An enameled round graphene aluminum alloy winding wire and a production process thereof

Abstract

The application relates to the technical field of electric wire and cable, and particularly discloses a varnished round graphene aluminum alloy winding wire and a production process thereof; the varnished round graphene aluminum alloy winding wire comprises a graphene aluminum alloy conductive wire core and an insulating layer, the insulating layer comprises a polyimide heat-resistant layer and a ceramization protective layer, the polyimide heat-resistant layer is located between the graphene aluminum alloy conductive wire core and the ceramization protective layer, and the ceramization protective layer comprises the following raw materials in parts by weight: 30-50 parts of low-density polyethylene, 40-60 parts of ethylene-octene copolymer, 50-80 parts of low-melting-point ceramization powder, 3-5 parts of a vulcanizing agent, 5-8 parts of an antioxidant and 5-8 parts of a lubricant; the winding wire prepared by the application has good heat resistance and strength under the synergistic action of various components.

Description

Technical Field

[0001] This application relates to the field of wire and cable technology, and in particular to an enameled round graphene aluminum alloy winding wire and its manufacturing process. Background Technology

[0002] Currently, enameled round wire is widely used in electrical equipment, such as power transformers, high-voltage motors, and other applications requiring high-performance winding wires. Traditional enameled wires mostly use copper or aluminum as the conductive core, with an outer layer coated with insulating varnish such as polyester, polyurethane, or polyimide.

[0003] However, pure aluminum or aluminum alloy conductors have low conductivity and mechanical strength, while copper conductors are expensive and suffer from the skin effect in high-frequency applications, affecting transmission efficiency. Conventional organic insulation layers have poor heat resistance and are prone to combustion and release toxic gases under high temperature or open flame conditions, making it difficult to meet the high safety requirements of fields such as new energy vehicles and aerospace. Summary of the Invention

[0004] In order to improve the electrical properties, strength and heat resistance of existing enameled round wires, this application provides an enameled round graphene aluminum alloy winding wire and its manufacturing process.

[0005] In a first aspect, this application provides an enameled round graphene aluminum alloy winding wire, which adopts the following technical solution: an enameled round graphene aluminum alloy winding wire, comprising a graphene aluminum alloy conductive core and an insulation layer, wherein the insulation layer comprises a polyimide heat-resistant layer and a ceramicized protective layer, wherein the polyimide heat-resistant layer is located between the graphene aluminum alloy conductive core and the ceramicized protective layer, and wherein the ceramicized protective layer comprises the following raw materials in parts by weight: 30-50 parts of low-density polyethylene, 40-60 parts of ethylene-octene copolymer, 50-80 parts of low-melting-point ceramicizing powder, 3-5 parts of vulcanizing agent, 5-8 parts of antioxidant, and 5-8 parts of lubricant.

[0006] By adopting the above technical solution, the addition of graphene can improve the strength of the aluminum alloy wire core and enhance the electrical performance of the winding wire. Simultaneously, introducing a polyimide heat-resistant layer between the graphene-coated aluminum alloy conductive wire core and the ceramicized protective layer provides initial heat protection for the winding wire, while the ceramicized protective layer provides a second layer of protection, thus providing dual heat protection for the conductive wire core and improving the durability of the winding wire in high-temperature environments.

[0007] The low-melting-point ceramicizing powder in the raw materials of the ceramicized protective layer is combined with low-density polyethylene and ethylene-octene copolymer. At room temperature, this combination promotes good flexibility and impact resistance in the ceramicized protective layer. Under high temperatures or in the presence of open flame, it rapidly ceramicizes to form a ceramic-like structure with certain strength and self-supporting capabilities, providing fire-resistant protection for the conductive core and improving the fire safety and heat resistance of the winding wire. Simultaneously, the low-melting-point ceramicizing powder accelerates the ceramicization process, enhancing the fire-resistant protective effect of the ceramicized protective layer. The ethylene-octene copolymer reduces the brittleness of the ceramicized protective layer, improves its flexibility, and cross-links with polyimide, increasing the bonding strength between insulation layers and enhancing the flexibility and impact resistance of the winding wire.

[0008] Preferably, the low-melting-point ceramic powder is one of phosphate glass powder and borosilicate glass powder.

[0009] Preferably, the surface of the low-melting-point porcelain powder is modified with γ-methacryloxypropyltrimethoxysilane. The modification method includes the following specific steps: mixing γ-methacryloxypropyltrimethoxysilane with the low-melting-point porcelain powder, stirring evenly, and heating and drying to obtain modified low-melting-point porcelain powder.

[0010] By adopting the above technical solution, the surface of the low melting point ceramic powder is modified with γ-methacryloxypropyltrimethoxysilane, which can reduce the moisture absorption of the ceramic powder and thus improve the strength and electrical properties of the ceramic protective layer.

[0011] Preferably, the mass ratio of γ-methacryloyloxypropyltrimethoxysilane to low-melting-point ceramic powder is (0.5-1):10.

[0012] Preferably, the polyimide heat-resistant layer comprises the following raw materials in parts by weight: 30-40 parts of polyimide resin, 5-10 parts of nano zinc oxide, 5-10 parts of polycarbonate, and 5-10 parts of mesoporous silica.

[0013] By adopting the above technical solutions, polyimide resin can provide the conductive core with good high-temperature resistance and ensure good electrical insulation performance, while also exhibiting good strength and dimensional stability, thus enhancing the durability of the winding wire. Polycarbonate can improve the brittleness of polyimide, enabling the polyimide heat-resistant layer to have good flexibility and resistance to bending fatigue, enhancing the interfacial adhesion between the polyimide heat-resistant layer and the ceramicized protective layer, and strengthening the protective effect of the insulation layer on the conductive core.

[0014] Adding appropriate amounts of nano-zinc oxide and mesoporous silica to the polyimide heat-resistant layer can accelerate the dissipation of heat from the conductive core to the outside, reduce the risk of local overheating, and at the same time reduce the thermal shrinkage of the polyimide heat-resistant layer at high temperatures, thereby improving the impact resistance and high-temperature performance of the polyimide heat-resistant layer.

[0015] Preferably, the pore diameter of the mesoporous silica is 20-40 nm.

[0016] Preferably, the graphene-aluminum alloy conductive wire core comprises the following raw materials in parts by weight: 85-95 parts aluminum, 1-3 parts copper, 0.3-0.5 parts graphene, and 0.03-0.05 parts rare earth.

[0017] By adopting the above technical solution, the combination of graphene and aluminum can enhance the tensile strength of the wire core. At the same time, graphene can synergistically enhance rare earth elements, inhibit grain growth, and improve the high-temperature stability of the wire core.

[0018] Preferably, the rare earth element is at least one of lanthanum, cerium, and scandium.

[0019] Secondly, this application provides a manufacturing process for enameled round graphene aluminum alloy winding wire, employing the following technical solution:

[0020] A manufacturing process for enameled round graphene aluminum alloy winding wire includes the following specific steps:

[0021] Low-density polyethylene, ethylene-octene copolymer, low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and refined to form a ceramic protective layer mixture;

[0022] The graphene aluminum alloy conductive core is first composited with a polyimide heat-resistant layer, and then the ceramicized protective layer mixture is melt-extruded onto the surface of the polyimide heat-resistant layer to form a ceramicized protective layer, thus producing an enameled round graphene aluminum alloy winding wire.

[0023] By adopting the above technical solutions, the strength, electrical performance, and heat and fire resistance of enameled round graphene aluminum alloy winding wires can be improved, enabling the winding wires to maintain good performance even in high-temperature environments.

[0024] The preferred manufacturing process for enameled round graphene aluminum alloy winding wire includes the following specific steps:

[0025] Aluminum, copper, graphene and rare earth elements are mixed, heated and melted to obtain a molten metal. The molten metal is then cast, rolled and drawn into a graphene aluminum alloy conductive wire core.

[0026] Polyimide resin, nano zinc oxide, polycarbonate, and mesoporous silica are mixed evenly and melt-extruded onto the surface of graphene aluminum alloy conductive wire core to form a polyimide heat-resistant layer.

[0027] Low-density polyethylene, ethylene-octene copolymer, low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and refined to form a ceramic protective layer mixture. Then, the ceramic protective layer mixture is melt-extruded onto the surface of a polyimide heat-resistant layer to form a ceramic protective layer, thus producing an enameled round graphene aluminum alloy winding wire.

[0028] In summary, this application has the following beneficial effects:

[0029] 1. Because this application uses graphene combined with aluminum alloy to form the conductive core, the strength and electrical performance of the core are enhanced. The conductive core is double-protected by a polyimide heat-resistant layer and a ceramicized protective layer, which enhances the heat resistance, strength, and durability of the winding wire. The use of low-melting-point ceramic powder combined with low-density polyethylene and ethylene-octene copolymer provides fire-resistant protection for the conductive core, improving the fire safety and heat resistance of the winding wire.

[0030] 2. In this application, polycarbonate and polyimide resin are combined in the polyimide heat-resistant layer to improve the high-temperature resistance of the conductive core and ensure the electrical performance of the winding wire. At the same time, nano-zinc oxide and mesoporous silica are used to synergistically enhance the heat dissipation from the conductive core, reduce the risk of local overheating, and improve the impact strength and high-temperature resistance of the polyimide heat-resistant layer. Detailed Implementation

[0031] The present application will be further described in detail below with reference to the embodiments.

[0032] All raw materials used in the examples are commercially available.

[0033] Example

[0034] Example 1

[0035] This embodiment provides an enameled round graphene aluminum alloy winding wire, including a graphene aluminum alloy conductive core and an insulation layer. The insulation layer includes a polyimide heat-resistant layer and a ceramicized protective layer, with the polyimide heat-resistant layer located between the graphene aluminum alloy conductive core and the ceramicized protective layer.

[0036] The ceramicized protective layer comprises the following raw materials in parts by weight: 40 kg of low-density polyethylene, 50 kg of ethylene-octene copolymer, 65 kg of low-melting-point ceramicizing powder, 4 kg of vulcanizing agent, 7 kg of antioxidant, and 7 kg of lubricant. The polyimide heat-resistant layer is made of polyimide resin.

[0037] The graphene aluminum alloy conductive wire core comprises the following raw materials in parts by weight: 90 kg aluminum, 2 kg copper, 0.4 kg graphene, and 0.04 kg rare earth elements.

[0038] The low-melting-point vitrifying powder is phosphate glass powder, purchased from Guangdong Nanhai Donggu New Material Co., Ltd.; the low-density polyethylene has a density of 0.915 g / cm³. 3 The vulcanizing agent is dicumyl peroxide, the antioxidant is antioxidant 1010, the lubricant is zinc stearate, the ethylene-octene copolymer is Dow POE-8999, the polyimide resin is Mitsui PL450A, and the rare earth element is lanthanum.

[0039] The manufacturing process of enameled round graphene aluminum alloy winding wire includes the following specific steps:

[0040] S1: Mix aluminum, copper, graphene and rare earth elements and heat to 750℃ to melt them to obtain a molten metal. Cast the molten metal into a billet, roll it, and draw it into a graphene aluminum alloy conductive wire core.

[0041] S2: Low-density polyethylene, ethylene-octene copolymer, low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and smelted at 180°C to form a ceramic protective layer mixture.

[0042] S3: Heat the polyimide resin to 400℃ and extrude it onto the surface of the graphene aluminum alloy conductive wire core to form a polyimide heat-resistant layer with an average thickness of 10μm. Then, extrude the ceramic protective layer mixture onto the surface of the polyimide heat-resistant layer to form a ceramic protective layer with an average thickness of 10μm, thus obtaining the enameled round graphene aluminum alloy winding wire.

[0043] Example 2

[0044] The difference between Example 2 and Example 1 is that the amount of low-density polyethylene used in the ceramic protective layer raw materials is 30 kg, the amount of ethylene-octene copolymer is 60 kg, the amount of low-melting-point ceramic powder is 50 kg, the amount of vulcanizing agent is 3 kg, the amount of antioxidant is 5 kg, and the amount of lubricant is 8 kg.

[0045] Example 3

[0046] The difference between Example 3 and Example 1 is that the amount of low-density polyethylene used in the ceramic protective layer raw materials is 50 kg, the amount of ethylene-octene copolymer is 40 kg, the amount of low-melting-point ceramic powder is 80 kg, the amount of vulcanizing agent is 5 kg, the amount of antioxidant is 8 kg, and the amount of lubricant is 5 kg.

[0047] Example 4

[0048] The difference between Example 4 and Example 1 is that the amount of aluminum used in the graphene aluminum alloy conductive wire core material is 85 kg, the amount of copper is 1 kg, the amount of graphene is 0.3 kg, and the amount of rare earth is 0.05 kg.

[0049] Example 5

[0050] The difference between Example 5 and Example 1 is that the amount of aluminum used in the graphene aluminum alloy conductive wire core material is 95 kg, the amount of copper is 3 kg, the amount of graphene is 0.5 kg, and the amount of rare earth is 0.03 kg.

[0051] Example 6

[0052] The difference between Example 6 and Example 1 is that the polyimide heat-resistant layer comprises the following raw materials in parts by weight: 35 kg of polyimide resin, 8 kg of nano zinc oxide, 8 kg of polycarbonate, and 8 kg of mesoporous silica. The average particle size of the nano zinc oxide is 50 nm, the diameter of the mesoporous silica is 20-40 nm, and the molecular weight (Mw) of the polycarbonate is 20,000.

[0053] The manufacturing process of enameled round graphene aluminum alloy winding wire includes the following specific steps:

[0054] S1: Mix aluminum, copper, graphene and rare earth elements and heat to 750℃ to melt them to obtain a molten metal. Cast the molten metal into a billet, roll it, and draw it into a graphene aluminum alloy conductive wire core.

[0055] S2: Low-density polyethylene, ethylene-octene copolymer, low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and smelted at 180°C to form a ceramic protective layer mixture.

[0056] S3: Polyimide resin, nano zinc oxide, polycarbonate, and mesoporous silica are mixed evenly and melt-extruded at 400°C onto the surface of the graphene aluminum alloy conductive wire core to form a polyimide heat-resistant layer with an average thickness of 10μm. Then, the ceramic protective layer mixture is extruded onto the surface of the polyimide heat-resistant layer to form a ceramic protective layer with an average thickness of 10μm, thus obtaining the enameled round graphene aluminum alloy winding wire.

[0057] Example 7

[0058] The difference between Example 7 and Example 6 is that the amount of polyimide resin used in the polyimide heat-resistant layer raw material is 30 kg, the amount of nano zinc oxide is 5 kg, the amount of polycarbonate is 10 kg, and the amount of mesoporous silica is 10 kg.

[0059] Example 8

[0060] The difference between Example 8 and Example 6 is that the amount of polyimide resin used in the polyimide heat-resistant layer raw material is 40 kg, the amount of nano zinc oxide is 10 kg, the amount of polycarbonate is 5 kg, and the amount of mesoporous silica is 5 kg.

[0061] Example 9

[0062] The difference between Example 9 and Example 6 is that polycarbonate is not used in the polyimide heat-resistant layer raw material.

[0063] Example 10

[0064] The difference between Example 10 and Example 6 is that mesoporous silica is not used in the polyimide heat-resistant layer material.

[0065] Example 11

[0066] The difference between Example 11 and Example 6 is that the surface of the low-melting-point ceramic powder in the ceramic protective layer raw material is modified with γ-methacryloyloxypropyltrimethoxysilane.

[0067] The manufacturing process of enameled round graphene aluminum alloy winding wire includes the following specific steps:

[0068] S1: Mix aluminum, copper, graphene and rare earth elements and heat to 750℃ to melt them to obtain a molten metal. Cast the molten metal into a billet, roll it, and draw it into a graphene aluminum alloy conductive wire core.

[0069] S2: Mix γ-methacryloxypropyltrimethoxysilane with low-melting-point ceramic powder and stir evenly. The mass ratio of γ-methacryloxypropyltrimethoxysilane to low-melting-point ceramic powder is 0.8:10. After heating and drying, modified low-melting-point ceramic powder is obtained. Low-density polyethylene, ethylene-octene copolymer, modified low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and smelted at 180°C to form a ceramic protective layer mixture.

[0070] S3: Polyimide resin, nano zinc oxide, polycarbonate, and mesoporous silica are mixed evenly and melt-extruded at 400°C onto the surface of the graphene aluminum alloy conductive wire core to form a polyimide heat-resistant layer with an average thickness of 10μm. Then, the ceramic protective layer mixture is extruded onto the surface of the polyimide heat-resistant layer to form a ceramic protective layer with an average thickness of 10μm, thus obtaining the enameled round graphene aluminum alloy winding wire.

[0071] Comparative Example

[0072] Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 1 is that no ceramic protective layer is used in the raw material of the enameled circular graphene aluminum alloy winding wire.

[0074] Comparative Example 2

[0075] The difference between Comparative Example 2 and Example 1 is that low-melting-point ceramicizing powder is not used in the raw materials of the ceramicized protective layer.

[0076] Comparative Example 3

[0077] The difference between Comparative Example 3 and Example 1 is that no polyimide heat-resistant layer is used in the raw material of the enameled circular graphene aluminum alloy winding wire.

[0078] Performance testing

[0079] The following performance tests were conducted on the enameled circular graphene aluminum alloy winding wires provided in Examples 1-11 and Comparative Examples 1-3 of this application. The specific test results are shown in Table 1.

[0080] Detection methods

[0081] I. Mechanical properties and thermal aging properties

[0082] The elongation at break of the prepared enameled circular graphene aluminum alloy winding wire was tested according to GB / T 2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 11: General Test Methods - Measurement of Dimensions and Mechanical Properties". The tensile strength of the enameled circular graphene aluminum alloy winding wire prepared in this application was tested according to GB / T1040.3-2006 "Determination of Tensile Properties of Plastics - Part 3: Test Conditions for Thin Plastics and Sheets", with a tensile speed of 250 mm / min. The tensile strength after aging was tested according to GB / T2951.12-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 12: General Test Methods - Thermal Aging Test", with aging conditions of 168 h and 100℃.

[0083] II. Volume Resistivity

[0084] The test was conducted in accordance with GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials", with a test temperature of 20℃.

[0085] III. Fire Resistance

[0086] Referring to GB / T19216.21-2003 "Line Integrity Tests for Cables or Optical Fibers under Flame Conditions - Part 21: Test Procedures and Requirements - Cables with Rated Voltages of 0.6 / 1.0kV and Below", the enameled round graphene aluminum alloy winding wire prepared in this application was tested for compliance during the test at a flame temperature of 800℃.

[0087] Table 1: Performance Test Results Data Table

[0088]

[0089] The performance test results show that the enameled cylindrical graphene aluminum alloy winding wire prepared in this application has good heat resistance and fire safety. Furthermore, under the synergistic effect of the various components, it also maintains good strength and electrical properties. A comparison of Comparative Examples 1-3 and Example 1 shows that Comparative Example 1 does not use a ceramicized protective layer, and Comparative Example 2 does not use low-melting-point ceramic powder. The performance test results show that the fire resistance and heat resistance of the winding wire are significantly reduced, resulting in loss of usability in environments containing open flames. This further illustrates that using a single polyimide heat-resistant layer to provide heat protection for the conductive core is limited and cannot maintain the safety of the winding wire in open flames. In Comparative Example 3, which does not use a polyimide heat-resistant layer, although the prepared winding wire still has a fire-resistant effect, its heat aging resistance and strength are significantly reduced. This further demonstrates that this application achieves a synergistic effect by combining a ceramicized protective layer and a polyimide heat-resistant layer, resulting in a winding wire that possesses good strength, aging resistance, and fire resistance.

[0090] As can be seen from Examples 9-10, Example 9 did not use polycarbonate and Example 10 did not use mesoporous silica. The heat aging resistance and tensile strength of the prepared winding wires were significantly reduced. This further illustrates that under the synergistic effect of the various components, the polyimide heat-resistant layer can provide heat protection for the conductive wire core.

[0091] As shown in Example 11, the surface modification of low-melting-point ceramic powder with γ-methacryloxypropyltrimethoxysilane can reduce the moisture absorption of the ceramic powder, thereby improving the strength and electrical performance of the winding assembly.

[0092] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A type of enameled round graphene aluminum alloy winding wire, characterized in that, The device comprises a graphene-aluminum alloy conductive core and an insulating layer. The insulating layer includes a polyimide heat-resistant layer and a ceramicized protective layer. The polyimide heat-resistant layer is located between the graphene-aluminum alloy conductive core and the ceramicized protective layer. The polyimide heat-resistant layer comprises the following raw materials in parts by weight: 30-40 parts polyimide resin, 5-10 parts nano zinc oxide, 5-10 parts polycarbonate, and 5-10 parts mesoporous silica. The ceramicized protective layer comprises the following raw materials in parts by weight: 30-50 parts low-density polyethylene, 40-60 parts ethylene-octene copolymer, 50-80 parts low-melting-point ceramicizing powder, 3-5 parts vulcanizing agent, 5-8 parts antioxidant, and 5-8 parts lubricant. The low-melting-point porcelain powder is one of phosphate glass powder and borosilicate glass powder. The surface of the low-melting-point porcelain powder is modified with γ-methacryloxypropyltrimethoxysilane. The modification method includes the following specific steps: mixing γ-methacryloxypropyltrimethoxysilane with the low-melting-point porcelain powder, stirring evenly, and heating and drying to obtain modified low-melting-point porcelain powder.

2. The enameled round graphene aluminum alloy winding wire according to claim 1, characterized in that, The mass ratio of γ-methacryloxypropyltrimethoxysilane to low-melting-point ceramic powder is (0.5-1):

10.

3. The enameled round graphene aluminum alloy winding wire according to claim 1, characterized in that, The mesoporous silica has a pore diameter of 20-40 nm.

4. The enameled round graphene aluminum alloy winding wire according to claim 1, characterized in that, The graphene-aluminum alloy conductive wire core comprises the following raw materials in parts by weight: 85-95 parts aluminum, 1-3 parts copper, 0.3-0.5 parts graphene, and 0.03-0.05 parts rare earth.

5. The enameled round graphene aluminum alloy winding wire according to claim 4, characterized in that, The rare earth element is at least one of lanthanum, cerium, and scandium.

6. A manufacturing process for enameled round graphene aluminum alloy winding wire as described in any one of claims 1-5, characterized in that, The specific steps include the following: Low-density polyethylene, ethylene-octene copolymer, low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and refined to form a ceramic protective layer mixture; The graphene aluminum alloy conductive core is first composited with a polyimide heat-resistant layer, and then the ceramicized protective layer mixture is melt-extruded onto the surface of the polyimide heat-resistant layer to form a ceramicized protective layer, thus producing an enameled round graphene aluminum alloy winding wire.

7. The manufacturing process of the enameled round graphene aluminum alloy winding wire according to claim 6, characterized in that, The specific steps include the following: Aluminum, copper, graphene and rare earth elements are mixed, heated and melted to obtain a molten metal. The molten metal is then cast, rolled and drawn into a graphene aluminum alloy conductive wire core. Polyimide resin, nano zinc oxide, polycarbonate, and mesoporous silica are mixed evenly and melt-extruded onto the surface of graphene aluminum alloy conductive wire core to form a polyimide heat-resistant layer. Low-density polyethylene, ethylene-octene copolymer, low-melting-point ceramic powder, vulcanizing agent, antioxidant and lubricant are mixed and refined to form a ceramic protective layer mixture. Then, the ceramic protective layer mixture is melt-extruded onto the surface of a polyimide heat-resistant layer to form a ceramic protective layer, thus producing an enameled round graphene aluminum alloy winding wire.

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