A phase change pad and a method of manufacturing the same

Abstract

The present application relates to the technical field of heat-conducting gaskets, and particularly relates to a phase-change gasket and a preparation method thereof. The phase-change gasket raw material comprises: pre-material a, pre-material b and coated phase-change microcapsules, and the mass ratio of pre-material a, pre-material b and coated phase-change microcapsules is 13-27:11.1-25.5:25-55; wherein, the pre-material a raw material comprises, by mass fraction: end-vinyl silicone oil 10-20 parts, end-hydrogen silicone oil 1-3 parts, adhesive 1-2 parts, and ethynylcyclohexanol 1-2 parts; and the pre-material b raw material comprises, by mass fraction: end-vinyl silicone oil 10-20 parts, diluent 1-5 parts, and catalyst 0.001-0.005 parts. The present application has excellent adhesion and heat-resistant stability, and the phase-change material has good sealing performance, a long service life, can store a large amount of heat during the phase-change process, and has good heat-distribution effect. The preparation method is simple to operate, has low production cost and is easy to implement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat-conducting gaskets, and particularly relates to a phase-change gasket and a preparation method thereof. BACKGROUND

[0002] Nowadays, computers, communications and consumer electronics (3C products) are accelerating towards thin and miniaturization, and the integration of semiconductor chips and electronic components continues to improve, resulting in a sharp increase in heat generated during device operation. Under this background, efficient thermal management technology has become a key breakthrough to ensure the stable operation of electronic devices and prolong their service life.

[0003] As one of the core components of the electronic device thermal management system, the heat-conducting gasket mainly fills the air gap between the heat-generating device and the heat sink / metal base, and quickly spreads the heat generated by the chip or PCB to the metal shell or diffusion plate through efficient heat conduction, thereby avoiding performance degradation or device failure caused by local overheating.

[0004] However, although the traditional heat-conducting material (such as heat-conducting silicone gasket) has a high thermal conductivity, its heat dissipation process often needs to rely on auxiliary structures such as heat pipes or metal sheets, resulting in increased overall design difficulty, and it is difficult to achieve efficient peak heat dissipation and uniform temperature distribution, which cannot meet the heat dissipation needs of high-power-density 3C products.

[0005] In recent years, phase-change materials have attracted widespread attention due to their unique passive thermal management characteristics. This type of material can efficiently absorb or release a large amount of latent heat through its reversible solid-liquid (or liquid-solid) phase change process without external power input, achieving dynamic balance of heat and providing a new idea for solving the heat dissipation problem of electronic devices. Among them, paraffin-based organic phase-change materials have become one of the most promising candidate materials due to their wide phase change temperature range (covering normal temperature to medium-high temperature interval), high phase change latent heat (strong heat storage capacity per unit mass), wide raw material sources and low cost.

[0006] However, the existing heat-conducting silicone gasket and phase-change energy storage material still have significant deficiencies in the thermal management of 3C products: although the traditional phase-change material has outstanding heat storage capacity, it generally faces problems such as weak adhesion to the substrate, easy peeling, and insufficient long-term stability, making it difficult to be directly applied to high-end electronic devices with strict requirements on space and reliability. Therefore, developing a phase-change gasket with high efficient heat storage and long-term stability has become a key technical requirement to improve the heat dissipation performance of 3C products. SUMMARY

[0007] The present application relates to the technical field of heat-conducting gaskets, and particularly relates to a phase-change gasket and a preparation method thereof.

[0008] A phase change gasket, the raw materials of which include: preform a, preform b, and coated phase change microcapsules, wherein the mass ratio of preform a, preform b, and coated phase change microcapsules is 13-27:11.1-25.5:25-55; wherein, preform a raw material by mass parts includes: 10-20 parts of vinyl-terminated silicone oil, 1-3 parts of hydrogen-terminated silicone oil, 1-2 parts of binder, and 1-2 parts of ethynylcyclohexanol; preform b raw material by mass parts includes: 10-20 parts of vinyl-terminated silicone oil, 1-5 parts of diluent, and 0.001-0.005 parts of catalyst.

[0009] Preferably, the vinyl content of the vinyl-terminated silicone oil is 5-8%.

[0010] Preferably, the degree of polymerization of the hydrogen-terminated silicone oil is 17000-17500.

[0011] Preferably, the adhesive is a KH560 coupling agent.

[0012] Preferably, the diluent is dimethyl silicone oil.

[0013] Preferably, the catalyst is a platinum catalyst, and the mass fraction of platinum in the platinum catalyst is 5000-10000 ppm.

[0014] Preferably, the phase change microcapsules are prepared by the following steps: the paraffin phase change microcapsules are soaked in a Tris-HCl buffer solution containing dopamine, the mass fraction of dopamine is 1-2.5%, the pH value of the Tris-HCl buffer solution containing dopamine is 8-9, the mixture is stirred at 40-70℃ for 5-10 hours, filtered, washed, and freeze-dried.

[0015] More preferably, the paraffin phase change microcapsules are prepared by the following steps: emulsifier, tetraethyl orthosilicate, and dibutyltin dilaurate are added to water, the pH of the system is adjusted to 4-5, and the mixture is stirred for 10-20 min. The mixture is then added to molten composite paraffin and stirred at 70-80℃ for 10-20 min. While stirring, the pH of the system is adjusted to 7-8. Then, dihydroxyl-terminated polydimethylsiloxane and γ-glycidyl etheroxypropyltrimethoxysilane are added and the mixture is stirred for 5-10 h. The mixture is aged for 10-15 h, centrifuged, the precipitate is washed, and then freeze-dried.

[0016] Specifically, the mass ratio of molten composite paraffin, emulsifier, tetraethyl orthosilicate, dibutyltin dilaurate, hydroxyl-terminated polydimethylsiloxane, and γ-glycidyl etheroxypropyltrimethoxysilane is 20-40:1-3:1-5:0.01-0.1:1-2:0.5-1.

[0017] Specifically, the emulsifier is Tween-80.

[0018] Specifically, the molten composite paraffin includes: paraffin and hexamethylene diisocyanate; the mass ratio of paraffin to hexamethylene diisocyanate is 20-40:1-3.

[0019] The preparation method of the above-mentioned phase change gasket includes the following steps: mixing preform material a and preform material b separately to obtain preform material a and preform material b; kneading the phase change microcapsules, preform material a, and preform material b together for 10-15 minutes, degassing under vacuum, rolling, and vulcanizing at 120-130℃ for 40-60 minutes.

[0020] Beneficial effects:

[0021] (1) The present invention coats the outer side of the paraffin with a polyurethane structural layer, which, together with the silica shell, forms a microcapsule. This not only improves the thermal stability and durability of the heat storage material and effectively increases the phase change heat utilization rate, but also makes it resistant to thermal shock. After thermal cycling, the phase change enthalpy value changes little, and it is safe and stable.

[0022] (2) The present invention combines a polydopamine structural layer on the surface of paraffin phase change microcapsules, which not only significantly increases the surface active sites and compatibility with the substrate, making the microcapsules have strong binding force in the system, but also effectively avoids the phenomenon of falling off by firmly binding the phase change material into the system, ensuring long-term stable temperature regulation effect, and can also synergistically enhance the adhesion of the product and greatly enhance the peel strength.

[0023] (3) This invention has excellent adhesion and heat resistance stability, and the phase change material has good sealing performance, long service life, can store a large amount of heat during the phase change process, and has good heat equalization effect. The preparation method of this invention is simple to operate, has low production cost and is easy to implement, which can greatly improve the economy and safety of heat storage. Attached Figure Description

[0024] Figure 1 This is a comparison chart of the phase transition points and phase transition enthalpy values ​​of the phase transition gaskets obtained in Example 5 and Comparative Examples 1-2.

[0025] Figure 2 This is a comparison chart of the peel strength and enthalpy change rate after thermal cycling of the phase change gaskets obtained in Example 5 and Comparative Examples 1-2. Detailed Implementation

[0026] The present invention will be further explained below with reference to specific embodiments.

[0027] The vinyl-terminated silicone oils used below are double-terminated vinyl silicone oils, purchased from Wuhan Kerry Chemical Co., Ltd., model MKR, with a vinyl content of 6.1-7.3%. The hydrogen-terminated silicone oils used below were purchased from Hubei Yamaide Biomedical Co., Ltd., with a viscosity (25℃) of 100 cP. The dimethyl silicone oils used below are from Dow Corning, with a viscosity of 100 mmHg. 2 / s. The dihydroxy-terminated polydimethylsiloxane used below was purchased from Wuhan Mouxiang Kejie Biotechnology Co., Ltd. The platinum catalyst used below was purchased from Shandong Huachen New Materials Co., Ltd., with a platinum content of 5000 ppm.

[0028] Example 1

[0029] A phase change gasket, the raw materials of which are composed of preform a, preform b and coated phase change microcapsules in a mass ratio of 13:11.1:25.

[0030] The raw materials for preform a include: 100g of vinyl-terminated silicone oil, 10g of hydrogen-terminated silicone oil, 10g of KH560 coupling agent, and 10g of ethynylcyclohexanol.

[0031] The raw materials for preform b include: 100g of vinyl-terminated silicone oil, 10g of dimethyl silicone oil, and 0.01g of platinum catalyst.

[0032] The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine with a mass fraction of 1% and a pH of 8-9. The mixture was stirred at 40℃ for 5 hours at a stirring speed of 50 r / min, filtered, washed, and freeze-dried.

[0033] Paraffin phase change microcapsules were prepared using the following steps: 10g Tween 80, 10g tetraethyl orthosilicate, and 0.1g dibutyltin dilaurate were added to 600g deionized water. The pH of the system was adjusted to 4-5 using 0.5mol / L hydrochloric acid. The mixture was stirred at 500r / min for 10min. Then, 200g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 20:1) was added. The mixture was stirred at 70℃ for 10min at a stirring speed of 1000r / min. Under stirring conditions, the pH of the system was adjusted to 7-8 using ammonia. 10g of dihydroxy-terminated polydimethylsiloxane and 5g of γ-glycidyl etheroxypropyltrimethoxysilane were added, and stirring was continued for 5h. The mixture was aged for 10h, centrifuged, and the precipitate was washed and freeze-dried.

[0034] The preparation method of the above-mentioned phase change gasket includes the following steps: adding preform material a to high-speed disperser a and stirring at 1000 r / min for 10 min to obtain preform material a; adding preform material b to high-speed disperser b and stirring at 1000 r / min for 10 min to obtain preform material b; adding the phase change microcapsules, preform material a, and preform material b to a kneader and kneading at 40 r / min for 10 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm film at a rolling speed of 15 cm / min, curing at 120℃ for 40 min, and then cooling to room temperature.

[0035] Example 2

[0036] A phase change gasket, the raw materials of which are composed of preform a, preform b and coated phase change microcapsules in a mass ratio of 27:25.5:55.

[0037] The raw materials for preform a include: 200g of vinyl-terminated silicone oil, 30g of hydrogen-terminated silicone oil, 20g of KH560 coupling agent, and 20g of ethynylcyclohexanol.

[0038] The raw materials for preform b include: 200g of vinyl-terminated silicone oil, 50g of dimethyl silicone oil, and 0.05g of platinum catalyst.

[0039] The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine with a mass fraction of 2.5% and a pH of 8-9. The mixture was stirred at 70°C for 10 hours at a stirring speed of 150 r / min, filtered, washed, and freeze-dried.

[0040] Paraffin phase change microcapsules were prepared using the following steps: 30g Tween 80, 50g tetraethyl orthosilicate, and 1g dibutyltin dilaurate were added to 1000g deionized water. The pH of the system was adjusted to 4-5 using 1.2mol / L hydrochloric acid. The mixture was stirred at 1000r / min for 20min. Then, 400g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 40:3) was added. The mixture was stirred at 80℃ for 20min at a stirring speed of 1500r / min. Under stirring conditions, the pH of the system was adjusted to 7-8 using ammonia. 20g of dihydroxy-terminated polydimethylsiloxane and 10g of γ-glycidyl etheroxypropyltrimethoxysilane were added. The mixture was stirred for 10h and aged for 15h. After centrifugation, the precipitate was washed and freeze-dried.

[0041] The preparation method of the above-mentioned phase change gasket includes the following steps: adding preform material a to high-speed disperser a and stirring at 1500 r / min for 20 min to obtain preform material a; adding preform material b to high-speed disperser b and stirring at 1500 r / min for 20 min to obtain preform material b; adding the phase change microcapsules, preform material a, and preform material b to a kneader and kneading at 60 r / min for 15 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm film at a rolling speed of 25 cm / min, curing at 130℃ for 60 min, and then cooling to room temperature.

[0042] Example 3

[0043] A phase change gasket, the raw materials of which are composed of preform a, preform b and coated phase change microcapsules in a mass ratio of 17:21.1:35.

[0044] The raw materials for preform a include: 180g of vinyl-terminated silicone oil, 15g of hydrogen-terminated silicone oil, 17g of KH560 coupling agent, and 13g of ethynylcyclohexanol.

[0045] The raw materials for preform b include: 180g of vinyl-terminated silicone oil, 20g of dimethyl silicone oil, and 0.04g of platinum catalyst.

[0046] The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine with a mass fraction of 1.5% and a pH of 8-9. The mixture was stirred at 60℃ for 7 hours at a stirring speed of 120 r / min, filtered, washed, and freeze-dried.

[0047] Paraffin phase change microcapsules were prepared using the following steps: 15g Tween 80, 40g tetraethyl orthosilicate, and 0.3g dibutyltin dilaurate were added to 1000g deionized water. The pH of the system was adjusted to 4-5 using 0.6mol / L hydrochloric acid. The mixture was stirred at 900r / min for 12min. Then, 350g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 25:2.5) was added. The mixture was stirred at 73℃ for 18min at a stirring speed of 1100r / min. Under stirring conditions, the pH of the system was adjusted to 7-8 using ammonia. 17g of dihydroxy-terminated polydimethylsiloxane and 6g of γ-glycidyl etheroxypropyltrimethoxysilane were added, and stirring was continued for 9h. The mixture was aged for 11h, centrifuged, and the precipitate was washed and freeze-dried.

[0048] The preparation method of the above-mentioned phase change gasket includes the following steps: adding preform material a to high-speed disperser a and stirring at 1300 r / min for 12 min to obtain preform material a; adding preform material b to high-speed disperser b and stirring at 1300 r / min for 13 min to obtain preform material b; adding the phase change microcapsules, preform material a, and preform material b to a kneader and kneading at 55 r / min for 12 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm thick sheet at a rolling speed of 22 cm / min, curing at 122℃ for 55 min, and then cooling to room temperature.

[0049] Example 4

[0050] A phase change gasket, the raw materials of which are composed of preform a, preform b and coated phase change microcapsules in a mass ratio of 23:15.7:45.

[0051] The raw materials for preform a include: 120g of vinyl-terminated silicone oil, 25g of hydrogen-terminated silicone oil, 13g of KH560 coupling agent, and 17g of ethynylcyclohexanol.

[0052] The raw materials for preform b include: 120g of vinyl-terminated silicone oil, 40g of dimethyl silicone oil, and 0.02g of platinum catalyst.

[0053] The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine with a mass fraction of 2% and a pH of 8-9. The mixture was stirred at 50°C for 9 hours at a stirring speed of 80 r / min, filtered, washed, and freeze-dried.

[0054] Paraffin phase change microcapsules were prepared using the following steps: 25g Tween 80, 20g tetraethyl orthosilicate, and 0.7g dibutyltin dilaurate were added to 600g deionized water. The pH of the system was adjusted to 4-5 using 1mol / L hydrochloric acid. The mixture was stirred at 700r / min for 18min. Then, 250g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 35:1.5) was added. The mixture was stirred at 77℃ for 12min at a stirring speed of 1300r / min. Under stirring conditions, the pH of the system was adjusted to 7-8 using ammonia. 13g of dihydroxy-terminated polydimethylsiloxane and 9g of γ-glycidyl etheroxypropyltrimethoxysilane were added, and stirring was continued for 7h. The mixture was aged for 13h, centrifuged, and the precipitate was washed and freeze-dried.

[0055] The preparation method of the above-mentioned phase change gasket includes the following steps: adding preform material a to high-speed disperser a and stirring at 1100 r / min for 18 min to obtain preform material a; adding preform material b to high-speed disperser b and stirring at 1100 r / min for 17 min to obtain preform material b; adding the phase change microcapsules, preform material a, and preform material b to a kneader and kneading at 45 r / min for 14 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm film at a rolling speed of 18 cm / min, curing at 128℃ for 45 min, and then cooling to room temperature.

[0056] Example 5

[0057] A phase change gasket, the raw materials of which are composed of preform a, preform b and coated phase change microcapsules in a mass ratio of 20:17.7:40.

[0058] The raw materials for preform a include: 150g of vinyl-terminated silicone oil, 20g of hydrogen-terminated silicone oil, 15g of KH560 coupling agent, and 15g of ethynylcyclohexanol.

[0059] The raw materials for preform b include: 150g of vinyl-terminated silicone oil, 30g of dimethyl silicone oil, and 0.03g of platinum catalyst.

[0060] The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine with a mass fraction of 1.8% and a pH of 8-9. The mixture was stirred at 55°C for 8 hours at a stirring speed of 100 r / min, filtered, washed, and freeze-dried.

[0061] Paraffin phase change microcapsules were prepared using the following steps: 20g Tween 80, 30g tetraethyl orthosilicate, and 0.5g dibutyltin dilaurate were added to 800g deionized water. The pH of the system was adjusted to 4-5 using 0.8mol / L hydrochloric acid. The mixture was stirred at 800r / min for 15min. Then, 300g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 15:1) was added. The mixture was stirred at 75℃ for 15min at a stirring speed of 1200r / min. Under stirring conditions, the pH of the system was adjusted to 7-8 using ammonia. 15g of dihydroxy-terminated polydimethylsiloxane and 7.5g of γ-glycidyl etheroxypropyltrimethoxysilane were added. The mixture was stirred for 8h and aged for 12h. After centrifugation, the precipitate was washed and freeze-dried.

[0062] The preparation method of the above-mentioned phase change gasket includes the following steps: adding preform material a to high-speed disperser a and stirring at 1200 r / min for 15 min to obtain preform material a; adding preform material b to high-speed disperser b and stirring at 1200 r / min for 15 min to obtain preform material b; adding the phase change microcapsules, preform material a, and preform material b to a kneader and kneading at 50 r / min for 13 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm thick sheet at a rolling speed of 20 cm / min, curing at 125℃ for 50 min, and then cooling to room temperature.

[0063] Comparative Example 1

[0064] A phase change gasket, the raw materials of which are composed of preform a, preform b and paraffin phase change microcapsules in a mass ratio of 20:17.7:40.

[0065] The raw materials for preform a include: 150g of vinyl-terminated silicone oil, 20g of hydrogen-terminated silicone oil, 15g of KH560 coupling agent, and 15g of ethynylcyclohexanol.

[0066] The raw materials for preform b include: 150g of vinyl-terminated silicone oil, 30g of dimethyl silicone oil, and 0.03g of platinum catalyst.

[0067] Paraffin phase change microcapsules were prepared using the following steps: 20g Tween 80, 30g tetraethyl orthosilicate, and 0.5g dibutyltin dilaurate were added to 800g deionized water. The pH of the system was adjusted to 4-5 using 0.8mol / L hydrochloric acid. The mixture was stirred at 800r / min for 15min. Then, 300g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 15:1) was added. The mixture was stirred at 75℃ for 15min at a stirring speed of 1200r / min. Under stirring conditions, the pH of the system was adjusted to 7-8 using ammonia. 15g of dihydroxy-terminated polydimethylsiloxane and 7.5g of γ-glycidyl etheroxypropyltrimethoxysilane were added. The mixture was stirred for 8h and aged for 12h. After centrifugation, the precipitate was washed and freeze-dried.

[0068] The preparation method of the above-mentioned phase change gasket includes the following steps: adding pre-material a to a high-speed disperser a and stirring at 1200 r / min for 15 min to obtain pre-material a; adding pre-material b to a high-speed disperser b and stirring at 1200 r / min for 15 min to obtain pre-material b; adding paraffin phase change microcapsules, pre-material a, and pre-material b to a kneader and kneading at 50 r / min for 13 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm film at a rolling speed of 20 cm / min, curing at 125℃ for 50 min, and then cooling to room temperature.

[0069] Comparative Example 2

[0070] A phase change gasket, the raw materials of which are composed of preform a, preform b and coated phase change microcapsules in a mass ratio of 20:17.7:40.

[0071] The raw materials for preform a include: 150g of vinyl-terminated silicone oil, 20g of hydrogen-terminated silicone oil, 15g of KH560 coupling agent, and 15g of ethynylcyclohexanol.

[0072] The raw materials for preform b include: 150g of vinyl-terminated silicone oil, 30g of dimethyl silicone oil, and 0.03g of platinum catalyst.

[0073] The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine with a mass fraction of 1.8% and a pH of 8-9. The mixture was stirred at 55°C for 8 hours at a stirring speed of 100 r / min, filtered, washed, and freeze-dried.

[0074] Paraffin phase change microcapsules were prepared using the following steps: 20g Tween 80 and 0.5g dibutyltin dilaurate were added to 800g deionized water and stirred at 800r / min for 15min. Then, 300g of molten composite paraffin (composed of paraffin and hexamethylene diisocyanate in a mass ratio of 15:1) was added and stirred at 75℃ for 15min at a stirring speed of 1200r / min. 15g of dihydroxy-terminated polydimethylsiloxane and 7.5g of γ-glycidyl etheroxypropyltrimethoxysilane were added and stirring was continued for 8h. The mixture was centrifuged, the precipitate was washed, and then freeze-dried.

[0075] The preparation method of the above-mentioned phase change gasket includes the following steps: adding preform material a to high-speed disperser a and stirring at 1200 r / min for 15 min to obtain preform material a; adding preform material b to high-speed disperser b and stirring at 1200 r / min for 15 min to obtain preform material b; adding the phase change microcapsules, preform material a, and preform material b to a kneader and kneading at 50 r / min for 13 min, degassing under vacuum, and feeding the mixture into a calender to roll a 0.2 mm thick sheet at a rolling speed of 20 cm / min, curing at 125℃ for 50 min, and then cooling to room temperature.

[0076] The phase change gaskets obtained in Example 5 and Comparative Examples 1-2 were subjected to the following performance tests:

[0077] (1) The phase transition point and phase transition enthalpy of each group of samples were determined using the German Netzsch DSC204C: the measurement temperature range was -20 to 100℃, and the heating rate was 10℃ / min.

[0078] (2) Peel strength test: Refer to GB / T2792-2014 "Test method for 180° peel strength of pressure sensitive adhesive tape" to test the 180° peel strength of each group of samples and steel plate.

[0079] During the testing process, the surface of the steel substrate must be sanded bidirectionally with P280 water-resistant sandpaper, followed by three cleanings with solvents such as acetone and ethyl acetate. The prepared samples must be conditioned for 20-40 minutes at 23℃±2℃ and 65%±5%RH. The test environment conditions are set at 23℃±2℃ and 50%RH±5%, with a peeling speed accurate to 300mm / min±10mm / min.

[0080] (3) Cold and hot cycle test: The cycle temperature is -40-85℃, the high and low temperature are maintained for 15 minutes, the heating and cooling time is 15 minutes, the number of cycles is 500, and after the cold and hot cycle, observe whether there is precipitation, wrinkles or powdering on the surface of each group of samples, and compare whether the phase transition enthalpy value before and after the test is ≤10%.

[0081] like Figure 1and Figure 2 As shown, the phase change gasket obtained in Example 5 had the highest phase change point, phase change enthalpy, and peel strength, while exhibiting the smallest enthalpy change rate after thermal cycling, which was superior to Comparative Examples 1-2 (P < 0.05). Neither the phase change gaskets obtained in Example 5 nor Comparative Examples 1-2 showed any precipitation, wrinkling, or powdering after thermal cycling.

[0082] The reason for the above results is that the present invention coats the paraffin wax with a polyurethane structural layer, which, together with the silica shell, forms microcapsules. This not only improves the thermal stability and durability of the heat storage material and effectively increases the phase change heat utilization rate, but also enhances its resistance to thermal shock. The phase change enthalpy change rate is small after thermal cycling, ensuring safety and stability. Furthermore, the present invention combines a polydopamine structural layer on the surface of the paraffin wax phase change microcapsules. This significantly increases the surface active sites and compatibility with the substrate, resulting in strong adhesion of the microcapsules within the system. By firmly binding the phase change material to the system, it effectively prevents detachment, ensuring long-term stable temperature regulation. Moreover, it synergistically enhances the adhesion of the product, greatly increasing peel strength.

[0083] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A phase change gasket, characterized in that, Its raw materials include: preform a, preform b, and coated phase change microcapsules, with the mass ratio of preform a, preform b, and coated phase change microcapsules being 13-27:11.1-25.5:25-55; Among them, the raw material a of the preform includes, by mass, 10-20 parts of vinyl-terminated silicone oil, 1-3 parts of hydrogen-terminated silicone oil, 1-2 parts of adhesive, and 1-2 parts of ethynylcyclohexanol. The raw materials for preform b include, by weight, 10-20 parts of vinyl-terminated silicone oil, 1-5 parts of diluent, and 0.001-0.005 parts of catalyst; The phase change microcapsules were prepared by the following steps: the paraffin phase change microcapsules were soaked in Tris-HCl buffer containing dopamine, the mass fraction of dopamine was 1%, the pH of the Tris-HCl buffer containing dopamine was 8-9, the mixture was stirred at 40℃ for 5h at a stirring speed of 50r / min, filtered, washed, and freeze-dried. Paraffin phase change microcapsules are prepared using the following steps: emulsifier, tetraethyl orthosilicate, and dibutyltin dilaurate are added to water, the pH of the system is adjusted to 4-5, and the mixture is stirred for 10-20 minutes. The mixture is then added to molten composite paraffin and stirred at 70-80℃ for 10-20 minutes. While stirring, the pH of the system is adjusted to 7-8. Then, dihydroxyl-terminated polydimethylsiloxane and γ-glycidyl etheroxypropyltrimethoxysilane are added, and the mixture is stirred for 5-10 hours. The mixture is aged for 10-15 hours, centrifuged, the precipitate is washed, and then freeze-dried.

2. The phase change gasket according to claim 1, characterized in that, The vinyl content of vinyl-terminated silicone oil is 5-8%.

3. The phase change gasket according to claim 1, characterized in that, The adhesive is KH560 coupling agent.

4. The phase change gasket according to claim 1, characterized in that, The diluent is dimethyl silicone oil.

5. The phase change gasket according to claim 1, characterized in that, The catalyst is a platinum catalyst, and the mass fraction of platinum in the platinum catalyst is 5000-10000 ppm.

6. The phase change gasket according to claim 1, characterized in that, The mass ratio of molten composite paraffin, emulsifier, tetraethyl orthosilicate, dibutyltin dilaurate, hydroxyl-terminated polydimethylsiloxane, and γ-glycidyl etheroxypropyltrimethoxysilane is 20-40:1-3:1-5:0.01-0.1:1-2:0.5-1; the emulsifier is Tween-80.

7. The phase change gasket according to claim 1, characterized in that, The molten composite paraffin wax comprises: paraffin wax and hexamethylene diisocyanate; the mass ratio of paraffin wax to hexamethylene diisocyanate is 20-40:1-3.

8. A method for preparing a phase change gasket as described in any one of claims 1-7, characterized in that, The process includes the following steps: mixing preform material a and preform material b separately to obtain preform material a and preform material b; kneading the coated phase change microcapsules, preform material a, and preform material b together for 10-15 minutes, degassing under vacuum, rolling, and vulcanizing at 120-130℃ for 40-60 minutes.

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