Temperature-sensitive heat-conducting composite cable material and preparation method thereof

Abstract

The invention discloses a temperature-sensitive heat-conducting composite cable material and a preparation method thereof. The temperature-sensitive heat-conducting composite cable material is prepared from the following raw materials in parts by weight: 30-45 parts of matrix resin, 10-20 parts of temperature-sensitive heat-conducting filler, 0.5-2.5 parts of a heat-conducting bridging agent, 0.1-0.5 part of a conductive temperature-sensitive reinforcing phase, 0.3-0.7 part of a crosslinking aid, 4-8 parts of high-heat-conductivity inorganic filler, 1-3 parts of an antioxidant and 1-3 parts of a flame-retardant monomer, the preparation method of the temperature-sensitive heat-conducting composite cable material comprises the following steps: polymerizing the temperature-sensitive heat-conducting filler component; under the action of an alternating electric field, the high-heat-conduction inorganic filler, the heat-conduction bridging agent and the temperature-sensitive heat-conduction filler form a continuous heat-conduction path; mixing the treated slurry with other components, extruding and granulating; and finally, the temperature-sensitive heat conduction sleeve is formed through double-layer co-extrusion. The invention solves the technical problems of poor heat-conducting property and insufficient temperature responsiveness of the traditional cable material, and can be applied to the field of high-performance power cable protection.

Description

Technical Field

[0001] This invention relates to the field of cable materials, specifically to a temperature-sensitive thermally conductive composite cable material and its preparation method. Background Technology

[0002] With the miniaturization, integration, and high power of electronic devices, the thermal management of cables, as key components for power and signal transmission, has become increasingly prominent. If the heat generated by cables during high-load operation cannot be dissipated effectively and promptly, it will lead to accelerated aging of insulation materials, deterioration of electrical performance, and even safety accidents. Therefore, developing cable materials with excellent thermal conductivity has become a key research focus in the industry.

[0003] Currently, common cable materials on the market mainly include polymers such as polyethylene, polyvinyl chloride, and cross-linked polyethylene. These materials themselves have low thermal conductivity, typically in the range of 0.1-0.3 W / (m·K), which is insufficient to meet the heat dissipation requirements of modern power cables and special cables. To improve the thermal conductivity of cable materials, researchers usually add thermally conductive fillers to the polymer matrix. CN102250481A discloses a high thermal conductivity plastic prepared by a two-step granulation method, achieving a high thermal conductivity with less filler. CN104559148A proposes a high thermal diffusivity polymer material that utilizes high thermal diffusivity thermally conductive fillers of different shapes to form a three-dimensional thermally conductive network during processing, generating a positive synergistic hybrid effect that significantly enhances the thermal conductivity of the polymer material.

[0004] In the field of cable-specific materials, CN114854121A discloses a thermally conductive, halogen-free, flame-retardant polyolefin cable material for automotive wiring harnesses. This material contains components such as ethylene-vinyl acetate copolymer, polysiloxane-grafted high-density polyethylene, and fluorinated macromolecule-grafted linear low-density polyethylene copolymer, which improves the material's thermal conductivity and heat resistance stability. CN104559147A introduces an anti-dripping, smoke-suppressing, environmentally friendly thermally conductive material, manufactured through surface treatment, melting, and extrusion processes. This solves the problems of performance degradation, flammability, and dripping associated with high-filling plastics. CN104017267A proposes a thermally conductive wire and cable insulation or sheathing material, in which the thermally conductive material is stacked with ethylene and its copolymers to form a cross-network, achieving a thermal conductivity of 3.305-4.867 W / (m·K) while maintaining good insulation performance.

[0005] However, existing cable materials still have the following problems: First, although traditional thermally conductive cable materials improve thermal conductivity by adding inorganic fillers, excessive filler content can lead to a decrease in mechanical properties and a deterioration in processing performance. Second, existing cable materials lack temperature sensitivity and cannot adaptively adjust their thermal conductivity according to changes in ambient temperature, thus failing to effectively meet the heat dissipation requirements of cables under different operating conditions. Third, the thermal conduction paths of existing thermally conductive cable materials are often randomly distributed, resulting in low thermal conductivity and difficulty in forming directional heat conduction paths. Fourth, cable materials are prone to thermal oxidation and aging in high-temperature environments, leading to material performance degradation and a shortened service life. Finally, existing thermally conductive cable materials often lack effective temperature monitoring functions, failing to reflect the cable's operating status in a timely manner and increasing the risk of cable overheating failure.

[0006] Therefore, there is an urgent need to develop a temperature-sensitive thermally conductive composite cable material that combines excellent thermal conductivity, temperature sensitivity, good mechanical properties, and aging resistance to meet the multifunctional requirements of modern power and signal transmission systems for cable materials. Summary of the Invention

[0007] The technical problem to be solved by this invention is to address the issues of insufficient thermal conductivity, limited temperature monitoring capability, and insufficient heat resistance and strength of existing cable materials, which lead to easy aging of cables under high-intensity use and increased fire risk. This invention provides a temperature-sensitive thermally conductive composite cable material that achieves the technical effects of high thermal conductivity, real-time temperature monitoring, and enhanced heat resistance and mechanical strength.

[0008] The objective of this invention is achieved through the following technical solution: a temperature-sensitive thermally conductive composite cable material, comprising the following raw materials in parts by weight: 30-45 parts of matrix resin, 10-20 parts of temperature-sensitive thermally conductive filler, 0.5-2.5 parts of thermally conductive bridging agent, 0.1-0.5 parts of conductive temperature-sensitive reinforcing phase, 0.3-0.7 parts of crosslinking aid, 4-8 parts of high thermal conductivity inorganic filler, and 1-3 parts of antioxidant.

[0009] Preferably, the temperature-sensitive thermally conductive composite cable material comprises the following raw materials in parts by weight: 30-45 parts of matrix resin, 10-20 parts of temperature-sensitive thermally conductive filler, 0.5-2.5 parts of thermally conductive bridging agent, 0.1-0.5 parts of conductive temperature-sensitive reinforcing phase, 0.3-0.7 parts of crosslinking aid, 4-8 parts of high thermal conductivity inorganic filler, 1-3 parts of antioxidant, and 1-3 parts of flame-retardant monomer.

[0010] Preferably, the matrix resin is composed of ethylene-vinyl acetate copolymer, polyphenylene sulfide and polyaramid fiber paper in a mass ratio of 5-6:2-3:1.0-1.5.

[0011] Preferably, the temperature-sensitive thermally conductive filler is at least one of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene.

[0012] More preferably, the temperature-sensitive thermally conductive filler is composed of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene in a mass ratio of 1.0-1.2:0.3-0.5:0.1-0.3:0.1-0.3;

[0013] The modified calixarene is obtained by reacting calixarene with acryloyloxypropyltrimethoxysilane in toluene at a molar ratio of 1:2 for 2-4 hours at 75-85°C.

[0014] Preferably, the thermally conductive bridging agent is an EDTA-zinc ammonium complex or a silane coupling agent KH792.

[0015] Preferably, the conductive temperature-sensitive reinforcing phase is at least one of PEDOT:PSS, polyaniline-dodecylbenzenesulfonic acid, and carboxylated single-walled carbon nanotubes.

[0016] Preferably, the crosslinking aid is at least one of benzophenone / triethanolamine photoinitiator system, 2-hydroxy-2-methylphenylacetone, and dicumyl peroxide.

[0017] Preferably, the high thermal conductivity inorganic filler is at least one of hexagonal boron nitride, spherical alumina, and plate-shaped aluminum nitride.

[0018] Preferably, the antioxidant is at least one of antioxidant 1010, antioxidant 168, and antioxidant BHT.

[0019] Preferably, the flame-retardant monomer is prepared by the following method:

[0020] A1. Under nitrogen protection, 80-100 mmol of 1,1,3,3-tetramethyldisiloxane and Karstedt catalyst were added to a microchannel reactor. The temperature was controlled at 60±2℃. 110-120 mmol of methyl acrylate in toluene solution was pumped in at a flow rate of 2 mL / min. The reaction residence time was 10-20 min. The solvent was removed online under reduced pressure to obtain intermediate M1 for later use.

[0021] A2. Mix M1 with 0.3-0.7M NaOH / ethanol-water, stir at 450-500rpm at 30-35℃, monitor pH online, hydrolyze for 20-40min, add 1M HCl dropwise until pH=2, then adjust to pH=7 with ammonia, a white solid precipitates, filter, freeze dry to obtain intermediate M2, for later use;

[0022] A3. At -5℃, a benzene solution of 90-110 mmol of phenylphosphonic dichlorophenate was added dropwise at 1 mL / min to a mixture of 150-170 mL of diethylene glycol dimethyl ether and 210-220 mmol of ethanolamine. Simultaneously, 210-220 mmol of triethylamine was introduced online to neutralize the solution to pH 7-8. The temperature was raised to 50-55℃ and reacted for 1-3 h. Then, the temperature was raised to 90-95℃ and reacted for 2-4 h. The reaction solution was separated by membrane separation to remove TEA hydrochloride and concentrated under reduced pressure to obtain intermediate M3 for later use.

[0023] A4. Add 95-105 mmol M2, 100-110 mmol M3 and 0.5 wt% tetrabutyl titanate to the reactor. First, purge with nitrogen. Prepolymerize at 140-145℃ and 50 mbar for 1-3 h. Then, heat to 170-180℃ and 10 mbar for condensation polymerization for 1-2 h. Terminate the reaction when the acid value drops to <5 mg KOH / g to obtain a pale yellow transparent flame-retardant monomer.

[0024] The flame-retardant monomer in this invention integrates siloxane flexible segments, phosphonamide rigid ring structures, and carboxyl reactive groups into the same molecule through low-temperature interfacial condensation, online neutralization, and a "one-pot two-step" process, achieving covalent bonding with the polyurethane backbone and improving flame-retardant efficiency by more than 30%. In addition, it utilizes the silicon-phosphorus synergistic effect: the molecule contains both silicon (Si-O-Si) and phosphorus (P=O / PN) structures. The phosphorus component decomposes at high temperature to generate phosphoric acid, promoting carbonization on the material surface and forming a carbon layer that isolates oxygen. The silicon component migrates to the material surface at high temperature to form a stable silicate glass layer, enhancing the strength of the carbon layer and inhibiting the release of combustible gases, which can further help improve the overall performance of the temperature-sensitive thermally conductive composite cable material.

[0025] This invention also provides a method for preparing a temperature-sensitive thermally conductive composite cable material, comprising the following steps:

[0026] S1. According to the weight parts, sulfonated calixarene, N-isopropylacrylamide, acrylamide and modified calixarene are mixed and polymerized at 60-70℃ for 8-12h to obtain a temperature-sensitive thermally conductive filler for later use.

[0027] S2. According to the weight proportions, the high thermal conductivity inorganic filler, thermal conductivity bridging agent and temperature-sensitive thermal conductivity filler are mixed to form a slurry. Under the action of an alternating electric field of 50-100V / mm and 1-5kHz, the slurry is oriented and arranged at 20-25℃ for 20-40 minutes to form a continuous thermal conductivity path.

[0028] S3. According to the weight parts, the slurry treated in step S2, the conductive temperature-sensitive reinforcing phase, the crosslinking aid, the antioxidant, the flame retardant monomer and the matrix resin are mixed, extruded and granulated, using a co-rotating twin-screw extruder, with a temperature gradient set, wherein zone 1 is 150-160℃, zone 2 is 160-170℃, zone 3 is 170-175℃, zone 4 is 175-180℃, and the die is 160-170℃. After melt extrusion, the material is water-cooled and pelletized to obtain the temperature-sensitive thermally conductive composite cable material.

[0029] S4. The temperature-sensitive thermally conductive composite cable material particles are fed into a double-layer co-extrusion extruder, wherein the inner layer extrusion temperature is 160-170℃ and the outer layer extrusion temperature is 160-170℃, forming a temperature-sensitive thermally conductive sleeve that can be fitted onto the outer periphery of the cable.

[0030] The temperature-sensitive thermally conductive composite cable material of this invention achieves breakthrough technical effects such as molecular-level compatibility, directional thermally conductive network construction, and synergistic amplification of temperature-sensitive and thermally conductive signals through multi-component synergistic reaction and innovative process design. The covalent bonding between C4A-Si and N-isopropylacrylamide is the core of improving interfacial strength. The surface of sulfonated calixarene (SC8A) is rich in sulfonic acid groups (-SO3H), which undergo dehydration condensation with the amide groups (-CONH-) of N-isopropylacrylamide (NIPA) at a polymerization temperature of 60-70℃, forming stable amide bonds (-SO2NH-). This reaction transforms the originally physically mixed filler and temperature-sensitive polymer into a chemically bonded connection, increasing the interfacial bonding energy from van der Waals forces (<50kJ / mol) to covalent bond energy (~300kJ / mol), achieving an interfacial shear strength increase of ≥40%36; simultaneously, the synergistic effect of the modified calixarene further enhances compatibility. The primary amine group (-NH2) contained in acrylamide (AAm) monomer can form a hydrogen bond network with the phenolic hydroxyl group at the lower edge of calixarene, while the tert-butyl group at the upper edge of calixarene interacts hydrophobically with the alkyl chain of the matrix resin. This multi-level bonding mode of "covalent bond + hydrogen bond + hydrophobic interaction" effectively inhibits the phase separation between traditional fillers and the matrix. Electric field response of high thermal conductivity inorganic fillers: Under an alternating electric field of 50-100 V / mm, lamellar boron nitride (h-BN) or fibrous carbon nanotubes (CNTs) become polarized due to the difference in dielectric constant (ε_filler>ε_matrix), aligning into a chain-like structure along the electric field direction. The electric field frequency of 1-5 kHz prevents the filler from agglomerating while orienting, forming a continuous thermally conductive pathway with low tortuosity. Thermally conductive bridging agents (such as silane coupling agent KH792) react simultaneously during the electric field: their methoxy groups (-OCH3) hydrolyze to silanol (-SiOH), which condenses with the hydroxyl groups on the surface of the inorganic filler to form Si-OM (M = filler metal); the amino group (-NH2) at the other end reacts with the carboxyl groups of the matrix resin. This process reduces the thermal resistance at the filler-matrix interface by 50% and increases the thermal conductivity to 2.32 W / (m·K). Furthermore, calixarene cavities encapsulating PEDOT:PSS form the signal amplification core; poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS) serves as the conductivity-sensitive enhancement phase, with its sulfonate groups (-SO3) - The material is encapsulated by a hydrophobic cavity of calixarene, forming a host-guest complex. Through innovative process integration (one-pot method + electric field curing), a synergistic enhancement of temperature sensitivity and thermal conductivity is achieved. This technological approach has universal reference value for the development of intelligent thermal management materials, with particularly promising prospects in areas such as overheating early warning for power cables and thermal runaway protection for new energy batteries.

[0031] The beneficial effects of this invention are as follows:

[0032] 1. This invention uses polyphenylene sulfide and polyaramid fiber paper as the matrix resin, combined with components such as temperature-sensitive thermally conductive filler, thermally conductive bridging agent, electrically conductive temperature-sensitive reinforcing phase, crosslinking aid and high thermal conductivity inorganic filler, to construct a multifunctional synergistic composite cable material, realizing the organic combination of thermal conductivity and temperature monitoring function.

[0033] 2. The thermal conductivity of the temperature-sensitive thermally conductive composite cable material of this invention reaches 1.35 W·m. -1 ·K-1 and above, exceeding the design target by 1.2W·m -1 The K-1 exhibits a temperature response sensitivity ΔR / R0 of 215% (ΔT = 2℃), exceeding the design target by 200%, and an insulation strength of over 22kV / mm, exceeding the design target by 20kV / mm. Its operating temperature range is expanded to -20℃ to 150℃, significantly outperforming existing technologies.

[0034] 3. This invention employs electric field-induced self-assembly thermal conductive network construction technology, which enables the temperature-sensitive thermal conductive filler to form oriented thermal conductive pathways under the action of an electric field. This increases the interfacial shear strength by ≥40%, reduces the interfacial thermal resistance by ≥50%, improves the temperature-sensitive response sensitivity by more than 5 times compared to pure NIPA, and increases the yield to more than 85%.

[0035] 4. The temperature-sensitive thermally conductive composite cable material of the present invention can dissipate heat quickly under high-intensity use conditions, effectively delaying aging and reducing the risk of fire. At the same time, it enables real-time temperature monitoring and intelligent control during charging, improving the safety and energy efficiency of charging equipment and enhancing the system's technological competitiveness. Detailed Implementation

[0036] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0037] Example 1

[0038] A method for preparing a temperature-sensitive thermally conductive composite cable material includes the following raw materials in parts by weight: 35 parts of matrix resin, 15 parts of temperature-sensitive thermally conductive filler, 1.5 parts of thermally conductive bridging agent, 0.3 parts of conductive temperature-sensitive reinforcing phase, 0.5 parts of crosslinking aid, 6 parts of high thermal conductivity inorganic filler, 2 parts of antioxidant and 2 parts of flame-retardant monomer.

[0039] The matrix resin is composed of ethylene-vinyl acetate copolymer, polyphenylene sulfide, and polyaramid fiber paper in a mass ratio of 5.5:2.5:1.2. This combination provides good mechanical strength and heat resistance while maintaining appropriate flexibility, making the cable less prone to breakage when bent and stretched.

[0040] The temperature-sensitive thermally conductive filler is composed of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene in a mass ratio of 1.1:0.4:0.2:0.2. The modified calixarene is prepared by reacting calixarene with acryloyloxypropyltrimethoxysilane in a 1:2 molar ratio in toluene at 80°C for 3 hours. This temperature-sensitive thermally conductive filler significantly improves the thermal conductivity of the material as the temperature increases, achieving adaptive temperature regulation.

[0041] The thermally conductive bridging agent is an EDTA-zinc ammonium complex, which can form a molecular bridge between the temperature-sensitive thermally conductive filler and the matrix resin, enhance the interfacial bonding force, and improve the overall thermal conductivity of the composite material.

[0042] The conductive temperature-sensitive reinforcing phase is a mixture of PEDOT:PSS and polyaniline-dodecylbenzenesulfonic acid in a mass ratio of 1:1. This conductive temperature-sensitive reinforcing phase exhibits significantly increased conductivity with rising temperatures, and works synergistically with the temperature-sensitive thermally conductive filler to further enhance the material's temperature responsiveness.

[0043] The crosslinking aid uses a benzophenone / triethanolamine photoinitiator system, which can efficiently initiate crosslinking reactions under ultraviolet light irradiation, thereby improving the network structure stability and heat resistance of the material.

[0044] The high thermal conductivity inorganic filler is a mixture of hexagonal boron nitride and spherical alumina in a mass ratio of 3:2. This combination forms a three-dimensional thermally conductive network, significantly improving the thermal conductivity of the material while maintaining low electrical conductivity.

[0045] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 2:1. This combination effectively prevents the material from oxidizing and aging at high temperatures, extending the cable's service life.

[0046] In a preferred embodiment, the flame-retardant monomer is prepared by the following steps:

[0047] First, under nitrogen protection, 90 mmol of 1,1,3,3-tetramethyldisiloxane and 0.5 mL of Karstedt catalyst were added to a microchannel reactor, the temperature was controlled at 60 °C, and 115 mmol of methyl acrylate in toluene solution was pumped in at a flow rate of 2 mL / min. The reaction residence time was 15 min, and the solvent was removed online under reduced pressure to obtain intermediate M1.

[0048] Then, M1 was mixed with a 0.5M NaOH / ethanol-water mixture and stirred at 480 rpm at 32°C. After hydrolysis for 30 min by online pH monitoring, 1M HCl was added dropwise until pH=2, and then ammonia was used to adjust the pH to 7, resulting in the precipitation of a white solid. The solid was then filtered and freeze-dried to obtain intermediate M2.

[0049] Next, at -5°C, a benzene solution of 100 mmol phenylphosphonic dichloromethyl chloride was added dropwise at 1 mL / min to a mixture of 160 mL diethylene glycol dimethyl ether and 215 mmol ethanolamine. Simultaneously, 215 mmol triethylamine was introduced online to neutralize the solution to pH 7.5. The temperature was raised to 52°C and reacted for 2 h, then raised to 92°C and reacted for 3 h. The reaction solution was separated by membrane separation to remove TEA hydrochloride, and concentrated under reduced pressure to obtain intermediate M3.

[0050] Finally, 100 mmol M2, 105 mmol M3 and 0.5 wt% tetrabutyl titanate were added to the reactor. Nitrogen gas was first purged, and prepolymerization was carried out at 142 °C and 50 mbar for 2 h. Then, the temperature was raised to 175 °C and 10 mbar for 1.5 h for condensation. The reaction was terminated when the acid value dropped to 3 mg KOH / g, and a pale yellow transparent flame retardant monomer was obtained.

[0051] The specific steps for preparing temperature-sensitive thermally conductive composite cable materials are as follows:

[0052] First, weigh the matrix resin, thermally conductive filler, thermally conductive bridging agent, thermally conductive and thermally sensitive reinforcing phase, crosslinking aid, highly thermally conductive inorganic filler, antioxidant and flame retardant monomer according to the above proportions.

[0053] Then, add all components to a twin-screw extruder, set the temperature to 160-180℃ and the screw speed to 80-100 rpm, mix evenly and then extrude to form the product.

[0054] Finally, the extruded material was subjected to cross-linking treatment under ultraviolet light irradiation at an intensity of 50 mW / cm². 2 The irradiation time was 3 minutes, and the final temperature-sensitive thermally conductive composite cable material was obtained.

[0055] The prepared temperature-sensitive thermally conductive composite cable material exhibits a thermal conductivity of 0.8 W / (m·K) at 25℃, which increases to 2.3 W / (m·K) at 85℃, demonstrating excellent temperature-sensitive thermal conductivity. Simultaneously, the material exhibits good flame retardant properties, with an oxygen index of 32%, meeting the V-0 flame retardant requirement. The material has a tensile strength of 18 MPa and an elongation at break of 280%, demonstrating good mechanical properties. Furthermore, the material remains stable within a temperature range of -40℃ to 150℃, retaining over 90% of its performance after thermal aging, making it suitable for cable applications in various harsh environments.

[0056] Example 2

[0057] A method for preparing a temperature-sensitive thermally conductive composite cable material includes the following steps:

[0058] S1: Preparation of temperature-sensitive thermally conductive filler: Sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene were mixed in a mass ratio of 1.1:0.4:0.2:0.2 and polymerized at 65℃ for 10 hours to obtain the temperature-sensitive thermally conductive filler, which was then set aside. The modified calixarene was obtained by reacting calixarene with acryloyloxypropyltrimethoxysilane at a molar ratio of 1:2 in toluene at 80℃ for 3 hours.

[0059] S2: Formation of thermal conductive pathways: According to the weight parts, the high thermal conductivity inorganic filler hexagonal boron nitride, the thermal bridging agent EDTA-zinc ammonium complex, and the temperature-sensitive thermal conductive filler prepared in step S1 are mixed to form a slurry. Under the action of an alternating electric field of 75V / mm and 3kHz, the slurry is oriented and arranged at 22℃ for 30 minutes to form a continuous thermal conductive pathway.

[0060] S3: Composite material preparation: According to the weight parts, the slurry treated in step S2, the conductive temperature-sensitive reinforcing phase PEDOT:PSS, the crosslinking aid benzophenone / triethanolamine photoinitiator system, antioxidant 1010, flame retardant monomer and matrix resin are mixed, extruded and granulated, using a co-rotating twin-screw extruder, with a temperature gradient set, wherein zone 1 is 155℃, zone 2 is 165℃, zone 3 is 172℃, zone 4 is 178℃, and the die is 165℃. After melt extrusion, the material is water-cooled and pelletized to obtain the temperature-sensitive thermally conductive composite cable material.

[0061] The flame-retardant monomer is prepared by the following method:

[0062] A1: Under nitrogen protection, 90 mmol of 1,1,3,3-tetramethyldisiloxane and Karstedt catalyst were added to a microchannel reactor. The temperature was controlled at 60±2℃. 115 mmol of methyl acrylate in toluene solution was pumped in at a flow rate of 2 mL / min. The reaction residence time was 15 minutes. The solvent was removed online under reduced pressure to obtain intermediate M1 for later use.

[0063] A2: Mix M1 with 0.5M NaOH / ethanol-water, stir at 480rpm at 32℃, monitor pH online, hydrolyze for 30 minutes, add 1M HCl dropwise until pH=2, then adjust to pH=7 with ammonia, precipitate a white solid, filter, freeze dry to obtain intermediate M2, for later use;

[0064] A3: At -5℃, 100 mmol of phenylphosphonic dichlorobenzene solution was added dropwise at 1 mL / min to a mixture of 160 mL of diethylene glycol dimethyl ether and 215 mmol of ethanolamine. Simultaneously, 215 mmol of triethylamine was introduced online to neutralize to pH 7-8. The temperature was raised to 52℃ and reacted for 2 hours, then raised to 92℃ and reacted for 3 hours. The reaction solution was separated by membrane separation to remove TEA hydrochloride, and concentrated under reduced pressure to obtain intermediate M3 for later use.

[0065] A4: Add 100 mmol M2, 105 mmol M3 and 0.5 wt% tetrabutyl titanate to the reactor, purge with nitrogen first, prepolymerize at 142℃ and 50 mbar for 2 hours, then heat to 175℃ and 10 mbar for 1.5 hours for condensation polymerization. Terminate the reaction when the acid value drops to <5 mg KOH / g to obtain a pale yellow transparent flame-retardant monomer.

[0066] S4: Preparation of temperature-sensitive thermal conductive sleeve: The temperature-sensitive thermal conductive composite cable material particles obtained in step S3 are fed into a double-layer co-extrusion extruder, wherein the inner layer extrusion temperature is 165℃ and the outer layer extrusion temperature is 165℃, forming a temperature-sensitive thermal conductive sleeve that can be sleeved on the outer periphery of the cable.

[0067] In a preferred embodiment, the thermally conductive bridging agent may also be the silane coupling agent KH792.

[0068] In another preferred embodiment, the conductive temperature-sensitive reinforcing phase may also be polyaniline-dodecylbenzenesulfonic acid or carboxylated single-walled carbon nanotubes.

[0069] In yet another preferred embodiment, the crosslinking aid may also be 2-hydroxy-2-methylphenylacetone or dicumyl peroxide.

[0070] In another preferred embodiment, the highly thermally conductive inorganic filler may also be spherical alumina or plate-shaped aluminum nitride.

[0071] In another preferred embodiment, the antioxidant may also be antioxidant 168 or antioxidant BHT.

[0072] The prepared temperature-sensitive thermally conductive composite cable material exhibits excellent thermal conductivity, with a significant increase in thermal conductivity as temperature rises, effectively solving the heat dissipation problem of the cable under high load operation. Simultaneously, the material possesses good flame retardant properties and mechanical strength, meeting the safety requirements for cable materials. The design of the temperature-sensitive thermally conductive sleeve enables effective protection and heat dissipation management of the cable, extending its service life.

[0073] Example 3

[0074] A temperature-sensitive thermally conductive composite cable material comprises the following raw materials in parts by weight: 30 parts of matrix resin, 10 parts of temperature-sensitive thermally conductive filler, 0.5 parts of thermally conductive bridging agent, 0.1 parts of conductive temperature-sensitive reinforcing phase, 0.3 parts of crosslinking aid, 4 parts of high thermal conductivity inorganic filler, 1 part of antioxidant, and 1 part of flame-retardant monomer.

[0075] The matrix resin is composed of ethylene-vinyl acetate copolymer, polyphenylene sulfide, and polyaramid fiber paper in a mass ratio of 5:2:1.0.

[0076] The temperature-sensitive thermally conductive filler is composed of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene in a mass ratio of 1.0:0.3:0.1:0.1.

[0077] The modified calixarene is obtained by reacting calixarene with acryloyloxypropyltrimethoxysilane in toluene at 75°C for 2 hours at a molar ratio of 1:2.

[0078] The thermally conductive bridging agent is an EDTA-zinc ammonium complex.

[0079] The conductive temperature-sensitive reinforcing phase is polyaniline-dodecylbenzenesulfonic acid.

[0080] The crosslinking aid is 2-hydroxy-2-methylphenylacetone.

[0081] The high thermal conductivity inorganic filler is hexagonal boron nitride.

[0082] The antioxidant is antioxidant 1010.

[0083] The flame-retardant monomer is prepared by the following method:

[0084] A1. Under nitrogen protection, 80 mmol of 1,1,3,3-tetramethyldisiloxane and Karstedt catalyst were added to a microchannel reactor. The temperature was controlled at 60 °C. 110 mmol of methyl acrylate in toluene solution was pumped in at a flow rate of 2 mL / min. The reaction residence time was 10 min. The solvent was removed online under reduced pressure to obtain intermediate M1 for later use.

[0085] A2. Mix M1 with 0.3M NaOH / ethanol-water and stir at 450 rpm at 30℃. After hydrolysis for 20 min by online pH monitoring, add 1M HCl dropwise until pH=2, then adjust to pH=7 with ammonia water. A white solid precipitates out. Filter and freeze dry to obtain intermediate M2 for later use.

[0086] A3. At -5℃, 90 mmol of phenylphosphonic dichlorobenzene solution was added dropwise at 1 mL / min to a mixture of 150 mL of diethylene glycol dimethyl ether and 210 mmol of ethanolamine. Simultaneously, 210 mmol of triethylamine was introduced to neutralize the solution online to pH 7. The temperature was raised to 50℃ and reacted for 1 h, then raised to 90℃ and reacted for 2 h. The reaction solution was separated by membrane separation to remove TEA hydrochloride, and concentrated under reduced pressure to obtain intermediate M3 for later use.

[0087] A4. Add 95 mmol M2, 100 mmol M3 and 0.5 wt% tetrabutyl titanate to the reactor, purge with nitrogen first, prepolymerize at 140℃ and 50 mbar for 1 h, then heat to 170℃ and 10 mbar for condensation for 1 h. Terminate the reaction when the acid value drops to <5 mg KOH / g to obtain a pale yellow transparent flame retardant monomer.

[0088] A method for preparing a temperature-sensitive thermally conductive composite cable material includes the following steps:

[0089] S1. According to the weight parts, sulfonated calixarene, N-isopropylacrylamide, acrylamide and modified calixarene are mixed and polymerized at 60℃ for 8h to obtain a temperature-sensitive thermally conductive filler for later use.

[0090] S2. According to the weight proportions, the high thermal conductivity inorganic filler, thermal conductivity bridging agent and temperature-sensitive thermal conductivity filler are mixed to form a slurry. Under the action of an alternating electric field of 50V / mm and 1kHz, the slurry is oriented and arranged at 20℃ for 20 minutes to form a continuous thermal conductivity path.

[0091] S3. According to the weight parts, the slurry treated in step S2, the conductive temperature-sensitive reinforcing phase, the crosslinking aid, the antioxidant, the flame retardant monomer and the matrix resin are mixed, extruded and granulated, using a co-rotating twin-screw extruder, with a temperature gradient set, wherein zone 1 is 150℃, zone 2 is 160℃, zone 3 is 170℃, zone 4 is 175℃, and the die is 160℃. After melt extrusion, the material is water-cooled and pelletized to obtain the temperature-sensitive thermally conductive composite cable material.

[0092] S4. The temperature-sensitive thermally conductive composite cable material particles are fed into a double-layer co-extrusion extruder, wherein the inner layer extrusion temperature is 160℃ and the outer layer extrusion temperature is 160℃, forming a temperature-sensitive thermally conductive sleeve that can be fitted onto the outer periphery of the cable.

[0093] Example 4

[0094] A temperature-sensitive thermally conductive composite cable material comprises the following raw materials in parts by weight: 45 parts of matrix resin, 20 parts of temperature-sensitive thermally conductive filler, 2.5 parts of thermally conductive bridging agent, 0.5 parts of conductive temperature-sensitive reinforcing phase, 0.7 parts of crosslinking aid, 8 parts of high thermal conductivity inorganic filler, 3 parts of antioxidant, and 3 parts of flame-retardant monomer.

[0095] The matrix resin is composed of ethylene-vinyl acetate copolymer, polyphenylene sulfide, and polyaramid fiber paper in a mass ratio of 6:3:1.5.

[0096] The temperature-sensitive thermally conductive filler is composed of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene in a mass ratio of 1.2:0.5:0.3:0.3.

[0097] The modified calixarene is obtained by reacting calixarene with acryloyloxypropyltrimethoxysilane in toluene at 85°C for 4 hours at a molar ratio of 1:2.

[0098] The thermally conductive bridging agent is an EDTA-zinc ammonium complex.

[0099] The conductive temperature-sensitive reinforcing phase is a P-carboxylated single-walled carbon nanotube.

[0100] The crosslinking aid is dicumyl peroxide.

[0101] The high thermal conductivity inorganic filler is spherical alumina.

[0102] The antioxidant is antioxidant 168.

[0103] The flame-retardant monomer is prepared by the following method:

[0104] A1. Under nitrogen protection, 100 mmol of 1,1,3,3-tetramethyldisiloxane and Karstedt catalyst were added to a microchannel reactor. The temperature was controlled at 60°C. A toluene solution of 120 mmol of methyl acrylate was pumped in at a flow rate of 2 mL / min. The reaction residence time was 20 min. The solvent was removed online under reduced pressure to obtain intermediate M1 for later use.

[0105] A2. Mix M1 with 0.7M NaOH / ethanol-water, stir at 500rpm at 35℃, monitor pH online, hydrolyze for 40min, add 1M HCl dropwise until pH=2, then adjust to pH=7 with ammonia, a white solid precipitates, filter, freeze dry to obtain intermediate M2, for later use.

[0106] A3. At -5℃, 110 mmol of phenylphosphonic dichlorobenzene solution was added dropwise at 1 mL / min to a mixture of 170 mL of diethylene glycol dimethyl ether and 220 mmol of ethanolamine. Simultaneously, 220 mmol of triethylamine was introduced to neutralize the solution online to pH 7. The temperature was raised to 55℃ and reacted for 3 h, then raised to 95℃ and reacted for 4 h. The reaction solution was separated by membrane separation to remove TEA hydrochloride, and concentrated under reduced pressure to obtain intermediate M3 for later use.

[0107] A4. Add 105 mmol M2, 110 mmol M3 and 0.5 wt% tetrabutyl titanate to the reactor, purge with nitrogen first, prepolymerize at 145℃ and 50 mbar for 3 h, then heat to 180℃ and 10 mbar for condensation for 2 h. Terminate the reaction when the acid value drops to <5 mg KOH / g to obtain a pale yellow transparent flame retardant monomer.

[0108] A method for preparing a temperature-sensitive thermally conductive composite cable material includes the following steps:

[0109] S1. According to the weight parts, sulfonated calixarene, N-isopropylacrylamide, acrylamide and modified calixarene are mixed and polymerized at 70℃ for 12h to obtain a temperature-sensitive thermally conductive filler for later use.

[0110] S2. According to the weight proportions, the high thermal conductivity inorganic filler, thermal conductivity bridging agent and temperature-sensitive thermal conductivity filler are mixed to form a slurry. Under the action of a 100V / mm, 5kHz alternating electric field, the slurry is oriented and arranged at 25℃ for 40 minutes to form a continuous thermal conductivity path.

[0111] S3. According to the weight parts, the slurry treated in step S2, the conductive temperature-sensitive reinforcing phase, the crosslinking agent, the antioxidant, the flame retardant monomer and the matrix resin are mixed, extruded and granulated, using a co-rotating twin-screw extruder, with a temperature gradient set, wherein zone 1 is 160℃, zone 2 is 170℃, zone 3 is 175℃, zone 4 is 180℃, and the die is 170℃. After melt extrusion, the material is water-cooled and pelletized to obtain the temperature-sensitive thermally conductive composite cable material.

[0112] S4. The temperature-sensitive thermally conductive composite cable material particles are fed into a double-layer co-extrusion extruder, wherein the inner layer extrusion temperature is 170℃ and the outer layer extrusion temperature is 170℃, forming a temperature-sensitive thermally conductive sleeve that can be fitted onto the outer periphery of the cable.

[0113] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A temperature-sensitive thermally conductive composite cable material, characterized in that: The raw materials include the following parts by weight: 30-45 parts of matrix resin, 10-20 parts of temperature-sensitive thermally conductive filler, 0.5-2.5 parts of thermally conductive bridging agent, 0.1-0.5 parts of conductive temperature-sensitive reinforcing phase, 0.3-0.7 parts of crosslinking aid, 4-8 parts of high thermal conductivity inorganic filler, 1-3 parts of antioxidant, and 1-3 parts of flame retardant monomer.

2. The temperature-sensitive thermally conductive composite cable material according to claim 1, characterized in that: The matrix resin is composed of ethylene-vinyl acetate copolymer, polyphenylene sulfide and polyaramid fiber paper in a mass ratio of 5-6:2-3:1.0-1.

5.

3. The temperature-sensitive thermally conductive composite cable material according to claim 2, characterized in that: The temperature-sensitive thermally conductive filler is at least one of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene.

4. The temperature-sensitive thermally conductive composite cable material according to claim 3, characterized in that: The temperature-sensitive thermally conductive filler is composed of sulfonated calixarene, N-isopropylacrylamide, acrylamide, and modified calixarene in a mass ratio of 1.0-1.2:0.3-0.5:0.1-0.3:0.1-0.3; The modified calixarene is obtained by reacting calixarene with acryloyloxypropyltrimethoxysilane in toluene at a molar ratio of 1:2 for 2-4 hours at 75-85°C.

5. The temperature-sensitive thermally conductive composite cable material according to claim 3, characterized in that: The thermally conductive bridging agent is an EDTA-zinc ammonium complex or a silane coupling agent KH792.

6. The temperature-sensitive thermally conductive composite cable material according to claim 3, characterized in that: The conductive temperature-sensitive reinforcing phase is at least one of PEDOT:PSS, polyaniline-dodecylbenzenesulfonic acid, and carboxylated single-walled carbon nanotubes.

7. The temperature-sensitive thermally conductive composite cable material according to claim 3, characterized in that: The crosslinking aid is at least one of benzophenone / triethanolamine photoinitiator system, 2-hydroxy-2-methylphenylacetone, and dicumyl peroxide.

8. The temperature-sensitive thermally conductive composite cable material according to claim 3, characterized in that: The high thermal conductivity inorganic filler is at least one of hexagonal boron nitride, spherical alumina, and plate-shaped aluminum nitride; the antioxidant is at least one of antioxidant 1010, antioxidant 168, and antioxidant BHT.

9. The temperature-sensitive thermally conductive composite cable material according to claim 3, characterized in that: The flame-retardant monomer is prepared by the following method: A1. Under nitrogen protection, 80-100 mmol of 1,1,3,3-tetramethyldisiloxane and Karstedt catalyst were added to a microchannel reactor. The temperature was controlled at 60±2℃. 110-120 mmol of methyl acrylate in toluene solution was pumped in at a flow rate of 2 mL / min. The reaction residence time was 10-20 min. The solvent was removed online under reduced pressure to obtain intermediate M1 for later use. A2. Mix M1 with 0.3-0.7M NaOH / ethanol-water, stir at 450-500rpm at 30-35℃, monitor pH online, hydrolyze for 20-40min, add 1M HCl dropwise until pH=2, then adjust to pH=7 with ammonia, a white solid precipitates, filter, freeze dry to obtain intermediate M2, for later use; A3. At -5℃, a benzene solution of 90-110 mmol of phenylphosphonic dichlorophenate is added dropwise at 1 mL / min to a mixture of 150-170 mL of diethylene glycol dimethyl ether and 210-220 mmol of ethanolamine. Simultaneously, 210-220 mmol of triethylamine is introduced online to neutralize to pH 7-8. The temperature is raised to 50-55℃ and reacted for 1-3 h, then raised to 90-95℃ and reacted for 2-4 h. The reaction solution is separated by membrane separation to remove TEA hydrochloride, and concentrated under reduced pressure to obtain intermediate M3 for later use. A4. Add 95-105 mmol M2, 100-110 mmol M3 and 0.5 wt% tetrabutyl titanate to the reactor. First, purge with nitrogen. Prepolymerize at 140-145℃ and 50 mbar for 1-3 h. Then, heat to 170-180℃ and 10 mbar for condensation for 1-2 h. Terminate the reaction when the acid value drops to <5 mg KOH / g to obtain a pale yellow transparent flame-retardant monomer.

10. A method for preparing a temperature-sensitive thermally conductive composite cable material as described in any one of claims 3-9, characterized in that: Includes the following steps: S1. According to the weight parts, sulfonated calixarene, N-isopropylacrylamide, acrylamide and modified calixarene are mixed and polymerized at 60-70℃ for 8-12h to obtain a temperature-sensitive thermally conductive filler for later use. S2. According to the weight proportions, the high thermal conductivity inorganic filler, thermal conductivity bridging agent and temperature-sensitive thermal conductivity filler are mixed to form a slurry. Under the action of an alternating electric field of 50-100V / mm and 1-5kHz, the slurry is oriented and arranged at 20-25℃ for 20-40 minutes to form a continuous thermal conductivity path. S3. According to the weight parts, the slurry treated in step S2, the conductive temperature-sensitive reinforcing phase, the crosslinking aid, the antioxidant, the flame retardant monomer and the matrix resin are mixed, extruded and granulated, using a co-rotating twin-screw extruder, with a temperature gradient set, wherein zone 1 is 150-160℃, zone 2 is 160-170℃, zone 3 is 170-175℃, zone 4 is 175-180℃, and the die is 160-170℃. After melt extrusion, the material is water-cooled and pelletized to obtain the temperature-sensitive thermally conductive composite cable material. S4. The temperature-sensitive thermally conductive composite cable material particles are fed into a double-layer co-extrusion extruder, wherein the inner layer extrusion temperature is 160-170℃ and the outer layer extrusion temperature is 160-170℃, forming a temperature-sensitive thermally conductive sleeve that can be fitted onto the outer periphery of the cable.