Phase change material ultra-flexible high-thermal-conductivity composite gasket and preparation method therefor

Abstract

The present invention relates to the technical field of thermally conductive materials, and specifically to a phase change material ultra-flexible high-thermal-conductivity composite gasket and a preparation method therefor. The gasket at least comprises a high-thermal-conductivity phase change gasket and an ultra-flexible thermally conductive gasket. Raw materials for preparing the high-thermal-conductivity phase change gasket at least comprise, in parts by weight, 30-130 parts of a thermally conductive powder, 0.5-10 parts of silicone, 0.5-5 parts of phase change wax, and 5-20 parts of polyisobutylene. By designing the high-thermal-conductivity phase change gasket in cooperation with the ultra-flexible thermally conductive gasket, the provided composite gasket can achieve full contact with an electronic device while ensuring high thermal conductivity and excellent compressibility and resilience, thereby meeting actual use requirements.

Description

A phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method Technical Field

[0001] This invention relates to the field of thermal conductive materials technology, specifically to a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. Background Technology

[0002] Currently, electronic devices are becoming increasingly miniaturized and integrated. During use, these devices often suffer from ineffective heat dissipation, leading to potential damage. This places higher demands on heat dissipation in electronic devices. To ensure normal operation, heat dissipation devices are necessary. However, direct contact between heat-generating and heat-dissipating components can create significant thermal resistance. Using thermal pads can effectively fill the gaps between components, forming a heat conduction path and improving thermal efficiency.

[0003] Currently, thermal pads are typically made with polymers as the matrix and ceramic powder as filler. However, this method cannot effectively fill the air gaps between the heat-generating device and the heat sink or metal base. To address this issue, traditional technologies use phase change thermal pads to overcome incomplete filling. For example, Chinese patent application CN117777955A discloses an overflow-proof thermal phase change pad and its preparation method. This method mainly introduces a semi-crosslinked support framework formed by the reaction of acrylic monomers and photoinitiators into the pad system to prevent the phase change matrix from overflowing or falling off. However, because it is filled with metal powder, it has electrical conductivity, which limits its application scenarios.

[0004] Therefore, ensuring the compressibility and resilience of thermal pads while maintaining sufficient contact with electronic components to meet practical application requirements remains a problem that needs to be solved. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a phase change material ultra-flexible high thermal conductivity composite gasket. By designing a high thermal conductivity phase change gasket in conjunction with an ultra-soft thermal conductivity gasket, the provided composite gasket ensures high thermal conductivity, excellent compressibility, and resilience while maintaining full contact with electronic devices, thus meeting practical application requirements.

[0006] The present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket, which includes at least a high thermal conductivity phase change gasket and an ultra-soft thermal conductivity gasket; by weight, the raw materials for preparing the high thermal conductivity phase change gasket include at least: 30-130 parts of thermally conductive powder, 0.5-10 parts of organosilicon, 0.5-5 parts of phase change wax, and 5-20 parts of polyisobutylene.

[0007] As a preferred technical solution, the raw materials for preparing the ultra-soft thermal pad, by weight, include at least: 150-300 parts of modified ceramic filler, 2-15 parts of vinyl silicone oil, 0.1-5 parts of methylsiloxane, 0.1-1 parts of hydrogen-containing silicone oil, 0.1-2 parts of inhibitor, and 0.2-2 parts of catalyst.

[0008] As a preferred technical solution, the thermally conductive powder is selected from one or a mixture of several of aluminum powder, angular alumina, spherical alumina, single crystal alumina, aluminum nitride, magnesium oxide, and zinc oxide.

[0009] Preferably, the thermally conductive powder is a combination of aluminum powder, spherical alumina, and single-crystal alumina.

[0010] Preferably, the mass ratio of aluminum powder, spherical alumina, and single crystal alumina is (20-70):(7-50):(3-10), and more preferably (50-70):(10-30):(5-10).

[0011] Preferably, the aluminum powder has a particle size of 0.1-20 μm, and more preferably includes at least one of 1 μm, 2 μm, 5 μm, 10 μm, and 20 μm.

[0012] Preferably, the particle size of the spherical alumina is 1-70 μm, and more preferably includes at least one of 1 μm, 2 μm, 5 μm, 10 μm, 20 μm, 40 μm, and 70 μm.

[0013] Preferably, the particle size of the single-crystal alumina is 0.3-5 μm, and more preferably includes at least one of 0.3 μm, 1.5 μm, 3 μm, and 5 μm.

[0014] As a preferred technical solution, the organosilicon is selected from at least one of octyltrimethoxysilane, dodecyltrimethoxysilane, n-octyltriethoxysilane, vinyltrimethoxysilane, and hexamethyldisilazane, preferably octyltrimethoxysilane.

[0015] As a preferred technical solution, the phase change wax has a phase change temperature of 40-125℃, and is preferably at least one of medium-temperature phase change wax (40-70℃), high-temperature phase change wax (70-100℃), and special phase change wax (70-125℃).

[0016] As a preferred technical solution, the number-average molecular weight of the polyisobutylene is 200-2400.

[0017] The modified ceramic filler is prepared by using a modification device to modify the ceramic filler with an organosiloxane.

[0018] As a preferred technical solution, the ceramic filler comprises at least the following components by weight: 5-20 parts of single-crystal alumina, 30-70 parts of spherical alumina, 1-5 parts of zinc oxide, and 20-40 parts of aluminum nitride.

[0019] Preferably, the ceramic filler comprises, by weight,: single-crystal alumina (1.5 μm, 5 parts; 5 μm, 10 parts), spherical alumina (1 μm, 5 parts; 2 μm, 15 parts; 40 μm, 30 parts), zinc oxide (0.5 μm, 3 parts), and aluminum nitride (20 μm, 5 parts; 120 μm, 27 parts).

[0020] Preferably, the zinc oxide has a particle size of 0.5-3 μm, and more preferably includes at least one of 0.5 μm, 1 μm, and 3 μm.

[0021] Preferably, the aluminum nitride has a particle size of 2-150 μm, and more preferably includes at least one of 2 μm, 10 μm, 20 μm, 80 μm, 100 μm, 120 μm, and 150 μm.

[0022] As a preferred technical solution, the organosiloxane is octyltrimethoxysilane and / or hexamethyldisilazane.

[0023] As a preferred technical solution, the preparation method of the modified ceramic filler is as follows: the ceramic filler is filled into the modification equipment, and then an organosiloxane is added, the amount of organosiloxane added being 0.2-5% of the mass of the ceramic filler; the modification equipment is closed to seal its cavity, and first stirred at 10-200 rpm for 0.5-90 min. After stirring, the modification equipment is opened, and the powder that is raised is manually scraped off. The modification equipment is closed again, and stirred at 150-500 rpm for 0.5-30 min. After stirring, the modified filler is poured out and baked in an oven at 50-170℃ for 0.5-24 h. After baking, it is taken out and cooled to obtain the modified ceramic filler.

[0024] As a preferred technical solution, the vinyl content in the vinyl silicone oil is 0.08-10 wt%, preferably 0.1-0.5 wt%.

[0025] Preferably, the vinyl content of the vinyl silicone oil is 0.18 wt% (Guangdong Chenxi New Material Technology Co., Ltd., CX-352M, single-end vinyl silicone oil).

[0026] As a preferred technical solution, the methylsiloxane is at least one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecylcyclohexasiloxane, preferably hexamethylcyclotrisiloxane.

[0027] As a preferred technical solution, the hydrogen-containing silicone oil is at least one of end-containing hydrogen-containing silicone oil, side-containing hydrogen-containing silicone oil, or end-side hydrogen-containing silicone oil.

[0028] Preferably, the hydrogen-containing silicone oil is a combination of end-containing hydrogen-containing silicone oil (Shanghai Jingri New Materials Technology Co., Ltd., grade DH007) and side-containing hydrogen-containing silicone oil (Shanghai Jingri New Materials Technology Co., Ltd., grade H020), and the mass ratio of the end-containing hydrogen-containing silicone oil to the side-containing hydrogen-containing silicone oil is (3-8):1, preferably 5:1.

[0029] As a preferred technical solution, the inhibitor is acetylenecyclohexanol.

[0030] As a preferred technical solution, the catalyst is a platinum catalyst.

[0031] This invention optimizes the selection and dosage control of raw materials for high thermal conductivity phase change pads, ensuring a tight bond between the pads and ultra-soft thermally conductive pads. This results in increased thermal conductivity and reduced interfacial thermal resistance in the composite phase change material ultra-soft high thermal conductivity gasket, better meeting practical application requirements. Specifically, by controlling heating conditions and stirring time, this invention disperses the phase change wax into the polyisobutylene system, ensuring the uniformity of the phase change system and guaranteeing subsequent film formation. This effectively prevents melt leakage and reduces the interfacial thermal resistance between the phase change material and the device components, better filling the air gaps between the heating element and the heat sink or metal base, thus expanding the application range. Conversely, excessively low temperatures lead to particulate impurities in the subsequently sprayed film, while excessively long stirring times result in increased film hardness, both failing to meet practical application requirements.

[0032] Furthermore, by controlling the introduction of aluminum powder, spherical alumina, and single-crystal alumina into the high thermal conductivity phase change pad, and by combining aluminum powder, spherical alumina, and single-crystal alumina of different particle sizes in the presence of organosilicon, the uniformity of the high thermal conductivity phase change pad is ensured, thereby ensuring the subsequent composite effect with the ultra-soft thermal conductive pad.

[0033] Furthermore, this invention optimizes the ultra-soft thermal pad by introducing modified ceramic fillers including single-crystal alumina, spherical alumina, zinc oxide, and aluminum nitride, so that the ceramic fillers are uniformly dispersed in the polymer system, ensuring that the thermal conductivity of the composite material pad is above 8.8 W / mk.

[0034] Another aspect of the present invention provides a method for preparing a phase change material ultra-flexible high thermal conductivity composite gasket, comprising at least the following steps:

[0035] (1) The thermally conductive powder, organosilicon, phase change wax and polyisobutylene are stirred and mixed to obtain the phase change base material;

[0036] (2) Vinyl silicone oil, methylsiloxane, hydrogen-containing silicone oil, inhibitor and modified ceramic filler are pre-mixed and then a catalyst is added and mixed to obtain a compound. The compound is extruded onto a base film, calendered and baked to obtain an ultra-soft thermally conductive pad.

[0037] (3) Heat the phase change base material, add diluent and stir to dilute it, then spray it onto the surface of the ultra-soft thermal conductive pad. After natural cooling, a high thermal conductivity phase change pad is formed on the surface of the ultra-soft thermal conductive pad, thus obtaining the phase change material ultra-soft high thermal conductivity composite material pad.

[0038] As a preferred technical solution, the preparation method of the phase change material ultra-flexible high thermal conductivity composite gasket includes at least the following steps:

[0039] (1) Place spherical alumina, single crystal alumina, organosilicon, phase change wax and polyisobutylene into a stirring vessel, heat to 120-140℃, stir at 5-30 rpm for 0.1-5 min, after stirring, add aluminum powder in 3 batches, stir at 10-50 rpm for 0.5-30 min, scrape the wall after stirring, and stir again at 10-50 rpm for 0.5-10 min, keeping the vacuum during stirring to obtain phase change base material;

[0040] (2) Add vinyl silicone oil, methylsiloxane, hydrogen-containing silicone oil, inhibitor, and modified ceramic filler to a mixing tank and stir at 10-50 rpm for 5-30 min. During stirring, maintain 20-30℃ and turn on the vacuum. After stirring, add the catalyst and stir at 30-50 rpm for 1-30 min. During stirring, turn on the vacuum and pass cooling water at 10-20℃. After stirring, scrape the wall and stir again at 5-20 rpm for 10-120 min. During stirring, turn on the vacuum. After stirring, a compound is obtained. The compound is extruded onto a fluoroplastic film using an extrusion plate and calendered at a uniform speed. The oven temperature is controlled at 100-130℃, the baking time is 30-100 min, and the thickness can be controlled at 0.3-5 mm to obtain an ultra-soft thermal conductive pad.

[0041] (3) Place the phase change base material into a spraying kettle and heat it to 90-120℃. Add a diluent, the amount of which is 0.5-50% of the mass of the phase change base material. Stir at 10-50 rpm for 0.5-10 min and then spray it evenly on the surface of the ultra-soft thermal conductive pad. Control the spraying thickness to 10-100 μm. Spray it evenly on the surface of the ultra-soft thermal conductive pad and let it cool naturally to 20-30℃ to obtain the phase change material ultra-soft high thermal conductivity composite material pad.

[0042] As a preferred technical solution, the diluent is an organosilicon diluent, preferably RH-2001-0.65 or Runhe.

[0043] The phase change material ultra-flexible high thermal conductivity composite gasket provided by this invention has a hardness of Shore 005-25, a breakdown voltage greater than 5kV / mm, and an interfacial thermal resistance as low as 4℃·cm. 2 / W. Beneficial effects

[0044] 1. This invention provides a phase change material ultra-flexible high thermal conductivity composite gasket. By designing a high thermal conductivity phase change gasket in combination with an ultra-soft thermal conductivity gasket, the provided composite gasket can ensure high thermal conductivity, excellent compressibility and resilience, while also making full contact with electronic devices to meet practical application requirements.

[0045] 2. This invention optimizes the selection of raw materials and the control of the amount added to the high thermal conductivity phase change pad, so that it is tightly bonded to the ultra-soft thermal conductive pad. At the same time, it increases the thermal conductivity of the composite phase change material ultra-soft high thermal conductivity composite material pad and reduces the interfacial thermal resistance, thus better meeting the needs of practical applications.

[0046] 3. By controlling the heating conditions and stirring time, this invention disperses the phase change wax into the polyisobutylene system, ensuring the uniformity of the phase change system and the subsequent film formation effect, while effectively preventing melt leakage. At the same time, it reduces the interfacial thermal resistance between the phase change material and the device components, better fills the air gap between the heating device and the heat sink or metal base, and expands the application range.

[0047] 4. This invention introduces aluminum powder, spherical alumina, and single-crystal alumina into the high thermal conductivity phase change pad. Under the condition of the presence of organosilicon, the uniformity of the high thermal conductivity phase change pad is ensured by combining aluminum powder, spherical alumina, and single-crystal alumina with different particle sizes, thereby ensuring the subsequent composite effect with the ultra-soft thermal conductive pad.

[0048] 5. This invention optimizes the ultra-soft thermal conductive pad by introducing modified ceramic fillers including single-crystal alumina, spherical alumina, zinc oxide, and aluminum nitride, so that the ceramic fillers are uniformly dispersed in the polymer system, ensuring that the thermal conductivity of the composite material pad is above 8.8 W / mk. Detailed Implementation

[0049] Example 1

[0050] Embodiment 1 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket, comprising a high thermal conductivity phase change gasket and an ultra-soft thermal conductivity gasket. By weight, the raw materials for preparing the high thermal conductivity phase change gasket include: 60 parts aluminum powder (Anshan Iron and Steel Group aluminum powder, 40μm), 5 parts single-crystal alumina (0.3μm), 5 parts spherical alumina (2μm), 10 parts spherical alumina (10μm), 0.5 parts organosilicon, 2 parts phase change wax, and 15 parts polyisobutylene. By weight, the raw materials for preparing the ultra-soft thermal conductivity gasket include: 200 parts modified ceramic filler, 5 parts vinyl silicone oil, 1 part methylsiloxane, 0.5 parts hydrogen-containing silicone oil, 0.1 parts inhibitor, and 0.2 parts catalyst.

[0051] The organosilicon is octyltrimethoxysilane.

[0052] The phase change wax is a medium-temperature phase change wax (40-70℃, Herun Technology).

[0053] The polyisobutylene has a number-average molecular weight of 1200, produced by Guochen Chemical.

[0054] The modified ceramic filler is prepared as follows: ceramic filler is filled into a modification device, and then an organosiloxane is added. The amount of organosiloxane added is 1% of the mass of the ceramic filler. The modification device is closed to seal the cavity. First, it is stirred at 100 rpm for 20 minutes. After stirring, the modification device is opened and the powder that is raised is manually scraped off. The modification device is closed again and stirred at 300 rpm for 10 minutes. After stirring, the modified filler is poured out and baked in an oven at 150°C for 3 hours. After baking, it is taken out and cooled to obtain the modified ceramic filler.

[0055] The ceramic filler comprises, by weight, 5 parts of single-crystal alumina (1.5 μm, 5 parts; 10 parts of 5 μm), 5 parts of spherical alumina (1 μm, 5 parts; 15 parts of 2 μm; 30 parts of 40 μm), 3 parts of zinc oxide (0.5 μm), and 5 parts of aluminum nitride (20 μm, 5 parts; 27 parts of 120 μm).

[0056] The organosiloxane is octyltrimethoxysilane.

[0057] The vinyl content of the vinyl silicone oil is 0.18 wt% (Guangdong Chenxi New Material Technology Co., Ltd., CX-352M, single-end vinyl silicone oil).

[0058] The methylsiloxane is hexamethylcyclotrisiloxane.

[0059] The hydrogen-containing silicone oil is a combination of end-containing hydrogen-containing silicone oil (Shanghai Jingri New Materials Technology Co., Ltd., grade DH007) and side-containing hydrogen-containing silicone oil (Shanghai Jingri New Materials Technology Co., Ltd., grade H020), with a mass ratio of end-containing hydrogen-containing silicone oil to side-containing hydrogen-containing silicone oil of 5:1.

[0060] The inhibitor is acetylcyclohexanol.

[0061] The catalyst is a platinum catalyst.

[0062] Embodiment 1 of the present invention provides a method for preparing a phase change material ultra-flexible high thermal conductivity composite gasket, comprising the following steps:

[0063] (1) Place spherical alumina, single crystal alumina, organosilicon, phase change wax and polyisobutylene into a stirring vessel, heat to 130°C, stir at 25 rpm for 3 min, add aluminum powder in 3 batches after stirring, stir at 15 rpm for 10 min, scrape the wall after stirring, stir again at 5 rpm for 10 min, keep the vacuum during stirring to obtain phase change base material;

[0064] (2) Add vinyl silicone oil, methylsiloxane, hydrogen-containing silicone oil, inhibitor, and modified ceramic filler to a mixing tank and stir at 10 rpm for 10 min. During stirring, maintain 25°C and turn on the vacuum. After stirring, add the catalyst and stir at 30 rpm for 5 min. During stirring, turn on the vacuum and pass cooling water at 17°C. After stirring, scrape the wall and stir again at 10 rpm for 120 min. During stirring, turn on the vacuum. After stirring, obtain the compound. Use an extrusion plate to press the compound onto a fluoroplastic film and calender it at a uniform speed. Control the oven temperature at 120°C and the baking time at 40 min. The thickness can be controlled at 0.3 mm to obtain an ultra-soft thermal conductive pad.

[0065] (3) Place the phase change base material into a spraying kettle and heat it to 100°C. Add a diluent at a rate of 20% of the phase change base material mass. Stir at 30 rpm for 5 minutes and then spray it evenly onto the surface of the ultra-soft thermal conductive pad. Control the spraying thickness to 50 μm and spray it evenly onto the surface of the ultra-soft thermal conductive pad. Allow it to cool naturally to 25°C to form a high thermal conductivity phase change pad on the surface of the ultra-soft thermal conductive pad. This yields the ultra-soft high thermal conductivity composite material pad of the phase change material.

[0066] The diluent is an organosilicon diluent, model RH-2001-0.65, Runhe.

[0067] Example 2

[0068] Example 2 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that the spraying thickness is controlled to be 80 μm in step (3).

[0069] Example 3

[0070] Example 3 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that, by weight, the raw materials for preparing the high thermal conductivity phase change gasket include: 70 parts of aluminum powder (Anshan Iron and Steel aluminum powder, 40μm), 5 parts of single crystal alumina (0.3μm), 5 parts of spherical alumina (2μm), 5 parts of spherical alumina (10μm), 0.5 parts of organosilicon, 2 parts of phase change wax, and 15 parts of polyisobutylene.

[0071] Example 4

[0072] Example 4 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that, by weight, the raw materials for preparing the ultra-soft thermal conductive gasket include: 150 parts of modified ceramic filler, 5 parts of vinyl silicone oil, 1 part of methylsiloxane, 0.8 parts of hydrogen-containing silicone oil, 0.1 parts of inhibitor, and 0.2 parts of catalyst.

[0073] Example 5

[0074] Example 5 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that step (1) is as follows: spherical alumina, single crystal alumina, organosilicon, phase change wax and polyisobutylene are put into a stirring vessel, heated to 100°C, and stirred at 25 rpm for 3 min. After stirring, aluminum powder is added in 3 batches and stirred at 15 rpm for 5 min. After stirring, the wall is scraped and stirred again at 5 rpm for 5 min. Vacuum is maintained during the stirring process to obtain the phase change base material.

[0075] Example 6

[0076] Example 6 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that step (1) is as follows: spherical alumina, single crystal alumina, organosilicon, phase change wax and polyisobutylene are put into a stirring vessel, heated to 100°C, and stirred at 25 rpm for 3 min. After stirring, aluminum powder is added in 3 batches and stirred at 15 rpm for 30 min. After stirring, the wall is scraped and stirred again at 5 rpm for 30 min. Vacuum is maintained during the stirring process to obtain the phase change base material.

[0077] Comparative Example 1

[0078] Comparative Example 1 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that, by weight, 60 parts of aluminum powder (Anshan Iron and Steel aluminum powder, 40μm) used in the preparation raw materials of the high thermal conductivity phase change gasket are replaced with 60 parts of spherical alumina 40μm.

[0079] Comparative Example 2

[0080] Comparative Example 2 of the present invention provides a phase change material ultra-flexible high thermal conductivity composite gasket and its preparation method. The specific implementation method is the same as that of Example 1, except that, by weight, the raw materials for preparing the high thermal conductivity phase change gasket include: 70 parts of aluminum powder (Anshan Iron and Steel Group aluminum powder, 40 μm), 5 parts of single crystal alumina (0.3 μm), 5 parts of aluminum powder (Anshan Iron and Steel Group aluminum powder, 2 μm), 5 parts of aluminum powder (Anshan Iron and Steel Group aluminum powder, 10 μm), 0.5 parts of organosilicon, 2 parts of phase change wax, and 15 parts of polyisobutylene.

[0081] Performance testing

[0082] The thermal conductivity, hardness, breakdown voltage, and interfacial thermal resistance of the phase change material ultra-flexible high thermal conductivity composite gasket provided in the embodiments of the present invention are tested using the following methods, and the test results are shown in Table 1.

[0083] (1) Thermal conductivity: measured according to standard ASTM D 5470-17 using Ruiling LW-9389 interface material thermal resistance and thermal conductivity measuring device (at 80°C).

[0084] (2) Hardness: Measured using a Shore 00 hardness tester (at 25°C) according to standard ASTM D2240.

[0085] (3) Interface thermal resistance: measured according to standard ASTM D 5470-17 using Ruiling LW-9389 interface material thermal resistance and thermal conductivity measurement device (at 80°C), with a 2mm thick gasket and a constant pressure of 10psi.

[0086] (4) Breakdown voltage: Measured according to standard ASTM D 149 using a breakdown voltage tester (at 25°C), using AC voltage (AC), a boost rate of 50V / s, a leakage current of 10mA, and boosted to breakdown voltage for measurement.

[0087] Table 1

[0088] Analysis of the table above shows that the phase change material ultra-flexible high thermal conductivity composite gaskets provided in Examples 1-4 of this invention simultaneously ensure that the thermal conductivity, hardness, breakdown voltage, and interfacial thermal resistance meet the requirements of actual filling applications. Examples 5 and 6, with changes in the preparation process conditions compared to Examples 1-4, affected the hardness and interfacial thermal resistance of the products. Comparative Examples 1 and 2, with changes in the raw materials used in the preparation of the high thermal conductivity phase change gaskets compared to Examples 1-4, affected the hardness, breakdown voltage, and interfacial thermal resistance of the products.

Claims

1. A phase change material ultra-flexible high thermal conductivity composite gasket, characterized in that, It includes at least high thermal conductivity phase change pads and ultra-soft thermal conductivity pads; By weight, the raw materials for preparing the high thermal conductivity phase change pad include at least: 30-130 parts of thermally conductive powder, 0.5-10 parts of organosilicon, 0.5-5 parts of phase change wax, and 5-20 parts of polyisobutylene; by weight, the raw materials for preparing the ultra-soft thermally conductive pad include at least: 150-300 parts of modified ceramic filler, 2-15 parts of vinyl silicone oil, 0.1-5 parts of methylsiloxane, 0.1-1 parts of hydrogen-containing silicone oil, 0.1-2 parts of inhibitor, and 0.2-2 parts of catalyst; the thermally conductive powder is a combination of aluminum powder, spherical alumina, and single-crystal alumina.

2. The phase change material ultra-flexible high thermal conductivity composite gasket according to claim 1, characterized in that, The aluminum powder has a particle size of 0.1-20 μm, the spherical alumina has a particle size of 1-70 μm, and the single crystal alumina has a particle size of 0.3-5 μm.

3. The phase change material ultra-flexible high thermal conductivity composite gasket according to claim 1, characterized in that, The hydrogen-containing silicone oil is a mixture of one or more of the following: end-containing hydrogen-containing silicone oil, side-containing hydrogen-containing silicone oil, or end-side-containing hydrogen-containing silicone oil.

4. The phase change material ultra-flexible high thermal conductivity composite gasket according to claim 1, characterized in that, The phase change temperature of the phase change wax is 40-125℃.

5. The phase change material ultra-flexible high thermal conductivity composite gasket according to claim 1, characterized in that, The number-average molecular weight of the polyisobutylene is 200-2400.

6. The phase change material ultra-flexible high thermal conductivity composite gasket according to claim 1, characterized in that, The modified ceramic filler is prepared by using a modification device to modify the ceramic filler with organosiloxane. The ceramic filler comprises at least the following components by weight: 5-20 parts of single-crystal alumina, 30-70 parts of spherical alumina, 1-5 parts of zinc oxide, and 20-40 parts of aluminum nitride.

7. The phase change material ultra-flexible high thermal conductivity composite gasket according to claim 1, characterized in that, The zinc oxide has a particle size of 0.5-3 μm, and the aluminum nitride has a particle size of 2-150 μm.

8. A method for preparing a phase change material ultra-flexible high thermal conductivity composite gasket according to any one of claims 1-7, characterized in that, At least the following steps are included: (1) The thermally conductive powder, organosilicon, phase change wax and polyisobutylene are stirred and mixed to obtain the phase change base material; (2) Vinyl silicone oil, methylsiloxane, hydrogen-containing silicone oil, inhibitor and modified ceramic filler are pre-mixed and then a catalyst is added and mixed to obtain a compound. The compound is extruded onto a base film, calendered and baked to obtain an ultra-soft thermally conductive pad. (3) Heat the phase change base material, add diluent and stir to dilute it, then spray it onto the surface of the ultra-soft thermal conductive pad. After natural cooling, a high thermal conductivity phase change pad is formed on the surface of the ultra-soft thermal conductive pad, thus obtaining the phase change material ultra-soft high thermal conductivity composite material pad.

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