Helically wrapped carbon nanotube metal composite heat-conducting yarn, preparation method and application thereof

Abstract

The application discloses a spiral-wound carbon nanotube metal composite heat-conducting yarn, which comprises a continuous carbon nanotube fiber core wire and at least one continuous metal wire wound on the outer surface of the continuous carbon nanotube fiber core wire; wherein the continuous metal wire is a preformed metal wire with independent mechanical integrity, the continuous metal wire extends spirally along the axial direction of the continuous carbon nanotube fiber core wire, and forms a parallel heat-conducting path with the continuous carbon nanotube fiber core wire. The application is different from carbon nanotube filler type heat-conducting fiber, metal coating fiber and silver nanowire composite fiber, and can have high heat conductivity, flexibility, bending resistance and weavability, and can be applied to flexible heat-dissipating materials, heat-conducting fabrics, intelligent textiles, wearable electronic devices, flexible heat management devices, electric heating fabrics and electronic device heat-dissipating connectors.

Description

Technical Field

[0001] This invention relates to the fields of flexible thermally conductive materials, thermally conductive yarns, smart textiles, and flexible thermal management materials, and particularly to a spiral-wound carbon nanotube-metal composite thermally conductive yarn, its preparation method, and its applications. Background Technology

[0002] With the development of flexible electronics, wearable devices, smart textiles, flexible sensors, portable electronic devices, and soft robots, higher demands are being placed on lightweight, flexible, weaveable materials with good thermal conductivity. Electronic devices and functional fabrics generate heat during operation. If this heat cannot be conducted and dissipated in a timely manner, it can easily lead to excessively high local temperatures, thereby affecting device performance, stability, and lifespan.

[0003] Traditional thermally conductive materials mainly include metal sheets, graphite sheets, thermally conductive silicone sheets, carbon fiber bundles, metal wires, and metallized fibers. Metal materials generally have high thermal conductivity, but they have a high density and are prone to fatigue damage during repeated bending or textile processing. Graphite fibers and carbon fibers have some thermal conductivity, but they are brittle and lack flexibility and weaving adaptability.

[0004] Carbon nanotube fibers are continuous macroscopic fibers assembled from a large number of carbon nanotubes. They possess lightweight, high flexibility, high specific strength, bending resistance, corrosion resistance, and good axial thermal conductivity. Due to the axial orientation of carbon nanotubes, continuous carbon nanotube fibers can serve as flexible thermally conductive fiber materials. However, individual carbon nanotube fibers still exhibit contact thermal resistance and interfacial defects between carbon nanotubes, leaving room for further improvement in their thermal conductivity and heat diffusion efficiency.

[0005] In existing thermally conductive composite fibers, common methods include dispersing carbon nanotubes as fillers in a polymer matrix and preparing the fibers through melt spinning or wet spinning, or forming metal coatings, metal particle layers, metal slurry layers, or silver nanowire layers on the fiber surface. However, these methods suffer from problems such as discontinuous thermal conductivity pathways in carbon nanotubes, poor adhesion stability of metal layers, easy breakage of thermal conductivity pathways, high interfacial thermal resistance, or unsuitability for repeated bending. Therefore, there is a need for a composite thermally conductive yarn that differs from carbon nanotube-filled thermally conductive fibers, metal-coated fibers, and silver nanowire composite fibers, simultaneously possessing continuous thermal conductivity pathways, flexibility, bending resistance, and weavability. Summary of the Invention

[0006] To address the shortcomings of the existing technology, the present invention aims to provide a spiral-wound carbon nanotube-metal composite thermally conductive yarn, which is a carbon nanotube fiber / continuous metal wire spiral-wound composite thermally conductive yarn. By spirally wrapping a continuous metal wire with independent mechanical integrity around the outer surface of a continuous carbon nanotube fiber core, the continuous carbon nanotube fiber core and the continuous metal wire together form a parallel thermally conductive path, thereby improving the thermal conductivity, flexibility and tensile strength of the composite yarn.

[0007] To achieve the above objectives, the present invention provides a spiral-wound carbon nanotube-metal composite thermally conductive yarn, comprising: Continuous carbon nanotube fiber core; and At least one continuous metal wire wrapped around the outer surface of the continuous carbon nanotube fiber core; The continuous metal wire is a pre-formed metal wire with independent mechanical integrity. The continuous metal wire extends in a spiral shape along the axial direction of the continuous carbon nanotube fiber core wire and forms a parallel thermal conduction path with the continuous carbon nanotube fiber core wire.

[0008] In some embodiments, there are two continuous metal wires, which are spirally wound around the outer surface of the continuous carbon nanotube fiber core. Specifically, the two continuous metal wires are spirally wound around the outer surface of the continuous carbon nanotube fiber core with the same winding direction and the same winding pitch. The phase difference between the two continuous metal wires in the circumferential direction of the continuous carbon nanotube fiber core is 60° to 180°. In some embodiments, there are two continuous metal wires, which are spirally wound around the outer surface of the continuous carbon nanotube fiber core. Specifically, the two continuous metal wires are cross-wound around the outer surface of the continuous carbon nanotube fiber core in opposite directions to form a cross-spiral thermal conductive structure.

[0009] In some embodiments, the continuous metal wire is silver wire, copper wire, gold wire, aluminum wire, nickel wire, titanium wire, stainless steel wire, silver-plated copper wire, silver-plated copper wire, tin-plated copper wire, nickel-plated copper wire, copper alloy wire, silver alloy wire, gold alloy wire, or aluminum alloy wire. The diameter of the continuous metal wire is 20 μm to 200 μm; the winding pitch of the continuous metal wire is 0.1 mm to 5 mm; the diameter of the continuous carbon nanotube fiber core is 5 μm to 1000 μm. The continuous carbon nanotube fiber core is a continuous carbon nanotube fiber prepared by methods such as carbon nanotube array spinning, floating catalytic spinning, wet spinning, and dry spinning; a thermally conductive bonding layer or intermittently distributed thermally conductive bonding points may be provided between the continuous carbon nanotube fiber core and the continuous metal wire. The thermally conductive adhesive layer or thermally conductive adhesive point comprises one or more of the following: thermally conductive adhesive, thermally conductive resin, silver paste, copper paste, carbon nanotube paste, graphene paste, thermally conductive silicone, boron nitride, aluminum nitride, aluminum oxide, silver powder, or copper powder.

[0010] In some embodiments, the continuous carbon nanotube fiber core is a continuous carbon nanotube fiber that has undergone one or more of the following treatments: solvent densification, mechanical twisting, stretching and orientation, hot pressing densification, and acidification. The axial thermal conductivity of the composite thermally conductive yarn is 50 W / m·K to 1000 W / m·K; the tensile strength of the composite thermally conductive yarn is not less than 200 MPa; and the elongation at break of the composite thermally conductive yarn is not less than 2%.

[0011] Another aspect of the present invention provides a method for preparing the spiral-wound carbon nanotube-metal composite thermally conductive yarn as described above, comprising the following steps: S1. Provide a continuous carbon nanotube fiber core wire and unwind the continuous carbon nanotube fiber core wire; S2. Provide at least one continuous metal wire with independent mechanical integrity, and unwind the continuous metal wire; S3. Control the tension of the continuous carbon nanotube fiber core and the continuous metal wire respectively, so that the continuous carbon nanotube fiber core enters the entanglement area; S4. Rotate the continuous metal wire around the continuous carbon nanotube fiber core wire, or rotate the continuous carbon nanotube fiber core wire relative to the continuous metal wire, so that the continuous metal wire is spirally wrapped around the outer surface of the continuous carbon nanotube fiber core wire. S5. Perform a shaping treatment on the wrapped composite yarn; S6. Wind up to obtain a carbon nanotube fiber / continuous metal wire spiral-wound composite thermally conductive yarn.

[0012] In some embodiments, in step S2, there are two or more continuous metal wires; in step S4, the two continuous metal wires are simultaneously and in the same direction wrapped around the outer surface of the continuous carbon nanotube fiber core. In some embodiments, in step S2, there are two or more continuous metal wires; in step S4, two of the continuous metal wires are wrapped around the outer surface of the continuous carbon nanotube fiber core in opposite directions.

[0013] In some embodiments, in step S3, the tension of the continuous carbon nanotube fiber core is 0.001 N to 10 N, and the tension of the continuous metal wire is 0.001 N to 5 N; In step S4, the winding pitch is controlled by adjusting the traction speed of the continuous carbon nanotube fiber core and the rotation frequency of the continuous metal wire around the continuous carbon nanotube fiber core. The winding pitch P satisfies the following:

[0014] Where P is the wrapping pitch, V is the traction speed of the continuous carbon nanotube fiber core, and n is the rotation frequency of the continuous metal wire around the continuous carbon nanotube fiber core. In step S5, the shaping process includes one or more of the following: heat shaping, hot pressing shaping, pressure roller shaping, thermally conductive adhesive bonding shaping, resin impregnation shaping, flexible protective layer coating shaping, laser welding shaping, or ultrasonic welding shaping.

[0015] Another aspect of the present invention provides the application of the spiral-wound carbon nanotube metal composite thermally conductive yarn as described above in flexible heat dissipation materials, thermally conductive fabrics, smart textiles, wearable electronic devices, flexible thermal management devices, electrically heated fabrics, medical thermotherapy fabrics, temperature sensors, flexible wires, electromagnetic shielding materials, or heat dissipation connectors for electronic devices.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. Formation of continuous parallel thermal conductivity pathways. Continuous carbon nanotube fiber cores provide axial thermal conductivity pathways, while continuous metal wires provide highly thermally conductive metal pathways. The two form a parallel thermal conductivity structure, improving the overall thermal conductivity of the composite yarn.

[0017] 2. Unlike filler-type thermally conductive fibers, this invention uses continuous carbon nanotube fibers as the core wire, rather than dispersing carbon nanotubes as fillers in a polymer matrix, thus resulting in better continuity of the thermal conductivity pathway.

[0018] 3. Unlike metal coatings or silver nanowire composite fibers, this invention uses pre-formed continuous metal wires with independent mechanical integrity, without relying on metal coatings, metal pastes, or silver nanowire networks, resulting in better thermal conductivity channel stability.

[0019] 4. Excellent flexibility and bending resistance. The continuous metal wire is spirally wound around the outer surface of the continuous carbon nanotube fiber core, which can release strain during bending, stretching or twisting, reducing the risk of wire breakage.

[0020] 5. The bimetallic wire structure improves thermal conductivity stability. When two continuous metal wires are used, multiple metal heat conduction paths can be formed, improving thermal redundancy and thermal conductivity stability after bending.

[0021] 6. Suitable for textile processing. The composite thermally conductive yarn of this invention has a yarn form and can be used for processing methods such as weaving, knitting, braiding, sewing, and embroidery.

[0022] 7. Wide range of applications. It can be applied to flexible heat dissipation materials, thermally conductive fabrics, smart clothing, wearable electronic devices, electrically heated fabrics, medical thermotherapy fabrics, electromagnetic shielding materials, and heat dissipation connectors for electronic devices. Attached Figure Description

[0023] Figure 1 Photographs of carbon nanotube fiber cores with different twists; Figure 2 Photographs of carbon nanotube fiber cores with different bundle amounts (diameters); Figure 3 Photo of a single-layer composite yarn with silver threads; Figure 4 This is a photograph of a double-wrapped composite yarn with silver threads. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0025] An embodiment of the present invention provides a helically wound carbon nanotube-metal composite thermally conductive yarn, comprising: Continuous carbon nanotube fiber core; and At least one continuous metal wire wrapped around the outer surface of the continuous carbon nanotube fiber core; The continuous metal wire is a pre-formed metal wire with independent mechanical integrity. The continuous metal wire extends in a spiral shape along the axial direction of the continuous carbon nanotube fiber core wire and forms a parallel thermal conduction path with the continuous carbon nanotube fiber core wire.

[0026] The continuous metal wire consists of two strands, which are spirally wound around the outer surface of the continuous carbon nanotube fiber core. Specifically, the two continuous metal wires are spirally wound around the outer surface of the continuous carbon nanotube fiber core with the same winding direction and the same winding pitch. The phase difference between the two continuous metal wires in the circumferential direction of the continuous carbon nanotube fiber core is 60° to 180°. In this configuration, there may be two continuous metal wires, which are spirally wound around the outer surface of the continuous carbon nanotube fiber core wire. Specifically, the two continuous metal wires are cross-wound around the outer surface of the continuous carbon nanotube fiber core wire in opposite directions to form a cross-spiral thermal conductive structure.

[0027] The continuous metal wire mentioned in this embodiment is silver wire, copper wire, gold wire, aluminum wire, nickel wire, titanium wire, stainless steel wire, silver-plated copper wire, silver-plated copper wire, tin-plated copper wire, nickel-plated copper wire, copper alloy wire, silver alloy wire, gold alloy wire, or aluminum alloy wire. The diameter of the continuous metal wire is 20 μm to 200 μm; the winding pitch of the continuous metal wire is 0.1 mm to 5 mm; the diameter of the continuous carbon nanotube fiber core is 5 μm to 1000 μm. The continuous carbon nanotube fiber core is a continuous carbon nanotube fiber prepared by methods such as carbon nanotube array spinning, floating catalytic spinning, wet spinning, and dry spinning; a thermally conductive bonding layer or intermittently distributed thermally conductive bonding points may be provided between the continuous carbon nanotube fiber core and the continuous metal wire. The thermally conductive adhesive layer or thermally conductive adhesive point comprises one or more of the following: thermally conductive adhesive, thermally conductive resin, silver paste, copper paste, carbon nanotube paste, graphene paste, thermally conductive silicone, boron nitride, aluminum nitride, aluminum oxide, silver powder, or copper powder.

[0028] In this embodiment, the continuous carbon nanotube fiber core is a continuous carbon nanotube fiber that has undergone one or more of the following treatments: solvent densification, mechanical twisting, stretching and orientation, hot pressing densification, and acidification. The axial thermal conductivity of the composite thermally conductive yarn is between 50 W / m·K and 1000 W / m·K. The tensile strength of the composite thermally conductive yarn is not less than 200 MPa. The elongation at break of the composite thermally conductive yarn is not less than 2%.

[0029] Another embodiment of the present invention provides a method for preparing the spiral-wound carbon nanotube-metal composite thermally conductive yarn as described above, comprising the following steps: S1. Provide a continuous carbon nanotube fiber core wire and unwind the continuous carbon nanotube fiber core wire; S2. Provide at least one continuous metal wire with independent mechanical integrity, and unwind the continuous metal wire; S3. Control the tension of the continuous carbon nanotube fiber core and the continuous metal wire respectively, so that the continuous carbon nanotube fiber core enters the entanglement area; S4. Rotate the continuous metal wire around the continuous carbon nanotube fiber core wire, or rotate the continuous carbon nanotube fiber core wire relative to the continuous metal wire, so that the continuous metal wire is spirally wrapped around the outer surface of the continuous carbon nanotube fiber core wire. S5. Perform a shaping treatment on the wrapped composite yarn; S6. Wind up to obtain a carbon nanotube fiber / continuous metal wire spiral-wound composite thermally conductive yarn.

[0030] In step S2, there are two or more continuous metal wires; in step S4, the two continuous metal wires are simultaneously and in the same direction wrapped around the outer surface of the continuous carbon nanotube fiber core. Alternatively, in step S2, there may be two or more continuous metal wires; in step S4, two of the continuous metal wires are wrapped around the outer surface of the continuous carbon nanotube fiber core wire in opposite directions.

[0031] In step S3, the tension of the continuous carbon nanotube fiber core is 0.001 N to 10 N, and the tension of the continuous metal wire is 0.001 N to 5 N. In step S4, the winding pitch is controlled by adjusting the traction speed of the continuous carbon nanotube fiber core and the rotation frequency of the continuous metal wire around the continuous carbon nanotube fiber core. The winding pitch P satisfies the following:

[0032] Where P is the wrapping pitch, V is the traction speed of the continuous carbon nanotube fiber core, and n is the rotation frequency of the continuous metal wire around the continuous carbon nanotube fiber core. In step S5, the shaping process includes one or more of the following: heat shaping, hot pressing shaping, pressure roller shaping, thermally conductive adhesive bonding shaping, resin impregnation shaping, flexible protective layer coating shaping, laser welding shaping, or ultrasonic welding shaping.

[0033] Another embodiment of the present invention provides the application of the spiral-wound carbon nanotube metal composite thermally conductive yarn as described above in flexible heat dissipation materials, thermally conductive fabrics, smart textiles, wearable electronic devices, flexible thermal management devices, electrically heated fabrics, medical thermotherapy fabrics, temperature sensors, flexible wires, electromagnetic shielding materials, or heat dissipation connectors for electronic devices.

[0034] The spiral-wound carbon nanotube-metal composite thermally conductive yarn provided in the above embodiments of the present invention includes a continuous carbon nanotube fiber core and at least one continuous metal wire wrapped around the outer surface of the continuous carbon nanotube fiber core.

[0035] The continuous metal wire is a pre-formed metal wire with independent mechanical integrity, unlike metal coatings, metal pastes, metal particle layers, or silver nanowire layers. The continuous metal wire extends spirally along the axial direction of the continuous carbon nanotube fiber core and forms a parallel thermal conduction path with the continuous carbon nanotube fiber core.

[0036] In this embodiment of the invention, two continuous metal wires are used. The two continuous metal wires can be arranged with the same winding direction and the same winding pitch, or they can be arranged in opposite winding directions and crossed. When the two continuous metal wires are wound in the same direction, it is preferable that there is a phase difference of 60° to 180° in the circumferential direction of the continuous carbon nanotube fiber core. The continuous metal wire can be silver wire, copper wire, gold wire, aluminum wire, nickel wire, titanium wire, stainless steel wire, silver-plated copper wire, silver-plated copper wire, tin-plated copper wire, nickel-plated copper wire, or alloy wire thereof. The diameter of the continuous metal wire is 20 μm to 200 μm. If the diameter is too small, the metal wire is prone to breakage during winding and use; if the diameter is too large, the flexibility of the composite yarn decreases, which is not conducive to textile processing. The winding pitch of the continuous metal wire is 0.1 mm to 5 mm. A smaller pitch is beneficial for increasing the metal wire coverage density and the number of heat conduction channels; a larger pitch is beneficial for improving flexibility and reducing metal content.

[0037] In this embodiment of the invention, the twist of the continuous carbon nanotube fiber core itself is 0-500 T / m (see...). Figure 1 The diameter of the continuous carbon nanotube fiber core ranges from 5 μm to 1000 μm (see...). Figure 2 A thermally conductive bonding layer or intermittently distributed thermally conductive bonding points are provided between the continuous carbon nanotube fiber core and the continuous metal wire. The thermally conductive bonding layer or thermally conductive bonding points may include thermally conductive adhesive, thermally conductive resin, silver paste, copper paste, carbon nanotube paste, graphene paste, thermally conductive silicone, boron nitride, aluminum nitride, aluminum oxide, silver powder, or copper powder.

[0038] Specific Example 1: Single silver wire spirally wrapped around carbon nanotube fiber composite thermally conductive yarn This embodiment provides a carbon nanotube fiber / continuous metal wire spiral-wound composite thermally conductive yarn, including a continuous carbon nanotube fiber core and a first continuous metal wire.

[0039] The continuous carbon nanotube fiber core is used as the core wire, and the first continuous metal wire is a silver wire. The silver wire is a pre-formed continuous metal wire with independent mechanical integrity, and it is spirally wound around the outer surface of the continuous carbon nanotube fiber core wire along its axial direction (see...). Figure 3 ).

[0040] In this embodiment, the diameter of the continuous carbon nanotube fiber core is 50 μm to 200 μm, the diameter of the silver wire is 10 μm to 50 μm, and the silver wire winding pitch is 1 mm to 10 mm.

[0041] In this structure, continuous carbon nanotube fiber cores and silver wires provide thermal conduction pathways, forming a parallel thermal conduction structure.

[0042] Specific Example 2: Double Silver Wire Co-directional Helical Wrapped Carbon Nanotube Fiber Composite Thermal Conductive Yarn This embodiment provides a double silver wire wrapped composite thermally conductive yarn, including a continuous carbon nanotube fiber core 1, a first continuous metal wire, and a second continuous metal wire.

[0043] Both the first and second continuous metal wires are silver wires. The two silver wires are spirally wound around the outer surface of the continuous carbon nanotube fiber core with the same winding direction and the same winding pitch.

[0044] Two silver wires are spaced apart along the circumference of the continuous carbon nanotube fiber core, preferably with a phase difference of 180°. This creates a uniformly distributed double-helix metal thermal conductivity pathway on the surface of the continuous carbon nanotube fiber core.

[0045] Compared to a single silver wire structure, this embodiment provides more metal heat conduction pathways and has better thermal stability during bending or weaving.

[0046] Specific Example 3: Double silver wires reverse-cross-wound carbon nanotube fiber composite thermally conductive yarn This embodiment provides a double silver wire cross-wound composite thermally conductive yarn, including a continuous carbon nanotube fiber core, a first continuous metal wire, and a second continuous metal wire.

[0047] Both the first and second continuous metal wires are silver wires. The first copper wire is spirally wound clockwise around the outer surface of the continuous carbon nanotube fiber core, and the second copper wire is spirally wound counterclockwise around the outer surface of the continuous carbon nanotube fiber core, thus forming a cross-spiral structure (see...). Figure 4 ).

[0048] This cross-helical structure enhances the mechanical interlocking effect between the continuous metal wire and the continuous carbon nanotube fiber core, improving the structural stability of the composite thermally conductive yarn during bending, stretching, twisting, and textile processing.

[0049] More specifically, the method for preparing the composite thermally conductive yarn includes the following steps:

[0050] S1, Continuous carbon nanotube fiber core unwinding A continuous carbon nanotube fiber core is provided, which is mounted on a core unwinding device and introduced into the wrapping area via a guide wheel.

[0051] Optionally, before entering the entanglement region, the continuous carbon nanotube fiber core may be subjected to solvent densification, mechanical twisting, stretching and orientation, hot pressing densification, plasma activation, acidification treatment, or thermally conductive slurry impregnation treatment to improve its axial thermal conductivity and interfacial bonding ability.

[0052] S2, Continuous wire unwinding Provide at least one continuous metal wire with independent mechanical integrity, and mount the continuous metal wire on a metal wire unwinding device.

[0053] Continuous metal wires can be silver wire, copper wire, gold wire, aluminum wire, nickel wire, titanium wire, stainless steel wire, silver-plated copper wire, silver-plated copper wire, tin-plated copper wire, nickel-plated copper wire, or alloy wire.

[0054] When two continuous metal wires are used, the two continuous metal wires can be installed at two unwinding positions on the same winding reel, or they can be installed in two separate winding mechanisms.

[0055] S3, Tension Control The tension of the continuous carbon nanotube fiber core and the continuous metal wire are adjusted separately by a tension control mechanism.

[0056] Preferably, the tension of the continuous carbon nanotube fiber core is 0.001 N to 10 N, and the tension of the continuous metal wire is 0.001 N to 5 N.

[0057] Tension control ensures that the continuous metal wire is uniformly and stably wrapped around the outer surface of the continuous carbon nanotube fiber core, while preventing the continuous carbon nanotube fiber core from being pulled apart or the continuous metal wire from undergoing excessive plastic deformation.

[0058] S4, Continuous metal wire spiral wrapping The continuous carbon nanotube fiber core is made to advance continuously along the axial direction, while the continuous metal wire is rotated around the continuous carbon nanotube fiber core by the wrapping device, so that the continuous metal wire is wrapped in a spiral shape around the outer surface of the continuous carbon nanotube fiber core.

[0059] When two continuous metal wires are used, the two continuous metal wires can be wrapped synchronously in the same direction, or they can be wrapped in opposite directions in a crisscross pattern.

[0060] The winding pitch P can be adjusted by regulating the traction speed V of the continuous carbon nanotube fiber core and the rotation frequency n of the continuous metal wire around the continuous carbon nanotube fiber core. P = V / n Where P is the wrapping pitch, V is the traction speed of the continuous carbon nanotube fiber core, and n is the rotation frequency of the continuous metal wire.

[0061] S5, Shaping Process The wrapped composite yarn is then subjected to a shaping process.

[0062] The shaping process can include heat shaping, hot pressing shaping, pressure roller shaping, thermally conductive adhesive bonding shaping, resin impregnation shaping, flexible protective layer coating shaping, laser welding shaping, or ultrasonic welding shaping.

[0063] Preferably, a thermally conductive adhesive layer or intermittently distributed thermally conductive adhesive points are introduced before or after wrapping to improve the contact stability between the continuous metal wire and the continuous carbon nanotube fiber core and reduce the interfacial thermal resistance.

[0064] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A spiral wrapped carbon nanotube metal composite heat conductive yarn, characterized by: include: Continuous carbon nanotube fiber core; as well as At least one continuous metal wire wrapped around the outer surface of the continuous carbon nanotube fiber core; The continuous metal wire is a pre-formed metal wire with independent mechanical integrity. The continuous metal wire extends in a spiral shape along the axial direction of the continuous carbon nanotube fiber core wire and forms a parallel thermal conduction path with the continuous carbon nanotube fiber core wire.

2. The spiral wrapped carbon nanotube metal composite thermal conductive yarn according to claim 1, wherein: The continuous metal wire consists of two strands, which are spirally wound around the outer surface of the continuous carbon nanotube fiber core. Specifically, the two continuous metal wires are spirally wound around the outer surface of the continuous carbon nanotube fiber core with the same winding direction and the same winding pitch. The phase difference between the two continuous metal wires in the circumferential direction of the continuous carbon nanotube fiber core is 60° to 180°.

3. The spiral wrapped carbon nanotube metal composite thermally conductive yarn according to claim 1, wherein: The continuous metal wire consists of two strands, which are spirally wound around the outer surface of the continuous carbon nanotube fiber core. Specifically, the two continuous metal wires are cross-wound around the outer surface of the continuous carbon nanotube fiber core in opposite directions to form a cross-spiral thermal conductive structure.

4. The spiral-wound carbon nanotube metal composite thermally conductive yarn according to claim 1, characterized in that: The continuous metal wire is silver wire, copper wire, gold wire, aluminum wire, nickel wire, titanium wire, stainless steel wire, silver-plated copper wire, silver-plated copper wire, tin-plated copper wire, nickel-plated copper wire, copper alloy wire, silver alloy wire, gold alloy wire, or aluminum alloy wire. The diameter of the continuous metal wire is 20 μm to 200 μm; the winding pitch of the continuous metal wire is 0.1 mm to 5 mm; the diameter of the continuous carbon nanotube fiber core is 5 μm to 1000 μm. The continuous carbon nanotube fiber core is a continuous carbon nanotube fiber prepared by methods such as carbon nanotube array spinning, floating catalytic spinning, wet spinning, and dry spinning; a thermally conductive bonding layer or intermittently distributed thermally conductive bonding points may be provided between the continuous carbon nanotube fiber core and the continuous metal wire. The thermally conductive adhesive layer or thermally conductive adhesive point comprises one or more of the following: thermally conductive adhesive, thermally conductive resin, silver paste, copper paste, carbon nanotube paste, graphene paste, thermally conductive silicone, boron nitride, aluminum nitride, aluminum oxide, silver powder, or copper powder.

5. The spiral-wound carbon nanotube metal composite thermally conductive yarn according to claim 1, characterized in that: The continuous carbon nanotube fiber core is a continuous carbon nanotube fiber that has undergone one or more of the following treatments: solvent densification, mechanical twisting, stretching and orientation, hot pressing densification, and acidification. The axial thermal conductivity of the composite thermally conductive yarn is 50 W / m·K to 1000 W / m·K; the tensile strength of the composite thermally conductive yarn is not less than 200 MPa; and the elongation at break of the composite thermally conductive yarn is not less than 2%.

6. A method for preparing a spiral-wound carbon nanotube-metal composite thermally conductive yarn according to any one of claims 1 to 5, characterized in that: Includes the following steps: S1. Provide a continuous carbon nanotube fiber core wire and unwind the continuous carbon nanotube fiber core wire; S2. Provide at least one continuous metal wire with independent mechanical integrity, and unwind the continuous metal wire; S3. Control the tension of the continuous carbon nanotube fiber core and the continuous metal wire respectively, so that the continuous carbon nanotube fiber core enters the entanglement area; S4. Rotate the continuous metal wire around the continuous carbon nanotube fiber core wire, or rotate the continuous carbon nanotube fiber core wire relative to the continuous metal wire, so that the continuous metal wire is spirally wrapped around the outer surface of the continuous carbon nanotube fiber core wire. S5. Perform a shaping treatment on the wrapped composite yarn; S6. Wind up to obtain a carbon nanotube fiber / continuous metal wire spiral-wound composite thermally conductive yarn.

7. The method for preparing the spiral-wound carbon nanotube-metal composite thermally conductive yarn according to claim 6, characterized in that: In step S2, there are two or more continuous metal wires; in step S4, the two continuous metal wires are simultaneously and in the same direction wrapped around the outer surface of the continuous carbon nanotube fiber core.

8. The method for preparing the spiral-wound carbon nanotube-metal composite thermally conductive yarn according to claim 6, characterized in that: In step S2, there are two or more continuous metal wires; in step S4, two of the continuous metal wires are wrapped around the outer surface of the continuous carbon nanotube fiber core wire in opposite directions.

9. The method for preparing the spiral-wound carbon nanotube-metal composite thermally conductive yarn according to claim 6, characterized in that: In step S3, the tension of the continuous carbon nanotube fiber core is 0.001 N to 10 N, and the tension of the continuous metal wire is 0.001 N to 5 N. In step S4, the winding pitch is controlled by adjusting the traction speed of the continuous carbon nanotube fiber core and the rotation frequency of the continuous metal wire around the continuous carbon nanotube fiber core. The winding pitch P satisfies the following: ； Where P is the wrapping pitch, V is the traction speed of the continuous carbon nanotube fiber core, and n is the rotation frequency of the continuous metal wire around the continuous carbon nanotube fiber core. In step S5, the shaping process includes one or more of the following: heat shaping, hot pressing shaping, pressure roller shaping, thermally conductive adhesive bonding shaping, resin impregnation shaping, flexible protective layer coating shaping, laser welding shaping, or ultrasonic welding shaping.

10. The application of the spiral-wound carbon nanotube metal composite thermally conductive yarn according to any one of claims 1 to 5 in flexible heat dissipation materials, thermally conductive fabrics, smart textiles, wearable electronic devices, flexible thermal management devices, electrically heated fabrics, medical thermotherapy fabrics, temperature sensors, flexible wires, electromagnetic shielding materials, or heat dissipation connectors for electronic devices.

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