High-flame-retardant aluminum alloy photovoltaic cable and preparation method thereof

Abstract

The invention discloses a high-flame-retardant aluminum alloy photovoltaic cable and a preparation method thereof, and relates to the technical field of cables. The preparation method of the high-flame-retardant aluminum alloy photovoltaic cable comprises the following steps: step 1, mixing ethylene-vinyl acetate copolymer, polyethylene, expanded graphite, modified montmorillonite, an initiator, a cross-linking agent and an auxiliary agent, performing melt blending, performing compression molding, and performing cold pressing to obtain an outer sheath; 2, aluminum alloy serves as a wire core, an oxygen isolation layer and an insulating layer are wrapped, and a basic wire core is obtained; and combining the basic wire cores, filling a mineral fireproof material, and wrapping an outer sheath to obtain the high-flame-retardant aluminum alloy photovoltaic cable. The prepared high-flame-retardancy aluminum alloy photovoltaic cable ensures the mechanical property on the premise of having high flame retardancy.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and particularly to a highly flame-retardant aluminum alloy photovoltaic cable and a preparation method thereof. Background Art

[0002] In recent years, with the global emphasis on renewable energy, photovoltaic power generation technology has developed rapidly. The large-scale construction of photovoltaic power stations has put forward higher requirements for the performance of supporting cables. As a key transmission component of the photovoltaic system, photovoltaic cables need to be exposed to complex outdoor environments for a long time and withstand harsh conditions such as ultraviolet radiation, high temperature, and humidity. Therefore, they must have excellent weather resistance, high flame retardancy, and stable mechanical properties. Among them, aluminum alloy photovoltaic cables have become an ideal choice for photovoltaic systems due to their outstanding high and low temperature resistance and long service life. However, traditional aluminum alloy cables still have deficiencies in the coordinated optimization of flame retardancy, environmental protection, and mechanical properties.

[0003] Currently, common flame-retardant cables on the market mostly use halogen-containing flame retardants (such as PVC). Although they have good flame retardant effects, they will release toxic gases such as dioxins when burning, which not only pollutes the environment but also may endanger the safety of personnel. Moreover, the flame retardancy of ordinary aluminum alloy cables still needs to be further improved. The higher the flame retardancy, the more it can meet the safety requirements of high-density wiring in photovoltaic power stations. In the prior art, although inorganic flame retardants such as aluminum hydroxide are environmentally friendly, a high filling amount (>60%) is required to meet the V-0 standard, which will lead to a significant decline in the mechanical properties and processing performance of the cable, affecting its practical application. And although nitrogen-phosphorus-based synergistic flame retardants have high flame retardancy efficiency, they have problems such as poor compatibility with the substrate and easy migration and failure. After long-term use, the flame retardant performance may decay, and at the same time, it will affect the mechanical properties of the cable.

[0004] In summary, to solve the above problems, it is of great significance to prepare a highly flame-retardant aluminum alloy photovoltaic cable. Summary of the Invention

[0005] The purpose of the present invention is to provide a highly flame-retardant aluminum alloy photovoltaic cable and a preparation method thereof to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: A preparation method of a highly flame-retardant aluminum alloy photovoltaic cable, comprising the following steps: Step 1: Mix ethylene-vinyl acetate copolymer, polyethylene, expanded graphite, modified montmorillonite, initiator, crosslinking agent, and auxiliary agent, and perform melt blending, molding by pressing, and cold pressing to obtain an outer sheath; Step 2: Use an aluminum alloy as the wire core, wrap an oxygen isolation layer and an insulating layer to obtain a basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap the outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0007] Preferably, the raw materials of the outer sheath include the following components: by weight, 40-50 parts of ethylene-vinyl acetate copolymer, 20-30 parts of polyethylene, 22-25 parts of expanded graphite, 5-8 parts of modified montmorillonite, 0.5-1 part of initiator, 2-3 parts of crosslinking agent, and 0.5-1 part of auxiliary agent.

[0008] Preferably, the preparation of the modified montmorillonite includes the following steps: adding montmorillonite and boric acid into absolute ethanol in sequence, heating to 70-75 °C and stirring for 4-5 hours; adding 1-amino-10-undecene and isopropyl p-aminobenzoate, and continuing to stir for 8-9 hours; washing with hot ethanol and drying to obtain modified montmorillonite.

[0009] Preferably, the raw materials of the modified montmorillonite include the following components: 10 parts of montmorillonite, 3-4 parts of boric acid, 1-2 parts of 1-amino-10-undecene, and 1-2 parts of isopropyl p-aminobenzoate; the montmorillonite is calcium-based montmorillonite with an interlayer spacing of 1.8-2.2 nm.

[0010] Preferably, the crosslinking agent includes an ionic liquid and triallyl isocyanurate with a mass ratio of (1.5-2):(0.5-1).

[0011] Preferably, the preparation method of the ionic liquid is: mixing 1-vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of (3.2-3.5):1 evenly, setting the temperature at 45-55 °C and stirring for 5-7 days under a nitrogen atmosphere; cooling, washing with ethyl acetate, and evaporating the solvent to obtain the ionic liquid.

[0012] Preferably, the polyethylene includes high-density polyethylene, low-density polyethylene, maleic anhydride grafted polyethylene, and ethylene-methyl acrylate zinc salt copolymer with a mass ratio of (10-15):(5-10):3:2.

[0013] Preferably, the conditions for melt blending are: blending at 150-180 °C and 50-100 rpm for 10-20 minutes; the conditions for molding by pressing are: molding by pressing at 170-180 °C and 8-12 Mpa; the conditions for cold pressing are: cold pressing at room temperature and 8-12 Mpa for 5-10 minutes.

[0014] Preferably, the raw materials of the mineral fireproof material include the following components, by weight, 25-35 parts of expanded perlite, 25-35 parts of aluminum hydroxide, 10-20 short-cut glass fibers, 5-12 parts of microsilica powder, 8-12 parts of vermiculite, 2-4 parts of titanium dioxide, 1-2 parts of organosilicon-based water repellent, and 0.5-1 part of sodium molybdate.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: By introducing expanded graphite and modified montmorillonite, an efficient flame retardant system is constructed; and by introducing crosslinking agents and polyethylene with specific components, the mechanical properties are effectively guaranteed; so that the prepared aluminum alloy photovoltaic cable ensures the mechanical properties on the premise of high flame retardancy.

[0016] In the solution, high flame retardancy is ensured by introducing expanded graphite and modified montmorillonite in specific proportions. Among them, expanded graphite is a common flame retardant, which has a unique layered structure and can form a dense carbon layer to effectively isolate the transfer of oxygen and heat, thereby inhibiting combustion and significantly improving the flame retardant performance. However, it has limitations: First, its dispersibility is poor; second, too much introduction has a great impact on the mechanical properties, and too little introduction reduces the flame retardancy. Therefore, montmorillonite is introduced in the solution. First, montmorillonite intercalates between the graphite to promote the dispersion of graphite; second, it forms a carbon-silicon double network barrier with graphite to achieve synergistic flame retardancy. Among them, montmorillonite is modified by successively grafting boric acid, 1-amino-10-undecene, and isopropyl p-aminobenzoate through the reaction of hydroxyl groups with boric acid and boric acid with amino groups; dispersing montmorillonite, and introducing elements such as boron and nitrogen into the modified montmorillonite to promote the improvement of flame retardancy. And the contained alkenyl can be effectively crosslinked in the cable to enhance the mechanical properties. In addition, compared with other montmorillonites, the introduction of montmorillonite with specific specifications has better comprehensive performance.

[0017] In the solution, to improve the mechanical properties and compatibility, polyethylene with a specific proportion is introduced; among them, high-density polyethylene cooperates with montmorillonite to provide rigidity and heat resistance, effectively improving the mechanical strength, while low-density polyethylene can improve flexibility and processing performance to avoid embrittlement; and maleic anhydride grafted polyethylene can be used as a compatibilizer to improve the interfacial bonding force between expanded graphite and the polymer matrix; and ethylene-zinc methacrylate copolymer can effectively improve the melt strength and impact resistance; therefore, the multi-component synergistic effect enables the cable to have excellent mechanical properties while maintaining high flame retardancy.

[0018] In the solution, a crosslinking agent composed of an ionic liquid and triallyl isocyanurate is used. By introducing it, the formation of a crosslinked network is effectively promoted, the mechanical properties and flame retardant properties are improved, and thus the practical application performance is improved. Among them, the ionic liquid is prepared by the reaction of 1-vinylimidazole and tris(2-chloroethyl) phosphate, which has both flame retardant and plasticizing effects and improves the molecular chain fluidity; cooperating with triallyl isocyanurate, the polymer aggregate shows a more ordered orientation and constructs a denser network. And the formation of the crosslinked network enhances the thermal stability and mechanical strength, enabling the outer sheath to still maintain its structural integrity at high temperatures. In addition, combined with the cold pressing process, the defects are further reduced. Detailed implementation mode

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] It should be noted that the following parts are by weight. There are no special restrictions on the purchase manufacturers of all the raw materials involved in the present invention. Exemplarily, it includes: in the following embodiments, the particle size of expanded graphite is 50-100 μm, and the expansion ratio ≥ 200 mL / g; montmorillonite is calcium-based montmorillonite with an interlayer spacing of 1.8-2.2 nm, and the model is HW-Ca-NA; the CAS number of boric acid is 10043-35-3; the CAS number of 1-amino-10-undecene is 25378-91-6; the CAS number of isopropyl p-aminobenzoate is 41904-76-7; the CAS number of 1-vinylimidazole is 1072-63-5; the CAS number of tris(2-chloroethyl) phosphate is 115-96-8; the vinyl acetate content of ethylene-vinyl acetate copolymer is 28-33%, and the melt index is 2-6 g / 10 min; the model of high-density polyethylene is ExxonMobil™-HDPE-HD6704; the model of low-density polyethylene is Dow™-LDPE-640I, the model of maleic anhydride grafted polyethylene is Admer®NF538, and the model of ethylene-zinc methacrylate copolymer is DuPont™-Surlyn®8920; the peroxide initiator is dicumyl peroxide; the relevant raw materials are all commercially available.

[0021] In the following embodiments, the raw materials of the mineral fireproof material include the following components, by weight, 30 parts of expanded perlite, 30 parts of aluminum hydroxide, 15 parts of chopped glass fiber, 10 parts of microsilica powder, 10 parts of vermiculite, 3 parts of titanium dioxide, 1.5 parts of organosilicon water repellent, and 0.5 part of sodium molybdate.

[0022] Example 1: A preparation method of a highly flame-retardant aluminum alloy photovoltaic cable, comprising the following steps: Pre-preparation: Add 10 parts of montmorillonite and 3.8 parts of boric acid to anhydrous ethanol in sequence, heat up to 70 °C and stir for 4 hours; add 2 parts of 1-amino-10-undecene and 1 part of isopropyl p-aminobenzoate, and continue to stir for 9 hours; wash with hot ethanol and dry to obtain modified montmorillonite; Mix 1-vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 evenly, set the temperature at 50 °C and stir for 7 days under a nitrogen atmosphere; cool, wash with ethyl acetate, and evaporate the solvent to obtain an ionic liquid; Step 1: Mix 42 parts of ethylene-vinyl acetate copolymer, 28 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride grafted polyethylene, ethylene-zinc methacrylate copolymer with a mass ratio of 13:10:3:2), 22 parts of expanded graphite, 6 parts of modified montmorillonite, 0.5 part of peroxide initiator, 2 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 1.5:0.5), and 0.5 part of antioxidant 1010, and conduct melt blending. The process conditions are: blend at 175 °C and 80 rpm for 15 minutes; mold at 180 °C and 10 Mpa; cold press at 10 Mpa for 5 minutes to obtain the outer sheath; Step 2: Use aluminum alloy as the wire core, wrap an oxygen isolation layer and an insulating layer to obtain the basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap the outer sheath to obtain the high-flame-retardant aluminum alloy photovoltaic cable.

[0023] Example 2: A method for preparing a high-flame-retardant aluminum alloy photovoltaic cable, comprising the following steps: Pre-preparation: Add 10 parts of montmorillonite and 3.8 parts of boric acid to anhydrous ethanol in sequence, heat up to 70 °C and stir for 4 hours; add 2 parts of 1-amino-10-undecene and 1 part of isopropyl p-aminobenzoate, and continue to stir for 9 hours; wash with hot ethanol and dry to obtain modified montmorillonite; Mix 1-vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 evenly, set the temperature at 50 °C and stir for 7 days under a nitrogen atmosphere; cool, wash with ethyl acetate, and evaporate the solvent to obtain the ionic liquid; Step 1: Mix 40 parts of ethylene-vinyl acetate copolymer, 30 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride grafted polyethylene, ethylene-zinc methacrylate copolymer with a mass ratio of 15:10:3:2), 22 parts of expanded graphite, 5 parts of modified montmorillonite, 0.5 part of peroxide initiator, 2.5 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 1.5:1), and 0.5 part of antioxidant 1010, and conduct melt blending. The process conditions are: blend at 175 °C and 80 rpm for 15 minutes; mold at 180 °C and 10 Mpa; cold press at 10 Mpa for 5 minutes to obtain the outer sheath; Step 2: Use aluminum alloy as the wire core, wrap an oxygen isolation layer and an insulating layer to obtain the basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap the outer sheath to obtain the high-flame-retardant aluminum alloy photovoltaic cable.

[0024] Example 3: A method for preparing a high-flame-retardant aluminum alloy photovoltaic cable, comprising the following steps: Pre-preparation: 10 parts of montmorillonite and 3.8 parts of boric acid were successively added to absolute ethanol, and the temperature was raised to 70 °C and stirred for 4 hours; 2 parts of 1-amino-10-undecene and 1 part of isopropyl p-aminobenzoate were added, and stirring was continued for 9 hours; washed with hot ethanol and dried to obtain modified montmorillonite; 1-Vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 were mixed evenly. Under a nitrogen atmosphere, the temperature was set at 50 °C and stirred for 7 days; cooled, washed with ethyl acetate, and the solvent was evaporated to obtain an ionic liquid; Step 1: 50 parts of ethylene-vinyl acetate copolymer, 20 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene, ethylene-zinc methacrylate copolymer with a mass ratio of 10:5:3:2), 25 parts of expanded graphite, 8 parts of modified montmorillonite, 0.5 part of peroxide initiator, 3 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 2:1), 0.5 part of antioxidant 1010 were mixed and melt-blended. The process conditions were: melt-blended at 175 °C and 80 rpm for 15 minutes; molded by compression at 180 °C and 10 Mpa; cold-pressed at 10 Mpa for 5 minutes to obtain an outer sheath; Step 2: Using aluminum alloy as the wire core, an oxygen isolation layer and an insulating layer were wrapped to obtain a basic wire core; the basic wire cores were combined, filled with mineral fireproof material, and wrapped with an outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0025] Comparative Example 1: Expanded graphite was introduced singly; the rest was the same as in Example 1; specifically, the following steps were included: Pre-preparation: 1-Vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 were mixed evenly. Under a nitrogen atmosphere, the temperature was set at 50 °C and stirred for 7 days; cooled, washed with ethyl acetate, and the solvent was evaporated to obtain an ionic liquid; Step 1: 42 parts of ethylene-vinyl acetate copolymer, 28 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene, ethylene-zinc methacrylate copolymer with a mass ratio of 13:10:3:2), 28 parts of expanded graphite, 0.5 part of peroxide initiator, 2 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 1.5:0.5), 0.5 part of antioxidant 1010 were mixed and melt-blended. The process conditions were: melt-blended at 175 °C and 80 rpm for 15 minutes; molded by compression at 180 °C and 10 Mpa; cold-pressed at 10 Mpa for 5 minutes to obtain an outer sheath; Step 2: Using aluminum alloy as the wire core, an oxygen isolation layer and an insulating layer were wrapped to obtain a basic wire core; the basic wire cores were combined, filled with mineral fireproof material, and wrapped with an outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0026] Comparative Example 2: Montmorillonite was directly introduced; the rest was the same as in Example 1; specifically, the following steps were included: Pre-preparation: 1-Vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 were mixed evenly. Under a nitrogen atmosphere, the temperature was set at 50 °C and stirred for 7 days; it was cooled, washed with ethyl acetate, and the solvent was evaporated to obtain an ionic liquid; Step 1: 42 parts of ethylene-vinyl acetate copolymer, 28 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene, ethylene-zinc methacrylate copolymer with a mass ratio of 13:10:3:2), 22 parts of expanded graphite, 6 parts of montmorillonite, 0.5 part of peroxide initiator, 2 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 1.5:0.5), 0.5 part of antioxidant 1010 were mixed and melt-blended. The process conditions were: melt-blended at 175 °C and 80 rpm for 15 minutes; molded under pressure at 180 °C and 10 Mpa; cold-pressed at 10 Mpa for 5 minutes to obtain an outer sheath; Step 2: Using aluminum alloy as the wire core, an oxygen barrier layer and an insulating layer were wrapped to obtain a basic wire core; the basic wire cores were combined, filled with mineral fireproof material, and wrapped with an outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0027] Comparative Example 3: The introduction amount of montmorillonite was increased; the rest was the same as in Example 1; specifically, the following steps were included: Pre-preparation: 10 parts of montmorillonite and 3.8 parts of boric acid were successively added to anhydrous ethanol, and the temperature was raised to 70 °C and stirred for 4 hours; 2 parts of 1-amino-10-undecene and 1 part of isopropyl p-aminobenzoate were added, and stirring was continued for 9 hours; washed with hot ethanol and dried to obtain modified montmorillonite; 1-Vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 were mixed evenly. Under a nitrogen atmosphere, the temperature was set at 50 °C and stirred for 7 days; it was cooled, washed with ethyl acetate, and the solvent was evaporated to obtain an ionic liquid; Step 1: 42 parts of ethylene-vinyl acetate copolymer, 28 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene, ethylene-zinc methacrylate copolymer with a mass ratio of 13:10:3:2), 18 parts of expanded graphite, 11 parts of modified montmorillonite, 0.5 part of peroxide initiator, 2 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 1.5:0.5), 0.5 part of antioxidant 1010 were mixed and melt-blended. The process conditions were: melt-blended at 175 °C and 80 rpm for 15 minutes; molded under pressure at 180 °C and 10 Mpa; cold-pressed at 10 Mpa for 5 minutes to obtain an outer sheath; Step 2: Using aluminum alloy as the wire core, wrap an oxygen isolation layer and an insulating layer to obtain a basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap an outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0028] Comparative Example 4: Adjust the components of polyethylene; the rest is the same as in Example 1; specifically including the following steps: Pre-preparation: Add 10 parts of montmorillonite and 3.8 parts of boric acid to anhydrous ethanol in sequence, heat up to 70 °C and stir for 4 hours; add 2 parts of 1-amino-10-undecene and 1 part of isopropyl p-aminobenzoate, and continue stirring for 9 hours; wash with hot ethanol and dry to obtain modified montmorillonite; Mix 1-vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of 3.2:1 evenly, set the temperature to 50 °C and stir for 7 days under a nitrogen atmosphere; cool, wash with ethyl acetate, and evaporate the solvent to obtain an ionic liquid; Step 1: Mix 42 parts of ethylene-vinyl acetate copolymer, 28 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene with a mass ratio of 15:8:5), 22 parts of expanded graphite, 6 parts of modified montmorillonite, 0.5 part of peroxide initiator, 2 parts of crosslinking agent (ionic liquid and triallyl isocyanurate with a mass ratio of 1.5:0.5), and 0.5 part of antioxidant 1010, and perform melt blending. The process conditions are: blend at 175 °C and 80 rpm for 15 minutes; mold at 180 °C and 10 Mpa; cold press at 10 Mpa for 5 minutes to obtain an outer sheath; Step 2: Using aluminum alloy as the wire core, wrap an oxygen isolation layer and an insulating layer to obtain a basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap an outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0029] Comparative Example 5: No ionic liquid is introduced; the rest is the same as in Example 1; specifically including the following steps: Pre-preparation: Add 10 parts of montmorillonite and 3.8 parts of boric acid to anhydrous ethanol in sequence, heat up to 70 °C and stir for 4 hours; add 2 parts of 1-amino-10-undecene and 1 part of isopropyl p-aminobenzoate, and continue stirring for 9 hours; wash with hot ethanol and dry to obtain modified montmorillonite; Step 1: Mix 42 parts of ethylene-vinyl acetate copolymer, 28 parts of polyethylene (high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene, zinc ethylene methacrylate copolymer with a mass ratio of 13:10:3:2), 22 parts of expanded graphite, 6 parts of modified montmorillonite, 0.5 part of peroxide initiator, 2 parts of triallyl isocyanurate, and 0.5 part of antioxidant 1010, and perform melt blending. The process conditions are: blend at 175 °C and 80 rpm for 15 minutes; mold at 180 °C and 10 Mpa; cold press at 10 Mpa for 5 minutes to obtain an outer sheath; Step 2: Use aluminum alloy as the wire core, wrap an oxygen isolation layer and an insulating layer to obtain a basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap an outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

[0030] Performance test 1: Conduct relevant performance tests on the outer sheaths prepared in the examples and comparative examples; among them, referring to the standard method of GB / T2951.11-2008, use an electronic universal testing machine, in dumbbell shape, at a tensile rate of 250 mm / min, to detect the tensile strength; referring to the standard method of ASTM D2863, use an oxygen index tester to detect the limiting oxygen index LOI; referring to the standard method of ASTM D3801, use a horizontal and vertical burning tester to test the UL-94 grade; the obtained data are shown in the following table:

[0031] Conclusion: It can be seen from the data in the above table that: a highly flame-retardant aluminum alloy photovoltaic cable with excellent mechanical properties is prepared in this application; by comparing the data of Comparative Examples 1-3 and Example 1, it shows that: in this application, by modifying montmorillonite and compounding it with expanded graphite, the flame retardancy can be effectively improved, but the ratio of the two needs to be effectively limited to maximize the comprehensive performance. By comparing the data of Comparative Example 4 and Example 1, it shows that: a specific ratio of the polyethylene component can effectively improve the interfacial property and crosslinking property, thereby improving the mechanical property and flame retardancy. By comparing the data of Comparative Example 4 and Example 1, it shows that: the introduction of ionic liquid can further improve the mechanical property and assist in improving the flame retardancy.

[0032] Finally, it should be noted that: the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a highly flame-retardant aluminum alloy photovoltaic cable, characterized in that: It includes the following steps: Step 1: Mix ethylene-vinyl acetate copolymer, polyethylene, expanded graphite, modified montmorillonite, initiator, crosslinking agent, and auxiliary agent, and conduct melt blending, compression molding, and cold pressing to obtain an outer sheath; Step 2: Use aluminum alloy as the wire core, wrap an oxygen barrier layer and an insulating layer to obtain a basic wire core; combine the basic wire cores, fill with mineral fireproof material, and wrap the outer sheath to obtain a highly flame-retardant aluminum alloy photovoltaic cable.

2. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 1, characterized in that: The raw materials of the outer sheath include the following components: by weight, 40-50 parts of ethylene-vinyl acetate copolymer, 20-30 parts of polyethylene, 22-25 parts of expanded graphite, 5-8 parts of modified montmorillonite, 0.5-1 part of initiator, 2-3 parts of crosslinking agent, and 0.5-1 part of auxiliary agent.

3. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 1, characterized in that: The preparation of the modified montmorillonite includes the following steps: Add montmorillonite and boric acid to anhydrous ethanol in sequence, heat up to 70-75°C and stir for 4-5 hours; add 1-amino-10-undecene and isopropyl p-aminobenzoate, and continue stirring for 8-9 hours; wash with hot ethanol and dry to obtain modified montmorillonite.

4. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 3, wherein: The raw materials of the modified montmorillonite include the following components: 10 parts of montmorillonite, 3-4 parts of boric acid, 1-2 parts of 1-amino-10-undecene, and 1-2 parts of isopropyl p-aminobenzoate; the montmorillonite is calcium-based montmorillonite with an interlayer spacing of 1.8-2.2 nm.

5. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 2, characterized in that: The crosslinking agent includes an ionic liquid and triallyl isocyanurate with a mass ratio of (1.5-2):(0.5-1).

6. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 5, characterized in that: The preparation method of the ionic liquid is: Mix 1-vinylimidazole and tris(2-chloroethyl) phosphate with a molar ratio of (3.2-3.5):1 evenly, set the temperature at 45-55°C and stir for 5-7 days under a nitrogen atmosphere; cool, wash with ethyl acetate, and evaporate the solvent to obtain the ionic liquid.

7. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 1, characterized in that: The polyethylene includes high-density polyethylene, low-density polyethylene, maleic anhydride-grafted polyethylene, and ethylene-methyl acrylate zinc salt copolymer with a mass ratio of (10-15):(5-10):3:

2.

8. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 1, characterized in that: The conditions for the melt blending are: blend at 150-180°C and 50-100 rpm for 10-20 minutes; the conditions for the compression molding are: compress at 170-180°C and 8-12 Mpa; the conditions for the cold pressing are: cold press at room temperature and 8-12 Mpa for 5-10 minutes.

9. The preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to claim 1, characterized in that: The raw materials of the mineral fireproof material include the following components, by weight, 25-35 parts of expanded perlite, 25-35 parts of aluminum hydroxide, 10-20 short-cut glass fibers, 5-12 parts of microsilica powder, 8-12 parts of vermiculite, 2-4 parts of titanium dioxide, 1-2 parts of organosilicon-based water repellent, and 0.5-1 part of sodium molybdate.

10. A highly flame-retardant aluminum alloy photovoltaic cable prepared by the preparation method of a highly flame-retardant aluminum alloy photovoltaic cable according to any one of claims 1-9.

Images