of terminal hydrogen-containing silicone oil with a hydrogen content of 0.08%, 5g of side hydrogen-containing silicone oil with a hydrogen content of 0.08%, and 0.05g of inhibitor into a planetary mixer and start stirring at a stirring speed of 800r / min for 2h. After stirring evenly, add 0.8g of platinum catalyst and 2000g of gallium indium tin alloy, stir evenly, heat to 150°C for reaction for 2h, and cool to obtain prepolymer 2;

[0036] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxy silane and dodecyl trimethoxy silane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h, and then cooled to obtain a thermal conductive filler 2;

[0037] The prepolymer 2 and the thermal conductive filler 2 were put into a planetary mixer, stirred at 100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 2.

[0038] Example 3

[0039] Put 100g of double-terminal vinyl silicone oil with a vinyl content of 400mpa.s and 0.45%, 15g of methyl vinyl silicone rubber with a molecular weight of 400,000 and a vinyl content of 0.17%, 10g of terminal hydrogen-containing silicone oil with a hydrogen content of 0.08%, 5g of side hydrogen-containing silicone oil with a hydrogen content of 0.08%, and 0.05g of an inhibitor into a planetary mixer and start stirring. Stir at a stirring speed of 800r / min for 2h. After stirring evenly, add 0.8g of platinum catalyst and 3000g of gallium indium tin alloy, stir evenly, heat to 150°C and keep for 2h, and cool to obtain prepolymer 3.

[0040] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxy silane and dodecyl trimethoxy silane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h, and then cooled to obtain a thermal conductive filler 3.

[0041] The prepolymer 3 and the thermal conductive filler 3 were put into a planetary mixer, stirred at 100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 3.

[0042] Example 4

[0043] 100 g of double-terminal vinyl silicone oil with a vinyl content of 0.45% and a molecular weight of 400,000, 15 g of methyl vinyl silicone rubber with a vinyl content of 0.17% and a molecular weight of 400,000, 10 g of terminal hydrogen-containing silicone oil with a hydrogen content of 0.08%, 5 g of side hydrogen-containing silicone oil with a hydrogen content of 0.08%, and 0.05 g of an inhibitor were put into a planetary mixer and stirred at a stirring speed of 1500 r / min for 2 h. After stirring evenly, 0.8 g of a platinum catalyst and 2000 g of a gallium indium tin alloy were added, stirred evenly, heated to 150° C. and maintained for 2 h, and cooled to obtain a prepolymer 4;

[0044] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxy silane and dodecyl trimethoxy silane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h, and then cooled to obtain a thermal conductive filler 4;

[0045] The prepolymer 4 and the thermal conductive filler 4 were put into a planetary mixer, stirred at 50-100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 4.

[0046] Example 5

[0047] Put 100g of double-terminal vinyl silicone oil with a vinyl content of 400mpa.s and 0.45%, 15g of methyl vinyl silicone rubber with a molecular weight of 400,000 and a vinyl content of 0.17%, 10g of terminal hydrogen-containing silicone oil with a hydrogen content of 0.08%, 5g of side hydrogen-containing silicone oil with a hydrogen content of 0.08%, and 0.05g of an inhibitor into a planetary mixer and start stirring. Stir at a stirring speed of 100r / min for 2h. After stirring evenly, add 0.8g of platinum catalyst and 2000g of gallium indium tin alloy. Stir evenly. Heat to 150°C and keep for 2h. Cool to obtain prepolymer 5.

[0048] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxysilane and dodecyl trimethoxysilane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h. After cooling, a thermal conductive filler 5 was obtained.

[0049] The prepolymer 5 and the thermal conductive filler 5 were put into a planetary mixer, stirred at 50-100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 5.

[0050] Comparative Example 1

[0051] 100 g of double-terminal vinyl silicone oil with a vinyl content of 0.45% and a molecular weight of 400,000, 15 g of methyl vinyl silicone rubber with a molecular weight of 0.17% and a vinyl content of 0.17%, 10 g of terminal hydrogen-containing silicone oil with a hydrogen content of 0.08%, 5 g of side hydrogen-containing silicone oil with a hydrogen content of 0.08%, and 0.05 g of an inhibitor were put into a planetary mixer and stirred at a stirring speed of 800 r / min for 2 h. After stirring evenly, 0.8 g of a platinum catalyst was added, stirred evenly, the temperature was raised to 150° C. and maintained for 2 h, and the prepolymer 1-1 was obtained after cooling;

[0052] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxy silane and dodecyl trimethoxy silane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h, and then cooled to obtain a thermal conductive filler 1-1;

[0053] The prepolymer 1-1 and the thermal conductive filler 1-1 were placed in a planetary mixer, stirred at 100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 1-1.

[0054] Comparative Example 2

[0055] Put 100 g of double-terminal vinyl silicone oil with a vinyl content of 0.45% and a molecular weight of 400,000, 15 g of methyl vinyl silicone rubber with a molecular weight of 0.17% and a vinyl content of 0.17% and 0.05 g of an inhibitor into a planetary mixer and stir at a stirring speed of 800 r / min for 2 h. After stirring evenly, add 0.8 g of a platinum catalyst and 2000 g of a gallium indium tin alloy and stir evenly. Heat to 150° C. and keep for 2 h. After cooling, obtain a prepolymer 2-2.

[0056] 1000 g of 15 μm spherical aluminum powder and 5 μm spherical aluminum powder in a ratio of 7:3 and 100 g of 0.5 μm zinc oxide were added into a planetary mixer, mixed and stirred at a speed of 150 r / min for 30 min, and then 10 g of a coupling agent prepared by mixing vinyl trimethoxy silane and dodecyl trimethoxy silane in a ratio of 3:7 was added, and stirring was continued for 2 h. The temperature was raised to 100° C. and maintained for 2 h. After cooling, a thermal conductive filler 2-2 was obtained.

[0057] The prepolymer 2-2 and the thermal conductive filler 2-2 were put into a planetary mixer, stirred at 100 r / min for 2 h, and vacuumed for degassing for 1 h to obtain a thermal conductive gel 2-2.

[0058] Performance Testing

[0059] Test 1: The thermal conductivity and thermal resistance of the thermally conductive gels in each embodiment and each comparative example were tested according to ASTM D5470.

[0060] Test 2: A 30 ml American-style rubber cartridge with a 14G needle was used to extrude the rubber cartridge at an air pressure of 0.6 MPa, and the extrusion rate of the thermally conductive gel in each embodiment and comparative example was characterized by the weight of the gel per minute.

[0061] Test 3: Use a glue dispenser to make 80 mm long, 5 mm wide, and 2 mm high glue strips of each embodiment and comparative example on grid paper, and then place them in a 50°C oven for 168 hours, observe the size of the oil seepage area, and use the sum of the oil seepage distances at both ends of the long strip to judge the oil seepage performance of the thermal conductive gel.

[0062] Test 4: Use the vertical flow test fixture to place the glue in a 125℃ oven, a -40℃~125℃ hot and cold shock chamber, and a constant temperature and humidity chamber with a temperature of 85℃ and a humidity of 85%, and then take it out to observe the changes in the state of the glue for 1000 hours.

[0063] Table 1 shows the test data.

[0064] Table 1

[0065]

[0066] According to the experimental results in Table 1, it can be seen that: in the analysis of Examples 1 to 5 and Comparative Example 1, the introduction of liquid metal in Examples 1 to 5 has an obvious effect on increasing the thermal conductivity of the gel and reducing the thermal resistance. The liquid metal is wrapped into microcapsules by silicone oil through mechanical stirring. After the silicone oil reacts completely, a network structure is formed, which makes it difficult for the liquid metal to precipitate. The microcapsule-shaped liquid metal has good fluidity. When used, the extrusion between the interfaces changes the contact between the thermal conductive powder and the liquid metal from a point to a surface, thereby greatly reducing the thermal resistance. In the analysis of Examples 1, 2, and 3, when the liquid metal contains When the content is too high, gold leakage is likely to occur, and when the content is too low, the thermal resistance of the gel is relatively large; when analyzing Examples 2, 4, and 5, the higher the stirring speed, the smaller the diameter dispersion of the capsule-shaped liquid metal. When the diameter of the capsule-shaped liquid metal is too large, gold leakage is very likely to occur, and when the diameter of the capsule-shaped liquid metal is too small, the contact area with the thermal conductive powder is relatively reduced, resulting in higher thermal resistance; when analyzing Example 2 and Comparative Example 2, the vinyl silicone oil and methyl vinyl silicone rubber are not cross-linked to form a network structure, and the liquid metal is prone to gold leakage. At the same time, the free small molecule silicone oil precipitates to the interface to cause vertical flow.

[0067] Example 6

[0068] like Figure 1-Figure 6 As shown, the planetary mixer includes:

[0069] A stirring tank 11, wherein a feeding port and a discharging port are respectively arranged at the top and the bottom of the stirring tank 11;

[0070] A material storage bin 12 is provided on the upper part of the mixing tank 11, a feeding pipe 13 is connected to the top of the material storage bin 12, and the feeding pipe 13 is rotatably connected to the feeding port; a material storage cavity is provided in the material storage bin 12, and a quantitative feeding valve 14 is connected to the bottom of the material storage cavity;

[0071] The stirring driving mechanism includes a driving wheel 7, a driven wheel 8 and a stirring motor 9. The stirring motor 9 is installed at the top of the stirring tank 11. The driving wheel 7 is connected to the output shaft of the stirring motor 9. The driven wheel 8 is connected to the feeding pipe 13, and the driven wheel 8 is meshed with the driving wheel 7.

[0072] A planetary wheel stirring mechanism, which is connected to the inner wall of the stirring tank 11 and is located below the storage bin 12. The planetary wheel stirring mechanism includes an outer gear ring 15 and a plurality of planetary wheels 16. The plurality of planetary wheels 16 are meshed and connected to the inner side of the outer gear ring 15. The top of the rotating shaft of the planetary wheel 16 is rotatably connected to the bottom of the storage bin 12. The quantitative feeding valve 14 is arranged above the center of the outer gear ring 15 and is not directly facing the planetary wheel 16.

[0073] A stirring paddle assembly, wherein the stirring shaft 17 of the stirring paddle assembly is connected to the bottom end of the rotating shaft of the planetary gear 16;

[0074] The cleaning plate 18 is rotatably connected to the inner wall of the mixing tank 11 , and a limiting ring 19 is provided on the inner wall of the mixing tank 11 for guiding the cleaning plate 18 .

[0075] The working principle and beneficial effects of the above technical solution are:

[0076] When the planetary mixer is in use, the stirring motor 9 is started, and the power of the stirring motor 9 is transmitted through the driving wheel 7 and the driven wheel 8 of the stirring drive mechanism, driving the storage bin 12 to rotate; when the storage bin 12 rotates, the planetary wheel 16 is driven to rotate along the inner side of the outer gear ring 15, and the planetary wheel 16 itself will also rotate around its own axis; with the revolution and rotation of the planetary wheel 16, the stirring shaft 17 drives the stirring paddle to perform planetary motion in the stirring tank 11, which can stir the materials in the stirring tank 11 in all directions, so that the materials are fully mixed, the material components are evenly distributed, and the quality of the gel product is guaranteed. The storage cavity in the storage bin 12 can store materials, and the materials are added to the storage cavity through the feeding pipe 13; the materials are added from the storage bin 12 to the stirring tank 11, and the quantitative feeding valve 14 can accurately control the amount of materials added to ensure that the amount of materials added each time meets the predetermined ratio. When the stirring paddle is stirring the material, the material may adhere to the inner wall of the stirring tank 11. The rotation of the cleaning plate 18 can scrape off the material and re-mix it into the material to avoid material waste. At the same time, the inner wall of the stirring tank 11 is kept clean to prevent material residue from affecting the subsequent stirring process. It is better adapted to the situation of multiple stirring preparations during gel preparation and improves the accuracy of ingredients in each stage of gel product preparation.

[0077] Example 7

[0078] On the basis of the above-mentioned embodiment 6, the stirring paddle assembly includes a plurality of stirring blades with variable diameters, and the stirring blades with variable diameters include:

[0079] An upper fixed plate 21 and a lower fixed plate 22, both of which are connected to the stirring shaft 17, and are supported and connected by a fixing block 23, and an elastic protective film is connected between the upper fixed plate 21 and the lower fixed plate 22;

[0080] A blade support plate 24, the blade support plate 24 is connected to the lower fixed plate 22;

[0081] A transmission shaft 25, the transmission shaft 25 is rotatably connected to one side of the blade support plate 24, two worm sections 26 are arranged on the transmission shaft 25, one end of the transmission shaft 25 is connected to the output end of the first motor 27, and the first motor 27 is installed on the blade support plate 24;

[0082] Worm gears 28, two worm gears 28 are rotatably connected to the blade support plate 24, and the two worm gears 28 are respectively meshed with the two worm areas 26;

[0083] The connecting rod assembly includes two groups of first connecting rods 29 and second connecting rods 31, the first connecting rods 29 are hinged to the second connecting rods 31, and the other ends of the first connecting rods 29 are hinged to the blade support plate 24, wherein one group of the first connecting rods 29 is connected to the rotating shaft of the worm gear 28;

[0084] The stirring blade 32 is hinged to the other end of the second connecting rod 31 .

[0085] The working principle and beneficial effects of the above technical solution are:

[0086] The existing stirring paddle assembly has a fixed stirring range when in use, so that the size and range of the stirring vortex formed by the material are fixed. Therefore, during the stirring process, there will be a stirring dead angle between adjacent stirring paddles and between the stirring paddle and the inner wall of the stirring tank 11, and the rotation trajectory of the material is fixed, which will also lead to uneven stirring. Therefore, a plurality of variable diameter stirring blades are set on the stirring paddle assembly. When in use, the first motor 27 is started, and its output end drives the transmission shaft 25 to rotate, and the two worm areas 26 on the transmission shaft 25 are respectively meshed with the two worm gears 28 for transmission; the rotation of the worm gear 28 will drive a group of first connecting rods 29 connected to its rotating shaft to move, and the linkage assembly composed of the first connecting rod 29 and the second connecting rod 31 will be linked, which will push the stirring blade 32 to expand or retract, thereby changing the stirring radius of the stirring paddle assembly.

[0087] Through the above-mentioned structural design, the stirring radius of the stirring paddle assembly can be adjusted by driving the first motor 27; during the stirring process, the stirring program is set by the controller to control the start and stop of the first motor 27, and the stirring radius of the stirring paddle assembly is controlled. For example, the first motor 27 from top to bottom is controlled to operate in sequence, so that the stirring radius from top to bottom gradually increases or decreases, and is cyclically adjusted; the stirring radius of the stirring paddle assembly is different from top to bottom, which effectively changes the flow direction of the material. At the same time, different stirring diameters can also be suitable for materials of different viscosities and reaction stages, thereby improving the stirring effect of the material.

[0088] Example 8

[0089] On the basis of the above-mentioned embodiment 7, the stirring blade 32 is hollow, and an arc-shaped baffle 33 is slidably connected inside the stirring blade 32, and a sliding column is connected to the arc-shaped baffle 33. The sliding column passes through the outer side surface of the stirring blade 32 and is connected to the ball 34. An elastic sleeve 35 is sleeved on the sliding column, and the elastic sleeve 35 abuts between the ball 34 and the stirring blade 32.

[0090] The working principle and beneficial effects of the above technical solution are:

[0091] When the stirring shaft 17 rotates, the stirring blade 32 is driven to rotate. When scraping is required before discharging, the stirring blade 32 is unfolded to a preset position; at the same time, the stirring shaft 18 rotates at a high speed, and the ball 34 moves away from the stirring shaft 18 under the action of centrifugal force, and compresses the elastic sleeve 35 to store energy; until the ball 34 contacts and engages with the cleaning plate 18, driving the cleaning plate 18 to rotate synchronously, scraping off the material attached to the inner wall of the stirring tank 11, and achieving the effect of material cleaning; when cleaning is completed, the stirring operation stops, the stirring shaft 17 stops moving, and the cleaning plate 18 continues to move a distance under the action of inertia to separate from the ball 34, and the ball 34 is quickly reset under the action of the elastic sleeve 35.

[0092] Through the above-mentioned structural design, the cleaning plate 18 and the stirring blade 32 with a clutch arrangement are used. When the stirring blade 32 performs a stirring operation within a preset range, the rotation of the stirring shaft 18 is not hindered, thereby reducing the resistance encountered during the stirring process. Compared with the fixed cleaning plate 18 and the stirring blade 32, deformation of the stirring shaft 18 and other structures during the stirring process, which may cause the cleaning plate 18 to jam, can be avoided. The two can be connected before discharging to achieve cleaning of the inner wall of the stirring tank 11, which is more flexible.

[0093] Example 9

[0094] On the basis of the above-mentioned embodiment 8, the cleaning plate 18 comprises:

[0095] A card plate 41, the card plate 41 is rotatably connected to the groove inside the cleaning plate 18, a card slot 42 corresponding to the ball 34 is provided on the card plate 41, and an elastic protective film is connected between the card plate 41 and the cleaning plate 18;

[0096] The spring piece 43 is connected between the side of the cleaning plate 18 and the clamping plate 41, and the spring piece 43 is bent;

[0097] A rotating disk 44, which is connected to the rotating shaft of the clamping plate 41, and on which a shifting block 45 and a pressing block 46 are arranged at intervals, and the pressing block 46 is located on a side of the rotating disk 44 away from the spring sheet 43;

[0098] A cam 47, wherein the cam 47 is rotatably connected in the groove, a rotating shaft of the cam 47 is connected to an output end of the second motor, and a protruding end of the cam 47 is located on a side of the shifting block 45 close to the spring 43;

[0099] The airbag 48 is connected to the cleaning plate 18 on the side away from the spring 43, and the cleaning plate 18 on this side is provided with an oblique cleaning angle;

[0100] A pressure rod 49 is slidably connected to the cleaning plate 18 , one end of the pressure rod 49 is pressed against the air bag 49 , and the other end is set in the groove to block the pressure block 46 .

[0101] The working principle and beneficial effects of the above technical solution are:

[0102] When the ball 34 contacts the cleaning plate 18, the ball 34 is engaged in the slot 42, or slides along the spring piece 43 into the slot 42 to engage with it; the arc-shaped engaging surface is used to squeeze out the raw materials when in contact, ensuring effective transmission. The stirring blade 32 drives the card plate 41 to move, thereby driving the entire cleaning plate 18 to rotate along the inner wall of the stirring tank 11; an oblique cleaning angle is set on one side of the cleaning plate 18 structure to facilitate scraping the raw materials on the inner wall of the stirring tank 11. The scraped raw material will slide along the oblique cleaning angle to the side of the cleaning plate 18 and adhere to the airbag 48; when the cleaning is completed, the second motor is started to drive the cam 47 to rotate, and the cam 47 drives the dial block 45 to rotate the turntable 44, driving the card plate 41 to rotate in the opposite direction, and squeezing the spring sheet 43 to store energy; at the same time, the pressure rod 49 squeezes the pressure block 46, and the pressure block 46 squeezes the airbag 48, causing the expanded surface of the airbag 48 to deform accordingly; when the cam 47 is separated from the dial block 45, the pressure block 46 is reset under the elastic force of the airbag 48, and the deformation of the surface of the airbag 48 is restored, and the raw materials attached to its surface are shaken off; the card plate 41 is reset under the action of the spring sheet 43, and the raw materials attached to the spring sheet 43 are shaken off. The self-cleaning of the cleaning plate 18 and the card plate 41 is effectively realized, further reducing the waste of raw materials and improving the accuracy of the gel ratio.

[0103] Finally, it should be noted that the above-mentioned embodiments only express several implementation methods of the present invention and are not intended to limit the invention. For those skilled in the art, any modification, equivalent replacement, improvement, etc. made without departing from the concept of the present invention should be included in the protection scope of the invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A low thermal resistance thermally conductive gel, characterized in that: The invention comprises the following components by weight percentage: 1-10% vinyl silicone oil, 0.1-1% methyl vinyl silicone rubber, 0.1-1% hydrogen-containing silicone oil, 0.0001-0.01% inhibitor, 0.01-0.1% platinum catalyst, 25-60% thermal conductive powder, 30-65% liquid metal and 0.0001-0.5% coupling agent.

2. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The vinyl silicone oil is a double-ended vinyl silicone oil with a viscosity of 100 to 5000 mpa.s.

3. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The methyl vinyl silicone rubber is a side-end vinyl-encapsulated methyl vinyl silicone rubber with a molecular weight of 400,000 to 700,000.

4. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The hydrogen-containing silicone oil is one of end hydrogen-containing silicone oil with a hydrogen content of 0.04-2% and side hydrogen-containing silicone oil with a hydrogen content of 0.04-2%, or a combination of the two.

5. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The inhibitor is at least one of phenylbutynol, methylbutynol and ethynylcyclohexanol.

6. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The platinum catalyst is a Custer platinum catalyst, and the platinum content is 1000-4000ppm.

7. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The thermally conductive powder comprises one or a combination of spherical aluminum powder, spherical aluminum nitride, and zinc oxide; the particle size of the spherical aluminum powder is 0.5 to 30 μm, the particle size of the spherical aluminum nitride is 0.5 to 30 μm, and the particle size of the zinc oxide is 0.1 to 1 μm.

8. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The liquid metal is one or a combination of gallium-indium alloy, gallium-tin alloy, gallium-cesium alloy, tin-indium alloy, gallium-indium-tin alloy, gallium-indium-cesium alloy, and gallium-tin-cesium alloy.

9. The low thermal resistance thermally conductive gel according to claim 1, characterized in that: The coupling agent is one or a combination of γ-methacryloxypropyltrimethoxysilane, dodecyltrimethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

10. A method for preparing a low thermal resistance thermally conductive gel according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, according to the raw material components, weigh the corresponding masses of vinyl silicone oil, methyl vinyl silicone rubber, hydrogen-containing silicone oil, and inhibitor, mix the above raw materials evenly, stir at a rate of 500-100 r / min, add the catalyst and continue to stir and mix evenly, continue to add liquid metal and stir, react at 125° C. to 150° C. for 2 to 5 hours, and cool to room temperature to obtain a prepolymer; Step 2: Add the thermal conductive powder and the coupling agent into a planetary mixer according to the mass ratio, stir, place in an environment of 80-100° C., react for 2 hours, and then cool to obtain a modified thermal conductive filler; Step 3: The prepolymer and the modified thermally conductive filler are put into a planetary mixer according to a mass ratio and stirred at room temperature to obtain a thermally conductive gel.

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