A phase change thermally conductive material based on block organosilicon copolymer and its preparation method

Abstract

This application provides a phase change thermal conductive material based on block copolymer, which, by weight percentage, comprises the following components: 1.5%-4.0% block copolymer polymer; 0.03%-0.10% antioxidant; 6%-12% nano-monocrystalline diamond powder; 20%-30% aluminum powder; 6%-10% monocrystalline silicon carbide; 8%-12% nano-zinc oxide; 0.01%-0.02% vulcanizing aid; 0.01%-0.02% high-temperature resistant surfactant; 0.15%-0.25% diluent; 0.10%-0.15% high-temperature resistant coupling agent; and 38%-52% high-boiling-point solvent. By modifying the polyolefin polymer through block grafting, the temperature resistance of the phase change thermal conductive material matrix resin is improved while maintaining the resin's thermoplastic properties, providing a more stable and reliable thermal conductive material for the heat dissipation design of large-scale server chips.

Description

Technical Field

[0001] This invention relates to the field of phase change thermal conductive materials, specifically to a phase change thermal conductive material based on block organosilicon copolymers and its preparation method. Background Technology

[0002] Currently, AI is experiencing explosive growth and rapid iteration. Traditional servers, primarily used for general-purpose computing, are struggling to meet the current demands of AI computing power, especially deep learning capabilities and the core requirements for large-scale parallel matrix operations. Modern dedicated hardware for large-scale model servers possesses extremely high parallel computing capabilities in neural network training and inference models. The energy efficiency of core components is significantly higher than that of traditional servers, resulting in enormous power consumption and heat generation. Ordinary phase-change thermal conductive materials are mostly designed for consumer electronics and can only withstand high temperatures temporarily. In high-power, high-heat environments, these materials will gradually undergo thermal degradation and aging, leading to a gradual increase in interfacial thermal resistance and a decrease in heat transfer rate, causing heat buildup and frequency reduction in server computing chips. Summary of the Invention

[0003] In view of the aforementioned problems, this application is made to provide a phase change thermally conductive material based on a block organosilicon copolymer and a method for preparing the same, which overcomes or at least partially solves the aforementioned problems, comprising: A phase change thermally conductive material based on block organosilicon copolymers, comprising the following components by weight percentage: Block copolymer polymers: 1.5%-4.0%; Antioxidant 0.03%-0.10%; Nano-single crystal diamond powder 6%-12%; aluminum powder 20%-30%; Single-crystal silicon carbide 6%-10%; Nano zinc oxide 8%-12%; Vulcanizing aid 0.01%-0.02%; High-temperature resistant surfactant: 0.01%-0.02%; Diluent 0.15%-0.25%; High-temperature resistant coupling agent 0.10%-0.15%; High-boiling-point solvents: 38%-52%.

[0004] Furthermore, the block copolymer polymer material is composed of one or more copolymers of hydroxyl-terminated polyisobutylene, hydroxy acrylate, SEBS, hydroxyl-terminated polydimethylsiloxane, trimethoxy-terminated polydimethylsiloxane, and triethoxy-terminated polydimethylsiloxane.

[0005] Furthermore, the antioxidant includes one or more of ionic antioxidants, hindered phenolic antioxidants, and phosphate ester antioxidants.

[0006] Furthermore, the sulfidation aid is one or more of isocyanate, organotin catalyst, sulfur, and peroxide.

[0007] Furthermore, the high-temperature resistant surfactant includes one or more of fluorinated alkyl surfactants, sodium dodecylbenzene sulfonate, and sodium α-alkenyl sulfonate.

[0008] Furthermore, the diluent includes one or more of microcrystalline wax, liquid paraffin, polyethylene wax, and naphthenic oil.

[0009] Furthermore, the coupling agent comprises one or more of the following: single-sided trimethoxy-terminated polydimethylsilane, γ-(methacryloyloxy)propyltrimethoxysilane, tridecafluorooctyltriethoxysilane, phthalate, trimethoxyphenylsilane, tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, and 4,4′-bis(triethoxysilane)-1,1′-biphenyl polyolefin.

[0010] Furthermore, the nano-single crystal diamond powder, aluminum powder, hexagonal silicon carbide, and thermally conductive ceramic powder with a particle size distribution of 0.1-20 μm are used.

[0011] Furthermore, the high-boiling-point solvent is one or more of butyl carbitol, butyl carbitol acetate, terpineol, and dibutyl phthalate.

[0012] A method for preparing a phase change thermally conductive material based on a block organosilicon copolymer as described in any of the above claims, wherein the components of the method, by weight percentage, consist of the following: 1.5%-4.0% block copolymer polymer; 0.03%-0.10% antioxidant; 6%-12% nano-monocrystalline diamond powder; 20%-30% aluminum powder; 6%-10% monocrystalline silicon carbide; 8%-12% nano-zinc oxide; 0.01%-0.02% vulcanizing aid; 0.01%-0.02% high-temperature resistant surfactant; 0.15%-0.25% diluent; 0.10%-0.15% high-temperature resistant coupling agent; and 38%-52% high-boiling-point solvent; the method includes the following steps: Nano-single crystal diamond powder, aluminum powder, hexagonal silicon carbide, high-boiling-point solvent and coupling agent are mixed and ultrasonically stirred until uniform. The temperature is raised to 70-90℃ for wet surface grafting modification treatment, and the modified powder is obtained by vacuum filtration and drying. A block copolymer polymer material is prepared, wherein the block copolymer polymer material is copolymerized from one or more of the following: hydroxyl-terminated polyisobutylene, hydroxy acrylate, SEBS, hydroxyl-terminated polydimethylsiloxane, trimethoxy-terminated polydimethylsiloxane, and triethoxy-terminated polydimethylsiloxane. The modified powder is added to the block copolymer polymer material and stirred at high speed until uniform. The temperature is raised to 120-150℃ and vacuum stirred to obtain a mixed phase change thermal conductive adhesive. The mixed phase change thermally conductive adhesive is heated to 120°C and calendered into 0.1-0.5mm thin sheets using a twin-roll calender to obtain a heat-resistant, oxygen-aging-resistant, high thermal conductivity phase change material.

[0013] This application has the following advantages: In the embodiments of this application, addressing the issue that large servers in the prior art generate enormous power consumption and heat, and that ordinary phase change thermal conductive materials will gradually undergo thermal degradation and aging under high power consumption and high heat environments, leading to a gradual increase in interfacial thermal resistance and a decrease in heat transfer rate, resulting in heat accumulation and frequency reduction in server computing chips, this application provides a phase change thermal conductive material based on block copolymers, which, by weight percentage, consists of the following components: 1.5%-4.0% block copolymer polymer; 0.03%-0.10% antioxidant; 6%-12% nano-monocrystalline diamond powder; 20%-30% aluminum powder; 6%-10% monocrystalline silicon carbide; 8%-12% nano-zinc oxide; 0.01%-0.02% vulcanizing aid; 0.01%-0.02% high-temperature resistant surfactant; 0.15%-0.25% diluent; 0.10%-0.15% high-temperature resistant coupling agent; and 38%-52% high-boiling-point solvent. By block grafting modification of polyolefin polymers, the temperature resistance of the phase change thermal conductive material matrix resin is improved while maintaining the thermoplastic properties of the resin. By composite filling with modified nano-single crystal diamond powder, aluminum powder, and hexagonal silicon carbide powder, a heat-resistant oxygen aging-resistant phase change thermal conductive material has been successfully prepared. It can operate for a long time in a high-temperature environment of 180-200℃, avoiding the pumping problem of traditional thermal grease under high pressure, and solving the thermal degradation and aging failure of phase change thermal conductive materials. This provides a more stable and reliable thermal conductive material for the heat dissipation design of large-scale server chips. Attached Figure Description

[0014] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart illustrating the steps of a method for preparing a phase change thermally conductive material based on a block organosilicon copolymer, as provided in an embodiment of this application. Detailed Implementation

[0016] To make the objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0017] The inventors discovered through analysis of existing technologies that ordinary phase change thermal conductive materials are mostly designed for the consumer electronics field and can only withstand high temperatures for a short period of time. If used in a high-power, high-heat environment, the materials will slowly undergo thermal degradation and aging, the interface thermal resistance will gradually increase, the heat transfer rate will decrease, and the server computing chip will accumulate heat and reduce its frequency.

[0018] One embodiment of this application provides a phase change thermally conductive material based on block organosilicon copolymers, which, by weight percentage, comprises the following components: Block copolymer polymers: 1.5%-4.0%; Antioxidant 0.03%-0.10%; Nano-single crystal diamond powder 6%-12%; aluminum powder 20%-30%; Single-crystal silicon carbide 6%-10%; Nano zinc oxide 8%-12%; Vulcanizing aid 0.01%-0.02%; High-temperature resistant surfactant: 0.01%-0.02%; Diluent 0.15%-0.25%; High-temperature resistant coupling agent 0.10%-0.15%; High-boiling-point solvents: 38%-52%.

[0019] It should be noted that the components work synergistically according to specific weight percentages to form a functional system that combines high thermal conductivity with resistance to heat and oxygen aging. Among them, aluminum powder, with the highest proportion of 20%-30%, becomes the core thermally conductive component, combined with 6%-12% nano-single-crystal diamond powder and 6%-10% single-crystal silicon carbide. The three types of thermally conductive powders form a complementary and synergistic effect, which greatly improves the heat transfer efficiency of the material. 1.5%-4.0% of block copolymer polymer material serves as the matrix resin, providing the material with good thermoplastic properties and temperature resistance. 8%-12% of nano-zinc oxide further assists in optimizing the thermal conductivity network and material stability.

[0020] Although functional additives constitute a very small percentage, their role is crucial. 0.03%-0.10% antioxidants effectively inhibit oxidative degradation of the material under high-temperature conditions; 0.01%-0.02% vulcanizing aids promote the cross-linking reaction of the matrix resin, enhancing the material's structural stability; while 0.01%-0.02% high-temperature resistant surfactants and 0.10%-0.15% high-temperature resistant coupling agents work together to improve the compatibility between the thermally conductive powder and the matrix resin, reducing interfacial thermal resistance. 0.15%-0.25% diluent allows for flexible adjustment of the material's viscosity, adapting to subsequent processing requirements and ensuring optimal molding results.

[0021] High-boiling-point solvents, comprising 38%-52% of the formulation, serve as crucial media, providing a stable environment for the mixing and reaction of various components and facilitating the smooth progress of wet surface grafting modification and melt copolymerization. Their high-boiling-point characteristics also prevent performance fluctuations caused by solvent evaporation during high-temperature processing and use. The precise matching and range optimization of the component proportions preserve the stability of core performance while allowing ample adjustment space for adaptation to different heat dissipation scenarios and process conditions. This ensures that the material maintains its core advantages of low thermal resistance and high heat transfer efficiency even during long-term operation at high temperatures of 180-200℃.

[0022] In the embodiments of this application, addressing the issue that large servers in the prior art generate enormous power consumption and heat, and that ordinary phase change thermal conductive materials will gradually undergo thermal degradation and aging under high power consumption and high heat environments, leading to a gradual increase in interfacial thermal resistance, a decrease in heat transfer rate, and the problem of heat accumulation and frequency reduction in server computing chips, this application provides a phase change thermal conductive material based on block copolymer, which, by weight percentage, consists of the following components: block copolymer polymer material 1.5%-4.0%; antioxidant 0.03%-0.10%; nano-single crystal diamond powder 6%-12%; aluminum powder 20%-30%; single crystal silicon carbide 6%-10%; nano-zinc oxide 8%-12%; vulcanizing aid 0.01%-0.02%; high-temperature resistant surfactant 0.01%-0.02%; diluent 0.15%-0.25%; high-temperature resistant coupling agent 0.10%-0.15%; and high-boiling-point solvent 38%-52%. By block grafting modification of polyolefin polymers, the temperature resistance of the phase change thermal conductive material matrix resin is improved while maintaining the thermoplastic properties of the resin. By composite filling with modified nano-single crystal diamond powder, aluminum powder, and hexagonal silicon carbide powder, a heat-resistant oxygen aging-resistant phase change thermal conductive material has been successfully prepared. It can operate for a long time in a high-temperature environment of 180-200℃, avoiding the pumping problem of traditional thermal grease under high pressure, and solving the thermal degradation and aging failure of phase change thermal conductive materials. This provides a more stable and reliable thermal conductive material for the heat dissipation design of large-scale server chips.

[0023] The following will further describe a phase change thermally conductive material based on block organosilicon copolymers in this exemplary embodiment.

[0024] In this embodiment, the block copolymer polymer material is one or more copolymers of hydroxyl-terminated polyisobutylene, hydroxy acrylate, SEBS, hydroxyl-terminated polydimethylsiloxane, trimethoxy-terminated polydimethylsiloxane, and triethoxy-terminated polydimethylsiloxane.

[0025] It should be noted that the block copolymer polymer material is the core matrix component of the phase change thermal conductive material. Its selection directly determines the material's temperature resistance, flexibility, and processing adaptability. Specifically, it can be selected from one or more of the following: organosilicon block modified polyisobutylene, organosilicon block modified acrylate, hydroxyl-terminated polyisobutylene, hydroxyl-terminated polydimethylsiloxane, hydroxyl acrylate, and SEBS. The dosage of a single component or the ratio of multiple components can be flexibly adjusted according to the different requirements of the target scenario for the material's rigidity, viscosity, and temperature resistance.

[0026] These block copolymer polymers have unique molecular structure advantages. The introduction of organosilicon blocks significantly improves the high temperature resistance and thermal stability of the matrix, while polyisobutylene, acrylate and other segments ensure the thermoplastic processability and interfacial wettability of the material. The terminal hydroxyl and other functional groups can also react synergistically with vulcanizing agents and coupling agents to further enhance the compactness of the internal structure of the material and the binding force between components.

[0027] The multi-component design provides ample room for adapting material performance. Whether it is an extreme heat dissipation scenario that pursues high temperature resistance or a conventional application scenario that focuses on flexibility and interface adhesion, the matrix material can achieve a balance in core properties such as resistance to high temperature aging of 180-200℃, low interfacial thermal resistance, and resistance to high pressure pumping by reasonably selecting the combination of components such as organosilicon block-modified polyisobutylene and hydroxyl-terminated polydimethylsiloxane, thus ensuring the stability of the phase change material.

[0028] In this embodiment, the antioxidant includes one or more of ionic antioxidants, hindered phenolic antioxidants, and phosphate ester antioxidants.

[0029] It should be noted that the antioxidants mentioned are functional additives that ensure the heat and oxygen aging resistance of phase change thermal conductive materials. Their selection includes one or more of ionic antioxidants, hindered phenolic antioxidants, and phosphate ester antioxidants, which can be flexibly combined according to the high-temperature application scenarios and the characteristics of the matrix resin. Ionic antioxidants exert a stable antioxidant effect due to the strong interaction of ionic bonds; hindered phenolic antioxidants can block oxidation chain reactions by capturing free radicals; and phosphate ester antioxidants have the dual function of decomposing hydrogen peroxide and assisting in antioxidant activity. All three types of antioxidants, used alone or in combination, can specifically inhibit the thermal degradation and aging failure of materials during long-term operation at 180-200℃.

[0030] The diverse selection and adaptable design of antioxidants can synergize with the molecular structure of block copolymer polymers, effectively delaying oxidative crosslinking and chain breakage of the matrix resin under high-temperature environments, while avoiding negative impacts on the material's thermal conductivity and interfacial compatibility. For example, when hindered phenolic and phosphate ester antioxidants are combined, they can exert a synergistic effect of "primary antioxidant + secondary antioxidant," significantly improving the material's anti-aging durability and ensuring that the phase change thermal conductive material can maintain stable thermal resistance and heat transfer efficiency even after long-term high-temperature use. Its diverse selection range covers antioxidant types with different mechanisms of action and provides flexible adjustment space for performance optimization under different production processes and usage environments, ultimately helping phase change thermal conductive materials meet the core requirements of long-term high-temperature resistance and anti-aging in high-power scenarios such as AI server computing chips.

[0031] In this embodiment, the sulfidation aid is one or more of isocyanate, organotin catalyst, sulfur, and peroxide.

[0032] It should be noted that the vulcanizing aids are the core components for regulating the crosslinking structure of block copolymer polymers. The selection includes one or more of isocyanates, organotin catalysts, sulfur, and peroxides, and can be flexibly chosen based on the functional group type of the matrix resin, processing temperature, and target crosslinking density. Isocyanates can undergo addition reactions with the hydroxyl groups of components such as hydroxyl-terminated polyisobutylene and hydroxyacrylates to form stable urea crosslinking bonds; organotin catalysts can accelerate the crosslinking reaction process and improve reaction efficiency; sulfur and peroxides, by initiating free radical polymerization of polymer segments, construct a dense crosslinking network. Different types of vulcanizing aids, used alone or in combination, can specifically optimize the structural stability and temperature resistance of the material.

[0033] The diverse selection of vulcanizing auxiliaries forms a highly efficient synergy with the matrix resin. During melt copolymerization at 70-100℃, they can precisely trigger the crosslinking reaction of block copolymer polymers, enhancing the material's mechanical strength and resistance to high-temperature deformation while preventing increased brittleness due to excessive crosslinking. For example, when organotin catalysts are combined with isocyanates, the activation energy of the reaction can be reduced while ensuring the uniform distribution of crosslinks. When peroxides are used as vulcanizing auxiliaries, they can rapidly form crosslinked structures during high-temperature processing, helping the material maintain morphological stability during long-term use at 180-200℃ and avoiding heat loss or pumping problems.

[0034] The diverse range of options not only adapts to the reaction characteristics of different block copolymer polymers, but also provides flexible space for adjusting process parameters. Ultimately, by constructing a stable cross-linked structure, the heat resistance and structural integrity of the material are improved, ensuring that the phase change thermal conductive material continues to perform stable heat transfer performance in high-power chip heat dissipation scenarios.

[0035] In this embodiment, the high-temperature resistant surfactant includes one or more of fluorinated alkyl surfactants, sodium dodecylbenzene sulfonate, and sodium α-alkenyl sulfonate.

[0036] It should be noted that the high-temperature resistant surfactant is a key additive for optimizing the compatibility of various components in phase change thermal conductive materials. The selection includes one or more of fluorinated alkyl surfactants, sodium dodecylbenzene sulfonate, and sodium α-alkenyl sulfonate, which can be flexibly adapted according to the surface characteristics of the thermally conductive powder and the polarity of the matrix resin. Fluorinated alkyl surfactants, due to the low surface energy of their fluorocarbon chains, can significantly reduce the interfacial tension between components. Sodium dodecylbenzene sulfonate and sodium α-alkenyl sulfonate, through the synergistic effect of hydrophilic and hydrophobic groups, achieve efficient dispersion of inorganic powders such as nano-single-crystal diamond powder and aluminum powder. Different types of surfactants, used alone or in combination, can effectively improve the wettability of inorganic powders to organic matrices and prevent powder agglomeration.

[0037] The diverse selection of high-temperature resistant surfactants synergizes well with the material system. During wet surface grafting modification at 70-90℃ and subsequent melt mixing, they can adsorb onto the surface of thermally conductive powders, forming a stable dispersion protective film, reducing interfacial thermal resistance caused by powder agglomeration, and improving the uniformity of the mixture. For example, fluorinated alkyl surfactants, when paired with non-polar organosilicon block-modified polyisobutylene matrices, can enhance the dispersion stability of the powder in the matrix; sodium dodecylbenzenesulfonate and sodium α-alkenylsulfonate are more suitable for hydroxyl-containing resin systems, strengthening the bonding force between the powder and the matrix through ionic bonding, and helping to build a continuous and efficient thermally conductive network.

[0038] The diverse range of choices covers surface active types with different polarities and mechanisms of action, and is compatible with material systems with different component combinations. At the same time, its high-temperature resistance ensures that it will not decompose or fail in long-term use at 180-200℃, and continuously maintains component compatibility and dispersion stability, ultimately helping phase change thermal conductive materials achieve the core requirements of low interfacial thermal resistance and high heat transfer efficiency.

[0039] In this embodiment, the diluent includes one or more of microcrystalline wax, liquid paraffin, polyethylene wax, and naphthenic oil.

[0040] It should be noted that the appropriate diluent can be flexibly selected based on the material's processing requirements, target flexibility, and phase transition temperature. Microcrystalline wax and polyethylene wax can moderately improve the system's rigidity while ensuring the material's high-temperature resistance; liquid paraffin and naphthenic oil, with their excellent compatibility and fluidity, effectively reduce the viscosity of the matrix resin. Different types of diluents, used alone or in combination, can specifically optimize the material's melt processing characteristics and interfacial adhesion. The diverse selection of diluents synergizes well with block copolymer polymers, ensuring uniform dispersion in the resin matrix during melt copolymerization at 70-100℃ and subsequent mixing and calendering processes. This reduces internal friction between components, facilitates thorough mixing of the thermally conductive powder and the matrix, and improves the material's ductility, ensuring smooth molding into 0.1-0.5mm sheets during calendering. For example, when naphthenic oil is combined with hydroxyl-terminated polydimethylsiloxane, it enhances the material's flexibility and interfacial wettability; when microcrystalline wax and polyethylene wax are combined, they can improve the material's shape stability without affecting thermal conductivity, preventing excessive deformation during high-temperature use.

[0041] In this embodiment, the coupling agent includes one or more of the following: single-sided trimethoxy-terminated polydimethylsilane, γ-(methacryloyloxy)propyltrimethoxysilane, tridecafluorooctyltriethoxysilane, phthalate, trimethoxyphenylsilane, tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, and 4,4′-bis(triethoxysilane)-1,1′-biphenyl polyolefin.

[0042] It should be noted that the coupling agent is a key component in constructing a stable bond between the organic matrix and the inorganic thermally conductive powder in the phase change thermally conductive material. The selection covers one or more of the following: single-sided trimethoxy-terminated polydimethylsilane, γ-(methacryloyloxy)propyltrimethoxysilane, tridecafluorooctyltriethoxysilane, phthalates, trimethoxyphenylsilane, tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, and 4,4′-bis(triethoxysilane)-1,1′-biphenyl polyolefin. The agent can be flexibly adapted based on the surface chemical characteristics of the thermally conductive powder (nanocrystalline diamond powder, aluminum powder, single-crystal silicon carbide, etc.) and the functional group type of the block copolymer polymer. These coupling agent molecules typically possess both inorganic-philic and organic-philic groups. The inorganic-philic end can undergo a condensation reaction with the hydroxyl groups on the surface of the thermally conductive powder to form a chemical bond, while the organic-philic end can copolymerize or physically entangle with the segments of the matrix resin.

[0043] The diverse selection of coupling agents and their synergistic effect with the material system create a highly efficient coating. During wet surface grafting modification at 70-90℃, they can uniformly coat the surface of thermally conductive powders, acting as a "bridge." This effectively inhibits powder agglomeration, improves the uniformity of powder dispersion in the matrix, strengthens the interfacial bonding between the powder and the matrix, reduces interfacial thermal resistance, and helps construct a continuous and efficient thermally conductive network. For example, when single-sided trimethoxy-terminated polydimethylsilane is adapted to an organosilicon-modified resin matrix, it can form a stable bond with the matrix through silicon-oxygen bonds; the double bond structure of γ-(methacryloyloxy)propyltrimethoxysilane can undergo copolymerization with acrylate resins, further improving interfacial compatibility; and tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, with its multifunctional characteristics, can simultaneously bind multiple powder particles and matrix segments, enhancing the overall integrity of the system. The wide range of options covers coupling types with different structures and mechanisms of action, which can be adapted to different combinations of thermally conductive powders and matrix resins, while also leaving room for process optimization. At the same time, its high temperature resistance ensures that it will not decompose or desorb in long-term use at 180-200℃, and maintains a stable bond at the organic-inorganic interface. Ultimately, it helps phase change thermal conductive materials achieve the core performance requirements of low thermal resistance, high thermal conductivity and long-term aging resistance.

[0044] In this embodiment, the nano-single crystal diamond powder, aluminum powder, hexagonal silicon carbide, and thermally conductive ceramic powder with a particle size distribution of 0.1-20 μm are used.

[0045] It should be noted that the nano-single-crystal diamond powder, aluminum powder, and hexagonal silicon carbide all belong to a thermally conductive ceramic powder system with a particle size distribution of 0.1-20 μm. They are the core functional components for achieving high thermal conductivity in phase change thermally conductive materials. These three types of powders, with their respective excellent thermal conductivity and particle size advantages, form a synergistic and complementary thermal conductivity network. Nano-single-crystal diamond powder possesses both ultra-high thermal conductivity and chemical stability, enabling rapid heat conduction; aluminum powder has high thermal conductivity and good processing adaptability, filling the voids within the system; and hexagonal silicon carbide, with its high temperature resistance and stable thermal conductivity, further optimizes the thermal conduction path. Its wide particle size distribution of 0.1-20 μm allows for the close packing of powders of different particle sizes, reducing voids and interfacial thermal resistance in the thermal conduction channels.

[0046] The selection of this particle size range not only suits the material preparation process and application scenario but also maximizes the performance advantages of the thermally conductive powder. During wet surface grafting modification at 70-90℃, a particle size of 0.1-20µm ensures that the coupling agent fully coats the powder surface, improving compatibility with the organic matrix. In subsequent melt mixing and calendering, this particle size range prevents powder agglomeration or sedimentation, ensuring uniform dispersion of the powder in the matrix. It also meets the molding requirements of 0.1-0.5mm thin sheets without affecting the interfacial adhesion of the material. Furthermore, powders within this particle size range exhibit structural stability at high temperatures, preventing the thermally conductive network from breaking due to thermal expansion or contraction, making them suitable for long-term use at 180-200℃.

[0047] The particle size of the three types of thermally conductive ceramic powders is uniformly controlled within the range of 0.1-20 μm, providing flexible space for adjusting the thermal conductivity of the material. By adjusting the proportion of powders with different particle sizes, the thermal conductivity and thermal resistance can be optimized in a targeted manner. For example, increasing the proportion of small-particle-size (0.1-5 μm) powders can fill the gaps between large-particle-size powders, improving the continuity of the thermal conductive network; adjusting the proportion of large-particle-size (5-20 μm) powders can further improve the overall thermal conductivity efficiency, ultimately meeting the core requirements of high-power scenarios such as AI server computing chips for efficient heat transfer. At the same time, in conjunction with the matrix resin and functional additives, a balance between the material's thermal conductivity and aging resistance can be achieved.

[0048] In this embodiment, the high-boiling-point solvent is one or more of butyl carbitol, butyl carbitol acetate, terpineol, and dibutyl phthalate.

[0049] It should be noted that the appropriate solvent can be flexibly selected based on the requirements of the preparation process, the solubility of the components, and the application scenario of the material. These solvents all possess the core characteristics of high boiling point and low volatility, and can remain stable during high-temperature processing such as melt copolymerization at 70-100℃ and wet surface grafting modification at 70-90℃, avoiding component concentration imbalance or incomplete reaction due to solvent evaporation. At the same time, they do not decompose or migrate under long-term material use conditions at 180-200℃, ensuring the stability of material performance.

[0050] The diverse selection of high-boiling-point solvents ensures good compatibility with the various components of the material. Their excellent solubility can fully disperse organic components such as block copolymer polymers, antioxidants, and vulcanization auxiliaries. Simultaneously, they provide a uniform reaction environment for the wet modification of inorganic thermally conductive powders such as nano-single-crystal diamond powder and aluminum powder, facilitating the full bonding of coupling agents to the powder surface and enhancing the modification effect. For example, butyl carbitol acetate, with its good solubility and volatility control, is a preferred solvent for wet modification and melt copolymerization. Dibutyl phthalate not only dissolves organic components but also moderately improves the flexibility and interfacial adhesion of the material. Butyl carbitol and terpineol, with their low toxicity and good environmental adaptability, are suitable for production scenarios with different environmental protection requirements. This diverse selection covers solvent types with different solubility and viscosity characteristics, adaptable to different component combinations and process parameter adjustments. While ensuring the smooth progress of the preparation process, it avoids negative impacts on the thermal conductivity and aging resistance of the material, ultimately contributing to the formation of a uniform and stable system for phase change thermally conductive materials.

[0051] Reference Figure 1 This application illustrates a method for preparing a phase change thermally conductive material based on a block copolymer, according to an embodiment of the present application. The method comprises the following components by weight percentage: 1.5%-4.0% block copolymer polymer; 0.03%-0.10% antioxidant; 6%-12% nano-monocrystalline diamond powder; 20%-30% aluminum powder; 6%-10% monocrystalline silicon carbide; 8%-12% nano-zinc oxide; 0.01%-0.02% vulcanizing aid; 0.01%-0.02% high-temperature resistant surfactant; 0.15%-0.25% diluent; 0.10%-0.15% high-temperature resistant coupling agent; and 38%-52% high-boiling-point solvent. The method includes the following steps: S110. Nano-single crystal diamond powder, aluminum powder, hexagonal silicon carbide, high-boiling-point solvent and coupling agent are mixed and ultrasonically stirred evenly. The temperature is raised to 70-90℃ for wet surface grafting modification treatment, and the modified powder is obtained by vacuum filtration and drying. Focusing on the modification of thermally conductive powders, core thermally conductive components such as nano-single-crystal diamond powder, aluminum powder, and hexagonal silicon carbide are mixed with high-boiling-point solvents and high-temperature resistant coupling agents in a specific ratio. The mixture is then ultrasonically stirred to ensure initial uniform dispersion, followed by wet surface grafting modification at 70-90℃. This temperature range activates the reactivity of the coupling agent, allowing its inorganic ends to fully bind with the hydroxyl groups on the powder surface, while also preventing excessive solvent evaporation. Finally, the modified powder, with excellent dispersibility and strong compatibility with the organic matrix, is obtained through vacuum filtration and drying, laying the foundation for constructing a continuous thermally conductive network.

[0052] S120. Prepare a block copolymer polymer material, wherein the block copolymer polymer material is copolymerized from one or more of the following: hydroxyl-terminated polyisobutylene, hydroxy acrylate, SEBS, hydroxyl-terminated polydimethylsiloxane, trimethoxy-terminated polydimethylsiloxane, and triethoxy-terminated polydimethylsiloxane. S130. The modified powder is added to the block copolymer polymer material, and after being stirred at high speed until uniform, the temperature is raised to 120-150℃ and vacuum stirred to obtain a mixed phase change thermal conductive adhesive. The modified powder is added to the block copolymer polymer material, and the powder agglomeration is broken by high-speed stirring, so that the powder is uniformly dispersed in the matrix. Then, the temperature is raised to 120-150℃ and vacuum stirring is carried out. This process can not only remove air bubbles and residual solvents in the system to avoid the formation of thermal conductivity defects, but also further strengthen the interfacial bonding between the organic matrix and the inorganic powder, reduce the interfacial thermal resistance, and finally obtain a uniform and stable mixed phase change thermal conductive adhesive.

[0053] S140. The mixed phase change thermally conductive adhesive is heated to 120°C and calendered into 0.1-0.5mm thin sheets using a twin-roll calender to obtain a heat-resistant, oxygen-aging-resistant, high thermal conductivity phase change material.

[0054] The mixed phase change thermally conductive adhesive is calendered into sheets of 0.1-0.5 mm using a two-roll calender heated to 120°C. The 120°C calendering temperature maintains the material's good flexibility and flowability, ensuring uniform sheet thickness and a smooth surface. This adapts to the interface bonding requirements of AI server computing chips and liquid cooling modules, ultimately yielding a phase change thermally conductive material with high thermal conductivity, resistance to heat and oxygen aging, and good interface compatibility. The entire preparation process features precise and controllable parameters, with each step working in synergy to fully leverage the performance advantages of each component, ensuring the material meets the long-term stable heat dissipation requirements of high-power scenarios.

[0055] Example 1: 800 parts of aluminum powder with a medium particle size of 10 μm, 300 parts of aluminum powder with a medium particle size of 3 μm, 400 parts of zinc oxide with a medium particle size of 600 nm, 4.8 parts of polydimethylsilane with a single-sided end-trimethoxy capping, 0.2 parts of tetrabutyl titanate, and 2000 parts of tris(3-,butylcarbitol acetate) were mixed in proportion and subjected to wet surface grafting modification treatment of the thermally conductive powder by ultrasonic stirring at a high temperature of 70-90℃. After filtration and drying, modified powder A1 was obtained. 45 parts of hydroxyl-terminated polyisobutylene, 45 parts of hydroxyl-terminated polydimethylsiloxane, 1 part of 1010 antioxidant, 1 part of 168 antioxidant, 0.5 parts of organotin catalyst, 7 parts of 2280 paraffin oil, 0.5 parts of sodium dodecylbenzenesulfonate, and 50 parts of butyl carbitol acetate were mixed in a certain proportion and then melt-copolymerized in a high-boiling-point solvent at 70-100℃ to obtain block copolymer polymer material B1. The prepared A1 modified powder was added to B1 and stirred at high speed until homogeneous. Then, the temperature was raised to 120-150℃ and vacuum stirred to obtain the thermally conductive phase change material C1. C1 is hot-pressed into thin sheets of 0.1-0.5 mm to obtain a heat-resistant, oxygen-aging-resistant, and highly thermally conductive phase change material.

[0056] Example 2: 800 parts of aluminum powder with a medium particle size of 10 μm, 300 parts of single-crystal silicon carbide with a medium particle size of 1 μm, 400 parts of nanodiamond powder with a medium particle size of 200 nm, 4.8 parts of tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, 0.2 parts of tetrabutyl titanate, and 2000 parts of butyl carbitol acetate were mixed in proportion and subjected to wet surface grafting modification of the thermally conductive powder by ultrasonic stirring at a high temperature of 70-90℃. After filtration and drying, modified powder A2 was obtained. 65 parts of hydroxyl-terminated polyisobutylene, 5 parts of hydroxyl acrylate, 20 parts of hydroxyl-terminated polydimethylsiloxane, 1 part of 1010 antioxidant, 1 part of 168 antioxidant, 0.5 parts of isocyanate, 7 parts of 2280 paraffin oil, 0.5 parts of fluoroalkyl surfactant, and 50 parts of butyl carbitol acetate were mixed in a certain proportion and then melt-copolymerized in a high-boiling-point solvent at 70-100℃ to obtain block copolymer polymer material B2. The prepared A2 modified powder was added to B2 and stirred at high speed until homogeneous. Then, the temperature was raised to 120-150℃ and vacuum stirred to obtain the thermally conductive phase change material C2. By hot-pressing C2 into thin sheets of 0.1-0.5 mm, a heat-resistant and oxygen-aging-resistant high thermal conductivity phase change material can be obtained.

[0057] Example 3: 800 parts of aluminum powder with a medium particle size of 10 μm, 300 parts of aluminum powder with a medium particle size of 2 μm, 400 parts of nanodiamond powder with a medium particle size of 200 nm, 4.8 parts of tridecafluorooctyltriethoxysilane, 0.2 parts of tetrabutyl titanate, and 2000 parts of butyl carbitol acetate were mixed in proportion and subjected to wet surface grafting modification treatment by ultrasonic stirring at a high temperature of 70-90℃. After filtration and drying, modified powder A3 was obtained. 80 parts of hydroxyl-terminated polyisobutylene, 10 parts of hydroxyl-terminated polydimethylsiloxane, 1 part of 1010 antioxidant, 1 part of 168 antioxidant, 0.5 parts of isocyanate, 7 parts of 2280 paraffin oil, 0.5 parts of fluoroalkyl surfactant, and 50 parts of butyl carbitol acetate were mixed in a certain proportion and then melt-copolymerized in a high-boiling-point solvent at 70-100℃ to obtain block copolymer polymer material B3. The prepared A3 modified powder was added to B3 and stirred at high speed until homogeneous. Then, the temperature was raised to 120-150℃ and vacuum stirred to obtain the thermally conductive phase change material C3. C3 is hot-pressed into thin sheets of 0.1-0.5 mm to obtain a heat-resistant, oxygen-aging-resistant, and highly thermally conductive phase change material.

[0058] Comparative Example: 800 parts of aluminum powder with a medium particle size of 10 μm, 300 parts of single-crystal silicon carbide with a medium particle size of 1 μm, 400 parts of nanodiamond powder with a medium particle size of 200 nm, 4.8 parts of tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, 0.2 parts of tetrabutyl titanate, and 2000 parts of butyl carbitol acetate were mixed in proportion. The thermally conductive powder was subjected to wet surface grafting modification treatment by ultrasonic stirring at a high temperature of 70-90℃. After filtration and drying, modified powder A4 was obtained. The phase change polymer material B4 was prepared by mixing 65 parts of polyisobutylene, 5 parts of acrylate, 20 parts of 64# paraffin wax, 1 part of 1010 antioxidant, 1 part of 168 antioxidant, 7.5 parts of 2280 paraffin oil, 0.5 parts of fluoroalkyl surfactant, 50 parts of butyl carbitol acetate, dibutyl phthalate, and butyl carbitol in a certain proportion and then melt-blending them in a high-boiling-point solvent at 70-100℃. The prepared A4 modified powder was added to B4 and stirred at high speed until homogeneous. Then, the temperature was raised to 120-150℃ and vacuum stirred to obtain the thermally conductive phase change material C4. C4 is hot-pressed into thin sheets of 0.1-0.5 mm to obtain a thermally conductive phase change material.

[0059] The above embodiments and comparative examples underwent thermal conductivity testing, thermal resistance testing, phase change temperature testing, and 180℃ / 500H temperature resistance testing. The results are shown in Table 1.

[0060] Table 1 Comparing the test data of the above embodiments, Example 1 showed the most stable thermal conductivity. However, due to the large proportion of silicone material, the rigidity of the molecular chain was increased, resulting in a higher phase change temperature, poor surface wettability at the interface layer, and higher thermal resistance. Examples 2 and 3 both reduced the proportion of silicone blocks, achieving a relatively balanced temperature resistance and flexibility of the copolymer molecular chain. Specifically, Example 2 involved melt copolymerization of hydroxyl-terminated polyisobutylene, hydroxyacrylate, and hydroxyl polydimethylsiloxane, resulting in a phase change material with relatively good surface adhesion and flexibility, as well as lower thermal conductivity and thermal resistance. After high-temperature aging tests, the material's thermal conductivity remained relatively stable. In the comparative example, the polymer resin matrix did not undergo cross-linking. Under high-temperature thermo-oxidative aging conditions, the matrix resin degraded, rearranged, and volatilized violently, causing the phase change thermally conductive material to lose its flexibility and become pulverized, unable to withstand high temperatures.

[0061] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0062] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0063] The foregoing has provided a detailed description of a phase change thermally conductive material based on block organosilicon copolymers and its preparation method. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A phase change thermally conductive material based on block organosilicon copolymers, characterized in that, By weight percentage, it consists of the following components: Block copolymer polymers: 1.5%-4.0%; Antioxidant 0.03%-0.10%; Nano-single crystal diamond powder 6%-12%; aluminum powder 20%-30%; Single-crystal silicon carbide 6%-10%; Nano zinc oxide 8%-12%; Vulcanizing aid 0.01%-0.02%; High-temperature resistant surfactant: 0.01%-0.02%; Diluent 0.15%-0.25%; High-temperature resistant coupling agent 0.10%-0.15%; High-boiling-point solvents: 38%-52%.

2. The phase change thermally conductive material according to claim 1, characterized in that, The block copolymer polymer material is composed of one or more copolymers of hydroxyl-terminated polyisobutylene, hydroxy acrylate, SEBS, hydroxyl-terminated polydimethylsiloxane, trimethoxy-terminated polydimethylsiloxane, and triethoxy-terminated polydimethylsiloxane.

3. The phase change thermally conductive material according to claim 1, characterized in that, The antioxidants include one or more of ionic antioxidants, hindered phenolic antioxidants, and phosphate ester antioxidants.

4. The phase change thermally conductive material according to claim 1, characterized in that, The sulfidation aid is one or more of isocyanate, organotin catalyst, sulfur, and peroxide.

5. The phase change thermally conductive material according to claim 1, characterized in that, The high-temperature resistant surfactant includes one or more of fluorinated alkyl surfactants, sodium dodecylbenzene sulfonate, and sodium α-olefin sulfonate.

6. The phase change thermally conductive material according to claim 1, characterized in that, The diluent includes one or more of microcrystalline wax, liquid paraffin, polyethylene wax, and naphthenic oil.

7. The phase change thermally conductive material according to claim 1, characterized in that, The coupling agent includes one or more of the following: single-sided trimethoxy-terminated polydimethylsilane, γ-(methacryloyloxy)propyltrimethoxysilane, tridecafluorooctyltriethoxysilane, phthalate, trimethoxyphenylsilane, tris(3-trimethoxysilylpropyl)cyclotriisocyanurate, and 4,4′-bis(triethoxysilane)-1,1′-biphenyl polyolefin.

8. The phase change thermally conductive material according to claim 1, characterized in that, The nano-single crystal diamond powder, aluminum powder, hexagonal silicon carbide, and thermally conductive ceramic powder with a particle size distribution of 0.1-20 μm are mentioned.

9. The phase change thermally conductive material according to claim 1, characterized in that, The high-boiling-point solvent is one or more of butyl carbitol, butyl carbitol acetate, terpineol, and dibutyl phthalate.

10. A method for preparing a phase change thermally conductive material based on a block organosilicon copolymer as described in any one of claims 1-9, characterized in that, The components of the method, by weight percentage, consist of the following: block copolymer polymer material 1.5%-4.0%; antioxidant 0.03%-0.10%; nano-monocrystalline diamond powder 6%-12%; aluminum powder 20%-30%; monocrystalline silicon carbide 6%-10%; nano-zinc oxide 8%-12%; vulcanizing aid 0.01%-0.02%; high-temperature resistant surfactant 0.01%-0.02%; diluent 0.15%-0.25%; high-temperature resistant coupling agent 0.10%-0.15%; high-boiling-point solvent 38%-52%; the method includes the following steps: Nano-single crystal diamond powder, aluminum powder, hexagonal silicon carbide, high-boiling-point solvent and coupling agent are mixed and ultrasonically stirred until uniform. The temperature is raised to 70-90℃ for wet surface grafting modification treatment, and the modified powder is obtained by vacuum filtration and drying. Prepare a block copolymer polymer material; wherein the block copolymer polymer material is copolymerized from one or more of the following: hydroxyl-terminated polyisobutylene, hydroxy acrylate, SEBS, hydroxyl-terminated polydimethylsiloxane, trimethoxy-terminated polydimethylsiloxane, and triethoxy-terminated polydimethylsiloxane; The modified powder is added to the block copolymer polymer material and stirred at high speed until uniform. The temperature is raised to 120-150℃ and vacuum stirred to obtain a mixed phase change thermal conductive adhesive. The mixed phase change thermally conductive adhesive is heated to 120°C and calendered into 0.1-0.5mm thin sheets using a twin-roll calender to obtain a heat-resistant, oxygen-aging-resistant, high thermal conductivity phase change material.

Images