Weather-resistant high-pump-resistant non-silicon phase-change thermal paste
By combining the chemical and physical anchoring mechanism of the dynamic covalent cross-linked matrix and the core-shell thermally conductive filler with a liquid crystal phase change synergist, a three-level gradient thermally conductive filler system was constructed. This system solved the problems of pump-out resistance, weather resistance and phase change stability of non-silicon thermally conductive media under high power density environments, and achieved high thermal conductivity and structural stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YINGDE HONGQING ELECTRONICS CO LTD
- Filing Date
- 2026-04-22
- Publication Date
- 2026-06-30
AI Technical Summary
Existing non-silicon thermally conductive media have weak anti-pumping ability and insufficient weather resistance under high power density environments. They are prone to aging due to ultraviolet erosion, and their phase change response and stability are out of balance. It is difficult to achieve both low initial thermal resistance and controllable flowability at high temperatures.
By employing a chemical and physical joint anchoring mechanism of a dynamically covalently cross-linked matrix and a core-shell thermally conductive filler, combined with a liquid crystal phase change synergist and functional additives, a three-level gradient thermally conductive filler system is constructed to achieve a two-stage phase change response and intelligent topological microflow.
The thermal conductivity of the thermal paste is improved, the pumping rate is reduced, and stability over a wide temperature range and high retention of thermal conductivity after UV aging are ensured, achieving an excellent balance between high-temperature structural stability and interface wetting.
Smart Images
Figure CN122302834A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic thermal management materials technology, specifically to a weather-resistant, pump-oil-resistant, non-silicon phase change thermal grease. Background Technology
[0002] As 5G base stations and high-performance chips evolve towards ultra-high power density, heat flux density increases significantly, placing stringent demands on the service reliability of thermal interface materials. Exploring novel thermally conductive media that combine efficient heat transfer with long-term stability has become an inevitable trend to ensure the operational lifespan of electronic equipment.
[0003] Existing non-silicon thermally conductive media still face challenges: weak resistance to pumping out, such as the CN111777993A solution which is prone to pumping out and oil leakage after thermal cycling; limited weather resistance, which is easily aging due to ultraviolet corrosion; and an imbalance between phase change response and stability, making it difficult to balance low initial thermal resistance and controllable flowability at high temperatures. Summary of the Invention
[0004] The purpose of this invention is to provide a weather-resistant, pump-oil-resistant, non-silicone phase change thermal grease to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal conductive paste, comprising the following components by mass fraction: The dynamic crosslinking matrix comprises 12%-20% based on dynamic covalent bond exchange, wherein the dynamic crosslinking matrix includes a polycaprolactone diol prepolymer segment; 75%-85% of surface-functionalized core-shell thermally conductive filler; 3%-6% of a liquid crystal phase change synergist capable of undergoing phase transition in the range of 35℃ to 45℃ and inducing the orderly arrangement of the thermally conductive filler; and 1%-3% of functional additives. One end of the liquid crystal phase change synergist reacts with the hydroxyl groups on the surface of the core-shell thermally conductive filler, and the other end of the epoxy group covalently bonds with the dynamic crosslinking matrix to achieve chemical anchoring of multiple combined functions. The functional additives include a phase change modifier with a melting point of 45℃ and an epoxy-containing coupling agent.
[0006] Furthermore, the dynamic crosslinking matrix is a prepolymer of carboxyl-terminated polybutadiene, polycaprolactone diol, and isophorone diisocyanate; the core-shell thermally conductive filler is spherical aluminum nitride coated with nano-silica. The non-silicon phase change thermally conductive paste has a three-level gradient thermally conductive filler system inside, including the spherical aluminum nitride coated with nano-silica as a macroscopic thermally conductive framework, boron nitride nanosheets as bridging fillers, and zinc oxide nanowires as micro-fillers that provide piezoelectric response.
[0007] Furthermore, the thickness of the nano-silica in the core-shell thermally conductive filler is 5nm-10nm, and the particle size of the spherical aluminum nitride is 5μm-20μm; the functional additives include 0.4%-1.5% phase change modifier, 0.2%-0.5% weathering agent, and 0.4%-1.0% coupling agent; the phase change modifier is polyethylene wax with a melting point of 45℃, the weathering agent is hindered amine light stabilizer 770, and the coupling agent is KH-560.
[0008] Furthermore, the functional additives precisely include 0.4%-1.5% phase change modifier, 0.2%-0.5% weathering agent, and 0.4%-1.0% coupling agent; the phase change modifier is polyethylene wax with a melting point calibrated at 45°C, the weathering agent is hindered amine light stabilizer 770 with free radical scavenging ability, and the coupling agent is epoxy-containing silane coupling agent KH-560; The functional additive also contains 0.5%-2% polybutylene terephthalate (PBT) micro powder. The number average molecular weight of PBT is 10,000-30,000, and the melting point is 220-230°C. This improves the mechanical strength and weather resistance of the dynamically cross-linked matrix at high temperatures and forms an ester exchange with polycaprolactone diol for synergistic toughening.
[0009] Furthermore, the preparation steps of the non-silicon phase change thermal paste are as follows: A core-shell thermally conductive filler coated with nano-silica and spherical aluminum nitride was prepared, and a three-level gradient thermally conductive filler system was constructed simultaneously during the preparation process. The core-shell thermally conductive filler was combined with boron nitride nanosheets and zinc oxide nanowires in a composite ratio. Prepolymer was prepared by mixing carboxyl-terminated polybutadiene with polycaprolactone diol, adding isophorone diisocyanate, and heating to 100°C for 1 hour. Core-shell thermally conductive filler, liquid crystal phase change synergist and functional additives are added sequentially to the prepolymer, dispersed by planetary stirring, ground by a three-roll mill, and degassed under vacuum to obtain the finished product.
[0010] Furthermore, the nano-silica is obtained by hydrolysis and condensation of tetraethyl orthosilicate, with a coating rate of ≥90%; the planetary stirrer rotates at 2000 rpm, and the gap between the three roller mills is 20 μm.
[0011] Furthermore, the thermal conductivity of the non-silicon phase change thermal paste is ≥6.0 W / m. K, anti-pumping rate ≤3%, stable working environment is -40℃ to 180℃, thermal conductivity decay rate ≤5% after 1000h of UV aging.
[0012] Furthermore, the non-silicone phase change thermal grease possesses a two-stage phase change response mechanism; the polyethylene wax in the functional additives constitutes a first-stage wetting phase change center initiated at 45°C, and the polycaprolactone diol in the dynamic crosslinked matrix constitutes a second-stage stress relaxation phase change center initiated at 60°C; the liquid crystal phase change synergist is pre-activated and transforms into a nematic phase when the real-time temperature exceeds the liquid crystal phase change critical point, constructing a pre-assembled orbital with heat flow orientation; when the temperature is further increased to 60°C, the pre-assembled orbital undergoes adaptive anisotropic alignment along the heat flow vector direction emitted by the external heat source; upgrading simple heat conduction to controlled intelligent topological microflow.
[0013] Furthermore, a covalent anchoring network exists between the core-shell thermally conductive filler and the dynamic crosslinking matrix; the siloxane end of the coupling agent forms a dehydration condensation bond with the nano-silica on the surface of the core-shell thermally conductive filler, and the epoxy end of the coupling agent forms a ring-opening crosslinking bond with the dynamic crosslinking matrix, which is used to chemically anchor the core-shell thermally conductive filler in situ within the dynamic crosslinking matrix.
[0014] Furthermore, the non-silicon phase change thermal paste contains a three-level gradient thermal conductive filler system. Based on the total mass of the three-level gradient thermal conductive filler system (100%), it is composed of 2%-5% boron nitride nanosheets, 1%-2% zinc oxide nanowires, and the remainder of the core-shell thermal conductive filler. The nano-silica, boron nitride nanosheets, and zinc oxide nanowires together construct a three-level gradient thermal conductive network, achieving a thermal conductivity of over 6.0 W / m·K for the non-silicon phase change thermal paste.
[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention abandons the traditional physical defense approach that relies solely on matrix viscosity, and introduces a chemical-physical joint anchoring mechanism between a dynamically cross-linked matrix and a core-shell thermally conductive filler. Through the cross-boundary molecular zipper effect of the coupling agent, not only is a stable covalent bond established between the nano-silica shell and the dynamic matrix, but the piezoelectric response of zinc oxide nanowires is also cleverly utilized to provide electrostatic coupling compensation during thermal shock alternation. This transforms simple mechanical stress into a fundamental change of dynamic chemical bond dissipation and physical topological entanglement working together to resist it, effectively locking the interface slip path. This invention constructs a non-silicon topological gel state with a highly stable internal structure. Relying on the synergistic gain of the flexible hydrocarbon backbone and the hindered amine light stabilizer, the intrinsic stability of the material is ensured while blocking the ultraviolet aging process. This invention constructs a fusion bridge between a two-stage phase change response mechanism and a liquid crystal pre-assembled track. By introducing a liquid crystal phase change synergist pre-activated at 35°C, a pre-set thermal flow orientation track is provided for the subsequent first-stage wetting at 45°C and second-stage stress relaxation at 60°C. This achieves a transformation from passive heating and melting to controlled intelligent topological microflow, enabling the thermally conductive filler to align anisotropically along the track and achieving an excellent balance between interface wetting and high-temperature structural stability. Attached Figure Description
[0016] Figure 1 This is a TEM schematic diagram of the core-shell thermally conductive packing of the present invention; Figure 2 This is the infrared spectrum of the dynamically cross-linked matrix of the present invention; Figure 3 This is a schematic diagram showing the thermal conductivity of the present invention before and after ultraviolet aging. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.
[0018] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0019] Example 1: Please see Figures 1 to 3 This invention provides a technical solution: a weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease; the non-silicone phase change thermal grease is composed of the following components by mass fraction: The dynamic crosslinking matrix comprises 12%-20% based on dynamic covalent bond exchange, wherein the dynamic crosslinking matrix includes a polycaprolactone diol prepolymer segment; 75%-85% of surface-functionalized core-shell thermally conductive filler; 3%-6% of a liquid crystal phase change synergist capable of undergoing phase transition in the range of 35℃ to 45℃ and inducing the orderly arrangement of the thermally conductive filler; and 1%-3% of functional additives. One end of the liquid crystal phase change synergist reacts with the hydroxyl groups on the surface of the core-shell thermally conductive filler, and the other end of the epoxy group covalently bonds with the dynamic crosslinking matrix to achieve chemical anchoring of multiple combined functions. The functional additives include a phase change modifier with a melting point of 45℃ and an epoxy-containing coupling agent.
[0020] The dynamic crosslinking matrix is a prepolymer of carboxyl-terminated polybutadiene, polycaprolactone diol, and isophorone diisocyanate; the core-shell thermally conductive filler is spherical aluminum nitride coated with nano-silica. The non-silicon phase change thermally conductive paste has a three-level gradient thermally conductive filler system inside, including the spherical aluminum nitride coated with nano-silica as the macroscopic thermally conductive framework, boron nitride nanosheets as bridging fillers, and zinc oxide nanowires as micro-fillers that provide piezoelectric response.
[0021] The thickness of the nano-silica in the core-shell thermally conductive filler is 5nm-10nm, and the particle size of the spherical aluminum nitride is 5μm-20μm; the functional additives include 0.4%-1.5% phase change modifier, 0.2%-0.5% weathering agent, and 0.4%-1.0% coupling agent; the phase change modifier is polyethylene wax with a melting point of 45℃, the weathering agent is hindered amine light stabilizer 770, and the coupling agent is KH-560.
[0022] The dynamic crosslinking matrix is a prepolymer generated by reacting carboxyl-terminated polybutadiene, polycaprolactone diol, and isophorone diisocyanate under a specific thermal field. The molecular design is not a simple physical blending, but rather utilizes the flexible hydrocarbon backbone provided by the carboxyl-terminated polybutadiene to impart excellent low-temperature resistance and stress dissipation capabilities to the material. Simultaneously, the crystallization and melting properties of polycaprolactone diol inject precise temperature-responsive targets into the entire crosslinking network. The core-shell thermally conductive filler is spherical aluminum nitride coated with nano-silica. The thickness of the nano-silica in the core-shell thermally conductive filler is 5nm-10nm, and the particle size of the spherical aluminum nitride is precisely controlled between 5μm-20μm. The nano-silica shell is achieved through in-situ growth using a hydrolysis-condensation process of tetraethyl orthosilicate, with a coating rate ≥90%. The non-silicon phase change thermal paste has a three-level gradient thermal conductive filler system, including spherical aluminum nitride coated with nano-silica as a macroscopic thermal conductive framework, boron nitride nanosheets as bridging fillers, and zinc oxide nanowires as microscopic fillers that provide piezoelectric response. The introduction of zinc oxide nanowires not only fills the dead zone of heat conduction at the nanoscale, but more importantly, its inherent weak piezoelectric response mechanism will play an irreplaceable electrostatic coupling anchoring role in subsequent thermal shock environments.
[0023] The functional additives precisely include 0.4%-1.5% phase change modifier, 0.2%-0.5% weathering agent, and 0.4%-1.0% coupling agent. The phase change modifier is a polyethylene wax with a melting point calibrated at 45℃; the weathering agent is a hindered amine light stabilizer 770 with free radical scavenging ability; and the coupling agent is an epoxy-containing silane coupling agent KH-560. Each of the three additives performs its specific function, collectively contributing to the system's excellent overall stability.
[0024] The functional additives also contain 0.5%-2% polybutylene terephthalate (PBT) micro powder, wherein the number average molecular weight of PBT is 10,000-30,000 and the melting point is 220-230℃, in order to improve the mechanical strength and weather resistance of the dynamic cross-linked matrix at high temperatures, and to form transesterification with polycaprolactone diol for synergistic toughening.
[0025] The preparation steps for non-silicon phase change thermal paste are as follows: A core-shell thermally conductive filler coated with nano-silica and spherical aluminum nitride was prepared, and a three-level gradient thermally conductive filler system was constructed simultaneously during the preparation process. The core-shell thermally conductive filler was combined with boron nitride nanosheets and zinc oxide nanowires in a composite ratio. Prepolymer was prepared by mixing carboxyl-terminated polybutadiene with polycaprolactone diol, adding isophorone diisocyanate, and heating to 100°C for 1 hour. Core-shell thermally conductive filler, liquid crystal phase change synergist and functional additives are added sequentially to the prepolymer, dispersed by planetary stirring, ground by a three-roll mill, and degassed under vacuum to obtain the finished product.
[0026] Nano-silica is obtained through the hydrolysis and condensation of tetraethyl orthosilicate, with a coating rate of ≥90%; the planetary stirrer rotates at 2000 rpm, and the gap between the three roller mills is 20 μm.
[0027] The thermal conductivity of non-silicon phase change thermal paste is ≥6.0 W / m. K, anti-pumping rate ≤3%, stable working environment is -40℃ to 180℃, thermal conductivity decay rate ≤5% after 1000h of UV aging.
[0028] The non-silicone phase change thermal grease possesses a two-stage phase change response mechanism. The polyethylene wax in the functional additives constitutes a first-stage wetting phase change center activated at 45°C, while the polycaprolactone diol in the dynamically crosslinked matrix constitutes a second-stage stress relaxation phase change center activated at 60°C. The liquid crystal phase change synergist is pre-activated and transforms into a nematic phase when the real-time temperature exceeds the liquid crystal phase change critical point (preferably 35°C in this embodiment), constructing a heat flow-oriented pre-assembled orbital. When the temperature further increases to 60°C, the pre-assembled orbital undergoes adaptive anisotropic alignment along the heat flow vector direction emitted by the external heat source, upgrading simple heat conduction to controlled intelligent topological microflow. When high-power devices begin to heat up and the temperature rises to 45°C, polyethylene wax undergoes a solid-liquid phase transition first, filling the air gaps caused by the roughness of the micro-interface. As the heat load increases and the temperature climbs to 60°C, polycaprolactone diol in the matrix begins to soften. At this point, the dynamically cross-linked matrix produces excellent micro-fluidity and stress absorption capacity. Meanwhile, the liquid crystal phase transition synergist, which has already completed the nematic phase transition at 35°C, fully utilizes the orientation orbits formed by the long axes of its molecules under the drive of the strong heat flow vector in the Z-axis direction (heat conduction direction). With the help of intermolecular forces, it drags the core-shell thermally conductive filler and boron nitride nanosheets, which are now truly suspended in the softened matrix, to overcome the original disordered Brownian motion and self-assemble into a high-speed thermally conductive columnar framework in the Z-axis direction, thereby significantly reducing the phenomenon of transverse thermal phonon scattering.
[0029] The self-assembly of a high-speed thermally conductive columnar skeleton is evaluated based on an adaptive fusion algorithm of multi-source thermal flow physics fields; input parameters are set as follows: real-time system temperature. Real-time heat flux vector intensity Real-time orientation sequence parameters of liquid crystal molecules The range of values is [0,1]. Viscous resistance release calculation: Quantifying the resistance release factor caused by the second phase transition using the Sigmoid function. ,Right now ,in, The material softening constant is preferably in the range of [0.5, 1.2]. Orientation driving force calculation: Calculate the effective drag force factor of liquid crystal molecules on the filler. ,in, The effective drag force factor of liquid crystal molecules on fillers; Multi-parameter dimensional fusion: To address the issue of the contribution of different dimensions of resistance release and effective heat flow drag to the construction of the heat conduction network, the resistance release factor is normalized. and effective drag force factor The weighted summation is then performed to calculate the overall self-assembly fluency score. : ; in, and The dimensionless value after Min-Max normalization. and For the contribution weighting coefficients calibrated in the experiment, set the following respectively: When the overall self-assembly smoothness score is... When the internal thermal conductivity exceeds the activation threshold of 0.85, it will break through the physical limit of the amorphous state, achieving a nonlinear leap from the initial 3.0 W / m·K to the target peak of 6.8 W / m·K.
[0030] A covalent anchoring network exists between the core-shell thermally conductive filler and the dynamic crosslinking matrix; the siloxane end of the coupling agent forms a dehydration condensation bond with the nano-silica on the surface of the core-shell thermally conductive filler, and the epoxy end of the coupling agent forms a ring-opening crosslinking bond with the dynamic crosslinking matrix, which is used to chemically anchor the core-shell thermally conductive filler in situ to the dynamic crosslinking matrix.
[0031] The non-silicon phase change thermal conductive paste has a three-level gradient thermal conductive filler system inside. Taking the total mass of the three-level gradient thermal conductive filler system as 100%, it is composed of 2%-5% boron nitride nanosheets, 1%-2% zinc oxide nanowires, and the balance of the core-shell thermal conductive filler. The nano-silica, boron nitride nanosheets and zinc oxide nanowires together construct a three-level gradient thermal conductive network, so that the thermal conductivity of the non-silicon phase change thermal conductive paste reaches more than 6.0 W / m·K.
[0032] Carboxyl-terminated polybutadiene reacts with isophorone diisocyanate to generate a dynamic amide / polyurethane network. During the mixing and degassing process, the dynamic network and the filler interface complete chemical self-assembly, constructing a non-silicon topological gel state that balances flowability and high-temperature structural stability.
[0033] In the process of preparing the prepolymer at 100℃ and subsequent planetary mixing, the coupling agent KH-560 acts as a cross-boundary molecular zipper; one end, through hydrolysis and condensation, binds to the nano-SiO2 shell on the surface of the core-shell thermally conductive filler; during mixing, the epoxy groups at the other end are excited by the thermal field to open the ring, undergoing irreversible chemical crosslinking with the active residues in the dynamic polyurethane matrix network; 2%-5% of the total mass of 2D boron nitride nanosheets and 1%-2% of the total mass of 1D piezoelectric zinc oxide nanowires, in Interspersed in the pores of the anchored 3D spherical aluminum nitride network, they form a dense packing. When strong thermal shock (rapid alternation from -40℃ to 180℃) causes a difference in the coefficient of thermal expansion (CTE), the weak piezoelectric effect generated by the zinc oxide nanowires further enhances the electrostatic coupling between the fillers. All the resulting severe shear stress is dissipated through the KH-560 chemical bonds to the elastic CTPB-PCL dynamic cross-linked network, completely eliminating the slippage and delamination of the filler at the interface with the matrix.
[0034] High-temperature structural stability is quantified using a combined chemical and physical topology seismic algorithm; the input parameter is set as: silicon-oxygen / epoxy grafting density per unit volume. Three-level gradient network spatial stacking density product Dynamic energy storage modulus of the matrix The cumulative interfacial shear stress integral caused by thermal cycling ; Calculation of chemical anchoring rigidity factor: Quantifying the absolute tear resistance brought by covalent bonds: ; Calculation of topological entanglement dissipation factor: Quantification of the physical damping dissipation force of a three-level gradient thermal conductivity network composed of nano-silica, boron nitride nanosheets, and zinc oxide nanowires in a dynamic matrix: ; Multi-parameter dimensional fusion: unifying the contributions of the microscopic chemical bonding energy dimension and the macroscopic mechanical damping dimension, and introducing a scalarized structural failure sensitivity bias coefficient. The preferred value is 0.01 to prevent the denominator from being zero; by jointly weighting and stress-penalizing the normalized chemical anchoring stiffness factor and topological entanglement dissipation factor, a comprehensive anti-pumping structural stability score is obtained. : ; in, and The coupling constant is used to adjust the ratio of rigid to flexible dissipation; the optimal system configuration is determined by this constant. , and The normalized chemical anchoring stiffness factor and topological entanglement dissipation factor are used; through chemical anchoring technology, the overall anti-pumping structural stability score is improved. Even after undergoing 1000 thermal shocks, the thermal paste maintains a high level of resistance, thus ensuring that its anti-pumping rate is kept within the extreme range of ≤3%.
[0035] The following is a comparison experiment of thermal conductivity before and after UV aging, and the test conditions are shown in Table 1 below: Table 1: UV Aging Test Conditions The comparison curve data are shown in Table 2 below: Table 2: Data from UV aging tests Curve drawing specifications (such as) Figure 3 (as stated): Coordinate axes: The horizontal axis represents "UV aging time (h)", ranging from 0 to 1200h, with intervals of 200h; the vertical axis represents... The axis is "thermal conductivity (W / (m)" K))”, range 1.0-8.0W / (m K), interval 1W / (m) K); Curve style: Thermal paste of the present invention (blue), labeled "The present invention (dynamic cross-linked non-silicone matrix + core-shell thermally conductive filler)"; conventional non-silicone paste (red); By leveraging the synergistic effect of dynamically cross-linked non-silicon matrix and core-shell thermally conductive filler, a high retention rate of thermal conductivity is achieved after UV aging, while suppressing pumping out under thermal cycling, thus solving the technical problems of poor weather resistance and weak resistance to pumping oil in traditional non-silicon phase change thermal paste. The curve of this invention shows that the thermal conductivity decreases gradually after 1000h of aging, with a retention rate of ≥90%, reflecting the synergistic effect of weather resistance and anti-pumping oil properties.
[0036] Traditional curve: The thermal conductivity drops sharply after aging for 400 hours, and the retention rate is ≤50% after 1000 hours. The thermal conductivity is greatly reduced due to the degradation of the linear matrix and the agglomeration of the filler.
[0037] It should be noted that all calculation formulas in this application employ regression analysis, including but not limited to machine learning algorithms, to deeply analyze the collected parameters and identify their natural trends and interrelationships. Specialized software, such as Python's Scikit-learn library or the R language, is used to automatically generate mathematical models that match the data. Then, cross-validation and other methods are used to objectively evaluate the model performance, and continuous feedback and optimization are combined to ensure that the created formulas truly reflect the inherent laws of the data, thereby guaranteeing their effectiveness and accuracy. In all calculation formulas in this application, the parameters in each formula undergo dimensionless processing within a consistent range to ensure that different physical quantities are compared on the same scale; dimensionless processing techniques include, but are not limited to, Min-Max Normalization and Z-Score standardization. The technical solution of this invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of various embodiments of this invention.
[0038] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.
[0039] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A weather-resistant, pump-oil-resistant, non-silicone phase change thermal grease, characterized in that, Non-silicone phase change thermal paste is composed of the following components by mass fraction: The dynamic crosslinking matrix comprises 12%-20% based on dynamic covalent bond exchange, wherein the dynamic crosslinking matrix includes a polycaprolactone diol prepolymer segment; 75%-85% of surface-functionalized core-shell thermally conductive filler; 3%-6% of a liquid crystal phase change synergist capable of undergoing phase transition in the range of 35℃ to 45℃ and inducing the orderly arrangement of the thermally conductive filler; and 1%-3% of functional additives. One end of the liquid crystal phase change synergist reacts with the hydroxyl groups on the surface of the core-shell thermally conductive filler, and the other end of the epoxy group covalently bonds with the dynamic crosslinking matrix to achieve chemical anchoring of multiple combined functions. The functional additives include a phase change modifier with a melting point of 45℃ and an epoxy-containing coupling agent.
2. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 1, characterized in that: The dynamic crosslinking matrix is a prepolymer of carboxyl-terminated polybutadiene, polycaprolactone diol, and isophorone diisocyanate; the core-shell thermally conductive filler is spherical aluminum nitride coated with nano-silica. The non-silicon phase change thermally conductive paste has a three-level gradient thermally conductive filler system inside, including the spherical aluminum nitride coated with nano-silica as the macroscopic thermally conductive framework, boron nitride nanosheets as bridging fillers, and zinc oxide nanowires as micro-fillers that provide piezoelectric response.
3. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 2, characterized in that: The thickness of the nano-silica in the core-shell thermally conductive filler is 5nm-10nm, and the particle size of the spherical aluminum nitride is 5μm-20μm; the functional additives include 0.4%-1.5% phase change modifier, 0.2%-0.5% weathering agent, and 0.4%-1.0% coupling agent; the phase change modifier is polyethylene wax with a melting point of 45℃, the weathering agent is hindered amine light stabilizer 770, and the coupling agent is KH-560.
4. The weather-resistant, pump-oil-resistant, non-silicone phase change thermal grease according to claim 3, characterized in that: The functional additives precisely include 0.4%-1.5% phase change modifier, 0.2%-0.5% weathering agent, and 0.4%-1.0% coupling agent; the phase change modifier is polyethylene wax with a melting point calibrated at 45℃, the weathering agent is hindered amine light stabilizer 770 with free radical scavenging ability, and the coupling agent is epoxy-containing silane coupling agent KH-560.
5. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 4, characterized in that: The preparation steps for non-silicon phase change thermal paste are as follows: A core-shell thermally conductive filler coated with nano-silica and spherical aluminum nitride was prepared, and a three-level gradient thermally conductive filler system was constructed simultaneously during the preparation process. The core-shell thermally conductive filler was combined with boron nitride nanosheets and zinc oxide nanowires in a composite ratio. Prepolymer was prepared by mixing carboxyl-terminated polybutadiene with polycaprolactone diol, adding isophorone diisocyanate, and heating to 100°C for 1 hour. Core-shell thermally conductive filler, liquid crystal phase change synergist and functional additives are added sequentially to the prepolymer, dispersed by planetary stirring, ground by a three-roll mill, and degassed under vacuum to obtain the finished product.
6. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 5, characterized in that: The nano-silica is obtained by hydrolysis and condensation of tetraethyl orthosilicate, with a coating rate of ≥90%; the planetary stirrer rotates at 2000 rpm, and the gap between the three roller mills is 20 μm.
7. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 6, characterized in that: The thermal conductivity of the non-silicon phase change thermal paste is ≥6.0 W / m. K, anti-pumping rate ≤3%, stable working environment is -40℃ to 180℃, thermal conductivity decay rate ≤5% after 1000h of UV aging.
8. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 7, characterized in that: The non-silicone phase change thermal grease has a two-stage phase change response mechanism. The polyethylene wax in the functional additives constitutes a first-stage wetting phase change center that starts at 45°C, and the polycaprolactone diol in the dynamic crosslinked matrix constitutes a second-stage stress relaxation phase change center that starts at 60°C. The liquid crystal phase change synergist is pre-activated and transforms into a nematic phase when the real-time temperature exceeds the liquid crystal phase change critical point, constructing a pre-assembled orbital with heat flow orientation. When the temperature is further increased to 60°C, the pre-assembled orbital undergoes adaptive anisotropic alignment along the heat flow vector direction emitted by the external heat source, upgrading simple heat conduction to controlled intelligent topological microflow.
9. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 4, characterized in that: A covalent anchoring network exists between the core-shell thermally conductive filler and the dynamic crosslinking matrix; the siloxane end of the coupling agent forms a dehydration condensation bond with the nano-silica on the surface of the core-shell thermally conductive filler, and the epoxy end of the coupling agent forms a ring-opening crosslinking bond with the dynamic crosslinking matrix, which is used to chemically anchor the core-shell thermally conductive filler in situ to the dynamic crosslinking matrix.
10. The weather-resistant, high-pump-oil-resistant, non-silicone phase change thermal grease according to claim 9, characterized in that: The non-silicon phase change thermal conductive paste has a three-level gradient thermal conductive filler system inside. Taking the total mass of the three-level gradient thermal conductive filler system as 100%, it is composed of 2%-5% boron nitride nanosheets, 1%-2% zinc oxide nanowires, and the balance of the core-shell thermal conductive filler. The nano-silica, boron nitride nanosheets and zinc oxide nanowires together construct a three-level gradient thermal conductive network, so that the thermal conductivity of the non-silicon phase change thermal conductive paste reaches more than 6.0 W / m·K.