A flame-retardant photovoltaic cable

Abstract

The present invention relates to the field of cable technology, and a flame retardant photovoltaic cable is proposed, comprising a conductor, an insulating layer and a sheath layer, wherein the insulating layer is located outside the conductor, and the sheath layer is located outside the insulating layer; the sheath layer is composed of a flame retardant sheath material, which includes the following components in parts by mass: 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 3 to 6 parts of maleic anhydride grafted polyethylene, 50 to 60 parts of a flame retardant, 1 to 3 parts of a cross-linking agent, 1 to 2 parts of an antioxidant, 0.5 to 1.5 parts of an ultraviolet absorber, and 2 to 3 parts of a lubricant; the flame retardant includes modified aluminum hydroxide and magnesium hydroxide; the modified aluminum hydroxide is aluminum hydroxide first modified with an aminosilane coupling agent and then modified with tris(2,3-epoxypropyl)phosphate. Through the above technical solution, the problem of poor flame retardancy of photovoltaic cables in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a flame-retardant photovoltaic cable. Background Art

[0002] Photovoltaic cables are used to connect photovoltaic power generation systems. They need to have good corrosion resistance, high and low temperature resistance, acid and alkali resistance, flame retardancy and other properties.

[0003] With the advancement of technology, the long-term and reliable operation of photovoltaic power stations has become a major concern in the industry. Consequently, the demand for photovoltaic cables is increasing, and higher performance requirements are being placed on them, particularly in terms of flame retardancy. Good flame retardancy can significantly prevent fires, significantly protecting personal and property safety. Therefore, providing a photovoltaic cable with excellent flame retardancy is a technical challenge that those skilled in the art urgently need to address. Summary of the Invention

[0004] The present invention provides a flame-retardant photovoltaic cable, which solves the problem of poor flame retardancy of photovoltaic cables in related technologies.

[0005] The technical solutions of the present invention are as follows:

[0006] A flame-retardant photovoltaic cable comprises a conductor, an insulation layer and a sheath layer, wherein the insulation layer is located outside the conductor, and the sheath layer is located outside the insulation layer;

[0007] The sheath layer is composed of a flame retardant sheath material, which includes the following components in parts by weight: 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 3-6 parts of maleic anhydride grafted polyethylene, 50-60 parts of flame retardant, 1-3 parts of cross-linking agent, 1-2 parts of antioxidant, 0.5-1.5 parts of ultraviolet absorber, and 2-3 parts of lubricant;

[0008] The flame retardant includes modified aluminum hydroxide and magnesium hydroxide;

[0009] The modified aluminum hydroxide is aluminum hydroxide that is first modified with an aminosilane coupling agent and then modified with tris(2,3-epoxypropyl)phosphate.

[0010] As a further technical solution, the insulating layer is a cross-linked polyethylene insulating layer.

[0011] As a further technical solution, the mass ratio of the modified aluminum hydroxide to magnesium hydroxide is 5:1 to 4:2.

[0012] The present invention limits the mass ratio of modified aluminum hydroxide to magnesium hydroxide to 5:1-4:2, thereby further improving the flame retardancy and strength of the photovoltaic cable.

[0013] As a further technical solution, in the modified aluminum hydroxide, the mass ratio of the aminosilane coupling agent to the aluminum hydroxide is 3~5:60.

[0014] As a further technical solution, in the modified aluminum hydroxide, the mass ratio of the aminosilane coupling agent to tris(2,3-epoxypropyl)phosphate is 1:2~4.

[0015] The present invention limits the mass ratio of aminosilane coupling agent to tris(2,3-epoxypropyl)phosphate in the modified aluminum hydroxide to 1:2-4, further improving the flame retardancy and strength of the photovoltaic cable. This is because when the amount of tris(2,3-epoxypropyl)phosphate is too low, the aluminum hydroxide surface cannot be completely coated; when the amount is too high, the excess tris(2,3-epoxypropyl)phosphate fails to modify the aluminum hydroxide and reduces the adhesion and shear force between the aluminum hydroxide and the substrate, resulting in poor dispersibility.

[0016] As a further technical solution, in the modified aluminum hydroxide, the mass ratio of the aminosilane coupling agent to tris(2,3-epoxypropyl)phosphate is 1:3.

[0017] As a further technical solution, the aminosilane coupling agent includes one or both of KH550 and KH602.

[0018] As a further technical solution, the preparation method of the modified aluminum hydroxide comprises the following steps:

[0019] S1. After mixing aluminum hydroxide and anhydrous ethanol, adding an aminosilane coupling agent, performing a modification, filtering, washing, and drying to obtain pretreated aluminum hydroxide;

[0020] S2. After mixing tris(2,3-epoxypropyl)phosphate and dimethyl sulfoxide, add the pretreated aluminum hydroxide, perform secondary modification, filter, wash, and dry to obtain modified aluminum hydroxide.

[0021] As a further technical solution, the temperature of the primary modification is 45-55° C. and the time is 10-12 hours.

[0022] As a further technical solution, the temperature of the secondary modification is 30-50° C. and the time is 4-7 hours.

[0023] As a further technical solution, the cross-linking agent includes one or both of triallyl isocyanurate and trimethylolpropane trimethacrylate.

[0024] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076;

[0025] The ultraviolet absorber includes one or more of ultraviolet absorber UV326, ultraviolet absorber UV320, and ultraviolet absorber UV329.

[0026] As a further technical solution, the lubricant includes one or more of polyethylene wax, zinc stearate, and calcium stearate.

[0027] The working principle and beneficial effects of the present invention are:

[0028] The flame retardant in the present invention includes modified aluminum hydroxide and magnesium hydroxide; the modified aluminum hydroxide is first modified with an aminosilane coupling agent and then with tris(2,3-epoxypropyl)phosphate. The two synergistically improve the flame retardancy and strength of the photovoltaic cable. This is because the surface of the aluminum hydroxide is grafted with amino groups after being modified with the aminosilane coupling agent. The amino groups react with tris(2,3-epoxypropyl)phosphate, resulting in the phosphate grafting of the aluminum hydroxide surface. This not only improves the flame retardancy, but also increases the strength by improving the inorganic properties of the aluminum hydroxide surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 This is a schematic structural diagram of the flame-retardant photovoltaic cable of the present invention;

[0031] In the figure: 1 is the conductor, 2 is the insulation layer, and 3 is the sheath layer. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] The parameters of the raw materials in the following examples and comparative examples are as follows:

[0034] Ethylene vinyl acetate copolymer is EVA 680;

[0035] Ethylene-octene copolymer is POE 8150;

[0036] Polyethylene is LDPE 2420D;

[0037] Maleic anhydride grafted polyethylene is LLDPE-g-MAH GR 202;

[0038] The particle size of magnesium hydroxide is 1250 mesh;

[0039] The particle size of aluminum hydroxide is 800 mesh.

[0040] Example 1

[0041] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0042] S2. After mixing 10 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0043] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0044] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 55 parts of modified aluminum hydroxide, 5 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 2 parts of antioxidant 1010, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160°C for 20 minutes. Then transfer them to a single-screw extruder (110°C / 115°C / 120°C / 120°C / 125°C / 125°C / 130°C) for extrusion. After granulation, transfer them to a wire extruder (155°C / 170°C / 170°C / 175°C) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0045] Example 2

[0046] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 3 g of KH602 was added dropwise, and the mixture was stirred at 45°C and 400 r / min for 12 h. The mixture was filtered, washed with ethanol, and dried at 80°C to obtain pretreated aluminum hydroxide;

[0047] S2. After mixing 6 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 30° C. and 400 r / min for 7 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0048] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0049] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 3 parts of maleic anhydride-grafted polyethylene, 45 parts of modified aluminum hydroxide, 5 parts of magnesium hydroxide, 1 part of trimethylolpropane trimethacrylate, 1 part of antioxidant 168, 0.5 part of ultraviolet absorber UV326, and 2 parts of zinc stearate, and knead the mixture at 160°C for 20 minutes. Then, transfer the mixture to a single-screw extruder (110°C / 115°C / 120°C / 120°C / 125°C / 125°C / 130°C) for extrusion. After granulation, transfer the mixture to a wire extruder (155°C / 170°C / 170°C / 175°C) for extrusion, and cover the outside of the semi-finished photovoltaic cable. The mixture is irradiated and cross-linked by an electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0050] Example 3

[0051] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0052] S2. After mixing 15 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0053] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0054] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 55 parts of modified aluminum hydroxide, 5 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 2 parts of antioxidant 1010, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160°C for 20 minutes. Then transfer them to a single-screw extruder (110°C / 115°C / 120°C / 120°C / 125°C / 125°C / 130°C) for extrusion. After granulation, transfer them to a wire extruder (155°C / 170°C / 170°C / 175°C) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0055] Example 4

[0056] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0057] S2. After mixing 20 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0058] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0059] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 55 parts of modified aluminum hydroxide, 5 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 2 parts of antioxidant 1010, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160°C for 20 minutes. Then transfer them to a single-screw extruder (110°C / 115°C / 120°C / 120°C / 125°C / 125°C / 130°C) for extrusion. After granulation, transfer them to a wire extruder (155°C / 170°C / 170°C / 175°C) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0060] Example 5

[0061] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0062] S2. After mixing 15 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0063] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0064] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 50 parts of modified aluminum hydroxide, 10 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 10102 parts of antioxidant, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160℃ for 20 minutes. Then transfer them to a single-screw extruder (110℃ / 115℃ / 120℃ / 120℃ / 125℃ / 125℃ / 130℃) for extrusion. After granulation, transfer them to a wire extruder (155℃ / 170℃ / 170℃ / 175℃) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0065] Example 6

[0066] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0067] S2. After mixing 15 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0068] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0069] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 45 parts of modified aluminum hydroxide, 15 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 10102 parts of antioxidant, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160℃ for 20 minutes. Then transfer them to a single-screw extruder (110℃ / 115℃ / 120℃ / 120℃ / 125℃ / 125℃ / 130℃) for extrusion. After granulation, transfer them to a wire extruder (155℃ / 170℃ / 170℃ / 175℃) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0070] Example 7

[0071] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0072] S2. After mixing 15 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0073] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0074] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 40 parts of modified aluminum hydroxide, 20 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 10102 parts of antioxidant, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and knead them at 160℃ for 20 minutes. Then transfer them to a single-screw extruder (110℃ / 115℃ / 120℃ / 120℃ / 125℃ / 125℃ / 130℃) for extrusion. After granulation, transfer them to a wire extruder (155℃ / 170℃ / 170℃ / 175℃) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0075] Example 8

[0076] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain pretreated aluminum hydroxide;

[0077] S2. After mixing 15 g of tris(2,3-epoxypropyl)phosphate and 500 g of dimethyl sulfoxide, add pretreated aluminum hydroxide, stir at 50° C. and 400 r / min for 4 h, filter, wash with ethanol, and dry at 80° C. to obtain modified aluminum hydroxide;

[0078] S3, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0079] S4. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride grafted polyethylene, 35 parts of modified aluminum hydroxide, 25 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 10102 parts of antioxidant, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160℃ for 20 minutes. Then transfer them to a single-screw extruder (110℃ / 115℃ / 120℃ / 120℃ / 125℃ / 125℃ / 130℃) for extrusion. After granulation, transfer them to a wire extruder (155℃ / 170℃ / 170℃ / 175℃) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0080] Comparative Example 1

[0081] S1. Wrapping a cross-linked polyethylene insulation layer on the outside of the conductor to obtain a semi-finished photovoltaic cable;

[0082] S2. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride-grafted polyethylene, 55 parts of aluminum hydroxide, 5 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 2 parts of antioxidant 1010, 1.5 parts of ultraviolet absorber UV320, and 3 parts of polyethylene wax, and mix them at 160°C for 20 minutes. Then, transfer the mixture to a single-screw extruder (110°C / 115°C / 120°C / 120°C / 125°C / 125°C / 130°C) for extrusion. After granulation, transfer the mixture to a wire extruder (155°C / 170°C / 170°C / 175°C) for extrusion, cover the outside of the semi-finished photovoltaic cable, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0083] Comparative Example 2

[0084] S1. After mixing 60 g of aluminum hydroxide and 600 g of anhydrous ethanol, 5 g of KH550 was added dropwise, and the mixture was stirred at 55° C. and 400 r / min for 10 h. The mixture was filtered, washed with ethanol, and dried at 80° C. to obtain modified aluminum hydroxide.

[0085] S2, covering the outside of the conductor with a cross-linked polyethylene insulation layer to obtain a semi-finished photovoltaic cable;

[0086] S3. Mix 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 6 parts of maleic anhydride-grafted polyethylene, 55 parts of modified aluminum hydroxide, 5 parts of magnesium hydroxide, 3 parts of triallyl isocyanurate, 2 parts of antioxidant 1010, 1.5 parts of ultraviolet absorber UV320 and 3 parts of polyethylene wax, and mix them at 160°C for 20 minutes. Then transfer them to a single-screw extruder (110°C / 115°C / 120°C / 120°C / 125°C / 125°C / 130°C) for extrusion. After granulation, transfer them to a wire extruder (155°C / 170°C / 170°C / 175°C) for extrusion, cover the outside of the photovoltaic cable semi-finished product, and irradiate and cross-link by electron accelerator with an irradiation dose of 10 Mrad to form a sheath layer to obtain a flame-retardant photovoltaic cable.

[0087] The sheath layers obtained in Examples 1 to 8 and Comparative Examples 1 to 2 were subjected to the following tests:

[0088] (1) Determine the oxygen index with reference to the method in GB / T 2406.2-2009 “Determination of combustion behavior of plastics by oxygen index method Part 2: Room temperature test”;

[0089] (2) Determine the tensile strength by referring to the method in GB / T 2951.11-2008 "General test methods for insulation and sheathing materials of electric and optical cables - Part 11: General test methods - Thickness and dimensions - Mechanical properties tests";

[0090] The results are recorded in Table 1.

[0091] Table 1 Tensile strength and oxygen index of the sheath layer

[0092]

[0093] As can be seen from Table 1, the sheath layer of the present invention has high tensile strength and oxygen index, providing a photovoltaic cable with good flame retardancy and high strength.

[0094] Compared with Comparative Examples 1-2, Examples 1-8 use aluminum hydroxide first modified with an aminosilane coupling agent and then modified with tris(2,3-epoxypropyl) phosphate, Comparative Example 1 uses unmodified aluminum hydroxide, and Comparative Example 2 uses aluminum hydroxide modified with an aminosilane coupling agent. The tensile strength and oxygen index of the sheath layers obtained in Examples 1-8 are higher than those in Comparative Examples 1-2, indicating that aluminum hydroxide modified with an aminosilane coupling agent and then modified with tris(2,3-epoxypropyl) phosphate can improve the flame retardancy and strength of photovoltaic cables.

[0095] The tensile strength and oxygen index of the sheath layer obtained in Example 3 are higher than those in Example 1 and Example 4, indicating that the mass ratio of aminosilane coupling agent to tris(2,3-epoxypropyl)phosphate is 1:2~4, which can further improve the flame retardancy and strength of the photovoltaic cable.

[0096] The tensile strength and oxygen index of the sheath layer obtained in Examples 5 to 7 are higher than those in the other examples, indicating that the mass ratio of modified aluminum hydroxide to magnesium hydroxide is 5:1 to 4:2, which can further improve the flame retardancy and strength of the photovoltaic cable.

[0097] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flame-retardant photovoltaic cable, characterized in that: The invention comprises a conductor, an insulating layer and a sheath layer, wherein the insulating layer is located outside the conductor, and the sheath layer is located outside the insulating layer; The sheath layer is composed of a flame retardant sheath material, which includes the following components in parts by weight: 25 parts of ethylene-vinyl acetate copolymer, 5 parts of ethylene-octene copolymer, 20 parts of polyethylene, 3-6 parts of maleic anhydride grafted polyethylene, 50-60 parts of flame retardant, 1-3 parts of cross-linking agent, 1-2 parts of antioxidant, 0.5-1.5 parts of ultraviolet absorber, and 2-3 parts of lubricant; The flame retardant comprises modified aluminum hydroxide and magnesium hydroxide in a mass ratio of 5:1 to 4:2; The modified aluminum hydroxide is aluminum hydroxide that is first modified with an aminosilane coupling agent and then modified with tris(2,3-epoxypropyl)phosphate; In the modified aluminum hydroxide, the mass ratio of the aminosilane coupling agent to tris(2,3-epoxypropyl)phosphate is 1:2-4.

2. The flame-retardant photovoltaic cable according to claim 1, characterized in that: In the modified aluminum hydroxide, the mass ratio of the aminosilane coupling agent to the aluminum hydroxide is 3-5:

60.

3. The flame-retardant photovoltaic cable according to claim 2, characterized in that: The preparation method of the modified aluminum hydroxide comprises the following steps: S1. After mixing aluminum hydroxide and anhydrous ethanol, adding an aminosilane coupling agent, performing a modification, filtering, washing, and drying to obtain pretreated aluminum hydroxide; S2. After mixing tris(2,3-epoxypropyl)phosphate and dimethyl sulfoxide, add the pretreated aluminum hydroxide, perform secondary modification, filter, wash, and dry to obtain modified aluminum hydroxide.

4. The flame-retardant photovoltaic cable according to claim 3, characterized in that: The temperature of the primary modification is 45-55° C. and the time is 10-12 hours.

5. The flame-retardant photovoltaic cable according to claim 3, characterized in that: The temperature of the secondary modification is 30-50° C. and the time is 4-7 hours.

6. The flame-retardant photovoltaic cable according to claim 1, characterized in that: The cross-linking agent includes one or both of triallyl isocyanurate and trimethylolpropane trimethacrylate.

7. The flame-retardant photovoltaic cable according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076; The ultraviolet absorber includes one or more of ultraviolet absorber UV326, ultraviolet absorber UV320, and ultraviolet absorber UV329.

8. The flame-retardant photovoltaic cable according to claim 1, characterized in that: The lubricant includes one or more of polyethylene wax, zinc stearate, and calcium stearate.

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