Preparation method of a highly insulating thermal conductive gasket

Abstract

The present invention discloses a preparation method of a highly insulating thermal conductive gasket, comprising the following steps: S1: Prepare the raw materials for preparation; S2: Prepare the equipment for preparation; S3: Prepare the thermal conductive particles; S4: Surface treatment of the thermal conductive particles; S5: Two-roll mixing; S6: Flat vulcanization; S7: Secondary vulcanization; S8: Prepare the release film; S9: Stick the prepared release film on the front and back of the gasket, and then it can be packaged for use. The preparation method of the highly insulating thermal conductive gasket described in the present invention has the advantages of visual distinguishability and high temperature resistance during use through the adhered blue release film. At the same time, the finished product is softer and more flexible, has a larger addition amount in the material, and has a lower cost. During use, the thermal conductivity increases rapidly, and the subsequent thermal conductivity can also be improved. When the material combines with the thermal conductive particles, their connection will be tighter, reducing the thermal resistance caused by voids, improving the dispersibility, and thus increasing the thermal conductivity.

Description

Technical Field

[0001] The present invention relates to the field of preparation of thermal conductive gaskets, and particularly to a method for preparing a highly insulating thermal conductive gasket. Background Art

[0002] Thermal conductive gaskets are used to fill the air gap between heat-generating devices and heat sinks or metal bases. Their flexible and elastic characteristics enable them to be used to cover very uneven surfaces. Heat is conducted from the separated devices or the entire PCB to the metal casing or diffusion plate, thereby improving the efficiency and service life of heat-generating electronic components. In the use of gaskets, pressure and temperature restrict each other. As the temperature rises, after the device operates for a period of time, the gasket material undergoes softening, creep, and stress relaxation phenomena, and the mechanical strength also decreases, and the sealing pressure drops. Most of the existing thermal conductive gaskets are attached with transparent release films, which are not easy to peel off during use, inconvenient for visual distinction, and have low heat resistance. At the same time, the manufacturing process of existing thermal conductive gaskets is numerous, and the production cost is also high. Summary of the Invention

[0003] The main object of the present invention is to provide a method for preparing a highly insulating thermal conductive gasket, which can effectively solve the problems in the background art.

[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A method for preparing a highly insulating thermal conductive gasket, comprising the following operating steps:

[0006] S1: Prepare the raw materials for preparation: including methyl vinyl silicone rubber, bis(2,5)-sulfurizing agent, AB two-component addition-curing liquid silicone rubber, spherical alumina particles, silicon carbide particles, aluminate coupling agent, silane coupling agent, absolute ethanol, and hydroxyl silicone oil;

[0007] S2: Prepare the equipment and instruments for preparation: mechanical stirrer, three-necked flask, oven, two-roll mill, mold, flat vulcanizer, hydraulic press, muffle furnace;

[0008] S3: Preparation of thermal conductive particles: Place the AB two-component addition-curing liquid silicone rubber, spherical alumina particles, and silicon carbide particles into a mechanical stirrer in sequence for stirring and mixing treatment, and make thermal conductive particles after mixing, and place them for standby;

[0009] S4: Surface treatment of thermal conductive particles: Add the silane coupling agent to absolute ethanol, in a three-necked flask, stir mechanically for a period of time to make it fully dispersed, then add the thermal conductive particles, stir while ultrasonic oscillating for about 30 minutes, filter the treated thermal conductive particles, and put them into an oven at 60 degrees for drying and standby after filtration. The drying time shall not exceed 15 minutes;

[0010] S5: Two-roll mixing: First, clean the rollers with a solvent, rotate and adjust the pitch. Put the vinyl silicone rubber base into the open mill and plasticize it five times. Then, sequentially add the bis(2,5)-sulfurizing agent, hydroxy silicone oil, and heat-conducting particles for mixing. The mixing times are at least five times until the material becomes a thin sheet and then take off the sheet.

[0011] S6: Plate vulcanization: Put the mixed product into a mold and hot-press it into shape in a plate vulcanizer at a temperature of 170 °C, a pressure of 10 MPa, relieve the pressure three times, and then hold the pressure for 10 min to press out a product with uniform thickness.

[0012] S7: Secondary vulcanization: Put the product into a muffle furnace, gradually heat it from room temperature to 220 °C, and then cool it with the furnace to complete the preparation of the gasket.

[0013] S8: Preparation of the release film: Prepare HDPE, PVC, PP, PS, and PE, put them into a mechanical stirrer for stirring. After stirring and mixing evenly, put them into the inner cavity of an extruder for plasticizing and extruding, and perform steps such as forming a tube blank by blow molding, cooling and traction, and coiling. Use the flat extrusion up-blowing method for the forming process. Use a right-angle die head, that is, the die head discharge direction is perpendicular to the extruder, the extruded tube ring is upward, and after being pulled to a certain distance, it is clamped by a herringbone plate. The extruded tube is blown into a bubble tube by the compressed air introduced from the bottom, and its transverse dimension is controlled by the amount of compressed air, and its longitudinal dimension is controlled by the traction speed. The bubble tube can obtain a blown film after cooling and shaping. During the preparation, dye it, put blue dye into it so that it becomes blue after shaping.

[0014] S9: Stick the prepared release film on the front and back of the gasket, and then it can be packaged for use.

[0015] Preferably, the density of the AB two-component addition-curing liquid silicone rubber after vulcanization is 0.95 g / cm3. The density of the spherical alumina particles is 3.8 g / cm3, the average particle size is 40 μm, 10 μm, and the purity is 99.9%. The density of the silicon carbide particles is 3.2 g / cm3, the average particle size is 80 μm, 40 μm, 2 μm, and the purity is 99.9%. There are two types of silane coupling agents, and the models are KH-550 and KH-570 respectively.

[0016] Preferably, the ratio of the silane coupling agents KH-550 and KH-570 to anhydrous ethanol is 1:100.

[0017] Preferably, the proportion of the methyl vinyl silicone rubber is 50 - 60 parts, the proportion of the bis(2,5) - vulcanizing agent is 1 - 4 parts, the proportion of the AB two - component addition - type liquid silicone rubber is 20 - 35 parts, the proportion of the spherical alumina particles is 15 - 18 parts, the proportion of the silicon carbide particles is 5 - 9 parts, the proportion of the aluminate coupling agent is 3 - 7 parts, the proportion of the absolute ethanol is 10 - 13 parts, and the proportion of the hydroxyl silicone oil is 1 - 4 parts.

[0018] Preferably, the proportion of the methyl vinyl silicone rubber is 55 parts, the proportion of the bis(2,5) - vulcanizing agent is 2 parts, the proportion of the AB two - component addition - type liquid silicone rubber is 30 parts, the proportion of the spherical alumina particles is 15 parts, the proportion of the silicon carbide particles is 7 parts, the proportion of the aluminate coupling agent is 4 parts, the proportion of the absolute ethanol is 11 parts, and the proportion of the hydroxyl silicone oil is 2 parts.

[0019] Preferably, the proportion of the methyl vinyl silicone rubber is 58 parts, the proportion of the bis(2,5) - vulcanizing agent is 4 parts, the proportion of the AB two - component addition - type liquid silicone rubber is 32 parts, the proportion of the spherical alumina particles is 17 parts, the proportion of the silicon carbide particles is 5 parts, the proportion of the aluminate coupling agent is 6 parts, the proportion of the absolute ethanol is 13 parts, and the proportion of the hydroxyl silicone oil is 4 parts.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In the present invention, through the sticky blue release film, it has the advantages of visual distinguishability and high heat resistance during use. At the same time, it can reduce the process steps. Moreover, this preparation method is simple to operate and convenient to prepare. Meanwhile, the finished product is softer and more flexible, has a larger addition amount in the material, and lower cost. When in use, the thermal conductivity increases rapidly, and the subsequent thermal conductivity can also be improved. When the material combines with the heat - conducting particles, their connection will be tighter, reducing the thermal resistance caused by voids, improving the dispersibility, and thus enhancing the thermal conductivity. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. Specific embodiment one:

[0024] The present invention relates to a preparation method of a high - insulation heat - conducting gasket, including the following operation steps:

[0025] S1: Prepare the raw materials for preparation: including methyl vinyl silicone rubber, bis(2,5)-sulfurizing agent, AB two-component addition-curing liquid silicone rubber, spherical alumina particles, silicon carbide particles, aluminate coupling agent, silane coupling agent, absolute ethanol, hydroxyl silicone oil. The density of the AB two-component addition-curing liquid silicone rubber after vulcanization should be 0.95 g / cm3. The density of the spherical alumina particles is 3.8 g / cm3, the average particle size is 40 μm, 10 μm, and the purity is 99.9%. The density of the silicon carbide particles is 3.2 g / cm3, the average particle size is 80 μm, 40 μm, 2 μm, and the purity is 99.9%. There are two types of silane coupling agents, with the models KH-550 and KH-570 respectively. The share of methyl vinyl silicone rubber is 50 - 60 parts, the share of bis(2,5)-sulfurizing agent is 1 - 4 parts, the share of AB two-component addition-curing liquid silicone rubber is 20 - 35 parts, the share of spherical alumina particles is 15 - 18 parts, the share of silicon carbide particles is 5 - 9 parts, the share of aluminate coupling agent is 3 - 7 parts, the share of absolute ethanol is 10 - 13 parts, and the share of hydroxyl silicone oil is 1 - 4 parts.

[0026] S2: Prepare the equipment and instruments for preparation: mechanical stirrer, three-necked flask, oven, two-roll mill, mold, flat vulcanizer, hydraulic press, muffle furnace.

[0027] S3: Preparation of heat-conducting particles: Place the AB two-component addition-curing liquid silicone rubber, spherical alumina particles, and silicon carbide particles into the mechanical stirrer in sequence for stirring and mixing treatment. After mixing, make heat-conducting particles and set aside. The share of methyl vinyl silicone rubber is 55 parts, the share of bis(2,5)-sulfurizing agent is 2 parts, the share of AB two-component addition-curing liquid silicone rubber is 30 parts, the share of spherical alumina particles is 15 parts, the share of silicon carbide particles is 7 parts, the share of aluminate coupling agent is 4 parts, the share of absolute ethanol is 11 parts, and the share of hydroxyl silicone oil is 2 parts.

[0028] S4: Surface treatment of heat-conducting particles: Add the silane coupling agent to absolute ethanol. In the three-necked flask, stir mechanically for a period of time to fully disperse it, then add the heat-conducting particles, and stir while ultrasonic oscillating for about 30 min. Filter the treated heat-conducting particles. After filtration, put them into an oven at 60 degrees for drying and set aside. The drying time should not exceed 15 minutes. The ratio of silane coupling agents KH-550 and KH-570 to absolute ethanol is 1:100.

[0029] S5: Two-roll mixing: Clean the rollers with a solvent in advance, rotate and adjust the roller spacing. Put the methyl vinyl silicone rubber into the two-roll mill for plasticization five times, then add the bis(2,5)-sulfurizing agent, hydroxyl silicone oil, and heat-conducting particles in sequence for mixing. The mixing times are at least five times until the material becomes thin and continuous, and then take off the sheet.

[0030] S6: Flat vulcanization: Put the kneaded product into a mold and hot-press it into shape in a flat vulcanizing machine at a temperature of 170°C, a pressure of 10 MPa, relieve the pressure 3 times, then hold the pressure for 10 minutes to press it into a product with a uniform thickness.

[0031] S7: Secondary vulcanization: Put the product into a muffle furnace, gradually heat it from room temperature to 220°C, and then cool it with the furnace to complete the preparation of the gasket.

[0032] S8: Preparation of the release film: Prepare HDPE, PVC, PP, PS, PE, put them into a mechanical stirrer for stirring. After stirring and mixing evenly, put them into the inner cavity of an extruder for plasticizing and extrusion, and form steps of tube blank blowing, cooling and traction, and coiling. Use the flat extrusion up-blowing method for the forming process, use a right-angle die head, that is, the die head discharge direction is perpendicular to the extruder, the extruded tube ring is upward, and after being pulled to a certain distance, it is clamped by a herringbone board. The extruded tube is blown into a bubble tube by the compressed air introduced from the bottom, and its transverse dimension is controlled by the amount of compressed air, and its longitudinal dimension is controlled by the traction speed. The bubble tube can obtain a blown film after cooling and shaping. During the preparation, it is dyed, and blue dye is put into it to make it blue after shaping.

[0033] S9: Stick the prepared release film on the front and back of the gasket, and then it can be packaged for use. Specific Example 2:

[0035] A preparation method of a highly insulating and heat-conducting gasket, including the following operating steps:

[0036] S1: Prepare raw materials for preparation: including methyl vinyl silicone rubber, bis(2,5)-sulfurizing agent, AB two-component addition-curing liquid silicone rubber, spherical alumina particles, silicon carbide particles, aluminate coupling agent, silane coupling agent, anhydrous ethanol, hydroxy silicone oil. The density of the AB two-component addition-curing liquid silicone rubber after vulcanization needs to be 0.95 g / cm3, the density of the spherical alumina particles is 3.8 g / cm3, the average particle size is 40 μm, 10 μm, and the purity is 99.9%. The density of the silicon carbide particles is 3.2 g / cm3, the average particle size is 80 μm, 40 μm, 2 μm, and the purity is 99.9%. There are two types of silane coupling agents, with the models being KH-550 and KH-570 respectively. The share of methyl vinyl silicone rubber is 50-60 parts, the share of bis(2,5)-sulfurizing agent is 1-4 parts, the share of AB two-component addition-curing liquid silicone rubber is 20-35 parts, the share of spherical alumina particles is 15-18 parts, the share of silicon carbide particles is 5-9 parts, the share of aluminate coupling agent is 3-7 parts, the share of anhydrous ethanol is 10-13 parts, and the share of hydroxy silicone oil is 1-4 parts.

[0037] S2: Prepare the equipment and instruments for preparation: mechanical stirrer, three-necked flask, oven, two-roll mill, mold, flat vulcanizer, hydraulic press, muffle furnace.

[0038] S3: Preparation of heat-conducting particles: Place the AB two-component addition-curing liquid silicone rubber, spherical alumina particles, and silicon carbide particles into a mechanical stirrer in sequence for stirring and mixing treatment. After mixing, make heat-conducting particles and set them aside for use. The proportion of methyl vinyl silicone rubber is 58 parts, the proportion of bis(2,5-dimethyl-2,5-hexanediol) dicumyl peroxide is 4 parts, the proportion of AB two-component addition-curing liquid silicone rubber is 32 parts, the proportion of spherical alumina particles is 17 parts, the proportion of silicon carbide particles is 5 parts, the proportion of aluminate coupling agent is 6 parts, the proportion of absolute ethanol is 13 parts, and the proportion of hydroxy silicone oil is 4 parts.

[0039] S4: Surface treatment of heat-conducting particles: Add silane coupling agent to absolute ethanol. In a three-necked flask, stir mechanically for a period of time to fully disperse it, then add heat-conducting particles, stir while ultrasonic oscillating for about 30 minutes, filter the treated heat-conducting particles, and after filtration, put them into an oven at 60 °C for drying and standby. The drying time should not exceed 15 minutes. The ratio of silane coupling agents KH-550 and KH-570 to absolute ethanol is 1:100.

[0040] S5: Two-roll mixing: Clean the rollers with a solvent in advance, rotate and adjust the pitch. Put methyl vinyl silicone rubber into the two-roll mill for plasticization five times, then add bis(2,5-dimethyl-2,5-hexanediol) dicumyl peroxide, hydroxy silicone oil, and heat-conducting particles in sequence for mixing. The mixing times are at least five times until the material becomes thin and continuous, and then take off the sheet.

[0041] S6: Flat vulcanization: Put the mixed product into a mold and hot press it into shape in a flat vulcanizer at a temperature of 170 °C, a pressure of 10 MPa, release the pressure three times, and then keep the pressure for 10 minutes to press the product into a uniform thickness.

[0042] S7: Secondary vulcanization: Put the product into a muffle furnace, gradually heat it from room temperature to 220 °C, and then cool it with the furnace to complete the preparation of the gasket.

[0043] S8: Preparation of release film: Prepare HDPE, PVC, PP, PS, and PE, put them into a mechanical blender for stirring. After stirring and mixing evenly, put them into the inner cavity of an extruder for plasticizing and extrusion, and perform steps of forming a tube blank, blowing, cooling and traction, and coiling. Use the flat extrusion up-blowing method for the forming process, and use a right-angle die head, that is, the die head discharging direction is perpendicular to the extruder, and the extruded tube ring is upward. After being pulled to a certain distance, it is clamped by a chevron plate. The extruded tube is blown into a bubble tube by the compressed air introduced from the bottom, and its transverse dimension is controlled by the amount of compressed air, and its longitudinal dimension is controlled by the traction speed. The bubble tube can obtain a blown film after cooling and shaping. During the preparation, it is dyed, and blue dye is put in so that it is blue after shaping.

[0044] S9: Stick the prepared release film on the front and back of the gasket, and then it can be used for packaging.

[0045] The blue release film of the present invention adhered has the advantages of being visually distinguishable and having high heat resistance during use. At the same time, it can reduce the process steps. Moreover, this preparation method is simple to operate and convenient to prepare. At the same time, the finished product is softer and more flexible, has a larger addition amount in the material, and has a lower cost. During use, the thermal conductivity increases rapidly, and the subsequent thermal conductivity can also be improved. When the material combines with the thermal conductive particles, their connection will be closer, reducing the thermal resistance brought by voids, improving the dispersibility, and thus increasing the thermal conductivity.

[0046] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a high-insulation thermal conductive gasket, characterized in that: The following operating steps are included: S1: Prepare the raw materials for preparation: including methyl vinyl silicone rubber, bis(2,5-dimethyl-2,5-di(tert-butylperoxy)hexane) vulcanizing agent, AB two-component addition-curing liquid silicone rubber, spherical alumina particles, silicon carbide particles, aluminate coupling agent, silane coupling agent, anhydrous ethanol, and hydroxyl silicone oil; S2: Prepare the equipment and instruments for preparation: mechanical stirrer, three-necked flask, oven, two-roll mill, mold, flat vulcanizer, hydraulic press, muffle furnace; S3: Preparation of heat-conducting particles: Place the AB two-component addition-curing liquid silicone rubber, spherical alumina particles, and silicon carbide particles into the mechanical stirrer in sequence for stirring and mixing treatment. After mixing, make heat-conducting particles and set aside for use; S4: Surface treatment of heat-conducting particles: Add the silane coupling agent to anhydrous ethanol. In the three-necked flask, stir mechanically for a period of time. After sufficient dispersion, add the heat-conducting particles, and stir while ultrasonic oscillating for about 30 minutes. Filter the treated heat-conducting particles. After filtration, put them into an oven at 60 °C for drying and standby. The drying time shall not exceed 15 minutes; S5: Two-roll mixing: Clean the rolls with a solvent in advance, rotate and adjust the roll distance. Put the methyl vinyl silicone rubber into the two-roll mill for plasticization five times, and then add bis(2,5-dimethyl-2,5-di(tert-butylperoxy)hexane) vulcanizing agent, hydroxyl silicone oil, and heat-conducting particles in sequence for mixing. The mixing times shall be at least five times until the material becomes thin and continuous, and then take off the sheet; S6: Flat vulcanization: Put the mixed product into the mold and hot-press it into shape in the flat vulcanizer at a temperature of 170 °C, a pressure of 10 MPa, relieve pressure three times, and then keep the pressure for 10 minutes to press it into a product with a uniform thickness; S7: Secondary vulcanization: Put the product into the muffle furnace, gradually heat it from room temperature to 220 °C, and then cool it with the furnace to complete the preparation of the gasket; S8: Preparation of release film: Prepare HDPE, PVC, PP, PS, PE, put them into the mechanical stirrer for stirring. After stirring and mixing evenly, put them into the inner cavity of the extruder for plasticizing extrusion, and form steps of tube blank blowing, cooling and traction, and coiling. Carry out the forming process by flat extrusion and upward blowing method, use a right-angle die head, that is, the die head discharge direction is perpendicular to the extruder, the extruded tube ring is upward, and after being pulled to a certain distance, it is clamped by the chevron plate. The extruded tube is blown into a bubble tube by the compressed air introduced from the bottom, and its transverse dimension is controlled by the amount of compressed air, and its longitudinal dimension is controlled by the traction speed. The bubble tube can be obtained after cooling and shaping to get a blown film. During the preparation, dye it, put in blue dye so that it becomes blue after shaping; S9: Stick the prepared release film on the front and back of the gasket, and then it can be packaged for use.

2. The preparation method of a highly insulating thermal conductive gasket according to claim 1, characterized in that: The density of the AB two-component addition-curing liquid silicone rubber after vulcanization shall be 0.95 g / cm3. The density of the spherical alumina particles is 3.8 g / cm3, the average particle size is 40 μm, 10 μm, and the purity is 99.9%. The density of the silicon carbide particles is 3.2 g / cm3, the average particle size is 80 μm, 40 μm, 2 μm, and the purity is 99.9%. There are two kinds of silane coupling agents, and the models are KH-550 and KH-570 respectively.

3. The preparation method of a highly insulating thermal conductive gasket according to claim 1, characterized in that: The ratio of the silane coupling agents KH-550 and KH-570 to absolute ethanol is 1:

100.

4. The preparation method of a highly insulating thermal conductive gasket according to claim 1, characterized in that: The share of the methyl vinyl silicone rubber is 50 - 60 parts, the share of the bis(2,5)-sulfur vulcanizing agent is 1 - 4 parts, the share of the AB two-component addition-curing liquid silicone rubber is 20 - 35 parts, the share of the spherical alumina particles is 15 - 18 parts, the share of the silicon carbide particles is 5 - 9 parts, the share of the aluminate coupling agent is 3 - 7 parts, the share of the absolute ethanol is 10 - 13 parts, and the share of the hydroxy silicone oil is 1 - 4 parts.

5. The preparation method of a highly insulating thermal conductive gasket according to claim 1, characterized in that: The share of the methyl vinyl silicone rubber is 55 parts, the share of the bis(2,5)-sulfur vulcanizing agent is 2 parts, the share of the AB two-component addition-curing liquid silicone rubber is 30 parts, the share of the spherical alumina particles is 15 parts, the share of the silicon carbide particles is 7 parts, the share of the aluminate coupling agent is 4 parts, the share of the absolute ethanol is 11 parts, and the share of the hydroxy silicone oil is 2 parts.

6. The preparation method of a highly insulating thermal conductive gasket according to claim 1, characterized in that: The share of the methyl vinyl silicone rubber is 58 parts, the share of the bis(2,5)-sulfur vulcanizing agent is 4 parts, the share of the AB two-component addition-curing liquid silicone rubber is 32 parts, the share of the spherical alumina particles is 17 parts, the share of the silicon carbide particles is 5 parts, the share of the aluminate coupling agent is 6 parts, the share of the absolute ethanol is 13 parts, and the share of the hydroxy silicone oil is 4 parts.