High-thermal-conductivity silica gel and preparation method thereof

Abstract

The invention relates to the technical field of heat conduction materials, in particular to high-heat-conduction silica gel and a preparation method thereof.The heat conduction performance and the mechanical strength of the high-heat-conduction silica gel are remarkably improved by introducing heat conduction filler prepared from graphene and boron nitride and optimizing the silicon source ratio of the high-heat-conduction silica gel. The stirring equipment is optimally arranged in the preparation process of the high-thermal-conductivity silica gel, the viscosity can be reduced by heating the interior of a mixture through a heating and uniform stirring structure, the attached mixture can be scraped and stirred in the silo, a plurality of stirring positions are expanded or retracted, different positions are stirred, the mixing uniformity is enhanced, and the high-thermal-conductivity silica gel is prepared. By means of the structure, all the components are easier to disperse, uniform distribution of heat can be guaranteed, mixing uniformity is enhanced, the position of the discharging port can be adjusted to make contact with the inner wall of a mold used for loading a gel mixture through the discharging structure, the mixture flows into the mold through the inner wall of the mold, bubbles generated when the mixture enters the mold are reduced, and the product quality is improved. The preparation efficiency of the silica gel is improved.

Description

Technical Field

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

[0002] As electronic devices develop towards high power, high integration and miniaturization, the heat generated by electronic components has increased dramatically. In order to effectively solve the heat dissipation problem, thermally conductive silicone gel is usually used as a thermal interface material to transfer the heat of the heat-generating components to the radiator or heat dissipation housing.

[0003] At present, China's patent application number: CN202310481282.0 discloses a thermally conductive silicone gel and a preparation method thereof, the method comprising: mixing vinyl silicone oil and a catalyst evenly, adding end hydrogen-containing silicone oil and mixing evenly, heating treatment, and then adding a plurality of side hydrogen-containing silicone oils with different viscosities to obtain a base silicone resin after reaction; adding a coupling agent to the base silicone resin, and then adding a thermally conductive filler, stirring evenly, and then vacuuming to remove bubbles to obtain a thermally conductive silicone gel.

[0004] However, the thermal conductivity and mechanical strength of the thermal conductive silicone gel in the prior art are relatively poor when used, and in the process of producing and preparing the thermal conductive silicone gel, heat is usually only transferred from the outside to the stirring equipment to stir the material in a fixed position. The viscosity of the material inside is relatively large, and the components are not easy to disperse, which can easily affect the uniformity of mixing. After stirring, the mixture is usually directly discharged into a loaded mold. During the falling process of the mixture, more bubbles are easily squeezed into the mixture, affecting the preparation efficiency of the silicone gel. Summary of the invention

[0005] The object of the present invention is to provide a high thermal conductivity silicone gel and a preparation method thereof to solve the problems raised in the above background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: a method for preparing a high thermal conductivity silicone gel, comprising the following steps:

[0007] S1. Material preparation: tetraethoxysilane is selected as the silicon source, graphene and boron nitride mixed in a mass ratio of 3:2 are used as thermal conductive fillers, acidic catalysts and ethanol solvents;

[0008] S2. Sol formation: The silicon source and the ethanol solvent are mixed and stirred by a stirring device, and then a catalyst is slowly added, and the temperature and pH value are controlled to promote hydrolysis and polycondensation reactions to form a uniform silica sol;

[0009] S3, adding thermal conductive filler: slowly adding the pretreated thermal conductive filler into the silica sol in the stirring device, and continuing to stir to ensure uniform dispersion of the thermal conductive filler;

[0010] S4, gelation process: the outlet of the stirring device is placed in contact with the inner wall of the mold, and then the mixture in the stirring device flows into the mold through the inner wall of the mold to reduce the generation of bubbles when the mixture enters the mold, and then it is left to stand at a suitable temperature and humidity to promote the formation of gel;

[0011] S5, drying and post-processing: drying the gel with hot air to remove excess solvent to obtain high thermal conductivity silicone gel;

[0012] Among them, the stirring equipment includes a stand, a silo fixed on the top side of the stand, a heat channel pipe embedded in the inner wall of the silo, a top cover installed on the top side of the silo, a driving motor fastened to the middle side of the top cover, a heating and stirring structure connected to the bottom output end of the driving motor for heating and stirring the mixture and preventing it from burning at the heating point, and a discharge structure with an adjustable discharge port end position embedded in the bottom side of the silo, a feed inlet and an air port are provided on the top cover, and the bottom side of the heating and stirring structure is connected to the inner wall of the silo.

[0013] Preferably, the mass ratio of the silicon source to the thermal conductive filler is 10:1 to 15:1, and the volume percentage of the silicon source in the entire solution system is between 10% and 30%.

[0014] Preferably, the heating and uniform stirring structure includes an expansion and contraction stirring assembly connected to the driving motor on the middle side of the top, a slip ring fastened to the outside of the top side of the expansion and contraction stirring assembly, two cylinders rotatably arranged on the left and right sides of the top of the slip ring, a positioning cross piece fixed to the outside of the middle and upper part of the expansion and contraction stirring assembly, and an internal heat stirring assembly connected to the bottom end of the expansion and contraction stirring assembly, the outer side of the slip ring is slidingly connected to the inside of the silo, the two cylinders are rotatably connected to the left and right sides of the bottom of the top cover, three positioning cross pieces are provided and are equidistantly distributed on the outside of the bottom of the expansion and contraction stirring assembly, and the outer side of the positioning cross piece is fixed to the silo, and the internal heat stirring assembly is connected to the middle and lower side of the inside of the silo.

[0015] Preferably, the expansion and contraction stirring assembly includes a shaft connected to the driving motor at the top end, a first hemispherical gear wrapped and fixed on the upper side of the outer surface of the shaft, a bracket arranged at the bottom of the first hemispherical gear, three sliding sleeves slidably connected to the top of the three protruding rods of the bracket, a pull rod rotatably connected to the middle part of the outer side of the sliding sleeve, a connecting rod plate rotatably connected to the bottom of the pull rod, a first fan gear and a second fan gear respectively connected to the left and right sides of the rear part of the connecting rod plate, a positioning frame fixed to the middle side of the rear part of the second fan gear, a second hemispherical gear rotatably connected to the rear part of the top side of the positioning frame, and a stirring rod fixed through the middle side of the interior of the second hemispherical gear, the shaft rod passes through and rotates in the middle side of the interior of the bracket, and the bottom end of the shaft rod is connected to the internal heat stirring assembly, the outer side of the bottom of the bracket is fixed to the positioning cross plate, the top side of the sliding sleeve is fastened to the slip ring plate, the rear side of the first fan gear is fixed to the bracket, and the right side of the first fan gear is meshed with the second fan gear, and the top side of the outer surface of the stirring rod passes through and rotates on the inner side of the rear of the positioning frame.

[0016] Preferably, the pull rod, the connecting rod piece, the first sector gear, the second sector gear, the positioning frame, the second hemispherical gear and the stirring rod are each provided in three groups, and the three groups are equidistantly distributed on the outside of the bracket.

[0017] Preferably, the internal heat stirring assembly includes a connecting frame fixedly connected to the bottom side of the outer surface of the shaft rod, and C-shaped sleeve blocks are locked and installed on the left and right sides of the bottom of the connecting frame. The two C-shaped sleeve blocks respectively wrap and slide on the left and right sides of the outer surface of the annular electric heating ring, and a supporting frame is fixedly connected to the inner side of the annular electric heating ring, and the middle side of the top of the supporting frame is rotatably connected to the shaft rod, an electric heating cylinder is installed at the bottom of the supporting frame, and the bottom of the electric heating cylinder is fastened to the silo, and scrapers are slidably arranged on the left and right sides of the electric heating cylinder, and a cross is fixedly connected to the middle and lower sides of the inside of the two scrapers, and the outer sides of the two C-shaped sleeve blocks are respectively connected to the two scrapers through cross bars, and the bottom and outer sides of the scrapers are respectively in contact with the bottom side and side walls of the silo.

[0018] Preferably, the discharging structure includes an upper support tube connected to the silo tube on the top side, a first motor fastened to the lower left side of the upper support tube, a rotating rod connected to the output end of the first motor, a lower support tube fastened to the bottom side of the rotating rod, and a nozzle assembly fixedly connected to the bottom side of the lower support tube, the rotating rod is installed at 45 degrees, and the top side of the rotating rod passes through and rotates inside the upper support tube.

[0019] Preferably, a disc is obliquely provided at the bottom of the upper support tube and the top of the lower support tube, the two discs are rotatably connected to each other, and a sealing ring is provided inside the connection between the two discs.

[0020] Preferably, the nozzle assembly includes a first barrel cover fixed to the top and the lower support barrel, a second motor fastened to the lower left side of the outer surface of the first barrel cover, a first moving gear connected to the bottom output end of the second motor, a first gear ring meshing and transmitting to the right side of the first moving gear, a second barrel cover fixed through the inner side of the first gear ring, a third motor fastened to the lower left side of the outer surface of the second barrel cover, a second moving gear connected to the bottom output end of the third motor, a second gear ring meshing and transmitting to the right side of the second moving gear, and a conical bottom barrel cover fixed through the inner side of the second gear ring, the second barrel cover is wrapped and rotated on the bottom side of the outer surface of the first barrel cover, the bottom side of the second barrel cover and the top side of the conical bottom barrel cover are both inclined, and the third motor is vertically arranged to the second gear ring, and the conical bottom barrel cover is wrapped and rotated on the bottom side of the outer surface of the second barrel cover.

[0021] In addition, the present invention also provides a high thermal conductivity silicone gel, which is prepared by using the above-mentioned preparation method of the high thermal conductivity silicone gel.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The high thermal conductivity silicone gel of the present invention significantly improves its thermal conductivity and mechanical strength by introducing thermal conductive fillers made of graphene and boron nitride and optimizing the silicon source ratio. In addition, a stirring device is optimally set during the preparation of the high thermal conductivity silicone gel. The mixture can be heated inside to reduce the viscosity through a heating and uniform stirring structure. The attached mixture can be scraped off and stirred inside the silo, and multiple stirring points can be expanded or retracted. Stirring at different positions can enhance the mixing uniformity, making it easier to disperse the components, ensuring uniform heat distribution, and enhancing the mixing uniformity. The discharge port can be adjusted to contact the inner wall of a mold for loading the gel mixture through a discharge structure, so that the mixture passes through the inner wall of the mold to flow into the mold, reducing the generation of bubbles when the mixture enters the mold, thereby improving the preparation efficiency of the silicone gel.

[0024] The present invention drives the sliding sleeve to change its height position on the bracket when the slip ring plate shifts longitudinally, so that the pull rod drives the second sector gear to rotate on the first sector gear through cooperation with the connecting rod plate, thereby rotating and changing the position of the positioning frame, and moving the second hemispherical gear on the surface of the first sector gear, thereby changing the direction and position angle of the stirring rod, and the pull rod, connecting rod plate, first sector gear, second sector gear, positioning frame, second hemispherical gear and stirring rod are all provided in three groups, and the mixture in the silo is stirred at multiple positions to improve the stirring efficiency.

[0025] The present invention discloses an upper support tube with a disc obliquely provided at the bottom and a lower support tube with a disc at the top. The two discs are rotatably connected to each other, and a sealing ring is provided inside the connection of the two discs to improve the sealing performance. The lower support tube can be rotated at the bottom of the upper support tube. The maximum range of rotation is such that a 90-degree angle is formed between the lower support tube and the upper support tube, thereby changing the orientation of the lower support tube. The cone-bottom tube cover is rotated in the direction of the inclined surface on the bottom side of the second tube cover to adjust and change the position angle of the bottom end of the cone-bottom tube cover, thereby moving the bottom end of the cone-bottom tube cover to contact the inner wall of the mold loaded with gel, thereby reducing the amount of excessive air squeezed into the mold when the mixture enters the mold, thereby reducing the generation of bubbles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the stirring device of the present invention;

[0027] Figure 2 For the present invention Figure 1 The front view of the connection between the middle silo and the discharge structure;

[0028] Figure 3 This is a schematic diagram of the structure of the heating and stirring structure of the present invention;

[0029] Figure 4 It is a schematic diagram of the structure of the expansion and contraction stirring assembly of the present invention;

[0030] Figure 5 It is a schematic diagram of the structure of the internal heat stirring component of the present invention;

[0031] Figure 6 It is a structural schematic diagram of the discharging structure of the present invention;

[0032] Figure 7 It is a schematic structural diagram of the nozzle assembly of the present invention.

[0033] In the figure: stand 1, silo 2, hot channel tube 3, top cover 4, drive motor 5, heating and stirring structure 6, discharging structure 7, expansion and contraction stirring component 61, sliding ring plate 62, cylinder 63, positioning cross plate 64, internal heat stirring component 65, shaft 611, first hemispherical gear 612, bracket 613, sliding sleeve 614, pull rod 615, connecting rod plate 616, first sector gear 617, second sector gear 618, positioning frame 619, second hemispherical gear 6110, stirring rod 6111, connecting frame 651, C-shaped sleeve block -652, annular electric heating ring -653, supporting frame -654, electric heating tube -655, scraper frame -656, cross -657, cross bar -658, upper support tube -71, first motor -72, rotating rod -73, lower support tube -74, nozzle assembly -75, sealing ring -721, first tube cover -751, second motor -752, first moving gear -753, first gear ring -754, second tube cover -755, third motor -756, second moving gear -757, second gear ring -758, cone bottom tube cover -759. DETAILED DESCRIPTION

[0034] In order to further explain the technical solution of the present invention, it is described in detail below through specific embodiments.

[0035] The present invention provides a method for preparing a high thermal conductivity silicone gel, comprising the following steps:

[0036] S1. Material preparation: tetraethoxysilane is selected as the silicon source, graphene and boron nitride mixed in a mass ratio of 3:2 as thermal conductive filler, an acidic catalyst and an ethanol solvent, wherein the acidic catalyst is hydrochloric acid with a concentration of 1M, and the amount of hydrochloric acid added is 0.5% of the mass of tetraethoxysilane, and the amount of ethanol solvent used is 1:1 of the mass of the silicon source;

[0037] S2. Sol formation: Mix the silicon source and the ethanol solvent by stirring with a stirring device, then slowly add the catalyst, control the temperature at 40 degrees, the pH value at 5, promote the hydrolysis and polycondensation reaction, and form a uniform silica sol. When the pH value in the reaction mixture needs to be adjusted, add hydrochloric acid dropwise to lower the pH, or add sodium hydroxide solution to increase the pH, and use pH test paper or pH meter to monitor the pH value to ensure that it is within the required range;

[0038] S3, adding thermal conductive filler: slowly adding the pretreated thermal conductive filler into the silica sol in the stirring device, and continuing to stir to ensure uniform dispersion of the thermal conductive filler;

[0039] S4, gelation process: the outlet of the stirring device is placed in contact with the inner wall of the mold, and then the mixture in the stirring device flows into the mold through the inner wall of the mold to reduce the generation of bubbles when the mixture enters the mold, and then it is left to stand at a suitable temperature and humidity to promote the formation of gel;

[0040] S5, drying and post-processing: drying the gel with hot air to remove excess solvent to obtain high thermal conductivity silicone gel;

[0041] The mass ratio of the silicon source to the thermal conductive filler is 10:1, and the concentration of the silicon source is 20% by volume.

[0042] See also Figure 1 , Figure 2 and Figure 3 The present invention provides a method for preparing high thermal conductive silicone gel. The stirring equipment includes a stand 1, a silo 2 that penetrates and is fixed to the top side of the stand 1, a heat channel pipe 3 embedded in the inner wall of the silo 2, and a flowing heating liquid or hot steam is discharged into the heat channel pipe 3 to transfer heat to the inside of the silo 2 to provide temperature for the preparation of thermal conductive silicone gel, a top cover 4 installed on the top side of the silo 2, a driving motor 5 fastened to the middle side of the top of the top cover 4, a heating and stirring structure 6 connected to the bottom output end of the driving motor 5 for heating and stirring the mixture and preventing it from burning at the heating position, and a discharge port end position embedded in the bottom side of the silo 2. The adjustable discharging structure 7 is provided with a feeding port and an air port on the top cover 4, so as to facilitate the addition of materials into the interior of the silo 2 for heating and stirring to prepare the high thermal conductivity silicone gel. The bottom side of the heating and stirring structure 6 is connected to the inner wall of the silo 2. By heating inside the mixture, the viscosity can be reduced, making it easier to disperse the components, and ensuring uniform heat distribution, thereby enhancing mixing uniformity. The discharging structure 7 can adjust the position of the discharging port to contact the inner wall of the mold used to load the gel mixture, so that the mixture can flow into the mold through the inner wall of the mold, thereby reducing the generation of bubbles when the mixture enters the mold, thereby improving the preparation efficiency of the silicone gel.

[0043] See also Figure 3 , Figure 4 and Figure 5The present invention provides a method for preparing a high thermal conductive silicone gel. The heating and uniform stirring structure 6 includes an expansion and contraction stirring assembly 61 connected to a driving motor 5 at the middle side of the top, so that the expansion and contraction stirring assembly 61 is driven to rotate by the driving motor 5 to stir. A slip ring 62 is fastened to the outside of the top side of the expansion and contraction stirring assembly 61, two cylinders 63 are respectively arranged on the left and right sides of the top of the slip ring 62, a positioning transverse piece 64 is fixed to the outer side of the middle and upper part of the expansion and contraction stirring assembly 61, and an internal heat stirring assembly 65 is connected to the bottom end of the expansion and contraction stirring assembly 61. Under the action of the cylinder 63, the slip ring 62 drives the expansion and contraction stirring assembly 61 to move so as to expand or retract multiple stirring places inside, thereby During stirring, stirring can be performed at different positions to enhance mixing uniformity. The outer side of the sliding ring 62 is slidably connected to the inside of the silo 2. Two cylinders 63 are rotatably connected to the left and right sides of the bottom of the top cover 4, so that the sliding ring 62 can stably perform longitudinal displacement in the silo 2. Three positioning transverse plates 64 are provided and are evenly distributed on the outer side of the bottom of the expansion and contraction stirring component 61, and the outer side of the positioning transverse plates 64 is fixed to the silo 2 to support and position the bottom of the expansion and contraction stirring component 61 through the positioning transverse plates 64. The internal heat stirring component 65 is connected to the lower middle side of the silo 2 so as to heat the mixture inside, and the mixture at the heated position can be scraped to prevent burning and affect the quality of the gel.

[0044] The expansion and contraction stirring assembly 61 includes a shaft 611 connected to the driving motor 5 at the top end, a first hemispherical gear 612 wrapped and fixed on the upper side of the outer surface of the shaft 611, and a bracket 613 arranged at the bottom of the first hemispherical gear 612, so that the shaft 611 drives the first hemispherical gear 612 to rotate on the bracket 613 through the driving motor 5, three sliding sleeves 614 slidably connected to the top of the three protruding rods of the bracket 613, a pull rod 615 rotatably connected to the middle part of the outer side of the slide sleeve 614, a connecting rod piece 616 rotatably connected to the bottom of the pull rod 615, and a connecting rod piece 616 respectively connected to the connecting rod piece 616. The first sector gear 617 and the second sector gear 618 on the left and right sides of the rear part, the positioning frame 619 fixed to the middle side of the rear part of the second sector gear 618, the second hemispherical gear 6110 rotatably connected to the rear part of the top side of the positioning frame 619, and the stirring rod 6111 passing through and fixed to the middle side of the second hemispherical gear 6110, the shaft rod 611 passes through and rotates in the middle side of the bracket 613, and the bottom end of the shaft rod 611 is connected to the internal heat stirring component 65, the bracket 613 limits the shaft rod 611 to ensure the stability of the movement of the internal heat stirring component 65 driven by the shaft rod 611, and the bottom end of the bracket 613 The outer side of the first sector gear 617 is fixed to the positioning transverse plate 64, the top side of the sliding sleeve 614 is fastened to the slip ring 62, the rear side of the first sector gear 617 is fixed to the bracket 613, and the right side of the first sector gear 617 is meshed with the second sector gear 618, so that when the slip ring 62 is longitudinally displaced, the sliding sleeve 614 is driven to change its height position on the bracket 613, so that the pull rod 615 drives the second sector gear 618 to rotate on the first sector gear 617 through the cooperation with the connecting rod 616, so that the position of the positioning frame 619 is rotated and changed, so that the second hemispherical gear 6110 is on the first sector gear 6 17 moves the surface position, thereby changing the direction, position and angle of the stirring rod 6111. The top side of the outer surface of the stirring rod 6111 penetrates and rotates on the inner side of the rear part of the positioning frame 619, which plays a positioning role and ensures the stability of the rotation of the stirring rod 6111. The pull rod 615, the connecting rod piece 616, the first sector gear 617, the second sector gear 618, the positioning frame 619, the second hemispherical gear 6110 and the stirring rod 6111 are all arranged in three groups, and the three groups are equidistantly distributed on the outside of the bracket 613, so as to stir the mixture in the silo 2 at multiple positions, so that each component is easier to disperse and the stirring efficiency is improved.

[0045] The internal heat stirring assembly 65 includes a connecting frame 651 fixedly connected to the bottom side of the outer surface of the shaft 611, so that the connecting frame 651 rotates with the shaft 611, and C-shaped sleeves 652 are locked and installed on the left and right sides of the bottom of the connecting frame 651. The two C-shaped sleeves 652 respectively wrap and slide on the left and right sides of the outer surface of the annular electric heating ring 653. Under the action of the connecting frame 651, the C-shaped sleeves 652 rotate on the surface of the annular electric heating ring 653, so as to scrape the mixture close to the surface of the annular electric heating ring 653 to prevent the mixture from sticking for a long time and causing it to burn. A supporting frame 654 is fixedly connected to the inner side of the annular electric heating ring 653, and the middle side of the top of the supporting frame 654 is rotatably connected to the shaft 611, so as to support the shaft 611 and the annular electric heating ring 653 through the supporting frame 654. 53 plays a supporting role. An electric heating cylinder 655 is installed at the bottom of the carrier frame 654, and the bottom of the electric heating cylinder 655 is fastened to the silo 2. Scrapers 656 are slidably arranged on the left and right sides of the electric heating cylinder 655. A cross 657 is fixedly connected to the middle and lower sides of the two scrapers 656, and the top side of the cross 657 is connected to the C-shaped sleeve 652. The outer sides of the two C-shaped sleeves 652 are respectively connected to the two scrapers 656 through cross bars 658. The bottom and outer sides of the scrapers 656 are respectively in contact with the bottom side and side wall of the silo 2, so that when the C-shaped sleeve 652 rotates, the scrapers 656 are driven to rotate on the outer surface of the electric heating cylinder 655 and the inner wall of the silo 2 through the cross 657 and the cross bar 658, so as to fully scrape and stir the mixture and improve the uniformity of material mixing.

[0046] See also Figure 2 , Figure 6 and Figure 7 The present invention provides a method for preparing high thermal conductive silicone gel. The discharging structure 7 includes an upper support tube 71 connected to the silo 2 at the top side, a first motor 72 fastened to the lower left side of the upper support tube 71, a rotating rod 73 connected to the output end of the first motor 72, a lower support tube 74 fastened to the bottom side of the rotating rod 73, and a nozzle assembly 75 fixedly connected to the bottom side of the lower support tube 74. Under the action of the first motor 72, the rotating rod 73 drives the lower support tube 74 to rotate at the bottom of the upper support tube 71. The rotating rod 73 It is installed at a 45-degree angle, and the top side of the rotating rod 73 passes through and rotates inside the upper support tube 71. Discs are obliquely opened at the bottom of the upper support tube 71 and the top of the lower support tube 74. The two discs are rotatably connected to each other, and a sealing ring 721 is provided inside the connection between the two discs to improve the sealing performance and allow the lower support tube 74 to rotate at the bottom of the upper support tube 71. The maximum range of rotation is to form a 90-degree angle between the lower support tube 74 and the upper support tube 71, thereby changing the orientation of the lower support tube 74.

[0047] Among them, the nozzle assembly 75 includes a first barrel cover 751 fixed to the top and the lower support barrel 74, a second motor 752 fastened to the lower left side of the outer surface of the first barrel cover 751, a first movable gear 753 connected to the bottom output end of the second motor 752, a first gear ring 754 meshing and transmitting to the right side of the first movable gear 753, and a second barrel cover 755 that passes through and is fixed on the inner side of the first gear ring 754. The second barrel cover 755 is wrapped and rotated on the bottom side of the outer surface of the first barrel cover 751. Under the action of the second motor 752, the first movable gear 753 drives the second barrel cover 755 to rotate to the bottom position of the first barrel cover 751 through the cooperation with the first gear ring 754. The third motor 756 is fastened to the lower left side of the outer surface of the second barrel cover 755, a second movable gear 757 connected to the bottom output end of the third motor 756, and a first movable gear 757 meshing and transmitting to the right side of the second movable gear 757. The second gear ring 758 on the side and the cone-bottom cylinder cover 759 that passes through and is fixed on the inner side of the second gear ring 758, the cone-bottom cylinder cover 759 is wrapped and rotated on the bottom side of the outer surface of the second cylinder cover 755, and the second movable gear 757 drives the cone-bottom cylinder cover 759 to rotate at the bottom position of the second cylinder cover 755 through the cooperation with the second gear ring 758 under the action of the third motor 756, the bottom side of the second cylinder cover 755 and the top side of the cone-bottom cylinder cover 759 are both inclined, and the third motor 756 is vertically arranged to the second gear ring 758, so that the cone-bottom cylinder cover 759 can rotate in the direction of the inclined surface at the bottom side of the second cylinder cover 755, and the position angle of the bottom end of the cone-bottom cylinder cover 759 is adjusted and changed, so that the bottom end of the cone-bottom cylinder cover 759 can be moved to contact the inner wall of the mold loaded with gel, and then the gel mixture is discharged into the mold, thereby reducing the generation of bubbles when the mixture enters the mold.

[0048] In addition, the present invention also provides a high thermal conductivity silicone gel, which is prepared by the above-mentioned preparation method of high thermal conductivity silicone gel, and its thermal conductivity and mechanical strength are significantly improved by introducing thermal conductive fillers prepared by graphene and boron nitride and optimizing the silicon source ratio.

[0049] The working principle of the stirring device used in the method for preparing high thermal conductivity silicone gel of the present invention is as follows:

[0050] First, add silicon source and ethanol solvent into the silo 2, circulate heating liquid or hot steam inside the heat channel tube 3 to transfer heat to the inside of the silo 2, and start the annular electric heating ring 653 and the electric heating cylinder 655 to directly heat the material inside the silo 2;

[0051] Second, start the driving motor 5 to rotate the shaft 611, and the shaft 611 drives the first hemispherical gear 612 to rotate on the bracket 613, so that the first hemispherical gear 612 drives the three second sector gears 618 to rotate on the positioning frame 619, so that the three stirring rods 6111 rotate inside the silo 2 to stir the material, and while the shaft 611 rotates, the connecting frame 651 rotates with the shaft 611, and under the action of the connecting frame 651, the C-shaped sleeve 652 rotates on the surface of the annular electric heating ring 653, so that the mixture close to the surface of the annular electric heating ring 653 is scraped, and when the C-shaped sleeve 652 rotates, the scraper frame 656 is driven to rotate on the outer surface of the electric heating tube 655 and the inner wall of the silo 2 through the cross 657 and the cross bar 658, so as to The mixture is fully scraped and stirred to improve the uniformity of material mixing and prevent the mixture from sticking for a long time and becoming burnt. During the stirring process, the two cylinders 63 can be controlled to start pushing downward and pulling upward. Under the action of the cylinder 63, the sliding ring 62 drives the sliding sleeve 614 to change the height position on the bracket 613, so that the pull rod 615 drives the second sector gear 618 to rotate on the first sector gear 617 through the cooperation with the connecting rod 616, so that the position of the positioning frame 619 is rotated and changed, and the second hemispherical gear 6110 moves on the surface of the first sector gear 617, thereby changing the direction and position angle of the stirring rod 6111, so as to stir the mixture in the silo 2 at multiple positions, so that each component is easier to disperse;

[0052] Third, while the silicon source and the ethanol solvent are stirred and mixed, the catalyst is slowly added, the temperature and pH value are controlled, and the hydrolysis and polycondensation reactions are promoted to form a uniform silica sol in the silo 2, and then the thermal conductive filler is slowly added to the silica sol in the stirring device, and stirring is continued to ensure uniform dispersion of the thermal conductive filler;

[0053] Fourth, when the mixing preparation is completed and the mixture needs to be discharged into the mold, the mold is first placed under the silo 2, and then the first motor 72, the second motor 752 and the third motor 756 are controlled to start. Under the action of the first motor 72, the rotating rod 73 drives the lower support tube 74 to rotate at the bottom of the upper support tube 71. The maximum rotation range forms a 90-degree angle between the lower support tube 74 and the upper support tube 71. Then, under the action of the second motor 752, the first movable gear 753 drives the second tube cover 755 to rotate at the bottom of the first tube cover 751 through cooperation with the first gear ring 754. Under the action of the third motor 756, the second movable gear 757 drives the cone-bottom tube cover 759 to rotate at the bottom of the second tube cover 755 through cooperation with the second gear ring 758. The position angle of the bottom end of the cone-bottom tube cover 759 is adjusted and changed so that the bottom end of the cone-bottom tube cover 759 moves and contacts the inner wall of the mold loaded with gel, and then the gel mixture is discharged into the mold to reduce the generation of bubbles when the mixture enters the mold.

[0054] The above description is only a preferred example of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a high thermal conductivity silicone gel, characterized in that: The preparation method comprises the following steps: S1. Material preparation: tetraethoxysilane is selected as the silicon source, graphene and boron nitride mixed in a mass ratio of 3:2 are used as thermal conductive fillers, acidic catalysts and ethanol solvents; S2. Sol formation: The silicon source and the ethanol solvent are mixed and stirred by a stirring device, and then a catalyst is slowly added, and the temperature and pH value are controlled to promote hydrolysis and polycondensation reactions to form a uniform silica sol; S3, adding thermal conductive filler: slowly adding the pretreated thermal conductive filler into the silica sol in the stirring device, and continuing to stir to ensure uniform dispersion of the thermal conductive filler; S4, gelation process: the outlet of the stirring device is placed in contact with the inner wall of the mold, and then the mixture in the stirring device flows into the mold through the inner wall of the mold to reduce the generation of bubbles when the mixture enters the mold, and then it is left to stand at a suitable temperature and humidity to promote the formation of gel; S5, drying and post-processing: drying the gel with hot air to remove excess solvent to obtain high thermal conductivity silicone gel; The stirring device comprises a frame (1), a silo (2) penetrating and fixed to the top side of the frame (1), a heat channel pipe (3) embedded in the inner wall of the silo (2), a top cover (4) installed on the top side of the silo (2), a driving motor (5) fastened to the middle side of the top of the top cover (4), a heating and stirring structure (6) connected to the bottom output end of the driving motor (5) for heating and stirring the mixture and preventing it from burning at the heating point, and a discharge structure (7) embedded in the bottom side of the silo (2) with an adjustable discharge port end position, wherein the top cover (4) is provided with a feed port and an air port, and the bottom side of the heating and stirring structure (6) is connected to the inner wall of the silo (2).

2. The method for preparing a high thermal conductivity silicone gel according to claim 1, characterized in that: The mass ratio of the silicon source to the thermal conductive filler is 10:1 to 15:1, and the volume percentage of the silicon source in the entire solution system is between 10% and 30%.

3. The method for preparing a high thermal conductivity silicone gel according to claim 1, characterized in that: The heating and uniform stirring structure (6) comprises an expansion and contraction stirring assembly (61) connected to the driving motor (5) at the middle side of the top, a slip ring (62) fastened to the outside of the top side of the expansion and contraction stirring assembly (61), two cylinders (63) rotatably arranged on the left and right sides of the top of the slip ring (62), a positioning transverse piece (64) fixed to the outside of the middle and upper part of the expansion and contraction stirring assembly (61), and an internal heat stirring assembly (65) connected to the bottom end of the expansion and contraction stirring assembly (61), the outside of the slip ring (62) is slidably connected to the inside of the silo (2), the two cylinders (63) are rotatably connected to the left and right sides of the bottom of the top cover (4), three positioning transverse pieces (64) are arranged and equidistantly distributed on the outside of the bottom of the expansion and contraction stirring assembly (61), and the outside of the positioning transverse piece (64) is fixed to the silo (2), and the internal heat stirring assembly (65) is connected to the middle and lower side of the inside of the silo (2).

4. The method for preparing a high thermal conductivity silicone gel according to claim 3, characterized in that: The expansion and contraction stirring assembly (61) comprises a shaft (611) whose top end is connected to the driving motor (5), a first hemispherical gear (612) wrapped and fixed on the upper side of the outer surface of the shaft (611), a bracket (613) arranged at the bottom of the first hemispherical gear (612), three sliding sleeves (614) slidably connected to the top of three protruding rods of the bracket (613), a pull rod (615) rotatably connected to the middle part of the outer side of the sliding sleeve (614), a connecting rod plate (616) rotatably connected to the bottom of the pull rod (615), a first sector gear (617) and a second sector gear (618) respectively connected to the left and right sides of the rear part of the connecting rod plate (616), a positioning frame (619) fixed to the middle side of the rear part of the second sector gear (618), and a positioning frame (619) rotatably connected to the positioning frame (619). A second hemispherical gear (6110) is provided at the rear of the top side of the positioning frame (619), and a stirring rod (6111) is passed through and fixed to the middle side of the second hemispherical gear (6110), the shaft rod (611) is passed through and rotated on the middle side of the interior of the bracket (613), and the bottom end of the shaft rod (611) is connected to the internal heat stirring component (65), the bottom outer side of the bracket (613) is fixed to the positioning transverse plate (64), the top side of the sliding sleeve (614) is fastened to the sliding ring plate (62), the rear side of the first sector gear (617) is fixed to the bracket (613), and the right side of the first sector gear (617) is meshed with the second sector gear (618), and the top side of the outer surface of the stirring rod (6111) is passed through and rotated on the inner side of the rear part of the positioning frame (619).

5. The method for preparing a high thermal conductivity silicone gel according to claim 4, characterized in that: The pull rod (615), the connecting rod sheet (616), the first sector gear (617), the second sector gear (618), the positioning frame (619), the second hemispherical gear (6110) and the stirring rod (6111) are all provided in three groups, and the three groups are equidistantly distributed outside the bracket (613).

6. The method for preparing a high thermal conductivity silicone gel according to claim 4, characterized in that: The internal heat stirring assembly (65) comprises a connecting frame (651) fixedly connected to the bottom side of the outer surface of the shaft (611), and C-shaped sleeves (652) are locked and installed on both the left and right sides of the bottom of the connecting frame (651), and the two C-shaped sleeves (652) are respectively wrapped and slid on the left and right sides of the outer surface of the annular electric heating ring (653), and the inner side of the annular electric heating ring (653) is fixedly connected to a supporting frame (654), and the middle side of the top of the supporting frame (654) is rotatably connected to the shaft (611), and the supporting frame (654) is connected to the shaft (611). 54) An electric heating tube (655) is installed at the bottom, and the bottom of the electric heating tube (655) is fastened to the silo (2), and scrapers (656) are slidably arranged on the left and right sides of the electric heating tube (655), and a cross (657) is fixedly connected to the middle and lower sides of the two scrapers (656), and the outer sides of the two C-shaped sleeves (652) are respectively connected to the two scrapers (656) through a cross bar (658), and the bottom and outer sides of the scrapers (656) are respectively in contact with the bottom side and side wall of the silo (2).

7. The method for preparing a high thermal conductivity silicone gel according to claim 1, characterized in that: The discharging structure (7) comprises an upper support tube (71) whose top side is connected to the silo (2), a first motor (72) fastened to the lower left side of the upper support tube (71), a rotating rod (73) connected to the output end of the first motor (72), a lower support tube (74) fastened to the bottom side of the rotating rod (73), and a nozzle assembly (75) fixedly connected to the bottom side of the lower support tube (74), wherein the rotating rod (73) is installed at a 45-degree angle, and the top side of the rotating rod (73) passes through and rotates inside the upper support tube (71).

8. The method for preparing a high thermal conductivity silicone gel according to claim 7, characterized in that: The bottom of the upper support tube (71) and the top of the lower support tube (74) are both provided with discs inclined thereon, the two discs are rotatably connected to each other, and a sealing ring (721) is provided inside the connection between the two discs.

9. The method for preparing a high thermal conductivity silicone gel according to claim 7, characterized in that: The nozzle assembly (75) comprises a first barrel cover (751) whose top is fixed to the lower support barrel (74), a second motor (752) fastened to the lower left side of the outer surface of the first barrel cover (751), a first moving gear (753) connected to the output end of the bottom of the second motor (752), a first gear ring (754) meshingly driven on the right side of the first moving gear (753), a second barrel cover (755) penetrating and fixed on the inner side of the first gear ring (754), a third motor (756) fastened to the lower left side of the outer surface of the second barrel cover (755), and a first gear ring (754) connected to the bottom of the third motor (756). A second moving gear (757) at the output end of the first cylinder cover (751), a second gear ring (758) meshingly transmitted with the right side of the second moving gear (757), and a conical bottom cylinder cover (759) penetrating and fixed on the inner side of the second gear ring (758), the second cylinder cover (755) wraps and rotates on the bottom side of the outer surface of the first cylinder cover (751), the bottom side of the second cylinder cover (755) and the top side of the conical bottom cylinder cover (759) are both inclined, and the third motor (756) is vertically arranged with the second gear ring (758), and the conical bottom cylinder cover (759) wraps and rotates on the bottom side of the outer surface of the second cylinder cover (755).

10. A high thermal conductivity silicone gel, characterized in that: The high thermal conductivity silicone gel is prepared by the preparation method of any one of claims 1 to 9.

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